A leading designer and manufacturer of mine hoists recently specified Twiflex VMS3/SPS brakes for use at the new Goldcorp Eleonore gold mine in northern Canada. The mine is projected to process 7,000 tons throughput per day, producing 600,000 ounces/year of gold over a 15 year lifecycle. Eleonore will be one of the largest underground mines in Canada and is expected to cost $1.4 billion to build. First production is expected in late 2014.
The order consisted of VMS3/SPS calipers for installation on a 20 ft. diameter double-drum, single-clutch mine hoist which has two brake discs: one disc is positioned on the fixed drum and one disc on the clutched drum. The fixed drum utilizes VMS3/SPS’s and the clutched drum has VMS3/SPS’s. Each brake produces 240 kN braking force at a 2.5 mm air gap with greater than 2 million cycles fatigue life available at this rating.
Twiflex Ltd. supplied VMS-DP brake calipers (with pedistals) plus a hydraulic power pack for each of the two primary mills.
The mine-ready, robust design of the VMS3/SPS features a strengthened housing which integrates additional springs for improved braking force. Totally sealed to give excellent corrosion and dust protection, the brake design offers set-up and maintenance advantages including tamper-proof pad/air-gap adjustment, external pad retraction, on-site torque adjustment and a “Park-Off” feature which allows for fast seal changes without special tools. Seals can be changed from the rear without having to remove the brake from its mounting.
The VMS3/SPS design also integrates small size pistons for quicker reaction times, coupled with an improved drainage system and a reduced retraction pressure of 137 bar at this rating. Braking force can be simply changed (up to 275 kN at 3mm air gap) by adding or removing shims located behind the rear cover. In addition, sensors can be supplied which work in conjunction with the customers’ PLC to signal brake on/off and pad wear.