Pump and pump control circuit apparatus and method

• US 20030099548A1
• Filed: 11/26/2001
• Published: 05/29/2003
• Est. Priority Date: 11/26/2001
• Status: Active Grant

• Current Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Original Assignee: Shurflo LLC (Pentair Plc (Ireland))
• Inventors: Wang, Congxiao Calvin, Meza, Humberto V.
• Granted Patent: US 6,623,245 B2
• Time in Patent Office: Days
• 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 diaphragm comprising:

a body lying substantially in a plane, the body having a first side and a second side opposite the first side; and

a plurality of pistons on the first side of the body, the plurality of pistons having distal ends substantially parallel to the plane of the body;

each one of the plurality of pistons coupled to the body via a convolute, each convolute having a side on the second side of the body lying at an angle with respect to the plane of the body.

2. The diaphragm of claim 1, wherein the plane is a first plane;

each of the plurality of pistons has a top surface lying in a second plane substantially parallel to the first plane;

the side of each convolute lies in a third plane located on the second side of the body and substantially parallel to the first and second planes; and

the third plane is at an angle with respect to the second plane.

3. The diaphragm of claim 1, wherein the convolute has a generally round shape and has an inner perimeter portion and an outer perimeter portion;

the inner perimeter portion located closer to a center of the body than the outer perimeter portion.

4. The diaphragm of claim 3, wherein the convolute is deeper at the outer perimeter portion than the inner perimeter portion so that the side of the convolute lies at an angle sloping away from the center of the body and away from the plane of the body.

5. The diaphragm of claim 3, wherein the convolute is larger at the outer perimeter portion than the inner perimeter portion so that the side of the convolute lies at an angle sloping away from the center of the body and away from the plane of the body

6. The diaphragm of claim 1, wherein the plurality of pistons are positioned with respect to the body portion so that the body portion is generally in the shape of a pentagon.

7. A pump comprising:

a pump housing;

at least two valves within the pump housing

a diaphragm having

a body generally lying in a plane, and

a plurality of pistons, a top surface of each one of the plurality of pistons lying substantially parallel to the plane of the body,

each one of the plurality of pistons coupled to the body via a convolute, a bottom surface of the convolute lying at an angle with respect to the plane of the body portion.

8. The pump of claim 7, wherein the top surface of each one of the plurality of pistons lies in a second plane substantially above the body portion, wherein the bottom surface of the convolute is lying in a third plane substantially below the body portion, and wherein the third plane is at an angle with respect to the second plane.

9. The pump of claim 7, wherein the convolute has an inner perimeter portion and an outer perimeter portion;

the inner perimeter portion is closer to a center point of the body portion than the outer perimeter portion; and

the convolute is deeper at the outer perimeter portion than the inner perimeter portion so that the bottom surface of the convolute lies at an angle sloping away from the center point of the body portion and away from the plane of the body portion toward the rear housing.

10. The pump of claim 7, wherein the convolute is integral with the pistons and with the body.

11. The pump of claim 7, further comprising five chambers within which are located five valves, wherein the plurality of pistons includes five pistons.

12. The pump of claim 11, wherein the plurality of pistons are positioned so that the body portion is generally in the shape of a pentagon.

13. 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.

14. The pump of claim 13, wherein the inlet chamber at least partially surrounds the outlet chamber.

15. The pump of claim 13, 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.

16. The pump of claim 13, wherein the inlet port is positioned tangentially with respect to a side of the outlet chamber.

17. The pump of claim 16, wherein the outlet port and the inlet port lie generally parallel to a side of the outlet chamber.

18. The pump of claim 13, further comprising a pressure sensor positioned within a perimeter of the outlet chamber.

19. The pump of claim 18, wherein the pressure sensor is positioned a distance from a center of the outlet chamber.

20. The pump of claim 18, wherein the pressure sensor is a silicon semiconductor pressure sensor.

21. 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.

22. The pump control circuit of claim 21, wherein the pressure sensor produces a signal representative of changes in the pressure in an outlet chamber in the pump.

23. The pump control circuit of claim 21, wherein the pressure sensor is a silicon semiconductor pressure sensor.

24. The pump control circuit of claim 21, 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.

25. The pump control circuit of claim 21, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

26. The pump control circuit of claim 25, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

27. The pump control circuit of claim 21, 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.

28. The pump control circuit of claim 27, wherein the comparator circuit has a gain approximately equal to the voltage of a battery connected to the pump control circuit.

29. The pump control circuit of claim 27, 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.

30. The pump control circuit of claim 29, wherein the transistor is a metal-oxide semiconductor field-effect transistor.

31. The pump control circuit of claim 29, wherein the transistor is capable of operating at a frequency of 1 kHz.

32. The pump control circuit of claim 29, 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.

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

sensing a pressure in the pump;

generating a pulse-width modulation control signal based on the sensed pressure; and

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

34. The method of claim 33, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

35. The method of claim 33, wherein generating a pulse-width modulation control signal based on the sensed pressure includes generating a pulse-width modulation control signal having a duty cycle, and further comprising reducing the duty cycle in order to reduce the power supplied to the pump and increasing the duty cycle in order to increase the power supplied to the pump.

36. The method of claim 33, and further comprising amplifying and filtering the sensed pressure before generating a pulse-width modulation control signal based on the sensed pressure.

37. 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.

38. The pump control circuit of claim 37, wherein the battery is a standard automotive battery.

39. The pump control circuit of claim 38, wherein the high threshold is approximately 14 volts and the low threshold is approximately 8 volts.

40. The pump control circuit of claim 37, 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.

41. The pump control circuit of claim 37, 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 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.

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

45. The pump control circuit of claim 43, wherein the transistor 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;

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.

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 48, 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.

50. The method of claim 47, 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.

51. 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.

52. The pump control circuit of claim 51, wherein the battery is a standard automotive battery.

53. The pump control circuit of claim 51, 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.

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

55. The pump control circuit of claim 51, wherein the pressure sensor is a silicon semiconductor pressure sensor.

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

57. The pump control circuit of claim 56, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

58. The pump control circuit of claim 51, 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.

59. The pump control circuit of claim 58, wherein the comparator circuit has a gain approximately equal to the voltage of the battery.

60. The pump control circuit of claim 58, 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.

61. The pump control circuit of claim 60, wherein the switch is a metal-oxide semiconductor field-effect transistor.

62. The pump control circuit of claim 60, wherein the switch is capable of operating at a frequency of 1 kHz.

63. The pump control circuit of claim 60, 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.

64. 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.

65. The method of claim 64, 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.

66. The method of claim 64, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

67. The method of claim 64, and further comprising amplifying and filtering the sensed pressure before comparing the sensed pressure to the shut-off pressure.

68. 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.

69. The pump control circuit of claim 68, wherein the pressure sensor is capable of sensing the pressure in an outlet chamber in the pump.

70. The pump control circuit of claim 68, wherein the pressure sensor is a silicon semiconductor pressure sensor.

71. The pump control circuit of claim 68, wherein an amplifier and filter circuit is coupled between the pressure sensor and the microprocessor.

72. The pump control circuit of claim 71, wherein the amplifier and filter circuit includes a potentiometer used to calibrate the pressure sensor.

73. The pump control circuit of claim 68, 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.

74. The pump control circuit of claim 73, wherein the comparator circuit has a gain approximately equal to the voltage of a battery connected to the pump control circuit.

75. The pump control circuit of claim 73, 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.

76. The pump control circuit of claim 75, wherein the switch is a metal-oxide semiconductor field-effect transistor.

77. The pump control circuit of claim 75, wherein the switch is capable of operating at a frequency of 1 kHz.

78. The pump control circuit of claim 75, 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.

79. 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; 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.

80. The method of claim 79, 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.

81. The method of claim 79, wherein sensing a pressure in the pump includes sensing a pressure in an outlet chamber in the pump.

82. The method of claim 79, and further comprising amplifying and filtering the sensed pressure before comparing the sensed pressure to the shut-off pressure.