JPH05262149A - Hst type traveling transmission - Google Patents

Abstract

PURPOSE:To prevent the sucking for the bubbles accompanied with the revolu tion of the gear of a reduction gear device and a differential gear device to a hydraulic pump and a hydraulic motor by nipping-installing a separating wall body between a half-divided transmission case, in order to separate the working oil for an HST transmission from the lubricating oil for the reduction gear device and the differential gear device. CONSTITUTION:As for an HST transmission in which a hydraulic pump P is installed on the side surface of the case of a hydraulic motor M accommodated in a right side transmission case 1a and the hydraulic pump P is constituted of the tight side transmission case 1a and a separating wall body 31, the working oil in a working oil tank for the HST transmission is sucked. Further, a lubricating oil tank for storing the lubricating oil for a reduction gear device and a differential gear device is constituted between a left side transmission case 1b and the separating wall body 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a hydraulic oil supply tank of an HST type traveling transmission for driving a drive axle of a tractor.

[0002]

2. Description of the Related Art Conventionally, the same applicant has filed an application for an HST type traveling transmission. For example, it is as in Japanese Utility Model Application No. 61-73481.

[0003]

However, in the prior art, the operating oil of the HST transmission attached to the mission case is used by sucking the lubricating oil in the mission case as it is. Especially in the case of a small mission case, the amount of lubricating oil accumulated inside is small, and the HST transmission device sucks the bubbles in the lubricating oil generated by the rotation of the gears as it is, and the pressure of the hydraulic pump is increased. There was a problem that it did not occur or the hydraulic motor stopped rotating.

The present invention solves the above-mentioned problems of the prior art. Conventionally, the lubricating oil used for the gear reduction device and the differential gear device and the hydraulic oil used for the HST transmission were configured in the same tank. The lubricating oil and the hydraulic oil are separated from each other by providing a separating wall inside the mission case.

[0005]

The object of the present invention is as described above. Next, the structure for achieving the object will be described.
In a mission case 1 that is equipped with an HST transmission and accommodates a reduction gear unit and a differential gear unit, in order to separate the hydraulic oil for the HST transmission unit from the lubricating oil of the reduction gear unit and the differential gear unit, the half transmission case 1a. ，
The separation wall body 31 is sandwiched between 1b.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The object and structure of the present invention are as described above. Next, the structure of the embodiment shown in the accompanying drawings will be described. FIG. 1 is a side view of a mower tractor equipped with the HST type traveling transmission of the present invention, FIG. 2 is a perspective view of the HST type traveling transmission of the present invention, FIG. 3 is a plan sectional view of the same, and FIG. FIG. 5 is a side sectional view of the hydraulic pump portion, FIG. 5 is a plan sectional view of the separation wall body 31, and FIG.

The structure of the mower tractor will be described with reference to FIGS. The engine E is placed in the front hood, and the pulley 2 is attached to the crankshaft of the engine E.
4 is attached. Also, the hydraulic pump P of the HST transmission
A pulley 22 is provided so as to be attached to the pump shaft, and a V belt 23 is interposed between the pulley 24 and the pulley 22. The pump shaft 14 of the hydraulic pump P is extended downward to P
The TO pulley 25 is fixed. The PTO pulley 2
5, the input pulley 27 of the mower device R is driven via the V belt 26. The drive axle 2 is projected left and right from the transmission case 1, and the rear wheels are fixedly attached to the tip.

Next, FIGS. 3, 4 and 5 will be described.
The mission case 1 is composed of left and right divided mission cases, and is composed of a right mission case 1a and a left mission case 1b. The separating wall 31 is sandwiched and fixed at the mating surface of the right mission case 1a and the left mission case 1b.
Therefore, the hydraulic motor shaft 3 penetrating the part of the separating wall 31.
An oil seal S is provided on the outer periphery of the above so that oil cannot pass back and forth between the split transmission cases 1a and 1b.

A hydraulic pump P is attached to the side surface of a hydraulic motor M housed in the right transmission case 1a shown in FIG. 3, and the hydraulic pump P is composed of the right transmission case 1a and a separating wall 31. The hydraulic oil in the hydraulic oil tank for the HST transmission is sucked.
Reference numeral 51 is an oil supply plug for that purpose. The construction of the hydraulic pump P is shown in FIG. The pump shaft 14 is fixed to the pulley 22 driven by the V-belt 23, and the rotation of the pump shaft 14 causes the piston holder 12 to rotate. Plural pistons 8 are fitted in the cylinder holes of the piston holder 12, and the rotation of the swash plate 9 changes the stroke of the piston 8 to change the discharge amount. Reference numeral 21 is a thrust bearing. The pressure oil discharged by the piston 8 is transferred from the oil passage of the pump case 30 to the oil passages 35a and 35b of the hydraulic motor M by opening to the mounting surface of the hydraulic pump P of the right transmission case 1a shown in FIG. Then, it flows into between the piston 7 and the cylinder of the piston holder 11. The hydraulic oil in the right transmission case 1a is sucked into the hydraulic pump P via the oil passage 35c shown in FIG.

Due to the amount of pressure oil flowing into the cylinder, a rotational force is generated in the piston holder 11 along the inclined thrust bearing 10, and the hydraulic motor shaft 3 rotates. The hydraulic motor shaft 3 passes through the separation wall body 31 via the oil seal S, and is bearing-supported inside the left transmission case 1b. The hydraulic motor shaft 3
The upper gear 4 drives the gear 5 on the intermediate shaft 6. The hydraulic motor shaft 3 is further extended, and the brake drum 13 is fixed to the portion protruding from the left-side mission case 1b.
The brake device B is configured.

The intermediate shaft 6 is bearing-supported between the separation wall body 31 and the left transmission case 1b. The engraved gear 6a on the intermediate shaft 6 meshes with the ring gear 15 of the differential gear device to rotate the differential gear device. In the diff gear device, the ring gear 15 also serves as a diff gear case, and the diff pinion shaft 16 is fixed in the opening inside the ring gear 15. The differential pinion 1 is attached to the differential pinion shaft 16.
7 and 17 are loosely fitted, and the diff pinions 17 and 17 are meshed with the side gears 19 and 19 which are spline-engaged with the drive axle 2. The side gears 19, 19 are fixedly mounted on the left and right drive axles 2, and the left and right retainers are held by the bearings 2a, 2a of the drive axle 2.

Left side mission case 1b and separating wall 31
And a lubricating oil tank that contains the lubricating oil for the reduction gear device and the differential device is configured. Reference numeral 50 is a lubrication plug for that purpose. And the separation wall body 31 which is an essential part of the present invention
Is configured as shown in FIG. The separating wall 3
Bearing holes 31c and 31d into which the bearings of the hydraulic motor shaft 3 and the bearings of the intermediate shaft 6 are fitted are opened on the left side of 1, and the tilted hole 31a into which the tilted thrust bearing 10 is fitted.
Is provided. Reference numeral 31b is an opening into which the support cylinder of the drive axle 2 is fitted, the outer circumference of the support cylinder is also formed in the hydraulic oil tank, and an oil seal is interposed in this portion to form a complete oil-tight structure. There is.

Next, referring to FIG. 4, a portion where the PTO pulley 25 is fixedly provided on the extension portion of the pump shaft 14 will be described. Since the PTO pulley 25 is not always necessary, the portion of the PTO shaft 28 can be inserted and fixed to the pump shaft 14.

[0014]

Since the present invention is configured as described above, it has the following effects. First, by forming a lubricating oil tank for the reduction gear device and the differential gear device and a hydraulic oil tank for the HST transmission device in separate chambers, bubbles created by rotation of the gears of the reduction gear device and the differential gear device are formed. However, it is not sucked into the hydraulic pump P or the hydraulic motor M, and it is possible to solve the problem that the piston is not operating due to the bubbles.

Secondly, since the division of the lubricating oil tank and the hydraulic oil tank can be performed by the separating wall 31 sandwiched between the right mission case 1a and the left mission case 1b, the separating wall 31 is added. Only by doing so, the purpose could be achieved, and the problem could be solved without increasing the cost.

[Brief description of drawings]

FIG. 1 is a side view of a mower tractor equipped with an HST type traveling transmission according to the present invention.

FIG. 2 is a perspective view of an HST type traveling transmission according to the present invention.

FIG. 3 is a plan sectional view of the same.

FIG. 4 is a side sectional view of a hydraulic pump portion of the HST transmission.

FIG. 5 is a plan sectional view of the separation wall body 31.

FIG. 6 is a perspective view of the split transmission cases 1a and 1b on the hydraulic motor mounting side.

[Explanation of symbols]

 1 mission case 1a right side mission case 1b left side mission case 2 drive axle 31 separating wall body M hydraulic motor P hydraulic pump

Claims (1)

[Claims] 1. In a mission case 1 equipped with an HST transmission device and accommodating a reduction gear device and a differential gear device, in order to separate hydraulic oil for the HST transmission device from lubricating oil for the reduction gear device and the differential gear device portion, An HST-type traveling transmission device characterized in that a separation wall body 31 is sandwiched and arranged between the half transmission cases 1a and 1b.