JPS6335852Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a steering/driving wheel device including the steering/driving wheels of agricultural or other self-propelled working vehicles. More specifically, this idea is a steering and driving system for self-propelled work vehicles in which the horizontal portion of the axle housing extending left and right from the axle case is positioned above the wheel rim of the steering and driving wheel. This invention relates to a drive wheel device.

In the steering/driving wheel device of a self-propelled work vehicle, the axle housings connected to the left and right sides of the axle case are formed into a gate shape as a whole including the axle case, and the two legs of such a gate shape An axle housing turning case part is provided in the steering wheel, and the steering/driving wheel is supported by its axle in the axle housing turning case part.

In general, such a steering/driving wheel device is disclosed in, for example, Japanese Utility Model Application Publication No. 116829/1984,
As disclosed in Publication No. 11404 and Publication of Utility Model Application No. 54-76035, etc., the horizontal part of the gate-shaped axle housing is located within the range of the wheel rim of the steering and driving wheel when viewed in the vertical direction. In addition, the housing part constituting the portal leg is located within the wheel rim as much as possible. The reason for this is that when a wheel of a self-propelled work vehicle is often driven on soft ground where the wheels become stuck, the housing part that makes up the portal leg moves while pushing away the soil. In order to avoid an increase in running resistance, and to reduce the possibility of the housing part interfering with crops etc. by increasing the distance between the gate-shaped legs, and to prevent the housing part from interfering with crops etc. This is to protect the support part from mud as much as possible.

However, in a self-propelled working vehicle such as a farm tractor that is driven through a ridged field, if the steering/driving wheel device has the above structure, the ground clearance of the horizontal part of the gate-shaped axle housing will increase. Because it is lower, the horizontal portion tends to interfere with things that protrude from the ground, such as ridges or crops planted on ridges.

For this reason, for example, as disclosed in Japanese Utility Model Application Publication No. 49-11414, the horizontal portion of the axle housing extending left and right from the axle case is positioned above the wheel rim of the steering and driving wheel. Certain steering and drive wheel systems have been proposed to be provided to increase the ground clearance of the horizontal portion.

By the way, in order to transmit driving force to the steering and driving wheels of a self-propelled work vehicle while allowing the steering and turning of the wheels, a transmission shaft is generally provided on the turning axis of the wheel, and the upper and lower portions of the transmission shaft are A bevel gear transmission mechanism is used in which upper and lower bevel gears are provided on the end, and the transmission shaft has bearings mounted on the fixed case part of the axle housing on the upper end side and on the rotating case part of the axle housing on the lower end side. However, when using an axle housing with a large vertical length of the portal leg in order to increase the ground clearance in a device equipped with such a transmission shaft,
It becomes difficult to stably support the rotating case part with respect to the fixed case part of the axle housing. For example, in the above-mentioned Utility Model Application Publication No. 49-11414, the fixed case part located on the upper side and the rotating case part located on the lower side are brought into contact with each other with their end surfaces, and the rotating case part is supported in a manner that allows the swinging case part to pivot freely. This is done via the above-mentioned transmission shaft and upper and lower bearings arranged between the transmission shaft and the swivel case part, and the swivel case part is not directly supported by the fixed case part, and the rotating transmission shaft cannot be swiveled. Since it is involved in supporting the case part, the support of the rotating case part is extremely unstable.

This unstable support of the swing case is not only undesirable in itself, but also puts a constraint on increasing the ground clearance of the horizontal portion of the axle housing, making it impossible to increase the ground clearance beyond a certain limit. Assume that there is no.

However, in order to increase the support strength of the swing case part, there is a support structure that is generally adopted in vehicles equipped with an axle housing with a low ground clearance. As disclosed in Publication No. 54-11404, the swing case part of the axle housing is supported by the fixed case part at the lower end side of the fixed case part, and a support arm extending upward from the swing case part is provided. When adopting a support structure that also supports the upper end of the fixed case part via a support arm,
In vehicles with high ground clearance in which the portal-shaped legs are located above the wheel rim and most of the legs protrude from the wheel rim, the gap between the wheel rim and the fixed case section In order to enable the above-mentioned support arm, which is to be extended upward at The wheel protrudes largely from the wheel rim, resulting in an increase in running resistance on soft ground and a decrease in the distance between the gate-shaped legs, which is undesirable.

Therefore, this idea was developed to increase the ground clearance of the horizontal part of the axle housing, which extends from the axle case to the left and right, above the wheel rim, thereby increasing the running resistance on soft ground. The axle housing rotating case part is supported extremely stably without causing other problems such as a decrease in the distance between the gate-shaped legs.
The present invention aims to provide a novel steering and driving wheel device for a self-propelled work vehicle.

Regarding the illustrated embodiment, the configuration of the steering and driving wheel device according to the invention will be explained.As shown in FIGS. 1 and 2, it is equipped with a pair of left and right front wheels 1 and a pair of left and right rear wheels 2. An engine 3 is mounted on one side of the front of the fuselage, and a transmission case 4, which forms part of the fuselage frame, is installed directly behind the engine 3.
The power of the engine 3 is transmitted to the left and right rear wheels 2 through the transmission case 4, and is also transmitted to the left and right front wheels 1 as necessary to cause the machine to travel, and to drive the work equipment. It is a self-propelled work vehicle that can be taken out as needed, and a passenger seat 5 is installed on the other side of the front of the machine, and the operator sitting on the passenger seat 5 operates the machine. This invention is implemented as follows in a self-propelled working vehicle configured to swing the left and right front wheels 1 using the handle 6.

That is, a differential device 8 (FIG. 3) for the left and right front wheels 1 is provided in the front axle case 7, which is rotatably supported by the fuselage around the longitudinal axis of the fuselage.
Power is transmitted to this differential device 8 from the inside of the transmission case 4 through the inside of the outer cylinder 9 (Fig. 2), and a power transmission shaft 10 (a second 3) are provided within the horizontal portion 11a of the front axle housing 11 extending left and right from the front axle case 7, and as shown in FIG.
A transmission shaft 12 is provided on the turning axis Y of the front wheel 1, and a small bevel gear 13 is fitted onto the upper end of the transmission shaft 12.
is the bevel gear 1 fitted onto the tip of the transmission shaft 10.
4, and a small bevel gear 15 fitted to the lower end of the transmission shaft 12 is supported by a swing case part 16, which supports the small bevel gear 15 so as to be able to swing freely around the swing axis Y. The axle case 7 meshes with a large bevel gear 17 for deceleration fitted in the axle case 7 to transmit power to each front wheel 1, which serves as both a steering wheel and a drive wheel. As shown clearly in FIG.
It is located above the tire 1c of the front wheel 1, and in the case shown in the figure, it is located above the tire 1c of the front wheel 1.

The front wheel axle 1a is supported by the rotating case portion 16 via a pair of ball bearings 30, 31 within the wheel rim 1b, and the large bevel gear 17 is supported by the axle 1.
It is installed on the inner end of a.

A fixed case portion 11b is connected and fixed to the end of the horizontal portion 11a of the axle housing by a fixture 18, and the fixed case portion 11b has a hollow portion whose lower end faces slightly above the large bevel gear 17. A shaft-shaped king pin 19 is integrally formed. The transmission shaft 12 is inserted into the king pin 19, and is connected to a ball bearing 22 provided on the boss portion of the small bevel gear 13 on the upper side and the small bevel gear 15 on the lower side.
It is rotatably supported by the king pin 19 via a needle bearing 23 provided on the boss portion of the king pin 19 .

On the other hand, the pivot case part 16 has a support cylinder part 16a extending upwardly from the outer circumferential side of the king pin 19 to almost the upper end position of the king pin 19.
They are connected and fixed by a fixture 32. By supporting this support portion 16a on its inner circumferential surface side by the king pin 19 via an upper needle bearing 20 and a lower ball bearing 21, the swing case portion 16 can be rotated around the swing axis Y. We are providing free support. Support tube part 1
The inner circumferential surface of the lower end of the rotating case part 16 and the inner circumferential surface of the upper end of the rotating case part 16 have annular slots 16b and 16c of equal diameter. , 16c, the ball bearing 21 is held astride between the support tube portion 16a and the rotating case portion 16.

Although not shown, the knuckle arm in the swing operation mechanism is provided on the swing case 16 by protruding from the outer peripheral surface of the upper end of the support tube portion 16a.
The lid 24 that closes the opening of the fixed case portion 11b above the kingpin 19 has a stopper portion 24 that restricts the amount of swing of the front wheel 1 around the longitudinal axis of the fuselage by coming into contact with a stopper 25 on the fuselage side.
A is formed.

In Figures 1 and 2, 26 is a PTO shaft extending rearward from the transmission case 4;
is the other PTO axis extending rearward from the aircraft,
Reference numeral 28 denotes a chemical liquid tank mounted on the body when the illustrated working vehicle is used as a speed sprayer.

The operation of the illustrated steering and driving wheel device is as is clear from the above description of the structure. transmitted to 1a,
Also, when the operating handle 6 (Fig. 1) is operated, the swing case part 16 moves to the king pin 19 with the support cylinder part 16a.
The vehicle is steered by turning the entire front wheel 1 while being guided by the front wheels. The axle housing horizontal portion 11a is provided at a high position as described above, and the transmission shaft 12 including the axle 1a and the small bevel gear 15
The lower portion occupies a small space inside the portion of the swing case portion 16 that is located outside the wheel rim 1b, and correspondingly, the swing case portion 16 is located on its inner surface (indicated by reference numeral A in FIG. 3). )
The height of the gate-shaped structure and Since the inner width is large, the axle housing 11 is unlikely to interfere with the ridges or crops when the illustrated work vehicle is used to cultivate the fields. Even if the front wheel 1 sinks in on soft ground, the above-mentioned shape of the swing case portion 16 prevents a significant increase in running resistance, and the opening of the swing case portion 16 to the outside is limited to the supporting cylinder portion 16a.
Since it is located at the upper end, that is, at a very high position, there is no possibility that mud will invade the swingable support part and obstruct the smooth swinging of the swing case part 16.

As is clear from the above description, in this invention, the axle housing horizontal portion 11a extending left and right from the axle case 7 is positioned above the wheel rim 1b of the steering/driving wheel 1.
In a steering/driving wheel device for a self-propelled work vehicle, the wheels 1 are mounted on the axle housing turning case portion 16.
an axle 1a is supported within the wheel rim 1b,
A large bevel gear 17 for deceleration is fixedly installed on the inner end of the axle 1a, and a hollow shaft-shaped king pin 19 whose lower end faces a position slightly above the large bevel gear 17 is attached to the axle housing. horizontal part 1
The transmission shaft 12 is integrally formed with a fixed case portion 11b connected and fixed to the end 1a, and has a small bevel gear 15 fixedly installed on the lower end thereof, which meshes with the large bevel gear 17 from above. 19 and rotatably supported by the king pin 19,
Further, a support tube portion 16a extending upwardly to approximately the upper end position of the king pin 19 on the outer peripheral side of the king pin 19 is connected and fixed to the axle housing turning case portion 16, and this support tube portion 16a is connected to and fixed to the axle housing turning case portion 16. A pair of upper and lower bearings 20, 21 on the inner circumference side
By supporting the king pin 19 through the axle housing, the axle housing rotating case portion 16 is supported so as to be able to rotate freely in steering, and the lower bearing 21 of the pair of bearings 20 and 21 described above
is held astride between the above-mentioned support tube portion 16a and the axle housing rotating case portion 16, and the following effects are achieved.

The pivoting case portion 16 of the axle housing is supported extremely stably, and there is no restriction on increasing the ground clearance of the horizontal portion 11a of the axle housing. i.e. axle housing horizontal part 1
1a is provided at a high position to increase the ground clearance, the axle 1 is fixed to the end of the horizontal portion 11a and is provided at a high position.
The hollow shaft-shaped king pin 19, which is integrally hung with its lower end facing a position slightly above the large bevel gear 17 on the inner end part a, is vertically long, so it is fixed to the swing case part 16 and the king pin 19 is fixed to the swing case part 16. The supporting cylinder portion 16a extending almost to the upper end position is also long, and by supporting the long supporting cylinder portion 16a on the king pin 19 via a pair of upper and lower bearings 20, 21, the rotating case The supporting part 16 is supported by the king pin 19, which is integral with the fixed case part 11b, and the supporting cylinder part 16a.
Since it is fixed to the swing case part 16, the swing case part 16 is directly supported by the fixed case part 11b, and the king pin 19 is formed in the shape of a hollow shaft. The combination of the large cross-sectional radius and high support strength allows the rotating case portion 16a to be supported extremely stably. In addition, the support of the swing case portion 16a is stabilized in this way, and the longer the axle housing horizontal portion 11a is positioned to increase the ground clearance, the longer the king pin 19 and the support tube portion 16a become, thereby stabilizing the support. Therefore, there are no restrictions on increasing the ground clearance of the axle housing horizontal portion 11a.

No increase in running resistance occurs on soft ground. That is, since the axle 1a is supported by the turning case part 16 within the wheel rim 1b and the large bevel gear 17 is installed on the inner end of the axle 1a, the axle 1a
a hardly protrudes from inside the wheel rim 1b in the width direction of the axle housing, and the small bevel gear 15 on the lower end of the transmission shaft 17 is meshed with the large bevel gear 17 from above. Since the lower portion of the transmission shaft 12 including the swivel case portion 16 is located only at its upper end portion, the lower portion of the swivel case portion 16 is located within the swivel case portion 16 as shown by reference numeral A in FIG. It can be formed into a shape that is offset in the direction of the wheel rim 1b so that the amount of protrusion from inside the wheel rim 1b is reduced. Furthermore, since the lower bearing 21 interposed between the support cylinder part 16a and the king pin 19 is held astride between the support cylinder part 16a and the swing case part 16, the support cylinder part 16a and the swing case Part 1
The bearing 21 plays the role of a fitting part (so-called spigot part) that should be provided for centering between the rotating case part 16, and by omitting the fitting part, the outer diameter of the upper end of the swing case part 16 is reduced. Therefore, the amount of protrusion of the upper end portion in the inner width direction of the axle housing is also suppressed to a small value. Therefore, in the axle housing having a gate-shaped structure, the lower portion of the leg portion is biased toward the inside of the wheel rim 1b as much as possible, so that even if the wheel sinks in, running resistance does not increase significantly.

The spacing between the legs of the portal structure, ie the internal width of the portal axle housing, is maintained large. In other words, the pivot case portion 16 in the leg portion of the portal structure
Since only the dense transmission shaft 12 is located as a transmission member in the upper part, the hollow shaft-shaped king pin 19 into which such transmission shaft 12 is inserted is
Of course, it can be formed with a small outer diameter,
Accordingly, the support tube portion 16a supported on the inner circumferential side of the king pin 19 via the upper and lower bearings 20, 21 can also be formed with a relatively small outer diameter, and the upper side of the leg of the portal structure can be formed to have a relatively small outer diameter. The part can be made elongated and occupy a small space in the inner width direction of the axle housing. In addition, as mentioned in the lower part of the leg of the portal structure, the wheel rim 1b
It can be pushed inward as much as possible. Therefore, the space in the axle housing inner width direction that each leg of the portal structure occupies outside the wheel rim 1b is kept small, and the distance between the legs is kept small. The inner width of the gate-shaped housing is maintained large.

The pivotable support for the pivot case part 16 is protected from mud and smooth steering turns are ensured. That is, the swing case part 16 is supported by the support cylinder part 16a as described above, and the part where the swing case part 16 opens to the outside is at the upper end position of the support cylinder part 16a. The opening extends upward from the fixed case part 11b at a high position to almost the upper end of the vertically installed king pin 19, so the opening part is located at an extremely high position, and the wheel may sink into it on soft ground. Even in such a case, the mud flying upwards will not enter the inside of the swing case portion 16 or its support, and the smoothness of steering and turning will not be hindered by such mud. be.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of a self-propelled working vehicle equipped with an embodiment of this invention, Fig. 2 is a schematic plan view of the working vehicle, and Fig. 3 is a longitudinal sectional front view of the main parts of the working vehicle. . 1...Wheel, 1a...Front wheel axle, 1b...Wheel rim, 11...Front axle case, 11...
...Front axle housing, 11a...Horizontal portion, 11b...Fixed case portion, 12...Transmission shaft, 13, 15...Small bevel gear, 16...Swivel case portion, 17...Large bevel gear, 19... kingpin,
20...needle bearing, 21...ball bearing.

Claims (1)

[Scope of utility model registration request] The axle housing horizontal portion 11a extending left and right from the axle case 7 is connected to the steering and driving wheel 1.
In a steering and driving wheel device for a self-propelled work vehicle, which is provided above the wheel rim 1b of the wheel 1, the axle shaft 1a of the wheel 1 is supported within the wheel rim 1b by the axle housing turning case portion 16. A large bevel gear 17 for deceleration is fixedly installed on the inner end of the axle 1a, and a hollow shaft-shaped king pin 19 whose lower end faces a position slightly above the large bevel gear 17, A fixed case portion 11 is connected and fixed to the end of the axle housing horizontal portion 11a.
A transmission shaft 12 having a small bevel gear 15 fixedly installed on the lower end thereof, which is formed integrally with the large bevel gear 17 and meshes with the large bevel gear 17 from above, is inserted into the king pin 19 and can be rotated by the king pin 19. A supporting cylinder portion 16a is provided supported by the king pin 19 and extends upwardly to approximately the upper end position of the king pin 19 on the outer peripheral side of the king pin 19. Support tube part 1
A pair of upper and lower bearings 2 are attached to the inner peripheral surface of 6a.
0 and 21 to support the axle housing rotating case part 16 so as to be able to freely steer and turn, and the lower bearing 21 of the pair of bearings 20 and 21 is A steering/driving wheel device characterized in that it is held astride between a support tube portion 16a and an axle housing turning case portion 16.