Rotary encoder

#This application is based on and claims the benefit of priority from Japanese Patent Application No. 2017-045772, filed on 10 Mar. 2017, the content of which is incorporated herein by reference.

#The present invention relates to a rotary encoder for detecting the rotation position or rotation speed of a shaft (rotation axis) of a servo motor, for example.

#There has been a known rotary encoder attached to a shaft of a servo motor used in NC machine tools, robots, or various industrial machines, for example, and used for detecting the rotation position or rotation speed of the shaft.

#FIG. 1 is a perspective view showing the configuration of a rotary encoder according to an embodiment of the present invention;

#FIG. 2 is a sectional view taken along a line II-II of FIG. 1 and showing a rotation unit in a rotary encoder according to a first embodiment;

#FIG. 3A is a sectional view showing part of a procedure of assembling the rotation unit in the rotary encoder according to the first embodiment;

#Exemplary embodiments of the present invention will be described below by referring to the drawings. Elements common between drawings or comparable elements in drawings will be identified by the same sign.

#FIG. 1 is a perspective view showing the configuration of a rotary encoder according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along a line II-II of FIG. 1 and showing a rotation unit in the rotary encoder according to the first embodiment.

#A rotary encoder 1 shown in FIGS. 1 and 2 is attached to a shaft (rotation axis) 2 of a servo motor used in machine tools, for example, and used for detecting the rotation position or rotation speed of the shaft 2. The rotary encoder 1 includes a rotation code plate 10, a boss 20, a light-emitting unit 30, and a light-sensitive unit 40. The rotation code plate 10 and the boss 20 form a rotation unit to be rotated by the shaft 2.