Electric oil pump

Abstract

An electric oil pump includes a rotor driven to rotate by a motor and a pump body having a pump chamber accommodating the rotor, an intake port for introducing oil into the pump chamber according to rotation of the rotor, a discharge port for discharging oil from the pump chamber according to rotation of the rotor, a first discharge passage communicated to a first communication hole provided in the discharge port and circulating oil discharged from the discharge port, the first discharge passage having a smaller cross sectional area than the discharge port, and a second discharge passage communicated to a second communication hole provided in the discharge port separately from the first communication hole and circulating oil discharged from the discharge port, the second discharge passage having a smaller cross sectional area than the discharge port.

1 . An electric oil pump comprising:
 a rotor driven to rotate by a motor; and   a pump body having:
 a pump chamber accommodating the rotor; 
 an intake port for introducing oil into the pump chamber according to rotation of the rotor; 
 a discharge port for discharging oil from the pump chamber according to rotation of the rotor; 
 a first discharge passage communicated to a first communication hole provided in the discharge port and circulating oil discharged from the discharge port, the first discharge passage having a smaller cross sectional area than the discharge port; and 
 a second discharge passage communicated to a second communication hole provided in the discharge port separately from the first communication hole and circulating oil discharged from the discharge port, the second discharge passage having a smaller cross sectional area than the discharge port. 
   
     
     
         2 . The electric oil pump according to  claim 1 , wherein the first discharge passage and the second discharge passage extend to joining faces to the oil supplying destinations in the pump body. 
     
     
         3 . The electric oil pump according to  claim 1 , wherein a first check valve opened/closed according to a pressure of oil discharged from the discharge port is provided in the first discharge passage, and a second check valve opened/closed according to a pressure of oil discharged from the discharge port is provided in the second discharge passage. 
     
     
         4 . The electric oil pump according to  claim 3 , wherein the second discharge passage includes, downstream the second check valve, an orifice for distributing an amount of flow to the first discharge passage and an amount of flow to the second discharge passage. 
     
     
         5 . The electric oil pump according to  claim 3 , wherein
 the first check valve is fixed by a fixing screw which advances through an opening hole formed in the pump body into the first discharge passage;   a tubular outer oil passage is formed between an outer circumferential face of a shank of the fixing screw and an inner circumferential face of the first discharge passage; and   an inner oil passage is formed on a radially inner side of the shank to communicate to the outer oil passage through a communication portion formed in the shank.