JPH06167279A - Vane pump and vane motor - Google Patents

Abstract

PURPOSE:To obtain a variable volume structure and elongate life of a bearing through cancellation of unbalanced force by arranging a pair of suction port and discharge port symmetrically to a center axis of a rotor, rotating a cam ring and adjusting the positions of a cam surface, the suction port, and the discharge port. CONSTITUTION:In a vane pump 1, cam ring 3 is rotated around a center axis 7. a rotor 13 arranged coaxially with a cam surface 5 on an inner periphery of the cam ring 3, and vanes 21 engaged with spiral grooves 19 formed with the rotor 13 is in sliding contact with the cam surface 5 while being rotated with the rotor 13. A pair of suction and discharge ports 9, 11 are arranged symmetrically to each other in respect to the center axis 7. The cam ring 3 is rotated for adjusting the position of the cam surface 5 in respect to the suction port 9 and discharge port 11. A diameter of the cam surface 5 is positioned, for instance, on each center of a line 29 which is obtained by connecting the suction ports 9 to each other and a line 31 which is obtained by connecting the discharge ports 11 to each other. The position of the diameter 27 is selected within a range 33 indicated by an arrow for adjusting a discharge rate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane type rotating device used as a vane pump or a vane motor.

[0002]

2. Description of the Related Art A 26.6 variable discharge vane pump is described after p40 of "Hydraulic equipment and application circuit (revised edition), November 30, 1946, published by Nikkan Kogyo Shimbun, Toshio Kaneko". There is.

In a vane pump, a vane engaged with a radial groove provided on a rotor arranged inside a cam surface having a circular cross section of a cam ring slides in contact with the cam surface as the rotor rotates, and adjacent vanes are formed. Oil is sucked from the suction port provided at the position where the volume of the pump chamber formed between the cam surface and the rotor increases with the rotation of the rotor, and the discharge provided at the position where the volume of the pump chamber decreases. Oil is discharged from the outlet.

[0004]

In the vane pump described in the above document, the rotor and the cam surface are eccentric to change the volume in the pump chamber, and the discharge amount is changed by changing the eccentric amount.

However, in the case of such eccentricity, a pressure difference occurs between the suction side and the discharge side, so that an unbalanced force is applied to the rotor bearing and the life is shortened.

Therefore, an object of the present invention is to provide a balanced vane pump and vane motor with variable capacity.

[0007]

A vane pump and a vane motor according to the present invention include a cam ring which is disposed between a pair of side plates and has an inner peripheral surface having a cam surface having an elliptical cross section and which is rotationally operated around its central axis. A rotor having coaxial radial grooves formed in the cam surface, a vane that movably engages with each groove and slides in contact with the cam surface, and a pair of suction ports and discharge ports provided on the side plates, respectively. Are arranged symmetrically with respect to the central axis.

[0008]

When used as a vane pump, the volume of the pump chamber formed by the adjacent vane, the cam surface, and the rotor changes with the rotation of the rotor because the cam surface has an elliptical cross section. It is sucked from the suction port at the position where the pump chamber volume increases and discharged from the discharge port at the position where the volume decreases. Further, when the cam ring (cam surface) is rotated with respect to the side plate, the volume change rate of the pump chamber at the suction port and the discharge port changes, and the discharge amount can be changed.

Since the pair of suction ports are provided at symmetrical positions with respect to the center of rotation of the rotor, the negative pressures generated at the suction ports cancel each other out via the rotor. Further, the positive pressures generated at the pair of discharge ports provided symmetrically with respect to the rotation center of the rotor also cancel each other out through the rotor. Thus, a balanced vane pump is constructed, and unlike the conventional example, unbalanced forces are not applied to the rotor, so that the life of the bearing is significantly improved.

When the rotor is reversed, the suction port and the discharge port are reversed so that the flow direction can be reversed. Further, when a pressurized liquid is applied from the suction port or the discharge port, the vane motor takes out the rotational force from the rotor. In this case as well, the output can be adjusted by adjusting the angular position of the cam ring, and since it is of the balanced type, the bearing of the rotor is not subjected to force due to the pressure difference, so that the life is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. This embodiment is used as the vane pump 1. It should be noted that members and the like without reference numerals are not shown.

As shown in each drawing, a cam surface 5 having an elliptical cross section is formed on the inner circumference of the cam ring 3. Cam ring 3
Is housed in the casing, and receives a rotational operation force from the outside, passes through the intersection of the major axis and the minor axis of the cam surface 5 and the central axis 7
Rotate around. Side plates of the casing 3 are liquid-tightly arranged on both sides of the cam ring 3 in the axial direction. On this side plate, a pair of suction ports 9 and 9 and discharge ports 11 and 11 are provided at symmetrical positions with respect to the central axis 7. The suction ports 9, 9 communicate with each other through oil passages provided on the side plates, and the discharge ports 11, 11 also communicate with each other through oil passages provided on the side plates.

Inside the cam surface 5, a rotor 13 has a central shaft 7
Is arranged coaxially with and is rotationally driven in the direction of arrow 17 by the drive shaft 15. Twelve grooves 19 are radially provided on the rotor 13, and vanes 21 are movably engaged with the grooves 19. When the rotor 13 rotates, the vane 21 is pressed against the cam surface 5 by centrifugal force and slides while the rotor 1 rotates.
Rotate with 3. A pump chamber 23 is formed by the adjacent vanes 21, 21 and the cam surface 5 and the outer peripheral surface of the rotor 13.

The cam ring 3 receives an operating force and is rotated in the direction of arrow 25 in FIG. 1, so that the suction ports 9 and 9 and the discharge port 1 are rotated.
The position of the cam surface 5 with respect to 1 and 11 is adjusted. Figure 1
Is a straight line 29 connecting the suction ports 9 and 9 with the long diameter 27 of the cam surface 5.
2 shows a state in which the major axis 27 is in the center of the straight line 29 and the straight line 31 connecting the discharge ports 11 and 11, and FIG. 3 shows a state in which the major axis 27 is on the straight line 31. ing.

In the state shown in FIGS. 1 and 3, the volume increase rate and the volume decrease rate of the pump chamber 23 before and after the straight lines 29 and 31 are the same at the suction ports 9 and 9 and the discharge ports 11 and 11, respectively. Neither suction nor discharge of hydraulic oil is performed, and the discharge amount is zero. On the other hand, in the state of FIG.
In the pump chamber 23
Is sucked in and the volume of the pump chamber is reduced at the discharge ports 11 and 11, and the hydraulic oil is discharged. The rate of change of the pump chamber volume decreases when the major axis 27 moves in either direction of the straight lines 29 and 31, so the discharge amount is maximum in the state of FIG. Therefore, by rotating the cam ring 3 and selecting the position of the major axis 27 between the position of FIG. 2 and the straight line 31 as indicated by the arrow 33 in FIG. 2, the discharge amount can be adjusted between the maximum and zero.

Further, no matter which angle the cam ring 3 is at, the suction ports 9 and 9 and the discharge ports 11 and 11 respectively have rotors 1.
Since they are located symmetrically with respect to 3, the negative pressures generated at the suction ports 9, 9 cancel each other out, and the positive pressures generated at the discharge ports 11, 11 cancel each other out. Therefore, the unbalanced force is not applied to the rotor 13, and the life of the bearing of the drive shaft 15 is significantly improved.

When the rotation direction of the rotor 13 is reversed, the suction ports 9 and 9 serve as discharge ports and the discharge ports 11 and 11 serve as suction ports, so that the flow direction of the hydraulic oil can be reversed.

In this way, the balanced vane pump 1 is constructed.

In this embodiment, when pressurized working oil is supplied from the suction ports 9 and 9 in the state shown in FIG.
Becomes a vane motor by rotating in the direction of arrow 17, and when the pressurized hydraulic oil is supplied to the discharge ports 11, 11, the direction of rotation of this vane motor is opposite to the direction of arrow 17. In the case of a vane motor, the output can be adjusted by adjusting the angle of the cam ring, and since it is a balanced type like the vane pump, the bearing of the rotor is not subjected to a force due to the pressure difference, so that the life is improved.

[0020]

According to the vane pump and vane motor of the present invention, the cam surface of the cam ring having an elliptical cross section is coaxial with the rotor, and each side plate has a pair of suction port and discharge port with respect to the central axis of the rotor. The cam rings are provided at symmetrical positions, and the cam ring is rotated to adjust the positions of the cam surface and the suction port and the discharge port. Therefore, the discharge amount can be adjusted when used as a vane pump, and the output can be adjusted when used as a vane motor. Further, in both the pump and the motor, the suction port and the discharge port cancel each other out, so that the life of the rotor bearing is significantly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a discharge amount is zero according to an embodiment.

FIG. 2 is a cross-sectional view showing a state in which the discharge amount is maximum in one embodiment.

FIG. 3 is a cross-sectional view showing a state in which the discharge amount is zero according to the embodiment.

[Explanation of symbols]

 1 Vane Pump 3 Cam Ring 5 Cam Surface 7 Center Shaft 9,9 Suction Port 11,11 Discharge Port 13 Rotor 19 Groove 21 Vane

Claims (1)

[Claims] 1. A cam ring which is arranged between a pair of side plates and has an inner peripheral surface having a cam surface of an elliptical cross section and which is rotated around its central axis, and a radial groove coaxially arranged in the cam surface. Rotor, a vane that movably engages with each groove and slides in contact with the cam surface, and a pair of suction ports and discharge ports provided on the side plates are arranged at symmetrical positions with respect to the central axis. A vane pump and a vane motor characterized by being provided.