Variable capacity type vane pump
View Patent ↗A variable capacity type vane pump with a first fluid pressure chamber and a second fluid pressure chamber provided at opposite sides of a pivot point of a cam ring includes a control valve for controlling a drive pressure of working fluid introduced from a pump chamber to the second fluid pressure chamber, a suction pressure of the working fluid sucked into the pump chamber is constantly introduced to the first fluid pressure chamber, and the cam ring pivots in a direction to decrease a discharge capacity due to a pressure in the pump chamber acting on an inner peripheral cam surface during an operation to reduce the drive pressure, whereas the cam ring pivots in a direction to increase the discharge capacity during an operation to increase the drive pressure.
1. A variable capacity type vane pump configured as a fluid pressure supply source, the vane pump comprising:
a rotor to be driven and rotated;
a plurality of vanes reciprocally provided on the rotor;
a cam ring having an inner peripheral cam surface, on which tip parts of the plurality of vanes are slidable when the rotor is rotated;
a pump chamber defined between adjacent vanes among the plurality of vanes;
a suction port configured to introduce working fluid sucked into the pump chamber;
a discharge port configured to introduce the working fluid discharged from the pump chamber;
a first fluid pressure chamber and a second fluid pressure chamber provided at opposite sides of a pivot point of the cam ring; and
a control valve configured to control a drive pressure of the working fluid introduced from the pump chamber to the second fluid pressure chamber by a drive force of a solenoid connected to the control valve, the control valve comprising a spool configured to be driven by the solenoid;
wherein
a suction pressure of the working fluid sucked into the pump chamber is constantly introduced to the first fluid pressure chamber, and
the cam ring pivots in a direction to decrease a discharge capacity due to a pressure in the pump chamber acting on the inner peripheral cam surface of the cam ring during an operation to reduce the drive pressure, whereas the cam ring pivots in a direction to increase the discharge capacity during an operation to increase the drive pressure.
2. The variable capacity type vane pump according to claim 1 , further comprising:
a restricting portion configured to restrict a movement of the cam ring so that the eccentricity of the cam ring with respect to the rotor does not become zero.
3. A variable capacity type vane pump configured as a fluid pressure supply source, the vane pump comprising:
a rotor to be driven and rotated;
a plurality of vanes reciprocally provided on the rotor;
a cam ring having an inner peripheral cam surface, on which tip parts of the plurality of vanes are slidable when the rotor is rotated;
a pump chamber defined between adjacent vanes among the plurality of vanes;
a suction port configured to introduce working fluid sucked into the pump chamber;
a discharge port configured to introduce the working fluid discharged from the pump chamber;
a first fluid pressure chamber and a second fluid pressure chamber provided at opposite sides of a pivot point of the cam ring; and
a control valve configured to control a drive pressure of the working fluid introduced from the pump chamber to the second fluid pressure chamber by a drive force of a solenoid connected to the control valve;
wherein
a suction pressure of the working fluid sucked into the pump chamber is constantly introduced to the first fluid pressure chamber,
the cam ring pivots in a direction to decrease a discharge capacity due to a pressure in the pump chamber acting on the inner peripheral cam surface of the cam ring during an operation to reduce the drive pressure, whereas the cam ring pivots in a direction to increase the discharge capacity during an operation to increase the drive pressure,
a virtual line connecting the pivot point of the cam ring and a rotation center of the rotor is a pivot center line,
a virtual line connecting the rotation center of the rotor and a start edge of the discharge port is a discharge port start edge line,
an angle of inclination of the discharge port start edge line with respect to the pivot center line is a discharge port start edge line inclination angle,
a virtual line connecting the rotation center of the rotor and an end edge of the discharge port is a discharge port end edge line,
an angle of inclination of the discharge port end edge line with respect to the pivot center line is a discharge port end edge line inclination angle,
an angle of intersection between center lines of adjacent vanes among the plurality of vanes is a vane angle, and
the discharge port end edge line inclination angle is larger than a sum of the discharge port start edge line inclination angle and the vane angle.