The elevator is a whole composed of the platform and the equipment, motors, cables and other auxiliary equipment used to control them. There will be some common failures in the daily operation of the elevator. So, how should we handle and maintain it?
1. Failure of the elevator
The elevators have been inspected and debugged before leaving the factory, and all technical indicators have reached the design requirements. When using, they only need to be connected to the power supply, and the hydraulic and electrical systems do not need to be adjusted. The elevator should be paid attention to when it is used, and it must be placed on a solid and flat ground to prevent it from tipping during work. Press the "up" or "down" button to make the table lift. If the table does not move, it should be stopped immediately for inspection. If you find that the working pressure of the electric lift is too high or the sound is abnormal, you should immediately shut down and check to avoid serious damage to the machine; check the working status of the shaft pin regularly every month. If you find that the shaft pin and screw are loose, you must lock it to prevent the shaft pin Shedding caused an accident. The hydraulic oil should be kept clean and replaced every 6 months; when maintaining and cleaning the lift, be sure to prop up the safety brace.
2. Maintenance of the lift
1. Monthly maintenance
When the elevator platform is under maintenance, people enter the interior of the elevator platform to work, and the elevator must be lifted to prevent the elevator platform from suddenly dropping and causing casualties.
A. Check the lubrication and wear of rollers, intermediate shafts and bearings; cylinder pins and bearings; boom hinge shafts and bearings;
B. Lubricate the above components. Extend bearing life.
C. Check the hydraulic oil quality and oil level. The hydraulic oil level should be 40-50 mm above the bottom of the tank when the lifting platform is raised to the highest level. When the oil color of the hydraulic oil becomes dark, the oil is sticky, or there are foreign objects such as gravel in the oil, the hydraulic oil should be replaced in time. The hydraulic system of the lifting platform should use 32# hydraulic oil.
2. Year-end maintenance
A. Check hydraulic and piping connections. If the pipeline is damaged, it should be replaced immediately; when the connection part is loose, tighten the pipe joint.
B. Remove and disassemble the drop valve, blow out the spool with compressed air and install it again.
C. Fully drain the hydraulic oil in the oil tank, open the oil tank, take out the oil suction filter, wash it and put it back into the oil tank, install it as it is. Fill the tank with new oil.
The lift does not lift or the lifting force is weak
⒈The pressure adjustment of the relief valve does not meet the requirements. Adjust the pressure to the required value
⒉ Check the internal leakage of the cylinder or replace the cylinder assembly
⒊The directional valve is jammed or internally leaked to check or replace the valve assembly
⒋The oil level is too low, the oil inlet filter is clogged, add enough oil, clean the oil filter
⒌ Check the fuel supply pump for faults or replace the pump
Ripper cannot lift or weak
⒈The pressure adjustment of the relief valve does not meet the requirements. Adjust the pressure to the required value
⒉ Leakage in the oil tank, please refer to the elimination method in 2.3.4.5 above
⒊The directional valve is stuck or leaking
⒋The oil level is too low, the oil inlet filter is blocked
⒌There is something wrong with the fuel supply pump
⒍Check the leakage of the one-way valve Check the damage of the one-way valve core and the valve seat, whether the one-way valve spring is fatigued or deformed
Operating lever is heavy
1. Check, adjust and replace the unqualified parts of the operating lever mechanism; clean the valves; check the cleanliness of the hydraulic oil
2. The control valve spool is clamped (manufacturing, installation problems, dirt problems)
The torque converter and its compensation system are faulty, such as weak torque converter, power shift failure, and high oil temperature.
1. Weak torque converter
⑴Insufficient amount of hydraulic oil
⑵ improper pressure regulation
⑶Insufficient back pressure Check the oil quality of the torque converter (whether the oil used in hydraulic transmission is misused), the amount, check the torque regulator, back pressure valve and its set pressure value
2. Power shift failure
⑴. Fast-return valve, pressure reducing valve, power transmission valve, directional valve are stuck and internal leakage
⑵. Serious oil pollution Check the cause of valve jamming and eliminate accordingly, filter or replace hydraulic oil
Hydraulic maintenance
For mechanized construction enterprises, the good condition of construction machinery technology is a direct factor for the normal production of enterprises. As far as the hydraulically driven construction machinery is concerned, the normal operation of the hydraulic system is a major sign of its good technical condition. Qualified hydraulic oil is the guarantee for the reliable operation of the hydraulic system, and correct maintenance is the basis for the reliable operation of the hydraulic system. Therefore, based on my work practice, I will make a rough discussion on the maintenance of the hydraulic system of construction machinery in the general operating environment.
Select hydraulic oil
Hydraulic oil plays the role of transmitting pressure, lubricating, cooling and sealing in the hydraulic system. Improper selection of hydraulic oil is the main reason for the early failure and the decline of durability of the hydraulic system. The hydraulic oil should be selected according to the grade specified in the random "Instruction Manual". In special cases, when the alternative oil is required, the performance should be the same as the original grade. Hydraulic oils of different brands cannot be mixed to prevent the hydraulic oil from chemical reactions and performance changes. Dark brown, milky white, smelly hydraulic oil is metamorphic oil and cannot be used.
Prevent impurities from entering
Clean hydraulic oil is the life of the hydraulic system. There are many precision couples in the hydraulic system, some have small damping holes, and some have gaps. Intrusion of solid impurities will cause strain on precision parts, card issuance, blockage of oil passages, etc., endangering the safe operation of the hydraulic system. The ways of general solid impurities invading the hydraulic system are: unclean hydraulic oil; unclean refueling tools; careless refueling, repair and maintenance; hydraulic components, etc. The solid impurities can be prevented from invading the system from the following aspects:
2/1 when refueling
The hydraulic oil must be filtered and filled, and the refueling tools should be clean and reliable. The filter at the fuel filler opening of the fuel tank cannot be removed in order to increase the fuel filling speed. Oilers should use clean gloves and work clothes to prevent solid impurities and fiber impurities from falling into the oil.
During 2/2 maintenance
Remove the fuel tank cap, filter cover, detection hole, hydraulic tubing and other parts of the hydraulic tank to avoid dust when the system oil channel is exposed. The dismantled parts must be thoroughly cleaned before they can be opened. For example, when disassembling the hydraulic oil tank filler cap, first remove the mud around the fuel tank cap, unscrew the fuel tank cap, and remove the debris remaining at the joints (do not rinse with water to prevent water from seeping into the fuel tank), and only open the fuel tank cap after confirming the cleaning. If you need to use the wiping material and hammer, you should choose the wiping material that does not remove fiber impurities and the special hammer with rubber attached to the hitting surface. Hydraulic components and hydraulic hoses should be carefully cleaned and assembled after being dried with high-pressure air. Use genuine packaging elements in good packaging. Clean the filter at the same time when changing the oil. Before installing the filter element, use the wiping material to carefully clean the bottom dirt in the filter housing.
Hydraulic cleaning
The cleaning oil must use the same hydraulic oil as that used in the system. The oil temperature is between 45 and 80°C, and the impurities in the system should be taken away as much as possible with a large flow rate. The hydraulic system should be cleaned repeatedly more than three times. After each cleaning, release all of the oil while the oil is hot. After cleaning, clean the filter, replace with a new filter and add new oil.
Prevent intrusion
3/1 prevent air from invading the hydraulic system
At normal pressure and temperature, hydraulic oil contains air with a volume ratio of 6 to 8%. When the pressure is reduced, the air will be freed from the oil, and the bubbles will burst to make the hydraulic components "cavitation" and generate noise. A large amount of air entering the oil will aggravate the "cavitation" phenomenon, increase the compressibility of the hydraulic oil, work instability, reduce work efficiency, and the actuator "crawling" and other adverse consequences. In addition, the air will oxidize the hydraulic oil and accelerate the deterioration of the oil. Pay attention to the following points to prevent air intrusion:
1. After maintenance and oil change, the air in the system should be removed according to the provisions of the random "Operating Instructions" to operate normally.
2. The oil suction pipe port of the hydraulic oil pump must not be exposed to the oil surface, and the oil suction pipe must be well sealed.
3. The seal of the oil pump drive shaft should be good, and it should be noted that when replacing the oil seal at this place, the "double lip" genuine oil seal should not be used instead of the "single lip" oil seal, because the "single lip" oil seal can only seal the oil in one direction, not The function of sealing gas. After a major repair of a Liugong ZL50 loader in this unit, the hydraulic oil pump experienced continuous "cavitation" noise, oil tank oil level automatically increased and other failures. After querying the repair process of the hydraulic oil pump, it was found that the oil seal of the hydraulic oil pump drive shaft was misused. Due to the "single lip" oil seal.
3/2 prevent water from invading the hydraulic system
Excessive moisture in the oil will cause corrosion of hydraulic components, emulsification and deterioration of the oil, reduce the strength of the lubricating oil film, and accelerate mechanical wear. In addition to preventing water intrusion during maintenance, it is also necessary to tighten the lid when the oil tank is not in use. It should be placed upside down; oil with a large water content should be filtered many times, and the dried filter paper should be replaced every time it is filtered. When there is no special instrument for testing, the oil can be dripped onto the hot iron plate without steam coming out and Burn immediately before filling.
