JPH10338044A - Lubricating structure for transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a surplus oil in an HST type transmission to be supplied to a part to be lubricated in a transmission case without piping. SOLUTION: A side case 10 is provided on one side of a transmission case 1 accommodating a transmission mechanism for a laterally traveling device, and one end of the side case is extended to load an HST type transmission. A power transmitting mechanism for connecting the output shaft of the HST type transmission 2 and the above transmission mechanism, is accommodated in the side case, and a surplus oil in the HST type transmission is discharged into the side case. When the surplus oil in the side case exceeds a specified quantity, the oil is discharged into the transmission case. A lubricating oil basin R2 is formed in the side case, and the shaft end of a shaft provided with a part to be lubricated is allowed to face the inside of the lubricating oil basin. The start end side of a lubricating oil passage 18a for the part to be lubricated is allowed to be open to the shaft end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for a work vehicle equipped with an HST transmission,
The present invention relates to a technique for using surplus oil generated in a T-type transmission as lubrication.

[0002]

2. Description of the Related Art Conventionally, an HST type transmission has been mounted on one side of a transmission case accommodating a transmission mechanism for a left-right traveling device, and a PTO shaft provided with a one-way clutch is provided in the transmission case. The power from the output shaft of the transmission is transmitted to the external working machine via a one-way clutch and a PTO shaft, and the excess oil generated in the HST transmission is transmitted through a pipe to the shaft of the PTO shaft. It is known that the oil is supplied to a lubricating oil passage provided therein to lubricate the one-way clutch. For example, as disclosed in Japanese Utility Model Publication No. 7-1541 by the same applicant.

[0003]

However, in the prior art, an H mounted on an outer surface of a transmission case is used.
The ST-type transmission causes an increase in the size of the entire transmission. Also, in lubricating the one-way clutch in the transmission case, the shaft end of the PTO shaft is projected outward of the transmission case, and the start end side of the lubricating oil passage of the one-way clutch provided in the PTO shaft is opened here. Excess oil of the HST transmission is introduced through a pipe. This piping has a problem that the number of assembling steps when the transmission is mounted on the machine is increased, and there is a possibility that the transmission may interfere with other devices, thereby causing damage to the piping and oil leakage.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, a side case is provided on one side of a transmission case accommodating a transmission mechanism for the left and right traveling devices, and one end of the side case is extended upward to form the HS.
A T-type transmission is mounted, and a power transmission mechanism that connects the output shaft of the HST-type transmission and the transmission mechanism is accommodated in the side case, and excess oil in the HST-type transmission is placed in the side case. Discharging the excess oil in the side case when the excess oil exceeds a predetermined amount, forming a lubricating oil reservoir in the side case. The shaft end of the shaft provided with the above is faced, and the starting end side of the lubricating oil passage with respect to the lubricating oil portion is opened at the shaft end.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a skeleton diagram of the transmission, FIG. 2 is a rear cross-sectional view of the transmission,
3 is an enlarged sectional view of the upper part, FIG. 4 is a sectional plan view of the upper part, FIG. 5 is a left side view of the transmission, FIG. 6 is a right side view thereof, and FIG. 7 is a sectional view showing a mounting portion of the filter and the strainer. 8 is a hydraulic circuit diagram.

An embodiment in which the transmission of the present invention is applied to a combine transmission case will be described. 1 to 4, the power transmission configuration will be described.
The HST transmission 2 is disposed above the transmission case 1 and is firmly fixed by a support structure described later. The HST type transmission 2 includes a hydraulic pump P in an HST case 5.
And the hydraulic motor M are arranged in the front-rear direction and in the horizontal direction. The pump shaft 3 serving as a power input shaft from the HST case 5
Is projected to one side (the left side in this embodiment) and the input pulley 4
And a driving force from an engine (not shown) is transmitted to the input pulley 4 via a V-belt 9.

When the input pulley 4 is rotated, the variable displacement hydraulic pump P housed in the HST case 5 is driven, and pressure oil from the hydraulic pump P is sent to the hydraulic motor M. At this time, by manually changing the shift arm of the hydraulic pump P, the volume of the hydraulic pump P is changed, and the discharge amount and the discharge direction are changed. The motor shaft 6 which becomes the output shaft of the hydraulic motor M by this pressure oil
Is continuously variable and driven. An output gear 7 is fixed on the motor shaft 6. The output gear 7 meshes with a gear 12 loosely fitted on an intermediate shaft 11 in a side case 10, which will be described later. Input gear 1 fixed to
4, and the power shifted by the HST transmission 2 is transmitted to a transmission mechanism for transmitting to the axle in the transmission case 1.

The transmission case 1 is composed of left and right half cases 1L and 1R. The transmission case 1 includes an input shaft 13, an auxiliary transmission shaft 15, a steering shaft 16, and a counter shaft 1.
7 and a PTO shaft 18 are rotatably and horizontally mounted in parallel, and gears 20 and 21 are provided on the input shaft 13 in the transmission case 1.
Is fixedly mounted, and the gear 20 is provided with the loose fitting gear 2 on the auxiliary transmission shaft 15.
2 always meshes with a gear 24 fixed on the counter shaft 17, and the gear 21 meshes with a loose fitting gear 23 on the auxiliary transmission shaft 15. The gear 2 is further provided on the counter shaft 17.
5 is fixed, and the gear 25 meshes with a gear 26 externally fitted on the PTO shaft 18 via a one-way clutch 29.
A PTO pulley 27 is fixed outside the transmission case 1 of the PTO shaft 18 so that rotational power synchronized with the HST transmission 2 can be taken out.

A clutch sliding body 30 is spline-fitted between the free-fitting gear 22 and the free-fitting gear 23 on the auxiliary transmission shaft 15 so as to be slidable in the left-right axial direction.
And a tooth portion 22a on the inner surface of each of the loose fit gears 23.
23a is formed so that the clutch sliding body 30 can be engaged with either the tooth portion 22a or the tooth portion 23a by the sliding operation of the clutch sliding body 30, and the clutch sliding body is provided on the input shaft 13. 8 is spline-fitted slidably in the left-right axial direction, and a loosely-fitting gear 28 is also rotatably loosely fitted. A tooth portion 28a is provided on a side surface of the loosely-fitting gear 28 so that it can mesh with the clutch sliding body 8. The loose fitting gear 28 meshes with the wide gear 31 on the auxiliary transmission shaft 15 and simultaneously slides the clutch sliding bodies 8 and 30 by an auxiliary transmission shifter (not shown), thereby providing high, medium and low gears. The configuration is such that three low-speed sub-speed rotations can be obtained. Thus, input shaft 1
3 transmits power to the auxiliary transmission shaft 15. The gear 31 is engraved on the auxiliary transmission shaft 15, and a brake drum 32 is fixed on the auxiliary transmission shaft 15 outside the transmission case 1, and by rotating the brake arm 33 (FIG. 3). The parking brake is braked.

A driving gear 34 is provided at the center of the steering shaft 16.
The drive gear 34 meshes with the gear 31 on the auxiliary transmission shaft 15 to transmit power. Internal teeth 34L and 34R are formed around the rotation axis on both sides of the drive gear 34. ing. On the other hand, hollow cylinders 35L and 35R are rotatably fitted on both sides of the drive gear 34 on the steering shaft 16, and spline-like teeth are formed on the outer peripheral surfaces of the hollow cylinders 35L and 35R. (Drive gear side) A clutch gear 35a is formed on the outer periphery, and the internal teeth 34L of the drive gear 34 are formed.
(Or 34R) so that the side clutch can be engaged with and disengaged from the side clutch.

The central portion of the teeth of the hollow cylindrical bodies 35L and 35R is always meshed with the reduction gears 36L and 36R as side gears, and the reduction gears 36L and 36R of the traveling drive shafts 19L and 19R supported at the lower part of the transmission case 1. The traveling drive shafts 19L and 19R are fixed to the inner end and the transmission case 1 and the axle cases 47L and 47R are connected via bearings.
, And driving sprockets 48L and 48R are fixed to the other outer ends of the traveling drive shafts 19L and 19R to drive the crawler.

On the other side (outside) teeth of the hollow cylindrical bodies 35L and 35R, rotating friction plates 37 for a multi-plate type side brake are locked so as not to rotate relatively. Are arranged between the friction plates 37, and the bearing cases 42 for supporting both outer ends of the steering shaft 16 are mounted. From the portion of the transmission case 1, the friction plates 38, 38 are provided on the inner periphery of a hollow cylindrical portion 1 a that is recessed and formed inward of the case.
Are locked so that they cannot rotate, and the friction plates 37 and 38
.. Constitute a side brake. A pushing portion is provided at the other end of the hollow cylindrical bodies 35L and 35R, and a piston member 41 is disposed in a bearing case 42 so as to face the friction plates 37, 38,. By turning a steering lever provided in the work vehicle, a steering switching valve 50 described later is switched to send pressure oil to a cylinder chamber formed in a bearing case 42, and the piston member 41 is turned on.
Is advanced inward into the transmission case, whereby the side clutch and the side brake are sequentially actuated so that the aircraft can be turned.

When the working vehicle is a combine, a mowing device is mounted as a working machine in front of the machine body, and the mowing device is moved up and down by controlling the expansion and contraction of a hydraulic cylinder 54. The piston member 41 for operating the side clutch / side brake is controlled by a hydraulic circuit shown in FIG. That is, the input shaft of the hydraulic pump P0 is fixedly mounted on the output shaft of the engine E in addition to the drive pulley 55 for driving the input pulley 4;
The hydraulic pump P0 is being driven. By driving the hydraulic pump P0, the lubricating oil in the transmission case 1 is sucked through the strainer 67. As shown in FIGS. 5, 6, and 7, the strainer 67 is suspended in the compartment of the transmission case 1 and the outlet side of the strainer 67 is branched into two, one of which is provided with a hydraulic pressure through a pipe 69. The other is connected to the suction port of the pump P0, and the other is further filtered by a filter 70 mounted on the upper surface of the transmission case 1 and connected to the suction port of the charge pump CP via a pipe 71, and discharged from the charge pump CP. The oil is charged in a closed circuit that fluidly connects the hydraulic pump P and the hydraulic motor M.

The oil discharged from the hydraulic pump P0 is:
As shown in FIG. 8, oil is sent to a flow divider 57 via a filter 56, and one of the divided oil flows is sent to the steering switching valve 50 by the flow divider 57, and the steering switching valve 50 By the switching operation of 50, the piston member 41 is supplied to one of the cylinder chambers. A drain hole is provided in the cylinder chamber at a stroke position corresponding to a side clutch disengagement position, and each drain hole communicates with the inside of the transmission case 1 via a side brake relief valve 58. When the side clutch is activated, the relief valve 58 for the side brake is opened, and when the brake is activated, the relief set pressure of the relief valve 58 for the side brake is increased.

The other oil flow divided by the flow divider 57 is connected to the hydraulic cylinder 54 via an elevating valve 59, a check valve 60 and the like, and the elevating valve 59 is manually switched by operating an unillustrated elevating lever. hand,
The hydraulic cylinder 54 can be controlled to expand and contract.
Reference numeral 61 denotes a relief valve for setting the operating pressure of the hydraulic cylinder 54. These directional control valve 59 and load check valve 6
The relief valve 61, the flow divider 57, and the side brake relief valve 38 are housed in a valve case 74. Then, the return oil from the elevation valve 59 is supplied to the oil cooler 63 via the oil passage 62, and the return oil is cooled. The oil cooler 63 is arranged near the radiator 65 of the engine E, and the oil cooler 63,
The radiator 65 is forcibly cooled by the cooling fan 66 of the engine E. As shown in FIG. 5, the cooled oil discharged from the oil cooler 63 passes through an HST through a pipe 64.
Returned to Case 5.

The HST case 5 contains a hydraulic pump P and a hydraulic motor M, and stores lubricating oil. Oil leaking from the rotary sliding portions of the hydraulic pump P and the hydraulic motor M is also used in the HST case 5. Is stored within. 2 and 6, the HST case 5 is closed by a lid 72, and the HST case 5 and the transmission case 1 are closed.
An oil hole 72 is attached to a side case 10 attached to the side
a, 43a, and when the lubricating oil in the HST case 5 exceeds a predetermined amount, it overflows and the oil holes 72a.
From 43a, it enters into the accommodation room R1 formed in the side case 10.

Further, as shown in FIG.
0, an oil reservoir R2 is formed continuously with the storage chamber R1, and an oil hole 43b is formed in the upper and lower middle part in the side case 10 so that lubricating oil flows from the storage chamber R1 into the oil reservoir R2. The oil hole 43b is opened so as to be positioned above the oil sump R2. An oil hole 1b is opened in the upper part of the side wall of the case half 1R so that the lubricating oil can further return into the transmission case 1 from the oil sump R2, and the oil hole 43b and the oil hole 43b are positioned so that the positions of both holes coincide. . Thus, when a predetermined amount or more of the lubricating oil is accumulated in the oil sump R2,
It overflows and returns to the transmission case 1 from the oil passage 1b.

A lubricating oil passage 18a is bored in the axial direction from one end face of the PTO shaft 18 so that the PTO shaft 1
8 is disposed facing the inside of the oil reservoir R2, and the other side of the lubricating oil passage 18a is opened in a direction perpendicular to the axis, and the PTO
It faces a one-way clutch 29 between the shaft 18 and the gear 26. In this way, the oil in the oil sump R2 is
8a, the lubricating oil flows into the one-way clutch 29 externally fitted to the PTO shaft 18 to lubricate.

The lubricating oil in the transmission case 1 is sucked up as hydraulic oil by a hydraulic pump P0 and is sent to an elevating valve 59 so as to drive a hydraulic cylinder 54 for driving a working machine, and is returned from the elevating valve 59. Oil is
The oil is sent to an oil cooler 63 via a pipe 62, cooled, and further fed into the HST case 5 via a pipe 64, mixed with leak oil from the hydraulic pump P and the hydraulic motor M in the HST case 5, The hydraulic pump P and the hydraulic motor M are cooled. Then, the oil overflowing from the HST case 5 enters the storage chamber R1 in the side case 10 through the oil holes 72a and 43a, and the side case 1 in contact with the outside air.
The oil which has been cooled again while flowing down the inside of the inner case 0 and overflowed from the oil reservoir R2 at the lower part of the side case 10
It is returned to mission case 1. Then, the return oil flows to the one-way clutch 29 to lubricate from the lubricating oil passage 18a provided on the axis of the PTO shaft 18 facing the oil reservoir R2. At this time, the liquid level L0 of the lubricating oil in the transmission case 1 is lower than the oil passage 1b and the lubricating oil passage 18a, so that the oil lubricating the one-way clutch 29 falls naturally and flows into the transmission case 1. .

[0020]

As described above, the present invention has the following advantages. That is, by employing the side case, the HST type transmission can be arranged in the empty space above the transmission case, and the transmission can be made compact as a whole. Also, HS
During operation of the T-type transmission, surplus oil is always generated from the transmission, and an oil sump can be easily formed in the side case due to the vertical difference between the HST-type transmission and the transmission case. The oil in the oil sump can be easily guided as lubricating oil to a portion to be lubricated, such as a one-way clutch, on the shaft without external piping.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a transmission.

FIG. 2 is a rear cross-sectional view of the transmission.

FIG. 3 is an enlarged sectional view of the upper part.

FIG. 4 is an upper plan sectional view of the same.

FIG. 5 is a left side view of the transmission.

FIG. 6 is a right side view of the same.

FIG. 7 is a cross-sectional view showing a mounting portion of a filter and a strainer.

FIG. 8 is a hydraulic circuit diagram.

[Explanation of symbols]

 P Hydraulic pump P0 Hydraulic pump M Hydraulic motor R1 Storage chamber R2 Oil reservoir 1 Transmission case 10 Side case 18 PTO shaft 18a Lubricating oil passage

Claims (1)

[Claims] 1. A side case is provided on one side of a transmission case accommodating a transmission mechanism for a left-right traveling device, and one end of the side case is extended upward to mount an HST-type transmission. A power transmission mechanism for connecting the output shaft of the HST type transmission and the transmission mechanism is housed, and excess oil in the HST type transmission is discharged into a side case, and the excess oil in the side case is reduced by a predetermined amount. When the pressure exceeds, the lubricating oil reservoir is formed in the side case so that the shaft end of the shaft provided with the lubricated portion faces the lubricating oil reservoir. An oil supply structure for a transmission, wherein a start end side of a lubricating oil passage with respect to the lubricating oil portion is opened at an end.