JP2010195316A - In-wheel motor and method for manufacturing the same - Google Patents

Abstract

In an in-wheel motor in which a speed reducer is disposed inside a rotor, the processing and assembly of members are facilitated.
An in-wheel motor (1) includes a stator (11), a rotor (12), and a hollow shaft that is provided inside the rotor (12) and is rotatably supported with respect to a first housing (2A) by a pair of bearings (13A, 13B). 20 and a speed reducer 50 disposed inside the hollow shaft 20. A disk-shaped member 22 is provided inside the hollow shaft 20. Between the disc-like member 22 and the speed reducer 50, a sun gear 31 constituting the speed reducer 50 is formed at the first end, and a sun gear shaft 30 attached to the disc-like member 22 is provided at the second end. It is done. The sun gear shaft 30 is spline-fitted with the disk-shaped member 22 and is fixed to the disk-shaped member 22 via the fixing member 40.
[Selection] Figure 1

Description

  The present invention relates to an in-wheel motor disposed in a wheel, and more particularly to an in-wheel motor having a reduction gear in a rotor and a manufacturing method thereof.

  An in-wheel motor is a motor which is arrange | positioned inside the wheel of the wheel with which a vehicle is provided, and drives the said wheel. Some in-wheel motors transmit the output of an in-wheel motor to a wheel via a speed reducer. However, such an in-wheel motor has a large size in the rotation axis direction. Since in-wheel motors may collide with scattered objects such as stones while the vehicle is running, it is preferable that the in-wheel motor is housed inside the wheel as much as possible.

  Patent Document 1 discloses a structure in which a speed reduction device using a planetary gear device is arranged inside a rotor of an in-wheel motor in a configuration in which the output of the in-wheel motor is transmitted to the wheels via the speed reduction device. The structure disclosed in Patent Document 1 is preferable because the size of the in-wheel motor in the rotation axis direction can be reduced.

Japanese Patent Laying-Open No. 2005-81871 (0017)

  By the way, in the structure which arrange | positions a reduction gear in the inside of a rotor, it is necessary to consider a structure so that an assembly and a process may be easy about the structure which connects a rotor and the input gear of a reduction gear. Patent Document 1 discloses that the sun gear of the speed reducer is fixed to the rotor via the sun gear disk, but it is difficult to process with a configuration in which the rotor and the sun gear are integrated, and the rotor and sun gear are There is room for examination of a specific fixing method.

  It is an object of the present invention to facilitate processing of power transmission means provided between a reduction gear and a rotor and assembly of the power transmission means and the rotor in an in-wheel motor in which a reduction gear is disposed inside the rotor. And

  In order to solve the above-described problems and achieve the object, the present invention provides an in-wheel motor that is attached to the inner periphery of a rotor and is rotatably supported by a housing of the in-wheel motor via a bearing. A cylindrical hollow shaft, a disk-shaped member provided inside the hollow shaft and partitioning the inside of the hollow shaft with respect to a rotation axis direction of the hollow shaft, a side portion of the hollow shaft, and the circle A speed reduction device disposed in a space formed by the plate-like member, a rotation element constituting the speed reduction device is provided at the first end, and a second end is a hole provided in the disk-like member A power transmission means that is inserted into and attached to, and a rotation restriction portion that is provided between the second end portion and the disk-like member and restricts the rotation of the power transmission means relative to the disk-like member; The disc-shaped member The said reduction gear Te an in-wheel motor which comprises a fixing member attached to the second end portion and said disk-shaped member of the power transmission means from the opposite side.

  As a preferred aspect of the present invention, in the in-wheel motor, the rotation restricting portion includes a spline formed at a second end portion of the power transmission means and a spline groove formed in the hole of the disk-shaped member. It is desirable to be composed of

  As a preferred aspect of the present invention, in the in-wheel motor, it is desirable that a root diameter of the spline is larger than a tip diameter of the sun gear.

  As a preferred aspect of the present invention, in the in-wheel motor, the spline module is preferably 0.75 to 1.5 and the spline has 30 to 40 teeth.

  As a preferred aspect of the present invention, in the in-wheel motor, the fixing member has a protrusion on the side facing the disk-shaped member, and is formed on the second end side of the power transmission means. It is desirable that the protrusion is fitted into a power transmission means side step and a disk-like member side step formed on the fixing member side of the hole.

  As a preferred aspect of the present invention, in the in-wheel motor, the distance between the disk-shaped member and the end surface of the hollow shaft on the side where the reduction gear is disposed is larger than the dimension of the reduction gear in the rotational axis direction. It is desirable to be large and 150 mm or less.

  As a preferred aspect of the present invention, in the in-wheel motor, the distance between the disk-shaped member and the end surface of the hollow shaft on the side where the speed reduction device is disposed is a dimension in the rotational axis direction of the speed reduction device. It is desirable that it is twice or more.

  As a preferred aspect of the present invention, in the in-wheel motor, it is desirable that the hollow shaft is supported by a pair of bearings, and the disk-shaped member is disposed between the pair of bearings.

  In order to solve the above-described problems and achieve the object, the present invention provides a casing for an in-wheel motor, in which a rotor is provided on the outer periphery and a disk-like member having spline grooves is provided therein. A sun gear shaft in which a sun gear is provided at a first end, a spline is formed at a second end, and a full screw is screwed into the disc-shaped member of a hollow shaft that is rotatably supported via a bearing. The spline is inserted into the spline groove of the disk-shaped member, the screw is screwed with a fixing member connecting the sun gear shaft and the disk-shaped member, and the fixing member is the disk-shaped. A method of manufacturing an in-wheel motor.

  As a preferred aspect of the present invention, in the method for manufacturing the in-wheel motor, before the fixing member is fixed to the disk-shaped member, the sun gear shaft is pulled out toward the fixing member, It is desirable to have a procedure for adjusting the positional relationship between the fixing member and the disk-shaped member in the circumferential direction.

  The present invention can facilitate the processing of power transmission means provided between the reduction gear and the rotor and the assembly of the power transmission means and the rotor in an in-wheel motor having a reduction gear disposed inside the rotor. .

FIG. 1 is a cross-sectional view showing a configuration of an in-wheel motor according to the present embodiment. FIG. 2 is a cross-sectional view of a hollow shaft constituting the in-wheel motor according to the present embodiment. FIG. 3A is an enlarged view showing a hollow shaft mounting side of the sun gear shaft. FIG. 3-2 is an enlarged view of a hole provided in the disk-shaped member. FIG. 4 is an enlarged view showing a fixing portion of the sun gear shaft included in the in-wheel motor according to the present embodiment. FIG. 5 is a perspective view showing a shaft included in the in-wheel motor according to the present embodiment and a fixing member that fixes the sun gear shaft to the disk-shaped member. FIG. 6 is an enlarged view showing the relationship among the protrusion of the fixing member, the disk-shaped member, and the sun gear shaft.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements disclosed in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range.

  The configuration of the in-wheel motor according to the present embodiment will be described. As shown in FIG. 1, the in-wheel motor 1 includes a housing 2, a stator 11, a rotor 12, a hollow shaft 20 to which the rotor 12 is attached to the outer periphery, and a reduction gear disposed inside the hollow shaft 20. 50. The in-wheel motor 1 is arrange | positioned inside the wheel which comprises the wheel of a vehicle, for example, and drives the said wheel. In this case, the in-wheel motor 1 is attached to at least two wheels.

  The casing 2 constituting the in-wheel motor 1 includes a cylindrical first casing 2A (cylindrical in the present embodiment) and a dish-shaped second casing 2B attached to both ends of the first casing 2A. The third housing 2C and the fourth housing 2D having a hub mounting portion. The first housing 2A, the second housing 2B, and the third housing 2C are integrated by fastening with bolts or the like. The fourth housing 2D is fastened and attached to the second housing 2B with the bolts 3. As described above, the housing 2 is configured integrally with the first housing 2A, the second housing 2B, the third housing 2C, and the fourth housing 2D.

  A motor 10 is disposed inside the first housing 2A. The motor 10 includes a stator 11 and a rotor 12. The stator 11 has a plurality of coils 11C configured by winding an electric wire around an iron core. The coils 11C are arranged in the circumferential direction of the first housing 2A. In the present embodiment, the stator 11 is press-fitted and fixed to the first housing 2A, and is provided on the inner wall of the first housing 2A. The rotor 12 is a cylindrical (cylindrical) member, and is arranged with a predetermined interval (for example, 0.5 mm or more and 1 mm or less) with respect to the inner peripheral surface of the stator 11. The rotor 12 rotates about the rotation axis Zr by a rotating magnetic field generated by the coil 11C of the stator 11.

  A cylindrical (cylindrical in this embodiment) hollow shaft 20 is attached to and fixed to the inner periphery of the rotor 12. When viewed from the hollow shaft 20, the rotor 12 is attached to the outer periphery of the hollow shaft 20. A pair of bearings 13 </ b> A and 13 </ b> B are attached to both ends of the hollow shaft 20. The bearings 13A and 13B are attached to the second housing 2B and the third housing 2C, respectively. With such a configuration, the hollow shaft 20 is rotatably supported by the first housing 2A via the pair of bearings 13A and 13B. Accordingly, the rotor 12 is rotatably supported by the housing 2.

  Here, the rotational axes of the rotor 12 and the hollow shaft 20 are both Zr, which is the rotational axis of the in-wheel motor 1. Since the rotor 12 rotates together with the hollow shaft 20, the rotational force of the rotor 12 is output via the hollow shaft 20. In this embodiment, ball bearings are used as the bearings 13A and 13B.

  As shown in FIGS. 1 and 2, the hollow shaft 20 includes a cylindrical (cylindrical) side portion 21 and a disk-like member 22 provided inside the side portion 21. The plate surface of the disk-shaped member 22 is orthogonal to the rotation axis Zr of the hollow shaft 20. The disc-like member 22 partitions the hollow shaft 20, more specifically, the inside of the side portion 21 of the hollow shaft 20 with respect to the rotation axis Zr direction of the hollow shaft 20.

  In the present embodiment, the side portion 21 of the hollow shaft 20 and the disk-like member 22 are configured as a single unit. For example, the shape of the hollow shaft 20 is roughly formed by forging or the like, heat-treated, and then the inside and the outside of the hollow shaft 20 are finished by cutting. Since the length of the tool used when cutting the inside of the hollow shaft 20 is limited, the distances L1 and L2 (see FIG. 2) from the both end faces 20T1 and 20T2 of the hollow shaft 20 to the disk-like member 22 are: It is set to a size that can be cut with a cutting tool. The size that can be cut with a cutting tool is 150 mm or less, preferably 100 mm or less.

  As shown in FIG. 2, stepped portions 26 </ b> A and 26 </ b> B for attaching bearings 13 </ b> A and 13 </ b> B are provided at both ends of the hollow shaft 20. A positioning member 27 for positioning and fixing the rotor 12 is provided on the outer peripheral portion of the hollow shaft 20. In the present embodiment, the positioning member 27 protrudes from the outer peripheral surface of the side portion 21 and is formed in an annular shape toward the circumferential direction of the hollow shaft 20. Further, a sun gear shaft 30 to be described later is inserted into the disk-shaped member 22 of the hollow shaft 20, and a hole 23 to be attached is formed. The hole 23 is formed so that the center thereof coincides with the rotation axis Zr of the hollow shaft 20.

  As shown in FIG. 1, the space inside the hollow shaft 20, more specifically, the space formed by the side portion 21 of the hollow shaft 20 and the disk-shaped member 22, and the space on the rotor 12 side, A reduction gear 50 is arranged. Thus, when the speed reducer 50 is arranged inside the hollow shaft 20, the size of the in-wheel motor 1 in the direction of the rotation axis Zr can be reduced. Here, the space in which the reduction gear 50 is arranged makes the distance L1 from the end surface 20T1 of the hollow shaft 20 to the disc-like member 22 larger than the dimension of the reduction gear 50 in the rotation axis Zr direction. Preferably, the distance L1 is 1.2 times or more the dimension of the reduction gear 50 in the direction of the rotation axis Zr. If it does in this way, the reduction gear 50 can be reliably arrange | positioned inside the hollow shaft 20, and the dimension increase of the motor 10 in the rotating shaft Zr direction can be suppressed. The dimension in the rotation axis Zr direction of the reduction gear 50 is a dimension in the rotation axis Zr direction of the reduction gear 50 from a carrier 53 to a ring gear 52 described later.

  The reduction gear 50 is a reduction gear using a planetary gear device. The reduction gear device 50 includes four elements, which are a sun gear 31, a planetary gear 51, a ring gear 52, and a carrier 53, as rotational elements. A plurality of planetary gears 51 are arranged around the sun gear 31 and mesh with the sun gear 31. The ring gear 52 is disposed outside the plurality of planetary gears 51 and meshes with each planetary gear 51. The carrier also supports the plurality of planetary gears 51 so as to be rotatable.

  In the present embodiment, the sun gear 31 that is the rotating element of the reduction gear 50 is provided at the first end 30T1 of the sun gear shaft 30 that is the power transmission means. Note that the rotation element of the reduction gear 50 provided at the first end of the power transmission means is not limited to the sun gear 31, but when it is desired to increase the reduction ratio, the rotation element is provided at the first end of the power transmission means. The rotating element of the reduction gear 50 provided is preferably the sun gear 31.

  The second end 30T2 of the sun gear shaft 30 is attached by being inserted into a hole 23 (see FIG. 2) formed in the disk-like member 22 of the hollow shaft 20 constituting the motor 10. Between the second end 30 </ b> T <b> 2 and the disk-like member 22, a rotation restricting portion that restricts the rotation of the sun gear shaft 30 relative to the disk-like member 22 is provided. In the present embodiment, the rotation restricting portion is constituted by a spline formed at the second end 30T2 of the sun gear shaft 30 and a spline groove formed at the hole 23 of the disk-like member 22. Further, the second end 30 </ b> T <b> 2 side of the sun gear shaft 30 is connected to the fixing member 40 via the full screw 5. The fixing member 40 is fixed to the disk-like member 22 of the hollow shaft 20.

  With such a configuration, the sun gear 31 transmits the rotational force of the motor 10, that is, the rotational force of the rotor 12 from the hollow shaft 20 to the reduction gear 50. When the wheel on which the in-wheel motor 1 is mounted generates a braking force, the braking force is transmitted to the hollow shaft 20 via the sun gear shaft 30.

  In the present embodiment, the ring gear 52 of the reduction gear 50 is attached and fixed to the fourth housing 2D by the bolt 4. The carrier 53 is connected to the drive shaft 60 of the in-wheel motor 1. As a result, the rotational force of the motor 10 is increased via the reduction gear 50 and output to the drive shaft 60. Here, the sun gear 31 and the carrier 53 rotate around a common rotation axis Zr (rotation axis of the reduction gear 50). The drive shaft 60 also rotates about the rotation axis Zr. Since the rotation axis Zr is the rotation axis of the motor 10, that is, the rotation axis of the rotor 12 and the hollow shaft 20, the sun gear 31, the carrier 53, the drive shaft 60, the rotor 12, and the hollow shaft 20 are all common. Rotates about the rotation axis Zr.

  The drive shaft 60 is attached to the hub inner ring 61. The hub inner ring 61 is rotatably supported by the fourth housing 2D via the bolt 6 and the hub outer ring 62 via the rolling element 63. A hub bolt 64 is attached to the hub inner ring 61. The wheel of the wheel is attached to the hub inner ring 61 via a hub bolt 64. With such a configuration, the output of the motor 10 is transmitted to the wheels via the speed reducer 50, the drive shaft 60, and the hub inner ring 61 to rotate the wheels.

  The sun gear shaft 30 is formed with a sun gear 31 at the first end 30T1, and the second end 30T2 is inserted and attached to the disk-like member 22 constituting the hollow shaft 20. Thus, the sun gear shaft 30 is configured as a separate member from the hollow shaft 20. Here, when the sun gear shaft 30 and the hollow shaft 20 are configured integrally, the first end portion 30T1 of the sun gear shaft 30 is located inside the hollow shaft 20, so that the processing for forming the sun gear 31 is very difficult. Further, the process of forming the sun gear shaft 30 on the hollow shaft 20 also takes time.

  However, the sun gear 31 can be easily processed with a hobbing machine or the like by configuring the hollow shaft 20 and the sun gear shaft 30 as separate members as in this embodiment. The hollow shaft 20 can also be manufactured by cutting a member formed into a cup-like rough shape. In this way, by forming the hollow shaft 20 and the sun gear shaft 30 as separate members, each processing becomes easy. As a result, manufacture of the in-wheel motor 1 becomes easy. Further, since it is not necessary to consider the space required for processing the sun gear shaft 30, an increase in the size of the sun gear shaft 30 in the direction of the rotation axis Zr can be suppressed. As a result, an increase in the size of the in-wheel motor 1 in the direction of the rotation axis Zr. Can be suppressed. Next, the mounting structure of the sun gear shaft 30 and the sun gear shaft 30 and the disc-like member 22 will be described.

  As shown in FIG. 1, the sun gear shaft 30 includes a first end 30T1 where the sun gear 31 is formed, a second end 30T2 attached to the disc-like member 22, a first end 30T1, and a second end. It is comprised by the intermediate part 32 which connects 30T2. As shown in FIG. 3A, the second end portion 30T2 of the sun gear shaft 30 is formed with a step portion 35 (power transmission means side step portion). As a result, a large outer diameter portion 30T21 and a small outer diameter portion 30T2s are formed at the second end 30T2 of the sun gear shaft 30.

  As illustrated in FIGS. 3A and 4, the spline 33 is formed in the large outer diameter portion 30T2l of the second end portion 30T2. In the present embodiment, as shown in FIG. 3A, the tooth root diameter 2 × r1 of the spline 33 is larger than the tooth tip diameter 2 × r2 of the sun gear 31. Here, r1 is the root radius of the spline 33, and r2 is the tooth tip radius of the sun gear 31. Thereby, the spline 33 can be easily processed.

  The intermediate portion 32 of the sun gear shaft 30 is preferably substantially tapered so that the diameter gradually increases from the first end 30T1 toward the second end 30T2. Thereby, the stress concentration in the intermediate portion 32 can be reduced. In the present embodiment, it is not excluded that the intermediate portion 32 has a stepped shape.

  As illustrated in FIGS. 3A and 4, a screw hole 34 is formed in the end surface 30 </ b> P of the second end 30 </ b> T <b> 2 of the sun gear shaft 30. As shown in FIGS. 1 and 4, the entire screw 5 is screwed into the screw hole 34. The entire screw 5 protrudes from the end face 30 </ b> P after being screwed into the screw hole 34. And the fixing member 40 mentioned later is screwed in all the screws 5 which protruded from the end surface 30P, and the sun gear shaft 30 and a fixing member are connected. For this reason, the length of the entire screw 5 is larger than the depth of the screw hole 34 and is necessary for reliably connecting the sun gear shaft 30 and the fixing member 40 after the entire screw 5 is screwed into the screw hole 34. It is set so that the protruding length of all the screws 5 can be secured.

  As shown in FIG. 3-2, the hole 23 formed in the disk-like member 22 of the hollow shaft 20 is a stepped hole having a step portion 25 (disk-like member side step portion). As described above, the hole 23 includes the large inner diameter portion 23L and the small inner diameter portion 23S. The small inner diameter portion 23S of the hole 23 is formed with a spline groove 24 that fits with the spline 33 formed at the second end 30T2 of the sun gear shaft 30. Since the spline groove 24 is formed only in the small inner diameter portion 23S of the hole 23, it can be easily formed by broaching.

  When the sun gear shaft 30 is attached to the disk-shaped member 22, the spline 33 of the sun gear shaft 30 is inserted into and fitted into the spline groove 24 of the disk-shaped member 22. As a result, the relative rotation between the sun gear shaft 30 and the disk-shaped member 22 is restricted, so that a rotational force can be transmitted between the disk-shaped member 22 and the sun gear shaft 30. As a result, the rotational force of the rotor 12 is transmitted to the reduction gear 50 via the sun gear shaft 30.

  As described above, the spline 33 formed at the second end 30T2 of the sun gear shaft 30 and the spline groove 24 formed in the hole of the disk-shaped member 22 constituting the hollow shaft 20 according to the present embodiment. It becomes a rotation restricting part. The rotation restricting portion is not limited to the spline 33 and the spline groove 24. For example, a key and a key groove may be used. However, it is preferable to use the spline 33 and the spline groove 24 because the torque that can be transmitted between the disk-shaped member 22 and the sun gear shaft 30 can be increased.

  As shown in FIGS. 1 and 4, the fixing member 40 is attached to the second end 30 </ b> T <b> 2 side of the sun gear shaft 30. The fixing member 40 is attached to the second end 30T2 side of the sun gear shaft 30 from the side opposite to the speed reduction device 50 with respect to the disk-like member 22. As shown in FIG. 4, the fixing member 40 is formed with a through hole 44 centered on the rotation axis Zr. A female screw 44S into which all the screws 5 are screwed is formed on the through hole 44 on the side where the sun gear shaft 30 is attached.

  As shown in FIG. 4, the fixing member 40 has a protrusion 41 on the side facing the disc-like member 22, that is, on the mounting side of the sun gear shaft 30. The protrusion 41 is formed in an annular shape around the rotation axis Zr. The protrusion 41 is between the step 35 (FIG. 3A) provided at the second end 30T2 of the sun gear shaft 30 and the step 25 (FIG. 3-2) provided in the hole of the disc-like member 22. Intervene in. Then, the protrusion 41 positions the sun gear shaft 30 and the disk-shaped member 22 so that the center of the sun gear shaft 30 and the center of the disk-shaped member 22 coincide.

  As shown in FIG. 5, the fixing member 40 includes a plurality of bolt through holes 42 penetrating in parallel with the through holes 44. The bolts 43 are respectively inserted into the bolt through holes 42, screwed into the screw holes 21 </ b> H provided in the disk-shaped member 22 of the hollow shaft 20, and fastened to fix the fixing member 40 to the disk-shaped member 22. As a result, the sun gear shaft 30 is fixed to the disk-like member 22 via the entire screw 5 and the fixing member 40.

  In the present embodiment, with such a configuration, the fixing member 40 positions the sun gear shaft 30 in the direction of the rotation axis Zr and fixes the sun gear shaft 30 so as not to move in the direction of the rotation axis Zr. The fixing member 40 receives a force (axial force) in the direction of the rotation axis Zr generated by using a helical gear for the sun gear 31. When a spur gear is used as the sun gear 31, almost no axial force is generated, but the fixing member 40 is necessary for positioning and fixing the sun gear shaft 30 in the direction of the rotation axis Zr.

  In the present embodiment, the rotational force between the hollow shaft 20 and the sun gear shaft 30 is transmitted by the spline 33 and the spline groove 24 (rotation restricting portion), and the axial force is transmitted by the disk-shaped member 22 via the fixing member 40. receive. As described above, in this embodiment, the rotational force and the axial force generated when the motor 10 rotates are shared by the spline 33, the spline groove 24, and the fixing member 40, respectively. Thereby, compared with the case where the fixing member 40 receives the rotational force and the axial force alone, the force that the fixing member 40 bears is reduced, so that the fixing member 40 can be downsized.

  In the present embodiment, the fixing member 40 is a disk-shaped structure, but the shape of the fixing member is not limited to this. For example, a plurality of arms having protrusions interposed between the step portion 35 (FIG. 3A) of the sun gear shaft 30 and the step portion 25 (FIG. 3-2) provided in the hole of the disc-like member 22 are provided. Further, it may be formed radially from a hole in which the female screw 44S into which the entire screw 5 is screwed is formed. Next, a method for attaching the sun gear shaft 30 to the disc-like member 22 (a method for manufacturing the in-wheel motor according to the present embodiment) will be described.

  First, the full screw 5 is screwed into the hole 34 of the sun gear shaft 30. Next, the spline 33 formed at the second end 30T2 of the sun gear shaft 30 is inserted into the spline groove 24 formed in the hole 23 of the disk-like member 22 constituting the hollow shaft 20, and the two are fitted together. . Alternatively, the full screw 5 may be screwed into the hole 34 of the sun gear shaft 30 after the spline 33 is inserted into the spline groove 24.

  By the above procedure, the sun gear shaft 30 in which the entire screw 5 protrudes from the end face 30P (see FIGS. 3A and 3B) of the second end 30T2 of the sun gear shaft 30 is inserted into the hole 23 of the disk-like member 22. It becomes a state. In this state, the sun gear shaft 30 and the disk-shaped member 22 are not fixed, so that the sun gear shaft 30 can move in the direction in which the hole 23 passes. Next, the entire screw 5 is screwed into the female screw 44 </ b> S formed in the through hole 44 of the fixing member 40.

  Next, as shown in FIG. 5, the fixing member 40 is fixed to the disk-like member 22 of the hollow shaft 20 with bolts 43. At this time, it is necessary to match the position of the bolt through hole 42 formed in the fixing member 40 with the position of the screw hole 21H formed in the disk-like member 22. When the position of the bolt through hole 42 and the position of the screw hole 21H do not match and the bolt 43 cannot be screwed into the screw hole 21H via the bolt through hole 42, the direction in which the fixing member 40 is separated from the disk-shaped member 22 The sun gear shaft 30 is pulled out and the fitting between the spline 33 of the sun gear shaft 30 and the spline groove 24 of the disk-like member 22 is released.

  Then, the fixing member 40 is rotated in the circumferential direction of the disk-like member 22 within the range of the pitch of the spline 33 and the spline groove 24, and the position of the bolt through hole 42 and the position of the screw hole 21H are roughly matched. Since the subsequent adjustment is an angle within one pitch of the spline 33 and the spline groove 24, fine adjustment is made by the screwing amount of the fixing member 40 with respect to all the screws 5. Therefore, as shown in FIG. 6, there is a slight gap between the end surface 30P of the second end 30T2 of the sun gear shaft 30 and the surface (sun gear shaft facing surface) 40P of the fixing member 40 facing the sun gear shaft 30. c1 needs to be formed.

  For this reason, as shown in FIG. 6, the surface (disk-shaped member facing surface) 40P1 facing the disk-shaped member 22 of the fixing member 40 and the surface (fixing member) facing the fixing member 40 of the disk-shaped member 22 A gap c1 is formed between the end surface 30P and the sun gear shaft facing surface 40P2 in a state where the facing surface) 22P is in contact therewith. The size of the gap c <b> 1 only needs to be such that the distance between the fixing member 40 and the sun gear shaft 30 approaches by fine adjustment of the fixing member 40. This fine adjustment is theoretically a rotation within one pitch of the spline 33 and the spline groove 24. Therefore, the clearance c1 may be the amount by which the fixing member 40 moves by one pitch of the spline 33 and the spline groove 24, but there is a certain margin. Therefore, it is preferable to set larger than this.

  In addition, as shown in FIG. 6, if the gap c <b> 2 is not formed between the protrusion 41 of the fixing member 40 and the disk-like member 22 and the sun gear shaft 30, the fixing member 40 is separated from the disk-like member 22. It will float. Therefore, a gap c2 is formed between the protrusion 41 and the step portion 35 of the sun gear shaft 30 in a state where the disk-shaped member facing surface 40P1 and the fixing member facing surface 22P are in contact with each other. A gap c <b> 3 is formed between the stepped portion of the disk-like member 22. In the present embodiment, the dimensions of the respective parts are set so that the gaps c1, c2, and c3 are formed in a state where the disk-like member facing surface 40P1 and the fixed member facing surface 22P are in contact with each other.

  When the bolt 43 can be screwed into the screw hole 21H through the bolt through hole 42 by the adjustment described above, the bolt 43 is tightened and the fixing member 40 is fixed to the disk-like member 22. Thereafter, the bearings 13A, 13B and the like are assembled and incorporated into the housing 2, whereby the in-wheel motor 1 is completed. Thus, before fixing the fixing member 40 to the disk-shaped member 22, the position of the bolt through hole 42 and the screw hole 21H is adjusted by adjusting the positional relationship between the fixing member 40 and the disk-shaped member 22. Can be matched. In this embodiment, the spline 33 and the spline groove 24 are used as a rotation restricting portion, and the sun gear shaft 30 and the fixing member 40 are connected by all bolts 5 so that the bolt through hole 42 and the screw hole 21H can be easily positioned. Can be adapted to This facilitates the assembly of the sun gear shaft 30 and the disk-shaped member 22, so that the in-wheel motor 1 can be easily assembled.

  In the adjustment described above, it is necessary to remove the fixing member 40 from the disk-shaped member 22. For this reason, when the projection 41 of the fixing member 40 is interposed between the step 35 provided at the second end 30T2 of the sun gear shaft 30 and the step 25 provided in the hole of the disc-like member 22, As shown in FIG. 6, a certain amount of gap t is required. The gap t is set to a certain extent so that the center of the sun gear shaft 30 and the center of the disc-like member 22 can be centered. That is, for the fitting between the two, a so-called clearance fit can be set to, for example, H7g6.

  The settable range of the modules and the number of teeth of the spline 33 and the spline groove 24 is determined from the adjustment amount of the positional relationship between the fixing member 40 and the disk-like member 22 and the magnitude of the transmission torque. Considering the pitch of the entire screw 5 and the clearance c1 between the end surface 30P of the sun gear shaft 30 and the sun gear shaft facing surface 40P2, the adjustment by screwing the fixing member 40 into the entire screw 5 may be about ± 5 degrees. preferable. That is, the number of teeth of the spline 33 and the spline groove 24 is about 36 teeth.

  Further, as described in detail, it is preferable that the root diameter of the spline 33 is larger than the tooth tip diameter of the sun gear 31. This is because the processing of the sun gear shaft 30 is taken into consideration. May be slightly larger than the tooth tip diameter of the sun gear 31. Therefore, if the dimensions of the sun gear 31 are determined, the dimensions of the spline 33 and the spline groove 24 are also substantially determined, so an appropriate number of teeth and a combination of modules are selected from the standard series. At this time, since the minimum value of the module is determined from the transmission torque of the spline 33 and the spline groove 24 and the surface pressure of the spline 33 and the spline groove 24, the module or more is selected.

  Considering these, the specifications of the spline 33 and the spline groove 24 are 0.75 to 1.5 for the module and 30 to 40 for the number of teeth. In addition, the transmission torque in this case is a transmission torque at the time of assuming the in-wheel motor 1 applicable to the passenger vehicle whose vehicle mass is about 1000 kg to 1200 kg.

  As described above, the rotational force of the rotor 12 is transmitted to the sun gear shaft 30 via the disk-like member 22 of the hollow shaft 20. Here, as shown in FIG. 1, the disk-like member 22 is preferably disposed between a pair of bearings 13 </ b> A and 13 </ b> B that support the hollow shaft 20. That is, as shown in FIG. 2, it is preferable to arrange the disk-shaped member 22 between the step portions 26A and 26B for attaching the bearings 13A and 13B.

  Here, in order to form the step portions 26A and 26B, the thickness of the side portion 21 of the hollow shaft 20 is thin at the portions of the step portions 26A and 26B (portion indicated by H in FIG. 2) and can be transmitted. Torque is limited. When the disk-shaped member 22 is disposed between the pair of bearings 13A and 13B, the rotational force of the rotor 12 is a disk before passing through a portion where the thickness of the side portion 21 is reduced (portion indicated by H in FIG. 2). Since it is transmitted to the shaped member 22, it is possible to avoid the limitation of the transmission torque by forming the step portions 26A and 26B. For this reason, the thickness of the step portions 26A and 26B can be further reduced by the amount that the torque transmission need not be taken into account, so that the weight of the hollow shaft 20 can be reduced.

  As described above, in this embodiment, since the hollow shaft and the power transmission means on which the gear is formed are separate members, the processing of the hollow shaft and the power transmission means is facilitated. Further, the power transmission means and the disk-shaped member of the hollow shaft are connected via a rotation restricting portion, and the power transmission means is fixed to the disk-shaped member via a fixing member. As a result, the rotational force and the axial force can be shared and received by the rotation restricting portion and the fixing member, respectively, so that it is possible to avoid a large burden from acting on one side. Furthermore, the spline fitting is used for the rotation restricting part, and the power transmission means and the fixing member are connected with all bolts. The rough adjustment is done by shifting the spline fitting, and the fine adjustment is about the screwing of the fixing member. It can be adjusted by changing. As a result, the positioning of the fixing member and the disk-shaped member is facilitated, so that the assembly of the power transmission means and the disk-shaped member 22 is facilitated and the assembly of the in-wheel motor is facilitated.

  As described above, the in-wheel motor and the manufacturing method thereof according to the present invention are useful for the structure in which the reduction gear is disposed inside the rotor.

DESCRIPTION OF SYMBOLS 1 In-wheel motor 2 Case 3, 4, 6, 43 Bolt 5 All bolt 10 Motor 11 Stator 12 Rotor 13A, 13B Bearing 20 Hollow shaft 21 Side part 21H, 23, 34 Hole 22 Disc-shaped member 24 Spline groove 25, 26A, 26B, 35 Stepped portion 30 Sun gear shaft 30T1 First end portion 30T2 Second end portion 31 Sun gear 33 Spline 40 Fixing member 41 Projection portion 42 Bolt through hole 44 Through hole 44S Female screw 50 Reduction gear 51 Planetary gear 52 Ring gear 53 Carrier 60 Drive shaft 61 Hub inner ring 62 Hub outer ring 63 Rolling element

Claims (10)

In-wheel motor
A cylindrical hollow shaft attached to the inner circumference of the rotor and rotatably supported by the housing of the in-wheel motor via a bearing;
A disk-shaped member provided inside the hollow shaft and partitioning the inside of the hollow shaft with respect to the rotation axis direction of the hollow shaft;
A reduction gear disposed in a space formed by a side portion of the hollow shaft and the disk-shaped member;
A power transmission means, wherein a rotating element constituting the speed reducer is provided at the first end, and the second end is inserted and attached to a hole provided in the disk-like member;
A rotation restricting portion that is provided between the second end portion and the disk-shaped member and restricts the rotation of the power transmission means with respect to the disk-shaped member;
A fixing member attached to the second end side of the power transmission means and the disk-shaped member from the opposite side to the speed reduction device with respect to the disk-shaped member;
An in-wheel motor comprising:   2. The in-wheel motor according to claim 1, wherein the rotation restricting portion includes a spline formed at a second end portion of the power transmission unit and a spline groove formed in the hole of the disk-shaped member. .   The in-wheel motor according to claim 2, wherein a tooth root diameter of the spline is larger than a tooth tip diameter of the sun gear.   4. The in-wheel motor according to claim 2, wherein the module of the spline is 0.75 to 1.5 and the number of teeth of the spline is 30 to 40. 5. The fixing member has a protrusion on the side facing the disk-shaped member,
The projection is fitted into a power transmission means side step formed on the second end side of the power transmission means and a disk-shaped member side step formed on the fixing member side of the hole. Item 5. The in-wheel motor according to any one of Items 1 to 4.   The distance between the disk-shaped member and the end surface of the hollow shaft on the side where the reduction gear is disposed is larger than the dimension in the rotation axis direction of the reduction gear and is 150 mm or less. The in-wheel motor according to item 1.   The in-wheel according to claim 6, wherein a distance between the disk-shaped member and the end surface of the hollow shaft on a side where the speed reduction device is disposed is 1.2 times or more a dimension in a rotation axis direction of the speed reduction device. motor.   The in-wheel motor according to any one of claims 1 to 7, wherein the hollow shaft is supported by a pair of bearings, and the disk-shaped member is disposed between the pair of bearings. The disk-shaped hollow shaft is provided with a rotor on the outer periphery and a disk-shaped member having spline grooves formed therein, and is rotatably supported by a housing of an in-wheel motor via a bearing. A step of inserting a spline of a sun gear shaft in which a sun gear is provided at a first end and a spline is formed at a second end of the member and a full screw is screwed into the spline groove of the disk-shaped member;
Screwing a fixing member that connects the sun gear shaft and the disk-shaped member to the screw;
Fixing the fixing member to the disk-shaped member;
The manufacturing method of the in-wheel motor characterized by including.   Before fixing the fixing member to the disk-shaped member, the sun gear shaft is pulled out to the fixing member side, and the positional relationship between the fixing member and the disk-shaped member in the circumferential direction of the disk-shaped member is determined. The manufacturing method of the in-wheel motor of Claim 9 which has the procedure to adjust.

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