Girth Gears: Rotary kiln Girth Gear,ball mill Girth Gear

Girth Gears offered find extensive application in different industry sectors including in sponge iron plants, steel & cement industry, mining industry, wind mills as well as in other industry sectors. These are made available in module range of 10 Module to 70 Module and in minimum diameters of 100 mm to 15000 mm. Further, these comprise maximum weight of 70 MT single pieces. Here the range of hardened & ground gear boxes/gears comprise Worm gear boxes, Helical / Double helical gears/gearboxes, Helical-Bevel gearboxes, Planetary Gearboxes and others.

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

Forging material process
• Forging
• Final rolling
• Furnace cooling
• Control on production
• Water quenching
• Hardness testing
• Rough machining
• Ultrasonic testing and dimensional inspection
• Final inspection certification

Standards/Certificates
• UNI EN ISO
• AWS
• ASTM
• ASME
• DIN

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