A challenge facing developers and operators of buildings and processing plant is ensuring their structures can flexibly cope with internal movement and production stresses.
These can be caused by heavy and changing loads, vibration and other common factors. Often movement within such structures is caused by factors such as climate, thermal movement, shrinkage, changing uses and operation of heavy plant including conveyors, motors, turbines and reticulation systems found throughout mining, energy, oil and gas, food and beverage, primary processing, manufacturing, water and waste water utility and wider industrial uses.
A no-maintenance, cost-efficient solution to many such issues is offered by Hercules Engineering through its range of Herculon Type D Bearings (HLD/SG, HLD/FF & HLD/FX)), which are proven on a wide range of applications ranging from steel and concrete beam structures through to materials handling and processing facilities.
Typically used under beams, slabs, pipe networks, pressure vessels and tank rooms, conveyors, ducts and small span bridges, Herculon HLD Bearings are part of a comprehensive range of Hercules composite slip joints and structural bearings incorporating engineered high performance combinations of engineered thermoplastics and metal facing surfaces.
They are engineered to minimise production downtime and maintenance by accommodating the vertical and horizontal stresses imposed by the shuddering and vibration of heavy motors, screens, processing equipment and the varying loads imposed by tanks, pipes and pressure vessels as they are loaded and unloaded.
"Among the big plusses of HLD Bearings, compared with more complicated and costly alternatives such as roller bearings, are benefits such as lower initial cost, easier installation and no maintenance for periods of 30 years or more," says David Booty, Manager, Hercules Engineering (a division of Cut to Size Plastics).
These sliding bearings – incorporating polymers proven globally for outstanding durability without lubrication or maintenance – were developed to fulfil the need for low-friction bearings on corbels and columns where continuous slip joints were not appropriate.
Type D Herculon Bearings (HLD/SG) are designed to accept a lateral load of 30 per cent of the vertical rated load, which can be up to 600 kN per bearing in stock sizes, with higher capacity available custom-engineered for particular applications. They are removable and replaceable, to minimise downtime and optimise production in high-value, high output plant such as mineral processing and oil, gas and energy infrastructure and conveyors in applications extending from ports to power plants.
Performance characteristics include
- Outstanding stick-slip performance, to provide smooth, easy movement under load
- Friction co-efficient 0.05 – 0.08 depending on stress
- Expansion capacity up to ± 40mm for standard Bearings. (Larger movements can be accommodated upon request)
- Maximum contact stress 10-12 MPa
- Maximum rotation up to 0.02 radians
- Maximum temperature 80 deg C (with higher temperatures accommodated by thermally insulating bearings or using high temperature materials, both as recommended by Hercules).
"As major industries such as resources move from the construction to production phases, they are particularly focussed on installations that will cost-effectively optimise production without maintenance or downtime," says Booty. "In this regard, it is essential to ensure that not only the production structures themselves, but also the structures in which plant is located, can handle the constant stresses of production and use with the flexibility required for long life without maintenance."