The role of automotive seals is to close the chamber oil (water) overflow of the gap, to prevent dust, sand and other dirt invade the chamber. If improper use or installation, it can not play its due role, affecting the normal work of the parts, or even cause damage, so all kinds of seals must be installed correctly. The following describes the installation of automotive seals learning.
Felt oil seal
Automotive felt seals with better sealing effect, mainly for the gasoline engine before and after the rear and some parts such as the rear axle. Use should pay attention to the following matters:
According to the sealing parts, select the specifications and thickness of the felt pad to meet the requirements, to ensure that the sealing device has a suitable installation tightness. Because if installed too tight, it will reduce the felt elasticity, sealing performance degradation; and, due to the pressure is too large, the frictional resistance increases, the felt due to overheating and early damage. If the installation is too loose, the permeability of the felt does not change and oil leakage occurs. Therefore, the felt seal must be properly preloaded during installation, and the natural thickness of the felt should normally be 1 / 4-1 / 3 larger than the seal size.
Felt seals must be saturated with oil before installation. The annular felt installed on the rotating part, if it is not immersed in the oil, will generate high temperature when the shaft rotates initially due to the dry friction with the shaft, resulting in the elastic failure of the contact surface and loss of sealing performance. Installed in the plane groove of the strip of felt, if not soaked in oil, installed after the adsorption of a large number of lubricating oil, so that their volume contraction, resulting in lax seal. At the same time, the cabinet room to reduce oil, affecting the lubrication quality.
In the process of using, should always check the seal of the felt seal, once the felt seal leakage or damage, should be promptly replaced. Whatever the reason, disassembly felt seal location, should check the elasticity of the felt seal, if necessary, to be replaced.
Skeleton self-tight rubber seal
Before installing the oil seal, it is necessary to check the surface of the journal is too rough, with or without scars, especially with or without long axial scars. Otherwise, it will easily damage the seal or accelerate the wear of the lip and destroy its sealing performance. If the surface of the shaft caused by improper disassembly
The more serious flaws, the seal lip and journal surface lax, resulting in fluid leakage. Surfacing or replacement of new shafts can be performed on the damaged area. If there are only minor problems such as metal burrs or flashing on the shaft, use a trowel for smoothing.
Install skeleton oil seal, must use special installation tools. If you do not have tools, first in the journal or shaft parts, roll a layer of transparent hard plastic film (commonly known as "cellophane"), the surface smear a little oil, the oil seal into the wrapped shaft Head, evenly force the oil seal slowly push to the journal, and then pull out the plastic film. Note: The direction of the lip can not be installed wrong, it should be oriented towards the inside of the stored oil, if the oil seal installed, it will inevitably cause oil leakage, sealing effect weakened or invalid. To avoid the oil seal crooked or hammer and other tools in the surface of the seal indiscriminate hit, otherwise easy to seal damage.
In the installation process, should keep the oil seal and journal parts clean, and be careful not to make the oil seal spring out of the spring out of the spring tank. If the self-tightening spring is slack, a section may be cut down depending on the situation, and the two ends may be securely connected.
Check the seal lip for breakage, cracking or oleochemical corrosion, otherwise replace the new oil seal.
Leather oil seal
Cowhide used to make oil seals must be of uniform thickness. The same oil seal leather can not be uneven thickness, otherwise the difference between the thickness of the oil, affecting the installation and sealing.
Strict selection of leather oil seal size. Generally can be slightly larger than the diameter of the sealing part, must not be too large; if too large, not only difficult to install, but also easy to produce deformation, affecting the sealing performance.
Prior to installation, it must be placed flat in warm lube oil and foamed before installation.
Rubber water blocking ring
Some engine cylinder block water ring is -O-shaped rubber parts, compared with the skeleton oil seal, the structure is simple, rely on the flexibility of rubber to seal. If improperly installed, will make a large number of coolant in the water jacket into the crankcase, resulting in deterioration of lubricants, poor lubrication quality. The installation of water blocking ring, you should note the following.
If the water blocking ring is too thin or the cylinder liner water seal groove is too deep, it will make the water blocking ring into the cylinder liner water seal groove can not be higher than the arc surface of a certain height. At this point, at the bottom of the tank can be tangled asbestos rope seal, coated with water-based calcium-based grease, then the water trap trapped into the water seal, and then the cylinder liner into the body hole.
If the choke ring is too thick, or if the cylinder liner seal is too shallow, it will cause the choke ring to load too much above the arc. This will not only make the cylinder liner installation difficult, but also squeeze the rubber seal or even squeeze the cylinder liner can be emery cloth rubber seal until it reaches the height of the water seal groove convex height, and then coated on the surface of the rubber ring Grease can be.
Rubber ring fitted cylinder liner protruding uneven, you should double-check, see the end is a rubber ring problem, or water seal slot problem, there will be problems with the replacement parts.
Into the cylinder liner water seal groove, the rubber ring and seal groove should be cleaned to avoid impurities, dirt with people. After the rubber ring is installed on the cylinder liner, it is necessary to check carefully whether it is twisted or not. In the installation of cylinder liner, the cylinder body should be carefully removed from the hole under the surface of the dirt, and in the next hole surface coated with a layer of lubricant, then the cylinder liner can be slowly pressed into the hole can be.