Axial slip ring assembly for electric motor

Abstract

An axial slip ring assembly for power transmission in a separately excited motor (SEM) rotor includes a slip ring housing, a first slip ring, a second slip ring, a brush housing, a plurality of brushes, and a plurality of springs. The slip ring housing is mounted to a rotor shaft of the SEM rotor for rotation about an axis of rotation. The first and second slip rings are connected to coil windings of the SEM rotor and disposed within the slip ring housing. The brush housing includes an axial brush housing face that is perpendicular to the axis of rotation. The plurality of brushes and the plurality of springs are disposed within the brush housing. The plurality of springs exert an axial force that causes the plurality of brushes to exert a constant axial force on the first and second slip rings.

Description

Technical Field

[0001] This disclosure relates to a slip ring assembly for an electric motor. More specifically, this disclosure relates to an axial slip ring assembly for axially transmitting current to the rotor of a synchronous motor (SEM). Background Technology

[0002] A typical SEM consists of a stator and a rotor. Unlike motors that use permanent magnets, the rotor of an SEM includes coil windings that generate a magnetic field. The rotor's magnetic field can be adjusted by applying current to the coil windings. An external power source applies current to a radial slip ring assembly, which transmits the current to the coil windings, causing the rotor to rotate.

[0003] A radial mounting sleeve is used to mount the radial slip ring assembly onto the rotor. The radial mounting sleeve occupies encapsulation space during the mounting of the radial slip ring assembly. This encapsulation space limits the positioning opportunities of the radial slip ring assembly on the rotor.

[0004] Therefore, in order to reduce the packaging space and increase the positioning opportunities of the slip ring assembly on the rotor, a new and improved slip ring assembly system is needed. Summary of the Invention

[0005] According to several aspects, an axial slip ring assembly is provided for power transmission in a separately excited motor (SEM) rotor, the SEM rotor including a rotor shaft and coil windings. The SEM rotor defines an axis of rotation. The axial slip ring assembly includes a slip ring housing. The slip ring housing is mounted to the rotor shaft of the SEM rotor. The slip ring housing rotates about the axis of rotation. The axial slip ring assembly also includes a first slip ring. The first slip ring is disposed within the slip ring housing and rotates with the slip ring housing. The first slip ring is connected to the coil windings of the SEM rotor. The first slip ring is perpendicular to the axis of rotation. The axial slip ring assembly also includes a second slip ring. The second slip ring is disposed within the slip ring housing and rotates with the slip ring housing. The second slip ring is connected to the coil windings of the SEM rotor. The second slip ring is perpendicular to the axis of rotation. The second slip ring is located radially outward of the first slip ring. The axial slip ring assembly also includes a brush housing. The brush housing includes an axial brush housing surface. The axial brush housing surface is perpendicular to the axis of rotation. The axial slip ring assembly also includes a plurality of brushes. The plurality of brushes are disposed within the brush housing. The axial slip ring assembly also includes a plurality of springs. Multiple springs are disposed within the brush housing. The multiple springs apply axial force along the axis of rotation to cause the multiple brushes to exert a constant axial force on the first and second slip rings.

[0006] In another aspect of this disclosure, the slip ring housing also includes an axial slip ring housing surface disposed parallel to the axial brush housing surface.

[0007] In another aspect of this disclosure, the slip ring housing also includes an inner groove. A first slip ring is disposed within the inner groove.

[0008] In another aspect of this disclosure, the slip ring housing also includes an outer groove. A second slip ring is disposed within the outer groove. The outer groove is located radially outward from the inner groove.

[0009] In another aspect of this disclosure, the slip ring housing also includes an intermediate surface. The intermediate surface is located between the inner groove and the outer groove.

[0010] In another aspect of this disclosure, the axial brush housing surface defines a groove parallel to the axis of rotation. Multiple brushes are disposed within the groove. Multiple springs are disposed within the groove.

[0011] In another aspect of this disclosure, the plurality of brushes further includes a first end. The first end is in contact with a plurality of springs. The plurality of brushes also includes a second end. The second end is opposite to the first end. The second end applies a constant axial force to a first slip ring and a second slip ring along the axis of rotation.

[0012] In another aspect of this disclosure, the axial slip ring assembly also includes a static structure. The static structure is stationary. The brush housing is mounted to the static structure.

[0013] In another aspect of this disclosure, a plurality of brushes, a first slip ring, and a second slip ring are axially aligned.

[0014] In another aspect of this disclosure, multiple brushes, a first slip ring, and a second slip ring are axially interleaved.

[0015] In another aspect of this disclosure, a plurality of brushes are arranged alternately in a circumferential direction within the brush housing.

[0016] In another aspect of this disclosure, a plurality of brushes are arranged circumferentially within a brush housing.

[0017] In another aspect of this disclosure, the multiple brushes include a positive brush group and a negative brush group.

[0018] In another aspect of this disclosure, the axial slip ring assembly also includes a power source. The power source applies current to the plurality of brushes.

[0019] In another aspect of this disclosure, multiple brushes transmit current to a first slip ring and through a coil winding to a second slip ring.

[0020] In another aspect of this disclosure, a first slip ring transfers current to the coil windings. The current in the coil windings generates a magnetic field, causing the SEM rotor to rotate.

[0021] According to several aspects, a separately excited motor (SEM) rotor is provided for power transmission, the SEM defining an axis of rotation. The SEM rotor includes a rotor shaft. The rotor shaft rotates about the axis of rotation. The SEM rotor also includes a laminated plate. The laminated plate is connected to the rotor shaft. The laminated plate rotates with the rotor shaft. The SEM rotor also includes coil windings. The coil windings are wound within the laminated plate. The SEM rotor also includes a gear. The gear is mounted to the rotor shaft. The gear rotates with the rotor shaft. The SEM rotor also includes an axial slip ring assembly. The axial slip ring assembly includes a slip ring housing. The slip ring housing is mounted to the rotor shaft. The slip ring housing rotates with the rotor shaft. The axial slip ring assembly also includes a first slip ring. The first slip ring is disposed within the slip ring housing. The first slip ring rotates with the slip ring housing. The first slip ring is connected to the coil windings of the SEM rotor. The first slip ring is perpendicular to the axis of rotation. The axial slip ring assembly also includes a second slip ring. The second slip ring is disposed within the slip ring housing. The second slip ring rotates with the slip ring housing. The second slip ring is connected to the coil windings of the SEM rotor. The second slip ring is perpendicular to the axis of rotation. The second slip ring is located radially outward from the first slip ring. The axial slip ring assembly also includes a brush housing. The brush housing includes an axial brush housing surface. The axial brush housing surface is perpendicular to the axis of rotation. The axial slip ring assembly also includes a static structure. The static structure is stationary. The brush housing is mounted to the static structure. The axial slip ring assembly also includes multiple brushes. The multiple brushes are disposed within the brush housing. The axial slip ring assembly also includes multiple springs. The multiple springs are disposed within the brush housing. The multiple springs apply an axial force along the axis of rotation to cause the multiple brushes to contact the first and second slip rings. The axial slip ring assembly also includes a power source. The power source supplies current to the multiple brushes. The multiple brushes transfer current from the power source to the first slip ring and through a coil winding to the second slip ring. The first slip ring transfers current to the coil winding. The current in the coil winding generates a magnetic field, causing the SEM rotor to rotate about the axis of rotation.

[0022] In another aspect of this disclosure, the SEM rotor also includes an iron wheel. The iron wheel is attached to the gear. The iron wheel rotates with the rotor shaft.

[0023] In another aspect of this disclosure, the SEM rotor also includes a speed sensor. The speed sensor is stationary. The speed sensor is adjacent to the iron wheel. The speed sensor calculates the rotor speed by detecting the rotational speed of the iron wheel as it rotates.

[0024] According to several aspects, an axial slip ring assembly is provided for power transmission in a separately excited motor (SEM) rotor, the SEM rotor including a rotor shaft and coil windings. The SEM rotor defines an axis of rotation. The axial slip ring assembly includes a slip ring housing. The slip ring housing is mounted to the rotor shaft of the SEM rotor. The slip ring housing rotates about the axis of rotation. The axial slip ring assembly also includes a first slip ring. The first slip ring is disposed within the slip ring housing. The first slip ring rotates with the slip ring housing. The first slip ring is connected to the coil windings of the SEM rotor. The first slip ring is perpendicular to the axis of rotation. The axial slip ring assembly also includes a second slip ring. The second slip ring is disposed within the slip ring housing. The second slip ring rotates with the slip ring housing. The second slip ring is connected to the coil windings of the SEM rotor. The second slip ring is perpendicular to the axis of rotation. The second slip ring is located radially outward from the first slip ring. The axial slip ring assembly also includes a brush housing. The brush housing includes an axial brush housing surface. The axial brush housing surface is disposed perpendicular to the axis of rotation. The axial slip ring assembly also includes a static structure. The static structure is stationary. The brush housing is mounted to the static structure. The axial slip ring assembly also includes multiple brushes. These brushes are housed within brush housings. The axial slip ring assembly also includes multiple springs. These springs are also housed within brush housings. The springs apply an axial force along the axis of rotation to cause the brushes to exert a constant axial force on the first and second slip rings. The axial slip ring assembly also includes a power source. The power source applies current to the brushes. The brushes transfer the current from the power source to the first slip ring and through a coil winding to the second slip ring. The first slip ring transfers the current to the coil winding. The current in the coil winding generates a magnetic field, causing the SEM rotor to rotate about the axis of rotation.

[0025] Further applicability will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0026] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way.

[0027] Figure 1 This is a cross-sectional view of an axial slip ring assembly mounted on a synchronous motor (SEM) rotor according to an exemplary embodiment.

[0028] Figure 2 This is an end view of an axial slip ring assembly according to an exemplary embodiment.

[0029] Figure 3 This is an end view of an alternative axial slip ring assembly according to an exemplary embodiment.

[0030] Figure 4 This is a cross-sectional view of an alternative axial slip ring assembly mounted on a SEM rotor according to an exemplary embodiment. Detailed Implementation

[0031] The following description is merely exemplary in nature and is not intended to limit the content, application, or purpose of this disclosure.

[0032] refer to Figure 1 The image shows a cross-sectional view of an axial slip ring assembly 10 mounted on a synchronous motor (SEM) rotor 12. The SEM rotor 12 is part of an SEM 13. A power source 14 located outside the SEM 13 applies current to the axial slip ring assembly 10. The power source 14 can be, but is not limited to, a direct current (DC) power source. The axial slip ring assembly 10 transfers current from the power source 14 to the SEM rotor. When current is transferred to the SEM rotor 12, it is converted into mechanical energy, causing the SEM rotor 12 to rotate. The SEM rotor 12 includes a rotor shaft 16, a laminate 18, coil windings 20, gears 22, an iron wheel 24, and a speed sensor 26.

[0033] The rotor shaft 16 defines a rotation axis 28 for its rotation. A laminate 18 is connected to the rotor shaft 16 and rotates with it. A coil winding 20 is wound around the laminate 18 and rotates with it. When current is transmitted to the coil winding 20, it generates a magnetic field that causes the SEM rotor 12 to rotate about the rotation axis 28. The current transmission will be described in detail below.

[0034] Gear 22 is mounted on rotor shaft 16 and rotates with rotor shaft 16. Rotation is a form of mechanical energy, and gear 22 transmits mechanical energy. For example, gear 22 can transmit mechanical energy to the machine (not shown) where SEM rotor 12 is located. Iron wheel 24 is attached to gear 22 and rotates with gear 22. Iron wheel 24 is made of iron material, such as, but not limited to, iron or steel. Speed ​​sensor 26 is mounted on stationary part 29 of SEM 13 and is positioned near iron wheel 24. When iron wheel 24 rotates, speed sensor 26 detects the rotation of iron wheel 24 and calculates the rotational speed of iron wheel 24. Iron wheel 24 rotates with rotor shaft 16 at the same rotational speed as SEM rotor 12, so speed sensor 26 calculates the speed of SEM rotor 12.

[0035] To enable the SEM rotor 12 to rotate, the axial slip ring assembly 10 is axially mounted on the SEM rotor 12 to transfer current from the power supply 14 to the coil winding 20. The axial mounting of the axial slip ring assembly 10 eliminates the need for a mounting sleeve, reducing the encapsulation space required during installation. This reduced encapsulation space increases the positioning opportunities of the axial slip ring assembly 10 on the SEM rotor 12. The axial slip ring assembly 10 includes a slip ring housing 30, a first slip ring 32, a second slip ring 34, a brush housing 36, a plurality of brushes 38, and a plurality of springs 40.

[0036] The slip ring housing 30 is axially mounted on the SEM rotor 12 and attached to the rotor shaft 16. The slip ring housing 30 rotates with the rotor shaft 16 about the rotation axis 28. The slip ring housing 30 includes an axial slip ring housing surface 42, an inner groove 44, an outer groove 46, and an intermediate surface 48.

[0037] The axial slip ring housing surface 42 is perpendicular to the rotation axis 28. The inner groove 44, outer groove 46, and intermediate surface 48 are provided on the axial slip ring housing surface 42. Figure 2 and Figure 3 As shown, the outer groove 46 is located radially outward from the inner groove 44. The intermediate surface 48 is located between the inner groove 44 and the outer groove 46.

[0038] Refer again Figure 1 The first slip ring 32 is perpendicular to the rotation axis 28 and is disposed within the inner groove 44 of the slip ring housing 30. The first slip ring 32 includes a first radial slip ring surface 50 and a first rear surface 52. The first radial slip ring surface 50 is axially aligned with the axial slip ring housing surface 42. The first rear surface 52 is opposite to the first radial slip ring surface 50. The first rear surface 52 contacts the coil winding 20, thereby allowing current to enter or exit the coil winding 20.

[0039] The second slip ring 34 is perpendicular to the rotation axis 28 and is disposed within the outer groove 46 of the slip ring housing 30. The second slip ring 34 is located radially outward from the first slip ring 32. The second slip ring 34 includes a second radial slip ring surface 54 and a second rear surface 56. The second radial slip ring surface 54 is axially aligned with the axial slip ring housing surface 42. The second rear surface 56 is opposite to the second radial slip ring surface 54. The second rear surface 56 contacts the coil winding 20, thereby allowing current to enter or exit the coil winding 20.

[0040] The brush housing 36 is axially mounted on the SEM rotor 12 and located near the slip ring housing 30. The brush housing 36 is mounted to the static structure 58 such that it is stationary and does not rotate. The brush housing 36 can be, but is not limited to, directly mounted to the static structure 58 using bolts or screws. The brush housing 36 includes an axial brush housing surface 60. The axial brush housing surface 60 is perpendicular to the rotor shaft 16 and parallel to the axial slip ring housing surface 42. The axial brush housing surface 60 defines a plurality of slots 62. The plurality of slots 62 are perpendicular to the axial brush housing surface 60. A plurality of brushes 38 and a plurality of springs 40 are disposed within the plurality of slots 62.

[0041] Multiple brushes 38 are connected to a power supply 14. The power supply 14 applies current to the multiple brushes 38. Each brush 38 includes a first end 64 and a second end 66. The first end 64 is opposite to the second end 66. The first end is in contact with multiple springs 40. The multiple springs 40 apply a constant axial force to the first end 64 along a rotation axis 28. The constant axial force acting on the first end 64 causes the second end 66 of the multiple brushes 38 to apply a constant axial force to a first radial slip ring surface 50 and a second radial slip ring surface 54. The constant axial force acting on the first radial slip ring surface 50 and the second radial slip ring surface 54 causes the current from the power supply 14 to be axially transmitted from the multiple brushes 38 to the first slip ring 32 and the second slip ring 34. The multiple brushes 38 also include a positive brush group (not shown) and a negative brush group (not shown).

[0042] A positive brush assembly (not shown) transmits current from power source 14 to coil winding 20. For example, the positive brush assembly can generate a constant axial force on the first radial slip ring surface 50. If the positive brush assembly generates a constant axial force on the first radial slip ring surface 50, the current applied by the power source is transmitted to the first slip ring 32. The first slip ring 32 is connected to coil winding 20 to transmit current to coil winding 20.

[0043] A negative brush assembly (not shown) transfers current from the coil winding 20 back to the power source 14. For example, the negative brush assembly can apply a constant axial force to the second radial slip ring surface 54. If the negative brush assembly applies a constant axial force to the second radial slip ring surface 54, the second slip ring 34 transfers current from the coil winding 20 to the negative brush assembly. A negative brush assembly of multiple brushes 38 transfers current back to the power source 14.

[0044] refer to Figure 2 This shows an end view of the axial slip ring assembly 10. Multiple brushes 38 exert a constant axial force on a first radial slip ring surface 50 and a second radial slip ring surface 54. The multiple brushes 38 are housed in a brush housing 36 (e.g., Figure 1 As shown, the brushes 38 are arranged circumferentially. When the first slip ring 32 and the second slip ring 34 rotate about the rotation axis 28, the multiple brushes 38 apply a constant axial force to the first slip ring 32 and the second slip ring 34. The constant axial force keeps the multiple brushes 38 in sliding contact with the first radial slip ring surface 50 and the second radial slip ring surface 54.

[0045] refer to Figure 3 This illustrates an alternative embodiment of the axial slip ring assembly 10, indicated by reference numeral 72. The axial slip ring assembly 72 includes a rotation axis 28, a first slip ring 32, a second slip ring 34, a first radial slip ring surface 50, a second radial slip ring surface 54, and an intermediate surface 48, as shown... Figure 1 and Figure 2 As shown. The axial slip ring assembly 72 also includes a plurality of brushes 74. The plurality of brushes 74 are housed in the brush housing 36 (as shown). Figure 1The brushes 74 are arranged alternately along the circumferential direction (as shown). When the first slip ring 32 and the second slip ring 34 rotate about the rotation axis 28, the multiple brushes 74 generate a constant force with the first slip ring 32 and the second slip ring 34. The constant force exerted by the multiple brushes 74 on the first slip ring 32 and the second slip ring 34 keeps the multiple brushes 74 in sliding contact with the first radial slip ring surface 50 and the second radial slip ring surface 54.

[0046] refer to Figure 4 It shows a cross-sectional view of an alternative embodiment of the axial slip ring 10 mounted on the SEM rotor 12, indicated by reference numeral 76. The SEM rotor 12 includes a power supply 14, a rotor shaft 16, a laminate 18, coil windings 20, gears 22, an iron wheel 24, a speed sensor 26, a rotation axis 28, and a static structure 58, as shown in the figure. Figure 1 As shown. The axial slip ring assembly 76 axially transmits current from the power source 14 to the coil winding 20. The axial slip ring assembly 76 includes a slip ring housing 78, a first slip ring 80, a second slip ring 82, a brush housing 84, a plurality of brushes 86, and a plurality of springs 88. The slip ring housing 78 is axially mounted on the SEM rotor 12 and mounted on the rotor shaft 16, rotating with the rotor shaft 16. The slip ring housing 78 includes an axial slip ring housing surface 90, an inner groove 92, an outer groove 94, and an intermediate surface 96.

[0047] The axial slip ring housing surface 90 is perpendicular to the rotation axis 28. An inner groove 92, an outer groove 94, and an intermediate surface 96 are disposed on the axial slip ring housing surface 90. The inner groove 92 and the outer groove 94 are axially staggered. The outer groove 94 extends axially inward from the inner groove 92 toward the coil winding 20. The outer groove 94 is also located radially outward from the inner groove 92. The intermediate surface 96 is located between the inner groove 92 and the outer groove 94.

[0048] A first slip ring 80 is disposed within an inner groove 92. A second slip ring 82 is disposed within an outer groove 94. The first slip ring 80 is axially aligned with the inner groove 92, and the second slip ring 82 is axially aligned with the outer groove 94, thereby offsetting the first slip ring 80 and the second slip ring 82 axially. This axial offset allows debris from the second slip ring 82 to fall radially to the outside of the first slip ring 80. Furthermore, by making the first slip ring 80 and the second slip ring 82 axially offset, wear and arcing problems are improved.

[0049] The brush housing 84 is axially mounted on the SEM rotor 12 and attached to the static structure 58. The brush housing 84 can be directly mounted to the static structure 58 using bolts or screws. The brush housing 84 is adjacent to the slip ring housing 78. The brush housing 84 includes an axial brush housing surface 98. The axial brush housing surface 98 is parallel to the axial slip ring housing surface 90. The axial brush housing surfaces 98 are axially staggered, matching the profile of the axial slip ring housing surface 90. The axial brush housing surface 98 defines a plurality of slots 100 perpendicular to the axial brush housing surface 98. A plurality of brushes 86 and a plurality of springs 88 are axially disposed within the plurality of slots 100.

[0050] Multiple springs 88 apply a constant axial force to multiple brushes 86 along the rotation axis 28. The constant axial force causes the multiple brushes 86 to apply a constant axial force to the first slip ring 80 and the second slip ring 82. The constant axial force enables the current applied by the power supply 14 to be axially transmitted to and from the coil winding 20 through the first slip ring 80 and the second slip ring 82.

[0051] The axial slip ring assemblies 10, 72, and 76 disclosed herein have several advantages. These advantages include: no sleeve is required when installing the axial slip ring assemblies 10, 72, and 76, thereby reducing the encapsulation space. With the reduction in encapsulation space during installation, the positioning opportunities of the axial slip ring assemblies 10, 72, and 76 on the SEM rotor 12 increase. Furthermore, by axially mounting the axial slip ring assemblies 10, 72, and 76, the installation process becomes easier, and the load control of the axial slip ring assemblies 10, 72, and 76 is improved.

[0052] The descriptions in this disclosure are merely exemplary in nature, and any modifications that do not depart from the spirit and scope of this disclosure are intended to fall within its scope. Such modifications should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. An axial slip ring assembly for realizing power transmission in a separately excited magnet motor (SEM) rotor, the SEM rotor including a rotor shaft and coil windings defining an axis of rotation, the axial slip ring assembly comprising: A slip ring housing, wherein the slip ring housing is mounted to the rotor shaft of the SEM rotor, and wherein the slip ring housing rotates about the axis of rotation; A first slip ring, wherein the first slip ring is disposed within the slip ring housing and rotates together with the slip ring housing, wherein the first slip ring is connected to the coil winding of the SEM rotor, and wherein the first slip ring is perpendicular to the axis of rotation; A second slip ring, wherein the second slip ring is disposed within the slip ring housing and rotates together with the slip ring housing, wherein the second slip ring is connected to the coil winding of the SEM rotor, wherein the second slip ring is perpendicular to the rotation axis, and wherein the second slip ring is located radially outward from the first slip ring; A brush housing, wherein the brush housing includes an axial brush housing surface, and wherein the axial brush housing surface is perpendicular to the axis of rotation; Multiple brushes, wherein the multiple brushes are disposed within the brush housing; and A plurality of springs, wherein the plurality of springs are disposed within the brush housing, and wherein the plurality of springs apply an axial force along the axis of rotation to cause the plurality of brushes to apply a constant axial force to the first slip ring and the second slip ring.

2. The axial slip ring assembly of claim 1, wherein, The slip ring housing also includes an axial slip ring housing surface that is parallel to the axial brush housing surface.

3. The axial slip ring assembly of claim 1, wherein, The slip ring housing also includes an inner groove, and the first slip ring is disposed within the inner groove.

4. The axial slip ring assembly of claim 3, wherein, The slip ring housing further includes an outer groove, wherein the second slip ring is disposed within the outer groove, and wherein the outer groove is located radially outward from the inner groove.

5. The axial slip ring assembly of claim 4, wherein, The slip ring housing also includes an intermediate surface, wherein the intermediate surface is located between the inner groove and the outer groove.

6. The axial slip ring assembly of claim 1, wherein, The axial brush housing surface defines a groove parallel to the axis of rotation, wherein the plurality of brushes are disposed within the groove, and wherein the plurality of springs are disposed within the groove.

7. The axial slip ring assembly according to claim 1, wherein, The plurality of brushes also include: A first end, wherein the first end is in contact with the plurality of springs; and The second end is opposite to the first end, and the second end applies a constant axial force to the first slip ring and the second slip ring along the axis of rotation.

8. The axial slip ring assembly of claim 1, wherein, The axial slip ring assembly also includes a static structure, wherein the static structure is stationary, and wherein the brush housing is mounted to the static structure.

9. The axial slip ring assembly of claim 1, wherein, The plurality of brushes, the first slip ring, and the second slip ring are axially aligned.

10. The axial slip ring assembly of claim 1, wherein, The plurality of brushes, the first slip ring, and the second slip ring are axially interleaved.

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