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Mechanical Hydraulic Paver Common Malfunctions

AKW GROUP | Updated: Sep 11, 2017

Mechanical hydraulic paver common faults

1 machine all action failure

Analysis: As the control valve 1, 2 control all the movements are not normal, the fault should be in the public part of the two, that is, before the valve part. According to the hydraulic system block diagram, the whole machine action failure reasons are:

1, lack of hydraulic oil, oil suction circuit is poor (such as oil filter plug), oil suction and other hydraulic pump caused by insufficient or not to absorb oil, making the whole machine failure.

2, pilot oil fault. This fault only exists in the servo-operated excavator, for the mechanical rod-operated excavator does not exist. Pilot oil circuit failure will lead to insufficient pilot oil pressure, making the operating system failure, which showed the whole action failure.

3, the hydraulic pump and the drive between the drive connection is damaged. So that the engine can not drive the hydraulic pump, the pump does not have the pressure oil output, making the machine does not move. 4, before and after the hydraulic pump are seriously worn or damaged, resulting in pump output flow, lack of pressure, which caused the machine action slow or no action, hydraulic pump power regulation system failure.

In the conduct of fault checking, should be in accordance with the first easy after the first, after the principle of the first to check, the specific method is as follows:

First check the hydraulic oil. Lack of enough to check the suction pipe is broken, the joints are loose and other similar phenomena, they will cause the pump part or serious suction; check the oil filter is blocked or sucking flat, if any should be replaced. And then check the four oil filter. If a large number of metal powder and particles, the hydraulic pump damage, need to repair.

In fact, in addition to damage to the hydraulic pump, the other actuators or bearings and other damage will make the oil return filter has a large number of metal powder and particles, but here is to discuss all the reasons for the whole action failure, thus ignoring other non-common parts. But sometimes the hydraulic pump due to long-term use lead to excessive wear and tear, so there is no obvious abnormal situation in the return filter, but still cause machine failure, which must be noted. If the first two checks are no exception, this time should check the pilot oil pressure, resulting in pilot oil fault failure points are: pilot pump, pilot oil out oil filter, pilot oil relief valve, other parts of the oil leakage , If found to lead the oil pressure is insufficient, should be the first easy to guide the fault point, and then troubleshooting. If the system is still not normal, this time should be divided into two cases, ① machine completely no action, in the operation of the machine when there is no load feeling. At this time to check the pump and the power transmission between the engine part, such as whether the transmission spline damage. ② slow action. At this time the following example of a single action failure phenomenon and the reasons for analysis.

1, the action is slow or no action (including the direction of action in a direction of action). According to the principle of failure to check the first easy to difficult, first check the pilot oil, shunt overload valve; if still normal, check the valve, see the corresponding spool is stuck; if still normal, you should check the implementation of components and Related to other parts. Such as a PC3 00 a blood type excavator, in the work of the turntable when the rotation can not stop, and so stop and then can not turn, and the machine all the other normal action. Because the two directions can not turn, the motor relief valve, fill valve failure can be ruled out; check the return filter, no abnormalities, it is estimated that the motor itself should be no problem; start after the operation of rotation, listening to the engine sound load Feel, hand touch the rotary motor tubing, obviously feel the pressure of oil into the motor, which infer the operating handle, pilot oil, valve operation are normal; so that the rotary gear box has become the main suspect object. If the work of the rotary deceleration system due to damage to the components caused by sudden damage to the drive, then the rotary motor and turntable contact interrupted, turn the turntable, when the motor stops, the brake can not turn the turntable, the turntable under the action of inertia continue to turn Z After the operation is stopped, the motor can not be rotated even if the motor is working properly and the power can not be transmitted to the turntable. According to this hypothesis analysis, the motor assembly is removed and it is found that the output shaft of the rotary motor is damaged and can not be engaged with the spline sleeve, and the power connection between the rotary motor and the gear reducer is interrupted.

2, action disorder Excavator sometimes do not need to manipulate some of their own action, the nature of this phenomenon is: the work loop should be closed when there is pressure oil into the implementation of components to make action. Possible points of failure are: joystick and pilot valve (mechanical control of the machine should be rod), valve spool and ask body. The specific inspection method is: to block the corresponding pilot valve to the pilot after the test machine, if the fault disappears, indicating failure in the joystick and pilot valve part of the Z should check whether the spool stuck, excessive friction wear or assembly errors; If the spool is normal, should continue to check with the valve core with the valve body and other components (such as oil seal), etc. are damaged.

There is a PC3 00-I excavator, each time in the work for some time, the left track will automatically walk, after a long stop and then start, the fault disappears, and then work for some time and then repeat the aforementioned phenomenon. This model for the mechanical rod-type control, will manipulate the left track of the rod removed, the failure does not disappear. Check that the spool is not in the middle, open the other end of the valve cover, the valve back to the middle, the fault disappears. After careful inspection found that the core hole in the hole there is an oil seal, the spool from the oil seal through the oil seal in the valve body and the valve core between the sealing effect, because this oil seal aging, sealing effect weakened, making the valve body In the pressure of the oil can slowly flow along the valve seat hole to the valve core has a sealed end of the seal when the oil to a certain extent, it will push the spool near the end of the rod, the spool away Bit, so crawler walking. Replace the oil seal after the failure disappears.