Power steering pump

Abstract

It is disclosed that a power steering pump. Which is characterized in that the front oil distributing plate is enclosed with front wall of the inner cavity of the pump body to form a front outlet cavity, a valve bore being formed at outer circumference side of the inner cavity of the pump body communicates with the front outlet cavity, a flow securing control valve is disposed within the valve bore, the front outlet cavity communicates with an oil outlet hole at the front portion of pump body through a high-pressure oil passage. The invention adopts a front high-pressure cavity configuration of the pump body to shorten the length of high-pressure oil passage, which hence avoids steering pump failure caused by aggressive overheating generated in the traditional configuration with excessive length of the flow passage and bending.

1 . A power steering pump, comprising a pump body ( 3 ) within which an inner cavity being formed, wherein a rear oil distributing plate ( 10 ), a blade assembly consisting of stators ( 12 ), rotors ( 13 ) and blades ( 14 ), front oil distributing plate ( 15 ), and pressing springs ( 16 ) being sequentially disposed within said inner cavity from its rear portion to front portion, a pump shaft ( 17 ) being mounted into said inner cavity of the pump body ( 3 ) after connecting the rear oil distributing plate ( 10 ), the blade assembly and the front oil distributing plate ( 15 ) in series into one together which front end projects outwards from the front portion of the pump body ( 3 ) and further mates with a drive gear ( 1 ), and which rear end is supported into the rear oil distributing plate ( 10 ), which is characterized in that the front oil distributing plate ( 15 ) is enclosed with front wall of the inner cavity of the pump body ( 3 ) to form a front outlet cavity (A), a valve bore being formed at outer circumference side of the inner cavity of the pump body ( 3 ) communicates with the front outlet cavity (A), a flow securing control valve is disposed within the valve bore, the front outlet cavity (A) communicates with an oil outlet hole ( 20 ) at the front portion of pump body ( 3 ) through a high-pressure oil passage ( 21 ), the outer circumference portion of the blade assembly is enclosed with inner wall of the inner cavity of the pump body ( 3 ) to form a rear cavity of the pump body ( 3 ), the valve bore communicates with said rear cavity of the pump body ( 3 ) through an oil return passage (B), the blades driven by a pump shaft ( 17 ) rotate to complete oil absorbing and draining process, the flow securing control valve controls the oil volume from the front outlet cavity (A) back to the oil return passage to maintain the oil volume drained from the front outlet cavity (A) through the oil outlet hole ( 20 ) at a constant value. 
     
     
         2 . A power steering pump of  claim 1 , wherein the front outlet cavity (A) is positioned vertically below the oil outlet hole, the high-pressure oil passage includes a horizontal oil passage and a longitudinal oil passage vertically below the oil outlet hole, wherein the horizontal oil passage in parallel with the pump shaft ( 17 ) which opening communicates with the front outlet cavity (A), the longitudinal oil passage perpendicular to the horizontal oil passage or inclined to it at an angle from 60 to 90 degree which opening communicates with the oil outlet hole. 
     
     
         3 . A power steering pump of  claim 1 , wherein an opening is formed at the rear portion of the inner cavity of the pump body ( 3 ) and enclosed by the rear oil distributing plate ( 10 ). 
     
     
         4 . A power steering pump in  claim 1 , wherein the front portion of the pump body ( 3 ) is a flange portion, and rolling bearings ( 2 ) and oil seals ( 18 ) are arranged between the flange portion and the pump shaft ( 17 ), wherein the oil seal ( 18 ) is utilized with dual lips and skeleton rotating oil seal configuration. 
     
     
         5 . A power steering pump of  claim 1 , wherein a sliding bearing ( 9 ) is further arranged between the pump shaft ( 17 ) and the rear oil distributing plate ( 10 ). 
     
     
         6 . A power steering pump in  claim 1 , wherein the rear oil distributing plate ( 10 ), the blade assembly and the front oil distributing plate ( 15 ) are connected in series through positioning pins into one together. 
     
     
         7 . A power steering pump of  claim 1 , wherein a conical valve being arranged within the flow securing control valve that comprises a conical valve core ( 6 ) and a pressure limiting spring ( 5 ), wherein a conical opening matched with the conical valve core ( 6 ) is arranged within a valve seat ( 8 ), the pressure limiting spring ( 5 ) compresses the conical valve core ( 6 ) to push it against the conical opening. 
     
     
         8 . A power steering pump of  claim 7 , wherein the valve seat ( 8 ) in the flow securing control valve is utilized with dual-layer strainer configuration, outer-layer strainer of said dual-layer strainer has 60 mesh with diameter Φ0.18, inner-layer strainer of said dual-layer strainer has 120 mesh with diameter Φ0.06, wherein both strainers are outward arc bulge configuration. 
     
     
         9 . A power steering pump in  claim 8 , wherein the oil return passage (B) is obliquely drilled in direction of the valve bore, wherein opening of the oil return passage (B) within the valve bore represents an ellipse shape. 
     
     
         10 . A power steering pump of  claim 9 , wherein, O-shape sealing rings are disposed between the outer circumference of the front oil distributing plate ( 15 ) and inner cavity wall of the pump body ( 3 ), and between the rear oil distributing plate ( 10 ) and inner cavity wall of the pump body ( 3 ) respectively, and an O-shape sealing ring is disposed on the surface of the flange portion of the pump body ( 3 ).