JPH0321281Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a front wheel drive device with adjustable wheel width in a four-wheel drive vehicle such as an agricultural tractor.

<Prior art> As shown in FIG. 5 (Japanese Utility Model Application Publication No. 57-179503), the conventional device has a sliding case 23 on both left and right ends of a front axle case 3 that has a built-in differential device 6, which can be extended and retracted. A gear case 24 supporting a king pin 40 is fixed to the outer end of each sliding case 23, and a differential yoke shaft 19 protrudes left and right from the differential device 6, and the power of the differential yoke shaft 19 is transmitted to the king pin 40. It is fitted to the transmission shaft 25 so as to be extendable and rotatable, and the differential yoke shaft 19
must be assembled at the time of assembling the differential device, and cannot be later incorporated into the differential device 6 disposed inside the front axle case 3.

This is because when the sliding case 23 is expanded or contracted by a hydraulic cylinder or other driving means, the transmission shaft 25
This is to prevent the differential yoke shaft 19 from moving as the differential yoke shaft 19 expands and contracts.

<Problems to be Solved by the Invention> However, the fact that the differential yoke shaft 19 cannot be inserted from the outer end of the front axle case 3 and assembled into the differential device 6 makes assembly and maintenance of the entire front wheel drive device very difficult. It's going to be a hassle.

<Means for Solving the Problems> In view of the problems of the conventional device, the present invention makes it possible to incorporate the differential yoke shaft 19 into the differential device 6 from the outer end of the front axle case 3, and allows the extension of the transmission shaft 25. The movement of the differential yoke shaft 19 during operation is prevented by providing a resilient member 28 between the two shafts.

That is, the specific configuration of the problem-solving means in the present invention is that sliding cases 23 are fitted inside the left and right ends of the front axle case 3 in which the differential device 6 is built in so that they can be expanded and contracted, and the outside of each sliding case 23 is fitted. King pin 4 on the end
0 is fixed, and the differential yoke shaft 19 protruding left and right from the differential device 6 and the transmission shaft 25 that transmits the power of this differential yoke shaft 19 to the king pin 40 are fitted so as to be expandable and contractable and integrally rotatable. The differential yoke shaft 19 is formed so that it can be assembled into the differential device 6 from the outer end side of the front axle case 3, and the transmission shaft 25 is attached to the differential yoke shaft 19.
In a front wheel drive device capable of adjusting wheel distance, in which a springing member 28 is fitted which springs toward the differential gear 6, the differential yoke shaft 19 has a large diameter portion 19a formed in the middle in the axial direction. One end of the resilient member 28 contacts the gear case 24 side of the portion 19a, and the position of the large diameter portion 19a on the differential device 6 side is regulated by contacting the bearing 20 that supports the differential yoke shaft 19 on the front axle case 3. It is in.

<Operation> When the sliding case 23 is extended outward from the front axle case 3 in the left-right direction, the transmission shaft 25 is also moved outward in the left-right direction. At this time, since the differential yoke shaft 19, which is assembled into the differential device 6 from the outer end of the front axle case 3, is not prevented from coming off in the outward direction of the shaft within the differential device 6, the frictional resistance caused by the fitting The differential yoke shaft 19 tries to move outward from the left and right along with the transmission shaft 25, but the springing member 28 interposed between the shafts 19 and 25 springs the differential yoke shaft 19 toward the differential device 6 and prevents the movement. Thus, the normal position relative to the differential device 6 is maintained. The differential yoke shaft 19 has a large diameter portion 1 in the middle in the axial direction.
9a, the elastic member 28 abuts on this large diameter portion 19a, and the large diameter portion 19a abuts on a bearing 20 supporting the differential yoke shaft 19 to regulate its position, and the differential yoke shaft 19 is Even when force is applied, the tooth contact of the differential device 6 is maintained normally without moving toward the differential device 6 side.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

In the embodiment shown in Figs. 1 to 3, reference numeral 1 denotes a front wheel drive device disposed at the front of the vehicle body of a four-wheel drive tractor, and a front wheel bearing stand (Fig. (not shown).

Reference numeral 3 denotes a front axle case, which is integrally formed with cylindrical portions 4 on the left and right sides, and supports a differential device 6 therein via a support case 5 attached to the rear side. Reference numeral 7 denotes a bevel pinion shaft supported by the support case 5, which is directly connected to a front wheel propulsion shaft 8 to which power is transmitted from the transmission case of the tractor, and meshes with a bevel gear 9.

In the differential device 6, 11 is a differential case, 12
13 is a case cover, 13 is a differential pinion shaft, 14 is a pair of differential bevel pinions, 15 is a pair of differential side gears, 16 is a differential lock mechanism, 17 and 18 are left and right bearing cases, and a pair of left and right differential yoke shafts. 19 is the bearing 2 in the bearing cases 17 and 18.
0, one end of which is spline-fitted to the differential side gear 15 and protrudes from the differential device to the left and right. The outer end of the differential yoke shaft 19 is inserted into the differential device 6 and is connected to the differential side gear 1.
5, and its largest large diameter portion 19
a is located outside the bearing 20, and therefore,
The differential yoke shaft 19 can be inserted into and removed from the differential device 6 disposed in the front axle case 3 from the left and right outer ends of the cylindrical portion 4 . That is, the position of the differential yoke shaft 19 is regulated so that the large diameter portion 19a on the differential device 6 side contacts the bearing 20 and does not move toward the differential device 6 side.

Reference numeral 23 denotes a sliding case, which is fitted inside the front axle case 3 so that it can slide and expand and contract at both left and right ends, a gear case 24 is fixed to a flange portion 23a at the outer end of the sliding case, and a cylindrical shaft portion 25a is provided inside the sliding case. A transmission shaft 25 is rotatably held via bearings 26 and 27. The cylindrical shaft portion 25a of the transmission shaft 25 is spline-fitted to the differential yoke shaft 19 such that it can freely slide and rotate integrally with the large diameter portion 1 of the differential yoke shaft 19.
A resilient member 28 made of a coil spring is interposed between 9a and the end surface of the cylindrical shaft portion 25a. This springing member 28 springs the differential yoke shaft 19 and the transmission shaft 25 in opposite directions. Therefore, the resilient member 28 fitted to the differential yoke shaft 19 has one end in contact with the large diameter portion 19a and the other end in contact with the cylindrical shaft portion 25a, and the differential yoke shaft 19 is connected to the transmission shaft 25 by the differential device 6. The differential yoke shaft 19 does not accompanies the outward movement of the transmission shaft 25, and there is no movement of the differential device 6 in the direction due to the rebound.

Reference numeral 29 denotes a rack and pinion mechanism for adjusting the expansion and contraction of the sliding case 23, which includes a rack 30 in the sliding direction formed on the upper surface of the sliding case 23, a pinion 31 meshing with the rack 30, and a rack and pinion mechanism of the front axle case 3. Cylinder part 4
It has an adjustment shaft 32 supported by and to which a pinion 31 is attached. Reference numeral 33 denotes a rotation locking bolt screwed onto the cylindrical portion 4, which engages with an axial groove 34 formed on the outer periphery of the sliding case 23 to prevent the sliding case 23 from rotating.

35 is a wheel fixing member, which has an inverted L-shaped cross section and is arranged to cover the cylindrical portion 4 and the sliding case 23 from the front to the upper surface, and its outer part is fixed to the sliding case 23 via bolts 36. , and is fixed to the cylindrical portion 4 via a bolt 37 in the middle thereof. The holes for the bolts 37 in the wheel width fixing member 35 are elongated holes in the left-right direction or a large number of round holes arranged in a row, and the sliding case 23 is attached to the front axle case 3 at a position adjusted for expansion and contraction by the rack and pinion mechanism 29. can be fixed.

A king pin 40 is supported by the gear case 24 via a bearing, and a knuckle pin 41 is provided on the upper part of the king pin 40. Kingpin 40 is 1
Power can be transmitted from the transmission shaft 25 via a pair of bevel gears 42 and 43.

An axle case 44 is attached to the lower part of the king pin 40 via a bearing 45, and supports an axle 46 to which a front wheel (not shown) is attached together with a case lid 47. A bevel pinion 48 is connected between the axle 46 and the king pin 40. Power can be transmitted using the bevel gear 49 and the bevel gear 49.

Figure 4 shows the main parts of a comparative example of the present invention.
The solid inside of the transmission shaft 25 is bored to form a hole 25b coaxial with the cylindrical shaft portion 25a, and a coil spring as a resilient member 28 is disposed within this light 25b, one end of which is connected to the differential yoke shaft 19. is in contact with the outer end surface of.

Although the resilient member 28 can be housed within the transmission shaft 25 as described above, it is easier to manufacture the resilient member 28 if it is fitted onto the differential yoke shaft 19 as in the above embodiment since there is no need to form the hole 25b. , it is possible to reduce costs.

In this FIG. 4, the cylindrical portion 4 of the front axle case 3
A coil spring 50 is fitted around the outer periphery of the sliding case 25 protruding from the casing 25, and is disposed in a compressed state between the end of the cylindrical portion 4 and the flange portion 23a of the sliding case 23.

The outer peripheral surface of the sliding case 25 is mirror-finished because it slides inside the cylindrical portion 4, and the outer peripheral surface of the sliding case 25 is finished with a mirror finish.
However, a coil spring 50 is fitted around its outer periphery in order to protect it more reliably from collisions with stones and the like and to prevent dents from occurring.

<Effects of the invention> According to the invention detailed above, the differential yoke shaft 1
9 has a large diameter portion 19a formed in the middle in the axial direction, and a resilient member 2 is provided on the gear case 24 side of this large diameter portion 19a.
8 is in contact with the differential device 6 of the large diameter portion 19a.
Since the side is in contact with the bearing 20 that supports the differential yoke shaft 19 on the front axle case 3 and its position is regulated,
The large diameter portion 19a formed on the differential yoke shaft 19 can abut one end of the resilient member 28 and the bearing 20, and insert the differential yoke shaft 19 from the outer end of the front axle case 3 into the differential device 6. Structure to be incorporated and transmission shaft 2
5 can be easily and inexpensively manufactured to prevent the differential yoke shaft 19 from moving along with the expansion of the differential yoke shaft 19, and the differential yoke shaft 19 can be prevented from moving even if it is rebounded toward the differential device 6 by the resilient member 28. Therefore, it is possible to maintain good tooth contact without affecting the tooth contact of the differential device 6.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is an overall sectional view, FIG. 2 is a partial sectional view of the main part,
3 is a cross-sectional view taken along the line -- in FIG. 2, FIG. 4 is a cross-sectional view showing a main part of a comparative example of the present invention, and FIG. 5 is a partial cross-sectional view of a conventional device. 3...Front axle case, 4...Cylinder part, 6...Differential device, 19...Differential yoke shaft, 19a...Large diameter part, 23...Sliding case, 24...Gear case,
25... Transmission shaft, 25a... Cylindrical shaft portion, 28... Resilient member, 40... King pin.

Claims (1)

[Scope of Claim for Utility Model Registration] A sliding case 23 is fitted in the left and right ends of the front axle case 3 in which the differential device 6 is built in so that it can be expanded and contracted,
A gear case 24 supporting a king pin 40 is fixed to the outer end of each sliding case 23, and a differential yoke shaft 19 protrudes left and right from the differential device 6, and a transmission shaft 25 transmits the power of the differential yoke shaft 19 to the king pin 40. The differential yoke shaft 19 is fitted to the front axle case 3 so as to be extendable and retractable and rotatably integral with the front axle case 3.
The front wheel drive unit is formed to be able to be assembled into the differential device 6 from the outer end side, and a springing member 28 that springs toward the differential device 6 side with respect to the transmission shaft 25 is fitted on the differential yoke shaft 19, and the wheel width can be adjusted. In the device, the differential yoke shaft 19 has a large diameter portion 19a formed in the middle in the axial direction, and one end of the resilient member 28 is brought into contact with the gear case 24 side of the large diameter portion 19a, and the differential device 6 of the large diameter portion 19a is brought into contact with the gear case 24 side. A front wheel drive device with adjustable wheel width, characterized in that the side of the differential yoke shaft 19 is in contact with a bearing 20 that supports the front axle case 3, and its position is regulated.