In order to maintain good bearing lubrication conditions and normal working environment, full performance of the bearing, extend the service life of rolling bearings must have an appropriate seal to prevent lubricant leakage and dust , moisture or other contaminants intrusion .
Sealed bearings can be divided into two categories comes sealed and applied seal . The so-called sealed bearings is to manufacture bearings comes into its own with the sealing performance of the device . If bearings with dust cover , seals and so on. This seal small footprint , easy installation and removal , the cost is relatively low.
The so-called sealed bearings plus performance device that is installed inside the cover , etc. {TodayHot} manufactured with a variety of performance sealing devices.
Sealed bearings plus a choice of several main factors should consider the following : A bearing lubricant and types ( grease and oil ) . ;
(2) bearing the working environment and the size of the space ; 3 advantage shaft support structure , allowing the angle of deviation ; 4 the peripheral speed of the sealing surface ; 5 bearing operating temperature ; 6 manufacturing cost.
Plus non-contact seal is divided into two kinds of contact . Are as follows : 1 ) non-contact seals Non-contact seal is a seal with the relative movement of the parts not in contact , and there is adequate clearance seal. This form of sealing , the work is hardly generated in the frictional heat , wear and tear, especially suitable for high speed and high temperature applications . Non-contact seals commonly used various forms gap type, style labyrinth and washers and other structures were used in different occasions.
Non-contact seal gap is preferably as small as possible . 2 ) contact seals Sealing contact with the seal is in contact with the relative movement of the parts without a gap seal. This sealing member since the sealing member in direct contact with a mating friction work in large , a large amount of heat is also easy to cause poor lubrication , wear of the contact surface is easy , and the effect of causing the sealing performance. Therefore , it is only suitable for medium and low-speed operating conditions. Contact seals commonly used form felt seals, cup sealing structure , used in different occasions.
According to the working conditions and working environment bearing seal degree requirements in engineering design often use a combination of sealed form , in order to achieve a better seal .