First, plunger tank
Insufficient thrust
1 Hydraulic system is insufficient. Check the relief valve to improve system pressure.
2 After the plunger and guide sleeve are wear, the gap is increased, and the oil can be severe. Replace the guide sleeve, the inner hole and the plunger outer circle fit gap is 0. 02-0. 03mm.
3 The oil port is damaged or the nut is not tightened, and it is severely leaked. Replace the tube connector or tighten the nut to prevent oil leakage.
2. There is crawling when working
1 The plunger cylinder shaft line is compressed. Parallelity should be in 0.1. 2mm.
2 The plunger cylinder shaft line is not perpendicular to the active end. The vertical degree should be about 0.1mm.
3 The gap between the plunger and the guide sleeve is too small. The requirements are within 0.02 ~ 0.03mm range.
Second, the Kobelco excavator piston tank
1. Generate crawling or local speed uneven
1 mixed gas in the cylinder. Open the exhaust valve and quickly exhaust the cylinder. Adding an exhaust valve without a free gas valve.
2 The piston rod is in the same shaft of the piston, and the coaxial degree should be in the range of 0.04 mm.
3 The piston rod is partially curved. Correction, the full length calibration value should be within 0.2 mm.
4 The seal is too tight or too loose.
5 low installation accuracy. Its parallelism, verticality should be within the range of use.
6 Cylindrical rust or puller. Turnover rust and burrs when it is slightly. When it is serious, it is necessary to process lithium beds.
The 7 rod end nut is tightened and the piston rod is deformed. The rod end nut should not be screwed too tightly, generally tightened (tightened by the cassette), so that the piston rod is in a natural state, and then lock the double nut.
2. Piston rod or cylinder cannot move
1 Long-term no rust. Demolition, remove rust, and severe, re-iron, and then distribute.
2. The seal seal is aging, failed, and the inner drain is serious. replace.
3 The precision in the cylinder is poor, rough or damaged, which increases the inner drain. Repair or replace.
4 Dirty into the lubrication component. Demolition, replace the oil if necessary.
5 Cylinder end seal is damaged. replace.
6 cylinder assembly quality difference (rod, the coaxial degree error between the piston and the end face, low installation accuracy, etc.). Re-assemble and install, unqualified parts should be replaced.
3. Insufficient thrust, slow working speed.
1 The gap between the red hole and the piston is too small or too shallow, so that the O-shaped seal forms a resistance. Re-formulate the gap, the car is deep.
2 The cylinder and the piston gap are too large, and the piston is interoperable. Re-formulate the piston.
3 piston rod bending. Correction, full length is in the range of 0.2mm.
4 The seal in the end face is too tight. Suitable relaxation screws and is limited to non-leakage.
5 The system leaks, causing insufficient pressure and traffic. Isors the system leakage components, fasten the joints, or perform relevant sealing processing. When the traffic is insufficient, it is more necessary to check whether the pump output flow and whether the pressure reaches the rated value.
6 The cylinder oily tube is flattened due to poor assembly. Replace the tubing and avoid it again.
7 The system is adjusted low. Adjusting the relief valve system pressure is within the specified range.
8 The oil temperature is too high. When the oil temperature specifies the value, the system should be made after cooling.
4. External leakage is serious
Outer leakage is the most problem in the piston cylinder failure, but also the most affected, environment.
(1) Piston rod leak
1 Leakage caused by the wear of the seal. The reasons for the wear of the seal is usually caused by the liquid sleeve in the sliding wear. Leakage caused by seal damage, the most critical Y-shaped seal is the lip side. When the seal is installed, the lip should be damaged. The seal should have no burr, and the transition portion should be smooth. The sealing lips cannot be loaded or unavailable, and it is more impossible to reverse. For small Y-shaped (ie yx), pay attention to the shaft, the hole is used, and the short lip should be a relative moving side (in the piston, the small YX-shaped short lip is opposite the cylinder relative moving side) Don't make a mistake. Sometimes, although the seal is not damaged, the seal lip is relatively rough, and it will also cause leakage.
2 Leakage caused by permanent deformation after sealing rubber compression. Due to the material problem of the seal, long-term compression, rubber loss elastic, resulting in leakage.
3 Leakage caused by external impurities into the seal. The sealing lip sometimes causes a leakage from the cylinder rod activity due to the outer minimal sand. To this end, it should be protected by a sealed dust cover in the wild operation.
4 Erroidly use a seal of cylinder. For V-shaped seals, the ends of the V-shaped seal lip side for cylinders are sharp, and the piston rod acts as a scratching effect when the piston rod is applied, thereby generating a piston rod to generate a droplet drop. The hydraulic cylinder is filled with a V-shaped seal lip end portion, which forms a thin oil film on the piston rod to lubricate.
(2) Outer leakage generated by the cylinder and end cover joint
Binding of the cylinder and end caps There are two ways of bolt fastening and threaded connection.
1 bolt fastening method. The bolt fastened manner has a flange connection, a semi-ring connection, and a fixed bolt connection. In this way, there are two O-ring seals and end sealing. In the O-ring sealing method, a leakage from a mating gap is generated; in the end face sealing method, the bolt is tightened, and a leak is generated.
2 thread connection method. Threaded connection is two types of internal threads and external threads. At large diameters, since the strength of the fastening end cap is often less than the rated torque, it is possible to increase the leak, so it is necessary to have a special tool to tighten and reach the torque value of the rated required.
(3) Leakage caused by hydraulic cylinders into oil port
This is mainly due to the looseness caused by the vibration caused by the vibration in the oil supply pressure impact or working, needs to be inspected and tightened.
