This series is a standardized single-row four-point contact ball slewing bearing with internal gear, designed for light to medium-duty rotary machinery applications. Featuring a compact monolithic structure, precision-machined internal gear and optimized four-point contact raceway geometry, IMO slewing bearings deliver reliable load capacity, smooth rotational performance and excellent dimensional stability, making them a versatile and cost-effective rotary solution for industrial automation, mobile equipment and general engineering machinery.
Typical Applications:
Construction machinery such as cranes and excavators
Aerial work platforms
Solar tracking systems
Radar and antenna positioning systems
Machine tools and robotics





| Inquiry | Type | Brand | Drawing No. | Dimensions And Weight | Mounting Holes | Gear | Tooth Forces Load Ratings | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Outside Dia Outer Ring | Inside Diameter Inner ring | Inside Dia Outer Ring | Outside Diameter Inner Ring | Weight | Pitch Arde Diameter Outer Ring | Number Of Holes Outer Ring | Pitch Arde Diameter Inner Ring | Number Of Holes Inner Ring | Pitch Arde Diameter | Module | Number of Teeth | Permissible Tooth Force | Maximum Permissible Tooth Force | Static | Dynamic | ||||||
| Da [mm] | di [mm] | Di [mm] | da [mm] | G [kg] | La [mm] | na | Li [mm] | ni | do [mm] | m [mm] | Z | Fz norm [kN] | fzmax [kN] | Corad[kN] | Coax[kN] | Corad[kN] | Coax[kN] | ||||
Engineered with a classic four-point contact ball design, the 12 series allows each precision steel ball to maintain four stable contact points with the hardened gothic arch raceways under operating loads. This advanced structure enables the bearing to simultaneously withstand combined axial loads, radial loads and overturning moments, which greatly improves overall rigidity and load uniformity compared with conventional rotary bearings. Whether operating under continuous rotation, intermittent cycling or alternating load conditions, Internal gear slewing bearings minimize vibration, friction fluctuation and mechanical fatigue, ensuring consistent and dependable dynamic performance throughout their service life.
The 12series features an integrated internal gear machined on the inner ring, bringing significant structural advantages for compact mechanical layouts. The precision involute gear teeth are manufactured with tight tolerance control and professional heat treatment, achieving low backlash, high meshing accuracy and steady torque transmission. Different from external gear models, the internal gear structure protects tooth surfaces from external impact, dust erosion and abrasive wear, while saving overall installation space and simplifying the drive system assembly. It perfectly matches standard drive pinions to realize quiet, efficient and maintenance-friendly power transmission for limited-space equipment designs.



