Application of high starting torque three-phase asynchronous motor on carding machine
1. Overview of high starting torque three-phase asynchronous motor
FXSQ132-4 high starting torque three-phase asynchronous motor is the main motor for the carding cylinder. It has the characteristics of high starting torque, small starting current and quick starting. For fast braking, the high starting torque three-phase asynchronous motor is equipped with a DC brake that is sensitive to the brakes. The brake is safe and reliable, and is suitable for occasions requiring frequent starting, large starting torque, small starting current and fast braking. High efficiency, energy saving, low temperature rise, strong anti-fiber blocking ability, safe and reliable, suitable for various textile, printing and dyeing machinery such as cotton, wool, hemp, silk and chemical fiber, can be dusty, short fiber, high temperature and humidity Working in the environment, it can also be used for other mechanical drives.
2. Structure, principle and characteristics of high starting torque three-phase asynchronous motor
2.1 structure
(1) Stator (still part)
1. Stator core: The stator core acts as part of the motor's magnetic circuit and places stator windings on it.
2. Stator winding: The stator winding is the circuit part of the motor, which is connected to three-phase alternating current to generate a rotating magnetic field.
Wiring method of stator three-phase winding
(1) Star connection method (Y connection)
(2) delta connection (△ connection)
3. Base
(2) Rotor (rotating part)
The rotor is a rotating part of the motor and includes components such as a rotor core, a rotor winding, and a rotating shaft.
Rotor core
Function: Part of the magnetic circuit of the motor and place the rotor windings. Generally, it is formed by punching and laminating a 0.5 mm thick silicon steel sheet, and the outer circumference of the silicon steel sheet is punched with uniformly distributed holes for arranging the rotor windings.
2. Rotor winding
The function is to cut the rotating magnetic field of the stator to generate an induced electromotive force and current, and form an electromagnetic torque to rotate the motor. According to the structure, it is divided into a squirrel cage rotor and a wound rotor.
(1) Squirrel-cage rotor: If the rotor core is removed, the entire winding is shaped like a squirrel cage, so it is called a cage winding. The small cage motor adopts a cast aluminum rotor winding, and is welded by a copper strip and a copper end ring for a motor of 100 KW or more.
(2) Wire-wound rotor: The wound rotor winding is similar to the stator winding, and is also a symmetrical three-phase winding, which is generally connected in a star shape, and three outgoing heads are connected to three collecting rings (slip rings) of the rotating shaft. Then connect with the external circuit through the brush.
3. Shaft
Used to transmit torque and support the weight of the rotor, usually made of medium carbon steel or alloy steel.
(3) Other attachments
End caps, bearings, bearing end caps, fans
2.2 Principle
When a symmetrical three-phase alternating current is passed into the three-phase stator winding, a rotating magnetic field is generated which rotates clockwise in the stator and rotor inner circular spaces at the synchronous rotational speed n1. Since the rotating magnetic field rotates at the n1 rotational speed and the rotor conductor is initially stationary, the rotor conductor will cut the stator rotating magnetic field to generate an induced electromotive force (the direction of the induced electromotive force is determined by the right-hand rule). Since both ends of the conductor of the conductor are short-circuited by the short-circuiting ring, an induced current substantially coincident with the direction of the induced electromotive force is generated in the rotor conductor under the action of the induced electromotive force. The current-carrying conductor of the rotor is subjected to an electromagnetic force in the stator magnetic field (the direction of the force is determined by the left-hand rule). The electromagnetic force generates an electromagnetic torque to the rotor shaft, and drives the rotor to rotate in the direction of the rotating magnetic field.
When the three-phase stator windings of the motor (each phase difference of 120 degrees electrical angle), after passing into the three-phase symmetrical alternating current, a rotating magnetic field is generated, which rotates the rotor windings to generate an induced current in the rotor windings (the rotor windings are closed) Path), the current-carrying rotor conductor generates electromagnetic force under the rotating magnetic field of the stator, thereby forming electromagnetic torque on the motor shaft, driving the motor to rotate, and the motor rotating direction is the same as the rotating magnetic field.
