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Explore the fine craftsmanship of series motor production

Date:2023-10-19   Author:XINDA MOTOR
In this article, we will explore the fine craftsmanship of series motor production. Although each manufacturer's motor design details are unique, we still use the most basic production mode as the main axis. What needs special attention is that the stator and rotor of the series motor use electromagnet excitation, so that the stator and rotor are equipped with enameled coils, which also relatively increases the complexity of production.

The following illustration shows the production process of a series motor, where the parts marked in white represent materials, orange represents the production process, blue represents the testing procedure, and the final motor output is marked in green. The upper part of the illustration shows the production process of the rotor, and the lower part shows the production process of the stator.


Motor production process

Before we begin, let's first elaborate on the white box, which is the motor material:

1. Silicon steel sheet: As the carrier of motor magnetism, since the stator and rotor of the series motor are designed with electromagnets, silicon steel sheets need to be used for manufacturing.

2. Shaft: It is a key component of the motor's power output. It is necessary to pay attention to whether the stiffness of the shaft can withstand the torque output by the motor, otherwise it may cause the shaft to deform or break.

3. Insulation material: Since the silicon steel sheet is conductive, insulation protection needs to be added between the enameled wire and the silicon steel sheet to prevent leakage of the motor. There are two types of insulation materials commonly used for the rotor of a series motor. One is to directly wrap silicon steel sheets with epoxy resin, and the other is to use a multi-piece wrapping method, including plastic upper and lower end caps and groove paper. The stator is usually wrapped in multiple pieces, and sometimes only grooved paper is used for insulation protection.

4. Commutator: The material of the mechanical commutation structure of the DC motor, composed of copper and bakelite. It is necessary to connect the enameled coil of the motor to the commutator to facilitate phase conversion when the motor is running; therefore, there is a hook under the commutator for hanging the enameled coil.

5. Enameled wire: As the carrier of electrical energy in the motor, it needs to be wound into a ring .

6. Slot paper: Also called slot wedge, it is different from the insulated slot paper. Its main purpose is to prevent the enameled coil from flying out due to centrifugal force when the rotor rotates. Therefore use slot wedges to block the slots. However, with the improvement of winding technology and the compactness of the enameled coil itself, this step has been gradually omitted.

7. Insulating paint: This is a transparent paint, mainly used to fix the enameled coil of the motor to prevent the coil from being damaged under the action of Lorentz force. In addition, it has some additional effects of auxiliary enameled coil heat dissipation. In a series motor, the rotor coil needs to be fixed with insulating paint, but the stator coil does not necessarily need to use insulating paint, because the stator itself is a fixed component, and the stator coil will not be affected by centrifugal force.

8. Shell: This is the shell of the motor, which is composed of two or three pieces. Due to price competition, most series motors adopt a simple upper and lower combination method, with relatively weak protection capabilities, which can only ensure the smooth assembly and operation of the motor stator and rotor.

9. Bearing: It is the connection between the stator and the rotor, ensuring that the rotating parts and the fixed parts are closely combined.

10. Carbon brush holder: The structure for installing carbon brushes, which includes three parts, insulating material, conductive material and elastic mechanism. The insulating material is used to prevent power leakage into the housing, the conductive material is used to connect the power supply, and the elastic mechanism is used to hold the carbon brush close to the commutator to facilitate the transmission of electrical energy.

11. Carbon brush: Composed of carbon and adhesive, it is an electrical energy transmission component between the stator and the rotor. It is a consumable product and has a clear life limit, so it is usually designed to be a replaceable structure.

In summary, as copper prices continue to rise, the influence of series motors is gradually weakening.