Polymer bearings contribute to heavy lifting success

Applying the correct polymer materials at every pivot point has created some of the most reliable heavy-duty scissor lifts in South Africa

Press release

Leading dock-levelling and materials-handling specialist REV Designs & Installations has steadily grown into one of South Africa’s most innovative engineering firms in the lifting-equipment sector.

Based in Springs, the company designs and manufactures a wide range of loading, docking and lifting equipment including some of the largest scissor lifts ever produced in the country. A key factor in the success of the business is the careful design and specification of materials and components which amplifies its equipment’s’ performance and results in trouble-free operation for its customers.

Above: The timber lift that led to the adoption of polymer bearings across all scissor lift designs of the company

A good example is the design and construction of three massive scissor lifts destined for the timber industry several years ago. Each capable of handling up to 40 tonnes per lift, the lifts were engineered for harsh, high dust sawmilling environments where the equipment is pushed hard and uptime is critical. It was during this period that founder and chief designer Ricardo Viljoen made a key engineering decision to move away from greased steel bearings and fully adopt igus high-performance polymer bearings across the key pivot points of the new lifts.

Above: REV Designs & Installations founder and chief designer Ricardo Viljoen and igus polymer bearing specialist Juan-Eric Davidtz at the company’s Brakpan manufacturing plant

According to Ricardo the switch has exceeded expectations. The original scissor lifts have now been in operation for around five years and the service history is striking. The machines were designed to be serviced quarterly with an annual inspection recommended. In practice REV has only been called back twice in five years a light annual service and again for a general inspection. Since that time not a single bush or bearing has failed.

This small move away from conventional design has saved the customer many hours and costs that would otherwise have been associated with servicing and maintaining greased steel bearings as well as the unavoidable failure of these bearings that would have previously allowed for several failures per lift per year.

“The igus polymer bearings have operated without lubrication nor adjustment and without any sign of wear severe enough to warrant replacement. The scissor lifts themselves have also run trouble-free reinforcing the success of the bearing choice and overall design. Our customer’s own maintenance teams have confirmed that there has “never been a problem with the bushes, never a problem with the scissor lift nor anything with the scissor lifts.

“This kind of long-term reliability in a demanding environment has had a direct impact on our design philosophy. Today, all new scissor lifts as well as numerous other loading and lifting solutions produced by the company are standardised on igus polymer plain bearings and bushings,” says Ricardo.

Above: The company is a specialist manufacturer of levelling and loading equipment

He explains that bearings need to be exceptionally strong to handle the massive forces generated during heavy lifting. At the same time they have to resist the ingress of debris that quickly seizes or damages metal-on-metal bearings. The sawmilling sector is a good case in point. It is notoriously harsh on mechanical systems with fine sawdust, moisture and abrasive debris constantly enter mechanical clearances destroying traditional bearings and requiring frequent greasing. Cleaning joints to remove grease and buildup also releases contaminants into the environment and if left ungreased the heavy loads and repetitive motion quickly accelerate wear.

Working closely with Juan-Eric Davidtz, igus’s polymer bearing specialist, REV is able to identify the correct iglide materials for each pivot point on scissor lift pivot, caster or other moving application. For example, the timber scissor lift incorporate 33 bushings and each one operates under slightly different conditions including load, movement or weight. Matching specific polymer formulations is critical to each requirement and ensures optimal performance throughout the system.

The long lifespan of the bearings with no measurable degradation after five years of hard service in this tough application has changed the way REV Designs engineers its equipment. Ricardo says the polymer bearings have become “integral to nearly all new designs” due to their ruggedness, predictable performance and dramatically reduced maintenance requirements.

Where earlier designs relied on steel or stainless-steel bearings that demanded daily greasing and constant monitoring the igus polymer solution has enabled REV to offer equipment with significantly longer service intervals and minimal maintenance. This has been particularly valuable in tough industries where stopping production to repair or lubricate lifting machinery can be extremely costly.

By partnering with igus and applying the correct polymer materials at every pivot point the company has created some of the most reliable heavy-duty scissor lifts in South Africa capable of operating in the harshest industrial environments.

Featured photo: Specialist lifts can be made to almost any size and specification