Eurobond Industries Pvt. Ltd.

Dear Sir,

We are having two wet iron ore grinding Ball mills. Both have same size of girth gear and pinion.

It has been observed that there is excess, non uniform wear on the girth gear teeth.

The wear point and the wear profile on all gear teeth are similar.

On visual inspection, it is very clear that the tooth profile of girth gear and pinion are not matching. The pressure angle of both gear and pinion teeth look different. As a result this problem has cropped up and the result is high vibration on the complete driving system.

The sizes of the girth gear and pinion details are as under:

a) Make of the Ball mill, girth gear &pinion: Chinese

b) For Ball mill sizes-

1. Primary Ball mill - 2700 mm dia. X 4000 mm length

2. Secondary Ball mill - 2700 dia. X 2700 mm length

c) Girth gear:

1. No. Of teeth - 178

2. Module - 20

3. PCD - 3560 mm

4. Face width - 400 mm

5. Material - Steel casting (grade - 45); Chinese standard

6. Hardness of the material - HB260 (BHN)

d) Pinion:

1. No. Of teeth - 21

2. Module - 20

3. PCD - 420 mm

4. Face width - 410 mm

5. Material - 40CrMo

6. Hardness - 55RC (induction hardened up to 2 mm depth)

We do not have the drawings and design of this gear from the supplier.

We are looking for the suitable solution to rectify this problem. In our opinion if the pinion profile of the new pinion is corrected, the things may improve.

You are therefore requested to depute your technical expert to inspect the wear profile, take the measurement of the tooth profile of both girth gear and pinion to establish the defect. And there after suitable rectification may be carried out.

Alternatively you may also provide the most appropriate solution as you find suitable.

We shall request you to depute your expert and submit the solution and offer at your earliest.

Thanks & Regard

Vikas Lakhera

Manager Purchase

EUROBOND INDUSTRIES PVT. LTD.

ISO 9001: 2008 Certified Company

Website:-www.eurobondindia.com

Plant/Production IOP Unit Head Office | Mumbai

Plot NO.18 -28 Industrial Area C-5, Gala & Shethia Enterprise Building,

Hargarh, Tahsil -Sihora, 3rd Floor, Road No.11 MIDC,

Distt. - Jabalpur (M.P.) INDIA Near Zenith House, Andheri (E),

IOP Jabalpur Office Plant/Production ACP Unit| Jammu

H.No.187, Sheetalpuri Colony EPIP, Kartholi, Bari Brahmana

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