A washing machine (laundry machine,clothes washer,or washer) is a machine designed to wash laundry,such as clothing,towels and sheets.The top-loading design or V-axis clothes washer,most popular in Australia,New Zealand,Canada,the United States and Latin America,places the clothes in a vertically-mounted perforated basket that is contained within a water-retaining tub,with a propeller-like agitator in the center of the bottom of the basket.Clothes are loaded through the top of the machine,which is covered with a hinged door.During the wash cycle,the outer tub is filled with water sufficient to suspend the clothing freely in the basket,and the movement of the agitator pulls the clothing downward in the center towards the agitator paddles.The clothing then moves outward and up the sides of the basket to repeat the process.Top-loaders are not well-suited to cleaning large objects such as pillows or sleeping bags due to the tendency for them to just float on the surface of the water without circulating,and the aggressive agitator action can damage delicate fabrics.
In most top-loading washers,if the motor spins in one direction,the gearbox drives the agitator; if the motor spins the other way,the gearbox locks the agitator and spins the basket and agitator together.Similarly if the pump motor rotates one way it recirculates the sudsy water; in the other direction it pumps water from the machine during the spin cycle.Because they usually incorporate a gearbox,clutch,crank,etc.,top-loading washers are mechanically more complex than front loading machines but are generally lower maintenance since there is no need for a door seal .However,the electro-mechanical components in conventional top-load washers have largely reached maturity.
The top-loader's spin cycle between washing and rinsing allows an extremely simple fabric softener dispenser,which operates passively through centrifugal force and gravity.The same objective must be accomplished by a solenoid-operated valve on a front loader.Another advantage to the top loading design is the reliance on gravity to contain the water,rather than potentially trouble-prone or short-lived front door seals.