Spherical Roller Bearings
5393 products
Loading filters…
Spherical Roller Bearings
What is a spherical roller bearing?
A spherical roller bearing is a self-aligning rolling bearing with two rows of barrel-shaped rollers. Its outer ring has a single, continuous raceway shaped like part of a sphere, while the inner ring has two raceways set at an angle to the bearing axis. Because the outer raceway is spherical, the inner ring, rollers, and cage can tilt within the outer ring, so the bearing adjusts automatically to misalignment and shaft deflection.
A standard bearing has four main parts:
- An inner ring with two raceways, which usually fits onto a shaft
- An outer ring with one spherical raceway, which usually sits in a housing
- Two rows of barrel-shaped (symmetrical) rollers
- One or two cages that keep the rollers evenly spaced, often with a guide ring between the two rows.
Many spherical roller bearings have a lubrication groove and holes in the outer ring.
- These let grease or oil be fed straight into the middle of the bearing, between the two rows of rollers.
- This spreads the lubricant to both rows evenly, which is particularly useful for relubrication in service.
The bearing is non-separable, meaning the rings, rollers, and cage stay together as one unit. Rings and rollers are usually made from hardened chrome steel (grade 52100). Cages are most commonly pressed steel, with machined brass and polyamide also available.
Why are spherical roller bearings essential?
They combine very high load capacity with the ability to self-align, which makes them the default choice for heavy machinery where loads are high and conditions are tough. They carry heavy radial loads together with axial loads in both directions, and they handle shock loads well. Because they adjust to misalignment, they cope with shaft deflection, mounting errors, and housings that are mounted on separate supports, which are common in large machines and long shafts.
They are available with a cylindrical or tapered bore. Tapered bore versions can be mounted on adapter or withdrawal sleeves, so they can be fitted onto plain shafts without a shoulder and are easier to remove. Their boundary dimensions are standardised internationally. So a bearing of a given reference has the same bore, outer diameter, and width, regardless of which reputable manufacturer makes it.
Typical applications include:
- Vibrating screens and crushers
- Conveyor pulleys
- Paper machines
- Industrial fans and blowers
- Large gearboxes
- Pumps
- Mining and quarrying equipment
- Wind turbine main shafts
- Marine propeller shafts
- Plummer block housings on general machinery
The main types of spherical roller bearings
- Open spherical roller bearings with a cylindrical bore - These are the standard design and by far the most common. They are pressed directly onto the shaft or into the housing.
- Tapered bore spherical roller bearings (K and K30) - These have a tapered bore and are mounted on a tapered shaft seat or on an adapter or withdrawal sleeve. The standard taper is 1:12 (K), while the wider 240 and 241 series often use a 1:30 taper (K30).
- Sealed spherical roller bearings - These have contact seals on both sides and are supplied pre-greased. They keep contaminants out in dirty conditions, such as conveyors and mining equipment, and reduce the need for relubrication.
- Vibrating screen bearings - These are specially designed for the high accelerations and vibration in vibrating screens and other vibrating machinery. They usually have stronger cages, tighter tolerances, and increased clearance.
- Spherical roller bearings with lubrication features (W33) - These have the lubrication groove and holes in the outer ring. On many modern designs, this feature is included as standard.
- Split spherical roller bearings - These have rings and cages split into two halves, so they can be fitted without removing other parts from the shaft. They are used where replacing a bearing would otherwise mean a long and costly strip-down, such as on long conveyor and fan shafts.
- Spherical roller thrust bearings - A related design that carries very heavy axial loads with some radial load, while still allowing misalignment.
Cage variants include:
- Pressed steel cages - Strong, cost-effective, and the standard choice in many sizes.
- Machined brass cages - Very robust, suited to high temperatures, vibration, shock loads, and high accelerations, such as in vibrating screens and crushers.
- Polyamide cages - Light and quiet, but typically limited to around 120°C in continuous use.
How to choose the right spherical roller bearing?
- Size and dimensions - The bore must suit the shaft; the outer diameter and width must fit the housing. For the same bore, a heavier dimension series has a larger outer diameter, larger rollers, and higher load capacity, but takes up more space.
- Load - Work out the radial and axial loads and whether they are steady or involve shocks. Compare them with the bearing’s basic dynamic load rating and basic static load rating, which are published in manufacturers’ catalogues. Spherical roller bearings handle heavy radial loads and moderate axial loads. For very heavy axial loads, a spherical roller thrust bearing may be better suited.
- Bore type - Choose a cylindrical bore for direct fitting onto a machined shaft, or a tapered bore with an adapter or withdrawal sleeve for plain shafts and easier removal.
- Internal clearance - C3 is greater than normal and is common wherever interference fits, or temperature differences reduce clearance in operation. C4 is larger still, for higher temperatures, heavier fits, and vibrating screens, while C2 is smaller than normal, used in applications needing minimal play. Tapered bore bearings lose some clearance as they are driven up the taper, so the starting clearance must allow for this.
- Cage - Pressed steel cages suit most general applications. Machined brass cages are better where there is heavy vibration, shock, or high temperatures.
- Environment and sealing - Use sealed bearings or well-sealed housings for dusty, wet, or dirty conditions, and high-temperature greases for hot environments.
Essential references and specialised ranges
How the numbering works:
The first two digits, 21, 22, 23, or 24. Identifies a spherical roller bearing.
The first three digits together indicate the dimension series: 222 is light, 223 is medium, 213 is a narrow medium series, 230, 231, and 232 are wider series, 238 and 239 are thin-section series, and 240 and 241 are extra wide series.
The last two digits indicate the bore:
From 04 upwards, multiply by five (for example, 22205 = 25mm and 22210 = 50mm)
For bores of 500mm and above, the bore is written in full after a slash, so a 230/500 has a 500mm bore.
Suffixes:
E = optimised internal design with higher load capacity
CC = two pressed steel cages with a guide ring
CA = one-piece machined brass cage
M = machined brass cage
K = tapered bore (taper 1:12)
K30 = tapered bore (taper 1:30)
W33 = lubrication groove and three lubrication holes in the outer ring
C2, C3, C4 = internal clearance smaller than normal (C2), or greater than normal (C3, C4)
2CS, 2CS5 = contact seals on both sides
VA405 = design for vibrating screens and other vibrating machinery
FAQ - All you need to know about spherical roller bearings
Why are they called “spherical” roller bearings?
The outer ring raceway is shaped like part of a sphere, with its centre on the bearing axis. This is what lets the inner ring and rollers tilt within the outer ring, so the bearing aligns itself with the shaft.
How much misalignment can they tolerate?
Typically between about 0.5° and 2°, depending on the bearing series and the load. This is far more than deep groove ball bearings or cylindrical roller bearings can tolerate. Check the manufacturer’s catalogue for the exact value for each series.
What is the difference between spherical roller bearings and self-aligning ball bearings?
Both are self-aligning, but spherical roller bearings use rollers, which make line contact with the raceways and carry much higher loads and shocks. Self-aligning ball bearings use balls, so they carry lighter loads, but run with lower friction and at higher speeds.
What is an adapter sleeve?
An adapter sleeve is a split, tapered sleeve that fits onto a plain shaft. A tapered bore bearing is pushed up the sleeve and tightened with a locknut and lock washer, which grips the bearing to the shaft. It allows the bearing to be fitted anywhere along the shaft without a shoulder, and makes removal easier.
Do spherical roller bearings need lubrication?
Yes, lubrication separates the rollers from the raceways, reduces friction, and protects against corrosion. They can be grease or oil lubricated, depending on speed and temperature. Open bearings with a W33 groove can be relubricated through the outer ring, while sealed bearings are supplied pre-greased.
Click here to learn how to maintain a bearing.
Can I replace a spherical roller bearing myself?
In many cases, yes. Smaller cylindrical bore bearings can be pressed on, while larger ones are usually heated with an induction heater so they expand onto the shaft. Tapered bore bearings must be driven up the taper by the correct amount, which is checked by measuring the reduction in internal clearance with feeler gauges or by measuring the axial drive-up. Never strike the bearing directly with a hammer, as this can damage the rings and rollers.
How do I identify a bearing I need to replace?
The reference is usually marked on the side face of the rings. If the markings are worn away, measure the bore, outer diameter, and width with callipers and match them against a size chart. Also check whether the bore is cylindrical or tapered, and whether the bearing has seals or a lubrication groove in the outer ring.
Click here to learn how to measure a bearing.
How can I tell if a bearing is worn or failing?
Warning signs include:
- Grinding, rumbling, or clicking noises
- Increased vibration
- Rough or uneven rotation
- Play in the shaft
- Overheating
- Discoloured or contaminated lubricant
