Bearing spacer

Abstract

The invention relates to a bearing spacer. The spacer is configured to abut the output shaft bearing. The spacer has an inner diameter and an outer diameter. The first wall extends from the inner diameter to the outer diameter and is configured to abut a radial surface of the output shaft bearing and a surface of the housing. The second wall is attached to the first wall at the inner diameter, extends from the inner diameter to the outer diameter, and is configured to abut a surface of the housing. The first wall and the second wall are axially spaced apart at the outer diameter.

Description

TECHNICAL FIELD

[0001] The present application relates to a spacer for use in a rotary electric machine. BACKGROUND

[0002] Rotary electric machines are subject to vibrations from moving parts of the rotary electric machine or the rotary electric machine environment that can interfere with the output shaft bearing. By supporting the output shaft bearing and dampening any vibrations, the reliability of the rotary electric machine can be improved. SUMMARY

[0003] In one embodiment, a spacer is provided that is configured to be received by an output shaft and abut an output shaft bearing. The spacer has an inner diameter and an outer diameter, the inner diameter configured to receive the output shaft. A first wall extends from the inner diameter to the outer diameter and is configured to abut a radial surface of the output shaft bearing and a surface of a housing. A second wall is attached to the first wall at the inner diameter, the second wall extending from the inner diameter to the outer diameter and configured to abut a surface of the housing. The first wall and the second wall are axially spaced apart at the outer diameter.

[0004] In another embodiment, a spacer is configured to be received by an output shaft and abut an output shaft bearing. The spacer includes an inner diameter and an outer diameter, the inner diameter configured to receive an output shaft coupled to a rotary electric machine. A first wall extends from the inner diameter to the outer diameter and is configured to abut a radial surface of the output shaft bearing and a surface of a housing, the housing surrounding the rotary electric machine. A second wall is attached to the first wall at the inner diameter, the second wall extending from the inner diameter to the outer diameter and configured to abut a surface of the housing. The first wall and the second wall are axially spaced apart at the outer diameter.

[0005] In another embodiment, a spacer is configured to be received by an output shaft and abut an output shaft bearing. The spacer has an inner diameter and an outer diameter, the inner diameter configured to receive the output shaft. A first wall extends from the inner diameter to the outer diameter and is configured to abut a radial surface of the output shaft bearing and a surface of a housing. A second wall is attached to the first wall at the inner diameter, the second wall extending from the inner diameter to the outer diameter and configured to abut an output shaft seal. The first wall and the second wall are axially spaced apart at the outer diameter. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a cross-sectional view illustrating an embodiment of a rotary electric machine having a spacer configured to be received by an output shaft and abut an output shaft bearing;

[0007] Figure 2 is a perspective view illustrating an embodiment of a spacer;

[0008] Figure 3 is a top view of an embodiment of a spacer;

[0009] Figure 4 is a side view alongFigure 3 a cross-sectional view of the spacer shown in FIG. 1 taken along line A-A;

[0010] Figure 5 is a cross-sectional view of a portion of a rotary electric machine having an embodiment of a spacer configured to be received by and abut an output shaft bearing;

[0011] Figure 6 is a cross-sectional view of a portion of a rotary electric machine having an embodiment of a spacer configured to be received by and abut an output shaft bearing, wherein the spacer is subjected to a load;

[0012] Figure 7 is a cross-sectional view of a portion of a rotary electric machine having another embodiment of a spacer configured to be received by and abut an output shaft bearing;

[0013] Figure 8 is a cross-sectional view of a portion of a rotary electric machine having yet another embodiment of a spacer configured to be received by and abut an output shaft bearing, wherein the spacer and an output shaft seal are integrated as one component; and

[0014] Figure 9 is a chart depicting the compression load performance of the present spacer compared to a wave spring and a square cross-section spacer. DETAILED DESCRIPTION

[0015] The spacer can be used in a rotary electric machine to dampen vibrations while securing an output shaft bearing in place. In some embodiments, the spacer is composed of a durable elastomeric material having a V-shaped cross-section that helps to resist high vibration environments. The spacer has an inner diameter and an outer diameter. A first wall extends from the inner diameter to the outer diameter and is configured to abut a radial surface of an output shaft bearing. A second wall is axially spaced apart from the first wall and is configured to abut a housing that encases the spacer and the output shaft bearing such that the spacer can be axially compressed to load the output shaft bearing. The spacer can have a groove extending circumferentially around the spacer from the outer diameter between the first wall and the second wall. The shape and size of the groove can be varied as needed for the intended embodiment to adjust the dampening and stiffness of the spacer.

[0016] In the past, rotating electrical machines relied on metallic wave springs to dampen vibrations transmitted from the housing of the rotating electrical machine to the output shaft bearing of the rotating electrical machine. However, metallic wave springs are prone to failure when subjected to significant vibrations. When used in a rotating machine, a failed metallic wave spring can shatter into pieces, which can mechanically bind the rotating machine. Accordingly, the elastomeric spacer of V-shaped cross-section disclosed herein has greater vibration dampening properties than metallic wave springs and can provide an axial force on the output shaft bearing while extending the life of the rotating machine and reducing the likelihood of mechanical binding that leads to catastrophic failure of the rotating electrical machine.

[0017] Figure 1 An embodiment of a spacer 10 for use with a rotating electrical machine 12 is shown. The rotating electrical machine 12 includes a housing 14, a stator assembly 16, and a rotor assembly 18. The housing 14 is a structural component configured to support components of the rotating electrical machine 12. The housing 14 can be made of a structurally strong material, such as a metal, and can encapsulate components of the stator assembly 16 and the rotor assembly 18, preventing external contaminants from entering the rotating electrical machine 12. The housing 14 can be adapted to include or receive fasteners, such as, but not limited to, bolts, screws, studs, lugs, clips, pins, brackets, and / or other fasteners, in order to couple to other machines or assemblies.

[0018] The stator assembly 16 is located within and supported by the housing 14. The stator assembly 16 can include laminations stacked axially together and bonded to form a stator shape, including stator slots. The stator can receive stator windings connected to a power source within the stator slots. By selectively controlling the current flowing through the stator windings, a rotating electromagnetic field can be induced in the area near the stator assembly, causing the rotor assembly 18 to move angularly relative to the stator assembly 16.

[0019] The rotor assembly 18 is supported by the housing 14 and is at least partially surrounded by the stator assembly 16. Figure 1 The illustrated embodiment depicts the rotor assembly 18 including a rotor 20, an output shaft 22, one or more output shaft bearings 24, the spacer 10, and an output shaft seal 26. Figure 1The rotor 20 may be formed from multiple stacked laminated iron plates bonded together and has slots spaced at an angle around the rotor 20, constraining permanent magnets 28, which are configured to interact with electromagnetic forces emitted by the stator assembly 16. The permanent magnets 28 are located between the inner rotor diameter and the outer rotor diameter. The output shaft 22 may be press-fitted into the inner rotor diameter to prevent angular displacement of the output shaft 22 relative to the rotor 20. In some embodiments, the output shaft 22 may be configured to interact with other machines, parts, and / or components, so that a portion of it may protrude beyond the housing 14.

[0020] The output shaft bearing 24 can be received within the housing 14 and support the output shaft 22. Figure 1 In the illustrated embodiment, the first output shaft bearing 30 and the second output shaft bearing 32 can receive the output shaft 22 on opposite sides of the rotor 20, such that the second output shaft bearing 32 abuts against the housing 14 on two radial surfaces. The first output shaft bearing 30 abuts against the housing 14 on one radial surface and against the spacer 10 on the other radial surface. The term "radial" as used herein refers to a surface extending radially outward from the axis of rotation of the shaft. The term "axial" is used to refer to an element extending axially along the axis of rotation of the shaft. Both the first output shaft bearing 30 and the second output shaft bearing 32 include an inner bearing portion 34 and an outer bearing portion 36, wherein the inner bearing portion 34 circumferentially surrounds at least a portion of the output shaft 22. The outer bearing portion 36 can be constrained by the housing 14 and surrounds the inner bearing portion 34, allowing the inner bearing portion 34 to rotate freely relative to the outer bearing portion 36. Any type of bearing capable of handling the loads experienced by the rotating motor 12 can be used. For example, multiple balls may be radially positioned between the inner bearing portion 34 and the outer bearing portion 36, and / or lubricant may fill the space between the inner bearing portion 34 and the outer bearing portion 36, thereby providing minimal friction for rotation of the inner bearing portion 34 constrained about the axis of the output shaft 22. An output shaft seal 26 may be located between the spacer 10, the housing 14, and the output shaft 22 to prevent contaminants from entering the housing 14 and to prevent lubricant from leaving the housing 14 along the output shaft 22. The output shaft seal 26 may be a flexible elastomer material to conform to the output shaft 22, despite the vibrations experienced by the output shaft 22 during operation.

[0021] like Figures 2-4In the illustrated embodiment, the spacer 10 has an inner diameter 38 configured to receive and abut the output shaft 22 and an outer diameter 40. A first wall 42 extends between the inner diameter 38 and the outer diameter 40 and is configured to abut a radial surface of the first output shaft bearing 30. At the outer diameter 40, the first wall 42 is configured to abut the radial surface of the first output shaft bearing 30 and an inner surface of the housing 14. On a radially opposite side of the spacer 10, a second wall 44 extends between the inner diameter 38 and the outer diameter 40 of the spacer 10, meeting the first wall 42 at the inner diameter 38. The first wall 42 and the second wall 44 extend radially outward away from the inner diameter 38 at an angle relative to each other. The second wall 42 is configured to abut the housing 14 or another component that ultimately contacts a portion of the housing 14. In Figure 1 In the illustrated embodiment, the second wall 44 abuts the output shaft seal 26, which is in contact with a portion of the housing 14, such that an axial force can be transmitted through the output shaft seal 26 and the spacer 10 to the bottom radial surface of the first output shaft bearing 30. The contact between the spacer 10 and the housing 14, the spacer 10 and the radial surface of the first output shaft bearing 30, or the spacer 10 and the output shaft seal 26 can form a seal between the spacer 10 and the housing 14, the spacer 10 and the radial surface of the first output shaft bearing 30, or the spacer 10 and the output shaft seal 26, such that lubricant cannot escape from the rotary electric machine 12 and contaminants cannot enter the rotary electric machine 12. The spacer can have a circumferential groove 46 extending radially inward between the first wall 42 and the second wall 44 from the outer diameter 40. The circumferential groove 46 forms a V-shaped cross section 48 throughout the spacer 10; however, the specific dimensions of the V-shaped cross section 48 can vary to adjust the stiffness and / or damping performance of the spacer 10. In some embodiments, however, the spacer can be configured such that the inner diameter of the spacer does not receive and / or abut the output shaft.

[0022] Figure 5 An embodiment of the rotary electric machine 12 is shown in which the first wall 42 of the spacer 10 abuts the first output shaft bearing 30 and the second wall 44 abuts the output shaft seal 26, which abuts the housing 14. In this case, the spacer 10 is under light axial load such that the spacer 10 contacts both the first output shaft bearing 30 and the output shaft seal 26, but the first wall 42 and the second wall 44 are spaced apart at the outer diameter 40 such that there is room for the spacer 10 to compress further if the axial force increases. In Figure 6 In the illustrated embodiment, the second wall 44 abuts the output shaft seal 26, which is in contact with a portion of the housing 14, such that an axial force can be transmitted through the output shaft seal 26 and the spacer 10 to the bottom radial surface of the first output shaft bearing 30. The contact between the spacer 10 and the housing 14, the spacer 10 and the radial surface of the first output shaft bearing 30, or the spacer 10 and the output shaft seal 26 can form a seal between the spacer 10 and the housing 14, the spacer 10 and the radial surface of the first output shaft bearing 30, or the spacer 10 and the output shaft seal 26, such that lubricant cannot escape from the rotary electric machine 12 and contaminants cannot enter the rotary electric machine 12. The spacer can have a circumferential groove 46 extending radially inward between the first wall 42 and the second wall 44 from the outer diameter 40. The circumferential groove 46 forms a V-shaped cross section 48 throughout the spacer 10; however, the specific dimensions of the V-shaped cross section 48 can vary to adjust the stiffness and / or damping performance of the spacer 10. In some embodiments, however, the spacer can be configured such that the inner diameter of the spacer does not receive and / or abut the output shaft.Figure 6 the compression shown and Figure 5 the expansion shown. Thus, constructing the spacer 10 with an elastomeric material allows the spacer 10 to reliably undergo multiple cycles between light axial loads and increased axial loads, such as axial loads that the spacer 10 frequently experiences due to vibrations of the rotating electric machine 12 itself or the environment of the rotating electric machine 12.

[0023] Figure 7 Another embodiment of the spacer 10 is shown, in which supplemental material 50 is inserted into the circumferential groove 46 circumferentially around the spacer 10 between the first wall 42 and the second wall 44. In Figure 7 In the embodiment shown, the supplemental material 50 has a triangular cross-section 52 and fills the entire circumferential groove 46 such that the supplemental material 50 abuts the housing 14. However, in other embodiments, the size, shape, and material composition of the supplemental material 50 can vary to adjust the damping and stiffness of the spacer 10 in combination with the supplemental material 50 for the intended embodiment.

[0024] In some embodiments, the spacer 10 and the output shaft seal 26 can be combined into a single component 54. Figure 8 The spacer 10 is shown abutting the first output shaft bearing 30 at the first wall 42, and the output shaft seal 26 extends from the second wall 44 toward the housing 14 and toward the output shaft 22. Combining the spacer 10 and the output shaft seal 26 into a single component 54 can reduce the complexity of the rotating electric machine 12 by reducing the total number of components while simultaneously reducing manufacturing costs.

[0025] Figure 9 is a graph showing the relationship between load and compression on various types of spacers. The spacer with the square cross-section 56 proved to be stiffer than ideal, while the spacer 10 with the V-shaped cross-section 48, 58 was able to largely mimic the compression performance of the metal wave spring 60. The spacer 10 with the V-shaped cross-section 48, 58 also sustained a greater peak load than the metal wave spring 60, thereby reducing the likelihood of failure.

[0026] It is to be understood that the foregoing description is that of one or more embodiments of the application. Various embodiments of the application are limited by the claims set forth below. Furthermore, the statements contained in the foregoing description relate to specific embodiments of the application and do not limit the scope of the application or the claims set forth below. One skilled in the art will readily recognize from the disclosure herein, that other embodiments than those described herein are possible and that modifications can be made to the embodiments described herein without departing from the spirit and scope of the application. Accordingly, the disclosure of this patent specification is intended to be illustrative, but not limiting, of the scope of the application, which is set forth in the following claims.

[0027] In this specification and in the claims, the terms "a," "an," and "the" are not limited to refer to one item unless it is used in conjunction with terms that indicate the number of items, such as "one," "two," "three," etc. In addition, the articles "a," "an," and "the" are used herein to refer to one or more (i.e., to "at least one") of something unless otherwise indicated by the context of the articles' usage. By using such terms, the applicant intends that there be a variety of items being referred to, which can be both singular and plural. The terms "comprising," "having," "including," and "containing" are to be construed open-ended, meaning that the listed steps or options need not be present for the method or composition to be deemed within the scope of the present disclosure. Other terms are to be construed using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.

Claims

1. A spacer configured to be received by an output shaft and abut an output shaft bearing, the spacer comprising: an inner diameter and an outer diameter; a first wall extending from the inner diameter to the outer diameter configured to abut a radial surface of the output shaft bearing; and a second wall attached to the first wall at the inner diameter extending from the inner diameter to the outer diameter configured to abut a surface of a housing, wherein the first wall and the second wall are axially spaced apart at the outer diameter and the spacer is axially compressible to load the output shaft bearing. The spacer has a V-shaped cross-section.

2. The spacer of claim 1, wherein, The inner diameter is configured to receive the output shaft.

3. The spacer of claim 1, wherein, The spacer further comprises a circumferential groove extending radially inward between the first wall and the second wall from the outer diameter.

4. The spacer of claim 2, wherein, Contact between the spacer and the housing forms a seal between the spacer and the housing.

5. The spacer of claim 4, wherein, Contact between the spacer and the radial surface of the output shaft bearing forms a seal between the spacer and the radial surface of the output shaft bearing.

6. The spacer of claim 4, wherein, Contact between the spacer and an output shaft seal forms a seal between the spacer and the output shaft seal.

7. The spacer of claim 4, wherein, 8. The spacer of claim 4, further comprising supplemental material located within the groove and between the first wall and the second wall.

9. The spacer of claim 4, wherein the spacer and output shaft seal are formed as a single component.

10. A spacer configured to be received by an output shaft and abut an output shaft bearing, the spacer comprising: an inner diameter and an outer diameter, the inner diameter configured to receive the output shaft coupled with a rotary electric machine; a first wall extending from the inner diameter to the outer diameter configured to abut a radial surface of the output shaft bearing and a surface of a housing surrounding the rotary electric machine; and a second wall attached to the first wall at the inner diameter extending from the inner diameter to the outer diameter configured to abut a surface of the housing, wherein the first wall and the second wall are axially spaced apart at the outer diameter. The spacer has a V-shaped cross-section. The spacer further comprises a circumferential groove extending radially inward between the first wall and the second wall from the outer diameter.

11. The spacer of claim 10, wherein, The spacer is made of an elastomeric material.

12. The spacer of claim 11, wherein, Contact between the spacer and the housing forms a seal between the spacer and the housing.

13. The spacer of claim 12, wherein, Contact between the spacer and the radial surface of the output shaft bearing forms a seal between the spacer and the radial surface of the output shaft bearing.

14. The spacer of claim 13, wherein, Contact between the spacer and an output shaft seal forms a seal between the spacer and the output shaft seal.

15. The spacer of claim 13, wherein, 17. The spacer of claim 13, further comprising supplemental material located within the groove and between the first wall and the second wall.

16. The spacer of claim 13, wherein, The spacer and shaft seal are formed as a single component.

19. A spacer configured to be received by an output shaft and abut an output shaft bearing, the spacer comprising:

18. The spacer of claim 13, wherein, an inner diameter and an outer diameter, the inner diameter configured to receive the output shaft; a first wall extending from the inner diameter to the outer diameter configured to abut a radial surface of the output shaft bearing and a surface of a housing; and ​ ​ a second wall attached to the first wall at the inner diameter extending to the outer diameter configured to abut a surface of an output shaft seal, wherein the first wall and the second wall are axially spaced apart at the outer diameter and the spacer is axially compressible.

20. The spacer of claim 19, wherein, the spacer further comprises a circumferential groove extending radially inward between the first wall and the second wall from the outer diameter, and the spacer is made of an elastomeric material.

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