Patent ID: 7374407

Claim:
A power transmission mechanism for transmitting driving power between a shaft and a rotor connected to the shaft, comprising: a cylindrical adapter located between a shaft and a rotor, the adapter having a first internally threaded portion in its inner peripheral surface and a first externally threaded portion in its outer peripheral surface, the first internally threaded portion being engaged with a second externally threaded portion of the shaft, the first externally threaded portion being engaged with a second internally threaded portion of the rotor; a screw seat arranged on the shaft, the screw seat having a screw seat surface; and wherein the adapter is screwed onto the shaft such that the adapter is pressed against the screw seat surface, and wherein the rotor is screwed onto the adapter such that the rotor is pressed against the screw seat surface, wherein the shaft is a drive shaft of a fluid machine, the fluid machine having a shaft seal device arranged between the drive shaft and a housing of said fluid machine, the shaft seal device sealing off from the outside of the housing, wherein the rotor for transmitting the driving power to the drive shaft is fastened to the drive shaft on the outside of the housing.