JPS6310338Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a front wheel drive device used in a four-wheel drive agricultural tractor or the like.

Conventionally, this type of agricultural tractor has been unsuitable for field work, such as inter-tilling and pest control, because it has been difficult to secure ground clearance for the front wheel drive device. Therefore, a dedicated working machine with a high ground clearance is required, but manufacturing a front wheel drive device for use only with this special working machine will lead to a significant increase in cost, and the required ground clearance will also make it difficult to carry out work and grow crops. Since the situation varies,
It would have been impossible to prepare various front wheel drive systems to accommodate this. On the other hand, the special public service in 1983-
As shown in Japanese Patent No. 38409, a front wheel drive device has been proposed in which the pinion shaft is configured with a double shaft so that it can be expanded and contracted by a spline, and the height can be adjusted using a vertical position adjustment device such as a screw.
This device has an extremely complicated structure, and since the upper and lower bevel gear cases are separated, it is difficult to reliably support the weight of the vehicle.

Therefore, in the present invention, a cylindrical portion is formed in the king pin case so as to cover the pinion shaft, a cylindrical inner circumferential surface of a shape that allows the cylindrical portion to be fitted is formed in the gear case, and the cylindrical portion of the king pin case is and a second cylindrical part having the same dimensions as the outer diameter of the cylindrical part of the king pin case, and having a predetermined length extending in the axial direction into which the pinion shaft is fitted. A spacer having a stepped shape is configured such that the first cylindrical portion is fitted into the cylindrical portion of the king pin case, and the second cylindrical portion is rotatable by supporting a thrust load on the cylindrical inner peripheral surface of the gear case. The present invention is characterized in that the front axle is disposed downwardly by being fitted over the king pin case, and the thrust force from the king pin case is supported by the gear case via the spacer, thereby solving the above-mentioned drawbacks. The object is to provide a front wheel drive device.

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

In the figure, reference numeral 1 denotes a front wheel drive device, which has a king pin case 5 fixed by bolts to a front axle center 2 that is swingably suspended on a tractor body. A drive shaft 6 to which power is transmitted from the transmission via a differential is rotatably supported in the axle center 2 by a radial bearing, and the upper part of a pinion shaft 7 is rotatably supported in the kingpin case 5 by a radial bearing. The drive shaft 6 and shaft 7 are interlocked with each other by bevel gears 8 and 9, respectively. Further, the lower part of the king pin case 5 is cylindrical so as to cover the shaft 7, and a bush 10 is press-fitted into the inner diameter side of the cylindrical portion 5a to rotatably support the shaft 7. A first cylindrical portion of a spacer 11 is press-fitted and fixed to the outer diameter side of the cylindrical portion 5a, and the spacer 11 has a second cylindrical portion having the same shape as the cylindrical portion 5a of the king pin case 5 at its lower part. 11a, and has a stepped shape with a predetermined length extending in the axial direction into which the pinion shaft 7 is inserted. Further, a gear case 13 is disposed to fit into the cylindrical portion 11a, and a bush 12 is press-fitted and fixed to a cylindrical circumferential surface 13a formed in the cylindrical portion 13a of the gear case 13. A thrust bearing 14 is disposed at the bottom and supports the spacer 11 rotatably and supports the load acting on the spacer 11. Furthermore, these king pin cases 5,
A pinion shaft 7 is housed across the spacer 11 and the gear case 13, and the lower end of the shaft 7 is rotatably supported by the gear case 13 via a bearing that is prevented from coming off by a cover 15. A bevel gear 17 is wedged together. Further, a front axle 22 is rotatably supported by a radial bearing on the gear case 13 and an axle cover 21 fixed to the case 13 with bolts 20, and a large diameter bevel gear 26 is wedged on the front axle 22. At the same time, the wheel is fixed outside the case 13.
On the other hand, an arm holder 27 is fixed to the upper part of the king pin case 5 coaxially with the pinion shaft 7 by a bolt 29, and a knuckle arm 32 is rotatably fitted into the holder 27 via a bush 30 and a washer 31. The tip of the arm 32 is fixed to the gear case 13.

Since this embodiment has the above-described configuration, the rotation of the drive shaft 6 is transmitted to the pinion shaft 7 via the bevel gears 8 and 9, and the rotation of the drive shaft 6 is transmitted to the pinion shaft 7 via the bevel gears 8 and 9.
The front axle 22 is rotated via 26 to drive the wheels and drive the tractor. Further, the steering force from the steering device rotates the knuckle arm 32 around the holder 27 and hence the shaft 7, thereby causing the gear case 13 to rotate around the cylindrical portion 5 of the kingpin case.
The wheel is steered by rotating around the cylindrical portion 11a of the spacer 11 fixed to a. At this time, as the pinion shaft 7 becomes longer, forces such as swinging or bending are applied to the shaft 7, but the shaft 7 is supported at its intermediate portion by a pusher 10 fixed to the kingpin case cylindrical portion 5a. Therefore, the shaft 7 will not oscillate laterally. Further, the weight of the vehicle acting on the axle center 2 acts on the spacer 11 fixed to the cylindrical portion 5a of the axle center 2 via the king pin case 5, and further acts from the cylindrical portion 11a of the spacer 11 via the bush 12 and the thrust bearing 14. It is received by the gear case 13 and supported by the wheels by the axle 22. At this time, a large bending moment acts on each case 5, 13 due to the increased ground clearance, that is, the presence of the spacer 11, but the spacer 11 is fitted and fixed to the cylindrical portion 5a of the king pin case 5. Based on the fact that the cylindrical portion 11a of the spacer 11 is fitted and supported by the cylindrical inner peripheral surface of the cylindrical portion 13a of the gear case 13, it is possible to reliably support the bush 12 and the bush 12 with a large receiving surface area. Cylindrical part 1 based on steering force by thrust bearing 14
Relative rotation between 1a and the inner circumferential surface of the cylinder can be performed smoothly. Furthermore, when changing the height above the ground, it is sufficient to change the spacer 11 to one of a different height, and further change the pinion shaft 7 and arm 32 to ones corresponding to that height.Furthermore, when using the tractor as a standard height tractor, Remove spacer 11,
The cylindrical portion 5a of the king pin case 5 may be directly inserted into the inner circumferential surface of the cylindrical portion 13a of the gear case 13.

As explained above, according to the present invention, the king pin case 5 has the cylindrical portion 5a so as to cover the pinion shaft 7, and the gear case 13 has a cylindrical inner peripheral surface shaped to fit the cylindrical portion 5a. 13a, and further includes a first cylindrical portion that can be fitted into the cylindrical portion 5a of the king pin case 5, and a second cylindrical portion 11 having the same dimensions as the outer diameter of the cylindrical portion of the king pin case.
A spacer 11 having a stepped shape having a predetermined length and extending in the axial direction by fitting the pinion shaft 7 thereinto, the first cylindrical portion thereof being fitted into the cylindrical portion 5a of the king pin case, and The second cylindrical portion 11a is connected to the cylindrical circumferential surface 13 of the gear case 13.
14 is rotatably fitted to support a thrust load on the front axle 14 to move the front axle 22 downward, and the thrust force from the king pin case 5 is applied to the gear case 13 through the spacer 11. Because of this, it is possible to obtain a front wheel drive system with a high ground clearance by simply adding a spacer to a front wheel drive system with a standard height, and by using most of the parts as is, there is a significant reduction in cost. It is possible to reduce costs, and by changing the height of the spacer 11, etc., it is possible to easily obtain front wheel drive devices with various ground clearances. Furthermore, even if a large bending moment or other force is applied to each case 5, 13 and pinion shaft 7 due to the increased ground clearance, the spacer 11
King pin case 5 and gear case 13 through
are in a fitted relationship, and can be reliably supported by the large receiving surface area.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention. 1...Front wheel drive device, 2...Axle center, 5...King pin case, 5a...Cylindrical part,
6... Drive shaft, 7... Pinion shaft, 11...
...Spacer, 11a...Cylindrical part, 13...Gear case, 13a...Cylindrical part (cylindrical circumferential surface),
22...Front axle.

Claims (1)

[Scope of utility model registration request] The pinion shaft is supported across the kingpin case fixed to the axle center and the gear case that rotatably supports the front wheel, and power is transmitted from the drive shaft supported at the axle center to the front axle via the pinion shaft. In addition, in a front wheel drive device that can rotate and steer a gear case around the pinion shaft, the king pin case has a cylindrical part so as to cover the pinion shaft, and the gear case has a cylindrical part that fits over the cylindrical part. a first cylindrical part having a cylindrical inner circumferential surface in a shape to obtain the desired shape, and further comprising a first cylindrical part that can be fitted into the cylindrical part of the king pin case, and a second cylindrical part having the same dimensions as the outer diameter of the cylindrical part of the king pin case. the first cylindrical part is fitted into the cylindrical part of the king pin case and the second cylindrical part is fitted with a spacer having a stepped shape of a predetermined length and extending in the axial direction by fitting the pinion shaft therein; is rotatably fitted to the cylindrical inner circumferential surface of the gear case to support a thrust load, and is configured to displace the front axle downward, and the thrust force from the king pin case is transmitted through the spacer. A front wheel drive device supported by the gear case.