Low power alternator esp. for motor vehicles - minimises whistling sound by interlocking rotor shell teeth of trapezoidal elevation

摘要

The low power alternator is esp. for providing electrical power to motor vehicles. The design minimises the whistling sound produced when in a low poad condition. The motor shaft (5) has twin roller bearings (6) and sprung bushes (9, 10) and is normally belt driven via a pulley. The rotor proper consists of two approximately identical shells (13) having cogs (16) or teeth facing towards each other but displaced radially from each other, ie. alternate around the shell circumference. The shell is made up of ferromagnetic material and defines the rotor coil volume, each tooth has an approximately trapezoidal elevation the inner edge having two slope angles. the distance between the large and small trapezoidal bases is between a quarter and a half of width of a stator pole measured along the alternator air-gap.