ball mill girth gear

A girth gear (also called ring gear, large gear rim or kiln gear) is the critical rotary transmission component of rotary kilns, ball mills, rod mills, dryers, coolers and other heavy-duty rotating equipment. It transfers torque from the pinion to the rotating shell and directly determines the running stability, load capacity and service life of the whole plant.

Henan Three Mining Machinery Technology Co., Ltd. is a professional large girth gear manufacturer based in Henan, China, with years of experience in designing, casting, machining and heat-treating heavy-duty gear rings. We produce one-piece girth gears and segmented (split) girth gears ranging from Ø1,000 mm to over Ø12,000 mm, with single-unit weight from 5 tons up to 80 tons. Standard materials include ZG45, ZG42CrMo, ZG35Mn, 42CrMo, 35SiMn and other cast carbon steels and alloy steels; special materials are available on request.

Our in-house workshop is equipped with a full set of large machining equipment: CNC vertical lathes (VTL), floor-type boring & milling machines, CNC gear hobbing machines, gear shaping machines, vertical heat-treatment furnaces, normalizing, annealing and quenching-and-tempering lines. We control the whole process in-house from casting blank, rough machining, finish turning, gear hobbing/milling to heat treatment. Tooth flanks are quenched or quenched-and-tempered to HB 220-280, and gear accuracy reaches ISO 1328 Grade 8 or above, delivering low noise, high wear resistance and high torque capacity.

For oversized gears that cannot be transported as a single piece, we offer two-piece or four-piece split girth gears bolted together on site, with high joint precision and excellent coaxiality. All products support third-party inspection (SGS, BV, MT/UT, magnetic particle inspection, hardness test, dimensional inspection). Material certificates, heat-treatment curves and inspection reports are provided.

We accept customized machining based on customer drawings or samples. Welcome customers from mining, cement, metallurgy, building materials and chemical industries to contact us for a quotation.