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.

Wogegen diese Dichtungen beständig sind – NBR (AS / SA / CS)

Die folgende Liste zeigt die Chemikalien, Flüssigkeiten und Gase, gegen die das NBR-Dichtelement (Nitrilkautschuk) der AS-, SA- und CS-Dichtungen zuverlässig beständig ist. Ein Häkchen in einer Temperaturspalte bedeutet, dass die Dichtung dieses Medium bei dieser Temperatur verträgt. Leere Felder bedeuten, dass das Medium bei dieser Temperatur nicht empfohlen wird — wählen Sie dann eine höherwertige Dichtung (FKM, Silikon oder PTFE).

Indikative Werte basierend auf industriellen Verträglichkeitstabellen (Parker O-Ring Handbook, Trelleborg, ERIKS). Der Endanwender ist für die Validierung der Eignung für seine spezifische Anwendung verantwortlich — Konzentration, Druck, mechanische Belastung und Einwirkdauer sind entscheidend. Im Zweifelsfall wenden Sie sich an Extreme Bearing für eine maßgeschneiderte Empfehlung.

Chemischer Stoff 20°C / 68°F 60°C / 140°F 100°C / 212°F
Formaldehyde (40%)
Ascorbic Säure
Citric Säure
Fettsäuren (>C6)
Oxalic Säure
Phthalic Säure
Stearic Säure
Tannic Säure (10%)
Tartaric Säure
Boric Säure
Carbonic Säure
Silicic Säure
Sulfite
Ammonia, wässrig
Natronlauge und Kalilauge
Lime (CaO)
Alum
Aluminium Chlorid
Aluminium Sulfat
Ammonium Chlorid
Brines, gesättigt
Bromide (K) Lösung
Calcium Chlorid
Chlorates of Na, K, Ba
Chlorides of Na, K, Ba
Copper salts (most)
Ferric Chlorid
Ferrous Sulfat
Lead acetate
Mercuric Chlorid
Mercury
Nickel salts
Nitrate von Na, K und NH3
Nitrit (Na)
Silver Nitrat
Natrium Carbonat
Natrium silicate
Natrium Sulfid
Stannic Chlorid
Sulphates (Na, K, Mg, Ca)
Zinc Chlorid
Cyclohexane
Naptha
Petroleum spirits
Paraffin wax
Dieselöle
Mineralöle
Pflanzliche und tierische Öle
Alcohols
Methanol
Glycerine
Glycols
Glycol, ethylene
Acetylene
Fluorierte Kältemittel
Sulphur
Destilliertes Wasser
Weiches Wasser
Hartes Wasser
Meerwasser
Moist Luft
Beer
Fruchtsäfte
Gelatine
Fleischsäfte
Milk products
Molasses
Starch
Sugar, syrups & jams
Tallow
Urea (30%)
Yeast
Detergents, synthetic
Silicone fluids
Netzmittel (<5%)
Ethanol
Isopropanol (IPA)
Propylene glycol
Wasser/glycol coolant
Hydraulikflüssigkeit (HL, HLP, HM, mineralisch)
Hydraulikflüssigkeit HFA (Öl in Wasser)
Hydraulikflüssigkeit HFC (Wasser-Glykol)
Bremsflüssigkeit (DOT 3/4, Glykol)
Benzin / petrol
Kerosene
Jet Kraftstoff (JP-4/JP-5/JP-8)
Heizöl / Kraftstoff Öl
LPG (propane, butane)
AdBlue (urea Lösung 32.5%)
Transformer Öl
Turbine Öl
Gear Öl
ATF-Getriebeöl
Silikonfett
Lithiumseifenfett
komprimiert Luft, trocken
Nitrogen (N2)
Carbon dioxide (CO2)
Hydrogen (H2)
Helium (He)
Argon (Ar)
Ethylene (C2H4)
Propylene (C3H6)
Methane (CH4)
Erdgas
Carbon monoxide (CO)
Kältemittel R22 (HCFC)
Kältemittel R134a (HFC)
Kältemittel R1234yf (HFO)
Kältemittel R717 (Ammoniak)
Kältemittel R744 (CO2)
Wein
Kaffee / Tee
Gemüsesaft
CIP-Reiniger alkalisch (1-3%)
Pentane
Hexane
Heptane
Octane
Isobutylene
Butanol (n-butanol)
n-Propanol
Oleic Säure
Palmitic Säure
Adipic Säure
Lauric Säure
Ammonium Sulfat
Ammonium Nitrat
Copper Sulfat
Zinc Sulfat
Magnesium Sulfat
Magnesium Chlorid
Barium Chlorid
Kalium Chlorid
Natrium thiosulphate
Kältemittel R32 (HFC)
Kältemittel R410A (HFC-Gemisch)
Kältemittel R454B (HFO-Gemisch)
Kältemittel R1234ze (HFO)
Kältemittel R290 (Propan)
Kältemittel R600a (Isobutan)
Sulphur hexafluoride (SF6)
Nitrous oxide (N2O)
Olive Öl
Soybean Öl
Palm Öl
Rapeseed (canola) Öl
Fish Öl
Butter
Cheese curds / whey
Eggs (raw / flüssig)
Senf
flüssig sugar / glucose syrup
Quaternary Ammonium compounds (QACs)
Chlorhexidine Lösung
Schneidöl (wasserlösliche Emulsion)
Schneidöl (pur, mineralisch)
HVO renewable Diesel
Marine heavy Kraftstoff Öl (HFO)
Bohrspülung (wasserbasiert)
Bohrspülung (ölbasiert)
Zementschlämme
Flugascheschlämme
Cyanide Lösung (gold mining, NaCN)