Knowledge of maintenance and maintenance of Loaders      

Basic knowledge of loader repair and maintenance of the 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 backward gear manipulation, and can realize the engine running to cut off power walking device, in order to adapt to the needs of loader and 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.

First, the purpose of preventive maintenance

1, through the loader running tracking inspection, scheduled to stop, do a good job of gearbox maintenance and repair arrangements.

2, to prevent the main mechanical failure and related parts damage, repair before the fault germination, in order to save a lot of maintenance costs.

3, make the whole machine parts have a longer service life, improve the efficiency of equipment, maintain good working performance.

4, reduce the difficulty and workload of maintenance.

Query two, fault repair and maintenance of loader:

1, when blocking, can not enter the gear smoothly. There are reasons:

(1) the pressure of the pressure valve is too low;

(2) the hydraulic pump is not working well and the seal is bad;

(3) hydraulic pipeline blockage;

(4) damage and leakage of clutch sealing ring;

(5) the valve stem is not in place.

2, when the gearbox changes, the gear can not be opened. There are reasons:

(1) piston ring bulging;

(2) clutch friction plate burnout;

(3) clutch return spring failure or damage;

(4) blockage of return oil pipeline.

3, gear, but the loader operation is weak, can not even walk. There are reasons:

(1) the wear of the friction plate is serious and the clearance is too large;

(2) the clutch automatic emptying valve seal, the pressure drop;

(3) the shift control valve is blocked;

(4) the shut-off valve can not return position;

(5) the transmission valve positioning spring fatigue or fracture, ball beating;

(6) the clutch piston ring, the sealing ring wear serious, so serious leakage.

4, the operation pressure is too low. There are reasons:

(1) the oil content of the transmission oil pan is insufficient;

(2) oil leakage in main oil channel;

(3) the jam of the transmission filter;

(4) steering pump (or hydraulic pump damage, resulting in serious leakage);

(5) improper adjustment of the pressure regulating valve of the gear box;

(6) the spring of the pressure valve is broken or broken.

5, automatic transmission gear or block. There are reasons:

(1) the positioning device of the shift control valve fails, and the main reason for the failure is the serious wear of the positioning steel ball or the failure of the spring;

(2) because of the long-term use of the shift lever, the position and length of the rod changes, and the proportion of the rod is not accurate, resulting in the deviation of the operating position, resulting in dislocation.

Three, how to carry out the repair and maintenance of loader?

According to 1, JB/Z194-83, and combined with the maintenance practice, should abide by the following provisions:

(1) daily maintenance: check the oil level low shell;

(2) 50 hours (or week): check the transmission handle is flexible and effective;

(3) 250 hours (only after the first 250 hours of work): clean the transmission oil pan and filter element of the transmission filter;

(4) 500 hours: cleaning the oil pan filter, replace the gearbox oil;

(5): 2000 hours of gearbox, torque converter overhaul maintenance.

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 change intervals

Changing oil at the correct time interval is the key to make the parts in the gearbox get the longest working life. Only to ensure reasonable oil change intervals, in order to play the lubrication and protection characteristics of lubricating oils. In general, it should be based on the maintenance cycle recommended by the whole machine manufacturer, but this is only relative, and must be combined with the oil sample extraction analysis results, in order to know the actual work. For example, the maintenance manual requirements of gearbox oil change interval is 500h, according to the operation of the loader, every 250h or 100h for a sample analysis of oil samples, to determine when the oil, but the oil used to 1000h should be replaced immediately. In addition to regular replacement of new oil, in the usual inspection, if the oil is found to degenerate or mixed with impurities, it should also be cleaned and checked, and replace the new oil.

(2) adopt the correct method of row and change oil

When oil is released, the oil temperature should reach 40~50 degrees, and the oil flow should be discharged in the case of agitation, as far as possible to completely empty dirty oil; when refueling, should use a filter device refueling machine to add oil.

(3) the use of transmission system of the right oil lubricating oil, gearbox used must conform to the standard. 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 lubrication oil, can effectively prolong the service life of the clutch friction plate. At the same time, the correct use of oil can obviously improve the wear resistance of gear, eliminate the clutch slipping phenomenon, control the brake tremor and abnormal sound, increase the braking force, and provide greater traction force. At present, the use of hydraulic transmission gearbox oil up to No. 6 and No. 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, the appropriate transmission oil, which can not only protect the gearbox, prolong the service life of the gear box, reducing gear box failure rate, the direct cost and can reduce the transmission oil maintenance and reduce gearbox maintenance manual and maintenance of parking time.

(5) all kinds of lubricating oil must be pure, and after a period of precipitation, in accordance with the quality requirements.

Filling tools, containers and the oiling mouth should be clean, prevent moisture and dirt into the oil.

Check the amount of oil when the vehicle must be in the longitudinal and transverse directions are in the state level.

Refueling, be sure to check the oil after no leakage phenomenon.

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.