JPS6251766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front wheel drive device, and by supporting the king pin in a so-called cantilever manner on a bevel gear case, the bearing capacity of the king pin can be reduced, and the reduction ratio can be increased. The main purpose is to make it possible to reduce the front wheel tread by fixing the wheels to the front wheel case.

In the front wheel drive system of a tractor, a king pin is inserted into and supported by a bevel gear case fixed to the end of the front axle case, and the front wheel case is rotatably mounted around the axis of this king pin. It is well known from publications such as US Pat. No. 2,306,958 and the like.

According to these conventional examples, the king pin is supported at both the upper and lower ends of the king pin via bearings in both the bevel gear case and the front wheel case. I couldn't make it big.

In addition, since the axle is rotatable in the front wheel case, a bevel gear is fixed to it and supported by a pair of inner and outer bearings, which naturally lengthens the axle, making it impossible to place the front wheel close to the kingpin, making it difficult to support the front wheel. was unstable, and the torrent was also large.

The present invention was devised in view of the above circumstances, and a bevel gear case having a built-in bevel gear mechanism that interlocks the differential output shaft and the king pin is attached to both ends of the front axle case. In a front wheel drive system, a front wheel case that supports each front wheel is rotatably provided around the axis of a king pin, and a bevel gear mechanism that interlocks the king pin and the front wheels is built into the front wheel case. , the bevel pinions constituting each of the bevel gear mechanisms are installed in a direction that applies a thrust force in the axial tensile direction to the kingpin, and the upper side of the kingpin inserted into the bevel gear case is above the upper bevel pinion and is mounted on the kingpin. The lower side of the king pin is supported so as not to tilt via a bearing only by a cylindrical portion formed above the lower bevel pinion and extending downwardly on the lower side of the bevel gear case, and further , an upper thrust regulating body is attached to the upper end of the kingpin, which is higher than the upper bearing, to receive the upward thrust force in the axial direction that is applied by the upper bevel pinion, and to the lower end of the kingpin, which is applied by the lower bevel pinion. A lower thrust regulating body is installed that receives a thrust force in the axial direction downward and transmits the thrust force to the upper thrust regulating body via a king pin, and a cylinder that protrudes laterally outward is attached to the inner wall of the front wheel case. A front wheel hub axle having a shape is integrally provided so that the inner side in the lateral direction is closed by the inner wall, the bevel gear body is rotatably fitted around the outer periphery of the hub axle, and the outer end surface of the bevel gear body in the lateral direction The present invention is characterized in that a disc mounting seat is integrally provided, and a front wheel disc is mounted to the disc mounting seat from the outside in the lateral direction.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a two-axle, four-wheel type tractor 1, which has a pair of left and right front wheels 2, a pair of left and right rear wheels 3, and
are attached to both ends of the front axle case 4, and the steering device 5 is attached to both ends of the front axle case 4.
It is said that it can be steered by

The rear wheels 3 are driven via a transmission device that changes the speed of the engine power as appropriate, and the transmission device is built in a transmission case 6 that also serves as the vehicle body.

The axial center of the front axle case 4 is rotatably suspended on the front wheel bearing stand 7 via a so-called center pin device 8 about an axis in the longitudinal direction.

A differential device is built in the front axle case 4, and the differential device is interlocked with the propulsion shaft device F by a transmission device in the transmission case 6, so that the front wheels and the rear wheels can be driven in synchronization or synchronization. ing.

Referring to Figures 2 and below, details of the front wheel drive system are shown.

Note that the front wheel drive device is provided at both ends of the front axle case 4, but since the left and right pair have the same configuration,
Below, only one will be explained in detail.

In FIG. 2, reference numeral 9 denotes a differential output shaft, which is inserted into and supported by the front axle case, has an end bevel pinion 10 attached via a spline, etc., and is supported by the outer end of the front axle case via a bearing 11. ing.

At the outer end of the front axle case there is a mounting flange 12.
is formed, and a bevel gear case 13 is attached to the mounting flange 12 with a dowel pin 1 as shown in FIG.
4 and bolts 14A so as to be detachable.

The bevel gear case 13 has an opening 15 at the top, and a constricted cylindrical portion 16 at the bottom, and the centers of the opening 15 and the cylindrical portion 16 are coaxial.

Furthermore, a king pin 17 is inserted into the bevel gear case 13 with a predetermined king pin angle. In this example, the upper end of the king pin 17 is supported via a radial bearing 18, and the king pin 1
The lower end side of 7 is inserted into the cylindrical portion 16 and is supported via a needle bearing 19 in this example.

The king pin 17 and the differential output shaft 9 are interlocked via a bevel gear mechanism 20.
An upper bevel pinion 21 is fitted and fixed to the upper end portion via a spline, a key, etc., and the upper bevel pinion 21 is connected to the bevel pinion 1 on the differential output shaft 9.
0 from above, a bevel gear mechanism 20 built into the bevel gear case 13 is configured here.

A lower bevel pinion 23 is fixed to the lower end of the king pin 17 via a collar 22 and is fixed to the lower bevel pinion 23 via a spline, a key, etc.
3 engages with a bevel gear 25 in the front wheel case 24 from below, and a bevel gear mechanism 26 that interlocks the king pin 17 and the front wheel is configured here.

That is, both upper and lower ends of the king pin 17 are supported only by the bevel gear case 13 via bearings 18 and 19, and a thrust screw shown by a nut is attached to a threaded portion formed on the king pin at the outer end of the shaft of the bearings 18 and 19. Force regulators 27 and 28 are screwed onto the kingpin 17 so as to take charge of the thrust force of bevel pinions 21 and 23, which are arranged so that a thrust force in the tensile direction indicated by the arrow AB acts on the king pin 17. .

That is, the upper thrust regulating body 27 receives the thrust force A in the axial direction upward acting from the upper bevel pinion 21 on the upper end side of the king pin 17 that is higher than the upper bearing 18 on the upper end side of the king pin 17.
is attached to the lower end side of the king pin 17 to receive the axially downward thrust force B exerted by the lower bevel pinion 23 and to transfer the thrust force B to the upper thrust regulating body 2 via the king pin 17.
A lower thrust regulating body 28 is attached to transmit the force to the engine 7.

The front wheel case 24 has a substantially L-shape when viewed from the rear, integrally comprising a lower case 29 and a side case 30.
A deceleration bevel mechanism 26 consisting of a lower bevel pinion 23 and a bevel gear 25 is built-in.

The lower case 29 is rotatably fitted into the cylindrical portion 16 of the bevel gear case 13 via an inner ring 31 and a bush 31', and is further supported via a thrust bearing 32.

The side case 30 has an opening 33 that opens laterally outward and allows the bevel gear 25 to be freely inserted and removed, and is integrally formed with a hollow axle 35 that protrudes outward from the inner wall 34. In this example, a bevel gear attachment body 37 is rotatably fitted on the mantle via two ball bearings 36.

The bevel gear attachment body 37 is ring-shaped, and the bevel gear 25 is attached to the inner end surface thereof via a knock pin 38 and a bolt 39.
A front wheel disk 41 is detachably attached to the outer end surface of the bevel gear attachment body 37 via a plurality of bolts 40.

Further, the opening 34 of the side case 30 is closed with a lid 44 via a dowel pin 42 and a bolt 43, and the upper end of the inner wall 34 of the side case 30 is provided with an axis that corresponds to the axis of the kingpin in this example. Parallel longitudinal mounting surfaces 45 are integrally formed to protrude, and a knuckle arm 46 is mounted to this mounting surface 45 in the following manner.

That is, a cylindrical front wheel hub shaft (axle) 3 is provided on the inner wall 34 of the front wheel case 24 and projects laterally outward.
5 is integrally provided so that the inner side in the lateral direction is closed by the inner wall 34, and the bevel gear bodies 25, 37 are rotatably fitted around the outer periphery of the hub shaft 35. A disk mounting seat is integrally provided on the outer end surface in the lateral direction, and the wheel disk 41 of the front wheel 2 is mounted to this disk mounting seat from the outside in the lateral direction.

A knuckle pin 47 is inserted into the upper opening 15 of the bevel gear case 13 so as to be coaxial with the king pin 17. In this embodiment, the knuckle pin 47 is fitted with an interference fit, and the knuckle pin 47 is fitted horizontally on the outer periphery of the insertion part of the knuckle pin. A notch is formed in the direction, and 2
By inserting a book pin or a flat plate 48, it is attached so as to be non-rotatable. Note that the pin or flat plate 48 can be omitted by increasing the interference fit.

In this example, the knuckle pin 47 has a cylindrical shape with the upper end closed, but it may also be a cylindrical shape with the top and bottom open or a solid cylinder. When it is cylindrical with the upper end closed as in this example, The bearing 18 can be lubricated by sealing lubricating oil such as grease into the hollow part through the oil supply plug mounting hole 49 formed in the hollow part. Therefore, in this case, the bearing 18 is equipped with a seal 18A.

The knuckle arm 46 integrally has a bottomed mantle fitting part 50 and an attached part 51, and the cylindrical mantle fitting part 50 is rotatably fitted onto the knuckle pin 47 via a bush 52, and the mantle fitting part 50 is rotatably fitted onto the knuckle pin 47 via a bush 52. As shown in FIG. 4, the attached portion 51 extending in the front and rear direction is superimposed on the longitudinal attachment surface 45 on the front wheel case side, and in this example, two bolts 53 are attached to each of the front and rear.
It is attached from the inside laterally.

At this time, a tap hole 45A is formed in the mounting surface 45, and a bolt insertion hole 51 is formed in the mounted part 51.
A is formed as a so-called blank hole corresponding to the tap hole 45A.

Although not shown, a steering arm protrudes forward, backward, or inward and is attached to the steering arm 46 either integrally or via bolts, and the steering force from the steering device 5 can be transmitted to this steering arm. At the same time, the left and right steering arms are linked together using tie rods, etc.

In addition, in FIG. 2, 54 is a retaining ring for the bearing 18, 55 is a seal ring interposed between the mantle fitting part 50 and the knuckle pin 47, and 56 is a lower case 29 of the bevel gear case 13 and the front wheel case 24.
Dust seal inserted in the joint between 57
58 is a lubricating oil passage that communicates between the cylindrical part 16 and the lower case 29; 59 is a lubricating oil passage formed in the outer periphery of the bearing 11; By supplying lubricating oil through the unillustrated oil supply plug provided in the front axle case 4, the lubricating oil is supplied to the lower case 29 while removing air through the passages 58 and 59.
level near the bearing and bevel gear case 13
It is possible to lubricate inside. Further, 60 is a bottom cover of the lower case, and 61 is an axle cover, both of which can be inserted and removed.

Although not shown, stoppers for regulating the cutting angle are formed on the inner wall 34 of the front wheel case 24 at positions symmetrical to the front and rear kingpins, and correspondingly stoppers are also formed on the bevel gear case.

The second embodiment shown in FIG. 5 has the same structure as the first embodiment shown in FIG. 2 except that a lubricating oil passage 58 is not formed, and common parts are indicated by common symbols.

Next, the effect will be explained.

When the differential output shaft 9 is driven, the king pin 17 is interlocked via the bevel gear mechanism 20, and the bevel gear attachment body 35 in this example is rotated around the axis of the axle 33 via the bevel gear mechanism 26, so that the front wheels 2 are decelerated as required. The rear wheels 3 are driven in synchronization or synchronization with the rear wheels 3 under (the speed may be increased).

When the steering device 5 is operated left and right, the knuckle arm 46 is rotatably fitted into the knuckle pin 47 which is inserted into the upper end opening 15 of the bevel gear case 13 so as not to be relatively rotatable, coaxially with the axis of the king pin 17. Attached portion 51 of the knuckle arm 46
is attached to the longitudinal mounting surface 45 on the side of the front wheel case 24 with bolts 53, so that the front wheel 2 can be rotated together with the front wheel case 24 around the axis of the king pin 17 and steered there.

The fall of the front wheel case 24 is mainly prevented by the knuckle pin 47, since the knuckle fitting part 50 of the knuckle arm 46 has a bottom and is fitted onto the knuckle pin 47, and the knuckle arm 46 is attached to the front wheel case 24 side with a bolt 53. A large load is not applied to the bolts 53, and therefore the bolts 53 can be screwed together from the inside in the lateral direction to easily attach the bolts 53 without being restricted by the front wheels 2.If one of the front wheels 2 lifts, the bolts 53 However, it can also provide sufficient support.

Torque from the differential output shaft 9 is transmitted to the king pin 17 via the bevel gear mechanism 20, and torque from the king pin 17 is transmitted to the front wheels 2 via the bevel gear mechanism 26.
0, the thrust force acting on the king pin 17 acts in the opposite direction as indicated by arrow AB, that is, in the axial direction of tension on the king pin 17. Even if it is small, the thrust force regulator 2
7.28 is sufficient.

Also, this means that the lowermost end of the king pin 17 does not need to be supported by the front wheel case 24, so the diameter of the bevel gear 25 can be increased.
This allows the reduction ratio to be increased.

Further, the axle 35 is fixedly installed in the front wheel case 24, and the bevel gear 25 is fitted onto the axle 35 so that it can rotate freely, and the support structure is simpler and more stable than in the case where the axle rotates. The length of the axle 35 may be shortened by supporting it on a cantilever.
Since the vehicle length of the axle 35 is short, the front wheel case 24 is brought closer to the bevel gear case 13, thereby reducing the length of the steering arm and enabling nimble steering.

According to the present invention, the kingpin is supported by upper and lower bearings in the bevel gear case fixed to both ends of the front axle case, and the upper and lower bevel pinions on the kingpin apply a thrust force in a tensile direction to the kingpin. Since the thrust force is offset by the thrust force, the bearing capacity is reduced and the reduction ratio can be increased.

In addition, the thrust force can be easily and reliably borne by the upper and lower regulating bodies, and the structure can be expected to be simplified.

An upper thrust regulator is attached to the upper end of the kingpin, which is higher than the upper bearing, to absorb the upward axial thrust force exerted by the upper bevel pinion. Since a lower thrust regulating body is installed which receives the thrust force in the downward direction and transmits the thrust force to the upper thrust regulating body via the king pin, the thrust forces are mutually canceled and the thrust force is received by the bevel gear case. I was able to suppress the
Here, there is no problem even if the upper and lower bearings are made smaller, and the entire case can be made more compact.

In addition, in the present invention, the hub shaft that projects laterally outward is integrally provided on the inner wall of the front wheel case, and this bevel gear body is rotatably fitted on the inner wall of the front wheel case. Since the support structure is simple and stable, and cantilever support can be adopted, the axial length of the hub shaft can be reduced, which is advantageous in terms of strength, and the structure of the front wheel case can be simplified.

Additionally, the hub axle, which is integrated with the inner wall of the front wheel case, is cylindrical to reduce weight, but since the inner end in the lateral direction is blocked by the inner wall, mud, etc. can get inside the cylindrical hub axle. There is no clogging from the inside, and even if the clogging occurs from the outside, it is easy to remove, and the strength of the base side of the hub shaft, that is, the inner wall, is also improved. Furthermore, a disk mounting seat is integrally provided on the lateral outer end surface of the bevel gear body fitted around the outer periphery of the hub axle, and since the front wheel disc is attached to this disk mounting seat, a flange, etc. for mounting the front wheel is separately provided. There is no need,
It is structurally simple, the front wheels can be placed closer to the kingpin, it can be made smaller, and the tread of the front wheels can be made smaller. Furthermore, since the overall structure is simplified, it can be made smaller and the assembly work is easier.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an example of a tractor to which the present invention is applied, FIG. 2 is a sectional elevational view of an example of the present invention, and FIG.
The figure is a half-cut sectional view of the bevel gear case mounting part.
FIG. 4 is a side view of the knuckle arm, and FIG. 5 is a sectional elevational view of the second embodiment of the present invention. 1... Tractor, 2... Front wheel, 4... Front axle case, 9... Differential output shaft, 13... Bevel gear case, 17... King pin, 18, 19... Bearing, 21, 23... Bevel pinion ,20,26
...Bevel gear mechanism, 24...Front wheel case, 2
7, 28 thrust force regulating body, 35... axle.

Claims (1)

[Claims] 1. Bevel gear cases 13 each having a built-in bevel gear mechanism 20 that interlocks the differential output shaft 9 and the king pin 17 are attached to both ends of the front axle case 4, and each of the bevel gear cases 13 has a In a front wheel drive device, a front wheel case 24 supporting the front wheel 2 is rotatably provided around the axis of the king pin 17, and a bevel gear mechanism 26 for interlocking the king pin 17 and the front wheel 2 is built in the front wheel case 24. Bevel pinions 21 and 23, which constitute the bevel gear mechanisms 20 and 26, respectively, are attached to the upper and lower sides to apply a thrust force in the axial tensile direction to the king pin 17, and are inserted into the bevel gear case 13. The upper side of the king pin 17 is placed above the upper bevel pinion 21 and extends downward to the bevel gear case 13 side via the bearing 18, and the lower side of the king pin 17 is placed above the lower bevel pinion 23 and extends downward to the bottom side of the bevel gear case 13. The cylindrical portion 16 is supported by a bearing 19 in a non-tilting manner only on the cylindrical portion 16 formed in the shape of a cylindrical shape. An upper thrust regulating body 27 is attached to receive the thrust force A in the upward direction, and is attached to the lower end side of the king pin 17.
The king pin 1 receives the axial downward thrust force B exerted by the lower bevel pinion 23.
A lower thrust regulating body 28 is attached to transmit the thrust force B to the upper thrust regulating body 27 via the upper thrust regulating body 27, and a cylindrical front wheel hub shaft that projects laterally outward is attached to the inner wall 34 of the front wheel case 24. 35 is integrally provided so that the inner side in the lateral direction is closed by the inner wall 34, and the bevel gear bodies 25, 37 are rotatably fitted around the outer periphery of the hub shaft 35. A front wheel drive device characterized in that a disk mounting seat is integrally provided on the outer end surface in the lateral direction, and a wheel disk 41 of the front wheel 2 is attached to the disk mounting seat from the outside in the lateral direction.