Centrifugal Seal (CS)

Bearing illustration

If dust and water get inside a bearing, this leads to premature failure. Therefore choosing the right protective seals is important for the working life of a stainless steel bearing unit. The centrifugal seal (CS) is designed for harsh conditions where there is a risk of contamination.

Why Choose a Centrifugal Seal?

Dusty, abrasive environments are one of the most difficult for bearings. Because when handling powders or in processes generating dust, the protection of bearings against contamination requires special consideration. Radial oil seals, such as the AS and SA seals made of nitrile rubber, are selected mainly for ordinary conditions. But they are generally unsatisfactory in harsh or dusty conditions. Over time, the nitrile rubber is attacked by dirt, water, sand and various other contaminants. Small particles get into the soft material of the rubber. And the lip can cause fretting of the shaft (causing a groove under the lip). Tiny particles of moisture on the shaft can be drawn past the lip. And a jet of water sprayed at high pressure directly at the lip seal penetrates past the seal into the bearing.

Bearing illustration

Extreme Bearing has developed the centrifugal seal to solve these problems! Many Extreme Bearing housings feature centrifugal seals specially developed to repel dirt and contaminants using centrifugal force generated by the shaft. The CS seal works for speeds up to 5 m/s and for temperatures from -25°C up to 95°C.

Triple Barrier Bearing Labyrinth Seal

Bearing illustration

CS seals are superior against sand, dirt and detergents

  1. Double Lip Centrifugal Seal - Primary barrier using centrifugal force
  2. Grease-filled Housing - Secondary barrier preventing contamination ingress
  3. 2-RS Bearing Seal - Tertiary protection integrated into bearing

Firstly, the centrifugal seal made of rubber attached to the shaft provides a primary barrier. Because it repels dirt and contaminants using the centrifugal force generated by the shaft. Secondly, the bearing housing is filled with grease to prevent contaminants from entering and damaging the bearing. Finally, there is a type of bearing seal called 2-RS to protect the bearing.

Working Principle

The rubber of the CS-seal clamps around the shaft and is turning with the shaft vertically against the stator ring. Because the lips are positioned vertically against the stator ring, the dirt will be repelled by the centrifugal force from the sealing lips. The rotor ring can be moved eccentrically in relation to the stator ring. In this way, the centrifugal seal is able to absorb any misalignment of the shaft without creating wear on the rubber lips.

Bearing illustration

The grease passes the retaining edge through the lubrication channels under the stator ring and between the two sealing lips and stator ring. This makes sure that any dirt is flushed away. The clamping of the rubber rotor ring around the shaft means that the bearing can be assembled even on a shaft which has suffered light surface damage such as a groove.

Key Benefits

Bearing illustration
  • Centrifugal Force Protection - Uses shaft rotation to repel contaminants
  • Double Lip Design - Enhanced sealing capability
  • Self-Cleaning Action - Grease flow flushes away dirt
  • Misalignment Tolerance - Eccentric movement capability
  • Damaged Shaft Tolerance - Can seal on slightly damaged surfaces
  • Speed Range - Up to 5 m/s
  • Temperature Range - -25°C to 95°C
  • Superior to Standard Seals - Outperforms AS/SA seals in harsh conditions

CS Seal Dimensions

When applying the CS bearing labyrinth seal, it must be taken into account that it is not flush with the surface of the housing and expands the dimensions of the housing slightly:

20 32 3
25 40 3
30 46 3
35 50 3
40 60 3
45 60 3
50 70 3
55 70 3
60 80 3

When to Use CS Centrifugal Seals

  • Dusty and abrasive environments
  • Washdown applications
  • High-pressure water spray areas
  • Powder handling processes
  • Detergent exposure
  • Food processing plants
  • Agricultural applications
  • Mining and quarries
  • Any environment where AS/SA seals fail prematurely

The CS centrifugal seal represents a significant advancement in bearing protection technology for harsh environments.

Contra o que estas vedações resistem – NBR (vedações AS / SA / CS)

A lista abaixo apresenta os produtos químicos, fluidos e gases contra os quais o elemento de vedação em NBR (borracha nitrílica) das vedações AS, SA e CS resiste de forma confiável. Uma marca numa coluna de temperatura indica que a vedação é adequada para esse meio a essa temperatura. As células vazias indicam que o meio não é recomendado a essa temperatura — opte então por uma vedação superior (FKM, silicone ou PTFE).

Valores indicativos baseados em tabelas industriais (Parker O-Ring Handbook, Trelleborg, ERIKS). O utilizador final é responsável por validar a adequação à sua aplicação específica — concentração, pressão, esforço mecânico e tempo de exposição importam. Em caso de dúvida, contacte a Extreme Bearing para uma recomendação personalizada.

Substância química 20°C / 68°F 60°C / 140°F 100°C / 212°F
Formaldehyde (40%)
Ascorbic ácido
Citric ácido
Ácidos gordos (>C6)
Oxalic ácido
Phthalic ácido
Stearic ácido
Tannic ácido (10%)
Tartaric ácido
Boric ácido
Carbonic ácido
Silicic ácido
Sulfitos
Ammonia, aquoso
Soda cáustica e potassa
Lime (CaO)
Alum
Aluminium cloreto
Aluminium sulfato
amónio cloreto
Brines, saturado
Bromide (K) solução
Calcium cloreto
Chlorates of Na, K, Ba
Chlorides of Na, K, Ba
Copper salts (most)
Ferric cloreto
Ferrous sulfato
Lead acetate
Mercuric cloreto
Mercury
Nickel salts
Nitratos de Na, K e NH3
nitrito (Na)
Silver nitrato
sódio carbonato
sódio silicate
sódio sulfureto
Stannic cloreto
Sulphates (Na, K, Mg, Ca)
Zinc cloreto
Cyclohexane
Naptha
Petroleum spirits
Paraffin wax
Óleos diesel
Óleos minerais
Óleos vegetais e animais
Alcohols
Methanol
Glycerine
Glycols
Glycol, ethylene
Acetylene
Refrigerantes fluorados
Sulphur
Água destilada
Água macia
Água dura
Água do mar
Moist ar
Beer
Sumos de fruta
Gelatine
Sucos de carne
Milk products
Molasses
Starch
Sugar, syrups & jams
Tallow
Urea (30%)
Yeast
Detergents, synthetic
Silicone fluids
Agentes molhantes (<5%)
Ethanol
Isopropanol (IPA)
Propylene glycol
água/glycol coolant
Fluido hidráulico (HL, HLP, HM, mineral)
Fluido hidráulico HFA (óleo em água)
Fluido hidráulico HFC (água-glicol)
Fluido de freio (DOT 3/4, glicol)
Gasolina
Kerosene
Jet combustível (JP-4/JP-5/JP-8)
óleo combustível / combustível óleo
LPG (propane, butane)
AdBlue (urea solução 32.5%)
Transformer óleo
Turbine óleo
Gear óleo
Fluido de transmissão ATF
Graxa de silicone
Graxa de sabão de lítio
comprimido ar, seco
Nitrogen (N2)
Carbon dioxide (CO2)
Hydrogen (H2)
Helium (He)
Argon (Ar)
Ethylene (C2H4)
Propylene (C3H6)
Methane (CH4)
gás natural
Carbon monoxide (CO)
Refrigerante R22 (HCFC)
Refrigerante R134a (HFC)
Refrigerante R1234yf (HFO)
Refrigerante R717 (amônia)
Refrigerante R744 (CO2)
Vinho
Café / chá
Sumo vegetal
Limpador CIP alcalino (1-3%)
Pentane
Hexane
Heptane
Octane
Isobutylene
Butanol (n-butanol)
n-Propanol
Oleic ácido
Palmitic ácido
Adipic ácido
Lauric ácido
amónio sulfato
amónio nitrato
Copper sulfato
Zinc sulfato
Magnesium sulfato
Magnesium cloreto
Barium cloreto
potássio cloreto
sódio thiosulphate
Refrigerante R32 (HFC)
Refrigerante R410A (mistura HFC)
Refrigerante R454B (mistura HFO)
Refrigerante R1234ze (HFO)
Refrigerante R290 (propano)
Refrigerante R600a (isobutano)
Sulphur hexafluoride (SF6)
Nitrous oxide (N2O)
Olive óleo
Soybean óleo
Palm óleo
Rapeseed (canola) óleo
Fish óleo
Manteiga
Cheese curds / whey
Eggs (raw / líquido)
Mostarda
líquido sugar / glucose syrup
Quaternary amónio compounds (QACs)
Chlorhexidine solução
Óleo de corte (emulsão solúvel em água)
Óleo de corte (puro, mineral)
HVO renewable diesel
Marine heavy combustível óleo (HFO)
Lama de perfuração (base água)
Lama de perfuração (base óleo)
Lama de cimento
Lama de cinza volante
Cyanide solução (gold mining, NaCN)