CN104428530A - Axial piston motor - Google Patents

Abstract

According to the present invention, an inclined rotation control mechanism (8) of an axial piston motor controls the inclined rotation angle of a swash plate (7). In this inclined rotation control mechanism (8), the internal space in one cylinder (81) is divided by one piston (82) into a first chamber (811) and a second chamber (812). The inclined rotation control mechanism (8) can thereby be made smaller and lighter, and the number of components can be reduced.

Description

axial piston motor

technical field

The invention relates to axial piston motors for example for construction machines, industrial machines and the like.

Background technique

Conventionally, as an axial piston motor, there is an axial piston motor described in Japanese Patent Laid-Open No. 2010-168974 (Patent Document 1). The axial piston motor includes: a drive shaft; a cylinder block fixed to the drive shaft; a plurality of cylinder pistons embedded in the cylinder block; a swash plate for supporting the plurality of cylinder pistons; a deflection for controlling the swash plate Angle deflection control mechanism.

The deflection control mechanism has two independent cylinders and piston rods respectively embedded in the two cylinders. One cylinder and piston rod and the other cylinder and piston rod are arranged on both sides of the drive shaft. The piston rods on both sides are respectively connected to the swash plate, and the swash plate is deflected by extending and contracting the respective piston rods.

Patent Document 1: Japanese Patent Laid-Open No. 2010-168974

Contents of the invention

The problem to be solved by the invention

However, in the above-mentioned conventional axial piston motor, there are following problems: the above-mentioned yaw control mechanism has two cylinders and two piston rods, so the yaw control mechanism is enlarged, and the weight of the yaw control mechanism is also increased. The number of parts increases.

Therefore, an object of the present invention is to provide an axial piston motor capable of reducing the size, weight, and number of parts of a yaw control mechanism.

solutions to problems

In order to solve the above-mentioned problems, the axial piston motor of the present invention is characterized in that it includes:

case;

a drive shaft rotatably mounted on the housing;

a cylinder block fixed to the drive shaft and having a plurality of cylinder holes arranged in the circumferential direction;

a plurality of cylinder pistons, which are embedded in the above-mentioned plurality of cylinder holes freely;

a swash plate supporting the plurality of cylinder pistons with a deflectable surface relative to the drive shaft; and

a deflection control mechanism for controlling the deflection angle of the swash plate relative to the drive shaft,

The above-mentioned deflection control mechanism includes:

cylinder;

a piston, which is arranged in the cylinder and divides the cylinder into a first chamber and a second chamber;

a rod linking said piston and said swash plate; and

The switching unit switches the flow of fluid into and out of the first chamber and the second chamber in the cylinder.

According to the axial piston motor of the present invention, the piston moves in the cylinder by allowing fluid to flow in and out of the first chamber and the second chamber in the cylinder, and the deflection angle of the swash plate can be adjusted.

In addition, in the above-mentioned yaw control mechanism, one piston divides the internal space of one cylinder into the first chamber and the second chamber, so that the yaw control mechanism can be reduced in size, weight, and number of parts.

In addition, in an axial piston motor according to one embodiment, the deflection control mechanism includes a stroke adjustment unit for adjusting an upper limit and a lower limit of a stroke of the piston within the cylinder.

According to the axial piston motor of this embodiment, the stroke adjustment unit adjusts the upper limit and the lower limit of the stroke of the piston. Accordingly, the upper limit and lower limit of the deflection angle of the swash plate (that is, the upper limit and lower limit of the motor capacity) can be easily adjusted by the stroke adjustment unit.

Furthermore, in the axial piston motor of one embodiment,

The above piston has:

a first pressure receiving surface facing the first chamber; and

Facing the second pressure receiving surface of the above-mentioned second chamber,

The area of the first pressure receiving surface is different from the area of the second pressure receiving surface.

Here, the first pressure receiving surface and the second pressure receiving surface refer to surfaces intersecting (eg, perpendicular to) the axis of the cylinder.

According to the axial piston motor of this embodiment, in the piston, the area of the first pressure receiving surface is different from the area of the second pressure receiving surface. Thus, when the area of the first pressure receiving surface is smaller than the area of the second pressure receiving surface, when the fluid flows through the first chamber and the second chamber, the piston moves toward the first chamber side, while the piston moves toward the first chamber. When the fluid flows only in the first chamber, the piston moves toward the second chamber. In this way, the fluid passage is connected to the first chamber and the second chamber, and only the fluid passage to the second chamber can be switched on and off, and the fluid circuit can have a simple structure.

The effect of the invention

According to the axial piston motor of the present invention, in the above-mentioned deflection control mechanism, the inner space of one cylinder is divided into the first chamber and the second chamber by one piston, so that the miniaturization, weight reduction and number of parts of the deflection control mechanism can be realized. reduce.

Description of drawings

FIG. 1 is a cross-sectional view showing an axial cylinder piston motor according to an embodiment of the present invention.

Fig. 2 is an enlarged sectional view of the deflection control mechanism.

Fig. 3 is a circuit diagram of the motor described above.

Detailed ways

Hereinafter, the present invention will be described in detail using the illustrated embodiments.

FIG. 1 is a cross-sectional view showing an axial piston motor according to an embodiment of the present invention. As shown in FIG. 1 , the motor includes: a housing 1; a drive shaft 3, which is rotatably mounted on the housing 1 by means of a bearing 2; and a cylinder block 4, which is fixed to the drive shaft 3.

The cylinder block 4 has a plurality of cylinder bores 40 arranged in the circumferential direction. The plurality of cylinder pistons 5 are fitted into the plurality of cylinder holes 40 to move forward and backward freely.

The top end of the cylinder piston 5 is formed in a spherical shape and connected to a shoe (Japanese: シュー) 6 . The shoe 6 is supported by a swash plate 7 positioned relative to the housing 1 . The swash plate 7 has a deflectable surface with respect to the drive shaft 3 , and supports the plurality of cylinder pistons 5 on the surface. The swash plate 7 is deflected by means of a deflection control mechanism 8 , and its deflection angle relative to the above-mentioned drive shaft 3 is controlled by the control mechanism 8 .

The casing 1 is provided with a first main passage 11 and a second main passage 12, and the first main passage 11 and the second main passage 12 are connected to the cylinder bore 40, and the working oil is supplied and discharged relative to the cylinder bore 40. .

A valve plate 9 is attached to the inner surface of the housing 1 to face the end surface of the cylinder block 4 . The valve plate 9 has arcuate first hole portions 91 and second hole portions 92 formed symmetrically.

At the bottom of each cylinder hole 40 , a hole portion 40 a for feeding and discharging working oil into and out of the cylinder hole 40 is formed. The end surface of the cylinder block 4 is in contact with the valve plate 9 .

The first main passage 11 of the casing 1 , the first hole 91 of the valve plate 9 , and the predetermined hole 40 a of the cylinder hole 40 can communicate with each other. The second main passage 12 of the housing 1 , the second hole portion 92 of the valve plate 9 , and the predetermined hole portion 40 a of the cylinder hole 40 can communicate with each other.

And, when hydraulic oil is supplied from the first main passage 11, the hydraulic oil flows into the predetermined cylinder hole 40 through the first hole portion 91, reciprocates the cylinder piston 5, and drives the cylinder block 4 and the drive shaft. 3 Rotate in one direction. Thereafter, the hydraulic oil in the cylinder bore 40 is discharged from the second main passage 12 through the second hole portion 92 . The pressure in the first main passage 11 on the supply side is higher than the pressure in the second main passage 12 on the discharge side.

On the other hand, when hydraulic fluid is supplied from the second main passage 12, the cylinder block 4 and the drive shaft 3 rotate in the other direction. Thereafter, the hydraulic oil in the cylinder bore 40 is discharged from the first main passage 11 described above.

The deflection control mechanism 8 includes: a cylinder 81 ; a piston 82 disposed in the cylinder 81 ; and a rod 83 connecting the piston 82 and the swash plate 7 . The cylinder 81 is formed as part of the housing 1 . The piston 82 has a sleeve shape. A rod 83 is inserted into the piston 82 .

The cylinder 81, the piston 82, and the rod 83 are concentrically arranged. The piston 82 can reciprocate within the cylinder 81 . The rod 83 is capable of reciprocating along the axis of the cylinder 81 together with the piston 82 .

When the piston 82 moves to the right in the figure, the inclination angle of the swash plate 7 becomes larger, and when the piston 82 moves to the left in the figure, the inclination angle of the swash plate 7 becomes smaller. When the piston 82 is moved to the far right in the figure, it is called the upper limit of the stroke of the piston 82, and when the piston 82 is moved to the far left in the figure, it is called the lower limit of the stroke of the piston 82.

As shown in FIG. 2 , the piston 82 has a cylindrical portion 820 a and a flange portion 820 b attached to one end of the cylindrical portion 820 a. The cylindrical portion 820 a can freely move forward and backward in the cylinder 81 . The flange portion 820b is arranged inside the cylinder 81 . The flange portion 820b partitions the inside of the cylinder 81 into a first chamber 811 and a second chamber 812 . That is, the flange portion 820b divides one closed space in the cylinder 81 into the first chamber 811 and the second chamber 812 . The first chamber 811 is located closer to the swash plate 7 than the second chamber 812 . The cylinder 81 is provided with a first passage 81 a communicating with the first chamber 811 and a second passage 81 b communicating with the second chamber 812 .

The flange portion 820b of the piston 82 has a first pressure receiving surface 821 facing the first chamber 811 and a second pressure receiving surface 822 facing the second chamber 812 . The first pressure receiving surface 821 and the second pressure receiving surface 822 are perpendicular to the axis of the cylinder 81 . The area of the first pressure receiving surface 821 is smaller than the area of the second pressure receiving surface 822 .

The deflection control mechanism 8 has a stroke adjustment unit 20 for adjusting the upper limit and lower limit of the stroke of the piston 82 inside the cylinder 81 . The stroke adjustment unit 20 has an upper limit adjustment shaft 21 for adjusting the upper limit of the stroke of the piston 82 and a lower limit adjustment shaft 22 for adjusting the lower limit of the stroke of the piston 82 .

The upper limit adjustment shaft 21 has a cylindrical threaded shaft portion 211 and a flange portion 212 attached to one end of the threaded shaft portion 211 .

The threaded shaft portion 211 penetrates the cover portion 23 attached to the axial end portion of the cylinder 81 . External threads are provided on the outer peripheral surface of the threaded shaft portion 211 , internal threads are provided on the inner peripheral surface of the cover portion 23 , and the threaded shaft portion 211 and the cover portion 23 are screwed together. A nut 24 is threadedly coupled to the threaded shaft portion 211 .

The flange portion 212 is arranged inside the cylinder 81 (second chamber 812). An O-ring 26 is fitted on the outer peripheral surface of the flange portion 212 . The axially outer end surface 212 a of the flange portion 212 can be in contact with the second pressure receiving surface 822 of the piston 82 .

Further, the position of the end surface 212 a of the flange portion 212 within the cylinder 81 can be adjusted by screwing the threaded shaft portion 211 forward and backward in the cover portion 23 . That is, the upper limit adjustment shaft 21 can adjust the upper limit of the stroke of the piston 82 .

The lower limit adjustment shaft 22 has a threaded shaft portion 221 , a guide shaft portion 222 attached to one end of the threaded shaft portion 221 , and a flange portion 223 attached to one end of the guide shaft portion 222 .

The threaded shaft portion 221 passes through the upper limit adjustment shaft 21 . External threads are provided on the outer peripheral surface of the threaded shaft portion 221, and internal threads are provided on the inner peripheral surface of the cylindrical threaded shaft portion 211 of the upper limit adjustment shaft 21, and the threaded shaft portion 221 and the cylindrical threaded shaft portion 211 are screwed together. . A nut 25 is screwed to the threaded shaft portion 221 .

The above-mentioned guide shaft portion 222 is inserted into the inside of the piston 82 freely. The flange portion 223 is arranged inside the piston 82 . An O-ring 27 is fitted on the outer peripheral surface of the guide shaft portion 222 . The axially inner end surface 223 a of the flange portion 223 can abut against the inner end surface 82 a inside the piston 82 .

Further, the position of the inner end surface 223 a of the flange portion 223 within the cylinder 81 can be adjusted by screwing the threaded shaft portion 221 forward and backward in the cylindrical threaded shaft portion 211 . That is, the lower limit adjustment shaft 22 can adjust the lower limit of the stroke of the piston 82 .

Fig. 3 shows a circuit diagram of the above motor. As shown in FIG. 3 , the first main passage 11 and the second main passage 12 are connected to the motor unit 50 composed of the drive shaft 3 , the cylinder block 4 , the cylinder piston 5 and the swash plate 7 . The first sub passage 13 branched from the first main passage 11 is connected to the first passage 81 a of the cylinder 81 . The second main passage 12 is connected to a second sub passage 14 .

The first valve passage 31 branched from the first sub passage 13 is connected to the switching portion 84 . The switching unit 84 is connected to the second passage 81 b of the cylinder 81 via the second valve passage 32 .

In the first sub passage 13 , a check valve is provided on the upstream side (on the side of the first main passage 11 ) of the connection point between the second sub passage 14 and the first valve passage 31 . A check valve is provided on the above-mentioned second secondary passage 14 .

The switching unit 84 is, for example, a solenoid valve, and has a first hole P1 , a second hole P2 , and a third hole P3 . The first hole P1 is connected to the first valve passage 31 , the second hole P2 is connected to the oil tank 33 , and the third hole P3 is connected to the second valve passage 32 .

The switching unit 84 switches the entry and exit of hydraulic fluid to and from the first chamber 811 and the second chamber 812 in the cylinder 81 . That is, the switching portion 84 has a first position S1 and a second position S2. In the first position S1 , the second chamber 812 communicates with the first valve passage 31 by connecting the third hole P3 to the first hole P1 . In the second position S2, the second chamber 812 communicates with the oil tank 33 by connecting the third hole P3 to the second hole P2. In addition, the first chamber 811 communicates with the first main passage 11 via a check valve.

Next, adjustment of the deflection angle of the above-mentioned swash plate 7 will be described. Here, it is assumed that high-pressure hydraulic oil is supplied to the first main passage 11 and low-pressure hydraulic oil is discharged from the second main passage 12 .

When the deflection angle of the swash plate 7 is increased, the switching portion 84 is placed at the second position S2. Thus, the second chamber 812 is connected to the oil tank 33 , and the first chamber 811 is connected to the first sub passage 13 . Accordingly, the high-pressure hydraulic oil in the first main passage 11 flows into the first chamber 811 through the first sub passage 13 , and the piston 82 moves toward the second chamber 812 side (right side in the drawing). The operating oil in the second chamber 812 is discharged to the oil tank 33 . As a result, the deflection angle of the swash plate 7 becomes large.

When the deflection angle of the swash plate 7 is reduced, the switching portion 84 is placed at the first position S1. Thus, the first chamber 811 and the second chamber 812 are connected to the first sub passage 13 . Accordingly, the high-pressure hydraulic oil in the first main passage 11 flows into the first chamber 811 through the first sub passage 13 , and flows into the second chamber 812 through the first valve passage 31 . At this time, since the area of the first pressure receiving surface 821 is smaller than that of the second pressure receiving surface 822, the piston 82 moves toward the first chamber 811 side (left side in the figure) due to the differential pressure. As a result, the deflection angle of the swash plate 7 becomes small.

In addition, when the high-pressure hydraulic oil is supplied to the second main passage 12 and the low-pressure hydraulic oil is discharged from the first main passage 11 , the high-pressure hydraulic oil in the second main passage 12 flows into the second main passage 14 via the second sub-passage 14 . A secondary passage 13 and a first valve passage 31.

According to the axial piston motor configured as described above, the piston 82 moves in the cylinder 81 by allowing operating oil to flow into and out of the first chamber 811 and the second chamber 812 in the cylinder 81 to adjust the deflection angle of the swash plate 7 .

In addition, in the above-mentioned yaw control mechanism 8, the internal space of one cylinder 81 is divided into the first chamber 811 and the second chamber 812 by one piston 82, so that the miniaturization, weight reduction and number of parts of the yaw control mechanism 8 can be realized. reduce.

In addition, the stroke adjusting unit 20 adjusts the upper limit and the lower limit of the stroke of the piston 82 . Thereby, the upper limit and the lower limit of the deflection angle of the swash plate 7 (that is, the upper limit and the lower limit of the motor capacity) can be easily adjusted by the stroke adjustment unit 20 .

Furthermore, the area of the first pressure receiving surface 821 is smaller than the area of the second pressure receiving surface 822 . As a result, when hydraulic oil flows into the first chamber 811 and the second chamber 812, the piston 82 moves toward the first chamber 811, and on the other hand, when only the hydraulic oil flows into the first chamber 811, the piston 82 moves toward the second chamber 812. Move sideways. In this way, the first chamber 811 and the second chamber 812 are connected to the hydraulic passage, and only the hydraulic passage to the second chamber 812 can be switched on and off, so that the hydraulic circuit can have a simple structure. .

In addition, this invention is not limited to embodiment mentioned above. The number of cylinder pistons and cylinder holes can be increased or decreased freely.

In the above embodiments, the first pressure receiving surface and the second pressure receiving surface of the piston are perpendicular to the axis of the cylinder, but they only need to intersect the axis of the cylinder.

In the above embodiment, the area of the first pressure receiving surface is smaller than the area of the second pressure receiving surface, but the area of the first pressure receiving surface may be larger than the area of the second pressure receiving surface.

In the above embodiment, the first chamber of the cylinder is always connected to the hydraulic passage, but the hydraulic passage to the first chamber may be switched on and off.

In the above-described embodiment, the stroke adjustment unit is provided, but the stroke adjustment unit may be omitted. Furthermore, in the above embodiment, the area of the first pressure receiving surface is different from the area of the second pressure receiving surface, but the area of the first pressure receiving surface and the area of the second pressure receiving surface may be the same. In this case, the inflow and discharge of hydraulic oil are performed to the first chamber and the second chamber, respectively.

Explanation of reference signs

1 shell

3 drive shaft

4 cylinder block

5 cylinder piston

7 ramps

8 deflection control mechanism

9 valve plate

11 The first main channel

12 The second main channel

13 The first secondary channel

14 The second auxiliary channel

31 The first valve channel

32 Second valve passage

20 Stroke adjustment department

21 upper limit adjustment axis

211 threaded shaft

212 Flange

22 Lower limit adjustment axis

221 threaded shaft

222 guide shaft

223 Flange

23 cover

40 cylinder bore

81 cylinders

811 Room 1

812 Second Room

82 Pistons

821 The first pressure receiving surface

822 Second pressure surface

83 rods

84 Switching Department

Claims (3)

1. an axial piston motor, is characterized in that, this axial piston motor comprises:

Housing;

Live axle, it is rotatably installed on above-mentioned housing;

Cylinder block, it is fixed on above-mentioned live axle, and has the multiple cylinder holes in circumferential array;

Multiple steam-cylinder piston, it movably embeds above-mentioned multiple cylinder holes;

Swash plate, the above-mentioned multiple steam-cylinder piston of the surface bearing that its utilization can deflect relative to above-mentioned live axle;

Deflection control mechanism, it is for controlling the deflection angle of above-mentioned swash plate relative to above-mentioned live axle, and above-mentioned deflection control mechanism has:

Cylinder;

Piston, it is configured in said cylinder, will be separated into the first Room and the second Room in this cylinder;

Bar, above-mentioned piston and above-mentioned swash plate link up by it;

Switching part, it carries out the switching of fluid-phase for the discrepancy of above-mentioned first Room in said cylinder and above-mentioned second Room.

2. axial piston motor according to claim 1, is characterized in that,

Above-mentioned deflection control mechanism has Traffic control system portion, and the trip adjustment part is for adjusting the upper and lower bound of the stroke of above-mentioned piston in said cylinder.

3. axial piston motor according to claim 1 and 2, is characterized in that,

Above-mentioned piston has towards the first compression face of above-mentioned first Room and the second compression face towards above-mentioned second Room,

The area of above-mentioned first compression face is different from the area of above-mentioned second compression face.