The difference between servo motor and general motor?

The difference between servo motor and general motor?

The insulation level, which is usually F or higher, strengthens the insulation strength of the ground and turns, especially considering the ability of insulation to withstand shock voltage. 2) to the problem of vibration and noise of the motor, the motor should be fully considered component and overall rigidity, trying to improve its natural frequency, in order to avoid and every force wave resonance phenomenon. 3) cooling mode: the general adoption of forced ventilation cooling, the main motor cooling fan is driven by an independent motor. To prevent shaft current measures, the bearing insulation measures should be applied to the capacity exceeding 160KW motors. Mainly produces magnetic circuit asymmetry, also can produce shaft current, while the rest of the high frequency component generated by the current role in combination, shaft current will increase greatly, which can lead to bearing damage, so often insulation measures. For constant power frequency converter motor, the special lubricating grease should be used to compensate the temperature of the bearings when the speed is over 3000 / min.

Principle of servo motor servo positioning by pulse, basically can understand it, servo motor to receive a pulse, will rotate one pulse of the corresponding point of view, so as to realize the displacement, because, the function of the servo motor itself has a pulse, so each rotation Angle of a servo motor, send out the corresponding number of pulses, in this way, and the servo motor to accept pulse forming the echo, or closed loop, as a result, the system will know how many pulses sent to the servo motor, how much charge pulse back again at the same time, in this way, can be very precise control of the motor rotation, so as to realize accurate positioning, can reach 0.001 mm. The characteristics of servo motor are: speed, location accuracy is very accurate. The torque is large; The scope of operation is broader; No rotation. Servo motor is mainly used for digital control system, and for high precision control.

The problem of motor insulation strength is the small and medium frequency converter, many of which are controlled by PWM. He is about several thousand to more than 10 KHZ carrier frequency, which makes the motor stator winding to withstand high voltage build-up rate, equivalent to impose great impulse voltage gradient on motor, the motor of the turn-to-turn insulation withstand ordeal. In addition, the rectangular produced by PWM inverter chopper superposition of impulse voltage on the motor running voltage, would pose a threat to ground insulation of motor, the ground under the repeated impact of high voltage insulation can accelerate ageing. 3, harmonic electromagnetic noise and vibration Ordinary asynchronous motor by inverter power supply, can make the electromagnetic, mechanical, ventilation and other factors caused by the vibration and noise becomes more complicated. The internal harmonic interference of the different time harmonic and the electromagnetism of electromagnetism in the frequency conversion power supply, form various electromagnetic excitation forces. When the frequency of the electromagnetic wave is consistent or close to the natural vibration frequency of the motor body, the resonant phenomenon will be generated to increase the noise. Because the frequency of the motor is wide, the speed varies widely, and the frequency of all kinds of electromagnetic waves is difficult to avoid the natural vibration frequency of each component of the motor.

The design of an ordinary asynchronous motor is designed by constant frequency constant pressure, and it is not possible to fully adapt to the requirements of variable frequency control. Under the influence of frequency converter for motor 1, the efficiency and the problem of temperature rise of the motor In either in the form of a frequency converter, both in the operation of the different degree of harmonic voltage and current, make the motor in non-sinusoidal voltage, power flow operation. Rejected materials is introduced, at the current widely used sine wave type PWM inverter as an example, the basic is zero, the low-order harmonic larger than the rest of the carrier frequency times the left and right sides of higher harmonic components as: 2 u + 1 (u for modulation ratio). Can lead to higher harmonic motor stator copper loss, rotor copper (aluminum), iron loss and the increase of the additional loss, the most significant is the rotor copper (aluminum) consumption. For asynchronous motor is close to the base wave frequency corresponds to the synchronous speed of rotation, therefore, higher harmonic voltage to a larger slip cutting rotor after conducting bar, will produce very big rotor loss. In addition, additional copper consumption due to the skin effect is considered. These losses will make motor extra heat, low efficiency, output power decreases, and such as ordinary three-phase asynchronous motor running in the inverter output non-sinusoidal power supply conditions, the temperature rise is to increases 10% ~ 20%.

Servo motor usually USES frequency conversion! General motors are generally used for positive frequency! The effect of a frequency converter on the general motor. The efficiency of the motor and the problem of temperature rise The problem of motor insulation strength 3, harmonic electromagnetic noise and vibration The motor is adaptable to frequent start-up and braking Low speed cooling problem The characteristics of variable frequency motor