摘要 |
The invention relates to machines such as compressors or pumps of the kind including an hourglass worm meshing with a toothed pinion. It is known to make the pinion of metal coated with a resilient material such as plastic rigidity fixed to the surface of the metallic pinion. According to the invention the metal pinion is covered with a plastic lining having teeth which engage the threads of the worm and prevent the metal teeth of the pinion from engaging those threads. The plastic lining is permitted a slight shifting about its average position respectively to the metal pinion. |