Engine-rotation detecting system

摘要

A first thrust limiting member and a second thrust limiting member are provided on a cam shaft rotatably carried between a lower cam shaft holder and an upper cam shaft holder which are fixed to an upper surface of a cylinder head 1, so that the first and second thrust limiting members and abut against the cam shaft holders 95 and 105. The second thrust limiting member has a plurality of detected projections provided around of an outer periphery thereof, so that the detected projections are detected by a TDC sensor 37 mounted to a head cover of the engine. Thus, the rotated position (phase), the angle of rotation and the number of rotations of an rotary shaft of an engine such as a cam shaft 6e and a crankshaft can be detected with good accuracy in a structure including a decreased number of parts, and the axial dimension of the rotary shaft of the engine can be reduced.