Rubber Suspension Technology
All ROSTA rubber suspension units comprise 3 major function.
It’s a torsional spring, it is a pivot bearing and anti-vibration mount. All in one single unit!
All ROSTA elements require no maintenance, are entirely noisless and have a long life.
This technology has virtually no limit in use and applications.
It gives you the following benefits: less components, no wear parts, better performance of the entire system and low life cycle cost, it is maintenance free!
Oscillating Conveyor Technology
For over 60 years ROSTA has supplied many screens and vibrating conveyor manufactureres with our oscillating mountings.
Is it a free oscillating or guided shaker conveyor? Or even a gyratory sifter? Contact us we have the right solution for your system.
ROSTA offers suspension systems with the highest levels of isolation and efficiency for all free oscillating vibrating systems, from onion sorting shakers to dewatering screens in mines.
We are specialized in the support of gyratory sifters and shaker screening from 50 to 40000 N.
Tensioning Technology
The concept and production of machine components for the maintenance-free tensioning of belts and chain drives has always been a core competence of ROSTA.
When using the ROSTA tensioning systems, problems such as the compensation of lengthening due to age and belt slip are no longer an issue in your machine design – you can simply forget the periodical re-tensioning maintenance!
Rosta Product Applications
Everybody has come into contact with rubber suspension units at some time, mostly unknowingly. In every amusement park there are hundreds of ROSTA units in ships, rafts, sledges and roller coasters. They ensure that the passengers can race on there vehicles through rapids and curves without shock and above all, injury. Safety rails, buffers and river bends are literally covered in elastic elements so that the ‘horse and rider’ survive the ride with amusement and not injury or shocks. (figs 1 & 2)


ROSTA rubber suspension units carry cable cars, ski lift seats (fig 3) and suspend railways in collieries. They also make sure that the electrical power from rails or overhead lines reach the motor at all times via pantographs maybe you have been on a tram or train that has had such a system. The applications that Rosta units can be put into are as extensible as the units themselves.
fig 3fig 4.
The Design
The rubber suspension unit is a torsion spring with four pre tensioned special inserts placed between the outer casing and inner square section rotated at 45°C. The high pretensioning force on the rubber inserts makes additional axial anchorage for the inner part unnecessary. The operating angle of the torsion spring is plus or minus 30°C. (fig 4) The rubber suspension system offers a broad selection of muti-functional machine components; it combines within a compact design spring, a torsion bearing and an oscillating damper. The natural inertia of the rubber results with rotational motion in intrinsic damping in the element that can absorb upto 30% of the excitation energy.
This torsion spring principle was developed by ROSTA over 50 years ago, originally as a low cost suspension for vehicles, today, however the emphasis is on the application of components for machinery construction, such as rubber suspension units in a standardised module, chain and belt tensioners, oscillating elements for screen suspensions and motor bases with automatic tensioning.
Oscillating suspension for screening and conveying equipment are one of the specialties within the product range. In mines and ore processing plants (fig 5) the units have made a name for themselves over the last decade as long lasting components in rugged use above and below ground. In the recycling of building rubble and waste (fig 6) too, one cannot do without the anti-overload supports for screens and oscillating conveyor troughs; they have replaced the fault-prone steel springs in several areas of screening technology.
Rubber components are important components of our “daily bread” for many machines and installations in flourmills and the subsequent processing of cereal products. As maintenance free and long lasting supports for all kinds of gyratory sifters (fig 7) and screens, ROSTA elements are to be found in the production of food stuffs wherever refinement and selection has to be done using vibration, e.g. when white flour has to be separated from the course grist in sifting screens. Corn flakes, nuts, fruit, vegetables and salads are sorted and de-watered using cost-saving oscillating processing. There is hardly a canning or packing factory where ROSTA suspensions are not used on oscillating equipment to simplify processing in a reliable manner.



Chain and Belt Tensioners
A list of possible applications for these rubber suspensions would be incomplete without mentioning chain and belt tensioners. Over 40 years ago this component was the first standardised product from ROSTA.
All chains wear, all belts wear and stretch, some considerably during there working life. Without some form of automatic tensioning (figs 8 & 9) device to compensate for this wear / stretch, belts would screech and only transmit a fraction of the torque and chains would tend to wear prematurely and be noisy, with the whipping action and eventual jumping of the sprockets perhaps causing damage to the rest of the drive or even the machine. With over 500,000 tensioning units installed every year, quiet, efficient and low maintenance operation can be obtained in virtually all open drive units.

