Abstract: In one example, a fluid flow restrictor has a housing outlet offset from a housing inlet along a fluid flow direction so as to define a channel therebetween. A rotatable body that is disposed in the channel defines a bore that extends entirely therethrough such that the bore defines a bore inlet and a bore outlet. The flow restrictor has an interior surface disposed in the bore that defines an orifice having a cross-sectional dimension that is less than a cross-sectional dimension of the channel such that the orifice can restrict a flow of fluid as the fluid flows between the housing inlet and outlet. The rotatable body is rotatable between 1) a first orientation, where the bore outlet is offset from the bore inlet along the fluid flow direction, and 2) a second orientation, where the bore inlet is offset from the bore outlet along the fluid flow direction.

Abstract: Fluid pump assembly driven by a reciprocating piston, having an improved coupling between a driving shaft and a driven shaft and a fast-shifting switching mechanism for changing the direction of movement to the piston.

Abstract: Fluid pump assembly driven by a reciprocating piston, having an improved coupling between a driving shaft and a driven shaft and a fast-shifting switching mechanism for changing the direction of movement to the piston.

Abstract: Fluid pump assembly driven by a reciprocating piston, having an improved coupling between a driving shaft and a driven shaft and a fast-shifting switching mechanism for changing the direction of movement of the piston.

Abstract: Fluid pump assembly driven by a reciprocating piston, having an improved coupling between a driving shaft and a driven shaft and a fast-shifting switching mechanism for changing the direction of movement of the piston.