The document discusses continuous miners used in underground mining. It describes the JOY continuous miner product line which includes three machine classes for different mining heights: 14CM, 12CM, and 12HM series. Key components of the continuous miners are described, including the cutter, gathering head, conveyor, traction, dust collector, hydraulics, and electrical systems. Specifications for the Joy 12CM15 continuous miner used in two mining projects are also provided.

1. CONTINUOUS
MINERS
Submitted by: Abhik Chatterjee & Harshit
Mishra
June, 2011.

2. Another view of the monster : -

3. INTRODUCTION :
 The JOY continuous miner product line has
been developed to meet the high productivity
requirements of today's underground mining
industry.
 Each machine employs Joy’s multi-motor
concept with outboard access to motors,
gearcases, controllers and other major
components.

4. Types available in the market : -
The continuous miner product range is
segmented by mining height requirements into
three machine classes for low, medium and
high-seam applications.
 14CM Series Continuous Miners
 12CM Series Continuous Miners
 12HM Series Continuous Miners

5. 14CM Series Continuous
Miners
 Application Specific
Cutting Systems
 Optimum Fluid Control
 Proven Conveyor
System
 Wethead Cutterhead
Systems

6. 12CM Series Continuous
Miners
 High Voltage
Capability
 Maintainability and
Serviceability
 Wethead
Cutterhead
Systems
 Dual-Sprocket
Chain Conveyor
System

7. 12HM Series Continuous
Miners
 Largest manufactured by Joy
 Heavy-duty crawler chain, along with a heavy-
duty drive system
 Can incorporate an onboard closed loop
cooling system.
 38 inch (965 mm) conveyor for increased
production capability.

8. The Continuous Miners used in
the Sarpi and Jajhra projects of
Joy are of the 12CM Series.
There are two CMs one in each
of the projects.
Focus : -

9. Main parts of a Continuous
Miner : -
 Cutter
 Gathering head
 Conveyor
 Traction
 Dust collector
 Manifold Hydraulics
 Electrical Circuits

10. Specification : -
 Joy 12CM15 is a high capacity, totally remote
controlled CM designed for medium to high
coal seam applications. The machine has
 Cutter head drum Diameter - 1.12m
 Cutting Width - 3.3m
 Max cutting height - 4.6m
 Conveyor width - 0.76m
with 2.41m/s speed

11. Specification : -
 CM is equipped with 2 cutter heads, with standard
clutch protected, AC induction Motors (170kw)
mounted parallel to centreline of boom frame.
 Each cutter motor connects to the gearing of gear
case using an internal torque shafts.
 2 gathering head motors (AC) of 40kw
 2 traction motors (DC) of 26kw
 1 pump motor of 52kw;
 1 dust collector fan motor 19kw.
 Total Weight of CM = 58 tonns(58376kg)

12. Cutter : - Left Cutter
Drum
Centre Cutter
Drum
Right Cutter

13. There are 2 cutter motor one in each side of the
machine.
AC induction, 1500 rpm
170kw each.
Cutter Motor.

14. Tungsten carbide teeth used for cutting.
Replaced when broken and treated as consumables.
Teeth.

15. 5 Ton Hydraulic Jack.
Cutter boom.
Cutter
Boom
Shear
Cylinders

16. Gathering head : -
Centrifugal Loading Arm

17. Consists of Gathering head
motors(2) which run
CLA’s(centrifugal loading arms)
which are responsible for loading
coal in to conveyor. These CLA’s
rotate in opposite direction to each
other. Gathering head motor (AC
induction) – 2 in no’s, each of 40kw.
GATHERING HEAD &
CONVEYOR

18. 2 gathering head motors drive
centrifugal loading arms, which are
responsible for gathering the cut coal
and convey it to conveyor. The
conveyor, having conveyor chain is
responsible for the movement of coal
from foot shaft to the end of conveyor,
which dumps into Shuttle car.
GATHERING HEAD &
CONVEYOR

19. There are 2 Gathering motor one in each side of the machine.
AC induction
40kw each.
Gathering Motor.

20. Above fig is the spline
groove where the
torque shaft sits.
Torque Shaft
Torque shafts of cutter
motors and Gathering
head motors.

21. Conveyor : -
Foot Shaft Flight

22. Foot shaft is a shaft with a (4 toothed)
sprocket, over which the flight bar chain
sits, whose construction is responsible for
movement of coal.
Rear Conveyor.

23. The movement of flight bar is >100mm from center ----chain
should be tightened.
The movement of flight bar is <50mm from center ----chain
should be loosened.
Conveyor Chain
Adjustment:

24. A loose chain may jam, a tight chain may
become overloaded causing high
temperature in the drive or foot shaft
leading to excessive wear. So, in order to
address this issue a tension adjustment
arrangement is made by incorporating a
spring at the end of the take up cylinder
to the side of swing conveyor.
Conveyor Chain
Adjustment:

25. Conveyor Lift Cylinder.

26. Gathering head is raised and lowered by a single
acting lift cylinder on each side of the machine. (pic
above)
Gathering Head Lift
Cylinder.

27. Traction : -

28. Incorporates Crawler chain, brakes, Traction
Motor, Traction planetary and Traction
Reducer.
Traction motors are of 26kw of DC.
Traction motors are connected with reducer
and the sun and planetary arrangement helps
the crawler chain to move which sits on the
sprocket connected with sun shaft.
Traction :

29. Traction Motor.

30. Traction Planetary, to which sun shaft is
connected.
Sun and Planetary arrangement.

31. Traction : -
 It is equipped with spring applied, hydraulically-
released traction brakes, which are normally
applied.
 Springs inside brake assembly push a piston
against brake disks results in stoppage.
 These are released when hydraulic pressure is
applied to compress the springs and retract the
piston.
 The brake has a wear indicator pin that should
protrude approximately 2-2.8mm from the face of
brake.

32. When machine is stationary, the solenoid is in its normal, closed
position, blocking hydraulic flow to the brakes. When brakes are
released a signal sent from the control system to traction brake
solenoid when ever its trams.
Spring used in traction.

33. This uses a slurry pump – motor to remove
slurry from dust collector sump. It is located
in the dust collector fan compartment.
Dust Collector.

34. Manifold Hydraulics : -
Test Unit for
measuring....
Flow
Pressure
Temp..
Power Fill
Used for oil
filling

35. Manifold Hydraulics : -
 Pump Circuit.
 Stabilizer Circuit.
 Conveyor Elevate Circuit.
 Conveyor Swing Circuit.
 Gathering Head Circuit.
 Shear Circuit.
 Power Take-Off Circuit.
 Water System.
 Traction Brake Circuit.

36. Gathering manifold gate:
 The gathering head circuit includes components
which permit pressure assist against the gathering
head.
 Components include sequence cartridge, a check
cartridge and a bleed off valve.
 In addition to it an accumulator is also connected to
the manifold, permits to place the head in float
position.
 Accumulator receives or supplies fluid to gathering
head cylinders as they retract or extend during float
function.

37. Stabilizer cylinder

38. Mounted under the rear of the machine
allows the operator to raise or lower the back
of the machine.
Consists of a single cylinder mounted (or
stab shoe) to the under side of the rear frame
When this is completely extended, the stab
shoe will be supporting part of the weight of
the machine.
 Extending the stabilizer cylinder lifts the rear
of the machine.
Stabilizer cylinder

39. Conveyor Elevate circuit:
 These cylinders position the end of the
conveyor at the proper height for loading
operations.
 The conveyor is hinged to the machine frame
and two single –acting, telescopic hydraulic
cylinders raise it.
 The second rating is a high pressure relief
setting to protect the hydraulic cylinders from
large pressure caused by roof falls.
 Conveyor elevate port relief protects the circuit
from over pressure and set between 120.6-

40. The conveyor swing cylinder allows
the machine operator to swing the rear
of the conveyor from side to side as
needed to assist loading.
Port relief settings for extend and
retract port relief valves protect the
circuit from over pressure. They are
89.6-96.5 bars.
Conveyor Swing circuit:

41. Electrical Circuits : -
 Pilot Control.
 Breaker Circuit.
 Control and Lighting Circuit.
 Pump Circuit.
 Cutter Circuit.
 Dust Collector Circuit.
 Conveyor Head circuit.
 Gathering Head Circuit.
 Traction Head Circuit.

42. Circuit Breakers:
BREAKER Function
Main Breaker Provides power to all other
breakers
Cutter & Gathering
Head/Conveyor breaker
Provides power to cutter &
gathering head/conveyor
motors circuits
Traction Breaker Provides power to traction
motor circuit
Lights breaker Provides lights to lighting
circuits.

43. Electrical System:
 The input power to the CM is a 3 phase 950v ac
(though 1100v or 1.1KV is the specified value).
 Traction motors are controlled with a dual 6SCR
drive system.
 A control Transformer drops the line voltage to
110v AC for the control circuit, and 12 volts for the
head light circuit.
 As the resistance to the drums at cutter motor is
increased, the current monitoring feature will
regulate the DC input voltage to tram motors, and
regulate the available tram speed to the machine.

44. Electrical System:
 Traction Motor voltages: Input to traction
determines the SCR power output or motor
voltage of the SCR firing package.
 With cutters off,
 SLOW – 90v dc
 MEDIUM – 180v dc
 FAST- 365v dc
 Current limit may reduce output voltage in any
speed if traction current is too high.

45. Electrical System:
 Traction Current limit is set at maximum 360A
dc and is non- adjustable.
 Traction current is monitored by current
transformers.
 Machine is designed to provide 270v ac 3
phase (A, B, C) to the power section @ 100%
machine voltage.
 Phase is not critical as long as both the drive
(left and right) are in same phase.