Considered the first of its kind, Twiflex has developed a modular safety brake system for the latest generation “gearless” SAG and Ball Mills of up to 20MW capacity. Known as the VMS-DP, the brake, which is spring applied and hydraulically released, can achieve a tangential breaking force of 737kN. Units can be stacked up to 3 high in order to achieve as much as 12MN of Brake torque!

The Twiflex VMS-DP brake is modular in design and was derived from the successful VMS-2SP brake used on many of the World’s, Mine Hoist applications. The brake itself consists of 2 spring packs (in a common housing) mounted on one side of the brake, reacting against a plate in a “floating” arrangement on the other side. The resulting caliper can produce 737kN Braking Force at 2mm air gap. The brake is opened and controlled in application, using 204bar of Hydraulic back pressure.

Typically the hydraulics allow the brake to operate in 3 distinct modes:1) Normal, 2) Creep and 3) Inch. The long and narrow profile of the brake lends itself to the new generation of gearless grinding Mills.

Twiflex have supplied the VMS-DP brakes to Metso for:

Sossego – 1 SAG mill 38′ diameter – 4 Twiflex VMS-DP brakes (plus hydraulics) with a combined brake torque of 12MNm

Telfer – 2 36′ diameter SAG mills – each fitted with 4 Twiflex VMS-DP brakes (plus hydraulics)

Collohuasi – 1 off 40′ diameter SAG Mill and 2 off 26′ diameter Ball Mills – 18 off Twiflex VMS-DP brakes plus Hydraulics.

To FFE-Minerals for:

Cowal Gold – 1 Ball Mill (22′ ), 36′ SAG – 4 VMS-DPbrakes (plus hydraulics).

And Farnell-Thomson for:

Newmont-Phoenix – 36′ SAG – 4 off VMS-DP (plus hydraulics).

Twiflex Ltd, 104 The Green, Twickenham is a leader in Advanced Braking Technology for Industrial and Mining Applications.