Abstract: A transformer for use on an underground mining machine, such as a shearer loader. The transformer is cylindrical in shape and contains a central cavity extending therethrough to allow positioning of the transformer about a drive shaft of the motor of the mining machine. A tubular housing surrounds a cylindrical iron core with such housing containing a helically wound coolant duct to allow coolant fluid to flow therethrough.

Abstract: An electrical power supply and liquid supply arrangement for a mining machine, particularly a longwall mining machine, wherein extended lengths of a power supply cable and liquid supply conduit are disposed within a housing structure extending along one side of the course of travel of the mining machine. A side arm on the mining machine extends through a slot in a face plate of the housing structure and carries at its outer end a junction box within which power cables leading from the mining machine can be connected to or disconnected from an external power cable. Clamped to the aforesaid junction box is the liquid supply conduit which can be selectively coupled to, or uncoupled from, a mating supply conduit leading to the interior of the mining machine. The arrangement permits connection or disconnection of the power supply and water supply members to or from the mining machine without any disassembly of the machine itself.