Twiflex has launched a larger, enhanced version of its VMS-2-SP safety brake, aimed specifically at the mine hoist market. Similar to the VMS-2, the VMS-3 is a spring applied, hydraulically released safety brake, but offers faster operation and superior performance, delivering a maximum static brake force of 300 kN (with 1-mm air gap), and 230 kN (with 3-mm air gap) of dynamic braking force, with the added benefit of infinite fatigue life.
The mine-ready design of the VMS-3 is characterized by a strengthened, longer housing, which integrates additional springs for improved braking force. Totally sealed to provide corrosion and dust protection, the new design offers users the set-up and maintenance advantages of tamper-proof pad/air-gap adjustment, the facility for external pad retraction, on-site torque adjustment and a park-off feature for achieving fast seal changes without the use of special tools, according to Twiflex.
The VMS-3 design also integrates small size pistons for quicker reaction times, coupled with an improved drainage system and reduced retraction pressure of between 120–160 bar (depending on rating). In addition, the status of the VMS-3 braking system can be linked to a PLC, providing warnings for such factors as low pad pressure and alarms for high oil temperature, low oil level and clogged pressure filters. www.twiflex.com