Patent ID: 8472033

Claim:
A method of detecting an amount of an axis displacement in a power transmission device, the power transmission device including a rotary shaft of a first drive source, a rotary shaft of a second drive source, and an automatic self-aligning engagement clutch which corrects misaligned positions of the rotary shaft of the first drive source and the rotary shaft of the second drive source to be concentric with each other when the rotary shafts are engaged, wherein the power transmission device is configured to transmit a driving force to a driven body by allowing the rotary shaft of the first drive source to engage with the rotary shaft of the second drive source through the automatic self-aligning engagement clutch, the method comprising: for each of the rotary shafts of the first and second drive sources, measuring an amount of an axis position variation between before and after engagement of the rotary shafts through the self-aligning engagement clutch by using non-contact sensors respectively provided to face the rotary shafts; and detecting an amount of a relative axis displacement of the rotary shaft of the second drive source relative to the rotary shaft of the first drive source on the basis of the amount of the axis position variation between before and after engagement.