Motor and electric power steering device

Abstract

Motor (1), comprising: a rotor (20) with a shaft (21) around an axially extending central axis, a rotor core (22) attached to the shaft (21), and a rotor magnet (23) attached to the rotor core (22); a stator (30) that radially surrounds the rotor (20) on the outside; a bearing that is axially arranged on one side of the stator (30) and supports the shaft (21); a tubular motor housing (11) that holds the stator (30) and opens on one side; a bearing holder (40) which is arranged on one side of the stator (30) and holds the bearing; a control board (60) which is arranged on one side of the bearing holder (40); a rotation sensor (61) which is attached to the control board (60); a control board housing (12) which is arranged on one side of the motor housing (11) and accommodates the control board (60); a sensor magnet (63) which is arranged further to one side than the bearing and is attached to the shaft (21); a non-magnetic contamination screen (50) which is arranged at least partially axially between the control board (60) and the bearing holder (40) and covers one side of the shaft (21), the bearing and the sensor magnet (63); wherein the stator (30) comprises a stator core (31) and a coil (33) which excites the stator core (31), wherein a bore (40a) is provided on the bearing holder (40) which passes axially through the bearing holder (40), wherein a coil line (34) is connected to the coil (33), which is at least partially inserted into the bore (40a), wherein one end of the coil line (34) is arranged further to one side than the bearing holder (40), and wherein the contamination screen (50) covers one side of the borehole (40a).

Description

Technical field

[0001] The present invention relates to a motor and an electric power steering device. background

[0002] There are electric motors in whose motor housing a circuit board is arranged (e.g. JP 2008 - 148 497 A).

[0003] There is an electric drive device and an electric power steering system that assists a vehicle steering system through the drive power of the electric drive device (e.g. EP 2 549 627 A1).

[0004] There is a motor unit in which a motor and a control device that controls the operation of the motor are integrally connected (e.g. JP 2014 - 180 170 A).

[0005] There is a rotating electric vehicle machine with a rotor, a stator, a frame, a power converter, a control board and a circuit board housing (e.g. JP 2015 - 61 408 A). Overview of the invention; Problem statement of the invention

[0006] With the aforementioned electric motors, there is a risk that contaminants located in the motor body may adhere to the circuit board and thus cause an electrical discontinuity in the lines provided on the circuit board.

[0007] In view of the above problem, the present invention, according to one embodiment, is based on the objective of providing a motor with a structure by which the adhesion of contaminants to a control board can be suppressed, and an electric power steering device with this motor. Means of solving the task

[0008] The present electric motor according to the embodiment comprises: a rotor with a shaft around an axially extending central axis, a rotor core attached to the shaft and a rotor magnet attached to the rotor core; a stator that radially surrounds the rotor on the outside; a bearing that is axially arranged on one side of the stator and supports the shaft; a tubular motor housing that holds the stator and opens on one side; a bearing holder that is located on one side of the stator and holds the bearing; a control board located on one side of the bearing holder; a rotation sensor that is attached to the control board; a control board housing located on one side of the motor housing and accommodating the control board; a sensor magnet located further to one side than the bearing and attached to the shaft; and a non-magnetic contamination screen located at least partially axially between the control board and the bearing holder and covering one side of the shaft of the bearing and the sensor magnet; wherein the stator comprises a stator core and a coil that excites the stator core, wherein a bore is provided in the bearing holder which passes axially through the bearing holder, where a coil lead is connected to the coil, which is at least partially inserted into the bore, wherein one end of the coil lead is positioned further to one side than the bearing holder, and the contamination screen covers one side of the borehole. Effect of the invention

[0009] According to the embodiment of the present invention, a motor with a structure by which the adhesion of contaminants to the control board can be suppressed, and an electric power steering device with this motor can be provided. Brief explanation of the drawings [ Fig. 1] Fig. Figure 1 is a sectional view showing the motor according to the present embodiment. [ Fig. 2] Fig. Figure 2 is a sectional view showing part of the engine according to the present embodiment. [ Fig. 3] Fig. Figure 3 is a perspective view showing part of the engine according to the present embodiment. [ Fig. 4] Fig. Figure 4 is a perspective view showing part of the engine according to the present embodiment. [ Fig. 5] Fig. Figure 5 is a schematic representation showing the electric power steering device according to the present embodiment. embodiment of the invention

[0010] All examples explained herein, which do not exhibit all features, or equivalents thereof, of any of the independent claims, serve to facilitate the understanding of the invention.

[0011] The following is a description of the motor according to an exemplary embodiment of the present invention with reference to the drawings. However, the present invention is not limited to the following embodiment, but can be modified as desired within the scope of the technical concept of the present invention. Furthermore, for the sake of clarity, the respective structures in the drawings may differ from the actual structures with regard to their scale, number, or the like.

[0012] The drawings accordingly show an xyz coordinate system as a three-dimensional Cartesian coordinate system. The z-axis in the xyz coordinate system runs parallel to a central axis J. Fig. 1. The x-axis runs vertically to the z-axis and corresponds to the transverse direction in Fig. 1. The y-axis runs vertically to the x- and y-axes.

[0013] In the following description, a positive side (one side, +Z side) in the Z direction is called the "back side" and a negative side (the other side, -Z side) in the Z direction is called the "front side." However, the terms "back side" and "front side" serve only for descriptive purposes and do not restrict actual spatial relationships or directions. Furthermore, except in exceptional cases, the direction parallel to the central axis J (Z direction) is called the "axial direction," the radial direction around the central axis J is called the "radial direction," and the circumferential direction with respect to the central axis J, i.e., the direction around the central axis J, is called the "circumferential direction."

[0014] <motor> Fig. Figure 1 is a sectional view showing the motor 1 according to the present embodiment. Fig. Figure 2 is a sectional view showing part of the motor 1 according to the present embodiment. Fig. 3 and Fig. Figures 4 are perspective views showing part of the motor 1 according to the present embodiment. Fig. 3 and Fig. 4. The illustration of a housing 10, a control board 60, etc., is omitted. In Fig. Figure 3 shows the condition before the application of a contamination screen 50.

[0015] As in Fig. As shown in Figure 1, the motor 1 comprises a housing 10, a rotor 20 with a shaft 21, a stator 30, a rear bearing 24, a front bearing 25, a sensor magnet 63, a bearing holder 40, a busbar unit 70, a contamination screen 50, a control board 60, a rotation sensor 61 and electronic components 64, 65.

[0016] [Housing] The housing 10 contains the respective components of the motor 1. The housing 10 comprises a motor housing 11 and a control board housing 12. That is, the motor 1 is equipped with the motor housing 11 and the control board housing 12.

[0017] The motor housing 11 is tubular and terminates at the rear (+Z). The motor housing 11 comprises a tubular motor mounting section 14, a base section 13, and a bracket 18 for a front bearing. The tubular motor mounting section 14 is tubular in shape and surrounds the stator 30 radially. In the present embodiment, the tubular motor mounting section 14 is cylindrical. The stator 30 is attached to the inner surface of the tubular motor mounting section 14. That is, the motor housing 11 holds the stator 30.

[0018] The base section 13 is located at the front (-Z) end face of the tubular motor mounting section 14. A bore 13a for an output shaft is provided in the base section 13. The bore 13a for the output shaft extends axially (in the z-direction) through the base section 13. The bracket 18 for a front bearing is located on the rear (+Z) face of the base section 13. The bracket 18 for a front bearing holds the front bearing 25.

[0019] The control board housing 12 is located on the rear side (+Z) of the motor housing 11. The control board housing 12 accommodates the control board 60. The control board housing 12 comprises a tubular control board mounting section 15 and a cover 16.

[0020] The tubular control board mounting section 15 is tubular in shape and surrounds the control board 60 radially. In the present embodiment, the tubular control board mounting section 15 is cylindrical. The tubular control board mounting section 15 is connected to the rear (+Z) end face of the tubular motor mounting section 14. In the present embodiment, the base section 13, the tubular motor mounting section 14, and the tubular control board mounting section 15 form a single, sack-cylindrical component that is open at the rear. The base section 13, the tubular motor mounting section 14, and the tubular control board mounting section 15 can also be designed as separate components.

[0021] The cover 16 closes the rear (+Z) opening of the tubular control board receiving section 15. The cover 16 comprises a cover body 16a, a support 16b, a conduit 19, and a connector 17. The support 16b extends forward (-Z) from the cover body 16a. The support 16b is located on the radial inner side of the tubular control board receiving section 15.

[0022] The cover 16 and the tubular control board mounting section 15 can also be manufactured as individual components. That is to say, the housing 10 can be manufactured as a single component.

[0023] The conductor 19 protrudes forward (-Z) from the support 16b. The conductor 19 is electrically connected to the control board 60. Although not shown, the conductor 19 is routed via the support 16b and the cover body 16a to the connector 17. The connector 17 extends rearward (+Z) from the cover body 16a. An external power source (not shown) is connected to the connector 17. The conductor 19 is electrically connected to the external power source via the connector 17. Thus, the control board 60 can be powered by the external power source via the conductor 19.

[0024] [Rotor] The rotor 20 comprises a shaft 21, a rotor core 22, and a rotor magnet 23. The shaft 21 is formed around a central axis J, which runs axially (Z-direction). The shaft 21 is supported by the front and rear bearings 25 and 24, rotating about its central axis J. The front (-Z) end end of the shaft 21 projects outward from the housing 10 through the bore 13a for an output shaft. A bore is provided at the rear (+Z) end end of the shaft 21. A fastening element 62 engages in the bore of the shaft 21. The fastening element 62 is a rod-shaped component and extends in the axial direction.

[0025] The shaft 21 is attached to the rotor core 22. The rotor core 22 has an axially through-bore. The shaft 21 passes through the through-bore of the rotor core 22. In other words, the rotor core 22 surrounds the shaft 21 circumferentially. The shaft 21 is preferably attached by pressing it into the through-bore of the rotor core 22. The rotor magnet 23 is attached to the rotor core 22. More precisely, the rotor magnet 23 is attached to the outer surface of the rotor core 22 along the circumferential direction. The rotor core 22 and the rotor magnet 23 rotate together with the shaft 21.

[0026] [Stator] The stator 30 is essentially cylindrical around the central axis J. The stator 30 surrounds the rotor 20 radially. The stator 30 comprises a stator core 31, a coil holder 32, and a coil 33. The stator core 31 comprises a core back 31a and a plurality of toothed parts 31b.

[0027] The core back 31a is cylindrical around the central axis J. Each tooth segment 31b extends from the inner surface of the core back 31a to the shaft 21. The tooth segments 31b are arranged equidistantly around the inner surface of the core back 31a in the circumferential direction. The coil holder 32 is attached to each tooth segment 31b.

[0028] The stator core 31 can be excited by the energized coil 33. The coil 33 is arranged on the coil holder 32. More precisely, the coil 33 is formed by winding a conductor wire around the coil holder 32. A coil lead 34 is connected to the coil 33. At least a portion of the coil lead 34 is inserted into a bore 40a of the bearing holder 40, which will be described later. The rear (+Z) end end 34a of the coil lead 34 is positioned further back than the bearing holder 40. The coil lead 34 can be either an end end of the conductor wire as a component of the coil 33 or a separate component from the conductor wire as a component of the coil 33.

[0029] [Rear bearing and front bearing] The rear bearing 24 is located on the rear side (+Z) of the stator 30. The rear bearing 24 is held by the bearing holder 40. The front bearing 25 is located on the front side (-Z) of the stator 30. The front bearing 25 is held by the bracket 18 for a front bearing of the motor housing 11.

[0030] The rear and front bearings 24, 25 support the shaft 21 of the rotor 20. In the present embodiment, the rear and front bearings 24, 25 correspond to a ball bearing. However, there is no particular restriction regarding the type of rear and front bearings 24, 25, so that another type of bearing, such as a plain bearing, can be used.

[0031] [Sensor magnet] As in Fig. As shown in Figure 2, the sensor magnet 63 is positioned further back (+Z) than the rear bearing 24. The sensor magnet 63 is positioned further back than the bearing holder 40. As shown in Figure 2. Fig. As shown in Figure 3, the sensor magnet 63 is ring-shaped. The mounting piece 62 is attached to the shaft 21. The shaft 21 engages in the through-hole of the mounting piece 62. As shown in Fig. As shown in Figure 2, the inner surface of the sensor magnet 63 engages the outer surface of the mounting piece 62. Thus, the sensor magnet 63 is attached to the shaft 21.

[0032] The rotation sensor 61 detects a change in the position of a magnetic pole of the sensor magnet 63. In the present embodiment, a magnetoresistive element is used as the rotation sensor 61. The sensor magnet 63 is arranged on the rear side (+Z) of the shaft 21. This allows for a higher resolution of the rotation sensor 61. As a result, the responsiveness of the motor 1 can be increased.

[0033] [Warehouse holder] As in Fig. As shown in Figure 1, the bearing holder 40 is arranged on the rear side (+Z) of the stator 30. The bearing holder 40 is attached to the inner surface of the tubular control board mounting section 15. In the top view (xy-plane), the bearing holder 40 is preferably circular around the central axis J. The bearing holder 40 is preferably made of metal. However, in the top view (xy-plane), the bearing holder 40 is not always circular, but can also be in another shape such as polygonal or the like.

[0034] The bearing holder 40 comprises a bracket 41 and an annular section 42. The bracket 41 is cylindrical around the central axis J. The bracket 41 opens axially (z-direction) on both sides. The rear bearing 24 is fitted radially inward into the bracket 41. Thus, the bearing holder 40 can hold the rear bearing 24.

[0035] The annular section 42 surrounds the holder 41 radially on the outside. In the present embodiment, the holder 41 and the annular section 42 form a single component. The annular section 42 has a plurality of bores 40a which extend axially (in the z-direction) through the annular section 42. That is, the bearing holder 40 has at least one bore 40a which extends axially through the bearing holder 40.

[0036] [Busbar unit] The busbar unit 70 is arranged on the rear side (+Z) of the bearing holder 40. The busbar unit 70 is arranged on the rear surface of the annular section 42 of the bearing holder 40. The busbar unit 70 comprises a busbar holder 71 and a busbar 72.

[0037] The busbar holder 71 holds the busbar 72. The busbar holder 71 is preferably made of synthetic resin. As in Fig. As shown in Figure 3, the busbar holder 71 comprises a main body 75, first projections 76 and second projections 77.

[0038] The main body 75 comprises a rear main body section 75a and a front main body section 75b. The rear and front main body sections 75a and 75b are preferably each annular in shape. The rear and front main body sections 75a and 75b overlap in the axial direction (z-direction). The rear main body section 75a is arranged on the rear side (+Z) of the front main body section 75b.

[0039] A plurality of through-holes are arranged on the rear main body section 75a, which extend axially (z-direction) through the rear main body section 75a. On a rear side 75c of the main body, on the rear side (+Z) of the rear main body section 75a, a plurality of first projections 76 are arranged. The first projection 76 extends rearward from the rear side 75c of the main body. That is, the first projection 76 extends rearward from the main body 75.

[0040] Several second projections 77 are arranged on the rear (+Z) surface of the front main body section 75b. Each second projection 77 extends rearward from the rear surface of the front main body section 75b. The second projection 77 extends further rearward through the through-bore located on the rear main body section 75a than the rear surface 75c of the main body.

[0041] As in Fig. As shown in Figure 4, the rear (+Z) end face of the second projection 77 is welded to the rear face 75c of the main body. This attaches the rear main body section 75a to the front main body section 75b.

[0042] As in Fig. As shown in Figure 3, insertion bores 56a are arranged on the flange 56 of the contamination screen 50. The first projection 76 is inserted into the insertion bore 56a. As shown in Fig. As shown in Figure 4, the rear (+Z) end face of the first projection 76 is positioned further back than the flange 56. The rear end face of the first projection 76 is welded to the rear surface of the flange 56. This secures the rear main body section 75a to the contamination screen 50, thereby attaching the busbar holder 71 to the contamination screen 50.

[0043] A trench 75d is arranged on the rear (+Z) face of the front main body section 75b. As in Fig. As shown in Figure 2, a portion of the busbar 72 is fitted into the groove 75d. The portion of the busbar 72 fitted into the groove 75d is superimposed on the rear main body section 75a and attached to the rear side of the front main body section 75b. Thus, the portion of the busbar 72 fitted into the groove 75d is held by the busbar support 71. That is, the busbar support 71 holds the busbar 72.

[0044] As in Fig. As shown in Figure 3, the busbar 72 has at least one coil terminal 73. The busbar 72 has several coil terminals 73. The coil terminals 73 are arranged on the radial inner side of the main body 75. Viewed from above (xy-plane), the coil terminal 73 has a U-shape, the opening of which is directed radially outwards. The front main body section 75b and the bearing holder 40 have through-holes through which the coil lead 34 passes. The coil terminal 73 is electrically connected to the coil lead 34. That is, the busbar 72 is electrically connected to the coil lead 34. The coil lead 34 is arranged between the opposing parts of the coil terminal 73. The adjacent parts of the coil connection 73 are then squeezed by a welding tool, clamping the coil lead 34, thereby connecting the coil connection 73 and the coil lead 34 to each other.However, the connection of the coil terminal 73 and the coil line 34 is not limited to the said procedure and there is no special restriction.

[0045] As in Fig. As shown in Figure 4, the busbar 72 has at least one external connection 74. This means that the busbar unit 70 includes at least one external connection 74. Referring to Fig. 4 The busbar unit 70 (i.e., the busbar 72) comprises three external connections 74. The external connection 74 extends in the axial direction (z-direction). The external connection 74 extends further rearward (+Z) than the contamination screen 50, beyond a recess 55 of the contamination screen 50, which will be described later.

[0046] Although not shown, the external terminal 74 is electrically connected to the (not shown) external power source. This means that the busbar 72 is electrically connected to the external power source. Therefore, the stator 30 can be supplied with power via the busbar 72 and the coil lead 34.

[0047] [Contamination screen] As in Fig. As shown in Figure 2, the contamination screen 50 is arranged axially (z-direction) between the control board 60 and the bearing holder 40. As described above, the contamination screen 50 is attached to the busbar holder 71.

[0048] The Contamination Shield 50 is a non-magnetic body. The preferred material for the Contamination Shield 50 is synthetic resin. As described in... Fig. As shown in Figure 4, the contamination screen 50 comprises a first convex section 51, a ring plate 53, a second convex section 52 and a flange 56.

[0049] As in Fig. As shown in Figure 2, the first convex section 51 is hollow inside and convex towards the rear (+Z). The first convex section 51 opens towards the front (-Z). As shown in Figure 2, the first convex section 51 is hollow inside and convex towards the rear (+Z). Fig. As shown in Figure 4, the first convex section 51 is preferably cylindrical around the central axis J.

[0050] As in Fig. As shown in Figure 1, the first convex section 51 covers the rear side (+Z) of the shaft 21 and the sensor magnet 63. That is, the contamination screen 50 covers the rear side of the shaft 21 and the sensor magnet 63. The first convex section 51 covers part of the rear side of the rear bearing 24.

[0051] As in Fig. As shown in Figure 2, part of the sensor magnet 63 is accommodated in the first convex section 51. If the rotor 20 is rotated together with the sensor magnet 63 and contaminants adhering to the sensor magnet 63 are splashed around, the contaminants adhere to the inside of the first convex section 51. These contaminants include, for example, particles, dust, magnetic powder, iron powder, etc. This prevents the contaminants from being dispersed inside the motor 1 by the sensor magnet 63.

[0052] The ring plate 53 is a plate-like section and extends radially outwards from the front (-Z) end face of the first convex section 51. As in Fig. As shown in Figure 4, the ring plate 53, viewed from above (xy-plane), is ring-shaped around the central axis J. As in Fig. As shown in Figure 2, the ring plate 53 covers part of the rear side (+Z) of the rear bearing 24. The ring plate 53 and the first convex section 51 cover the entire rear side of the rear bearing 24. That is, the contamination screen 50 covers the rear side of the rear bearing 24.

[0053] According to the present embodiment, the contamination screen 50 is arranged axially (z-direction) between the control board 60 and the bearing holder 40. The contamination screen 50 covers the rear side (+Z) of the shaft 21, the rear bearing 24, and the sensor magnet 63. Thus, the contamination screen 50 blocks contaminants located in a gap between the rear bearing 24 and the shaft 21, as well as contaminants forming on the sensor magnet 63, thereby preventing the contaminants from adhering to the control board 60. Therefore, according to the present embodiment, the motor has a structure that prevents the contaminants from adhering to the control board 60.

[0054] The contaminants that emerge from the gap between the rear bearing 24 and the shaft 21 include, for example, those contaminants located between the shaft 21 and the rotor core 22. Furthermore, the contaminants that form on the sensor magnet 63 include, for example, iron powder or the like, which adheres to the sensor magnet 63.

[0055] The second convex section 52 is hollow inside and convex towards the rear (+Z). The second convex section 52 is arranged radially outside the first convex section 51. The second convex section 52 opens forward (-Z). As in Fig. As shown in Figure 4, the second convex section 52 is annular in shape. The second convex section 52 is preferably annular around the central axis J.

[0056] As in Fig. As shown in Figure 2, the second convex section 52 covers the rear side (+Z) of the bore 40a of the bearing holder 40. That is, the contamination screen 50 covers the rear side of the bore 40a of the bearing holder 40. Therefore, even if contaminants adhering to the stator 30 splash onto the rear side of the bearing holder 40 through the bore 40a, through which the coil lead 34 passes, it can be prevented that the contaminants originating on the stator 30 adhere to the control board 60.

[0057] The second convex section 52 covers the rear side (+Z) of the coil lead 34. The second convex section 52 covers the rear side of the coil terminal 73. That is, the contamination shield 50 covers the rear side of the coil terminal 73. Therefore, even if the motor 1 has the busbar unit 70, it can be prevented that contaminants penetrating through the bore 40a onto the rear side of the bearing holder 40 adhere to the control board 60.

[0058] The second convex section 52 covers the rear side (+Z) of the multiple coil terminals 73. Therefore, when providing multiple coil terminals 73, the number of second convex sections 52 can be reduced. Consequently, the design of the contamination screen 50 can be simplified. In the present embodiment, the second convex section 52 covers the rear side of all coil terminals 73.

[0059] The second convex section 52 comprises a second back shield 52a, which is located on the rear side (+Z). The first convex section 51 comprises a first back shield 51a, which is located on the rear side. The second back shield 52a is located further forward (-Z) than the first back shield 51a. That is, the rear end of the second convex section 52 is located further forward than the rear end of the first convex section 51. Thus, the space behind the second convex section 52 can be increased. This prevents components attached to the control board 60 from coming into contact with the contamination shield 50.

[0060] Part of the coil connection 73 is accommodated in the second convex section 52. Therefore, the second back side 52a of the second convex section 52 can be positioned axially (z-direction) further forward (-Z). This further increases the space behind the second convex section 52. Contaminants entering the rear side (+Z) of the bearing holder 40 from the bore 40a can adhere to the inside of the second convex section 52. Thus, dispersal of contaminants inside the motor 1 can be suppressed.

[0061] A concave section 53a is arranged radially between the first and second convex sections 51, 52. That is, the contamination screen 50 includes a concave section 53a which is arranged radially between the first and second convex sections 51, 52. The concave section 53a is concave towards the front side (-Z). As shown in Fig. As shown in Figure 4, the concave section 53a, viewed from the top (xy-plane), is externally ring-shaped around the central axis J. The bottom surface of the concave section 53a corresponds to the rear (+Z) surface of the ring plate 53. Since the contamination screen 50 has the concave section 53a, the space behind (+Z) the contamination screen 50 can be further enlarged.

[0062] The first convex section 51 includes a first interior surface 51b, i.e., an interior surface of the first convex section 51 on the rear side (+Z). The second convex section 52 includes a second interior surface 52b, i.e., an interior surface of the second convex section 52 on the rear side. As in Fig. As shown in Figure 2, one of the front (-Z) surfaces of the contamination screen 50, which is located radially between the first and second convex sections 51, 52, is positioned further forward than the first and second inner surfaces 51b, 52b.

[0063] One of the front (-Z) surfaces of the contamination shield 50, which is located radially between the first and second convex sections 51, 52, corresponds to the front surface 54 of the ring plate on the front side of the ring plate 53. That is, the front surface 54 of the ring plate is arranged further forward (-Z) than the first and second inner surfaces 51b, 52b.

[0064] Thus, an axial gap (in the z-direction) between the contamination screen 50 and the bearing holder 40 can be reduced radially between the first and second convex sections 51, 52. Likewise, an axial gap (in the z-direction) between the contamination screen 50 and the busbar unit 70 can be reduced radially between the first and second convex sections 51, 52. This prevents contaminants adhering to the sensor magnet 63 and contaminants located between the shaft 21 and the rear bearing 24 from migrating to the side of the second convex section 52. Therefore, the dispersion of contaminants inside the motor 1 can be suppressed.

[0065] The bearing holder 40 comprises a holder back 41a, which is arranged on the rear side (+Z) of the bearing holder 40. An axial distance (in the z-direction) between the front face 54 of the ring plate and the holder back 41a is designated L1. An axial distance between the front face 54 of the ring plate and the rear side of the busbar holder 71 is designated L2. More precisely, an axial distance between the front face 54 of the ring plate and the rear face 75c of the main body on the rear side of the rear main body section 75a is designated L2. In the present embodiment, the holder back 41a corresponds to the rear end face of the holder 41.

[0066] An axial distance (in the z-direction) between the first inner surface 51b of the first convex section 51 and the rear of the holder 41a is designated L3. An axial distance between the first inner surface 51b and the rear of the main body 75c is designated L4. An axial distance between the second inner surface 52b and the rear of the holder 41a is designated L5. An axial distance between the second inner surface 52b and the rear of the main body 75c is designated L6.

[0067] The distance L1 is smaller than the distances L3, L4, L5, and L6. The distance L2 is smaller than the distances L3, L4, L5, and L6. That is, the distance between the front 54 of the ring plate and the holder's rear 41a, or the distance between the front 54 of the ring plate and the rear 75c of the main body, is smaller than the distance between the first inner surface 51b and the second inner surface 52b and the holder's rear 41a, or the rear surface 75c of the main body.

[0068] Thus, the axial gap between the contamination screen 50 and the bearing holder 40 or the busbar unit 70 can be further reduced radially between the first and second convex sections 51, 52. This allows for better suppression of contaminant dispersion inside the motor 1.

[0069] In the present embodiment, the distance L2 is smaller than the distance L1. The distances L1 and L2 are preferably equal to or smaller than the size of the contaminants generated at the drive of the motor 1. This better prevents the dispersal of contaminants within the motor 1. The contaminants generated at the drive of the motor 1 are, for example, those emanating from the stator 30, the sensor magnet 63, and the gap or similar between the shaft 21 and the rear bearing 24.

[0070] The flange 56 extends radially outwards from the front (-Z) end face at the radial outer edge of the second convex section 52. The front face of the flange 56 is in contact with the rear face 75c of the main body 75. As shown in Fig. As shown in Figure 3, the flange 56 according to the present embodiment has a ring shape concentric to the central axis J, which is partially cut out.

[0071] A recess 55 is arranged on the flange 56. That is, the contamination screen 50 has a recess 55. The recess 55 is formed, for example, along the y-direction. As shown in Fig. As shown in Figure 4, the external connection 74 of the busbar 72 extends further rearward (+Z) than the contamination screen 50 via the recess 55. This not only simplifies the design of the contamination screen 50, but also allows the external connection 74 to be routed to the rear side of the contamination screen 50.

[0072] At flange 56, as in Fig. Figure 3 shows insertion bores 56a and insertion recesses 56b. The insertion bores 56a and the insertion recesses 56b are arranged radially outside the second convex section 52. As shown in Fig. As shown in Figure 4, at least a portion of the first projection 76 is inserted into the insertion bore 56a. At least a portion of the second projection 77 is inserted into the insertion recess 56b. That is, the contamination shield 50 comprises an insertion section, designed as a bore or recess, into which at least a portion of the projection on the busbar holder 71 is inserted. This allows the contamination shield 50 to be positioned circumferentially to the busbar holder 71.

[0073] Viewed in the axial direction (z-direction), all second projections 77 are positioned within the insertion recesses 56b. Therefore, the front (-Z) surface of the flange 56 can be brought into contact with the rear 75c of the main body, thus allowing the contamination screen 50 to be attached to the busbar holder 71. This enables the space on the front side of the contamination screen 50 to be easily and tightly sealed.

[0074] In the present embodiment, the contamination screen 50 covers the entire rear side (+Z) of the busbar 72 by means of the first and second convex sections 51, 52, the ring plate 53 and the flange 56.

[0075] In the present embodiment, the interior of the housing 10 is divided axially by the contamination screen 50, the busbar unit 70, and the bearing holder 40. One of the divided interior spaces of the housing 10, located on the front side (-Z) of the contamination screen 50, is, for example, tightly sealed. That is, the drive of the motor 1 is tightly sealed in the front interior space of the housing 10. Specifically, the one of the interior spaces of the housing, located on the front side (-Z) of the contamination screen 50, is tightly sealed by the contamination screen 50 covering the front main body section 75b and the through-hole of the bearing holder 40 through which the coil lead 34 passes. The drive of the motor 1 comprises, for example, the following: B. the rotor 20, the stator 30, the rear and front bearings 24, 25 and the sensor magnet 63.

[0076] This prevents contaminants generated at the drive of motor 1 from migrating into one of the partitioned interior spaces of the housing 10, which is located on the rear side (+Z) of the contamination screen 50. Thus, according to the present embodiment, it is prevented that the contaminants generated at the drive of motor 1 adhere to the control board 60.

[0077] The term "room is tightly sealed" in this description encompasses the case where contaminants located within the tightly sealed room cannot escape outside the room. That is to say, the term "tightly sealed room" in this description also includes the case where a gap is provided connecting the room to the outside, provided that the contaminants can be contained within the room.

[0078] [Control board] The control board 60 is, as in Fig. Figure 1 shows the bearing holder 40 located on its rear side (+Z). The control board 60 is located on the rear side (+Z) of the contamination screen 50. In this embodiment, the circuit board side of the control board 60 is perpendicular to the axial direction (z-direction). The circuit board side of the control board 60 refers, for example, to a front side 60a of the control board located on the front side (-Z) of the control board 60. However, the circuit board side of the control board 60 need not always be perpendicular to the axial direction.

[0079] The control board 60 is attached to the support 16b of the control board housing 12. Referring to Fig. In Figure 1, the control board 60 is screwed to the control board housing 12. However, there is no particular restriction regarding the fastening method of the control board 60, so the control board 60 can be fastened by a different method. Although not shown, the circuit board side of the control board 60 is designed as a printed circuit board.

[0080] For example, a structure in which the shaft 21 passes through the control board 60 makes it difficult to provide a shield against contaminants on the control board 60. Furthermore, since a radial gap is created between the shaft 21 and the control board 60, the contaminants cannot be adequately blocked by the shield.

[0081] In contrast, according to the present embodiment, the control board 60 is arranged on the rear side (+Z) of the shaft 21. Therefore, the design of the contamination shield 50 for preventing contaminants from adhering to the control board 60 can be simplified. Furthermore, the contamination shield 50 can easily block the contaminants.

[0082] [Rotation sensor and electronic components] As in Fig. As shown in Figure 2, the rotation sensor 61 is attached to the control board 60. More precisely, the rotation sensor 61 is attached to the front side 60a of the control board. The rotation sensor 61 is positioned axially (in the z-direction) across the contamination screen 50 opposite the sensor magnet 63. The rotation sensor 61 serves to detect the rotation of the sensor magnet 63. In the present embodiment, the rotation sensor 61 corresponds to a magnetoresistive element. However, the rotation sensor 61 is not limited to a magnetoresistive element and can, for example, also be a Hall effect sensor.

[0083] Electronic components 64 and 65 are attached to the control board 60. More precisely, electronic components 64 and 65 are attached to the front 60a of the control board. Electronic components 64 and 65 are relatively large components compared to other components attached to the control board 60. Electronic components 64 and 65 are equivalent to, for example, an electrolytic capacitor, an inductor, or the like.

[0084] The electronic components 64, 65 are located axially (in the z-direction) opposite the concave section 53a of the contamination screen 50. Therefore, even if the contamination screen 50, the control board 60, or the like has a dimensional error, contact between the electronic components 64, 65 and the contamination screen 50 can be prevented.

[0085] The front (-Z) end face 64a of the electronic component 64 is accommodated in the concave section 53a. This facilitates the positioning of the control board 60 axially closer to the contamination screen 50, and the axial dimension (in the z-direction) of the entire motor 1 can thus be reduced. Likewise, the rotation sensor 61 can easily be positioned axially closer to the sensor magnet 63. Therefore, the measurement accuracy of the rotation sensor 61 can be increased.

[0086] The present embodiment is not limited to the structures mentioned.

[0087] In the present embodiment, for example, at least a part of the contamination shield 50 can be arranged axially between the control board 60 and the bearing holder 40. That is, in the present embodiment, for example, a part of the contamination shield 50 can be arranged further back than the control board 60 and further forward than the bearing holder 40.

[0088] In the present embodiment, the contamination screen 50 only needs to cover at least the rear side of the shaft 21, the rear bearing 24, and the sensor magnet 63. That is, according to the present embodiment, the contamination screen 50 does not need to cover, for example, the rear side of the bore 40a of the bearing holder 40 and / or the coil connection 73.

[0089] In the present embodiment, at least a part of the sensor magnet 63 can be accommodated in the first convex section 51. That is to say, according to the present embodiment, the entire sensor magnet 63 can be accommodated in the first convex section 51.

[0090] In the present embodiment, at least a part of the coil connection 73 can be accommodated in the second convex section 52. That is to say, according to the present embodiment, the entire coil connection 73 can be accommodated in the second convex section 52.

[0091] In the present embodiment, a second convex section 52 can further be provided for each coil terminal 73. One of the second convex sections 52 covers the rear side of one of the coil terminals 73.

[0092] Furthermore, in the present embodiment, the front end 64a of the electronic component 64 does not always have to be accommodated in the concave section 53a. In the present embodiment, the electronic components 64, 65 can also be located, for example, axially opposite the first convex section 51 or the second convex section 52.

[0093] In the present embodiment, the sensor magnet 63 can also be attached by gripping the outer surface of the shaft 21. The rear end face of the sensor magnet 63 and the rear end face of the shaft 21 can have the same axial position. According to this design, a Hall effect sensor 61 is preferably used, for example.

[0094] In the present embodiment, the busbar holder 71 can also be designed as a single component. The busbar unit 70 can be manufactured, for example, by overmolding the busbar 72. Furthermore, the second projection 77 and the insertion recess 56b of the contamination screen 50 do not need to be provided.

[0095] In the present embodiment, the bearing can also be provided only on the rear side of the stator 30 and the shaft 21 can be supported in a cantilevered manner.

[0096] Furthermore, in the present embodiment, the control board 60 does not always have to be attached to the housing 10. For example, a support can be provided that extends rearward from the contamination screen 60, and the control board 60 can be supported by this support.

[0097] In the present embodiment, a part of the bearing holder 40 can also be arranged further back than the sensor magnet 63.

[0098] <Elektrische Servolenkvorrichtung> Next, a device according to one embodiment is described in which the motor 1 is mounted according to the present embodiment. In this embodiment, it is shown by way of example that the motor 1 is mounted in an electric power steering device. Fig. Figure 5 is a schematic representation showing the electric power steering device 2 according to this embodiment.

[0099] The electric power steering device 2 is installed in a steering mechanism for vehicle wheels. The electric power steering device 2 serves to reduce steering effort by means of hydraulics. As in Fig. As shown in Figure 5, the electric power steering device 2 according to the present embodiment comprises the motor 1, a steering shaft 114, a hydraulic pump 116 and a control valve 117.

[0100] The steering shaft 114 transmits the input from a steering wheel 111 to a wheelset axle 113 with wheels 112. The hydraulic pump 116 generates hydraulic pressure at a working cylinder 115, which transmits a hydraulic drive force to the wheelset axle 113. The control valve 117 regulates the oil flow in the hydraulic pump 116. The motor 1 is used as the drive source for the hydraulic pump 116 in the electric power steering device 2.

[0101] The electric power steering device 2 with the motor 1 according to the preceding embodiment can suppress the adhesion of contaminants to the control board 60 of the motor 1. This can increase the reliability of the electric power steering device 2.

[0102] The structures listed above can be combined accordingly, as long as they are mutually consistent. Explanation of reference symbols 1 engine 2 Electric power steering device 10 cases 11 Engine housing 12 control board housings 20 Rotor 21st wave 22 Rotor core 23 Rotor magnet 24 Rear Camp 30 Stator 31 Stator core 33 coil 34 coil lead 40 bearing holders 40a borehole 50 contamination screen 51 First convex section 51b First inner surface 52 Second convex section 52b Second inner surface 53a Concave Section 54 Front of the ring plate 55 Exclusion 56a Insertion bore 56b Inlet recess 60 Control board 61 Rotation sensor 63 Sensor magnet 64, 65 Electronic components 70 busbar units 71 busbar holders 72 busbar 73 Coil connection 74 External connection 75 Main body 76 First lead 77 Second lead J Central axis< / motor>

Images