How is electrical current conveyed from the revolving portion of the crane to the lower crane structure?

Electrical current is conveyed from the revolving portion of the crane to the lower crane structure through the collector ring system. This system is specifically designed to facilitate the transfer of electrical power to rotating components without the need for sliding contacts, which can wear out over time. The collector ring consists of a series of conductive rings and brushes that maintain an effective electrical connection as the crane rotates.

This method is highly effective in cranes because it minimizes wear and tear and provides a reliable connection, ensuring that power is continuously supplied even while the crane is in motion. Other options, such as wiring harnesses or power cables, may have limitations in flexibility or could be prone to damage as the crane rotates, whereas the collector ring system is specifically tailored for this purpose. Wireless transmission does not apply in this context since the capacity and reliability required for crane operations must be supported by a robust physical connection.