In the past the conventional method of driving large ball mills included some form of speed reducing gear between the higher speed driving motor and the lower speed ball mill. Process developments in the mining and cement industries have increasingly tended toward the use of ever larger ball mills for grinding their products. As the horsepower drive ratings required have …

Gearless mill drives (GMDs) are the grinding solution of choice in challenging environments. By eliminating bolt-on mechanical components such as ring-gears, pinions, couplings and gearboxes, GMDs offer ore producers unrivalled availability, efficiency and durability, while reducing operating expenditure, according to GMD provider ABB.

The mill and its gearless drive is one of industry's largest installations (the ring motor is almost 20 meters high) and one of the pivotal applications in a concentrator plant. (20),。

The Gearless Mill Drive (GMD) is potentially the most critical bottleneck in the mine production process. Each hour of downtime can result in a heavy financial loss. 3 "To improve productivity and reaction times in emergency situations, the mining

SIMINE Gearless mill drives – outstanding reliability for your mine The gearless concept The gearless drive avoids any contact between the rotating mill and the static parts of the motor. This allows for contin-uous workflow without maintenance on the gears or the pinions. What used to be downtime is now productive time.

A cycloconverter-fed gearless mill drive is a drive system that has hardware and software protection functions to protect the equipment in case of abnormal operating conditions, malfunctions or failures. For demanding applications in the mining industry, protections systems need to be reviewed considering special or abnormal operating ...

Gearless mill drives are a well established solution for grinding applications in the minerals and mining industries. The paper describes the functionality and technical features of such drive systems as well as their advantages compared to other drive solutions. Due to the variable speed operation the grinding process can be optimized for ores with varying grinding properties.

Updates on geared vs gearless drive solutions for grinding mills. SME 2013 Abstract. The current paper looks at evaluating the merits of large geared mills versus gearless driven mills by evaluating the following factors: The capability of currently available systems in terms of power and mill diameter;

Instability in gearless mill drive motors by Peter Warner, Anglo American Technical Division In 2006 Anglo Platinum ordered two 26-foot ball mills from FFE Minerals – Vecor and two 17,5 MW gearless mill drives (GMDs) from ABB for the 600 kilo tonne per month concentrator for the Potgietersrust Platinum North expansion project.

A gearless drive for the drum of a cement mill or the like wherein the pole wheel, i.e. the rotor of a low-speed electric motor surrounds the drum and is connected to it by a circumferential array of uniformly spaced studs which project radially from the drum and are received in a similar array of uniformly spaced recesses located in the pole wheel structure.

Gearless Drives for grinding mills. Gearless Drives are well proven stateof- the-art technology for large grinding mills. Siemens, the company that introduced Gearless Mill Drives (GMD) to mining industry started up its first …

The poles of the gearless or synchronous motor (also called wrap-around motor or ring motor) are directly installed on the pole flange of the mill shell, turning the mill body into the rotor. The stator is then wrapped around the mill. The gearless motor is fed by a cycloconverter which has a rated output frequency of around 5 Hz for the GMD drive.

Download scientific diagram | Gearless motor drive scheme. from publication: Technical Evaluation and Practical Experience of High-Power Grinding Mill Drives in Mining Applications | Grinding mill ...

Gearless mill drives - Grinding ABB. ABB's GMD is the most powerful mill drive system in the market to power semiautogenous (SAG), ball and autogenous (AG) mills, This 'workhorse' for grinding operations combines a robust, service-friendly and fit for purpose

Gearless mill drive system in iron ore ­processing. ABB was recently contracted to supply gearless mill drive (GMD) systems for two 38 foot semiautogenous grinding (SAG) mills at the Serra Azul iron ore mine in Brazil. …

Gearless Mill Drive (GMD), accionamientos sin engranajes para molinos ABB. MAYO 2009 7 mecánica, la eficiencia es mayor, la disponibilidad es más alta, teniendo a su vez ventajas medio ambientales. En la …

A Gearless Mill Drive (GMD) is a major investment for a plant, and a host of processes are dependent on its reliable performance. This makes its potential downtime one of the biggest risks any mining company faces. It's also one that can …

The origins of the failure can be traced back to c. 1994 when PT Freeport Indonesia ordered its first gearless drive for their 34 ft SAG mill. The motor had to fit through a tunnel on the road to the site. This necessitated a change in the frame design from that used in older motors to allow clearance in the tunnel [8].

A gearless mill drive is a major investment for a plant and as the beating heart of the production process is essential. Thus, having knowledge of how to make most of your GMD is crucial. The following advanced digital …

Gearless mill drive (GMD) technology has further expanded the use of large SAG milling allowing Metso Outotec to produce the world's largest SAG mill of 42' in diameter drawing power at 28 MW. Today, Metso Outotec is the world leading supplier of gearless SAG mills operating globally.

Gearless mill drive systems connect the motor directly to the mill, as the name suggests this eliminates the need for gears, gearboxes and couplings. The benefits are a touchless drive system which means less interface and higher equipment availability, Siemens boast above 95% availability when maintained and installed correctly.

That is why the gearless drive of a grinding mill is one of the most crucial pieces of equipment in the concentrator and why it is subject to particularly high demands. Siemens has provided about 80 SIMINE Gearless mill drives to the mining industry since 1980. In these thirty-plus years, SIMINE Gearless mill drives have accumulated a combined ...

Gearless mill drive system (GMD) Go gearless to meet your business objetives by exceeding standard availability targets in your grinding operations. ABB's GMD is the most powerful mill drive system in the market to power semiautogenous (SAG), ball and autogenous (AG) mills, This 'workhorse' for grinding operations combines a robust ...

ABB Gearless Mill Drives are Operational in Chile. Officials at power and automation technology group ABB have announced the successful commission of three gearless mill drive systems at Codelco's Mina Ministro Hales (MMH) in Chile; the state-run Codelco is the No. 1 copper miner in the world's most copper-prolific nation; ABB also provided ...

Meanwhile, ABB—which claims to have invented and delivered the first gearless mill drive system in 1969—reported: • That it had, in early 2007, completed a $41-million order for installation and commissioning of four …

Eleven 5MW gearless drives with synchronous motors running at low speeds (50-60rpm) drive three conveyors; two with four motors each and one with three. Two 20MW conveyors transport the ore from the open pit operation to the surface, overcoming an elevation change of around 1,300m, while the second conveyor feeds into a slightly smaller, 15MW ...

Title: Revolutionary Drive Controller for Gearless Mills Author: CHLEBOM Created Date: 4/1/2016 2:28:11 PM