Electric machine comprising an excitation coil separator with an

Abstract

The invention relates to an electric machine including an excitation coil separator with an integrated coolant flow path. A rotor for an electric machine includes a shaft. A plurality of rotor laminates are mounted to the shaft. The plurality of rotor laminates includes a plurality of rotor teeth. The plurality of excitation coils are arranged around respective rotor teeth of the plurality of rotor teeth. A plurality of field coil separators extend axially along the rotor between adjacent ones of the plurality of field coils. Each of the plurality of field coil separators includes a coolant circulation system. The coolant circulation system includes a plurality of external coolant flow paths. Each of the plurality of field coil separators includes a resilient frame and a housing overmolded onto the resilient frame, the housing including an outer surface.

Description

Technical Field

[0001] Exemplary embodiments relate to the field of electric motors, and more particularly to a cooling system for an electric machine having a wound field rotor. Background Art

[0002] During operation, an electric motor generates heat. Generally, the rotating components of an electric motor may support a fan member that directs air flow through the internal motor components. Air flow can assist in smaller systems such as alternators and systems installed in open areas such as generators. Air flow is not always sufficient in high-output systems, especially those installed in enclosed areas such as a motor vehicle engine compartment.

[0003] An electric motor used, for example, as a prime mover in a vehicle generally includes a liquid coolant system. The electric motor includes a stator and a rotor. The liquid cooling system may include an inlet for receiving coolant and an outlet for directing the coolant to a heat exchange system. The coolant may flow in a sheath disposed radially outside the stator of the electric motor. Additional coolant may be directed onto the rotor or between the rotor and the shaft supporting the rotor.

[0004] Cooling the outer surface of the rotor laminations and the interface between the rotor laminations and the shaft is beneficial. However, the rest of the rotor also generates heat, which may reduce the overall operating efficiency. Therefore, the industry would benefit from a cooling system that interacts with the internal rotor surface and the rotor winding surface to improve operating efficiency. Summary of the Invention

[0005] According to a non - limiting example, a rotor for an electric machine includes a shaft that includes an outer surface section, an inner surface section, and an opening. The inner surface section defines a flow path, and the opening defines a passage extending through the outer surface section from the flow path. The shaft defines the axis of rotation of the rotor. A plurality of rotor laminations are mounted to the outer surface section. The plurality of rotor laminations include an outer surface portion, a plurality of rotor teeth, and an inner surface portion disposed on the shaft. The plurality of rotor laminations include a plurality of coolant channels extending between the inner surface portion and the outer surface portion. A plurality of field coils are disposed around respective ones of the plurality of rotor teeth. The plurality of coolant channels extend axially along the plurality of rotor laminations between adjacent ones of the plurality of field coils. A plurality of field coil separators extend axially along the rotor between adjacent ones of the plurality of field coils. Each of the plurality of field coil separators includes a coolant circulation system. The coolant circulation system includes a plurality of external coolant flow paths. Each of the plurality of field coil separators includes an elastic frame and a housing overmolded onto the elastic frame, the housing including an outer surface.

[0006] According to a non - limiting example, an electric machine includes a housing that includes an interior. A stator is disposed in the interior and fixedly connected to the housing. The stator includes a stator core and a plurality of stator windings supported by the stator core. The plurality of stator windings have a first end turn and a second end turn. The first end turn is axially spaced from the second end turn by the stator core. A rotor is disposed in the interior and rotatably supported within the stator. The rotor includes a shaft that includes an outer surface section, an inner surface section, and an opening. The inner surface section defines a flow path, and the opening defines a passage extending through the outer surface section from the flow path. The shaft defines the axis of rotation of the rotor. A plurality of rotor laminations are mounted to the outer surface section. The plurality of rotor laminations include an outer surface portion, a plurality of rotor teeth, and an inner surface portion disposed on the shaft. The plurality of rotor laminations include a plurality of coolant channels extending between the inner surface portion and the outer surface portion. A plurality of field coils are disposed around respective ones of the plurality of rotor teeth. The plurality of coolant channels extend axially along the plurality of rotor laminations between adjacent ones of the plurality of field coils. A plurality of field coil separators extend axially along the rotor between adjacent ones of the plurality of field coils. Each of the plurality of field coil separators includes a coolant circulation system. The coolant circulation system includes a plurality of external coolant flow paths. Each of the plurality of field coil separators includes an elastic frame and a housing overmolded onto the elastic frame, the housing including an outer surface.

[0007] According to a non - limiting example, a field coil separator includes an elastic frame configured to be loaded into a plurality of coolant channels between adjacent ones of the plurality of field coils by first compressing the elastic frame and then releasing the elastic frame. Description of the Drawings

[0008] The following description should not be regarded as limiting in any way. Referring to the accompanying drawings, like elements are numbered similarly:

[0009] Figure 1 is a cross-sectional side view of an electric machine including a rotor according to a non-limiting example, the rotor having an excitation coil separator provided with an integrated coolant flow path;

[0010] Figure 2 is according to a non-limiting example Figure 1 perspective view of a rotor of, the rotor including a first balance ring and a second balance ring;

[0011] Figure 3 is according to a non-limiting example Figure 2 perspective view of a rotor of, the rotor without a first balance ring and a second balance ring;

[0012] Figure 4 is according to a non-limiting example Figure 2 axial end view of a rotor of;

[0013] Figure 5 is a perspective view of a part of a rotor laminate of a rotor according to a non-limiting example, the rotor having an excitation coil separator provided with an integrated coolant flow path;

[0014] Figure 6 is according to a non-limiting example along Figure 4 cross-sectional view of a rotor taken along line 6-6 in;

[0015] Figure 7 is a perspective view of an elastic frame of an excitation coil separator according to a non-limiting example, the elastic frame including a base element, a first spring member, and a second spring member;

[0016] Figure 8 is according to a non-limiting example Figure 8 perspective view of an elastic frame of, the elastic frame including a first housing member disposed on the base element;

[0017] Figure 9 is according to a non-limiting example Figure 9 perspective view of an elastic frame of, the elastic frame including a second housing member disposed on the first spring member and a third housing member disposed on the second spring member;

[0018] Figure 10 is an axial end view of an excitation coil separator according to a non-limiting example, wherein the first spring member and the second spring member are compressed between adjacent excitation coils of the rotor during installation;

[0019] Figure 11 is an axial end view of an exciting coil separator according to a non - limiting example, in a state after a first spring member and a second spring member are released; and Figure 10 is a partial exploded perspective view of a wound coil rotor according to a non - limiting example, showing mechanical fasteners passing through each exciting coil separator.

[0020] Figure 12 is according to a non - limiting example Figure 3 of a wound coil rotor, showing mechanical fasteners passing through each exciting coil separator. DETAILED DESCRIPTION

[0021] A detailed description of one or more embodiments of the disclosed apparatus and methods is given herein by way of example and not limitation with reference to the accompanying drawings.

[0022] According to a non - limiting example, an electric machine is generally designated by 10 in Figure 1 . The electric machine 10 includes a housing 12 having an outer surface 14 and an inner surface 16 that defines an interior 18 of the housing 12. A stator 20 is fixedly attached to the inner surface 16. The stator 20 includes a stator core 21 that supports a plurality of stator windings 22 having a first end turn 24 and a second end turn 26. A wound field rotor 28 is rotatably mounted within the housing 12 radially inward of the stator 20. The wound field rotor 28 is supported on a shaft 30 within the housing 12.

[0023] In a non - limiting example, the shaft 30 includes a first end 32 supported by a first bearing 34 and a second end 36 supported by a second bearing 38. A rotational axis “A” is defined between the first end 32 and the second end 36. The shaft 30 includes an outer surface section 39 and an inner surface section 41 that defines a coolant flow path 43. A coolant, such as oil, passes from a coolant supply system 46 through the coolant flow path 43. As will be described more fully herein, the oil flowing through the wound field rotor 28 is sprayed onto the first end turn 24 and the second end turn 26 and is allowed to collect within the interior 18 of the housing 12 before flowing to a coolant discharge system and a recirculation system 48.

[0024] In Figure 2 and Figure 3 shown non - limiting example, the wound field rotor 28 includes an inner surface portion 56( Figure 4) and a plurality of rotor laminations 54 of the outer surface portion 58. The plurality of laminations define a plurality of rotor teeth 60. In a non-limiting example, a plurality of field coils 64 extend around each of the plurality of rotor teeth 60. In a non-limiting example, the wound field rotor 28 includes a first axial end 68 and a second axial end 70. The first axial end 68 supports a first balance ring 80 that covers a first portion of the plurality of field coils 64, and the second axial end 70 supports a second balance ring 82 that covers a second portion of the plurality of field coils 64.

[0025] The first balance ring 80 includes a first plurality of outlet openings 86, and the second balance ring 82 includes a second plurality of outlet openings 88. As will be described more fully herein, coolant flowing through the shaft 30 passes over the plurality of field coils 64 and exits from the first balance ring 80 and the second balance ring 82. The coolant flows through the first plurality of outlet openings 86 and is sprayed onto the first end turn 24 and flows through the second plurality of outlet openings 88 and is sprayed onto the second end turn 26 to facilitate cooling of the stator 20.

[0026] In Figure 4 and Figure 5 the non-limiting example shown, a plurality of coolant channels 92 pass through the plurality of rotor laminations 54 between adjacent rotor teeth of the plurality of rotor teeth 60. The plurality of coolant channels 92 extend axially along axis "A" between adjacent rotor teeth of the plurality of rotor teeth 60. Each of the plurality of coolant channels 92 extends radially from the inner surface portion 56 to the outer surface portion 58. The plurality of coolant channels 92 convey coolant from the coolant flow path 43 along the outer surface of each of the plurality of field coils 64.

[0027] In a non-limiting example, a plurality of field coil separators (one of which is designated 100) are disposed between each rotor tooth 60. The field coil separator 100 supports the plurality of field coils 64. As Figure 6 shown, the field coil separator 100 forms a coolant circulation system 104 that guides coolant over the outer surface of each of the plurality of field coils 64 and then guides the coolant into each of the first balance ring 80 and the second balance ring 82. In a non-limiting example, the field coil separator 100 includes a resilient frame 108 having a housing 110.

[0028] As Figure 7As shown, the resilient frame 108 is formed of a continuous piece of non-magnetic material such as stainless steel. The resilient frame 108 includes a first axial end 111 and a second axial end 112 opposite the first axial end 111. The resilient frame 108 includes a base element 114 having a first leg 116 and a second leg 118. The first leg 116 includes a first end 120 and a second end 122. The second leg 118 includes a first end portion 124 and a second end portion 126. The first end 120 and the first end portion 124 are connected by a bend 128. In a non-limiting example, the first leg 116 and the second leg 118 may include a plurality of openings 130. The plurality of openings 130 can be used to reduce the total weight of the resilient frame 108. Of course, it should be understood that the resilient frame 108 can be formed of other materials including elastomeric flexible plastic composites and plastics.

[0029] In a non-limiting example, a first spring member 134 extends from the second end 122 of the first leg 116 at a first angle, and a second spring member 136 extends from the second end portion 126 of the second leg 118 at a second angle. As will be described in more detail herein, the first spring member 134 and the second spring member 136 facilitate the installation and retention of the excitation coil separator 100 between adjacent excitation coils in the plurality of excitation coils 64. In a manner similar to that discussed in connection with the base element 114, the first spring member 134 and the second spring member 136 are formed with openings 138 that can be used to reduce the total weight of the resilient frame 108.

[0030] In a non-limiting example, the housing 110 includes a first housing member 142 that defines a first outer surface 144. The first outer surface 144 extends along the first leg 116 and the second leg 118 and includes a plurality of coolant guiding elements 146 that form a plurality of external coolant flow paths 150 that radially outwardly direct coolant from the plurality of coolant channels 92. The plurality of coolant guiding elements 146 are shown extending in the radial direction. However, it should be understood that depending on the desired coolant flow characteristics, the plurality of guiding elements 146 can be arranged at various angles. That is, the plurality of coolant guiding elements 146 can extend radially parallel to the axis of rotation of the rotor 54 as shown, or at other angles. When the rotor is spinning, the coolant guiding elements 146 can engage and support adjacent excitation coils in the plurality of excitation coils 64. The first housing member 142 also includes a plurality of notches 152 at the bend 128. The plurality of notches 152 facilitate the transition of coolant from the plurality of coolant channels 92 to the plurality of external coolant flow paths 150 on the first outer surface 144.

[0031] In a non - limiting example, the housing 110 further includes a second housing member 156 on the first spring member 134 and a third housing member 158 on the second spring member 136. The second housing member 156 defines a second outer surface 160, and the third housing member 158 defines a third outer surface 162. The second housing member 156 includes a first plurality of channels 164, and the third housing member 158 includes a second plurality of channels 166( Figure 6 ). The first plurality of channels 164 are in fluid communication with a first internal coolant return channel 170 formed in the second housing member 156. The second plurality of channels 166 are in fluid communication with a second internal coolant return channel 172 formed in the third housing member 158.

[0032] As Figure 9 shown, the first internal coolant return channel 170 defines a first coolant return conduit 178, and the second internal coolant return channel 172 defines a second coolant return conduit 180. The first coolant return conduit 178 and the second coolant return conduit 180 extend substantially parallel to the axis "A" and axially direct the coolant flowing through the plurality of field coils 64 outwardly into the first balance ring 80 and the second balance ring 82. As described herein, the coolant passes through the first plurality of openings 86 and is sprayed onto the first end turn 24, and passes through the second plurality of openings 88 and is sprayed onto the second end turn 26 to facilitate cooling of the stator 20.

[0033] In a non - limiting example, the second housing 156 and the third housing 158 do not include the coolant return channels 172 and 178 and do not include the first plurality of channels 164. When the coolant flows radially outward and axially toward the first axial end 68 and the second axial end 70, the coolant flows from the notch 152 and meanders through the coolant guiding element 146. In this non - limiting example, the plurality of notches 152 may include only one or two notches located near the axial middle (not separately marked) of the first housing member 142.

[0034] In a non - limiting example, secondary coolant guiding elements (not shown), similar to the coolant guiding element 146, may be located on the second housing 156 and the third housing 158. These secondary coolant guiding elements engage adjacent field coils among the plurality of field coils 64. Similarly, the coolant guiding element 146 may also engage adjacent field coils among the plurality of field coils 64.

[0035] In a non-limiting example, the field coil 64 forms an external coolant flow path 150 that exists between the first outer surface 144 of the first housing member 142, the second outer surface 160 of the second housing member 156, and / or the third outer surface 162 of the third housing member 158 and the plurality of field coils 64.

[0036] In a non-limiting example, the second housing member 156 includes a first inner surface section 190, and the third housing member 158 includes a second inner surface section 192. The first inner surface section 190 includes a first semi-circular recess 194 that extends between the first axial end 111 and the second axial end 112 of the resilient frame 108. Similarly, the second inner surface section 192 includes a second semi-circular recess 196 that extends between the first axial end 111 and the second axial end 112 of the resilient frame 108. The first semi-circular recess 192 and the second semi-circular recess 194 form a generally cylindrical channel 200 that passes through the field coil separator 100 in a direction that is generally parallel to the axis of rotation “A” of the wound field rotor 28.

[0037] In a non-limiting example, the generally cylindrical channel 200 receives mechanical fasteners 220 that are used to secure the first balance ring 80 and the second balance ring 82 to the wound field rotor 28, as Figure 12 shown. Additional fasteners (such as Figure 2 shown at 228 in

[0038] are connected to each mechanical fastener 220. In addition to securing the first balance ring 80 and the second balance ring 82 to the wound field rotor 28, the mechanical fasteners 200 also support the first spring member 134 and the second spring member 136. That is, when installed, the fasteners 200 prevent the first spring member 134 and the second spring member 136 from deflecting inwardly and release the field coil separator 100 from the wound field rotor 28. Figure 10As shown, the first spring member 134 and the second spring member 136 are compressed, and the field coil separator 100 is installed between adjacent field coils among the plurality of field coils 64. Once in place, the first spring member 134 and the second spring member 136 are released. The first spring member 134 and the second spring member 136 engage adjacent field coils among the plurality of field coils 64 and remain in place between the rotor teeth 60. Once installed, the first balance ring 80 and the second balance ring 82 can be connected to the mechanical fasteners 220 passing through each of the generally cylindrical channels 200, thereby effectively locking each field coil separator to the wound field coil rotor 28. With this arrangement, the field coil separator 100 guides the coolant flowing through the rotor laminate 54 along the surfaces of adjacent field coils among the plurality of field coils 64 into the balance rings 80 and 82, flows out from the outlet openings 88 and 86, and is then axially ejected onto the first end turn 24 and the second end turn 26 of the stator 20.

[0039] The term "about" is intended to include the degree of error associated with the measurement of a particular quantity based on the equipment available at the time of filing this application. For example, "about" can include a range of ±8% or 5% or 2% of a given value.

[0040] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that when used in this specification, the terms "comprises" and / or "comprising" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0041] Although the invention has been described with reference to one or more exemplary embodiments, those skilled in the art will understand that various changes can be made and equivalents can be substituted for its elements without departing from the scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the basic scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode for carrying out the invention, but that the invention will include all embodiments falling within the scope of the claims.

Claims

1. A rotor for an electric motor, the rotor comprising: a shaft including an outer surface segment, an inner surface segment, and an opening, the inner surface segment defining a flow path, the opening defining a passage extending from the flow path through the outer surface segment, the shaft defining an axis of rotation of the rotor; a plurality of rotor laminations mounted to the outer surface segment, the plurality of rotor laminations comprising an outer surface portion, a plurality of rotor teeth, and an inner surface portion disposed on the shaft, the plurality of rotor laminations comprising a plurality of coolant channels extending between the inner surface portion and the outer surface portion; a plurality of field coils disposed about respective ones of the plurality of rotor teeth, the plurality of coolant passages extending axially along the plurality of rotor laminations between adjacent ones of the plurality of field coils; as well as A plurality of field coil separators extend axially along the rotor between adjacent ones of the plurality of field coils, each of the plurality of field coil separators comprising a coolant circulation system including a plurality of external coolant flow paths, wherein each of the plurality of field coil separators comprises a resilient frame and a shell overmolded onto the resilient frame, the shell comprising an outer surface.

2. The rotor of claim 1 , wherein the resilient frame comprises a base element and a first spring member, and the field coil separator is configured to be loaded into the plurality of coolant channels between adjacent field coils of the plurality of field coils by first compressing the first spring member and then releasing the first spring member. 3 . The rotor of claim 2 , wherein each of the plurality of field coil separators comprises a second spring member. 4 . The rotor of claim 3 , wherein the first spring member is configured to engage one of the plurality of field coils, and the second spring member is configured to engage an adjacent field coil of the plurality of field coils.

5. The rotor according to claim 4, wherein: The base element extends substantially along a radius of the rotor, the first spring member extends from the base element at a first angle, and the second spring member extends from the base element at a second angle.

6. The rotor of claim 5, wherein the base element includes a first housing member having a first outer surface, the first spring member includes a second housing member having a second outer surface, and the second spring member includes a third housing member having a third outer surface.

7. The rotor of claim 6, wherein the second housing member includes a first inner surface segment and the third housing member includes a second inner surface segment, the first inner surface segment includes a first semicircular recess and the second inner surface segment includes a second semicircular recess, the first semicircular recess and the second semicircular recess forming a generally cylindrical channel.

8. The rotor according to claim 7, further comprising: A mechanical fastener extends through the generally cylindrical passage substantially parallel to the axis of rotation of the rotor, the mechanical fastener preventing the first and second spring members from deflecting inwardly.

9. The rotor of claim 6, wherein each of the first outer surfaces includes a plurality of coolant directing elements defining the plurality of outer coolant flow paths directing coolant from the base element, the first spring member, and the second spring member.

10. The rotor of claim 9, wherein at least one internal coolant return passage comprises a first coolant return conduit disposed in the second housing member and a second coolant return conduit disposed in the third housing member, the first coolant return conduit and the second coolant return conduit extending substantially parallel to the rotational axis of the rotor.

11. The rotor according to claim 10, wherein: The second housing member includes a first plurality of channels extending between the second exterior surface and the first coolant return conduit, and the third housing member includes a second plurality of channels extending between the third exterior surface and the second coolant return conduit.

12. The rotor according to claim 7, wherein: The plurality of cooling guide elements engage adjacent field coils of the plurality of field coils.

13. A motor, comprising: a housing, the housing comprising an interior; a stator disposed in the interior and fixedly connected to the housing, the stator comprising a stator core and a plurality of stator windings supported by the stator core, the plurality of stator windings having first end turns and second end turns, the first end turns being axially spaced apart from the second end turns by the stator core; a rotor disposed in the interior and rotatably supported within the stator, the rotor comprising: a shaft including an outer surface segment, an inner surface segment, and an opening, the inner surface segment defining a flow path, the opening defining a passage extending from the flow path through the outer surface segment, the shaft defining an axis of rotation of the rotor; a plurality of rotor laminations mounted to the outer surface segment, the plurality of rotor laminations comprising an outer surface portion, a plurality of rotor teeth, and an inner surface portion disposed on the shaft, the plurality of rotor laminations comprising a plurality of coolant channels extending between the inner surface portion and the outer surface portion; a plurality of field coils disposed about respective ones of the plurality of rotor teeth, the plurality of coolant passages extending axially along the plurality of rotor laminations between adjacent ones of the plurality of field coils; and a plurality of field coil separators extending axially along the rotor between adjacent ones of the plurality of field coils, wherein each of the plurality of field coil separators comprises a resilient frame and a housing overmolded onto the resilient frame, the housing comprising an outer surface, The resilient frame includes a base element, a first spring member configured to engage one of the plurality of excitation coils, and a second spring member configured to engage an adjacent excitation coil of the plurality of excitation coils.

14. The electric machine of claim 13, wherein the plurality of rotor laminations include a first axial end and a second axial end, the first axial end being spaced apart from the first axial end along the rotational axis, the first axial end supporting a first balancing ring, the first balancing ring including a first plurality of outlet openings, the first plurality of outlet openings guiding coolant passing from a selected one of the plurality of excitation coil separators to the first end turns, and the second axial end supporting a second balancing ring, the second balancing ring including a second plurality of outlet openings, the second plurality of outlet openings guiding coolant passing from a selected one of the plurality of excitation coil separators to the second end turns. 15 . The electric machine of claim 14 , each of the plurality of field coil separators comprising a coolant circulation system including a plurality of external coolant flow paths and at least one internal coolant return channel.

16. The electric machine according to claim 15, wherein: The base element extends substantially along a radius of the rotor, the first spring member extends from the base element at a first angle, and the second spring member extends from the base element at a second angle.

17. The electric machine according to claim 16, wherein: The base element includes a first housing member having a first outer surface, the first spring member includes a second housing member having a second outer surface, and the second spring member includes a third housing member having a third outer surface.

18. The electric machine of claim 17, wherein the second housing member includes a first inner surface segment and the third housing member includes a second inner surface segment, the first inner surface segment includes a first semicircular recess, and the second inner surface segment includes a second semicircular recess, the first semicircular recess and the second semicircular recess forming a generally cylindrical channel.

19. The electric machine according to claim 18, further comprising: A mechanical fastener extends through the generally cylindrical passage substantially parallel to the axis of rotation of the rotor, the mechanical fastener preventing the first and second spring members from deflecting inwardly.

20. The electric machine of claim 17, wherein each of the first outer surfaces includes a plurality of coolant directing elements defining the plurality of external coolant flow paths directing coolant from the base element, the first spring member, and the second spring member.

21. The electric machine of claim 20, wherein the at least one internal coolant return passage comprises a first coolant return conduit disposed in the second housing member and a second coolant return conduit disposed in the third housing member, the first coolant return conduit and the second coolant return conduit extending substantially parallel to the rotational axis of the rotor.

22. The electric machine of claim 21 wherein the second housing member includes a first plurality of channels extending between the second exterior surface and the first coolant return conduit, and the third housing member includes a second plurality of channels extending between the third exterior surface and the second coolant return conduit.

23. An excitation coil separator, comprising: An elastic frame is configured to be loaded into the plurality of coolant channels between adjacent ones of the plurality of field coils by first compressing the elastic frame and then releasing the elastic frame.

24. The field coil separator according to claim 23, wherein: The field coil separator includes a first spring member, and the first spring member is configured to engage a field coil of the plurality of field coils.

25. The field coil separator of claim 23, wherein the first spring member includes at least one secondary coolant directing element, and the secondary coolant directing element engages one of the plurality of field coils.

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