Method and apparatus for cooling a rotor assembly

Abstract

A rotor assembly includes a rotor core having a rotatable shaft and defining at least one rotor post and a winding wound around the post, the winding defining a set of rotor winding end turns. A support assembly for rotor winding end turns is rotatably coupled to a rotatable shaft and defines a cavity in fluid communication with a fluid coolant flow. Rotor winding end turns extend into the cavity.

Description

Background Art

[0001] Electric machines such as electric motors or generators are used in energy conversion. Such electric machines operate by the interaction of magnetic fields and current-carrying conductors to generate force or electricity, respectively. Typically, electric motors convert electrical energy into mechanical energy. Conversely, generators convert mechanical energy into electrical energy. For example, in the aircraft industry, it is common to combine motor mode and generator mode in the same electric machine, where the electric machine in motor mode plays the role of starting the engine and acts as a generator depending on the mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] In the attached picture:

[0003] Figure 1 is an isometric view of a gas turbine engine with a generator in accordance with various aspects described herein.

[0004] Figure 2 According to the various aspects described in this article Figure 1 An isometric view of the exterior of the generator.

[0005] Figure 3 According to the various aspects described in this article Figure 2 The line III-III is intercepted Figure 2 Schematic cross-sectional view of a generator.

[0006] Figure 4 The present invention illustrates various aspects of the present invention. Figure 3 A partially exploded perspective view of the rotor core and end winding support assembly of a generator.

[0007] Figure 5 According to the various aspects described in this article Figure 4 A perspective view of a first collar of an end winding support assembly.

[0008] Figure 6 According to the various aspects described in this article Figure 4 A perspective view of the second collar of the end winding support assembly.

[0009] Fig. 7A According to the various aspects described in this article Figure 4 A perspective view of the coupling disc of the end winding support assembly.

[0010] Figure 7B Illustrated is a cross-section of a portion of the coupling disk of FIG. 7 according to various aspects described herein.

[0011] Figure 8 According to the various aspects described in this article Figure 4 A perspective view of the support disc of the end winding support assembly.

[0012] Fig. 9A According to the various aspects described in this article Figure 4 A perspective view of the coolant distribution ring of the end winding support assembly.

[0013] Fig. 9B is a perspective front view of another non-limiting aspect of a coolant distribution ring according to various aspects described herein.

[0014] Fig.10 According to the various aspects described in this article Figure 4 A perspective view of the spacer disc of the end winding support assembly.

[0015] Fig.11A According to the various aspects described in this article Figure 4 A perspective view of the assembled end winding support assembly.

[0016] Fig. 11B is taken along line VV according to various aspects described herein Fig.11A A cross section of a portion of a rotor assembly with some parts omitted.

[0017] Fig.12 is an enlarged cross-section of another example rotor core and end winding support assembly according to various aspects described herein.

[0018] Fig.13 An exemplary process flow diagram of a method of cooling a rotor assembly according to various aspects described herein is illustrated. DETAILED DESCRIPTION

[0019] Aspects of the present disclosure may be implemented in any environment where electric motors are used, whether the motors provide drive or generate electricity. For the purposes of this description, such electric motors will generally be referred to as motors, motor assemblies, or similar language, which is intended to clarify that one or more stator / rotor combinations may be included in the machine. Although the present description is primarily directed to motors that provide power generation, it may also be applicable to motors that provide drive or motors that provide both drive and power generation. In addition, although the present description is primarily directed to an aircraft environment, aspects of the present disclosure may also be applicable to any environment where electric motors are used. Therefore, a brief overview of the envisioned environment should help to facilitate a more comprehensive understanding.

[0020] As used herein, terms such as “first,” “second,” “third,” etc. may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0021] Although various elements of a "set" will be described, it will be understood that a "set" may include any number of respective elements, including only one element. As used herein, the terms "axial" or "axially" refer to a dimension along the longitudinal axis of the generator or along the longitudinal axis of a component disposed within the generator.

[0022] As used herein, the terms "radial" or "radially" refer to the dimension extending between the central longitudinal axis, the outer circumference, or a circular or annular component disposed thereon. The use of the terms "proximal" or "proximally" by itself or in combination with the terms "radial" or "radially" refers to moving in a direction toward the central longitudinal axis, or a component being relatively closer to the central longitudinal axis than another component.

[0023] All directional references (e.g., radial, axial, upper, lower, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise) are used for identification purposes only to assist the reader in understanding the present disclosure and do not create limitations, especially as to position, orientation, or use thereof. Connection references (e.g., attached, coupled, connected, and joined) are to be interpreted broadly and may include intermediate members between a range of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other.

[0024] As used herein, a "wet" cavity generator includes a cavity housing a rotor and a stator that is exposed to a free liquid coolant (e.g., a coolant that moves freely within the cavity). In contrast, in a "dry" cavity generator, the rotor and stator may be cooled by a coolant contained in a fluid-tight passage (e.g., that does not move freely around the cavity).

[0025] As used herein, the term "underlie" refers to a relative position that is radially closer to the axis of rotation of a rotatable shaft. Also as used herein, the term "overlie" refers to a relative position that is radially farther from the axis of rotation of a rotatable shaft.

[0026] As used herein, the term "electrically insulating" refers to a material that exhibits low electrical conductivity (e.g., less than about 10 -8 Siemens / meter (S / m)) of the material.

[0027] The aspects of the present disclosure described herein are directed to motors, and more specifically to rotor assemblies for motors. As described herein, the rotor assembly may include a rotatable element defining a central axis of rotation and defining a periphery. A set of rotor windings may be wound around the periphery. For the purpose of illustration, exemplary aspects will be described herein in the form of a motor (specifically, a generator) for a gas turbine engine and having a rotor assembly. However, it will be appreciated that in a non-limiting example, the motor may be in the form of a generator, a motor, a permanent magnet generator (PMG), or a starter / generator (S / G), etc. However, it will also be understood that the various aspects of the present disclosure described herein are not limited thereto, and may have general applicability in other motors or systems. For example, the present disclosure may have applicability to systems in other engines or vehicles, and may be used to provide benefits in industrial, commercial, and residential applications.

[0028] For example, conventional wound rotor generators are the main source of electrical energy for industrial and commercial applications. They are commonly used to convert the mechanical power output of steam turbines, gas turbines, reciprocating engines and hydro turbines into electrical power. Typically, these motors include a central rotatable assembly or "rotor" surrounded by a fixed assembly or "stator". A small air gap separates the rotor and the stator. The rotor includes a rotatable shaft and a "rotor core" having one or more sets of conductive rotor windings. The rotor windings can be wound axially around a set of posts or rotor teeth, and slots are defined between the set of posts or rotor teeth. The number of groups of rotor windings typically defines the number of electrical phases of the motor. A portion of the windings of a conventional rotor (e.g., an end turn portion) typically extends through the rotor or overhangs on the rotor. The end turns of the rotor windings in some motors are supported and / or covered by a housing, a cover or other structure. In some cases, the rotor core can be oil cooled.

[0029] In operation, the rotor core of a conventional electric machine, such as a motor, generator, etc., is driven to rotate by a rotation source, such as a mechanical machine or electric machine, which may be a gas turbine engine for some aircraft. The rotor typically rotates at a relatively high number of revolutions per minute (rpm) (e.g., 20,000-500,000 rpm).

[0030] Due to the relatively linear relationship between the rotational speed and shaft power of an electric machine, increasing the rated speed of a generator can increase the power density and efficiency of the generator. Therefore, there is a growing demand for conventional electric machines, such as generators, to operate at higher and higher speeds. However, due to the high rotational speeds, relatively large centrifugal and axial forces can be exerted on the generator, and in particular on the rotor windings. Over time, the repeated application of strong centrifugal forces and vibrations under normal operation can weaken or damage the rotor windings.

[0031] Therefore, rotors typically require a sturdy construction to withstand such forces over long periods of time, and despite this sturdy construction, such rotors typically also need to be balanced to minimize vibrations of the rotor windings, thereby reducing the risk of failures associated with improper balancing and deflection or relative movement of the rotor windings at high rotational speeds.

[0032] In addition, conventional rotor end winding support structures are typically not continuous in the winding end turn region, having open areas or gaps within or between support elements. At higher rotational speeds, such discontinuous architecture in the winding end turn support structure can result in windage losses. Windage losses limit or reduce the operating efficiency of the generator, resulting in the need for additional oil cooling or reduced operating speeds.

[0033] Therefore, there is a need for a high speed electric machine with improved rotor winding end turn retention and support while reducing windage losses. For example, there is a need for a rotor core with an improved rotor winding end turn support structure to improve the dynamic balance of the rotor core, reduce deflection or relative movement of the rotor winding end turns, and reduce windage losses while enabling easier and less costly assembly than conventional arrangements.

[0034] Additionally, heat is generated in the rotor due to the flow of current through the windings, and there is a changing magnetic field in the rotor, causing the temperature in the rotor to rise. It is desirable to cool the rotor to protect the motor from heat-related damage and to increase the motor power density to allow more power from a smaller physical size electric motor.

[0035] The exemplary drawings are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the drawings attached herein may vary.

[0036] Figure 1A gas turbine engine 10 having an auxiliary gearbox (AGB) 12 and an electric machine or generator 14 is illustrated in accordance with aspects of the present disclosure. The gas turbine engine 10 may be a turbofan engine commonly used in modern commercial and military aviation (such as the General Electric GEnx or CF6 series engines), or it may be a variety of other known gas turbine engines, such as a turboprop or turboshaft engine. The AGB 12 may be coupled to a turbine shaft (not shown) of the gas turbine engine 10 via a mechanical power takeoff 16. The gas turbine engine 10 may be any suitable gas turbine engine used in modern aviation, or it may be a variety of other known gas turbine engines, such as a turboprop or turboshaft engine. The type and details of the gas turbine engine 10 are not germane to the present disclosure and will not be further described herein. Although a generator 14 is shown and described, aspects of the present disclosure are not limited thereto, and the aspects may include any electric machine, such as, but not limited to, a motor or generator.

[0037] Figure 2 A non-limiting example of a generator 14 and its housing 18 according to aspects of the present disclosure is more clearly illustrated. The generator 14 may include a clamping interface 20 for clamping the generator 14 to an AGB (not shown). A plurality of electrical connections may be provided on the exterior of the generator 14 to provide electrical power transmission to and from the generator 14. The electrical connections may be further connected by cables to an electrical power distribution node of an aircraft having a gas turbine engine 10 to power various items on the aircraft (such as lights and seat back monitors). The generator 14 may include a liquid coolant system for cooling or dissipating heat generated by components of the generator 14 or by components near the generator 14 (a non-limiting example of which may be the gas turbine engine 10). For example, the generator 14 may include a liquid cooling system using oil as a coolant.

[0038] The liquid cooling system may include a cooling fluid inlet port 82 and a cooling fluid outlet port 84 for controlling the supply of coolant to the generator 14. In one non-limiting example, the cooling fluid inlet port 82 and the cooling fluid outlet port 84 may be used to cool at least a portion of the rotor or stator of the generator 14. The liquid cooling system may also include a second coolant outlet port 91 shown at a rotatable shaft portion of the generator 14. Optionally, by way of non-limiting example, the liquid cooling system may include a rotatable shaft coolant inlet port 94 or a generator coolant outlet port 95. Although not shown, aspects of the present disclosure may also include other liquid cooling system components, such as a liquid coolant reservoir fluidly coupled to the cooling fluid inlet port 82, the rotatable shaft coolant inlet port 94, the cooling fluid outlet port 84, or the generator coolant outlet port 95, and a liquid coolant pump (not shown) that forces the supply of coolant through ports 82, 84, 94, 95 or the generator 14.

[0039] exist Figure 3 The non-limiting interior of the generator 14 is illustrated in FIG. Figure 3 yes Figure 2 The generator 14 shown in FIG. 1 is a cross-sectional view taken along line III-III. A rotatable shaft 40 is located within the generator 14 and is the main structure for supporting a variety of components. The rotatable shaft 40 may have a single diameter or a diameter that may vary along its length. The rotatable shaft 40 is supported by spaced bearings 42 and 44 and is configured to rotate around an axis of rotation 41. Several elements of the generator 14 have fixed components and rotating components, wherein the fixed components are fixed relative to the housing 18, and the rotating components are disposed on the rotatable shaft 40 or are rotatably fixed relative to the rotatable shaft 40. Examples of these elements may include a motor 50 housed in a cavity 51. The rotating component may include a rotor 52, and the corresponding fixed component includes a stator 54 or a stator core. In this way, the rotor 52 is disposed on the rotatable shaft 40 and rotates with the rotatable shaft 40. The fixed component may be mounted to any suitable portion of the housing 18. Together, the fixed component defines an interior through which the rotatable shaft 40 extends and rotates relative to it.

[0040] It will be appreciated that the rotor 52 may have a set of rotor poles and the stator 54 may have a set of stator poles. The set of rotor poles may generate a set of magnetic fields relative to the set of stator poles such that rotation of the rotor magnetic field relative to the stator poles generates current in the corresponding stator components.

[0041] At least one of the rotor poles and the stator poles may be formed by a core with a post and a wire wound around the post to form a rotor winding or coil, wherein the rotor winding has at least one winding end turn. The illustrated aspect of the present disclosure includes at least one set of stator windings 90 arranged longitudinally along the housing 18, i.e., parallel to the housing 18 and the axis of rotation 41. The set of stator windings 90 may also include a set of stator winding end turns 92 extending axially beyond opposite ends of the longitudinal length of the stator 54.

[0042] The components of the generator 14 may be any combination of known generators. For example, 50 may be a synchronous or asynchronous generator. In addition to the accessories shown in this regard, there may be other components that need to operate for a specific application. For example, in addition to the electromechanical accessories shown, there may be other accessories driven from the same rotatable shaft 40, such as a liquid coolant pump, a fluid compressor, or a hydraulic pump.

[0043] As explained above, the generator 14 may use a cooling fluid such as oil as a coolant and, therefore, may include a cooling system 80. The cooling fluid or oil may be used to dissipate heat generated by the electrical and mechanical functions of the generator 14. The cooling system 80 using the cooling fluid may also provide lubrication for the generator 14. In the illustrated aspect, the generator 14 may be an oil-cooled wet cavity type cooling system 80, which includes a cooling fluid inlet port 82 and a cooling fluid outlet port 84 for controlling the supply of cooling fluid to the cooling system 80. The cooling system 80 may also include, for example, a cooling fluid reservoir 86 and various cooling passages. The rotatable shaft 40 may provide one or more channels or paths for a coolant or fluid coolant flow 85 (schematically shown as arrows) for the rotor 52 and a second coolant outlet port 91, where residual, unused or unused oil may be discharged from the rotatable shaft 40.

[0044] In a non-limiting example of the generator 14, the fluid coolant flow 85 may be further directed, exposed, sprayed, or otherwise deposited onto the set of stator windings 90, the set of stator winding end turns 92, or onto an alternative or additional component. In this example, the fluid coolant flow 85 may flow radially outward from the rotatable shaft 40 toward the set of stator windings 90 or the set of stator winding end turns 92. In this sense, the coolant may cool the corresponding set of stator windings 90 or the set of stator winding end turns 92.

[0045] Figure 4A partially exploded perspective view of a rotor assembly 96 such as for a main electric machine is illustrated, with some parts omitted for clarity. As shown, the rotor assembly 96 may include a rotor core 100 such as a laminated rotor core 100, which is rotatably connected to rotate with the rotatable shaft 40 around the axis of rotation 41. The rotor assembly 96 may include at least one end winding support assembly 140. The end winding support assembly 140 is coupled to the rotatable shaft 40 to rotate with it. Each end winding support assembly 140 may include a first collar 141, a second collar 142, a coupling disk 143, and a support disk 144, respectively. In non-limiting aspects, the end winding support assembly 140 may include a coolant distribution ring 145. In addition, in yet other aspects, the end winding support assembly may include a spacer disk 146. The first collar 141 may include a first wall 151 and a second wall 152. The second collar 142 may include a third wall 253 and a fourth wall 254. The coupling disk 143 may include a fifth wall 155 and a sixth wall 156. In various aspects, each of the first wall 151 , the second wall 152 , the third wall 153 , the fourth wall 154 , the fifth wall 155 , and the sixth wall 156 may be annular.

[0046] The rotor assembly 96 may further define an axial first end 102 and an axial second end 104 axially spaced from the first end 102. The rotor assembly 96 may include at least one rotor pole 106 defined by a rotor post 108 and formed when at least a portion of the rotor core 100 is wound with one or more sets of electrically conductive rotor wires or rotor windings 110 or coils around a respective rotor post 108. Figure 4 , an aspect having four rotor poles 106 is shown, with three rotor poles 106 visible in the illustration. Other aspects are not so limited, and the rotor assembly 96 may alternatively have fewer than four rotor poles 106, or more than four rotor poles 106, without departing from the scope of the present disclosure, and the aspects may be applicable to rotor assemblies 96 having any desired number of rotor poles 106. The rotor windings 110 wound around the rotor posts 108 may define respective axial winding portions 111 extending axially along the rotor core 100 and respective rotor winding end turns 112 extending axially beyond the rotor core 100. In the perspective view of the illustrated example, each rotor post 108 may radially underlie a respective set of rotor windings 110. Although rotor winding 110 or rotor winding end turns 112 may refer to a group or multiple windings or end turns, the end turn may include only one of the group of rotor windings 110, or only a portion of the group of rotor windings 110 extending axially beyond rotor core 100, such as only at first end 102 or second end 104.

[0047] Each set of rotor winding end turns 112 may define a respective collar or arcuate bend 113 that axially overhangs or extends beyond the rotor core 100. In non-limiting aspects, each bend 113 may also define a respective channel 116 extending radially therethrough. For example, in non-limiting aspects, each channel 116 may have a respective circumferential width defined by the circumferential width of the corresponding rotor post 108. Additionally, a set of radially extending end turn passages 114 may be defined by gaps formed between immediately adjacent rotor winding end turns 112. The rotor end turn passages 114 are disposed in fluid communication with the second collar 142 and the support disk 144.

[0048] Although a substantially rectangular rotor winding 110 cross-section is illustrated, any geometric cross-section may be included in aspects of the present disclosure, including but not limited to circular, oval, square, etc. Non-limiting aspects of the present disclosure may also be included in which the set of rotor windings 110 includes a layer of electrically insulating material (not shown) outside of and encapsulating the set of rotor windings 110 to electrically isolate the set of rotor windings 110 from another set of rotor windings 110 and nearby conductive parts.

[0049] A respective end winding support assembly 140 may be coupled to each end of the rotatable shaft 40 of the rotor assembly 96 such that rotation of the rotatable shaft 40 results in rotation of the end winding support assembly 140. In non-limiting aspects, the respective end winding support assembly 140 may be coupled to an end (e.g., the first end 102 or the second end 104) of the rotor assembly 96. In other aspects, the respective end winding support assembly 140 may be rotatably coupled to the rotatable shaft 40 at both the first end 102 and the second end 104 of the rotor assembly 96.

[0050] The first wall 151 may be arranged to face the ends 102, 104 of the rotor core 100 and may define a first hole 161. The second wall 152 may be coupled to the first wall 151 and extend axially inwardly from the first wall 151 toward the rotor core 100. The second wall 152 is arranged radially above the rotor winding end turns 112 of the rotor winding relative to the rotation axis 41 of the rotatable shaft 40.

[0051] The second collar 142 may be disposed between the first collar 141 and the rotor core 100. The third wall 253 may be disposed to face or face the ends 102, 104 of the rotor core 100 and may define a second hole 162. The fourth wall 254 may be coupled to the third wall 253 and extend axially inwardly from the third wall 253 toward the rotor core 100. The fourth wall 254 is radially disposed between the rotor winding end turns 112 and the second wall 152 of the first collar 141. In non-limiting aspects, the fourth wall 254 may also be disposed radially above the rotor winding end turns 112 relative to the rotation axis 41 of the rotatable shaft 40.

[0052] The fifth wall 155 of the coupling plate 143 is arranged to face or face the respective ends 102, 104 of the rotor core 100. The sixth wall 156 is coupled to the fifth wall 155 and extends axially from the fifth wall 155 toward the rotor core 100. The sixth wall 156 may circumferentially surround and be coupled to the rotatable shaft 40.

[0053] The support disk 144 may circumferentially surround and be coupled to the rotatable shaft 40. In a non-limiting aspect, the support disk 144 may be disposed between the rotor core 100 and the second collar 142. In some aspects, the support disk 144 may include a radially outer periphery 189. In a non-limiting aspect, the radially outer periphery 189 may define a set of first slots 185 or gaps therethrough. The first slots 185 may be circumferentially spaced from one another around the support disk 144. The first slots 185 may be sized to operatively receive a corresponding rotor winding 110 axially therein. In a non-limiting aspect, a portion of the support disk 144 may be disposed within one or more of the channels 116 defined by the rotor winding end turns 112, wherein the rotor winding end turns 112 are disposed in corresponding first slots 185.

[0054] Although Figure 4 A non-limiting example of an end winding support assembly 140 configured for a 4-pole rotor assembly 96 is depicted, but other aspects are not so limited. It will be appreciated that aspects as disclosed herein are not limited to any particular number of rotor poles, and aspects of the end winding support assembly 140 may be applicable to rotor assemblies 96 having any desired number of poles.

[0055] Figure 5 Depicted Figure 4 In a non-limiting aspect, the first wall 151 may define an axially inwardly facing (eg, facing toward Figure 4 The annular first surface 151a of the rotor core 100 and the opposite axially outwardly facing (eg, away from Figure 4 The first wall 151 may also include an annular third surface 151c that faces radially inward and defines the first hole 161. The third surface 151c may extend from the first surface 151a to the second surface 151b. The first hole 161 may be sized to receive the rotatable shaft 40 therethrough. The second wall 152 may have a radially inward (e.g., toward Figure 4 The annular fourth surface 152a of the rotor core 100 and the opposite radially outwardly facing (eg, away from Figure 4 The fifth surface 152b may define a first diameter D1.

[0056] Figure 6 Depicted Figure 4 The third wall 253 may define an axially inwardly facing annular sixth surface 253a (eg, facing toward the Figure 4 The rotor core 100) and the opposite axially outwardly facing annular seventh surface 253b (eg, facing away from Figure 4 The third wall 253 may also include an annular eighth surface 253c that faces radially inward and defines the second hole 162. The eighth surface 253c may extend axially from the sixth surface 253a to the seventh surface 253b. The second hole 162 may be sized to receive the rotatable shaft 40 therethrough. The fourth wall 254 may have a ninth surface 254a that faces radially outward (e.g., facing away from the rotatable shaft 40). Figure 4 ) and an opposite radially inwardly facing tenth surface 254 b (eg, facing toward the rotor core 100 ).

[0057] In non-limiting aspects, the sixth surface 253a of the third wall 253 can define thereon a set of first grooves 255. The first grooves 255 can have a circumferential width and extend radially across the sixth surface 253a, such as from the eighth surface 253c to the ninth surface 254a of the fourth wall 254. The first grooves 255 are circumferentially spaced apart from one another.

[0058] The tenth surface 254b of the fourth wall 254 may define a set of second grooves 256. The second grooves 256 may be arranged to be in fluid communication with the set of first grooves 255. The second grooves 256 have a circumferential width and may extend axially across the tenth surface 254b, for example, from the sixth surface 253a to the opposite end at the axial extent of the fourth wall 254. The second grooves 256 are circumferentially spaced from each other. In non-limiting aspects, the second grooves 256 may be tapered. For example, one or more of the second grooves 256 may be shallower at the tenth surface 254b than at the diametrical end at the radial extent of the fourth wall 254. The first grooves 255 and the second grooves 256 may define a coolant collection surface.

[0059] Additionally or alternatively, the tenth surface 254b of the fourth wall 254 may define a set of third grooves 257. The third grooves 257 have an axial width and extend circumferentially along the tenth surface 254b. The third grooves 257 are axially spaced apart from each other. The third grooves 257 may be arranged to be in fluid communication with the set of second grooves 256 or the set of first grooves 255 or both. In non-limiting aspects, the third grooves 257 and the second grooves 256 are arranged at an angle relative to each other. For example, as illustrated, in some aspects, the third grooves 257 may be arranged orthogonally relative to the second grooves 256. In other aspects, the third grooves 257 may be arranged at any desired angle (e.g., non-parallel) relative to the second grooves 256. The third grooves 257 may define a coolant collection surface.

[0060] Fig. 7A Depicted Figure 4 A more detailed perspective view of the coupling disc 143, and Figure 7B It is taken along line IV-IV Fig. 7A 7 and 8. Fig. 7A , the fifth wall 155 and the sixth wall 156 can cooperatively define a third hole 163, which can be sized to receive the rotatable shaft 40 therethrough. For example, the fifth wall 155 can define an eleventh surface 155a that faces axially inward (e.g., facing axially toward the eleventh surface 155a). Figure 4 The rotor core 100) and the opposite axially outwardly facing twelfth surface 155b (eg, axially facing away from Figure 4 The fifth wall 155 may further include a thirteenth surface 155c facing radially inward (eg, facing radially inward). Figure 4 The rotor core 100) and the opposite radially outwardly facing fourteenth surface 155d (eg, radially away from Figure 4 The fourteenth surface 155d may define a radially outer periphery 159 of the coupling disk 143. The thirteenth surface 155c facing radially inward may define a third hole 163. The thirteenth surface 155c may extend from the eleventh surface 155a to the twelfth surface 155b.

[0061] In non-limiting aspects, the twelfth surface 155b may define a recess 155e or seat portion defined thereon. The recess 155e may be annular and disposed along the radially outer periphery 159 of the coupling disk 143 (e.g., on the twelfth surface 155b). The recess 155e may be recessed from an adjacent or abutting portion of the twelfth surface 155b by a depth D1. The depth D1 may be based on the thickness of the first wall 151 of the first collar 141 ( Figure 5 ). The recess 155e or seat portion may provide a seating surface for the first wall 151.

[0062] In some non-limiting aspects, the coupling plate 143 may define a lip 155f. The lip 155f may be coupled to the eleventh surface 155a and extend axially therefrom. The lip 155f is arranged to face the eighth surface 253c ( Figure 6 ). The lip 155f may be annular and arranged to circumferentially surround the third hole 163.

[0063] The sixth wall 156 may extend axially inward from the eleventh surface 155a (eg, axially toward the Figure 4 The sixth wall 156 may include an annular, radially inwardly facing fifteenth surface 156c and an opposite, annular, radially outwardly facing sixteenth surface 156b. The sixth wall 156 may define a set of apertures 258 therethrough. The apertures 258 may extend from the fifteenth surface 156c to the sixteenth surface 156b. In non-limiting aspects, the apertures 258 may be circumferentially spaced from each other around the sixth wall 156. The sixth wall 156 may cooperate with the radially inwardly facing thirteenth surface 155c to further define the third hole 163. The fifteenth surface 156c may be concentrically aligned with the thirteenth surface 155c of the fifth wall 155. The fifteenth surface 156c or the thirteenth surface 155c or both may define the third hole 163.

[0064] In a non-limiting aspect, the coupling disk 143 may further include an annular seventh wall 157. The seventh wall 157 may circumferentially surround the rotatable shaft 40. The seventh wall 157 may be coupled to the twelfth surface 155b and extend axially outwardly (eg, away from the twelfth surface 155b). Figure 4 The seventh wall 157 may cooperate with the fifteenth surface 156c or the thirteenth surface 155c or both to further define the third hole 163. For example, the seventh wall 157 may include an annular, radially inwardly facing seventeenth surface 157c and an opposite annular, radially outwardly facing eighteenth surface 157f. The seventeenth surface 157c may be concentrically aligned with the thirteenth surface 155c of the fifth wall 155.

[0065] Figure 8 A non-limiting aspect of the support disk 144 is depicted. In a non-limiting aspect, the support disk 144 may include an annular disk having a first face 181 and an opposing second face 182. The first face 181 may be disposed facing or facing the ends 102, 104 of the rotor core 100 ( Figure 4 In various aspects, the second face 182 can face axially outward (eg, axially away from Figure 4 The support disk 144 may define a fourth aperture 164 sized to receive the rotatable shaft 40 ( Figure 4For example, the support disk 144 may include a radially inwardly facing nineteenth surface 186 (eg, facing Figure 4 rotatable shaft 40). The support disk 144 may include a twentieth surface 187 facing radially outwardly opposite the nineteenth surface 186. The twentieth surface 187 may define a second diameter D2. In a non-limiting aspect, the twentieth surface 187 may define a radial outer periphery 189. The nineteenth surface 186 and the twentieth surface 187 may extend axially between the first face 181 and the second face 182. In a non-limiting aspect, the twentieth surface 187 may define a set of first slots 185 or gaps therethrough. The first slots 185 may be circumferentially spaced apart from each other around the radial outer periphery 189 of the support disk 144.

[0066] Fig. 9A depicts a perspective view of non-limiting aspects of the coolant distribution ring 145, and Fig. 9B A cross section of another aspect of the coolant distribution ring 145 is depicted. Referring also to FIGS. 9 and Fig. 9A In a non-limiting aspect, the coolant distribution ring 145 may include an annular disk having a third face 631 and an opposing fourth face 632. The third face 631 may be arranged facing the ends 102, 104 of the rotor core 100 ( Figure 4 ), and the fourth face 632 may face axially outward (eg, axially away from Figure 4 The coolant distribution ring 145 may include a twenty-first surface 621 facing radially inward (eg, facing Figure 4 The twenty-first surface 621 may define a fifth hole 165 sized to receive the rotatable shaft 40 therethrough ( Figure 4 ). The coolant distribution ring 145 may include a 22nd surface 622 facing radially outwardly opposite to the 21st surface 621. In non-limiting aspects, the 22nd surface 622 may be an outer peripheral surface. The 21st surface 621 and the 22nd surface 622 may extend axially between the third face 631 and the fourth face 632.

[0067] In some aspects, the twenty-first surface 621 can be a relatively smooth surface. In other non-limiting aspects, the twenty-first surface 621 can define a set of channels or fourth grooves 625 thereon. When assembled, the fourth grooves 625 can be arranged to be in fluid communication with the rotatable shaft 40 ( Figure 4 ). As such, the set of fourth grooves 625 can cooperatively define a coolant reservoir.

[0068] The coolant distribution ring 145 may also define a set of channels 627 extending radially therethrough in fluid communication with the twenty-first surface 621. For example, the channels 627 may extend from a first end 627a disposed at the twenty-first surface 621 to an opposite second end 627b at the twenty-second surface 622. Each channel 627 may include a coolant inlet 628 defined on the twenty-first surface 621, and a corresponding coolant outlet 629 defined on the twenty-second surface 622 at the opposite second end 627b.

[0069] The channels 627 may be spaced circumferentially around the coolant distribution ring 145. The channels 627 may be sized to allow a fluid coolant stream 85 (not shown) to flow therethrough. In non-limiting aspects, the channels 627 may also be in fluid communication with respective coolant outlets 629. At least a subset of the coolant outlets 629 may define respective spray nozzles 629a at radially distal ends. The spray nozzles 629a may be disposed on the twenty-second surface 622 at circumferentially spaced intervals.

[0070] Fig.10 A perspective view of a non-limiting aspect of the spacer disk 146 is depicted. In a non-limiting aspect, the spacer disk 146 can include an annular disk having a first face 781 and an opposing second face 782. In a non-limiting aspect, the spacer disk 146 can be formed of an electrically insulating material. For example, the spacer disk 146 can electrically insulate the support disk from the coolant distribution ring 145 or other conductive portion. In other non-limiting aspects, the radially outer surface of the spacer disk 146 can be coated with an electrically insulating material.

[0071] The first surface 781 may be arranged facing the ends 102, 104 of the rotor core 100 ( Figure 4 In various aspects, the second face 182 can face axially outward (eg, axially away from Figure 4 The spacer disk 146 may define a sixth aperture 166 sized to receive the rotatable shaft 40 ( Figure 4 For example, the spacer disk 146 may include a radially inwardly facing twenty-third surface 786 (eg, facing toward Figure 4 The spacer disk 146 may include a 24th surface 787 facing radially outwardly opposite the 23rd surface 786. The 24th surface 787 may define a third diameter D3. In a non-limiting aspect, the third diameter D3 is less than the second diameter D2 ( Figure 8 ).

[0072] In a non-limiting aspect, the twenty-fourth surface 787 can define a radially outer periphery 789 of the spacer disk 146. The twenty-third surface 786 and the twenty-fourth surface 787 can extend axially between the first face 781 and the second face 782. In a non-limiting aspect, the twenty-fourth surface 787 can define a set of second slots 785 or gaps therethrough. The second slots 785 can be circumferentially spaced from one another around the radially outer periphery 789 of the spacer disk 146. The second slots 785 can be sized to operatively receive respective rotor windings 110 axially therein.

[0073] Fig.11A Depicted Figure 4 A perspective view of the assembled rotor assembly 96, and Fig. 11B It is taken along line VV Fig.11A 1 is a cross-section of a portion of rotor assembly 96 , with some portions (eg, rotor winding end turns 112 and coolant distribution ring 145 ) omitted for clarity.

[0074] Also refer to Figures 11 and Fig.11A , the first wall 151 of the first collar 141 may be coupled to the fifth wall 155 of the coupling disk 143 along the third surface 151c along the radially outer periphery 159. For example, in non-limiting aspects, the radially outwardly facing fourteenth surface 155d of the fifth wall 155 may be coupled to the third surface 151c of the first collar 141. Additionally or alternatively, the radially inner portion of the first wall 151 may be disposed in a nested relationship in an annular recess 155e or seat portion defined along the radially outer periphery 159 of the coupling disk 143. When assembled, the recess 155e may receive a portion of the first wall 151 therein such that the first surface 151a of the first wall 151 and the twelfth surface 155b of the fifth wall 155 may cooperatively define a continuous axially outwardly facing surface 158 via a nested relationship. By arranging a continuous axially outer facing surface 158 , undesirable gaps, openings, or other discontinuities at the respective ends 102 , 104 of the rotor core 100 may be reduced compared to conventional arrangements, and a corresponding beneficial reduction in windage losses may be obtained.

[0075] The first collar 141 may also be coupled to the support disk 144. For example, the first collar 141 may be coupled to the radially outer periphery 189 (e.g., the twentieth surface 187) of the support disk 144 along the fifth surface 152b. In non-limiting aspects, the first collar 141 may be coupled to the support disk 144 via an interference fit, friction, or press fit engagement between the first collar 141 and the support disk 144. For example, in non-limiting aspects, the first diameter D1 may be arranged to be less than or equal to the second diameter D2 to enable a press fit between the second wall 152 of the first collar 141 and the fourth wall 254 of the second collar 142. Other aspects are not so limited, and it is contemplated that the first collar 141 may be coupled to the support disk 144 via any desired attachment mechanism.

[0076] In addition, when assembled, the second collar 142 can be optionally coupled to the support disc 144. For example, the second collar 142 can be coupled to the lip 155f of the coupling disc 143 along the eighth surface 253c. In other non-limiting aspects, the second collar 142 can be coupled to the sixteenth surface 156d of the coupling disc 143 along the eighth surface 253c. In non-limiting aspects, the second collar 142 can be coupled to the coupling disc 143 via an interference fit, friction, or press fit engagement between the second collar 142 and the coupling disc 143. Other aspects are not so limited, and it is contemplated that the second collar 142 can be coupled to the coupling disc 143 by any desired attachment mechanism. In still other aspects, the second collar 142 can be disposed between the first collar 141 and the support disc 144 without being coupled to the coupling disc 143.

[0077] In addition to being coupled to the first collar 141 and the second collar, the coupling disc 143 is also coupled to the rotatable shaft 40. The coupling disc 143 may be coupled to the rotatable shaft 40 (shown in FIG. 7 ) via one or more of the fifth wall 155, the sixth wall 156, and the seventh wall 157. For example, the coupling disc 143 may be fixed to the rotatable shaft 40 along the radially inwardly facing thirteenth surface 155c, the fifteenth surface 156c, the seventeenth surface 157c (shown in FIG. 7 ), or a combination thereof using one or more bolts, screws, pins, keys, splines, or other known fasteners (not shown). In other non-limiting aspects, the coupling disc 143 may be coupled to the rotatable shaft 40 via an interference fit, friction, or press fit engagement between the coupling disc 143 and the rotatable shaft 40. Other aspects are not so limited, and it is contemplated that the coupling disc 143 may be rotatably coupled to the rotatable shaft 40 by any desired attachment mechanism. It will be appreciated that when so coupled, rotation of the rotatable shaft 40 will result in corresponding rotation of the coupling disc 143.

[0078] In addition to being coupled to the first collar 141, the support disc 144 is also coupled to the rotatable shaft 40. For example, in a non-limiting aspect, the support disc 144 can be secured to the rotatable shaft 40 along the nineteenth surface 186 using one or more bolts, screws, pins, keys, splines, or other known fasteners (not shown). In other non-limiting aspects, the support disc 144 can be coupled to the rotatable shaft 40 via an interference fit, friction, or press fit engagement between the support disc 144 and the rotatable shaft 40. Other aspects are not so limited, and it is contemplated that the support disc 144 can be rotatably coupled to the rotatable shaft 40 via any desired attachment mechanism.

[0079] It will be appreciated that when so coupled, rotation of the rotatable shaft 40 will result in corresponding rotation of the support disk 144 and the coupling disk 143 , thereby resulting in rotation of the first and second collars 141 , 142 .

[0080] Fig.12 A portion of another exemplary aspect of rotor assembly 96 is schematically illustrated to provide a better understanding of the arrangement and operation of the various aspects. Fig.12 The aspects depicted in Fig. 11B , one notable difference being that the second collar 142 is not coupled to the sixth wall 156 of the coupling disc 143. As illustrated, the end winding support assembly 140 includes a first collar 141, a second collar 142, a coupling disc 143, a support disc 144, a coolant distribution ring 145, and a spacer disc 146. The coupling disc 143 and the support disc 144 are shown rotatably coupled to the rotatable shaft 40. The first collar 141, the second collar 142, and the coolant distribution ring 145 are shown circumferentially surrounding and coupled to the coupling disc 143.

[0081] The coolant distribution ring 145 may be fixedly coupled to the coupling disk 143 using one or more bolts, screws, pins, keys or other known fasteners. In other non-limiting aspects, the coolant distribution ring 145 may be coupled to the coupling disk 143 via an interference fit, friction or press fit engagement between the first coolant distribution ring 145 and the coupling disk 143. For example, the twenty-first surface 621 of the coolant distribution ring 145 may be fixedly coupled to the twelfth surface 155b of the coupling disk 143. In addition, the set of orifices 258 may be in fluid communication with the twelfth surface 155b. Other aspects are not limited in this regard, and it is contemplated that the coolant distribution ring 145 may be rotatably coupled to the coupling disk 143 by any desired attachment mechanism. It will be appreciated that when so coupled, rotation of the coupling disk 143 will result in rotation of the coolant distribution ring 145.

[0082] An annular gap or cavity 275 is radially defined between the outer periphery or radially outwardly facing twenty-second surface 622 of the coolant distribution ring 145 and the radially inwardly facing ninth surface 254a of the fourth wall 254 of the second collar 142. The cavity 275 may extend axially between the spacer disk 146 and the third wall 253 of the second collar 142. The rotor winding end turns 112 are configured to extend into the cavity 275.

[0083] The coolant distribution ring 145 is disposed at least partially below the rotor winding end turns 112. In this example, "below" refers to a relative position that is radially closer to the rotation axis 41 of the rotatable shaft 40. In a non-limiting aspect, the twenty-second surface 622 is disposed proximate to and facing the rotor winding end turns 112. In a non-limiting aspect, the second collar 142 may be at least partially above the rotor winding end turns 112. In this example, "above" refers to a relative position that is radially farther from the rotation axis 41 of the rotatable shaft 40.

[0084] In this manner, the coolant distribution ring 145 and the second collar 142 can cooperatively support or otherwise limit radial movement of the rotor winding end turns 112 disposed within the cavity 275. Additionally, the spacer disk 146 and the second collar 142 can cooperatively support or otherwise limit axial movement of each rotor winding end turn 112 disposed within the cavity 275.

[0085] A portion of the rotor winding 110 extending axially from the rotor core 100 may be disposed in and axially extend through a set of first slots 185 of the support disk 144. For example, a portion of each rotor winding 110 may extend axially from the rotor core 100 and axially pass through a corresponding first slot 185. The circumferential width of each first slot 185 may be configured to retentively receive the rotor winding 110 therein. In this manner, the support disk 144 may support or otherwise limit lateral movement of each rotor winding 110 disposed within the corresponding first slot 185.

[0086] Similarly, another portion of the rotor winding 110 extending axially from the rotor core 100 may be further disposed in a set of second slots 785 to extend axially therethrough. For example, a portion of each rotor winding 110 may extend axially from the rotor core 100 and axially pass through a corresponding second slot 785. The circumferential width of each second slot 785 may be configured to securely receive the rotor winding 110 therein. In this manner, the spacer disk 146 may support or otherwise limit lateral movement of each rotor winding 110 disposed within the corresponding second slot 785.

[0087] In operation, refer to Figure 3During operation of the generator 14, the magnetic field generated by the set of rotor windings 110 relative to the rotation of the set of stator windings 90 generates electricity in the stator windings 90. This magnetic interaction also generates heat in the set of rotor windings 110, the rotor winding end turns 112, and the stator windings 90. According to aspects described herein, the fluid coolant flow 85 may enter the rotatable shaft 40 of the rotor assembly 96 via one of the cooling fluid inlet port 82, the coolant inlet port 94, or both.

[0088] Reference again Fig.12 In operation, the end winding support assembly 140 is arranged to enable a fluid coolant flow (indicated by a solid arrow) 85 to flow radially therethrough. The fluid coolant flow 85 is delivered from the rotatable shaft 40 to the cavity 275 and a set of rotor winding end turns 112. The fluid coolant flow 85 may then be delivered from the end winding support assembly 140 axially toward the rotor core 100 or radially toward the stator winding 90, or both.

[0089] For example, the rotatable shaft 40 may define a first coolant conduit 250 that is fluidly connected to a coolant source 251. The coolant source 251 may be, but is not limited to, a cooling fluid inlet port 82 ( Figure 3 ). The direction or location of the coolant source 251 is not limited by the illustrations and may be disposed in any location that is fluidly coupled to the first coolant conduit 250. It is also contemplated that additional conduits, pumps, valves, or other devices may be included to fluidly connect the coolant source 251 and the first coolant conduit 250 without departing from the scope of the present disclosure. The fluid coolant flow 85 may be conveyed through the rotatable shaft 40 via the first coolant conduit 250. For example, the first coolant conduit 250 may include a radially extending portion 259. The radially extending portion 259 may fluidly couple the first coolant conduit 250 and the coupling disk 143. In operation, due to the centrifugal force of the rotatable shaft 40, the fluid coolant flow 85 may flow radially outward through the radially extending portion 259 from the axis of rotation 41 toward the coupling disk 143.

[0090] The coupling plate 143 may receive the fluid coolant flow 85 from the first coolant conduit 250 via the radially extending portion 259 of the first coolant conduit 250 at the thirteenth surface 155c or the fifteenth surface 156c or both. For example, the fluid coolant flow 85 may be collected on or at the thirteenth surface 155c or the fifteenth surface 156c or both and centrifugally conveyed radially outward through a set of orifices 258 to the coolant distribution ring 145.

[0091] The fluid coolant flow 85 may be centrifugally conveyed through the coolant distribution ring 145. For example, the fluid coolant flow 85 may be centrifugally conveyed from the twenty-first surface 621 to the twenty-second surface 622 via a set of channels 627. In operation, the channels 627 may be in fluid communication with the rotatable shaft 40 or the set of fourth grooves 625, or both, to receive the fluid coolant flow 85 therefrom.

[0092] The fluid coolant flow 85 may be centrifugally delivered from the coolant distribution ring to the cavity 275. For example, the coolant may be radially discharged from the passage 627 to the cavity 275 via the coolant outlet 629. The coolant outlet 629 is arranged to provide the fluid coolant flow 85 radially outward therefrom. In non-limiting aspects, the coolant outlet 629 may be configured to operatively spray fine atomized particles of coolant fluid toward the rotor winding end turns 112 and the end turn passages 114 within the cavity 275.

[0093] Fluid coolant flow 85 is centrifugally delivered to end turn passages 114 between rotor winding end turns 112. Fluid may flow radially outward through end turn passages 114 passing between rotor winding end turns 112, which transfers heat from a set of rotor windings 110 to the coolant by conduction.

[0094] The fluid coolant stream 85 may be radially discharged from the rotor end turn passage 114 and received by the second collar 142. For example, the fluid coolant stream 85 may be received by the sixth surface 253a of the third wall 253 or the tenth surface 254b of the fourth wall 254, or both. In non-limiting aspects, the fluid coolant stream 85 may be received in the fluid collection surface of the second groove 256, the third groove 257, or both. The fluid coolant stream 85 received in the third groove 257 may be centrifugally transferred to the second groove 256. Additionally or alternatively, the fluid coolant stream 85 received in the first groove 255 may be centrifugally transferred to the second groove 256.

[0095] As illustrated, in non-limiting aspects, one or more of the second grooves 256 may taper along the tenth surface 254 b to define an angle 268 relative to the rotational axis 41 such that the second grooves 256 may receive and redirect the fluid coolant flow 85 axially outward from the rotor end turn passage 114 and toward the support disk 144 and discharge it from the cavity 275.

[0096] The fluid coolant flow 85 may be radially exhausted from the second collar 142 and the radial rotor end turn passages 114. The fluid coolant flow 85 redirected by the second collar 142 may be routed axially inwardly from the cavity 275 and through a set of first slots 185.

[0097] Fig.13A method 700 of cooling a set of rotor winding end turns 112 of a rotor assembly 96 is illustrated. Although described with respect to the rotor assembly 96, it will be appreciated that the method 700 may be applied to any electric machine. Figure 4 to Figure 1 The method is described with respect to the rotor assembly 96 of 1, but is otherwise not limited thereto, and the method 700 may be implemented with any electric machine without departing from the scope of the present disclosure.

[0098] At 710 , method 700 includes disposing a set of rotor windings 110 extending from rotor core 100 into corresponding slots 185 defined in support disk 144 coupled to rotatable shaft 40 extending from rotor core 100 .

[0099] At 720, method 700 may include coupling a first wall 151 of first collar 141 to a coupling disk 143 circumferentially surrounding and coupled to rotatable shaft 40, and coupling a second wall 152 of first collar 141 to a radially outer periphery 189 of support disk 144. A non-limiting example of coupling the second wall 152 of first collar 141 to the radially outer periphery 189 of support disk 144 may include a press fit.

[0100] At 730, method 700 may include coupling the third wall 253 of the second collar 142 to the coupling disk 143 between the first wall 151 and the support disk 144. A non-limiting example of coupling the third wall 253 of the second collar 142 to the coupling disk 143 may include a press fit.

[0101] At 740, the method 700 may include disposing a set of rotor winding end turns 112 into a cavity 275 extending radially between the coolant distribution ring 145 and the fourth wall 254 of the second collar 142. In a non-limiting aspect, the cavity may extend axially between the support disk 144 and the third wall 253 of the second collar 142. In a non-limiting aspect, the cavity 275 may extend radially between the coolant distribution ring 145 and the fourth wall 254 of the second collar 142.

[0102] At 745, the method 700 may include routing the fluid coolant flow 85 radially outward from the rotatable shaft 40 to the coupling disk 143. A non-limiting example of routing the fluid coolant flow 85 to the coupling disk 143 may include routing the fluid coolant flow 85 through the rotatable shaft 40 via the first coolant conduit 250. The first coolant conduit 250 may include a radially extending portion 259 through which the fluid coolant flow 85 may flow radially outward from the axis of rotation 41 due to the centrifugal force of the rotatable shaft 40.

[0103] At 750, method 700 may include delivering fluid coolant flow 85 through coupling disk 143 to coolant distribution ring 145. For example, due to the centrifugal force of rotatable shaft 40 driving the rotation of coupling disk 143, fluid coolant flow 85 may be delivered radially outward through a set of apertures 258 defined through sixth wall 156 of coupling disk 143.

[0104] At 755, method 700 may include delivering the fluid coolant flow 85 radially outward through the coolant distribution ring 145 to the cavity 275. For example, the fluid coolant flow 85 may be delivered radially outward through a set of channels 627 extending radially through the coolant distribution ring 145 due to the centrifugal force of the rotatable shaft 40 driving the rotation of the coolant distribution ring 145.

[0105] At 760, the method 700 may include routing the fluid coolant flow 85 radially through the end turn passages 114 defined between adjacent rotor winding end turns 112. Heat from a set of rotor winding end turns 112 is transferred by conduction to the fluid coolant flow 85. The conduction of heat to the fluid coolant flow 85 may cause the fluid coolant flow 85 to remove heat from the rotor assembly 96.

[0106] At 765 , the method 700 may include delivering the fluid coolant flow 85 from the end turn passage 114 to the fourth wall 254 of the second collar 142 .

[0107] At 770, the method 700 may include routing the fluid coolant flow 85 from the cavity 275 through the corresponding slots 185 defined in the support disk 144. For example, in non-limiting aspects, routing the fluid coolant flow 85 axially inward from the cavity 275 may include routing the fluid coolant flow 85 axially inward toward the rotor core 100 or radially outward toward the stator 54, or both.

[0108] The depicted order is for illustrative purposes only and is not intended to limit method 700 in any way, as it will be appreciated that portions of the method may be performed in a different logical order, may include additional or intervening portions, or described portions of the method may be divided into multiple portions, or described portions of the method may be omitted without detracting from the described method.

[0109] The present disclosure also contemplates many other possible aspects and configurations in addition to those shown in the above-described figures. For example, one aspect of the present disclosure contemplates coolant conduits extending along alternative portions or lengths of a set of rotor windings. In another example, the windings or coolant conduits may also include intervening heat-conductive layers to facilitate heat conduction while, for example, avoiding conductive relationships between corresponding components. Additionally, the design and placement of various components such as valves, pumps, or conduits may be rearranged so that many different in-line configurations may be achieved.

[0110] Aspects as disclosed herein improve upon existing methods by securing, protecting, and constraining the rotor winding end turns 112. Aspects as disclosed herein prevent movement of the rotor winding end turns 112 and provide mechanical and electrical isolation between the rotor winding end turns 112 and nearby parts.

[0111] Aspects disclosed herein provide methods and apparatus for cooling a set of rotor windings or a set of rotor winding end turns during electric machine operation (e.g., motor or generator operation). One advantage that can be achieved in the above aspects is that the above aspects have significantly improved heat transfer to remove heat from a set of rotor windings or a set of rotor winding end turns. The improved heat transfer between a set of rotor winding end turns and a coolant conduit coupled to a coolant channel provides for heat removal from the rotor winding end turns to the coolant in a much more efficient manner.

[0112] Increased heat dissipation of the rotor winding end turns allows for higher speed rotation of the rotor, which otherwise might generate too much heat. Higher speed rotation can result in improved power generation or improved generator efficiency without increasing the size of the generator. Reduced heat losses in the motor allow for higher efficiency and greater power density of the generator.

[0113] Reliability is also an important feature when designing aircraft components. The above-described rotor end winding support assembly can provide additional physical stability and improved cooling for the rotor winding end turns. The stability and cooling provided by aspects as described herein allow for improved performance and reliability.

[0114] To the extent not yet described, the different features and structures of each aspect may be used in combination with each other as desired. The fact that a feature may not be shown in all aspects is not intended to be interpreted as it cannot be, but is done so for the sake of brevity of description. Therefore, various features of different aspects may be mixed and matched as desired to form new aspects, whether or not these new aspects are explicitly described. The present disclosure covers the combination or arrangement of the features described herein.

[0115] This written description uses examples to disclose aspects of the disclosure, including the best mode, and also enables any person skilled in the art to practice aspects of the disclosure, including making and using any device or system and performing any combined methods. The patentable scope of the disclosure is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

[0116] Further aspects of the disclosure are provided by the subject matter of the following clauses:

[0117] A support assembly for a set of rotor winding end turns extending from a rotor core of an electric machine having a rotatable shaft, the support assembly comprising: a first collar including a first wall, the first wall having an annular first surface facing an axial end of the rotor core, an opposite annular second surface and an annular third surface, the annular third surface defining a first hole extending from the annular first surface to the annular second surface, the first collar also including an annular second wall coupled to the first wall and extending axially toward the rotor core from the first wall, the annular second wall being arranged radially above the rotor winding end turns, the annular second wall having an annular fourth surface facing radially outward and an opposite annular fifth surface facing the rotor winding end turns; a second collar axially disposed between the rotor core and the first collar, including a third wall disposed between the first wall and the rotor winding end turns, the third The wall has an annular sixth surface facing the axial end of the rotor core, an opposite seventh surface, the third wall also includes an annular eighth surface defining a second hole, the second collar also includes an annular fourth wall connected to the third wall and extending axially from the third wall toward the rotor core and arranged between the rotor winding end turns and the annular second wall; and a coupling disk, which includes an annular fifth wall facing the axial end of the rotor core, the coupling disk also includes an annular sixth wall connected to the annular fifth wall and extending axially from the annular fifth wall toward the rotor core and radially below the rotor winding end turns, the annular sixth wall circumferentially surrounding and connected to the rotatable shaft; wherein the first collar is connected to the annular fifth wall along the annular third surface at the outer periphery of the coupling disk, and wherein the second collar is connected to the coupling disk along the annular eighth surface.

[0118] A support assembly according to the preceding clause, wherein the second collar is electrically insulating.

[0119] A support assembly according to any preceding clause, further comprising a support disk defining a fourth aperture and a radial outer periphery, the fourth aperture being sized to receive the rotatable shaft therethrough, the support disk further defining a set of radially extending first slots sized to axially receive corresponding rotor windings therein, the support disk being coupled to the rotatable shaft at the fourth aperture and being axially disposed between the rotor core and the second collar; and wherein the annular fifth surface of the first collar is coupled to the radial outer periphery of the support disk.

[0120] A support assembly according to any preceding clause, wherein the annular fifth surface of the first collar is coupled to the radially outer periphery of the support disc via an interference fit.

[0121] A support assembly as described in any preceding clause, wherein the coupling disc is coupled to the rotatable shaft via an interference fit.

[0122] A support assembly according to any preceding clause, further comprising a coolant distribution ring defining a central fifth aperture and circumferentially surrounding and coupled to the annular sixth wall of the coupling plate, the coolant distribution ring being radially disposed between the annular sixth wall and end turns of the rotor winding.

[0123] A support assembly as described in any preceding clause, wherein a cavity is defined radially between the coolant distribution ring and the second collar, and wherein the rotor winding end turns extend into the cavity.

[0124] A support assembly as described in any preceding clause, wherein the coolant distribution ring comprises a set of radially extending channels defined therethrough in fluid communication with the set of rotor winding end turns.

[0125] A support assembly according to any preceding clause, wherein the annular sixth wall of the coupling plate defines a set of apertures extending radially therethrough in fluid communication with the coolant distribution ring.

[0126] A support assembly as described in any preceding clause, wherein the annular fourth wall of the second collar includes a radially inwardly facing tenth surface defining a set of axially extending grooves in fluid communication with the coolant distribution ring.

[0127] A support assembly as described in any preceding clause, wherein the axially extending groove defines a taper.

[0128] A support assembly as described in any preceding clause, wherein the radially inwardly facing tenth surface further defines a set of circumferentially extending grooves in fluid communication with the axially extending grooves.

[0129] A support assembly according to any of the preceding clauses, further comprising a spacer disk axially disposed between the support disk and the coolant distribution ring and rotatably coupled to the rotatable shaft, the spacer disk further comprising a radially outer surface defining a set of radially extending, circumferentially spaced second slots sized to receive corresponding rotor windings therein.

[0130] A support assembly as described in any preceding clause, wherein the spacer disc is formed from an electrically insulating material.

[0131] A support assembly as described in any preceding clause, wherein respective rotor winding end turns extend through corresponding second slots.

[0132] A method for cooling a set of rotor winding end turns of a rotor core of an electric machine, comprising: disposing a set of rotor windings extending from the rotor core into corresponding first slots defined in a support disk, the support disk being coupled to a rotatable shaft extending from the rotor core; coupling a first wall of a first collar to a coupling disk circumferentially surrounding and coupled to the rotatable shaft, and coupling a second wall of the first collar to a radially outer periphery of the support disk; coupling a third wall of a second collar to the coupling disk between the first wall and a spacer disk; disposing a set of rotor winding end turns into a cavity radially defined between a coolant distribution ring and a fourth wall of the second collar and axially defined between the support disk and the third wall of the second collar, the fourth wall being coupled to the third wall and extending axially from the third wall toward the rotor core; delivering a fluid coolant flow radially outward from the rotatable shaft to the coupling disk; delivering the fluid coolant flow through the coupling disk to the coolant distribution ring; and delivering the fluid coolant flow radially outward through the coolant distribution ring to the cavity.

[0133] A method according to any preceding clause, further comprising delivering the fluid coolant flow radially through end turn passages defined between adjacent rotor winding end turns.

[0134] A method as in any preceding clause, further comprising delivering the fluid coolant flow from the end turn passage to the fourth wall of the second collar.

[0135] A method according to any preceding clause, further comprising conveying the flow of fluid coolant from the cavity through the respective first slots defined in the support plate.

[0136] The method of any preceding clause, wherein conveying the fluid coolant flow from the cavity comprises conveying the fluid coolant flow axially inwardly and radially outwardly.

Claims

1. A support assembly for a set of rotor winding end turns extending from a rotor core of an electric machine having a rotatable shaft, the support assembly comprising: a first collar including a first wall having an annular first surface facing an axial end of the rotor core, an opposite annular second surface, and an annular third surface, the annular third surface defining a first hole extending from the annular first surface to the annular second surface, the first collar also including an annular second wall coupled to the first wall and extending axially from the first wall toward the rotor core, the annular second wall being arranged radially above the rotor winding end turns, the annular second wall having an annular fourth surface facing radially outward and an opposite annular fifth surface facing the rotor winding end turns; a second collar, axially disposed between the rotor core and the first collar, comprising a third wall disposed between the first wall and the rotor winding end turns, the third wall having an annular sixth surface facing the axial end of the rotor core, an opposite seventh surface, the third wall further comprising an annular eighth surface defining a second hole, the second collar further comprising an annular fourth wall coupled to the third wall and extending axially from the third wall toward the rotor core and disposed between the rotor winding end turns and the annular second wall; as well as a coupling plate including an annular fifth wall facing the axial end of the rotor core, the coupling plate further including an annular sixth wall coupled to the annular fifth wall and extending axially from the annular fifth wall toward the rotor core and radially below the rotor winding end turns, the annular sixth wall circumferentially surrounding and coupled to the rotatable shaft; wherein the first collar is coupled to the annular fifth wall along the annular third surface at an outer periphery of the coupling disc, and wherein the second collar is coupled to the coupling disc along the annular eighth surface.

2. The support assembly according to claim 1, wherein: The second collar is electrically insulating.

3. The support assembly of claim 1 further comprising a support disk defining a fourth aperture and a radially outer periphery, the fourth aperture being sized to receive the rotatable shaft therethrough, the support disk further defining a set of radially extending first slots sized to axially receive corresponding rotor windings therein, the support disk being coupled to the rotatable shaft at the fourth aperture and being axially disposed between the rotor core and the second collar; in, The annular fifth surface of the first collar is coupled to the radially outer periphery of the support disk.

4. The support assembly according to claim 3, wherein: The annular fifth surface of the first collar is coupled to the radially outer periphery of the support disk via an interference fit.

5. The support assembly according to claim 1, wherein: The coupling disk is coupled to the rotatable shaft via an interference fit.

6. The support assembly of claim 3 further comprising a coolant distribution ring defining a central fifth aperture and circumferentially surrounding and coupled to the annular sixth wall of the coupling plate, the coolant distribution ring being radially disposed between the annular sixth wall and end turns of the rotor winding.

7. The support assembly according to claim 6, wherein: A cavity is defined radially between the coolant distribution ring and the second collar, and wherein the rotor winding end turns extend into the cavity.

8. The support assembly according to claim 6, wherein: The coolant distribution ring includes a set of radially extending passages defined therethrough in fluid communication with the set of rotor winding end turns.

9. The support assembly according to claim 6, wherein: The annular sixth wall of the coupling plate defines a set of apertures extending radially therethrough in fluid communication with the coolant distribution ring.

10. A method of cooling a set of rotor winding end turns of a rotor core of an electric machine, comprising: disposing a set of rotor windings extending from the rotor core into respective first slots defined in a support disk coupled to a rotatable shaft extending from the rotor core; coupling a first wall of a first collar to a coupling disk circumferentially surrounding and coupled to the rotatable shaft, and coupling a second wall of the first collar to a radially outer periphery of the support disk; coupling a third wall of the second collar to the coupling plate; disposing a set of rotor winding end turns into a cavity radially defined between a coolant distribution ring and a fourth wall of the second collar and axially defined between the support disk and the third wall of the second collar, the fourth wall being coupled to the third wall and extending axially from the third wall toward the rotor core; delivering a flow of fluid coolant radially outward from the rotatable shaft to the coupling disk; delivering the fluid coolant flow through the coupling plate to the coolant distribution ring; and The fluid coolant flow is delivered radially outward through the coolant distribution ring to the cavity.

Images