Four point contact ball bearings with locating slots

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Four Point Contact Bearings

Four-point contact ball bearings are a type of single-row angular contact ball bearing designed to handle main axial loads in both directions as well as limited radial loads. They are characterized by a unique design where the inner ring is split into two halves, allowing the bearing to contact the balls at four points under radial load.

ZMS supplies high quality four point contact ball bearings in China for 15 years. There are famous manufacturers in the world like SKF, FAG, NSK and so on. The quality will be perfect. But if you need high quality from China with better price and need custom made for you. Please get in touch with us.

Main bearing series:
QJ2 series
QJ3 series
QJ10 series
We can also supply four point contact ball bearings with locating slots.

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Features

Design: Consists of a solid outer ring, a split inner ring, and a ball-and-cage assembly. The raceways are designed with a high contact angle (typically 35°), enabling the bearing to support axial loads in both directions.

Space-Saving: Requires less axial space than double-row angular contact bearings, effectively acting as two single-row angular contact bearings in one compact unit.

Cage Materials: Typically uses brass or polyamide cages, with brass offering durability for high-speed or high-temperature applications and polyamide providing lightweight and low-noise operation.

High load capacity: A large number of balls are incorporated, giving the bearing its high load carrying capacity.

High-Speed Capability: Suitable for high-speed applications, especially under pure axial loads, due to optimized raceway geometry and cage design.

Applications

Rotary Tables and Indexing Tables
Used in machine tools and CNC equipment for precise rotation and positioning.

Industrial Gearboxes
Supports combined axial and radial loads from gears, especially in compact gearbox designs.

Aerospace Applications
Used in aircraft gearboxes, control systems, and other components where space is limited and loads are complex.

Robotics
Applied in robot joints and arms, where multi-directional loads and high precision are required.

Automotive Transmissions and Differentials
Handles the thrust and radial loads in automotive gear assemblies.

Pump and Compressor Shafts
Used to support impeller shafts that experience both radial and bidirectional axial loads.

Cranes and Lifting Equipment
Employed in slewing rings and turntables for handling large overturning moments and axial loads.

Wind Turbines
Used in main shafts and yaw systems, where space-saving and load-carrying capacity are important.

Medical Equipment
Found in CT scanners and other rotating medical devices requiring compact, precise bearings.

Marine Propulsion Systems
Supports propeller shafts and other components exposed to complex load conditions.

Customization

We can custom made four point angular contact ball bearings by customer requirements with special angle or with locating slots. And if there ia any other requirements, we can also checking the possibility for you.

Frequently Asked Question

What does the QJ prefix mean in bearings?

The “QJ” prefix indicates a four-point contact ball bearing. ZMS offers the widely used QJ200 and QJ300 series, featuring a split inner ring designed to support heavy axial loads in both directions.

Can four point contact bearings take radial loads?

They are primarily designed for pure axial loads in both directions. If a radial load is present, it must be only a fraction of the axial load. ZMS recommends consulting our engineering team for complex load applications.

The Power of the Split Inner Ring (QJ Series)

QJ Series is the horizontally split inner ring. Why is this structurally important?
This two-piece inner ring design allows for a significantly larger number of precision balls to be incorporated into the bearing assembly compared to standard deep groove ball bearings. This massive ball complement directly translates to an exceptionally high load-carrying capacity, making it the premier choice for heavy-duty screw compressors and industrial retarders.

Designed for Pure Axial Guidance

In typical high-performance gearbox applications, four-point contact ball bearings are deliberately used as pure thrust bearings.
Engineering Best Practice: When used solely for axial guidance, these bearings should be mounted with radial clearance in the housing. This prevents them from being subjected to unintended radial loads, which would cause three-point or four-point friction, leading to rapid heat generation and premature failure. They are perfectly paired with cylindrical roller bearings (which handle the radial loads).

Robust Machined Brass Cages for High Speeds

Because four-point contact bearings are frequently utilized in high-speed applications like air compressors and blowers, standard stamped steel cages are often insufficient. ZMS equips our QJ series bearings with robust, window-type machined brass cages (typically denoted by MA or MPA suffixes). These cages are outer-ring guided to withstand intense centrifugal forces, minimize vibration, and provide superior resistance to wear and elevated temperatures.