JP2849202B2 - Wheel motor with reduction gear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

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

[Prior art]

In recent years, electric vehicles have been actively developed from the viewpoint of environmental problems. The electric vehicles developed so far include a method in which a motor is replaced with a conventional engine and connected to a crankshaft, or a motor is connected to a pair of front or rear power transmission shafts and driven, There is a method using a wheel motor with a speed reducer, which is driven by connecting a motor via a speed reducer. Among these, as the latter example of a wheel motor with a speed reducer, there has been proposed a structure in which a speed reducer is disposed in the wheel in a direction outside the vehicle body so as to obtain a desired reduction ratio (Japanese Patent Application Laid-Open No. Sho 62 (1987)). -175217). This wheel motor with a speed reducer is used in mining dump trucks and the like, and is usually used for double tires (two tires). Therefore, there was not much restriction on the driving mechanism in the full length direction.

[Problems to be solved by the invention]

However, when trying to apply the structure of the wheel motor with a speed reducer to a general vehicle, the motor portion protrudes from the wheel because one wheel is used. There is a problem in that the stones bounce and hit the motor unit, causing damage. Further, in a wheel motor with a speed reducer, it is necessary to prevent the vehicle body from interfering with the motor and the speed reducer when the wheel moves up and down or turns. Therefore, the installation space for the motor and the speed reducer is limited. Therefore, it is required to reduce the size of the motor and the speed reducer as much as possible in order to dispose the motor and the speed reducer in the limited space. Further, in an electric vehicle, in order to obtain a high output with respect to the weight of the vehicle body, the output torque must be considerably increased while reducing the size and weight of the motor. To satisfy the above requirements, the gap between the rotor and the stator is made as narrow as possible, and a high-performance permanent magnet is mounted on the rotor. However, such a motor has a problem that when the rotor is mounted on the housing, the attracting force is strong, so that the rotor is attracted to the stator, and the impact at that time causes the surface of the permanent magnet to be scratched or damaged. Therefore, in order to prevent such an accident, a special jig for suppressing the attraction force of the permanent magnet and the amount of eccentricity during insertion and smoothly inserting the rotor is required. SUMMARY OF THE INVENTION An object of the present invention is to provide a wheel motor with a speed reducer, which can solve the above-mentioned problems, can shorten the overall length, can obtain a small-sized high output, and can easily assemble a rotor. .

[Means for Solving the Problems]

For this purpose, the present invention provides an electric motor () having a stator (21) around which a coil (22) is wound and a rotor (23) rotating opposite to the stator (21) inside a case body (10). 20) and a wheel motor with a reduction gear housing a reduction mechanism (30) for connecting between a rotor (23) and an output flange (52) to which a wheel (54) is attached, wherein the stator (21) Is fixed to the inner wall of the case body (10), and the rotor (23) is constituted by an iron core on a hollow cylinder provided with a thin portion (26) protruding in the axial direction from a width facing the stator (21), The case body (10) is provided at two points on both ends of the thin portion (26) and the opposite side of the thin portion (26) in the axial direction.
The input gear (33) is spline-fitted inside the hollow core of the rotor (23), and the output rotary shaft (51) connected to the output gear (32).
Is connected to the output flange (52), and the case body (10) is moved from the position supporting the thin portion (26) to the rotor (2).
(3) An extension having a width in which at least the stator (21) and the rotor (23) face each other in a certain axial direction is provided.

[Action and effect of the invention]

By adopting the hollow rotor as described above and disposing the reduction mechanism in the hollow portion, the rotor can be flattened and the overall length can be reduced. In addition, when the rotor is assembled, it is configured so that the rotor is guided from the end of the case-side extension via a bearing, so that a simple jig can be used to prevent the permanent magnet from adsorbing to the stator, making it smooth. The rotor of the housing can be assembled.

【Example】

Hereinafter, embodiments will be described 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, a case main body 10 has a two-part structure including a cylindrical support-side housing 11 and a wheel-side housing 12, both of which are fixed by bolts (not shown). Further, the plate 13 and the cover 14 of the support-side housing 11 are fixed to the opposite side of the wheel-side housing 12 with bolts (not shown), and are fixed to the support 61 with bolts 62. An oil pump motor 16 is provided at the bottom, and the 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. In addition, cover for oil cooling
A number of cooling fins 15 and heat pipes
17 are provided. An electric motor 20 having a flat and hollow rotor 23 is provided inside the case body 10.
Is accommodated in the hollow portion of the rotor 23,
30 are housed. A stator 21 of the electric motor 20 is press-fitted and fixed to an 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 formed of a hollow iron core, and a permanent magnet 24 is fixed to the outer periphery with a holding band 25,
At one end, a thin portion 26 protruding in the axial direction from the permanent magnet 24
Are provided, and are rotatably supported at the thin portion 26 and opposite ends. In the illustrated example, one end is supported by the ball pairing 41 on the housing 11 side, the other end is supported by the ball bearing 42 on the ring gear 31 side of the planetary gear reduction device 30, and the A ring gear 31 is press-fitted into the housing 12 and fixed by bolts. Therefore, the ring gear 31 also serves as the housing 12 side supporting the thin portion 26 by the ball bearing 42, and the mounting position of the ball bearing 42 from the tip thereof 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 from the end of the case-side extended portion, that is, the end of the ring gear 31 via the ball bearing 42. Therefore, the outer peripheral portion of the ring gear 31 serving as the guide surface is provided with a step in the middle to make the diameter on the tip side slightly smaller. Further, the sun gear 33 of the planetary gear reduction device 30 is supported by the ball bearing 43 on the housing 11 side,
The rotor 23 is spline-fitted inside the hollow. The pinion shaft 34 is connected to an output carrier 51 serving as an output rotation shaft.The pinion gear 32 is rotatably supported on the pinion shaft 34 by a needle bearing 45, and is disposed so as to always mesh with the ring gear 31 and the sun gear 33. I have. The output flange 52 is connected to the output carrier 51
The ring gear 31 is spline-fitted around the outer periphery of the ring gear 31 and is immovably fixed in the axial direction by a nut 53. The ring gear 31 is supported by a double-row angular bearing 44 on the outside where the pinion gear 32 meshes. A disc plate 56 of a brake is spline-fitted to the output flange 52, and a wheel 54 holding a tire 55 is mounted by bolts and nuts. The support 61 is a cylindrical member having an external gear at its upper end. The support 61 is rotatably supported on the knuckle 63 by an uncular bearing 46 and a nut 64, so that a thrust force is supported. Further, a cover internal 66 is fixed to the knuckle 63 with bolts. Then, an internal gear 65 having internal teeth is fixed to the steering lever 67 with bolts, is rotatably supported on the cover internal 66 by a ball bearing 47 and a needle rotor bearing 48, and is rotatable with the external teeth of the support 61. The gears 65 are arranged so as to mesh with each other to form a speed increasing gear. In this way, the internal gear 65 is
Is rotated, the rotation angle is amplified, for example, twice, and the support 61 rotates. Fix the ring gear 31 to the housing 12 as described above,
Inside, the output flange 52 and the output carrier 51 are supported by the double row angular bearing 44, and the rotor 23 of the electric motor 20 and the sun gear 33 of the planetary gear reduction device 30 are spline-fitted. The inclination of the shaft due to the misalignment of 44 can be eliminated, and concentricity of the planetary gear reduction device 30 can be improved. Also, a planetary gear reduction device utilizing the hollow portion of the rotor 23
Since 30 is arranged, the length in the axial direction can be shortened to make it flat and compact, high-speed rotation can be achieved, and acceleration / deceleration performance can be improved. In this case, since the rotor is flat and has a large diameter, even if the rotor is supported at two points, the supporting interval is short, and the effect of misalignment between the housings is likely to occur. And the torque characteristics vary. In order to solve this problem, in the present invention, a thin portion is provided on the side of the rotor and two points are supported so as to be sandwiched from both sides near the outer periphery of the rotor at both ends, so that the diameter of the support portion can be increased, The concentricity can be improved, and the fluctuation of the inclination of the rotor and the interval between the rotor and the stator can be reduced. Therefore, it is possible to eliminate variations in performance due to the form of the rotor. Next, the procedure for assembling the rotor will be described. FIG. 2 is a diagram showing a configuration of each of a stator side and a rotor side, and FIG. 3 is a diagram for explaining a procedure of assembling the rotor. First, before the rotor is assembled, the ring gear 31 and the stator 21 are press-fitted and fixed to the housing 12 as shown in FIG.
Double row angular bearing 44, output carrier 5
1. The output flange 52 and the like are assembled.
On the other hand, the sun gear 33 and the ball bearings 41 and 42 are incorporated into the rotor 23 as shown in FIG. Thereafter, as shown in FIG. 3 (a), using a mounting jig 71 for mounting the housing 12 and a mounting jig 72 for mounting the rotor assembly, a bolt 74 is attached to each of the mounting jigs 71 and 72.
Attach the housing 12, rotor assembly with 73, bolt 75
The mounting jig 72 is mounted on the housing 12 by tightening. When tightening bolts 75, first
The ball bearing 42 attached to the thin portion 26 of the 23 contacts the tip of the ring gear 31 to guide the rotor 23 as shown in FIG. Here, the position where the permanent magnet 24 of the rotor 23 does not face the stator is still before the sun gear and the pinion gear mesh with each other. When the bolt 75 is further tightened, the permanent magnet 24 and the stator 21 overlap as shown in FIG. 7B, and an attractive force acts between the permanent magnet 24 and the stator core, but the contact between the ball bearing 42 and the ring gear 31 occurs. Since the rotor 23 is supported at two points, that is, the contact point between the mounting jig 71 and the bolt 75, the contact between the permanent magnet 24 and the stator 21 can be avoided by the clearance between the permanent magnet 24 and the stay 21. While inserting the rotor 23, it is possible. Thereafter, the rotor 23 is completely assembled in the housing 12 while the sun gear 31 and the pinion gear 32 mesh with each other as shown in FIG. It should be noted that the present invention is not limited to the above embodiment, 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. Further, although the planetary gear reduction device is provided as a reduction device in the hollow portion of the rotor, another reduction device may be provided. As is apparent from the above description, according to the present invention, the flat hollow rotor is employed, and the reduction gear is disposed in the hollow portion, so that the axial length can be reduced. Therefore, even when the present invention is applied to a general vehicle with a single tire, the motor does not largely protrude, and damage to the motor due to rocks during derailing or running can be prevented. In addition, since a thin portion is provided at the end of the rotor and bearings are arranged so as to be sandwiched from both sides near the outer periphery of the rotor at the end opposite to the thin portion, the rotor is rotatably supported at two points. Thus, a change in the gap between the stator and the rotor can be suppressed, and the motor performance can be stabilized.
Then, an extension of the housing is provided on the thin portion side,
Guide the rotor with bearings along this extension,
Since the permanent magnets are assembled, it is possible to prevent the permanent magnets and the stator from coming into contact with each other due to the attraction between the permanent magnets of the rotor and the iron core of the stator during assembly, thereby preventing damage to the permanent magnets. Further, since the gap between the rotor and the stator can be narrowed, the output performance of the motor can be improved and stabilized.

[Brief description of the drawings]

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 view showing a configuration of each of a stator side and a rotor side.

FIG. 3 is a diagram for explaining a procedure for assembling a rotor.

[Explanation of symbols]

 10 Case body 16 Oil pump motor 17 Heat pipe 20 Motor 30 Planetary gear reducer 51 Output carrier 52 Output flange 54 Wheel 55 Tire 61 Support 63 Knuckle 65 Internal gear 66 Cover internal 67 Lever

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60K 7/00

Claims (1)

(57) [Claims] A coil (22) is provided inside a case body (10).
An electric motor (2) having a stator (21) around which is wound and a rotor (23) rotating opposite to the stator (21).
0) and a wheel motor with a reduction gear housing a reduction mechanism (30) for connecting between the rotor (23) and the output flange (52) to which the wheel (54) is attached, wherein the stator (21) Is fixed to the inner wall of the case body (10), and the rotor (23) is constituted by an iron core on a hollow cylinder provided with a thin portion (26) protruding in the axial direction from a width facing the stator (21), Thin part (26) and thin part in axial direction (26)
The input gear (33) is spline-fitted into the hollow inside of the iron core of the rotor (23). An output rotary shaft (51) connected to the output gear (32) is connected to the output plunge (52), and the case body (10) is a shaft with the rotor (23) from a position supporting the thin portion (26). At least stator in direction (21)
A wheel motor with a speed reducer, characterized by being provided with an extension having a width facing the rotor and the rotor (23).