Double-row Ball Slewing Ring Bearing

Double-row ball slewing ring with same diameter balls is usually used for wind driven generators and concrete pump trucks. In wind driven generator applications, double-row ball slewing ring is often installed at the bottom of propellers for variable pitch control which requires zero clearance, large start friction moment and high running accuracy.

With compact construction, the double-row ball slewing ring bearing decreases the diameter of mounting holes in the inner and outer ring and increases the loading capacity.

Double-row ball slewing ring bearing usually comprises 3 rings, steel balls and spacers can enter the upper and lower raceways directly. Two sets of steel ball are placed based on the force analysis. With such configuration, the 90° bearing angles of the upper and lower arc raceway enable the bearing to take large axial force and tilting moment. Special design is needed for the raceway when the radial force is greater than one tenth axial force

Slewing Bearing Details

Range of external diameter: 100 mm to 15000 mm

Ring material: 42CrMo / 50Mn/ C45

Ball/roller material: GCr15

Cage material: steel 20 or ZL102 cast aluminum alloy

Spacer material: nylon 6 / nylon 66

Quenching hardness of raceway: HRC55-62

Tooth type: no gear, internal gear, external gear

1. Inner Ring
2. Outer Ring
3. Seal
4. Spacer
5. Ball/Roller

Advantages:

Double-row Angular Contact Ball Bearings can take axial load in eighter direction and are the equivalent of arranging two Single-row Angular Contact Bearings in a back-to-back configuration. These bearings are ideal if axial space is limited, as they take up less space compared to using two single row bearings

Application:

Double row contact ball slewing bearings are widely used for the following applications:

Excavator

Crawler crane

Port machinery

Amusement facilities