In the past, the mine was facing a lot of problems because of its AFC drives equipped with two two-speed motors. The two-speed motors were replaced with Voith Fluid Couplings (type 562 DTPKWL2) to prevent chain breaks as well as gearbox and motor break downs in the future.

The couplings provide a lot of benefits for AFC drives. “Based on the hydrodynamic principle, the fluid couplings protect the whole drive train from overload situations, which often happen at Chang Ping,” said Mao Weihong, head of the mechanical and electrical department of Chang Ping. “The 562 DTPKWL2-1000 couplings are so powerful they can easily handle blockages of the AFC without downtime or damage of the equipment.”

Mao is very satisfied with the change. He compliments the reliability of the couplings and especially their soft start function. “For upcoming mining projects, we will also rely on Voith fluid couplings to raise our productivity,” Mao said.

Since the installation of the couplings in 2009, the AFC has experienced no chain breaks. This also means significantly reduced maintenance efforts. Nowadays, the 225 m (740 ft) wide and 1,000 m (3,300 ft) long coal panels produce a yearly output of 3 million tons.