Application of frequency converter in roller rig

The roller rig is the main perforating device for open pit mines, especially large open pit mines. In order to maintain the better drilling state of the roller rig in different rock layers, the slewing mechanism of the rig is required to perform stepless speed regulation according to the nature of the rock formation. The lifting/traveling mechanism of the rig also requires stepless speed regulation. At present, the slewing mechanism and the lifting/traveling mechanism of the roller rig are generally DC motor drives. There are three main types of speed control devices: (1) The roller rigs using thyristor DC speed control devices are: YZ-55, YZ-35 and YZ-12; (2) KY- using high-power magnetic amplifier speed control device Type 250 roller rig and 45R type wheel rig imported from the United States; (3) Type 60R roller rig imported from the United States using DC genset speed control device.
The application of variable frequency speed control technology on the roller rig is not only for energy saving, but more importantly, it is to improve the production efficiency of the rig and reduce the maintenance workload. The motor of the slewing mechanism is installed at the top of the drill pipe, and the working conditions are extremely bad. The DC motor used in the past is often damaged, the maintenance workload is large, and the normal operation and efficiency of the roller rig are affected. Therefore, the use of a rugged AC squirrel-cage motor instead of a DC motor, and the use of a frequency converter to replace the DC converter, has become the development direction of the electric drive of the roller rig. The difficulty in applying the variable frequency speed control technology on the roller rig is that the rig's turning mechanism and the like have high performance requirements for the speed regulating device, because the drilling rig may be stuck during the drilling work due to different geological conditions of the rock formation, so that the slewing The mechanism is blocked, which requires the mechanical characteristic curve of the governor to have the characteristics of the excavator, and has the function of immediate reversal and immediate restart and drilling; the roller rig has large vibration and high anti-vibration requirements for the speed control equipment. The application of variable frequency speed regulation in the roller rig is firstly applied by the US company BE on the 55R roller rig. The frequency conversion speed regulation of the roller rigs in mines in China is still under development and testing, and has not been promoted and applied.

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