CPC F16H 25/2204 (2013.01) [F16H 57/01 (2013.01); F16H 2057/012 (2013.01)] | 12 Claims |
1. A preload detectable screw device comprising:
a screw shaft including an outer helical groove;
a single nut fitted on the screw shaft, the single nut including an inner helical groove, and a return path to which a passage formed between the outer groove and the inner groove is connected;
a plurality of rolling elements placed in the passage and the return path; and
a strain sensor attached to an outer surface of the single nut,
wherein at least one hole is provided between an attachment surface, to which the strain sensor is attached, of the single nut and an inner surface, to which the inner groove is formed, of the single nut.
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