The four-point contact ball bearings are radial single row angular contact ball bearings featuring raceways that can handle axial loads acting in both directions. A limited radial load can be supported for a given axial load.
With the rapid development of machinery industry, the application range of single row ball slewing bearing has been gradually expanded, and slewing bearings have been widely used instead of original bearings. Construction machinery is the initial application of single row ball slewing bearing is also the most widely used places, such as earth-moving machinery, excavators, dismantling machines, heap picking machines, graders, rollers, tamping machines, rock drilling machines, boring machines and so on.
Single row ball slewing bearing applications are:
(1) Engineering ships: dredgers
(2) feeding machinery: disc feeder, sand mixer
(3) Concrete machinery: concrete pump truck, concrete mixing cloth rod machine, belt cloth
(4) Light Industry Machinery: Beverage Machinery, Bottle Blowing Machine, Packaging Machinery, Filling Machine, Rotary Bottle Finisher, Injection Molding Machine
(5) Special vehicles: bridge detection vehicles, fire engines, gondola machines, flat girder trucks, aerial vehicles, self-propelled aerial work platforms
(6) Crane type: Wheel Crane, Crawler Crane, Portal Crane, Tower Crane, Forklift, Crane, Gantry Crane
(7) Foundation treatment machinery: impact reverse circulation drilling rig, rotary drilling rig, impact rotary drilling rig, rotary drilling rig, reverse circulation rotary drilling rig, positive circulation rotary drilling rig, long spiral engineering drilling rig, submersible engineering drilling rig, static pressure pile Machine, pile driver and so on.
The bearings are comprised of two rings, each of which contains a precision raceway that is induction hardened on the surface to a specified depth. Each ring is made from a medium carbon steel forging.slewing bearings have raceways constructed in a four-point contact configuration, with 45° contact angles as standard. Other raceway configurations are available, such as crossed roller and Four-point contact. These other options are often considered in cases where very high loads or special stiffness requirements are needed.
Precision rolling elements specifically hardened chrome alloy steel balls facilitate relative ring rotation between the inner and outer rings. Rollers as rolling elements are also often used.
Spacers, Spacer Balls & Separators
Spacers, typically made from a plastic material, are commonly used to separate balls to prevent them from rubbing directly against each other. Sometimes spacer balls are utilized instead of spacers. In this case these are balls that are slightly smaller than the load carrying balls, placed between each load carrying ball. Occasionally, application parameters warrant the use of a separator.