Standard Angular Contact Ball Bearing

QIBR precision angular contact ball bearings offer solutions to enhance bearing rigidity, reduce noise and vibration, improve high-speed performance, and extend service life

• QIBR precision angular contact ball bearings achieve significantly improved rigidity by using a larger number of large ceramic balls and a design with a larger groove curvature radius coefficient, which greatly increases the bearing's preload.

• Noise and Vibration Reduction: To reduce bearing noise and vibration, the bearing raceway waviness and surface roughness are optimized, and a lightweight cage with optimized guided clearance is used.

• Reliability and Longevity: The bearings are made from high-purity bearing steel, and the reliability and longevity are enhanced through austenite grain and carbide size refinement during the bearing blank processing. This greatly improves the contact fatigue life of the bearing. The surfaces of the inner and outer raceways undergo vacuum ion nitriding treatment, significantly enhancing the bearing's wear resistance.

• High-Speed Performance: For high-speed applications, such as the QIBR QHCG... series bearings, a super high-speed design is used, with a speed factor DmN value of up to 3 million (oil-air lubrication) and 2 million (grease lubrication).

QIBR Precision Angular Contact Ball Bearings

High-speed precision angular contact ball bearings are available in various precision grades: standard precision is ISO Class 4 (ABEC 7), P4A (dimensional accuracy of ISO Class 4 with rotational accuracy higher than ISO Class 4), and ISO Class 2 (ABEC 9)

QIBR Precision Angular Contact Ball Bearings Preload Methods and Characteristics

Angular contact ball bearing axial preload can be categorized into two types based on the method of applying preload: positional preload and constant pressure preload.

• Positional Preload: Positional preload refers to a method where the axial position of the bearing remains relatively unchanged during use. The required preload can be achieved by adjusting the width of the spacer between two bearings. Another approach involves grinding a certain amount of pre-deformation on the end faces of the inner or outer rings of a matched pair of bearings, achieving preload upon installation. Positional preload significantly enhances the rigidity of the bearing support system.

• Constant Pressure Preload: Also known as constant force preload, this method ensures that the axial preload of the bearing remains constant during operation. The preload is achieved by adjusting the compression of a spring. Compared to positional preload, constant pressure preload is less effective at improving the axial rigidity of the support system under the same preload. However, with positional preload, the thermal expansion of the shaft and changes in radial clearance caused by temperature differences between the inner and outer rings can affect the amount of preload deformation, while constant pressure preload does not have these issues. Generally, positional preload is preferred when high rigidity is required, whereas constant pressure preload is more suitable for high-speed applications.

QIBR Precision Angular Contact Ball Bearing Pairing

To enhance bearing load capacity and rigidity, angular contact ball bearings used in machine tool spindles are typically employed in pairs or groups. Common methods include duplex or multi-bearing arrangements. When pairing bearings, the following performance parameters must be controlled between any two bearings:

1. The difference in average inner and outer diameters between any two precision angular contact ball bearings.

2. The difference in radial runout of the inner and outer rings between any two precision angular contact ball bearings.

3. The difference in actual contact angles between any two precision angular contact ball bearings.

4. The difference in protrusion between adjacent precision angular contact ball bearings.