JP2000229596A - All-wheel drive vehicle - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the sealing performance of a meshing portion between a hydraulic motor and a hub without increasing the size of the hub. SOLUTION: A hub 41 is formed in a bottomed cylindrical shape and a cylindrical portion 4 is formed.
A circular recess 63 is formed by 1c and the bottom 41a. The bottom portion 41a is rotatably supported on an axle 42 by a bearing 61. The outer peripheral portion of the disc-shaped cover 43 for supporting the hydraulic motor 7 is positioned at the boundary between the cylindrical portion 41c and the bottom portion 41a. A labyrinth seal 68 is formed between the outer peripheral portion of the disc-shaped cover 43 and the cylindrical portion 41c. A seal member 69 is provided on the bottom side of the circular recess 63 from the labyrinth seal 68.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-wheel drive vehicle for driving front wheels by hydraulic pressure.

[0002]

2. Description of the Related Art Conventionally, as this kind of all-wheel drive type vehicle, there is one disclosed in, for example, JP-A-9-156570. The all-wheel drive vehicle disclosed in this publication drives a rear wheel in conjunction with rotation of an output shaft of an engine and drives a hydraulic motor for front wheels with a hydraulic pump that operates in conjunction with rotation of the output shaft. In addition, the motorcycle is a motorcycle that drives the front wheels. A part of the hydraulic motor faces the inside of the hub, and these two parts are gear-coupled in the hub.

In the hub, an axle is penetrated by a boss formed in an axis portion, and both ends of the boss in a vehicle width direction are rotatably supported by the axle by bearings. One end of the boss extends radially outward, and a cylindrical portion having a spoke connection flange is formed on an outer peripheral portion of the extended portion. The tubular portion is formed so as to open toward one side of the vehicle body, and an internal gear is attached to a portion corresponding to the bottom of a circular recess formed by the tubular portion.

[0004] The hydraulic motor is supported by a disk-shaped cover fixed to the axle side, and an output gear meshes with the internal gear in the circular recess. The cover is formed so as to close the circular concave portion of the hub, and faces just inside an opening edge of the cylindrical portion. A seal member is interposed between the outer peripheral surface of the cover and the inner peripheral surface of the opening edge to prevent foreign substances such as muddy water, sand, and pebbles from entering the hub.

[0005]

However, in the all-wheel drive type vehicle constructed as described above, the seal member interposed between the hub and the disc-shaped cover for supporting the hydraulic motor is provided on the outermost side of the hub. Since it is located, there is a problem that the stones that jump up on the front wheels and the projections on the road surface are liable to be damaged due to collision, and the seal member is easily worn by muddy water. If the sealing property of the seal member is reduced, the meshing portion between the hydraulic motor and the hub is worn by muddy water or the like that has entered the hub.

The above-mentioned problem can be solved by providing a member for protecting the seal member.
However, such a configuration results in a large hub.

The present invention has been made to solve such a problem, and an object of the present invention is to improve the sealing performance of a meshing portion between a hydraulic motor and a hub without increasing the size of the hub.

[0008]

In order to achieve this object, an all-wheel drive vehicle according to the invention described in claim 1 is provided.
The hub is formed in a cylindrical shape with a bottom and a circular concave portion is formed by a cylindrical portion and a bottom portion, the bottom portion is rotatably supported on an axle by a bearing, and an outer peripheral portion of a disk-shaped cover for supporting a hydraulic motor is formed by the cylindrical portion. A labyrinth seal is formed between the outer peripheral portion and the cylindrical portion, and a seal member is disposed on the bottom side of the labyrinth seal.

According to the present invention, since the seal member is located at the deepest portion from one side of the hub to the other side, pebbles and road surface projections do not directly hit the seal member. In addition, since the labyrinth seal is formed outside the seal member, the seal member can be sealed by the labyrinth seal even if muddy water or the like enters the circular concave portion of the hub. Further, since the seal member and the labyrinth seal are arranged in a recessed portion, and the axial end of the hub does not protrude to the side, the hub can be formed compact in the vehicle width direction.

The all-wheel drive vehicle according to the second aspect of the invention is the all-wheel drive vehicle according to the first aspect, wherein the gear coupling portion between the hydraulic motor and the hub and the cover are brought close to each other. It is.

According to the present invention, since the hydraulic motor can be supported near the gear coupling portion, the hydraulic motor can be firmly supported.

According to a third aspect of the present invention, there is provided an all-wheel drive vehicle according to the first or second aspect, wherein the hub is supported on the axle by one double-row rolling bearing. Things.

According to the present invention, the work of mounting the hub on the axle is simplified. At the same time, the boss through which the axle passes in the hub can be formed relatively short, and the hub can be reduced in weight.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Hereinafter, an embodiment of an all-wheel drive vehicle according to the present invention will be described in detail with reference to FIGS. Here, a description will be given of a form adopted when the present invention is applied to an all-wheel drive motorcycle.

FIG. 1 is a left side view showing a schematic configuration of an all-wheel drive motorcycle, FIG. 2 is a right side view thereof, FIG.
FIG. 4 is a rear view. FIG. 5 is a diagram showing the configuration of the hydraulic system, FIG. 6 is a cross-sectional view of a hydraulic unit interposed in the hydraulic system, and FIG. 7 is a cross-sectional view of the hydraulic control on-off valve taken along line VII-VII in FIG. ) Shows a fully closed state, and FIG. 2B shows a fully opened state. FIG. 8 is a front view of the hydraulic unit. 9 is a sectional view showing a schematic configuration of a front wheel hub, FIG. 10 is a sectional view of a front wheel hub, and FIG. 11 is an enlarged sectional view showing a main part of the hub.

In these figures, reference numeral 1 denotes an all-wheel drive motorcycle according to this embodiment. The motorcycle 1 transmits the power of an engine 2 to a rear wheel 4 by a chain 3 to drive the rear wheel 4 and supplies hydraulic pressure to a hydraulic motor 7 of a front wheel 6 by an engine-driven hydraulic pump 5. The front wheel 6 is driven by a hydraulic motor 7.

In the drawing, reference numeral 8 denotes a conventionally known telescopic front fork for supporting the front wheel 6, 9 denotes a steering handle, 10 denotes a fuel tank, and 11 denotes a seat. In this embodiment, the engine 2 is a four-cycle single cylinder type engine. A carburetor 12 is connected to the rear side of the vehicle body of the cylinder head 2a, and an exhaust pipe 13 is connected to the front side of the vehicle body. The exhaust pipe 13 is formed to extend rearward on the right side of the vehicle body, and has a muffler 14 connected to a rear end.

The rear wheel drive system of the motorcycle 1 has a conventional structure in which a rear wheel 4 is connected to an engine output shaft 15 projecting from a crankcase 2b via a sprocket 16 and a rear wheel power transmission means 17 comprising the chain 3. It has a well-known structure. As shown in FIG. 5, the front wheel drive system includes the hydraulic pump 5 on the engine side, a hydraulic unit 21 for controlling hydraulic pressure, the hydraulic motor 7 on the front wheel side, and the like.

As shown in FIGS. 1 and 2, the hydraulic pump 5 is supported on a crankcase 2b via a bracket 22, and an input shaft 5a (see FIG. 5) is connected to the engine output shaft 15 by sprockets 23a, 23b. And a power transmission means 25 for a front wheel comprising a chain 24. The engine output shaft 1 of the front wheel power transmission means 25
The fifth sprocket 23a is provided with the rear wheel power transmission
Is provided on the outside of the vehicle body from the sprocket 16.

As described above, by connecting the hydraulic pump 5 to the engine output shaft 15 by the front wheel power transmission means 25, the input shaft 5a of the hydraulic pump 5 is synchronized with the rear wheel 4.
Rotates. In this embodiment, the hydraulic pump 5 is arranged and supported at the right end of the vehicle body on the crankcase 2b (not shown), and the weight can be balanced with the front wheel power transmission means 25 located on the left side of the vehicle body. It has a structure. By adopting this structure, the input shaft 5a extends from one end in the vehicle width direction to the other end in the vehicle width direction above the crankcase 2b. Therefore, the input shaft 5a is mounted on the bracket 22 fixed to the crankcase 2b via the bearing 26. It is rotatably supported. The front wheel power transmission means 25 may be of a belt type.

As shown in FIGS. 5 to 8, the hydraulic unit 21 has a unitized structure in which a plurality of members to be described later are assembled to one housing 27, and is shown in FIGS. As shown in FIG. 2, the muffler 14 is disposed on the opposite side in the vehicle width direction, and is supported by a body frame 29 via a stay 28 (see FIGS. 1 and 2). In this embodiment, the hydraulic unit 21 is viewed from the side of the vehicle body.
The hydraulic unit 21 is arranged so that the muffler 14 and the muffler 14 overlap. The hydraulic unit 21 and the muffler 14
Are disposed above the rear wheel 4 when viewed from the side.

As shown in FIGS. 5 and 6, the plurality of members provided in the hydraulic unit 21 include an oil filter 30, an inflatable pressurizing means 31, and an operation switching valve 32.
And a check valve 33 and a relief valve 34.

Housing 27 for mounting these members
As shown in FIG. 6, is formed to be long in the left-right direction of FIG. The oil filter 30 is loaded in the lower part of the housing 27 and the pressurizing means 31 is loaded in the upper part. Further, one end of the housing 27 in the longitudinal direction (the axial direction of the oil filter 30 and the pressurizing means 31). The operation switching valve 32, the check valve 33, and the relief valve 34 are attached to the left end (in the figure, the end portion). The oil filter 30 and the pressurizing means 31 are arranged close to each other in the vertical direction so that their axes are parallel to each other. The hydraulic oil chamber 35 has a structure in which a portion for loading the oil filter 3 and a portion for loading the pressurizing means 31 communicate with each other, and a pressure applied by the pressurizing means 31 is transmitted to the entire region in the hydraulic oil chamber 35. ing.

The oil filter 30 has a structure in which foreign matter is filtered by hydraulic fluid flowing into the shaft from outside the filter element 30a, and an oil outflow provided at one end in the axial direction at the shaft. The tube 36 and the other end are supported by the housing 27. The oil outlet pipe 36 is connected to an oil outlet 27a of the housing 27 (see FIG. 6).

The pressurizing means 31 has a structure in which air or an inert gas is filled in a compressed state in a bladder 31a formed in a bag shape with rubber, and the right end in FIG. . The hydraulic oil in the hydraulic circuit according to the present embodiment is pressurized to about 5 atm by the pressurizing means 31. The pressurization is performed in order to prevent the hydraulic pressure on the suction side from decreasing when the rotational speed of the hydraulic pump 5 is significantly increased, thereby preventing cavitation. The inflatable pressurizing means is not limited to such a bladder (gas bag) type, and the free piston is operated with one side facing the hydraulic oil and the other side facing the high-pressure gas chamber. Any type, such as a gas piston type that pressurizes oil, can be adopted.

Here, the configuration of the hydraulic circuit of the front wheel drive system will be described in more detail with reference to FIG. The hydraulic pump 5 that supplies the hydraulic pressure to the hydraulic circuit is of an axial plunger type known as a so-called swash plate pump, and the hydraulic pump 21 is connected to the hydraulic oil suction port 5 b through a first hydraulic oil return passage 37. The hydraulic oil outlet 27a is connected. The operation switching valve 32 is interposed in the first hydraulic oil return passage 37.

On the other hand, the hydraulic oil discharge port 5c of the hydraulic pump 5
Connects the hydraulic oil inlet 7a of the hydraulic motor 7 by a hydraulic oil supply passage 38 composed of a flexible hydraulic hose or the like. The hydraulic unit 21 is connected in the middle of the hydraulic oil supply passage 38 via a bypass passage 39.

The hydraulic motor 7 is of an axial plunger type known as a so-called swash plate motor.
As shown in FIGS. 9 to 11, an output shaft 40 protruding from one end is gear-coupled to a hub 41 of the front wheel 6, which will be described later, and is supported by a disk-shaped cover 43 fixed to an axle 42 of the front wheel 6. That is, when the hydraulic pressure is supplied to the hydraulic motor 7 and the output shaft 40 rotates, this rotation is transmitted to the hub 41 via the gear coupling portion, and the front wheel 6 is driven.

In this embodiment, when the rear wheel 4 and the front wheel 6 are running at substantially the same rotational speed, the hydraulic motor 7 synchronizes with the front wheel 6 while the hydraulic pressure is supplied. It is configured to rotate. That is, even if the hydraulic motor 7 rotates by hydraulic pressure, when the rotation speeds of the rear wheel 4 and the front wheel 6 are substantially equal, no front wheel driving force is generated.

The housing 44 of the hydraulic motor 7 is shown in FIG.
As shown in FIG.
The portion protruding rightward from the vehicle body 1 from the front fork 8 does not hit the front fork 8. In this embodiment, as shown in FIGS. 1 and 2, the hydraulic motor 7 is controlled so that the hydraulic motor 7 does not protrude radially outward from the hub 41 when viewed from the side of the vehicle body. Has formed.

The housing 44 of the hydraulic motor 7 has a hydraulic oil inlet 7a (see FIG. 5) and a hydraulic oil outlet 7b at a portion located behind the front fork 8 in the vehicle body. The hydraulic oil outlet 7b is connected to the hydraulic oil chamber 3 of the hydraulic unit 21 through a second hydraulic oil return passage 45, as shown in FIG.
5 is connected. The hydraulic oil flowing from the hydraulic motor 7 to the hydraulic unit 21 through the second hydraulic oil return passage 45 flows into the hydraulic oil chamber 35 from a hydraulic oil inlet 27b formed in a lower portion of the housing 27 in FIG. The hydraulic oil inlet 27b and the hydraulic oil outlet 27a are connected to the housing 2
7 is formed near one end of the oil filter 30.

Each of the hydraulic oil supply passage 38 and the second hydraulic oil return passage 45 is formed by a flexible hydraulic hose or the like, is piped along the front fork 8, and has a hydraulic oil inlet 7a of the hydraulic motor 7. And exit 7b
(Not shown).

As shown in FIG. 5, the bypass passage 39 includes an operation switching valve 32 of the hydraulic unit 21 and a check valve 33.
And the relief valve 34. Operation switching valve 32
Has a structure in which the operating oil flows only through the first operating oil return passage 37 in the ON state, and the first operating oil return passage 37 communicates with the bypass passage 39 in the OFF state. That is, in the ON state, only the ports A and C among the ports indicated by the reference signs A to C in FIG.
In the F state, all of the ports A to C come to communicate with each other.

As a result, when the operation switching valve 32 is turned ON, the hydraulic oil is supplied from the hydraulic pump 5 to the hydraulic motor 7, the hydraulic oil chamber 35 in the hydraulic unit 21, the oil filter 30, and the hydraulic switching system 32. And the hydraulic motor 7 rotates. When the rear wheel 4 and the front wheel 6 rotate approximately equally, the front wheel 6 is not driven by the hydraulic motor 7, and as a result, the motorcycle 1 travels only with the rear wheel driving force. Further, for example, when the rear wheel 4 idles due to running in a mud, a driving force using the hydraulic motor 7 as a power source is generated in the front wheel 6, and the mud can be escaped by the rotation of the front wheel 6.

On the other hand, when the operation switching valve 32 is turned off, the hydraulic oil supply passage 38 and the first hydraulic oil return passage 37 are communicated with each other via the bypass passage 39 and the operation switching valve 32. The hydraulic pressure supplied to the hydraulic motor 7 decreases, and the front wheel 6 is no longer driven by the hydraulic motor 7. Therefore, during operation, the operation switching valve 32 is
When the FF operation is performed, only rear wheel drive is performed as in a general motorcycle. Even when the rear wheels are driven, the hydraulic motor 7 rotates together with the front wheels 6, so the hydraulic pump 5 is also used at this time.
Hydraulic motor 7 to hydraulic unit 2 from hydraulic oil supply passage 38
1 → The working oil circulates in the hydraulic system composed of the first working oil return passage 37.

The specific structure of the operation switching valve 32 will be described with reference to FIGS. The operation switching valve 32 includes a valve housing 49 attached to the housing 27 via two connection pipes 47 and 48, and a valve body 50 fitted and supported in the valve housing 49 so as to be able to move up and down in a vertical direction. I have.

The lower connecting pipe 47 of the two connecting pipes 47 and 48 is screwed to the valve housing 49 in advance. The connection pipe 48 located on the upper side is screwed to the housing 27 while penetrating the valve housing 49 via the packing 48a, and the valve housing 49 is connected to the housing 2.
7 At this time, the other end of the connection pipe 47 is fitted to the hydraulic oil outlet 27a of the housing 27. The lower connection pipe 47 constitutes a part of the first hydraulic oil return passage 37,
The upper connection pipe 48 forms a part of the bypass passage 39. The remaining portions of the first hydraulic oil return passage 37 and the bypass passage 39 are formed by a flexible hydraulic hose or the like. Of course, a metal pipe may be used in combination.

The valve housing 49 is, as shown in FIG.
First communication passage 51 communicating with first hydraulic oil return passage 37
And a second communication passage 52 communicating with the bypass passage 39, and a valve body fitting hole 53 communicating the two communication passages 51, 52 is formed. The valve body 50 is fitted into the valve body fitting hole 53 so as to be able to advance and retreat.

The operation wire 54 is connected to the upper end of the valve body 50 as shown in FIG. This valve body 50 is shown in FIG.
By moving downward as shown in (a), the valve body fitting hole 53 between the two communication passages 51 and 52 is closed, and FIG.
By moving the valve body 50 upward as shown in (b), the two communication passages 51 and 52 communicate with each other through the valve body fitting hole 53. The operation wire 54 is connected to a switching lever 55 provided on a grip portion of the steering handle 9 as shown in FIGS. That is, by operating the switching lever 55, the operation switching valve 32 can be switched between the ON state and the OFF state. By adopting this structure, the rider can arbitrarily switch and run.

The check valve 33 is a ball-type check valve. As shown in FIG. 6, an operation valve is provided between a connection pipe 48 on the operation switching valve 32 and a hydraulic oil chamber 35 in the housing 27. It is interposed so that hydraulic oil flows only in the direction from the oil chamber 35 to the connection pipe 48. Thus, check valve 3
By interposing the rear wheel 3, the rear wheel brake is applied in a sharp curve, for example, and even when the rear wheel 4 is locked and the hydraulic pump 5 is stopped, the front wheel 6 rotates freely and the curve is not hindered. Can pass.

That is, even if the hydraulic pump 5 is locked and the supply of hydraulic oil from the hydraulic pump 5 to the hydraulic motor 7 is stopped, the hydraulic oil is supplied from the hydraulic oil chamber 35 through the check valve 33 to the hydraulic motor 7. , The front wheel 6 and the hydraulic motor 7 can rotate freely.

As shown in FIG. 6, the relief valve 34 has a valve body 56 movably supported in a vertical direction with respect to the housing 27, and a compression coil spring 57 for urging the valve body 56 in a closing direction. And a spring biased type provided with an adjusting screw 58 for setting the pressure at which the relief valve 34 is opened. The bypass passage 39 between the check valve 33 and the connecting pipe 48, the housing 27 It is interposed between the inner working oil chamber 35. In this embodiment, the relief valve 34 is provided near the end of the pressurizing means 31 in the housing 27.

This relief valve 34 is connected to a bypass passage 39.
When the internal pressure, that is, the pressure in the hydraulic oil supply passage 38 becomes higher than a set pressure (for example, several hundred atmospheres), the structure is opened to allow the hydraulic oil to flow from the bypass passage 39 to the hydraulic oil chamber 35. By providing the relief valve 34 in this manner, the front wheel 6 is firmly gripped on the road surface at the time of all-wheel drive, but even if the rear wheel 4 idles due to mud or the like, the rotation of the hydraulic pump 5 is significantly increased. When the hydraulic pressure exceeds the set pressure of the relief valve 34, the pressure is released toward the hydraulic oil chamber 35, so that the hydraulic circuit such as the hydraulic oil supply passage 38 can be prevented from being damaged.

As shown in FIGS. 10 and 11, the front wheel hub 41 used in the all-wheel-drive motorcycle according to this embodiment is formed in a bottomed cylindrical shape that opens to the right side of the vehicle body (the upper side in FIG. 10). Then, a boss 41b for axle penetration is formed integrally with the axis portion of the bottom portion 41a. This boss 41
b is shorter than the conventional one so as to be accommodated between the left end surface of the hub 41 of the vehicle body and the center of the front wheel 6 in the vehicle width direction (the center is indicated by a dashed line C in FIG. 10). Forming
The axle 42 is rotatably supported by one return-type ball bearing 61. The left side of the vehicle body at the boss 41b (FIG. 10)
(A lower side in FIG. 2), a seal member 62 is interposed between the end portion and the axle 42. A brake disk 63 for a disk brake is mounted on an end surface on the left side of the vehicle body at the bottom 41a of the hub 41.

The bottom portion 41a of this hub 41 and the cylindrical portion 41
c, the hydraulic motor 7 is inserted from the right side of the vehicle body into the circular concave portion 63, and the output gear 65 of the hydraulic motor 7 is meshed with the internal gear 64 fixed at the boundary between the bottom portion 41a and the cylindrical portion 41c. I have. The output gear 65 is fixed to the output shaft 40 of the hydraulic motor 7.

Disc-shaped cover 43 for supporting hydraulic motor 7
Is formed integrally with a boss 66 through which the axle 42 penetrates, and a disk 67 extending radially outward from the boss 66, and the disk 67 is formed inside the circular recess 63. The circular concave portion 63 is closed from the right side of the vehicle body so as to be close to 64. The disc-shaped cover 43 is held on the front fork 8 via a rotation stopper (not shown).

The outer peripheral edge of the disk 67 is located at the boundary between the bottom portion 41a and the cylindrical portion 41c of the hub 41 and on the right side of the vehicle with respect to the internal gear 64. In order to prevent foreign matter such as muddy water and sand from entering the gear coupling portion of the hydraulic motor 7, a seal structure described below is provided between the outer peripheral edge of the disk 67 and the inner peripheral surface of the cylindrical portion 41 c. Is interposed. This seal structure includes a labyrinth seal indicated by reference numeral 68 in FIGS. 10 and 11 and a seal member indicated by reference numeral 69.

The labyrinth seal 68 has a circular plate 67 opposed to the inner peripheral surface of the cylindrical portion 41c of the hub 41 at a small interval.
Is formed by forming a concave groove 68a on the outer peripheral surface 67a. The position of the labyrinth seal 68 is
Is slightly to the left of the vehicle body from the center in the vehicle width direction.

The sealing member 69 is disposed on the bottom side (left side of the vehicle body) of the circular recess 63 with respect to the labyrinth seal 68 and is fixed to the inner peripheral surface of the cylindrical portion 41c.
A lip 69a is in sliding contact with an outer peripheral surface 67c of a cylindrical portion 67b formed so that the outer diameter is smaller than the portion constituting the labyrinth seal 68 on the outer peripheral portion.
In addition, many holes 41d in the circumferential direction formed in the cylindrical portion 41c.
Is for reducing the weight of the hub 41 and for discharging muddy water or the like that has entered the circular recess 63 of the hub 41 to the outside of the hub by centrifugal force. The muddy water that tries to enter is stopped by the rotation.

According to the all-wheel-drive motorcycle 1 configured as described above, the seal member 69 interposed between the disc-shaped cover 43 supporting the hydraulic motor 7 and the hub 41 is located at the innermost position of the hub 41. Therefore, pebbles flying during traveling and projections on the road surface do not directly hit the seal member 69. Moreover, since the labyrinth seal 68 is formed outside the seal member 69, the seal member 69 can be sealed by the labyrinth seal 68 even if muddy water or the like enters the circular concave portion 63 of the hub 41.

Since the seal member 69 and the labyrinth seal 68 are located at the innermost position of the hub 41 as shown in this embodiment, the axial end of the hub 41 does not protrude to the side. The hub 41 can be made compact in the vehicle width direction, and the hub 41 can be downsized. Further, since the boss 41b of the hub 41 is supported on the axle 42 by one return-type ball bearing 61, the hub 41 is connected to the axle 42 as compared with a conventional structure in which bearings are provided at both ends in the vehicle width direction. The work to attach to the camera becomes simple. At the same time, the boss 41b of the hub 41 can be formed relatively short, and the weight of the hub 41 can be reduced.

In the all-wheel drive motorcycle 1 shown in this embodiment, since all the members provided in the hydraulic circuit of the front wheel drive system are assembled to the housing 27 to form the hydraulic unit 21, the assembling work of the front wheel drive system is performed. Is easy. this is,
The components of the front wheel drive system are integrated into three units: a hydraulic pump 5 mounted on the engine 2, a hydraulic motor 7 mounted on the front wheels 6, and a hydraulic unit 21, and they are connected by a hydraulic hose, a pipe or the like. This is because the assembly of the hydraulic circuit is completed by the work. Piping work for hydraulic hoses and pipes is easy, and assembly is simple, so maintenance is easy.

Further, relatively small auxiliary devices such as valves and an oil filter 30 for the front wheel drive system are connected to the hydraulic unit 2.
Since the parts are collected at one location and supported by the vehicle body frame 29, the number of members such as mounting brackets can be reduced as much as possible as compared with a case where the auxiliary machines are mounted on the vehicle body frame 29, respectively. In addition, one housing 27 has an oil filter 30 and an inflatable pressurizing means 3.
1. Since the check valve 33 and the relief valve 34 are incorporated, the number of parts may be reduced by the amount of the housing and the space for accommodating the parts may be narrower than when each of these members is formed independently. There is no need for piping work.

Further, the hydraulic unit 21 has the oil filter 30 and the inflatable pressurizing means 31 juxtaposed so as to be close to each other so that the axes are parallel to each other. It can be formed compact even with a structure in which it is housed. In addition, since the hydraulic oil inlet 27b and the hydraulic oil outlet 27a are provided at the longitudinal end of the housing 27, the piping is connected to the hydraulic unit 2
1 can be connected by piping in the direction in which it becomes longer. Therefore, as shown in this embodiment, the oil filter 30 and the inflatable pressurizing means 31 are arranged vertically and the longitudinal direction of the hydraulic unit 21 is parallel to the front-rear direction of the vehicle body. Can be compactly mounted on the side of the vehicle body.

Further, since the front wheel drive system auxiliary equipment is integrally formed as the hydraulic unit 21, the degree of freedom in the position where the hydraulic unit 21 is mounted can be improved. That is, as shown in the present embodiment, the hydraulic unit 21 is disposed on the opposite side of the muffler 14 in the vehicle width direction, and the weight distribution in the vehicle width direction can be balanced.
Although not shown, the hydraulic unit 21 may be disposed near the engine 2. By employing this structure, heavy objects (the engine, the hydraulic pump 5 and the hydraulic unit 21) can be collected near the center of gravity of the vehicle, and the weight can be concentrated. As shown in the present embodiment, by arranging the hydraulic unit 21 on the opposite side of the muffler 14 in the vehicle width direction and above the rear wheel 4, the maintenance of the hydraulic unit 21 is facilitated. There is also.

In this embodiment, since the hydraulic pump 5 is mounted on the crankcase 2b, not only can the weight be concentrated as described above, but also the hydraulic oil supply passage 38 and the first operating The connection of the pipe forming the oil return passage 37 is easy. In addition, since the hydraulic pump 5 is located near the engine output shaft 15, the connection between the two is easy, and the chain 24 connecting the engine output shaft 15 and the hydraulic pump 5 may be short.

In addition, the operation switching valve 3 of the hydraulic unit 21
2 is operated by the operation lever 55 of the steering handle 9, so that the vehicle is traveling between rear wheel drive and all wheel drive using both the rear wheel 4 and the front wheel 6. Even if there is, you can easily switch. In this case, as shown in this embodiment, even when hydraulic pressure is supplied from the hydraulic pump 5 and the hydraulic motor 7 rotates, it is merely synchronized with the rotation of the front wheel 6 and the hydraulic motor 7 drives the front wheel. As a result, the vehicle may be driven only by the rear wheel driving force without supplying the force, and the front wheel driving force by the hydraulic motor 7 may be generated only when the rear wheel idles due to mud or the like, so that the mud can be escaped. Alternatively, the driving force may always be generated by the front wheel 6 and the rear wheel 4.

Second Embodiment Another embodiment of the all-wheel drive vehicle according to the present invention is shown in FIG.
This will be described in detail with reference to FIG. 12 is a cross-sectional view showing another embodiment of the front wheel hub, FIG. 13 is a left side view of the all-wheel drive motorcycle, FIG. 14 is a right side view thereof, and FIG. 15 is a cross-sectional view of the hydraulic unit. In these drawings, the same or equivalent members as those described in FIGS. 1 to 11 are denoted by the same reference numerals, and detailed description is omitted.

The hub 41 of the front wheel 6 according to this embodiment
As shown in FIG. 12, a boss 41b is formed so as to extend from the center of the front wheel 6 in the vehicle width direction to the right side of the vehicle body, and both ends of the boss are formed by bearings 71 and 72 to form an axle 42.
It is supported rotatably. These bearings 71, 72
Of these, the bearing 71 located on the right side of the vehicle body is a needle bearing, and the bearing 72 located on the left side of the vehicle body is a single row ball bearing.
Even if the hub 41 is formed in this manner, the same effect as when the first embodiment is adopted can be obtained.

The engine 2 of the all-wheel-drive motorcycle 1 according to this embodiment is of a two-cycle, single-cylinder type, and has a hydraulic pump 5 mounted on a cylinder head 2a as shown in FIGS. The input shaft (not shown) of the hydraulic pump 5 is also connected to the engine output shaft 15 by the chain type front wheel power transmission means 25 as in the case of the first embodiment. The front wheel power transmission means 25 may be of a belt type.

The all-wheel-drive motorcycle 1 according to this embodiment does not include an operation switching valve in the front-wheel drive system. Therefore, as shown in FIG. 15, the hydraulic unit 21 includes an oil filter 30, an inflatable pressurizing unit 31,
The check valve 33 and the relief valve 34 are provided integrally with the housing 27, and a hydraulic hose 73 is connected to a hydraulic oil outlet 27 a and a hydraulic oil inlet 27 b of the housing 27, respectively. Even if the operation switching valve 32 is not provided, there is no hindrance to implementing running by all-wheel drive.

The hydraulic unit 21 is provided with only the oil filter 30 and the inflatable pressurizing means 31 integrally, and the other valves are distributed to the hydraulic pump 5 side and the hydraulic motor 7 side and united therewith. can do. That is, a hydraulic system can be configured by the hydraulic unit 21, the hydraulic pump unit, the hydraulic motor unit, and the hydraulic hoses connecting these components to each other. FIG. 16 shows an example of a hydraulic circuit when adopting this embodiment. FIG. 16 is a configuration diagram showing another example of the hydraulic circuit of the front wheel drive system. In this figure, the same or equivalent members as those described with reference to FIGS. 1 to 11 are denoted by the same reference numerals, and detailed description is omitted.

In the hydraulic unit 21 shown in FIG. 16, only the oil filter 30 and the inflatable pressurizing means 31 are integrally assembled to the housing 27. In this example, the operation switching valve 32 and the check valve 33 are interposed between the hydraulic oil supply passage 38 and the second hydraulic oil return passage 45, respectively. Note that the operation switching valve 32 is not provided in the motorcycle 1 according to the present embodiment, and is indicated by a two-dot chain line. If the operation switching valve 32 is provided, it can be at the position shown in FIG. The check valve 33 is connected to the second hydraulic oil return passage 4.
The structure in which the hydraulic oil flows only from 5 to the hydraulic oil supply passage 38 is adopted. The relief valve 34 is provided with a hydraulic oil supply passage 38.
Between the first hydraulic oil return passage 37 and the first hydraulic oil return passage 37, and when the hydraulic pressure in the hydraulic oil supply passage 38 exceeds a set value, the hydraulic oil flows out to the first hydraulic oil return passage 37. I have.

The relief valve 34 may be interposed between the hydraulic oil supply passage 38 and the second hydraulic oil return passage 45 on the hydraulic motor 7 side. In any case, it is integrated into three units. The hydraulic pump unit is denoted by reference numeral 100 in FIG. 16, and the hydraulic motor unit is denoted by reference numeral 200.

The hydraulic pump 5 shown in FIG. 16 is provided at the right end of the vehicle body on the crankcase 2b. This hydraulic pump 5 is provided as shown in FIGS. 17 and 18. Position can be changed.

FIGS. 17 and 18 show examples of mounting a hydraulic pump. In these figures, FIGS.
For members that are the same or equivalent to those described in
The same reference numerals are given and detailed description is omitted.

The hydraulic pump 5 shown in FIG. 17 is disposed on the crankcase 2b at substantially the center in the vehicle width direction, and the input shaft 5a is gear-coupled to the engine output shaft 15. By adopting this structure, maintenance of the front wheel power transmission device 25 becomes unnecessary, and the weight in the vehicle width direction can be balanced, and the weight can be concentrated.

The hydraulic pump 5 shown in FIG. 18 is disposed on the left end of the vehicle body on the crankcase 2b, and the input shaft 5a is driven by a chain-type or belt-type power transmission device 25 for a front wheel to output the engine output shaft. 15. By adopting this structure, the input shaft 5a of the hydraulic pump 5 can be formed as short as possible, and the weight can be reduced.

Further, in each of the above-described embodiments, the check valve 33 is provided in the hydraulic circuit so that the rotation of the front wheel 6 is continued even when the rear wheel 4 is locked by the brake during traveling. However, instead of the check valve 33, a one-way clutch (not shown) that allows the rotation of the front wheel 6 even when the hydraulic motor 7 is stopped is provided at a gear coupling portion between the front wheel hub 41 and the hydraulic motor 7. May be worn. In addition, in the above-described embodiment, an example in which the present invention is applied to a motorcycle is shown. However, it goes without saying that the present invention can be applied to other vehicles such as a motorcycle and a small four-wheeled vehicle. Nor.

[0070]

As described above, according to the first aspect of the present invention, since the seal member is located at the deepest part from one side of the hub to the other side, pebbles and road surface protrusions are formed on the seal member. There is no direct hit. Moreover, since a labyrinth seal is formed outside this seal member,
Even if muddy water or the like enters the circular concave portion of the hub, the seal member can be sealed by the labyrinth seal. Further, since the seal member and the labyrinth seal are arranged in a recessed portion, and the axial end of the hub does not protrude to the side, the hub can be formed compact in the vehicle width direction.

According to the second aspect of the present invention, since the hydraulic motor can be supported near the gear coupling portion, the hydraulic motor can be strongly supported.

According to the third aspect of the present invention, the assembling work of the hub is facilitated, and the weight of the hub can be reduced.

[Brief description of the drawings]

FIG. 1 is a left side view showing a schematic configuration of an all-wheel drive motorcycle.

FIG. 2 is a right side view showing a schematic configuration of an all-wheel drive motorcycle.

FIG. 3 is a front view showing a schematic configuration of an all-wheel drive motorcycle.

FIG. 4 is a rear view showing a schematic configuration of the all-wheel drive motorcycle.

FIG. 5 is a diagram showing a configuration of a hydraulic system.

FIG. 6 is a cross-sectional view of a hydraulic unit interposed in a hydraulic system.

FIG. 7 is a sectional view taken along line VII-VII of the operation switching valve in FIG. 6;

FIG. 8 is a front view of a hydraulic unit.

FIG. 9 is a sectional view showing a schematic configuration of a front wheel hub.

FIG. 10 is a sectional view of a front wheel hub.

FIG. 11 is an enlarged sectional view showing a main part of the hub.

FIG. 12 is a sectional view showing another embodiment of the hub of the front wheel.

FIG. 13 is a left side view of the all-wheel drive motorcycle.

FIG. 14 is a right side view of the all-wheel drive motorcycle.

FIG. 15 is a sectional view of a hydraulic unit.

FIG. 16 is a configuration diagram showing another example of the hydraulic circuit of the front wheel drive system.

FIG. 17 is a diagram showing a mounting example of a hydraulic pump.

FIG. 18 is a diagram showing an example of mounting a hydraulic pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 5 ... Hydraulic pump, 6 ... Front wheel, 7 ... Hydraulic motor, 40 ... Output shaft, 41 ... Hub, 41a ... Bottom part, 4
1b: boss, 41c: cylindrical portion, 42: axle, 43: disk-shaped cover, 61: bearing, 63: circular recess, 64: internal gear, 65: output gear, 68: labyrinth seal, 69:
Seal member.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Leif Gustavson S-194 27 Sweden, Ubud Landsvsvip, O, Box 722 In Orleans Racing Activieburg (72) Inventor Robert V. Turigg 1119 N.N. Netherlands・ Schiphol-Like Kohlhohenran 101 P.C. O.BOX 75033 Inside Yamaha Motor Europe NV

Claims (3)

[Claims] 1. A rear wheel is driven by an engine, and a circular recess is formed in a hub of a front wheel to open toward one side,
A disk-shaped cover for closing the circular recess is provided on the axle,
A seal member is interposed between the outer peripheral portion of the cover and the hub, and a hydraulic motor is supported by the cover, and the output shaft of the hydraulic motor and the hub are gear-coupled in the circular recess closed by the cover. In the all-wheel drive vehicle in which the hydraulic motor is driven by a hydraulic pump driven by the engine, by forming the hub into a cylindrical shape with a bottom, the circular concave portion is formed by the cylindrical portion and the bottom portion of the hub. The bottom portion is rotatably supported on the axle by a bearing, and the outer peripheral portion of the cover is positioned at the boundary between the cylindrical portion and the bottom portion. A labyrinth seal is provided between the outer peripheral portion of the cover and the cylindrical portion. Wherein the seal member is disposed on the bottom side of the labyrinth seal. 2. The all-wheel drive vehicle according to claim 1, wherein the gear coupling portion between the hydraulic motor and the hub and the cover are brought close to each other. 3. The all-wheel drive vehicle according to claim 1, wherein the hub is supported on the axle by one double-row rolling bearing.