Precision electric spindleIt is a high-speed and high stiffness precision motor supported by precision rolling bearings, lubricated with lubricating oil, and cooled by external circulating water. The lathe spindle is generally vertical, and the correct use method directly affects the machining quality of the lathe and the working life of the spindle.

The reverse braking process of precision electric spindle is to first cut off the three-phase positive power supply of the motor, and then connect it to different phase sequence power supplies, that is, reverse power supply, which changes the direction of the rotating magnetic field and enters the braking state. When the direction of electromagnetic torque is opposite to the direction of rotational speed, due to the influence of inertia, the electromagnetic torque will not suddenly change. The principle of electromagnetic torque changing from positive to negative braking causes the rotor to rapidly decelerate under the combined action of electromagnetic torque and negative load torque. When the rotor comes to a complete stop, the power should be cut off, otherwise the motor will start in reverse. The advantages of this method are significant braking effect, simple structure, and easy implementation. The disadvantages are low accuracy, difficulty in accurately controlling braking time, and the tendency to cause the motor to start in the opposite direction, resulting in a large braking current and requiring a series resistor in the main circuit. If the running time is too long and the braking frequency is too high, the resistor is prone to burning out due to severe heating. In addition, the braking torque is large, and sudden reaction forces can generate significant impact forces, which can easily cause significant mechanical damage to the transmission mechanism. So this method is also not applicable, this is the brake of the original lathe.

The armature of the motor is tightly connected to the pulley of the motor. On the one hand, due to power outage, the motor speed decreases; On the other hand, the motor instantly connects to the electromagnetic coil, generating a magnetic yoke through alternating current. Under the strong action of the magnetic yoke, it firmly supports the pulley, causing the spindle to quickly rotate and stop. Among them, the armature and brake pad have good suction and braking effects. After braking, the electromagnetic coil loses power and the pulley returns to freedom, ready for the next start. This braking method is widely used on lathes, especially ordinary lathes. Due to its good braking effect, low electrical loss, and the ability to replace brake pads after braking failure, it does not affect the service life of the motor at all.