Operation and Maintenance of Tower Crane Slewing Mechanism
The tower crane slewing mechanism is driven by an electric motor. Power is transmitted through a fluid coupling, planetary gear reducer, and a primary pinion to drive the slewing bearing. This machine employs a wound rotor motor, which offers advantages such as smooth starting and stopping, low inertia, high transmission efficiency, and long service life, thereby improving the operating performance of the tower crane. To ensure accurate slewing positioning, an electromagnetic brake is installed in the mechanism to achieve slewing braking. The brake only functions to position the slewing when the slewing motor stops working and the crane boom rotation tends to stop. However, the brake should be released after the slewing motion stops, i.e., braking by energizing and releasing by de-energizing. When not in operation, the tower crane boom can rotate with the wind direction.
Troubleshooting of Tower Crane Slewing Mechanism
- The tower crane slewing mechanism should not be operated or stored in an environment with corrosive gases such as acids or alkalis. The operating temperature range is -20°C to 40°C. The duty cycle of the tower crane slewing motor should not exceed 40%; the motor operating level is M5; the inner bearings of the tower crane slewing motor need to be replaced with calcium-based grease every 6 months.
- Before installation, a comprehensive inspection should be conducted to ensure that all connecting bolts are tightened and that the electrical circuit functions normally after being energized.
- When assembling the reducer with the upper turntable, it is necessary to tighten the bolts and ensure that the output gear is parallel to and correctly meshed with the slewing bearing.
- The reducer uses medium-load industrial gear oil, N100 in winter and N150 in summer. The oil must be replaced with new oil after the first 3 months of operation, and then replaced every 1500 hours of operation. When changing the oil, all old oil in the housing must be drained and the housing cleaned. The cleaning process should be carried out carefully to maintain cleanliness, and then new oil should be added.
- Prolonged use of the electromagnetic brake is strictly prohibited during operation to avoid premature damage.
