The commutator end of the traction motor is equipped with a brush device, which is used to connect the rotating armature winding with the external circuit. The brush device is composed of a brush, a brush holder, a brush holder, a brush rod and a brush holder ring. The structure of the brush device and the performance of the brush have a great impact on the commutation performance of the traction motor. In order to ensure good commutation effect, the brush device shall meet the following requirements:
〔1〕 The electric brush shall have good current collection performance and commutation ability.
〔2〕 The brush holder can be adjusted in the axial, radial and tangent directions of the commutator. Axial adjustment is to ensure that the brush is in the center of the commutator, and radial adjustment is to ensure the distance between the bottom surface of the brush box and the outer surface of the commutator; The circumferential direction adjustment is to ensure that the brush is accurately on the center line of the main pole.
〔3〕 The working surface of the brush and commutator shall be kept in tight and reliable contact, and the brush pressure shall be stable and uniform.
〔4〕 The brush device shall have high mechanical strength and be able to withstand vibration and impact.
〔5〕 Insulation such as brush rod shall have high dielectric strength and shall not cause flashover or arcing fault due to moisture and pollution.
The rotor of the traction motor is supported on the base through two armature bearings and end caps. The armature bearing not only bears the radial load, but also bears the axial load caused by armature vibration when the locomotive runs on the turnout and curve.