Hydraulic pump port plate with variable area metering notch

Patent metadata

Field	Value
Publication number	US-10227964-B2
Application number	US-201514839128-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Aug 28, 2015
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

A port plate for a swashplate type axial piston pump is described herein. The port plate includes an inlet port, a discharge port, and a first metering notch in fluidic communication via a first passage with a metering notch area adjustment valve configured to adjust the effective area of the metering notch. The first metering notch is disposed at a leading edge of one of the inlet port or the discharge port.

First claim

What is claimed is:

1. A port plate for a swashplate type axial piston pump, the port plate comprising:
a port plate body;
a port extending through the port plate body, wherein the port is an inlet port or a discharge port;
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 the first metering notch,
wherein the first metering notch is disposed at a leading edge of the port;
wherein the first area adjustment valve is fluidly connected via a second area adjustment passage with the leading edge of the port, such that when the swashplate type axial piston pump is in operation, oil may flow from the first metering notch, through the first area adjustment valve and through the second area adjustment passage into the port when the first area adjustment valve is in an open position.

2. The port plate of claim 1 , wherein the first area adjustment valve increases the effective area of the first metering notch when in an open position.

3. The port plate of claim 2 , wherein the first area adjustment valve is biased to the open position by a spring.

4. The port plate of claim 3 , wherein
pressurized fluid within the second area adjustment passage biases the first area adjustment valve to a closed position from the open position.

5. The port plate of claim 4 , wherein the first area adjustment valve is in the open position when the pressure of the pressurized fluid within the second area adjustment passage is below an opening threshold, and
wherein the first area adjustment valve is in a closed position when the pressure of the pressurized fluid within the second area adjustment passage is above a closing threshold.

6. The port plate of claim 2 , wherein the first area adjustment valve is a solenoid valve.

7. The port plate of claim 1 , wherein the first area adjustment valve is disposed in a cavity within the port plate body.

8. The port plate of claim 1 , further comprising a second metering notch in fluidic communication via a third area adjustment passage with a second area adjustment valve configured to adjust the effective area of the second metering notch,
wherein the second metering notch is disposed at a leading edge of the other of the inlet port or the discharge port at which the first metering notch is disposed.

9. 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;
a port extending through the port plate body, wherein the port is an inlet port or a discharge port;
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 the first metering notch,

wherein the first metering notch is disposed at a leading edge of the port; and
wherein the first area adjustment valve is fluidly connected via a second area adjustment passage with the leading edge of the port such that oil may flow from the first metering notch, through the first area adjustment valve and through the second area adjustment passage into the port when the first area adjustment valve is in an open position.

10. The swashplate-type axial piston pump of claim 9 , wherein the first area adjustment valve increases the effective area of the first metering notch when in the open position.

11. The swashplate-type axial piston pump of claim 10 , wherein the first area adjustment valve is biased to the open position by a spring.

12. The swashplate-type axial piston pump of claim 11 , wherein
pressurized fluid within the second area adjustment passage biases the first area adjustment valve to a closed position.

13. The swashplate-type axial piston pump of claim 12 , wherein the first area adjustment valve is in the open position when the pressure of the pressurized fluid within the second area adjustment passage is below an opening threshold, and
wherein the first area adjustment valve is in the closed position when the pressure of the pressurized fluid within the second area adjustment passage is above a closing threshold.

14. The swashplate-type axial piston pump of claim 10 , wherein the first area adjustment valve is a solenoid valve.

15. The swashplate-type axial piston pump of claim 9 , wherein the first area adjustment valve is disposed in a cavity within the port plate body.

16. The swashplate-type axial piston pump of claim 9 , further comprising a second metering notch comprising a channel in the port plate body, the second metering notch being in fluidic communication via a third area adjustment passage with a second area adjustment valve configured to adjust the effective area of the second metering notch,
wherein the second metering notch is disposed at a leading edge of the other of the inlet port or the discharge port at which the first metering notch is disposed.

17. 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.

18. The method of claim 17 , further comprising:
rotating the pumping chamber about the central axis of the swashplate-type axial piston pump and towards a discharge port of the port plate;
adjusting an effective area of a discharge port metering notch by controlling a discharge port metering notch area adjustment valve actuator;
rotating the pumping chamber across the discharge port metering notch and into fluidic communication with the discharge port; and
rotating the pumping chamber across the discharge port while expelling fluid through the discharge port and into an outlet passage.

19. The method of claim 17 , wherein rotating the pumping chamber across the inlet port while drawing fluid through the inlet port and into the pumping chamber comprises retracting a plunger from an approximate bottom-dead-center position to an approximate top-dead-center position as the pumping chamber moves from a leading edge of the inlet port to a trailing edge of the inlet port.

20. The method of claim 18 , wherein rotating the pumping chamber across the discharge port while expelling fluid through the discharge port and into the outlet passage comprises extending a plunger from an approximate top-dead-center position to an approximate bottom-dead-center position as the pumping chamber moves from a leading edge of the discharge port to a trailing edge of the discharge port.

Assignees

• Caterpillar Inc

Inventors

• Graf Kevin J
• Sun Kaimei
• Du Hongliu

Classifications

• F04B1/303

  by turning the valve plate · CPC title

• F04B1/188

  Plate-like distribution members · CPC title

• F04B1/2042 Primary

  Valves · CPC title

• F04B1/32

  by varying the relative positions of a swash plate and a cylinder block · CPC title

• F04B1/2057

  Conical · CPC title