Fisher & Paykel Limited

John J Williams

Frank W Shacklock

Gerald David Duncan

Dennis E Smith

Graeme D Thomas

John G Borrows

David J Ensor

Keith D Ferguson

Christian John Gianni

Roger A Chalk

A method and apparatus for controlling the speed of a multi-phase, brushless DC electrically commutated motor (ECM). Voltage is commutated to the windings of the ECM based on rotor position information derived from back EMF or Hall effect sensors. The application of the commutating voltages is arranged such that the voltage applied to the windings always leads the back EMF generated in the windings by a selected constant lead angle. The speed of the motor is then controlled by pulse width modulating (PWM) the voltage applied to the windings of the ECM.

Electronically commutated motor control

A method of controlling the commutation of power to an electric motor back EMF sensing or Hall effect sensors is disclosed. At least part of the current waveform is sensed in at least one motor winding and is used to establish information relating to the appropriate commutation pattern required to commutate power to the motor and control motor parameters e.g. motor speed.

Methods of and/or apparatus for electronically commutated motor control

An electric motor (2) for a clothes washing machine including the motor and a drive, the motor having a stator (25) held outboard of a frame carrying bearings (37, 38) in which a shaft (11) rotates, the shaft carrying the rotor (21) outboard of the stator (25), and permanent magnets (17) on an inner face of the rotor. The stator (25) is formed as an annular helical yoke edgewise wound from a strip of magnetic material and having an inner face and an outer face, the strip having pole pieces (8) formed integrally therewith extending from one edge of the strip and the strip being edgewise wound whereby the pole pieces coincide in stacked groups to form a plurality of poles arranged at equally spaced intervals extending radially outwardly from the outer face of the yoke. Energizable stator windings (26) are wound directly on the poles (8) of the stator and are adapted to be energized through an electronic commutation circuit (65,66) and the rotor (21) is mounted for rotation exteriorly of and relative to the stator, the rotor comprising a backing ring (16) of magnetic material and a series of permanent magnets (17) held at spaced-apart intervals on an inner surface of the backing ring (16) and opposing the poles (8) of the stator (25).

Electric motor for clothes washing machine drive

A method of providing a desired water level in a laundry machine by energising the motor of the machine intermittently to produce changes in velocity of the spin tub, agitator and a load of clothes in the spin tub. The changes in velocity are measured and from the measurements the mass of the load of clothes is determined. A desired volume of water necessary for an optimum wash of the load of clothes is then determined and this volume of water is admitted to the washing container of the laundry machine.

Laundry machines and/or methods of controlling the same

A method, control device and appartaus for providing a desired water level in a laundry machine (1) by energizing the motor (10) of the machine intermittently to produce changes in velocity of the spin tub (3), agitator (4) and a load of clothes in the spin tub. The changes in velocity are measured and from the measurements the mass of the load of clothes is determined. A desired volume of water necessary for an optimum wash of the load of clothes is then determined and this volume of water is admitted (17) to the washing container (2) of the laundry machine.

Laudry machines and/or methods of controlling the same

A close washing machine includes a cabinet (2), a stationary water container (3) mounted in the cabinet and having a base and a side wall, downwardly extending ribs (4a, 5) on the base, a bearing tube (6) on the base supported by the ribs, vertically spaced bearings (20, 21) mounted on the bearing tube and having a vertical shaft (13) rotatably mounted therein, a seal between the shaft and bearing tube mounted above the bearing, an agitator (7) mounted on the shaft for rotation therewith, a perforated spin tub (4) within the container supported by bearings mounted on the shaft for rotatably supporting the spin tub, an electric motor type drive system having a stator (31) and a rotor and driving the vertical shaft (13) to rotatably oscillate the agitator or rotate the spin tub and agitator together in one direction. The stator is fixed to the container (3) and the rotor is fixed to the shaft (13) so that the bearings (20, 21) provide relative rotation of the stator and rotor. An interconnecting device between the spin tub and agitator is adapted to be operated to interconnect the spin tub and agitator for rotation together in one direction by the shaft to produce a spin action and to disconnect the spin tub from the agitator so that only the agitator is rotatable in an oscillating manner by rotary oscillation of the rotor to produce a washing action.

Laundry machine

A method of manufacturing an electric motor stator (31) and rotor (43) including holding magnetic elements (29, 32, 53) thereof in position in dies and injecting a plastics material into the dies to provide bearing carrier mountings in the stator substantially concentric with pole faces (33) of the stator and poles of the rotor, providing a bearing (21) in the stator bearing carrier (27), mounting a shaft (13) in the bearing (21), with the shaft running in a further bearing mounting tube (6), and mounting the hub (51) of the rotor onto the shaft (13) so that operation of the motor drives the shaft. The motor and drive so made is mounted to drive an agitation and spin tub of a laundry machine.

Method of manufacturing a motor element of an electric motor

An electric motor, a drive and a clothes washing machine including the motor and drive, the motor having a stator held outboard of a frame carrying bearings in which a shaft rotates, the shaft carrying the rotor outboard of the stator, the rotor having permanent magnets on an inner face thereof. The shaft carries an agitator and a spin tub of the clothes washing machine, and interconnecting members between a part rotatable with the agitator and a part rotatable with the spin tub are movable axially on the shaft relative to each other by a buoyancy system which is operated by the absence or presence of water in a container of the clothes washing machine to connect the spin tub and the agitator, to be driven by the shaft continuously in one direction for spinning clothes when water is at a low level in or absent from the container, and to disconnect the spin tub from the shaft, leaving the agitator still connected to the shaft when sufficient water is in the container so that rotation of the shaft backwards and forwards by the motor washes clothes in the spin tub by backwards and forwards movement of the agitator.

Intermediate bearing drives for clothes washing machines

An electric motor, a drive and a clothes washing machine including the motor and drive are described, the motor having a stator held outboard of a frame carrying bearings in which a shaft rotates, the shaft carrying the rotor outboard of the stator, the rotor having permanent magnets on an inner face thereof. The shaft carries an agitator and a spin tub of the clothes washing machine and interconnecting members between a part rotatable with the agitator and a part rotatable with the spin tub are movable axially on the shaft relative to each other by a buoyancy system which is operated by the absence or presence of water in a container of the clothes washing machine to connect the spin tub and the agitator to be driven by the shaft continuously in one direction for spinning clothes when water is at a low level in or absent from the container and to disconnect the spin tub from the shaft, leaving the agitator still connected to the shaft when sufficient water is in the container so that rotation of the shaft backwards and forwards by the motor washes clothes in the spin tub by backwards and forwards movement of the agitator.

Growing community of inventors

Auckland, New Zealand

John J Williams