JPS621110B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a differential hydraulic motor. A differential hydraulic motor is mainly used as a drive device for left and right drive theory in hydraulically driven vehicles, but a differential motor can be easily created by simply connecting two hydraulic motors in parallel to two supply/discharge circuits. Because it can be obtained, it has been widely used in recent years. A conventional differential hydraulic motor includes variable displacement hydraulic motors 3 and 4 for left and right drive wheels 1 and 2, respectively, as shown in FIG.
, and connect the two hydraulic motors 3 and 4 in parallel to the two supply and discharge circuits 5 and 6 so that the left and right drive wheels 1 and 2 rotate in the same direction. The capacity conversion levers 7 and 8 are mechanically interlocked and connected by a connecting rod or the like. Reference numeral 9 in FIG. 1 is a four-way hydraulic switching valve that selectively connects the two supply/discharge circuits 5 and 6 to the hydraulic pump 10 and the oil tank 11. In this way, in the conventional differential hydraulic motor, the capacity conversion levers 7 and 8 of the independent variable capacity hydraulic motors 3 and 4 are mechanically interlocked and connected to each other on the outside of the hydraulic motors 3 and 4. It required a large amount of space and had a complicated structure.

The present invention seeks to provide a compact and simple differential hydraulic motor. An embodiment of the differential hydraulic motor of the present invention will be described in detail based on FIG. In FIG. 2, 1 is a case of a differential hydraulic motor, and 2 and 3 are output shafts rotatably supported at the left and right ends of the case 1 so that their outer ends protrude from the left and right ends of the case 1, respectively. Each output shaft 23 is adapted to rotate on the same axis A. Reference numeral 4 denotes an inclined plate which is arranged in a tilt-adjustable manner inside the center of the case 1 by means of a support shaft 5 perpendicular to the axis A, and the inclined plate 4 can be tilted from the outside of the case 1 by appropriate means. It is adjustable. Cylinder blocks 6 and 7 are attached to the inner ends of the output shafts 2 and 3, respectively, so that they can rotate about the axis A on both sides of the inclined plate 4. A large number of cylinder holes 8 and 9 parallel to the cylinder hole 1 are arranged at equal intervals on a circumference centered on the axis A. The connection between the cylinder block 6 and the inner end of the output shaft 2 and the connection between the cylinder block 7 and the inner end of the output shaft 3 are spline connections that allow relative movement in the direction of the axis A, respectively. Reference numeral 10 denotes a valve plate that is attached to the inner left end of the case 1 and comes into sliding contact with the outer end of the cylinder block 6. On the sliding contact surface of the cylinder block 6 of the valve plate 10, two supply/discharge ports provided in the case 1 are connected. Two connected supply/discharge grooves (not shown) are bored, and the cylinder hole 8 can be selectively connected to the case 1 by rotating the cylinder block 6 with respect to the valve plate 10.
It is designed to be connected to the two supply and discharge ports of. Reference numeral 11 denotes a piston that is slidably fitted into each cylinder hole 8 of the cylinder block 6 in an oil-tight manner, and has its end protruding from the inner end of the cylinder block 6. 4 in a slidable manner. Reference numeral 12 denotes a valve plate that is attached to the inner right end of the case 1 and comes into sliding contact with the outer end of the cylinder block 7. On the sliding contact surface of the cylinder block 7 of the valve plate 12,
Two supply/discharge grooves (not shown) are bored, each connected to a supply/discharge port provided in the case 1, and the cylinder hole 9 can be selectively connected to the case 1 by rotating the cylinder block 7 relative to the valve plate 12. It is designed to be connected to the two supply and discharge ports of.
Reference numeral 13 denotes a piston that is slidably fitted into each cylinder hole 9 of the cylinder block 7 in an oil-tight manner, and has its end protruding from the inner end of the cylinder block 7. 4 in a slidable manner. piston 11 and piston 13
have their respective end portions slidably in contact with the front and back surfaces of the inclined needle plate 4 in opposing manner.

The differential hydraulic motor of the present invention is constructed as described above, and the output shaft 2, cylinder block 6, piston 11, valve plate 10, and inclined plate 4 constitute one axial plunger type hydraulic motor. , the output shaft 3, cylinder block 7, piston 13, valve plate 12 and inclined plate 4 constitute one axial plunger type hydraulic motor, and the inclined plate 4 of these two hydraulic motors is shared. be. Pressure oil is supplied to and discharged from the differential hydraulic motor of the present invention through two supply and discharge grooves in the case 1 connected to two supply and discharge grooves in the valve plate 10 so that the output shaft 2 and the output shaft 3 rotate in the same direction. Pressure oil is supplied to and discharged from the two supply and discharge ports of the case 1 which are connected to the port and the two supply and discharge grooves of the valve plate 12, respectively, and the hydraulic circuit may be constructed in the same manner as shown in FIG.

When the differential hydraulic motor of the present invention is driven, the inclined plate 4 receives the same thrust force on its front and back sides by the pistons 11 and 13, and therefore the force acting on the supporting shaft 5 of the inclined plate 4 is extremely small. This, together with the fact that the inclined plates of two axial plunger type hydraulic motors are also used, achieves a compact and simple structure of the differential hydraulic motor of the present invention.

[Brief explanation of the drawing]

FIG. 1 is an explanatory hydraulic circuit diagram of a conventional differential hydraulic motor, and FIG. 2 is an explanatory sectional view of the differential hydraulic motor of the present invention.

Claims (1)

[Claims] 1 A differential motor, which includes an inclined plate 4 whose tilting can be adjusted on a support shaft 5 orthogonal to the axis A, and which is arranged rotatably about the axis A on both sides of the inclined plate 4, and which is rotatable about the axis A. A pair of cylinder blocks 6, 7 having a large number of cylinder holes 8, 9 parallel to each other, and a pair of cylinder blocks 6, 7 having two supply/discharge grooves slidingly in contact with each outer end of the pair of cylinder blocks 6, 7, respectively. A pair of valve plates 10, 1 which selectively connect cylinder holes 8, 9 to two supply/discharge grooves by rotation of
2. Pistons 11 and 13 which are slidably fitted into the cylinder holes 8 and 9 of the respective cylinder blocks 6 and 7 in an oil-tight manner and whose respective protruding ends are slidably engaged with each side surface of the inclined plate 4; , and output shafts 2 and 3 that take out the rotation of each cylinder block 6 and 7 separately.