Several Major Factors Affect Oil Sealing Performance

HONGLEI is a leading enterprise in China, our products have passed the testing of Hebei Province Rubber Products Inspection Center. We have passed ISO 9001:2000 quality management system certification and produce over 10,000 products every day. Our main product lines include: automotive oil seals, agricultural oil seals, tractor hub oil seals, valve stem seals, precision rubber parts, O-rings. We also accept customers' own design and OEM design orders, always focusing on quality products with competitive price and best service.

Temperature

Low temperatures can cause the lip of a polyurethane or rubber seal to freeze and become brittle and brittle, reducing elasticity and causing leakage, or even the entire seal to become hard and brittle. High temperatures can cause the seal to expand and soften, resulting in a rapid increase in frictional resistance to seal movement and a reduction in pressure-bearing capacity.

Polyurethane or rubber seals are recommended for a continuous operating temperature range of -10°C to +80°C. Increased velocity, poor surface roughness, and poor lubrication can produce frictional heating that raises the lip temperature above the meson temperature.

Working pressure

Cylinders have starting pressure, working pressure and shock pressure. The minimum starting pressure is set according to the cylinder diameter and use pressure conditions. For low pressure work, seals with low frictional properties and low starting resistance must be selected.

At high pressures, the deformation of the seal under pressure is considered to prevent extrusion of the support ring. There are also special requirements for beveling accuracy and play. The effects of temperature and pressure on seal performance are interrelated and should be considered together.

Side load

In order to ensure that the cylinder in the work of the maximum load, no lateral load, the cylinder in the design, processing to take into account the cylinder "different axis" of the heavy load state, the impact on the seal.

In the industrial heavy load, long stroke fixed cylinder structure of the cylinder design, the piston using long size straight column piston design, easy to guide, reduce unloading. In addition, at least six guide straps should be used in the cylinder head. Piston near the cylinder rod end should have more than four guide bands, the other end of the piston should have two guide bands. The service life of the cylinder depends on the guide band fit clearance and load capacity, which seriously affects the sealing performance.

Pressure shock

Many factors can produce pressure shocks. For example, when the excavator lift is operating normally, external stone guilt can cut into the arm of the excavator. When a crane is lifting, the shaking caused by heavy loads can have a significant impact on the cylinder. The instantaneous high-pressure hydraulic shock may be several times the normal operating pressure of the system. Such high pressures can squeeze seals into gaps or tear seal lips in a very short period of time, causing serious damage to the seals.

Seal Installation

Before seal installation, check the cylinder head groove and piston step, groove surface roughness, no sharp angle, burr, collision. The groove size and precision should meet the geometric standard requirements of the seal. The width of the guide band groove should be closely matched with the guide band, and there should be no loose defects.

Cylinder seal installation requires a clean environment to ensure a clean assembly installation. Pay attention to identifying the seal direction during installation to avoid assembly failure due to wrong installation direction. When installing seals in the slot, do not use metal tools to avoid damage to the seal surface.