Worm Gear Solutions for Coal Pulverisers

Coal Pulverisers 


Renold Gears specialises in providing replacement worm gears for coal pulverisers, at coal fired power stations, and has a unique replication program to provide interchangeable replacements for existing CE/Alstom coal pulverisers installed worldwide. The coal pulverisers at power generation plants grind the coal to a fine dust before it is mixed with warm air and blown into the furnace where it ignites in a similar way to if it were a gas.

The replacement worm gears can be manufactured from original drawings or by employing Renold Gears' unique method of taking a profile from a worm shaft on site, anywhere in the world, using a profile plug lifting technique.

A two part epoxy putty is applied to the original worm shaft and when hardened the plug is measured using a coordinate measuring machine and the data entered into Renold's unique profile generating software which replicates the original profile. This enables the precise manufacture of a master worm, thread-milling cutter, thread-grinding wheel profile and gear-hobbing tool. In many instances a replacement wheel can be manufactured whilst the original gear is still being used.

The company is also expert in producing high quality custom made worms and worm wheels. In the production of worm gearing the unique Renold gear form is widely respected for its performance and reliability in a wide variety of applications such as coal pulverisers.

Renold supply huge centre distance worm gears up to 54" (1220mm) gearing centres. Each gear set is manufactured using the highest specification, centrifugally cast, bronze alloy worm wheel rims to ensure maximum tooth strength.

Worm shafts are manufactured from high quality alloy steel with the threads case hardened to produce a uniform, hardened thread flank of 56 – 60 R/C and precision ground to a 32 RMS finish. The gear teeth are hobbed to a 64 RMS finish and to a predetermined backlash and lead correction for each size of mill.

Contact us for more information: