Rotor assembly and method of cooling

Abstract

A rotor assembly includes a rotor core having a rotatable shaft and defining at least one rotor post, a winding wound around the post defining an end turn, and a winding support assembly coupled to the rotatable shaft. The end turns define a set of channels therethrough and are disposed in a first chamber defined by the winding support assembly.

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 isometric view of the rotor assembly and winding supports of a generator.

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

[0008] Figure 5B According to the various aspects described in this article Figure 5A A perspective view of a second side of the first winding support disk.

[0009] Figure 5C According to the various aspects described in this article Figure 5B The line VII-VII intercepts Figure 5B Cross section of the first winding support disk.

[0010] Figure 6 According to the various aspects described in this article Figure 5C A perspective view of the fourth wall of the first winding support disk.

[0011] Figure 7The present invention illustrates various aspects of the present invention. Figure 4 Isometric view of the second winding support disk of the rotor assembly.

[0012] Figure 8 According to the various aspects described in this article Figure 4 An isometric view of the exterior of the rotor assembly.

[0013] Fig. 9 The present invention illustrates various aspects of the present invention. Figure 4 An enlarged cross-sectional view of a winding support assembly of a rotor assembly.

[0014] Fig.10 An exemplary flow chart of a method of cooling a rotor assembly according to various aspects described herein is illustrated.

[0015] Fig.11 An exemplary method flow chart of a method of assembling a winding support assembly according to various aspects described herein is illustrated. DETAILED DESCRIPTION

[0016] Aspects of the present disclosure may be implemented in any environment where electric motors are used, whether the electric 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 a 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 facilitate a more comprehensive understanding.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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).

[0021] 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.

[0022] 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.

[0023] The aspects of the present disclosure described herein are directed to motors, and more specifically to rotor assemblies for motors. As described herein, a 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 to form a coil. For purposes 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.

[0024] 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 groups of conductive rotor windings or coils. The rotor windings can be wound axially around a group of posts or rotor teeth, thereby defining slots between the 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.

[0025] 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).

[0026] 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.

[0027] 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.

[0028] Additionally, the rotor end winding support structure is 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.

[0029] 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 expensive assembly.

[0030] 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 damage, and to increase the motor power density to allow more power from a smaller physical size electric motor.

[0031] The exemplary drawings are for illustration purposes only, and the dimensions, positions, order, and relative sizes reflected in the drawings attached hereto may vary.

[0032] Figure 1 A gas turbine engine 10 having an auxiliary gearbox (AGB) 12 and an electric motor 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 or motor, such as, but not limited to, a motor or generator.

[0033] Figure 2A 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.

[0034] 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.

[0035] exist Figure 3 The non-limiting interior of the generator 14 is best seen in Figure 3 yes Figure 2The 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 various 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 includes 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.

[0036] 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.

[0037] At least one of the rotor poles and the stator poles may be formed from a core with a post and a wire wound around the post to form a winding, wherein the winding has at least one 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.

[0038] 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.

[0039] As explained above, the generator 14 may use a cooling fluid such as oil, and therefore may include a cooling system 80. The cooling oil or fluid may be used to dissipate the 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.

[0040] 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.

[0041] Figure 4 A partially exploded perspective view of a rotor assembly 96, such as for a main electric machine, is illustrated. As shown, the rotor assembly 96 may include a rotor core 100, such as a laminated rotor core, which is rotatably connected to rotate with the rotatable shaft 40. The rotor assembly 96 may include a set of winding support assemblies 130. Each winding support assembly 130 may include a first winding support disk 131, a second winding support disk 132, and a retaining ring 133, respectively.

[0042] The rotor assembly 96 may also define a first end 102 and a 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 around respective rotor posts 108. 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 the 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.

[0043] 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. Each set of rotor winding end turns 112 may define a circumferential width 112a, a radial height 112b, and an axial length 112c. In non-limiting aspects, each bend 113 may also define a respective channel 116 extending radially therethrough. For example, in non-limiting aspects, each respective 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 between immediately adjacent rotor winding end turns 112.

[0044] A respective winding support assembly 130 may be rotatably 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 winding support assembly 130. In non-limiting aspects, the respective winding support assembly 130 may be coupled to one end (e.g., the first end 102 or the second end 104) of the rotor assembly 96. In other aspects, the respective winding support assembly 130 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.

[0045] The first winding support disk 131 may be an annular member having a first side 131a that faces axially inward (e.g., toward the rotor core 100) defining a first surface 141 and a second side 131b that faces axially outward (e.g., away from the rotor core 100) defining a second surface 142. In a non-limiting aspect, the first winding support disk 131 may include an annular first wall 151 that defines a radially inwardly facing third surface 143. In a non-limiting aspect, the first winding support disk 131 may define a set of first fastener apertures 161 that are sized to receive fasteners therethrough.

[0046] The third surface 143 may define a hole 146 extending from the first surface 141 to the second surface 142, and the hole 146 is sized to receive the rotatable shaft 40 therethrough. In non-limiting aspects, the third surface 143 may be in fluid communication with the rotatable shaft 40 and configured to receive the fluid coolant flow 85 from the rotatable shaft 40. As such, in non-limiting aspects, the third surface 143 may define a coolant collection surface. The first winding support disk 131 may be fixed to the rotatable shaft 40 via the third surface 143 using one or more bolts, screws, pins, keys, splines, or other known fasteners (not shown). In other non-limiting aspects, the first winding support disk 131 may be coupled to the rotatable shaft 40 via an interference fit, friction, or press fit engagement between the first winding support disk 131 and the rotatable shaft 40. Other aspects are not so limited, and it is contemplated that the first winding support disk 131 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 a corresponding rotation of the first winding support disk 131 .

[0047] The second winding support disk 132 may include a radially inner or radially central portion 138 and a radially outer portion 134 (e.g., a peripheral portion) disposed radially outward from the radially central portion 138. In various aspects, the radially central portion 138 may define a hole 135 therethrough. In non-limiting aspects, the radially central portion 138 may be coupled to the radially outer portion 134 via a set of radially extending spokes 136. For example, in some aspects, each spoke 136 may include a first end 136a coupled to the radially central portion 138 and an opposite second end 136b coupled to the radially outer portion 134. The spokes 136 may be circumferentially spaced apart from each other around the second winding support disk 132.

[0048] In non-limiting aspects, the number of spokes 136 may correspond to the number of rotor poles 106 of the rotor assembly 96. In various aspects, each spoke 136 may be operatively disposed between the rotor core 100 and a corresponding set of rotor winding end turns 112. For example, in non-limiting aspects, each spoke 136 may be disposed within a corresponding channel 116 and extend radially through the channel 116. In this sense, each set of rotor winding end turns 112 may be at least partially wrapped or wrapped around a corresponding spoke 136. In non-limiting aspects, each corresponding spoke 136 may have a width defined by the width of the corresponding rotor post 108. Other aspects are not so limited, and each corresponding spoke 136 may have a width that is narrower than the corresponding rotor post 108 or wider than the corresponding rotor post 108 without departing from the scope of the present disclosure.

[0049] In some aspects, each spoke 136 can be at least partially surrounded by a corresponding set of rotor winding end turns 112 and can provide support or limit axial deflection or relative axial movement for the corresponding set of rotor winding end turns 112. The radial center portion 138 of the second winding support disk 132 can be 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.

[0050] In non-limiting aspects, the second winding support disk 132 can receive the rotatable shaft 40 through the hole 135. The second winding support disk 132 can be fixed to the rotatable shaft 40 using one or more bolts, screws, pins, keys or other known fasteners. In other non-limiting aspects, the second winding support disk 132 can be coupled to the rotatable shaft 40 via an interference fit, friction or press fit engagement between the second winding support disk 132 and the rotatable shaft 40. Other aspects are not so limited, and it is contemplated that the second winding support disk 132 can 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 second winding support disk 132.

[0051] Although Figure 4 A non-limiting example of a second winding support disk 132 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 second winding support disk 132 may be applicable to rotor assemblies 96 having any desired number of poles.

[0052] In non-limiting aspects, the radially outer portion 134 of the second winding support disk 132 may include a set of elements or segments 137. In non-limiting aspects, the segments 137 may be circumferentially spaced from each other. Each segment 137 may be coupled to a corresponding second end 136b of a corresponding spoke 136. In non-limiting aspects, the number of segments 137 may correspond to the number of rotor poles 106 of the rotor assembly 96. In non-limiting aspects, one or more of the segments 137 may define a set of second fastener apertures 162, which are sized to receive fasteners therethrough. In various aspects, the second fastener apertures may be arranged to align with the first fastener apertures 161.

[0053] As shown, in some aspects, the segments 137 may define an arcuate shape. Other aspects are not limited thereto, and the segments 137 may define any desired shape without departing from the scope of the present disclosure. Each segment 137 may include a corresponding outwardly facing radially outer surface 137b and an opposite inwardly facing radially inner surface 137a. In non-limiting aspects, the radially inner surface 137a may be below at least a portion of the radially outer surface 137b.

[0054] The radially outer portion 134 (e.g., the segment 137) can 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. For example, in non-limiting aspects, each segment 137 can be above a corresponding set of rotor winding end turns 112. In this manner, each segment can limit radial deflection or relative radial movement of the corresponding set of rotor winding end turns 112.

[0055] In non-limiting aspects, the retaining ring 133 may be arranged to surround the first winding support disk 131 or the second winding support disk 132 or both. For example, the retaining ring 133 may include an annular first leg 133a and an annular second leg 133b. The first leg 133a may be above the first winding support disk 131 or radially around the first winding support disk 131. The second leg 133b may be arranged transversely to the first leg 133a. For example, the second leg 133b may extend radially inward away from the first leg 133a and be arranged to face the second side 131b of the first winding support disk 131. In non-limiting aspects, the retaining ring 133 may define a set of third fastener apertures 163, which are sized to receive fasteners therethrough. The retaining ring 133 may be rigidly or fixedly coupled to the first winding support disk 131 or the second winding support disk 132 or both. For example, the retaining ring 133 may be coupled to the first winding support disk 131 using bolts or other fasteners 118 disposed through respective third fastener apertures 163 and respective first fastener apertures 161 or second fastener apertures 162, or a combination thereof. In other aspects, the retaining ring 133 may additionally or alternatively be coupled to the second winding support disk 132 via fasteners 118. It will be appreciated that when so coupled, rotation of the rotatable shaft 40 will result in corresponding rotation of the second winding support disk 132 and the retaining ring 133. When so arranged, the retaining ring 133 and the second winding support disk 132 may limit or prevent radial deflection or relative radial movement of the first winding support disk 131. Additionally, in some aspects, the retaining ring 133 and the first winding support disk 131 may cooperatively limit axial deflection or relative axial movement of the rotor winding end turns 112.

[0056] Will also refer to Figure 5A , Figure 5B and Figure 5C Non-limiting aspects of the first winding support disk 131 are described in further detail. Figure 5A A perspective view of exemplary, non-limiting aspects of the first side 131 a of the first winding support disk 131 is depicted. Figure 5B A perspective view of another non-limiting aspect of the first winding support disk 131 relative to the second side 131b is depicted, and Figure 5C Depicted is the observation from line IV-IV Figure 5B A cross-sectional view of the first winding support disk 131. Figure 5A A non-limiting example of a first winding support disk 131 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 that these aspects may be applicable to rotor assemblies 96 having any desired number of poles.

[0057] like Figure 5AAs shown in FIG. 1 , in non-limiting aspects, the first side 131a of the first winding support disk 131 may include a second wall 152 and a third wall 153. In some non-limiting aspects, as shown in FIG. Figure 5C As shown in , the first winding support disk 131 may also include a fourth wall 154. In addition, the first wall 151 may also define a radially outwardly facing fourth surface 144 that is spaced apart from the third surface 143. It will be appreciated that while various aspects are described herein as having a single first wall 151, second wall 152, third wall 153, and fourth wall 154 for ease of description and brevity, other aspects are not limited thereto and may include any number of first walls 151, second walls 152, third walls 153, and fourth walls 154 as desired without departing from the scope of the present disclosure. For example, in a non-limiting aspect, the rotor core 100 may include a set of rotor winding end turns 112 (such as Figure 4 ), and the first winding support plate 131 may include a plurality of first walls 151, second walls 152, third walls 153 and fourth walls 154 (as shown in Figure 5A ), which each correspond to a corresponding rotor winding end turn 112.

[0058] In some aspects, the third surface 143 can be a relatively smooth surface. In other non-limiting aspects, the third surface 143 can define one or more channels or grooves 143a thereon. The one or more grooves 143a can surround the rotatable shaft 40 ( Figure 4 ). The one or more grooves 143a may be arranged to be in fluid communication with the rotatable shaft 40. As such, the one or more grooves 143a may operatively define a coolant reservoir.

[0059] The second wall 152 and the third wall 153 may extend radially outward from the fourth surface 144 and axially inward from the first surface 141. The second wall 152 and the third wall 153 are circumferentially spaced from each other to define a circumferential gap 167a therebetween. In non-limiting aspects, the circumferential gap 167a may be defined by a distance equal to or greater than the circumferential width 112a of the corresponding set of rotor winding end turns 112. As such, during assembly, the corresponding set of rotor winding end turns 112 ( Figure 4 ) can be snugly received in the circumferential gap 167a and held between the second wall 152 and the third wall 153. Further, in non-limiting aspects, the second wall 152 and the third wall 153 can have respective axial lengths ( 112c ) equal to the axial length 112c of the corresponding set of rotor winding end turns 112. Figure 4 ).

[0060] The fourth wall 154 can extend between the second surface 142 and the third surface 143 and extend axially inward from the first surface 141 (e.g., toward the Figure 414. The fourth wall 154 is radially spaced apart from the fourth surface 144 in a radially outward relationship. In a non-limiting aspect, the fourth wall 154 can be fixedly coupled to the first surface 141 of the first wall 151. In a non-limiting aspect, the fourth wall 154 can be radially spaced apart from the fourth surface 144 by a distance equal to or greater than a radial height 112b of a corresponding set of rotor winding end turns 112. As such, during assembly, a corresponding set of rotor winding end turns 112 ( Figure 4 ) can be snugly received and held between the second wall 152 and the third wall 153.

[0061] like Figure 5C As shown in FIG. 1 , in non-limiting aspects, the second wall 152, the third wall 153, the fourth wall 154, the fourth surface 144 of the first wall 151, and the first surface 141 of the first winding support disk 131 (as shown in FIG. Figure 4 ) are arranged to cooperatively define a first chamber 181 therebetween. The first chamber 181 is sized to receive the rotor winding end turns 112 ( Figure 4 ).

[0062] The first wall 151 may also include a set of first channels 171 defined therethrough. The first channels 171 may be sized to allow a coolant fluid to flow therethrough. In non-limiting aspects, the first channels 171 may be circumferentially spaced apart from each other around the first wall 151. Each first channel 171 may extend radially from a first end 171a at the third surface 143 to an opposite second end 171b at the fourth surface 144. As such, each second end 171b is disposed radially outward from the corresponding first end 171a. Each first channel 171 may include a coolant inlet 174a defined on the third surface 143, and a corresponding coolant outlet 174b defined on the fourth surface 144 at the opposite second end 171b.

[0063] In various aspects, the first channel 171 can be in fluid communication with the third surface 143 or one or more grooves 143a or both to receive a fluid coolant flow therefrom. Each coolant outlet 174b can be a respective spray nozzle and can be disposed on the fourth surface 144 at circumferentially spaced intervals.

[0064] The second surface 142 of the first wall 151 may define a recess 165 or seat portion defined thereon. The recess 165 may be annular and disposed along the radially outer circumferential periphery of the second side 131b of the first wall 151. The recess 165 may be recessed from an adjacent or abutting portion of the second surface 142 by a depth D1. The depth D1 may be based on the second leg 133b ( Figure 4142 and 143, respectively, to provide a seating surface for the second leg 133b. In this manner, when assembled, the recess 165 or seat portion can receive the second leg 133b of the retaining ring such that the second surface 142 and the second leg 133b cooperatively define a continuous axially outwardly facing surface.

[0065] In non-limiting aspects, the fourth wall 154 can be formed as an integral part of the first winding support disk 131. For example, in some aspects, the first winding support disk 131 and the fourth wall 154 can be molded or otherwise formed as a single structure. In other non-limiting aspects, the fourth wall 154 can include a separate element from the first winding support disk 131.

[0066] For example, refer to Figure 6 , illustrates a non-limiting example of aspects of the fourth wall 154. As shown, the fourth wall can define a set of apertures or passages 169 extending radially therethrough.

[0067] Figure 7 1 is an isometric view of a non-limiting aspect of the second winding support disk 132. The radially outer portion 134 of the second winding support disk 132 may include a set of second channels 156 defined therethrough. The second channels 156 may be sized to allow a cooling fluid (e.g., oil) to flow therethrough. In some aspects, each segment 137 may include one or more corresponding second channels 156. In other aspects, only a subset of the segments 137 may include one or more second channels 156. Each second channel 156 may include a coolant inlet 156a defined by a corresponding radial inner surface 137a at the opposite second end of the second channel 156 and a coolant outlet 156b defined by a corresponding radial outer surface 137b. In non-limiting aspects, each second channel 156 may be defined by a corresponding fluid collection surface 159 disposed between the coolant inlet 156a and the coolant outlet 156b. The fluid collection surface 159 may extend radially through the corresponding segment 137. In a non-limiting aspect, each coolant inlet 156a of the second winding support disk 132 may be coupled in fluid communication with a corresponding fluid collection surface 159 .

[0068] Figure 8Non-limiting aspects of the rotor assembly 96 with the first winding support disk 131 and the retaining ring 133 installed are depicted. The retaining ring 133 is shown as being secured to the first winding support disk 131 via fasteners 118. As shown, the retaining ring 133 can be arranged to surround the first winding support disk 131. For example, the retaining ring 133 can be above or radially around the periphery of the winding support disk 131. An annular gap 170 can be defined between the retaining ring 133 and the rotor core 100. The second leg 133b is depicted as being received on the recess 165 in a nested relationship. As can be seen, the second leg 133b of the retaining ring 133 and the first winding support disk 131 cooperatively define a continuous axially outwardly facing surface 166 via a nested relationship. By arranging the continuous axially outwardly facing surface 166, undesirable gaps, openings or other discontinuities can be reduced compared to conventional arrangements, and a beneficial reduction in windage losses caused thereby can be obtained.

[0069] Furthermore, the retaining ring 133 can limit or prevent axial movement of the first winding support disk 131. Additionally, in various aspects, the retaining ring 133 and the second winding support disk 132 can cooperatively limit radial deflection or relative movement of the rotor winding end turns 112.

[0070] Fig. 9 Picture shows Figure 4 96 to better understand the operation of various non-limiting aspects. As illustrated, a winding support assembly 130 including a first winding support disk 131 and a second winding support disk 132 is rotatably coupled to the rotatable shaft 40. The second winding support disk 132 may include a radially inner or radially central portion 138 and a radially outer portion 134 disposed radially outward from the radially central portion 138.

[0071] The retaining ring 133 is rotatably coupled to the second winding support disk 132, for example, via fasteners 118 (not shown). The fourth wall 154 is coupled to the first winding support disk 131 and cooperates with the second wall 152, the third wall 153, the fourth surface 144 of the first wall 151, and the first surface 141 of the first winding support disk 131 to define a first chamber 181. The rotor winding end turns 112 can be retainedly received within the first chamber 181. The retaining ring 133 surrounds the first winding support disk 131. For example, the retaining ring 133 may include a first leg 133a and a second leg 133b. The first leg 133a may be above the first winding support disk 131 or radially around the first winding support disk 131. The second leg 133b may be arranged transversely to the first leg 133a. The first leg 133a may be radially spaced from and around the fourth wall 154. When so arranged, the first leg 133a, the fourth wall 154 and the first surface 141 of the first winding support disk 131 may cooperatively define a second chamber 182 therebetween. Fig. 9, the radially outer portion 134 of the second winding support disk 132 may be disposed in the second chamber 182. A set of radially extending end turn passages 114 are arranged to be in fluid communication with the passage 169 defined through the fourth wall 154. A set of radially extending end turn passages 114 fluidly couple each first channel 171 to the coolant inlet 156a of the second winding support disk 132 and the corresponding fluid collection surface 159. The annular gap 170 is arranged to extend radially between the retaining ring 133 and the rotor core 100. The insulating layer 180 may be axially located between at least a portion of the rotor core 100 and the winding support assembly 130.

[0072] refer to Figure 4 During 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 further generates heat in the set of rotor windings 110 and the stator windings 90. According to aspects described herein, a coolant fluid may enter the rotatable shaft 40 of the rotor assembly 96 via the inlet port 82.

[0073] Reference again Fig. 9 In operation, a fluid coolant flow (indicated by solid arrows) 85 is delivered from the rotatable shaft 40 to a set of rotor winding end turns 112 and stator winding end turns (not shown). For example, the rotatable shaft 40 may define a coolant conduit 150 that is fluidly connected to a coolant source 155. The coolant source 155 may be, but is not limited to, a cooling fluid inlet port 82 ( Figure 3 ). The direction or location of the coolant source 155 is not limited by the illustrations and is contemplated to be in any location that is fluidly coupled to the coolant conduit 150. It is further contemplated that additional conduits, pumps, valves, or other devices may be included to fluidly connect the coolant source 155 and the coolant conduit 150. The fluid coolant flow 85 may be conveyed through the rotatable shaft 40 via the coolant conduit 150. The coolant conduit 150 may include a radially extending portion 157 through which the fluid coolant flow 85 may flow radially outward from the axis of rotation 41 due to the centrifugal force of the rotation of the rotatable shaft 40 during operation. The radially extending portion 157 fluidly couples the coolant conduit 150 and the first winding support disk 131.

[0074] The first winding support disk 131 may then receive the fluid coolant flow 85 from the coolant conduit 150 at the third surface 143, for example, via the radially extending portion 157. For example, the fluid coolant flow 85 may be collected on or in one or more grooves 143a. The fluid coolant flow 85 may then be centrifugally delivered from the third surface 143 to the coolant inlet 174a of the first channel 171, and further centrifugally delivered to the coolant outlet 174b through the first channel 171. The coolant outlet 174b may be arranged to provide the fluid coolant flow 85 radially outward therefrom. For example, in a non-limiting aspect, the coolant outlet 174b 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 first chamber 181.

[0075] The fluid coolant stream 85 is then centrifugally delivered to the end turn passages 114. The fluid coolant stream 85 may flow radially outward through the end turn passages 114 passing between the rotor windings 110. Heat from a set of rotor windings 110 may be transferred to the fluid coolant stream 85 by conduction. The fluid coolant stream 85 may radially exit from the radially extending end turn passages 114 and pass through the radially extending passages 169 defined through the fourth wall 154.

[0076] In non-limiting aspects, the fluid collection surface 159 of the second winding support disk 132 is arranged to receive the fluid coolant flow 85 from the radially extending passage 169 defined through the fourth wall 154. The fluid coolant flow 85 received by the fluid collection surface 159 (such as in a radially outward direction) is delivered to the second passage 156. For example, the fluid coolant can be collected by the fluid collection surface 159 and redirected toward the coolant outlet 156b via the corresponding second passage 156, such as in an axially inward direction (e.g., toward the rotor core 100). Additionally or alternatively, the second passage 156 can be angled (shown as angle 168) relative to the rotation axis 41 so that the second passage 156 receives the fluid coolant flow 85 and redirects the received fluid coolant flow 85 radially outward from the rotor end turn passage 114. The angle 168 can be configured to further radially redirect the fluid conveyed by the second passage 156 outward to discharge the fluid coolant flow 85 through the annular gap 170. Optionally, the coolant outlet 156 b may be configured to direct the coolant toward a set of stator windings (not shown) or a set of stator winding end turns (not shown) above the rotor winding end turns 112 .

[0077] 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.

[0078] Fig.10 A method 200 for 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 200 may be applied to any electric machine. Figures 4 to 9 The method is described with respect to the rotor assembly 96 illustrated in FIG. 2 , but is otherwise not limited thereto and the method 200 may be implemented with an electric machine and a rotor assembly without departing from the scope of the present disclosure.

[0079] For example, in non-limiting aspects, the winding support assembly 130 including the first winding support disk 131 and the second winding support disk 132 may be rotatably coupled to the rotatable shaft 40. The retaining ring 133 may be rotatably coupled to the second winding support disk 132. The fourth wall 154 may be coupled to the first winding support disk 131, cooperating with the second wall 152, the third wall 153, the fourth surface 144 of the first wall 151, and the first surface 141 of the first winding support disk 131 to define a first chamber 181. The rotor winding end turns 112 may be disposed within the first chamber 181. The annular gap 170 is arranged to extend radially between the retaining ring 133 and the rotor core 100.

[0080] At 210, the method 200 includes delivering the fluid coolant flow 85 to the first winding support disk 131. A non-limiting example of delivering the fluid coolant flow 85 to the first winding support disk 131 may include delivering the fluid coolant flow 85 through the rotatable shaft 40 via the coolant conduit 150. The coolant conduit 150 may include a radially extending portion 157 through which the fluid coolant flow 85 may flow radially outward from the rotation axis 41 due to the centrifugal force of the rotatable shaft 40.

[0081] At 220, the method 200 may include delivering the fluid coolant flow 85 through the first winding support disk 131 to the first chamber 181. In non-limiting aspects, the first chamber 181 may be defined by the first winding support disk 131. For example, the first winding support disk 131 may be annular, having a first side 131a that faces axially inward (e.g., toward the rotor core 100) defining a first surface 141 and a second side 131b that faces axially outward (e.g., away from the rotor core 100) defining a second surface 142. In non-limiting aspects, the first winding support disk 131 may also include a first wall 151 that defines a radially inwardly facing third surface 143. The third surface 143 may define a hole 146 that extends from the first surface 141 to the second surface 142, and the hole 146 is sized to receive the rotatable shaft 40 therethrough and is configured to receive the fluid coolant flow 85 from the rotatable shaft 40. The first winding support disk 131 may be fixed to the rotatable shaft 40 via the third surface 143. The first wall 151 may also include a set of first channels 171 defined therethrough. Each first channel 171 may extend radially from a first end 171a at the third surface 143 to an opposite second end 171b at the fourth surface 144. Each first channel 171 may include a coolant inlet 174a defined on the third surface 143, and a corresponding coolant outlet 174b defined on the fourth surface 144 at the opposite second end 171b. In non-limiting aspects, delivering the fluid coolant flow 85 through the first winding support disk 131 to the first chamber 181 may include delivering the fluid coolant flow 85 from the coolant conduit 150 through the first channel 171 to the first chamber 181.

[0082] At 230 , the method 200 may include routing the fluid coolant flow 85 radially through the end turn passages 114 defined between adjacent rotor winding end turns 112 disposed in the first chamber 181 .

[0083] At 240, the method 200 may include delivering the fluid coolant flow 85 from the first chamber 181 to the second chamber 182. For example, the second chamber 182 may be defined between the first leg 133a and the fourth wall 154 of the retaining ring 133. When so arranged, the first leg 133a, the fourth wall 154, and the first surface 141 of the first winding support disk 131 may cooperatively define the second chamber 182 therebetween. The radially outer portion 134 of the second winding support disk 132 may be disposed in the second chamber 182.

[0084] At 250, the method 200 may include delivering the fluid coolant flow 85 to the second winding support disk 132 in the second chamber 182. A non-limiting example of delivering the fluid coolant flow 85 to the second winding support disk 132 may include delivering the fluid coolant flow 85 from the first chamber 181 to a set of second channels 156 defined through the second winding support disk 132. Another non-limiting example of delivering the fluid coolant flow 85 from the first chamber 181 to the second winding support disk 132 may include delivering the fluid coolant flow 85 to the second channels 156 through the radially extending passages 169 defined through the fourth wall 154.

[0085] One or more of the first chamber 181, the fourth wall 154, the set of radially extending end turn passages 114, the second winding support disk 132, or the second chamber 182 may convey or direct the fluid coolant flow 85 in thermally conductive relationship with the set of rotor winding end turns 112 such that heat from the 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 and the thermally conductive relationship described herein may result in the fluid coolant flow 85 removing heat from the rotor assembly 96.

[0086] At 260 , method 200 may further include discharging fluid coolant flow 85 axially inward toward a set of rotor windings 110 . It is also contemplated that method 200 may include redirecting fluid coolant flow 85 through second passage 156 disposed at angle 168 relative to rotational axis 41 of rotor assembly 96 .

[0087] A non-limiting example of axially inwardly discharging the fluid coolant flow 85 may include collecting the fluid coolant flow 85 by the fluid collection surface 159 and redirecting the fluid coolant flow 85 in an axially inward direction (e.g., toward the rotor core 100) via the second channel 156 toward the coolant outlet 156b. The second channel 156 may be angled (shown as angle 168) relative to the rotation axis 41 so that the second channel 156 receives the fluid coolant flow 85 and redirects the received fluid coolant flow 85 radially outward from the rotor end turn passage 114. The angle 168 may be configured to further radially redirect the fluid conveyed by the second channel 156 outward to discharge the fluid coolant flow 85 through the annular gap 170. Optionally, the coolant outlet 156b may be configured to direct the coolant toward a set of stator windings (not shown) or a set of stator winding end turns (not shown) above the rotor winding end turns 112.

[0088] In non-limiting aspects, the method 200 may further include directing the fluid coolant flow 85 radially outward through the annular gap 170 at 260. In non-limiting aspects, directing the fluid coolant flow 85 radially outward may include directing the fluid coolant flow 85 radially outward toward the annular gap 170 by the second passage 156. Redirecting the fluid coolant flow 85 from the second passage 156 toward the annular gap 170 allows the fluid coolant flow 85 to flow radially outward from the rotor assembly 96.

[0089] The depicted order is for illustrative purposes only and is not intended to limit method 200 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.

[0090] Fig.11 A method 300 of assembling the winding support assembly 130 is illustrated. Although the method 300 will be described with respect to the rotor assembly 96, it will be appreciated that the method 300 may be applied to any electric machine. Figures 4 to 9 The method is described with respect to the rotor assembly 96 and winding support assembly 130 illustrated in FIG. 1 , but is otherwise not limited thereto and the method 300 may be implemented with other electric machines and rotor assemblies without departing from the scope of the present disclosure.

[0091] In non-limiting aspects, the rotor assembly 96 may include a rotor core 100, such as a laminated rotor core, rotatably connected to rotate with a rotatable shaft 40. The rotatable shaft 40 defines an axis of rotation 41 and includes a coolant conduit 150 in fluid communication with a coolant source 155. The rotor assembly 96 may include a set of winding support assemblies 130. Each winding support assembly 130 may include a first winding support disk 131, a second winding support disk 132, and a retaining ring 133, respectively.

[0092] The rotor assembly 96 may also define a first end 102 and a 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 around respective rotor posts 108. 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.

[0093] Each set of rotor winding end turns 112 may define an arcuate curved portion 113 that axially overhangs or extends beyond the rotor core 100. Each set of rotor winding end turns 112 may define a circumferential width 112a, a radial height 112b, and an axial length 112c. In non-limiting aspects, each curved portion 113 may also define a corresponding channel 116 extending radially therethrough. For example, in non-limiting aspects, each corresponding channel 116 may have a corresponding circumferential width defined by the circumferential width of the corresponding rotor post 108. In addition, a set of radially extending end turn passages 114 may be defined by gaps between adjacent rotor winding end turns 112.

[0094] At 310, the method 300 may include arranging the first winding support disk 131 to be axially spaced from the rotor core 100 to define a first chamber 181. The first winding support disk 131 may include an axially inwardly facing first side 131a defining a first surface 141 and an axially outwardly facing second side 131b defining a second surface 142. The first side 131a includes an annular first wall 151 having a radially inwardly facing third surface 143 and a radially outwardly facing fourth surface 144 spaced opposite to the third surface 143, the third surface 143 defining a hole 146 sized to receive the rotatable shaft 40 therethrough, the first wall 151 being rotatably coupled to the rotatable shaft 40 along the third surface 143. The first side 131a may further include a second wall 152 and a third wall 153 extending radially from the fourth surface 144 and axially from the first surface 141 and circumferentially spaced apart from each other, and a fourth wall 154 extending between the second wall 152 and the third wall 153 and radially spaced apart from the fourth surface 144. The second wall 152, the third wall 153, the fourth wall 154, the first surface 141, and the fourth surface 144 cooperatively define a first chamber 181 therebetween.

[0095] In non-limiting aspects, the first wall 151 may define a set of first channels 171 extending radially through the first wall 151 from the third surface 143 to the fourth surface 144 in fluid communication with the coolant conduit 150. The fourth wall 154 may define a set of apertures 169 therethrough in fluid communication with the set of first channels 171 and the first chamber 181.

[0096] At 320, method 300 includes disposing a set of rotor winding end turns 112 in first chamber 181. At 330, method 300 may also include coupling first winding support disk 131 to rotatable shaft 40. For example, first winding support disk 131 may be coupled to rotatable shaft 40 along third surface 143 of first wall 151.

[0097] At 340, the method 300 may further include arranging a retaining ring 133 surrounding the first winding support disk 141 to cooperatively define a second chamber 182 between the first winding support disk 141 and the retaining ring 133. The retaining ring 133 may have an annular first leg 133a that is radially spaced from and surrounds the fourth wall 154, wherein the first leg 133a and the fourth wall 154. In non-limiting aspects, the retaining ring 133 may further include an annular second leg 133b extending radially inward from the first leg 133a. The second leg 133b may be coupled to the second surface 142. A set of apertures 169 of the fourth wall 154 may be in fluid communication with the second chamber 182. In non-limiting aspects, the second surface 142 and the second leg 133b cooperatively define a continuous axially outwardly facing surface 166.

[0098] At 350, the method 300 may further include coupling the second winding support disk 132 to the rotatable shaft 40. The second winding support disk 132 may include a radially central portion 138 and a radially outer portion 134. In non-limiting aspects, the second winding support disk 132 may be coupled to the rotatable shaft 40 at the radially central portion 138. The radially inner portion 138 may also be coupled to the radially outer portion 134 via a set of radially extending spokes 136. In non-limiting aspects, the radially outer portion may be over a set of rotor winding end turns 112 while being surrounded by the retaining ring 133. In non-limiting aspects, the radially outer portion 134 may define a set of radially extending second channels 172 in fluid communication with the first chamber 181. The radially outer portion 134 may be disposed in the second chamber 182.

[0099] The depicted order is for illustrative purposes only and is not intended to limit method 300 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.

[0100] Aspects as disclosed herein improve upon existing methods by securing, protecting, and constraining rotor winding end turns. Aspects as disclosed herein prevent movement of end turns and provide mechanical and electrical isolation between rotor winding end turns and nearby parts.

[0101] Aspects disclosed herein also 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 the set of rotor winding end turns and the coolant conduits coupled to the first and second channels provides for heat removal from the rotor winding end turns to the coolant in a much more efficient manner.

[0102] Increased heat dissipation of the rotor winding end turns allows for higher speed rotation where otherwise too much heat may be generated. Higher speed rotation may result in improved power generation or improved generator efficiency without increasing the size of the generator. The described aspects with fluid passages for wet cavity machines also enable cooling of the stator windings or end turn sections, which further reduces heat losses in the motor. Reduced heat losses in the motor allow for higher efficiency and greater power density of the generator.

[0103] Reliability is also an important feature when designing aircraft components. The above-described rotor assembly can provide additional physical stability and improved cooling for the rotor end windings. The stability and cooling provided by the winding support assembly allows for improved performance and reliability.

[0104] 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.

[0105] 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.

[0106] Further aspects of the disclosure are provided by the subject matter of the following clauses:

[0107] 19. The 19- - year-old described invention of claim 18, wherein the rotor assembly comprises a first rotor core, the second rotor core being rotatably coupled to the first rotor core and defining at least one rotor post; a set of rotor windings wound around the rotor post and defining a corresponding set of rotor winding end turns; and a winding support assembly fixed to the rotatable shaft, the winding support assembly comprising: a first winding support disk axially spaced from the rotor core, having an axially inwardly facing first side defining a first surface and an axially outwardly facing second side defining a second surface, the first side comprising an annular first wall having a radially inwardly facing third surface defining an aperture and a radially inwardly facing third surface engaging the first surface. A fourth surface facing radially outward with three surfaces relatively spaced apart, the hole size is designed to receive the rotatable shaft passing therethrough, the annular first wall is rotatably connected to the rotatable shaft along the third surface, the first side also includes a second wall and a third wall extending radially from the fourth surface and axially from the first surface and circumferentially spaced apart from each other, and a fourth wall extending between the second wall and the third wall and radially spaced apart from the fourth surface; wherein the second wall, the third wall, the fourth wall, the first surface and the fourth surface cooperatively define a first chamber therebetween; and wherein the set of rotor winding end turns are received in the first chamber.

[0108] A rotor assembly according to the preceding clause, wherein the first wall defines a set of first channels in fluid communication with the coolant conduit, the set of first channels extending radially through the first wall from the third surface to the fourth surface.

[0109] A rotor assembly according to any preceding clause, wherein the fourth wall defines a set of apertures therethrough in fluid communication with the set of first channels and the first chamber.

[0110] A rotor assembly as claimed in any preceding clause, wherein the third surface defines a groove thereon surrounding the rotatable shaft, the groove being in fluid communication with the set of first channels.

[0111] A rotor assembly according to any preceding clause, further comprising a retaining ring surrounding the first winding support disc, the retaining ring having an annular first leg surrounding the fourth wall and radially spaced apart from the fourth wall, wherein the annular first leg and the fourth wall cooperatively define a second chamber therebetween.

[0112] A rotor assembly according to any preceding clause, wherein the set of apertures of the fourth wall are in fluid communication with the second chamber.

[0113] A rotor assembly according to any preceding clause, wherein the retaining ring further comprises an annular second leg extending radially inwardly from the annular first leg, the annular second leg being coupled to the second surface.

[0114] A rotor assembly according to any preceding clause, wherein the second surface defines an annular recess along a circumferential periphery of the second side, wherein the annular second leg is received in the recess.

[0115] A rotor assembly as described in any preceding clause, wherein the second surface and the annular second leg cooperatively define a continuous axially outwardly facing surface.

[0116] A rotor assembly according to any preceding clause, further comprising a second winding support disk, the second winding support disk comprising a radial center portion and a radial outer portion, the radial center portion being coupled to the rotatable shaft and further coupled to the radial outer portion via a set of radially extending spokes, the radial outer portion being over the set of rotor winding end turns and surrounded by the retaining ring.

[0117] A rotor assembly as claimed in any preceding clause, wherein the radially outer portion defines a set of radially extending second channels defined therethrough, the set of radially extending second channels being in fluid communication with the first chamber.

[0118] A rotor assembly as claimed in any preceding clause, wherein each respective spoke is disposed between corresponding end turns of the set of rotor windings and the rotor core.

[0119] A rotor assembly as claimed in any preceding clause, wherein the radially outer portion is disposed in the second chamber.

[0120] A rotor assembly as described in any preceding clause, wherein the set of rotor winding end turns define an end turn passage extending radially therethrough.

[0121] A method for cooling a set of rotor winding end turns supported by a first winding support disk rotatably coupled to a rotor assembly, the method comprising: delivering a fluid coolant flow to the first winding support disk; delivering the fluid coolant flow through a first channel defined through the first winding support disk and to a first chamber at least partially defined by the first winding support disk; delivering the fluid coolant flow radially outward through end turn passages defined between adjacent rotor winding end turns disposed in the first chamber; and delivering the fluid coolant flow from the first chamber to a second chamber at least partially defined by the first winding support disk.

[0122] A method according to any preceding clause, further comprising delivering the fluid coolant flow to a radially outer portion of a second winding support disk disposed at least partially in the second chamber.

[0123] A method according to any preceding clause, wherein said delivering said fluid coolant flow to said radially outer portion of said second winding support disk comprises redirecting said fluid coolant flow in an axially inward direction through a second channel defined through said radially outer portion of said second winding support disk.

[0124] A method according to any preceding clause, wherein the second passage extends through the radially outer portion of the second winding support disc at an angle relative to the axis of rotation of the rotor assembly.

[0125] A method as in any preceding clause, further comprising directing the fluid coolant flow axially outwardly through the second winding support disk towards the rotor winding end turns.

[0126] A method according to any preceding clause, further comprising conveying the fluid coolant flow radially outwardly from the second winding support disk through the second winding support disk.

[0127] A method of assembling a winding support assembly for a rotor of an electric machine, the rotor comprising a rotatable shaft having an axis of rotation and defining a coolant conduit in fluid communication with a coolant source, a rotor core rotatably coupled to the rotatable shaft and defining at least one rotor post, a set of rotor windings wound around the rotor post and defining a corresponding set of rotor winding end turns, the method comprising: arranging a first winding support disk axially spaced from the rotor core to define a first chamber.

[0128] A method according to any preceding clause, wherein the first winding support disk includes a first side facing axially inward defining a first surface and a second side facing axially outward defining a second surface, the first side including an annular first wall, the annular first wall having a third surface facing radially inward defining a hole and a fourth surface facing radially outward spaced relative to the third surface, the hole being sized to receive the rotatable shaft therethrough, the first wall being rotatably connected to the rotatable shaft along the third surface, the first side also including a second wall and a third wall extending radially from the fourth surface and axially from the first surface and circumferentially spaced from each other, a fourth wall extending between the second wall and the third wall and spaced radially relative to the fourth surface, wherein the second wall, the third wall, the fourth wall, the first surface and the fourth surface cooperatively define the first chamber therebetween.

[0129] A method according to any preceding clause, wherein the first wall defines a set of first channels in fluid communication with the coolant conduit, the set of first channels extending radially through the first wall from the third surface to the fourth surface.

[0130] A method according to any preceding clause, wherein the fourth wall defines a set of apertures through the fourth wall in fluid communication with the set of first channels and the first chamber.

[0131] A method according to any preceding clause, further comprising arranging the set of rotor winding end turns in the first chamber.

[0132] A method as in any preceding clause, further comprising coupling the first winding support disc to the rotatable shaft.

[0133] A method as in any preceding clause, wherein coupling the first winding support disk to the rotatable shaft comprises coupling the annular first wall to the rotatable shaft along the third surface.

[0134] A method according to any preceding clause, wherein the first wall defines a set of first channels in fluid communication with the coolant conduit, the set of first channels extending radially through the first wall from the third surface to the fourth surface.

[0135] A method according to any preceding clause, further comprising arranging a retaining ring to surround the first winding support disc and define a second chamber between the retaining ring and the first winding support disc.

[0136] A method according to any preceding clause, wherein the set of apertures of the fourth wall are in fluid communication with the second chamber.

[0137] A method as in any preceding clause, wherein the retaining ring further comprises an annular second leg extending radially inwardly from the first leg, the second leg being coupled to the second surface.

[0138] A method as in any preceding clause, wherein the second surface and the second leg cooperatively define a continuous axially outwardly facing surface.

[0139] A method as in any preceding clause, further comprising coupling a second winding support disc to the rotatable shaft.

[0140] A method according to any preceding clause, wherein the second winding support disc comprises a radially central portion and a radially outer portion and is further coupled to the radially outer portion via a set of radially extending spokes.

[0141] A method according to any preceding clause, wherein said coupling a second winding support disc to the rotatable shaft comprises coupling the second winding support disc to the rotatable shaft along the radial centre portion.

[0142] A method according to any preceding clause, wherein the radially outer portion is above the set of rotor winding end turns and is surrounded by the retaining ring.

[0143] A method as in any preceding clause, wherein the radially outer portion defines a set of radially extending second channels defined therethrough, the set of radially extending second channels being in fluid communication with the first chamber.

[0144] A method according to any preceding clause, wherein the radially outer portion is disposed in the second chamber.

Claims

1. A rotor assembly, comprising: a rotatable shaft having an axis of rotation and defining a coolant conduit in fluid communication with a coolant source; a rotor core rotatably coupled to the rotatable shaft and defining at least one rotor post; a set of rotor windings wound around the rotor limbs and defining a corresponding set of rotor winding end turns; as well as a winding support assembly fixed to the rotatable shaft, the winding support assembly comprising: a first winding support disk axially spaced from the rotor core having a first side facing axially inwardly defining a first surface and a second side facing axially outwardly defining a second surface, the first side including an annular first wall having a radially inwardly facing third surface defining an aperture sized to receive the rotatable shaft therethrough and a radially outwardly facing fourth surface spaced opposite the third surface, the annular first wall being rotatably coupled to the rotatable shaft along the third surface, The first side further includes a second wall and a third wall extending radially from the fourth surface and axially from the first surface and circumferentially spaced from each other, a fourth wall extending between the second wall and the third wall and spaced radially opposite the fourth surface; wherein the second wall, the third wall, the fourth wall, the first surface, and the fourth surface cooperatively define a first chamber therebetween; and Wherein, the set of rotor winding end turns are received in the first chamber.

2. The rotor assembly according to claim 1, wherein: The annular first wall defines a set of first channels in fluid communication with the coolant conduit, the set of first channels extending radially through the annular first wall from the third surface to the fourth surface.

3. The rotor assembly according to claim 2, wherein: The fourth wall defines a set of apertures therethrough in fluid communication with the set of first channels and the first chamber.

4. The rotor assembly according to claim 3, wherein: The third surface defines a groove thereon surrounding the rotatable shaft, the groove being in fluid communication with the set of first channels.

5. The rotor assembly of claim 3, further comprising a retaining ring surrounding the first winding support disk, the retaining ring having an annular first leg surrounding the fourth wall and radially spaced from the fourth wall, wherein: The annular first leg and the fourth wall cooperatively define a second chamber therebetween.

6. The rotor assembly according to claim 5, wherein: The set of apertures of the fourth wall are in fluid communication with the second chamber.

7. The rotor assembly according to claim 5, wherein: The retaining ring also includes an annular second leg extending radially inwardly from the annular first leg, the annular second leg coupled to the second surface.

8. The rotor assembly according to claim 7, wherein: The second surface defines an annular recess along a circumferential perimeter of the second side, wherein the annular second leg is received in the annular recess.

9. The rotor assembly according to claim 8, wherein: The second surface and the annular second leg cooperatively define a continuous axially outwardly facing surface.

10. A method of cooling a set of rotor winding end turns supported by a first winding support disk rotatably coupled to a rotor assembly, the method comprising: delivering a flow of fluid coolant to the first winding support disk; delivering the fluid coolant flow through a first passage defined through the first winding support disk and into a first chamber at least partially defined by the first winding support disk; directing the fluid coolant flow radially outwardly through end turn passages defined between adjacent rotor winding end turns disposed in the first chamber; as well as The fluid coolant flow is delivered from the first chamber to a second chamber at least partially defined by the first winding support disk.

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