Grinding Mills

Our gearless drive systems are unparalleled in the mining industry. Siemens is the world leader for gearless wrap-around (ring) motors.

Siemens pioneered gearless drive technology utilizing cyclo-converter drives (CCV) and has supplied the world's largest system - a 30,000 HP, 40 foot diameter gearless drive.

The first gearless drive was commissioned and has been operating for over 25 years. Since then, Siemens has built 27 ring motors for the mining industry.

The closed-loop control in the cyclo-converter drive offers excellent torque variation with negligible harmonics. The harmonics produced in the torque are significantly below 2%. The Transvektor® control used on high-power mill drives has gone through long development phase with considerable experience gained during the last 27 years.

Features like electronic Frozen Charge Protection, inching and complete operator maintenance and diagnostic screens are the result of 25 years of listening to our customer.

Siemens has solutions for mills ranging in size from 500 H.P. to 30,000 H.P. Siemens supplies many different types of drive and control systems to meet the requirement of our customers' grinding needs. Some of our drive solutions for grinding mills are:

We offer a complete line of mill motors for fixed speed applications. The choice of a drive system should be an in-depth analysis to determine the right balance between costs and benefits; each option offering their respective advantages. We offer drive systems that provide full torque at zero speed and offer full inching capability, eliminating the need for starting clutches and separate inching drives.

Our IGBT drives, with the active front end, can adjust the power factor to either lagging, leading or unity. This results in reduced harmonics and increased power efficiency. Further, reactive power of other loads can be compensated within the power reserves of the converter. We can also provide full by-pass capability if required. Our team of mining application engineers can discuss which option best meets your needs.