【正文】 ned, the control torque is also determined. While in a predetermined period of time to run when the motor normally does not overload. However, if the following conditions so that it can be overloaded: 1. Power supply voltage is low, are not required torque, the motor stops rotating. 2. Mistakenly set the torque limit adjustment agencies, so that it is greater than stop torque, generated too large a result of continuous torque, the motor stops rotating. 3. Such as the point of action as intermittent use of heat generated savings of up, more than the allowable temperature rise of the motor. 4. Torque limit for some reason, institutional circuit failure, so that torque is too large. 5. Use of environmental temperature is too high, relative to the heat capacity of the motor down. The above is the excessive number of reasons, for these reasons should be generated by motor overheating in advance, taking into account, and to take measures to prevent overheating. In the past to protect the motor way is to use fuses, overcurrent relays, thermal relays, thermostats, etc., but these approaches also have their pros and cons of this change for the electrical device load devices, is absolutely reliable protection method is not. Must therefore take all methods bined approach. However, as the load on each electrical device is different, it is difficult to propose a unified approach. In most cases, but generally, you can also find mon ground. Overload protection taken by the way, be grouped into two types: 1. Changes in input current to the motor to judge。 2. Lockedrotor protection of motor thermal relay 3. Pairs of short circuit faults using fuse or overcurrent relays. Valve electric device to prevent overload of the right choice and is very much related and should pay attention to. In consideration of economic aspects limiting torques is a continuous challenge when developing Torque Limiters as an overload protection. The new generation of the backlashfree Torque Limiters. The new generation of the backlashfree Torque Limiters has been designed for being used in powertransmission and servo applications. Important requirements such as being backlashfree, short reaction times and long service life have been further optimized. The constructive benefit is ensured through fast availability of applications after a crash. For limited installations The further development and optimization of the already well established backlashfree Torque Limiter series SK has brought about an appropriate design for each application. The transmittable torques can be accurate defined and set. Even in regard to restricted installation space now, the couplings represent the latest stateoftheart. Areas of applications of the Torque Limiters ranging from to 2,800 Nm can be found in any type of mechanical dynamic drives are being continously improved by the use of preset Torque Limiters. When the overload occurs the Torque Limiters disengage in milli seconds. The movement of the Actuation ring can be sensed, and used to control and shut down the machine. Immediate availabillity of the machine after reengagement of the Torque Limiter can be assured. Increased economic efficiency Optimized disc springs and materials adapted to the use of the coupling allow for the pact and reliable design, better performance and wer mass. Also a long service life and maintenance free operation are importtant consierations when selecting couplings. Smaller couplings bined with a higher torque density additionally result in a cost