Renold Gears Goes Underground
Renold Gears has been chosen to take part in what will be the first major refurbishment of London Underground stations in over 25 years. A team of companies headed up by main contractor, Metronet Trans4, will work together on the refurbishment of a total of 59 stations with Queensway station, on the central line, being the first to receive what is being described as a full station upgrade. Renold gears has been selected for its expertise in the design, manufacture and installation of lift gears by OTIS, the company in overall charge of the lift replacement at the selected stations. During the work the station will close for 12 months.
At Queensway station, the main platform lift to the ticket hall is being replaced, and Renold Gears will supply the drive package for the new one. This is a double lift and the two drive packages will be supplied, one for the left and one for the right-hand side. The lift is designed to carry 47 people a distance of 30 metres, and will be operational 20 hours a day, 364 days a year.
On an application like this it hardly needs stating that reliability and safety are key design factors. However, for this particular lift, it was also important that the drive package should operate silently. The drive solution developed by Renold Gears consists of a 1,000rpm, 65kW, DC Bull motor driving through a Renold Hi-Tec, RB, flexible brake-drum coupling, which in turn is connected to a 69:2 ratio TWU20 wormgear unit. The gearbox is from Renold Gears' industrial range but has been modified to suit an elevator drive application by cutting the teeth with minimum backlash and reducing the shaft and bearing end floats to almost zero. The worm wheel rim is also bolted to its centre to offer maximum strength for elevator applications.
In case of an unexpected power cut there is an emergency drive package, powered by a diesel generator, that would safely transport the lift to the nearest passenger exit point in the case of an emergency. This consists of a Renold Gears', 60:1 ratio, ePM Series PW50 worm gear unit driven by a 4kW motor. Inbetween the gearbox and motor there is a size 25 Gearflex coupling manufactured by Renold Clutches & Couplings. If all else fails there is a shaft extension on the non-drive end of the motor onto which a hand wheel can be connected, so that the lift could, if necessary, be powered manually.
For further information, please contact: Gears Sales