US Patent 8018108 Compact high power alternator

An apparatus for converting between mechanical and electrical energy, particularly suited for use as a compact high power alternator for automotive use and “remove and replace” retrofitting of existing vehicles. Various aspects of the invention provide a means of significantly increasing the output of permanent magnet alternators while addressing the issues of radial loading applied to a permanent magnet alternator rotor. Another aspect of the invention allows for the production of power in two discrete voltages. An aspect of this invention allows for a marked increase in output capability without increasing axial length through the use of magnetic fringing. One aspect of the invention offers an effective means of mounting a skewed stack that eliminates or reduces cogging that is present in a permanent magnet machine without negatively impacting airflow. Another aspect of the invention reduces cogging by radially offsetting opposing magnets of a dual rotor permanent magnet machine.