There are many kinds of shearer faults, but there are mainly three kinds of faults, namely mechanical system fault, hydraulic system fault and electrical system fault.
Common fault types of the cutting part are shown in the table.
| S/N | Fault classification | Origin |
| 1 | Abnormal noise of operating clutch | The copper sleeve is severely worn |
| 2 | Deposited oil in motor cavity | The coal cinder blocks the oil overflow port, and the oil leakage accumulates in the motor cavity |
| 3 | Clutch cannot rotate | The safety pin of the operating clutch is broken |
| 4 | Sliding seal leaks oil | The sliding seal ring loses elasticity, or the flange plate falls off due to loose bolts |
| 5 | Rocker arm gearbox planet carrier floating seal failure | Floating seal structure design problem or unqualified installation |
| 6 | Bearing damage | Bearing overload or poor lubrication |
| 7 | Rocker arm cannot be lifted | The voltage is abnormal or the solenoid valve is damaged |
| 8 | Wear, scuffing and corrosion of gear surface | High temperature of tooth surface contact point; The gearbox is poorly lubricated; Poor gear manufacturing process; Poor noodles in fully mechanized mining face |
| 9 | Broken internal gear ring | Gear fatigue damage or motor torque shaft fails to achieve overload protection |
(1) Mechanical system failure. Mechanical system faults mainly include bearing faults and gear faults. Bearing failure is mainly caused by wear. This kind of wear is generally caused by the friction increase caused by the untimely filling of lubricating oil or the displacement of the installation position. Therefore, the analysis of bearing failure focuses on bearing quality and maintenance. For gears, tooth surface wear and contact fatigue are common fault manifestations. The main cause of this kind of fault is also the increase of friction force for a long time;
(2) Hydraulic system failure. The occurrence rate of hydraulic system failure is generally high and the situation is complex, which usually includes brake system failure and height adjustment system failure. There are many specific causes, such as: damaged solenoid valve, low oil pressure, poor gasket assembly, failure of safety valve or reversing valve, etc;
(3) Electrical system failure. Electrical system failures mainly include failures of components such as pump motor, rocker arm, electric cabinet, frequency converter, cutting motor, etc.
The cutting part of the shearer is a frequent fault location, which is the key research object of the author; At the same time, the causes of cutting part failures are relatively complex. The failure rate of its gears and rolling bearings accounts for 90% or more of the total transmission failures, and the failure frequency is extremely high. The gear is an important part in the cutting section, which transmits all cutting energy when the gear runs at high speed.
Common fault forms of gears include: gear fracture, pitting and peeling of gear surface, gluing of gear surface, wear of gear surface and plastic deformation of gear surface. The common cause of the above faults of the gear is that the gear is overloaded and prone to fatigue fracture. The shearer frequently starts and stops under heavy load or operates wrongly (such as cutting the top and the ground), and the gear at the cutting part is easy to produce vibration and impact, which causes the gear overload to break.
The other fault mechanism is that the gear has poor lubrication or excessive impurities, and abrasive substances are introduced into the cutting area, resulting in abrasive wear, pitting and peeling. With the increase of service time, the lubrication gradually fails, the temperature of the gear meshing area rises, and local overheating causes tooth surface scuffing; In addition, the gear accuracy grade is not enough or the material strength is not high, resulting in plastic deformation of the gear and sharp tooth profile; Or the bearing is damaged or the meshing clearance is adjusted improperly.
Therefore, the cutting gear of shearer is taken as the main fault research object to predict and classify its faults.