China Tapered Roller Bearings - Quality Suppliers and Factory Direct Products for Optimal Performance
Main Structural Types
Tapered roller bearings are classified into three primary structural types:
- Single-row
- Double-row
- Four-row
The main parameters of tapered roller bearings have been optimized, increasing the number of rollers and their effective length. The meticulous design of the rollers and raceways significantly improves geometric contact, stress distribution, and lubricant film formation, enhancing roller motion conditions. Consequently, compared to earlier models of the same size, these bearings offer higher load capacity and extended rated service life.
Double-row tapered roller bearings can withstand combined radial and axial loads (primarily radial) as well as bidirectional axial loads. A spacer is placed between the two inner rings, allowing clearance adjustment and uniform load distribution by varying the spacer thickness. These bearings are suitable for medium to low-speed applications.
Dimensions
Single-row tapered roller bearings are available in both metric and inch series, both widely used.
- Metric series bearings conform to ISO 355:1977
- Bearings with prefix F–J comply with AFBMA Standard 19.1
- Inch series tapered roller bearings comply with AFBMA Standard 19 (1974)
Permitted Misalignment
Tolerances
For tapered roller bearings of the same designation, the inner rings (with roller and cage assemblies) or outer rings are interchangeable. After swapping inner or outer components, the total bearing width T must remain within tolerance limits.
Standard metric tapered roller bearings are manufactured with normal tolerance. Products with tolerance classes P6X, P6, P5, P4, and P2 are also available. Bearings with P5 tolerance or higher are primarily used for machine tool spindles. Chamfer dimension tolerances comply with ISO 582:1979. F–J series bearings are generally produced to P6X tolerance, with chamfer dimensions adhering to inch series bearing chamfer tolerances.
Standard inch series tapered roller bearings are manufactured with normal tolerance. Products with tolerance classes CL2, CL3, CL0, and CL00 are available upon request.
Internal Clearance
Internal clearance in single-row tapered roller bearings is established only after mounting and adjustment against a counter-oriented bearing. The radial clearance for double-row tapered roller bearings follows the values provided in the table below.
Cages
- Standard bearings: High-quality stamped steel cages
- Larger bearings: Machined brass cages
- Special applications: Injected nylon 66 cages
Minimum Load
To prevent destructive sliding between rollers and raceways caused by inertial forces and lubricant friction during high-speed operation, a minimum radial load must be applied. This can be estimated using the formula:
• Frm — Minimum radial load (N)
• C — Basic dynamic load rating (N)
Single-Row Tapered Roller Bearings
When calculating the dynamic equivalent load, the axial component force generated under radial loads must be considered. The formulas on the next page account for various mounting configurations and load conditions. These formulas apply only when bearings are adjusted to zero clearance without preload.
In the illustrated configurations, Bearing A always carries radial load Fra, and Bearing B always carries radial load Frb. Both Fra and Frb are treated as positive. Radial loads act at the pressure center (denoted as a in bearing tables). Additionally, an external axial force Ka acts on the shaft or housing. The axial load factors for A and B can be found in the bearing tables.
Double-Row Tapered Roller Bearings