Switched reluctance wash

Washing machines have been around for a long time, but there is room for technical advances in even the most familiar household equipment. A top-loading washing machine with a 9.5-kilogram capacity, that is efficient and quiet and operates with minimal vibration, will enter Australian stores after a long-running R&D venture between CSIRO and Electrolux.

The new machine will have one of the largest capacities, by a kilogram or more, of any domestic top-loading washing machine, but it is the inner technical developments that make the machine a step-change in washing machine technology.

The collaboration between Electrolux and CSIRO Industrial Physics at Lindfield, Sydney, has produced a washing machine with few moving parts and no gearbox – the Achilles heel of many conventional top-loading washing machines.

CSIRO team leader, physicist Dr. Stephen Collocott, says the new Westinghouse top-loader, being built by Electrolux, employs an electric motor very different to those commonly used in washing machines.

The heart of the new washer is a direct-drive, switched-reluctance motor with an advanced electronic control system. The switched-reluctance motor is considered ideal on several counts: it is compact yet powerful and produces maximum torque (twisting force) at low speed, so no gearbox is required. It also operates well at high speeds for the spin cycle.

The CSIRO-developed electronic control system for the switched-reluctance motor allows the speed, direction and position of the rotor to be precisely controlled to agitate the wash. The symmetry of the switched-reluctance motor direct-drive system produces a quiet, low-vibration washing machine.

Wayne Burford, product engineering manager at Electrolux, says CSIRO specialists had the motor and control technology know-how and Electrolux engineers had the skills to apply it to a washing machine and deliver consumer benefits. He says the final product makes optimum use of integrated sensing systems to manage water use and temperature (for improved efficiencies), to match motor output to the wash load, and conduct self-diagnosis if something requires user intervention.

Dr. Collocott says prototypes have been under intensive testing for some time, cycling through heavy wash, rinse and spin cycles, and have proved to be exceptionally reliable.