Rotor mounting device and rotor mounting method

A rotor mounting device for inserting the rotor of a motor into a rotor housing which is mounted to an engine and coaxially mounting the rotor to a crankshaft. The rotor mounting device is provided with a rotor supporting member, a rotor positioning member engaging with some of the bolt insertion holes formed in the rotor to position the rotor, a temporarily fixing bolt for temporarily fixing therotor to the rotor supporting member, a driving shaft having a front end engaged with an end of the crankshaft and axially movably supporting the rotor supporting member through a screw mechanism, a base member for rotatably supporting the base end side of the driving shaft and allowing the rotor supporting member to approach and separate from the base member, a base positioning member engaging with the rotor housing, and a fastening mechanism engaging with the head of a connecting bolt inserted through at least one of the bolt insertion holes and supported by the rotor supporting member so asto urge the connecting bo