Selection factors and matters needing attention of electric dynamometer
1 、 in the test of AC and DC motors and power tools, the dynamometer is often used as a testing device. The dynamometer mainly tests the torque, speed and output power of the motor. However, not every power dynamometer can meet all the requirements of motor testing, mainly considering three factors:
First, the torque test range, the torque of the dynamometer is usually not to exceed the maximum torque value.
Second, speed test range, torque speed sensor dynamometer is usually the maximum speed can not exceed the bear, if long time overspeed will greatly shorten the service life of the dynamometer, especially mechanical wear.
Third, dynamometer power usually refers to the standard power dynamometer can absorb, because the dynamometer (general hysteresis, magnetic, eddy current dynamometer is by absorbing heat to reach the energy consumption) is measured AC and DC motor or electric tool output power. Strictly speaking, this indicator can not exceed, otherwise, the dynamometer will easily be burned out because the heat does not go out;
2, electric dynamometer should be selected not only to meet the speed, torque and power of the three main technical indicators, but also to see if the specific requirements of the test, the general motors need to test, no-load loss, no-load speed and stall torque and other parameters, but also need to consider!
3, in the dynamometer selection, the best motor all test data in the dynamometer performance parameters of 30%~90% between. Because the dynamometer test accuracy in this interval is the most guaranteed.
4, the commonly used dynamometer mainly has the following classification: hysteresis dynamometer, magnetic particle dynamometer, eddy current dynamometer, power dynamometer (direct current and AC power dynamometer).
Dynamometer according to the speed can be rated as: eddy current dynamometer, power dynamometer, hysteresis dynamometer, magnetic particle dynamometer;
(1) the eddy current dynamometer can not stop the motor or power tools, but its speed limit is high, usually 20000~30000RPM; torque can also be great.
(2) the speed of hysteresis dynamometer is generally less than 20000 rpm, but it can be blocked, but the power is not too large. The torque is generally below 20Nm.
(3) the speed of the magnetic particle dynamometer is low, usually 1500~5000RPM, but the torque can be bigger, and the motor can also be blocked.
5, electric dynamometer without water cooling, air cooling can only; eddy current dynamometer, measuring the magnetic hysteresis dynamometer, dynamometer requires water cooling and air cooling at the same time, some small power hysteresis dynamometer without water cooling can meet the testing requirements; dynamometer in the use process, must to open the cooling function.