Power steering pump

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.