JPS6146279Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to the structure of a transmission device used in small-sized special agricultural tractors and the like.

In the transmission of a small special tractor, when arranging the countershaft and pinion shaft that do not transmit power on the same axis, the support of the countershaft and the support of the pinion shaft are overlapped in the circumferential direction, and the width is taken up by the bearing part as much as possible. This problem has been solved by making the transmission case shorter in front and rear length, and by providing a collar shaft to ensure sufficient durability and easy machining.

The purpose of the present invention is as described above, and the structure of the present invention will be explained based on the structure of the embodiment shown in the attached drawings. Figure 2 is the same front view, Figure 3
The figure is also a rear view. It has a low floor and high tilt stability so that work can be done under the branches of orchards or inside greenhouses, and it is configured to be able to turn within a narrow range. The fuselage is structured around a chassis frame 21, and the engine 10 is installed in the engine compartment 9 at the rear of the fuselage, and is connected to the rear axle device 5 of the rear wheels 8.
5, it has a low floor structure. Further, the rear wheels 8 are used as steering wheels so that the vehicle can be turned in a small radius, and the operator 2 operates a steering handle 3 in the cockpit 1 to enable the vehicle to be steered in a small radius. Since the rear wheels were used as steering wheels to improve the turning speed like a forklift, if the rear wheels were to be driven on top of the rear wheels, the drive system for the steering wheels would be complicated, so the front wheels 7 are used as driving wheels.
The transmission case 12 is placed at the front, the chassis frame 21 and the front axle case 17.
7 is permanently installed. Power is transmitted from the engine 10 to the input shaft 23 of the transmission case 12 by a V-belt, a universal joint, and a transmission shaft.
Link devices 6 for attaching work equipment protrude from the front part of the chassis frame 21, so that a rotary mower device, a snow blower, a rotary tiller device, etc. can be attached.

Power transmission to these working machines is performed between the chassis frame 21 by a PTO shaft 19 that protrudes from the front and rear of the machine body.

When the transmission case 12 is located at the front of the machine, the support bearing of the PTO shaft 19 becomes eccentric, so the transmission case 12 is eccentric and a PTO bearing device is installed on the longer front axle 17.
The PTO shaft 19 is supported.

A rear axle device 55 for the rear wheels 8, 8 is pivotally supported on a part of the chassis frame 21 by a center pin 20. 15 is a gear shift lever, 13 is an accelerator lever, 4 is a control column, and 11 is a seat.

The driver's cab 11 is configured to be able to rotate as a whole around the pivot 5 and to be openable and closable.

FIG. 4 is a side sectional view of the mission case 12.
5 is a side view of the transmission case 12, FIG. 6 is a front view of the transmission case 12, FIG. 7 is a perspective view of the transmission shifter section, FIG. 8 is a rear view of the transmission shifter section, and FIG. 9 is a front view of the transmission case 12. FIG. 3 is a side view of a speed change shifter section.

From the crankshaft of the engine 10 to the input shaft 23,
Power is transmitted through the belt tension clutch, transmission shaft, and universal joint.

A carved gear 39 is provided at the rear end of the input shaft 23 facing into the transmission case 12, and the front end of the speed change shaft 24 is supported by a bearing in a bearing hole provided inside the rear end of the shaft. ing. The rear end of the speed change shaft 24 is connected to a brake shaft 26 by a coupling 25.

The brake shaft 26 protrudes into the brake case 16 and is spline-fitted to a brake shoe 28. The brake shoe 28 is connected to the brake arm 31
The brake arm shaft 30 is opened and expanded to apply braking by rotating the brake arm shaft 30. Brake case 1
In this embodiment, a brake device such as No. 6 is provided at the front of the machine body as an extension of the input shaft 23, and is configured so that maintenance, repair, etc. of the brake can be easily performed.

The engraved gear 39 of the input shaft 23 is the counter shaft 35
It is constantly meshed with the upper fixed gear 42 and transmits power to the counter shaft 35. A transmission gear train with three forward speeds and one reverse speed is provided between the counter shaft 35 and the speed change shaft 24.

In the case of reverse gear, the sliding gear 4 on the transmission shaft 24
1 meshes with the reverse gear 51 shown in FIG. The reversing gear 51 is always in mesh with the carved gear 45 on the counter shaft 35. In the case of the first forward gear, the sliding gear 41 on the speed change shaft 24 meshes with the fixed gear 44 on the counter shaft 35.

In the second forward stage, the sliding gear 40 meshes with the fixed gear 43.

In the third forward speed, the internal teeth 40a at the front of the sliding gear 40 are directly connected to the carved gear 39 of the input shaft 23.

A fixed gear 46 is fixedly attached to the front portion of the speed change shaft 24 beyond the bearing 56. The fixed gear 46 is always in mesh with a fixed gear 47 fixed to the outer peripheral spline 50a on the collar shaft 50. The collar shaft 50 is a cylindrical shaft body, and a bearing 49 is supported at the rear portion of the outer periphery, and a spline portion 50a is carved at the front portion. Further, a counter shaft 35 is pivotally supported at the rear of the inner circumference of the collar shaft 50 via a needle bearing 48, and an inner circumferential spline is provided at the front position of the inner circumference, and meshes with the outer circumferential spline 34b of the pinion shaft 34.

Pinion 34a of pinion shaft 34 and differential device 3
No. 3 ring gear 32 is always in mesh. Front axles 27L and 27R protrude from the differential device 33 to both sides. Further, one end of the pinion 34a forms a biting part 50b on the inner periphery of the collar shaft 50, and is inserted into the collar shaft 50.

Further, the shifting of the sliding gears 40 and 41 on the transmission shaft 24 is performed by the transmission shifters 37 and 38 which are slidably supported on the transmission shifter shaft 36.

A detent device 37a is provided at the slidable support portion of the shifter 37 to the shifter shaft 36, and a detent device 38a is also configured to the slidable support portion of the speed shifter 38 to the speed shifter shaft 36, so that the sliding gear Prevents engagement and natural dislodgement.

The speed shifters 37 and 38 are one shifter shaft 3
Both of them are slidably supported in the front and rear positions on the gear shift lever 15, and engagement convex portions 37b and 38b, which are engaged by the gear lever 15a at the tip of the gear shift lever 15, move on the gear shifter shaft 36 to the gear shifter 37. - It extends to the middle part of 38, and the engagement convex parts 37b and 38b face each other to form a U-shaped insertion part for the gear shift lever.

By tilting the speed change lever 15 left and right, either the speed change shifter 37 or 38 is selected, and the speed change lever 15
The transmission gears are brought into engagement by tilting back and forth. The horizontally tiltable positions of the shift lever 15 are limited so that the mutual transfer from the engaging convex portion 37b to the engaging convex portion 38b is performed only when both shifters 37 and 38 are in the neutral position.

As shown in FIGS. 5 and 6, the reversing gear 51 is fixed to the lid 12b of the mission case 12 with the bearing bosses 12c and 12c of the reversing gear shaft protruding, and can be attached and removed from the side. 12a is a mounting surface for the front axle 17.

As described above, the present invention has the input shaft 23 and the speed change shaft 24.
are arranged on the same axis, and the counter shaft 35 and pinion shaft 34 are arranged on the same axis in parallel with both axes,
The input shaft 23 and the gear shift shaft 24 are directly connected, or the gears on the counter shaft 35 to which the power is transmitted mesh with the gears on the shift shaft 24 to perform multiple gear shifts, and the rotation after shifting is transferred from the gear 46 on the shift shaft 24. , in a configuration in which the transmission is transmitted to the pinion shaft 34 via the gear 47,
Opposed parts of the counter shaft 35 and pinion shaft 34 are arranged on the intermediate wall part of the transmission case 12, and a collar shaft 50 is fitted on the outer periphery of the opposed part, so that the counter shaft 3
5 and the inner diameter of the collar shaft 50 are supported via a bearing 48, and the pinion shaft 34 and the inner diameter of the collar shaft 50 are coupled via a spline portion 50a.
The outer diameter of the transmission case 1 is
2, and the spline portion 50
Since the inner diameter portion of the gear 47 is engaged with the gear 47, the following effects are achieved.

First, although the short portions of both the counter shaft 35 and the pinion shaft 34 are fitted into the collar shaft 50, the bearing 49 on the outer periphery of the collar shaft 50 can be made wide, so that the collar shaft 50 can be reliably mounted on the mission. Since the case 12 can be supported by bearings and there is no risk of tilting, both shafts supported inside the collar shaft 50 can be reliably supported by bearings even if only short portions thereof are inserted.

Second, if the pinion shaft 34 and the collar shaft 50 are integrated, it can be easily made with the same structure as the present invention, but the collar shaft 50 and the pinion shaft 50
4a, the pinion cannot be machined because a cutting device for machining the pinion cannot be placed between them. It is also easy to process by dividing it into two parts and spline fitting them together.

Thirdly, by configuring the bearing portions of the pinion shaft and the counter shaft to overlap each other in this manner, the length of the transmission case can be shortened.

[Brief explanation of the drawing]

Figure 1 is an overall side view of a small special agricultural tractor equipped with the device of the present invention, Figure 2 is a front view of the same,
FIG. 3 is a rear view, FIG. 4 is a side sectional view of the transmission case 12, FIG. 5 is a side view of the transmission case 12, FIG. 6 is a front view of the transmission case 12, and FIG. 7 is a gear shifter. FIG. 8 is a rear view of the shifter section, and FIG. 9 is a side view of the shifter section. 12...Mission case, 23...Input shaft, 24
...speed change shaft, 34...pinion shaft, 34a...pinion, 34b...spline section, 35...counter shaft, 48, 49...bearing, 50...collar shaft, 50a
...Spline section.

Claims (1)

[Scope of utility model registration request] The input shaft 23 and the speed change shaft 24 are arranged on the same axis, and the counter shaft 35 and the pinion shaft 34 are arranged on the same axis in parallel with both shafts, and the input shaft 23 and the speed change shaft 24 are directly connected or power is transmitted. The gears on the counter shaft 35 and the gears on the transmission shaft 24 are engaged to perform a multi-stage transmission, and the rotation after the transmission is transferred to the transmission shaft 2.
4, the counter shaft 3
5 and the opposing portion of the pinion shaft 34 are disposed on the intermediate wall portion of the transmission case 12, and the collar shaft 50 is fitted onto the outer periphery of the opposing portion.
The inner diameter of the pinion shaft 34 and the collar shaft 50 are supported via the bearing 48, and the inner diameter of the pinion shaft 34 and the collar shaft 50 are the spline portion 50.
The outer diameter of the collar shaft 50 is supported on the intermediate wall of the transmission case 12 via a bearing 49, and a spline portion 50a is provided to engage the inner diameter of the gear 47. Characteristics of agricultural tractor transmissions.