Abstract:
A high performance drive system for a mineral mining installation employs separate main and auxiliary drives with wheels around with a chain is entrained. Each drive is composed of an asynchronous motor and spur gearing. An additional over-ride planetary gearing unit is incorporated in at least one of the drives to distribute loading as evenly as possible. The planetary gearing is operable to provide a transmission ratio which can be varied in accordance with load or rotational speed of the drive(s). The planetary gearing unit has two sets of planet wheels on a common carrier. One set of planet wheels mesh with an input sun wheel and the other set of wheels mesh with an output sun wheel. The sets of planet wheels are disposed so that one wheel of one set meshes with an adjacent wheel of the other set. A further control motor drives a pinon which meshes with the carrier and this further motor is operated in accordance with e.g. the load or rotational speed of the drive(s). With the further motor stationary the transmission ratio of the planetary gearing is 1:1.
Abstract:
A longwall coal-mining machine has a gearcase at each of its ends, each gearcase carrying two ranging arms respectively mounting a cutter drum and a lump breaker, and also carrying a haulage drive. Each gearcase comprises a casing having therein first and second co-axial and mutually-spaced transverse horizontal shafts projecting through opposite sides of the casing driven by individual transmissions located in the gearcase and from an electric motor and a hydraulic motor, respectively, both outside the casing. Rotation of the second shaft drives the mining machine along a longwall face. Rotation of the first shaft actuates a cutter drum through a gear train and also actuates a lump breaker through a gear transmission.