#worm_wheel  gear with the thread of a worm
  supertype:  gear_wheel__gear__cogwheel  a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion
  part of:  worm_gear  gear consisting of a shaft with screw thread (the worm) that meshes with a toothed wheel (the worm wheel); changes the direction of the axis of rotary motion

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