U.S. patent application number 10/583850 was filed with the patent office on 2007-07-19 for in-wheel motor system.
This patent application is currently assigned to Kabushiki Kaisha Bridgestone. Invention is credited to Yasuhiro Suzuki, Katsumi Tashiro.
Application Number | 20070163824 10/583850 |
Document ID | / |
Family ID | 34708826 |
Filed Date | 2007-07-19 |
United States Patent
Application |
20070163824 |
Kind Code |
A1 |
Suzuki; Yasuhiro ; et
al. |
July 19, 2007 |
In-wheel motor system
Abstract
An in-wheel motor 3 and a wheel 2 or a hub 4 are interconnected
by a flexible coupling 10 in which a motor-side plate 11A and an
intermediate plate 11B are interconnected by a plurality of first
slide members 12A, each comprising a roller member 12p moving along
a stepped surface 12K formed on the intermediate plate 11B in such
a manner that they can move in a predetermined direction (direction
A) and the intermediate plate 11B and a wheel-side plate 11C are
interconnected by a plurality of second slide members 12B having
the same structure as the first slide member 12A in such a manner
that they can move in a direction (direction B) orthogonal to the
above direction A and which has a small number of parts and is
easily assembled. Therefore, even when the motor shaft and the
wheel shaft become eccentric to each other, the drive torque of the
motor 3 can be transmitted to the wheel 2 without fail and the
assembly work efficiency of the in-wheel motor can be enhanced.
Inventors: |
Suzuki; Yasuhiro; (Tokyo,
JP) ; Tashiro; Katsumi; (Tokyo, JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
Kabushiki Kaisha
Bridgestone
|
Family ID: |
34708826 |
Appl. No.: |
10/583850 |
Filed: |
December 22, 2004 |
PCT Filed: |
December 22, 2004 |
PCT NO: |
PCT/JP04/19242 |
371 Date: |
June 21, 2006 |
Current U.S.
Class: |
180/65.51 |
Current CPC
Class: |
F16D 3/04 20130101; B60K
7/0007 20130101; Y02T 10/7072 20130101; B60K 2007/0092 20130101;
B60K 2007/0038 20130101 |
Class at
Publication: |
180/065.5 |
International
Class: |
B60K 1/00 20060101
B60K001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2003 |
JP |
2003-425668 |
Claims
1. An in-wheel motor system having a hollow direct drive motor
which is provided in a wheel and whose stator side is supported to
a part around the wheel of a vehicle by elastic bodies and/or an
attenuation mechanism, wherein a motor rotor and a wheel or a hub
are interconnected by a coupling mechanism which comprises a
wheel-side plate connected to the wheel or hub, a motor-side plate
connected to the rotating side case of the motor, an intermediate
plate interposed between these two plates, and first and second
slide members for interconnecting between the wheel-side plate and
the intermediate plate and between the intermediate plate and the
motor-side plate, each having roller members whose moving
directions are limited by guide portions, and arranged in such a
manner that their moving directions are orthogonal to each
other.
2. The in-wheel motor system according to claim 1, wherein contact
portions which extend in the moving directions of the roller
members and are brought into contact with the side faces of the
roller members are provided on the intermediate plate to limit the
moving directions of the roller members.
3. The in-wheel motor system according to claim 1 or 2, comprising
an elastic annular dust boot for storing the first and second slide
members.
4. An in-wheel motor system having a hollow direct drive motor
which is provided in a wheel and whose stator side is supported to
a part around the wheel of a vehicle by elastic bodies and/or an
attenuation mechanism, wherein a motor rotor and a wheel or a hub
are interconnected by a coupling mechanism which comprises a
wheel-side plate connected to the wheel or hub, a motor-side plate
connected to the rotating side case of the motor, an intermediate
plate interposed between these two plates, and first and second
slide members for interconnecting between the wheel-side plate and
the intermediate plate and between the intermediate plate and the
motor-side plate, each consisting of linear bearings and a rod, and
arranged in such a manner that their moving directions are
orthogonal to each other.
5. The in-wheel motor system according to claim 4, comprising an
elastic annular dust boot for storing the first and second slide
members.
6. An in-wheel motor system having a hollow direct drive motor
which is provided in a wheel and whose stator side is supported to
a part around the wheel of a vehicle by elastic bodies and/or an
attenuation mechanism and a coupling member having a slide
mechanism for connecting the rotor of the motor to the wheel or
hub, wherein an elastic annular dust boot for storing the slide
mechanism is provided.
Description
BACKGROUND OF THE INVENTION
[0001] 1. [Field of the Invention]
[0002] The present invention relates to an in-wheel motor system
for use in a vehicle having direct drive wheels as drive
wheels.
[0003] 2. [Description of the Prior Art]
[0004] It is generally known that, in a vehicle having a suspension
mechanism such as a spring around a wheel, as the mass of parts
under the spring such as a wheel, knuckle and suspension arm,
so-called "unsprung mass" increases, changes in the ground holding
force of a tire when running on an uneven road become larger,
thereby deteriorating road holding properties.
[0005] In a vehicle driven by a motor such as an electric car, an
in-wheel motor system incorporating a motor in a wheel is being
employed. However, in a conventional in-wheel motor whose
non-rotating part is fixed to a spindle shaft connected to a part
such as an upright or knuckle which is one of the parts around a
wheel of the vehicle and whose rotor as a rotating part can rotate
together with the wheel, the above unsprung mass increases by the
weight of the in-wheel motor, whereby changes in the ground holding
force of the tire become large, thereby deteriorating road holding
properties (refer to patent documents 1 to 3, for example).
[0006] To solve the above problem, there is proposed an in-wheel
motor system as shown in FIG. 7 in which a non-rotating side case
3a supporting a stator 3S is elastically supported to a knuckle 5
as a part around the wheel of a vehicle by a buffer mechanism 50
having two plates 54 and 55 whose moving directions are limited to
the vertical direction of the vehicle by direct-acting guides 51
and which are interconnected by springs 52 and a damper 53 moving
in the vertical direction of the vehicle and a rotating side case
3b supporting a rotor 3R and a wheel 2 are interconnected by a
flexible coupling 60 as a drive force transmission mechanism which
can become eccentric in the radical direction of the wheel 2 (refer
to patent document 4, for example).
[0007] More specifically, as shown in FIG. 8, the above flexible
coupling 60 comprises a plurality of hollow disk-like plates 61A to
61C and direct-acting guides 62A and 62B for interconnecting
between the adjacent plates 61A and 61B and between the adjacent
plates 61B and 61C and guiding the above adjacent plates 61A and
61B and the adjacent plates 61B and 61C in the radial direction of
the disk. As shown in FIG. 9, each of the above direct-acting
guides 62A and 62B comprises a guide rail 62x having a projection
extending in the radial direction of the above plates 61A to 61C, a
guide member 62y having a recess extending in the radial direction
of the above plates 61A to 61C to be engaged with the above guide
rail 62x, and a plurality of steel balls 62m interposed between the
projection of the above guide rail 62x and the recess of the guide
member 62y to smoothly slide the above guide rail 62x and the guide
member 62y.
[0008] Since the above guide rail 62x and the guide member 62y
slide so as to guide the above adjacent plates 61A and 61B and the
adjacent plates 61B and 61C in the radial direction of the disk,
the in-wheel motor 3 can move in the working direction of the above
direct-acting guides 62A and 62B, that is, the radial direction of
the disk but not in the rotation direction. Therefore, by
connecting the rotating side case 3b of the motor 3 to the wheel 2
by the above flexible coupling 60, drive torque can be transmitted
from the motor 3 to the wheel 2 efficiently.
[0009] In the in-wheel motor system constituted as described above,
the in-wheel motor 3 is elastically supported to the knuckle 5
which is a part around the wheel of a vehicle to be float mounted
to the part by the above buffer mechanism 50 so that the motor 3
itself can be used as the weight of a dynamic damper, thereby
making it possible to improve ground holding performance and riding
comfort when running on a bad road. Since the motor shaft and the
wheel shaft are interconnected by the above flexible coupling 60 in
such a manner that they can become eccentric to each other in any
direction, torque can be transmitted from the motor 3 to the wheel
2 efficiently.
[0010] In the above method, the motor 3 vibrates in the vertical
direction independently of the parts around the wheel of the
vehicle, a certain measure of spacing is required between the motor
3 and the wheel 2. Therefore, when the vehicle runs on a graveled
road and gravel enters this spacing, the motor may be damaged by
the vibration of the motor 3 in the wheel 2. To cope with this, the
present applicant proposes a method for preventing the entry of a
stone or dust into the above spacing by blocking the spacing
between the above motor 3 and the wheel 2 from the outside with a
first annular dust boot 9A having a wavy section in the direction
perpendicular to the shaft and the deformation of a coupling
portion by a stepping stone or the entry of dust into the
direct-acting guides 62A and 62B by forming a barrier on the inner
side of the flexible coupling 60 with a second annular dust boot 9B
as shown in FIG. 6 (Japanese Patent Application No.
2002-251401).
Patent document 1: Japanese Patent No. 2676025
Patent document 2: Japanese Examined Patent Publication No.
9-506236
Patent document 3: Japanese Unexamined Patent Application No.
10-305735
Patent document 4: WO 02/083446 A1
SUMMARY OF THE INVENTION
[0011] Although the above flexible coupling 60 can transmit the
drive torque of the motor 3 to the wheel 2 efficiently, as it has a
large number of parts and comprises the direct-acting guides 62A
and 62B which require high assembly accuracy, it takes long to
mount the above direct-acting guides 62A and 62B to the above
plates 61A to 61C, thereby reducing productivity. Further, since
the above direct-acting guides 62A and 62B are expensive, the whole
system costs dear.
[0012] Although grease is filled into the above direct-acting
guides 62A and 62B to smoothen their movements and the above dust
boots 9A and 9B can prevent the entry of a stone or dust from the
outside, the above grease may leak out into the motor 3 from the
periphery of the flexible coupling 60.
[0013] It is an object of the present invention which has been made
in view of the above problem of the prior art to provide an
in-wheel motor system capable of transmitting the drive torque of a
motor to a wheel very efficiently with simple constitution and
comprising a flexible coupling which is easily assembled.
[0014] According to a first aspect of the present invention, there
is provided an in-wheel motor system having a hollow direct drive
motor which is provided in a wheel and whose stator side is
supported to a part around the wheel of a vehicle by elastic bodies
and/or an attenuation mechanism, wherein
[0015] a motor rotor and a wheel or a hub are interconnected by a
coupling mechanism which comprises a wheel-side plate connected to
the wheel or hub, a motor-side plate connected to the rotating side
case of the motor, an intermediate plate interposed between these
two plates, and first and second slide members for interconnecting
between the wheel-side plate and the intermediate plate and between
the intermediate plate and the motor-side plate, each having roller
members whose moving directions are limited by guide portions, and
arranged in such a manner that their moving directions are
orthogonal to each other.
[0016] According to a second aspect of the present invention, there
is provided an in-wheel motor system, wherein contact portions
which extend in the moving directions of the above roller members
and are brought into contact with the side faces of the roller
members are provided on the intermediate plate to limit the moving
directions of the roller members.
[0017] According to a third aspect of the present invention, there
is provided an in-wheel motor system comprising an elastic annular
dust boot for storing the first and second slide members.
[0018] According to a fourth aspect of the present invention, there
is provided an in-wheel motor system having a hollow direct drive
motor which is provided in a wheel and whose stator side is
supported to a part around the wheel of a vehicle by elastic bodies
and/or an attenuation mechanism, wherein
[0019] a motor rotor and a wheel or a hub are interconnected by a
coupling mechanism which comprises a wheel-side plate connected to
the wheel or hub, a motor-side plate connected to the rotating side
case of the motor, an intermediate plate interposed between these
two plates, and first and second slide members for interconnecting
between the wheel-side plate and the intermediate plate and between
the intermediate plate and the motor-side plate, each consisting of
linear bearings and a rod, and arranged in such a manner that their
moving directions are orthogonal to each other.
[0020] According to a fifth aspect of the present invention, there
is provided an in-wheel motor system according to claim 4,
comprising an elastic annular dust boot for storing the first and
second slide members.
[0021] According to a sixth aspect of the present invention, there
is provided an in-wheel motor system having a hollow direct drive
motor which is provided in a wheel and whose stator side is
supported to a part around the wheel of a vehicle by elastic bodies
and/or an attenuation mechanism and a coupling member having a
slide mechanism for connecting the rotor of the motor to the wheel
or hub, wherein
[0022] an elastic annular dust boot for storing the slide mechanism
is provided.
[0023] According to the present invention, the rotor of a hollow
direct drive motor provided in a wheel and the wheel or the hub are
interconnected by a coupling mechanism which comprises first and
second slide members for interconnecting between the wheel-side
plate and the intermediate plate and between the intermediate plate
and the wheel-side plate, having roller members whose moving
directions are limited by guide portions and arranged in such a
manner that their moving directions are orthogonal to each other.
Even when the motor shaft and the wheel shaft become eccentric to
each other, the drive torque of the motor can be transmitted to the
wheel without fail, the assembly becomes easy and the work
efficiency can be improved.
[0024] When first and second slide members, each consisting of
linear bearings and a rod, are used in place of the above first and
second slide members having the above roller members, the same
effect can be obtained.
[0025] When the motor rotor and the wheel are interconnected by a
coupling member having a slide mechanism comprising first and
second slide members having the above roller members or first and
second slide members, each consisting of linear bearings and a rod,
if an elastic annular dust boot for storing the above slide
mechanism is provided, the entry of dust or water into the slide
mechanism or the diffusion of grease filled into the slide portions
of the slide mechanism can be prevented effectively.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a longitudinal sectional view showing the
constitution of an in-wheel motor system according to Embodiment 1
of the present invention;
[0027] FIGS. 2(a) and 2(b) are diagrams showing the constitution of
a flexible coupling according to Embodiment 1;
[0028] FIGS. 3(a) and 3(b) are diagrams showing the constitution of
a flexible coupling according to Embodiment 2 of the present
invention;
[0029] FIG. 4 is a longitudinal sectional view showing the
constitution of an in-wheel motor system according to Embodiment 3
of the present invention;
[0030] FIGS. 5(a) and 5(b) are diagrams showing the operation of a
dust boot according to Embodiment 3;
[0031] FIG. 6 is a longitudinal section showing the constitution of
an in-wheel motor system comprising a flexible coupling and a dust
boot according to the present invention;
[0032] FIG. 7 is a diagram showing the constitution of a
conventional in-wheel motor system of the prior art;
[0033] FIG. 8 is a diagram showing the constitution of a
conventional flexible coupling of the prior art; and
[0034] FIG. 9 is a diagram showing an example of a direct-acting
guide.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] Preferred embodiments of the present invention will be
described hereinunder with reference to the accompanying
drawings.
Embodiment 1
[0036] FIG. 1 shows the constitution of an in-wheel motor system
according to Embodiment 1 of the present invention. In FIG. 1,
reference numeral 1 denotes a tire, 2 a wheel consisting of a rim
2a and a wheel disk 2b, and 3 an outer rotor type in-wheel motor
which comprises a stator 3S fixed to a non-rotating side case 3a
arranged on the inner side in the radial direction and a rotor 3R
fixed to a rotating side case 3b rotatably connected to the above
non-rotating side case 3a through a bearing 3j and arranged on the
outer side in the radial direction.
[0037] Numeral 4 denotes a hub connected to the wheel 2 at its
rotary shaft, 5 a knuckle connected to an axle 6, 7 a suspension
member composed of a shock absorber, 8 a brake unit composed of a
brake disk mounted to the above hub 4, 10 a flexible coupling
comprising a plurality of slide members 12A and 12B having roller
members 12p which are mounted on the opposed surfaces of a
motor-side plate 11A and a wheel-side plate 11C in such a manner
that their moving directions become orthogonal to each other, and
50 a buffer mechanism for elastically supporting the non-rotating
side case 3a supporting the stator 3 to the above knuckle 5 as a
part around the wheel of the vehicle, comprising two plates 54 and
55 whose moving directions are limited to the vertical direction of
the vehicle by direct-acting guides 51 and which are interconnected
by springs 52 and a damper 53 moving in the vertical direction of
the vehicle.
[0038] As shown in FIGS. 2(a) and 2(b), the above flexible coupling
10 is constituted such that a pair of roller members 12p and 12p
having a convex portion forming part of a spherical surface and
constituting first slide members 12A are mounted in a direction
parallel to the direction A on the opposite sides in the
circumferential direction of the motor-side plate 11A, a pair of
roller members 12p and 12p constituting second slide members 12B
are mounted in a direction parallel to the direction B orthogonal
to the above direction A on the wheel-side plate 11C at positions
90.degree. shifted from the positions of the above roller members
12p, and guide grooves 12q having a concave portion corresponding
to the convex portions of the roller members 12p of the first and
second slide members 12A and 12B are formed on the front and rear
surfaces opposed to the above roller members 12p of the
intermediate plate 11B. The end portions of the roller members 12p
are rotatably stored in the above guide grooves 12q. A stepped
portion 12m is formed on the motor-side plate 11A side of the above
intermediate plate 11B, the above guide grooves 12q are formed in
this stepped portion 12m, a stepped portion 12n is also formed on
the wheel-side plate 11C side of the intermediate plate 11B, the
above guide grooves 12q are formed in this stepped portion 12n, the
sectional form of a stepped surface 12K between the above stepped
portion 12m and the motor-side plate 11A side of the intermediate
plate 11B extending in the above direction A and the sectional form
of a stepped surface 12K between the above stepped portion 12n and
the wheel-side plate 11C side of the above intermediate plate 11B
extending in the direction B are made corresponding to the shape of
the above roller members 12p, for example, a curve having the same
curvature as that of the above roller members 12p, and the above
roller members 12p and 12p are brought into contact with the above
stepped surfaces 12K, whereby the above stepped surfaces 12K serve
as a guide to limit the moving directions of the above roller
members 12p and 12p. Therefore, the above motor-side plate 11A and
the intermediate plate 11B can be interconnected in such a manner
that they can move in the direction A, and the intermediate plate
11B and the wheel-side plate 11C can be interconnected in such a
manner that they can move in the direction B orthogonal to the
above direction A.
[0039] Since the distance between the motor-side plate 11A and the
wheel-side plate 11C can be made small by forming the above stepped
portions 12m and 12n in the intermediate plate 11B, the thickness
and weight of the flexible coupling 10 can be reduced.
[0040] Although guide holes may be formed in place of the above
guide grooves 12q, the guide grooves 12q are preferably formed to
reduce the size and weight of the flexible coupling 10.
[0041] Since the above roller members 12p do not need to be brought
into contact with the intermediate plate 11B, the guide grooves 12q
may be omitted.
[0042] The above stepped surfaces 12K may be made flat and guide
members having the same contact surface as the above stepped
surfaces 12K to be brought into contact with the above roller
members 12p may be provided on the opposite side to the above
stepped surfaces 12K of the above roller members 12p on the
intermediate plate 11B to limit the moving directions of the roller
members 12p. In this case, the number of parts increases though the
side shape of the intermediate plate 11B is simplified. Therefore,
it is preferred that the moving directions of the above roller
members 12p and 12p should be limited by the above stepped surfaces
12K.
[0043] In the flexible coupling 10 of this embodiment, as the
motor-side plate 11A and the intermediate plate 11B can move in the
direction A by the above first slide members 12A, and the
intermediate plate 11B and the wheel-side plate 11C can move in the
direction B orthogonal to the above direction A by the above second
slide members 12B as described above, the motor-side plate 11A and
the wheel-side plate 11C can move in all directions. Therefore,
even when the motor shaft and the wheel shaft become eccentric to
each other due to the vibration of the motor when running on a bad
road, the above eccentricity is absorbed by the first and second
slide members 12A and 12B, thereby making it possible to transmit
the drive force of the motor 3 to the wheel 2 smoothly.
[0044] According to Embodiment 1, since the in-wheel motor 3 and
the wheel 2 are interconnected by the flexible coupling 10 in which
the motor-side plate 11A and the intermediate plate 11B are
interconnected by the first slide members 12A comprising the roller
members 12p moving along the stepped surfaces 12K formed on the
intermediate plate 11B in such a manner that they can move in the
predetermined direction (direction A), and the intermediate plate
11b and the wheel-side plate 11C are interconnected by the second
slide members 12B like the above first slide members 12A in such a
manner that they can move in the direction (direction B) orthogonal
to the above direction A, even when the motor shaft and the wheel
shaft become eccentric to each other, the drive torque of the motor
3 can be transmitted to the wheel 2 without fail.
[0045] Since the flexible coupling 10 of the present invention has
a small number of parts and is easily assembled, the assembly work
efficiency of the in-wheel motor 3 can be enhanced and productivity
can be improved.
Embodiment 2
[0046] In the above Embodiment 1, the flexible coupling 10 in which
the slide members 12A and 12B having the roller members 12p whose
moving directions are orthogonal to each other are used to
interconnect between the motor-side plate 11A and the intermediate
plate 11B and between the intermediate plate 11B and the wheel-side
plate 11C has been described. When a flexible coupling 20 in which
slide members 22A and 22B, each consisting of linear bearings 22p
and a rod 22q inserted into these linear bearings 22P and moving
linearly, are used in place of the above slide members 12A and 12B
to interconnect between a motor-side plate 21A and an intermediate
plate 21B and between the intermediate plate 21B and a wheel-side
plate 21C as shown in FIGS. 3(a) and 3(b), the same effect can be
obtained.
[0047] In the above flexible coupling 20, the linear bearings 22p
and 22p are installed in a direction parallel to the direction A on
the opposite sides in the circumferential direction of the
motor-side plate 21A, cut-outs 21m and 21m are formed on the
motor-side plate 21A side of the intermediate plate 21B, and both
ends of the rod 22q to be inserted into the linear bearings 2p are
fixed to both end surfaces of the above cut-outs 21m and 21m so
that the motor-side plate 21A and the intermediate plate 21B are
interconnected by the above slide members 22A. The linear bearings
22p and 22p are installed in a direction parallel to the direction
B on the opposite sides in the direction B orthogonal to the
direction A at positions 90.degree. shifted from the positions of
the above slide members 22A on the wheel-side plate 21C, cut-outs
21n and 21n are formed at positions 90.degree. shifted from the
above cut-outs 21m and 21m on the wheel-side plate 21C side of the
intermediate plate 21B, and both ends of the rod 22q to be inserted
into the above linear bearings 22p are fixed to both end surfaces
of the above cut-outs 21n and 21n. Thereby, the motor-side plate
21A and the intermediate plate 21B can move in the direction A, and
the wheel-side plate 21C and the intermediate plate 21B can move in
the direction B in FIGS. 3(a) and 3(b). Therefore, the motor-side
plate 21A and the wheel-side plate 21C can move in all directions.
Even when the motor shaft and the wheel shaft become eccentric to
each other, the torque of the motor 3 can be transmitted to the
wheel 2 smoothly.
[0048] In the above Embodiments 1 and 2, the wheel-side plate 11C
or 21C is directly connected to the wheel 2. When the above
wheel-side plate 11C or 21C is connected to the hub 4 connected to
the wheel 4 at its rotary shaft, the same effect can be
obtained.
Embodiment 3
[0049] FIG. 4 shows the constitution of an in-wheel motor system
according to Embodiment 3 of the present invention. In FIG. 4,
reference numeral 1 denotes a tire, 2 a wheel consisting of a rim
2a and a wheel disk 2b, and 3 an outer rotor type in-wheel motor
which comprises a stator 3S fixed to a non-rotating side case 3a
arranged on the inner side in the radial direction and a rotor 3R
fixed to a rotating side case 3b rotatably connected to the above
non-rotating side case 3a through a bearing 3j and arranged on the
outer side in the radial direction.
[0050] Numeral 4 denotes a hub connected to the wheel 2 at its
rotary shaft, 5 a knuckle connected to an axle 6, 7 a suspension
member composed of a shock absorber, 8 a brake unit composed of a
brake disk mounted to the above hub 4, 9A the first annular dust
boot shown in FIGS. 7, and 9M an elastic dust boot having a wavy
section according to the present invention.
[0051] 50 denotes a buffer mechanism for elastically supporting the
non-rotating side case 3a supporting the stator 3 to the above
knuckle 5, comprising two plates 54 and 55 whose moving directions
are limited to the vertical direction of the vehicle by
direct-acting guides 51 and which are interconnected by springs 52
and a damper 53 moving in the vertical direction of the vehicle,
and 60 a flexible coupling comprising a plurality of hollow
disk-like plates 61A to 61C interconnected by direct-acting guides
62A and 62B which are arranged in such a manner that their moving
directions become orthogonal to each other.
[0052] As shown in FIGS. 5(a) and 5(b), the above dust boot 9M
comprises an annular boot 9a for covering the outer sides of the
direct-acting guides 62A and 62B arranged in the circumferential
directions of the hollow disk-like plates 61A to 61C of the above
flexible coupling 60 and an annular boot 9b for covering the inner
sides of the direct-acting guides 62A and 62B, and the both annular
boots 9a and 9b are interposed between the motor-side plate 61A and
the wheel-side plate 61C, thereby making it possible to protect the
direct-acting guides 62A and 62B from the outside. That is, as
barriers are formed on the inner sides and the outer sides of the
direct-acting guides 62A and 62B of the above flexible coupling 60
by the above dust boot 9M, the deformation of the above coupling
portion by a stepping stone and the entry of dust into the
direct-acting guides 62A and 62B can be prevented and the leakage
of grease filled into the slide portions of the direct-acting
guides 62A and 62B which are a slide mechanism to the outside can
be prevented.
[0053] Since the above dust boot 9M is an elastic member having a
wavy section, it expands and contracts along with the movement of
the above flexible coupling 60. Therefore, unrequired force is not
applied to the above flexible coupling 60, thereby making it
possible to move the above flexible coupling 60 smoothly.
[0054] According to Embodiment 3, in the in-wheel motor system in
which the non-rotating side case 3a of the motor 3 is connected to
the knuckle 5 by the buffer mechanism 50 and the rotating side case
3a of the motor 3 is connected to the wheel 2 by the flexible
coupling 60, the direct-acting guides 62A and 62B which are the
slide mechanism of the above flexible coupling 60 are stored in the
elastic dust boot 9M having a wavy section. Therefore, the entry of
a stone or dust into the above direct-acting guides 62A and 62B can
be prevented and the leakage of grease filled into the
direct-acting guides 62A and 62B which are slide portions to the
outside can be prevented, thereby making it possible to greatly
improve the reliability of the in-wheel motor system.
[0055] In the above Embodiment 3, the direct-acting guides 62A and
62B which are the slide mechanism of the conventional flexible
coupling 60 are stored in the dust boot 9M. The present invention
is not limited to this. For example, by applying the present
invention to the above in-wheel motor systems of Embodiments 1 and
2, the entry of a stone or dust into the slide members 12A and 12B
of the above flexible coupling 10 or the slide members 22A and 22B
of the above flexible coupling 20 can be prevented and the leakage
of grease from the above slide members 12A and 12B or 22A and 22B
to the outside can be prevented. Stated more specifically, when the
annular boot 9a for covering the outer sides of the slide members
12A and 12B, each consisting of the roller member 12p and the guide
groove 12q, as the slide mechanism of the above flexible coupling
10 and the annular boot 9b for covering the inner sides of the
above slide members 12A and 12B are installed between the
motor-side plate 11A and the wheel-side plate 11C and the above
slide members 12A and 12B are stored in the elastic dust boot 9M
having a wavy section which comprises the above annular boots 9a
and 9b as shown in FIG. 6, the entry of a stone or dust into the
above slide members 12A and 12B can be prevented and the leakage of
grease filled into the roller members 12p and the guide grooves 12q
which are the slide portions of the above slide members 12A and 12B
to the outside can be prevented, thereby making it possible to
greatly improve the reliability of the in-wheel motor system.
[0056] Even when the slide members 22A and 2B, each consisting of
the linear bearings 22p and the rod 22q, are used in place of the
above slide members 12A and 12B, if the above slide members 22A and
22B are stored in the elastic dust boot 9M, the same effect can be
obtained.
INDUSTRIAL FEASIBILITY
[0057] As having been described above, according to the present
invention, since the rotor of the in-wheel motor and the wheel or
the hub are interconnected by the flexible coupling which has a
small number of parts and is easily assembled, productivity can be
improved and the in-wheel motor can be manufactured at a low
cost.
[0058] Since the slide mechanism of the coupling member is stored
in an elastic annular dust boot, the entry of dust and water into
the slide mechanism and the diffusion of grease filled into the
slide portions of the above slide mechanism to the outside can be
prevented effectively.
* * * * *