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.

Waar Deze Afdichtingen Tegen Bestand Zijn – NBR (AS / SA / CS)

Onderstaande lijst toont de chemicaliën, vloeistoffen en gassen waar het NBR (nitrilrubber) afdichtelement van AS-, SA- en CS-afdichtingen betrouwbaar tegen bestand is. Een vinkje in een temperatuurkolom betekent dat de afdichting dat medium bij die temperatuur aankan. Lege cellen betekenen dat het medium bij die temperatuur niet wordt aanbevolen — kies dan een hoogwaardiger afdichting (FKM, silicone of PTFE).

Indicatieve waarden, gebaseerd op industriële compatibiliteitstabellen (Parker O-Ring Handbook, Trelleborg, ERIKS). De eindgebruiker is verantwoordelijk voor het valideren van de geschiktheid voor de specifieke toepassing — concentratie, druk, mechanische belasting en blootstellingstijd zijn van belang. Bij twijfel: neem contact op met Extreme Bearing voor toepassingsspecifiek advies.

Chemische stof 20°C / 68°F 60°C / 140°F 100°C / 212°F
Formaldehyde (40%)
Ascorbinezuur
Citroenzuur
Vetzuren (>C6)
Oxaalzuur
Ftaalzuur
Stearinezuur
Tanninezuur (10%)
Wijnsteenzuur
Boorzuur
Koolzuur
Kiezelzuur
Sulfieten
Ammoniak, waterig
Natronloog & kaliloog
Kalk (CaO)
Aluin
Aluminiumchloride
Aluminium sulfaat
Ammoniumchloride
Pekel, verzadigd
Bromide (K) oplossing
Calciumchloride
Chloraten van Na, K, Ba
Chloriden van Na, K, Ba
Koperzouten (meeste)
IJzer(III)chloride
IJzer(II)sulfaat
Loodacetaat
Kwik(II)chloride
Kwik
Nikkelzouten
Nitraten van Na, K en NH3
nitriet (Na)
Zilvernitraat
Natriumcarbonaat
Natriumsilicaat
Natriumsulfide
Tin(IV)chloride
Sulfaten (Na, K, Mg, Ca)
Zinkchloride
Cyclohexane
Nafta
Petroleumether
Paraffinewas
Dieselolie
Minerale oliën
Plantaardige en dierlijke oliën
Alcohols
Methanol
Glycerine
Glycolen
Ethyleenglycol
Acetyleen
Gefluoreerde koudemiddelen
Zwavel
Water, gedestilleerd
Water, zacht
Water, hard
Zeewater
Vochtige lucht
Bier
Vruchtensappen
Gelatine
Vleessappen
Zuivelproducten
Melasse
Zetmeel
Suiker, siropen & jam
Talg
Urea (30%)
Gist
Synthetische reinigingsmiddelen
Siliconenvloeistoffen
Bevochtigingsmiddelen (<5%)
Ethanol
Isopropanol (IPA)
Propyleenglycol
Water/glycol-koelvloeistof
Hydraulische vloeistof (HL, HLP, HM, mineraal)
Hydraulische vloeistof HFA (olie-in-water-emulsie)
Hydraulische vloeistof HFC (water-glycolmengsel)
Remvloeistof (DOT 3/4, glycol)
Benzine
kerosine
Vliegtuigbrandstof (JP-4/JP-5/JP-8)
Stookolie / brandstofolie
LPG (propaan, butaan)
AdBlue (ureumoplossing 32,5%)
Transformatorolie
Turbineolie
Tandwielolie
ATF-transmissievloeistof
Siliconenvet
Lithiumzeepvet
gecomprimeerde lucht, droog
Stikstof (N2)
Kooldioxide (CO2)
Waterstof (H2)
Helium (He)
Argon (Ar)
Ethyleen (C2H4)
Propyleen (C3H6)
Methaan (CH4)
Aardgas
Koolmonoxide (CO)
Koudemiddel R22 (HCFC)
Koudemiddel R134a (HFC)
koudemiddel R1234yf (HFO)
Koudemiddel R717 (ammoniak)
Koudemiddel R744 (CO2)
Wijn
Koffie / thee
Groentesap
CIP-reiniger, alkalisch (1-3%)
Pentane
Hexane
Heptane
Octane
Isobutylene
Butanol (n-butanol)
n-Propanol
Oliezuur
Palmitinezuur
Adipinezuur
Laurinezuur
Ammoniumsulfaat
Ammoniumnitraat
Kopersulfaat
Zinksulfaat
Magnesiumsulfaat
Magnesiumchloride
Bariumchloride
Kaliumchloride
Natriumthiosulfaat
Koudemiddel R32 (HFC)
Koudemiddel R410A (HFC-mengsel)
Koudemiddel R454B (HFO-mengsel)
Koudemiddel R1234ze (HFO)
Koudemiddel R290 (propaan)
Koudemiddel R600a (isobutaan)
Zwavelhexafluoride (SF6)
Distikstofoxide (N2O)
Olijfolie
Sojaolie
Palmolie
Raapzaadolie (canola)
Visolie
Boter
Wrongel / wei
Eieren (rauw / vloeibaar)
Mosterd
Vloeibare suiker / glucosestroop
Quaternaire ammoniumverbindingen (QACs)
Chloorhexidine-oplossing
Snijolie (wateroplosbare emulsie)
Snijolie (puur, mineraal)
HVO hernieuwbare diesel
Marine zware stookolie (HFO)
Boormodder (waterbasis)
Boormodder (oliebasis)
Cementslurry
Vliegas-slurry
Cyanideoplossing (goudwinning, NaCN)