Large Diameter Three-row Roller Slewing Ring for Truck Crane

Large Diameter Three-row Roller Slewing Ring

The three-row roller slewing ring is a heavy-duty rotary component adopting a load-separated roller layout. The upper and lower roller rows take axial loads and tilting moments, while the middle roller row bears radial loads independently. Load paths are separated for optimized force distribution. Different from point-contact ball slewing bearings, it works on line contact between rollers and raceways, which reduces contact stress greatly. It delivers superior static & dynamic load capacity and structural rigidity, excellent deformation resistance under the same outer diameter, making it the preferred option for applications with large tilting moments and continuous heavy loads.

Rings are forged from 50Mn alloy steel and pre-treated by quenching and tempering to secure substrate toughness. All three raceways are induction hardened with controlled hardening depth and surface hardness HRC55–62, to resist wear, pitting and early fatigue spalling under alternating loads. The internal gear can be induction hardened on tooth flanks. It transmits driving torque while maintaining gear wear resistance without sacrificing the bearing’s structural rigidity.

Every unit is inspected on raceway hardness, gear tolerance, internal clearance and critical mounting dimensions. Preload condition is well controlled to guarantee uniform load sharing among rollers and prevent overloading on individual rollers. Standard double-lip seals block mud, sand and water from entering raceway cavity, stabilizing lubrication condition and consistent load performance under long-term heavy service.

It is widely adopted for heavy machinery such as large cranes, stacker-reclaimers, tunneling equipment, heavy grapples and mining rotary fixtures, suitable for severe conditions with eccentric load, shock load and continuous high overturning moment.

Features & performance advantages

Separated load-bearing layout of triple cylindrical roller rows provides ultra-high load capacity and rigidity, minimal deflection under heavy load. Superior anti-tilting performance over single-row or double-row ball slewing bearings, suitable for eccentric load and cyclic shock load conditions.

Balanced property of tough substrate and hard raceway surface, combining impact resistance and wear resistance, less prone to ring cracking and permanent indentation.

Static load rating, dynamic load rating and allowable tilting moment together with load curves are available for structural calculation. Internal clearance and roller assembly precision are strictly controlled to achieve even load sharing.

Specification

Our showcase

Why Choose Us

Tailored product according to your drawings or samples

Professional technical support anytime

Customization drawings / OEM / ODM available

Direct factory price, stable delivery

Strict quality inspection & full set of shipping documents

Fast delivery & safe packaging (plywood pallet/case)

One-year quality warranty

Certificates

FAQ

Q1.  Can the gear teeth be reworked after scratch or wear damage?

A: Minor surface denting and shallow wear can be repaired by re-machining at our factory, on condition that the ring body is not deformed and no root crack exists. Repair is NOT recommended if tooth root cracks, plastic deformation, spalling or broken teeth occur, as base material integrity is compromised; replacement is the safer option. Re-hardening and backlash re-verification are mandatory after tooth rework.

Q2: Is the gear backlash of this internal geared slewing bearing adjustable on site?

A: The gear backlash is preset during manufacturing and cannot be adjusted by the bearing itself. Meshing backlash is adjusted by changing the mounting center distance of the mating drive pinion. If a different backlash value is required, the specification must be confirmed prior to production, and the bearing will be machined accordingly.

*For technical consultation or custom quotations, please provide gear parameters (module, number of teeth, face width, accuracy requirements, operating conditions, etc.). Our engineering team will deliver a professional solution tailored to your specific needs.