Angular contact Ball Bearings-Chrome Steel

Angular contact ball bearings are a common type of rolling bearing. Their design allows them to simultaneously handle radial and axial loads, making them widely used in high-precision, high-speed, or dual-direction load applications. Below are the key points:

Angular Contact Ball Bearing Code Structure

The code typically consists of prefix, basic code, and suffix:
Example: 7205 B EC P4 UA C3

Prefix

Indicates special design or material (e.g., HC represents hybrid ceramic balls).

Basic Code

Contains bearing type, size series, and bore diameter:

  • 719: Ultra-light series (same bore diameter but smaller outer diameter).
  • 70: Light series (e.g., 7005).
  • 72: Medium series (e.g., 7205).
  • 73: Heavy series (e.g., 7305).

Suffix

Represents characteristics such as contact angle, precision, seal, and clearance:

  • Contact Angle:
    • C: 15°
    • AC: 25°
    • A: 30°
    • B: 40°

Basic Structure

  1. Inner and Outer Ring Design:
    The raceways on the inner and outer rings form an angle (contact angle), creating an asymmetrical structure. Typically, one side has a higher shoulder to position the balls securely.

  2. Rolling Elements:
    Uses spherical balls, which make point contact with the raceways, minimizing friction and enabling high-speed operation.

  3. Contact Angle:
    The angle between the line of contact of the ball and raceway and the bearing axis (commonly 15°, 25°, 30°, or 40°).

Installation Methods

  1. Back-to-Back (DB):
    Provides high resistance to overturning moment; ideal for complex loading conditions.

  2. Face-to-Face (DF):
    Allows better adjustment of preload and accommodates thermal expansion.

  3. Tandem (DT):
    Improves single-direction axial load capacity (e.g., turbochargers).

Important Considerations

  1. Preload Adjustment:
    Excessive preload increases friction and heat generation, while insufficient preload results in clearance, reducing accuracy.

  2. Lubrication and Sealing:
    High-speed applications require high-quality grease or oil lubrication while preventing the ingress of contaminants.

  3. Paired Usage:
    A single bearing supports only single-direction axial force; dual-direction loading requires paired installation.