- Aug 01, 2014 -
Advantages and disadvantages of speed regulating mode of bridge crane
The speed control performance is poor and there is no stable low speed crane, when it is necessary to stop. The driver can only take the way of "point car" operation, which not only increases the labor intensity of the driver, but also increases the number of electrical connections and the number of motor starting times, which greatly reduces the working life of electrical appliances and motors, and also brings serious impact to the mechanical structure.
Some bridge cranes have higher requirements for accurate parking, and the stability and low speed to control the time in order to achieve the accurate requirements. Some cranes should use program control, numerical control, remote control and so on. The application of these technologies often needs to realize the speed regulation requirements, so that it is possible to avoid the advantages and disadvantages of the speed regulation mode of the bridge crane.
Changing the parameters of the motor is that most of the speed regulation of bridge cranes should be carried out during the operation process, and the number of times of transformation is more. Therefore, the mechanical speed change is generally not very suitable, most of which need electric speed regulation. Electric speed regulation is divided into two categories: DC speed regulation and AC speed regulation.
Most of the crane uses winding rope winding way to lift the goods is the "goods" of poor following performance (swinging). It is difficult to achieve high precision positioning, resulting in the level of automation in the handling process is not high. So the anti pendulum and anti pendulum are also an indicator of the speed regulation of the crane. The use of slow and small acceleration to overcome the swing is the primary stage of the stop pendulum, which has sacrificed production efficiency. It is the general situation of high efficient bridge crane to use the speed control system to control the acceleration of the operating mechanism and destroy the swing period to reach the pendulum. Speed control system better, by using the angle detection device forming angle closed-loop speed control performance index of dynamic link, use good, follow the change of rope angle in the control process, don't always keep the wire rope swing, this is called the anti swing system, can greatly improve the level of automation, to improve system.
The product of uniform and stable speed and precise time of bridge crane is equal to the exact displacement (parking). From this sentence, we can see that speed regulation is not the only condition for precise displacement, it needs the support of perfect control system and many hardware and software.