The meaning of the suffix letters of precision angular contact ball bearings

Example bearing model: SH6-7208CYDU/GL P4 SH6-: Material symbol Outer ring·Inner ringu003dbearing steel, ballu003dceramic (no symbol): Outer ring·Inner ring·Ballu003dBearing steel 7: Single row angular contact ball bearing Type code 2 Size series code 9: 19 series 0: 10 series 2: 02 series 08 Inner diameter code 00: Inner diameter size 10 mm 01: 12mm 02: 15mm 03: 17mm 04～: (Inner diameter code) × 5mm contact angle code C: 15° 7200 AC: 25° Y cage code Y: polyamide resin cage DU assembly code U: free assembly (single) DU: free assembly (2 sets) DB: back-to-back assembly DF: face to face Assembly DT: series assembly/GL preload grade code/GE: micro preload/GL: light preload/GM: medium preload/GH: heavy preload P4 accuracy grade code P5: JIS 5 P4: JIS 4 Grade features ● The balls of angular contact ball bearings and the raceways of the inner ring and outer ring can be contacted at an angle in the radial direction. In single use, the axial load is limited to a single direction, which is suitable for bearing the combined load of axial load and radial load. ● Because this bearing has a contact angle, an axial component of force will be generated when a radial load is applied. Therefore, it is generally used in a symmetrical or matched form on both sides of the shaft. ● There are also types that use ceramic balls. There are two types of contact angles: 15° and 25°. 15° is used for high speed applications. 25° is suitable for occasions that require axial rigidity. The cage is made of polyamide as the standard. Please use polyamide cages below 12. Dimensional accuracy and rotation accuracy are based on JIS grade 5 or 4. Please refer to page 7. Preload ● Set 4 types of standard preload. Select the desired preload based on the selection criteria in the table on the right. ● For the standard preload of each series and size, please refer to pages 16-18. Assembling For the use of multi-row assembly, please refer to pages 12-13. Ceramic ball type In order to reduce the centrifugal force of the ball during high-speed rotation, a ceramic ball with a lower density than the bearing steel is used. ● The various characteristics of ceramics and bearing steel are shown in the table below. ● Add 'SH6-' to the beginning of the bearing model with ceramic ball. ● The preload and axial rigidity are about 1.2 times of the bearing steel ball type. Preload symbol selection criterion E (micro preload) Prevents machine vibration and improves accuracy L (light preload) High speed (dmn value of 500,000) still has a certain rigidity M (medium preload) At standard speed, the ratio is lighter High rigidity H with higher preload (heavy preload) Maximum rigidity is produced at low speeds. Characteristic unit Ceramic (Si3N4) bearing steel (SUJ2) heat resistance °C 800 180 density g/cc 3.2 7.8 linear expansion coefficient 1/°C 3.2×10-6 12.5×10-6 hardness Hv 1400~1700 700~800 longitudinal Modulus of elasticity GPa 314 206 Poisson's ratio − 0.26 0.30 Corrosion resistance − Good and bad magnetism − Non-magnetic strong magnetic conductivity − Insulator conductor crystal bonding state − Common combination of metal bonding ceramic and bearing steel characteristics comparison preload selection reference angle Contact the ball bearing.