Patent ID: 7042188

Claim:
A servo motor with a built-in drive circuit in which a servo motor portion provided in a cylindrical case and composed of a stator and a rotor is servo-driven by a sensor circuit portion, a drive control circuit portion, and a motor drive circuit portion, said servo motor comprising: an absolute encoder operable to detect rotation of said servo motor portion; a sensor circuit board; a motor drive board; cooling fins operable to dissipate heat from said servo motor; and an electromagnetic mechanical brake which is released when said servo motor portion is being driven, wherein said electromagnetic mechanical brake is engaged by an action of a spring when said servo motor portion is not to be driven, wherein said electromagnetic mechanical brake comprises: a stationary brake plate; and a movable brake plate; wherein, when said servo motor portion is not to be driven, said movable brake plate is pressed against said stationary brake plate by the action of said spring; wherein said drive control circuit portion is coupled to said sensor circuit board; wherein said motor drive circuit portion and a power device are coupled to said motor drive board; wherein said drive control circuit portion is operable to control said electromagnetic mechanical brake and said motor drive circuit portion; and wherein, when power is off, positional data at that time is stored in a nonvolatile memory.