| 摘要 |
PROBLEM TO BE SOLVED: To provide a door opening/closing device that has high output efficiency.SOLUTION: A door opening/closing device comprises: a motor; and an output shaft disposed on the axial extension of the motor, and to which power of the motor is transmitted. The door opening/closing device opens/closes a door via the output shaft by driving the motor. In the door opening/closing device, the position degree of the output shaft on each end face is set to &phgr;0.01 or greater and &phgr;0.1 or less. The speed reduction mechanism includes a planetary gear mechanism having a sun gear disposed on the axial extension of the output shaft. The position degree or concentricity of the axis of the sun gear on at least one end face thereof with respect to the axis of the sun gear on a reference face orthogonal to this axis is set to &phgr;0.01 or greater and &phgr;0.1 or less. |
