Oil pump

Abstract

An oil pump of the present invention includes a housing ( 10, 20 ) which includes an inlet port ( 44 b ) to suck oil, a discharge port ( 52 ) to discharge oil, and a purge port ( 24 ) to eject air-mixed oil, an inner rotor ( 71, 81 ) which is arranged in the housing as being rotatable about a predetermined axis line (S), an outer rotor ( 72, 82 ) which is arranged in the housing to be rotated as being interlocked with the inner rotor, and a filter member ( 90 ) which is arranged at the housing from the outside thereof to prevent foreign matter from entering through the purge port. According to the above, entering of foreign matter and the like can be prevented even when oil is sucked through the purge port.

1 . An oil pump, comprising:
 a housing which includes an inlet port to suck oil, a discharge port to discharge oil, and a purge port to eject air-mixed oil with air mixed;   an inner rotor which is arranged in the housing as being rotatable about a predetermined axis line;   an outer rotor which is arranged in the housing to be rotated as being interlocked with the inner rotor; and   a filter member which is arranged at the housing from the outside thereof to prevent foreign matter from entering through the purge port.   
     
     
         2 . The oil pump according to  claim 1 ,
 wherein the purge port is arranged at a range capable of providing communication, concurrently with the inlet port, with a pump chamber defined by the inner rotor and the outer rotor.   
     
     
         3 . The oil pump according to  claim 1 ,
 wherein the housing includes a housing body including a concave portion for containing the inner rotor and the outer rotor, and a housing cover which is connected to the housing body to close an opening of the housing body,   the purge port is formed at the housing cover, and   the filter member is attached to the housing cover from the outside.   
     
     
         4 . The oil pump according to  claim 1 ,
 wherein the inner rotor and the outer rotor include an upstream rotor including a first inner rotor and a first outer rotor and a downstream rotor including a second inner rotor and a second outer rotor, the upstream rotor and the downstream rotor being arranged adjacently in a direction of the axis line,   the housing includes a spacer member which is interposed between the upstream rotor and the downstream rotor,   the inlet port is arranged to be faced to the upstream rotor,   the discharge port is arranged to be faced to the downstream rotor,   the purge port is arranged to be faced to the upstream rotor, and   a communication port which introduces oil discharged from the upstream rotor to the downstream rotor is arranged at the spacer member.   
     
     
         5 . The oil pump according to  claim 4 ,
 wherein the inlet port is arranged at the spacer member between the upstream rotor and the downstream rotor to be faced to the upstream rotor.   
     
     
         6 . The oil pump according to  claim 1 ,
 wherein the inner rotor and the outer rotor are formed in four blades and five nodes.   
     
     
         7 . The oil pump according to  claim 1 ,
 wherein the purge port is formed to be opened in an approximate L-shape as being elongated in the radial direction passing through the axis line and being elongated in a rotation direction of the inner rotor and the outer rotor at an outer edge thereof in the radial direction.