Patent ID: 7425784
Filing Date: 2008-09-16
Classification: H02K

Abstract:
1. An alternator for use in an automotive vehicle, the alternator comprising: a frame; a rotor having a rotor shaft rotatably supported in the frame; and a pulley for driving the rotor, the pulley being connected to the rotor shaft and positioned outside the frame, wherein: the pulley includes pulley grooves for engaging with projections of a driving belt, a first flange formed at a front end of the pulley, and a second flange formed at a rear end of the pulley, the second flange having a diameter larger than an outer diameter of the pulley grooves and smaller than a diameter of the first flange; the frame includes a projected portion circularly formed on a front end of the frame, the projected portion being positioned radially outside of the second flange and forming a gap between the diameter of the second flange and a radial inside of the projected portion; a collar is disposed on a rear end surface of the pulley in close contact therewith, and an outer diameter of the collar faces an inner periphery of the frame, forming a second gap; and a size of the gap and a size of the second gap are substantially equal, and an axial gap between the frame and the pulley positioned between the gap and the second gap is wider than the size of the gap and the second gap.