| 摘要 |
<p>A speed variator for a laundry washing machine comprising a drum (6) mounted for rotation in a laundering tub (5) and adapted to be rotated at different speeds by a motor (7) via a transmission belt (8) interconnecting a driving pulley (9) of motor (7) and a driven pulley (10) associated with the drum. The driving pulley (9) of the speed variator is of the variable-diameter type and cooperates with a number of radially expandable flyweights (14)> The driving pulley (9) and the motor (7) are carried by a rotatable carrier arm (19) having one of its ends hingedly connected to a lower portion of the tub (5), while its other end is connected to a piston (29) mounted for reciprocating displacement to different operating positions in a cylinder (39) connected through a solenoid valve (31) to the water supply circuit of the machine. The carrier arm (19) is biased by a torsion spring (25) to a position in which the driving pulley (9) is effective to keep the belt (8) under tension against the action caused by the radial expansion of the flyweights (14). The piston (29) acts on the carrier arm (19) in a manner to interdict or to permit the radial expansion of the flyweights (14) to varying degrees depending on the respective position of the piston. As a result, the effective diameter of the driving pulley (9) is varied by different degrees, permitting the drum (6) to be rotated at variable speeds.</p> |
