The driving part of an extruder

The transmission part is usually composed of motor, reducer and bearing. In the process of extrusion, the screw speed must be stable, can not change with the screw load, so as to maintain the quality of the product uniform. But in different occasions to require the screw can change speed, in order to achieve a device can extrude different plastics or different products. Therefore, this part of the general use of AC commutator motor, DC motor and other devices, in order to achieve a continuously variable speed, the general screw speed is 10~100 RPM.
The function of the transmission system is to drive the screw and supply the torque and speed required by the screw in the extrusion process. It is usually composed of motor, reducer and bearing. Under the premise of the same structure, the manufacturing cost of reducer is roughly proportional to its size and weight. Because the shape and weight of the reducer is large, it means that the material consumed in manufacturing is more, and the bearings used are also relatively large, which increases the manufacturing cost.
The same screw diameter extruder, the high speed and high efficiency extruder than the conventional extruder consumes more energy, the motor power doubled, the frame size of the reducer increased correspondingly is necessary. But high screw speed means low deceleration ratio. The reducer of the same size, compared with the low reduction ratio and the large reduction ratio, the gear modulus increases, and the capacity of the reducer to bear the load increases. Therefore, the increase of the volume weight of the reducer is not proportional to the increase of the motor power. If the amount of extrusion is used as the denominator, divided by the weight of the reducer, the number of high-speed and efficient extruders is small, and the number of ordinary extruders is large. In terms of unit output, the motor power of high speed and high efficiency extruder is small and the reducer weight is small, which means that the unit production cost of high speed and high efficiency extruder is lower than that of ordinary extruder.