Apparatus for measuring angular position and displacement of a rotary table and accuracy analyzing apparatus therefor

摘要

A measuring apparatus 2 comprises: a base 10 fixed onto the rotary table 83; a rotational angular position detector 35 having first and second members 36 and 37 mounted in relatively rotatable fashion about a preset rotational center axis, one member being provided with a scale and the other with a reading device, wherein the first member 36 is mounted fixedly on the base 10; a restraining mechanism 55 which engages with the second member 37 of the rotational angular position detector 35 and thereby restrains rotation of the second member 37, while allowing the base 10 and the rotational angular position detector 35 to move in vertical direction; and a ring-shaped detection member 49 mounted perpendicularly on the base 10 by orienting center axis at right angles to the upper surface of the rotary table 83 and accommodating therein the rotational angular position detector 35.