ELECTRONIC CONTROL FOR A ROTARY FLUID DEVICE

• US 20100021313A1
• Filed: 07/28/2008
• Published: 01/28/2010
• Est. Priority Date: 07/28/2008
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Galloway, Phillip W., Williams, Kevin Stuart, Devan, Stephen Marshall
• Granted Patent: US 10,100,827 B2
• Time in Patent Office: Days
• US Class Current: 417/44.100
• CPC Class Codes: F04B 1/328 by changing the inclination of the axis of the cylinder barrel relative to the swash plate
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 2203/0201 Current
• CPC Class Codes: F04B 2203/0202 Voltage
• CPC Class Codes: F04B 2203/0209 Rotational speed
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/103 Responsive to speed
• CPC Class Codes: F04B 49/106 Responsive to pumped volume
• CPC Class Codes: F04B 49/20 by changing the driving speed

Abstract

A fluid device system includes a fluid pump, an electric motor in engagement with the fluid pump, and a controller. The electric motor is adapted for rotation in response to an electric signal. The controller is adapted to communicate the electric signal to the electric motor. The controller includes a lookup table having a plurality of performance data related to the fluid pump and the electric motor. The performance data from the lookup table is used by the controller to set aspects of the electrical signal communicated to the electric motor in order to achieve a desired attribute of the fluid pump.

Claims

1. A fluid device system comprising:

a fluid pump having a fluid inlet and a fluid outlet;

an electric motor having a shaft coupled to the fluid pump, the electric motor being adapted for rotation in response to an electrical signal;

a controller adapted to communicate the electrical signal to the electric motor, the controller including a lookup table having a plurality of performance data related to the fluid pump and the electric motor, wherein the plurality of performance data from the lookup table is used by the controller to set aspects of the electrical signal communicated to the electric motor in order to achieve a desired attribute of the fluid pump.

2. A fluid device system as claimed in claim 1, wherein the aspects of the electrical signal are voltage, phase current, phase angle, or combinations thereof.

3. A fluid device system as claimed in claim 2, wherein the desired attribute of the fluid pump is selected from the group consisting of generally constant horsepower output, pressure compensation, and combinations thereof.

4. A fluid device system as claimed in claim 1, wherein the electric motor is a brushless DC motor and the fluid pump is an axial piston type pump.

5. A fluid device system as claimed in claim 1, wherein the fluid pump is a fixed displacement pump.

6. A fluid device system as claimed in claim 1, further comprising at least one sensor in electrical communication with the controller, wherein the at least one sensor is adapted to sense the rotational speed of the shaft of the electric motor and the position of the shaft.

7. A fluid device system as claimed in claim 6, wherein the at least one sensor is a resolver.

8. A fluid device system as claimed in claim 1, further comprising a housing including a main body having a first end portion and a second end portion, wherein the first end portion is adapted to receive the fluid pump and the second end portion is adapted to receive the electric motor.

9. A fluid device system as claimed in claim 1, wherein the lookup table provides a correlation between current supplied to the electric motor and the speed of the electric motor.

10. A fluid device system as claimed in claim 1, wherein the lookup table provides a correlation between speed of the electric motor and a phase angle between a supplied voltage and current to the electric motor.

11. A fluid device system as claimed in claim 10, wherein the lookup table further provides a correction between fluid temperature and the phase angle.

12. A fluid device system comprising:

a rotary fluid device including;

a housing having a main body with a first end portion and an opposite second end portion, the first end portion defining a first chamber and the second end portion defining a second chamber;

a fixed displacement pumping assembly disposed in the first chamber of the first end portion;

an electric motor disposed in the second chamber of the second end portion, wherein the electric motor includes a shaft that is coupled to the pumping assembly;

a plurality of sensors adapted to sense operating parameters of the rotary fluid device;

a controller in electrical communication with the electric motor of the rotary fluid device and the plurality of sensors, the controller including;

a microprocessor;

a storage media in communication with the microprocessor, the storage media having at least one lookup table that includes performance characteristics of the rotary fluid device; and

wherein the lookup table is used by the controller to achieve a desired attribute of the rotary fluid device.

13. A fluid device system as claimed in claim 12, wherein the desired attribute of the rotary fluid device is generally constant horsepower.

14. A fluid device system as claimed in claim 12, wherein the plurality of sensors includes a speed sensor for sensing the rotational speed of the shaft and a position sensor for sensing the rotational position of the shaft and a temperature sensor for sensing temperature of fluid within the rotary fluid device.

15. A fluid device system as claimed in claim 14, wherein a resolver senses the rotational speed and position of the shaft.

16. A fluid device system as claimed in claim 12, wherein the lookup table provides a correlation between current supplied to the rotary fluid device and speed of the rotary fluid device.

17. A fluid device system as claimed in claim 12, wherein the lookup table provides a correlation between speed of the rotary fluid device, temperature of fluid within the rotary fluid device and a phase angle between voltage and current supplied to the rotary fluid device.

18. A fluid device system as claimed in claim 12, wherein the microprocessor is a field programmable gate array.

19. A method for controlling a rotary fluid device, the method comprising:

receiving at least one sensed operating parameter of a rotary fluid device, wherein the rotary fluid device includes an electric motor coupled to a fluid pump;

determining a voltage, phase current, phase angle or combinations thereof to be supplied to the electric motor to generally achieve a desired attribute of the rotary fluid device, wherein the determination is based on the sensed operating parameter of the rotary fluid device and a lookup table that includes a plurality of performance data for the rotary fluid device; and

outputting the voltage, phase current, phase angle or combinations thereof to the electric motor.

20. A method for controlling a rotary fluid device as claimed in claim 19, wherein the lookup table provides correlations between current supplied to the electric motor and speed of the fluid pump and between speed of the fluid pump, temperature of fluid within the fluid pump and a phase angle between voltage and current supplied to the electric motor.