Girth Gear And Pinion Segmented Ring Gear For Large-Diameter Components Low Maintenance Cost And Longevity

AISI 4140 Steel Girth Gear 24.25 Module 212T Gear Wheel For Drying machine

Girth Gear Description

From a split-design perspective, a girth gear is a segmented ring gear engineered to address challenges in machining,

transporting, and installing large-diameter components. Typically comprising 2 to 8 segments,

it is bolted together to form a complete tooth ring.

Key Features

Characterised by segmented casting or forging, each segment is joined via flanges and high-strength bolts,

with locating shoulders at the joints; Advantages include reduced single-piece machining and transport complexity,

facilitating on-site installation and commissioning. Individual segments can be replaced in case of localised damage,

resulting in low maintenance costs and suitability for super-large equipment.

Working Principle

The number of segments is determined during design based on diameter. Each segment is machined with pre-formed flanges

and locating structures. During on-site assembly, locating shoulders ensure coaxiality and continuous pitch between segments,

which are then secured with high-strength bolts to form a unified structure.

During operation, the segmented structure achieves overall rigidity through bolt preload, meshing with pinions to transmit torque.

Load distribution remains uniform across segments, preventing stress concentration at joints.

Applications

Suitable for super-large rotating equipment, including:
- Large ball mills exceeding 10 metres in diameter
- Extra-long rotary kilns
- Large paper machine cylinders
- Rotating mechanisms of port ship unloaders

Technical Specifications