WASHING MACHINES

• US 20070113595A1
• Filed: 11/06/2006
• Published: 05/24/2007
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Fisher & Paykel Appliances Limited (Fisher & Paykel Appliances Holdings Limited)
• Original Assignee: Fisher & Paykel Appliances Limited (Fisher & Paykel Appliances Holdings Limited)
• Inventors: SARGEANT, ADRIAN, HARWOOD, JONATHAN, JOHNSON, HUGH, HILL, GREGORY, DUNCAN, ANNA, LEE, GEOFFREY
• Granted Patent: US 7,810,362 B2
• Time in Patent Office: Days
• US Class Current: 68/12.10
• CPC Class Codes: D06F 2103/14 Supply, recirculation or draining of washing liquid
• CPC Class Codes: D06F 2103/18 Washing liquid level
• CPC Class Codes: D06F 2103/48 of the motor driving the pump
• CPC Class Codes: D06F 2105/08 Draining of washing liquids
• CPC Class Codes: D06F 2105/46 Drum speed; Actuation of motors, e.g. starting or interrupting
• CPC Class Codes: D06F 33/42 of draining
• CPC Class Codes: D06F 39/082 detecting faulty draining operations, e.g. filter blockage, faulty pump
• CPC Class Codes: D06F 39/085 Arrangements or adaptations of pumps
• CPC Class Codes: D06F 39/087 Water level measuring or regulating devices
• CPC Class Codes: F04D 13/06 the pump being electrically driven
• CPC Class Codes: F04D 15/0066 by changing the speed, e.g. of the driving engine
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y10T 137/794 With means for separating solid material from the fluid

Abstract

The present invention relates to a washing machine (7) and pump (8) for a washing machine (7). The pump is driven by a brushless DC motor (38). The pump can be controlled to improve the operation of the washing machine. In one aspect the invention comprises a washing machine (7) with a variable speed pump (8) for pumping out wastewater, a controller (50) for controlling the speed of the pump and a sensor (10) for determining the flow-rate of water being pumped from the washing machine, wherein the controller (50) controls the speed of the pump to maintain the flow-rate at a desirable level.

Claims

1. A washing machine adapted to drain water at a preferred flow-rate comprising:

a bowl adapted to hold water,

a variable speed pump adapted to drain water from the bowl,

a sensor adapted to sense one or more parameters that can be utilised to determine the drain flow-rate of water from the bowl,

a controller adapted determine the drain flow rate using the one or more sensed parameters and adapted to control the speed of the pump, and

a store adapted to store data defining a preferred drain flow-rate,

wherein the controller is adapted to control the speed of the pump to drain water at a preferred flow-rate as defined by data in the store.

2. A washing machine according to claim 1 wherein the data defining a preferred drain flow-rate defines one or more preferred flow-rates.

3. A washing machine according to claim 2 wherein the data defines a range of preferred flow-rates.

4. A washing machine according to claim 3 wherein the data defines a range of preferred flow-rates of 15 to 25 litres per minute.

5. A washing machine according to claim 1 wherein the sensor is a pressure sensor that can sense the water pressure at multiple instants in the bowl and wherein the water pressure at an instant indicates the water level in the bowl and wherein the controller is adapted to calculate the drain flow-rate of water from the bowl from the change in water level in the bowl.

6. A washing machine according to claim 1 wherein the sensor senses current drawn by the pump at multiple instants and wherein the controller is adapted to calculate the drain flow-rate of water from the bowl from the change in current drawn by the pump.

7. A washing machine according to claim 5 wherein the controller is adapted to control the speed of the pump by:

calculating the drain flow-rate of water from the bowl,

comparing the calculated drain flow-rate with a preferred drain flow-rate defined by data stored in the store,

increasing the pump speed if the drain flow-rate is less than a preferred drain flow-rate, and

decreasing the pump speed if the drain flow-rate is more than a preferred drain flow-rate.

8. A washing machine according to claim 6 further comprising a store adapted to store data defining the speed of the pump, wherein the controller is adapted to alter the data to define a new speed when the speed of the pump is increased or decreased.

13. A method according to claim 1 wherein the one or more parameters are sensed at multiple instants in the bowl using a water pressure sensor.

14. A method according to claim 1 wherein the one or more parameters indicate current drawn by the pump at multiple instants.

9. A method of controlling a washing machine comprising a bowl and a variable speed pump for draining water from the bowl, the method comprising:

sensing one or more parameters that can be utilised to determine the drain flow-rate of water from the bowl

calculating the drain flow-rate of water from the bowl using the one or more sensed parameters,

comparing the calculated drain flow-rate with a preferred drain flow-rate defined by stored data,

increasing the pump speed using a controller if the drain flow-rate is less than a preferred drain flow-rate, and

decreasing the pump speed using a controller if the drain flow-rate is more than a preferred drain flow-rate.

10. A method according to claim 9 wherein the data defining a preferred drain flow-rate defines one or more preferred flow-rates.

11. A method according to claim 10 wherein the data defines a range of preferred flow-rates.

12. A method according to claim 11 wherein the data defines a range of preferred flow-rates of 15 to 25 litres per minute.

15. A washing machine comprising a bowl for holding water

a bowl adapted to hold water,

a spin basket nested within the bowl such that a space is defined between an outer water of the spin basket and an inner wall of the bowl,

a variable speed pump adapted to pump water into the bowl and/or spin basket,

a controller adapted to control the speed of the pump, and

wherein the controller is adapted to increase the speed of the pump to pump water into the spin basket, and the controller is adapted to decrease the speed of the pump to pump water on to the outer wall of the spin basket to remove debris.

16. A washing machine according to claim 15 wherein the controller is adapted to increase the speed of the pump to a first speed to pump water into the spin basket, and the controller is adapted to decrease the speed of the pump to a second speed to pump water on to the outer wall of the spin basket to remove debris.

17. A washing machine according to claim 16 wherein the first speed is 2000 rpm and the second speed is 1000 rpm or 600 rpm

18. A method for removing debris from a spin basket of a washing machine, the spin basket being nested in a bowl, the method comprising:

operating a pump to pump water into the spin basket by increasing the speed of the pump, and

operating the pump to pump water onto an outer wall of the spin basket to remove debris by decreasing the speed of the pump.

19. A method according to claim 18 wherein to pump water into the spin basket the pump is operated at a first speed, and to pump water on to the outer wall of the spin basket to remove debris the pump is operated a second speed.

20. A method according to claim 19 wherein the first speed is 2000 rpm and the second speed is 1000 rpm or 600 rpm

21. A washing machine comprising:

a bowl adapted to hold water,

an inlet with a valve adapted for connection to a water supply, the inlet and valve allowing controlled introduction of water into the bowl when the inlet is connected to a water supply,

a variable speed pump adapted to recirculate water within the bowl,

a sensor adapted to measure one or more parameters indicative of current drawn by the pump during operation,

a controller adapted to control the speed of the pump and to control introduction of water into the bowl by controlling the valve, and

wherein the controller is adapted to;

receive input from the sensor and determine pump current from the one or more parameters indicative of current,

detect ventilation if the pump current is less than a threshold, and

reduce the speed of or stop the pump and/or introduce water into the bowl if ventilation is detected in order to reduce the effects of ventilation.

22. A washing machine according to claim 21 wherein the threshold is a 20% reduction in pump current from a reference value.

23. A washing machine according to claim 21 further comprising a ventilation timer and a pump timer, wherein if the controller detects ventilation, the controller is adapted to:

stop the pump,

increase the ventilation timer,

determine a measure of a pump timer value with respect to a ventilation timer value, and

operate the valve to introduce water into the bowl based on a first relationship of the measure to a first threshold.

24. A washing machine according to claim 23 wherein the controller is further adapted to:

start the pump upon operating the valve to introduce water into the bowl

increase the pump timer,

determine a measure of the pump timer value with respect to the ventilation timer value, and

operate the valve to prevent introduction water into the bowl based on a second relationship of the measure to a second threshold.

25. A washing machine according to claim 24 wherein the measure is the ratio of the pump timer value to the ventilation timer value, and the first relationship is the ratio of the pump timer value to ventilation timer value exceeding the first threshold.

26. A washing machine according to claim 24 wherein second relationship is the ratio of the pump timer value to ventilation timer value exceeding the second threshold.

27. A washing machine according to claim 23 wherein the ventilation timer and pump timer are implemented in the controller.

28. A method of alleviating the effects of ventilation in a washing machine comprising a bowl adapted to hold water and a variable speed pump adapted to recirculate water within the bowl, the method comprising:

sensing one or more parameters indicative of current drawn by the pump during operation,

determining pump current from the one or more parameters indicative of current,

detecting ventilation if the pump current is less than a threshold, and

reducing the speed of or stopping the pump and/or introducing water into the bowl if ventilation is detected in order to reduce the effects of ventilation.

29. A method according to claim 28 wherein the threshold is a 20% reduction in pump current from a reference value.

30. A method according to claim 29 further comprising:

increase a ventilation timer upon stopping the pump,

determining a measure of a pump timer value with respect to a ventilation timer value, and

operating a valve in an inlet coupled to a water supply to introduce water into the bowl based on a first relationship of the measure to a first threshold.

31. A method according to claim 30 further comprising:

starting the pump upon operating the valve to introduce water into the bowl,

increasing the pump timer,

determining a measure of the pump timer value with respect to the ventilation timer value, and

operating the valve to prevent introduction water into the bowl based on a second relationship of the measure to a second threshold.

32. A method according to claim 31 wherein the measure is the ratio of the pump timer value to the ventilation timer value, and the first relationship is the ratio of the pump timer value to ventilation timer value exceeding the first threshold.

33. A method according to claim 32 wherein second relationship is the ratio of the pump timer value to ventilation timer value exceeding the second threshold.

34. A washing machine comprising:

a pump operated by a motor, the pump adapted to pump water within the washing machine,

a sensor adapted to sense one or more parameters of the motor that can be utilised to determine the motor speed, and

a controller coupled to the sensor and the motor, the controller adapted to;

determine the motor speed using the one or more sensed parameters,

detect a blockage in the pump when the motor speed falls below a threshold speed, and

control the motor to dislodge the blockage when a blockage is detected.

35. A washing machine according to claim 34 wherein the threshold speed is zero.

36. A washing machine according to claim 34 wherein the motor is a stepper motor.

37. A washing machine according to claim 36 wherein the controller is adapted to control the motor to dislodge the blockage by stopping the motor and then restarting the motor by applying a first excitation.

38. A washing machine according to claim 37 wherein the controller is further adapted to:

re-determine the motor speed using the one or more sensed parameters,

re-detect a blockage in the pump if the motor speed falls below a threshold speed, and

control the motor to dislodge the blockage by stopping the motor a second time and restarting the motor by applying a second excitation that promotes a higher average current to provide a higher torque than the first excitation.

39. A washing machine according to claim 38 wherein the controller is further adapted to:

re-determine the motor speed using the one or more sensed parameters,

re-detect a blockage in the pump if the motor speed falls below a threshold speed, and

control the motor to dislodge the blockage if a blockage is re-detected by stopping the motor a third time and stepping the motor backwards.

40. A washing machine according to claim 39 wherein the controller is further adapted to control the motor to dislodge the blockage by restarting the motor.

41. A washing machine according to claim 40 wherein the controller is further adapted to:

re-determine the motor speed using the one or more sensed parameters,

re-detect a blockage in the pump if the motor speed falls below a threshold speed, and

control the motor to dislodge the blockage if a blockage is re-detected by stopping the motor a fourth time and restarting the motor.

42. A washing machine according to claim 34 wherein the sensor is a back emf sensor from which motor commutation rate is inferred, wherein the motor commutation rate indicates motor speed, and wherein the controller detects a blockage in the pump when the motor speed falls below a threshold speed by detecting when the motor commutation rate falls below exceeds a threshold rate.

43. A method for dislodging a blockage in a water pump in a washing machine, the water pump being operated by a motor, the method comprising:

sensing one or more parameters of the motor that can be utilised to determine the motor speed,

determining the motor speed using the one or more sensed parameters,

detecting a blockage in the pump when the motor speed falls below a threshold speed, and

controlling the motor to dislodge the blockage if a blockage is detected.

44. A method according to claim 43 wherein the threshold speed is zero.

45. A method according to claim 43 wherein the motor is a stepper motor.

46. A method according to claim 45 wherein controlling the motor to dislodge the blockage comprises stopping the motor and then restarting the motor by applying a first excitation.

47. A method according to claim 46 further comprising:

re-determining the motor speed using the one or more sensed parameters,

re-detecting a blockage in the pump if the motor speed falls below a threshold speed, and

controlling the motor to dislodge the blockage if a blockage is re-detected by stopping the motor a second time and restarting the motor by applying a second excitation that promotes a higher average current to provide a higher torque than the first excitation.

48. A method according to claim 47 further comprising:

re-determining the motor speed using the one or more sensed parameters,

re-detecting a blockage in the pump if the motor speed falls below a threshold speed, and

controlling the motor to dislodge the blockage if a blockage is re-detected by stopping the motor a third time and stepping the motor backwards.

49. A method according to claim 48 further comprising controlling the motor to dislodge the blockage by restarting the motor.

50. A method according to claim 49 further comprising:

re-determining the motor speed using the one or more sensed parameters,

re-detecting a blockage in the pump if the motor speed falls below a threshold speed, and

controlling the motor to dislodge the blockage if a blockage is re-detected by stopping the motor a fourth time and restarting the motor.

51. A method according to claim 43 wherein the one or more sensed parameters are motor back emf wherein the motor back emf indicates motor commutation rate which motor speed, and wherein a blockage is detected in the pump when the motor speed falls below a threshold speed by detecting when the motor commutation rate fall below a threshold rate.

52. A washing machine comprising a pump operated by a motor, a controller for controlling rotation of the pump, and a speed sensor for sensing speed of the pump rotor, wherein zero speed indicates a blockage in the impeller, wherein upon detecting zero speed the controller can control the motor of the pump to step the motor in reverse to dislodge the blockage.

53. A method of controlling a washing machine with a pump operated by a motor, the method comprising sensing the speed of the pump rotor, wherein upon detecting zero speed indicates a blockage, the method further comprising controlling the motor of the pump to step the motor in reverse to dislodge the blockage.

54. A washing machine with a bowl adapted to hold water in an interior portion, the washing machine comprising:

a pump coupled to the bowl and adapted to pump water from the bowl, the pump comprising;

a housing coupled to or integrated with the bowl

an outlet in the housing coupled to a recirculation conduit for recirculation of water to the bowl interior,

a pump actuator disposed in the housing for transferring water to the outlet and recirculation conduit, and

a conduit to provide fluid communication between the exterior of the housing and the outlet to substantially equalise water pressure such that water in the recirculation conduit does not rise above the water level in the washing machine bowl.

55. A washing machine according to claim 54 wherein the pump actuator is an impeller and the pump further comprises a motor arranged to rotate the impeller.

56. A washing machine according to claim 54 wherein the outlet protrudes from the housing and has an outer wall defining an interior portion in fluid communication with the housing, wherein the outlet comprises an aperture in the outer wall and further comprising housing cover on which the conduit is disposed wherein the housing and the housing cover are arranged such that the conduit is aligned to provide fluid communication between the interior of the bowl and the interior portion of the outlet.

57. A washing machine pump for installation in a washing machine with a bowl adapted to hold water in an interior portion, the pump being adapted to be coupled to the bowl and to pump water from the bowl, the pump comprising:

a housing for coupling to the bowl,

an outlet in the housing adapted to be coupled to a recirculation conduit of a washing machine for recirculation of water to the bowl interior,

a pump actuator disposed in the housing for transferring water to the outlet and recirculation conduit, and

a conduit to provide fluid communication between the exterior and the outlet interior to substantially equalise pressure in the outlet with ambient pressure.

58. A washing machine pump according to claim 57 wherein the pump actuator is an impeller and the pump further comprises a motor arrange to rotate the impeller.

59. A washing machine according to claim 58 wherein the outlet protrudes from the housing and has an outer wall defining an interior portion in fluid communication with the housing interior, wherein the outlet comprises an aperture in the outer wall and further comprising a housing cover on which the conduit is disposed wherein the housing and the housing cover are arranged such that the conduit is aligned to provide fluid communication between ambient pressure and the interior portion of the outlet.

60. A washing machine pump comprising a housing with a recirculation outlet and a housing cover adapted for coupling to a washing machine bowl, the housing cover comprising a conduit for providing fluid communication between the housing and a washing machine bowl on which the pump is installed to equalise water pressure an interior portion of the bowl and an interior of the housing.

61. A washing machine pump comprising a housing adapted to be installed on the exterior of a washing machine bowl, the housing having a recirculation and a drain outlet, a valve disposed in the housing to alternately abut against and close the drain and recirculation outlets, and a housing cover adapted to be installed in a washing machine bowl, the housing cover comprising a conduit providing fluid communication between the housing and a washing machine bowl on which the pump is installed to reduce unseating forces of the valve when abutted against the recirculation or drain outlets.

62. A washing machine pump comprising:

a housing for coupling to the bowl of a washing machine, the housing comprising a interior for an impeller,

an impeller rotatably disposed in the interior, and

one or more outlets in the housing,

wherein the impeller comprises a first set of impeller blades positioned on a first surface that are adapted to transfer water through the outlets upon rotation of the impeller, and the impeller comprises a second set of impeller blades positioned on a second surface, the second set of impeller blades being adapted to create a vortex in the housing to emit debris from the impeller that is on or adjacent the second surface.

63. A washing machine pump according to claim 62 wherein first surface is a top surface of the impeller and the second surface is a bottom surface of the impeller and wherein the recess comprising a bearing and wherein the impeller rotates on a bearing adjacent the bottom surface.

64. A washing machine pump according to claim 63 wherein the impeller is second set of impeller blades comprises one or more elongated protrusions extending radially on the bottom surface.

65. A washing machine pump for a washing machine, the pump comprising a rotatable impeller with vanes on the upper surface to pump water, and vanes on the underside that, during operation, produce a centrifugal action that emits foreign objects from the impeller assembly.

66. A washing machine pump for installation in a washing machine with a bowl adapted to hold water in an interior portion, the pump being adapted to be coupled to the bowl and to pump water from the bowl, the pump comprising:

a housing for coupling to the bowl such and a housing cover with an aperture, the housing and housing cover arranged to define a housing interior that is in fluid communication with the bowl interior via the aperture, and

a filter for filtering water entering the housing interior via the aperture,

wherein the filter comprises a profiled wall extending from the housing cover and encircling the aperture to define a volute around the aperture, and

and wherein the filter comprises a hood disposed above the wall, the hood having a perimeter, said perimeter have a profile substantially corresponding with that of the profiled wall to allow for a profiled space between the perimeter and the profiled wall,

wherein the profiled space allows water to enter the volute but substantially prevents elongated objects entering the volute.

67. A washing machine pump according to claim 66 wherein the profiled wall is shaped to provide an exterior shape is substantially non-planar in shape.

68. A washing machine pump according to claim 66 wherein the profiled wall is shaped to provide angular portions in the exterior shape.

69. A washing machine pump according to claim 66 wherein the profiled wall is shaped to provide curved portions in the exterior shape.

70. A washing machine with a bowl adapted to hold water in an interior portion, the washing machine comprising:

a pump coupled to the bowl and adapted to pump water from the bowl, the pump comprising;

a housing coupled the bowl and a housing cover with an aperture, the housing and housing cover arranged to define a housing interior that is in fluid communication with the bowl interior via the aperture, and

a filter for filtering water entering the housing interior via the aperture,

wherein the filter comprises a profiled wall extending from the housing cover and encircling the aperture to define a volute around the aperture, and

and wherein the filter comprises a hood disposed above the wall, the hood having a perimeter, said perimeter have a profile substantially corresponding with that of the profiled wall to allow for a profiled space between the perimeter and the profiled wall,

wherein the profiled space allows water from the bowl to enter the volute but substantially prevents elongated objects from the bowl entering the volute.

71. A washing machine according to claim 70 wherein the profiled wall is shaped to provide an exterior shape is substantially non-planar in shape.

72. A washing machine according to claim 70 wherein the profiled wall is shaped to provide angular portions in the exterior shape.

73. A washing machine according to claim 70 wherein the profiled wall is shaped to provide curved portions in the exterior shape.

74. A pump for a washing machine comprising an inlet filter for filtering water entering the pump, the filter formed from a profiled wall forming a volute around the inlet to the pump, and a hood disposed above the wall, the hood having a lip around the perimeter, said perimeter have a profile commensurate with that of the wall, but allowing for a shaped space between the inside of the lip and the profiled wall, such that water can enter the volute, but the shaped space preventing elongated objects entering the volute.

75. A washing machine pump for installation in a washing machine with a bowl adapted to hold water in an interior portion, the pump being adapted to be coupled to the bowl and to pump water from the bowl, the pump comprising:

a housing for coupling to the bowl, the housing having an interior,

an impeller disposed in the interior,

a motor for driving the impeller,

a housing cover comprising a first aperture for fluid communication to the housing interior and comprising a wall extending from the housing cover and encircling the first aperture to define a volute around the first aperture, and

a hood disposed above the wall, the hood comprising a second aperture for venting air bubbles.

76. A washing machine pump according to claim 75 further comprising a bulb in the hood for accommodating air bubbles, wherein the second aperture is in the bulb.

77. A washing machine pump according to claim 76 wherein the bulb is adapted to accommodate lint.

78. A washing machine pump according to claim 76 wherein the bulb tapers from above the first aperture to a second portion adjacent a conduit to provide for increase water flow and lower pressure above the conduit, wherein the conduit is in fluid communication with a drain of the housing.

79. A washing machine with a bowl adapted to hold water in an interior portion, the washing machine comprising:

a housing for coupling to the bowl, the housing having an interior,

an impeller disposed in the interior,

a motor for driving the impeller,

a housing cover comprising a first aperture for fluid communication between the bowl interior and the housing interior and comprising a wall extending from the housing cover and encircling the first aperture to define a volute around the first aperture, and

a hood disposed above the wall, the hood comprising a second aperture for venting air bubbles into the bowl interior.

80. A washing machine according to claim 79 further comprising a bulb in the hood for accommodating air bubbles, wherein the second aperture is in the bulb.

81. A washing machine according to claim 80 wherein the bulb is adapted to accommodate lint.

82. A washing machine according to claim 80 wherein the bulb tapers from above the first aperture to a second portion adjacent a conduit to provide for increase water flow and lower pressure above the conduit, wherein the conduit is in fluid communication with a drain of the housing.

83. A washing machine with a variable speed pump for pumping out wastewater, a controller for controlling the speed of the pump and a sensor for determining the flow-rate of water being pumped from the washing machine, wherein the controller controls the speed of the pump to maintain the flow-rate at a desirable level.

84. A method of controlling a washing machine with a variable speed pump for pumping out wastewater, the method comprising determining the flow-rate of water being pumped from the washing machine, and controlling the speed of the pump to maintain the flow-rate at a desirable level.

85. A washing machine with a variable speed pump and a pump controller, wherein the spray pattern for recirculation of water in the washing machine can be altered by varying the pump speed using the controller.

86. A method of controlling a washing machine with a variable speed pump and a pump controller, the method comprising varying the pump speed using a controller to alter the spray pattern during recirculation of water.

87. A washing machine with a variable speed pump for recirculating water within a washing machine bowl, a controller for controlling the speed of the pump and introduction of water into the washing machine bowl, and a sensor for determining the current in the pump stator, wherein the controller controls the washing machine to introduce further water into the washing machine bowl when the current level is below a threshold indicating that the pump is ventilating.

88. A method of controlling a washing machine with a variable speed pump for recirculating water within a washing machine bowl, the method comprising determining the current in the pump stator, and controlling the washing machine to introduce further water into the washing machine bowl when the current level is below a threshold indicating that the pump is ventilating.