Forged Ring 65HRC Large Vertical Mill Ring Castings And Forgings

With more than 1000 girth gears sold over the world CITICIC Gear is a leading supplier in the cement and mineral industry. And as member of AGMA (American Gear Manufacturers Association), we do actively take part in defining the standard for gear rating calculations and service factors. 

We provide girth gears in three different designs

Fabricated steel
- forged ring
- rolled plate 

Cast steel  

Ductile (Nodular) cast iron  

Fabricated gears became more common in the past and are constructed with forged steel gear rim materials and electro welded body structure. The rings are manufactured from a whole block of high resistance alloy steel. After the rough machining of the ring, we carry out hardening and tempering heat treatment in order to improve the mechanical characteristic and therefore its relevant performance.  

Avantages of fabricated girth gears

The forged material structure excludes the risk of inclusions

Structure defects like gas holes, micro shrinkage, pin holes, hot tears, sand and slag inclusions are avoided Hence, repair welding of the body structure and e.g. grinding of toothed areas is not required.

The fabricated manufacturing procedure excludes the need for patterns and risers

Rim material has higher hardness and higher strength than the material used for the underlying structure (i.e. web, gussets)

These features will reduce the lead time and costs. Fabricated manufacturing ensures a fast delivery.

This is especially beneficial in an emergency situation, where the existing gear rim is suffering from damage   

Features

External teeth 
Maximum diameter: 16000 mm 
Toothed face width: 1700 mm 
Maximum module: 45 by hob 
Maximum module: 65 gear finishing cutter

Internal teeth 
Maximum Diameter: 6500 mm 
Maximum module: 25.4 
Toothed face width: 400 mm

Applications 
Our girth gears are applied in the cement and minerals industries: 
Various types of horizontal mills 
Rotary dryers 
Rotary kilns 
Any other large gear ring application

Pinions

CITICIC Gear invested in significant resources and achieved many innovations with pinions. The right combination of material, hardness and finishing between pinion and gear is crucial for a long lifetime of the installed equipment. We design and manufacture pinions to match every customers need, no matter how unique the situation might be. 

Pinion design

bored

solid on shaft / integral

self aligned

spur, helical or double helical

Materialization

forged alloyed steel

through hardened, case hardened or quenched and tempered

Spur, helical or double helical

carburized

induction

nitrided

Characteristics

gear cutting with hobs

the gear quality is checked by profile tester

tooth flank modification
profile correction 
lead correction (straight/barrel)

designs /ratios according to ISO-DIN-A.G.M.A.

FEM/FEA simulation software

Standards/Certificates

UNI EN ISO

AWS

ASTM

ASME

DIN

Applications 
Our pinions are applied in the cement and minerals industries:

Ball - mills

ROD - mills

Semi Autogeneous Grind (SAG)

Rotary kilns/coolers/dryers

Advantages

One Source

Original Equipment Manufacture (OEM) Technical Drawings

Gearing technical expertise for kilns and grinding mills

State of the art manufacturing facilities and quality

Global sales and service support