Application of torque motor in wire surface equipment

YLJ, YDLJ series torque three-phase asynchronous motor is a special motor with soft mechanical characteristics and wide speed range. When the load increases, the motor speed can automatically decrease, while the output torque increases to maintain balance with the load. The torque motor has high stall torque and small stall current, and can withstand stall operation for a certain period of time. Due to the high rotor resistance, high loss, and high heat generation, especially when running at low speed and stalling, the motor is equipped with an independent axial flow or centrifugal fan on the rear cover (except for 100 frame size and below with small output torque) for forced ventilation cooling. The torque motor is equipped with a thyristor control device, which can be used for voltage and speed regulation. The speed range can reach 1:4, and the speed change rate is ≤10%. The characteristics of this series of motors make it suitable for winding, unwinding, stalling and speed regulation and other purposes. It is widely used in textile, wire and cable, metal processing, red making, rubber, plastics and printing machinery and other industrial fields.

1. Reeling in:

The surface treatment of metal wire is a very important process. When the product is wound, the diameter of the reel gradually increases. It is very important to keep the tension of the wound product unchanged during the whole process, because too much tension will make the wire diameter thinner or even break, or cause uneven thickness of the product, while too little tension can cause winding slack. In order to keep the tension unchanged during the winding process, the output torque of the motor driving the reel must be increased when the diameter of the product wound on the reel increases. At the same time, in order to keep the line speed of the wound product unchanged, the speed of the reel must be reduced accordingly. The mechanical characteristics of the torque motor can just meet this requirement.

The torque motor has the following advantages when winding:

1. The tension remains stable from empty to full tray.

2. The tension is easy to adjust and can be repeated correctly after one adjustment.

3. Reliable structure, easy maintenance, simple control and operation, and low cost.

2. Release the wire (brake constant power characteristic)

Unwinding is also called loosening, unwinding, unwinding, etc. In industrial production, it is sometimes necessary to transport the product wound on the drum to the next process. During the transportation process, it is required to apply a tension opposite to the transmission direction to the product, and at the same time, it is required to keep the linear speed and counter-tension of the product transmission constant as the drum diameter changes, which requires the motor to have a braking constant power characteristic. By utilizing the mechanical characteristics of the torque motor in the braking state, the rolled product can be loosened before processing, which can prevent the product from affecting the quality due to looseness and tightness during the unwinding process. The principle is the same as that of winding.

3. Stepless speed regulation

The mechanical characteristics of torque motors are very soft. When the load increases, the motor speed decreases and the output torque increases, and the output torque is proportional to the square of the voltage. If the load is fixed, the motor speed will change with the voltage. Therefore, in a device with a constant load, any speed can be obtained by changing the input voltage of the motor through a voltage regulator. However, when the torque motor runs at a low speed, its efficiency is extremely low, which is not conducive to long-term low-speed operation.

4. Stalling

Torque motors can also be used flexibly according to their various characteristics. For example, they have the characteristics of current series motors and can partially replace DC motors. For example, their rotors have high resistance characteristics and large starting (locking) torque, so they can be used in opening and closing gates (valves) and drag systems with large resistance torques. They can also be used in devices with frequent forward and reverse rotations or other similar movements due to their large starting (locking) torque, small starting (locking) current, and high mechanical strength of solid rotors.