ZZ Slewing Bearing

Internal Gear Slewing Ring for Compact Excavator – Space-Efficient and Durable Rotation Solution

For compact excavators, space is always a constraint — yet smooth, reliable rotation is essential. That’s why an internal gear slewing ring is often the preferred solution for the upper structure rotation mechanism. It allows for compact design while maintaining strength, precision, and long-term performance.

At ZZ, we manufacture internal gear slewing rings specifically designed for use in compact and mini excavators, offering both standard models and OEM custom options.

Why Use Internal Gear Slewing Bearings?

To begin with, internal gear configurations provide better protection from external elements, such as mud, sand, and debris — which are common in excavation environments.

Additionally, the internal gear design results in a cleaner profile and fewer exposed components, reducing the risk of gear wear.
Moreover, it allows for tight radius installation, saving space and improving integration with hydraulic motor drives.

Typical applications include:

  • Mini & compact excavators (1–10 ton)
  • Skid-steer excavators
  • Urban utility and landscaping machines
  • Remote-controlled demolition equipment

Key Features:

  • Outer diameter: 400mm–1200mm
  • Gear type: internal module gears (DIN 3967 compliant)
  • Load support: axial, radial, and tilting
  • High-strength forged steel structure
  • Optional corrosion-resistant coatings (for humid regions)

ZZ ensures every slewing ring goes through hardening and precision grinding to guarantee long service life, even under constant pivoting and vibration.

Real Case Example

A European excavator OEM required a 620mm internal gear slewing ring for a 3.5-ton tracked excavator. We provided a double-sealed, grease-filled unit with precision-cut teeth, helping them reduce noise and backlash while increasing durability.

How to Order

Simply share:

  • Excavator model and tonnage
  • Desired gear module and number of teeth
  • Load specs and application type

We’ll recommend the best-fit slewing ring and send a quote within 24 hours.

Frequently Asked Questions

Expert Insights and Reliable Solutions to Your Most Common Questions.

ZZ Slewing Bearing supplies a full range of slewing bearings to meet different industrial needs:

  • Single row four point contact slewing bearings Application: medium loads, precise rotation.
  • Double row ball bearings  Application: higher radial and axial loads.
  • Cross roller bearings –Application: high rigidity, suitable for robots and machining centers.
  • Three row roller bearings – Application: extreme loads in heavy equipment.
  • Ball combine roller bearings –Application:  precise rotational adjustment applications.
  • Customized bearings – tailored for specific equipment requirements.

Typical selection parameter for ZZ clients:

Load type: axial, radial, and tilting moment.

Rotation RPM: ensures long service life.

Installation space & mounting dimensions: inner/outer ring diameter, bolt circle.

Precision & rigidity requirements: critical for cranes, excavators, and robots.

ZZ engineers provide professional selection guidance according to your equipment and drawings.

ZZ Slewing Bearing selects materials for strength, wear resistance, and long-term durability:

Slewing ring: 42CrMo, 50Mn, C45N, 40CrNiMo, C48E.

Special forging spare parts: carburized/hardened steels for gear teeth (20CrMnTi, 18CrNiMo7‑6).

Corrosion resistant: SS 304, 316L, duplex stainless steel.

Surface treatments: heat treatment, quenching, carburizing, induction hardening, and surface coating(Four-Layer Packing, Strong Anti-Rust Oil, Black Oxide Treatment, Jet Black Paint Finish, Hot-Dip Galvanizing (CGL), Electro-Galvanizing (EGL), Hot-Dip Galvanizing + Paint Finish)

Correct installation with flat surfaces.

Proper lubrication using grease.

Avoid overloading or shock loads over capacity.

Monitor operating conditions regularly to prevent debris entry.

Typical factors observed by ZZ engineers:

  • Insufficient or incorrect lubrication.
  • (dust, metal particles) in raceways.
  • Rolling element or track damage.
  • Uneven mounting surfaces or misalignment.
  • Incorrect bolt torque(below grade 8.8) or preloading.

In-stock: 3–7 days.

Custom: 2–6 weeks depending on size, load, and precision.

Warranty: 1 year

Lifetime Free Spare Parts: Glue, seals, steel ball

Yes — ZZ Slewing Bearing offers:

Detailed installation manuals.

Online engineering support.

Guidance for lubrication, maintenance, and troubleshooting solution.

Full range of materials and heat treatments for various load conditions.

High precision and strict quality inspection standards.

Engineering support before and after delivery.

Customization to exact equipment requirements.

Proven performance in cranes, excavators, robotics, wind turbines, and heavy machinery etc.

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