Spherical Roller Bearings

Commonly found in the steel industry, the spherical roller bearings have many options including tapered bore, sealing, various grease types and mounting arrangements. Spherical roller bearings are able to adjust center alignment to handle inclination of the axle or shaft. It has an outer ring with a spherical raceway surface and an inner ring, which holds two rows of barrel-shaped rolling elements.

Spherical roller bearings can easily be mounted on a shaft by means of an adapter or withdrawal sleeve. The bearing is capable of supporting heavy loads, and is therefore often used in industrial machinery. When heavy axial load is applied to the bearing, the load on rollers of another row is disappeared, and can cause problems. Attention must therefore be paid to operating conditions.

Physical Characteristics

• Spherical roller bearings consist of an outer ring having a continuous spherical raceway
• Within which operates two rows of barrel-shaped rollers which are in turn guided by an inner ring with two raceways separated by a center rib.
• This bearing has self-aligning properties, and therefore is suited for use where misalignment between the inner and outer rings occurs from housing installation error or shaft flexure.
• Spherical roller bearings have a large capacity for radial loads, axial loads in either direction, and complex loads. .

In addition to bearings with cylindrical bore, those with tapered bore are also available. Bearings with tapered bore are specified by attaching the suffix "K" to the end of the bearing's basic number. The standard taper ratio is 1:12 for bearings with a "K" suffix, but for bearings in series 240 and 241 the suffix "K30" indicates the taper ratio for a bearing is 1:30. Most tapered bore bearings incorporate the use of adapters and withdrawal sleeves for shaft mounting.

Types Of Spherical roller bearings

Type	Standard type (B type)	C type	213 type	E type
Construction
Bearing series	Does not include C type	Series 222, 223, and 213 with bore dia. of 50 mm or less; series 24024 to 24038.	Series 213 with bore dia. of 55 mm or more	Series 22211 to 22218
Rollers	Asymmetrical	Symmetrical	Asymmetrical	Symmetrical
Roller guide method	Unified inner ring center rib	By guide ring between the 2 rows of rollers	By guide ring between rows of rollers on outer ring raceway	High precision cage (no guide ring, center rib)
cage type	Pressed cage; machined cage	Pressed cage	Machined cage	Molded resin cage

Other types are:

Sealed Bearings
Sealed spherical roller bearings are used when the load is heavy and the other conditions may not be favorable. The seal has two washers, one to be attached to the inner ring and one to the outer. When the inner ring rotates, the washer acts as a flinger.

Bearings For Vibrating Screens
Vibratory applications, such as vibrating screens or exciters, induce accelerations of rollers and cages in the bearings thus exerting more on the bearing. These bearings may have cylindrical or tapered bores

Spherical roller bearings Specifications & Standards

Dimensions - The boundary dimensions of the drawn cup needle roller bearings are in accordance with ISO.

Tolerance - They are usually meant for normal tolerance but can be enhanced.

Standard cage types - Standard cage types for spherical roller bearings are shown in the table below. In general, pressed cages are standard for small sized bearings, and machined cages are standard for large sized bearings.

E type bearings use as their standard cage type a cage molded from a newly developed glass fiber reinforced polyamide 46 resin, which has excellent heat resistance qualities (allowable operating temperatures up to 150°C), strength, as well as unsurpassed oil resistance. A standard cage may however not be able to be used for high-speed specifications, in high temperature atmospheres, or under excessive vibration/impact conditions.

Allowable misalignment - Spherical roller bearings possess the same self-aligning properties as other self-aligning bearings. The allowable misalignment angle will vary according to dimension series and load conditions, but the following misalignment angles are generally standard:

Normal load (loads equivalent to 0.09 Cr): …………0.009rad (0.5°) Light load: …………………………………………………0.035rad (2°)

Internal Clearance - Spherical roller bearings are produced as standard with Normal radial internal clearance and most are also available with a greater C3 clearance.

Radial Internal Clearance of Spherical Roller Bearings with Cylindrical Bore

Bore diameter		Radial internal clearance
d		C2		Normal		C3		C4		C5
over	incl.	min	max	min	max	min	max	min	max	min	max
mm
18	24	10	20	20	35	35	45	45	60	60	75
24	30	15	25	25	40	40	55	55	75	75	95
30	40	15	30	30	45	45	60	60	80	80	100
40	50	20	35	35	55	55	75	75	100	100	125
50	65	20	40	40	65	65	90	90	120	120	150
65	80	30	50	50	80	80	110	110	145	145	185
80	100	35	60	60	100	100	135	135	180	180	225
100	120	40	75	75	120	120	160	160	210	210	260
120	140	50	95	95	145	145	190	190	240	240	300
140	160	60	110	110	170	170	220	220	280	280	350
160	180	65	120	120	180	180	240	240	310	310	390
180	200	70	130	130	200	200	260	260	340	340	430
200	225	80	140	140	220	220	290	290	380	380	470
225	250	90	150	150	240	240	320	320	420	420	520
250	280	100	170	170	260	260	350	350	460	460	570
280	315	110	190	190	280	280	370	370	500	500	630
315	355	120	200	200	310	310	410	410	550	550	690
355	400	130	220	220	340	340	450	450	600	600	750
400	450	140	240	240	370	370	500	500	660	660	820
450	500	140	260	260	410	410	550	550	720	720	900
500	560	150	280	280	440	440	600	600	780	780	1 000
560	630	170	310	310	480	480	650	650	850	850	1 100
630	710	190	350	350	530	530	700	700	920	920	1 190
710	800	210	390	390	580	580	770	770	1 010	1 010	1 300
800	900	230	430	430	650	650	860	860	1 120	1 120	1 440
900	1 000	260	480	480	710	710	930	930	1 220	1 220	1 570
1 000	1 120	290	530	530	780	780	1 020	1 020	1 330	1 330	1 720
1 120	1 250	320	580	580	860	860	1 120	1 120	1 460	1 460	1 870
1 250	1 400	350	640	640	950	950	1 240	1 240	1 620	1 620	2 060
1 400	1 600	400	720	720	1 060	1 060	1 380	1 380	1 800	1 800	2 300
1 600	1 800	450	810	810	1 180	1 180	1 550	1 550	2 000	2 000	2 550

Adapters and Withdrawal Sleeves af Spherical Roller Bearings

Adapters are used for installation of bearings with tapered bore on cylindrical shafts. Withdrawal sleeves are also used to install and disassemble bearings with tapered bore onto and off of cylindrical shafts. In disassembling the bearing from the shaft, the nut is pressed down against the edge of the inner ring utilizing the bolt provided on the withdrawal sleeve, and then the sleeve is drawn away from the bearing's inner diameter surface. (Precision of adapter and withdrawal sleeve are stipulated JIS B 1552 and JIS B 1556).

For bearings with a bore diameter of 200 mm or more, high pressure oil (hydraulic) type adapters and withdrawal sleeves have been standardized to make installation and disassembly easier. As shown in the diagram construction is designed to reduce friction by injecting high pressure oil between the surfaces of the adapter sleeve and bearing inner bore by means of a pressure fitting.

If the oil supply inlet is attached in the nut side of the adapter, the supplementary suffix "HF" should be added to the bearing number; if the oil supply inlet is attached on the opposite side, the suffix "HB" should be added to the bearing number. For adapter sleeves, the supplementary suffix "H" is added to the bearing's number in both cases.

The hydraulic sleeve nut is equipped with holes for bolts used for mounting and dismounting and holes for hydraulic piping. The suffix SP or SPB is added to the bearing number of the nut.

Radial Bearings :
Deep Groove Ball Bearings | Self Aligning Ball Bearings | Angular Contact Ball Bearings | Cylindrical Roller Bearings | Needle Roller Bearings | Spherical Roller Bearings | Taper Roller Bearings