JPS6316630B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention provides a vehicle in which a differential gear device is arranged to provide differential rotation to left and right drive axles.
This relates to the configuration of the drive case.

(b) Prior Art The present inventor previously filed a patent application for a transmission according to Japanese Patent Application No. 104819/1982, and the drive case thereof was constructed as follows.

That is, the differential gear case with the input case portion extended is opened downward, the differential gear device is inserted through the opening, both ends of the differential gear device are supported by axle cases attached to the left and right sides of the differential gear case, and the differential pinion shaft is vertically aligned. The bearing case that supports the shaft was attached to the bottom of the differential gear case, and finally the bottom of the differential gear case was sealed with a case lid.

According to this configuration, the mold for the differential gear device housing portion of the die-cast differential gear case is drawn out in two directions, the axle axis direction and the differential pinion axis direction, which are perpendicular to each other. The axle case mounting surface and bearing case mounting surface require chamfering. There were other problems.

Moreover, as mentioned above, there are many parts to be attached to the differential gear case, and a large number of bolt holes must be machined from multiple directions, resulting in an increase in the number of assembly steps.

(c) Problems to be Solved by the Invention An object of the present invention is to process the chamfering process so that when the drive case is made of aluminum die-casting, the precision mold for housing the differential gear device can be drawn out in only one direction. By eliminating the need for and simply assembling on the casting surface, in a running vehicle,
This is an attempt to reduce the cost of the drive case, which had a large cost impact.

Further, the present invention utilizes the fact that the drive case is split into front and rear parts, and can be assembled by sandwiching the differential gear device and other parts between the parts, thereby reducing the number of assembly steps.

(d) Means for Solving the Problems The objects of the present invention are as described above, and the configuration for achieving the objects will now be explained.

In a drive case in which a differential gear device is disposed inside, and a differential pinion shaft 4 that engages with a differential ring gear 15 of the differential gear device is arranged to vertically input from a lower gear 3, the drive case passes through axles 1L and 1R that also serve as differential side gear shafts. The drive case is divided into front and rear parts by upper and lower dividing lines, and the differential gear device and the differential pinion shaft 4 are sandwiched between the two cases, and one case has a cavity for arranging the transmission member for driving the gear 3. An extending portion 2a having a portion is formed.

(e) Embodiments and operations The purpose and structure of the present invention are as described above. Next, the structure of the embodiments shown in the attached drawings and the operations of the invention will be explained.

Fig. 1 is a rear view of the drive case of the present invention divided along a dividing line P, Fig. 2 is a top view of the entire drive case, Fig. 3 is a side sectional view, and Figs. 4A and 4B are counters. FIG. 5 is a side sectional view showing the assembled state of the gear 20 and the counter gear shaft, FIG. 5 is a side partial sectional view of the entire drive case of the present invention in an exploded state, and FIG. 6 is a rear sectional view of another embodiment in an exploded state. It is a diagram.

As can be understood from FIGS. 2 and 3, the drive case of this embodiment has an integrally formed axle case portion, which is divided into front and rear parts by an upper and lower dividing line P passing through the centers of the axles 1L and 1R. A front drive case 2 and a rear drive case 5 are constructed, and an extension part 2a whose inside is cast into a hollow part protrudes forward from the front drive case 2, and an HST type transmission is mounted on the top surface of the tip. 16 is placed there. The HST type transmission 16 may have a pump shaft and a motor shaft on the same axis, or may have a pump shaft and a motor shaft installed together.
In FIG. 3, the pump shaft 22 and motor shaft 17
HST type transmission 1 with both left and right side
6 is arranged on the extending portion 2a of the front drive case 2. A V-pulley 21 is fixed to the pump shaft 22, and power is transmitted from the engine of the vehicle through a V-belt.

The rotation after the HST type transmission 16 has been continuously variable for forward and reverse movement is transmitted from the motor shaft 17 to the inside of the front drive case 2.

A gear 18 is attached to the tip of the motor shaft 17 inserted into the front part of the hollow part of the extension part 2a of the front drive case 2.
is fixedly installed, and the gear 18 and the counter gear 20 mesh with each other. The counter gear 20 is supported by a counter shaft 19 near the middle of the extending portion 2a of the front drive case 2. The other side of the counter gear 20 meshes with the gear 3 fixed to the differential pinion shaft 4 to reduce the rotation of the motor shaft 17 and transmit it to the differential pinion shaft 4. The differential pinion shaft 4 is arranged vertically, and has a pinion gear 4a cut into its upper end, and the pinion gear 4a meshes with a differential ring gear 15 of a differential gear device.

In the embodiment shown in FIG. 1, a friction pin 9 of the traveling brake device is provided above the gear 3 of the differential pinion shaft 4.
is located.

Counter shaft 1 supporting counter gear 20
9 is installed in the cavity of the extending portion 2a in the following manner.

That is, a deep groove 33 and a shallow groove 34 are provided in the shaft insertion hole 38 on the extending portion 2a, and a locking knob 19a protruding from the upper end of the counter shaft 19 is inserted into the deep groove 33 and the shallow groove 3.
4 to fix one of the counter shafts 19.

First, fit the O-ring 30 into the O-ring groove 19b, insert the counter shaft 19 from the upper shaft insertion hole 38, and insert the locking knob 19a into the deep groove 33 while passing the bearing 30 of the gear 20. When fitted, the tip of the counter shaft 19 protrudes from the lower end of the bearing wall 2c, exposing the O-ring groove 19c. (4th B
Figure) Next, after fitting the O-ring 31 into the O-ring groove 19c, pull it up using the locking knob 19a.
The ring 31 is guided by the O-ring guide surface 35 and fits into the lower shaft insertion hole 39 without being cut. 36 is a bearing bush.

After the O-ring 31 is fitted into the shaft insertion hole 39, the locking knob 19a is rotated 90 degrees and fitted into the shallow groove 34 to lock the counter shaft 19 to prevent it from falling. To prevent the shaft 19 from coming off,
HST type transmission 1 placed and fixed on the extension part 2a
This is done by placing the end of 6 on top of the counter shaft 19. (Fig. 4A) The traveling brake device includes the friction pin 9, the rotating arm 10, the brake arm shaft 8, and the brake arm 13.
It is composed of etc. Each half of the friction pin 9 is also supported on the mating surfaces of the front drive case 2 and rear drive case 5, so that they can be assembled together when the two are assembled.

Then, by protruding the brake arm 13 fixed to the brake arm shaft 8 to the outside of the differential gear device and rotating the brake arm 13, the rotating arm 10 rotates, and the friction pin resists the brake release spring. 9 is pushed down and braking is performed on the upper surface of gear 3.

Further, in the embodiment shown in FIG. 1, the differential case of the differential gear device is constituted by left and right cases 6 and 7 of the same shape. Constructing the differential cases 6 and 7 from the same component reduces costs. The pinion shaft 14 that supports the differential pinion 24 is fixed by being fitted inside the differential ring gear 15 when the left and right differential cases 6 and 7 are assembled.

Conventionally, the differential ring gear 15 was fixed with bolts to the protruding flange portion of the integrally constructed differential case, but in this embodiment, the differential ring gear 15 is arranged between the left and right differential cases 6 and 7, which are divided into the same type. They are held in the center and fastened together by long bolts 25 that pass through the left and right differential cases 6 and 7.

The differential pinion 24 on the pinion shaft 14 meshes with the left and right differential side gears 12 and 11 to transmit differential rotation to the left and right axles 1L and 1R. The axles 1L and 1R also serve as left and right differential side gear shafts.

In FIG. 5, the main parts constituting the drive case of the present invention are shown disassembled, and the axles 1L and 1R are placed on the mating surface of the dividing line P between the front drive case 2 and the rear drive case 5. If a differential gear device, a differential pinion shaft 4, and a brake device are further provided, a friction pin 9 is sandwiched and supported.

In the embodiment shown in FIG.
Split into front drive case 2 and rear drive case 5
In doing so, the aforementioned brake device was eliminated,
Furthermore, an example is shown in which a conventional differential case 26 is used instead of having the left and right differential cases equally shaped.

Furthermore, according to the embodiment shown in FIG. 7, the axle cases 50 and 51 are integrally formed with the front and rear drive cases 2 and 5, whereas the structure shown in FIG. is made of a pipe, and a pair of tongues 50a and 51a are formed on the inner end thereof so as to match the dividing line P of the drive case, and the tongues are attached with bolts when assembling the front and rear drive cases 2 and 5. 50a, 51
A is made to be tightened together.

FIG. 7A is a perspective view of the pipe axle case 50.

Next, according to the embodiment shown in FIG. 8, left and right bearing portions 52b and 53b of the differential gear device are integrally formed at inner ends of the tongues 52a and 53a of each axle case 52 and 53, respectively.

FIG. 8A is a perspective view thereof. Figure 9 shows the 7th
FIG. 9 is a view from above of the embodiment of FIG. 8;

FIG. 10 shows a traveling work vehicle equipped with the drive case of the present invention as a front wheel drive type.

(F) Effects of the Invention Since the present invention is configured as described above, it has the following effects.

First, the structure of the conventional drive case is such that the differential gear device is inserted from the bottom and the left and right axle cases are opened.
This required assembly with a bearing case, and the die-cast drive case required chamfering. In contrast, in the present invention, by dividing the drive case that houses the differential gear device in the front-rear direction, there is no need for an insertion hole on the lower surface of the drive case, and the molds for both cases can be pulled out in only one direction. Therefore, each supporting portion of the differential gear device and the differential pin shaft can be precisely manufactured without requiring chamfering.

Second, the differential gear device and differential pinion shaft are supported by both cases at the same time when the front and rear drive cases are assembled, which eliminates the need for conventional axle cases and bearing cases, reducing assembly man-hours.

Thirdly, the hollow portion of the extending portion 2a formed in one of the front and rear divided cases can be simultaneously formed by punching out the mold of the case, making it possible to eliminate the conventional sealing case lid.

[Brief explanation of the drawing]

Figure 1 is a rear view of the drive case of the present invention divided along dividing line P, Figure 2 is a plan view of the entire drive case, Figure 3 is a side sectional view, and Figures 4A and 4B are counters. A partially sectional side view showing the assembly process of the gear 20 and the counter gear shaft, FIG. 5 is a side view of the drive case in an exploded state, FIG. 6 is a rear view of another embodiment in a split state, and FIG. 7 7A is a rear exploded cross-sectional view of an embodiment in which the axle case is a separate part made of pipe and is fastened together when the front drive case and rear drive case are tightened; FIG. 7A is a perspective view of the axle case in FIG. 7; 8A is a perspective view of the axle case of FIG. 8, and FIG. 9 is a drive case of the embodiment of FIGS. 7 and 8. Overall top view, No. 10
The figure is an overall side view of a traveling work vehicle equipped with the drive case of the present invention as a front wheel drive type. 1...Axle, 2...Front drive case, 2a...
Extension part, 4...Differential pinion shaft, 5...Rear drive case, 6, 7...Differential case, 16...HST
type transmission.

Claims (1)

[Claims] 1. In a drive case in which a differential gear device is disposed inside and a differential pinion shaft 4 that engages with a differential ring gear 15 of the differential gear device is arranged to vertically input from a lower gear 3, axles 1L and 1R that also serve as differential side gear shafts are connected. The drive case is divided into front and rear parts by a passing upper and lower parting line, and the differential gear device and the differential pinion shaft 4 are sandwiched between both cases, and the transmission member for driving the gear 3 is disposed in one case. A drive case structure in which a differential gear device is arranged, characterized in that an extending portion 2a having a hollow portion is formed.