Spherical roller bearings - SKF

1 Spherical roller bearings Spherical roller bearings Spherical roller bearings Designs and variants 5. CC, CA and E design bearings 5. Sealed bearings 6. bearings for vibratory applications 8. bearings for wind energy applications 10. Customized bearings 10. bearings for high-speed applications 10. Bearing data 11. (Dimension standards, tolerances, internal clearance, permissible misalignment). Loads 14. (Minimum load, axial load carrying capacity, equivalent dynamic bearing load, equivalent static bearing load). Temperature limits 15. Permissible speed 15. Design considerations 16. Free space on both sides of the bearing 16. Abutments for sealed bearings 16. bearings on sleeves 17. Appropriate bearing housings 18. Mounting 18. Designation system 20.

2 Product tables 1 Spherical roller bearings 22. 2 Spherical roller bearings on an adapter sleeve 54. 3 Spherical roller bearings on a withdrawal sleeve 62. 3. Spherical roller bearings Spherical roller bearings Spherical roller bearings have two rows of Long service life symmetrical rollers, a common sphered The rollers are manufactured to such tight outer ring raceway and two inner ring race- dimensional and geometrical tolerances ways inclined at an angle to the bearing axis that they are practically identical in a roller (ig. 1) The centre point of the sphere in the set The symmetrical rollers self-adjust outer ring raceway is at the bearing axis (ig. 3), providing optimal load distribution along the roller length and together with Bearing features the special proile prevent stress peaks at the roller ends (ig.)

3 4). Accommodate misalignment Low friction Spherical roller bearings are self-aligning Self-guiding rollers keep friction and fric- like self-aligning ball bearings or CARB tional heat at low levels (ig. 5) A loating bearings (ig. 2) guide ring guides unloaded rollers so that they enter the load zone in the optimal High load carrying capacity position Spherical roller bearings are designed to accommodate both heavy radial loads and Robust axial loads in both directions All SKF Spherical roller bearings contain strong window- or prong-type cages Fig. 1 Fig. 2. Spherical roller bearing Self-aligning property of the bearing 4. Designs and variants Designs and CC, CA and E design are indicated in the product table by the designation sufix CA.

4 Variants bearings are indicated in the product table by the designation sufix ECA for larger bearings CC design bearings and have an optimized internal design for SKF standard assortment increased load carrying capacity have two stamped window-type steel The assortment of SKF Spherical roller bear- cages, an inner ring without langes and a E design bearings ings is the widest available on the market loating guide ring centred on the inner The standard assortment includes: ring (ig. 6) have two stamped window-type steel are indicated in the product table by the cages, an inner ring without langes and a CC, CA and E design bearings designation sufix C or CC loating guide ring centred on the inner sealed bearings are indicated in the product table by the ring (d 65 mm) or on the cages bearings for vibratory applications designation sufix EC or ECC for larger (d > 65 mm) (ig.)

5 6). bearings for wind energy applications bearings and have an optimized internal are indicated in the product table by the design for increased load carrying capacity designation sufix E. All SKF Spherical roller bearings are have an optimized internal design for SKF Explorer bearings (page 7) and almost CA design bearings increased load carrying capacity all bearings are available with the option of a tapered bore Depending on the bearing have a machined double prong-type brass Cages series, the tapered bore has: cage, an inner ring with a retaining lange on both sides and a loating guide ring For information about the suitability of a taper 1:12 (designation sufix K) centred on the inner ring (ig. 6) cages, refer to Cages, page 187, in Rolling a taper 1:30 (designation sufix K30) The langes on the inner ring are bearings , PUB BU/P1 17000/1 EN.

6 Designed to keep the rollers in place when For sizes and variants not listed in the swivelling the bearing during mounting or product tables, contact SKF maintenance and are not designed to guide the rollers or accommodate any axial load Fig. 3 Fig. 4 Fig. 5. Self-adjusting property of the rollers Load distribution over the roller length Optimal roller guidance Fig. 6. Basic design bearings CC design CA design E design 5. Spherical roller bearings Annular groove and lubrication grease life for sealed bearings The seals are itted in a recess on the outer holes ring and seal against the inner ring (ig. 8) The grease life for sealed bearings is pre- On larger bearings , the seals are ixed by a sented as L10, i e the time period at the end CC and CA design bearings are available retaining ring (ig.)

7 9) of which 90% of the bearings are still reliably with an annular groove and three lubri- bearings sealed on both sides are lubri- lubricated, and depends on the load, operat- cation holes in the outer ring (designation cated for the life of the bearing and are vir- ing temperature and speed value It can be sufix W33) or three lubrication holes in tually maintenance-free ( grease life for obtained for bearings with standard SKF. the outer ring (designation sufix W20) sealed bearings ) They are illed with one of LGEP 2 grease (designation sufix VT143). (ig. 7) the following greases (table 1): from: E design bearings have an annular groove and three lubrication holes as standard SKF LGEP 2 grease (designation sufix diagram 1, for light load (P 0,067 C).

8 (ig. 6, page 5) This feature is not identi- VT143) as standard diagram 2, page 8, for normal load ied in the bearing designation (no desig- SKF LGHB 2 grease (designation sufix (P 0,125 C). nation sufix) GEM9) or LGWM 2 grease (designation sufix GLE) on request The grease life is valid under the following operating conditions: For additional information about greases, Sealed bearings refer to Selecting a suitable SKF grease , horizontal shaft page 116, in Rolling bearings , PUB BU/P1 inner ring rotation have the same features and internal 17000/1 EN operating temperature within the green design as open Spherical roller bearings temperature zone of the grease (table 1). are available with a cylindrical bore as stationary machine standard low vibration levels are supplied grease lubricated and should load ratio Fa/Fr e (product table, not be washed page 22).

9 Are equipped with an annular groove and rotational speed below the limiting speed three lubrication holes in the outer ring, (product table) and below the limits listed except for those with the designation in table 2, page 8. sufix W. are itted with a contact seal, on one or For other operating conditions, the grease both sides, made of one of the following life can be estimated by multiplying the relu- materials: brication interval for open bearings (Esti- sheet steel reinforced NBR (designation mating the relubrication interval for grease , sufix CS or RS) page 111, in Rolling bearings , PUB BU/P1. sheet steel reinforced HNBR (designa- 17000/1 EN) by a factor of 2,7. tion sufix CS5 or RS5). sheet steel reinforced FKM (designation sufix CS2).

10 Fig. 7 Fig. 8 Fig. 9. Annular groove and lubrication holes Seals itted in outer ring recess Seals ixed by a retaining ring W33. W20. 6. Designs and variants Relubrication of sealed bearings Diagram 1. W equired service life is longer than grease life for sealed Spherical roller bearings with designation sufix VT143 where the grease life, the bearings may require P 0,067 C. relubrication A suitable grease quantity to relubricate sealed bearings can be obtained using grease life L10 [h]. G p = 0,0015 D B 30 000. 25 000. where Gp = grease quantity [g] 20 000. nd m D = bearing outside diameter [mm]. =. 15 000. 25. B = bearing width [mm]. 00. 50. 0. 00. 75. 0. 00. The grease should be applied slowly through 10. 10 000. 0. 0. the lubrication holes in the outer ring, pref- 12.