Paradox planetary gear reduction gear mechanism, the planetary gear set, and as well as the rotation bearing device

摘要

A gear mechanism having extremely less backlash, capable of suppressing the rattling noise of gears, having a large loading resistance in the thrust direction, and capable of transmitting high torque by using the gears transmitting a force by the meshing of the gears with each other in place of the transmission of the force by friction. The gear mechanism is formed by disposing the plurality of spur gears in the meshed state with each other. The screw-like gears (2) and (4) are disposed on the same axis as the spur gears (1) and (3) in the meshed state with each other. The screw-like gears (2) and (4) adjacent to each other are formed in screw shapes having lead angles extending in the reverse directions to each other and equal in angle to each other. The spur gear (1) and the screw-like gear (2) are rotated integrally with each other to transmit its rotation to the spur gear (3) and the screw-like gear (4) adjacent to each other.