A rotating device includes a cylinder body, a front end cover, a rear end cover, a main shaft, an eccentric rotor assembly and an isolation mechanism. The eccentric rotor assembly includes an eccentric shaft, a rolling piston wheel and at least one rolling bearing. In the rotating device, the eccentric shaft is isolated from the rolling piston wheel by the rolling bearing and the two are rotated, and the cylinder body is reliably sealed by an elastic pre-tightening force. Further provided are a rotor compressor using the rotating device, and a fluid motor. A rotating valve body and a rotating valve body reset mechanism in the rotating device are also improved.