SKF single row deep groove ball bearings are the most widely used bearing type. single row deep groove ball bearings are available capped or open. Some SKF open bearings are also available capped, which may have recessed in the ring side faces.
SKF inch bearings in the EE(B), RLS and RMS series are intended as aftermarket items and, therefore, we recommend not using these bearings for new arrangement designs.
For technical details of SKF single row deep groove ball bearings, please refer to SKF deep groove ball bearings.
SKF single row deep groove ball bearings capped
Selection guidelines for different capping devices under various operating conditions are as follow
| Requirement | Shields | Non-contact seals |
Low-friction seals |
Contact seals | ||
|---|---|---|---|---|---|---|
| Z | RZ | RSL | RST | RSH | RS1 | |
| Low friction | +++ | +++ | ++ | ++ | O | O |
| High speed | +++ | +++ | +++ | + | O | O |
| Grease retention | O | + | +++ | +++ | +++ | ++ |
| Dust exclusion | O | + | ++ | ++ | +++ | +++ |
| Water exclusion | ||||||
| static | – | – | O | +++ | +++ | ++ |
| dynamic | – | – | O | + | ++ | + |
| high pressure | – | – | O | O | +++ | O |
Shields
- are identified by the designation suffix Z
- are primarily intended for applications where the inner ring rotates
- are fitted in the outer ring and form a narrow gap with the inner ring
- are made of sheet steel
- are available as standard with an extension in the shield bore, expect some sizes without extension
- protect from dirt and debris without friction losses
Non-contact seals
- are identified by the designation suffix RZ
- provide better sealing effectiveness than shields
- can be operated at the same speeds as shields
- form an extremely narrow gap with the inner ring shoulder
- are made of sheet steel reinforced NBR (oil- and wear-resistant)
Low-friction seals
- are identified by the designation suffixes RSL or RST
- provide better sealing effectiveness than non-contact seals
- are made of sheet steel reinforced NBR (oil and wear-resistant)
RSL design
- can be operated at the same speeds as shields
- make virtually no contact with a recess in the inner ring shoulder
- are available for 60, 62, 63 series bearings in two designs, depending on the size
RST design
- make positive contact with a recess in the inner ring shoulder for good sealing effectiveness
- are available on request for 60, 62 and 63 series bearings in three RST designs, depending on the size
Contact seals
- are identified by the designation suffixes RSH, RSH2, RS1 or RS2
- are made of sheet steel reinforced
- NBR
- FKM (designation suffix RS2 or RSH2, available on request)
Bearings with designation suffix VA947 are equipped with seals made of blue food-compatible NBR.
The material is FDA and EC approved. FDA approval is based on compliance with CFR 21 section 177.2600 'Rubber articles intended for repeated use' for use in contact with aqueous and fatty foods. EC approval is based on compliance with the overall migration requirements of the German BfR recommendation XXI for category 3 materials. - are available in different designs depending on the bearing they are used with:
- for 60, 62 and 63 series bearings in two RSH designs, depending on the size
- for RS1 designs, with sealing either against the inner ring shoulder or against a recess in the inner ring side face; the relevant design is determined by dimension d1 or d2.
WARNING
Seals made of FKM (fluoro rubber) exposed to an open flame or temperatures above 300 °C (570 °F) are a health and environmental hazard! They remain dangerous even after they have cooled.
Greases for SKF capped bearings
SKF bearings capped on both sides are lubricated for the life of the bearing and are virtually maintenance-free. They are filled with one of the following greases:
- standard deep groove ball bearings, please refer to the table below.
- deep groove ball bearings with designation suffix VA947
→ GFM food-grade grease, registered by NSF as category H1
The NSF registration confirms the grease fulfils the requirements listed in the US Food and Drug Administration's guidelines under 21 CFR section 178.3570 (lubricant acceptable with incidental food contact for use in and around food processing areas). - inch deep groove ball bearings
- D < 63.5 mm → MT47
- D ≥ 63.5 mm → MT33
| Bearings in diameter series |
SKF standard greases in bearings with outside diameter | |||
|---|---|---|---|---|
| D ≤ 30 mm | 30 < D ≤ 62 mm | D > 62 mm | ||
| d < 10 mm | d ≥ 10 mm | |||
| 8, 9 | LHT23 | LT | MT47 | MT33 |
| 0, 1, 2, 3 | MT47 | MT47 | MT47 | MT33 |
On request, bearings can be supplied with the following special greases:
- high temperature grease GJN
- wide temperature range grease HT or WT
- wide temperature range and low-noise grease LHT23
- low temperature grease LT
The technical specifications of SKF standard and special greases for capped deep groove ball bearings
The standard grease is not identified in the bearing designation (no designation suffix). Special greases are indicated by the corresponding grease suffix. Check availability of bearings with special grease prior to ordering.
Grease for SKF capped bearings
- is presented as L10, i.e. the time period at the end of which 90% of the bearings are still reliably lubricated
- depends on:
- the operating temperature
- the ndm value
- grease performance factor (GPF, refer to the SKF standard and special greases for capped deep groove ball bearings)
The indicated grease life is valid under this combination of operating conditions:
- horizontal shaft
- inner ring rotation
- light load (P ≤ 0,05 C)
- operating temperature within the green temperature zone of the grease
- stationary machine
- low vibration levels
Where the operating conditions differ as described below, the grease life obtained from the diagrams should be adjusted:
- vertical shafts → 50% of the obtained value
- heavier loads (P > 0,05 C) → apply reduction factor
When capped bearings must operate under certain extreme conditions, such as very high speeds or high temperatures, grease may appear on the capping diameter. For bearing arrangements where this would be detrimental, appropriate actions could be taken.
SKF Explorer bearings
SKF Explorer rolling bearings accommodate higher load levels and provide extended service life. Optimized internal geometry reduces friction, wear and heat generation, allowing heavier loads to be accommodated. Advanced surface finish reduces friction and enhances lubricating conditions.
Benefits of using SKF Explorer bearings include:
- significantly extended service life
- increased uptime and productivity
- extended lubricant life
- reduced sensitivity to misalignment
- reduced noise and vibration
- enabling downsized applications
Cages for SKF single row deep groove ball bearings
Depending on their design, series and size, SKF single row deep groove ball bearings are fitted with one of the cages. The standard stamped steel cage is not identified in the bearing designation. When used at high temperatures, some lubricants can have a detrimental effect on polyamide cages.
| Steel cages | Polymer cages | Brass cages | ||||
|---|---|---|---|---|---|---|
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| Cage type | Ribbon-type, ball centred | Riveted, ball centred | Snap-type, ball centred | Snap-type, ball centred | Snap-type, ball centred | Riveted, ball, outer ring or inner ring centred |
| Material | Stamped steel | Stamped steel | PA66, glass fibre reinforced | PA46, glass fibre reinforced | PEEK, glass fibre reinforced | Machined brass |
| Suffix | - | - | TN9 | TN9/VG1561 | TNH | M, MA or MB |
| Metric bearing | Standard | Standard | Standard for ICOS oil sealed bearing units | Check availability | Check availability | Standard |
| Inch | - | Standard | Standard | - | - | - |