The working condition of the excavator cylinder is very hard. Challenges are as follows: the working pressure of the hydraulic system is large; the impact pressure is relatively high; the lateral load is large; the working temperature and the moving frequency are relatively high. Therefore, the performance of the excavator cylinder will have a direct impact on the quality of the entire machine.

Excavator cylinder components mainly include: a cylinder, piston, piston rod, bumper, external seals and standard parts.

YBAS SEALS is one of the most reliable and most professional excavator seal manufacturer in China, we pay attention to quality, control costs. We can provide the most competitive price and best quality for customers. Our main products: oil seal, seal kit and o-ring kit box. We specialize in the spare parts: boom cyl kit, arm cyl kit, bucket cyl kit, hyd(main) pump kit control valve kit etc. and loose parts for Caterpiller, Komatsu, Hitachi, Kobelco, Kato, Sumitomo, Volvo, Hyundai, Doosan and Daewoo excavators. We export large quantity to Africa and Asian countries, deal to high quality and reasonable price. We are ready to refer you our favourable price and relative samples, for quality evaluation and marketing activities.

1. Piston seals

The seal of the piston is composed of a wear ring, an anti-pollution seal ring and a combined seal ring.

The wear ring can support and guide the piston to avoid eccentricity or scratching, and it has a certain effect on enhancing the durability of the seal. The support belt must be a product with high load carrying capacity.

Wear ring for the general use of cloth to strengthen the interlayer phenolic resin. It has good wear resistance and bearing pressure. The pressure of the phenolic cloth guide belt can reach 300Mpa, which is ten times that of the Teflon bronze guide belt. The anti-pollution sealing ring can effectively avoid the oil mixing in the cylinder. Impurities cause damage to the seal. And to provide a guarantee for the life of the seal.

The material of the anti-pollution sealing ring is a polytetrafluoroethylene resin with good immersion impurities. It has a slit and a hydraulic bypass groove in the structure, which can effectively avoid the accumulation of oil pressure.

Two-way combination seals are often used in cylinder piston seals because they save space.

2. Sealing of the piston rod

The sealing structure of the piston rod includes: a sealing ring, a buffer ring, a retaining ring and a dust seal.

The seal ring has the function of sealing hydraulic oil. There is a high demand for the choice of sealing ring material, which not only has good impact resistance, wear resistance and crush resistance but also has superior sealing properties. The buffer ring acts as a buffer for decompression of the high pressure oil in the high pressure oil, thereby further reducing the pressure of the main seal. There is a retaining ring at the bottom end of the seal, which has strong anti-squeezing ability, so it can effectively prevent the buffer ring from being squeezed. In addition, the pressure generated by the retaining ring and the main seal can lubricate between the piston rod and the guide sleeve. Friction, but this requires that the buffer ring must have a reflow property to prevent excessive pressure between the buffer ring and the main seal. Therefore, the material of the buffer ring must have good wear resistance and crush resistance. Impact resistance.

The dust ring not only effectively isolates the dust, it also protects the equipment, and it also protects against oil. The movement of the live rod in the guide sleeve requires a certain oil film to be lubricated. The outer lip of the dust ring is likely to cause the oil film to aggregate to form an external leak. Therefore, this requires the inner lip of the dust seal to have a certain anti-scratch effect, hinder the leakage of the oil film.

3. Static seals

Excavators are sealed with O-rings, using nitrile rubber as raw material, and Shore hardness is in the range of 75-90. Because of the high system pressure, the 0-ring needs to be added with a retaining ring to avoid the occurrence of the O-ring being squeezed into the fit gap.

Standard of the sealing performance:

(1) Clearance of the seal ring

In the piston seal and piston rod seal, there is a certain gap between the movements. Factors affecting the gap size include: system pressure, seal material and section thickness, dynamic edge diameter and environmental degree. If the gap is large, not only will the tearing of the sliding edge of the seal root and the stationary side cause the root to be squeezed out, causing the seal to fail. Therefore, the size of the gap has a direct impact on the sealing performance, service life and processing cost of the seal.

(2) Guide belt width

Depending on the use of the guide belt to allow deformation, the corresponding curve can be selected, and the smaller telescopic deformation can ensure the guiding effect. The minimum guide strip width can be determined from the corresponding values and formulas, and then the appropriate guide strip width can be selected.

(3) Assembly and inspection of oil cylinders

When assembling the cylinder, firstly, the parts of each part are separately loaded into the relevant components, and then installed from the inside to the outside.

It is important to choose the correct excavator cylinder seal. YBAS offers professional and high quality seal kits.