Crusher Bearing

A crusher bearing carries heavy radial load, repeated shock and a shaft that does not always stay straight under that load. In jaw crushers, impact crushers, hammer mills and vibrating screens, the usual answer is the spherical roller bearing, mostly from the 22200, 22300 and 23200 series. Cone crushers are the exception: their main bearings are special designs made for each crusher model. Below we cover which bearing sits where, the sizes by shaft diameter, how vibrating screen bearings differ from standard ones, clearance, tapered bores and adapter sleeves, lubrication, the usual failure causes and what to send with an inquiry.

Which bearing goes where in a crusher or screen

Each machine type puts a different kind of load on its bearings, and that decides the design.

• Jaw crushers. The eccentric shaft is supported by two outer bearings in the frame, and the swing jaw (the Pitman) hangs on two inner bearings on the same shaft. Timken’s crusher white paper notes that both positions typically use spherical roller bearings, because they carry high radial loads and accommodate the misalignment that a long, heavily loaded shaft produces [1]. Loads spike when material that cannot be crushed passes through the jaws [1].
• Impact crushers and hammer mills. The rotor shaft usually runs in spherical roller bearings mounted in solid or split pillow block housings [1]. The rotor is heavy and runs faster than a jaw crusher shaft, so balance and lubrication matter as much as load capacity.
• Cone and gyratory crushers. These use special cylindrical roller, tapered roller thrust and cylindrical roller thrust bearings that are specific to each crusher model [1]. They are not catalogue items. Order them with the crusher maker’s part number or a drawing.
• Vibrating screens and feeders. The exciter shaft runs in spherical roller bearings, usually from the 22300 series or the wider 23300 series [3]. These bearings see high radial load, impact, g-forces from the vibration and misalignment caused by shaft and housing deflection [3].
• Conveyors around the plant. Belt conveyors that feed and discharge the crusher use mounted units and spherical roller bearings on the pulleys. The conveyor bearing page covers them.

Machine and position	Load	Common bearing choice
Jaw crusher, eccentric shaft (frame)	Heavy radial, shock, misalignment	Spherical roller, 22300 or 23200 series
Jaw crusher, Pitman	Heavy radial, shock, reciprocating motion	Spherical roller, size set by the crusher maker
Impact crusher or hammer mill rotor	Radial, shock, higher speed	Spherical roller in pillow block housings
Cone crusher main bearings	Very high radial and thrust	Special bearings to the crusher maker’s design
Vibrating screen exciter	Radial, vibration, misalignment	Spherical roller, 22300 or 23300, screen design
Feeder and conveyor pulleys	Radial	Spherical roller in plummer blocks, or mounted ball bearing units

Why spherical roller bearings suit crushers

A spherical roller bearing has two rows of barrel-shaped rollers running on a common spherical raceway in the outer ring. That shape lets the inner ring and roller set tilt relative to the outer ring, so the bearing keeps running when the shaft bends under load or the two housings are not perfectly in line. Two rows of rollers also give a high radial load rating for the size.

The series number tells you the section. The 22200 series is the lighter section for a given bore. The 22300 series has a larger outside diameter and greater width, and carries more load, which is why screen bearings are built in that series [3]. The 23200 series keeps the outside diameter of the 22200 series but is wider, for more load in the same housing bore. If you are replacing a bearing, keep the series of the original: changing from 22300 to 22200 to save money puts a lighter bearing into a position designed for a heavier one.

Ball bearings and cylindrical roller bearings do appear in smaller crushing equipment and in drive motors, but on the main shaft of a jaw crusher, an impact crusher or a screen exciter the spherical roller bearing is the standard choice. The spherical roller bearing category page explains cages, suffixes and the 22200 and 23000 series in more detail.

Crusher bearing sizes by shaft diameter

The bore of a cylindrical bore bearing equals the shaft diameter at the seat. These are the 22200 and 22300 sizes on this site, with boundary dimensions d × D × B in millimetres.

Shaft (mm)	22200 series	d × D × B	22300 series	d × D × B
40	22208	40 × 80 × 23	22308	40 × 90 × 33
45	22209	45 × 85 × 23	22309	45 × 100 × 36
50	22210	50 × 90 × 23	22310	50 × 110 × 40
55	22211	55 × 100 × 25	22311	55 × 120 × 43
60	22212	60 × 110 × 28	22312	60 × 130 × 46
70	22214	70 × 125 × 31	22314	70 × 150 × 51
75	22215	75 × 130 × 31	22315	75 × 160 × 55
80	22216	80 × 140 × 33	22316	80 × 170 × 58
100	22220	100 × 180 × 46	22320	100 × 215 × 73

Wider sizes such as 23220, 23224 and 23230 are also listed for heavier shafts. If you only have the old bearing, measure the bore, the outside diameter and the width and look them up in the bearing size finder. Brand numbers for the same sizes are in the spherical roller bearing cross reference.

Vibrating screen bearings are a separate design

A vibrating screen bearing has the same boundary dimensions as the standard bearing of the same number, so it fits the same housing. The difference is inside, and it matters because the load on a screen bearing is unusual: the unbalanced weights on the exciter shaft make the load rotate with the shaft, so the outer ring sees load all the way round its raceway.

The large bearing makers publish dedicated designs for this:

• Cage. FAG’s screen bearings, design 223..-E1-T41A for bores from 40 to 150 mm, use surface-hardened sheet steel window cages guided on the outer ring [2]. The cage has to survive the vibration accelerations without breaking up.
• Tolerances. FAG restricts the bore tolerance to the upper half of the normal range and the outside diameter tolerance to the middle of the range [2]. NTN’s screen bearings also have reduced bore and outside diameter tolerances [3].
• Clearance. FAG supplies these bearings with C4 clearance as standard and uses C3 only in special cases [2]. NTN’s VS1 and VS2 suffixes describe C3-based and C4-based ranges with the lower third of the range removed [3]. Timken’s vibratory design is made to the upper two-thirds of C4 [4].
• Fits. Because the outer ring carries the rotating load, it gets the tight fit: FAG gives P6 for the housing and a sliding fit of g6 or f6 for the shaft [2], and NTN gives P7 and h6 [3]. This is the reverse of most machines, where the inner ring is the tight one.
• Lubrication features. A lubrication groove with holes in the outer ring is normal, so grease reaches the middle of the bearing [3][4].
• Misalignment. FAG lists a permissible dynamic misalignment of up to 0.15 degrees for its screen bearings [2].

The practical point for buyers: a standard 22316 with C4 clearance is not the same part as a 22316 screen bearing from a screen maker’s parts list. The bearings on this site are standard designs. If your screen calls for a vibratory design, send the full designation with every suffix. We will tell you which features we can match, and any we cannot are marked as exceptions on the specification sheet rather than quietly substituted.

Clearance: C3 and C4

Radial internal clearance is the free movement between the rings and the rollers before the bearing is mounted. The classes are C2, CN (normal, also written C0), C3, C4 and C5, from tightest to loosest, and Timken notes that most applications use normal or C3 [4].

Clearance shrinks after mounting. An interference fit on the inner ring reduces the clearance by roughly 80% of the fit, and an interference fit on the outer ring by roughly 60% [4]. Heat does the same: when the inner ring runs warmer than the outer ring, it expands more and takes up clearance. A screen bearing has a tight outer ring and runs warm, which is why C4 is standard there [2]. Jaw and impact crushers vary by design: many run on normal clearance, others on C3 where the inner ring fit is tight or the bearing runs warm.

The rule is simple: keep the clearance class of the original bearing and write it in the model number, for example 22312 C3 or 22316 C4. If the original was C4 and the replacement is ordered without a suffix, the bearing may run hot or seize within days. Our guide to bearing internal clearance explains the classes and how they are measured. Put the class in the inquiry for every line, so the quote can be checked against it.

Tapered bore and adapter sleeves

Many crusher and screen bearings have a tapered bore, marked with the suffix K for a 1:12 taper [4]. The bearing is mounted on a tapered shaft seat, or on an adapter sleeve that clamps onto a plain shaft. An adapter sleeve has a smaller bore than the bearing, so the shaft is one size down from the bearing number. In Timken’s catalogue, for example:

Bearing	Adapter sleeve	Shaft (mm)
22208 K	H 308	35
22308 K	H 2308	35
22210 K	H 310	45
22310 K	H 2310	45
22212 K	H 312	55
22312 K	H 2312	55
22216 K	H 316	70
22316 K	H 2316	70
22220 K	H 320	90
22320 K	H 2320	90

Source: [4].

Driving the bearing up the taper expands the inner ring and reduces the radial clearance, and the sleeve is then locked with a locknut and lock washer [4]. Measure the clearance with feeler gauges before and during the drive-up, and stop at the reduction the bearing maker’s table gives for that size. A bearing pushed too far loses its running clearance. One left too loose can turn on the sleeve, wear the shaft and fail early.

The models on this site are listed with a cylindrical bore. If you need the K version, the W33 lubrication groove, or the sleeve, nut and washer as well, put each item in the inquiry and we will confirm what we can supply for that size.

Lubrication and sealing

Crusher and screen bearings are usually grease lubricated and relubricated on a schedule, with labyrinth or contact seals in the housing to keep dust out. Timken’s white paper names poor lubrication as one of the main causes of crusher bearing failure [1]. Its advice is practical:

• Follow the crusher maker’s relubrication schedule and grease type [1].
• Do not over-grease. Excess grease churns, generates heat and breaks down, which can cause early failure [1].
• Do not mix different greases or lubricants [1].
• Frequent relubrication also purges contamination from the bearing, and contamination that keeps coming back points to a sealing problem [1].
• Keep the grease gun, the fittings and the grease itself clean, because the grit that ruins crusher bearings is in the air around them.

Vibrating screens use either grease or oil. FAG’s guide shows screen arrangements with grease, oil sump, recirculating oil and oil splash lubrication [2]. In the grease versions, fresh grease fed into the bearing pushes the old, possibly contaminated grease out, and a labyrinth seal keeps dust out [2]. In the oil versions the oil level and oil cleanliness decide bearing life. The bearing lubrication basics article covers grease quantity and relubrication in more detail.

Why crusher bearings fail early

When a crusher bearing fails, the bearing is rarely the root cause. Look at these first:

1. Abrasive wear. Fine grit gets past worn seals and leaves the raceways a frosty grey [1]. As material wears away, the clearance grows and the bearing gets noisy.
2. Debris dents. Larger particles are rolled into the raceways and leave dents. The edges of the dents become the starting points of spalling [1].
3. Inadequate lubrication. Wrong viscosity, too little or too much lubricant, or lubricant that has broken down. It shows as fine spalling, heat damage and oxidized lubricant stains [1].
4. Loose fits. A reused shaft may be undersized and a housing may be worn or out of round. The ring then turns on its seat, the bore shows fretting corrosion, and the new bearing fails the same way [1]. Check the seats at every replacement.
5. Shock from uncrushable material. Tramp steel or oversize blocks send a load spike through the shaft and bearings [1].
6. Wrong clearance. A standard clearance bearing in a screen that needs C4, or a tapered bore bearing driven too far up its sleeve.
7. Damage during fitting. Hammer blows on the outer ring or the cage mark the raceways before the machine starts. Heat or press the bearing on through the ring that has the tight fit.

If the same position fails twice, measure the shaft and housing seats and check the seals before ordering again.

How to write a crusher bearing inquiry

An inquiry with these items can usually be priced in one round:

1. The full number with every prefix and suffix, for example 22316 K C3 or 22312 C4. A missing suffix is the most common reason a wrong bearing gets ordered.
2. Whether the original is a vibrating screen design, and the screen maker’s designation if you have it.
3. The bore type: cylindrical or tapered (K), and whether you also need adapter sleeves, locknuts and lock washers.
4. The quantity for each model.
5. The machine type and position: jaw crusher frame or Pitman, impact crusher rotor, screen exciter.
6. A photo of the old bearing and its markings, or the drawing if you build the machine.
7. Any marking or packaging requirement. Rings can carry your authorized brand, the factory brand, or no brand.

Send your model numbers and quantities to sales@fuli-bearings.com or through the contact page. The quotation request template has a copy-ready format, and how to avoid ordering the wrong bearing lists the usual mistakes. We check each number against the standard designations, mark any item we cannot meet as an exception on the specification sheet rather than substituting it, and send the quote. An inspection report can cover dimensions, radial clearance, rotation noise, vibration, appearance, material certificate and batch traceability. Export documents are the commercial invoice, packing list and CCPIT certificate of origin, plus an FTA Form COO where the destination country qualifies.

Backed by 20+ years of bearing export experience in Linqing, Shandong. FULI ships to 50+ countries & regions.

Sources

1. https://www.timken.com/wp-content/uploads/2017/04/Crusher-Bearings-Technical-White-Paper.pdf
2. https://www.rmbearings.co.uk/pictures/pdfs/FAG%20SPHERICALS%20VIBRATING%20SCREENS.pdf
3. https://help.bdsbearing.com/hubfs/Knowledge%20Base/NTN/NTN%20Spherical%20Roller%20Bearings%20for%20Vibrating%20Screens%20A-1800.pdf
4. https://www.timken.com/wp-content/uploads/2024/07/Timken-Spherical-Roller-Bearing-Catalog.pdf