Wheel Loader Maintenance

Wheel Loader Maintenance

Date:Jan 22, 2018

Discussion on the maintenance of loader

According to the length of the working time of the wheel loader, the operating environment and the actual technical condition of the loader, the six level maintenance period can be adjusted properly.

The contents of the maintenance at all levels are as follows:

Day maintenance

It is done by the driver on its own, before driving every day and after taking the car. The contents of the work are as follows:

1. check the engine oil, lower oil scale line should be higher than the gas, such as oil dipstick line, we should find out the reason to increase (diluted);

2. check oil tank oil surface;

3. check the tightening and sealing of the engine, torque converter, hydraulic pump and steering gear, and whether there is overheating.

4. inspection of oil leakage, leakage, leakage, leakage, leakage of electricity, and so on.

5. check the bolt of the drive shaft and the universal joint and the pin of each pin to be loose or lost.

6., keep vehicle clean appearance of the car, no oil, dirt and other debris;

7. check the whole machine everywhere have unusual noise, chattering and so on abnormal phenomenon.

Weekly maintenance

It is done once a week by professional maintenance personnel, except for the daily maintenance.

1. according to the specified position and the specified oil (fat) grade refueling;

2. cleaning oil coarse filter, fuel oil filter and air filter filter core;

3. check and adjust the tightness of the fan and generator belt.

4. check and add oil in the injection pump body.

5. check the level and density of the battery electrolysis and the electrolysis level at the 10 ~ 15mm of the plate, and the distilled water should not be added.

6. check and adjust the free travel of each pedal.

7. check the throttle, parking brake, transmission and other joystick are not stuck, inflexible and so on.

Three, month maintenance

The professional maintenance staff will do it once a month, except for the completion date and the weekly maintenance work.

1. cleaning oil fine filter and fuel filter filter cartridge;

2. check the tire pressure and wear, the pressure is 0.27 ~ 0.39MPa (2.8 ~ 3.0kgf / cm2), and the lower limit is taken when the soft ground is done on the ground.

3. check frame, working device by large parts of the weld force, no cracking phenomenon is unsoldering.

Failure prevention and daily maintenance of wheel loader gearbox

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 loader 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.

1. 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.

Two, common failures 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 fails, the main cause of failure is the serious wear of the positioning steel ball, or the failure of the spring.

(2) because of the long-term use of shift lever, the position and length of pole change, the proportion of bar is not accurate, resulting in deviation of operation position, resulting in dislocation.

Three. 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) fixed oil exchange interval

The key to the longest working life in the gearbox is to exchange oil at 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) adopting the correct method of row and oil exchange

When the oil is released, the oil temperature should reach 40~50 degrees, and the oil flow should be discharged under the condition of agitation. The dirty oil should be drained as far as possible. When adding oil, the oil dispenser with filter device should be added to it.

(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 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.

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