摘要 |
<p>Methods and systems for turning a cutting drum of a mining machine at a maintenance speed. One mining machine includes a cutting drum with a plurality of bits mounted on the drum and a cutting drum turning mechanism. The cutting drum turning mechanism includes a power source, a cutter motor, a switch, and a variable frequency drive. The state has a first and a second state. The first state electrically couples the power source and the cutter motor to operate the cutting drum at a cutting, and the second state electrically couples the variable frequency drive and the cutter motor to operate the cutting drum at a maintenance speed less than the cutting speed.</p> |