JPH10132055A - Transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix and support an HST type speed change gear by the first and the second projections from both side, so as to fix more solidly than supporting by one side, by providing the HST type speed change gear at the upper side of a transmission case which houses a transmission mechanism to a running device. SOLUTION: In a transmission case 1 housing a transition mechanism for the left side and the right side running devices, the first and the second projections 10 and 49 projecting to the upper side from the upper surface of the transmission case 1 form its both side surfaces are provided integral, and an HST type speed change gear 2 composed by arranging a hydraulic motor and a hydraulic pump in parallel is provided laterally on the transmission case 1 to make the hydraulic pump and the hydraulic motor almost in the horizontal codition, and the HST type speed change gear 2 is held and fixed between both projections. On the other hand, a drive train 12 on order to link and connect the output shaft 6 of the HST type speed change gear 2, with the input shaft 3 if the transmission mechanism, is provided in the first projection 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for arranging an HST type transmission on an upper portion of a transmission case housing a transmission mechanism for a traveling device.

[0002]

2. Description of the Related Art Conventionally, an HST-type transmission is connected to a transmission case accommodating a transmission mechanism for a left-right traveling device, and power is input from an engine to a pump shaft of the HST-type transmission. Is connected to the input shaft of the transmission case, the power shifted by the HST transmission is transmitted to the transmission case, the PTO shaft is driven, and the auxiliary transmission is performed in the transmission case, via the left and right side clutches. A technique for driving the axle by driving is known. For example, as disclosed in Japanese Utility Model Publication No. 7-1541 by the same applicant.

[0003]

However, in the prior art, since the HST type transmission is oriented in a direction in which the hydraulic pump and the hydraulic motor are disposed substantially vertically, the HST type transmission is mounted on the upper surface of the transmission case. In order to reduce the amount of protrusion from the transmission, the HST transmission must be attached to the outer surface of the transmission case, and its mounting portion has its own weight and the reaction force during torque transmission. Therefore, the mounting portion needs to be strong enough to withstand these forces, the wall of the transmission case on the mounting side needs to be thick, and the left and right sides for mounting the HST transmission on that side. The weight balance was lost.

[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, in a transmission case accommodating a transmission mechanism for the left and right traveling devices, first and second projections projecting upward from the upper surface of the transmission case from both side surfaces thereof are integrally provided, and a hydraulic pump and a hydraulic motor are arranged in parallel. The HST-type transmission is horizontally disposed above the transmission case such that the hydraulic pump and the hydraulic motor are substantially horizontal, and the HST-type transmission is clamped and fixed between the projecting portions. A drive train for interlocking connection between the output shaft of the HST transmission and the input shaft of the transmission mechanism is provided inside the one protruding portion. Further, the first projecting portion is a side case provided on one side surface of a transmission case, wherein a case body of the guide case having an opening for incorporating the drive train, and a lid closing the opening. It consists of. Further, the second protruding portion is made of a hard plate material attached to the other side surface of the transmission case.

[0005]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a skeleton diagram of the traveling power transmission mechanism, FIG. 2 is a rear cross-sectional view of the transmission, FIG. 3 is an enlarged expanded cross-sectional view of the same, FIG. 4 is an upper plan cross-sectional view thereof, FIG. Is a right side view, and FIG. 7 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 the support structure of the present invention described later. The HST type transmission 2 has a hydraulic pump P and a hydraulic motor M arranged in the HST case 5 in the front-rear direction and in the horizontal direction. A pump shaft 3 serving as a power input shaft protrudes from the HST case 5 to one side (left side in the present embodiment), and an input pulley 4 is fixedly provided, and a driving force from an engine (not shown) is input to the input pulley via a V belt 9. 4

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 swash plate hydraulic pump P is changed, and the discharge amount and the discharge direction are changed. The motor shaft 6 serving as the output shaft of the hydraulic motor M is continuously variable-speed driven by this pressure oil 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. The power transmitted by the HST transmission 2 is transmitted to a transmission mechanism for transmitting to the axle in the transmission case 1 by meshing with the input gear 14 fixed to the transmission gear 2.

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 portions of the teeth of the hollow cylindrical bodies 35L and 35R are 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.
The driving sprockets 48L and 48R are fixed to the other outer ends of the traveling drive shafts 19L and 19R to drive the crawlers.

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 (steering) brake. The other ends (outer ends) of the hollow cylindrical bodies 35L and 35R
, A piston member 41 is disposed in a bearing case 42 so as to face the friction plates 37, 38,..., And is provided with a steering lever provided on a work vehicle (not shown). By turning, a steering switching valve 50 described later is switched to send pressure oil to a cylinder chamber formed in the bearing case 42,
By advancing the piston member 41 inward into the transmission case, the side clutch and the side brake are sequentially operated so that the body 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, and the hydraulic cylinder 54 and the 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, the 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 the 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 parts 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 in the housing 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 housing 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 naturally falls and flows.

The present invention relates to the transmission case 1
As shown in FIG. 6, the side case 10 attached to one side (right side) of the first side is fixed so that the upper end thereof extends upward from the upper surface of the transmission case to form a first projecting portion. As shown in FIG. 5, a support plate 49 is fixed to the (left) side surface with its upper end extending upward from the upper surface of the transmission case and fixed to form a second projecting portion. The left and right outer surfaces of the HST case 5 and the first projecting portion of the side case 10 and the second projecting portion of the support plate 29 are fixed to bolts 73, 73,. The support plate 49 is made of a hard plate material such as an iron plate,
The HST transmission 2 is firmly supported above the transmission case by bolts from both left and right sides, and the HST transmission 2 is arranged so as to lie in an empty space above the transmission case 1 to achieve compactness.

The side case 10 has a case body 10a having an opening for incorporating a gear, and a lid 10b for closing the opening.
Between the case body 10a and the lid 10b.
1 is formed, and the motor shaft 6 of the HST-type transmission 2 is projected into the accommodation chamber R1 to fix the gear 7 therein.
The intermediate shaft 11 is supported at a vertically central position between the side oil passage plate 43 and the inside of the side case 10, and a gear 12 is rotatably mounted on the intermediate shaft 11 via a bearing via a gear.
Is meshed with the output gear 7 and the transmission case 1
The gear 12 is also meshed with an input gear 14 fixed on an input shaft 13 protruding into the accommodation room R1 to form a drive train for transmitting power from the HST transmission 2 to the transmission case.

[0022]

As described above, the present invention has the following advantages. That is, since the HST-type transmission is arranged above the transmission case and can be fixedly supported by the first and second protrusions from both sides thereof, it can be more firmly fixed than supported by one side. Therefore, the HST type transmission can be stably supported, and the weight balance is excellent. Then, the variable speed rotation from the HST-type transmission can be introduced into the transmission case via the drive train in the first projecting portion, and the first projecting portion can be used as both a support member and a transmission case. Further, the continuously variable transmission unit can be installed in a slight dead space above the transmission case, and the hydraulic pump and the hydraulic motor are arranged horizontally, so that the center of gravity can be kept as low as possible.

[0023] Further, the projecting portion can be formed without complicating the mold of the transmission case, and the drive train can be easily incorporated into the projecting portion. Can also be done easily. In addition, since the configuration is made as in claim 3, the protruding portion can be simply configured while having strength without complicating the mission case type.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a traveling power transmission mechanism.

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

FIG. 3 is an enlarged expanded 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 hydraulic circuit diagram.

[Explanation of symbols]

 P Hydraulic pump M Hydraulic motor R1 Housing 1 Transmission case 6 Output shaft of HST transmission 7 Drive train 10 Side case 10a Case body 10b Lid 12 Drive train 13 Input shaft of transmission mechanism 14 Drive train 49 Support plate 72 Lid

Claims (3)

[Claims] 1. A transmission case in which a transmission mechanism for a left-right traveling device is housed, first and second projections projecting upward from an upper surface of the transmission case from both side surfaces thereof are integrally provided, and a hydraulic pump and a hydraulic motor are provided. Are arranged horizontally above the transmission case such that the hydraulic pump and the hydraulic motor thereof are substantially horizontal, and the HST type transmission is sandwiched and fixed between these protruding portions. On the other hand, HS
A transmission provided with a drive train for interlockingly connecting an output shaft of a T-type transmission and an input shaft of the transmission mechanism. 2. A side case in which the first projecting portion is provided on one side surface of a transmission case, wherein a case body of the side case having an opening for incorporating the drive train, and closing the opening. The transmission according to claim 1, further comprising a lid. 3. The transmission according to claim 1, wherein said second projecting portion is made of a hard plate material attached to the other side surface of the transmission case.