Double-Row Step Bore Ball Slewing Bearings

Double-row step bore ball slewing bearings feature two independent ball raceways – one primarily for axial loads and one for radial loads. The step bore (countersunk) mounting holes allow bolts to sit flush with the mounting surface, saving space and preventing interference.

Key structural features:

• Double-row ball design – Two independent raceways for higher load capacity (30-50% more than single-row)
• Step bore mounting holes – Countersunk design for flush bolt installation
• Separate load paths – Axial and radial loads handled by dedicated ball rows
• High-quality steel balls – GCr15 bearing steel for durability
• Forged steel rings – 50Mn or 42CrMo material
• Hardened raceways – Induction hardened to HRC58-62
• Segmented cage – Brass or steel cage for ball separation
• Gear options – External (021/022), internal (023/024), or gearless (020)

Series code reference:

• 020 series – Gearless design for external drive
• 021/022 series – External gear for pinion drive
• 023/024 series – Internal gear for compact drive

Double-row step bore ball slewing bearings are ideal for medium-heavy applications requiring higher capacity than single-row designs:

• Construction machinery – Cranes, excavators, concrete pumps, aerial platforms
• Industrial equipment – Rotary tables, indexing equipment, packaging machinery
• Renewable energy – Wind turbine yaw systems, solar trackers
• Material handling – Conveyor turntables, stackers, reclaimers
• Other applications – Medical equipment, robotic turntables, antenna systems