maintenance content
Gearbox is one of the important parts of machine drive wheel loader, it is responsible for the transmission of the engine from the speed and torque to the final drive system, and change the transmission ratio between the engine and the wheels, loading machine forward and reverse gear control, and can realize the engine running condition to cut off power walking device, in order to adapt to the and the need of driving, easy to start and stop the engine safety.
But in the loader working process, due to gearbox failure caused by improper use and maintenance of the rate has been high, especially in the use of not strictly comply with the maintenance procedures, the lack of timely inspection and maintenance, formation of gearbox fault and damage acceleration, harm will even expand the fault.
The purpose of preventive maintenance
1, through the tracking of the running of the loader, there is a planned shutdown to do a good job of maintenance and repair arrangements for the gearbox.
2, to prevent major mechanical failures and related parts damage, repair before the failure of the fault, in order to save a large amount of maintenance costs.
3, the whole machine parts have long service life, improve the efficiency of equipment and maintain good working performance.
4, reduce the difficulty and workload of maintenance.
Precautions for the maintenance of Loaders
1. Mastering the operating specifications of the loader
For the loader operator, should master the skills of equipment, in accordance with the safety technical code for correct operation of loaders, truly achieve the "three" (understand the structure, understand the principle and understand the performance), "four" (use, maintenance, inspection, remove common fault). Not only to open the equipment, but also to understand the equipment will check the maintenance equipment, in order to ensure that the loader life longer.
2, reducing the impact of the environment on the loader
Many users will ignore the impact of environmental climate on the lifespan of the loader. As is known to all, most of the engineering machinery and equipment are open-air operations. According to the different works, the location of work will also change. The equipment will be easily influenced by the temperature, environment and climate of the site. If the machinery of long-term fixed site work, it is best to have a stop room (shed), or use the upper cover, as far as possible to reduce the damage caused by the sun and rain. Therefore, the corresponding measures of machine protection should be taken according to the climate and environment.
3, do not neglect maintenance because of the tight period of time
Not because the construction period of the construction unit is tight, the importance of the neglect of maintenance, maintenance of engineering machinery equipment as long as the error that be careless with, the normal operation of no fault, you can sleep without any anxiety; not timely maintenance will have great potential, there are many big accidents, so save the real days and months multiplying, at the time of the accident it is too late, therefore, can not forget to catch the loading machine maintenance engineering.
4. Adopt appropriate maintenance methods
The loader can not be repaired until it has to be repaired. When the fault is found, it should be repaired and repaired in time. Maintenance practice can adopt the following methods: one is the part of transposition, many parts of construction machinery such as bulldozers, excavators track pin, diesel engine cylinder, in operation are often subjected to unidirectional load, resulting in uneven wear, if timely replacement by unbalanced load parts, make them wear leveling and it can prolong the service life. The two is to adopt advanced brush plating and adhesive repair technology, and also to quickly and economically repair defective parts, such as wearable surfacing, spraying diamond electroplating, magnetic plating, laser plating and so on.
5. The use of qualified accessories and oils
During the maintenance of loaders, the replacement of spare parts can not be cheap and replace the inferior accessories 名媛直播. This is very damaging to the equipment, and the probability of failure at later stage will increase. Also, when changing oil, hydraulic oil, gear oil and other oil 名媛直播, we must choose the suitable type of loader's oil, and not replace the low quality low quality oil 名媛直播.
Common faults and causes of wheel loader gearbox
1, when the gear is hung, it can not enter the gear smoothly.
The reasons are as follows:
(1) pressure valve pressure is too low;
(2) the hydraulic pump is not working well, and the seal is not good.
(3) plugging in hydraulic pipeline;
(4) the seal ring of the clutch is damaged and leaked.
(5) the valve stem is not in place.
2. When the gearbox is variable, the gear can not be removed. The reasons are as follows:
(1) the piston ring expands to death;
(2) the friction disc of the clutch is burnt down;
(3) the clutch return spring is invalid or damaged.
(4) block the oil back line.
3, it has been hung up, but the loader is weak and can not even walk.
The reasons are as follows:
(1) the wear of the friction plate is serious and the gap is too large.
(2) clutch automatic emptying valve seal is not strict, so that the pressure drop;
(3) blocking the line of the shift control valve.
(4) the shut-off valve can not be returned to the position;
(5) the positioning spring of the transmission valve is tired or broken, and the steel ball is beating.
(6) the clutch piston ring, the seal ring is seriously worn, so that the leakage is serious.
4, the control pressure is too low.
The reasons are as follows:
(1) the oil base of the gearbox is not enough.
(2) oil leakage in main oil channel;
(3) the gearbox filter is blocked;
(4) damage to the steering pump (or hydraulic pump), causing serious internal leakage;
(5) the pressure adjustment of the transmission pressure valve is not adjusted;
(6) the spring of the retaining pressure valve is invalid or broken.
5, the gearbox is automatically removed or disorderly.
The reasons are as follows:
(1) the shift control valve positioning device failure, failure is mainly caused by positioning steel ball wear, or spring failure; (2) the shift lever used for a long time, position and length of the bar changes, bar proportion is not accurate, the operation position deviation, resulting in dislocation.
How to carry on the preventive maintenance of the gearbox
1, according to JB / Z19483, combined with the maintenance practice, should abide by the following provisions:
(1) daily maintenance: check oil low - shell oil level;
(2) 50 hours (or weekly): check the flexible and effective speed control handle;
(3) 250 hours (only after the first 250 hours of work): cleaning the gearbox oil pan and the transmission filter cartridge of the gearbox;
(4) 500 hours: cleaning the oil bottom shell filter and changing the oil liquid of the gearbox.
(5) 2000 hours: the disintegration inspection and overhaul of the gearbox and torque converter.
2, hydraulic transmission oil is the carrier of energy transmission work, in hydraulic transmission system, the working fluid pressure, temperature and flow rate are decided by the transmission can work normally, so the transmission of daily maintenance work, should pay special attention to the hydraulic transmission oil inspection and replacement.
(1) the key to get the longest working life of the components in the gearbox is the proper interval between the fixed oil exchange interval and the correct time interval. Only by ensuring a reasonable interval of oil change can the lubricating and protective properties of the lubricating oil be brought into play. Generally speaking, it should be based on the recommended maintenance cycle for the whole machine manufacturer, but this can only be relative, and must be combined with the oil sample extraction and analysis results, so that we can know the actual working situation. For example, the maintenance manual requires the transmission interval of the gearbox to be 500h. According to the operation of the loader, we take a sample analysis of the oil sample every 250h or 100h to decide when to change the oil, but when the lubricating oil is used to 1000h, it should be changed immediately. In addition to the regular replacement of new oil, in the usual inspection, such as when the oil is found to be deteriorated or mixed with impurities, it should also be cleaned and replaced with new oil.
(2) when using the correct method of discharging and changing oil, the temperature of the oil should reach 40~50 degrees, and the oil flow should be discharged under the condition of agitation. The dirty oil must be drained as far as possible. When adding oil, we should use the refueling machine with filter device to add oil.
(3) using the correct transmission system oil, the lubricating oil used in the gearbox must be in accordance with the specification. It should be noted that cannot be added to the diesel engine gear box, because diesel engine oil can reduce the friction between the piston and other moving parts, and the transmission system is to make the oil friction between certain friction in combination, the friction force is essential for the normal work of the transmission system. Only the correct use of lubricating oil can effectively prolong the working life of the clutch friction plate. Meanwhile, the correct use of oil can obviously improve the gear's wear resistance, eliminate the clutch slip phenomenon, control the brake's trembling and abnormal sound, increase the braking force and provide greater traction. At present, the most used hydraulic transmission oil for gearbox is No. 6 and 8 hydraulic transmission oil.
(4) replace the filter cycle reference manual provides maintenance, replace the filter in a timely manner, while cleaning filter, oil drain plug, magnet air plug, according to the standard amount of lubricating oil. If transmission oil viscosity is too large, will cause the transmission efficiency is low, liquidity is not good, bad heat, and may be part of the dry friction between the high speed, the relative motion of the components of bad lubrication; if the gearbox oil viscosity is too small, can increase the amount of leakage, caused by the transmission to control oil pressure is too low, the formation of fault, oil film strength between the transmission parts of large load is not enough, resulting in early wear of the transmission components, and thus bad lubrication. At the same time, the gearbox in the normal work because the oil stirring gear will produce a small amount of air bubbles, in order to prevent bubbles accumulate, resulting in cavitation phenomenon, the oil film thickness is reduced thereby affecting the internal transmission clutch and the control valve, the gearbox oil must have anti foaming properties. Therefore, adopting proper transmission oil can not only protect gearbox, extend the service life of gearbox, reduce the failure rate of gearbox, but also reduce the direct cost of gearbox oil change maintenance, and reduce the maintenance time of gearbox, manual and maintenance.
(5) all kinds of lubricants must be pure, and after a period of precipitation, meet the requirements of the specified quality. The filling tools, containers and each oil injection should be scrubbed to prevent water and dirt from entering the oil. When the oil is checked, the vehicle must be horizontally and horizontally. Be sure to check the oil leakage after refuel and oil change.
Therefore, to strengthen the loader gearbox fault prevention and routine maintenance in the process of daily use is very necessary, which can not only reduce the work efficiency is low, because downtime caused by the delay time, but also can prevent and avoid greater subsequent failure, reduce maintenance costs, improve the security of the machine.
