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.

Frente a qué resisten estos sellos – NBR (sellos AS / SA / CS)

La lista siguiente muestra los productos químicos, fluidos y gases frente a los que el elemento de sellado de NBR (caucho nitrílico) de los sellos AS, SA y CS es fiablemente resistente. Una marca en una columna de temperatura indica que el sello es apto para ese medio a esa temperatura. Las celdas vacías indican que el medio no se recomienda a esa temperatura — elija un sello de mayor grado (FKM, silicona o PTFE).

Valores indicativos basados en tablas industriales (Parker O-Ring Handbook, Trelleborg, ERIKS). El usuario final es responsable de validar la idoneidad para su aplicación específica — concentración, presión, esfuerzo mecánico y tiempo de exposición importan. En caso de duda, contacte con Extreme Bearing para una recomendación a medida.

Sustancia química 20°C / 68°F 60°C / 140°F 100°C / 212°F
Formaldehyde (40%)
Ascorbic ácido
Citric ácido
Ácidos grasos (>C6)
Oxalic ácido
Phthalic ácido
Stearic ácido
Tannic ácido (10%)
Tartaric ácido
Boric ácido
Carbonic ácido
Silicic ácido
Sulfitos
Ammonia, acuoso
Sosa cáustica y potasa
Lime (CaO)
Alum
Aluminium cloruro
Aluminium sulfato
amonio cloruro
Brines, saturado
Bromide (K) solución
Calcium cloruro
Chlorates of Na, K, Ba
Chlorides of Na, K, Ba
Copper salts (most)
Ferric cloruro
Ferrous sulfato
Lead acetate
Mercuric cloruro
Mercury
Nickel salts
Nitratos de Na, K y NH3
nitrito (Na)
Silver nitrato
sodio carbonato
sodio silicate
sodio sulfuro
Stannic cloruro
Sulphates (Na, K, Mg, Ca)
Zinc cloruro
Cyclohexane
Naptha
Petroleum spirits
Paraffin wax
Aceites diésel
Aceites minerales
Aceites vegetales y animales
Alcohols
Methanol
Glycerine
Glycols
Glycol, ethylene
Acetylene
Refrigerantes fluorados
Sulphur
Agua destilada
Agua blanda
Agua dura
Agua de mar
Aire húmedo
Beer
Zumos de fruta
Gelatine
Jugos de carne
Milk products
Molasses
Starch
Sugar, syrups & jams
Tallow
Urea (30%)
Yeast
Detergents, synthetic
Silicone fluids
Agentes humectantes (<5%)
Ethanol
Isopropanol (IPA)
Propylene glycol
agua/glycol coolant
Fluido hidráulico (HL, HLP, HM, mineral)
Fluido hidráulico HFA (aceite en agua)
Fluido hidráulico HFC (agua-glicol)
Líquido de frenos (DOT 3/4, glicol)
Gasolina
Kerosene
Jet combustible (JP-4/JP-5/JP-8)
combustibleóleo / combustible aceite
LPG (propane, butane)
AdBlue (urea solución 32.5%)
Transformer aceite
Turbine aceite
Gear aceite
Fluido de transmisión ATF
Grasa de silicona
Grasa de jabón de litio
comprimido aire, seco
Nitrogen (N2)
Carbon dioxide (CO2)
Hydrogen (H2)
Helium (He)
Argon (Ar)
Ethylene (C2H4)
Propylene (C3H6)
Methane (CH4)
gas natural
Carbon monoxide (CO)
Refrigerante R22 (HCFC)
Refrigerante R134a (HFC)
Refrigerante R1234yf (HFO)
Refrigerante R717 (amoníaco)
Refrigerante R744 (CO2)
Vino
Café / té
Zumo vegetal
Limpiador CIP alcalino (1-3%)
Pentane
Hexane
Heptane
Octane
Isobutylene
Butanol (n-butanol)
n-Propanol
Oleic ácido
Palmitic ácido
Adipic ácido
Lauric ácido
amonio sulfato
amonio nitrato
Copper sulfato
Zinc sulfato
Magnesium sulfato
Magnesium cloruro
Barium cloruro
potasio cloruro
sodio thiosulphate
Refrigerante R32 (HFC)
Refrigerante R410A (mezcla HFC)
Refrigerante R454B (mezcla HFO)
Refrigerante R1234ze (HFO)
Refrigerante R290 (propano)
Refrigerante R600a (isobutano)
Sulphur hexafluoride (SF6)
Nitrous oxide (N2O)
Olive aceite
Soybean aceite
Palm aceite
Rapeseed (canola) aceite
Fish aceite
Mantequilla
Cheese curds / whey
Eggs (raw / líquido)
Mostaza
líquido sugar / glucose syrup
Quaternary amonio compounds (QACs)
Chlorhexidine solución
Aceite de corte (emulsión soluble en agua)
Aceite de corte (puro, mineral)
HVO renewable diésel
Marine heavy combustible aceite (HFO)
Lodo de perforación (base agua)
Lodo de perforación (base aceite)
Lechada de cemento
Lechada de ceniza volante
Cyanide solución (gold mining, NaCN)