L46A1 Mast Section the step-by-step speed regulation modes of tower crane lifting mechanism
1. Electronic speed regulation of winding motor rotor series
This speed regulation can change the speed of the motor by connecting the variable resistance in series in the rotor winding and controlling the contactor with the master signal sent by the operating handle, so as to realize the requirements of smooth start and uniform speed regulation. Some wound rotor series electronic speed regulation, but also can increase the electromagnetic shift reducer, this way can use speed control gear number to double.
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2. Double speed wound rotor series resistance speed regulation
There are two kinds of pole pairs in the motor, which can be adjusted by series resistance and pole changing.
3. Double motor drive speed regulation
This kind of speed regulation is mostly driven by two winding motors. Two wound motors are connected by gears with a speed ratio of 1:2, one as the driving motor and the other as the braking motor. Double motor speed regulation can also be driven by one winding motor plus one cage motor or two multi speed cage motors, and different speed regulation characteristics can be obtained. This hoisting mechanism can adjust speed in load movement, achieve the drop of air speed at the maximum speed, thereby improving production efficiency, lifting load can accurately position, work smoothly, and the speed range is large, up to 1:40. But the mechanism is relatively complicated, and its transmission parts need to be specially designed and manufactured. Mainly used in large and medium-sized tower crane.
4. Variable pole speed regulation
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By changing the pole number, squirrel cage motor can obtain high and low working speed and slow positioning speed of one gear, which can basically meet the speed regulation requirements of tower crane and simplify the mechanism. However, when shifting, the impact is large, the speed regulation range is about 1:8, and it can not operate at low speed for a long time. It is mainly used for light and small tower crane under 40t. M. Pole changing speed regulation can also be combined with electromagnetic shift reducer to double the number of speed regulation gears. This speed regulation is mainly used in tower crane with lifting capacity of 450-900kn. M, which is becoming increasingly popular.
