US Patent 11162574 Speed reduction mechanism and motor with speed reducer

Provided are a speed reduction mechanism and a motor with a speed reducer, which are highly efficient and compact. The present invention is provided with: an eccentric shaft rotated about a motor axis by the rotational force of a motor section and having an outer peripheral surface having a center at a position eccentric to the motor axis; a rocking gear rotatably supported by the outer peripheral surface through a ball bearing and having inner teeth and outer teeth; a ring gear having inner teeth which mesh with the outer teeth of the rocking gear and which are concentric with the motor axis; and an output section having outer teeth which mesh with the inner teeth of the rocking gear and which are concentric with the motor axis.