Hydraulic pump of automatic transmission

Abstract

A hydraulic pump of an automatic transmission includes: a pump housing; a pump cover attached to the pump housing; a bush attached to the pump housing; a rotor mounted between the pump cover and the pump housing; an oil input port between the pump housing and the pump cover; an oil output port between the pump housing and the pump cover; and a substantially vertical drain hydraulic line between the pump housing and the pump cover.

1 . A hydraulic pump of an automatic transmission, comprising:
 a pump housing;   a pump cover attached to the pump housing;   a bush attached to the pump housing;   a rotor mounted between the pump cover and the pump housing;   an oil input port between the pump housing and the pump cover;   an oil output port between the pump housing and the pump cover; and   a drain hydraulic line between the pump housing and the pump cover, wherein the drain hydraulic line is substantially vertical.   
   
   
       2 . The hydraulic pump of  claim 1 , wherein the oil input port, the oil output port, and the drain hydraulic line are disposed on the pump cover. 
   
   
       3 . The hydraulic pump of  claim 1 , wherein the drain hydraulic line is connected to an oil reservoir. 
   
   
       4 . The hydraulic pump of  claim 3 , further comprising a sealing member between the pump housing and the bush, wherein surplus oil remains at a joint between the sealing member and the bush. 
   
   
       5 . The hydraulic pump of  claim 4 , wherein the drain hydraulic line is connected to the joint between the sealing member and the bush through a drain hole of the pump housing.