US Patent 7810362 Recirculation control in a washing machine

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.