Systems and methods for rotor assemblies and rotor cooling arrangments

Abstract

A rotor chipset assembly and an electric motor including the assembly are provided. The assembly comprises a printed circuit board having opposing first and second surfaces, the printed circuit board including a plurality of electronic components each having an outward surface, wherein the first, second, and outward surfaces define a board surface profile; a cooling jacket coupled to the printed circuit board, the cooling jacket including an inner surface that faces the board surface profile, wherein the cooling jacket includes a fluid inlet port proximate a first end of the printed circuit board, and wherein the cooling jacket includes a first jacket portion that faces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board; and a coolant fluid pathway volume defined by the board surface profile and the inner surface of the cooling jacket.

Description

SYSTEMS AND METHODS FOR ROTOR ASSEMBLIES AND ROTOR COOLINGARRANGMENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims the benefit of U.S. Provisional Patent Application No. 63 / 553,029, filed February 13, 2024, and U.S. Provisional Patent Application No. 63 / 536,302, filed September 1, 2023, each of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This disclosure relates generally to thermal and system management of electronic devices and, more particularly, to compact electronic devices that are liquid-cooled and capable of firmware flashing or data download.BACKGROUND

[0003] Electric motors of various types have been produced and used in many industries and contexts. Electric motors may include power electronics, power converters, and control electronics (collectively electronic devices). Example power electronics include power switching elements such as insulated gate bipolar transistor (IGBT), metal-oxide-semiconductor field-effect transistor (MOSFET), gallium nitride (GaN) transistor switches, and the like. Example power converters include alternating current (AC) to direct current (DC) rectifiers, DC to AC inverters, and DC to DC converters. AC to DC rectifiers, also referred to as AC / DC rectifiers, convert AC power to DC power. DC to AC inverters, also referred to as DC / AC inverters, convert DC power to AC power. DC to DC converters, also referred to as DCZDC converters, convert an input DC power from a first DC voltage level to a second DC voltage level. Example control electronics include microcontrollers, field programmable gate arrays (FPGAs), and applicant specific integrated circuits (ASICs). Control electronics may integrate or include power electronics or power converters therein.

[0004] In an electric motor, the power electronics, power converters, and control electronics may collectively provide for motor operation, motor control, data transfer, and the like.SUMMARY

[0005] Power electronics (e g., IGBTs, MOSFETs, SiC or GaN switches, etc.) may be described in terms of power efficiency, power density, and cost, among other characteristics. Generally, it is desirable to have power electronics with higher power efficiency, higher power density, and lower cost. Similarly, power converters may be described in terms of power (conversion) efficiency, power density, and cost, among other characteristics. Generally, it is desirable to have power converters with higher power efficiency, higher power density, and lower cost. To provide for higher power efficiency or power density, the present disclosure provides for, in part, improved cooling systems with the ability to conduct thermal energy away from heatgenerating elements, such as power devices, within a power converter. In some of the embodiments described herein, the power devices include liquid cooling using a non-conductive fluid, such as non-conductive automotive transmission fluid (ATF) as the liquid medium, and direct jet impingement cooling. Moreover, where control electronics are placed in hard-to-reach locations (e.g., to increase compactness), it tends to become more difficult to update the firmware on the control electronics. In some of the embodiments described herein, the control electronics and associated chipsets include an accessible input / output (VO) port which facilitates firmware flashing, data download and upload, software installation, and the like.

[0006] According to an aspect of the present disclosure, a rotor chipset can include a printed circuit board having a first surface and a second surface opposite the first surface. The printed circuit board can include a rotor winding terminal connector and a plurality of electronic components each having an outward surface. The first surface, the second surface, and the outward surfaces of the plurality of electronic components can define a board surface profile. A cooling jacket can be coupled to the printed circuit board. The cooling jacket can include an inner surface that faces the board surface profile and a fluid inlet port proximate a first end of the printed circuit board. The cooling jacket can include a first jacket portion that faces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board. A coolant pathway volume can be defined by the board surface profile and the inner surface of the cooling jacket.

[0007] According to another aspect of the present disclosure, an electric motor can include a stator assembly, a rotor assembly including an interior cavity, and a rotor chipset assemblydisposed within the interior cavity. The rotor chipset assembly can include a printed circuit board having a first surface and a second surface opposite the first surface. The printed circuit board can include a plurality of electronic components each having an outward surface, wherein the first surface, the second surface, and the outward surfaces of the plurality of electronic components define a board surface profile. A cooling jacket can be coupled to the printed circuit board. The cooling jacket can include an inner surface that faces the board surface profile. The cooling jacket can include a fluid inlet port proximate a first end of the printed circuit board. The cooling j acket can include a first jacket portion that faces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board. A coolant fluid pathway volume can be defined by the board surface profile and the inner surface of the cooling jacket.

[0008] According to yet another aspect of the present disclosure, an electric motor can include a stator assembly including a stator winding and a rotor assembly configured to rotate about a rotor axis relative to the stator assembly. The rotor assembly can include a shaft defining an interior cavity having a shaft inlet and a shaft outlet. A rotor winding can be coupled to the shaft. A cooling jacket can be configured to be received with the interior cavity of the shaft. The cooling jacket can include a main body configured to house a rotor chipset and a plurality of fins extending from the main body. The main body and the plurality of fins can be configured define a flow path for coolant through interior cavity from the inlet to the outlet.

[0009] According to still another aspect of the present disclosure, a rotor assembly can include a shaft defining a rotor axis and an interior cavity. A rotor winding can be coupled to the shaft and a rotor chipset can be disposed within the interior cavity. A bus bar can extend through an opening defined in the shaft. The bus bar can be configured to couple the rotor winding to the rotor chipset.

[0010] According to yet another aspect of the present disclosure, a rotor assembly can include a shaft having a flange disposed on an end of the shaft, a lamination stack, and a rotor winding. A balance ring can be configured to retain the rotor winding on the shaft between the lamination stack and the balance ring. The balance ring can define an inner lip and the flange can be configured to deform over the inner lip to retain the rotor winding on the shaft.

[0011] According to still another aspect of the present disclosure, a method of assembling a rotor can include arranging a winding on a rotor shaft and deforming a flange of the rotor shaft over a balance ring to secure the winding on the rotor shaft.

[0012] According to yet another aspect of the present disclosure, a rotor assembly can include a shaft defining a rotor axis and a lamination stack. The lamination stack can include a first pole and a second pole that are spaced apart to define a winding channel therebetween. A rotor winding can be positioned within the winding channel. An insert can extend axially through the winding channel to direct coolant across the rotor winding.

[0013] According to still another aspect of the present disclosure, an insert for a rotor assembly having a winding channel can include a main body configured to extend in a first direction along the winding channel. The main body can define a first channel extending in the first direction along the main body and a second channel extending in the first direction along the main body parallel to the first channel. A first duct can extend between the first channel and the second channel in a second direction that is at a non-zero angle relative to the first direction.

[0014] The foregoing and other aspects and advantages of the present disclosure will be apparent from the following description. In the description, reference is made to the accompanying drawings that form a part of said description, and in which there are shown one or more example embodiments by way of illustration. These examples do not necessarily represent the full scope of the invention, however, and reference is therefore made to the claims and herein for interpreting the scope of the invention. Like reference numerals will be used to refer to like parts in different drawings and in the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The invention will be better understood and features, aspects, and advantages other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such detailed description makes reference to the following drawings.

[0016] FIG. 1 is a diagram of an example electric drive system, according to aspects of the present disclosure.

[0017] FIG. 2 is a diagram of an example rotor control circuit topology, according to aspects of the present disclosure.

[0018] FIGS. 3A-3C illustrate diagrams of example rotor drive circuits in accordance with various aspects of the present disclosure.

[0019] FIG. 4 is a schematic of an example electronic motor, according to aspects of the present disclosure.

[0020] FIG. 5 is an exploded partial view of an example electronic motor, according to aspects of the present disclosure.

[0021] FIG. 6A is a plan view of a rotor chipset assembly including a rotor chipset and a cooling jacket, according to aspects of the present disclosure.

[0022] FIG. 6B is a plan view of the rotor chipset assembly of FIG. 6A with the cooling jacket shown in phantom.

[0023] FIG. 6C is an axonometric view of the rotor chipset assembly of FIG. 6A.

[0024] FIG. 6D is a schematic view of a coolant flow path through the rotor chipset assembly of FIG. 6 A.

[0025] FIG. 7 is an axonometric view of the rotor chipset assembly of FIG. 6A installed in a rotor shaft.

[0026] FIG. 8 is a process flow of an example thermal management method, according to aspects of the present disclosure.

[0027] FIG. 9 is a process flow of an example system management method, according to aspects of the present disclosure.

[0028] FIG. 10A is a cross-sectional view of a motor assembly including an example coolant flow path, according to aspects of the present disclosure.

[0029] FIG. 10B is a cross-sectional view of the motor assembly of FIG. 10A including another example coolant flow path.

[0030] FIG. 10C is a cross-sectional view of a rotor assembly of the motor assembly of FIG. 10 A.

[0031] FIG. 10D is an axonometric view for a bus bar assembly of the motor assembly of FIG. 10 A.

[0032] FIG. 10E is an axonometric view of a rotor shaft of the motor assembly of FIG. 10A.

[0033] FIG. 11 is a cross-sectional view of the motor assembly of FIG. 10A, with a connector removed to allow an external device to connect with a rotor chipset.

[0034] FIG. 12 is a plan view of an end of the motor assembly of FIG. 11.

[0035] FIG. 13 is an axonometric view of a rotor chipset assembly installed in a rotor shaft of the motor assembly of FIG. 10A.

[0036] FIG. 14 is a side view of rotor chipset assembly of FIG. 13.

[0037] FIG. 15 is a partial cross-sectional view of the rotor chipset assembly, taken through line XV-XV in FIG. 14.

[0038] FIG. 16A is a cross-sectional view of an example rotor assembly of the motor assembly of FIG. 10 A.

[0039] FIG. 16B is an axonometric view of another example rotor assembly of the motor assembly of FIG. 10A.

[0040] FIG. 16C is a partial cross-sectional view of the example rotor assembly of FIG. 16B.

[0041] FIG. 16D is another partial cross-sectional view of the example rotor assembly of FIG.16B.

[0042] FIG. 17 is a partial axonometric view of end windings of the rotor assembly of FIG. 16A.

[0043] FIG. 18 is a detail view of an opening to allow coolant flow through winding guide of the rotor assembly of FIG. 16A.

[0044] FIG. 19 is a detail view of flow channels in an end cap of the rotor assembly of FIG. 16A.

[0045] FIG. 20 is another detail view of flow channels in the end cap of the rotor assembly of FIG. 16A.

[0046] FIG. 21 is a partial axonometric view of outlets for coolant provided on the rotor assembly of FIG. 16A.

[0047] FIG. 22 is a partial axonometric view of another example of a rotor chipset assembly, according to aspects of the present disclosure.

[0048] FIG. 23 is a cross-sectional view of the rotor chipset assembly of FIG. 22.

[0049] FIG. 24 is an exploded view of the rotor chipset assembly of FIG. 24.

[0050] FIG. 25 is a partial cross-sectional view a rotor winding disposed between a lamination stack and an end cap of the rotor assembly of FIG. 10C.

[0051] FIG. 26 is a partial cross-sectional view of an example insert disposed within a winding channel defined within the lamination stack of the rotor assembly of FIG. 10C.

[0052] FIG. 27 is a detail cross-sectional view of the insert of FIG. 26 disposed between first and second rotor windings within the winding channel.

[0053] FIG. 28 is a front, top, and left axonometric view of the insert of FIG. 26.

[0054] FIG. 29 is a front, top, and right axonometric view of the insert of FIG. 26.

[0055] FIG. 30 is a schematic side view of another example insert including opposing projections and ducts, according to aspects of the present disclosure.

[0056] FIG. 31 is a front, top, and left axonometric view of an example insert including crossholes.

[0057] FIG. 32 is a left side view of the insert of FIG. 31.

[0058] FIG. 33 is a cross-sectional view of the insert of FIG. 32, taken through line XXXIII-XXXIII.

[0059] FIG. 34 is a cross-sectional view of the insert of FIG. 32, taken through line XXXIV- XXXIVDETAILED DESCRIPTION

[0060] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and may also include fluid and electrical connections.

[0061] The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention.

[0062] One or more embodiments are described and illustrated in the following description and accompanying drawings. These embodiments are not limited to the specific details provided herein and may be modified in various ways. Further, other embodiments may exist that are not expressly described herein. Also, functions described as being performed by multiple components may be consolidated and performed by a single component. Similarly, functions described herein as being performed by one component may be performed by multiple components in a distributed manner. Additionally, a component described as performing particular functionality may also perform additional functionality not expressly described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not expressly listed.

[0063] As used in the present application, “non-transitory computer-readable medium” comprises all computer-readable media but does not consist of a transitory, propagating signal. Accordingly, non-transitory computer-readable medium may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a RAM (Random Access Memory), register memory, a processor cache, or any combination thereof.

[0064] In addition, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. For example, the use of “comprising,” “including,” “containing,” “having,” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Additionally, the terms “connected” and “coupled” are used broadly and encompass both direct and indirect connectingand coupling, and may refer to physical or electrical connections or couplings. Furthermore, Also as used herein, unless otherwise limited or defined, “or” indicates a non-exclusive list of components or operations that can be present in any variety of combinations, rather than an exclusive list of components that can be present only as alternatives to each other. For example, a list of “A, B, or C” indicates options of: A; B; C; A and B; A and C; B and C; and A, B, and C. Correspondingly, the term “or” as used herein is intended to indicate exclusive alternatives only when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of” For example, a list of “one of A, B, or C” indicates options of: A, but not B and C; B, but not A and C; and C, but not A and B. A list preceded by “one or more” (and variations thereon) and including “or” to separate listed elements indicates options of one or more of any or all of the listed elements. For example, the phrases “one or more of A, B, or C” and “at least one of A, B, or C” indicate options of: one or more A; one or more B; one or more C; one or more A and one or more B; one or more B and one or more C; one or more A and one or more C; and one or more of A, one or more of B, and one or more of C. Similarly, a list preceded by “a plurality of’ (and variations thereon) and including “or” to separate listed elements indicates options of multiple instances of any or all of the listed elements. For example, the phrases “a plurality of A, B, or C” and “two or more of A, B, or C” indicate options of: A and B; B and C; A and C; and A, B, and C.

[0065] Also as used herein, unless otherwise limited or defined, “substantially parallel” indicates a direction that is within ± 12 degrees of a reference direction (e.g., within ± 6 degrees or ± 3 degrees), inclusive. Similarly, unless otherwise limited or defined, “substantially perpendicular” similarly indicates a direction that is within ± 12 degrees of perpendicular a reference direction (e.g., within ± 6 degrees or ± 3 degrees), inclusive. Correspondingly, “substantially vertical” indicates a direction that is substantially parallel to the vertical direction, as defined relative to the reference system (e.g., a local direction of gravity, by default), with a similarly derived meaning for “substantially horizontal” (relative to the horizontal direction). Discussion of directions “transverse” to a reference direction indicate directions that are not substantially parallel to the reference direction. Correspondingly, some transverse directions may be perpendicular or substantially perpendicular to the relevant reference direction.

[0066] FIG. 1 illustrates an electric drive system 100 that includes a motor 102 (e.g., an electric motor) and a motor controller 104 coupled to the motor 102. The motor controller 104 is configured to operate the motor 102 to drive a load 110. The load 110 can be an additional geartrain such as a gear set, a vehicle wheel, a pump, a compressor, or another motor where multiple motors can be linked and operated in parallel.

[0067] The electric motor 102 has an output shaft 107 rotatable with respect to a motor housing 105, which is considered to be a datum with respect to rotations and other motions of motor components. In use, the output shaft 107 can be coupled to the load 110 to which the motor 102 can impart rotary power when electrically activated by appropriate electrical power and signals from the motor controller 104. The output shaft 107 may extend through the motor and be exposed at both ends, meaning that rotary power can be transmitted at both ends of the motor. The motor housing 105 can be rotationally symmetric about the rotation axis of output shaft 107, but may be of any external shape and can generally include means for securing the motor housing 105 to other structures to prevent housing rotation during motor operation.

[0068] The motor 102 includes an active magnetic component, such as a stator assembly 106, and a passive magnetic component, such as a rotor assembly 108. For illustration purposes, in the following, “stator” is used as a representative example of the active magnetic component and “rotor” is used as a representative example of the passive magnetic component.

[0069] The rotor assembly 108 is associated with the stator assembly 106 and can be disposed within the stator assembly 106 (e.g., in an internal rotor radial-gap motor); parallel to the stator assembly (e.g., in an axial-gap motor or in a linear motor); or around the stator assembly (e.g., in an outer rotor radial -gap motor). The rotor assembly 108 is rotationally coupled to the output shaft 107, such that any rotational component of resultant rotor motion is transmitted to the output shaft 107, causing the output shaft 107 to rotate. The stator assembly 106 is fixed to the motor housing 105 such that during operation, the rotor assembly 108 moves about the stator assembly 106 or parallel to the stator assembly 106. As described more fully below, electrical activity in the stator assembly 106, properly controlled, drives motion of the rotor assembly 108. For example, the motor controller 104 may be in in communication with both a stator drive circuit 225 and a rotor power circuit 330 (see FIG. 3A). The stator drive circuit 225 can be a part of the drive circuit that connects a DC power supply to the stator windings 215 of the stator assembly 106. The stator drive circuit 225 includes a stator inverter network that is connected to the DC power supply to receive power. The stator inverter network is further connected to the stator windings 215 and to the motor controller 104. The motor controller 104 controls the stator drive circuit 225 and, in particular, thestator inverter network, to selectively drive the stator windings 215 with current from the DC power supply to induce magnetic fields that rotate the rotor assembly 108.

[0070] Continuing, current flowing through a loop of electric wire will result in a substantially uniform magnetomotive force (MMF) resulting in a motor pole within the wound, or encircled, region. In a typical motor, such a loop has a sufficient diameter to carry the desired current load, but is thin enough that a skin depth of the drive frequency fully penetrates the loop. Many turns, or coextending loops of wire wound as a group, may be used to increase the pole magnetic field strength. This topology is typically referred to as a wound field pole. Such a set of coextending loops wound as a group is referred to as a coil. For the purposes of this disclosure, one or more coils acting together within the stator or rotor are referred to as a winding.

[0071] In some instances, coils can overlap and encompass multiple teeth on either a rotor assembly or a stator assembly. Such overlapping coils can be referred to as an armature or a distributed winding. A pole is a magnetic center of this distributed winding, and as such, the pole can move relative to the individual coils within such a distributed winding depending upon the drive current passing through the winding.

[0072] The stator assembly 106 defines multiple stator poles with associated electrical windings and the rotor assembly 108 includes multiple rotor poles. The rotor assembly 108 defines, together with the stator assembly 106, a nominal air gap between the stator poles and the rotor poles, such as the example as illustrated with further details throughout this disclosure. The rotor assembly 108 is movable with respect to the stator assembly 106 along a motion direction (e.g., a circumferential direction).

[0073] In some examples, the motor 102 is a wound field synchronous motor (WFSM), and the rotor assembly 108 includes field windings that are selectively driven with current to induce magnetic fields that interact with the magnetic fields of the stator assembly 106 to rotate the rotor assembly 108. In other examples, the rotor assembly 108 includes a combination of a permanent magnets and field windings. Accordingly, although some of the features disclosed herein are primarily described with respect to WFSM-type motors, the features are also applicable to other motor types and operational schemes which may be synchronous or otherwise. Thus, in some examples, the motor 102 is not a synchronous motor but, rather, another type of motor (e.g., an asynchronous motor). Nevertheless, operation of the motor 102 can happen under synchronous conditions, where such synchronous conditions overcome the inefficiencies of asynchronousoperating systems wherein low power factors and high reactive currents can reduce efficiency or prevent efficient operation of a machine. Further, some examples of synchronous machines described herein include use of stranded conductors, bar windings, litz wire, or the like (e.g., for the windings on the rotor), which spreads out current across a larger conductor for more efficient and thermally stable operation versus solid conductors or conductors that may be present on an asynchronous machine (e.g., squirrel cage), which may pool current on the surface of the exterior of the rotor.

[0074] Further, as is known to those skilled in the art, an electric machine serving as an electric motor that outputs mechanical power from input electric power may also operate in reverse and serve as an electric generator that outputs electric power from input mechanical power. Accordingly, for ease of description, the electric machines described herein will generally be referred to as motors (e.g., the motor 102), but are meant to also encompass electric generators and devices that may operate as both an electric motor and an electric generator.

[0075] FIG. 2 illustrates an example circuit schematic for rotor control (e.g., for control of the rotor assembly 108 illustrated in FIG. 1). In the illustrated example, a rotor winding 200 is coupled to an active rectifier circuit 202 that rectifies currents in the rotor winding 200. A microcontroller 204 is connected to the rotor winding 200 or the active rectifier circuit 202. The microcontroller 204 may include various components such as estimators, converters, comparators, logic circuits, transistors, memories, processors, and the like.

[0076] In examples, the microcontroller 204 may be configured to measure or estimate rotor current 7R and rotor voltage FR and, based on these values, determine an estimated stator AC voltage Fs. Based on Fs, the microcontroller 204 controls switchable elements of the active rectifier circuit 202 to impose the desired timings and levels on the rotor currents. A digital memory in the microcontroller 204 may store one or more mathematical models of the stator-rotor system and use these models in conjunction with digital logic to determine estimated stator signal parameters.

[0077] Examples of control functions that may be performed based on Fs include one or more of the following. A phase of a stator AC voltage is estimated, and the rotor current / voltage waveform is controlled in quadrature to control power transfer (e.g., to maximize power transfer). A frequency of the stator AC voltage is estimated, and the rotor current / voltage waveform is controlled to have a frequency matching the frequency of the stator AC voltage or to have adifferent predefined relationship with the stator AC voltage. An amplitude of the stator AC voltage is estimated, and the rotor voltage waveform is controlled to have an amplitude matching the amplitude of the stator AC voltage or twice the amplitude of the stator AC voltage, or to have a different predefined relationship with the stator AC voltage.

[0078] In various implementations, other logic operations besides the ones in this example may be used to cause the rotor currents / voltages to have a particular magnitude, frequency, phase, or other parameter, based on measured or estimated rotor currents or voltages induced by stator voltages. Estimator units may take, as input, data besides measured or estimated ER and 7R; for example, instead of or in addition to measuring or estimating these values, a rotor circuit may detect polarity-switching events in PR or IR and make estimations based on those events. In addition, besides the example estimated stator-side parameters Es, / s, and cps, other stator-side parameters may be estimated (e.g., stator current Is or stator current / voltage polarity switching events). Phase-locked loop methods may be used to synchronize the rotor frequency to the stator frequency, to set a particular relative phase of the rotor frequency, or to perform other rotor-side controls.

[0079] The rotor assembly may be configured to wirelessly receive power (e.g., via rotor winding 200 from a stator-side power source), harvest the power, and use the power to power the microcontroller 204 and drive the rotor winding 200 or another rotor winding of the rotor assembly 108 to generate a magnetic pole or poles. FIG. 3A provides a diagram of a rotor assembly (e.g., the rotor assembly 108) including rotor windings 315 and a rotor power circuit 330. In this example, the rotor power circuit 330 includes a rotor inverter 350 (e.g., including the abovedescribed power switching elements) connected to a slip ring 355 that is connected to a rotor output circuit 360 configured to distribute current to the rotor windings 315. The rotor inverter 350 is driven by the motor controller 104, and may receiver power wireless therefrom, to provide power from a power supply to the slip ring 355. The slip ring 355 may provide a connection between stationary components (e.g., the rotor inverter 350) and rotating components of the rotor assembly 108 (e.g., the rotor output circuit 360 and the rotor windings 315). The slip ring connection may be one or more of a conductive coupling, an inductive coupling, or a capacitive coupling, such as described above. The rotor output circuit 360 includes the traces, terminals, and other on-board circuit elements (e.g., resistors, capacitors, etc.) that connect the rotor windings 315 to the slip ring 355. As illustrated, four channels 365 are provided from the rotor inverter 350 to the rotor windings315, enabling up to four rotor phases. For clarity, each channel 365, although drawn as a single line, may define a complete electrical circuit. In some examples, each channel 365 may represent a separate conductive path. In some examples, a portion of one or more of the channels 365 connecting two elements (e.g., the rotor inverter 350, slip ring 355, rotor output circuit 360, or rotor windings 315) may be implemented by a shared conductor that is multiplexed (e.g., time multiplexed or frequency multiplexed). In other examples, more or fewer channels 365 are provided.

[0080] FIGS. 3B and 3C provide additional diagrams of a rotor assembly (e.g., the rotor assembly 108) including a rotor drive circuit 300. In these examples, the rotor assembly 108 uses embedded power transfer and embedded communications (e.g., control signals for a rotor chipset) from the stator windings 215 to the rotor drive circuit 300 or the rotor windings 315, represented by the four channels 370 to transfer power and communications from the stator windings 215 to the rotor drive circuit 300 or the rotor windings 315. It is appreciated that power transfer between the stator windings 215, the rotor drive circuit 300, or the rotor windings 315 may occur wirelessly (e g., by inductive transfer). To simplify the diagram, the rotor power circuit and a rotor communication circuit are illustrated as a combined circuit, namely, a rotor power-communication circuit 375. In the non-limiting example illustrated in FIG. 3B, the rotor drive circuit 300 may be connected to the rotor windings 315 via four circuit or conductive paths 380, enabling up to four rotor phases. In other examples, more or fewer conductive paths 380 are provided. For clarity, each conductive path 380, although drawn as a single line, may define a complete electrical circuit. The rotor windings 315 can also be a part of the rotor drive circuit 300, such that that the rotor windings 315 and the rotor power-communication circuit 375 can also be arranged in parallel in the rotor drive circuit 300. Alternatively, and as illustrated in FIG. 3C, the rotor windings 315 receive power directly from the stator windings 215 via the four channels 370, the rotor windings 315 being arranged in series with the rotor drive circuit 300 (i.e., the rotor power-communication circuit 375). Although not illustrated in FIGS. 3B and 3C, in addition to transmitting the power and communications via channels 370, current through the stator windings 215 also generates magnetic fields that generate torque on the rotor assembly 108 and control field modulation for rotation of the rotor assembly 108 incorporating the stator windings 215. Additionally, in some examples, rather than embedded power transfer and communications, a slip ring (e.g., the slip ring 355) is provided for power transfer and communications to the rotor drive circuit 300 via brushed,inductive, or capacitive couplings. In some examples, the rotor winding 200 of FIG. 2 is an example of a rotor winding of the rotor windings 315, and the microcontroller 204 or the active rectifier circuit 202 are examples of components of the rotor drive circuit 300 or of the rotor powercommunication circuit 375.

[0081] FIG. 4 illustrates an example of a motor 400 in accordance with various aspects of the present disclosure. The motor 400 includes a stator assembly 410, a rotor assembly 420 that rotates within the stator assembly 410, a rotor chipset assembly 430 disposed within the rotor assembly 420, and a drive head end cap assembly 440. The drive head end cap assembly 440 forms a part of a motor housing, which houses the stator assembly 410, the rotor assembly 420, and the rotor chipset assembly 430.

[0082] FIG. 5 illustrates an exploded view of certain components of or corresponding to the motor 400 (namely, the stator assembly 410, the rotor assembly 420, the rotor chipset assembly 430, the drive head end cap assembly 440, and inverter assembly 505), and shows the rotor chipset assembly 430 in more detail as including a rotor chipset 500 (e.g., a rotor chipset assembly) and a chipset housing 510. FIG. 5 also illustrates a pathway 450 for a coolant fluid, as will be discussed in greater detail below. The motor 400 may correspond to the motor 102 illustrated in FIG. 1 and described above.

[0083] In general, the motor 400 can be operatively coupled with a power source (e.g., a battery) via the inverter assembly 505. As shown in FIG. 5, the inverter assembly 505 can be configured to control a flow of electric current to and from the motor 400 (e.g., for charging and discharging the power source) and may include one or more inverter modules 506. In the illustrated embodiment, the inverter assembly 505 includes six inverter modules 506. In other examples, a power conversion assembly (e.g., inverter assembly 505) can fewer or more than six inverter modules 506. In some cases, the number of inverter modules 506 provided for a motor can correspond to system characteristics. For example, if more torque or power is needed for a motor, more inverter modules 506 can be provided. Correspondingly, if less power is required, fewer inverter modules 506 can be provided, which can reduce a total volume, weight, and cost of a vehicle drive unit, for example.

[0084] Each of the inverter modules 506 can operate to invert a DC signal into an AC signal (e.g., a power signal), such as for supply power to a motor from a DC power source (e.g., a battery). The inverter modules 506 of a vehicle drive unit can convert a DC input into a three phase ACvoltage output for driving the motor 400. Tn some cases, the inverter modules 506, to drive the motor 400, can invert a DC signal into a single-phase AC signal, or an AC signal with more than 3 phases. Additionally, each of the inverter modules 506 can operate to convert an AC signal to a DC signal, such as for charging a DC power source (e.g., a battery) from a motor (e.g., for regenerative braking) or AC power mains. Further, the each of the inverter modules 506 can operate to convert a first DC signal to a second DC signal (e.g., for DC / DC charging).

[0085] Each inverter module 506 can include a circuit board on which is mounted one or more pairs of power switching elements, for example, a pair of field effect transistors (FETs) for outputting each respective phase of AC signal output by the inverter assembly 505. Additionally, each phase of AC current produced by an ACM can be filtered to produce the desired signal characteristics and filter out unwanted frequencies or amplitudes of AC current. In some examples, an AC signal from FETs of an ACM can be filtered by an LC filter before the signal is provided to power a downstream AC load (e.g., a motor). In some examples, the inverter assembly 505 may also be bidirectional in that the one or more of the inverter modules 506 may convert received AC voltage (e.g., from the motor 400 or AC grid ) to DC voltage (e.g., to charge a vehicle battery).

[0086] Correspondingly, electrical current can be provided to the rotor chipset 500, which can control operation of the motor 400. With additional reference to FIGS. 6A-6D, The rotor chipset 500 may include a printed circuit board (PCB) 610 configured to support a plurality of electronic components 616, such as, for example, a microcontroller or other control electronics configured to store, execute, or implement firmware or software to control the operation of the rotor assembly 420, one or more transistors (e.g., FETs), and one or more I / O ports (e.g., a USB port). In some examples, the electronic components of the rotor chipset 500 (e.g., on the printed circuit board thereof) can include the active rectifier circuit 202 and microcontroller 204 (see FIG. 2), the rotor output circuit 360 (see FIG. 3A), or the rotor drive circuit 300 (see FIG. 3B). Additionally, the rotor chipset 500 may further house components such as energy storage devices (e.g., capacitors, supercapacitors, inductors, batteries, or combinations thereof), switches (e.g., MOSFETs, IGBTs, GaN transistors, etc.), diodes, or a local microcontroller (MCU) with low voltage power supply. In some implementations, however, such energy storage devices are not included in the rotor chipset 500 itself. As illustrated, the PCB 610 has a first surface 612 and a second surface 614 opposite the first surface 612. The electronic components 616 (e.g., resistors, capacitors, transistors, inductors, logic gates, FPGAs, memory components, processing components, ports,etc.) are mounted on the PCB 610. In FIG. 6D, electronic components 616 are disposed on both the first surface 612 and the second surface 614; however, in some implementations the electronic components 616 may be disposed only on one surface of the PCB 610.

[0087] In addition to the electrical components discussed above, a rotor chipset can also include port or other terminals configured to communicate with external devices. For example, still referring to FIGS. 6A-6D, the rotor chipset 500 can include a connection port 618 . The connection port 618 may be an electronic connection port, for example, an I / O port, configured to receive an external connection cable (e.g., Universal Serial Bus (USB) port). In this way, an external device can be coupled with the rotor chipset 500, such as for programming the rotor chipset, diagnostic testing, etc. Additionally, the rotor chipset 500 may further include tangs or pins 640 (e g., motor connection terminals) through which the PCB 610 may connect to the motor 400. More specifically, the pins 640 may be configured to connect to one or more rotor windings of the rotor assembly 420 (e.g., to end terminals of the rotor windings). Such rotor windings may be similar to, for example, the rotor winding 200 (FIG. 2) or the rotor windings 315 (FIGS. 3A- 3B). Accordingly, the pins 640 may also be referred to as rotor winding terminal connectors. In the illustrated example, the pins 640 are secured to an end of the PCB 610 that is opposite another end to which the connection port 618 is secured. It is appreciated the number and position of pins 640 may vary in accordance with requirements of a particular implementation.

[0088] According to further aspects of the disclosure, a rotor chipset can be coupled to rotate with a rotor and may form part of a cooling path through an electric motor. As shown in FIGS.4 and 5, the rotor chipset 500 and the chipset housing 510 extend substantially in an axial direction of an interior cavity 422 of the rotor assembly 420. More specifically, the interior cavity 422 can be formed within a shaft 424 of the rotor assembly 420 and the chipset housing 510 can be configured to be received therein. In other non-limiting examples, the chipset housing 510 can be integrally formed with the shaft 424. In either case, the rotor chipset assembly 430 can be secured and located with the chipset housing 510 and the shaft 424 during an assembled state of the motor 400. As illustrated, the chipset housing 510 can be configured as a cylindrical housing so as to conform to the shape of the interior cavity 422 of the rotor assembly 420; however, this shape is illustrative and not limiting. Correspondingly, an outer surface 704 of the chipset housing 510 may be configured to engage an inner surface of the rotor assembly 420. As illustrated, the outer surface of the chipset housing 510 includes a flange (or flanges) 706 that may be slidably received in aslot of the rotor assembly (not illustrated). As illustrated, the flanges 706 of the chipset housing 510 can be located at one end of the chipset housing 510 approximately 180 degrees apart along an outer circumference of the chipset housing 510, in alignment with the slots 702. The flanges 706 and slots 702 are also visible in FIG. 5. The chipset housing 510 may include an anti -vibration system configured to reduce a fibrational force on the rotor chipset assembly 430 during an operation of the motor 400.

[0089] A chipset housing can be configured to retain a rotor chipset within a rotor shaft and may rotationally lock the rotor chipset to rotate with the rotor assembly. For example, an inner surface of the chipset housing 510 may be configured to couple to the rotor chipset 500 (e.g., a printed circuit board (PCB), a cooling jacket, or both). As illustrated, the inner surface of the chipset housing 510 includes a slot (or slots) 702 that slidably receives a PCB 610 of the rotor chipset 500. The slots 702 may have a width slightly greater than the thickness of the PCB 610 to provide a snug fit. In some cases, a chipset housing and rotor chipset can be configured to allow electrical connections between the rotor chipset and an external device (e.g., for servicing or programming of the rotor chipset), or between the rotor chipset and rotor windings (e.g., to allow wireless communications from a stator to the rotor chipset via the rotor windings, as generally described above). For example, the chipset housing 510 may defined one or more openings to allow the pins 640 to couple to the rotor windings 200.

[0090] Operation of an electric motor, including a rotor chipset, generates heat, which can be dissipated to the surrounding environment to maintain a desired operating efficiency thereof. In some cases, a liquid coolant can be provided to extract heat generated by the electric motor and dissipated it to the surrounding environment. As mentioned above, the motor can be part of a shared coolant loop that is configured to provide coolant to the motor and other components of drive system. For example, a coolant can be a dielectric ATF that can flow through the motor, an inverter, and a transmission. For example, coolant can flow from a transmission, though an inverter, and into the motor, where it can then flow to a heat exchanger to dissipate absorbed heat before flowing back to the transmission. In other examples a flow path for coolant can be configured different, and may include one or more filters arranged along the flow path to remove contaminants from the coolant.

[0091] As illustrated, coolant fluid flows within a motor housing along the pathway 450 that extends through the inverter modules 506 of the inverter assembly 505, through a pathway in thedrive head end cap assembly 440, to and through the rotor chipset assembly 430, and finally through windings of the rotor assembly 420. The coolant fluid may then pass through a heat exchanger and loop back through the motor 400 via the pathway 450. However, in other implementations the heat exchanger may be disposed at a different position along the pathway 450 (i.e., not necessarily between the rotor assembly 420 and the inverter assembly 505). Additionally, in some implementations, a different coolant fluid flow path is provided (e.g., that does not include the inverter modules 506, the drive head end cap assembly 440, or motor windings.

[0092] To help provide cooling to a rotor chipset, a cooling jacket can be coupled to the rotor chipset to control direct a flow of coolant along the rotor chipset. For example, a cooling jacket can be configured to direct fluid along particular electrical components, as well as to control a rate of heat dissipation thereof. For example, a cross-sectional area of the cooling path formed by the cooling jacket can be configured to increase or decrease a rate of fluid flow in different areas of the rotor chipset. As illustrated in FIGS. 6A-6D, the rotor chipset 500 includes a cooling jacket 620 coupled to the PCB 610. The outward surface of the electronic components (e.g., the top and side surfaces), together with the first surface 612 and the second surface 614, define aboard surface profile. The cooling jacket 620 includes an inner surface 617 that faces the board surface profile and is substantially matched to the board surface profile, thereby to define a coolant pathway volume 630. Put another way the inner surface 617 can be contoured to follow the board surface profile. The inner surface 617 can be offset from the board surface profile to define an envelope therearound that acts as the coolant pathway volume 630, which forces coolant fluid through tight channels around the electronic components 616. In some examples, the clearance between the inner surface 617 and the PCB 610 is dimensioned so as to minimize the time needed to fill a volume defined by the cooling jacket 620 with coolant. Put another way, the spacing between the inner surface 617 and PCB 610 increases fluid velocity through the cooling jacket 620 and allows a volume thereof to be filled with coolant to enhance cooling of the PCB 610. This can be particularly advantageous when pumping coolant into the cooling j cket using, for example, mechanically driven pumps that may only be activated once the rotor is activated. Moreover, the rapid cooling provided by this arrangement is helpful when machine loading occurs very quickly after an electric pump is activated, as filling the volume of the cooling jacket quickly before thermal loading occurs helps to improve the thermal efficiency of the power components disposed within the cooling jacket.

[0093] In some cases, a cooling jacket can be formed as single- or multi-piece cooling jacket. As illustrated in FIG. 6D, the cooling j acket 620 is configured as a multi-piece cooling jacket that includes a first jacket portion 622 covering the first surface 612 and those electronic components 616 mounted on the first surface 612, and a second jacket portion 624 covering the second surface 614 and those electronic components 616 mounted on the second surface 614. However, in some implementations the cooling jacket 620 may be of a unitary construction. The first jacket portion 622 and the second jacket portion 624 (or, where a unitary construction is used, portions of the cooling jacket 620 disposed on opposite sides of the PCB 610) may be balanced. For example, the mass of the first jacket portion 622 may be approximately equal to the mass of the second jacket portion 624. In another example, a distance between a center of mass of the first jacket portion 622 and the first surface 612 may be approximately equal to a distance between a center of mass of the second jacket portion 624 and the second surface 614. By balancing the halves of the cooling jacket 620, the rotor chipset 500, and thus the rotor chipset assembly 430, may retain the capability to operate at high rotational speeds. FIG. 7 illustrates the rotor chipset assembly 430 in an assembled state, with the cooling jacket 620 affixed to the PCB 610 and both components residing within the chipset housing 510. The cooling jacket 620 includes a first jacket portion 622 covering the first surface 612 and those electronic components 616 mounted on the first surface 612, and a second jacket portion 624 covering the second surface 614 and those electronic components 616 mounted on the second surface 614. However, in some implementations the cooling jacket 620 may be of a unitary construction. The first jacket portion 622 and the second jacket portion 624 (or, where a unitary construction is used, portions of the cooling jacket 620 disposed on opposite sides of the PCB 610) may be balanced. For example, the mass of the first jacket portion 622 may be approximately equal to the mass of the second jacket portion 624. In another example, a distance between a center of mass of the first jacket portion 622 and the first surface 612 may be approximately equal to a distance between a center of mass of the second jacket portion 624 and the second surface 614. By balancing the halves of the cooling jacket 620, the rotor chipset 500, and thus the rotor chipset assembly 430, may retain the capability to operate at high rotational speeds. FIG. 7 illustrates the rotor chipset assembly 430 in an assembled state, with the cooling jacket 620 affixed to the PCB 610 and both components residing within the chipset housing 510.

[0094] In general, a cooling jacket can define an inlet and an outlet to allow coolant to flow through the cooling jacket to cool a rotor chipset. For example, still referring to FIGS. 6A-6D, atone end of the PCB 610, the cooling jacket 620 can define a fluid inlet port 626, configured to receive a flow of coolant into the coolant pathway volume 630. Additionally, the cooling jacket 620 can define fluid outlet ports 628 to allow fluid to exit the coolant pathway volume 630. As illustrated the fluid outlet ports 628 628 are positioned opposite the fluid inlet port 626 so fluid flow across the rotor chipset 500. In some cases, the configuration of the fluid inlet port 626 and the fluid outlet port 628 can allow fluid to be automatically pumped though the cooling jacket 620 due to rotation of the rotor assembly 420. More specifically, coolant can be supplied to the fluid inlet port 626, and then centripetal forces feed fluid through the coolant pathway volume 630 and over the plurality of electronic components 616. Coolant fluid enters at a fluid entry portion of the fluid inlet port 626 and exits via fluid outlet ports 628 628, as shown by an arrow in FIG. 6D. The fluid outlet ports 628 628 may be disposed at any portion along the surface of the cooling jacket 620; alternatively, the cooling jacket 620 may be sealed such that fluid both enters and exits through the fluid inlet port 626.

[0095] Fluid exit portions and fluid inlet ports of a cooling jacket can be arranged to control pumping through the cooling jacket and motor during motor operation. In some examples, the relative size or position of the fluid exit portions and the fluid inlet ports can prevent the rotational pumping effects from evacuating coolant from an internal volume of the cooling jacket though the fluid exit portions faster than the coolant can be replaced via coolant from the fluid inlet ports. This ensures that the internal volume of the cooling jacket remains filled with coolant during motor operation so that the rotor chipset receives a flow of coolant. For example, when installed in a rotor (e.g., the rotor assembly 108), the fluid outlet ports 628 628 can be at a first radial distance relative to the rotor axis that is equal to or less than a second radial distance (e.g., a maximum radial distance) of the fluid inlet port 626. As shown in FIGS. 6C and 6D, the fluid outlet ports 628 628 extend perpendicular to the rotor axis (e.g., rotor axis 1021 in FIG. 11). The openings begin along an inner surface of the cooling jacket 620 that is at a first radial distance 629 from the rotor axis 1021. Exit portions can also be arranged differently, for example, to extend parallel to an axis of a rotor. In some cases, exit portions can be formed by a gap between first and second jackets of a cooling jacket (see e.g., FIGS. 23 and 24). The fluid inlet port 626 is configured as a round opening that is concentric with the rotor axis 1021. The fluid inlet port 626 defines a radius so that outermost perimeter of the fluid inlet port 626 is at a second radial distance 627 from the rotor axis 1021. The second radial distance 627 is greater than the first radial distance 629. This arrangementallows coolant 1040 to be pumped into the cooling jacket 620 at an equal or greater rate than the coolant 1040 exiting the fluid outlet ports 628 628, thereby allowing the coolant pathway volume 630 to be filled as fast as possible. Put another way, an inlet flow rate through the fluid entry portion is greater than or equal to an outlet flow rate through the fluid outlet ports 628 628. Excess coolant flow from the fluid inlet port 626 that in unable to enter the inner volume of cooling j acket 620 for cooling the rotor chipset 500, as well as flow exiting the fluid outlet ports 628, can be collected by other features and directed to a component external to the rotor chipset assembly 430 (e.g., rotor / stator windings) so as to make more efficient use of pumping power.

[0096] In other examples, components of a rotor chipset assembly can be arranged differently to ensure coolant coverage during operation. In particular, components of a rotor chipset, such as critical heat generating components (e.g., power components such as FETs, converters, drivers, and processing circuitry such as microprocessors, FPGA, DSP, ASIC, as well as other circuit elements) can be positioned radially outward from inlets and exits of a cooling jacket.

[0097] Positioning these components at a greater radial distance than the inlets and exits can create coolant collection regions in conjunction with the shape of the cooling jacket. These collection regions can help to retain coolant due to the higher centripetal forces acting on the coolant in these regions. This in turn helps to ensure that the volume defined by the rotor chipset (e.g., the fluid pathway volume) is filled with coolant as quickly as possible to improve cooling of the rotor chipset components. In some examples, these collection regions help to keep the fluid pathway volume filled with coolant even as rotor speed changes during operation (e.g., via the use of drive pumps, such as electric pumps). In cases where rotor rotation ceases, coolant can be retained by pooling in the collection regions, depending on the rotational position of the rotor chipset relative to a direction of gravity. In the illustrated example, the cooling jacket 620 defines a collection region 650 where an internal area, and thus a portion of the flow path, is position at a third radial distance 652 that is greater than both the first radial distance 629 and the second radial distance 627. A component 654 (e.g., a heat generating component) of the rotor chipset 500 extends into the collection region 650. In other examples, the number of cooling regions may be different.

[0098] In some cases, an inlet for a cooling jacket can be configured as a dual-use port to also provide access to rotor chipset terminal or other communication port. For example, the fluid inlet port 626 can be aligned with the connection port 618 and dimensioned to receive an electronicconnector through (e.g., a connector corresponding to the connection port 618 , such as a USB cable). Accordingly, the fluid inlet port 626 can be used for both receiving coolant fluid and an electronic connector, may, thus, also be referred to as a cable input port, a common inlet port, a dual-use inlet port, or a multi-use inlet port.

[0099] FIGS. 8 and 9 illustrate example methods of thermal and system management according to various aspects of the present disclosure. In particular, FIG. 8 illustrates an example of a method 800 of thermal management of a rotor chipset, such as the rotor chipset assembly 430 described above, whereas FIG. 9 illustrates an example of a method 900 of system management of the rotor chipset, such as the rotor chipset assembly 430 described above. For purposes of illustration, methods 800 and 900 are described as being performed in the context of the motor 400 illustrated in FIGS. 4-7

[0100] The method 800 includes operating the motor 400 at block 802. At block 804, a coolant fluid is injected through the fluid inlet port 626 of the rotor chipset 500 of the motor 400, which can be performed before (e.g., if using a pump, such as an electric pump, to drive coolant flow) or during motor 400 operation. The coolant fluid may be injected from inverter assembly 505, for example along the pathway 450 and via the drive head end cap assembly 440.

[0101] After the coolant fluid has been injected into the rotor chipset 500, at block 806 movement of the coolant fluid through the coolant pathway volume 630 is caused. The movement may be caused by centripetal force resulting from rotation of the rotor assembly 420 (and thus rotation of the rotor chipset 500), by fluid pressure resulting from incoming fluid presented at the fluid inlet port 626, or a combination thereof. For example, as long as the fluid outlet ports 628 628 are disposed radially outward from an outermost extent of the fluid inlet portions (e.g., the central portions of the fluid inlet port 626), the coolant fluid will pass through the coolant pathway volume 630 as desired.

[0102] After block 806, the coolant fluid exiting the rotor chipset 500 may loop back through the motor 400, and in some implementations may further cool additional components (e.g., rotor windings, stator coils, inverter assemblies, etc.) before returning to the fluid inlet port 626. Thus, while block 802 is continuously being performed, blocks 804 and 806 may be continually performed to continually cool the rotor chipset 500.

[0103] The method 900 can begin at block 902 of ceasing operation of the motor 400. If, however, the motor 400 is not currently operating at the time the method 900 is performed, block 902 may be omitted. In either case, while the motor 400 is not in operation, at block 904 a connection cable (e.g., a USB cable or a Thunderbolt cable) is inserted through the fluid inlet port 626 of the rotor chipset 500. In order to provide access to the fluid inlet port 626, prior to block 902 the motor 400 may be partially disassembled (e.g., the drive head end cap assembly 440 or a small access cover may be removed) or any coolant fluid may be drained.

[0104] Subsequently, the connection cable is connected to the connection port 618 at block 906, and information to or from the controller of the rotor chipset 500 is transmitted via the connection cable and the connection port 618 at block 908. Block 908 may be a “flashing” operation, in which firmware associated with the rotor chipset 500 (e.g., in a microcontroller thereof) is updated or installed. For example, the microcontroller of the rotor chipset 500 may receive firmware or a firmware update from an external device (e.g., laptop, desktop computer, tablet, etc.). The received firmware or firmware update may be stored on a memory corresponding to the microcontroller. Block 908 may additionally or alternatively include a data download operation, in which information (e.g., machine parameters, temperature under operating conditions, debug information, and the like) is downloaded from the rotor chipset 500 to, for example, an external device. After the information transfer at block 908 is complete, at block 910 the connection cable is disconnected from the connection port 618 and removed from the fluid inlet port 626.

[0105] Methods 800 and 900 may be performed in any order, any number of times. In one example, an iteration of method 900 may be performed during an initial manufacturing process of the motor 400, or may be performed after the motor 400 has been manufactured but before it has been installed (e.g., in a vehicle). Subsequently, method 800 may be performed any number of times. If, at some point in the future, the firmware of the rotor chipset 500 requires an update, method 800 may cease and method 900 may be performed again, after which method 800 may resume.

[0106] In other implementations, a rotor chipset and cooling jacket can be configured differently, while still adhering to the operational principles discussed above. For example, a chipset can be disposed within a rotor shaft. The chipset may include a cooling jacket that can be configured to position the chipset within the rotor shaft, and which can be further configured todirect a flow of coolant to other motor components (e.g., rotor windings, etc.) as part of a larger cooling system. For example, FIGS. 10-21 depict aspects of another non-limiting example of a motor 1000. Similar to the motor 400, the motor 1000 generally includes a stator 1010 (e.g., a stator assembly) and a rotor 1020 (e.g., a rotor assembly). The rotor 1020 is configured to move relative to the stator 1010. While other arrangements are possible, in this case, the rotor 1020 is disposed within the stator 1010 and configured to rotate relative to the stator 1010 about a rotor axis 1021 (e.g., with the rotor 1020 nested in the stator 1010 in concentric configuration about the rotor axis 1021). More specifically, the stator 1010 can include stator windings 1015 that can produce a rotating stator magnetic field in response to an applied electrical current (e.g., a current provided by inverter assembly 505). Correspondingly, the rotor 1020 can include rotor winding 1025. The stator magnetic field can interact with rotor windings 1025 to induce a current therein, which results in the rotor 1020 producing a corresponding rotor magnetic field. The rotor magnetic field and stator magnetic field can be controlled relative to one another to produce a magnetomotive force that causes the rotor 1020 to rotate about the rotor axis 1021.

[0107] As generally discussed above, a rotor can include a chipset that can be configured to control current within rotor windings to control a rotor magnetic field. As shown in FIGS. 10A- 10C, the motor 1000 includes a rotor chipset 1030 that is configured to control current within the rotor windings 1025 to control a flow of current therethrough (e.g., a current induced by the stator 1010). For example, the rotor chipset 1030 can include various electrical components (e.g., power electronic componentry, as generally described above) to provide active or passive rectification of the current in the rotor windings 1025, or to otherwise adjust the strength or angular position of the rotor magnetic field relative to the stator magnetic field. Additionally, the rotor chipset 1030 can include various terminals or I / O ports to facilitate connections to external devices or other rotor components. In particular, the rotor chipset 1030 includes a connection interface 1018 (e.g., a USB or other I / O port, include male or female connectors thereof) that can be configured to couple with an external device 1019 (see FIG. 11), such as for programming the rotor chipset, diagnostic testing, etc. Additionally, the rotor chipset 1030 further includes terminals 1034 configured to couple with the rotor 1020. For example, the terminals 1034 can be configured to couple the rotor windings 1025. In this way, the rotor chipset 1030 can be in electrical communication with the rotor windings 1025 and may receive or send communications between the stator 1010 and the rotor 1020 (e.g., by modulating the current flow in the windings 1015, 1025to embed signals in the respective magnetic field, which results in corresponding currents in opposite winding 1015, 1025). In some cases, the terminals 1034 may couple to another PCB 1038 (e.g., a capacitor bank), which can also be disposed in within the rotor shaft 1024 (e.g., in an interior cavity thereof).

[0108] To connect a rotor chipset to a winding, a rotor may further include a bus bar that is configured to couple between a winding and the rotor chipset. In some cases, the bus bar may be integrated with a retainer that can be received within a rotor shaft. The retainer can provide electrical isolation for the bus bar and windings. For example, as shown in FIG. 10C, the rotor 1020 includes bus bars 1027 that are configured to provide an electric connection between the rotor windings 1025 and the rotor chipset 1030. The bus bar 1027 may be permanently or removably coupled therebetween the rotor windings 1025 and the rotor chipset 1030. In particular, the bus bars 1027 can be soldered to the rotor windings 1025 and can further define terminals 1029 configured to couple with terminals 1034 of the rotor chipset 1030. Correspondingly, the bus bars 1027 may extend through a rotor shaft 1024, as described in greater detail below. As illustrated, the terminals 1029, 1034 can be configured as spring loaded terminals to allow the rotor chipset 1030 to releasably couple the bus bars 1027. In other applications, other terminal types (e.g., screw, solder, etc.) may be used. Moreover, the bus bars 1027 may also help to rotationally fix the rotor chipset 1030 relative to the rest of the rotor 1020.

[0109] With additional reference to FIGS. 10D and 10E, the bus bars 1027 can be secured in a retainer 1031. The retainer 1031 can be configured to couple to the rotor shaft 1024 and may be made of a material (e.g., a polymeric or other type of material) configured to provide electrical insulation of the bus bars 1027. As illustrated, the terminals 1029 can be provided within bosses 1039 that extend from a main body 1041 of the retainer 1031. In this case, the bosses 1039 extend radially inward from the main body 1041; however, they may also extend radially outward from the main body 1041. The bosses 1039 can extend through openings in the rotor shaft 1024 to allow the bus bar 1027 to couple between the rotor windings 1025 and the rotor chipset 1030. Accordingly, the main body 1041 can be secured inside or outside of the rotor shaft 1024 while the bosses 1039 pass between the inside and outside of the rotor shaft 1024. The bus bars 1027 extend through the bosses 1039 between the main body 1041 and the terminals 1029, such that the bus bars 1027 extend through a rotor shaft 1024, as described in greater detail below.

[0110] As also shown in FIG. 10D, protrusions 1035 can be positioned around the terminals 1029 (e.g., on the bosses 1039) to help align the rotor chipset 1030 and cooling jacket 1050 (e.g., the rotor chipset assembly) during installation of the rotor chipset assembly into the rotor shaft 1024, as well as to provide rotational support to the rotor chipset assembly. The protrusions 1035 can be shaped differently depending on the particular application. For example, the protrusions 1035 may be asymmetrically shaped or unequally spaced from one another to ensure proper installation of the retainer 1031 (i.e., provide a poka-yoke mechanism for installation). Here, the protrusions 1035 are shaped as arcuate fins that are curved to extend circumferentially relative to the rotor axis 1021. The protrusions 1035 are positioned radially outward from the terminals 1029. The protrusions 1035 can help to electrically isolate terminals 1029, 1034 from the rotor shaft1024.[OHl] The retainer 1031 may be further configured to interlock with other rotor components, such as winding guides, end caps, cooling jackets, PCB housings, etc., to provide electrical isolation to the rotor windings 1025, rotor chipset 1030, PCB 1038, etc. For example, the retainer 1031 (e.g., the main body 1041 thereof) is illustrated as having an annular shape configured to be received in a housing 1068 for the PCB 1038. The annular shape can function as an alignment feature that can ensure appropriate polarity of the rotor chipset 1030 during assembly. The annular shape can also provide rotational support to the rotor chipset 1030 during dynamic and steady state operations of the motor 1000. Correspondingly, the rotor shaft 1024 may define openings or slots 1033 that are configured to receive the retainer 1031 (e.g., the bosses 1039 defined by the retainer 1031) and allow the bus bars 1027 to extend between an interior cavity 1022 and the rotor windings1025. In the illustrated example, the retainer 1031 is configured to couple to an exterior of the rotor shaft 1024 so that the bosses 1039 extend through the openings therein to place the terminals 1029 on the interior cavity 1022. The bosses 1039 can thereby rotationally lock with the rotor shaft 1024 and help to prevent stresses from changes in rotational velocity from being transferred to the rotor chipset 1030. Installing the retainer 1031 on the outside of the rotor shaft 1024 can allow for easier maintenance of the system. In some cases, the mating surfaces of the retainer 1031 (e.g., an inner surface thereof) and the rotor shaft 1024 (e.g., an outer surface thereof) can be tapered (e.g., with mating frustoconical shapes). The tapered shape of the mating surfaces can help to reduce or eliminate backlash or other play between the retainer 1031 and rotor shaft 1024, further improving- 21 -the rotational locking therebetween, and preventing stresses from changes in rotational velocity from being transferred to the rotor chipset 1030.

[0112] In some cases, a retainer for a bus bar can allow for the passage of coolant out of a rotor shaft. For example, still referring to FIG. 10D, the retainer 1031 defines slots 1033 that allow for coolant 1040 passage through the retainer 1031 to exit the rotor shaft 1024. As described in greater detail below, the rotor shaft 1024 can include openings to allow coolant 1040 to exit the rotor shaft 1024 for cooling of the rotor windings 1025. The slots 1033 are configured as open, u-shaped slots, but they may also be configured differently, for example, as closed slots or as having a different shape. The slots 1033 can be arranged to so that one or more slots 1033 are aligned with the openings in the rotor shaft 1024. In this case, the retainer 1031 includes eight slots 1033, with each slot corresponding to an opening in the rotor shaft 1024. The slots 1033 are evenly distributed about a circumference of the retainer 1031. In other examples, the number of slots may be different or they may be arranged differently. Correspondingly, the slots 1033 can help to control a distribution of coolant 1040 to the rotor windings 1025. For example, an area of the slots 1033 may be different to provide for an even or uneven distribution to the rotor windings 1025 (e.g., to each individual winding or to each end of the windings). By controlling the flow of coolant, more even winding temperatures can be achieved.

[0113] Similar to the motor 400, the rotor chipset 1030 can be coupled to a rotor shaft 1024 of the rotor 1020, and more specifically, disposed with in an interior cavity 1022 defined within the rotor shaft 1024. Correspondingly, the rotor chipset 1030 may be disposed in or form part of a coolant path of the motor 1000. That is coolant 1040 can flow along the coolant path, which may be at least partially defined by the rotor chipset 1030, to absorb heat generated by the rotor chipset 1030 so that the heat can be dumped to the surrounding environment. In some cases, the coolant path can form a portion of a shared coolant path for a larger cooling system. As one particular example, a coolant path may be part of a cooling system for an integrated drive unit for a vehicle. Accordingly, coolant 1040 provided to the coolant path may also be used to cool other drive unit components, for example, a transmission, inverter, etc. To that end, the rotor 1020 can include define an inlet 1042 to allow coolant to enter the rotor 1020, and more specifically, the interior cavity 1022 of the rotor shaft 1024. Accordingly, coolant 1040 entering the rotor 1020 may first pass through the interior cavity 1054 to flow over the rotor chipset 1030 before cooling other rotor components. In that regard, the interior cavity 1054 can form a first flow channel 1055 for thecoolant 1040. In some cases, coolant 1040 may first fill the interior cavity 1054, after which excess coolant 1040 flow (e.g., overflow from the interior cavity 1054) can be distributed to other rotor 1020 components. The inlet 1042 can be configured as, or to receive, a connector 1044 (see FIG. 10A) that can be configured to couple with, for example, a coolant supply line. As generally described above, the connector 1044 may be removable to allow access to the rotor chipset 1030. For example, as shown in FIGS. 11 and 12, the connector 1044 can be removed so that the external device 1019 can be inserted therethrough to couple with the rotor chipset 1030 via the connection interface 1018. Thus, the inlet 1042 can be a dual -use inlet that can allow for connecting to the rotor chipset 1030 and for cooling the rotor chipset 1030. Additionally, the connector 1044 may include an input tube 1045, which can form a seal or have a tight clearance with other rotor components (e.g., a cooling jacket) to reduce or prevent coolant from flooding rotor bearings 1047.

[0114] As generally discussed above, a rotor chipset assembly may include a cooling jacket that can help to position the rotor chipset within a rotor and that can define at least a portion of a coolant path through motor. For example, as illustrated in FIGS. 10-12, the rotor chipset 1030 can be positioned within a cooling jacket 1050. The rotor chipset 1030 and the cooling jacket 1050 can collectively form a chipset assembly. The cooling jacket 1050 can be configured to receive the rotor chipset 1030 and to control a flow of fluid around the rotor chipset 1030 to effectuate cooling. In particular, the cooling jacket 1050 can include a main body 1052 that defines an interior cavity 1054, which is configured to receive the rotor chipset 1030. As similarly discussed above, the main body 1052, and thus the interior cavity 1054, can be contoured in accordance with the shape for the rotor chipset 1030. As such the main body 1052 may be offset from the rotor chipset 1030 so the coolant 1040 can flow between the main body 1052 and the rotor chipset 1030.

[0115] Correspondingly, the main body 1052 can define an inlet 1056 (e.g., a jacket inlet) that is configured to allow fluid entering the inlet 1042 (e.g., a rotor or main inlet) to flow into the interior cavity 1054 and along the rotor chipset 1030. The inlet 1056 may be configured to seal with the input tube 1045, as described above. Additionally, the main body 1052 can optionally define an outlet 1058 (e.g., an intermediary outlet) to allow coolant 1040 to flow out of the interior cavity 1054 of the main body 1052. In the non-limiting example illustrated in FIG. 10A, the outlet 1058 allows coolant 1040 to flow out of the interior cavity 1054 and into the interior cavity 1022 of the rotor shaft 1024, where it can be distributed to other components of the motor 1000. As will be described in greater detail below, the outlet 1058 can be positioned at an axial center (e.g., acenter of an axial length of the motor 1000) to allow for more even coolant 1040 distribution. In some cases, multiple outlets 1058 can be provided and arranged to provide even coolant flow. For example, outlets 1058 can be provided on opposite sides of the rotor chipset 1030. In some aspects, the outlets 1058 can be located in areas of the main body 1052 of known thermal risk (e.g., areas that exhibit high temperatures under high load during operation). That is, the outlets 1058 can be strategically positioned along the main body 1052 to remove coolant 1040 at such locations and return coolant to a volume with more bulk fluid flow (e.g., the interior cavity 1022 of the rotor shaft 1024), which in turn can reduce the risk of coolant damage under high temperatures at areas of known thermal risk in the main body 1052.

[0116] Further, the main body 1052 can define an outlet 1059 (e.g., a main outlet, see also FIG. 24) to allow coolant 1040 to exit the interior cavity 1054 and cool additional power components (e.g., the rotor windings 1025 or the PCB 1038). The outlet 1059 is positioned opposite the inlet 1056 to allow coolant 1040 to flow along substantially the entire length of the rotor chipset 1030 and is formed between a first jacket 1051 and a second jacket 1053 of the cooling j acket 1050. As illustrated in the non-limiting example of FIG. 10B, the outlet 1059 may be located adjacent to the housing 1068. It is contemplated that the outlet 1059 may be provided as an opening in sealing features that are disposed between the main body 1052 and the housing 1068 (i.e., the PCB 1038). As a result, coolant 1040 may flow directly from the outlet 1059 into the housing 1068, where the coolant 1040 can be circulated (e.g., to cool the PCB 1038 or capacitor bank 1037) before exiting the housing 1068 and flowing into the interior cavity 1022 of the rotor shaft 1024, as indicated by solid arrow 1063.

[0117] In some examples, coolant 1040 fills the housing 1068 before being allowed to exit the housing 1068 and enter the interior cavity 1022 of the rotor shaft 1024. In particular, coolant 1040 may enter the housing 1068 through the outlet 1059 and flow over the PCB 1038, as indicated by dashed arrows 1075. Further, the PCB 1038 or the housing 1068 may include additional intermediate outlets 1077 therein to direct coolant out of the housing 1068. While the number or position of the intermediate outlets 1077 may vary, it is contemplated that the intermediate outlets 1077 may be provided as through holes in the PCB 1038, which in some cases, can be arranged concentrically with respect to the outlet 1059. Moreover, each of the intermediate outlets 1077 may define a first radius that is less than a second radius of the housing 1068 or less than a third radius of the outlet 1059. This arrangement allows coolant 1040 to be pumped into the housing1068 at an equal or greater rate than the coolant 1040 exiting the intermediate outlets 1077, thereby allowing a volume of the housing 1068 to be filled as fast as possible. This in turn can help to maintain coolant flow across any power components within the housing 1068 or on the PCB 1038, which can further improve power efficiency due to enhanced heat rejection.

[0118] In some cases, a cooling jacket can be configured to position and rotationally lock rotor chipset to a rotor shaft. For example, with additional reference to FIGS. 13 and 14, the cooling jacket 1050 can include a plurality of fins 1060 (e.g., walls) extending from the main body 1052. The fins 1060 can be configured to engage with interior walls of the rotor shaft 1024 to radially position the rotor chipset 1030 in the interior cavity 1022. Additionally, the cooling jacket 1050 can also axially position the rotor chipset 1030 within interior cavity 1022 of the rotor shaft 1024. For example, the axial ends of the cooling jacket 1050 can engage with the rotor shaft 1024 or other components within the interior cavity 1022. In the illustrated example, a first end 1062 of the cooling jacket 1050 is configured to engage the rotor shaft 1024. More specifically, the first end 1062 defines a flange 1064 that is received within the interior cavity 1022, or a counterbore, defined in the rotor shaft 1024. Additionally, a second end 1066 of the cooling jacket 1050 is configured to engage the housing 1068 for the PCB 1038, which is also retained in the interior cavity 1022. The housing 1068 may further house a capacitor bank 1037 (see FIG. 11). Further still, the cooling jacket 1050 (e.g., the second end 1066) can also be configured to rotationally lock the rotor chipset 1030 or the housing 1068 relative to the rotor shaft 1024. As illustrated in FIG. 13, in particular, the first end 1062 includes protrusions 1070 that are configured to be received in a corresponding one or more of the recesses 1073 formed in the rotor shaft 1024. The protrusions 1070 and recesses 1073 act as detents to prevent the cooling jacket 1050 from rotating within the rotor shaft 1024. Similarly, the fins 1060 or main body 1052 at the second end 1066 can engage with recesses 1069 formed in the housing 1068, which may itself be rotationally locked to the rotor shaft 1024, to further prevent relative rotation between the rotor shaft 1024 and the cooling jacket 1050. In other examples, relative rotation can be prevented in other ways, for example, via a frictional or press fit connection between the fins 1060 and the interior walls of the rotor shaft 1024. In that regard, at least some of the fins 1060 may be configured to engage with the walls of the interior cavity 1022. Accordingly, at least a portion of the fins 1060 can define an outer surface 1061 (e.g., an outer peripheral surface) that can engage with the walls of the interior cavity 1022.The outer surface 1061 of the cooling jacket can be shaped in accordance with a shape of the interior cavity 1022. In this case, the outer surface 1061 is shaped to follow a cylindrical profde.

[0119] Relatedly, as illustrated in FIG. 14, the cooling jacket 1050 is configured as a multipiece cooling jacket having a first jacket 1051 and a second jacket 1053 that can be coupled to one another to secure the rotor chipset 1030 therein. Each of the first jacket 1051 and the second jacket 1053 can include corresponding portions of the main body 1052 and the fins 1060. In other examples, the cooling jacket 1050 can be configured differently, for example, as a monolithic cooling jacket.

[0120] A cooling jacket can also be used to guide coolant flow through a rotor to provide more efficient, even, and predictable cooling. That is, the fins of a cooling jacket can be configured to define flow paths through a rotor shaft to direct coolant flow through the shaft to other rotor component, such as windings. In particular, a cooling jacket can be configured to provide a substantially equal distribution of coolant along the axial direction. For example, coolant can be evenly distributed to each end of the rotor shaft, where it may exit radially from the rotor shaft to provide cooling to rotor windings (e.g., at the ends of the rotor windings) Equal distribution of coolant in the axial direction (e.g., to each end) can help with maintaining rotor balance and to reduce hot spots in the rotor windings that could result in reduced performance. For example, a first winding (e.g., a coil of a winding) sacrificing its distribution of coolant to as second winding may cause the first winding to overheat and lower the effective limit of the entire rotor system. That is, once any coil reaches its peak thermal lime the entire system must typically be limited. This is because, traditionally, rotor temperature is inferred through voltage / current feedback information on the stator and though model based estimates. Hard thermal limits of rotor windings may be given margin for errors in measurement, modeling, manufacturing, and damage of the machine over time. Accordingly, the more the design can ensure equal distribution of coolant, the more even and consistent the winding temperatures will be. In turn, this allows for small margins to be used when predicting rotor temperature, which allows operation over a greater range of temperatures.

[0121] Still referring to FIGS. 10A-14, the cooling jacket 1050 is configured to distribute coolant 1040 along the axial length of the rotor 1020. More specifically, the cooling jacket 1050 is configured to direct the coolant 1040 entering the inlet 1042 to the center of the rotor shaft 1024 (e.g., a center relative to the length of the rotor 1020 along the rotor axis 1021). From there, thecooling jacket 1050 can direct the coolant 1040 along the outer circumference (e.g., walls) of the interior cavity 1022 and axially outward toward each end of the rotor 1020. Accordingly, the main body 1052 and fins 1060 can be arranged to form flow paths for the coolant 1040. In particular, coolant 1040 entering the interior cavity 1022 can flow from inlet 1042, through the inlet 1056, and into the interior cavity 1054 of the cooling jacket 1050. Coolant 1040 within the interior cavity 1054 can exit at the center of the rotor shaft 1024 via the optional outlets 1058 (as illustrated in FIG. 10A) or at the end of the shaft via the outlets 1059 (as illustrated in FIG. 10B). In some cases, due to the arrangement of the outlets 1058, 1059 or the circumferential forces present during rotation of the rotor 1020, the coolant 1040 may be flung (radially) outward toward the walls of the interior cavity, where it may then flow to each end of the rotor 1020 (see FIG. 10A). In some cases, the fins 1060 can be configured so coolant 1040 exiting the outlets 1058 may flow to either end of the rotor 1020. In other cases, the fins 1060 can be configured to distribute coolant 1040 differently. For example, fluid from one side of the rotor chipset 1030 may flow to a first end of the rotor 1020, while fluid from the other side of the rotor chipset 1030 may flow to a second end of the rotor 1020. In either case, the centripetal forces pulling the coolant 1040 to the walls of the interior cavity 1022 can act to pump the coolant 1040 into and throughout the rotor 1020. Correspondingly, it is possible the cooling jacket 1050 can be configured such that the rotor 1020 acts as a self-priming pump, and may cause or aid in coolant flow throughout the entire coolant system (e.g., a coolant system for an integrated drive unit). Put another way, the motor 1000 can function as a pump (e g., a centrifugal pump) for a cooling system, with the cooling jacket 1050 forming an impeller of the pump.

[0122] The coolant 1040 can also exit the interior cavity 1054 via the outlet 1059. As illustrated, the outlet 1059 is provided at the end of the cooling jacket 1050, opposite the inlet 1056. The outlet 1059 is arranged to direct the exiting coolant 1040 to the capacitor bank 1037 and PCB 1038. That is, the outlet 1059 can be shaped to direct coolant flow to a capacitor bank or other electronic components disposed within the rotor shaft 1024. In this case, the outlet 1059 has a flared shape to disperse flow to the capacitor bank 1037. In some cases, the outlet 1059 is configured to receive a seal that can seal with the capacitor bank 1037. In some cases, the coolant 1040 can flow through the capacitor bank 1037. That is, coolant 1040 can enter the housing 1068 to flow along the capacitors in the capacitor bank 1037. In some cases, the coolant 1040 can flow around the capacitor bank 1037 (e.g., outside the housing 1068) for indirect cooling of thecapacitors. In either case, coolant 1040 can subsequently flow radially outward to exit the rotor shaft 1024.

[0123] As mentioned above, in some cases, coolant entering a cooling jacket inlet may first fill the interior cavity thereof (e.g., interior cavity 1054). This can improve cooling of electronic components when system loading (e.g., torque demand) may be high while coolant flow is comparatively low, such as at startup. Accordingly, excess or overflow coolant can be distributed directly to the axial center of the rotor by the cooling jacket. To do so, fins of the cooling jacket can be arranged to define a flow path from an inlet of the cooling jacket to the center of the rotor shaft, and from the center of the rotor shaft to the ends of the rotor to be distributed to the windings or other parts of the motor (e.g., stator windings). For example, with additional reference to FIG. 15, the cooling jacket 1050 can be configured to define a flow path so that excess coolant 1040 provided at the inlet 1056 can be directed to the axial center of the interior cavity 1022. More specifically, the cooling jacket 1050 can define orifices 1071 configured to direct excess coolant 1040 radially outward toward the walls of the interior cavity 1022.

[0124] Once the coolant 1040 exits the orifices 1071, the coolant 1040 can flow along second flow channels 1072 toward the axial center of the rotor 1020. The second flow channels 1072 can extend axially and can be defined by the cooling jacket 1050 fins 1060 and the walls of the interior cavity 1022, such that coolant 1040 flows between the cooling jacket 1050 and the walls of the interior cavity 1022. Accordingly, the fins 1060 that define the second flow channels 1072 may also define the outer surface 1061 of the cooling jacket 1050. The outer surface 1061 may be in sealing engagement with the walls of the interior cavity 1022. In some cases, the outer surface 1061 may fully seal with the walls of the interior cavity 1022, or may partially seal with the walls of the interior cavity 1022 to limit leakage across the boundary. Upon reaching the center of the rotor shaft 1024, the coolant 1040 may enter a chamber 1074 formed by the cooling jacket 1050 and the walls of the interior cavity 1022 at the axial center of the rotor 1020. In some cases, coolant 1040 from the interior cavity 1054 may also enter the chamber 1074 via the optional outlets 1058 to mix with the coolant 1040 from the second flow channels 1072. Accordingly, coolant 1040 entering inlet 1056 may flow to the chamber 1074 through either the interior cavity 1054 or the second flow channels 1072 so that it can be distributed evenly back to the ends of the rotor 1020.

[0125] To allow flow back to the ends of the rotor 1020, the coolant 1040 can flow along third flow channels 1076 toward the axial center of the rotor 1020. The third flow channels 1076 canextend axially (e.g., to be parallel to the second flow channels 1072) and can be defined by the cooling jacket 1050 fins 1060 and the walls of the interior cavity 1022, such that coolant 1040 flows between the cooling jacket 1050 and the walls of the interior cavity 1022. The fins 1060 that define the second flow channels 1072 may also define the outer surface 1061 of the cooling jacket 1050 and be in sealing engagement with the walls of the interior cavity 1022. In addition, the fins 1060 may define cutouts 1078 at the chamber 1074 to allow coolant 1040 to enter the third flow channels 1076 to flow to the ends of the rotor 1020. Additional cutouts 1078 may also be formed in other fins 1060. The cutouts 1078 can be formed in various ways. As illustrated, the cutouts 1078 are formed as a region of the outer surface 1061 of the fins 1060 that is not in contact with the walls of the interior cavity 1022. In other examples, cutouts can be formed as holes within the fins 1060.

[0126] Coolant 1040 exiting the interior cavity 1054 through outlet 1059 can also flow to the ends of the rotor shaft 1024. For example, as further described above, coolant 1040 exiting the interior cavity 1054 through outlet 1059 can flow along a fourth flow channel 1079. The fourth flow channel 1079 can extend through or around the capacitor bank 1037. In some cases, the fourth flow channel 1079 can merge with the third flow channel 1076 upon reaching the walls of the interior cavity 1022 of the rotor shaft 1024.

[0127] After flowing through the rotor shaft, coolant can be directed to other rotor components, in particular, the rotor windings. Accordingly, openings can be provided in a rotor shaft to allow coolant to flow from and interior cavity of the rotor to the rotor windings. For example, with additional reference to FIGS. 16A and 17, the rotor shaft 1024 can define a plurality of outlets or openings 1090 configured to allow coolant 1040 to flow from the third flow channels 1076 to the ends of the rotor windings 1025, where the coolant 1040 can exit the rotor shaft 1024. In that regard, the openings 1090 can be outlets for the rotor shaft 1024. As illustrated, the openings 1090 can be arranged circumferentially about each end of the rotor shaft 1024 so that fluid can enter the rotor windings 1025 along the radial direction. Additionally, while the number of openings may vary, it is preferrable that the openings are arranged to provide coolant 1040 to each of the rotor windings 1025 to achieve more even cooling. Here, one opening 1090 is provided at each end of the rotor shaft 1024 for each rotor winding (e.g., for eight windings, each end of a rotor shaft can include eight openings). In other cases, more or fewer openings may be used, such that multiple openings may be provided for a winding, or multiple windings may share an opening.

[0128] In some examples, openings may be provided at other locations along a rotor shaft to equally distribute coolant to either end of a rotor by leveraging centripetal forces generated during rotor motion. For example, and with reference to FIGS. 16B-16D, the openings 1090 may be located at an axial center of a rotor shaft 1024. Correspondingly, coolant 1040 exits the rotor shaft 1024 at the axial center thereof instead of at either end of the rotor shaft 1024. As discussed above, coolant 1040, can enter the rotor shaft 1024 through an inlet 1042, which can be provided as an input tube 1045 that can be configured to couple with, for example, a coolant supply line. Accordingly, coolant 1040 can be axially injected into the rotor shaft 1024 (i.e., into the interior cavity 1022 defined by the rotor shaft 1024) and circulated therethrough before exiting the rotor shaft 1024 at the openings 1090. It is contemplated that flow paths may be provided in the interior cavity 1022 via housings or retainers (e.g., the main body 1041 of the retainer 1031) to direct the coolant 1040 from the inlet 1042 to the openings 1090 (see FIGS. 10D and 10E), or such housings or retainers may be omitted. That is, locating the openings 1090 at the axial center of the rotor shaft may provide cooling advantages (e.g., more even cooling or reducing complexity of the rotor 1020) that are independent of any internal components housed within the rotor shaft 1024.

[0129] Referring specifically to FIGS. 16C and 16D, the openings 1090 may be disposed circumferentially around the axial center of the rotor shaft 1024 (e.g., a center of an axial length of the rotor 1020 that is equidistant from either end of the rotor 1020). In some examples, the openings 1090 may be equally spaced from one another around the circumference of the rotor shaft 1024. In this way, coolant exiting the interior cavity 1022 through the openings 1090 may be evenly distributed to either end of the rotor 1020 via centripetal forces generated during rotor rotation. In particular, coolant 1040 exiting the interior cavity 1022 can flow along fifth flow channels 1091 to either end of the rotor 1020. In the non-limiting illustrated example, the fifth flow channels 1091 can be provided as axial channels that are defined between abutting surfaces of the rotor shaft 1024 and a lamination stack 1108 of the rotor assembly. While the fifth flow channels 1091 are illustrated as cutouts (e.g., stamped cutouts) within the lamination stack 1108, it is contemplated that flow channels can also be formed by cutouts in the rotor shaft 1024, or cutouts in the rotor shaft 1024 and the lamination stack 1108. Further, while the number of fifth flow channels 1091 may vary, it is preferrable that the fifth flow channels 1091 are arranged to receive coolant 1040 from each of the openings 1090 to provide the coolant 1040 to each of the rotor windings 1025 to further optimize cooling. That is the number of fifth flow channels 1091 cancorrespond with the number of openings 1090. With reference to FIG. 16D, centripetal forces can cause the coolant 1040 to flow to either end of the rotor 1020 through the fifth flow channels 1091. At distal ends of the fifth flow channels 1091, coolant 1040 can flow radially outward and across the rotor windings 1025.

[0130] Upon leaving a rotor shaft (e.g., via openings at either end of the rotor shaft or openings at an axial center of the rotor shaft), coolant can flow within an annulus behind and radially inside the rotor windings. The annulus can be a third coolant channel configured to allow circumferential flow of the coolant flow in the circumferential direction for more even distribution and to minimize rotational imbalances due to coolant flow. Correspondingly, coolant can exit the annulus through an exit hole through the windings. The coolant can flow axially out of the exit hole before flowing radially outward due to centripetal forces on the coolant. The exit holes can be out of alignment (e g., circumferentially offset) with the openings in the rotor shaft, or the distal ends of the flow channels (e.g., fifth flow channels 1091) formed between the rotor shaft and the lamination stack, to further minimize rotational imbalances in the rotor. For example, as shown in FIGS. 16D, 17, and 18, the rotor 1020 defines a fourth flow channel 1094 that extends circumferentially behind (e.g., axially inside to be closer to the axial center of the rotor 1020) and radially inside the rotor windings 1025. In this case, the fourth flow channel 1094 is defined by an axial end of the lamination stack 1108 and a winding guide 1096, which is configured to help retain the rotor windings 1025. Correspondingly the winding guide 1096 can define end openings 1098 (e.g., exits) to allow coolant 1040 to flow from the fourth flow channel 1094 and over the rotor windings 1025. While the openings 1090 in the rotor shaft 1024 are illustrated in FIGS. 17 and 18 as being located at ends of the rotor shaft 1024, it is contemplated that openings 1090 may alternatively be located at the axial center of the rotor shaft 1024, as illustrated in FIG. 16D. In such a configuration, coolant 1040 may flow axially along the fifth flow channels 1091 between the rotor shaft 1024 and the lamination stack 1108 before entering the entering fourth flow channel 1094 and flowing over the rotor windings 1025. Accordingly, coolant can be provided to winding guide through a variety of different paths, such as those described above.

[0131] Due to high rotational speeds of a rotor during operation, in some instances, coolant directed at the windings may be flung off the rotor prematurely, which can reduce cooling efficiency and evenness since the coolant would not capture as much heat due to the short contact time and greater flow rates of coolant would be needed to effectuate cooling. To help the coolantremain in contact with the rotor windings, a cover can be placed over the ends of the windings. The cover and windings can work together to help maintain coolant flow over the windings. For example, with additional reference to FIGS. 19 and 20, the rotor 1020 can include an end cap 1100 secured over each of the ends of the rotor windings 1025. The end cap 1100 can function similar to the cooling jacket 1050 in that it can be shaped in accordance with the shape of the rotor windings 1025 to provide a cooling path for the coolant 1040. Accordingly, the winding guide 1096 and end cap 1100 can form a cooling can for the rotor windings 1025. It is appreciated that the flow path between rotor winding 1025 and end cap 1100 may be tightly contoured to the rotor windings 1025 to hold the coolant 1040 against the rotor windings 1025.

[0132] Correspondingly, the rotor windings and the end cap can be shaped to further control the flow and dispersion of coolant on the rotor windings. For example, still referring to FIGS. 17- 20, the rotor windings 1025 can be shaped so that the coolant 1040 will move to either end of the rotor winding 1025 due to centripetal forces move the fluid along the winding surface towards the outer diameter of the rotor 1020. For example, and axial length or cord length of the rotor winding 1025 may increase moving radially outward from the rotor axis 1021. Similarly, the end cap 1100 can be shaped (e.g., include geometric features) to help control the flow of coolant 1040. For example, the end cap 1100 defines grooves 1104 along the flow path to help direct coolant flow along the direction of the grooves 1104. The grooves 1104 can aid in distributing the coolant 1040 evenly over the rotor winding 1025. In this case, the end cap 1100 defines a plurality of grooves 1104 at each rotor winding 1025. Here, the grooves 1104 are configured as V-shaped groove. More specifically, the grooves 1104 are centered on each rotor winding 1025, with the legs of the “v” extending radially outward. In other examples, the grooves can be shaped differently.

[0133] Upon reaching the outer diameter of the rotor, coolant can exit the rotor to be supplied to other motor components. In particular, coolant exiting the rotor can be flung by centripetal force to the stator (e.g., across an air gap between the rotor and stator). For example, with additional reference to FIG. 21, openings 1112 can be formed along the outer diameter of the rotor 1020, between the end cap 1100 and the winding guide 1096. Coolant 1040 can flow out of the openings 1112, where it can be flung onto the stator 1010 to provide additional cooling. Additional openings may also be provided between the end cap 1100 and lamination stack 1 108 of the rotor 1020 to allow for additional flow to the stator 1010. In this way, the coolant 1040 may only be pump once while providing cooling to multiple components (e.g., the rotor chipset 1030, rotor 1020, and thestator 1010). It is appreciated that while FIGS. 17-21 depict one end of the rotor 1020, the other end of the rotor 1020 can be substantially identical with regard to the flow path arrangement and corresponding structures.

[0134] Relatedly, as mentioned above the clearance provided between the rotor windings and end cap that forms the flow path can be small to ensure contact between coolant and windings. During assembly, the windings are typically coated in a varnish or other protective coating. To prevent the flow path along the windings from becoming clogged, the windings can be coated with varnish prior to installation of the end cap. Once the windings are coated, the end cap can be installed. Accordingly, it may be necessary to secure the end cap on the rotor. In some cases, this can be done using another rotor component, such as a balance ring that can help to minimize rotation imbalances in the rotor. For example, as shown in FIG. 16A, the end cap 1100 can be coupled to the winding guide 1096. To help secure the end cap 1100 on the winding guide 1096, a balance ring 1110 can be placed over the end cap 1100. The balance ring 1110 can seat over the end cap 1100 to secure the end cap 1100 and rotor windings 1025 between the balance ring 1110 and the winding guide 1096. In some cases, the winding guide 1096 can be configured to prevent rotation of the balance ring 1110 during operation, relative to the rest of the rotor 1020 (e.g., to ensure co-rotation of all rotor component). Here, as shown in FIG. 21, the winding guide 1096 can define protrusions 1114 that are configured to engage with (e.g., be received in) corresponding recesses 1116 formed in the balance ring 1110. In other examples, the balance ring 1110 can be rotationally fixed to the rotor 1020 in other ways.

[0135] Correspondingly, in some cases, a balance ring may also be axially secured to a rotor. According to aspects of the disclosure, a balance ring can be secured without the use of separate fasteners, as are typically used in conventional rotor construction. For example, as shown in FIG. 16A, the balance ring 1110 can be secured to the rotor 1020 via the rotor shaft 1024. More specifically, the rotor shaft 1024 may include flanges 1120 at each end. The flanges 1120 can be bent or folded over the balance ring 1110 (e.g., over a radially inner lip of the balance ring 1110) to secure the balance ring 1110 on the rotor 1020 (e.g., via a roll-forming process). In this way, the flanges 1120 can act as retention features that provide axial compression to the rotor 1020. In particular, the flanges 1120 can provide axial compression to the lamination stacks 1 108, rotor windings 1025, winding guides 1096, end caps 1100, and the balance ring 1110. By constructing the rotor 1020 in this way, rotor complexity can be reduced while providing increased structuralintegrity. For example, the balance ring 1110 and the end cap 1100, alone or in combination, can provide mechanical support to the rotor winding 1025 over a range of rotor speeds.

[0136] As mentioned above, a cooling jacket can be configured differently to control coolant distribution within a rotor. The particular design of a coolant jacket may account for differently sized rotors, coolant viscosity, etc., as well as other operating parameters of the motor, such as operating temperature, range of operating speeds, etc. For example, referring to FIGS. 22 and 23, another example of a rotor chipset assembly that includes a rotor chipset 1030 and a cooling jacket 1050. The rotor chipset assembly is configured to be retained within a rotor shaft (e.g., rotor shaft 1024) to control flow of a coolant 1040 through the rotor shaft and around the rotor chipset 1030. The rotor chipset 1030 is retained within an interior cavity 1054 of a main body 1052 of the cooling jacket 1050 that envelopes the rotor chipset 1030 while permitting flow of coolant 1040 along the rotor chipset 1030 for cooling. As similarly discussed above, the main body 1052, and thus the interior cavity 1054, can be contoured in accordance with the shape for the rotor chipset 1030. As such the main body 1052 may be offset from the rotor chipset 1030 so the coolant 1040 can flow between the main body 1052 and the rotor chipset 1030. Correspondingly, the main body 1052 can define an inlet 1056 (e.g., a jacket inlet) that allows coolant 1040 entering the inlet 1042 (e.g., a rotor or main inlet) to flow into the interior cavity 1054 and along the rotor chipset 1030. The inlet 1056 may be configured to seal with an input tube 1045, as described above. Additionally, the main body 1052 can define an outlet 1058 to allow coolant 1040 to flow out of the interior cavity 1054 of the main body 1052 and into the interior cavity 1022 of the rotor shaft 1024, where it can be distributed to other components of the motor. In some cases, multiple outlets 1058 can be provided and arranged to provide even coolant flow. For example, outlets 1058 can be provided on opposite sides of the rotor chipset 1030.

[0137] A plurality of fins 1060 extend from the main body 1052 to define outer surfaces 1061 that engage with the interior surface of the rotor shaft 1024. The fins 1060 aid in controlling flow of coolant 1040 external to the main body 1052 for distribution to the ends of the rotor shaft 1024. In the illustrated example, the fins 1060 are configured as axial fins (e.g., linear fins extending from a first end to a second end of the rotor shaft). The fins 1060 are also arranged radially about a rotor axis to define chambers 1074 between each pair of fins 1060. The fins 1060 can be spaced so that, when the chipset assembly is secured in the rotor shaft, each chamber 1074 is aligned with one or more coils of a rotor (e.g., rotor winding 1025). This can improve coolant distribution atthe ends of the windings by providing a reservoir of coolant 1040 that flows out of the rotor shaft (e g., at openings 1090) to the end windings. In some embodiments, the fins 1060 are configured as bulkheads that isolate the chambers 1074 from one another. In other embodiments, the fins 1060 are configured as baffles that allow flow of coolant 1040 therebetween. In the illustrated example, the fins 1060 are baffles that include openings 2011 to allow limited flow between adjacent chambers 1074.

[0138] In operation, rotation of a rotor can cause coolant flow through a rotor shaft for cooling of a rotor chipset therein. For example, referring to FIG. 23, rotation of a rotor can induce coolant 1040 flow through the rotor chipset assembly. Coolant 1040 can enter the rotor shaft and the cooling jacket 1050 via the inlet 1056 in the main body 1052. The inlet 1056 is arranged so that all coolant entering the rotor shaft via the input tube 1045 (e.g., an injection port 1049 formed by the cooling jacket 1050) for dispersion to rotor chipset 1030 or end windings first enters the interior cavity 1054 of the main body 1052. Once in the interior cavity 1054, coolant 1040 can flow along a first flow channel 1055 through the interior cavity 1054 and along the rotor chipset 1030 to the outlet 1058, or along a second flow channel 1072 to exit the interior cavity 1054 via openings 2002 without flowing along the rotor chipset 1030. Coolant 1040 flowing along the first flow channel 1055 can flow along one or both sides of the rotor chipset 1030. Coolant 1040 exiting the outlets 1058 and the openings 2002 enters into the chambers 1074. At least one outlet 1058 or opening 2002 can be provided for each chamber 1074. During startup, coolant 1040 may first flow along the first flow channel 1055 until the interior cavity 1054 is filled or near filled with coolant 1040, after which coolant may begin flowing along the second flow channel 1072.

[0139] The interior cavity 1054 of the main body 1052 can be shaped to direct flow between the first flow channel 1055 and the second flow channel 1072. In the illustrated example, the main body 1052 is shaped to direct a portion of the coolant 1040 flow entering the interior cavity 1054 toward openings 2002 for allowing flow along the second flow channel 1072. Coolant 1040 flow entering the interior cavity 1054 along the axial direction is split by the end of the rotor chipset 1030 to go along each of a first and a second side of the rotor chipset 1030. A first portion of the coolant 1040 continues to flow along the first flow channel 1055 to the outlet 1058 while a second portion of the coolant 1040 flow at least partially in radial direction to a flow control region 2004 of the main body 1052 that is configured to direct the flow along the second flow channel 1072. In the illustrated example, the flow control region 2004 is defined by a concave inner surface 2006of the main body 1052. The concave inner surface 2006 causes flow reversal of the second portion of the coolant 1040 so that it is directed toward the openings 2002. In other examples, other types of flow control elements, fins, protrusions, walls, etc. can be provided to direct flow to the openings 2002 for flow along the second flow channel 1072. Rotation of the rotor 1020 may also cause centripetal forces on the coolant 1040 that causes coolant 1040 to flow radially outward to the flow control region 2004.

[0140] Coolant 1040 exiting the outlets 1058 and the openings 2002 can empty into the chambers 1074. Once in the chambers 1074, the centripetal forces on the coolant 1040 can force the coolant 1040 to the walls of the rotor shaft 1024. Continued pumping of coolant 1040 into the chamber 1074 causes the coolant 1040 to flow axially toward the ends of the rotor shaft (e.g., to a first end 1062 and a second end 1066) where the coolant 1040 exits the rotor shaft 1024 through openings (e.g., openings 1090 in FIGS. 10E, 13, 15, and 17) in the ends of the rotor shaft 1024. Like the chambers 1074, each opening 1090 can be aligned with an end winding of the rotor 1020 to allow coolant 1040 to flow to other parts of the system, as generally discussed above. In some cases, each of the chambers 1074 may correspond to a respective one or more of the openings 1090.

[0141] In some cases, the cooling jacket 1050 may include end walls 2010 that defined the ends of the chambers 1074. The end walls 2010 can help retain coolant 1040 in the chambers 1074 for more even distribution to each end of the rotor. The end walls 2010 define drain ports 2013 for each of the chambers 1074 through which the coolant 1040 can flow to move from the chamber 1074 to the openings 1090. In some examples, the end walls 2010 can form the end chambers 2012 at each end of the rotor shaft. The end walls 2010 act as baffles to control coolant movement (e.g., to control sloshing of coolant 1040) Coolant 1040 from one or more of the chambers 1074 (e.g., first chambers) can converge and mix within the end chambers 2012 (e.g., second chambers) before exiting the rotor shaft. The end chambers 2012 can provide additional means for controlling the dispersion of coolant 1040 to the rotor windings and may also house other rotor components. For example, one of the end chambers 2012 can house a capacitor bank 1037 or a PCB 1038. The coolant 1040 can thereby extract and remove heat from addition components arranged within the rotor shaft.

[0142] In some cases, a cooling jacket can be configured to enhance self-priming capabilities, such that coolant can automatically begin flowing via rotation of the rotor without the need for anauxiliary pump. Correspondingly, as mentioned above, it is possible the cooling jacket 1050 can be configured so that the rotor 1020 acts as a self-priming pump, and may cause or aid in coolant flow throughout the entire coolant system (e.g., a coolant system for an integrated drive unit). Put another way, the motor 1000 can function as a pump (e.g., a centrifugal pump) for a cooling system, with the cooling j acket 1050 forming an impeller of the pump.

[0143] In some embodiments, a cooling jacket can include an impeller or other pumping element that can remove excess air and pump coolant, thereby priming the cooling system of the rotor. As best shown in FIG. 22, the cooling jacket 1050 includes a flange 1064 that defines the injection port 1049. The flange 1064 is further shaped to cause priming of the cooling system at startup and to cause continuing pumping of coolant 1040 during operation. Specifically, the flange 1064 defines ports 2014 that pump air out of the system during startup and enhance coolant flow. In other examples, a flange can be arranged differently, for example, to include vanes or blades that also cause a pumping or priming action.

[0144] As generally discussed above, cooling jackets (e.g., any of the cooling jackets disclosed herein) can be used to provide structural support to a rotor chipset through various connections to other rotor components. In some examples, a cooling j acket can be configured to provide direct structural support to components of a rotor chipset within an interior cavity of the cooling jacket, including both the PCB and any electronic components affixed thereto (e.g., capacitors, power electronic components, processors, etc.). Providing direct support to the rotor chipset can help to prevent component separation by reducing bending forces on the board and relative movement between the board and the electronic components, as may occur due to rotation of the rotor, both at steady state, in particular at higher rotational speeds, and during periods of acceleration and deceleration, which result in increased shear and normal forces on the chipset. Supports within a cooling jacket may also provide other advantages, including acting as flow control elements to direct a path of coolant flow through the cooling jacket (e.g., by changing direction, splitting, and converging flows within the cooling jacket), as well as controlling a local flow velocity at specific components. For example, supports can be arranged to direct coolant flow to specific electronic components or regions of a PCB, as well as to control a local flow velocity at the component to provide a desired amount of heat dissipation. This allows the temperature of each component (e.g., electronic components or regions of the PCB) to be optimized for performance. Accordingly,supports can enhance thermal management within the cooling jacket and the cooling jacket can further enhance thermal management of the motor system as a whole.

[0145] As illustrated in FIG. 24, the cooling jacket 1050 is configured as a clamshell with a first half 1051 and a second half 1053 (e.g., first and second jackets). The first half 1051 and the second half 1053 can be held together via the rotor shaft 1024, or they may be mechanically secured to one another (e.g., via adhesive, ultrasonic welding, snap-fit connections, etc.) to form the interior cavity 1054 therein that receives the rotor chipset 1030. In some case, the first half 1051 and the second half 1053 can include alignment features to help with assembly of the cooling jacket 1050. Here the first half 1051 and the second half 1053 include alignment features configured as grooves 1065; however other types of alignment features can also be used, for example, pins, tabs, etc. Both the first half 1051 and the second half 1053 can define supports 1067 (e g., bosses, landings, pins, etc.) that are arranged along the interior surfaces that define the interior cavity 1054. Each support 1067 is arranged to align with a particular component mounted on the PCB 1038, or the PCB 1038 itself. The particular number of supports 1067 can vary depending on the types and quantity of components secured to the PCB 1038 and some supports 1067 may be configured to support one or more components. The shape of each support 1067 can also vary depending on the shape of the component being supported.

[0146] Supports can be constructed in a number of ways. In some cases, a support can be configured to always be in contact with the corresponding component, or the support can be spaced from a component by predetermined distance to allow for some relative movement between the component and the support. In the illustrated example, the supports 1067 are pre-formed to conform with a corresponding component of the rotor chipset 1030 or the PCB 1038. For example, a first support 1067A may be configured to conform with a corresponding component of the rotor chipset 1030, and the second supports 1067B may be configured to conform with the PCB 1038. The supports 1067 project from the first half 1051 and the second half 1053 of the cooling j acket 1050. In this case, the supports 1067 are monolithically formed with the cooling jacket 1050, but they may also be separate components. The supports 1067 can be fixed supports with fixed shapes that conform to the supported component. In other examples, supports can be conformable supports that can change shape during assembly to conform with a supported component. For example, a support can be made of a deformable material can be provided at a component location. Upon assembling the rotors chipset 1030 in the cooling jacket 1050, the component can contactand deform the support, such that support conforms to the component shape. In some cases, a support can be a resilient material (e.g., rubber, foam, etc.) that can resiliently flex to accommodate the shape of the component. In some examples, the deformable material can be permanently deformable to take the shape of the component. For example, a support can be a metal or plastic tab that can be permanently deformed onto or by the component. In the case of a metal tab, the tab can be bent to conform to the component. In the case of a plastic tab, the tab can be deformed by heating or ultrasonic welding. In some examples, a support can be a liquid that can deform around the component, which can then cure or dry into a solid state to take on the shape of the component. The liquid can be a highly viscous liquid to reduce unwanted spreading during assembly. The liquid can be, for example, an epoxy, silicone, an expandable foam, etc. Accordingly, when cured, the support can be hard and rigid, or soft and ductile. In some cases, multiple types of supports can be used. For example, with respect to the illustrated supports 1067, a liquid compound can be applied to one or more supports, which can cure into the shape of the supported component.

[0147] As discussed above, windings can be enclosed by covers, end caps, or winding guides to provide coolant pathways within a rotor assembly. In particular, components of a rotor assembly can form a winding channel (e.g., a cooling can) that can enclose windings therein and direct coolant across the windings.

[0148] Typically, rotor windings are typically coated in a vanish or other protective coating (e.g., after the rotor is assembled, completely or partially) to insulate the windings and enhance their rigidity, which helps to hold the windings in place (e.g., in place within a winding channel). However, varnish can act as a thermal insulator that may impede heat transfer between the windings and coolant, thereby reducing the thermal efficiency of the rotor assembly. In addition, applying varnish to windings can increase overall manufacturing time, cost, and complexity. To eliminate the need to coat windings with varnish, a rotor assembly may include an insert that retains windings in place within a winding channel. Specifically, an insert can be positioned within a winding channel formed within a lamination stack of a rotor assembly to compress the windings against the lamination stack. In some aspects, an insert can be used to separate (e.g., bifurcate) a winding channel into multiple sections that each include a winding therein. Further, an insert may define a plurality of channels or ducts therealong to optimize coolant circulation within a winding channel and across rotor windings by, for example, directing fresh coolant to a warmest region of a rotor winding (e.g., a center of a rotor winding). It is contemplated that an insert may bemanufactured using any suitable material such as, for example, aluminum, aluminum alloys, copper, graphite, a ceramic compound, a polymer, thermoplastic polyurethane, or any combination thereof. Moreover, an insert can be manufactured using a variety of suitable techniques, such as, for example, casting, die casting, extrusion, stamping, machining, forging, powder metallurgy, 3D printing, injection molding, metal foaming, etc.

[0149] As illustrated in the non-limiting example of FIGS. 25-27, the rotor windings 1025 can generally be enclosed by opposing end caps 1100 and disposed within the lamination stack 1108. In some examples, the lamination stack 1108 can have a first pole 1109A and a second pole 1109B that are spaced apart from one another to define a winding channel 1200 therebetween. Additional winding channels can be formed between other poles of the lamination stack 1108. In particular, the winding channel 1200 can extend through the lamination stack 1108 along the rotor axis 1021 (e g., substantially parallel, or skewed to extend at least partially in a circumferential direction, such as a corkscrew or spiral, with respect to the rotor axis 1021, see FIG. 10C) and between opposing end caps 1100. The rotor windings 1025 can be disposed within the winding channel 1200. To that end, the winding channel 1200 may form a cooling can for the rotor winding 1025. That is, the winding channel 1200 can define a flow path for coolant through the lamination stack 1108 and across the rotor winding 1025 to thermally regulate the rotor winding 1025 during operation of the rotor 1020. In some examples, the rotor 1020 can include a retaining member 1204 positioned within the winding channel 1200 to cover the rotor winding 1025, add rigidity to the lamination stack 1108, or prevent the rotor winding 1025 from exiting the winding channel 1200. The retaining member 1204 can be disposed parallel with respect to the rotor axis 1021 (see FIG. 10C) and can span a distance between opposing end caps 1100 (i.e., a distance defined by the lamination stack 1108 along a direction that is parallel with respect to the rotor axis 1021). In this way, the retaining member 1204 can act as a sidewall of the winding channel 1200 help to retain coolant that flows along the rotor windings 1025.

[0150] It is contemplated that a rotor winding can be held in place within a winding channel in variety of ways such as, for example, by compressing the rotor winding within the winding channel (e.g., between a lamination stack or a retaining member). In some cases, an insert can be positioned in a winding channel to aid in retaining windings therein, for example, by preventing individual wires or wraps of wires from moving during operation. An insert can also be used to help direct coolant flow across the windings, as may optimize cooling. For example, an insert canoccupy extra space within the winding channel to keep the bulk flow of coolant near the winding, as opposed to flowing along a middle of a channel. This keeps flow against the windings, as may also increase flow velocity, which can improve cooling capacity. In some cases, an insert can also be configured to direct coolant flow along the winding, as may allow for coolant to be directed to regions of the winding that are subject to increase heat generation (e.g., an axial center of a winding).

[0151] In the non-limiting example illustrated in FIGS. 26 and 27, the rotor 1020 can further include an insert 1208 disposed within the winding channel 1200 to hold the rotor winding 1025 in place and direct coolant within the winding channel 1200. In some aspects, the insert 1208 can be coupled to the lamination stack 1108 or the retaining member 1204, and the insert 1208 can extend into the winding channel 1200 therefrom. In addition, the insert 1208 can extend in a first or axial direction along the winding channel 1200. Thus, it will be understood that the insert 1208 can be unitary with the lamination stack 1108 or the retaining member 1204, although the insert 1208 may also be a separate component that is coupled to the lamination stack 1108 or the retaining member 1204. In some cases, the insert 1208 can be fixedly secured to the lamination stack 1108 or the retaining member 1204 (e.g., via fasteners, adhesives, welding, etc.). In the illustrated nonlimiting example, a top end 1212 (e.g., a radially outer end with respect to the rotor axis 1021) of the insert 1208 can be coupled to the retaining member 1204 such that the insert 1208 can extend radially inward within the winding channel 1200 (e.g., toward the rotor axis 1021, see FIG. 10C). In still other examples, the insert 1208 may be in a floating arrangement within the winding channel 1200.

[0152] Correspondingly, the insert 1208 can hold the rotor winding 1025 in place by preventing movement of the wires that make up the rotor windings 1025. In some cases, the insert 1208 may radially or circumferentially compress the rotor winding 1025 against the lamination stack 1108. In this way, the insert 1208 can prevent the rotor winding 1025 from becoming disordered within the winding channel 1200 (e.g., shifting from a desired position due to centrifugal motion of the rotor 1020, vibrations, or other external forces acting on the motor 102), thereby retaining the winding in place. The interlocking nature of the insert 1208 and the rotor winding 1025 is such that maintaining the shape of the rotor winding 1025 can in turn hold the insert 1208 in place within the winding channel 1200, as will be discussed below. Thus, the rotorwinding 1025 and the insert 1208 can cooperate to hold one another in place within the winding channel 1200.

[0153] The winding channel 1200 can also be shaped to help hold the rotor winding in place and prevent the rotor winding 1025 from becoming disordered within the winding channel 1200. For example, the winding channel 1200 formed in the lamination stack 1108 can a plurality of sides, such as, for example, three, four, five, six, or more sides. In the illustrated non-limiting example, the winding channel 1200 may include a substantially hexagonal shape. Specifically, a first half of the winding channel 1200 may include a first segment 1209 A, a second segment 1209B, and a third segment 1209C. A first angle 1210A can be formed between the first segment 1209A and the second segment 1209B, and a second angle 1210B can be formed between the second segment 1209B and the third segment 1209C. In some examples, the first angle 1210A is between about 20 degrees and about 180 degrees, or between about 90 degrees and about 120 degrees, or about 150 degrees, or about 120 degrees, or about 90 degrees. In the illustrated nonlimiting example, the first angle 1210A and the second angle 1210B are each about 120 degrees. The resulting geometry of the winding channel 1200 helps to keep individual wires or windings stacked neatly therein, which can improve the power density of the system. In other examples, the magnitude of each of the first angle and the second angle can be different.

[0154] In some examples, a winding jacket 1216 can extend along an inner surface of the lamination stack 1108 to at least partially enclose (e.g., wrap around) the rotor winding 1025 to help direct coolant flow along the rotor winding 1025 and limit coolant contact with the lamination stack 1108. Relatedly, the winding jacket 1216 may comprise an insulative material (e g., Nomex® or another insulating material) to at least partially electrically or thermally insulate the rotor winding 1025 from the lamination stack 1108 or the insert 1208. In some examples, the insert 1208 supports the winding jacket 1216 to hold or retain the rotor winding 1025 in place. In particular, the insert 1208 can contact the inner arms 1220 of the winding j acket 1216 that at least partially wrap around the rotor winding 1025, meaning that the winding j acket 1216 may be at least partially disposed between the rotor winding 1025 and the insert 1208. Thus, the insert 1208 may press against the inner arms 1220 of the winding j acket 1216 to compress the rotor winding 1025 within the winding jacket 1216 or the lamination stack 1 108 to insulate the rotor winding 1025 in place.

[0155] In some examples, the winding jacket 1216 may fully enclose the rotor winding 1025 so as to electrically insulate the rotor winding 1025 from the lamination stack 1108 or the insert1208. Further, the insulative material of the winding jacket 1216 may be pliable such that the winding jacket 1216 conforms to the shape of any surrounding components (e.g., the rotor winding 1025, the lamination stack 1108, or the insert 1208). For example, the winding jacket 1216 may curve around an indent 1217 formed in the lamination stack 1108 such that the inner arms 1220 can each, in part, define an undulating profile. It is contemplated that the indent 1217 in the lamination stack 1108 can help to keep the rotor winding 1025 in place by allowing individual windings to move slightly (e.g., during rotor motion) while maintaining a substantially ordered winding or packing pattern, which in turn can increase the power density of the rotor winding 1025.

[0156] In addition, an insert can serve as a partition or wedge that separates a channel into two or more portions to keep coolant tight against one or more rotor windings, which in turn can increase fluid velocity across the rotor winding(s) or increase fluid contact time, which can lead to increased heat transfer. For example, the insert 1208 can extend radially inward from the retaining member 1204 to bifurcate the winding channel 1200 into a first winding channel 1200A and a second winding channel 1200B. The rotor winding 1025 can include a first winding 1025 A and a second winding 1025B, the first winding 1025A disposed in the first winding channel 1200A (i.e., on one side of the insert 1208) and coupled to the first pole 1109A, and the second winding 1025B disposed in the second winding channel 1200B (i.e., on the other side of the insert 1208) and coupled to the second pole 1109B. The insert 1208 can define clearances with each of the first and second windings 1025 A, 1025B, and the clearances can increase fluid velocity or fluid contact time along the first and second windings 1025 A, 1025B, which in turn can increase the amount of heat that can be transferred out of the rotor 1020. While the insert 1208 in the non-limiting example is illustrated as extending radially inward to split the winding channel 1200 into two portions, it is contemplated that an insert may define additional shapes or branches (e.g., branches extending in radial or circumferential directions) to split a winding channel into more than two portions to alter the flow of coolant through the winding channel and across the winding(s). For example, an insert may include an axial branch and a circumferential branch that split a winding channel into four portions (e.g., quadrants). Correspondingly, it is contemplated that in other examples, more than one insert may be used within a winding channel.

[0157] Referring specifically to FIG. 27, the insert 1208 can have a main body that defines a tapered profile that narrows (e.g., in a direction perpendicular to a radial direction relative to themotor) as it extends radially inward toward the rotor axis 1021 (see FIG. 10C). Tn some cases, the sides of the insert 1208 that face the rotor windings 1025 can have undulating profile to direct coolant flow or to conform to the undulating shape of the rotor windings 1025. In some examples, the undulating shape of the insert 1208 surface can be shaped to follow a contour of the rotor windings 1025, such as to maintain an offset distance between the insert 1208 and the rotor windings 1025 and allow for coolant flow therebetween. Put another way, the undulating profile of the insert 1208 can be shaped to conform to the rotor windings 1025 (e.g., so that the insert 1208 and the rotor windings 1025 interlock).

[0158] In some examples, an insert can include at least one array or grid-like side surface to accommodate a rotor winding and direct coolant thereacross. In particular, an insert may define a plurality of channels and grooves to direct fresh coolant to warmer regions of a rotor winding (e.g., a center of the rotor winding) to increase the thermal efficiency of a rotor assembly. For example, the insert 1208 can include a channel 1228 (e.g., a plurality of channels) to direct coolant through the winding channel 1200 and across the rotor winding 1025, which can help to prevent fluid blockage caused by winding shifts during operation. In some aspects, the undulating profile of the insert 1208 can also help to maintain the arrangement of the rotor winding 1025 within the winding channel 1200. As illustrated in the non-limiting example, the rotor winding 1025 may also define an undulating profile that corresponds to the profile of the insert 1208. Specifically, the insert 1208 can define a left or first surface 1232 that abuts the first winding 1025 A and an opposite right or second surface 1236 that abuts the second winding 1025B. Each of the surfaces 1232, 1236 of the insert 1208 can define channels 1228 to receive corresponding profiles (e.g., protruding wires that define outer profiles) of each of the first and second windings 1025 A, 1025B, respectively. That is, the surfaces 1232 1236 can define undulating profiles that are shaped to conform to the first winding 1025 A and the second winding 1025B, respectively.

[0159] Thus, in some examples, the insert 1208 may be disposed substantially centrally within the winding channel 1200 (e.g., between the first and second windings 1025 A, 1025B such as to be equidistant therefrom). Moreover, the profile of the insert 1208 can help decrease the volume and increase the surface area of the insert 1208 to allow for more space within the winding channel 1200 for the rotor winding 1025, which in turn can improve the power output of the rotor 1020. In particular, the insert 1208 may comprise a volume of between about 5% and between about 50% of the volume of the winding channel 1200, or between about 5% and about 25% of the volume ofthe winding channel 1200, or between about 5% and about 15% of the volume of the winding channel 1200, or between about 10% and about 20% of the volume of the winding channel 1200, or less than about 15% of the volume of the winding channel 1200.

[0160] In some examples, an insert can include grooves that are angled to direct fresh coolant axially inward (i.e., toward warmer regions of a rotor winding) and direct used coolant axially outward (i.e., out of a winding channel), thereby leading to greater cooling efficiency within a winding channel. Referring now to the non-limiting example illustrated in FIG. 28, the insert 1208 can define a bottom end 1240 (i.e., an end of the insert 1208 closest to the rotor axis 1021, see FIG. 10C) opposite the top end 1212, and the first surface 1232 and the second surface 1236 can extend between the top end 1212 and the bottom end 1240. Further, the insert 1208 can define a front end 1244 (e.g., a first end) and a back end 1248 (e.g., a second end) proximate the end caps 1100. The surfaces 1232, 1236 each extending between the front end 1244 and the back end 1248. As discussed above, the insert 1208 can include a tapered profile such that the top end 1212 is wider than the bottom end 1240. Correspondingly, the surfaces 1232, 1236 can slope inward toward the bottom end 1240 from the top end 1212.

[0161] In some examples, the channels 1228 can extend axially (i.e., in the first direction along the main body of the insert 1208) along the surfaces 1232, 1236 to accommodate the rotor winding 1025 and direct coolant axially therealong (see FIG. 27). That is, the channels 1228 can extend between the front end 1244 and the back end 1248 in a direction that is substantially parallel with respect to the rotor axis 1021 (see FIG. 10C). In some examples, the channels 1228 define substantially arcuate profiles. Specifically, each channel 1228 can define one or more concave curves that transition into linear edges that serve as connection points (i.e., ridges) between adjacent channels 1228.

[0162] With additional reference to FIG. 29, the insert 1208 can further include one or more ducts 1252 to direct coolant radially or axially along the surfaces 1232, 1236 thereof (i.e., through a winding channel). Specifically, the ducts 1252 can be defined by the surfaces 1232, 1236. The ducts 1252 can define radial pathways for coolant to flow along the insert 1208 (i.e., from the bottom end 1240 toward the top end 1212), and such pathways may overlap or intersect with the channels 1228 to promote crossflow along the surfaces 1232, 1236 (e.g., between channels). In particular, the channels 1228 can extend axially (i.e., substantially parallel with respect to the rotor axis 1021, see FIG. 10C), while the ducts 1252 can extend radially or be angled with respect to therotor axis 1021 to define an array or grid-like pathway pattern on the surfaces 1232, 1236. For example, a duct 1252 (e.g., a first duct) may extend between a first channel 1228A and a second channel 1228B that extends substantially parallel with respect to the first channel 1228A. In particular, a duct 1252 (e.g., a second duct) can extend between the first channel 1228A and the second channel 1228B in a second direction that is at a non-zero angle relative to the first or axial direction, thus creating a flow path between the first channel 1228 A and the second channel 1228B, which has axial and radial components. In this way, crossflow between the channels 1228 and ducts 1252 can be provided, which can increase heat transfer and cooling efficiency. In some examples, a non-zero angle may be defined between each duct 1252 and the rotor axis 1021 (see FIG. 10C). In this way, the ducts 1252 can direct coolant in a particular direction (e.g., radially inward or outward) as it travels along the surfaces 1232, 1236 of the insert 1208, which in turn can allow fresh coolant to be provided to different regions of the rotor winding 1025 (e g., a center of the rotor winding 1025, see FIG. 27).

[0163] In the illustrated non-limiting example, the ducts 1252 may extend diagonally along the insert 1208. For example, the ducts 1252 extend in a direction from the bottom end 1240 (e.g., a radially inner side) toward the top end 1212 (e.g., a radially outer side) and from the top end 1212 toward the back end 1248 (or vice versa). In this way, pathways provided by the channels 1228 and the ducts 1252 can cooperate to direct coolant radially outward due to centrifugal forces of the rotor 1020 (see FIG. 25) as it travels across the surfaces 1232, 1236 (i.e., from the front end 1244 to the back end 1248). This may be particularly advantageous, for example, to facilitate a more equal temperature distribution across the length of a rotor winding by providing fresh coolant to the warmest region (e.g., a center) of the rotor winding. In some examples, the ducts 1252 are angled between about 5 degrees and about 90 degrees with respect to the rotor axis 1021, or between about 5 degrees and about 60 degrees with respect to the rotor axis 1021, or between about 5 degrees and about 30 degrees with respect to the rotor axis 1021, or between about 20 degrees and about 40 degrees with respect to the rotor axis 1021, or about 30 degrees with respect to the rotor axis 1021.

[0164] Further, ducts defined by a surface of an insert can also be disposed at different angles relative to one another to direct coolant in multiple directions along the surface(s) of the insert. For example, a surface of an insert can define one or more ducts arranged in opposing V-shaped configurations to direct fresh coolant (e.g., coolant supplied by flowing around ends of windingsdisposed within end caps) to an axial center of the insert and used coolant radially outward from the center of the insert to enhance cooling. That is, a surface of an insert can define a first plurality of ducts to bring fresh coolant into a center of a rotor winding and a second plurality of ducts to direct used coolant (e.g., coolant that has absorbed heat from the rotor winding) out of the center of the rotor winding.

[0165] Referring now to FIG. 30, another example of an insert 1308 is illustrated which is similar to the insert 1208 (see FIG. 29) in some aspects, except that the insert 1308 can include ducts disposed at multiple different angles. As shown, the insert 1308 can include one or more channels 1328 (e.g., a first channel 1329A, a second channel 1329B, and a third channel 1329C) that are formed along a side surface 1332 of the insert 1308 that extends between a front end 1344 and a back end 1348. That is, the channels 1328 can extend in a direction that is substantially parallel to a rotor axis 1321. As discussed above, the channels 1328 can help secure a rotor winding within a winding channel, and the channels 1328 can further provide axial pathways for coolant to travel along (e.g., between the axial ends of the insert 1208) to regulate the temperature of a rotor winding.

[0166] Further, the insert 1308 can define an undulating or tapered profile such that a top end 1312 of the insert 1308 can be wider than a bottom end 1340 of the insert 1308. In some examples, the bottom end 1340 is also tapered with respect to the rotor axis 1321 to help direct coolant toward a center of the insert 1308 (i.e., to a warmest part of a rotor winding). For example, the bottom end 1340 may extend radially outward (i.e., toward the top end 1312) so as to define a V-shaped recess 1342 serving as a coolant pathway to direct coolant toward the center of the insert 1308. In particular, the bottom end 1340 of the insert 1308 can define a first leg 1346A that extends radially outward (i.e., away from the rotor axis 1321) from the front end 1344 to an apex point 1350 that can be disposed along a center of the insert 1308 (e.g., a centerline with respect to an axial length of the insert 1308). Thus, fresh coolant (e.g., coolant supplied by flowing around portions of the rotor winding 1025 disposed within the end caps 1100, see FIGS. 19 and 20) can be directed from the front end 1344 toward the apex point 1350 along the first leg 1346A. Moreover, the bottom end 1340 can define a second leg 1346B that extends radially outward from the back end 1348 to the apex point 1350 such that the first leg 1346A and the second leg 1346B converge at the apex point 1350. In other examples, the bottom end 1340 (e.g., the first leg 1346A and the second leg 1346B) may be curved so as to define a substantially concavely curved recess rather than the V-shaped recess 1342. That is, the bottom end 1340 can curve radially outward from the front end 1344 and the back end 1348 toward a center of the insert 1308, which can help retain coolant and direct it inward toward the center of the insert 1308. In some examples, the bottom end 1340 receives coolant from a corresponding feature in the winding guide 1096 (e.g., the fourth flow channel 1094, see FIG. 19).

[0167] When, for example, a flow of coolant is introduced at the back end 1348 of the insert 1308 (e g., via coolant flow through provided the end caps 1100, see FIGS. 19 and 20) the tapered profile defined by the bottom end 1340 can help direct the coolant to the center of the insert by following the profile of the first leg 1346A. This in turn can help to ensure that fresh coolant is being introduced to the center of the insert 1308, which helps to further improve cooling efficiency. The coolant can absorb heat from a rotor winding as it flows along the bottom end 1340 and travels to the apex point 1350, and the correspondingly angled profile of the second leg 1346B can then help direct the used coolant away from the center of the insert 1308 and out toward the front end 1344.

[0168] It is contemplated that the legs 1346 may define any suitable combination of linear or arcuate paths to direct coolant toward the center of the insert 1308. In the non-limiting example, the legs 1346 can each define linear paths that converge at the apex point 1350 and that are in fluid communication with the V-shaped recess 1342 to distribute coolant radially along the length of the rotor winding 1025 (see FIG. 27). In some examples, the legs 1346 are each angled between about 1 degree and about 30 degrees with respect to the rotor axis 1321, or between about 1 degree and about 15 degrees with respect to the rotor axis 1321, or between about 1 degrees and about 5 degrees with respect to the rotor axis 1321, or less than about 5 degrees with respect to the rotor axis 1321.

[0169] Relatedly, the insert 1308 can include a duct 1352 (e.g., a first duct 1353A and a second duct 1353B) formed within the side surface 1332 to direct coolant therealong. Similar to the insert 1208 of FIG. 29, the channels 1328 can extend substantially parallel with respect to the rotor axis 1321, but the ducts 1352 may be disposed at different angles with respect to the rotor axis 1321. In the non-limiting example illustrated in FIG. 30, the duct 1352 can include a first plurality of ducts 1352A disposed on a bottom or inner half 1354 of the insert 1308 (e.g., a portion of the insert 1308 that extends between the bottom end 1340 and a midplane MP) and a second plurality of ducts 1352B disposed on a top or outer half 1358 of the insert 1308 (e.g., a portion of the insert1308 that extends between the top end 1312 and the midplane MP). Tn some aspects, the first and second pluralities of ducts 1352 define different patterns on the side surface 1332 to direct coolant to and from particular locations along the insert 1308. For example, the first plurality of ducts 1352A may extend at a first angle with respect to the rotor axis 1321, and the second plurality of ducts 1352B may extend at a second angle with respect to the rotor axis 1321. In this way, the ducts 1352 may intersect one another, in addition to the channels 1328, which can help promote turbulent flow over the side surface 1332 and disrupt thermal boundary layer formation therealong. Correspondingly, promoting turbulent coolant flow can also disrupt thermal boundary layer formation along surfaces of a rotor winding that abut the insert 1308.

[0170] Alternatively, the first and second pluralities of ducts 1352 may define opposing patterns on the side surface 1332 of the insert 1308 to draw fresh coolant into a center of a rotor winding and urge used coolant away from the center of the rotor winding. Specifically, and similar to the tapered profile of the bottom end 1340 of the insert 1308, each duct in the first plurality of ducts 1352A can be angled toward the axial center of the insert 1308 (i.e., toward the midplane MP) to direct fresh coolant thereto. That is, each duct in the first plurality of ducts 1352A can be angled radially outward (i.e., away from the rotor axis 1321) or axially inward (i.e., toward the center of the insert 1308 from the front end 1344 or the back end 1348) to direct coolant into a center of a rotor winding. It is contemplated that each duct in the first plurality of ducts 1352A can define any suitable path to direct coolant toward a center of a rotor winding, such as linear paths, arcuate paths, or any combination thereof.

[0171] In the illustrated non-limiting example, each duct in the first plurality of ducts 1352 A may define a V-shaped profile, similar to that of the bottom end 1340 of the insert 1308. Put another way, each duct in the first plurality of ducts 1352A may include a first leg 1360A that extends radially outward from the front end 1344 to a first apex point 1364 that can be disposed along a center of the insert 1308. Each duct in the first plurality of ducts 1352A can further include a second leg 1360B that extends radially outward from the back end 1348 to the first apex point 1364 such that the first leg 1360A and the second leg 1360B converge at the first apex point 1364. In other examples, each duct in the first plurality of ducts 1352A may be similar to the ducts 1252 of FIG. 29 (e.g., ducts that are substantially parallel to one another or disposed on a shared angle relative to the rotor axis 1321, see FIG. 10C).

[0172] Correspondingly, each duct in the second plurality of ducts 1352B can also be angled toward the center of the insert 1308 (i.e., toward the midplane MP) to direct used coolant out of a center of a rotor winding. That is, each duct in the second plurality of ducts 1352B can be angled radially inward (i.e., toward from the rotor axis 1321) or axially inward (i.e., toward the center of the insert 1308 from the front end 1344 or the back end 1348). In this way, the second plurality of ducts 1352B can direct coolant (e.g., coolant that flows across a center of a rotor winding via the first plurality of ducts 1352A and absorbs heat from the center of the rotor winding) radially outward and axially outward from the center of the rotor winding. It is contemplated that each duct in the second plurality of ducts 1352B can define any suitable path to direct coolant toward a center of a rotor winding, such as linear paths, arcuate paths, or any combination thereof.

[0173] In the illustrated non-limiting example, each duct in the second plurality of ducts 1352B may define a V-shaped profile opposite the first plurality of ducts 1352A. In some examples, the first plurality of ducts 1352 A and second plurality of ducts 1352B may be symmetric about the midplane MP, or the second plurality of ducts 1352B can be axially offset from the first plurality of ducts 1352A. In particular, each duct in the second plurality of ducts 1352B may include a third leg 1368A that extends radially inward from the front end 1344 to a second apex point 1370 that can be disposed along a center of the insert 1308. Each duct in the second plurality of ducts 1352B can further include a fourth leg 1368B that extends radially inward from the back end 1348 to the second apex point 1370 such that the third leg 1368A and the fourth leg 1368B converge at the second apex point 1370.

[0174] In other examples, each duct in the second plurality of ducts 1352B may be similar to the ducts 1252 of FIG. 29 (e.g., ducts that are substantially parallel to one another or disposed on a shared angle relative to the rotor axis 1021, see FIG. 10C). In particular, the first duct 1359A can extend between the first channel 1329A and the second channel 1329B in a second direction that is at a non-zero angle relative to a first direction in which the channels 1329A, 1329B extend (e.g., an axial direction). In some aspects, the third channel 1329C also extends in the first direction, and the second duct 1359B extends between the first channel 1329A and the third channel 1329C in a third direction (e.g., a direction that is different than the first direction). In some examples, the second direction is different than the third direction, or the second direction is parallel with respect to the third direction. In this way, the first duct 1359A and the second duct 1359B can provide cross-flow between the channels 1329A, 1329B, 1329C. For example, the first duct 1359A maybe configured to direct a flow of fluid (e.g., coolant) from the front end 1344 of the main body of the insert 1308 to the back end 1348, thereby defining a flow path with components corresponding to the first direction or the second direction. However, the second duct 1359B may be configured to direct a flow of fluid from the back end 1348 of the main body of the insert 1308 to the front end 1344, thereby defining a flow path with components corresponding to the first direction or the third direction. The first and second ducts 1359A, 1359B may be positioned in a variety of different locations on the side surface 1332 to accomplish such cross-flow. In some examples, the first and second ducts 1359A, 1359B are positioned between the front end 1344 of the main body of the insert 1308 and an axial center of the insert 1308, as illustrated in FIG. 30.

[0175] As discussed above, ducts may intersect channels to provide crossflow along a side of an insert, which can increase heat transfer and cooling efficiency. To further optimize heat transfer, an insert can include pores (e.g., openings, holes, etc.) that define fluid pathways between opposing sides of the insert. These additional pathways can help promote turbulent flow and improve mixing by encouraging coolant to flow from side-to-side (i.e., in a circumferential direction). This in turn can help to promote more even cooling, as coolant passing back and forth between sides of an insert can help to equalize a temperature of the coolant as it flows through a winding channel and captures heat from the power components (e.g., rotor windings) contained therein. Put another way, a porous insert can define a tortuous path for coolant to flow through a winding channel to improve contact time and, as a result, heat exchange. Moreover, centripetal forces generated by rotor motion can pull coolant through differently angled pores in an insert, which can both help to impinge the coolant directly onto rotor windings and help distribute coolant equally on either side of the insert. That is, pores in sides of an insert can help to free any fluid that is trapped unequally on a particular side of the insert or prevent unequal fluid buildup entirely, which can help to increase fluid velocity or contact time along rotor windings.

[0176] Referring now to FIGS. 31-34, another example of an insert 1408 is illustrated which is similar to the inserts 1208, 1308 discussed above in some aspects, except that the insert 1408 may be porous to promote more even cooling and improve heat transfer. As illustrated in FIGS. 31 and 32, the insert 1408 can include channels 1428 and ducts 1452 that are formed in the side surfaces 1432, 1436 of the insert 1408, the channels 1428 and ducts 1452 being substantially similar to the channels 1228 and ducts 1252 of the insert 1208 discussed above (see FIG. 29). In some aspects, the insert 1408 can further include pores 1410 within the side surfaces 1432, 1436to promote crossflow therebetween. It is contemplated that the pores 1410 can be arranged in columns or rows in the side surfaces 1432, 1436, or the position of the pores 1410 can be varied to alter the cooling profile provided by the insert 1408 (e.g., the pores 1410 may be randomly positioned along the side surfaces 1432, 1436, arranged in a grid-like formation along the side surfaces 1432, 1436, concentrated towards a center of the insert 1408 rather than at axial ends of the insert, etc.). Further, an insert can be manufactured using a variety of suitable techniques to form pores therein, such as, for example, casting, die casting, extrusion, stamping, machining, forging, powder metallurgy, 3D printing, injection molding, metal foaming etc.

[0177] In the illustrated non-limiting example, the pores 1410 are arranged in columns 1411 (e.g., a first set of columns 1411A and a second set of columns 141 IB). In some aspects, adjacent columns 1411 can be radially offset with respect to one another such that the first set of columns 1411A can be disposed closer to a bottom side 1440 of the insert 1408 and the second set of columns 141 IB can be disposed closer to a top side 1412 of the insert 1408. While each column 1411 is shown as including four pores 1410, it is contemplated that fewer or more pores 1410 (e.g., one, two, five, six, eight, or ten pores) can be used to adjust the cooling profile of the insert 1408.

[0178] Pores within an insert can be configured to cause cross flow between opposing sides of an insert. For example, each of the pores 1410 can define a cross-sectional area. The cross-sectional area can vary between one of the first side surface 1432 and the second side surface 1436 to cause cross flow between the side surfaces 1432, 1436 in response to rotation of the rotor 1020. More specifically, a first cross-sectional area of a pore along one of the first side surface 1432 and the second side surface 1436 can be greater than a second cross-sectional area along the other of the first side surface 1432 and the second side surface 1436. As the rotor 1020 rotates, coolant is caused to flow from the side defining the second cross-sectional area to the side defining the first cross-sectional area. In the illustrated example, each of the columns 1411 is configured to cause flow in a particular direction; however, other flow arrangements are also contemplated.

[0179] Referring now to FIG. 33, the pores 1410 in the first set of columns 1411 A are arranged so as to direct the coolant 1040 from the second side surface 1436 to the first side surface 1432. To accomplish this, the openings of the pores 1410 in the first set of columns 1411 A located on the second side surface 1436 (e.g., the cross sectional area corresponding to the pore 1410) may be narrower than the openings of the pores 1410 located on the first side surface 1432 such that that the centripetal forces generated during rotor motion pulls coolant 1040 through the pores 1410in the first set of columns 1411 A (i.e., from the second side surface 1436 to the first side surface 1432). Similarly, with reference to FIG. 34, the pores 1410 in the second set of columns 141 IB may be arranged to cause slow in a direction opposite to the pores 1410 in the first set of columns 1411A. That is, the pores 1410 in the second set of columns 141 IB direct the coolant 1040 in the opposite direction (e.g., from the first side surface 1432 to the second side surface 1436). Accordingly, the openings of the pores 1410 in the second set of columns 141 IB located on the second side surface 1436 may be narrower than the openings of the pores 1410 located on the second side surface 1436 such that that the centripetal forces generated during rotor motion pulls coolant 1040 through the pores 1410 in the second set of columns 141 IB (i.e., from the first side surface 1432 to the second side surface 1436). In some examples, the pores 1410 are angled with respect to a bottom plane BP defined by the bottom side 1440 of the insert 1408 to facilitate coolant 1040 flow between the side surfaces 1432, 1436. For example, each pore 1410 may define a third angle 1414 with respect to the bottom plate BP that is between about 1 degree and about 60 degrees, or between about 1 degree and about 30 degrees, or between about 5 degrees and about 15 degrees, or about 12 degrees.

[0180] FURTHER EXAMPLES

[0181] Example 1 : A rotor chipset assembly comprising: a printed circuit board having a first surface and a second surface opposite the first surface, the printed circuit board including a rotor winding terminal connector and a plurality of electronic components each having an outward surface, wherein the first surface, the second surface, and the outward surfaces of the plurality of electronic components define a board surface profile; a cooling jacket coupled to the printed circuit board, the cooling jacket including an inner surface that faces the board surface profile, wherein the cooling jacket includes a fluid inlet port proximate a first end of the printed circuit board, and wherein the cooling jacket includes a first jacket portion that faces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board; and a coolant fluid pathway volume defined by the board surface profile and the inner surface of the cooling jacket.

[0182] Example 2: The rotor chipset assembly of Example 1, wherein the printed circuit board includes an electronic connection port located proximate the first end.

[0183] Example 3: The rotor chipset assembly of Example 2, wherein the electronic connection port is a Universal Serial Bus (USB) connection port.

[0184] Example 4: The rotor chipset assembly of any one of Examples 1 to 3, wherein the fluid inlet port of the cooling jacket is dimensioned to receive an electronic connector therethrough.

[0185] Example 5: The rotor chipset assembly of any one of Examples 1 to 4, wherein a distance between a center of mass of the first jacket portion and the first surface is approximately equal to a distance between a center of mass of the second jacket portion and the second surface.

[0186] Example 6: The rotor chipset assembly of any one of Examples 1 to 5, wherein the fluid inlet port includes a fluid entry portion located at a first radial distance from a center line of the fluid inlet port, the cooling j acket includes a fluid exit portion located at a second radial distance from a center line of the fluid inlet port, and the second distance is greater than or equal to the first distance.

[0187] Example 7: The rotor chipset assembly of Example 6, wherein an inlet flow rate through the fluid entry portion is greater than an outlet flow rate through the fluid exit portion.

[0188] Example 8: The rotor chipset assembly of Example 6 or Example 7, wherein a coolant fluid exiting the fluid exit portion is directed to cool a component external to the rotor chipset assembly.

[0189] Example 9: The rotor chipset assembly of any one of Examples 1 to 8, wherein a coolant fluid is received from an inverter assembly via the fluid inlet port.

[0190] Example 10: The rotor chipset assembly of any one of Examples 1 to 9, further comprising a housing, wherein an inner surface of the housing is configured to engage at least one of the printed circuit board or the cooling jacket and wherein an outer surface of the housing is configured to engage an inner surface of a rotor of a motor assembly.

[0191] Example 11 : An electric motor comprising: a stator assembly; a rotor assembly including an interior cavity; and a rotor chipset assembly disposed within the interior cavity, the rotor chipset assembly comprising: a printed circuit board having a first surface and a second surface opposite the first surface, the printed circuit board including a plurality of electronic components each having an outward surface, wherein the first surface, the second surface, and the outward surfaces of the plurality of electronic components define a board surface profile, a cooling jacket coupled to the printed circuit board, the cooling jacket including an inner surface that faces the board surface profile, wherein the cooling jacket includes a fluid inlet port proximate a first end of the printed circuit board, and wherein the cooling j acket includes a first jacket portion thatfaces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board, and a coolant fluid pathway volume defined by the board surface profile and the inner surface of the cooling jacket.

[0192] Example 12: The electric motor of Example 11, wherein the printed circuit board includes an electronic connection port located proximate the first end.

[0193] Example 13 : The electric motor of Examples 11 or 12, wherein the fluid inlet port of the cooling jacket is dimensioned to receive an electronic connector therethrough.

[0194] Example 14: The electric motor of any one of Examples 11 to 13, wherein a distance between a center of mass of the first jacket portion and the first surface is approximately equal to a distance between a center of mass of the second jacket portion and the second surface.

[0195] Example 15: The electric motor of any one of Examples 11 to 14, wherein the fluid inlet port includes a fluid entry portion located at a first radial distance from a center line of the fluid inlet port, the cooling jacket includes a fluid exit portion located at a second radial distance from a center line of the fluid inlet port, and the second distance is greater than or equal to the first distance.

[0196] Example 16: The electric motor of Example 15, wherein an inlet flow rate through the fluid entry portion is greater than an outlet flow rate through the fluid exit portion.

[0197] Example 17: The electric motor of Example 15 or Example 16, wherein a coolant fluid exiting the fluid exit portion is directed to cool a component of the rotor assembly.

[0198] Example 18: The electric motor of any one of Examples 11 to 17, further comprising a coolant fluid pathway that permits a flow of coolant fluid from an end cap portion of the electric motor, through the fluid inlet port of the rotor chipset assembly, through the coolant fluid pathway volume of the rotor chip set assembly, and to a portion of the rotor assembly.

[0199] Example 19: The electric motor of any one of Examples 11 to 18, wherein the rotor chipset assembly further comprises a housing, wherein an inner surface of the housing is configured to engage at least one of the printed circuit board or the cooling jacket and wherein an outer surface of the housing is configured to engage an inner surface of the rotor assembly.

[0200] Example 20: The electric motor of Example 19, wherein the housing includes an antivibration system configured to reduce a vibrational force on the rotor chipset assembly during an operation of the electric motor.

[0201] Example 21 : The electric motor of any one of Examples 1 1 to 20, wherein the printed circuit board extends in an axial direction of the interior cavity.

[0202] Example 22: The electric motor any one of Examples 11 to 21, wherein the cooling jacket includes a support extending from the inner surface of the cooling jacket, the support arranged to engage with and provide support to a corresponding one of the plurality of electronic components.

[0203] Example 23 : The electric motor of Example 22, wherein the support is one of a plurality of supports that are arranged to control a flow of coolant through the coolant fluid pathway.

[0204] Example 24: The electric motor of Example 22 or Example 23, wherein the support is a rigid support that is monolithically formed with the cooling jacket and shaped in accordance with a shape of the electronic component.

[0205] Example 25: The electric motor of any one of Examples 22 to 23, wherein the support is a deformable support that is configured to conform with a shape of the electronic component when the printed circuit board is coupled to the cooling jacket.

[0206] Example 26: An electric motor comprising: a stator assembly including a stator winding; and a rotor assembly configured to rotate about a rotor axis relative to the stator assembly, the rotor assembly including: a shaft defining an interior cavity having a shaft inlet and a shaft outlet; a rotor winding coupled to the shaft; and a cooling jacket configured to be received with the interior cavity of the shaft, the cooling j acket including a main body configured to house a rotor chipset and a plurality of fins extending from the main body, the main body and the plurality of fins configured define a flow path for coolant through interior cavity from the inlet to the outlet.

[0207] Example 27: The electric motor of Example 26, wherein the cooling jacket defines a jacket inlet, a jacket outlet, and a chamber between the jacket inlet and the jacket outlet along the flow path.

[0208] Example 28: The electric motor of Example 27, wherein the chamber is positioned at the center of the shaft relative to a length of the shaft taken along the rotor axis.

[0209] Example 29: The electric motor of Example 27 or Example 28, wherein the flow path includes at least one of a first flow channel defined within the main body and a second flow channel defined by the plurality of fins, which extend between the jacket inlet and the chamber.

[0210] Example 30: The electric motor of Example 29, wherein the second flow channel is defined between the cooling jacket and walls of the interior cavity of the shaft.

[0211] Example 31 : The electric motor of Example 29 or Example 30, wherein the flow path further includes a third flow channel extending between the chamber and the shaft outlet.

[0212] Example 32: The electric motor of Example 31, wherein the second flow channel and the third flow channel extend along the rotor axis.

[0213] Example 33 : The electric motor of Example 31 or Example 32, wherein the shaft outlet includes a first shaft outlet at a first end of the shaft and a second shaft outlet at a second end of the shaft, and the third flow channel extends between each of the first shaft outlet and the second shaft outlet.

[0214] Example 34: The electric motor of Example 33, wherein coolant is distributed equally to each of the first end of the shaft and the second end of the shaft.

[0215] Example 35: The electric motor of any one of Examples 31 to 34, wherein fluid from the shaft outlet is supplied to a fourth flow channel configured to provide coolant to the rotor winding.

[0216] Example 36: The electric motor of Example 35, wherein coolant exits the fourth flow channel to flow over the rotor winding, the coolant exiting from an opening that is circumferentially offset from the shaft outlet.

[0217] Example 37: The electric motor of Example 36, wherein the fourth flow channel is configured as an annular flow channel that is axially and radially inside the rotor winding, and wherein the fourth flow channel extends between the shaft and a winding guide that is configured to support the rotor winding and that defines the opening to allow coolant to flow over the rotor winding.

[0218] Example 38: The electric motor of any one of Examples 26 to 37, further comprising an end cap configured to hold the coolant against the rotor winding.

[0219] Example 39: The electric motor of Example 38, wherein the end cap defines a plurality of grooves configured to control the distribution of coolant over the rotor winding.

[0220] Example 40: The electric motor of Examples 38 or 39, wherein rotation of the rotor assembly causes coolant from the rotor winding to flow across an air gap between the rotor assembly and the stator assembly to provide coolant to the stator winding.

[0221] Example 41 : The electric motor of any one of Examples 26 to 40, wherein the plurality of fins defines an outer surface configured to engage with walls of the interior cavity and a plurality of cutouts that correspond with the flow path.

[0222] Example 42: The electric motor of any one of Examples 26 to 41, wherein the cooling jacket further includes a protrusion configured to be received in a recess defined in the shaft to rotationally fix the cooling jacket with the shaft.

[0223] Example 43 : The electric motor of any one of Examples 26 to 42, wherein the cooling jacket is configured to pump coolant along the flow path due to rotation of the rotor assembly.

[0224] Example 44: An integrated drive unit comprising the electric motor according to any one of Examples 26 to 43.

[0225] Example 45: The integrated drive unit of Example 44, further comprising a transmission and an inverter unit, wherein the flow path is a portion of a shared coolant path extending through the transmission, inverter unit, and electric motor.

[0226] Example 46: A rotor assembly, comprising: a shaft defining a rotor axis and an interior cavity; a rotor winding coupled to the shaft; a rotor chipset disposed within the interior cavity; and a bus bar extending through an opening defined in the shaft, the bus bar configured to couple the rotor winding to the rotor chipset.

[0227] Example 47: The rotor assembly of Example 46, wherein the bus bar is secured in a retainer that is configured to be received in the interior cavity of the shaft and to electrically isolate the bus bar from the shaft.

[0228] Example 48: The rotor assembly of Examples 46 or 47, wherein the bus bar is disposed within a protrusion that is configured to be received in the opening in the shaft.

[0229] Example 49: The rotor assembly of any one of Examples 46 to 48, wherein the rotor chipset is disposed in a cooling jacket that is configured to control a flow of coolant through the shaft.

[0230] Example 50: The rotor assembly of any one of Examples 46 to 49, wherein a first end of the bus bar is configured to permanently couple to the winding and a second end of the bus bar includes a first terminal configured to releasably couple to a corresponding terminal of the rotor chipset.

[0231] Example 51 : A rotor assembly, comprising: a shaft including a flange disposed on an end of the shaft; a lamination stack; a rotor winding; and a balance ring configured to retain the rotor winding on the shaft, between the lamination stack and the balance ring, wherein the balance ring defines an inner lip and the flange is configured to deform over the inner lip to retain the rotor winding on the shaft.

[0232] Example 52: The rotor assembly of Example 51, wherein the flange provides axial compression to the balance ring, the rotor winding, and the lamination stack, relative to a rotor axis defined by the shaft.

[0233] Example 53: The rotor assembly of Examples 51 or 52, further comprising a winding guide positioned between the rotor winding and the lamination stack to support the rotor winding.

[0234] Example 54: The rotor assembly of any one of Examples 51 to 53, further comprising an end cap configured to enclose the winding on the winding guide, the end cap positioned between the rotor winding and the balance ring.

[0235] Example 55: The rotor assembly of any of Example 54, wherein the end cap and the winding guide form a cooling can configured to distribute coolant over the rotor winding.

[0236] Example 56: The rotor assembly of Example 54 or Example 55, wherein the end cap and the winding guide configured to electrically isolate the rotor winding from the shaft and the balance ring.

[0237] Example 57: A method of assembling a rotor, the method comprising: arranging a winding on a rotor shaft; and deforming (e g., bending, crimping, etc.) a flange of the rotor shaft over a balance ring to secure the winding on the rotor shaft.

[0238] Example 58: The method of Example 57, further comprising coupling a winding guide to the rotor shaft, the winding guide configured to support the winding on the rotor shaft.

[0239] Example 59: The method of Example 58, further comprising coupling an end cap to the rotor shaft, the end cap configured to enclose the winding on the winding guide.

[0240] Example 60: The method of any one of Examples 57 to 59, further comprising inserting a rotor chipset assembly into an interior cavity of the rotor shaft.

[0241] Example 61 : The method of Example 60, further comprising inserting a rotor chipset in a cooling jacket to form the rotor chipset assembly.

[0242] Example 62: The method of any one of Examples 57 to 61, further comprising coupling a bus bar between the rotor winding and a rotor chipset.

[0243] Example 63: A rotor assembly, comprising: a shaft defining a rotor axis; a lamination stack including a first pole and a second pole that are spaced apart to define a winding channel therebetween; a rotor winding positioned within the winding channel; and an insert that extends axially through the winding channel to direct coolant across the rotor winding.

[0244] Example 64: The rotor assembly of Example 63 further comprising a winding jacket positioned in the winding channel to retain the rotor winding therein.

[0245] Example 65: The rotor assembly of Example 63 or Example 64, wherein the rotor winding includes a first winding coupled to the first pole and a second winding coupled to the second pole, and wherein the insert is positioned between the first winding and the second winding within the winding channel.

[0246] Example 66: The rotor assembly of Example 65, wherein the insert defines a first surface that faces the first winding and a second surfaces that faces the second winding, the first surface and the second surface each defining undulating profiles that are shaped to conform to the first winding and the second winding.

[0247] Example 67: The rotor assembly of Example 66, wherein the first surface of the insert includes a channel to direct coolant axially along the rotor winding.

[0248] Example 68: The rotor assembly of Example 67, wherein the channel extends in a direction that is substantially parallel with respect to the rotor axis.

[0249] Example 69: The rotor assembly of any one of Examples 66 to 68, wherein the first surface of the insert includes a second channel and a duct that extends between the first channel and the second channel at a non-zero angle relative to the rotor axis.

[0250] Example 70: The rotor assembly of Example 69, wherein the duct is positioned to direct coolant radially outward at an axial center of the rotor winding.

[0251] Example 71 : The rotor assembly of Example 70, wherein the insert defines a midplane between a radially inner half and a radially outer half, and wherein the duct is one of a plurality of ducts including a first plurality of ducts disposed on the inner half of the insert and a second plurality of ducts disposed on the outer half of the insert.

[0252] Example 72: The rotor assembly of Example 71 , wherein the first plurality of ducts are configured to direct coolant radially outward and axially into the winding channel, and wherein the second plurality of ducts are configured to direct coolant radially outward and axially outward from the winding channel.

[0253] Example 73: An insert for a rotor assembly having a winding channel, the insert comprising: a main body configured to extend in a first direction along the winding channel, the main body defining: a first channel extending in the first direction along the main body, a second channel extending in the first direction along the main body parallel to the first channel, and a first duct extending between the first channel and the second channel in a second direction that is at a non-zero angle relative to the first direction.

[0254] Example 74: The insert of Example 73, wherein the first channel, the second channel, and the first duct are formed on a side of the insert that is shaped to conform with a rotor winding that is received in the winding channel.

[0255] Example 75: The insert of Example 73 or Example 74, wherein the main body further defines: a third channel extending in the first direction along the main body parallel to the first channel, and a second duct extending between the first channel and the third channel, the first duct configured to direct a flow of fluid from a first end of the main body to a second end of the main body and the second duct configured to direct a flow of fluid from the second end of the main body toward the first end of the main body.

[0256] Example 76: The insert of Example 75, wherein the main body defines a center between the first end and the second end, and each of the first duct and the second duct are positioned between the first end and the center.

[0257] Other examples and uses of the disclosed technology will be apparent to those having ordinary skill in the art upon consideration of the specification and practice of the invention disclosed herein. The specification and examples given should be considered exemplary only, and it is contemplated that the appended claims will cover any other such examples or modifications as fall within the true scope of the invention.

[0258] The Abstract accompanying this specification is provided to enable the United States Patent and Trademark Office and the public generally to determine quickly from a cursoryinspection the nature and gist of the technical disclosure and in no way intended for defining, determining, or limiting the present invention or any of its examples.

Claims

CLAIMSWhat is claimed is:

1. A rotor chipset assembly comprising: a printed circuit board having a first surface and a second surface opposite the first surface, the printed circuit board including a rotor winding terminal connector and a plurality of electronic components each having an outward surface, wherein the first surface, the second surface, and the outward surfaces of the plurality of electronic components define a board surface profile; a cooling jacket coupled to the printed circuit board, the cooling jacket including an inner surface that faces the board surface profile, wherein the cooling jacket includes a fluid inlet port proximate a first end of the printed circuit board, and wherein the cooling jacket includes a first jacket portion that faces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board; and a coolant fluid pathway volume defined by the board surface profile and the inner surface of the cooling jacket.

2. The rotor chipset assembly of claim 1, wherein the printed circuit board includes an electronic connection port located proximate the first end.

3. The rotor chipset assembly of claim 2, wherein the electronic connection port is a Universal Serial Bus (USB) connection port.

4. The rotor chipset assembly of any one of claims 1 to 3, wherein the fluid inlet port of the cooling jacket is dimensioned to receive an electronic connector therethrough.

5. The rotor chipset assembly of any one of claims 1 to 4, wherein a distance between a center of mass of the first jacket portion and the first surface is approximately equal to a distance between a center of mass of the second jacket portion and the second surface.

6. The rotor chipset assembly of any one of claims 1 to 5, wherein the fluid inlet port includes a fluid entry portion located at a first radial distance from a center line of the fluid inlet port, the cooling jacket includes a fluid exit portion located at a second radial distance from a center line of the fluid inlet port, and the second distance is greater than or equal to the first distance.

7. The rotor chipset assembly of claim 6, wherein an inlet flow rate through the fluid entry portion is greater than an outlet flow rate through the fluid exit portion.

8. The rotor chipset assembly of claim 6 or claim 7, wherein a coolant fluid exiting the fluid exit portion is directed to cool a component external to the rotor chipset assembly.

9. The rotor chipset assembly of any one of claims 1 to 8, wherein a coolant fluid is received from an inverter assembly via the fluid inlet port.

10. The rotor chipset assembly of any one of claims 1 to 9, further comprising a housing, wherein an inner surface of the housing is configured to engage at least one of the printed circuit board or the cooling jacket and wherein an outer surface of the housing is configured to engage an inner surface of a rotor of a motor assembly.

11. An electric motor comprising: a stator assembly; a rotor assembly including an interior cavity; and a rotor chipset assembly disposed within the interior cavity, the rotor chipset assembly comprising: a printed circuit board having a first surface and a second surface opposite the first surface, the printed circuit board including a plurality of electronic components each having an outward surface, wherein the first surface, the second surface, and the outward surfaces of the plurality of electronic components define a board surface profile,a cooling jacket coupled to the printed circuit board, the cooling jacket including an inner surface that faces the board surface profde, wherein the cooling jacket includes a fluid inlet port proximate a first end of the printed circuit board, and wherein the cooling jacket includes a first jacket portion that faces the first surface of the printed circuit board and a second jacket portion that faces the second surface of the printed circuit board, and a coolant fluid pathway volume defined by the board surface profile and the inner surface of the cooling jacket.

12. The electric motor of claim 11, wherein the printed circuit board includes an electronic connection port located proximate the first end.

13. The electric motor of claim 11 or claim 12, wherein the fluid inlet port of the cooling jacket is dimensioned to receive an electronic connector therethrough.

14. The electric motor of any one of claims 11 to 13, wherein a distance between a center of mass of the first jacket portion and the first surface is approximately equal to a distance between a center of mass of the second jacket portion and the second surface.

15. The electric motor of any one of claims 11 to 14, wherein the fluid inlet port includes a fluid entry portion located at a first radial distance from a center line of the fluid inlet port, the cooling jacket includes a fluid exit portion located at a second radial distance from a center line of the fluid inlet port, and the second distance is greater than or equal to the first distance.

16. The electric motor of claim 15, wherein an inlet flow rate through the fluid entry portion is greater than an outlet flow rate through the fluid exit portion.

17. The electric motor of claim 15 or claim 16, wherein a coolant fluid exiting the fluid exit portion is directed to cool a component of the rotor assembly.

18. The electric motor of any one of claims 11 to 17, further comprising a coolant fluid pathway that permits a flow of coolant fluid from an end cap portion of the electric motor, through the fluid inlet port of the rotor chipset assembly, through the coolant fluid pathway volume of the rotor chipset assembly, and to a portion of the rotor assembly.

19. The electric motor of any one of claims 11 to 18, wherein the rotor chipset assembly further comprises a housing, wherein an inner surface of the housing is configured to engage at least one of the printed circuit board or the cooling jacket and wherein an outer surface of the housing is configured to engage an inner surface of the rotor assembly.

20. The electric motor of claim 19, wherein the housing includes an anti -vibration system configured to reduce a vibrational force on the rotor chipset assembly during an operation of the electric motor.

21. The electric motor of any one of claims 11 to 20, wherein the printed circuit board extends in an axial direction of the interior cavity.

22. The electric motor any one of claims 11 to 21, wherein the cooling jacket includes a support extending from the inner surface of the cooling j acket, the support arranged to engage with and provide support to a corresponding one of the plurality of electronic components.

23. The electric motor of claim 22, wherein the support is one of a plurality of supports that are arranged to control a flow of coolant through the coolant fluid pathway.

24. The electric motor of claim 22 or claim 23, wherein the support is a rigid support that is monolithically formed with the cooling jacket and shaped in accordance with a shape of the electronic component.

25. The electric motor of claim 22 or claim 23, wherein the support is a deformable support that is configured to conform with a shape of the electronic component when the printed circuit board is coupled to the cooling jacket.

26. An electric motor comprising: a stator assembly including a stator winding; and a rotor assembly configured to rotate about a rotor axis relative to the stator assembly, the rotor assembly including: a shaft defining an interior cavity having a shaft inlet and a shaft outlet; a rotor winding coupled to the shaft; and a cooling jacket configured to be received with the interior cavity of the shaft, the cooling jacket including a main body configured to house a rotor chipset and a plurality of fins extending from the main body, the main body and the plurality of fins configured define a flow path for coolant through interior cavity from the inlet to the outlet.

27. The electric motor of claim 26, wherein the cooling jacket defines a jacket inlet, a jacket outlet, and a chamber between the jacket inlet and the jacket outlet along the flow path.

28. The electric motor of claim 27, wherein the chamber is positioned at the center of the shaft relative to a length of the shaft taken along the rotor axis.

29. The electric motor of claim 27 or claim 28, wherein the flow path includes at least one of a first flow channel defined within the main body and a second flow channel defined by the plurality of fins, which extend between the jacket inlet and the chamber.

30. The electric motor of claim 29, wherein the second flow channel is defined between the cooling jacket and walls of the interior cavity of the shaft.

31. The electric motor of claim 29 or claim 30, wherein the flow path further includes a third flow channel extending between the chamber and the shaft outlet.

32. The electric motor of claim 31, wherein the second flow channel and the third flow channel extend along the rotor axis.- 1 -33. The electric motor of claim 31 or claim 32, wherein the shaft outlet includes a first shaft outlet at a first end of the shaft and a second shaft outlet at a second end of the shaft, and the third flow channel extends between each of the first shaft outlet and the second shaft outlet.

34. The electric motor of claim 33, wherein coolant is distributed equally to each of the first end of the shaft and the second end of the shaft.

35. The electric motor of any one of claims 31 to 34, wherein fluid from the shaft outlet is supplied to a fourth flow channel configured to provide coolant to the rotor winding.

36. The electric motor of claim 35, wherein coolant exits the fourth flow channel to flow over the rotor winding, the coolant exiting from an opening that is circumferentially offset from the shaft outlet.

37. The electric motor of claim 36, wherein the fourth flow channel is configured as an annular flow channel that is axially and radially inside the rotor winding, and wherein the fourth flow channel extends between the shaft and a winding guide that is configured to support the rotor winding and that defines the opening to allow coolant to flow over the rotor winding.

38. The electric motor of any one of claims 26 to 37, further comprising an end cap configured to hold the coolant against the rotor winding.

39. The electric motor of claim 38, wherein the end cap defines a plurality of grooves configured to control the distribution of coolant over the rotor winding.

40. The electric motor of claim 38 or claim 39, wherein rotation of the rotor assembly causes coolant from the rotor winding to flow across an air gap between the rotor assembly and the stator assembly to provide coolant to the stator winding.-n-41 . The electric motor of any of claims 26 to 40 wherein the plurality of fins defines an outer surface configured to engage with walls of the interior cavity and a plurality of cutouts that correspond with the flow path.

42. The electric motor of any one of claims 26 41, wherein the cooling j acket further includes a protrusion configured to be received in a recess defined in the shaft to rotationally fix the cooling jacket with the shaft.

43. The electric motor of any one of claims 26 to 42, wherein the cooling jacket is configured to pump coolant along the flow path due to rotation of the rotor assembly.

44. An integrated drive unit comprising the electric motor according to any one of claims 26 to 43.

45. The integrated drive unit of claim 44, further comprising a transmission and an inverter unit, wherein the flow path is a portion of a shared coolant path extending through the transmission, inverter unit, and electric motor.

46. A rotor assembly, comprising: a shaft defining a rotor axis and an interior cavity; a rotor winding coupled to the shaft; a rotor chipset disposed within the interior cavity; and a bus bar extending through an opening defined in the shaft, the bus bar configured to couple the rotor winding to the rotor chipset.

47. The rotor assembly of claim 46, wherein the bus bar is secured in a retainer that is configured to be received in the interior cavity of the shaft and to electrically isolate the bus bar from the shaft.

48. The rotor assembly of claim 46 or claim 47, wherein the bus bar is disposed within a protrusion that is configured to be received in the opening in the shaft.

49. The rotor assembly of any one of claims 46 to 48, wherein the rotor chipset is disposed in a cooling jacket that is configured to control a flow of coolant through the shaft.

50. The rotor assembly of any one of claims 46 to 49, wherein a first end of the bus bar is configured to permanently couple to the winding and a second end of the bus bar includes a first terminal configured to releasably couple to a corresponding terminal of the rotor chipset.

51. A rotor assembly, comprising: a shaft including a flange disposed on an end of the shaft; a lamination stack; a rotor winding; and a balance ring configured to retain the rotor winding on the shaft, between the lamination stack and the balance ring, wherein the balance ring defines an inner lip and the flange is configured to deform over the inner lip to retain the rotor winding on the shaft.

52. The rotor assembly of claim 51, wherein the flange provides axial compression to the balance ring, the rotor winding, and the lamination stack, relative to a rotor axis defined by the shaft.

53. The rotor assembly of claim 51 or claim 52, further comprising a winding guide positioned between the rotor winding and the lamination stack to support the rotor winding.

54. The rotor assembly of any one of claims 52 to 53, further comprising an end cap configured to enclose the winding on the winding guide, the end cap positioned between the rotor winding and the balance ring.

55. The rotor assembly of claim 54, wherein the end cap and the winding guide form a cooling can configured to distribute coolant over the rotor winding.

56. The rotor assembly of claim 54 of claim 55, wherein the end cap and the winding guide configured to electrically isolate the rotor winding from the shaft and the balance ring.

57. A method of assembling a rotor, the method comprising: arranging a winding on a rotor shaft; and deforming a flange of the rotor shaft over a balance ring to secure the winding on the rotor shaft.

58. The method of claim 57, further comprising coupling a winding guide to the rotor shaft, the winding guide configured to support the winding on the rotor shaft.

59. The method of claim 58, further comprising coupling an end cap to the rotor shaft, the end cap configured to enclose the winding on the winding guide.

60. The method of any one of claims 57 to 59, further comprising inserting a rotor chipset assembly into an interior cavity of the rotor shaft.

61. The method of claim 60, further comprising inserting a rotor chipset in a cooling jacket to form the rotor chipset assembly.

62. The method of any one of claims 57 to 61, further comprising coupling a bus bar between the rotor winding and a rotor chipset.

63. A rotor assembly, comprising: a shaft defining a rotor axis; a lamination stack including a first pole and a second pole that are spaced apart to define a winding channel therebetween; a rotor winding positioned within the winding channel; and an insert that extends axially through the winding channel to direct coolant across the rotor winding.

64. The rotor assembly of claim 63 further comprising a winding j acket positioned in the winding channel to retain the rotor winding therein.

65. The rotor assembly of claim 63 or claim 64, wherein the rotor winding includes a first winding coupled to the first pole and a second winding coupled to the second pole, and wherein the insert is positioned between the first winding and the second winding within the winding channel.

66. The rotor assembly of claim 65, wherein the insert defines a first surface that faces the first winding and a second surfaces that faces the second winding, the first surface and the second surface each defining undulating profiles that are shaped to conform to the first winding and the second winding.

67. The rotor assembly of claim 66, wherein the first surface of the insert includes a channel to direct coolant axially along the rotor winding.

68. The rotor assembly of claim 67, wherein the channel extends in a direction that is substantially parallel with respect to the rotor axis.

69. The rotor assembly of any one of claims 66 to 68, wherein the first surface of the insert includes a second channel and a duct that extends between the first channel and the second channel at a non-zero angle relative to the rotor axis.

70. The rotor assembly of claim 69, wherein the duct is positioned to direct coolant radially outward at an axial center of the rotor winding.

71. The rotor assembly of claim 70, wherein the insert defines a midplane between a radially inner half and a radially outer half, and wherein the duct is one of a plurality of ducts including a first plurality of ducts disposed on the inner half of the insert and a second plurality of ducts disposed on the outer half of the insert.

72. The rotor assembly of claim 71, wherein the first plurality of ducts are configured to direct coolant radially outward and axially into the winding channel, and wherein the second plurality of ducts are configured to direct coolant radially outward and axially outward from the winding channel.

73. An insert for a rotor assembly having a winding channel, the insert comprising: a main body configured to extend in a first direction along the winding channel, the main body defining: a first channel extending in the first direction along the main body, a second channel extending in the first direction along the main body parallel to the first channel, and a first duct extending between the first channel and the second channel in a second direction that is at a non-zero angle relative to the first direction.

74. The insert of claim 73, wherein the first channel, the second channel, and the first duct are formed on a side of the insert that is shaped to conform with a rotor winding that is received in the winding channel.

75. The insert of claim 73 or claim 74, wherein the main body further defines: a third channel extending in the first direction along the main body parallel to the first channel, and a second duct extending between the first channel and the third channel, the first duct configured to direct a flow of fluid from a first end of the main body to a second end of the main body and the second duct configured to direct a flow of fluid from the second end of the main body toward the first end of the main body.

76. The insert of claim 75, wherein the main body defines a center between the first end and the second end, and each of the first duct and the second duct are positioned between the first end and the center.

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