JP2506113B2 - Vehicle hydraulic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic transmission for a vehicle.

(Prior Art) When a hydraulic transmission is used in various vehicles such as a lawn mower and a cultivator, the hydraulic transmission is generally arranged at a location apart from a power source such as an engine or an electric motor.

In the related art, the drive shaft of the oil pump and the power source side are connected by a power transmission shaft or a belt pulley mechanism.

(Problems to be Solved by the Invention) However, in the conventional device, as disclosed in Japanese Patent Publication No. 38-7172, no measures are taken when a belt pulley mechanism is used in a device using a power transmission shaft. ,
Therefore, if the hydraulic transmission is to be applied to vehicles of other models, it is preferable that the power source side can be connected to the drive shaft of the oil pump by the power transmission shaft, but it can be connected to the power source side by using the belt pulley mechanism. When trying to connect, there was a disadvantage that a large design change was required and it was difficult to easily apply it to various models.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide a hydraulic transmission for a vehicle that can be easily applied to various models and that can be assembled easily and with high accuracy. It is in.

(Means for Solving the Problems) In order to achieve the above object, the structure of the present invention is provided with a substrate 35 having flat mounting surfaces 35A and 35B formed on both side surfaces thereof, and each of the mounting surfaces 35A of the substrate 35. , 35B inner case 97A, 97B respectively
And the oil pump 27 or the oil motor 29 is housed in each of the inner cases 97A and 97B.
Attach the outer cases 37 and 39 to A and 35B, respectively, and attach the inner case 97
A and 97B are accommodated, and at least one of the outer cases 37 and 39 accommodates a speed reduction mechanism 31 for reducing the output from the oil motor 29, and is opposed to the drive shaft 55 of the oil pump 27 from the inner case 97A. The extending portion 55A extending to the side surface 217 side of the outer case 37 is formed, and the power of the power source is transmitted to the extending portion 55A of the oil pump 27 at different portions of the outer case facing the extending portion 55A. Two or more insertion portions 207 for inserting the power transmission shaft 201 into the outer case 37 are formed, and a lid 229 for closing an unused portion of the insertion portion 227 is provided.

(Action) Insert the drive shaft 55 of the oil pump 27 and the power source side into the insertion portions 207, 22.
7, the power transmission shaft 201 and the belt pulley mechanism 233 can be connected together, and the unused insertion portion 227 is closed by the lid 229. Therefore, the hydraulic transmission 13 can be easily applied to various models.

Also, the assembly is based on the substrate 35, the inner case 97A, 97B,
It is only necessary to assemble the outer cases 37, 39 and the like in order, and the hydraulic transmission 13 can be easily assembled with high accuracy.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a plan view of a notch of a main part of a riding lawn mower, FIG. 2 is a side view of a hydraulic transmission, FIG. 3 is a sectional development view of the hydraulic transmission, and FIG. 4 is A- in FIG. The figure which combined the BB line cross section with the A line arrow view, FIG. 5 is D in the CC line arrow view of FIG.
-The figure which combined the D line arrow view is shown.

1 is a riding lawn mower, 3 is a front wheel, 5 is a rear wheel, 7 is a cutter housing, 9 is a seat, 11 is a handle, and left and right rear wheels 5,
A hydraulic transmission 13 is arranged between the five. An engine is mounted as a power source on the riding lawn mower 1, and the power of the engine is input to the hydraulic transmission 13 via a power transmission shaft 201 extending in the front-rear direction, and the hydraulic transmission 13 shifts the power to the left or right. Is transmitted to the axles 21, 21 of the vehicle to drive the left and right rear wheels 5, 5, and the engine power is transmitted to the lawn mowing cutter in the cutter housing 7 to rotate the cutter.

The hydraulic transmission 13 includes an oil pump 27 and two oil motors 29, 29 driven by the oil pump 27.
And the reduction mechanisms 31 and 31 provided between the oil motors 29 and the left and right axles 21, the case 33, and the like, and the left and right axles 21 and 21 are arranged coaxially.

The case 33 has a substrate 35 located substantially in the center and a substrate 35.
The left and right outer cases 37 and 39, which are fastened to the flat left and right mounting surfaces 35A and 35B with bolts through packings 36 and 38, and the left and right inner cases 97A and 97B, respectively, as shown in FIGS. Middle portions 41 and 43 indicate bolt mounting portions of the left and right outer cases 37 and 39.

The left and right mission chambers 45, 47 are defined by the outer cases 37, 39 on the left and right sides of the substrate 35, respectively.
47 is a through hole formed in the substrate 35 and communicates with each other. Lubrication oil is stored in the mission chambers 45 and 47, and the oil pump 2
7, oil motor 29,29, reduction mechanism 31, left and right axle 21,21
The inner end portion of is housed in the mission chambers 45 and 47.

The oil pump 27 is disposed on the left mounting surface 35A of the substrate 35 with its drive shaft 55 parallel to the axle 21. In the embodiment, a swash plate type variable displacement axial piston pump is used as the oil pump 27.

The oil pump 27 is mounted on the left mounting surface 35A of the base plate 35 with a packing 56 with a pump case 57, and a drive shaft that is inserted into the pump case 57 and is rotated by engine power.
55 and the pump case 57 that is inclined with respect to the axis of the drive shaft 55.
Mounted on the swash plate 59, a cylinder block 61 that is spline-engaged with the drive shaft 55 and rotates integrally with the drive shaft 55, and is moved in the cylinder block 61 on a thrust bearing 63 of the swash plate 59 to reciprocate. A plurality of pistons 65 for performing the above, and a valve plate 71 having a suction port 67 and a discharge port 69 are formed. In FIG. 3, 68 denotes a bearing and 70 denotes an oil seal.

The swash plate 59 is connected to a gear shift lever on the handle 11 side via a shaft 73, a lever 75, etc., and the inclination angle of the swash plate 59 with respect to the drive shaft 55 can be set to an arbitrary value by operating the gear shift lever. . In the embodiment, it is possible to switch between three stages of forward, neutral and reverse.

A bulging part that bulges to the left at the upper part of the left outer case 37.
203 is formed, and the rear portion of the power transmission shaft 201 is inserted into the mission chamber 45 from an insertion portion 207 formed on the front surface 205 of the bulging portion 203. The insertion portion 207 is composed of a bearing hole 209 and the like, and the rear portion of the power transmission shaft 201 is supported via a bracket 211 and a bearing 213, and 215 in the drawing denotes an oil seal. Then, the drive shaft 55 of the oil pump 27 is formed with an extending portion 55A exposed from the pump case 57 and extending to the side surface 217 side of the bulging portion 203, and the power transmission shaft 201 and the extending portion 55A are connected to the bevel gears 219 and 221. Engage and connect.

The tip of the extending portion 55A is supported by the bearing portion 223 on the side surface 217 of the bulging portion via the bearing 224.

Further, an insertion portion 227 is formed on the lower surface 225 of the bulging portion 203,
The unused portion of the insertion portion 227 is liquid-tightly closed by the lid 229.

The insertion portion 227 is composed of the bearing hole 231 and the like as described above. As shown in FIGS. 2 and 3, this insertion portion 227 is used when the engine and the extension portion 55A are connected via the belt pulley mechanism 233.

Engine power extended by belt pulley mechanism 233 55A
The rotary shaft 237 of the pulley 235,
7 is inserted into the mission chamber 45, the rotary shaft 237 is supported via a bracket 239 and a bearing 241, and the bevel gears 243 and 245 are meshed with each other, and the insertion portion 207 is closed by a lid not shown. As shown in FIG. 2, the pulley 235 is disposed above and behind the axle and on the lower side of the left outer case 37. In the figure, 247 is an oil seal, 249 is a belt for transmitting engine power to the pulley 235, and 251, 253 are A pulley and a belt for transmitting engine power to the cutter side are shown.

The right end of the drive shaft 55 is inserted through the bearing hole 83 of the substrate 35,
The board 35 is projected to the right mounting surface 35B side. And in the embodiment, a gear type oil pump (trochoid pump) 85 for supplying oil to the suction port 67 of the oil pump 27 in this portion,
A so-called charge pump 85 is provided. The oil pump 85 includes a gear 87 that rotates integrally with the drive shaft 55, a case 89 that houses the gear 87, a suction port 91, a discharge port 93, and the like.

The left and right oil motors 29 are mounted on the left and right mounting surfaces 35A of the board 35,
35B, each output shaft 95 is arranged coaxially in parallel with the axle 21, and a swash plate type fixed displacement axial piston motor is used as the oil motor 29 in the embodiment.

The oil motor 29 includes a motor case 97, an output shaft 95 arranged in the motor case 97, a swash plate 101 provided in the motor case 97 to be inclined with respect to the axis of the output shaft 95, and an output shaft. A cylinder block 103 that is spline-engaged with 95 and rotates integrally with the output shaft 95, a plurality of pistons 107 that are incorporated in the cylinder block 103 and move on a thrust bearing 105 of the swash plate 101 to make a reciprocating motion, and an inlet port 109. And a valve plate 113 having an outlet port 111 formed therein.

The case 97A of the oil motor 29 mounted on the left mounting surface 35A of the board 35 is formed integrally with the case 57 of the oil pump 27, and the case 97B of the oil motor 29 mounted on the right mounting surface 35B of the board 35 is the gear type oil. The size is formed so as to cover the pump 85. In the embodiment, the cases 97A and 97B each constitute an inner case. The case 97B is attached to the right attachment surface 35B with a bolt through the packing 114, and 106 and 108 in FIGS. 4 and 5 indicate the bolt attachment portions of the cases 97A and 97B.

Spaces 1 are provided on the left and right sides of the substrate 35 by the cases 97A and 97B.
15, 117 are defined, and the space portions 115, 117 are communicated with each other through a through hole (not shown) formed in the substrate 35. The space portions 115, 117 store oils for the oil pumps 27, 85 and the oil motor 29, and the right case 97B. An oil reservoir 119 that bulges downward is formed in the lower part of the.

The inner end of each output shaft 95 is supported by a bearing hole 121 of the base plate 35, both inner end surfaces 95A, 95A are brought into contact with each other in the bearing hole 121, 122 in FIG. 3 is a bearing, and 124 is an oil seal.

The outer ends of the output shafts 95 are supported by the bearings 123 of the left outer case 37 and the right outer case 39 via bearings 125, respectively.
Install a small-diameter reduction gear 127 near the outer edge of 95.

The left and right axles 21 have their inner ends supported by the bearing holes 129 of the base plate 35, and the inner ends thereof are supported by the bearing portions 131 of the left and right outer cases 35, 37 through bearings 135 and oil seals 137, respectively. The inner end surface 21A of each axle 21 abuts in the bearing hole 129, and the rear wheel 5 is attached to the outer end of each axle 21.

A large-diameter reduction gear 139 meshing with the reduction gear 127 is attached to a portion of the axles 21 near the cases 37 and 39, and the reduction gears 31 and 139 reduce the power of the engine.
Is configured.

A brake mechanism 141 for braking the axle 21 is arranged on the inner side surface of each of the reduction gears 139.

The brake mechanism 141 is the case 1 attached to the board 35.
43, the anchor pin 145 supported by the case 143, the brake shoe 147 supported by the anchor pin 145, and the case 143.
And a cam 149 for expanding the brake shoe 147 supported by the cam 149. The cam 149 includes a joint 151, a rod 153, a joint 155, and a rod.
It is connected to the brake operator via 157, lever 159 and the like.

Next, the oil passages of the oil pumps 27, 85 and the oil motor 29 will be described.

The suction passage 161 for supplying oil to the suction port 91 of the gear type oil pump 85 is opened in the oil sump 119 and
35, and a filter 163 is attached to the opening.

The discharge passage 165 for guiding the discharge oil from the discharge port 93 of the gear type oil pump 85 extends upward at approximately the center of the front and rear direction of the substrate 35, and the front branch passage 16 extends upward at the upper portion.
7 and the rear branch passage 169 extending rearward, and the discharge passage 165
A relief valve 171 is provided inside.

On the other hand, the inlet ports 109, 109 of the left and right oil motors 29 are communicated with the outlet ports 111, 111 by oil passages 173, 175 extending in the left-right direction, that is, the thickness direction of the substrate 35.

Further, the suction port 67 of the oil pump 27 and the oil passage 175
Is a front oil passage formed vertically in front of the center of the substrate 35.
The discharge port 69 of the oil pump 27 and the oil passage 173 are made to communicate with each other by a rear oil passage 179 formed in the up-down direction behind the center of the substrate 35.

Then, the upper portion of the front oil passage 177 is connected to the front branch passage 167 and the upper portion of the rear oil passage 179 is connected to the rear branch passage 169 via check valves 181 and 183, respectively.

Further, a switching valve 265 is attached to the upper left side surface 261 of the substrate 35,
The switching valve 265 includes a valve body 264 having an internal oil passage 263 formed therein. By operating the switching valve 265, the oil passage locations downstream of the check valves 181, 183 and the oil passage locations upstream of the check valves 181, 183 are communicated,
The switching valve 265 is configured to be freely shut off, and the operation of the switching valve 265 is performed by operating a neutral lever arranged on the handle side.

 Next, the operation of the hydraulic transmission 13 will be described.

The drive shaft 55 is rotated by the power of the engine, and the oil is first sucked into the suction passage 161, the discharge passage 165 by the gear type oil pump 85,
It is supplied to the front oil passage 177 via the front branch passage 167. Then, when moving forward, each piston 65 reciprocates due to the rotation of the cylinder block 61 due to the rotation of the drive shaft 55, and oil is transferred to the front oil passage 17
7, suction from suction port 67, discharge port 69, rear oil passage 17
9, oil passage 173, inlet port 109 to oil motor 29
Supply to. And each piston 107 of the oil motor 29
The cylinder block 103 is rotated by rotating the cylinder block 103, the output shaft 95 is rotated by the rotation of the cylinder block 103, the power of the engine is transmitted to the axle shaft 21 via the speed reduction mechanism 31, and the oil is discharged from the outlet port 111 and the oil. It reaches the front oil passage 177 via the passage 175 and is circulated from the front oil passage 177 to the suction port 67 of the oil pump 27.

The gear shifting is performed by changing the inclination angle of the swash plate 59 of the oil pump 27, the swash plate 59 becomes parallel to the base plate 35 during neutral, the piston 65 does not reciprocate, and the check valves 181, 18
Both 3 maintain the closed state, and the oil is returned from the relief valve 171 to the oil sump 119.

When moving backward, the inclination angle of the swash plate 59 is opposite to the inclination angle when moving forward, and the oil supplied from the oil pump 85 flows from the rear branch passage 169 and the rear oil passage 179 to the oil pump opposite to the time when moving forward.
It is sucked into the discharge port 69 of 27, discharged from the suction port 67, and supplied from the front oil passage 177 and the oil passage 175 to the outlet port 111 of the oil motor 29. Then, the output shaft 95 is rotated in the direction opposite to that of the forward movement, and the oil is supplied to the inlet port 109,
From oil passage 173 and rear oil passage 179 to discharge port 69 of oil pump 27
The oil is circulated during the forward and backward movements while being supplemented with the oil supplied by the oil pump 85.

Further, the oil flow by the oil pump 27 is the sum of the oil flows by the left and right oil motors 29, 29. Therefore, when the direction of the lawnmower 1 is changed, the left and right axles 21, 21 have a rotational difference.

When the switching valve 261 is operated regardless of the speed change state, the oil discharged from the discharge port 69 of the oil pump 27 is returned to the suction port 67, or the oil discharged from the suction port 67 is discharged to the discharge port. Returned to 69, the oil motor 29 is not driven and the axle 21 becomes free.

Therefore, according to this embodiment, the insertion portion 227 can connect between the engine side and the drive shaft 55 of the oil pump 27 by either the power transmission shaft 201 or the belt pulley mechanism 233.
The hydraulic transmission 13 can be easily applied to various models.

Also, the assembly is based on the substrate 35, the inner case 97A, 97B,
It is only necessary to assemble the outer cases 37, 39 and the like in order, and the hydraulic transmission 13 can be easily assembled with high accuracy.

In the embodiment, the case where the gear type oil pump 85 is used is explained, but the gear type oil pump 85 is omitted, and the oil pressure transmission is realized by the oil pump 27 and the oil motor 29.
13 may be configured.

Further, the types of the oil pump 27 and the oil motor 29 are not limited to those of the embodiment, and other types may be used, and at least one of the oil pump 27 and the oil motor 29 may be a variable displacement type. You can use it.

Further, although the case where the oil pump 27 and the oil motor 29 are connected by a closed circuit has been described, the oil pump 27 and the oil motor 29 may be connected by an open circuit. The axle 21 may be driven.

(Effects of the Invention) As is apparent from the above description, according to the present invention, it is possible to obtain a hydraulic transmission of a vehicle that can be easily applied to various models and that can be assembled easily and with high accuracy. it can.

[Brief description of drawings]

FIG. 1 is a plan view of a notch of a main part of a riding lawn mower, FIG. 2 is a side view of a hydraulic transmission, FIG. 3 is a sectional development view of the hydraulic transmission, and FIG. 4 is A- in FIG. The figure which combined the BB line cross section with the A line arrow view, FIG. 5 is D- in the CC line arrow view of FIG.
The figure which combined the D line arrow view is shown. In the figure, 1 is a lawn mower, 3 is a front wheel, 5 is a rear wheel, 11 is a steering wheel, 13 is a hydraulic transmission, 21 is an axle, 27 and 85 are oil pumps, 29 is an oil motor, 31 is a speed reduction mechanism. , 37, 39 are outer cases, 97A, 97B are inner cases, 207, 227 are insertion parts, 229
Is a lid.

Claims (1)

(57) [Claims] 1. A board having flat mounting surfaces formed on both side surfaces thereof, an inner case is mounted on each of the mounting surfaces of the board, and an oil pump or an oil motor is housed in each inner case. An outer case is attached to each of the mounting surfaces to accommodate the inner case, and at least one of the outer cases accommodates a speed reduction mechanism that reduces the output from the oil motor, and the drive shaft of the oil pump is exposed from the inner case. A power transmission shaft that forms an extension portion that extends to the side surface of the opposing outer case, and that transmits the power of the power source to the extension portion at different portions of the outer case that face the extension portion of the oil pump. A hydraulic transmission for a vehicle, which is provided with two or more insertion portions for inserting the inside of the outer case, and is provided with a lid for closing an unused portion of the insertion portion.