1. Transmission form of crane trolley operating mechanism The trolley operating mechanisms of small and medium-sized cranes all adopt the form of centralized drive, as shown in Figure 2-11(a), while the trolley operating mechanisms of large cranes usually adopt the form of separate drives.

Top-running bridge cranes are often installed in production workshops for lifting equipment or workpieces. Reducing the dead weight of the overhead traveling bridge crane trolley can effectively reduce the dead weight of the crane's main beam and the whole machine, and also reduce the wheel pressure load of the crane on the workshop corbels.

With the needs of economic construction and the acceleration of industrialization, box-girder bridge cranes, as important equipment for material production and loading and unloading, are widely used in production workshops, warehouses and other fields.

(1) The comprehensive error of the overload limiter should not be greater than 5%, and the number of lifting and lifting weight can be recorded. (2) When the load reaches 90% of the rated lifting capacity, an alarm signal should be issued; when it is 100-110% of the rated lifting capacity, the power supply for the lifting control of the hanging object should be automatically cut off through interlock control.

The most common crane used in the workshop - the electric overhead traveling crane is the most common type of crane used in the workshop. Equipped with CD and MD hoists, they are light and small cranes. The lifting capacity range is generally between 1-16t and the span is between 6-25 meters. For larger tonnage lifting capacity and span, it is best to choose an electric double-girder crane. The use environment is controlled within the range of -30-+40℃.

The trolley operating mechanism of the overhead traveling bridge crane is the transport mechanism of the entire crane, including the motor, controller, coupling, transmission shaft, reducer, angular bearing box and trolley wheels, etc.