Changzhou Tongce Electronic Technology Co., Ltd. has a long history of dynamometers. Based on the different currents used by dynamometers, Weiheng editors classify them into DC dynamometers, AC dynamometers, and eddy current dynamometers.
Composition and function of DC dynamometer: It is composed of a DC motor, a load cell, and a speed measuring generator. The stator of a DC motor is supported by independent bearing seats and can freely swing within a certain angle range. The casing is equipped with a force measuring arm, which, in conjunction with a load cell, can detect the torque acting on the stator. According to the principle of DC motor, the electromagnetic torque of the motor is applied to both the stator and rotor simultaneously. The torque received by the stator is equal in magnitude and opposite in direction to the torque received by the rotor, so the torque on the shaft can be measured by the stator. The mechanical torque caused by bearings, brushes, and wind-induced friction during operation can result in unequal torque on the stator and rotor, which requires consideration of measurement errors.
A DC dynamometer can operate as a DC generator and serve as a load for the tested power machinery to measure the output torque on the shaft of the tested machinery; It can also be operated as a DC motor to drive other machinery and measure the input torque on its shaft. The product of torque and the speed measured by the tachometer generator is the shaft power. This is the origin of the name dynamometer.
Composition and function of AC dynamometer: It is usually composed of a three-phase AC commutator motor, a load cell, and a speed measuring generator. Its power measurement principle is the same as that of a DC dynamometer.
Eddy current function: a device that uses eddy currents to generate braking torque and measure mechanical torque. It consists of an electromagnetic slip clutch (see electromagnetic speed regulating asynchronous motor), a load cell, and a speed measuring generator. The input shaft of the tested power machinery is connected to the electromagnetic slip clutch, driving the armature to rotate. The magnetic pole is stopped by the force measuring arm installed on it, and can only swing within a certain range by one angle. With the help of a load cell, the electromagnetic torque between the armature and the magnetic pole can be directly read from this swing angle. When measuring errors such as wind and friction losses are excluded, this electromagnetic torque is equal to the output torque of the tested power machinery. Eddy current dynamometer can only generate braking torque and cannot operate as an electric motor. It is generally used to measure power machinery where the speed increases while the torque decreases, or where the torque changes while the speed remains basically unchanged.