Pump and pump control circuit apparatus and method

• US 6,623,245 B2
• Filed: 11/26/2001
• Issued: 09/23/2003
• Est. Priority Date: 11/26/2001
• Status: Expired due to Fees

• Current Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Original Assignee: Shurflo Pump Manufacturing Company, Inc.
• Inventors: Meza, Humberto V., Wang, Congxiao Calvin
• Primary Examiner(s): Freay, Charles G.
• Assistant Examiner(s): Liu, Han L
• Application Number:
  US09/994,378
• Publication Number:
  US 20030099548A1
• Time in Patent Office: 666 Days
• Field of Search: 417/44.1, 417/44.2, 417/44.4, 417/44.11, 417/53, 417/269, 417/313, 417/472, 417/507, 417/566, 417/572, 417/25, 417/26, 417/559, 417/569, 417/423.14, 417/571, 137/852, 137/854, 914/72, 915/07
• US Class Current: 417/44.1
• CPC Class Codes: F04B 2205/04 Pressure in the outlet chamber
• CPC Class Codes: F04B 43/0054 particularities of the flexible members
• CPC Class Codes: F04B 43/04 Pumps having electric drive
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

A method and apparatus for a pump and a pump control system. The apparatus includes pistons integrally formed in a diaphragm and coupled to the diaphragm by convolutes. The convolutes have a bottom surface angled with respect to a top surface of the pistons. The apparatus also includes an outlet port positioned tangentially with respect to the perimeter of an outlet chamber. The apparatus further includes a non-mechanical pressure sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump. The control signal is based on the pressure within the pump, the current being provided to the pump, and the voltage level of the battery.

Claims

1. A pump comprising:

a housing having

an inlet port;

an outlet port;

an inlet chamber in fluid communication with the inlet port;

an outlet chamber in fluid communication with the outlet port; and

a valve selectively separating the inlet chamber from the outlet chamber;

the outlet port positioned to receive fluid exiting tangentially from the outlet chamber.

2. The pump of claim 1, wherein the inlet chamber at least partially surrounds the outlet chamber.

3. The pump of claim 1, wherein the outlet chamber is generally in the shape of a pentagon, and wherein the outlet port is positioned tangentially with respect to a first side of the pentagon.

4. The pump of claim 1, wherein the inlet port is positioned tangentially with respect to a side of the outlet chamber.

5. The pump of claim 4, wherein the outlet port and the inlet port lie generally parallel to a side of the outlet chamber.

6. The pump of claim 1, further comprising a pressure sensor positioned within a perimeter of the outlet chamber.

7. The pump of claim 6, wherein the pressure sensor is positioned a distance from a center of the outlet chamber.

8. The pump of claim 6, wherein the pressure sensor is a silicon semiconductor pressure sensor.

9. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of producing a signal representative of changes in pressure in the pump, the pressure sensor being a silicon semiconductor pressure sensor;

a microcontroller coupled to receive the signal from the pressure sensor, the microcontroller programmed to control the speed of the pump by generating a pulse-width modulation control signal; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal.

10. The pump control circuit of claim 9, wherein the pressure sensor produces a signal representative of changes in the pressure in an outlet chamber in the pump.

11. The pump control circuit of claim 9, wherein the pulse-width modulation control signal has a duty cycle that is reduced in order to reduce the power supplied to the pump and that is increased in order to increase the power supplied to the pump.

12. The pump control circuit of claim 9, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

13. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of producing a signal representative of changes in pressure in the pump;

a microcontroller coupled to receive the signal from the pressure sensor, the microcontroller programmed to control the speed of the pump by generating a pulse-width modulation control signal;

an amplifier and filter circuit coupled between the pressure sensor and the microprocessor, the amplifier and filter circuit including a potentiometer used to calibrate the pressure sensor; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal.

14. The pump control circuit of claim 13, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

15. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of producing a signal representative of changes in pressure in the pump;

a microcontroller coupled to receive the signal from the pressure sensor, the microcontroller programmed to control the speed of the pump by generating a pulse-width modulation control signal; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal, the output power stage including a comparator circuit which determines whether the control signal is a high control signal or a low control signal, an output of the comparator circuit being positive for a high control signal and negative for a low control signal, and the comparator circuit having a gain approximately equal to the voltage of a battery connected to the pump control circuit.

16. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of producing a signal representative of changes in pressure in the pump;

a microcontroller coupled to receive the signal from the pressure sensor, the microcontroller programmed to control the speed of the pump by generating a pulse-width modulation control signal; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal,

the output power stage including a comparator circuit which determines whether the control signal is a high control signal or a low control signal,

an output of the comparator circuit being positive for a high control signal and negative for a low control signal, and

the output power stage including a transistor coupled between the comparator circuit and the pump,

wherein the transistor conducts power to the pump if the output of the comparator circuit is positive, and

wherein the transistor does not conduct power to the pump if the output of the comparator circuit is negative.

17. The pump control circuit of claim 16, wherein the transistor is a metal-oxide semiconductor field-effect transistor.

18. The pump control circuit of claim 16, wherein the transistor is capable of operating at a frequency of 1 kHz.

19. The pump control circuit of claim 16, wherein the output power stage includes at least one diode coupled between the transistor and the pump in order to release inductive energy generated by the pump.

20. A pump control circuit for use with a pump, the circuit comprising:

an input power stage designed to be coupled to a battery;

a microcontroller coupled to the input power stage, the microcontroller programmed to sense the voltage of the battery and to generate a control signal if the voltage of the battery is below a high threshold and above a low threshold; and

an output power stage coupled to receive the control signal from the microcontroller and capable of controlling the application of power to the pump in response to the control signal.

21. The pump control circuit of claim 20, wherein the battery is a standard automotive battery.

22. The pump control circuit of claim 21, wherein the high threshold is approximately 14 volts and the low threshold is approximately 8 volts.

23. The pump control circuit of claim 20, and further comprising a voltage divider circuit coupled between the input power stage and the microcontroller so that the voltage sensed by the microcontroller is a fraction of the voltage of the battery.

24. The pump control circuit of claim 20, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

25. The pump control circuit of claim 24, wherein the comparator circuit has a gain approximately equal to the voltage of the battery.

26. The pump control circuit of claim 24, wherein the output power stage includes a transistor coupled between the comparator circuit and the pump, wherein the transistor conducts power to the pump if the output of the comparator circuit is positive, and wherein the transistor does not conduct power to the pump if the output of the comparator circuit is negative.

27. The pump control circuit of claim 26, wherein the transistor is a metal-oxide semiconductor field-effect transistor.

28. The pump control circuit of claim 26, wherein the transistor is capable of operating at a frequency of 1 kHz.

29. The pump control circuit of claim 26, wherein the output power stage includes at least one diode coupled between the transistor and the pump in order to release inductive energy generated by the pump.

30. A method of controlling a pump, the method comprising:

coupling a battery having a voltage to the pump;

sensing the voltage;

generating a control signal if the sensed voltage is below a high threshold and above a low threshold; and

controlling the application of power to the pump in response to the control signal.

31. The method of claim 30, wherein coupling a battery having a voltage to the pump includes coupling a standard automotive battery having a voltage of approximately 13.6 volts to the pump.

32. The method of claim 31, wherein generating a control signal if the sensed voltage is below a high threshold and above a low threshold includes generating a control signal if the sensed voltage is below approximately 14 volts and above approximately 8 volts.

33. The method of claim 30, and further comprising determining whether the generated control signal is a high control signal or a low control signal, providing power to the pump if the control signal is a high control signal, and not providing power to the pump if the control signal is a low control signal.

34. A pump control circuit for use with a pump, the circuit comprising:

an input power stage designed to be coupled to a battery;

a pressure sensor capable of sensing a pressure in the pump;

a microcontroller coupled to the input power stage and the pressure sensor,

the microcontroller programmed to sense the voltage of the battery and to determine a shut-off pressure based on the sensed voltage, and

the microcontroller programmed to generate a high control signal if the sensed pressure is less than the shut-off pressure and a low control signal if the sensed pressure is greater than the shut-off pressure; and

an output power stage coupled to receive the control signal from the microcontroller so that the output power stage provides power to the pump if the control signal is a high control signal and does not provide power to the pump if the control signal is a low control signal.

35. The pump control circuit of claim 34, wherein the battery is a standard automotive battery.

36. The pump control circuit of claim 34, and further comprising a voltage divider circuit coupled between the input power stage and the microcontroller so that the voltage sensed by the microcontroller is a fraction of the voltage of the battery.

37. The pump control circuit of claim 34, wherein the pressure sensor is capable of sensing a pressure in an outlet chamber in the pump.

38. The pump control circuit of claim 34, wherein the pressure sensor is a silicon semiconductor pressure sensor.

39. The pump control circuit of claim 34, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

40. The pump control circuit of claim 39, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

41. The pump control circuit of claim 34, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

42. The pump control circuit of claim 41, wherein the comparator circuit has a gain approximately equal to the voltage of the battery.

43. The pump control circuit of claim 41, wherein the output power stage includes a switch coupled between the comparator circuit and the pump, wherein the switch conducts power to the pump if the output of the comparator circuit is positive, and wherein the switch does not conduct power to the pump if the output of the comparator circuit is negative.

44. The pump control circuit of claim 43, wherein the switch is a metal-oxide semiconductor field-effect transistor.

45. The pump control circuit of claim 43, wherein the switch is capable of operating at a frequency of 1 kHz.

46. The pump control circuit of claim 43, wherein the output power stage includes at least one diode coupled between the transistor and the pump in order to release inductive energy generated by the pump.

47. A method of controlling a pump, the method comprising:

coupling a battery having a voltage to the pump;

sensing the voltage;

determining a shut-off pressure based on the sensed voltage;

sensing a pressure in the pump;

comparing the sensed pressure to the shut-off pressure; and

providing power to the pump if the sensed pressure is less than the shut-off pressure and not providing power to the pump if the sensed pressure is greater than the shut-off pressure.

48. The method of claim 47, wherein coupling a battery having a voltage to the pump includes coupling a standard automotive battery having a voltage of approximately 13.6 volts to the pump.

49. The method of claim 47, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

50. The method of claim 47, and further comprising amplifying and filtering the sensed pressure before comparing the sensed pressure to the shut-off pressure.

51. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump the pressure sensor being a silicon semiconductor pressure sensor;

a current sensing circuit capable of sensing a current being provided to the pump;

a microcontroller coupled to the pressure sensor and the current sensing circuit,

the microcontroller programmed to determine a current limit threshold based on the sensed pressure, and

the microcontroller programmed to generate a high control signal if the sensed current is less than the current limit threshold and a low control signal if the sensed current is greater than the current limit threshold; and

an output power stage coupled to receive the control signal from the microcontroller so that if the control signal is a low control signal the power provided to the pump is reduced until the sensed current is less than the current limit threshold.

52. The pump control circuit of claim 51, wherein the pressure sensor is capable of sensing the pressure in an outlet chamber in the pump.

53. The pump control circuit of claim 51, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

54. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump;

a current sensing circuit capable of sensing a current being provided to the pump;

a microcontroller coupled to the pressure sensor and the current sensing circuit,

the microcontroller programmed to determine a current limit threshold based on the sensed pressure, and

the microcontroller programmed to generate a high control signal if the sensed current is less than the current limit threshold and a low control signal if the sensed current is greater than the current limit threshold;

an amplifier and filter circuit coupled between the pressure sensor and the microprocessor the amplifier and filter circuit including a potentiometer used to calibrate the pressure sensor; and

an output power stage coupled to receive the control signal from the microcontroller so that if the control signal is a low control signal the power provided to the pump is reduced until the sensed current is less than the current limit threshold.

55. The pump control circuit of claim 54, wherein the output power stage includes a comparator circuit which determines whether the control signal is a high control signal or a low control signal, and wherein an output of the comparator circuit is positive for a high control signal and negative for a low control signal.

56. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump;

a current sensing circuit capable of sensing a current being provided to the pump;

a microcontroller coupled to the pressure sensor and the current sensing circuit,

the microcontroller programmed to determine a current limit threshold based on the sensed pressure, and

the microcontroller programmed to generate a high control signal if the sensed current is less than the current limit threshold and a low control signal if the sensed current is greater than the current limit threshold; and

an output power stage coupled to receive the control signal from the microcontroller so that if the control signal is a low control signal the power provided to the pump is reduced until the sensed current is less than the current limit threshold,

the output power stage including a comparator circuit which determines whether the control signal is a high control signal or a low control signal,

an output of the comparator circuit being positive for a high control signal and negative for a low control signal, and

the comparator circuit having a gain approximately equal to the voltage of a battery connected to the pump control circuit.

57. A pump control circuit for use with a pump, the circuit comprising:

a pressure sensor capable of sensing a pressure in the pump;

a current sensing circuit capable of sensing a current being provided to the pump;

a microcontroller coupled to the pressure sensor and the current sensing circuit,

the microcontroller programmed to determine a current limit threshold based on the sensed pressure, and

the microcontroller programmed to generate a high control signal if the sensed current is less than the current limit threshold and a low control signal if the sensed current is greater than the current limit threshold; and

an output power stage coupled to receive the control signal from the microcontroller so that if the control signal is a low control signal the power provided to the pump is reduced until the sensed current is less than the current limit threshold,

the output power stage including a comparator circuit which determines whether the control signal is a high control signal or a low control signal,

an output of the comparator circuit being positive for a high control signal and negative for a low control signal, and

the output power stage including a switch coupled between the comparator circuit and the pump,

wherein the switch conducts power to the pump if the output of the comparator circuit is positive, and

wherein the switch does not conduct power to the pump if the output of the comparator circuit is negative.

58. The pump control circuit of claim 57, wherein the switch is a metal-oxide semiconductor field-effect transistor.

59. The pump control circuit of claim 57, wherein the switch is capable of operating at a frequency of 1 kHz.

60. The pump control circuit of claim 57, wherein the output power stage includes at least one diode coupled between the transistor and the pump in order to release inductive energy generated by the pump.

61. A method of controlling a pump, the method comprising:

sensing a pressure in the pump;

determining a current limit threshold based on the sensed pressure;

sensing a current being provided to the pump;

comparing the sensed current to the current limit threshold;

providing power to the pump if the sensed current is less than the current limit threshold and reducing the power provided to the pump if the sensed current is greater than the current limit threshold until the sensed current is less than the current limit threshold; and

coupling a standard automotive battery having a voltage of approximately 13.6 volts to the pump.

62. A method of controlling a pump, the method comprising:

sensing a pressure in an outlet chamber in the pump;

determining a current limit threshold based on the sensed pressure;

sensing a current being provided to the pump,

comparing the sensed current to the current limit threshold; and

providing power to the pump if the sensed current is less than the current limit threshold and reducing the power provided to the pump if the sensed current is greater than the current limit threshold until the sensed current is less than the current limit threshold.

63. A method of controlling a pump, the method comprising:

sensing a pressure in the pump;

determining a current limit threshold based on the sensed pressure;

sensing a current being provided to the pump;

comparing the sensed current to the current limit threshold;

providing power to the pump if the sensed current is less than the current limit threshold and reducing the power provided to the pump if the sensed current is greater than the current limit threshold until the sensed current is less than the current limit threshold; and

amplifying and filtering the sensed pressure before comparing the sensed pressure to the shut-off pressure.