The working principle of double row tapered roller bearings is based on their unique structural design, which achieves the bearing of radial and axial combined loads through the cooperation of inner and outer ring tapered raceways and tapered rollers, as follows:
1. Structural characteristics
Double row design: consisting of two inner rings, an integral outer ring, spacers, and conical rollers. The two inner rings are separated by a spacer to form an independent roller arrangement.
Conical raceway: The inner and outer raceway are conical, and the rollers are in linear contact with the raceway. The extension of the contact line intersects the same point on the bearing axis to ensure pure rolling friction.
2. Bearing mechanism
Radial load: When the bearing is subjected to radial force, the rollers roll on the raceway, evenly distributing the force to the inner and outer rings.
Axial load: The tapered design of the rollers allows the bearing to simultaneously withstand bidirectional axial forces, and the axial load capacity is proportional to the contact angle (outer race raceway angle). The larger the contact angle, the stronger the axial load capacity.
Joint load: By optimizing the contact angle and number of rollers, the bearing can efficiently transmit the combined radial and axial loads.
3. Clearance adjustment
Spacer adjustment: By changing the thickness of the spacer and adjusting the relative position of the two inner rings, the radial clearance and preload of the bearing can be controlled to ensure even load distribution.
Factory pre adjustment: Some bearings have completed clearance adjustment before leaving the factory, and users can directly install and use them.
4. Performance advantages
High rigidity: The double row structure significantly improves the radial and axial stiffness of the bearing, reducing deformation.
Low friction: The pure rolling design of the rollers and raceways reduces the friction coefficient and minimizes heat generation.
Long life: Optimized design of roller and raceway geometry contact, improved stress distribution, and extended bearing life.
5. Application Fields
Heavy duty machinery, such as rolling mills, gearboxes, and lifting equipment, can withstand large radial and axial loads.
Precision equipment: Machine tool spindle, requiring high rigidity and low vibration.
Industrial transmission: engineering machinery, mining machinery, suitable for harsh working conditions.
6. Typical application cases
Rolling mill: Double row tapered roller bearings are used to support rolling rolls, withstand rolling forces and axial thrust, and ensure rolling accuracy.
Gearbox: In the gearbox of a wind turbine, the bearings bear the radial and axial forces generated by gear meshing, ensuring transmission stability.
7. Technical parameters and selection
Contact angle selection: Choose the appropriate contact angle (usually 10 °~30 °) according to the axial load requirements.
Accuracy level: P5 level or above bearings are used for high-precision applications (such as machine tool spindles).
Clearance adjustment: It is necessary to accurately calculate the thickness of the spacer according to the working conditions to avoid interference or excessive clearance.
summarize
Double row tapered roller bearings achieve efficient transmission of radial and axial combined loads through the coordination of tapered raceways and rollers. Their double row structure, clearance adjustment mechanism, and high rigidity design make them an ideal choice for heavy-duty and high-precision applications.