a machine used for coal mining

1. LONGWALL MINING
MACHINE:SHEARER
SHEARER

2. GENERAL DESIGN
• Machine body containing electric motors,hydraulic
equipment and controls mounted over Amoured
face conveyor
• Horizontal cutting drums are mounted on the face
side of the machine,laced with cutting picks and
rotating in a plane parallel to face
• Hydraulic roofs installed for support

3. DESIGN

4. PRINCIPLE OF OPERATION
Working under the steel canopies of hydraulic,
movable roof supports, a shearer runs back and forth
along the face,taking a cut during each pass.
The cut coal spills into an armored chain conveyor
running along the entire length of the face.
This face conveyor dumps the coal onto belt conveyors
for transport out of the mine.
As the cutting machine passes each roof support, the
support is moved closer to the newly cut face to prop
up the exposed roof.

5. POWERING MECHANISM
• . To move the machine, up to four electrically
powered main motors are used
• Each motor is operated by a gear unit and a gear
wheel engaging with a lantern wheel, a type of
chain.
• Hydraulic power is used for hydraulic ranging arms
• Hydraulic power for roof supports

6. TYPES
• Double drum ranging shearer
• Single drum ranging shearer
• Single drum fixed shearer
• Plows

7. APPLICABILITY
• Double drum ranging shearer are used in thick
seams
• For less than 52 inches of clearance,single drum
machines are used
• Plows are used in thin seams

8. SAFETY FEATURES
• Emergency stop switch
• Automatic pre start warning devices
• System which automatically stops haulage in case of
over tensioning of electrical supply cable
• All operating controls for systems powered
hydraulically shall be designed to automatically
return to the "OFF" position on loss of pressure, to
avoid inadvertent start-up when the electrical power
supply to the shearer is energised