Hydraulic piston pump with a variable displacement throttle mechanism

摘要

A radial piston pump has a plurality of cylinders within which pistons reciprocally move. Each cylinder is connected to a first port by an inlet passage that has an inlet check valve, and is connected to a second port by an outlet passage that has an outlet check valve. A throttling plate extends across the inlet passages and has a separate aperture associated with each inlet passage. Rotation of the throttling plate varies the degree of alignment of each aperture with the associated inlet passage, thereby forming variable orifices for altering displacement of the pump. Uniquely shaped apertures specifically affect the rate at which the variable orifices close with throttle plate movement, so that the closure rate decreases with increased closure of the variable orifices.

主权项

1. A pump comprising:
a cylinder block with an inlet port, an outlet port, a plurality of cylinders disposed in the cylinder block, a plurality of inlet passages each connected between the inlet port and a different one of the plurality of cylinders, and a plurality of outlet passages each connected between the outlet port and a different one of the plurality of cylinders; a plurality of pistons each slideably received in a different one of the plurality of cylinders; a drive shaft rotatably received in the cylinder block for driving the plurality of pistons within the plurality of cylinders; and a throttle member extending across the plurality of inlet passages and having a plurality of control apertures there through, wherein each control aperture has a transverse cross sectional shape with a primary region from which a tapered region projects, the throttle member being moveable relative to the cylinder block to alter alignment between the plurality of inlet passages and the plurality of control apertures.