Patent ID: 8536480

Claim:
An encoder dampening mechanism for an electric spot welding gun equipped with a servo motor that is accommodated inside of a motor housing and causes a rotor to rotate, and an encoder that detects a rotation angle of the rotor, the mechanism comprising: a thin plate that is formed with a top surface that is larger in a surface area than a base surface of the encoder, and on which the base surface of the encoder is installed within the top surface of the thin plate; and a thin plate mounting portion that connects the thin plate to the motor housing via a cushioning material that dampens vibration, the encoder includes a flange that encloses the main body of the encoder and fixes to the flange installation part of the thin plate, the surface of the thin plate includes the flange installation part and an encoder main body installation part that installs the base surface of the encoder, the thin plate mounting portion that includes the cushioning material is disposed on an outer side of the flange installation part and the encoder main body installation part on the surface of the thin plate, and the surface area on the inner side from the thin plate mounting portion on the surface of the thin plate is larger than the base surface of the encoder.