Instrumental unit

摘要

An instrumental unit includes: a step motor; a gear including: a gear body rotated by torque of the step motor, the gear body including a first surface formed with a recess and a second surface opposite to the first surface; and a rotary shaft projecting from the first and second surfaces; a controlling spring accommodated in the recess, a center of the controlling spring through which the rotary shaft projects, the controlling spring having lengths in long and short axis directions orthogonal to each other and having a line-symmetric shape with respect to each of the long and short axis directions; and a case accommodating the step motor, the gear body and the controlling spring, an inner surface of the case including: a first portion supporting the second surface; and a second portion pressing the controlling spring in the recess of the first surface.

主权项

1. An instrumental unit comprising:
a step motor; a gear including: a gear body configured to be rotated by torque of the step motor, the gear body including a first surface formed with a recess and a second surface opposite to the first surface; and a rotary shaft projecting from the first and second surfaces of the gear body; a controlling spring accommodated in the recess of the first surface of the gear body, having a center through which the rotary shaft projects, the controlling spring having lengths in a long axis direction and in a short axis direction which are orthogonal to each other and having a line-symmetric shape with respect to each of the long and short axis directions; and a case accommodating the step motor, the gear body and the controlling spring, an inner surface of the case including: a first portion supporting the second surface of the gear body; and a second portion configured to press the controlling spring in the recess of the first surface of the gear body.