JP2004237770A - Transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify an operation for detaching a part of a HST type transmission device from a mission case and require only a small space for arranging right and left oil path plates and the HST type transmission device, in a constitution of a transmission mounted to a riding type lawn mower and the like, driving and changing a speed of the travelling, and transmitting a power to a lawn mowing device. <P>SOLUTION: Right and left axle gear boxes 2 are installed on right and left faces of a mission case with an input shaft 11 projected on an engine side and a PTO shaft 12 projected on a side opposite to the engine. Right and left HST type transmission devices are installed on a face opposite to the engine of the mission case, and a PTO case 7 with a PTO brake mechanism and a PTO clutch mechanism arranged inside are arranged between the right and left HST type transmission devices. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transmission that is mounted on a riding lawn mower or the like to drive and change the speed and transmit power to a lawn mower device.
[0002]
[Prior art]
Conventionally, as for the configuration of a transmission used in a riding lawn mower, a technique as disclosed in Japanese Patent Application Laid-Open No. 2000-71790 has been known.
[0003]
[Patent Document 1]
JP 2000-71790 A
[Problems to be solved by the invention]
However, in the prior art transmission, the HST transmission is sandwiched between the transmission case and the left and right axle gearboxes. If a failure or malfunction occurs in the part, the HST-type transmission cannot be repaired unless the axle gearbox is also removed.
In the present invention, the HST-type transmission device is configured so that the operation of removing the HST-type transmission device from the transmission case can be easily performed and the left and right oil passage plates and the HST-type transmission device do not take a large space. . Further, the transmission can be compactly arranged between the engine and the lawn mower device.
[0005]
[Means for Solving the Problems]
The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.
In claim 1, an axle gearbox having an axle is provided on each of left and right surfaces of a transmission case having an input shaft protruding toward the engine and a PTO shaft protruding from the side opposite to the engine. A continuously variable transmission for driving the axle is provided at left and right positions on the opposite surface.
According to a second aspect, in the transmission according to the first aspect, a PTO case including the PTO shaft and a PTO clutch mechanism for controlling driving of the PTO shaft is disposed between the left and right continuously variable transmissions. Things.
According to a third aspect, in the transmission according to the first aspect, the continuously variable transmission is an HST-type transmission, and an oil passage plate of the HST-type transmission is mounted on the transmission case.
According to a fourth aspect, in the transmission according to the first aspect, the shift operation shafts 13L and 13R protrude in the left-right direction from the HST cases 16L and 16R constituting the left and right HST-type transmissions HL and HR.
According to a fifth aspect, in the transmission according to the first aspect, a mechanical parking brake mechanism including parking brake plates 38L and 38R and a parking brake cam 50 is disposed in the left and right axle gear boxes 2L and 2R. .
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a side view showing a state in which a transmission of the present invention is mounted on a riding lawn mower. In FIG. 1, the overall structure of the riding lawn mower will be described.
A long body frame FM is arranged from the front end to the rear end of the body. At the front end of the body frame FM, left and right front caster wheels 32L and 32R are arranged at right and left positions with a distance between ruts.
At the rear of the front caster wheels 32L and 32R, a lawnmower mower M is suspended and arranged at the left and right center positions of the body frame FM. Power is transmitted via the universal joint device 34 from the PTO shaft 12 of the transmission T arranged rearward toward the input gear box 33 of the mower mower device M.
Since the mower mower M is suspended from the ground so as to be able to move up and down, the power transmission system can be moved up and down by the universal joint device 34.
[0007]
At the rear of the mower M, there is disposed a transmission T which is fixed to the body frame FM and constitutes a main part of the present invention. The body frame FM at the rear of the transmission T has a vibration-proof rubber 10. The engine EN is mounted via the reference numeral 10.
The crankshaft of the engine EN is arranged in the horizontal direction, the flywheel 5 is interposed at the part where the crankshaft protrudes forward, and a universal joint device 35 is provided at the front of the flywheel 5. The power is input to the input shaft 11 of the transmission T via the universal joint device 35. The input shaft 11 drives, in addition to the PTO shaft 12, a pair of left and right continuously variable transmissions, exemplified by HST type transmissions HL and HR to be described later.
At the rear of the engine EN, a radiator fan 54 and a radiator 3 are arranged. The transmission T, the engine EN, and the like are covered with a hood cover 6, and a seat S is disposed above the hood cover 6 at a position above the transmission T.
At left and right positions of the seat S, steering operation levers 30L and 30R for operating the shift operation shafts 13L and 13R of the left and right HST transmissions HL and HR are provided upright. The speed change operation shafts 13L and 13R are provided with speed change arms 44L and 44R, and the speed change operation shafts 13L and 13R are rotated by turning the speed change arms 44L and 44R forward and backward by the steering operation levers 30L and 30R. It is configured to be operated.
[0008]
While sitting in the seat S, the operator operates the left and right steering operation levers 30L and 30R to operate the steering direction of the riding lawn mower. The right and left steering operation levers 30L and 30R are tilted forward to advance straight ahead. When the steering operation levers 30L and 30R are tilted rearward in the left and right directions, the vehicle travels straight and backward.
By tilting only one of the steering operation levers 30L and 30R back and forth, one of the left and right wheels 31L and 31R stops rotating, and only the other rotates in the forward or reverse direction to perform steering turning. Is
By tilting the left and right steering operation levers 30L and 30R in the completely opposite directions, the left and right wheels 31L and 31R are rotated in the completely opposite directions and the interlining turn is performed. .
When the left and right wheels 31L and 31R rotate by operating the steering operation levers 30L and 30R to steer or turn the body of the riding lawn mower, the front caster wheels 32L and 32R rotate independently. Then, it freely moves left and right in that direction.
[0009]
FIG. 2 is a cross-sectional view of the transmission of the present invention taken along line BB of FIG.
FIG. 3 is a cross-sectional view of FIG.
FIG. 4 is a front view of the transmission of the present invention,
FIG. 5 is a sectional view taken along the line EE in FIG.
FIG. 6 is a sectional view taken along the line DD in FIG.
FIG. 7 is a sectional view taken along the line FF of FIG.
[0010]
2 to 7, the overall configuration of the transmission T of the present invention will be described.
The transmission T is a left and right HST type including a central transmission case NC, left and right axle gearboxes 2L and 2R, and left and right oil passage plates 4L and 4R attached to the transmission case NC on the side opposite to the engine EN. The transmission HL / HR, the PTO device K disposed between the left and right HST-type transmissions HL / HR, and a charge pump device further attached to a surface of the transmission case NC on the engine EN side. It is composed of CP.
[0011]
In the above configuration, the transmission case NC is formed by bonding the front transmission case 14 and the rear transmission case 15 which are divided and joined by a vertical surface having a surface facing in the front-rear direction, on the front and rear surfaces. On the engine EN side of the rear transmission case 15, a charge pump case 17 of the charge pump device CP is fixed. A pump space in which a pump gear 18 is fitted is provided on the mating surface of the charge pump case 17 and the rear transmission case 15.
Left and right oil passage plates 4L and 4R are provided at left and right positions on the front surface of a transmission case NC constituted by the front transmission case 14 and the rear transmission case 15, and are further provided on the front surfaces of the left and right oil passage plates 4L and 4R. Are provided with cases 16L and 16R of the left and right HST transmissions HL and HR. Transmission operation shafts 13L and 13R for tilting the swash plates of the left and right variable displacement hydraulic pumps PL and PR are projected from right and left outer surfaces of the HST type transmissions HL and HR. The speed change operation shafts 13L and 13R can be separately operated on the left and right sides by the above-described steering operation levers 30L and 30R.
[0012]
The input shaft 11 is supported by bearings through the charge pump case 17. The input shaft 11 passes through the inside of a transmission case NC formed by a front transmission case 14 and a rear transmission case 15, and It extends to the inside of the PTO case 7 of the PTO device K attached to the front of the front transmission case 14.
A traveling power split gear 24 is fixed on the input shaft 11 in the transmission case NC, and a PTO power transmission gear 23 is fixed on the input shaft 11 in the PTO case 7.
[0013]
The traveling power split gear 24 fixed on the input shaft 11 in the transmission case NC is engaged with pump gears 25L and 25R disposed on the left and right sides thereof. The pump shafts 8L and 8R of the hydraulic pumps PL and PR of the HST transmissions HL and HR attached to the front of the transmission case NC protrude into the transmission case NC and are connected to the pump gears 25L and 25R, respectively. Thus, the rotation of the input shaft 11 drives the hydraulic pumps PL and PR from the left and right pump gears 25L and 25R via the driving power split gear 24 and the pump shafts 8L and 8R.
The pressure oil discharged from the hydraulic pumps PL / PR is sent to the left and right hydraulic motors ML / MR via oil passages (closed circuits) in the left and right oil passage plates 4L / 4R and circulated. The hydraulic motors ML and MR are driven. Then, the rotational force of the hydraulic motors ML / MR is output from the motor shafts 9L / 9R into the transmission case NC, and the traveling input shafts 26L / 26R supported between the front transmission case 14 and the rear transmission case 15. Through the bevel gears 27L and 27R.
[0014]
Axle gear boxes 2L and 2R each having a single axle 1L and 1R are mounted on the left and right outer surfaces of the transmission case NC opposed to the traveling input shafts 26L and 26R, respectively. The rotation of the bevel gears 27L and 27R The axle input shafts 28L, 28R supported in the gearboxes 2L, 2R are transmitted to bevel gears 29L, 29R fixed to portions protruding into the transmission case NC, and are small-diameter gears on the axle input shafts 28L, 28. From 37L / 37R, it is transmitted to final gears 40L / 40R on axles 1L / 1R via gears 36L / 36R on counter shafts 42L / 42R and small diameter gears 41L / 41R.
Left and right wheels 31L and 31R in FIG. 1 are fixed to axles 1L and 1R driven by the final gears 40L and 40R.
The axles 1L, 1R are provided with a plurality of pin holes 1a, 1a, 1a,... So that the axial fixing positions of the left and right wheels 31L, 31R can be changed. .. Can be adjusted by replacing a pin (not shown) on the wheel side with respect to. The adjustment of the distance between the ruts is not based on the above-mentioned method, but may be performed, for example, by interposing a spacer between the transmission case NC and each of the axle gear boxes 2L and 2R.
The configuration of the left and right HST-type transmissions HL and HR, the left and right axle gear boxes 2L and 2R, and the axles 1L and 1R is configured symmetrically with respect to the input shaft 11.
The left and right axle gearboxes 2L and 2R are formed by bonding two cases, an outer case 2a and an inner case 2b, and the left and right axle gearboxes 2L and 2R are connected to the right and left outside of the transmission case NC. The axles 1L and 1R are fixedly mounted on the side surfaces so as to face the outer ends of the axles 1L and 1R. In FIG. 5, the motor shafts 9L and 9R to the axles 1L and 1R are arranged on a straight line in the horizontal direction. However, depending on the vehicle configuration, the positions of the axles 1L and 1R with respect to the motor shafts 9L and 9R are changed. The axle gearboxes 2L and 2R may be appropriately adjusted around the axle input shafts 28L and 28R and fixed to the transmission case NC so as to be offset in the raising or lowering direction.
[0015]
Next, referring to FIG. 5, a PTO clutch mechanism 20 and a PTO brake mechanism 21 arranged inside the PTO case 7 attached to the front of the transmission case NC will be described.
The front part of the PTO shaft 12 is supported by a bearing in the PTO case 7. The other end of the PTO shaft 12 is supported by a bearing in an oil passage inheriting case 19 provided in a front transmission case 14 constituting a transmission case NC.
Pressure oil from the charge pump device CP is supplied into the oil passage inheriting case 19 through an oil receiving port 12a opened on the rear surface of the rear transmission case 15, and the oil is passed through a shaft drilling oil passage 12b in the PTO shaft 12. Thus, the actuator 22a in the hydraulic cylinder 22 is configured to slide back and forth.
[0016]
When the actuator 22a in the hydraulic cylinder 22 is pushed by the pressure oil in the direction of the oil passage inheriting case 19 and slides, the friction plate of the PTO clutch mechanism 20 is pressed and the clutch is engaged, so that the input shaft 11 The power transmitted from the upper PTO power transmission gear 23 to the loose fitting gear 39 on the PTO shaft 12 acts to transmit the power to the PTO shaft 12. Conversely, when the pressure oil is released from the actuator 22a, the clutch is disengaged, and the pressing pin 22c connected to the actuator 22a is pushed in the direction of the PTO brake mechanism 21 by the biasing spring, thereby causing the friction plate of the PTO brake mechanism 21 to move. It is configured so as to be pressed and locked to the PTO clutch case 7 side so that a braking force enough to stop the inertial rotation of the PTO shaft 12 is applied.
[0017]
The hydraulic oil supplied to the HST type transmissions HL and HR by the charge pump device CP is also used as the lubricating oil inside the transmission T, and is provided below the input shaft 11 on the rear surface of the rear transmission case 15. The lubricating oil filtered by the threaded line filter 43 is sucked into the charge pump device CP through a pipe. The supply of pressure oil from the charge pump device CP to the left and right HST-type transmissions HL and HR is supplied not through a drilled oil passage in the case but through an externally provided pipe. Further, a part of the pressure oil of the charge pump device CP is taken out and supplied to the elevation switching valve 55, so that the hydraulic pump or the like that moves the lawn mower device M up and down can be externally taken out of the hydraulic pressure. .
As described above, the pressure oil for operating the PTO clutch mechanism 20 and the PTO brake mechanism 21 also uses part of the pressure oil from the charge pump device CP.
[0018]
A parking brake lever (not shown) is disposed on the riding lawn mower. By rotating the parking brake lever, a parking brake plate 38L on the axle input shaft 28L shown in FIG. The parking brake cam 50, which applies a braking pressure to 38R, is rotated. The parking brake mechanism is configured as a wet, mechanical braking mechanism, and the parking brake cam 50 is configured in a cam shape in which a part of a round shaft is cut out. It is engaged with a pressing actuator disposed on the parking brake plates 38L and 38R.
[0019]
2 to 7, the left and right oil passage plates 4L and 4R are attached to the front surface of the front transmission case 14 on the side opposite to the engine EN side of the transmission case NC. HST cases 16L and 16R constituting the HST type transmissions HL and HR are provided on the front surfaces of the oil passage plates 4L and 4R.
Further, a PTO case 7 constituting a PTO device K is attached to the front of a front transmission case 14 constituting a transmission case NC between the left and right HST cases 16L and 16R. However, the HST cases 16L and 16R and the PTO case 7 may be configured as a single case integrally formed and attached to the front surface of the front transmission case 14.
[0020]
Next, the configuration of the hydraulic circuit of the present invention will be described with reference to FIG.
The hydraulic oil of the HST type transmission HL / HR also serves as the lubricating oil in the transmission case NC. The lubricating oil in the transmission case NC is supplied to the charge pump case 17 of the charge pump CP from the suction port 46 to the charge pump CP in FIG. ing. The charge pump CP rotates a pump gear 18 fixed on the input shaft 11, and the discharged pressure oil is supplied to a predetermined pressure by a charge pressure setting pressure reducing valve 57 arranged in the charge pump case 17. And is taken out of the charge pump case 17 through the port 57a, divided into two directions, and supplied to the charge ports 45, 45 of the HST type transmissions HL, HR. The charge ports 45 are formed in the upper portions of the left and right oil passage plates 4L and 4R as shown in FIG. It should be noted that the port 57a is connected to the charge ports 45, 45 with no piping, and an opening is formed in the mating surface between the charge pump case 17 and the oil passage plates 4L, 4R via the transmission case NC to the oil passage plates 4L, 4R. It can also be connected by road.
[0021]
Drain oil discharged at the time of pressure adjustment by the charge pressure setting pressure reducing valve 57 is supplied to a PTO switching valve 56 built in the charge pump case 17, and the pressure oil switched by the PTO switching valve 56 becomes It is taken out of the charge pump case 17 through the port 56a and is supplied to the hydraulic cylinder 22 of the PTO clutch mechanism 20 formed in the PTO case 7. The hydraulic cylinder 22 is supplied by a pipe from an oil passage inheriting case 19 formed in the front transmission case 14 via a shaft bore oil passage 12 b in the PTO shaft 12.
Further, a port 55a for taking out the high-pressure oil on the primary side of the pressure reducing valve 57 for setting the charge pressure through the resistance valve to the outside of the charge pump case 17 is provided. It is supplied from the switching valve 55 to the lifting cylinder 51. The lift arm 49 is rotated by the lift cylinder 51 to lift and lower the lawn mower device M.
[0022]
As shown in FIGS. 4 and 7, push pins 47 and 48 for opening the bypass circuit are arranged above the left and right oil passage plates 4L and 4R. As shown in the hydraulic circuit of FIG. 8, the push pins 47 and 48 for opening the bypass circuit are used for charging in order to short-circuit the hydraulic paths (closed circuits) of the hydraulic pumps of the HST type transmissions HL and HR and the hydraulic motor. The check valve is mechanically opened and closed.
When the check valve is opened by the bypass pins 47 and 48 for opening the bypass circuit, the hydraulic motor can freely rotate.
When the engine EN stops and the HST type transmissions HL / HR cannot be operated to drive the axles 1L / 1R, the rotational resistance of the axles 1L / 1R due to the HST type transmissions HL / HR is eliminated. Thus, the rotation of the engine EN at the time of start-up is facilitated, and the driven lawn mower equipped with this transmission can be driven by an external driving force such as pushing or thrusting.
These bypass pins 47 and 48 for opening the bypass circuit can be opened and closed by an operator from outside.
[0023]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
Axle gearboxes 2L and 2R having axles 1L and 1R on the left and right surfaces of a transmission case NC having an input shaft 11 protruding toward the engine EN and a PTO shaft 12 protruding from the side opposite to the engine EN. And the continuously variable transmissions HL and HR for driving the axles 1L and 1R are provided at the left and right positions on the surface of the transmission case NC opposite to the engine EN. When the HR is removed, there is no need to remove the left and right axle gear boxes 2L and 2R, and maintenance can be easily performed.
[0024]
As described in claim 2, the PTO case 7 having the PTO shaft 12 and the PTO clutch mechanism 20 for controlling the driving of the PTO shaft 12 is arranged between the left and right continuously variable transmissions HL and HR. Since the continuously variable transmissions HL and HR protrude from the transmission case NC, it is absolutely necessary to provide front and rear spaces in this portion. Since the PTO case 7 is arranged, the overall configuration of the transmission T can be made compact. Further, with such a configuration, the case 16L / 16R of the continuously variable transmission HL / HR and the PTO case 7 can be formed as an integral case.
[0025]
According to a third aspect of the present invention, the continuously variable transmissions HL and HR are HST type transmissions, and the oil passage plates 4L and 4R of the HST type transmission are mounted on the transmission case NC, so that the HST type transmission can be simplified. It can be removed and repaired.
[0026]
As described in claim 4, the speed change operation shafts 13L and 13R protrude left and right from the HST cases 16L and 16R constituting the left and right HST type transmissions HL and HR, so that the steering operation is arranged on the side of the seat S. By arranging the axis of the speed change operation shafts 13L and 13R in the left and right direction that is the direction that matches the front and rear direction that is the operation direction of the levers 30L and 30R, the steering operation levers 30L and 30R and the speed change operation shafts 13L and 13R The link mechanism between them can be simply configured.
[0027]
Since the mechanical parking brake mechanism constituted by the parking brake plates 38L and 38R and the parking brake cam 50 is disposed in the left and right axle gear boxes 2L and 2R as in claim 5, the parking brake provided on the side of the seat S. The link mechanism between the lever and the lever is simplified, and a mechanical parking brake mechanism can be constructed at low cost.
[Brief description of the drawings]
FIG. 1 is a side view showing a state in which a transmission of the present invention is mounted on a riding lawn mower.
FIG. 2 is a cross-sectional view of the transmission of the present invention, taken along the line BB in FIG. 4;
FIG. 3 is a sectional view taken along the line CC in FIG. 4;
FIG. 4 is a front view of the transmission of the present invention.
FIG. 5 is a sectional view taken along the line EE in FIG. 4;
FIG. 6 is a sectional view taken along the line DD in FIG. 4;
FIG. 7 is a sectional view taken along the line FF in FIG. 2;
FIG. 8 is a hydraulic circuit diagram of the transmission of the present invention.
[Explanation of symbols]
NE Engine K PTO device FM Airframe T Transmission M Lawn mower S Seat HL / HR HST transmission NC Transmission case 1a Pin hole 1L / 1R Axle 2L / 2R Left and right axle gearbox 3 Radiator 4L / 4R Left and right oil passage Plate 5 Flywheel 6 Bonnet cover 7 PTO case 8L ・ 8R Pump shaft 9L ・ 9R Motor shaft 10 Anti-vibration rubber 11 Input shaft 12 PTO shaft 13L ・ 13R Shift operation shaft 14 Front transmission case 15 Rear transmission case 16L ・ 16R HST case 17 Charge pump case 18 Pump gear 19 Oil passage inheriting case 20 PTO clutch mechanism 21 PTO brake mechanism 22 Hydraulic cylinder 22a Actuator 23 PTO power transmission gear 24 Running power split gear 25L / 25R Pump gear 26・ 26R Tube shaft 27L ・ 27R Bevel gear 28L ・ 28R Axle shaft 29L ・ 29R Bevel gear 30L ・ 30R Steering operation lever 31L ・ 31R Left and right wheels 32L ・ 32R Front caster wheel 33 Input gear box 34 ・ 35 Universal joint device 36 Gear 37 Small-diameter gear 39 Gear 40L / 40R Final gear 42L / 42R Counter shaft 43 Line filter 44 Shift arm 45/45 Charge port 46 Suction port 47/48 Push pin for opening the bypass circuit 49 Lift arm 50 Parking brake cam 51 Lifting cylinder 54 Radiator fan 55 Elevating switching valve 56 PTO switching valve 57 Reducing valve for charge pressure setting

Claims (5)

An axle gearbox with an axle is attached to each of the left and right sides of the transmission case with the input shaft protruding on the engine side and the PTO shaft protruding on the side opposite to the engine. A transmission having a continuously variable transmission for driving the axle at a position. 2. The transmission according to claim 1, wherein a PTO case including the PTO shaft and a PTO clutch mechanism for controlling driving of the PTO shaft is disposed between the left and right continuously variable transmissions. . The transmission according to claim 1, wherein the continuously variable transmission is an HST-type transmission, and an oil passage plate of the HST-type transmission is mounted on the transmission case. 2. The transmission according to claim 1, wherein the speed change operation shaft protrudes outward in the left and right directions from the speed change cases forming the left and right continuously variable transmissions. 2. The transmission according to claim 1, wherein a mechanical parking brake mechanism including a parking brake plate and a parking brake cam is disposed in the left and right axle gear boxes.

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