In brief
A deep groove ball bearing is the most widely used type of rolling bearing; it carries radial loads and limited axial loads in both directions.
Contents
What is Deep groove ball bearing?
Deep groove ball bearings have deep, uninterrupted raceway grooves in the inner and outer rings, in which the balls roll. This geometry allows axial loads in both directions as well as radial loads. Deep groove ball bearings are non-separable, low-maintenance and suitable for high speeds. Compared with angular contact ball bearings, they carry lower axial loads; compared with roller bearings, lower radial loads.
They are available open, with sheet steel shields or with contact or low-friction seals. Sealed bearings are greased at the factory and lubricated for life. Other variants are bearings with a snap ring groove, double-row designs and stainless steel bearings for damp or food-related environments. Important parameters are dimensions, load ratings, limiting speed, internal clearance, for example normal clearance or the larger C3 clearance, and the type of sealing.
Deep groove ball bearings are standard in electric motors, fans, pumps, conveyor rollers and small gearboxes. They are therefore among the bearing items most frequently stocked by maintenance departments. Failures are mostly caused by aged grease, contamination, misalignment or improper installation. For motors on frequency inverters, electrically insulated versions are also used.
In practice: maintenance and procurement
When ordering, the complete designation counts: basic number plus suffixes for seal, internal clearance and, where applicable, high-temperature or food-grade grease. For electric motors on inverters, it should be checked whether electrically insulated bearings were originally fitted.
Synonyms and abbreviations: DGBB · radial deep groove ball bearing · 6000 series bearing · single-row deep groove ball bearing
Frequently asked questions
What do 2RS and 2Z mean on deep groove ball bearings?
The suffixes indicate sealing on both sides. Usually, RS stands for an elastomer seal and Z for a sheet steel shield; the preceding 2 means on both sides. Seals give better protection against dirt and moisture, while shields cause less friction. The exact notation differs between manufacturers, so the suffix should be copied exactly.
What does C3 mean on a deep groove ball bearing?
C3 denotes an internal clearance that is larger than normal clearance. It is chosen when the inner ring heats up more than the outer ring in operation or when tight fits reduce the clearance. This is the case, for example, in many electric motors. A bearing with normal clearance instead of C3 can run too hot there and fail early.
What information is needed to replace a deep groove ball bearing?
The safest option is the complete designation from the bearing or from the spare parts list. Without it, the bore, outside diameter and width are needed, as well as sealing, internal clearance, operating temperature and speed. In special environments such as wet areas, food processing or high heat, details of material and grease are also important.
Can deep groove ball bearings be relubricated?
Bearings sealed on both sides are greased for life and are not relubricated. Open bearings in housings with a grease nipple can be relubricated through the housing bore; the grease type, quantity and interval are specified by the machine or bearing manufacturer. Too much grease increases friction and temperature and is just as harmful as too little.