Introduction to contact type sealing of rolling bearings

Aug 15, 2023

For rolling bearings, the sealing of the bearings is very important, because the use environment of different bearing is different, and some bearings are used in a bad environment. When the bearing is not well sealed, there will be dirty things entering the dirty things entering. Inside the bearing, the abnormal sound, stuck and not smooth in the bearing process of the bearing, will soon damage the bearing. Then we have to consider the sealing and actual use of the bearing when choosing a bearing. Today we will introduce the contact type of rolling bearing.

1. Radial seal. Commonly used radial contact seals include felt circles seal, oil sealing, filler sealing and sealing ring seal. Because in such sealing devices, the sealing parts directly contact the shaft or other components, so the inevitable friction and wear in the work will be inevitable and increase the temperature. 

Specific as follows: 

1.1 Felt circles seal: suitable for working environment with a temperature of less than 100°C. Pouring oil before installation of the felt ring has a good sealing effect. After short-term use, the felt ring will become a secret cover without a pre-pressure state. Due to the severe friction, it is only used in the occasion of the circular speed less than 4m/s.

1.2 Filler sealing: The sealing effect is good, and its advantage is that it can be tightened by bolts, which can improve the seal pressure and compensate for wear, but the friction is large, suitable for low-speed rotation motion.

1.3 Oil sealing divided into three categories:

1.3.1 Internal oil seal is mainly prevented from overflowing the lubricant. The permitted circular speed is determined by the sealing material. Generally, it can be used to slider the contact surface to be less than 10m/s (the bucket is a stainless car) or less than 15m/s (the neck polishing) place.

1.3.2 Lip-shaped oil seal can prevent lubricant from overflowing and dust invasion. The permitted circular speed is determined by the sealing material, and the applicable speed is the same as the interior ordinary oil seal.

1.3.3 Extra-oriented ordinary oil seal is mainly prevented from invading dust. The permitted circular speed is determined by the sealing material, and the applicable speed is the same as the introverted ordinary oil seal.

1.4 Sealing ring densely sealing ringing piston, placed between the sleeves with a ring groove (rotating with the shaft) and the bearing cover (static) round hole, each contact surface needs to be hardly processed and polished; sealing requirements are required; If requirements are not high, you can use only one ring, and you can use 2 to 4 rings when it is required; the sealing ring is made of chromium-containing abrasion resistant cast iron, which can be used to slide at a sliding speed of less than 100m/s; Inside, you can also use the sealing ring of tin bronze.

2. End faced sealing, end face contact sealing is a sealing structure that has developed rapidly in recent years. Commonly used end surface seals are mainly sealing, floating oil sealing device, and self-lubricating material sealing.

2.1 Metal cushion ring sealing the outer seal, the inner seal, and the exterior double seal sealing parts are stamped with a galvanized special band steel.

2.2 Floating oil sealing is composed of three parts: floating seats, O-type circles and floating rings. It has good anti-pollution performance, has strong adaptability to vibration and charm, is not sensitive to dust, and has high pressure.

2.3 Self-lubricating material seal: The sealing material has a self-lubricating performance, the friction factor is low, which is suitable for working at a higher slide speed.

Different sealing methods adapt to different types of bearings and different types of working environments. Users must choose appropriate sealing according to the specific conditions of their own equipment, so as to make the bearing use longer and stable.