| 摘要 |
<p>A speed variator for a laundry washing machine comprising a drum (6) mounted 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 the motor and a driven pulley (10) associated with the drum. The speed variator includes the driving pulley (9) which is provided with flyweights (16) housed in a cavity (15) of the pulley and radially expandable for varying the effective diameter of the pulley and thus the transmission ratio. The speed variator additionally includes a hydraulic piston (17) guided in a cylinder (18) connected to the water supply circuit of the machine via a solenoid valve (19) displacement between different operating positions, said piston cooperating with the flyweights for interdicting or permitting the radial expansion thereof to varying degrees. The internal cavity (15) of the driving pulley (9) is defined by planar or arcuate surface portions (25-29 and 31-35, respectively) interconnected by inclined ramps or arcuate transitions of different radius of curvature, respectively, permitting the flyweights (16) to radially expand to and be retained in different positions depending on the rotational speed of the driving pulley and the operating position assumed by the piston (17).</p> |
