How to solve common problems of truck crane revolving mechanism

All hydraulic pressure is the important development direction of modern automobile crane. For hydraulic car crane, Its rotary drive and its motion control mainly based on hydraulic system. Therefore, the common failure of rotary mechanism is related to hydraulic system. Secondly, the rotary mechanism consists of a supporting device, a rotary drive device and a rotary table. Its important mechanical component, rotary support, is an important mechanical component, which not only bears the self-weight of the rotating part of the crane, but also the vertical force of lifting load and the force of tilting torque. In the process of use, there must be wear and tear, and gradually the related mechanical parts can deteriorate and even damage. Therefore, the common failure of the rotary mechanism is also related to the mechanical part.On the basis of this, the failure analysis of car crane can be made from two aspects of mechanical failure and hydraulic system failure.Experience shows that slewing mechanism main common faults of rotary bearing clearance is too large, slow rotation system (weakness) or fixed, the system pressure is not normal, oil and slewing brake valve doesn't lock, etc. 
1.)  Unable or unable to turn (system pressure is normal)
1. The hydraulic motor fails, the power cannot be output normally, repair or replace.
2. Failure of the reducer, affecting power transmission, inspection and adjustment.
3. Overload. People must be re-checked to avoid overload.
4. Overflow valve, manual control valve failure, operator should check and adjustment.
2.). No rotation (normal pressure)
1. Rotary reducer gear or worm gear, worm gear damage, inspection and maintenance.
2. The hydraulic motor plunger or the bearing is stuck or worn seriously, check the maintenance.
3. The hydraulic motor output shaft is broken and renewed.
3.). The hydraulic pressure of rotary hydraulic system is low
1. The fault phenomenon
If the truck crane is in no-load and light load, the sound and speed of its rotation are normal, and when the crane is reloaded, it will be difficult to turn around or even not move.
2. The cause of the failure
Possible causes of this phenomenon are: rotary hydraulic system in low pressure relief valve, hydraulic motor wear, severe leakage or low pressure control valve set, and the operating valve stem wear serious, internal drainage, and pressure loss, etc.
3. troubleshooting
The troubleshooting method is first adjusted.There are two kinds of adjustments: one is to adjust the load when it is under load, and then adjust it when it is stopped, until it is normal in the reload condition;The pressure gauge is used to adjust the pressure of the overflow valve according to the requirements of the instruction manual (the size of the rotary pressure is related to the vehicle);The second is the hydraulic motor and the control valve overhaul, replace the wear parts.
4.). The rotary support clearance is too large
1. Reason
Rotary reducer worm gear, drive gear and rotary support gear are badly worn.
2. Elimination method
Check the clearance with a dial, such as over sized, disassembly and rotary support, and replace the relevant parts.
5.). oil leak
If the combined surface of hydraulic components is leaking oil, the cleaning shall be removed and the combination surface shall be ground with oil stone or fine sandpaper. If the conditions are available, the grinding machine can be used for processing.If the pipe thread connection is loose, tighten it.The replacement of the seal is damaged;If the hydraulic element is leaking oil, replace the shell or element.

Pre:A Convenient Mobile Automobile Maintenance Lifting Machine

Next:What does the truck crane driver should pay attention to