Mast, drill rod, power head, winch are important components of rotary drilling rigs involved in direct hole forming. The verticality of the mast directly determines the verticality of the pile hole, the normal extension and retraction of the drill rod and the normal lifting of the wire rope ensure the depth of the pile driver's hole, and the rotation of the power head determines the drilling degree and construction efficiency of the pile. This part is the most prone to failure except for the engine and hydraulic system. Therefore, maintaining correct maintenance and care can reduce the failure rate of this part. Once a failure occurs in this part, we must analyze it in detail and know how to solve the problem.
1. Insufficient torque of the power head of the rotary drilling rig
Fault phenomenon: The power head torque of the rotary drilling rig is insufficient during drilling construction, the forward and reverse speeds of the power head are not enough, and there are abnormal noises when the power head motor and reducer are running.
Fault analysis: Insufficient torque of the power head can be considered from two aspects: hydraulic and mechanical: 1. Insufficient hydraulic oil pressure in the hydraulic system; 2. Power head motor failure, reducer failure or gearbox failure, etc.
Cause of failure:
1. Insufficient pilot pressure or too low pressure of relief valve setting;
2. Damage to power head motor or large leakage of hydraulic oil;
3. Damage to power head reducer parts;
4. Damage to power head gearbox mechanical device.
Troubleshooting method:
1. Check the main system pressure of the hydraulic system and it is normal, indicating that there is no problem with the hydraulic system and mechanical damage is considered;
2. During the inspection of the hydraulic system, it was found that the reducer and motor had a small range of periodic abnormal noise when the power head was running. Disassemble the power head motor, check the motor and output shaft, and they are normal;
3. Remove the reducer and disassemble the reducer. Note: When disassembling, the disassembly environment should be kept clean and the disassembly sequence should be paid attention to for installation. Carefully check the inside of the reducer and find that the gear is damaged. When disassembling the reducer, pay attention to the order of parts arrangement, all bolts, gaskets and parts should be cleaned, and the reducer should be kept clean when installing;
4. Replace the damaged gear, reinstall the reducer and motor, restore the drilling rig power head, and the drilling rig resumes normal operation.
Troubleshooting experience: Mechanical damage to the power head reducer will cause insufficient output torque of the power head, and abnormal noise can be heard. Be sure to find the problem in time to avoid the expansion of the damage range.
2. The mast cylinder of the rotary drilling rig leaks oil, and the mast is not vertical
Fault phenomenon: The mast cylinder of the small rotary drilling rig leaks oil, and the mast is not vertical.
Fault analysis: The mast cylinder piston rod head is broken or the mast cylinder oil seal is damaged, causing the mast cylinder to leak oil; the mast is not vertical, you can start from the cylinder and the mast cylinder balance valve, and the cylinder leakage or balance valve leakage can also cause the mast to be not vertical.
Fault cause:
1. The mast piston joint head is broken; 2. The mast hydraulic cylinder oil seal is damaged; 3. The balance valve leaks.
Troubleshooting method:
1. Inspection found cracks on the joint head of the cylinder piston. Further inspection: disassemble the mast cylinder for inspection and find some obvious spots and shallow grooves on the surface of the cylinder;
2. Open the entire cylinder and oil seal and find that the cylinder oil seal and O-ring are damaged, and the gasket is cracked, causing oil leakage in the cylinder;
3. Replace the oil seal, sealing ring and gasket, and reinstall the cylinder. The test shows no leakage, and the drilling rig returns to normal.
3. The rope press of the rotary drilling rig cannot rotate
Fault phenomenon: The rope press of the small rotary drilling rig is stuck and cannot rotate, and the wire rope is severely worn.
Fault analysis: The rope press cannot rotate and the wire rope is severely worn. Generally, the rope press is not maintained in time, and there is a lack of lubricating oil in the rope press, which causes the rope press to rotate inflexibly and deform, and even the internal bearing of the rope press is damaged and stuck, and the rope press wears the wire rope.
Fault cause:
1. Lack of lubricating grease inside the rope press;
2. Deformation of the rope press;
3. Damage and jamming of the internal bearing of the rope press.
Troubleshooting method:
1. On-site inspection of the rope press, no deformation, and serious wear on the surface of the rope press;
2. Disassemble the rope press and check that there is a lack of lubricating grease in the rope press;
3. Further disassemble the rope press and find that the internal bearing of the rope press is damaged, causing the rope press to be unable to rotate;
4. Replace the internal bearing of the rope press, reinstall the rope press, add lubricating grease, and troubleshoot.
What is "maintenance" - Before the machine breaks down, you should perform maintenance on the machine according to the maintenance manual, such as grease, change engine oil, change filter element, change hydraulic oil, etc. When a fault occurs, you should eliminate and repair it in time to prevent the fault from expanding.
