JPH10295734A - Electric assist wheel chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve waterproof and dustproof functions of a storage chamber in a wheel hub, by equipping a bearing to support a hand rim onto a body frame and a bearing to rotatably support a wheel hub relative to the hand rim hub onto the body frame. SOLUTION: A first seal bearing 48 to rotatably support a hand rim hub 43 onto a body frame side is equipped in between a ring body 46 for supporting a heel hub 32 end fastened to the hand rim hub 43 and an axle 37. A second seal bearing 49 to rotatably support a wheel hub 32 rotatable relative to the hand rim hub 43 onto a body frame side is equipped between the wheel hub 32 and the outer end part of the wheel hub 32 in the axis direction. Thus sealing of a storage chamber 41 in the outer end side in the axis line direction is secured. Since a seal material to generate friction force is not used, increase of friction loss is prevented and waterproof and dustproof functions can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric assist wheelchair which applies an assist force corresponding to a torque input to a hand rim from an electric motor to a wheel hub of a rear wheel.

[0002]

2. Description of the Related Art An electric assist wheelchair in which an assist power corresponding to an input torque is applied to a rear wheel is already known, for example, from Japanese Patent Application Laid-Open No. 8-117291.

[0003]

By the way, in order to prevent the phase difference detecting means and the transmission mechanism housed in the storage chamber formed in the wheel hub from being adversely affected by water or dust, the storage chamber must be moved into the storage chamber. It is necessary to prevent intrusion of water and dust, and in the above-mentioned conventional device, a labyrinth structure is provided between the axial end portions of the wheel hub and the covers respectively closing both ends of the storage chamber. However, such a labyrinth structure has insufficient waterproof and dustproof effects, and it is difficult to completely eliminate adverse effects of water and dust on the phase difference detecting means and the transmission mechanism.

Therefore, it is desired to improve the waterproof and dustproof functions of the storage room to improve the reliability and durability of the phase difference detecting means and the power transmission mechanism.
It is desired to prevent dust. In particular, on the axially outer end side of the wheel hub, a bearing for rotatably supporting the hand rim hub on the body frame side and a bearing for rotatably supporting the wheel hub on the body frame side by freely rotating relative to the hand rim hub. If such a bearing is used to obtain the waterproof and dustproof function of the storage room, it is possible to prevent an increase in friction loss,
A simple and low cost seal structure would be obtained.

The present invention has been made in view of the above circumstances, and can improve the waterproof and dustproof functions of the storage chamber on the axially outward side of the wheel hub with a simple structure that avoids an increase in friction loss. An object of the present invention is to provide an electric assist wheelchair.

[0006]

According to one aspect of the present invention, a wheel rim for a rear wheel and a hand rim connected to the hand rim and disposed axially outward of the wheel hub are provided. A hub connected to the hub via a power transmission member that transmits the rotational torque from the hand rim hub to the wheel hub while elastically deforming in response to the rotational torque input to the hand rim; A phase difference detecting means for detecting a rotational phase difference between the hand rim hub and the wheel hub; and an electric motor fixedly supported on the vehicle body frame side and exerting an assisting force according to a detected value of the phase difference detecting means. A power transmission mechanism for transmitting power to the wheel hub, wherein the power assist wheelchair is housed in a housing room formed in the wheel hub; An axle penetrating coaxially through the wheel hub is fixedly supported by the vehicle body frame, and a first seal bearing is provided between an inner periphery of the ring body coaxially fixed to the hand rim hub and an outer periphery of the axle; A second seal bearing is provided between the outer periphery of the wheel hub and the inner periphery of the wheel hub.

According to the first aspect of the invention, the bearing for rotatably supporting the hand rim hub on the vehicle body frame side is a seal bearing, and the wheel hub is capable of freely rotating relative to the hand rim hub. The bearing for rotatably supporting the wheel rim on the vehicle body frame side is also a seal bearing, so that the hand rim hub and the wheel hub are rotatable relative to each other, and the bearing for supporting the axle, that is, the body frame, is used to support the axially outer end of the wheel hub. The seal of the storage room on the side can be achieved, and a simple structure that avoids an increase in friction loss and the number of parts can be achieved, and the storage room is waterproof and dustproof on the outside in the axial direction of the wheel hub. Can be increased.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, a cover fixed to the vehicle body frame by closing an inner end side of the storage chamber along the axial direction of the axle. In addition, by mounting an annular seal member that resiliently contacts the axially inner end of the wheel hub, waterproofing of the storage chamber on the axially inner end side of the wheel hub,
The dustproof function can be enhanced, and the waterproof and dustproof function of the storage chamber can be improved by the configuration of the first aspect of the present invention. Thus, the reliability and durability of the phase difference detecting means and the transmission mechanism in the storage room can be improved.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect of the present invention, the power transmission member is substantially C-shaped in a plane perpendicular to the axis of the hand rim hub and the wheel hub. A phase difference detecting means, which is formed in the shape of a letter and is arranged in a space between the hand rim hub and the wheel hub surrounding the ring body and accommodated in the accommodation chamber, is provided between the first and second seal bearings. By providing between the connecting arm connected to the body and the wheel hub, the space occupied by the power transmission member in the direction along the axis of the hand rim hub and the wheel hub is reduced, and the hand rim hub is brought closer to the wheel hub. And the width of the wheelchair can be set to be small, and the connecting portion between the power transmission member and the phase difference detecting means is first and second. It becomes unnecessary to provide a special seal structure to the connecting part by placing between the two seal bearings.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 to 12 show an embodiment of the present invention. FIG. 1 is a side view of an electric assist wheelchair, FIG. 2 is a rear view taken along line 2-2 of FIG. 1, and FIG. 2 is an enlarged vertical sectional view taken along line 3-3 in FIG. 4, FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3, FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. 3 is a front view of the slip ring as viewed from the direction of the line 6-6 in FIG. 3, FIG. 7 is a rear view of the inner cover as viewed from the direction of the line 7-7 in FIG. 3, and FIG. FIG. 9 is a front view of the outer cover as viewed from the direction of the arrow -8, FIG. 9 is a rear view of the slip ring as viewed from the direction of the arrow 9-9 in FIG. 3, and FIG. FIG. 1 is a circuit diagram showing a configuration of a circuit.
1 is a timing chart showing the output from the rotation speed detection terminal and the waveform shaping result thereof, and FIG. 12 is 12-12 in FIG.
It is sectional drawing which follows a line.

First, in FIG. 1, a body frame 14 of the electric assist wheelchair is provided with an upper frame 16 and a pair of left and right lower frames 17.
There is supported on the upper frame 16, the seat rear wheel disposed on the left and right sides of the seat 15 W _R ... and the rear wheels W _R ... front pair of right and left disposed in front of the W _F ... is both lower frames 17 ... Respectively supported.

The upper frame 16 has a handrail 18a at the top.
The seat 15 is formed in an endless series with
Are arranged on both left and right sides of the seat 15 and two side frames 18 below the seat portion 15a to support two portions of the seat 15 which are spaced apart in front of and behind the seat portion 15a.
Cross members 19 and 20 erected between them,
A cross member 21 is provided between the side frames 18 behind the backrest 15b to support the backrest 15b of the seat 15.

The lower frame 17 extends in the front-rear direction at positions spaced below the upper frame 16, and includes a front wheel support 22, a rear wheel support 23, and front and rear wheel supports 22, 23. A pair of upper and lower pipe-like frame members 24 and 25 for connecting between them is formed, and an intermediate portion between the two frame members 24 and 25 is formed to be curved downward.

At the front end of the front wheel support portion 22, there is integrally provided a support tube 22a which is slightly inclined rearward as it goes upward, and a support rod 26 penetrating the support tube 22a is positioned at its height. Is adjustable and fixedly supported by the support cylinder 22a. Thus, the left and right lower frames 17 ...
Are provided between the lower ends of the support rods 26 supported by the support cylinders 22a at the front end.
A cross member 2 is provided between the rear portions of the front wheel support portions 22.
8 is erected.

The front wheels W _F are casters, is supported by a lower end of the support member 30 having a front axle 29 which extends vertically to the upper end, the front wheel shaft 29 is secured to the front-rear direction intermediate portion of the front-wheel support portion 22 It is rotatably supported by a bearing housing 31.

2 and 3, the rear wheel W
_R is provided at a wheel hub 32 formed in a ring shape, a plurality of spokes 33 radially extending from a plurality of locations spaced apart in a circumferential direction of the wheel hub 32, and outer ends of the spokes 33. It comprises a rim 34 and a tire 35 mounted on the rim 34.

Lower frame 17 of body frame 14
The wheel support portion 23 after, which the cover 36 for covering the inner end of the wheel hub 32, one end portion of the axle 37 is a rear wheel W _R and coaxially fixed as removable axle 37
Extends outward through the cover 36 and the wheel hub 32. An electric motor 38 having a rotation axis is fastened to the cover 36 at a position shifted from the axis of the axle 37.

The wheel hub 32 integrally includes a cylindrical first hub half 39 having the same axis as the axle 37 and having a diameter decreasing toward the outside, and a sleeve 40a coaxially surrounding the axle 37. Having the first hub half 39
And a second hub half 40 bolted to the axially outer end of each of the spokes 33. Half of each spoke 33 is connected to the first hub half 39, and the remaining half of the spokes 33 are connected to the first hub half 39.
Are connected to the second hub half 40. Moreover, the cover 36
On the outer peripheral edge of the wheel hub 32, the inner surface of the inner end of the first hub half 39 in the wheel hub 32 is resiliently prevented so as to prevent dust from entering the storage chamber 41 surrounded by the cover 36 and the wheel hub 32. An annular sealing member 42 that comes into sliding contact is mounted.

Referring also to FIG. 4, the wheel hub 32
A hand rim hub 43 is disposed coaxially with the axis of the axle 37 on the outside in the axial direction of the hand rim hub 43.
A ring-shaped hand rim 45 coaxial with the axle 37 is provided at an outer end of the plurality of spokes 44 extending radially from the rim.

A ring body 46 coaxial with the axle 37 has a plurality of bolts 47 on the inner side in the axial direction of the hand rim hub 43.
The ring body 46 is fixed to the wheel hub 3.
2 into the axially outer end. Moreover the inner circumference of the ring member 46, between the outer circumference of the axle 37, the inner ring and the first seal bearing 48 ₁ the sealing material 48a is provided between the outer ring, the bearing having no seal member 48 ₂ DOO is arranged by arranging a first seal bearing 48 ₁ axially outward. A wheel hub 3 along the axial direction of the axle 37;
A second seal bearing 49 in which a seal material 49a is provided between the inner ring and the outer ring is provided between the outer periphery of the outer end of the second hub half 40, that is, the outer periphery of the ring body 46 and the outer periphery of the ring body 46.
Is provided. Further, the cover 36 in the storage room 41
A support plate 50 serving as a support member is fastened to the inner surface of the wheel hub 32. A bearing 51 is provided between the support plate 50 and the inner end of the wheel hub 32 in the axial direction, that is, the outer periphery of the inner end of the sleeve 40a. Can be That is, the wheel hub 32
Of the wheel hub 32 is rotatably supported by a ring plate 46, and the axially inner end of the wheel hub 32 is rotatably supported by a support plate 50 fixed to the vehicle body frame 14. 32 is rotatable around the axis of the axle 37, and the hand rim hub 43 is rotatable about the axis of the axle 37 to enable relative rotation with the wheel hub 32.

A drive shaft 52 connected to the electric motor 38 protrudes into the storage chamber 41, and a transmission mechanism 60 provided between the drive shaft 52 and the wheel hub 32 is stored in the storage chamber 41. You. The transmission mechanism 60 includes a drive gear 53 fixed to a drive shaft 52 and a wheel hub 32.
And a driven gear 54 meshed with the drive gear 53 while being coupled to the sleeve 40a of the rear wheel 40a via the transmission mechanism 60. It is possible to give to W _R.

[0023] At the center portion the outer surface of Handorimuhabu 43, the ring body 46 and the first seal bearing provided between the axle 37 48 ₁ and the bearing 48 ₂ is disengaged axially outward of the axle 37 A concave portion 57 is provided to face a nut 56 screwed to the outer end of the axle 37 to prevent the outer end of the axle 37 and the cap 58 that resiliently engages with the nut 56 to cover the outer end of the axle 37 and the nut 56. , Is fitted into the opening end of the recess 57.

Referring also to FIG. 5, the hand rim hub 4
The wheel hub 32 and the wheel hub 32 elastically deform the rotational torque input to the hand rim hub 43 in response to the rotation operation of the hand rim 45 by human power.
Through a power transmission member 61 for transmitting the power to the vehicle. The power transmission member 61 is formed in a substantially C shape in a plane perpendicular to the axis of the axle 37, and surrounds the ring body 46 in a space between the hand rim hub 43 and the second hub half 40 of the wheel hub 32. One end of the power transmission member 61 is connected to the hand rim hub 4 by a connecting pin 62 that is pressed into the hand rim hub 43.
3 and the other end of the power transmission member 61 is connected to the second hub half 40 of the wheel hub 32 by bolts 63. Moreover, the wheel hub 32 of the hand rim hub 43
An annular groove 67 centering on the axis of the axle 37 is provided on a surface facing the power transmission member 61, and the power transmission member 61 is housed and arranged in the groove 67.

Hand rim hub 43 and wheel hub 3
2, an angular displacement regulating mechanism 66 for regulating the relative angular displacement of the two 43, 32 is provided. The angular displacement regulating mechanism 66 includes the connecting pin 62 and the connecting pin 6.
And a circular regulating recess 64 provided in the second hub half 40 of the wheel hub 32 such that the head of the second hub is gently inserted. The hand rim hub 43 is provided with an operation hole 64 for rotating the head of the bolt 63.

When a rotational torque is input to the hand rim hub 43, the hand rim hub 43 and the wheel hub 32 can be relatively angularly displaced within the relative angular displacement regulated by the angular displacement regulating mechanism 66. Due to the relative angular displacement, the power transmission member 61 transmits the rotation torque to the wheel hub 32 while being elastically deformed by a deformation amount corresponding to the input rotation torque.

In the storage room 41, a slip ring 68 is provided.
And an inner cover 69 arranged so as to cover the inner side of the slip ring 68 along the axial direction of the axle 37, and an inner cover 69 arranged so as to cover the outer side of the slip ring 68 along the axial direction of the axle 37. The outer cover 70 is stored.

The slip ring 68 includes a plurality of bolts 71
Are fixed to the inner surface of the outer end portion of the first hub half 39 of the wheel hub 32, and rotate integrally with the wheel hub 32. As shown in FIG. 6, first to third conductive tracks 72, 73, 74 each formed in an annular shape are provided on one surface of the slip ring 68, that is, a surface facing the inner cover 69. Are provided concentrically with the axle 37 at intervals sequentially from the radially outer side to the inner side, and are formed in a ring shape further inward than the third conductive track 74 along the radial direction of the slip ring 68. The formed rotation speed detection track 75 is provided concentrically with each of the conductive tracks 72 to 74. That is, the slip ring 68 is formed of a non-conductive material in the shape of a ring plate, and the first to third conductive tracks 72 to 74 are formed of a conductive material in a foil shape on one surface of the slip ring 68. Each is provided. The rotation speed detecting tracks 75 are disposed at a plurality of positions, for example, twelve positions, equidistantly arranged in the circumferential direction of the slip ring 68, and are formed of a conductive material, and the poles 76 are formed between the poles 76. A plurality of, for example, twelve electrical resistors 77... Moreover, each of the poles 76... Is connected to twelve places at equal intervals in the circumferential direction of the third conductive track 74.
6 have the same potential as the third conductive track 74 in common.

On the other hand, the slip ring 6 of the inner cover 69
7, the first brush 78 that slides on the first conductive track 72 and the second brush 78 that slides on the second conductive track 73 are positioned at circumferentially spaced positions on the surface facing the second conductive track 73. The second brush 79, the third brush 80 slidably in contact with the third conductive track 74, and the rotation number detection brush 81 slidably in contact with the rotation number detection track 75 are fixed.

The inner cover 69 has arms 82, 8 extending radially outward at two places spaced apart in the circumferential direction.
2 are integrally provided, and the tips of the guide pins 83... Planted on the support plate 50 fixed to the cover 36 are inserted through the arms 82. Each guide pin 83
, A bowl-shaped receiving member 84 that comes into contact with the arm portion 82 is mounted so as to be movable in the axial direction of each guide pin 83.
Springs 85 are provided between them. These springs 85 exert a relatively weak spring force for urging the inner cover 69 so that the brushes 78 to 81 resiliently slide on the corresponding tracks 72 to 75, respectively.

An annular groove 86 is formed on the outer periphery of the inner cover 69.
Are provided, and a conductive wire (not shown) connected to each of the brushes 78 to 81 is drawn out from the annular groove 86 outward.

The first and second seal bearings 48 ₁ , 49 of the ring body 46 fastened to the hand rim hub 43.
The bolts 89... Are provided at two places spaced apart in the circumferential direction of the ring body 46 between them, that is, at the inner end in the axial direction of the ring body 46.
Thus, the connecting member 88 is fixed. Moreover, the connecting member 88
Are fixed to the ring body 46 by bolts 89 in through holes 90 provided in the sleeve 40a of the second hub half 40 of the wheel hub 32, and are disposed in the storage chamber 41. The through holes 90 are formed in such a size that the relative angular displacement between the wheel hub 32, ie, the sleeve 40a, and the hand rim hub 43, ie, the connecting arms 88, is allowed.

Referring also to FIG. 8, the outer cover 70
Are connected to the connecting member 88 at two locations in the circumferential direction by bolts 91.
9 is arranged so as to face the opposite side. Moreover, a cylindrical regulating cylinder 70a surrounding the sleeve 40a is provided integrally with the inner peripheral portion of the outer cover 70, and the inner peripheral portions of the slip ring 68 and the inner cover 69 are connected to the slip ring 68. The distance between the inner and outer covers 69, 70 is regulated to be maintained at a predetermined value, and is supported by the regulating cylinder 70a.

The other surface of the slip ring 68, ie, the first
In addition, the hand rim hub 43 is provided between the outer cover 70 and a surface opposite to the surface on which the third conductive tracks 72 to 74 and the rotation speed detecting track 75 are provided and which faces the inner cover 69. A phase difference detecting means 94 for detecting a relative angular displacement between the wheel hub 32, ie, the slip ring 68, and the hand rim hub 43, ie, the outer cover 70, according to the input torque is provided.

As shown in FIG. 9, the phase difference detecting means 94 is formed in an arc shape centered on the axis of the axle 37, and is provided with a conductive portion 95 provided on the other surface of the slip ring 68.
An electric resistance portion 96 formed in an arc shape about the axis of the axle 37 and provided on the other surface of the slip ring 68 on the inner side of the conductive portion 95, and an outer cover 70 for slidingly contacting the conductive portion 95. The fourth brush 97 fixed to the
And a fifth brush 98 fixed to the outer cover 70 so as to be in electrical communication with the electrical resistance portion 96 and to be in sliding contact with the electrical resistance portion 96.

One end 96a of the electric resistance section 96 is connected to the second conductive track 73, and the other end 96b of the electric resistance section 96 is connected to the third conductive track 74.

The electric circuit of the slip ring 68, the inner cover 69 and the outer cover 70 is shown in FIG.
It is configured as shown by 0. That is, slip ring 6
8 and the first conductive track 72 of the first to third brushes 78 to 80 and the rotation speed detecting brush 81 fixed to the inner cover 69 at a fixed position with respect to the outer cover 70, respectively. The first brush 78 that slides is connected to the torque detection terminal 99, and the second brush 79 that slides in contact with the second conductive track 73 is connected to the positive side of the battery 100, and the third brush that slides in contact with the third conductive track 74. 80 is grounded. In addition, the second conductive track 72 conducts to one end 96a and the third conductive track 7
The fifth brush 98 slidably in contact with the electrical resistance portion 96 whose third end is electrically connected to the other end portion 96 b includes the fourth brush 97 and the conductive portion 9.
5 to the first conductive track 72. Therefore, the electric resistance portion 96 in the phase difference detecting means 94
A voltage corresponding to the output voltage of the battery 100 is acting between both ends of the slip ring 68 and the outer cover 70 according to the torque input to the hand rim hub 43. A voltage output corresponding to the distance between the contact position of the fifth brush 98 with the electric resistance section 96 and both ends of the electric resistance section 96 is output from the torque detection terminal 99 as a value corresponding to the input torque.

The rotational speed detecting brush 81 slidingly in contact with the rotational speed detecting track 75 is connected to the positive side of the battery 100 via the voltage dividing resistor 101, and the rotational speed detecting brush 81 and the voltage dividing resistor A rotation speed detection terminal 102 is connected between the terminals 101. Moreover, the rotation speed detection track 75
Are electrically connected to the third conductive track 74, and the respective electrodes 76 are in a state of being commonly grounded.
Therefore, when the slip ring 68 rotates, the rotational speed detecting terminal 102 is connected to the rotational speed detecting track 75 and the rotational speed detecting brush 81 shown in FIG. As a result, a voltage output that changes as shown in FIG.
11 (c) by shaping the waveform of the output from
As shown by, it is possible to obtain a pulse-like electric signal that changes periodically. Moreover, the frequency of the pulse-like electric signal is controlled by the slip ring 68, that is, the wheel hub 3
The number of rotations of the slip ring 68, that is, the rotation speed of the wheel hub 32, can be detected by counting the output of the pulse signal per unit time.

[0039] Incidentally, the rotational direction of the traveling direction, i.e. the rear wheel W _R of the wheelchair are determined by the rotation direction determination means 103. As shown in FIG. 12, the rotation direction discriminating means 103 is driven by the rotation direction detection switch 104 fixedly disposed on the support plate 50 and the driven gear 54 by frictional contact when the driven gear 54 rotates. It comprises a friction spring 105 mounted on an annular groove 54a provided on the outer periphery of the base of the driven gear 54 to rotate, and a regulating pin 106 for regulating a rotation range of the friction spring 105 driven by the driven gear 54. You.

As shown in FIG.
When the driven gear 54 rotates in the counterclockwise direction of No. 2, a pressing portion 105a that contacts the detector 104a of the rotation direction detection switch 104 to make the rotation direction detection switch 104 conductive is formed in a substantially U-shape and provided integrally. . Moreover, the support plate 5
0, a regulating pin 106 is implanted so as to be located within the pressing portion 105a. When the pressing portion 105a contacts the regulating pin 106, the rotation of the friction spring 105 following the driven gear 54 is prevented. Will be blocked.

In the rotation direction determining means 103,
The rear wheel W _R i.e. the wheel hub 32 is the backward direction (Fig. 12
(In the clockwise direction), the friction spring 105 follows the rotation of the driven gear 54 and
4 is rotated clockwise in FIG.
05a is a detector 104a of the rotation direction detection switch 104
From the control pin 106 as shown by the solid line in FIG.
When the wheel hub 32 rotates in the forward direction (counterclockwise direction in FIG. 12),
Following the rotation of the driven gear 54, the friction spring 105 rotates counterclockwise in FIG. 12 around the axis of the driven gear 54, and as shown by a chain line in FIG.
The detector 104a of the rotation direction detection switch 104 is pressed by the pressing portion 105a that has been rotated to the position regulated by. Therefore, the rotation direction detection switch 104
Before the rear wheel W _R, reverse it is determined by the on and off.

Next, the operation of this embodiment will be described. A power transmission member 61 for transmitting torque while elastically deforming from the hand rim hub 43 to the wheel hub 32 includes:
The rear wheel W is formed in a substantially C shape in a plane perpendicular to the rotation axis of the hand rim hub 43 and the wheel hub 32.
_The space occupied by the power transmission member 61 can be set as small as possible in the direction along the axis of _R. Therefore, the structure for torque detection can be made compact and the width of the wheelchair can be set relatively small. Become.

Since the power transmission member 61 is housed and arranged in an annular groove 67 provided on the surface of the hand rim hub 43 facing the wheel hub 32, the power transmission member 61 is provided between the hand rim hub 43 and the wheel hub 32. Transmission member 61
Is located, the hand rim hub 43
Can be brought closer to the wheel hub 32, and the width of the wheelchair can be set smaller.

An axle 37 coaxially penetrating the wheel hub 32 is fixed to the vehicle body frame 14, and is fixed to the hand rim hub 43, and a ring 46 inserted into the axially outer end of the wheel hub 32 rotates with the axle 37. The wheel hub 32 is freely supported, and the axially outer end of the wheel hub 32 is
6, the inner end of the wheel hub 32 in the axial direction, that is, the sleeve 40a, is rotatably supported by a support plate 50 fixed to the vehicle body frame 14, and the power transmission member 61 surrounds the ring body 46. Are located in Therefore, the power transmission member 61 is
In addition, despite being provided between the hand rim hubs 43, both ends in the axial direction of the wheel hub 32 can be rotatably supported by the axle 37 and the support plate 50 fixed to the body frame 14, so that the rear wheel W _R so as to support the road surface load acting in the axial direction end portions of the rear wheel W _R, it is possible to increase the support rigidity of the rear wheel W _R in a compact structure.

Further, the hand rim hub 43 is connected to the vehicle frame frame.
A first seal bearing for rotatably supporting the
48₁The ring body 4 fastened to the hand rim hub 43
6 and the axle 37, and the hand rim hub 4
3 to freely rotate the wheel hub 32
Second seal shaft rotatably supported on the body frame 14 side
An abutment 49 is an axis of the ring body 46 and the wheel hub 32.
It is provided between the outer end portion in the direction. That is,
The wheel hub 43 and the wheel hub 32 are relatively rotatable.
To support the axle 37, that is, the body frame 14.
Two bearings 48 ₁, 49 as sealed bearings
And the storage chamber 41 on the axially outer end side of the wheel hub 32.
Seal can be achieved without fail,
Avoids the increase in friction loss because no metal is used
With a simple configuration that avoids an increase in the number of parts.
Of the storage chamber 41 on the axially outer side of the hub 32,
The dustproof function can be enhanced. In addition, a storage room
41 which is fixed to the body frame 14 by closing the inner end side of
The bar 36 is resilient at the axially inner end of the wheel hub 32.
Since the annular sealing member 42 that comes into contact with the
Prevention of the storage chamber 41 on the inner end side in the axial direction of the wheel hub 32
Water and dustproof function can be enhanced,
The waterproof and dustproof function of the storage room on the outside in the axial direction is improved.
Combined with that, the waterproof and dustproof function of the storage room 41 is further enhanced
The phase difference detecting means 94 in the storage chamber 41
And to improve the reliability and durability of the transmission mechanism 60.
Can be.

The phase difference detecting means 94 is provided between the wheel hub 32 and the connecting arm 88 connected to the ring body 46 between the first and second seal bearings 48 ₁ , 49 and transmits power. Since the connecting portion between the member 61 and the phase difference detecting means 94 is arranged between the first and second seal bearings 48 ₁ , 49, it is not necessary to provide a special sealing structure at the connecting portion.

Further, the power transmission member 61 is connected to the wheel hub 3.
2 and a connecting pin 62 connected to the hand rim hub 43
Is used as a component of the angular displacement regulating mechanism 66, so that the angular displacement regulating mechanism 66 can be configured while avoiding an increase in the number of components.

By the way, the operation of the electric motor 38 is determined not only by the input torque detected by the phase difference detecting means 94 and the rotational speed obtained from the rotational speed detecting terminal 102 but also by the discrimination result by the rotational direction discriminating means 103. It is controlled based on this. Therefore, even if a backward torque is input from the hand rim 45 during forward running or a forward torque is input from the hand rim 45 during backward running, the operation direction and the amount of operation of the electric motor 38 do not suddenly change. The direction and the operation amount can be changed slowly. For example, at the time of forward torque input during forward running, by using a regenerative brake that matches the torque input and the number of revolutions at that time, smooth deceleration or coasting can be obtained, and the same applies at the time of forward input during reverse running. is there.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0050]

As described above, according to the first aspect of the present invention, the wheel rim hub and the wheel hub are rotatable relative to each other, and the bearing for supporting the axle, that is, the body frame, is used to make the outer end of the wheel hub in the axial direction. The seal of the storage chamber on the side is achieved, and a simple configuration that avoids an increase in the number of parts while avoiding an increase in the traction loss, provides a waterproof and dustproof function for the storage chamber on the outside in the axial direction of the wheel hub. Can be enhanced.

According to the second aspect of the present invention, it is possible to enhance the waterproof and dustproof function of the storage chamber on the inner end side in the axial direction of the wheel hub, and to store the wheel hub on the outer side in the axial direction of the wheel hub. The waterproof and dustproof function of the storage room is improved, and the waterproof and dustproof function of the storage room can be further enhanced.
It is possible to further improve the reliability and durability of the phase difference detecting means and the transmission mechanism in the storage room.

According to the third aspect of the present invention, the width of the wheelchair can be set small by bringing the hand rim hub close to the wheel hub, and a special portion is provided at the connecting portion between the power transmission member and the phase difference detecting means. There is no need to provide a seal structure.

[Brief description of the drawings]

FIG. 1 is a side view of an electric assist wheelchair.

FIG. 2 is a rear view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged vertical sectional view of a main part of FIG.
It is sectional drawing which follows a line.

FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3;

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG.

FIG. 6 is a front view of the slip ring as viewed from the direction of arrows 6-6 in FIG. 3;

FIG. 7 is a rear view of the inner cover as viewed from the direction of arrows 7-7 in FIG. 3;

FIG. 8 is a front view of the outer cover as viewed from the direction of arrows 8-8 in FIG. 3;

FIG. 9 is a rear view of the slip ring as viewed from the direction of arrows 9-9 in FIG. 3;

FIG. 10 is a circuit diagram showing a configuration of an electric circuit for torque detection and rotation speed detection.

FIG. 11 is a timing chart showing an output from a rotation speed detection terminal and a waveform shaping result thereof.

FIG. 12 is a sectional view taken along line 12-12 in FIG. 3;

[Explanation of symbols]

14 ... body frame 32 ... wheel hub 36 ... cover 37 ... axle 38 ... electric motor 41 ... storage chamber 42 ... seal member 43 ... hand rim hub 45 ... Hand rim 46 ・ ・ ・ Ring body 48 ₁・ ・ ・ First seal bearing 49 ・ ・ ・ Second seal bearing 60 ・ ・ ・ Transmission mechanism 61 ・ ・ ・ Power transmission member 88 ・ ・ ・ Connection arm 94 ・ ・ ・ Position phase difference detection means W _R ··· rear wheel

Claims (3)

[Claims] 1. A wheel hub (32) for a rear wheel (W _R ).
And a hand rim hub (43) connected to the hand rim (45) and disposed outside of the wheel hub (32) in the axial direction, elastically deforms in accordance with the rotational torque input to the hand rim (45). While being connected via a power transmission member (61) for transmitting the rotational torque from the hand rim hub (43) to the wheel hub (32), the hand rim hub (4) is elastically deformed by the power transmission member (61).
3) a phase difference detecting means (94) for detecting a rotational phase difference between the wheel hub (32) and a vehicle body frame (14).
A transmission mechanism (60) that is fixedly supported on the side and transmits power of an electric motor (38) to the wheel hub (32) that exerts an assisting force according to a detection value of the phase difference detection means (94). The wheel hub (32)
An axle (37) coaxially penetrating the wheel hub (32) is fixedly supported by a body frame (14), and the hand rim hub is provided in an electric assist wheelchair stored in a storage chamber (41) formed therein. The inner periphery of a ring body (46) coaxially fixed to (43) and the axle (37);
A first seal bearing (48 ₁ ) is provided between the outer periphery of the wheel hub (3) and the outer periphery of the ring body (46).
An electric assist wheelchair, wherein a second seal bearing (49) is provided between the inner circumferences of (2). 2. The wheel hub (32) is attached to a cover (36) fixed to a body frame (14) by closing an inner end side of a storage chamber (41) along an axial direction of the axle (37).
The electric assist wheelchair according to claim 1, wherein an annular seal member (42) that resiliently contacts the inner end portion in the axial direction is mounted. 3. The power transmission member (61) is substantially C-shaped in a plane perpendicular to the axis of the hand rim hub (43) and the wheel hub (32), and surrounds the ring body (46). The phase difference detecting means (94) arranged in the space between the hand rim hub (43) and the wheel hub (32) and housed in the housing chamber (41) comprises:
The wheel hub (32) is provided between a connecting arm (88) connected to the ring body (46) and the wheel hub (32) between first and second seal bearings (48 ₁ , 49). Or the electric assist wheelchair according to 2.