Oil pump device

Abstract

An oil pump device includes an oil circulation flow channel; a gear pump section including a drive gear unit and a driven gear unit; a first branching flow channel that branches from the oil circulation flow channel and communicates with the gear pump section; a hydraulic control valve that drives the driven gear unit; a second branching flow channel that branches from the oil circulation flow channel and communicates with a second small-diameter passage section; a solenoid valve that includes a drain discharge port; an orifice that is disposed between the second small-diameter passage section and the solenoid valve; and a spring that elastically urges the driven gear unit. The solenoid valve performs control in such a manner that the second branching flow channel and the second small-diameter passage section are put to a communicating state or a non-communicating state, and that the drain discharge port communicates with the second small-diameter passage section in the non-communicating state.

1 . An oil pump device comprising:
 an oil circulation flow channel;   a gear pump section including:
 a drive gear unit that does not move in an axial direction; 
 a driven gear unit that moves back and forth in the axial direction; and 
 a second small-diameter passage section in which a second small-diameter shaft section of the driven gear unit slides; 
   a first branching flow channel that branches from the oil circulation flow channel and communicates with the gear pump section;   a hydraulic control valve that is disposed on the first branching flow channel and drives the driven gear unit in the axial direction;   a second branching flow channel that branches from the oil circulation flow channel and communicates with the second small-diameter passage section;   a solenoid valve that is disposed on the second branching flow channel and includes a drain discharge port;   an orifice that is disposed between the second small-diameter passage section and the solenoid valve; and   a spring that is disposed in the second small-diameter passage section and elastically urges the driven gear unit in a direction in which meshing area is increased, wherein   the solenoid valve performs control in such a manner that the second branching flow channel and the second small-diameter passage section are put to a communicating state or a non-communicating state, and that the drain discharge port communicates with the second small-diameter passage section in the non-communicating state.   
     
     
         2 . The oil pump device according to  claim 1 , wherein the orifice is provided from the inside to the outside of the second small-diameter passage section. 
     
     
         3 . The oil pump device according to  claim 1 , wherein the hydraulic control valve is controlled in such a manner that the first branching flow channel is put to a communicating state or a non-communicating state in accordance with a movement of a spool in the hydraulic control valve. 
     
     
         4 . The oil pump device according to  claim 3 , wherein
 the hydraulic control valve is provided with a relief discharge port,   the second small-diameter passage section communicates with the relief discharge port through a relief flow channel, and   the hydraulic control valve performs control in such a manner that the relief flow channel is shut off when the first branching flow channel is in the non-communicating state, and the relief flow channel and the relief discharge port are open when the first branching flow channel is in the communicating state.   
     
     
         5 . The oil pump device according to  claim 1 , wherein
 the second small-diameter passage section communicates with a drain flow channel through the solenoid valve in a low revolution range and a medium revolution range of an engine, and   the second branching flow channel communicates with the orifice through the solenoid valve in a high revolution range of the engine.