JPH04185532A - Wheel motor with decelerator - Google Patents

Abstract

PURPOSE:To stabilize motor performance by disposing a decelerator at the hollow part of a flat hollow rotor, shortening the length in the axial direction, supporting the rotor so as to rotate freely at two points, a thin wall part, provided at one end part of the motor, and the end part on the reverse side. CONSTITUTION:An electric motor 20 having a hollow rotor 23 is housed in a case main body 10, while the hollow part of the rotor 23 houses a planetary decelerator 30 therein. The stator 21 of the motor 20 is force-fixed to the inner wall of the housing 12 and a coil 22 is wound therearound. The rotor 23 is provided at its one end with a thin wall part 26 protruding from a permanent magnet 24 in the axial direction, and supported so as to rotated freely at the tin wall part 26 and both ends thereof. An arrangement is made such that in assembling the rotor 23 by inserting it from the left side it is guided from the foremost end of a ring gear 31.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a wheel motor with a reduction gear used in an electric vehicle.

[Conventional technology]

In recent years, electric vehicles have been actively developed from the viewpoint of environmental issues. Electric vehicles that have been developed so far include systems in which the motor is replaced with a conventional engine and connected to a crankshaft, or the motor is connected to a pair of front or rear power transmission shafts, or each wheel is driven separately. Another method uses a wheel motor with a reduction gear, which connects and drives a motor via a reduction gear. Among these, as an example of the latter type of wheel motor with a reduction gear, one has been proposed in which a reduction gear is disposed in the wheel toward the outside of the motor body to obtain a desired reduction ratio (Japanese Patent Laid-Open No. 62 -175217)). This wheel motor with a speed reducer is used in mining dump trucks and the like, and is usually used with double tires (two tires). Therefore, there were not many restrictions on the overall length of the drive mechanism.

[Problem to be solved by the invention]

However, when trying to apply the structure of the wheel motor with reducer to a general vehicle, since there is only one wheel, the motor part protrudes from the wheel, causing damage to the motor part when the wheel comes off the wheel, or when the vehicle is running. However, problems such as stones flying around and hitting the motor part may cause damage. Furthermore, in a wheel motor with a reduction gear, it is necessary to prevent the vehicle body, the motor, and the reduction gear from interfering with each other when the wheels move up and down or turn. Therefore, the installation space for the motor and reducer is limited. Therefore, in order to arrange the motor and the speed reducer within the restricted space, it is required to reduce the size of these as much as possible. Furthermore, in an electric vehicle, in order to obtain high output relative to the vehicle weight, the output torque must be increased considerably even though the motor is made smaller and lighter. In order to meet each of the above requirements, the gap between the rotor and stator is made as narrow as possible, and high-performance permanent magnets are attached to the rotor. However, in such a motor, there is a problem that when the rotor is assembled into the housing, the rotor is attracted to the stator due to the strong attraction force, and the surface of the permanent magnet is scratched or damaged by the impact generated at that time. Therefore, in order to prevent such accidents, a special jig is required to suppress the attraction force of the permanent magnets and the amount of eccentricity during insertion, and to smoothly insert the rotor. The present invention is intended to solve the above-mentioned problems, and aims to provide a wheel motor with a reducer that can shorten the overall length, be compact, obtain high output, and have a simple rotor assembly. .

[Means to solve the problem]

To this end, the present invention provides a stator fixed to the case side,
A hollow cylindrical rotor supported by bearings on the case side.
The output flange is supported by a bearing on the case side and the wheel is attached to it, the input gear is supported on the rotor side, the output gear is supported on the output flange side, and the wheel is equipped with a reduction gear that is installed in the hollow part of the rotor. In the motor, a thin-walled portion is provided at the end of the rotor, and the rotor is configured to be rotatably supported by bearings at two points on both axial ends of the thin-walled portion and the end opposite to the thin-walled portion, and
The bearing is installed from the tip of the case side extension at a position that is at least the opposite width of the rotor and stator, and when the rotor is assembled, the rotor is guided from the tip of the case side extension via the bearing. shall be.

[Action and effects of the invention]

By employing a hollow rotor and arranging a speed reduction mechanism in the hollow portion as described above, the rotor can be flattened and its overall length can be shortened. When assembling the rotor, the rotor is guided from the tip of the case-side extension via the bearing, so a simple jig can prevent the permanent magnets from adhering to the stator, allowing smooth installation. The rotor can be assembled into the housing.

【Example】

Examples will be described below with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of a wheel motor with a reduction gear according to the present invention. In FIG. 1, the case body 10 has a two-part structure consisting of a cylindrical support-side housing 11 and a wheel-side housing 2, both of which are fixed with bolts (not shown). Furthermore, the support side housing 11 is fixed to a side opposite to the wheel side housing I2 with a plate 13 and a cover 14 with bolts (not shown), and is fixed to the port 61 with bolts 62. Further, an oil pump motor 16 is provided at the bottom, and oil is circulated and cooled from an oil reservoir 18 at the bottom through an oil passage formed between the plate 13 and the cover 14. moreover,
A large number of cooling fins 15 and heat vibes 17 are provided on the outer peripheral surface of the cover 14 to cool the oil. An electric motor 20 having a flattened and hollow rotor 23 is housed inside the case body IO, and a planetary gear reduction gear 3o is housed in the hollow portion of the rotor 23. A stator 21 of the electric motor 20 is press-fitted and fixed to the inner wall of the housing 12, and a coil 22 is wound around the stator 21. The rotor 23 of the electric motor 20 is composed of a hollow iron core, and a permanent magnet 24 is fixed to the outer periphery with a holding band 25, and a thin-walled part 26 protruding from the permanent magnet 24 in the axial direction is provided at one end of the rotor 23. It is rotatably supported at the thin wall portion 26 and both ends on the opposite side thereof. In the illustrated example, one end is supported by a pole bearing 41 on the housing 11 side, the other end is supported by a ball bearing 42 on the ring gear 31 side of the planetary gear reduction device 30, and the ring gear of the planetary gear reduction device 30 is supported by a ball bearing 42. 3
1 is press-fitted into the housing 12 and fixed with bolts. I want ring gear 31 or ball bearing 4.
2 also serves as the side of the housing I2 that supports the thin walled portion 26, and the pole bearing 42 is attached from the tip thereof at a position that is equal to or larger than the facing width of the rotor 23 and the stator 21. When the rotor 23 is inserted and assembled from the left side in the figure, the rotor 23 is guided by the tip of the case side extension, that is, the tip of the ring gear 31 via the ball bearing 42. Therefore, the outer periphery of the ring gear 31, which serves as the guide surface, is provided with a step in the middle and has a slightly smaller diameter on the tip side. Further, the sun gear 33 of the planetary gear reduction device 30 is supported by a ball bearing 43 on the housing 11 side, and is spline-fitted into the hollow inside of the rotor 23. The pinion shaft 34 is connected to an output carrier 51 that serves as an output rotating shaft, and the pinion gear 32 is
It is rotatably supported by the pinion shaft 34 by a needle bearing 45, and is disposed so as to always mesh with the ring gear 31 and sun gear 33. The output flange 52 is connected to the output carrier 5
A double-row angular bearing 44 is spline-fitted to the outer periphery of the ring gear 1 and fixed so as not to be movable in the axial direction by a nut 53, and is engaged with the pinion gear 32 of the ring gear 31.
Supported by A brake disc plate 56 is spline-fitted to this output flange 52, and a wheel 5 holding a tire 55 is fitted to the output flange 52.
Attaches with 4 bolts and nuts. The support 61 is a cylindrical member having external teeth on the upper part, and is rotatably supported by the knuckle 63 by an angular bearing 46 and a nut 64, so that thrust force is supported. Furthermore, a cover internal 66 is fixed to this knuckle 63 with bolts. An internal gear 65 having internal teeth is fixed to the steering lever 67 by bolts, and is rotatably supported by a cover internal 66 by a ball bearing 47 and a needle roller bearing 48. Gears 65 are disposed to mesh with each other, forming a speed increasing gear. When the internal gear 65 rotates as the lever 67 is steered in this manner, the rotation angle is amplified by, for example, twice, and the support 61 also rotates. The ring gear 31 is fixed to the housing 12 as described above, and the output flange 52 and the output carrier 51 are supported by the double-row angular bearing 44 inside thereof, and the rotor 23 of the electric motor 20 and the sun gear of the planetary gear reduction device 30 are 33 is spline-fitted, so that the inclination of the shaft due to misalignment of the double-row angular bearing 44 can be eliminated, and the concentricity of the planetary gear reduction device 30 can be improved. In addition, since the planetary gear reduction device 30 is arranged using the hollow part of the rotor 23, the length in the axial direction can be shortened, making it flat and compact, enabling high-speed rotation and improving acceleration and deceleration performance. can. In this case, the rotor is flat and has a large diameter (
Therefore, even if two points are supported, the support interval will be shortened,
The effect of misalignment between the housings is likely to occur, and the inclination of the rotor causes variations in the distance between the stator and rotor magnets, resulting in variations in torque characteristics. To solve this problem, in the present invention, a thin wall part is provided next to the rotor, and the rotor is supported at two points near the outer circumference of the rotor at both ends, so that the diameter of the support part can be increased. Furthermore, the concentricity can be improved, and the inclination of the rotor and fluctuations in the gap between the rotor and the stator can be reduced. Therefore, variations in performance due to the shape of the rotor can be eliminated. Next, the procedure for assembling the rotor will be explained. FIG. 2 is a diagram showing the respective configurations of the stator side and the rotor side, and FIG. 3 is a diagram for explaining the procedure for assembling the rotor. First, before assembling the rotor, on the one hand, as shown in Figure 2 (
As shown in a), a ring gear 31 and a stator 21 are press-fitted into the housing 12, and inside thereof a pinion gear 32, a double-row angular bearing 44, an output carrier 51. The output flange 52 and the like are assembled. On the other hand, as shown in FIG.
etc. will be incorporated. After that, as shown in FIG. 3(a), using the assembly jig 71 for attaching the housing 12 and the assembly jig 72 for attaching the rotor alignment, attach the bolts 74 and 73 to the respective assembly jigs 71 and 72. The assembly jig 7 is installed by attaching the housing I2 and rotor alignment and tightening the bolts 75.
2 to the housing 12. When the bolt 75 begins to be tightened, the ball bearing 42 attached to the thin wall portion 26 of the rotor 23 comes into contact with the tip of the ring gear 31 to guide the rotor 23, as shown in FIG. At this point, the permanent magnets 24 of the rotor 23 are still at a position where they do not face the stator, and the sun gear and pinion gear have not yet engaged. When the bolts 75 are further tightened, the permanent magnets 24 and the stator 21 overlap as shown in FIG. Since the rotor 23 is supported at two contact points between the assembly jig 71 and the bolts 75, contact between the permanent magnets 24 and the stator 21 must be avoided by the clearance between the permanent magnets 24 and the stator 21. Then, as shown in the same figure (C1), the sun gear 31 and pinion gear 32 are engaged with each other, and the rotor 23 is inserted into the housing 1.
Completely assembled into 2. Note that the present invention is not limited to the above embodiments, and various modifications are possible. For example, in the above embodiment, one of the ring gear and the sun gear is used as the input gear, but other combinations may be used. Furthermore, although the planetary gear reduction device is provided as a reduction device in the hollow portion of the rotor, other reduction devices may be provided. As is clear from the above description, according to the present invention, since a flat hollow rotor is employed and a speed reduction device is disposed in the hollow portion, the length in the axial direction can be shortened. Therefore, even when applied to single-tire general vehicles, it does not protrude significantly, and it is possible to prevent damage to the motor caused by stones that are thrown when the wheels come off the wheels or while driving. In addition, a thin wall is provided at the end of the rotor, and bearings are placed between the thin wall and the opposite end of the rotor to sandwich it from both sides, thereby supporting the rotor at two points so that it can rotate freely. , changes in the gap between the stator and rotor can be suppressed, and motor performance can be stabilized. Then, an extension part of the housing is provided on this thin-walled part side, and the rotor is guided by a bearing along this extension part and assembled, so that the permanent magnet of the rotor and the iron core of the stator are attracted to each other during assembly. The force can be used to prevent the permanent magnets from coming into contact with the stator, thereby preventing damage to the permanent magnets. Furthermore, since the gap between the rotor and the stator can be narrowed, the output performance of the motor can be improved and stabilized.

[Brief explanation of drawings]

[FIG. 1] FIG. 1 is a sectional view showing one embodiment of a wheel motor with a reduction gear according to the present invention. FIG. 2 is a diagram showing the respective configurations of a stator side and a rotor example.

[Figure 3] The diagram is for explaining the procedure for assembling the rotor.

[Explanation of symbols]

10... Case body 16... Oil pump motor 17... Heat vibrator 20... Motor 30... Planetary gear reduction gear 51... Output carrier 52... Output flange 54... Wheel 55...Tire 61...Support 63...Knuckle 65...Internal gear 66...Cover internal 67...Lever Applicant: Aisin AW Duburi Ni Co., Ltd. Agent: Patent attorney A Department Ryukichi (7 others) Nagi 2 (a) 恢恢

Claims (1)

[Claims] Claim 1: A stator fixed to the case side, a hollow cylindrical rotor supported by bearings to the case side, an output flange supported by bearings to the case side and to which a wheel is attached, an input gear supported by the rotor side and an output. In a wheel motor with a speed reducer, which has an output gear supported on the flange side and a speed reduction mechanism disposed in a hollow part of the rotor, a thin walled part is provided at the end of the rotor, and a shaft between the thin walled part and the opposite end is provided. The rotor is configured to be rotatably supported by bearings at two points at both ends in the direction, and the bearing mounting position from the tip of the extension on the case side is at least the opposite width of the rotor and stator, so that when the rotor is assembled, the rotor A wheel motor with a reduction gear, characterized in that it is configured to be guided from the tip of a case-side extension through a bearing.