Hydraulic Pump Port Plate with Variable Area Metering Notch

A swashplate-type axial piston pump comprising:

• a swashplate;
• a plurality of pumping chambers, each pumping chamber including:
• a plunger connected to the swashplate via a slipper foot configured to slide along a plunger engagement surface of the swashplate, and
• a pumping chamber barrel in which an associated plunger undergoes reciprocal motion;
• and
• a port plate including:
• a port plate body;
• an inlet port extending through the port plate body;
• a discharge port extending through the port plate body;
• and
• a first metering notch comprising a channel in the port plate body, the first metering notch being in fluidic communication via a first area adjustment passage with a first area adjustment valve configured to adjust the effective area of first the metering notch,
• wherein the first metering notch is disposed at a leading edge of one of the inlet port or the discharge port.

A method for operating a swashplate-type axial piston pump, the method comprising:

• rotating a pumping chamber about a central axis of the swashplate-type axial piston pump and towards an inlet port of a port plate;
• adjusting an effective area of an inlet port metering notch by controlling an inlet port metering notch area adjustment valve actuator;
• rotating the pumping chamber across the inlet port metering notch and into fluidic communication with the inlet port;
• and
• rotating the pumping chamber across the inlet port while drawing fluid through the inlet port and into the pumping chamber.