Gear pump device

Abstract

In the present invention, polishing lines 71 f are connected to an outer circumferential high-pressure region, but are not connected to each area that is a low-pressure region. In this configuration, the polishing lines 71 f are connected to the outer circumferential high-pressure region where there is high discharge pressure, so high-pressure brake fluid is introduced within the polishing lines 71 f . Therefore, a pushback effect is obtained, wherein gear pumps 19 and 39 are pushed back on the basis of the high-pressure brake fluid pressure. Furthermore, the polishing lines 71 f are connected to the outer circumferential high-pressure region but are not connected to each area that is a low-pressure region, so high-pressure can be maintained within the polishing lines 71 f , and a reduction in the pushback effect can be prevented. Accordingly, a decrease in the loss torque reduction effect can be prevented, and the loss torque can be further reduced.

1 . A gear pump device comprising:
 a gear pump which has an outer rotor having an inner tooth portion and an inner rotor meshed with the outer rotor while forming a plurality of void portions and performs a suction/discharge operation of a fluid by rotating the outer rotor and the inner rotor based on rotation of a shaft inserted into a center hole of the inner rotor;   a case that forms a housing portion that houses the gear pump; and   a sealing mechanism disposed between the case and one of pump shaft direction end surfaces of the gear pump and, in the gear pump, partitioning a low-pressure side including a suction side sucking a fluid and a periphery of the shaft, and a high-pressure side including a discharge side discharging the fluid and a part of gaps between an outer periphery of the outer rotor and the case,   the other end surface of the pump shaft direction end surfaces in the gear pump being brought into contact with a sliding surface of the case based on pressing force of the sealing mechanism to seal a portion between the low-pressure side and the high-pressure side of the gear pump on the end surface, wherein,   in the sliding surface, a fluid feeding groove which is made of a line radially extending from the center of the gear pump and in which the fluid in the gap between the outer periphery of the outer rotor and the case, which is on the high-pressure side, is fed is formed, and   the fluid feeding groove is spaced apart from the center hole and the suction side.   
     
     
         2 . The gear pump device according to  claim 1 , wherein the fluid feeding groove is not formed in a range in which a confinement portion having a maximum volume is located among the plurality of void portions. 
     
     
         3 . The gear pump device according to  claim 1 , wherein of the plurality of void portions, the fluid feeding groove has a portion formed at a place where the fluid feeding groove communicates with, a void portion caused to communicate with the suction side and being in a low-pressure state as a low-pressure portion, and a place communicating with a gap between the outer periphery of the outer rotor being in a high-pressure state and the case as a high-pressure portion, and the low-pressure portion and the high-pressure portion are separated from each other. 
     
     
         4 . The gear pump device according to  claim 1 , wherein the fluid feeding grooves are constituted by radial curves, and an intermediate position located between both ends of each of the fluid feeding grooves is located in front of the gear pump in a rotational direction of the gear pump. 
     
     
         5 . The gear pump according to  claim 1 , wherein the fluid feeding groove is formed in a radial shape which extends in a tangential direction of a virtual circle which is set at a center position of the gear pump. 
     
     
         6 . The gear pump device according to  claim 5 , wherein the fluid feeding groove is formed such that, of the fluid feeding groove, an and portion on an inner peripheral side of the gear pump is more forward than an end portion on an outer peripheral side in the rotational direction of the gear pump. 
     
     
         7 . The gear pump device according to  claim 2 , wherein of the plurality of void portions, the fluid feeding groove has a portion formed at a place where the fluid feeding groove communicates with, a void portion caused to communicate with the suction side and being in a low-pressure state as a low-pressure portion, and a place communicating with a gap between the outer periphery of the outer rotor being in a high-pressure state and the case as a high-pressure portion, and the low-pressure portion and the high-pressure portion are separated from each other. 
     
     
         8 . The gear pump device according to  claim 2 , wherein the fluid feeding grooves are constituted by radial curves, and an intermediate position located between both ends of each of the fluid feeding grooves is located in front of the gear pump in a rotational direction of the gear pump. 
     
     
         9 . The gear pump device according to  claim 3 , wherein the fluid feeding grooves are constituted by radial curves, and an intermediate position located between both ends of each of the fluid feeding grooves is located in front of the gear pump in a rotational direction of the gear pump. 
     
     
         10 . The gear pump according to  claim 2 , wherein the fluid feeding groove is formed in a radial shape which extends in a tangential direction of a virtual circle which is set at a center position of the gear pump. 
     
     
         11 . The gear pump according to  claim 3 , wherein the fluid feeding groove is formed in a radial shape which extends in a tangential direction of a virtual circle which is set at a center position of the gear pump. 
     
     
         12 . The gear pump device according to  claim 10 , wherein the fluid feeding groove is formed such that, of the fluid feeding groove, an and portion on an inner peripheral side of the gear pump is more forward than an end portion on an outer peripheral side in the rotational direction of the gear pump. 
     
     
         13 . The gear pump device according to  claim 11 , wherein the fluid feeding groove is formed such that, of the fluid feeding groove, an and portion on an inner peripheral side of the gear pump is more forward than an end portion on an outer peripheral side in the rotational direction of the gear pump.