JPS63301126A - Hydraulic type speed change gear for vehicle - Google Patents

Abstract

PURPOSE:To obtain the compact constitution by arranging a reduction case for accommodating a reduction mechanism connected with an axle onto the axle side of a driving shaft and installing an oil pump, oil motor, and an oil passage for connecting the both onto the outer wall surface of the reduction case. CONSTITUTION:As for a vehicle such as lawn mower, a power source such as engine and electric motor is arranged at the position separated from a driving wheel. In this case, a reduction case 21 into which a reduction gear mechanism connected with an axle 33 is accommodated is arranged on the axle 33 side of the driving wheel. An oil pump 15 driven by the driving source and an oil motor 17 which is driven by the oil pump 15 and drives a reduction gear mechanism are installed on the outer wall surface of the case 21. In this case, at least one among the pump 15 and the motor 17 is formed into a variable capacity type. Further, the inside of the case 21 is constituted to an oil tank. Further, an oil passage for connecting the pump 15 and the motor 17 is formed on the wall part of the case 21.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a hydraulic transmission system for a vehicle.

(Prior art) For example, in various vehicles such as lawn mowers and tillers, a power source such as an engine or an electric motor is installed at a location separated from the driving wheels, and the power source is powered by an oil pump, oil motor, etc. A hydraulic transmission device that changes speed and transmits it to the driving wheels is disclosed in Japanese Patent Publication No. 38-7172 and Japanese Patent Publication No. 5
It is known from the publication No. 0-33283.

(Problem to be Solved by the Invention) However, when the output shaft of an oil motor is directly connected to the axle of the drive wheel as in Japanese Patent Publication No. 3B-7172, a large capacity oil pump and oil motor must be used. There is an unavoidable problem.

Furthermore, in Japanese Patent Publication No. 50-33283, a reduction mechanism is provided to reduce the size of the oil pump and oil motor. Since the pump and oil motor were housed in the system, the number of parts increased, the hydraulic transmission became larger, and the oil pump and oil motor had problems with poor cooling performance.

The present invention has been devised in view of the above circumstances, and an object of the present invention is to ensure the cooling performance of an oil pump and an oil motor, and to reduce the size of a vehicle while suppressing an increase in the number of parts. It is located in providing hydraulic transmission.

(Means for Solving the Problem) In order to achieve the above object, the present invention has a configuration in which a power source 9 such as an engine or an electric motor is disposed at a location apart from the drive wheels 5. 33 side, f&! connected to the axle 33.
A reduction case 21 housing the mechanism 19 is disposed, and an oil pump 15 driven by the power of the power source 9 is attached to the outer wall surface of the reduction case 21. An oil motor 17 for driving the reduction case 21 is attached to the outer wall surface of the reduction case 21, and at least one of the oil pump 15 and the oil motor 17 is of a variable displacement type, and the inside of the reduction case 21 is connected to the oil pump 15.
and an oil tank of the oil motor 17, and an oil passage connecting the oil pump 15 and the oil motor 17 is formed in the wall of the reduction case 21.

(Function) The reduction mechanism 1 is connected between the oil motor 17 and the axle 33 of the drive wheel 5.
9, the oil pump 15 and oil motor 17 with small capacities can be used.

In addition, the reduction case 21 on the axle 33 side of the drive wheel 5
Use the oil pump15. Since the oil motor 17 is provided, an increase in the number of parts can be suppressed and the hydraulic transmission 13 can be made more compact.

Further, since the oil pump 15 and the oil motor 17 are attached to the outer wall surface of the reduction case 21, the oil pump 15 and the oil motor 17 are excellently cooled.

Furthermore, since the oil passages for the oil pump 15 and the oil motor 17 are formed on the wall of the reduction case 21, the oil passage structure can be simplified.

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

FIG. 1 is a side view of the lawn mower, FIG. 2 is a left side view of the hydraulic transmission, FIG. 3 is a right side view of the same, and FIG. 4 is an exploded view of the same.

l is a walk-behind power lawn mower, 3 is the front wheel, 5 is the rear wheel, 7
is the handle, and the engine 9 is located between the front and rear wheels at 3.5 degrees.
The lawn mowing canter 11 is rotationally driven by the engine power, and the left and right rear wheels 5 are driven by the engine power via the hydraulic transmission 13.

The hydraulic transmission 13 is disposed between the left and right rear wheels 5.

The hydraulic transmission 13 includes an oil pump 15 driven by engine power, an oil motor 17 driven by the oil pump 15, a reduction mechanism 19, a reduction case 21, and the like.

The reduction case 21 includes a case body 23 that is open on the right side, and a lid body 25 that is attached to the right side of the case body 23.
The reduction chamber 27 has a gear 29 with a small diameter.
The reduction mechanism 19 is accommodated in a gear 31 having a large diameter.

Oil is injected into the reduction chamber 27, the reduction case 21 also serves as an oil tank, and the bottom 121A of the reduction case 21 is attached to the frame 22 side.

The axle 33 of the rear wheel 5 is horizontally installed in the lower part of the reduction case 21 via a sealing material 35, and the axle 33 is provided with the gear 31.
to be installed.

The oil pump 15 is attached to the front surface 37 of the upper part of the reduction case 21, and the oil motor 17 is attached to the left side surface 39 of the upper part of the reduction case 21.

In the embodiment, a swash plate type variable displacement axial piston pump was used as the oil pump 15, and a swash plate type fixed displacement axial piston motor was used as the oil motor 17.

The oil pump 15 includes a pump case 41, a drive shaft 43 disposed inside the pump case 41, a swash plate 45 built into the pump case 41 so as to be tiltable, and a cylinder block that rotates together with the drive shaft 43. 47, a plurality of pistons 49 that are incorporated into the cylinder block 47 and reciprocate while rotating on the thrust bearing 46 of the swash plate 45, and a valve plate 55 in which a suction boat 51 and a discharge port 53 are formed.

The front end of the drive shaft 43 is made to protrude forward of the pump case 41, and an output shaft 59 on the engine side is connected to this portion via a universal joint 57.

The angle of inclination of the swash plate 45 is set by swinging the lever 8-63 with the pin 61 as a fulcrum, and the swinging of the lever 63 is performed by operating the gear shifter 8-65 provided on the handle 7 side. In the embodiment, it is possible to switch between forward, neutral, and reverse, and 66 in FIG. 1 indicates a throttle lever.

The oil motor 17 includes a motor case 67, an output shaft 69 disposed inside the motor case 67, and a swash plate 71 built into the motor case 67 and configured with a thrust bearing.
a cylinder block 73 that rotates together with the output shaft 69;
Cylinder Pro 1. A valve plate 8 includes a plurality of pistons 75 that are incorporated in the swash plate 73 and reciprocate while rotating on the swash plate 71, an inlet boat 77, and an outlet boat 79.
1.

The right end of the output shaft 69 is made to protrude into the induction chamber 27, and the gear 29 is attached to this portion.

Next, the oil passages of the oil pump 15 and the oil motor 17 will be explained with reference to FIGS. 5 to 8.

Fig. 5 is a diagram of the reduction case seen from the V arrow in Fig. 2, Fig. 6 is a view from the ■ arrow in Fig. 5, and Fig. 7 is a view from the ■ - in Fig. 5.
■ Line sectional view, Figure 8 shows a hydraulic circuit diagram.

First, a suction passage 83 that supplies oil to the oil pump 15
is an oil passage 87 whose lower end opens 84 into the reduction chamber 27 and which extends upward within the left side wall 85 of the reduction case 21;
, an oil passage 89 connected to the oil passage 87 and extending to the left side, and an oil passage 91 connected to the left end of the oil passage 89 and extending in the vertical direction,
The oil passage 93 is connected to the upper end of the oil passage 91 and extends in the front-rear direction, and the oil passage 95 is connected to the front end of the oil passage 93 and extends to the right side to connect to the suction boat 51.

An oil filter 97 is attached to the opening 84, as indicated by 9 in the figure.
9 indicates a shielding plate.

Discharge port 53 of oil pump 15 and oil motor 17
The oil passage 101 that connects the inlet boat 77 includes an oil passage 103 that connects to the discharge port 53 and extends to the left side, an oil passage 105 that connects to the left end of the oil passage 103 and extends downward,
The inlet boat 7 is connected to the oil passage 105 and extends rearward.
It consists of an oil passage 107 connected to 7.

An oil passage 109 connecting the outlet boat 79 of the oil motor 17 and the suction boat 51 of the oil pump 15 is an oil passage 109 that connects to the outlet boat 79 and extends upward.
11, the oil passage 93 and the oil passage 95 connected to this oil passage 111, and an oil pump 15 and an oil motor 1.
7 is connected in a closed circuit.

The oil passage 91 constituting the suction passage 83 has a lower end connected to the oil passage 1.
07, and check valves 113 are installed above and below the oil passage 91, respectively.
, 115 are arranged.

Furthermore, an oil passage 117 that extends in the vertical direction and connects to the oil passage 93, 107, and an oil passage 119 that connects to the oil passage 117 and opens into the reduction case 21 are formed at the rear of the left wall portion 85.

A switching valve 121 is inserted into the oil passage 117.

The switching valve 121 is connected to a neutral lever 123 provided on the handle 7 side via a wire 125 and an arm 127, and the arm 127 is connected to the upper surface 129 of the reduction case 21.
It is arranged on the left side of the frame via a bracket 131.

In the embodiment, the switching valve 121 is a spool valve consisting of a shaft portion 121A and two large diameter portions 121B and 121C, and an oil passage 121D connects the circumferential surface of the upper large diameter portion 121B and the circumferential surface of the shaft portion 121A. It is formed. Then, with the neutral lever 123 swung toward the handlebar 7,
As shown in FIG. 0, the oil passages 93, 107, 119 are shut off via the large diameter portions 121B, 121C, and with the neutral L/par 123 separated from the handle 7, as shown in FIG. The oil passages 93, 107, 119 are configured to communicate with each other via the oil passage 121D and the shaft portion 121A, and the arm 127 is connected to the oil passages 93, 119 by a spring 133.
107 and 119 are biased in a direction to communicate with each other.

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

The drive shaft 43 of the oil pump 15 is rotated by the output shaft 59 on the engine side.

When moving forward, the cylinder block 47 rotates due to the rotation of the drive shaft 43, causing each piston 49 to reciprocate, and the oil is passed through the oil filter 97, the oil passage 87°89.91, the check valve 113, and the oil passages 93, 95. The oil is then sucked in through the suction port 51 and supplied to the inlet port 77 of the oil motor 17 through the discharge port 53 and oil passages 103, 105, and 107.

Then, each piston 75 of the oil motor 17 is reciprocated to rotate the cylinder block 73, and the rotation of the cylinder block 73 rotates the output shaft 69, and the power of the engine is transmitted to the axle 33 via the reduction mechanism 19. be done. Oil is circulated from the outlet port 79 to the suction port 51 of the oil pump 15 via oil passages 111, 93.95.

This flow is shown in FIG. 8 by solid line arrows.

Shifting is performed by changing the angle of inclination of the swash plate 45 using the shift lever 65. When in neutral, the swash plate 45 is perpendicular to the drive shaft 43, the piston 49 does not reciprocate, and no oil circulates.

When moving backward, the angle of inclination of the swash plate 45 is opposite to the angle of inclination when moving forward, and oil is sucked in from the discharge port 53 via oil passages 87, 89° 91, check valve 115, oil passages 107, 105° 103. , suction port 51, oil passages 95, 93,
Outlet boat 7 of oil motor 17 via 111
Supply to 9.

Then, each piston 75 of the oil motor 17 is reciprocated to rotate the cylinder block 73 and the output shaft 69 in the opposite direction to the forward movement, and the axle 33 is reversed. Oil is circulated from the inlet port 77 to the discharge port 53 of the oil pump 15 via oil passages 107, 105, and 103. This flow is shown in FIG. 8 by dotted arrows.

When moving forward or backward, the neutral lever 12
3 in the direction away from the handle 7, oil is not supplied to the oil motor 17 due to the operation of the switching valve 121, the oil motor 17 is stopped, and the axle 33 is in a free state.

In the above, the output shaft 69 of the oil motor 17 and the rear wheel 5
Since the reduction mechanism 19 is disposed between the axles 33 of the hydraulic equipment 15, the oil pump 15 and the oil motor 17 need only be small-sized ones designed for low-torque, high-speed rotation.
．． 17 can be made compact.

In addition, since the reduction case 21 on the axle 33 side that houses the speed reduction mechanism 19 is used, and the oil pump 15 and oil motor 17 are attached to this reduction case 21,
It is possible to suppress an increase in the number of parts and to make the hydraulic transmission 13 more compact.

In addition, the oil pump 1 is mounted on the outer surface of the reduction case 21.
5. Since the oil motor 17 has been installed, the oil pump 1
5. Excellent cooling performance for the oil motor 17.

Furthermore, since the oil passages for the oil pump 15 and the oil motor 17 are formed on the wall of the reduction case 21, the oil passage structure can be simplified.

In addition, a hydraulic transmission 13 is installed at a location separated from the engine 9.
Since the oil pump 15. oil motor 17
are not directly affected by the vibrations of the engine 9, and the oil pump 15,
1. The durability of the oil motor 17 can be improved.

In the embodiment, an axial piston pump is used as the oil pump 15, and an axial piston motor is used as the oil motor 17. However, the types of the oil pump 15 and the oil motor 17 are not limited to those in the embodiment. , other types may be used, and at least one of the oil pump 15 and the oil motor 17 may be of a variable displacement type.

Further, in the embodiment, check valves 113 and 115 are provided in the oil passages to allow forward and reverse movement, but these check valves 113 and 115 may not be provided and the circuit may be configured to perform only forward movement.

Further, the oil passage connecting the oil pump 15 and the oil motor 17 may be a closed circuit or an open circuit.

(Effects of the Invention) As is clear from the above description, according to the present invention, the oil pressure of the vehicle can be reduced in size while ensuring the cooling performance of the oil pump and oil motor, and suppressing an increase in the number of parts. type transmission can be obtained.

[Brief explanation of drawings]

Figure 1 is a side view of the lawn mower, Figure 2 is a left side view of the hydraulic transmission, Figure 3 is a right side view of the same, Figure 4 is an exploded view of the same, and Figure 5 is the second view. Figure 6 is a view of the reduction case viewed from the V arrow in Figure 5, Figure 7 is a view from the ■ arrow in Figure 5.
8 is a circuit diagram, and FIGS. 9 and 10 are sectional views showing the operating state of the switching valve. In the drawing, 5 is a rear wheel, 7 is an engine, 13 is a hydraulic transmission, 15 is an oil pump, 17 is an oil motor, and 19
is a reduction mechanism, 21 is a reduction case, 33 is an axle,
113 and 115 are check valves, and 121 is a switching valve. Patent applicant: Agent for Honda Motor Co., Ltd.
Patent Attorney Part 2 1) Yu-Immediate Questions Patent Attorney Kuni Ohashi Yuryo Patent Attorney
Udo Koyama Patent Attorney No 1)
Shigeru procedural amendments stamped) December 24, 1986

Claims (1)

[Scope of Claims] In a vehicle in which a power source such as an engine or an electric motor is disposed at a location separated from the drive wheels, a reduction case housing a deceleration mechanism connected to the axle is disposed on the axle side of the drive wheels. , an oil pump driven by the power of the power source is attached to the outer wall surface of the reduction case, an oil motor driven by the power of the oil pump and driving the reduction mechanism is attached to the outer wall surface of the reduction case, At least one of the oil pump and the oil motor is of a variable displacement type, the interior of the reduction case is configured as an oil tank for the oil pump and the oil motor, and an oil passage connecting the oil pump and the oil motor is formed on a wall of the reduction case. A hydraulic transmission device for a vehicle, characterized in that: