Angular Contact Ball Bearings

• Four-point contact ball bearings are radial single-row angular contact ball bearings whose raceways are designed to support axial loads acting in both directions. A limited radial load (load ratio) can also be supported for a given axial load. The outer ring, ball, and cage assembly can be installed separately from the inner ring halves, making the bearing separable.

• Structure of four-point contact ball bearing

• The structure of four-point contact ball bearings can be divided into three parts: outer ring, inner ring, and steel balls.

• The bearing raceways of the outer and inner rings are peach-shaped cross-sections. When the pure axial load acts, the steel ball, and the ferrule become two-point contact, which can bear bidirectional axial load.

• The four-point contact ball bearing is separable, and a single bearing can replace the angular contact ball bearings combined in the front or back. It can bear radial and bidirectional axial loads and limit axial displacement in two directions. It occupies less axial space than the current specification's double-row angular contact ball bearing.

• Compared to other types of ball bearings, the four-point contact ball bearing will has a smaller axial clearance and a higher limit speed when the radial clearance remains the same. These bearings are suitable for handling pure or combined axial and radial loads are the dominant force. Because it is a double-half inner ring (or outer ring), the number of balls is increased and has a larger bearing capacity.

• Naming of four-point contact ball bearings:

• The four-point contact ball bearings naming includes bearing type, dimension series, aperture, and cage codes.

• Bearing type code: The bearing type is named by the main bearing load, such as QJ's bearing type code of a four-point contact ball bearing.

• Dimension series code: use numbers to indicate the dimension series of bearings, such as 02 series, 03 series, etc.

• Aperture code: Use numbers to indicate the aperture size of the bearing. When less than 04, 00 represents 10mm, 01 represents 12mm, 02 represents 15mm, and 03 represents 17mm. When it is greater than 04, the bearing aperture = number x5 (mm).

• Cage code: Use the letter M to represent the machined brass cage.

• Application of four-point contact ball bearings:

• The four-point contact ball bearing is a kind of bearing that can bear radial and axial load at the same time. It has extremely high load capacity and good rigidity, so it is widely used in industrial machinery, automobiles, aerospace, and other fields.

• For example, such bearings can be installed in engines, transmissions, steering gears, rear axles, and wheels. Four-point contact ball bearings are often used on machine tools in grinding machine spindles and gear processing machine tools. In aerospace, such bearings are installed in aircraft engines, landing gear, and flight control systems.

• In addition, four-point contact ball bearings can also be used in oil drilling rigs, iron and steel machinery, and other fields.

• In short, four-point contact ball bearings are widely used in various fields because of their high load capacity and good rigidity.

• Classification of four-point contact ball bearings:

Four-point contact ball bearings can be divided into the QJ and QJF series.

The contact angle of QJ series four-point contact ball bearings is 35° or 45°.

QJ Series - Four-point contact ball bearings

QJF Series - Four-point contact ball bearings