| 摘要 |
Equipment for use in the winning and/or conveying of coal in underground mine workings has means for tensioning and fixing an endless-loop traction chain. An overload clutch (4, 5) between a motor (2) and gearbox (3) is adapted as a slipping clutch having an electronic controller with a rotary speed monitor (8) and comparator (9) which measure the rotary speed of the slipping clutch input and output (4, 5). The electronic controller is connected to an electrohydraulic switch having a valve system for the normal operation of the overload clutch, and to a load measuring instrument (7) as a data pickup. An operating mode selector (11) provides modes "tensioning the chain" and "normal operations". An adjustable reduced pressure compared with the normal operating pressure can be introduced through the operating mode selector (11) to provide slipping of the clutch (4, 5) for the purpose of tensioning the traction chain. The driving motor (2) can be switched off through the rotary speed comparator (9) when the clutch is slipping at the reduced pressure setting, while an hydraulically-actuated holding brake (10) can be applied simultaneously by the electronic controller. <IMAGE> |
