Drive unit for an electric vehicle

Abstract

A drive unit for an electric vehicle is provided. One example provides a drive unit for an electric vehicle comprising a first housing section forming a first compartment housing an electric inverter and a second housing section forming a second compartment housing an electric motor. The drive unit housing further includes an inlet port for receiving fluid and a common wall separating the first and second compartments. The common wall defines a fluid path in fluid communication with the inlet port to circulate the fluid to cool the electric inverter. The drive unit also includes an outlet port in fluid communication with the fluid path to discharge the fluid.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 135,466, filed January 8, 2021, and U.S. Provisional Patent Application No. 63 / 135,474, filed January 8, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to electric vehicles, and in certain embodiments, to powertrain components of electric vehicles. Background Technology

[0004] Electric powertrain systems for electric vehicles, including electric sport vehicles (e.g., all-terrain vehicles (ATVs), personal boats (PWCs), and snowmobiles), typically include: a battery system; one or more electric motors, each with a corresponding electronic power inverter (sometimes called a motor controller); and various auxiliary systems (e.g., cooling systems). The efficiency of these system components in terms of size, weight, and energy consumption improves vehicle performance (e.g., responsiveness, range, and reliability) and cost, especially for electric sport vehicles where space and weight are critical. Summary of the Invention

[0005] Some embodiments of this disclosure relate to a drive unit housing that accommodates an inverter and an electric motor. Optionally, the drive unit housing may include a common wall separating the inverter and the electric motor into different compartments. Advantageously, the drive unit housing can provide a space-saving enclosure for the inverter and the electric motor, and can also improve performance by reducing the length of the electrical connection between the inverter and the electric motor.

[0006] One example provides a drive unit for an electric vehicle, the drive unit comprising: a housing having a first compartment and a second compartment separated from each other by a common wall; an electric inverter disposed in the first compartment and having a set of electrical output terminals; and an electric motor disposed in the second compartment and having electrical input terminals electrically connected to the output terminals via one or more openings extending through the common wall.

[0007] According to one example of this disclosure, a drive unit for an electric vehicle is provided. The drive unit includes a housing having a first compartment and a second compartment separated from each other by a common wall. The drive unit further includes: an electric inverter disposed in the first compartment and having a set of electrical output terminals; and an electric motor disposed in the second compartment and having electrical input terminals electrically connected to the output terminals via one or more openings extending through the common wall.

[0008] In some examples, the input terminal of the electric motor includes electrical leads extending through the one or more openings into the first compartment.

[0009] In some examples, the periphery of the housing is confined within a generally longitudinal form factor, with the first and second compartments axially arranged relative to each other along the longitudinal axis of the longitudinal form factor. The longitudinal form factor can typically be cylindrical. The inverter may include a set of solid-state switches providing electrical power to the electrical output terminals, the switches and output terminals being disposed within the first compartment such that the set of output terminals is axially aligned with the electrical input terminals of the electric motor to reduce the conductor length between the electric motor and the set of solid-state switches. Optionally, the electrical output terminals are arranged along an arc to be axially aligned with the electrical input terminals. The inverter may also include, or alternatively may include, a set of capacitors to receive DC power from a battery source, the capacitors being offset from the set of solid-state switches in the radial direction of the longitudinal form factor.

[0010] According to one example, a drive unit housing for an electric vehicle is provided. The housing includes a first housing section and a second housing section, the first housing section defining a first compartment for receiving an electric inverter, and the second housing section defining a second compartment for receiving an electric motor. The first housing section and the second housing section are detachably coupled to each other, wherein the first compartment and the second compartment are separated by a common wall.

[0011] In some examples, the peripheries of the first and second housing segments are confined within a generally longitudinal profile factor, wherein the first and second housing segments are axially arranged relative to each other along the longitudinal axis of the longitudinal profile factor. When the electric motor is disposed within the second compartment, the longitudinal axis of the longitudinal profile factor can be aligned with the axis of the rotor shaft of the electric motor.

[0012] In some examples, the first housing segment includes a generally tubular peripheral shell defining the outer periphery of the first compartment and having a first open end and a second open end. A common wall may be coupled to and close the first open end. The first housing segment may also include, or alternatively may include, a cover plate detachably coupled to the tubular peripheral shell to cover the second open end. Optionally, the common wall and the tubular peripheral shell comprise an integrally joined component. The cover plate may include electrical terminals for connection from the battery system to the inverter.

[0013] In some examples, the second housing segment includes: a generally tubular peripheral shell defining the outer periphery of the second compartment and having a first open end and a second open end; and a cover plate coupled to the first end and closing the first end. Optionally, when the tubular peripheral shell is coupled to the common wall, the common wall closes the second end.

[0014] In some examples, the common wall includes a bearing recess on the side facing the second compartment to receive the end of the rotor shaft of the electric motor.

[0015] In some examples, the first compartment includes a first compartment portion that houses the capacitors of the inverter and a second compartment portion that houses the power switching electronics and control electronics of the inverter.

[0016] In some examples, the common wall includes one or more openings extending through it to provide an electrical connection from the electric motor to the electric inverter. Power leads from the stator of the electric motor can reach the first compartment from the second compartment through the one or more openings.

[0017] According to one example of this disclosure, an electric vehicle is provided. The electric vehicle includes: a battery system; an inverter electrically connected to the battery system; an electric motor electrically connected to the inverter to propel the electric vehicle; and a housing having a first compartment for receiving the inverter and a second compartment for receiving the electric motor, the first and second compartments being separated by a common wall.

[0018] Some embodiments of this disclosure provide a drive unit that defines fluid paths to circulate fluid and / or cool an electric inverter and / or an electric motor. The fluid paths may be integrally formed within the drive unit so that they do not extend beyond the periphery of the drive unit. For example, the fluid paths may be formed in a common wall separating different compartments of the drive unit, in an outer wall of the drive unit housing, and / or in the rotor shaft of the electric motor. In this way, the fluid paths can effectively cool the drive unit without significantly increasing its overall footprint.

[0019] One example provides a drive unit housing for an electric vehicle, the drive unit housing including a first housing section and a second housing section, the first housing section having peripheral sidewalls forming a first compartment for receiving an electric inverter, and the second housing section having peripheral sidewalls forming a second compartment for receiving an electric motor. The first compartment is separated from the second compartment by a common wall containing fluid paths for fluid circulation to cool the electric inverter, and the peripheral sidewalls of the second housing section contain fluid paths for fluid circulation to cool the electric motor.

[0020] According to one example, a drive unit housing for an electric vehicle is provided. The housing includes: a first housing section forming a first compartment for receiving an electric inverter; a second housing section forming a second compartment for receiving an electric motor; an inlet port for receiving fluid; a common wall separating the first and second compartments, the common wall defining a fluid path in fluid communication with the inlet port to circulate the fluid to cool the electric inverter; and an outlet port in fluid communication with the fluid path to discharge the fluid.

[0021] In some examples, the fluid path of the common wall is a first fluid path, and the second housing segment includes a peripheral sidewall that defines a second fluid path in fluid communication with the inlet port to circulate the fluid and cool the electric motor. The first fluid path of the common wall may be connected in series with the second fluid path of the peripheral sidewall of the second housing segment between the inlet port and the outlet port. Optionally, the first fluid path and the second fluid path may form a continuous fluid path between the inlet port and the outlet port. This continuous fluid path may be contained within a longitudinal profile defined by the periphery of the drive unit housing.

[0022] In some examples, the peripheral sidewall of the second housing segment includes a cylindrical housing extending around the periphery of the stator of the electric motor, and the second fluid path extends around the outer periphery of the cylindrical housing. The second fluid path may extend spirally around the outer periphery of the cylindrical housing.

[0023] In some examples, the electric motor includes a hollow rotor shaft that defines a third fluid path in fluid communication with an input port to circulate the fluid and cool the electric motor. The first fluid path along the common wall and the second fluid path along the peripheral sidewall may be connected in series with the third fluid path along the hollow rotor shaft. Optionally, the first, second, and third fluid paths form a continuous fluid path between the inlet port and the outlet port.

[0024] In some examples, the common wall defines a bearing recess in which the end of the hollow rotor shaft is disposed. The common wall may include a tube extending from the bearing recess to be received within the end of the hollow rotor shaft, the tube and the end of the hollow rotor shaft forming at least a portion of the third fluid path.

[0025] In some examples, the periphery of the drive unit housing is confined within a generally longitudinal shape factor, with the first and second compartments axially arranged relative to each other along the longitudinal axis of the longitudinal shape factor. The longitudinal shape factor may be generally cylindrical and / or the common wall may be generally circular. The inlet and outlet ports are confined within the generally longitudinal shape factor. For example, the first housing segment may define a first recess and / or a second recess, with the inlet port disposed in the first recess and the outlet port disposed in the second recess.

[0026] In some examples, the inverter includes a capacitor mounted to the common wall, and the fluid path is arranged to first pass through the capacitor downstream of the inlet port.

[0027] In some examples, the first housing segment may be separable from the second housing segment.

[0028] According to one example of this disclosure, a drive unit for an electric vehicle is provided. The drive unit includes an inverter, an electric motor electrically connected to the inverter, and a housing. The housing includes: a first housing section having peripheral sidewalls forming a first compartment for receiving the inverter; a second housing section having peripheral sidewalls forming a second compartment for receiving the electric motor, the first and second compartments being separated from each other by a common wall; and a continuous fluid path extending through the first and second housing sections to circulate fluid for cooling the inverter and the electric motor.

[0029] According to one example of this disclosure, a method for cooling a drive unit of an electric vehicle is provided. The drive unit may include an inverter, an electric motor, and a housing, the inverter and the electric motor being disposed within the housing. The method includes: receiving fluid via an inlet port of the housing; circulating the fluid through a fluid path formed in a common wall of the housing to cool the inverter, the common wall separating a first compartment of the housing in which the inverter is disposed and a second compartment of the housing in which the electric motor is disposed; and discharging the fluid via an outlet port of the housing.

[0030] In some examples, the fluid path is a first fluid path, and the method includes circulating the fluid through a second fluid path formed in the peripheral sidewall of the housing to cool the electric motor.

[0031] Additional and / or alternative features and aspects of this technology will become apparent from the following description and accompanying drawings. Attached Figure Description

[0032] Figure 1 Examples illustrate electric vehicles, particularly electric sports vehicles, which include a drive unit according to an example of this disclosure.

[0033] Figure 2 A block diagram illustrating an electric vehicle that includes a drive unit according to this disclosure.

[0034] Figures 3A-3C A perspective view illustrating an example of a drive unit according to this disclosure.

[0035] Figure 4 An exploded view of a portion of a drive unit according to an example of this disclosure is provided for illustration.

[0036] Figure 5 A perspective view illustrating a portion of the inverter housing of a drive unit according to an example of this disclosure.

[0037] Figure 6 This is a cross-sectional view of a drive unit housing according to an example of this disclosure.

[0038] Figure 7 This is a cross-sectional view of a drive unit according to an example of this disclosure.

[0039] Figure 8 A perspective view illustrating a portion of the common wall of a drive unit housing according to an example of this disclosure.

[0040] Figure 9This is a schematic diagram illustrating a cross-sectional view of the hollow portion of a motor shaft according to an example of this disclosure.

[0041] Figures 10A-10B A perspective view illustrating a portion of a fluid circulation path network for circulating heat transfer fluid through a drive unit, according to an example of this disclosure.

[0042] Figure 11 A flowchart illustrating an example method according to this disclosure is provided. Detailed Implementation

[0043] In the following detailed description, reference is made to the accompanying drawings, which form part of the detailed description and illustrate specific examples in which the present disclosure may be practiced by way of example. It should be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not limiting. It should be understood that, unless otherwise specifically indicated, features of the various examples described herein may be combined with each other in part or in whole.

[0044] Electric powertrain systems for electric vehicles, including electric sports vehicles (e.g., motorcycles, all-terrain vehicles (ATVs), personal boats (PWCs), (e.g., side-by-side) universal task vehicles (UTVs), and snowmobiles), typically include: a battery system; one or more electric motors, each with a corresponding electronic power inverter (sometimes called a motor controller); and various auxiliary systems (e.g., a cooling system). The efficiency of these system components in terms of size, weight, and energy consumption improves vehicle performance (e.g., responsiveness, range, and reliability) and cost, especially for electric sports vehicles where space and weight are critical.

[0045] Figure 1 The general example illustrates an electric vehicle 10 including an electric drive unit 30 according to an example of this disclosure. Although illustrated as a snowmobile for illustrative purposes, the electric vehicle 10 can be other types of electric vehicles, including other types of sport vehicles such as personal boats (PWCs) and side-by-side vehicles. The electric vehicle 10 includes a seat 11 (shown as a straddle seat) to accommodate the operator of the electric vehicle 10. The electric vehicle 10 employs an electric power system 12 including a battery system 14, an electric motor 16, and an electronic power inverter 18 for controlling the electric motor 16. The power system 12 is configured to propel the electric vehicle by driving one or more wheels (e.g., in the case of a motorcycle, ATV, or UTV), by driving annular tracks (e.g., in the case of a snowmobile), or by driving a propeller or impeller (e.g., in the case of a PWC).

[0046] In some examples, the electric motor 16 may be a permanent magnet synchronous electric motor. The electric motor 16 may have a power output between 120 and 180 horsepower. Alternatively, the electric motor 16 may have a maximum output power greater than 180 horsepower. In some examples, the battery system 14 may comprise a rechargeable multi-cell lithium-ion battery or other types of batteries. The battery system 14 may comprise multiple battery modules, each containing multiple battery cells. For example, the battery cells may be pouch cells, cylindrical cells, and / or prismatic cells. The battery modules may be housed within a battery casing to protect them from impact, water, and / or debris. In some examples, the battery system 14 may be configured to output electrical power at, for example, between 300 and 400 volts or up to 800 volts.

[0047] According to one example of this disclosure, as will be described in more detail herein, the drive unit 30 includes a housing having a first compartment 22 and a second compartment 24 separated from each other by a common wall 26. In one example, as illustrated by the example, an inverter 18 is disposed in the first compartment 22 and a motor 16 is disposed in the second compartment 24. The housing 20 together with the motor 16 and inverter 18 disposed therein forms the drive unit 30 of the electric vehicle 10.

[0048] As will be described in more detail below, by housing the motor 16 and inverter 18 together within the housing 20, the drive unit 30 provides a volumetrically efficient form factor (e.g., a generally longitudinal form factor, such as a cylindrical form factor), which consumes less space within the electric vehicle 10. Additionally, the drive unit 30 provides a shortened conductor length between the output terminals of the inverter 18 and the input terminals of the motor 16, which reduces inductance and line losses (compared to a separately housed motor-inverter combination). Therefore, according to this disclosure, the drive unit 30 offers efficiency in both space and performance compared to conventional, separately housed motor-inverter combinations.

[0049] Figure 2The block diagram illustrating an example of an electric vehicle 10 provides a general example, wherein, in addition to including an electric powertrain 12 employing a drive unit 30, the electric vehicle 10 further includes a thermal management system 32. In one example, the thermal management system 32 manages the temperature (e.g., cooling) of the components of the electric powertrain 12, including the battery system 14, the motor 16, and the inverter 18. The thermal management system 32 can be a closed-loop cooling system and / or an open-loop cooling system. The thermal management system 32 can utilize a liquid-to-liquid cooling system (e.g., in the case of PWC), a snow-to-liquid cooling system (e.g., in the case of a snowmobile), an air-to-liquid cooling system (e.g., using a radiator), or a combination thereof. According to an example of this disclosure, as will be described in more detail below, the housing 20 of the drive unit 30 includes a fluid circulation path network 34, through which heat transfer fluid circulates, as indicated by arrow 36, to manage the temperature of the motor 16 and the inverter 18.

[0050] Figures 3A-3C Example illustration: a perspective view of the drive unit 30 according to the example of this disclosure. Figure 4 The following is an exploded view illustrating a portion of a drive unit 30 according to one example. In some examples, housing 20 includes a first housing section 40 forming a first compartment 22 for accommodating an inverter 18, and a second housing section 42 forming a second compartment 24 for accommodating an electric motor 16. The first housing section 40 and the second housing section 42 may each include at least some walls or other structural members of housing 20. Although the first housing section 40 and the second housing section 42 form the first compartment 22 and the second compartment 24, respectively, the first housing section 40 and the second housing section 42 may not completely enclose the first compartment 22 and the second compartment 24.

[0051] In one example, the periphery of housing 20 is constrained by a generally longitudinal shape factor 44 (in Figure 3A Within the (diagrammatically represented by dashed lines) shape, the first housing segment 40 and the second housing segment 42, which respectively form the first compartment 22 and the second compartment 24, are arranged longitudinally relative to each other within the shape factor. In one example, as illustrated by the example, the shape factor 44 is generally cylindrical, wherein the first housing segment 40 and the second housing segment 42 are arranged longitudinally relative to each other along the longitudinal axis 48 of the generally cylindrical shape factor 44. The common wall 26 is generally circular. In one example, the longitudinal axis 48 of the shape factor 44 generally coincides with the longitudinal axis of the shaft 46 of the motor 16 (i.e., the rotor shaft) (which extends from the second housing segment 42). In the example, as described below, the first housing segment 40 and the second housing segment 42 are separable from each other.

[0052] In one example, the first housing segment 40 includes a common wall 26 that provides a base for the first housing segment 40 and is disposed transverse to the longitudinal axis 48 of the profile factor 44. The common wall 26 may be integrally formed with the first housing segment 40. In one example, the common wall 26 is generally circular, but any suitable shape may be adopted. The first housing segment 40 further includes a peripheral sidewall shell 50. In one example, as illustrated by the example, the peripheral sidewall shell 50 is annular or strip-shaped to form a generally tubular or circumferentially extending peripheral sidewall. In one example, the annular or strip-shaped peripheral sidewall shell 50 may be formed by partial or continuous curved wall segments, or it may be formed by a plurality of straight wall segments extending from the common wall 26, which together form the annular or strip-shaped peripheral sidewall shell 50. In one example, the peripheral sidewall housing 50 extends orthogonally from the common wall 26 and longitudinally relative to the profile factor 44, wherein the common wall 26 and the circumferentially extending sidewall 50 together are generally canister-shaped or cup-shaped to form a first compartment 22 for accommodating the inverter 18. An end cap 52 is detachably coupled to the sidewall housing 50 to surround the first compartment 22.

[0053] In one example, the second housing segment 42 includes a peripheral sidewall housing 54, which is detachably coupled to a common wall 26, for example via a plurality of fasteners 55 (e.g., screws or bolts) arranged around the peripheral sidewall housing 50 of the first housing segment 40. In one example, the peripheral sidewall housing 54 is annular or tubular to form a generally tubular or circumferentially extending peripheral sidewall. In one example, the peripheral sidewall housing 54 extends orthogonally from the common wall 26 and longitudinally relative to a shape factor 44, wherein the common wall 26 serves as the base of the second housing segment 42, and the common wall 26 and the peripheral sidewall housing 54 together are drum-shaped to form a second compartment 24 for receiving the motor 16. An end cap 56 is detachably coupled to the end of the peripheral sidewall housing 54 opposite to the common wall 26 to surround the second compartment 24. Alternatively, the end cap 56 may be integrally formed with the sidewall housing 54 of the second housing section 42, such that the common wall 26 serves as an end plate for surrounding the second compartment 24.

[0054] Although the common wall 26 is described as part of the first housing segment 40, in other examples, the common wall 26 may be part of the second housing segment 42. In other examples, the common wall 26 may be separable from both the first housing segment 40 and the second housing segment 42.

[0055] In one example, end cap 52 includes positive and negative DC connection terminals 60 and 62 extending therethrough for capacitors of inverter 18 (see [link]). Figure 7 The 120 in the middle) to the battery system 14 (see Figure 1 and 2 Electrical connections. In one example, end cap 52 includes electrical connector 64 for connecting low voltage and control signals to the control circuitry of inverter 18 (see [link]). Figure 7 (124 in the middle).

[0056] In one example, as will be described in more detail below, the first housing section 40 includes an inlet fluid port 66 and an outlet fluid port 68 (see [link to documentation]). Figure 3B-3C A fluid path 66 is used to connect the fluid path of the thermal management system 32 to the fluid path within the housing 20 of the drive unit 30 for cooling the motor 16 and the inverter 18. An inlet 66 can receive fluid from the thermal management system 32, and an outlet 68 can discharge fluid back into the thermal management system 32. It should be noted that in other examples, the inlet fluid port 66 and the outlet fluid port 68 may be reversed, and in other examples, more than one inlet fluid port and / or outlet fluid port may be used. In one example, as illustrated by the example, the sidewall housing 50 includes recesses 70 and 72, wherein the inlet fluid port 66 and the outlet fluid port 68 are respectively disposed in said recesses 70 and 72 such that the inlet fluid port 66 and the outlet fluid port 68 are positioned within the range of form factor 44.

[0057] In one example, such as Figure 3A As illustrated, a plurality of channels 73 extend circumferentially around the sidewall housing 54 of the second housing section 42. When the housing sleeve 75 is disposed around the outer periphery of the sidewall housing 54, the channels 73 become fluid paths 74 extending around the outer periphery of the second housing section 42 (see [link to example]). Figure 6 ), wherein such a fluid path 74 is part of a fluid path network 34, and fluid 36 passes through a thermal management system 32 (see Figure 2 The fluid path network 34 circulates to cool the motor 16. In some examples, the fluid path 74 may form a continuous spiral around the sidewall housing 54. In other examples, the fluid path 74 may be separate paths arranged parallel to each other. In still other examples, the fluid path 74 may be a continuous path with a zigzag configuration. Any number of suitable implementations may be employed.

[0058] Now for reference Figure 4 , Figure 4 The example illustrates that end cap 52 is removed from the sidewall housing 50 of the first housing section 40, and shows the first housing compartment 22 and the second housing compartment 24. The motor 16 includes a rotor 76 and a stator 78, which are disposed within the second compartment 24 of the second housing section 42. This will be described in more detail below (see...). Figure 9The end 80 of shaft 46 facing the common wall 26 is hollow so that heat transfer fluid can circulate through it to cool motor 16. A set of electrical input leads 84 extends from stator 78 for connection to inverter 18 in compartment 22 of first housing section 40.

[0059] In one example, the first compartment 22 of the first housing section 40 includes a first compartment portion 90 for accommodating the capacitors of the inverter 18, and electronic control components and switching components (e.g., insulated gate bipolar transistors) (IGBTs) for accommodating the inverter 18 (see [link]). Figure 7 The second compartment portion 92 (122 and 124 in the diagram). In one example, one or more openings 94 extend through the common wall 26 to enable electrical connection between the input leads 84 of the stator 78 and the output terminals of the inverter 18. In one example, the input leads 84 from the stator 78 extend through the openings 94 into the second compartment portion 92 for connection to the output terminals of the inverter 18. In other examples, the output terminals of the inverter 18 may extend through the openings 94 into the second housing section 42 for connection to the input leads 84 of the stator 78.

[0060] Figure 5 A perspective view of the first housing section 40 is shown for illustration, with the end cap 52 removed. In one example, the input power lead 84 of the stator 78 extends through a set of openings 94 in the common wall 26 and terminates at a set of terminals 96 (illustrated as terminals 96a, 96b, and 96c) in the second compartment section 92. Sensor wiring 98 extends from the motor 16 through the common wall 26 to the inverter control electronics. This is achieved by extending through a set of openings 94 in the common wall 26 (see also...) Figure 8 The inverter 18 is aligned with the input leads 84 and terminals 96 of the stator 78, reducing the length of the conductor path between the inverter 18 and the stator 78. This, in turn, reduces inductance and power loss, thereby improving the electrical efficiency of the drive unit 30.

[0061] As discussed in further detail elsewhere herein, housing 20 includes a network of fluid paths 34 (also referred to as a fluid network) extending therethrough for cooling motor 16 and inverter 18. In one example, in addition to inlet port 66 and outlet port 68, fluid path network 34 includes a fluid chamber 100 in a common wall 26, the fluid chamber 100 having a fluid inlet 102 and a fluid outlet 104 connecting the fluid chamber 100 to other portions of fluid path network 34. It should be noted that, in Figure 5 The cover on the fluid chamber 100 is not shown. In one example, a power switching network (e.g., an IGBT) is mounted above the fluid chamber 100 to a common wall 26 for cooling by circulating fluid through the fluid chamber 100.

[0062] Figure 6 According to an example cross-sectional view of housing 20, the sidewall housing 50 of the first housing segment 40 extends continuously and integrally from the common wall 26 and forms a first compartment 22 together with the end cap 52. The first compartment 22 includes a first compartment portion 90 for housing capacitors of the inverter 18, and a second compartment portion 92 for housing control electronics and switching electronics of the inverter 18. In one example, the common wall 26 includes a bearing recess 110 facing the second compartment 24, wherein the bearing recess 110 is for receiving the end 80 of the shaft 46 of the electric motor 16 and heat transfer fluid circulates through the bearing recess 110, as described below.

[0063] The sidewall housing 54 and end cap 56 of the second housing section 42, together with the common wall 26, form a second compartment 24. The end cap 56 includes a bearing recess 112 for receiving the opposite end of the shaft 46 of the motor 16 and a hole 114 extending therefrom. Gaskets 116 and 118 form a seal between the common wall 26 and the sidewall housing 54 to seal the second compartment 24, and a seal between the end cap 52 and the sidewall housing 50 to seal the first compartment 22.

[0064] Figure 7 This is a cross-sectional view of a drive unit 30 according to an example. The DC capacitor 120 of the inverter 18 is disposed in the first compartment portion 90, while the power switching network 122 and control electronics 124 of the inverter 18 are disposed in the second compartment portion 92. The input power lead 84 from the stator 78 of the motor 16 extends through the common wall 26 and terminates at a terminal 96 in the second compartment portion 92. The motor 16 is disposed within the second compartment 24, wherein the hollow end 80 of the shaft 46 is disposed within a bearing recess 110 of the common wall 26.

[0065] Figure 8 For illustrative purposes, a perspective view of a portion of a first housing section 40 facing a second (motor) compartment 24 is provided, comprising a common wall 26 and a sidewall housing 50. In one example, as illustrated, the sidewall housing 50 extends continuously from the common wall 26 such that the common wall 26 and the sidewall housing 50 form a single base member of the first housing section 40. Multiple ribs (e.g., ribs 130) extend from the inner surface of the sidewall housing 50 to support a central hub 132, which includes bearing recesses 110 for supporting the hollow end 80 of a shaft 46 of a motor 16. Also illustrated is a set of openings 94 through the common wall 26, exemplified as openings 94a-94c arranged along an arc to connect with the input leads 84 of the stator 78 (see [link to original text]). Figure 4Alignment. Although three openings 94a-94c are shown in the figure, this is merely exemplary. In one example, the common wall 26 may contain a single opening 94 for the input lead 84 and terminal 96, or any other suitable number of openings 94.

[0066] In one example, end wall 26 includes a portion of a fluid path network 34 through which heat transfer fluid circulates to cool components of motor 16 and inverter 18. The fluid path network 34 (see Figure 10), which will be described in more detail below, includes an inlet port 66 and an outlet port 68, and a fluid chamber 100 having an inlet 102 and an outlet 104 (see Figure 100). Figure 5 In one example, network 34 further includes tube 134, which extends within hub 132 and will be described below (see [link to documentation]). Figure 9 The fluid extends into the hollow end 80 of the shaft 46 to form an inlet fluid path and an outlet fluid path within the shaft 46, so that the heat transfer fluid can circulate therein to cool the motor 16.

[0067] Figure 9 This is a schematic diagram illustrating the circulation of heat transfer fluid within the hollow end 80 of shaft 46 as a general example. As illustrated, a tube 134 extends from a bearing recess 110 (located within hub 132) into the hollow end 80 of shaft 46 to form an inlet fluid path 136 within the tube 134 and an outlet fluid path 138 between the outer wall of the tube 134 and the inner wall of shaft 46. Thus, the tube 134 and the hollow end 80 of shaft 46 form fluid paths within shaft 46. In one example, the inlet fluid path 136 and the outlet fluid path 138 are in fluid communication with fluid paths 140 and 142 of fluid path network 34 (see Figure 10 below), respectively.

[0068] Figure 10A and 10B A perspective view illustrating a portion of a fluid path network 34 for circulating heat transfer fluid through housing 20 to cool components of motor 16 and inverter 18, according to an example. Figure 10A and 10B The example illustrates the network 34 as seen from the second (motor) compartment 24 and the first (inverter) compartment 22, respectively.

[0069] In one example, as illustrated, the heat transfer fluid is received via inlet port 66 and travels through path 140 to inlet fluid path 136 within pipe 134 inside shaft 46 (see example 136). Figure 9The fluid then travels through outlet fluid path 138 and exits shaft 46 via fluid path 142, which is concentrically arranged around end 80 of shaft 46. The fluid then travels through fluid path 144 to cool DC capacitor 120 of inverter 18 (see...). Figure 7 The fluid path 144 near the first compartment portion 90 of the first compartment 22 forms a fan-shaped semi-circular path along or within the common wall 26.

[0070] Then, fluid enters chamber 100 through inlet opening 102, where the fluid in chamber 100 cools the power switching network 122 and control electronics 124 of the inverter 18 located in the second compartment portion 92 of the first compartment 22 (see [link]). Figure 7 Then, the fluid leaves the chamber 100 via the outlet opening 104 and travels through the fluid path 146 to the fluid path 74 circumferentially disposed around the sidewall housing 54 surrounding the second housing section 42 to cool the motor 16 (see, for example, see...). Figure 3A and 7 Then, the fluid leaves fluid path 74 and reaches outlet port 68.

[0071] In one example, the fluid path network 34 forms a continuous fluid path through the housing 20, such that the components of the drive unit 30 are cooled in series (e.g., shaft 46, capacitor 120, power switching network 122, and motor stator 78). In one example, the fluid path of the common wall 26 is connected in series with the fluid path of the peripheral sidewall 54 of the second housing section 42 between the inlet port 66 and the outlet port 68. In one example, the fluid paths of the common wall 26 and the peripheral sidewall 54 of the second housing section 42 are connected in series with the fluid path within the hollow end 80 of the shaft 46 of the electric motor 16.

[0072] By employing a single continuous cooling loop, the cooling system is simplified (compared to systems using parallel paths), allowing the fluid path network 34 of this disclosure to provide high efficiency and require fewer components compared to known systems. Furthermore, positioning the fluid path network 34 within the housing 20 (i.e., within the form factor 44), including providing the inlet port 66 and outlet port 68 on the end cap 52 of the first housing section 40, maintains the periphery of the drive unit 30 within the generally longitudinally extending form factor 44 (see [link to documentation]). Figure 3A As mentioned above, such a form factor is efficient in terms of volume and provides improved installation convenience in electric vehicles (especially electric sports vehicles).

[0073] It should be noted that the fluid path network 34 specifically described herein is for illustrative purposes and represents only one exemplary implementation of the fluid path network 34. In the illustrated example, the fluid path network 34 travels from the inlet port 66 to the shaft 46, to a channel within the common wall 26, to a circumferentially arranged path 74 in the sidewall housing 54, and finally to the outlet port 68. In other examples, the configuration of the fluid path network 34 and the order in which the components are cooled may differ from those exemplified herein. In another example, the fluid path network 34 may travel from the inlet port 66 to a channel within the common wall 26, to the shaft 46, and to a circumferentially arranged path 74 in the sidewall housing 54, such that the components of the inverter 18 are cooled before the components of the motor. For example, the fluid path network 34 may be implemented such that heat transfer fluid is first directed to cool the DC capacitor 120 of the inverter 18, because such a capacitor may have limited thermal tolerance. Any number of configurations are possible. Furthermore, in some examples, one or more paths in the fluid path network may be omitted. For example, the fluid path network can omit the fluid path in axis 46. The fluid path can travel from inlet port 66 to a channel within common wall 26, to a circumferentially arranged path 74 in sidewall housing 54, and finally to outlet port 68.

[0074] The housing 20 may be made wholly or partially of metal, metal alloy, composite material, and / or plastic. Similarly, the channels / paths of the fluid path network 34 may be made wholly or partially of metal, metal alloy, composite material, and / or plastic. It should be further noted that the components of the housing 20 (including the channels / paths of the fluid path network 34) can be manufactured according to any known technology, including machining, casting, and 3D printing.

[0075] In one example, the profile factor 44 of the housing 20 of the drive unit 30 for a sports vehicle 10 can have a length of 10 cm to 30 cm and a diameter or width of 20 cm to 30 cm. In one example, the thickness of the common wall 26 can be between 3 mm and 8 mm, which provides sufficient thickness to accommodate the channel 144 and the chamber 100. It should be understood that the profile factor 44 and the thickness of the common wall 26 can have any suitable dimensions, and these dimensions can vary depending on the application and power requirements of the drive unit 30.

[0076] Figure 11The flowchart illustrates, for example, a method 200 for cooling components of a drive unit according to an example of this disclosure. Method 200 may be performed, for example, by a drive unit housing (e.g., housing 20). Block 202 includes receiving fluid via an inlet port of the housing. For example, block 202 may include an inlet 66 for receiving fluid. Block 204 includes circulating the fluid. In some examples, the fluid is circulated through fluid paths formed in the housing to cool an inverter and / or an electric motor. For example, block 204 may include circulating fluid through fluid paths formed in a common wall (e.g., common wall 26) of the housing to cool the inverter. The common wall may separate a first compartment of the housing in which the inverter is disposed and a second compartment of the housing in which the electric motor is disposed. Alternatively or additionally, block 204 may include circulating fluid through fluid paths formed in a peripheral sidewall of the housing (e.g., peripheral sidewall housing 54) to cool the electric motor. Alternatively or additionally, block 204 may include a fluid path that circulates fluid through a rotor shaft (e.g., shaft 46) formed in the electric motor to cool the electric motor. Block 206 includes an outlet port of the housing, such as outlet port 68, to discharge fluid.

[0077] Although specific examples have been illustrated and described herein, various alternative and / or equivalent implementations may be used instead of the specific examples shown and described without departing from the scope of this disclosure. This application is intended to cover any modifications or variations of the specific examples discussed herein.

[0078] Exemplary embodiments of this disclosure will now be provided.

[0079] Exemplary Example 1: A drive unit for an electric vehicle, comprising:

[0080] A housing having a first compartment and a second compartment separated from each other by a common wall; an inverter disposed in the first compartment and having a set of electrical output terminals; and an electric motor disposed in the second compartment and having electrical input terminals electrically connected to the electrical output terminals via one or more openings extending through the common wall.

[0081] Exemplary Example 2: According to the drive unit of Exemplary Example 1, the electrical input terminal of the electric motor includes an electrical lead extending through the one or more openings into the first compartment.

[0082] Exemplary Example 3: According to the drive unit of Exemplary Example 1, the periphery of the housing is confined within a generally longitudinal shape factor, and the first compartment and the second compartment are axially arranged relative to each other along the axis of the longitudinal shape factor.

[0083] Exemplary Example 4: According to the driving unit of Exemplary Example 3, the longitudinal shape factor is approximately cylindrical.

[0084] Exemplary Example 5: According to the drive unit of Exemplary Example 1, the inverter includes a set of solid-state switches that provide electrical power to the electrical output terminals. The switches and the electrical output terminals are disposed in the first compartment such that the set of electrical output terminals are axially aligned with the electrical input terminals of the electric motor to minimize the conductor length between the electric motor and the set of solid-state switches.

[0085] Exemplary Example 6: According to the driving unit of Exemplary Example 5, the electrical output terminals are arranged along an arc to be axially aligned with the electrical input terminals.

[0086] Exemplary Example 7: According to the drive unit of Exemplary Example 5, the inverter includes a set of capacitors to receive DC power from a battery source, the capacitors being laterally offset from the set of solid-state switches along the radial direction of the cylindrical profile factor.

[0087] Exemplary Example 8: A drive unit housing for an electric vehicle, comprising: a first housing section defining a first compartment for receiving an electric inverter; and a second housing section defining a second compartment for receiving an electric motor, the first housing section and the second housing section being separably coupled to each other, wherein the first compartment and the second compartment are separated by a common wall.

[0088] Exemplary Example 9: According to the drive unit housing of Exemplary Example 8, the first housing segment includes the common wall.

[0089] Exemplary Example 10: A drive unit housing according to Exemplary Example 8, wherein the peripheries of the first housing segment and the second housing segment are confined within a generally longitudinal profile factor, wherein the first housing segment and the second housing segment are axially disposed relative to each other along the axis of the longitudinal profile factor.

[0090] Exemplary Example 11: According to the drive unit housing of Exemplary Example 10, when the electric motor is disposed in the second compartment, the axis of the longitudinal profile factor is aligned with the axis of the rotor shaft of the electric motor.

[0091] Exemplary Example 12: According to the drive unit housing of Exemplary Example 8, the first housing segment includes: a tubular peripheral housing defining the outer periphery of the first compartment and having a first open end and a second open end; the common wall coupled to the first open end and closing the first open end; and a cover plate detachably coupled to the tubular peripheral housing to cover the second open end.

[0092] Exemplary Example 13: According to the drive unit housing of Exemplary Example 12, the common wall and the tubular peripheral housing include connected components.

[0093] Exemplary Example 14: According to the drive unit housing of Exemplary Example 12, the cover plate includes electrical terminals for connecting from the battery system to the inverter unit.

[0094] Exemplary Example 15: According to the drive unit housing of Exemplary Example 8, the second housing segment includes: a tubular peripheral outer shell defining the outer periphery of the second compartment and having a first open end and a second open end; and a cover plate connected to the first end and closing the first end.

[0095] Exemplary Example 16: According to the drive unit housing of Exemplary Example 15, when the tubular peripheral outer shell is connected to the common wall, the common wall closes the second end.

[0096] Exemplary Example 17: According to the drive unit housing of Exemplary Example 8, the common wall includes a bearing recess on the side facing the second compartment to receive the end of the rotor shaft of the electric motor.

[0097] Exemplary Example 18: According to the drive unit housing of Exemplary Example 8, the first compartment includes a first compartment portion that houses the capacitors of the inverter and a second compartment portion that houses the power switching electronics and control electronics of the inverter.

[0098] Exemplary Example 19: According to the drive unit housing of Exemplary Example 8, the common wall includes one or more openings extending therethrough to provide an electrical connection of the electric motor to the electric inverter.

[0099] Exemplary Example 20: A drive unit housing according to Exemplary Example 19, wherein electrical power leads from the stator of the electric motor pass through the one or more openings from the second compartment to the first compartment.

[0100] Exemplary Example 21: A drive unit housing for an electric vehicle, comprising: a first housing section having a peripheral sidewall forming a first compartment to accommodate an electric inverter; and a second housing section having a peripheral sidewall forming a second compartment to accommodate an electric motor, the first compartment being separated from the second compartment by a common wall, the common wall including a fluid path for fluid circulation to cool the electric inverter, and the peripheral sidewall of the second housing section including a fluid path for fluid circulation to cool the electric motor.

[0101] Exemplary Example 22: According to the housing of Exemplary Example 21, the fluid path of the common wall is connected in series with the fluid path of the peripheral sidewall of the second housing segment between the fluid inlet port and the fluid outlet port.

[0102] Exemplary Example 23: According to the housing of Exemplary Example 22, the fluid paths of the common wall and the peripheral sidewalls are connected in series with the fluid path in the hollow rotor shaft of the electric motor disposed in the second housing section.

[0103] Exemplary Example 24: According to Exemplary Example 21, the periphery of the housing is confined within a generally longitudinal shape factor, and the first compartment and the second compartment are axially disposed relative to each other along the axis of the longitudinal shape factor.

[0104] Exemplary Example 25: According to the driving unit of Exemplary Example 24, the longitudinal profile factor is approximately cylindrical.

[0105] Exemplary Example 26: According to the drive unit of Exemplary Example 21, the first housing segment includes the common wall.

[0106] Exemplary Example 27: According to the driving unit of Exemplary Example 21, the first housing segment can be separated from the second housing segment.

[0107] Exemplary Example 28: A drive unit for an electric vehicle includes: a housing comprising: a first housing section having peripheral sidewalls forming a first compartment; and a second housing section having peripheral sidewalls forming a second compartment, the first and second compartments being separated from each other by a common wall; an electric inverter disposed in the first compartment, the electric inverter including inverter components mounted to the common wall; and an electric motor disposed in the second compartment, the common wall including fluid paths for fluid circulation to cool the electric inverter and the peripheral sidewalls of the second housing section including fluid paths for fluid circulation to cool the electric motor.

[0108] Exemplary Example 29: According to the drive unit of Exemplary Example 28, the electric motor includes a hollow rotor shaft having an inlet fluid path and an outlet fluid path to allow fluid to circulate through the shaft to cool the electric motor, the end of the rotor shaft being disposed in a bearing recess on the common wall, and the inlet fluid path and the outlet fluid path being in fluid communication with the fluid path of the common sidewall via the end of the rotor shaft.

[0109] Exemplary Example 30: According to the drive unit of Exemplary Example 29, the fluid path of the common wall, the inlet fluid path and the outlet fluid path of the rotor shaft, and the fluid path of the peripheral sidewall of the second housing section form a continuous fluid path between the fluid inlet port and the fluid outlet port.

[0110] Exemplary Example 31: According to the drive unit of Exemplary Example 30, the electric inverter includes a set of capacitors mounted to the common wall, and the fluid path is arranged to first pass through the capacitor downstream of the fluid inlet port.

[0111] Exemplary Example 32: According to the drive unit of Exemplary Example 27, the peripheral sidewall of the second housing segment includes a cylindrical housing extending around the periphery of the stator segment of the electric motor, and the fluid path extends around the outer periphery of the cylindrical housing.

[0112] Exemplary Example 33: According to the driving unit of Exemplary Example 32, the fluid path extends in a spiral manner around the outer periphery of the cylindrical housing.

[0113] Exemplary Example 34: According to the drive unit of Exemplary Example 28, the periphery of the housing is confined within a generally longitudinal shape factor, and the first compartment and the second compartment are axially arranged relative to each other along the axis of the longitudinal shape factor.

[0114] Exemplary Example 35: According to the driving unit of Exemplary Example 34, the longitudinal profile factor is approximately cylindrical.

[0115] Exemplary Example 36: A drive unit housing for an electric vehicle, comprising: a first housing section having a peripheral sidewall forming a first compartment for accommodating an electric inverter; and a second housing section having a peripheral sidewall forming a second compartment for accommodating an electric motor, the first compartment being separated from the second compartment by a common wall, the first housing section and the second housing section having a periphery limited within a generally longitudinal profile factor and axially disposed relative to each other along an axis of the longitudinal profile factor; and a continuous fluid path extending through the first housing section and the second housing section between an inlet port and an outlet port to circulate fluid to cool the electric inverter and the electric motor.

[0116] Exemplary Example 37: According to the drive unit housing of Exemplary Example 36, the continuous fluid path includes a portion disposed in a common sidewall.

[0117] Exemplary Example 38: According to the drive unit housing of Exemplary Example 36, the continuous fluid path is connected in series with the fluid path within the hollow rotor shaft of the electric motor.

[0118] Exemplary Example 39: According to the drive unit housing of Exemplary Example 38, the continuous fluid path is in fluid communication with the fluid path within the hollow rotor shaft via a portion of the fluid path disposed within the common wall.

[0119] Exemplary Example 40: According to the drive unit of Exemplary Example 36, the continuous fluid path includes a spiral path arranged around the periphery of the second housing segment to cool the electric motor.

Claims

1. A drive unit housing (20) for an electric vehicle (10), comprising: A first housing section (40) forms a first compartment (22) for accommodating an inverter (18), the inverter including a capacitor and a power switching network; The second housing section (42) forms a second compartment (24) for accommodating an electric motor (16). The inlet port (66) for receiving fluid; A common wall (26) separates the first compartment (22) and the second compartment (24), the common wall (26) providing a base for the first housing section (40) to form the first compartment (22), the common wall (26) providing a base for the second housing section (42) to form the second compartment (24), the common wall (26) defining a fluid path (34) in fluid communication with the inlet port (66) to allow the fluid to circulate to cool the inverter (18), the fluid path (34) including a fluid channel and a fluid chamber (100), wherein fluid flows through the fluid channel to cool the capacitor and then enters the fluid chamber (100) to cool the power switching network; as well as An outlet port (68) is in fluid communication with the fluid path (34) to discharge the fluid.

2. The drive unit housing according to claim 1, wherein, The fluid path of the common wall is a first fluid path, and the second housing section includes a peripheral sidewall that defines a second fluid path in fluid communication with the inlet port to allow the fluid to circulate and cool the electric motor.

3. The drive unit housing according to claim 2, wherein the first fluid path of the common wall is connected in series with the second fluid path of the peripheral sidewall of the second housing segment between the inlet port and the outlet port.

4. The drive unit housing according to claim 3, wherein the first fluid path and the second fluid path form a continuous fluid path between the inlet port and the outlet port.

5. The drive unit housing according to claim 4, wherein the continuous fluid path is contained within a longitudinal shape factor defined by the periphery of the drive unit housing.

6. The drive unit housing according to any one of claims 2 to 5, wherein the peripheral sidewall of the second housing segment comprises a cylindrical housing extending around the periphery of the stator of the electric motor, and the second fluid path extends around the outer periphery of the cylindrical housing.

7. The drive unit housing according to claim 6, wherein the second fluid path extends in a spiral manner around the outer periphery of the cylindrical housing.

8. The drive unit housing according to any one of claims 2 to 5, wherein the electric motor includes a hollow rotor shaft defining a third fluid path in fluid communication with the inlet port to circulate the fluid to cool the electric motor.

9. The drive unit housing according to claim 8, wherein the first fluid path of the common wall and the second fluid path of the peripheral sidewall are connected in series with the third fluid path of the hollow rotor shaft.

10. The drive unit housing according to claim 9, wherein the first fluid path, the second fluid path, and the third fluid path form a continuous fluid path between the inlet port and the outlet port.

11. The drive unit housing according to claim 8, wherein the common wall defines a bearing recess, and the end of the hollow rotor shaft is disposed in the bearing recess.

12. The drive unit housing of claim 11, wherein the common wall includes a tube extending from the bearing socket to be received within an end of the hollow rotor shaft, the tube and the end of the hollow rotor shaft forming at least a portion of the third fluid path.

13. The drive unit housing according to any one of claims 1 to 5, wherein the periphery of the drive unit housing is confined within a generally longitudinal shape factor, and the first compartment and the second compartment are axially disposed relative to each other along the longitudinal axis of the longitudinal shape factor.

14. The drive unit housing according to claim 13, wherein the longitudinal shape factor is a generally cylindrical shape.

15. The drive unit housing according to claim 14, wherein the common wall is generally circular in shape.

16. The drive unit housing according to claim 13, wherein the inlet port and the outlet port are confined within the generally longitudinal shape factor.

17. The drive unit housing according to claim 16, wherein the first housing segment defines a first recess and a second recess, the inlet port is disposed in the first recess, and the outlet port is disposed in the second recess.

18. The drive unit housing according to any one of claims 1 to 5, wherein: The capacitor is mounted to the common wall, and the fluid path is arranged to first pass through the capacitor downstream of the inlet port; and The power switching network is mounted to the common wall above the fluid chamber.

19. The drive unit housing according to any one of claims 1 to 5, wherein: The first housing section can be separated from the second housing section; and The common wall is integrally formed with the first shell section.

20. A drive unit for an electric vehicle, comprising: Electric inverter; An electric motor electrically connected to the inverter; as well as Housing, the housing comprising: A first housing section having peripheral sidewalls forming a first compartment for accommodating the inverter, the inverter including capacitors and a power switching network; A second housing section having peripheral sidewalls forming a second compartment for accommodating the electric motor; the first and second compartments are separated from each other by a common wall, the common wall providing a base for the first housing section to form the first compartment and for the second housing section to form the second compartment; as well as A continuous fluid path extends through the first housing section and the second housing section to circulate fluid to cool the electric inverter and the electric motor. The continuous fluid path includes a fluid channel and a fluid chamber, wherein fluid flows through the fluid channel to cool the capacitor and then enters the fluid chamber to cool the power switching network.

21. A method for cooling a drive unit for an electric vehicle, the drive unit comprising a drive unit housing according to claim 1, the method comprising: Fluid is received via the inlet port of the drive unit housing; The fluid is circulated through a fluid path formed in a common wall of the drive unit housing to cool the electric inverter. The common wall separates a first compartment of the drive unit housing in which the electric inverter is disposed and a second compartment of the drive unit housing in which the electric motor is disposed. The common wall provides a base for the first housing section and a base for the second housing section. as well as The fluid is discharged through the outlet port of the drive unit housing.

22. The method according to claim 21, wherein, The fluid path is a first fluid path, and the method includes circulating the fluid through a second fluid path formed in the peripheral sidewall of the drive unit housing to cool the electric motor.

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