BMG’s Nord-Lock range of bolting solutions includes expander system pivot pin components that comprise advanced pivot pin technology, to offer dependable solutions that combat the challenges of lug wear.
Pivots, which are at the centre of any rotational movement, often experience lug wear, which occurs due to the clearance between the bore and the conventional pin. This is commonly repaired with line boring – a technique associated with high costs and protracted downtime.
“Through Nord-Lock’s advanced expander system, which consists of a comprehensive range of components, BMG specialists are able to supply the correct pivot to prevent the problems that lug wear causes excavators, mobile cranes and dump trucks, in order to maximise uptime, enhance safety on site and minimise maintenance costs,” says national product manager – Nord-Lock Group, Fasteners Division, BMG, Wean Marais.
“The expander system – which comprises an assembly that includes an axle tapered at both ends, two expansion sleeves, two tension washers and two fasteners – has been designed for convenient onsite repairs. Even in a situation where the lugs are badly worn, a repair can be made in the field, with minimum downtime. The sleeves of the expander system simply expand to conform with the wear pattern and lock the system in place, without the need for time-consuming and costly welding and line boring. Once retorqued, the system locks from both sides, significantly increasing stability.
“This system has also been designed to improve safety on site. By replacing a traditional straight pin with an expander system pivot pin of the same diameter, the risk of axle breakage is reduced and the strength of the machine is enhanced through the system’s double-sided axial locking design.
“There are many other benefits, which include a permanent solution to lug wear, quick and easy installation and removal, increased service life of bushings, bearings and seals and greater safety. A key advantage of this system over conventional pivot pins is pressure distribution. A conventional system only distributes the load onto a very small
area, whereas the expander system distributes pressure over the whole contact area in the direction of the force.
“There is no need for additional fastening holes, threads or welding of locking rings on the machine and no need for fine machining in the lugs, as this system makes it possible to use wide tolerances. The expander system can also be combined with Nord-Lock washers for enhanced efficiency in vibration-intense applications.”
BMG’s customised expander system pivot pins are specifically adapted to suit exact requirements, through the use of specific materials, hardening treatments, surface coatings and the correct tolerance for each application.
