Oil pump

Abstract

An oil pump, includes an inner rotor having outer teeth; an outer rotor having inner teeth which form cells together with the outer teeth, the outer rotor rotating with a prescribed amount of eccentricity with respect to the center of rotation of the inner rotor; an outer ring which causes the center of rotation of the outer rotor to swing along a fan-shaped rotation trajectory having a radius equal to the amount of eccentricity, with respect to the center of rotation of the inner rotor; an operating means which causes a swinging movement of the outer ring; and a pump housing which has a rotor chamber having an intake port and a discharge port, the portion between a final end section of the intake port and a start end section of the discharge port being taken to be a first sealing land.

1 . An oil pump, comprising:
 an inner rotor having outer teeth;   an outer rotor having inner teeth which form cells together with the outer teeth, the outer rotor rotating with a prescribed amount of eccentricity with respect to the center of rotation of the inner rotor;   an outer ring which causes the center of rotation of the outer rotor to swing along a fan-shaped rotation trajectory having a radius equal to the amount of eccentricity, with respect to the center of rotation of the inner rotor;   an operating means which causes a swinging movement of the outer ring; and   a pump housing which has a rotor chamber having an intake port and a discharge port, the portion between a final end section of the intake port and a start end section of the discharge port being taken to be a first sealing land, and which houses the inner rotor, the outer rotor and the outer ring,   wherein the oil pump is provided with no less than three and no more than eight tooth shape sections, each formed of an outside position tooth shape formed in the rotor chamber and an inside position tooth shape which is formed in the outer ring to form a pair with the outside position tooth shape and which intermeshes therewith at all times while moving, and a prescribed interval is provided between the adjacent tooth shape sections.   
     
     
         2 . The oil pump according to  claim 1 , wherein the number of tooth shape sections is no less than three and no more than six. 
     
     
         3 . The oil pump according to  claim 1 , wherein the number of tooth shape sections is four or five. 
     
     
         4 . The oil pump according to  claim 1 , wherein the number of tooth shape sections is four. 
     
     
         5 . The oil pump according to  claim 1 , wherein an operating protrusion, one side of which in a swinging direction is taken to be a first pressure receiving surface and the other side of which is taken to be a second pressure receiving surface, is formed on an outer circumference of the outer ring, an operating chamber in which the operating protrusion is accommodated swingably is formed adjacently to and in connection with the rotor chamber, a first oil passage for sending oil to the first pressure receiving surface by the operating means and a second oil passage for sending oil to the second pressure receiving surface by the operating means are formed in the operating chamber, and the operating protrusion is configured to swing due to an oil pressure differential between the first oil passage side and the second oil passage side.