JP3596230B2 - Wheel support structure - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a supporting structure of the wheel equipped with Lee N'narota type wheel motor.
[0002]
[Prior art]
A wheel motor is a motor whose rotating shaft is integrated with the axle of the wheel.To drive the wheel with an electric motor, the loss of power transmission is minimized and the driving efficiency is increased. It has been proposed. It has been considered that such a wheel motor is used as a drive wheel of an electric vehicle, or is used instead of a driven wheel for controlling the attitude of a normal engine-driven vehicle.
[0003]
Wheel motors can be roughly classified into an inner rotor type and an outer rotor type from the structural point of view. As inner rotor type wheel motors, for example, Japanese Patent Application Laid-Open No. 5-184017 discloses a "motor control for electric vehicle". Apparatus ".
[0004]
[Problems to be solved by the invention]
However, in the electric vehicle disclosed in the related art, little consideration is given to a suspension for suspending wheels. Generally, the position of the connection point between the suspension arm and the wheel support is designed from the viewpoint of maneuverability, running stability, and the like. However, in this conventional electric vehicle, the presence of a drive motor (wheel motor) is hindered. It has been difficult to bring the aforementioned connection point to a desired position.
[0005]
[Means for Solving the Problems]
The support structure for a wheel on which the inner rotor type wheel motor according to the present invention is mounted has been made to solve such a problem.
[0007]
That is, the wheel supporting structure equipped with the wheel motor of the present invention is a wheel supporting structure equipped with an inner rotor type wheel motor, and the wheel motor is provided so as to be rotatable around the axle of the wheel. A rotor that rotates integrally and a stator that is fixed to a wheel support that rotatably supports the wheels and creates a magnetic field that moves along the outer periphery of the rotor, the stator being wound with a coil for creating a magnetic field A plurality of teeth made of a magnetic material are provided on the outer periphery of the rotor, and the teeth on which the coils are wound are radially arranged within a predetermined angle range centered on the axle, and a wheel support and a suspension supporting the wheel support are provided. The connection point with the arm is located within the angle range other than the predetermined angle range around the axle on which the teeth are arranged and within the rim width of the wheel. And it is characterized in that is.
[0008]
According to this wheel support structure , since the teeth of the stator of the wheel motor are radially arranged within a predetermined angle range around the rotation axis or the axle, conversely, outside the predetermined angle range, the vicinity of the outer periphery of the rotor There is space due to the absence of stator teeth. Therefore, various mechanisms around the wheels can be arranged in this space.
According to the wheel support structure of the present invention, the connection point between the wheel support and the suspension arm that supports the wheel support is in an angular range other than the predetermined angular range around the axle on which the teeth are arranged. And within the rim width of the wheel. In other words, the position where the connection point between the wheel support and the suspension arm is arranged is a space because the teeth of the stator do not exist. Therefore, the degree of freedom for arranging the connection point at a desired position from the viewpoint of maneuverability and running stability is high.
[0009]
In the wheel motor in the wheel support structure of the present invention, the wheel motor includes a disk brake having a rotor disk fixed to the wheel, and a caliper fixed to the wheel support and braking the rotation of the rotor disk, wherein the calipers are arranged with teeth. It is desirable to be arranged within an angle range other than the predetermined angle range around the axle.
[0010]
With regard to the position in the axle direction, the caliper can be arranged at substantially the same position as the stator of the wheel motor, so that the width of the entire wheel portion including the wheel motor and the brake device in the axle direction is set to that of a normal wheel without a wheel motor. It can be reduced to the same extent.
[0013]
In the wheel motor used in the wheel support structure of the present invention, it is preferable that the stator and the rotor are housed in a liquid-tight casing. The stator and the rotor are not exposed to water or dust splashed by the wheels during traveling.
[0014]
In the wheel motor used in the wheel support structure of the present invention, it is desirable that the thickness of the permanent magnet provided on the outer peripheral surface of the rotor be thin at both ends in the radial direction of the rotor. When the permanent magnet is formed in such a shape, the magnetomotive force at that portion is larger than the magnetomotive force at both ends because the central portion is thick, and the magnetic flux of the rotating magnetic field generated by the stator passes at both ends because the magnetomotive force is thin at both ends. Cheap. Therefore, the output torque that is substantially proportional to the product of the magnetomotive force of the permanent magnet and the magnetic flux of the moving magnetic field generated by the stator is stabilized, and torque ripple is suppressed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a sectional view showing the internal structure of a wheel on which a wheel motor according to an embodiment of the present invention is mounted, and FIG. 2 is a sectional view taken along line II-II of FIG. This wheel is a front wheel of a rear wheel drive vehicle, is a driven wheel, and is a steering wheel. The driving force of the wheel motor according to the present embodiment is appropriately used as auxiliary power according to the traveling state of the vehicle.
[0016]
The suspension to which the wheels are attached is of a high mount double wishbone type, and a wheel support 12 is mounted between the lower arm 10 and the upper arm 11 via ball joints 13 and 14 so as to be steerable. A shock absorber 15 having a coil spring 16 is provided between the lower arm 10 and a vehicle body (not shown).
[0017]
A case 20 for housing a wheel motor is fixed to the wheel support 12 outside the vehicle by bolts 21. As shown in FIG. 2, the case 20 is a box body having an open bottom and a bottom having a shape in which a sector-shaped key portion has a circular shape. Further, the case 20 has a convex body 22 serving as an axle at the center of the sector key portion, and a hub bearing 23 is fitted therein. A nut 25 is screwed to the convex body 22 via a resolver support 24 also serving as a spacer in a state where the hub bearing 23 is fitted to the convex body 22, whereby the inner race of the hub bearing 23 is formed. It is fixed to the convex body 22.
[0018]
Nine teeth 31 around which the stator coil 30 is wound are embedded in the fan-shaped portion of the case 20 from the outside of the vehicle. Each tooth 31 is formed of a silicon steel sheet laminate in which a large number of silicon steel sheets each having a surface covered with an insulating film are stacked, and a very small portion is welded and joined in a thickness direction by laser welding or the like. A coil 30 is wound around each of the teeth 31 configured as described above, is arranged radially in the case 20 so that the tip of each of the teeth faces the axle, and is fixed to the case 20 with bolts 32 together with the stator cover 33. .
[0019]
Between the teeth 31 and the stator cover 33, a wiring board 34 and a power supply line 35 drawn from outside are arranged.
[0020]
A predetermined wiring is provided on the wiring board 34, and each terminal of each stator coil 30 is connected to three power supply lines 35 of U phase, V phase, and W phase by the wiring. This makes it possible to form a moving magnetic field for rotating the rotor inside the stator, that is, on the axle side.
[0021]
The contact surfaces of the teeth 31 are provided with a key-shaped notch 36 with which the teeth 31 are mutually engaged, and the positional relationship between the teeth 31 is fixed by the key-shaped notch 36. Thus, the two teeth 31 at both ends in the nine teeth 31 be fixed to the casing 20 by bolts 32, it can fix the position with respect to the nine teeth 31 across the axle. However, in the present embodiment, all the teeth 31 are fixed with bolts 32 in order to firmly fix the teeth 31 to the case 20.
[0022]
An axle hub 27 is fastened and fixed to the outer race of the hub bearing 23 by a bolt 28 together with the rotor 26 of the motor. That is, the spacer 29 and the rotor 26 are fitted into the axle hub 27 from the inside of the vehicle, and the axle hub 27 is further fitted into the outer race of the hub bearing 23 from the outside of the vehicle, and is fixed to a member integrated with the outer race with the bolt 28. I have. Thus, the motor rotor 26 and the axle hub 27 are integrally mounted rotatably around the axle.
[0023]
The rotor 26 is formed of a silicon steel sheet laminate in which annular silicon steel sheets each having an insulating film formed on the surface thereof are stacked. The outer circumferential surface of the rotor 26 is uneven in the circumferential direction, and a total of 18 permanent magnets 40 are fixed to the respective recesses by an adhesive over the entire circumference.
[0024]
In each of the permanent magnets 40, the radial thickness of the rotor 26 is thin at both ends in the circumferential direction. Specifically, the permanent magnet 40 is a flat columnar body having upper and lower bottom surfaces in a substantially home base shape, the height direction of the columnar body is made to coincide with the direction of the rotation axis of the motor, and the convex side surface is bonded to the rotor 26 with an adhesive. Etc.
[0025]
By setting the permanent magnet 40 in such a shape and arrangement, it is possible to significantly increase the output torque and reduce the torque ripple. That is, as described above, the permanent magnet 40 of this embodiment increases the magnetomotive force by increasing the thickness at the central portion in the rotation direction, and reduces the thickness at both ends to facilitate the passage of magnetic flux. The change in the thickness is smooth. On the other hand, the output torque is substantially proportional to the product of the magnetic force of the magnet and the magnetic flux generated by the stator. Therefore, a large output torque can be obtained while suppressing the torque ripple. In other words, the wheel motor of this embodiment can obtain a stable high rotation output torque with respect to the angular position of the rotor.
[0026]
Further, since the thickness of the central portion in the rotation direction of the permanent magnet 40 is made sufficiently large, it is difficult to demagnetize, and the pole reversal due to the magnetic flux of the stator can be prevented.
[0027]
Further, the fixed surface of the permanent magnet 40 with the rotor 26 is convex in the circumferential direction of the rotor, and the outer peripheral surface of the rotor 26 is a concave portion having the same shape as the convex side surface of the permanent magnet 40. The fixed permanent magnet 40 is not easily shifted in the circumferential direction (rotation direction) of the rotor 26. Therefore, the rotational force applied to the permanent magnet 40 is well transmitted to the rotor 26 without much depending on the adhesive force of the adhesive fixing the permanent magnet 40 to the rotor 26, and thus it is easy to generate a rotational torque.
[0028]
The ratio of the open angle formed by the line connecting the center of the adjacent permanent magnet 40 to the axle, that is, the center axis of the convex body 22, that is, the magnet open angle and the open angle of the adjacent teeth 31 is (A / 8) :( A / 9) = 9: 8. Here, the value A is an angle value in an angle range around the axle on which the nine teeth 31 are arranged. That is, just eight permanent magnets out of the eighteen permanent magnets 40 arranged on the entire outer periphery of the rotor 26 fall within the arc formed by the tips of the nine teeth 31. This results in an 8-pole, 9-coil inner rotor type motor having a fan-shaped stator.
[0029]
It should be noted that a permanent magnet on the rotor side may be arranged so that ten permanent magnets correspond to nine teeth arranged in the same manner as in this embodiment, and a motor with 10 poles and 9 coils may be used. In this case, the ratio between the magnet opening angle and the teeth opening angle is (A / 10) :( A / 9) = 9: 10. In addition, a two-pole three-coil or four-pole three-coil motor can be used. When a (n ± 1) -pole n-coil motor is used, the ratio of the magnet opening angle to the teeth opening angle is n: (n ± 1).
[0030]
A seal member 41 slidably in close contact with the outer peripheral surface of the spacer 29 fixed to the axle hub 27 is press-fitted into the stator cover 33. The seal member 41 has a rubber lip provided on the inner periphery of the metal ring, and the lip slidably contacts the spacer 29. Thus, the inside of the motor is sealed by the case 20, the hub bearing 23, the axle hub 27, the stator cover 33, and the seal member 41, so that dust and water from the outside do not enter.
[0031]
A lid 52 having a shaft 51 fixed to the inner rotor of the resolver 50 is fixed to the opening of the axle hub 27 outside the vehicle with bolts. On the other hand, the stator of the resolver 50 is fixed to the resolver support 24, and when the rotor of the resolver 50 rotates with the rotation of the axle hub 27, that is, the rotation of the motor rotor, an angle signal corresponding to the rotation angle is output. This angle signal is sent to a controller of a power supply provided in the vehicle body, and the controller supplies driving power corresponding to the angle to the stator coil 30 via the power supply line 35.
[0032]
A disc wheel 43 is fastened to a hub portion of the axle hub 27 with a hub bolt 44 and a nut 45 so as to sandwich a rotor disc 42 of a disc brake. The caliper 51, which forms a disk brake together with the rotor disk 42, is fixed to the wheel support 12, and its position is within an angular range other than a predetermined angular range around the axle on which the teeth 31 are arranged.
[0033]
Similarly to the caliper 51, the position of the ball joint 14, which is a connection point between the lower arm 10 and the wheel support 12, is also within an angle range other than a predetermined angle range around the axle on which the teeth 31 are arranged. The position of the ball joint 14 is designed from the viewpoint of running performance and steering stability. In many cases, it is desired to place the ball joint 14 inside the rim width of the disc wheel 43 as in the present embodiment. Even in such a case, since the stator is fan-shaped, the entire wheel motor can be accommodated within the rim width, and further the ball joint can be arranged within the rim width.
[0034]
FIG. 3 is a sectional view showing an internal structure of a wheel on which a wheel motor according to a second embodiment of the present invention is mounted, and FIG. 2 is a sectional view taken along line IV-IV of FIG. This wheel is a front wheel of a rear wheel drive vehicle, a driven wheel, and a steering wheel, as in the first embodiment described above.
[0035]
In the first embodiment, the wheel motor is disposed outside the vehicle of the wheel support 12, that is, between the wheel support 12 and the rotor disk 42 of the disc brake. However, in the wheel of this embodiment, the wheel motor is The support 17 is arranged inside the vehicle.
[0036]
The suspension configuration is the same as that of the first embodiment, and a wheel support 17 is mounted between the lower arm 10 and the upper arm 11 via ball joints 13 and 14 so as to be steerable. A shock absorber 15 having a coil spring 16 is provided between the lower arm 10 and a vehicle body (not shown).
[0037]
A hub bearing 60 is inserted into a cylindrical axle bearing portion of the wheel support 17, and an outer race thereof is fixed. An axle hub 61 is inserted into the inner race of the hub bearing 60 from the outside of the vehicle, and the axle hub 61 is fixed to the inner race of the hub bearing 60 by tightening a male thread portion protruding into the vehicle with a nut 62. A shaft 63 on which a spline is formed is provided further ahead of the male screw portion of the axle hub 61, and is spline-fitted to the rotation center of the rotor support 64 of the wheel motor.
[0038]
As shown in FIG. 4, the case 70 of the wheel motor is a box body having a fan-shaped keyed portion extending in a circular shape and an upper bottom having an open bottom at the center of the keyed portion.
[0039]
Nine teeth 71 around which a stator coil 72 is wound are embedded in the fan-shaped portion of the case 70 from the outside of the vehicle. Each tooth 71 is formed of a silicon steel sheet laminate in which a large number of silicon steel sheets each having a surface covered with an insulating film are stacked, and a very small portion is welded and joined in a thickness direction by laser welding or the like. A coil 72 is wound around each of the teeth 71 configured as described above, and the teeth 71 are radially arranged in the case 70 so that the tips of the teeth 71 face the axle, and are fixed to the case 70 with bolts 73. Then, the fan-shaped portion in which the teeth 71 are stored is covered with the stator cover 74.
[0040]
An opening at the center of the key portion of the case 70 is cylindrical, and the inner race of the ball bearing 75 is fixed to the outer periphery thereof. The outer race of the ball bearing 75 is fixed to a member on the rotor side of the wheel motor.
[0041]
The rotor support 64 is a disk having a central portion formed with an opening into which the spline shaft 63 is fitted. A rotor 65 made of a cylindrical silicon steel sheet laminate is fixed together with a rotor frame 68 with bolts 66.
[0042]
The outer peripheral surface of the rotor 65 is an irregular surface having a constant period along the circumferential direction, and eighteen permanent magnets 67 are fixed to the concave portion with an adhesive.
[0043]
The relationship between the number of the permanent magnets 67 and the number of the teeth 71 of the stator is the same as in the first embodiment, and the ratio between the opening angle of the permanent magnet 67 and the opening angle of the teeth 71 is 9: 8. Therefore, just eight permanent magnets out of the eighteen permanent magnets 67 arranged on the entire outer periphery of the rotor 65 fit within the arc formed by the tips of the nine teeth 71, thereby forming a fan-shaped stator. The inner rotor type motor has eight poles and nine coils.
[0044]
Each of the permanent magnets 67 is a columnar body having upper and lower bottom surfaces in the form of a flat and substantially home base, similarly to the first embodiment. The radial thickness of the rotor 65 is thin at both ends in the circumferential direction. For the same reason as in the embodiment, it is possible to significantly increase the output torque and reduce the torque ripple. Further, since the thickness of the permanent magnet 67 at the central portion in the rotation direction is sufficiently large, it is difficult to demagnetize, and it is possible to prevent pole reversal due to the magnetic flux of the stator. Further, since the permanent magnet 67 is fixed to the concave portion of the rotor 65, it is easy to output a rotational torque for the same reason as in the first embodiment.
[0045]
A resolver 76 is housed inside the cylindrical portion 77 located at the key of the fan shape of the case 70, and the outer stator of the resolver 76 is fixed. On the other hand, a resolver rotor shaft 78 fixed to the rotor support 64 with screws is fixed to the rotor of the resolver 76.
[0046]
The wheel motor thus configured is mounted and fixed to the wheel support 17 from the inside of the vehicle in a state where the shaft 63 that rotates integrally with the axle hub 61 is spline-fitted to the center opening of the rotor support 64. . Therefore, the rotational torque of the rotor 65 is transmitted from the rotor support 64 to the axle hub 61 via the spline shaft 63.
[0047]
A rotor disk 80 of a disk brake and a disk wheel 81 of a wheel are fastened and fixed to the outside of the axle hub 61 by bolts 82 and nuts 83, whereby the rotor 65 of the wheel motor, the axle hub 61, the rotor disk 80, and the disk wheel 81 rotates coaxially and integrally.
[0048]
In this embodiment, as in the first embodiment, the stator does not surround the entire outer periphery of the rotor, and the teeth of the stator are radially arranged within a predetermined angle range around the axle. Therefore, a space is created in the remaining angular range near the rotor, and the ball joint 14 and the disc brake caliper 81, which are the connection points between the wheel support 17 and the suspension lower arm 14, can be disposed there. In other words, when arranging the ball joint 18 and the caliper 81, the existence of the wheel motor does not hinder the arrangement, and the layout can be designed in the same manner as an ordinary wheel having no wheel motor.
[0049]
【The invention's effect】
As described above, according to the wheel support structure of the present invention, the teeth of the stator are radially arranged within a predetermined angle range around the rotation axis or the axle. A space is formed near the outer periphery due to the absence of the teeth of the stator, and various mechanisms around the wheels can be arranged in this space. In particular, since the connection point between the suspension arm and the wheel support is located within the rim width of the disk wheel, good maneuverability and running stability can be expected.
[0050]
Further, according to this onset bright, it is possible to fit within the rim width of the disc wheel in a thick part in the axle direction as caliper of the disc brake.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a wheel on which a wheel motor according to a first embodiment of the present invention is mounted.
FIG. 2 is a plan view taken along the line II-II in FIG.
FIG. 3 is a sectional view showing a wheel on which a wheel motor according to a second embodiment of the present invention is mounted.
FIG. 4 is a plan view when cut along the line IV-IV in FIG. 3;
[Explanation of symbols]
12, 17 ... wheel support, 14 ... ball joint, 20, 70 ... case, 23, 60 ... hub bearing, 26, 65 ... rotor, 27, 61 ... axle hub, 30, 72 ... coil, 31, 71 ... teeth, 42, 80: rotor disk, 43, 81: disk wheel, 50, 76: resolver.

Claims (5)

A supporting structure of a wheel equipped with an inner rotor type wheel motor, the wheel motor includes a rotor which rotates with the wheel and integrally rotatably provided around the axle of the wheel, said wheel A stator that is fixed to a wheel support that rotatably supports and generates a magnetic field that moves along the outer periphery of the rotor,
The stator comprises a plurality of teeth made of a magnetic material with coils wound for making the magnetic field on the outer periphery of the rotor, wherein the teeth coil is wound in a predetermined angular range about the wheel axis , Arranged radially ,
A connection point between the wheel support and the suspension arm supporting the wheel support is within an angle range other than the predetermined angle range around the axle on which the teeth are arranged and within a rim width of the wheel. A wheel support structure , wherein the wheel support structure is disposed on a wheel. A plurality of permanent magnets are provided at equal intervals on the outer periphery of the rotor, and a magnet opening angle formed by a line connecting the center of the permanent magnets adjacent to each other and the axle and an opening angle of the teeth adjacent to each other. The wheel support structure according to claim 1, wherein the ratio is n: n ± 1. A disc brake having a rotor disc fixed to the wheel and a caliper fixed to the wheel support and braking the rotation of the rotor disc, wherein the caliper is centered on the axle on which the teeth are arranged. The wheel support structure according to claim 1, wherein the wheel support structure is disposed within an angle range other than the predetermined angle range. The wheel support structure according to claim 1, wherein the stator and the rotor are housed in a liquid-tight casing. The wheel supporting structure according to claim 2, wherein the permanent magnet has a radial thickness of the rotor that is reduced at both circumferential ends of the rotor.

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