Fault diagnosis of hoist hydraulic station and brake system

1. common failures and troubleshooting of hydraulic pressure station and brake system

(1) there is no oil pressure; the brake does not loosen the brake

1) causes no pressure of the hydraulic pump to rotate in the opposite direction or the hydraulic pump output without the liquid; electro-hydraulic proportional relief valve device on the heart - powder die orifice plug; the hydraulic pump suction port is not smooth, oil filter clogging; the proportional pilot pressure valve poppet valve in the dirt, the cone valve does not close.

2) treatment method: first, correct the rotation direction of the pump, eliminate the hydraulic pump fault. The relief valve open for cleaning, requires heart valve in vivo flexible movement, using compressed air to Chuitong orifice. Remove filter core, clean and check whether the suction line is blocked or not. Open the pressure valve, take the cone valve heart down to clean.

(2) the system pressure, but not up to the required pressure of system pressure is not up to the required value is the reason of oil pressure system with air suction, the oil in the oil tank has a lot of bubbles, or overflow valve, solenoid valve internal leakage. To deal with this kind of fault, mainly from the following aspects:

1) check the pump suction port leaks: hydraulic pump suction pipe joint screw is tightened; the oil filter is tightened and transmitting device is tightened; the check line oil filter to the hydraulic pump suction mouth of the leaks, especially over the spherical compensation are tight; check the hydraulic pump cover screw is tightened, the tightening should pay attention to the rotation axis side side to tighten the screw, so as not to be overdone, so that the heat pump.

2) take the relief valve heart valve cleaning, if the heart valve in vivo activity is not flexible, can be held by hand grinding in the body and heart valve.

3) take the solenoid valve, valve heart cleaning, requiring the valve heart in vivo flexible movement, to ensure that the work of the valve in place.

(3) two brake oil pressure value is poor, resulting in two brake oil pressure value, the reason of poor holding pressure is:

1) the large relief valve on the block of oil has dirt stuck, so that the valve heart is not tight.

2) one-way throttle valve opening is too large, the accumulator of a large number of oil discharge, all through the overflow valve back to the tank, can not play the role of oil.

3) there is dirt in the hole of the electromagnetic directional valve, and the leakage is too large. In view of this kind of fault to take heart valve cleaning, remove dirt, make the heart valve in place, and then adjust the one-way throttle valve, the opening to open a small, to throttle and fill oil.

 (4) braking time or braking distance is too large, safe and reliable. The condition of braking is that the braking torque meets the requirement of 3 times static torque, that is, the braking torque

From the above formula, we can see that the braking time or braking distance is too long, mainly from the following 3 points: first, the brake disc and brake shoe have oil, paint or similar things, reducing the friction coefficient of the brake shoe. The solution is to wash the brake discs with trichloroethylene and replace the oil stained brake shoes. Brake seal damage or disc spring assembly is defective, so that the role of the brake disc on the positive pressure N reduced, the treatment is to replace the seal or plate spring set. Check whether the load is in static tension F. Within the allowable range, adjust the brake shoe clearance and hoist speed in the allowable range.

(5) between the valve and the oil block has a large number of infiltration between valve and oil circuit block there are a large number of oil leakage reason is the valve on the floor of the O ring is damaged or a long time, the plastic deformation, no seal, remove the oil leakage treatment is the valve, replace the O - ring has been replaced with bad the.

2. diagnostic and maintenance methods

TE121 hydraulic station and its braking system are safe and reliable in principle and structure, but due to improper use and maintenance, there will be a variety of faults. For this purpose, it is necessary to know the performance and the possible failures and the troubleshooting methods of the hydraulic station before use. At the same time, it is important to strengthen the selection and proper use of hydraulic oil, and the management of hydraulic oil filtration. It is very important for improving the safety and reliability of hoist braking system.

Hoist fault occurs, under normal circumstances, aiming at the phenomenon, first check the maintenance record lifting machine, hydraulic oil test and related drawings and data, and then observe the pressure gauge and the oil level indicator, and then check the clearance of disc brake, the disc spring group is normal, the flow circuit, hydraulic pump and the motor connecting joints have leakage phenomenon, the valve is normal, the thermometer is normal. Through the above intuitive feeling, and then carefully study the hydraulic system diagram, comprehensive analysis, you can initially determine the cause of failure and troubleshooting methods.