Common problems of excavator seals (collection version)

What are the sealing problems of our most common excavator seals in daily life?
1. Question: What kinds of seals are there for the excavator cylinder?
Answer: The hydraulic cylinder of the hydraulic excavator includes three major parts, the boom cylinder, the stick cylinder and the bucket cylinder, and four cylinders. Because each oil cylinder directly controls its working device, frequently reciprocates to realize its movement in a large thrust range, and most of them have no outer protective device, so the failure rate is relatively high in the entire hydraulic system. , Different components have different oil cylinder seals, mainly including gray rings, O-rings, and dust-proof rings, which are all different in size. It is recommended that you determine the size of the car and the oil seal of that component.

2. Question: What are the seals in the excavator?
Answer: The whole vehicle of the excavator includes various types of hydraulic cylinders, proportional valves, distribution valves, pressure valves, hydraulic pumps and other hydraulic oil system seals, as well as non-hydraulic oil systems such as engines and gearboxes. Seals etc.

3. Question: Does the seal (oil seal) need to be sealed when the excavator is installed (replaced)?
Answer: Most seals (oil seals) do not use sealant. Of course, except for some special parts. If the seal is not tight, we can consider the combined use of seals and sealant (588 sealant).

4. Question: Will the excessive sealing of the engine cover of the excavator be the cause of the high temperature?
Answer: There are many reasons for the problem of high water temperature. If the engine cover is not changed, it will not cause high temperature. Check the belt, the amount of water in the water tank, and whether there is any bubbles in the water tank. Engine problems are not small problems. Long-term high temperature will greatly affect the life of the engine. careful!

5. Question: What are the maintenance kits for excavator seals? How to classify it?
Answer: Oil cylinder repair kits; main pump repair kits; engine repair kits; basically these three kinds of seal repair kits.

6. Question: The rotary pump of the excavator seal always leaks oil! what to do?

Answer: The reasons and solutions for the total oil leakage of the rotary pump of the excavator seal:
1. The seal is aging. Seals need to be replaced.
2. The hydraulic oil seal of the rotary motor of the excavator leaks oil, and the hydraulic oil leaks into the gear box. The hydraulic oil seal of the swing motor needs to be replaced.
3. Too much oil is added. Refueling needs to be properly controlled.
Note: oil leakage must be changed. The operation of the excavator for a short time will not be affected, but a long time may cause the wear of the slewing support main support.
Knowledge point extension: The rotary pump of the excavator relies on the rotation of one or more rotors in the pump to suck and discharge liquid, also known as the rotor pump.

7. Question: What is the seal on the bucket of the excavator? Where to buy it? That is, are the two sides of the pin at the connection between the bucket shovel and the oil shovel called O-rings?

Answer: If it is the rubber ring that plays a sealing role, the scientific name should be called “filler oil seal”, and it is called a seal in vernacular; if it is a steel collar at both ends of the pin, it is called “O-shaped circlip”; find a professional to make seals Manufacturers; the latter is sold by the Mechanical and Electrical Products Distribution Department.

8. Question: How to solve the pressure relief problem of the excavator?

Answer: First of all, we have to solve the types of excavator pressure relief, and solve the problems you encounter according to the actual situation.

1. Manufacturing and assembly factors: All hydraulic components and sealing components of the excavator have strict requirements for dimensional tolerances, surface treatment, surface finish, and shape and position tolerances. If there is an out-of-tolerance during the manufacturing process, such as: the piston radius of the cylinder, the depth or width of the sealing groove, the hole size of the seal is out of tolerance, or the out-of-round due to processing problems, etc., the parts themselves have congenital leakage points. Leakage occurs after assembly or during use.

2. Assembly factors: The hydraulic components should avoid brutal operation during assembly. If excessive force is used, the parts will be deformed, especially when the cylinder body and sealing flange are hit with copper rods. Dip the parts with a little hydraulic oil, press them in gently, and use diesel oil when cleaning, especially rubber components such as seals, dust-proof rings, O-rings, etc. If gasoline is used, it will easily age and lose its original elasticity, thus losing its sealing function .

3. Oil pollution and damage to excavator accessories can be subdivided into four reasons: gas pollution, particle pollution, water pollution and damage to accessories, which may also cause pressure relief.

4. Design factors: The reliability of the hydraulic system of the excavator depends to a large extent on the design of the hydraulic system seal and the selection of seals. Due to the unreasonable selection of the sealing structure in the design, the selection of the seals does not meet the specifications. In the design It does not take into account the compatible type of hydraulic oil and sealing materials, load conditions, ultimate pressure, working speed, changes in ambient temperature, etc.

These all directly or indirectly cause hydraulic system leakage to varying degrees. In addition, since the working environment of the excavator will inevitably have dust and impurities, it is necessary to choose a suitable dust-proof seal in the design to prevent dust and other dirt from entering the system to damage the seal and pollute the oil, resulting in leakage.

9. Q: How to install the excavator plate relief valve seal?

Answer: The flow valve is a hydraulic pressure control valve, which mainly plays the role of constant pressure overflow, pressure stabilization, system unloading and safety protection in hydraulic equipment.

Disassembly steps: 1. Unscrew the 4 bolts 2. Take off the pilot valve body 3. Unscrew the handle nut, screw it in with M5 screws, and pull out the pilot valve core, gasket and spring 4. Take out the lower part of the main valve body spring , main spool

Assembly process: pay attention to the integrity of the O-ring. When assembling, put the main valve core, spring, etc. into the valve body in the above order, and hold the valve core with your fingers to slide up and down freely. 2. Put the valve core, gasket and spring in order Pilot valve body 3. Unscrew the handle nut to the front end, screw it into the pilot valve body, and tighten it with a wrench

10. Question: Is it easy to change the seal of the high pressure oil pump of the excavator?

Answer: Excavator high-pressure oil pumps are all variable plunger pumps. The seal itself is easy to replace, but once the plunger pump is disassembled, it is easy to go wrong during the reinstallation process. If it is not installed in place, the direct test run will cause the plunger pump to be scrapped, so after replacing the seal, it must be cranked manually to confirm that it is correct before starting the engine.

11. Question: Where are the excavator seals leaking oil? Common oil leakage analysis of seals?

answer:
1. Excavator engine exhaust pipe high oil leakage fault – possible causes of the fault:

1. First of all, this is not the engine oil that comes with the engine, it may be that there is too much engine oil.

2. There are cracks in the cylinder head. Why does the excavator leak oil?

3. The valve guide of the excavator is faulty, causing the exhaust pipe of the excavator engine to leak oil.

4. The seal of the excavator supercharger to the intermediate body is broken, so the engine oil is discharged along with the exhaust pipe.

5. The crankcase pressure of the excavator is high. Why does the excavator leak oil?

6. The cylinder liner, piston, and piston seals of the excavator engine are worn. Why does the excavator leak oil?

7. The separation effect of the oil and gas separator of the excavator is not good, which causes the oil leakage failure phenomenon of the exhaust pipe of the excavator engine.

8. There are also defects in the design or manufacture of other parts such as the body and piston.

Second, the inspection method for the oil leakage failure of the exhaust pipe of the excavator engine:

1. First check whether there is much engine oil leaking from the exhaust pipe? If not much (less than five drops per day), it may be normal.

2. If there is a lot of leakage, it is necessary to consider whether the engine cylinder liner, piston, piston seal, etc. are worn, causing the engine exhaust pipe of the excavator C to leak oil.

3. If not, then check to see if there is too much oil added. Why is the excavator leaking oil?

4. If not, continue to check the seal of the supercharger intermediate to see if the seal is damaged.

12. Question: Which seals are mainly used for excavator cylinders?

Answer: Mainly end cover seals and piston seals, collectively referred to as seal rings (seals)