Reverse drive oil pump

A positive displacement pump for a fluid machine having an oil supply comprising:

• a shaft having a rotational axis and including a first portion, an overhung portion extending from said first portion and oil distribution means;
• a pump housing and bearing member having a continuous bore receiving said first portion in a bearing relationship;
• annular eccentric rotor means located in said continuous bore and receiving said overhung portion which extends through said rotor means;
• driving means connecting said rotor means and said overhung portion in a driving relationship such that a limited amount of relative rotational movement is permitted between a first position when said shaft is rotating about its rotational axis in a first direction and a second position when said shaft is rotating about its rotational axis in a second direction;
• a pair of circumferentially spaced radially extending bores in said pump housing;
• a pair of vane means located in said radially extending bores and in biased contact with said rotor means;
• said rotor means, said pair of vane means and said continuous bore coacting to define a pair of trapped volumes and said shaft and said rotor means have means for supplying oil from said oil supply to said trapped volumes during a suction stroke and for supplying oil from said trapped volumes to said oil distribution means during a discharge stroke whether said shaft is rotating about its rotational axis in either said first or said second direction;
• said driving means and said means for supplying oil from said oil supply being located on said overhung portion at opposite ends of said annular rotor.