Patent ID: 8823225

Claim:
A rotating electrical machine, comprising: a stator of a substantially annular shape, a rotor arranged inside an annular ring of the stator for rotating about a rotation axis, a detection element for detecting the rotation of the rotor, a circuit board for implementing the detection element, the detection element being provided on the circuit board, and a flange part formed in a vicinity of one end part of the rotor, wherein the detection element and the circuit board are arranged outside the stator in the direction along the rotation axis, the detection element is a reflection type light projecting/receiving sensor, the flange part is located between the stator and the circuit board and projects from the rotor towards an outer circumference of the rotating electrical machine so as to block between the stator and the circuit board, and the circuit board extends in a direction parallel to the flange part and has an outermost end part that is arranged at a position so as not to protrude from an outermost circumference of the flange part.