In-wheel motor

Abstract

An in-wheel motor (30, 330) includes: a bracket portion (70, 370); stators (50, 350) connected to the holder part; rotors (40, 340) having shafts (31, 331) and field poles and connected to the rim (10); bearings (60, 360) that rotatably support the shaft; and a rotation angle sensor (80, 380). The shaft extends to a position facing an inner circumferential surface of the holder portion in a radial direction of the shaft. The rotation angle sensor is provided with: rotor-side sensor parts (81, 381) that are attached to the shaft at positions facing the inner peripheral surface of the holder part in the radial direction; and a holder-side sensor unit (82, 382) that outputs a signal corresponding to the rotation angle of the rotor-side sensor unit. The in-wheel motor is provided with seal covers (110, 410) for closing the space between the rotor-side sensor unit and the bracket-side sensor unit.

Description

Citation of related applications

[0001] This application is based on Japanese Patent Application No. 2022-133177 filed on August 24, 2022, and the contents thereof are cited herein. Technical Field

[0002] The present disclosure relates to an in-wheel motor, at least a portion of which is accommodated in a space inside a wheel rim. The wheel rim has a rim portion on which a tire can be mounted and a disc portion provided on a side surface of the rim portion. Background Art

[0003] As described in Patent Document 1, the following type of in-wheel motor is known: a hub bearing that rotatably supports the shaft of a rotor is provided on a bracket fixed to a vehicle body, and a resolver that serves as a rotation angle sensor for detecting the rotation angle of the rotor is arranged radially outside the hub bearing. Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent No. 6194750 Summary of the invention

[0005] In the in-wheel motor described in Patent Document 1, an oil seal is provided between the outer yoke constituting the rotor and the bracket in order to prevent water and / or dust from entering the motor. Here, due to vibration or impact from the road surface, external force acts on the bracket, and the bracket may deform. At this time, there is a possibility that a gap is generated between the bracket and the oil seal, and water and / or dust may enter the motor through the gap and adhere to the rotation angle sensor.

[0006] A main object of the present disclosure is to provide an in-wheel motor capable of suppressing the occurrence of water and / or dust adhering to a rotation angle sensor.

[0007] The present invention provides an in-wheel motor, which is suitable for a mobile body including a rim, wherein the rim has a rim portion on which a tire can be mounted and a disc portion provided on a side of the rim portion, and at least a portion of the in-wheel motor is accommodated in a space inside the rim surrounded by the disc portion and the rim portion, and the rim is rotated. The in-wheel motor includes: a tubular bracket portion extending in the vehicle width direction of the moving body; a stator connected to the bracket portion; a rotor having a shaft extending in the vehicle width direction and an excitation pole and connected to the rim; a bearing provided at a position closer to the vehicle width direction outer side than the bracket portion in the axial direction of the shaft and rotatably supporting the shaft; and Rotation angle sensor, The shaft extends inward in the vehicle width direction in the axial direction to a position facing the inner peripheral surface of the bracket portion in the radial direction of the shaft. The rotation angle sensor has: a rotor-side sensor portion mounted on the shaft at a position opposing the inner peripheral surface of the bracket portion in the radial direction; and a bracket-side sensor portion which is mounted on an inner peripheral surface of the bracket portion at a position opposite to the rotor-side sensor portion in the radial direction of the shaft and outputs a signal corresponding to a rotation angle of the rotor-side sensor portion, The bracket portion is fixed to the cover portion in a state where the opening portion on the inner side in the vehicle width direction of the bracket portion is fixed to the cover portion of the chassis portion of the mobile body or the cover portion constituting the chassis portion is closed. A sealing cover is provided on the inner peripheral side of the bracket portion and seals an opening portion on the inner side of the bracket portion in the vehicle width direction, the rotor-side sensor portion, and a space between the bracket-side sensor portion.

[0008] The bracket part of the present disclosure extends in the vehicle width direction and is tubular. Therefore, the shaft can be inserted from the opening of the bracket part on the outside of the vehicle width direction to the inner space of the bracket part. In detail, the shaft extends axially toward the inside of the vehicle width direction to a position opposite to the inner peripheral surface of the bracket part in the radial direction.

[0009] In addition, in the present disclosure, a rotor-side sensor portion extending radially outward is installed at a position on the shaft that is offset inward in the vehicle width direction relative to the bearing and radially opposite to the inner peripheral surface of the bracket portion. A bracket-side sensor portion is installed at a position in the bracket portion that is radially opposite to the rotor-side sensor portion.

[0010] The bracket part is fixed to the cover part in a state where the opening part on the inner side of the bracket part in the vehicle width direction is fixed to the cover part of the chassis part or the cover part constituting the chassis part is closed. Here, due to the external force acting on the cover part, a gap is generated between the bracket part and the cover part. At this time, there is a concern that water and / or dust enter through the gap, and the entered water and / or dust adheres to the rotor side sensor part or the bracket side sensor part.

[0011] Therefore, the present disclosure includes a sealing cover, which is provided on the inner peripheral side of the bracket part and seals the opening on the inner side of the bracket part in the vehicle width direction and the rotor side sensor part and the bracket side sensor part. Therefore, even if a gap is generated between the bracket part and the cover part and water and / or dust enter from the gap, the sealing cover can prevent water and / or dust from adhering to the rotor side sensor part and the bracket side sensor part. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a cross-sectional view of the wheel unit according to the first embodiment. Figure 2 yes Figure 1 An enlarged view of the wheel hub bearing and bracket part of the structure. Figure 3 This is a diagram showing the bracket portion with the resolver, cover, seal cover, etc. removed, as viewed from the inside in the vehicle width direction. Figure 4 This is a diagram showing the bracket portion with the cover removed, as viewed from the inside in the vehicle width direction. Figure 5 This is an enlarged view of the bracket portion and its surrounding area according to the second embodiment. Figure 6 This is an enlarged view of the bracket portion and its surrounding area according to the third embodiment. Figure 7 It is a cross-sectional view of a wheel unit according to a fourth embodiment. Figure 8 yes Figure 7 An enlarged view of the bracket portion and its surrounding parts in the structure. DETAILED DESCRIPTION

[0013] Hereinafter, multiple embodiments are described with reference to the accompanying drawings. In multiple embodiments, functionally and / or structurally corresponding parts and / or associated parts are sometimes marked with the same reference numerals or reference numerals that are different by more than one hundred. For the corresponding parts and / or associated parts, reference can be made to the description of other embodiments.

[0014] <1st Shishi Form> Below, refer to Figure 1 and Figure 2 The first embodiment of the in-wheel motor disclosed in the present invention is described. The in-wheel motor and the rim on which the tire is mounted together constitute a wheel unit as a driving wheel. The wheel unit of this embodiment is suitable for vehicles such as electric vehicles and hybrid vehicles.

[0015] The wheel unit includes a rim 10. The rim 10 has a cylindrical flange portion 11 and a disc-shaped plate portion 12 provided at an end portion of the flange portion 11 on the outer side in the vehicle width direction. A tire 13 is mounted on the outer periphery of the rim 10.

[0016] The wheel unit has an in-wheel motor 30 that rotates the wheel rim 10. The in-wheel motor 30 is mounted on the chassis of the vehicle. Specifically, the in-wheel motor 30 is mounted on the knuckle 20 of the suspension device constituting the chassis. The knuckle 20 includes a mounting portion 21 extending in the up-down direction, a lower arm 22 extending from the lower end of the mounting portion 21 to the inner side in the vehicle width direction, and an upper arm 23 extending from the upper end of the mounting portion 21 to the inner side in the vehicle width direction. The in-wheel motor 30 is mounted on the mounting portion 21. In addition, in the present embodiment, an example in which the wheel unit is not a steering wheel is shown, but the wheel unit may also be a steering wheel.

[0017] At least a portion of the in-wheel motor 30 is accommodated in a space radially inward relative to the wheel rim 11, that is, in a space inside the wheel rim 10, and applies rotational power to the wheel rim 10. The in-wheel motor 30 is an outer rotor type motor, and includes a shaft 31 extending in the vehicle width direction, a rotor 40, and a stator 50 arranged radially inward of the rotor 40.

[0018] The rotor 40 includes a cylindrical magnet holding portion 41 and a magnet unit 42 arranged on the inner circumferential surface of the magnet holding portion 41. In the magnet holding portion 41, the portion from the outer end to the inner end in the vehicle width direction is opposite to the inner circumferential surface of the rim portion 11. The magnet unit 42 is formed in a cylindrical shape concentric with the rotation center axis of the rotor 40, and has a plurality of magnets fixed to the inner circumferential surface of the magnet holding portion 41. That is, the in-wheel motor 30 of the present embodiment is a surface magnet type synchronous machine (SPMSM). In the magnet unit 42, the magnets are arranged in a manner in which the polarity changes alternately along the circumferential direction of the rotor 40. Thus, in the magnet unit 42, a plurality of magnetic poles are formed along the circumferential direction. The magnet is, for example, a permanent magnet with polar anisotropy, a sintered neodymium magnet with an intrinsic coercive force of 400 [kA / m] or more, and a residual magnetic flux density Br of 1.0 [T] or more. Incidentally, the in-wheel motor 30 may be an interior-mounted magnet synchronous machine (IPMSM).

[0019] In the magnet holding portion 41, the inner end in the vehicle width direction is a curved portion that is curved radially inward of the rotor 40. The rotor 40 includes a disc-shaped flat plate portion 43 as a connecting portion that connects the outer end in the vehicle width direction of the magnet holding portion 41 and the shaft 31. The disk portion 12 is fixed to the flat plate portion 43 by bolts and nuts. As a result, the rotor 40 and the rim 10 rotate integrally. In addition, the magnet holding portion 41 and the flat plate portion 43 can be composed of a non-magnetic body (for example, aluminum or synthetic resin) or a magnetic body (for example, iron).

[0020] The stator 50 includes: a cylindrical stator winding 51 arranged at a position radially opposite to the magnet unit 42; a cylindrical stator core 52 provided radially inside the stator winding 51; and a base 53 provided radially inside the stator core 52. The stator core 52 is made of a magnetic body (specifically, a soft magnetic body), for example, an electromagnetic steel plate.

[0021] The stator winding 51 has a plurality of phase windings, and the phase windings of each phase are arranged in a predetermined order along the circumferential direction to form a cylindrical shape. In the present embodiment, the stator winding 51 is composed of three-phase windings of U phase, V phase, and W phase. Each phase winding is formed by winding a plurality of turns of a conductor material, and has a pair of intermediate conductor portions parallel to each other and extending in the axial direction (vehicle width direction) of the shaft 31, and a pair of lap portions connecting the pair of intermediate conductor portions at both ends of the axial direction, and is formed into a ring shape by a pair of intermediate conductor portions and a pair of lap portions.

[0022] In the present embodiment, the stator core 52 has a slotless structure without pole teeth for forming slots. This structure may be any one of the following (A) to (C).

[0023] (A) Structure: In the stator 50, an inter-conductor component is provided between each intermediate conductor portion in the circumferential direction, and the following magnetic material is used as the inter-conductor component: when the circumferential width dimension of the inter-conductor component of one magnetic pole is set to Wt, the saturation magnetic flux density of the inter-conductor component is set to Bs, the circumferential width dimension of the magnet of one magnetic pole is set to Wm, and the residual magnetic flux density of the magnet constituting the magnet unit 42 is set to Br, the relationship Wt×Bs≤Wm×Br is satisfied.

[0024] (B) Structure: In the stator 50, an inter-conductor member is provided between each intermediate conductor portion in the circumferential direction, and a non-magnetic material is used as the inter-conductor member.

[0025] (C) Structure: In the stator 50, no inter-conductor member is provided between the intermediate conductor portions in the circumferential direction.

[0026] The base portion 53 is a structure for connecting the structure on the stator 50 side of the in-wheel motor 30 to the mounting portion 21 of the knuckle 20. In addition, the base portion 53 is a structure for rotatably supporting the shaft 31.

[0027] The base portion 53 includes: a cylindrical core mounting portion 54, which has a function as a shell of the stator 50 and extends in the vehicle width direction; and an annular ring portion 55, which extends radially inward from the outer end portion in the vehicle width direction of the core mounting portion 54. A through hole 56 for inserting the shaft 31 is formed in the center portion of the annular portion 55. The stator core 52 is mounted on the radial outer end portion of the core mounting portion 54. A hollow portion is formed on the radial inner side of the core mounting portion 54. The bracket portion 70 is arranged in the hollow portion.

[0028] The bracket portion 70 includes a cylindrical main body portion 71 extending in the axial direction of the shaft 31 and a circular bracket side flange portion 72 extending radially outward from the outer end portion of the main body portion 71 in the vehicle width direction. The bracket portion 70 is composed of a non-magnetic body, specifically, a non-magnetic metal material (such as aluminum). The bracket portion 70 of this embodiment is configured as a member different from the base portion 53. In the bracket side flange portion 72, a plurality of bolt insertion holes 72a for inserting bolts 92 in the axial direction are formed at predetermined intervals along the circumferential direction.

[0029] The in-wheel motor 30 includes a hub bearing 60 that supports the shaft 31 so as to be rotatable relative to the annular portion 55 constituting the base portion 53. The hub bearing 60 is a rolling bearing including a cylindrical outer ring 61, an inner ring 62, and a plurality of rolling elements 63 (e.g., balls) disposed between the outer ring 61 and the inner ring 62.

[0030] The outer ring 61 includes an outer ring cylindrical portion 61 a extending in the axial direction of the shaft 31 and an annular outer ring side flange portion 61 b ​​extending radially outward from an axially intermediate portion of the outer ring cylindrical portion 61 a .

[0031] The radial inner end of the annular portion 55 is an annular bearing mounting portion 55a that is recessed from the outer side in the vehicle width direction toward the inner side in the vehicle width direction. In the bearing mounting portion 55a and the outer ring side flange portion 61b, the same number of bolt insertion holes 55b and 61c that penetrate in the axial direction for inserting the bolts 92 are formed at predetermined intervals in the circumferential direction. The bolt insertion hole 61c of the outer ring side flange portion 61b is an internal threaded hole formed with an internal thread.

[0032] The bracket side flange portion 72 is in contact with the end surface of the bearing mounting portion 55a on the inner side in the vehicle width direction, and the outer ring side flange portion 61b is in contact with the end surface of the bearing mounting portion 55a on the outer side in the vehicle width direction. In this state, the bolt 92 is inserted into each bolt insertion hole 72a, 55b, 61c with the head of the bolt 92 facing the inner side in the vehicle width direction, and the external thread of the bolt 92 is screwed into the bolt insertion hole 61c, that is, the internal thread hole. In this way, the bracket portion 70 and the hub bearing 60 are fixed relative to the annular portion 55.

[0033] The inner ring 62 of the hub bearing 60 includes an inner ring cylindrical portion 62a formed into a cylindrical shape with a smaller diameter than the outer ring 61, and an inner ring side flange portion 62b extending from one axial end of the inner ring cylindrical portion 62a in a direction intersecting (orthogonal) with the axial direction. The shaft 31 is fixed to the inner ring cylindrical portion 62a. In the inner ring side flange portion 62b, a plurality of protrusions 62c extending outward in the vehicle width direction are formed at predetermined intervals along the circumferential direction. An external thread is formed at the front end of the protrusion 62c. A through hole 43a is formed in the flat plate portion 43 of the rotor 40. In a state where the inner ring side flange portion 62b abuts against the end surface of the flat plate portion 43 in the vehicle width direction and the protrusion 62c is inserted into the through hole 43a, the nut 90 is screwed into the external thread of the front end of the protrusion 62c. As a result, the flat plate portion 43 is fixed to the inner ring 62. Therefore, the inner ring 62, the rotor 40, and the rim 10 rotate integrally.

[0034] An annular restricting portion 34 extending radially outward is formed in the axial middle portion of the shaft 31. An external thread is formed in the front end portion 35 on the outside in the vehicle width direction of the shaft 31. With the restricting portion 34 in contact with the axial end surface of the inner ring cylindrical portion 62a, the nut 91 is screwed into the external thread of the front end portion 35. Thus, the shaft 31 is fixed to the inner ring 62.

[0035] In the main body 71 of the bracket 70, the portion that is axially away from the opening portion on the outside in the vehicle width direction by the first prescribed length is the thick wall portion 75. In the main body 71, the portion that is axially away from the opening portion on the inside in the vehicle width direction by the second prescribed length is the thin wall portion 73 (equivalent to the "seal arrangement portion"). In the main body 71, the middle wall portion 74 (equivalent to the "sensor arrangement portion") is between the thick wall portion 75 and the thin wall portion 73. The inner diameter dimension of the middle wall portion 74 is larger than the inner diameter dimension of the thick wall portion 75, and the inner diameter dimension of the thin wall portion 73 is larger than the inner diameter dimension of the middle wall portion 74. The outer diameter dimensions of the thick wall portion 75, the middle wall portion 74 and the thin wall portion 73 are the same.

[0036] The boundary between the thin-walled portion 73 and the middle-walled portion 74 is a first step portion 76, and the boundary between the middle-walled portion 74 and the thick-walled portion 75 is a second step portion 77. Figure 3 As shown, the first step portion 76 and the second step portion 77 are in an annular shape.

[0037] The in-wheel motor 30 includes a resolver 80 as a rotation angle sensor for detecting the rotation angle (electrical angle) of the rotor 40. The resolver 80 includes a resolver rotor 81 (equivalent to a "rotor-side sensor unit") mounted on the inner end of the shaft 31 in the vehicle width direction, and a resolver stator 82 (equivalent to a "bracket-side sensor unit") arranged opposite to the radial outer side of the resolver rotor 81. The resolver rotor 81 is in the shape of a circular plate and is arranged coaxially with the shaft 31 when the shaft 31 is inserted therethrough. The resolver stator 82 includes a back yoke in the shape of an annular ring and a coil 83 wound on a plurality of pole teeth extending radially inward from the back yoke. The coil 83 includes an excitation coil and a pair of output coils.

[0038] The excitation coil is excited by a sinusoidal excitation signal, and the magnetic flux generated in the excitation coil by the excitation signal interlinks with the pair of output coils. At this time, since the relative arrangement relationship between the excitation coil and the pair of output coils changes periodically according to the rotation angle of the resolver rotor 81, the number of magnetic fluxes interlinked with the pair of output coils changes periodically. As a result, a signal corresponding to the rotation angle is output from the output coil.

[0039] A through hole 57 is formed in the annular portion 55 of the base portion 53 and penetrates in the axial direction. A power line 58 is inserted into the through hole 57, which electrically connects the stator winding 51 to the inverter and through which a three-phase alternating current flows. The inverter is electrically connected to the power storage unit. The power storage unit is, for example, a battery such as a lithium-ion battery. The switch control of the upper and lower arm switches constituting the inverter is performed by the control device. As a result, the rotor 40 rotates and the wheel unit rotates. In the present embodiment, the inverter, the power storage unit and the control device are arranged in a portion other than the wheel unit in the vehicle (for example, a chassis portion or a vehicle body portion).

[0040] Next, the mounting positions of the resolver rotor 81 and the resolver stator 82 will be described.

[0041] First, the mounting position of the resolver rotor 81 will be described. The inner end portion of the shaft 31 in the vehicle width direction is the small diameter portion 36. In addition, the portion of the shaft 31 adjacent to the small diameter portion 36 in the axial direction is the large diameter portion 37 having a larger radial dimension than the small diameter portion 36. Between the small diameter portion 36 and the large diameter portion 37 is a step portion 38 that abuts against the axial end surface of the resolver rotor 81. The step portion 38 is opposite to the inner peripheral surface of the thin-walled portion 73 in the radial direction. The portion of the shaft 31 adjacent to the large diameter portion 37 in the axial direction is the restriction portion 34. An external thread is formed at the front end portion 39 of the small diameter portion 36.

[0042] The small diameter portion 36 is radially opposed to the inner peripheral surface of the middle wall portion 74 of the bracket portion 70. With the resolver rotor 81 inserted through the small diameter portion 36 and the end of the resolver rotor 81 abutting against the step portion 38, the nut 93 is screwed into the external thread of the front end portion 39 of the small diameter portion 36. As a result, the resolver rotor 81 is sandwiched between the step portion 38 and the nut 93, and the resolver rotor 81 is attached to the shaft 31.

[0043] The step portion 38 provided on the shaft 31 can easily position the resolver rotor 81 in the axial direction. In addition, the coaxiality of the resolver rotor 81 with respect to the rotation center axis of the shaft 31 can be improved. This can improve the calculation accuracy of the electrical angle.

[0044] The shaft 31 extends inwardly in the vehicle width direction relative to the hub bearing 60. Therefore, the resolver rotor 81 can be mounted on the vehicle width direction inner end of the shaft 31. As a result, the outer diameter of the resolver rotor 81 can be made smaller than the outer diameter of the outer ring cylindrical portion 61a, and in this embodiment, smaller than the outer diameter of the inner ring cylindrical portion 62a.

[0045] Next, the mounting position of the resolver stator 82 will be described. The resolver stator 82 is mounted to the bracket portion 70 in a state where an end portion of the resolver stator 82 abuts against the second step portion 77 of the bracket portion 70 .

[0046] A through hole 74a is formed in the middle wall portion 74 at a portion radially opposite to the resolver stator 82, through which a wiring 84 (specifically, a wiring harness) electrically connected to the coil 83 is inserted. The wiring 84 passes through the through hole 74a and is led out from the inside of the bracket portion 70 to the outside. The wiring 84 led out to the outside passes through the space surrounded by the bracket portion 70 and the base portion 53 and is arranged along the direction in which the upper arm 23 extends.

[0047] A tubular sealing member 85 is provided between the through hole 74a and the wiring 84. The sealing member 85 is made of, for example, synthetic resin. The sealing member 85 can prevent foreign matter from penetrating into the bracket portion 70 through the gap between the through hole 74a and the wiring 84.

[0048] The control device installed in the vehicle includes a resolver digital converter. The resolver digital converter supplies an excitation signal to an excitation coil included in the coil 83 via wiring 84. The resolver digital converter calculates an electrical angle based on detection of signals from a pair of output coils included in the coil 83 and the excitation signal.

[0049] In the present embodiment, the bracket portion 70 is not made of a magnetic body such as iron but is made of a non-magnetic metal material, so that leakage of magnetic flux from the resolver stator 82 to the bracket portion 70 can be suppressed, thereby improving the calculation accuracy of the electrical angle.

[0050] The opening portion on the inner side in the vehicle width direction of the main body portion 71 of the bracket portion 70 is covered by a cover 100 (equivalent to the "cover portion"). The cover 100 is in the shape of a circular plate, and a plurality of bolt insertion holes 100a are formed at predetermined intervals on the peripheral portion of the cover 100. At the inner end portion of the thin-walled portion 73 in the vehicle width direction, the same number of internal threaded holes 73a as the bolt insertion holes 100a are formed at predetermined intervals along the circumferential direction. In a state where the flat surface of the peripheral portion of the cover 100 abuts against the end face of the thin-walled portion 73, the bolt 101 is inserted through the bolt insertion hole 100a and the internal threaded hole 73a, and the external thread of the bolt 101 is screwed into the internal threaded hole 73a. Thus, the cover 100 is fixed to the bracket portion 70.

[0051] The mounting portion 21 of the knuckle 20 is formed with a bolt insertion hole 21a. The cover 100 is formed with an internal thread hole 100b. When the mounting portion 21 is in contact with the cover 100, the bolt 94 is inserted through the bolt insertion hole 21a and the internal thread hole 100b, and the external thread of the bolt 94 is screwed into the internal thread hole 100b. Thus, the cover 100 is fixed to the knuckle 20.

[0052] In the present embodiment, the resolver 80 is covered by the bracket 70, thereby preventing foreign matter such as water and / or dust from entering the space surrounded by the bracket 70 from the outside. Here, due to vibration or impact of the vehicle from the road surface, an external force acts on the cover 100, and the cover 100 is deformed. At this time, there is a possibility that a gap is generated between the cover 100 and the thin-walled portion 73 of the bracket 70, and water and / or dust enter the bracket 70 through the gap and adhere to the resolver 80. At this time, the resolver 80 may be corroded or deteriorated.

[0053] Therefore, in the present embodiment, a structure is adopted in which water and / or dust are difficult to adhere to the resolver 80 even when a gap is generated between the cover 100 and the thin wall portion 73 of the bracket portion 70. Figure 2 to Figure 4 This structure will be described. Figure 3 This is a diagram of the bracket portion 70 when the resolver 80 , the cover 100 , the sealing cover 110 , and the like are not attached, as viewed from the inner side in the vehicle width direction. Figure 4 This is a view of the bracket portion 70 in a state where the seal cover 110 is mounted and the cover 100 is not mounted, as viewed from the inner side in the vehicle width direction.

[0054] The in-wheel motor 30 includes a sealing cover 110 that seals the opening of the bracket portion 70 on the inner side in the vehicle width direction and the resolver rotor 81 and the resolver stator 82. The sealing cover 110 is in the shape of a disk. The sealing cover 110 may be made of a non-magnetic body (e.g., aluminum or synthetic resin) or a magnetic body (e.g., iron).

[0055] A plurality of (six) bolt insertion holes 110a are formed at a peripheral edge of the sealing cover 110 at predetermined intervals in the circumferential direction. Figure 3 As shown, the first step portion 76 is provided with the same number of internal threaded holes 76a as the bolt insertion holes 110a at predetermined intervals in the circumferential direction. The first step portion 76 is provided with an annular groove 76b extending over the entire circumference closer to the radial inner side than the internal threaded holes 76a. An elastic annular sealing member 112 is disposed in the groove 76b as a sealing material. The sealing member 112 in this embodiment is an O-ring.

[0056] When the sealing member 112 is pressed against the peripheral portion of the sealing cover 110 and becomes compressed, and the peripheral portion of the sealing cover 110 is in contact with the first step portion 76, the bolt 111 (equivalent to the "fixing portion") is inserted through the bolt insertion hole 110a and the internal thread hole 76a, and the external thread of the bolt 111 is screwed into the internal thread hole 76a. Thus, the sealing cover 110 is fixed to the first step portion 76. Thus, even if water and / or dust enters the bracket portion 70 from the gap between the bracket portion 70 and the cover 100, it is possible to prevent water and / or dust from adhering to the resolver rotor 81 and the resolver stator 82.

[0057] The radial thickness dimension of the middle wall portion 74 of the bracket portion 70 is greater than the radial thickness dimension of the thin wall portion 73 of the bracket portion 70. Therefore, the first step portion 76 is not easily deformed, and a gap is not easily generated between the sealing cover 110 and the first step portion 76. Thus, it is possible to reliably suppress the occurrence of water and / or dust adhering to the resolver rotor 81 and the resolver stator 82.

[0058] The radial thickness dimension of the thick wall portion 75 of the bracket portion 70 is greater than the radial thickness dimension of the middle wall portion 74 of the bracket portion 70. Therefore, the second step portion 77 is not easily deformed, and the coaxiality between the resolver stator 82 and the shaft 31 is not easily deteriorated. As a result, the detection accuracy of the resolver 80 for the electrical angle can be improved.

[0059] <Modification of the first embodiment> A plurality of annular grooves 76b may be formed in a radial direction in the first step portion 76. In this case, the sealing member 112 may be disposed in each groove 76b.

[0060] The sealing member for sealing between the sealing cover 110 and the first step portion 76 is not limited to an O-ring, and may be, for example, an annular gasket (eg, a metal gasket). In this case, the groove 76 b may not be formed in the first step portion 76 .

[0061] In addition, the sealing material is not limited to the sealing member, and may be, for example, a liquid gasket or an adhesive.

[0062] The portion of the main body 71 of the bracket 70 that is on the inner side of the thin-walled portion 73 in the vehicle width direction may also be a cover embedding portion having an outer diameter dimension equal to that of the thin-walled portion 73. The inner diameter dimension of the cover embedding portion is larger than the inner diameter dimension of the thin-walled portion 73, and the radial thickness dimension of the cover embedding portion is smaller than the radial thickness dimension of the thin-walled portion 73. In this case, it is sufficient to form an internal thread hole 73a for the external thread of the bolt 101 to be screwed into the annular step portion between the thin-walled portion 73 and the cover embedding portion. In a state where the peripheral portion of the cover 100 abuts against the annular step portion between the thin-walled portion 73 and the cover embedding portion, the cover 100 is fixed to the bracket 70 by the bolt 101.

[0063] <Second embodiment> Below, refer to Figure 5 The second embodiment will be described with the differences from the first embodiment as the center. In this embodiment, an elastic annular outer sealing member 102 is provided between the peripheral portion of the cover 100 and the thin-walled portion 73 of the bracket portion 70. The outer sealing member 102 of this embodiment is an O-ring.

[0064] An annular groove 73b is formed over the entire circumference at the vehicle width direction inner end portion of the thin portion 73 at a position radially inward of the internal threaded hole 73a. A sealing member 102 is disposed in the groove 73b.

[0065] With the outer sealing member 102 pressed against the peripheral edge of the cover 100 and in a compressed state, and the peripheral edge of the cover 100 abutting against the annular end surface of the thin-walled portion 73 on the inner side in the vehicle width direction, the bolt 101 is inserted through the bolt insertion hole 100a and the internal thread hole 73a, and the external thread of the bolt 101 is screwed into the internal thread hole 73a. Thus, the cover 100 is fixed to the bracket portion 70.

[0066] According to the present embodiment described above, it is possible to more reliably suppress the entry of water and / or dust into the bracket portion 70 .

[0067] <Modification of Second Embodiment> A plurality of annular grooves 73b may be formed in a radial direction in the vehicle width direction inner end of the thin-walled portion 73. In this case, the outer sealing member 102 may be disposed in each groove 73b.

[0068] The outer sealing member for sealing between the cover 100 and the bracket portion 70 is not limited to an O-ring, and may be, for example, an annular gasket (eg, a metal gasket). In this case, the groove 73 b may not be formed at the inner end of the thin-walled portion 73 in the vehicle width direction.

[0069] In addition, the outer sealing material is not limited to the sealing member, and may be, for example, a liquid gasket or an adhesive.

[0070] <Third Embodiment> Below, refer to Figure 6 The third embodiment will be described with the differences from the first embodiment as the center. In this embodiment, the opening of the bracket portion 70 on the inner side in the vehicle width direction is covered by the mounting portion 21 (corresponding to the “cover portion”) of the knuckle 20 instead of the cover 100 .

[0071] The mounting portion 21 is provided with bolt insertion holes 21 b of the same number as the internal thread holes 73 a at predetermined intervals in the circumferential direction.

[0072] With the mounting portion 21 in contact with the bracket portion 70 , the bolt 101 is inserted through the bolt insertion hole 21 b and the internal thread hole 73 a , and the external thread of the bolt 101 is screwed into the internal thread hole 73 a . Thus, the bracket portion 70 is fixed to the knuckle 20 .

[0073] According to the present embodiment described above, the opening of the bracket portion 70 on the inner side in the vehicle width direction can be closed while reducing the number of components of the in-wheel motor 30 .

[0074] <Fourth embodiment> Below, refer to Figure 7 and Figure 8 The fourth embodiment will be described with the differences from the first embodiment as the center. In this embodiment, an inner rotor type in-wheel motor 330 is used instead of an outer rotor type. In addition, in this embodiment, descriptions of structures similar to those of the first embodiment are appropriately omitted.

[0075] The in-wheel motor 330 includes a shaft 331 extending in the vehicle width direction, a rotor 340 , and a stator 350 disposed radially outward of the rotor 340 .

[0076] The rotor 340 includes a cylindrical magnet unit 341 and a rotor core 342 provided radially inside the magnet unit 341. Incidentally, the in-wheel motor 330 may be an embedded magnet type synchronous machine.

[0077] The stator 350 includes: a cylindrical stator winding 351, which is arranged at a position opposite to the magnet unit 341 in the radial direction; a cylindrical stator core 352, which is provided on the radially outer side of the stator winding 351; and a base 353. The base 353 includes: a cylindrical core mounting portion 354, which has a function as a shell of the stator 350 and extends in the vehicle width direction; and an annular ring portion 355, which extends radially inward from the outer end portion in the vehicle width direction of the core mounting portion 354. A through hole 356 for inserting the shaft 331 is formed in the central portion of the ring portion 355. The stator core 352 is mounted on the radially outer end portion of the core mounting portion 354.

[0078] The in-wheel motor 330 includes a hub bearing 360 that supports the shaft 331 so as to be rotatable relative to the annular portion 355. The hub bearing 360 is a rolling bearing including a cylindrical outer ring 361, an inner ring 362, and a plurality of rolling elements 363 (e.g., balls) disposed between the outer ring 361 and the inner ring 362. The outer ring side flange portion of the outer ring 361 is fixed to the disc portion 12. The shaft 331 is fixed to the inner ring 362.

[0079] The in-wheel motor 330 includes a bracket portion 370. The bracket portion 370 includes a cylindrical main body portion 371 extending in the axial direction of the shaft 331 and an annular bracket side flange portion 372 extending radially outward from the inner end portion in the vehicle width direction of the main body portion 371. The bracket side flange portion 372 is fixed to the core mounting portion 354 by bolts 401.

[0080] In the main body 371 of the bracket 370, the portion that is axially away from the opening portion on the outside in the vehicle width direction by the first predetermined length is the thick wall portion 375. In the main body 371, the portion that is axially away from the opening portion on the inside in the vehicle width direction by the second predetermined length is the thin wall portion 373 (equivalent to the "seal member configuration portion"). In the main body 371, the middle wall portion 374 (equivalent to the "sensor configuration portion") is between the thick wall portion 375 and the thin wall portion 373. The inner diameter dimension of the middle wall portion 374 is larger than the inner diameter dimension of the thick wall portion 375, and the inner diameter dimension of the thin wall portion 373 is larger than the inner diameter dimension of the middle wall portion 374.

[0081] The boundary between the thin wall portion 373 and the middle wall portion 374 is a first step portion 376, and the boundary between the middle wall portion 374 and the thick wall portion 375 is a second step portion 377. The first step portion 376 and the second step portion 377 are annular.

[0082] The resolver stator 382 constituting the resolver 380 is attached to the bracket portion 370 in a state in which an end portion of the resolver stator 382 abuts against the second step portion 377 of the bracket portion 370 .

[0083] A resolver rotor 381 constituting the resolver 380 is attached to the vehicle width direction inner end portion of the shaft 331. The shaft 331 is formed with a small diameter portion 336, a large diameter portion 337, and a step portion 338 corresponding to the small diameter portion 36, the large diameter portion 37, and the step portion 38 of the first embodiment. The resolver rotor 381 is attached to the shaft 331 in a state where the resolver rotor 381 is inserted through the small diameter portion 336 and the end portion of the resolver rotor 381 abuts against the step portion 338.

[0084] In addition, a through hole 374a is formed in the middle wall portion 374 at a portion radially opposite to the resolver stator 382, ​​through which a wiring 384 (specifically, a wiring harness) electrically connected to the coil 383 of the resolver stator 382 is inserted. The wiring 384 passes through the through hole 374a and is led out from the inside of the bracket portion 370 to the outside. Figure 7 and Figure 8 In the figure, for convenience, the tubular sealing member provided between the through hole 374a and the wiring 384 is omitted from illustration.

[0085] The opening portion on the inner side in the vehicle width direction in the main body portion 371 of the bracket portion 370 is covered by a cover 400 (equivalent to the "cover portion"). The cover 400 is in the shape of a circular plate, and a plurality of bolt insertion holes 400a are formed at a predetermined interval along the circumferential direction on the peripheral portion of the cover 400. The same number of internal thread holes 372a as the bolt insertion holes 400a are formed at a predetermined interval along the circumferential direction on the peripheral portion of the opening portion of the bracket side flange portion 372. In a state where the flat surface of the peripheral portion of the cover 400 abuts against the end face of the bracket side flange portion 372, the bolt 402 is inserted through the bolt insertion hole 400a and the internal thread hole 372a, and the external thread of the bolt 402 is screwed into the internal thread hole 372a. Thus, the cover 400 is fixed to the bracket portion 370.

[0086] In addition, the cover 400 has an internal thread hole 400b. When the mounting portion 21 is in contact with the cover 400, the bolt 94 is inserted through the bolt insertion hole 21a and the internal thread hole 400b, and the external thread of the bolt 94 is screwed into the internal thread hole 400b. Thus, the cover 400 is fixed to the knuckle 20.

[0087] The in-wheel motor 330 includes a sealing cover 410 that seals the opening of the bracket portion 370 on the inner side in the vehicle width direction, the resolver rotor 381, and the resolver stator 382. The sealing cover 410 is in the shape of a disk. The sealing cover 410 may be made of a non-magnetic body (e.g., aluminum or synthetic resin) or a magnetic body (e.g., iron).

[0088] A plurality of bolt insertion holes 410a are formed at a predetermined interval in the circumferential direction on the peripheral portion of the sealing cover 410. The same number of internal threaded holes 376a as the bolt insertion holes 410a are formed at a predetermined interval in the circumferential direction on the first step portion 376. An annular groove 376b is formed over the entire circumference of the first step portion 376 at a position closer to the radial inner side than the internal threaded hole 376a. An elastic annular sealing member 412 is arranged in the groove 376b as a sealing material. The sealing member 412 of the present embodiment is an O-ring.

[0089] When the sealing member 412 is pressed against the peripheral portion of the sealing cover 410 and becomes compressed, and the peripheral portion of the sealing cover 410 is in contact with the first step portion 376, the bolt 411 (equivalent to the "fixing portion") is inserted through the bolt insertion hole 410a and the internal thread hole 376a, and the external thread of the bolt 410 is screwed into the internal thread hole 376a. Thus, the sealing cover 410 is fixed to the first step portion 376. Thus, similarly to the first embodiment, even if water and / or dust enters the bracket portion 370 from the gap between the bracket portion 370 and the cover 400, it is possible to suppress the occurrence of water and / or dust adhering to the resolver rotor 381 and the resolver stator 382.

[0090] <Other embodiments> In addition, each of the above-mentioned embodiments may be implemented with the following modifications.

[0091] In the fourth embodiment, similarly to the second embodiment, an outer sealing material may be provided between the cover 400 and the bracket portion 370 .

[0092] The inner ring of the hub bearing and the shaft may also be constructed as one component.

[0093] The bracket portion and the base portion of the stator may be formed as a single component.

[0094] The lead-out position of the wiring 84 is not limited to Figure 2 The wiring 84 may be led out from the inside of the bracket 70 to the outside through a through hole provided between the bracket 70 and the cover 100. The through hole is not limited to the inner end of the bracket 70 in the vehicle width direction, but may also be formed in the cover 100.

[0095] Alternatively, the wiring 84 may be passed through a through hole provided between the bracket-side flange portion 72 of the bracket portion 70 and the annular portion 55 of the stator 50 , and led out from the inside of the bracket portion 70 to the outside.

[0096] The bracket part is not limited to a circular tube shape, and may be a quadrilateral (for example, a square or a rectangle) or other angular tube shape. In addition, the bracket part may be made of a magnetic body (for example, iron).

[0097] In the first to third embodiments, instead of fixing the flat plate portion 43 of the in-wheel motor 30 to the disk portion 12 of the rim 10 , the magnet holding portion 41 of the in-wheel motor 30 may be fixed to the rim portion 11 .

[0098] In the first to third embodiments, the rim portion 11 of the wheel rim 10 may be a magnet holding portion of the in-wheel motor 30, and the disc portion 12 may be a flat plate portion. That is, the rotor 40 of the in-wheel motor 30 may also function as the wheel rim.

[0099] ·exist Figure 1 In the illustrated structure, a bearing for rotatably supporting the vehicle width direction inner end of the shaft 31 may be mounted on the inner peripheral surface of the bracket portion 70. In this case, the bearing may be provided, for example, on the axial side of the cover 100 relative to the resolver 80.

[0100] The bracket portion may be formed of a magnetic metal material (for example, soft magnetic iron).

[0101] The rotation angle sensor is not limited to a resolver, and may be, for example, a magnetic encoder including a magnet portion including a permanent magnet as a rotor-side sensor portion and a magnetic sensor including a Hall element as a holder-side sensor portion.

[0102] · The inverter can also be built into the in-wheel motor.

[0103] The rotating electric machine is not limited to the radial gap type rotating electric machine shown in the first to fifth embodiments, and may be an axial gap type rotating electric machine.

[0104] The rotating electrical machine may be a winding-excitation type synchronous machine having an excitation winding in the rotor or stator instead of a permanent magnet synchronous machine. The rotating electrical machine is not limited to a synchronous machine, and may be an induction machine, for example.

[0105] The mobile body with wheels equipped with in-wheel motors may be an unmanned guided vehicle or a forklift. An unmanned guided vehicle is, for example, an AGV (Automatic Guided Vehicle) or an autonomous mobile robot (AMR) used in factories.

[0106] As a mobile body with wheels equipped with an in-wheel motor, a small electric vehicle for riding, such as an electric wheelchair or a senior vehicle (Japanese: セニアカー), may be used. The small electric vehicle is, for example, a vehicle with a running speed of 10 km / h or less.

[0107] · Hereinafter, characteristic structures extracted from the above-mentioned embodiments will be described. [Structure 1] An in-wheel motor (30, 330) is suitable for a mobile body including a rim (10), wherein the rim has a rim portion (11) on which a tire (13) can be mounted and a disc portion (12) provided on a side of the rim portion, and at least a portion of the in-wheel motor is accommodated in a space inside the rim surrounded by the disc portion and the rim portion, and the rim is rotated. The in-wheel motor includes: a tubular bracket portion (70, 370) extending in the vehicle width direction of the moving body; a stator (50, 350), connected to the bracket portion; A rotor (40, 340) having a shaft (31, 331) extending in the vehicle width direction and an excitation pole, and connected to the rim; a bearing (60, 360) which is provided at a position closer to the outside in the vehicle width direction than the bracket portion in the axial direction of the shaft and rotatably supports the shaft; and Rotation angle sensor (80, 380), The shaft extends inward in the vehicle width direction in the axial direction to a position facing the inner peripheral surface of the bracket portion in the radial direction of the shaft. The rotation angle sensor has: a rotor-side sensor portion (81, 381) mounted on the shaft at a position opposite to the inner peripheral surface of the bracket portion in the radial direction; and a bracket-side sensor unit (82, 382) mounted on an inner peripheral surface of the bracket unit at a position opposite to the rotor-side sensor unit in the radial direction of the shaft and outputting a signal corresponding to a rotation angle of the rotor-side sensor unit, The bracket part is fixed to the cover part in a state where the opening part on the inner side of the bracket part in the vehicle width direction is closed by a cover part (100, 400) fixed to the chassis part (20) of the moving body or a cover part (21) constituting the chassis part, A sealing cover (110, 410) is provided on the inner peripheral side of the bracket part and seals the opening on the inner side of the bracket part in the vehicle width direction, the rotor side sensor part and between the bracket side sensor part. [Structure 2] According to the in-wheel motor of structure 1, the bracket portion is formed with: a sensor arrangement portion (74, 374) for arranging the bracket-side sensor portion; and a seal arrangement portion (73, 373) adjacent to the sensor arrangement portion on the inner side in the vehicle width direction and having an inner diameter larger than that of the sensor arrangement portion, In the bracket portion, the sealing cover is fixed to the bracket portion in a state where the peripheral edge portion of the sealing cover abuts against an annular step portion (76, 376) between the sensor placement portion and the seal member placement portion. [Structure 3] According to the in-wheel motor of Structure 2, a radial thickness dimension of the sensor arrangement portion in the bracket portion is larger than a radial thickness dimension of the seal arrangement portion in the bracket portion. [Structure 4] The in-wheel motor according to structure 2 or 3, wherein a sealing material (112, 412) is provided between the sealing cover and the bracket. [Structure 5] The in-wheel motor according to the fourth aspect, wherein an annular groove (76b, 376b) extending in the circumferential direction is formed in the step portion. The sealing material includes an annular sealing member (112, 412), The sealing member is arranged in the groove. [Structure 6] The in-wheel motor according to the fifth aspect comprises a fixing portion (111) for fixing a portion of the step portion which is closer to the outside in the radial direction than the groove and a peripheral edge portion of the sealing cover. [Structure 7] The in-wheel motor according to any one of configurations 1 to 6, wherein an outer sealing material (102) is provided between the inner end portion of the bracket in the vehicle width direction and the cover portion. [Structure 8] An in-wheel motor according to any one of structures 1 to 7, wherein the rotation angle sensor is a resolver, the resolver includes a resolver rotor as the rotor-side sensor portion, and includes an excitation winding and a resolver stator (82, 382) for winding the excitation winding as the bracket-side sensor portion. [Structure 9] In the in-wheel motor according to Configuration 8, the bracket portion is made of a non-magnetic body.

[0108] Although the present disclosure is described based on the embodiments, it should be understood that the present disclosure is not limited to the above-mentioned embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and methods, and other combinations and methods containing only one element, above or below them, also belong to the scope and thought range of the present disclosure.

Claims

1. An in-wheel motor, the in-wheel motor (30, 330) being suitable for a mobile body including a rim (10), the rim having a rim portion (11) on which a tire (13) can be mounted and a disc portion (12) provided on a side surface of the rim portion, at least a portion of the in-wheel motor being accommodated in a space inside the rim surrounded by the disc portion and the rim portion, and causing the rim to rotate, The in-wheel electric motor comprises: A tubular bracket portion (70, 370) extending in the vehicle width direction of the moving body; a stator (50, 350), connected to the bracket portion; A rotor (40, 340) having a shaft (31, 331) extending in the vehicle width direction and an excitation pole, and connected to the rim; A bearing (60, 360) is provided in the axial direction of the shaft at a position closer to the outside in the vehicle width direction than the bracket portion and supports the shaft to be rotatable; as well as Rotation angle sensor (80, 380), The shaft extends inward in the vehicle width direction in the axial direction to a position facing the inner peripheral surface of the bracket portion in the radial direction of the shaft. The rotation angle sensor has: a rotor-side sensor portion (81, 381) mounted on the shaft at a position opposite to the inner peripheral surface of the bracket portion in the radial direction; and a bracket-side sensor unit (82, 382) mounted on an inner peripheral surface of the bracket unit at a position opposite to the rotor-side sensor unit in the radial direction of the shaft and outputting a signal corresponding to a rotation angle of the rotor-side sensor unit, The bracket part is fixed to the cover part in a state where the opening part on the inner side of the bracket part in the vehicle width direction is closed by a cover part (100, 400) fixed to the chassis part (20) of the moving body or a cover part (21) constituting the chassis part, A sealing cover (110, 410) is provided on the inner peripheral side of the bracket part and seals the opening on the inner side of the bracket part in the vehicle width direction, the rotor side sensor part and between the bracket side sensor part.

2. The in-wheel motor according to claim 1, characterized in that: The bracket portion is formed with: a sensor configuration portion (74, 374) for configuring the bracket-side sensor portion; and a seal configuration portion (73, 373) adjacent to the sensor configuration portion inwardly in the vehicle width direction and having an inner diameter larger than that of the sensor configuration portion. In the bracket portion, the sealing cover is fixed to the bracket portion in a state where the peripheral edge portion of the sealing cover abuts against an annular step portion (76, 376) between the sensor placement portion and the seal member placement portion.

3. The in-wheel motor according to claim 2, characterized in that: The radial thickness dimension of the sensor arrangement portion in the bracket portion is greater than the radial thickness dimension of the seal arrangement portion in the bracket portion.

4. The in-wheel motor according to claim 2 or 3, characterized in that: A sealing material (112, 412) is arranged between the sealing cover and the bracket.

5. The in-wheel motor according to claim 4, characterized in that: The step portion is formed with an annular groove (76b, 376b) extending in the circumferential direction. The sealing material includes an annular sealing member (112, 412), The sealing member is arranged in the groove.

6. The in-wheel motor according to claim 5, characterized in that: A fixing portion (111, 411) is included, and the fixing portion fixes a portion of the step portion that is closer to the outside in the radial direction than the groove and a peripheral edge portion of the sealing cover.

7. The in-wheel motor according to any one of claims 1 to 3, characterized in that: An outer sealing material (102) is provided between the inner end portion of the bracket in the vehicle width direction and the cover portion.

8. The in-wheel motor according to any one of claims 1 to 3, characterized in that: The rotation angle sensor is a resolver, The resolver includes a resolver rotor as the rotor-side sensor unit, and includes an excitation winding and a resolver stator (82, 382) around which the excitation winding is wound as the bracket-side sensor unit.

9. The in-wheel motor according to claim 8, characterized in that: The bracket portion is made of a non-magnetic body.

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