A longwall mining shield base lift. The base lift includes a hydraulic cylinder having an apparatus for coupling the hydraulic cylinder to the longwall mining shield, a cylinder rod having a first end extending into the hydraulic cylinder and a second end for extending toward ground beneath the longwall mining shield, the second end being threaded axially, and a threaded wear pad threaded onto the cylinder rod. The wear pad includes a plurality of spanner holes for rotating the wear pad with a lever, at least one threaded retaining hole extending axially through the wear pad, and a retaining bolt threaded through the retaining hole until it contacts the cylinder rod.

The present invention pertains to a method for monitoring operation of a mining machine unit, particularly of a longwall mining system, having a shield unit connected to a material removing unit by means of an actuator for adjusting a distance between the shield unit and the material removing unit, the method comprises the steps of determining a position change of the shield unit during an actuating operation of the actuator; and a step of detecting a malfunction of the mining machine unit based on the determined position change.

A longwall mining shield base lift. The base lift includes a hydraulic cylinder having an apparatus for coupling the hydraulic cylinder to the longwall mining shield, a cylinder rod having a first end extending into the hydraulic cylinder and a second end for extending toward ground beneath the longwall mining shield, the second end being threaded axially, and a threaded wear pad threaded onto the cylinder rod. The wear pad includes a plurality of spanner holes for rotating the wear pad with a lever, at least one threaded retaining hole extending axially through the wear pad, and a retaining bolt threaded through the retaining hole until it contacts the cylinder rod.

Disclosed is a magnetically controlled material-based magnetorheological pilot operated safety valve for a hydraulic support. The safety valve comprises a valve body, a valve core, a reset spring, and a pilot valve; the valve core is disposed in a valve core chamber provided in the valve body, and the pilot valve is disposed in a pilot valve chamber provided in the valve body; the pilot valve includes a magnetically controlled shape memory alloy, an electromagnet, a push rod, a piston, a magnetorheological fluid control coil, and a pilot valve core, which are arranged sequentially from left to right; a plurality of magnetically controlled material control coils are provided on the electromagnet; the magnetically controlled shape memory alloy runs through the electromagnet and is then connected to the push rod, the push rod is connected to the piston, the magnetorheological fluid lies between the piston and the pilot valve core.

Disclosed is a magnetically controlled material-based magnetorheological pilot operated safety valve for a hydraulic support. The safety valve comprises a valve body, a valve core, a reset spring, and a pilot valve; the valve core is disposed in a valve core chamber provided in the valve body, and the pilot valve is disposed in a pilot valve chamber provided in the valve body; the pilot valve includes a magnetically controlled shape memory alloy, an electromagnet, a push rod, a piston, a magnetorheological fluid control coil, and a pilot valve core, which are arranged sequentially from left to right; a plurality of magnetically controlled material control coils are provided on the electromagnet; the magnetically controlled shape memory alloy runs through the electromagnet and is then connected to the push rod, the push rod is connected to the piston, the magnetorheological fluid lies between the piston and the pilot valve core.

A method for operating a continuous mining machine having a device continuously providing provisional roof support, wherein the mining machine a rolling roof-protection portion which is fixed on a main machine frame of the continuous mining machine via a front column structure and a rear column structure. While the machine is cutting, the roof-protection device performs continuous load holding on a roof, and after cutting, performs support operations, thereby achieving simultaneous performance of cutting and support operations, and improving tunneling efficiency. Different support strengths are configured according to the hardness, completeness, and quality indicators of rock on a mine roof, such that the device is able to effectively support the roof.

An equipment system for a self-retaining mining method mainly comprises a transition support, an end support, a following support, and a fast-retracting support. Working face gateroads do not need to advance in mining, and a coal mining machine may be used to cut a neat coal wall at the end of a district. The entry rib is automatically formed after roof caving, thus forming a gateroad in a re-mining process. The coal mining machine is under digital control when its end cuts the coal, automatically enabling the end to laterally cut the coal wall to form a vertical straight line, which is used as the entry rib of the gateroad. A scrapper conveyor works in coordination with an arc-shaped coal grabbing plate of the coal mining machine to clean up float coal at the end as much as possible.

An apparatus and method for protecting a person servicing a longwall shear such changing bits on a drum, embodiments relating to a base plate to be secured to an underside of a shield canopy and a slide plate movably connected to the underside of the base plate such that the slide plate can advance out from the shield canopy to allow a person to service a longwall shear while being protected by the slide plate from falling rock and other debris, and the slide plate can then retract back under the shield canopy.

A longwall mining shield base lift method. The method includes removing an old wear pad and installing a new wear pad.

A wear pad for a longwall mining shield base lift. The wear pad includes at least one spanner hole for rotating the wear pad with a lever, at least one threaded retaining hole, and a retaining bolt threaded through the retaining hole until it contacts a cylinder rod to which the wear pad is to be attached.