Polysius
Screen first.
Crush smarter.
polysius® Roller Screen / WobblerScreen first. Crush smarter.
The polysius® roller screen / wobbler separates fines before the primary[RH1] and secondary crusher, reducing crusher load, wear and energy consumption while improving process stability and total plant output. Efficient removal of wet and sticky material, minimizing clogging and reducing wear at the crusher behind.[HT2] [RH1]and secondary [HT2]Wir sollte hier noch einen Wichtigen Punkt ergänzen "Efficient removal of wet and sticky material, minimizing clogging and reducing wear at the crusher behind.
Every ton that bypasses the crusher is a ton you never pay to crush
The roller screen / wobbler is a process machine, not simply a pre-screen. Fine material is separated ahead of the primary crusher and bypasses the crushing process entirely — and everything downstream of that decision gets easier.
Benefit list
Reduced primary crusher load
Reduced crusher wear
Reduced power consumption
Reduced risk of clogging and material build-up inside the crusher
Increased lifetime of downstream equipment
Higher screening efficiency
Lower overall production costs
Improved total plant output
Self-cleaning by design
The rotating shafts are equipped with specially designed three-lobe discs. Their geometry creates the characteristic material movement that conveys, screens, loosens and separates — which is what makes difficult feed material manageable in the first place.
Diagram labels
Feed up to 2,000 mm
Impact table for enhanced shaft protection: Absorbs the impact of heavy feed material, reducing dynamic loads and preventing shaft deformation for improved roller screen reliability and service life.
Three-lobe discs convey and loosen
Chain-linked shafts, one drive
Fines pass through the 20–150 mm gap
Scraper under every single shaft
Central drive
Oversize to the primary crusher
Diagram caption: Schematic of the deck: three-lobe discs on chain-linked shafts, a scraper under every shaft, and the screening gap that sets the separation size.
The drawing is schematic. Disc proportions, shaft spacing and the number of shafts are illustrative — if a general arrangement drawing is available, the geometry can be matched to it.
Why it stays clean
A scraper is installed underneath each individual shaft, continuously removing material from the rotating components. The combination of rotating three-lobe discs and a shaft-by-shaft scraper system is what keeps the machine working when material is wet, sticky or clay-containing.
The same geometry that conveys the oversize also loosens the earthy and clayey parts adhering to it, so they are separated with the fines instead of travelling on into the crusher.
Screening performance, without the vibration
Difficult feed material is where conventional vibrating screens struggle. The roller screen can provide a more compact and more efficient solution, particularly for coarse, wet and sticky feed.
| Aspect | Roller screen / wobbler | Conventional vibrating screen |
| Wet and sticky feed | Handled by rotating discs and shaft-by-shaft scrapers | Tends to blind as material adheres to the deck |
| Clogging and blinding | Reduced tendency — the deck cleans itself in operation | Requires cleaning stops when material builds up |
| Coarse lumps | Feed sizes up to 2,000 mm conveyed across the deck | Top size limited by deck and vibration design |
| Material movement | Continuous conveying and screening in one pass | Screening by vibration, conveying handled separately |
| Installation space | Compact footprint | Usually a larger installation envelope |
| Impact loads | Heavy-duty design engineered for large impact loads | Impact loading generally limited by deck construction |
Engineered for heavy impact
The machine is designed for extremely demanding applications and large impact loads. Maximum robustness, minimum unnecessary downtime.
Heavy-duty construction
A robust structure dimensioned for the impact loads that coarse feed material puts into a pre-screen from the first metre of drop. Impact table for enhanced shaft protection: Absorbs the impact of heavy feed material, reducing dynamic loads and preventing shaft deformation for improved roller screen reliability and service life.
Bearings on both sides
Rotating shafts supported by heavy-duty bearing housings on both sides, so the load path is defined and the shaft is not cantilevered.
Bolted wear liners
Replaceable, bolted wear liners and armour plates above the shafts. When they are worn, they are exchanged rather than welded over.
Robust shaft and disc design
Shafts and three-lobe discs dimensioned for the same duty as the rest of the machine — the discs are working components, not a screen surface.
Scraper under every shaft
Not one cleaning device for the deck, but a scraper for each individual shaft. It is the detail that holds screening efficiency over time.
Proven drive concept
A drive arrangement developed for demanding operating conditions rather than adapted from a lighter application.
Two drive concepts
SRK — chain drive (standard)
The shafts are mechanically linked on both sides, so several shafts run from a single drive. One drive can be sufficient for a roller screen with ten shafts: less drive complexity, robust torque transmission and synchronised shaft operation.
SRE — single shaft drive (alternative)
An alternative drive configuration for applications and customer requirements where individual shaft drive is the better answer.
Automatic lubrication (option)
An automatic lubrication system can be supplied as an option, reducing maintenance effort and supporting reliable long-term operation.
One machine concept, configured to your application
Deck arrangement, staging, screening gap and drive are selected according to the feed material, the required separation, the crusher type and the plant layout.
Single deck or double deck
Different cut sizes on one deck possible
With or without impact table
Application-specific screening gaps from 20 to 150 mm
SRK chain drive or SRE single shaft drive
Optional automatic lubrication
Screen widths up to 3,000 mm
Can be installed in front of all types of crusher
Every ton bypassed around the crusher is a ton that does not need to be crushed.
Screening efficiency is a maintenance result
A roller screen rarely fails suddenly. It loses efficiency slowly, as the gaps close and the discs stop being cleaned — and the loss shows up as crusher load downstream before anyone looks at the screen.
| Symptom | What it indicates | Typical action |
| Fines carried over into the crusher | Screening gaps partly closed by build-up or disc wear | Scrapers checked and reset, disc geometry measured |
| Material build-up on the discs | Scrapers worn, misadjusted or no longer in contact | Scraper blades replaced and contact re-established |
| Uneven transport across the deck | Chain stretch, shafts running out of synchronisation | Chain tension corrected or chain and sprockets renewed |
| Rising drive load or drive trips | Blocked deck, seized shaft or bearing running dry | Deck cleared, bearing housings and lubrication checked |
| Wear liners thinned or loose | Armour plates above the shafts at the end of their life | Bolted liners exchanged during a planned shutdown |
| Separation size drifting upward | Disc geometry reduced by wear, widening the gap | Discs replaced in a planned shutdown |
Table caption: Typical symptoms on a roller screen, and where they come from.
The wear parts that matter
Most of the maintenance effort sits in a short list of parts. Kept in stock and replaced on condition they are inexpensive; run to failure they take the whole feed line, and the crusher behind it, with them.
Three-lobe discs and their fastening
Bolted wear liners and armour plates
Scraper blades and their mountings
Chains, sprockets and tensioning elements
Shaft bearings, bearing housings and seals
Best-practice check: Scraper contact checked at every inspection — the cheapest thing on the machine and the first to cost you efficiency.
Original spare parts
Disc geometry, material and fastening are matched to the feed. A replacement that only fits geometrically changes the wear behaviour and, with it, the separation size over time.
Parts to the original drawing and specification
Stock level matched to lead time and criticality
Replacement grouped into planned shutdowns
Best-practice check: No critical wear part with a lead time longer than the interval it is expected to last.
Four-step ladder
Level 1 · Inspect — scraper contact, chain tension, gap dimensions, liner thickness and bearing condition recorded against the last inspection
Level 2 · Adjust — scrapers reset and chains re-tensioned, the work that restores screening efficiency without replacing anything
Level 3 · Replace — scraper blades, wear liners, chains, sprockets, bearings and discs exchanged on condition, inside a planned window
Level 4 · Rebuild — deck and drive train overhauled, with the chance to change disc geometry or screening gap while the machine is open anyway
A compact footprint is what makes a retrofit possible
Compared with conventional screening solutions, the roller screen / wobbler can require less installation space. In suitable applications it can be integrated into an existing crushing plant to improve performance without rebuilding the crushing system.
A pre-screen added ahead of an existing primary crusher, engineered into the steel structure and chute arrangement that is already there.
Removing fines from the crusher feed frees capacity in the crusher you already own, often without touching the crusher itself.
Where the crusher is the bottleneck, taking the material that does not need crushing out of its feed is usually the shortest route to relief.
Less abrasive fine and sticky material passing through the crusher means longer wear part life in the crusher and in the equipment behind it.
Crushing energy spent on material that was already fine enough is energy that can simply be avoided.
A controlled, consistent crusher feed instead of whatever the quarry delivered that morning — the basis for stable downstream operation.
One complete crushing solution
The roller screen is not an isolated machine. It is selected against the feed material and against the crusher it feeds, which is why we would rather look at the whole chain than at one machine in it.
Process chain
Feed material analysis → Roller screen selection → Primary crusher selection → Process design → Engineering → Installation → Commissioning → Wear optimisation → Spare parts → Service → Modernisation
Closing line
The right pre-screen can make the whole crushing plant perform better: higher availability, longer equipment lifetime, lower wear, lower power consumption, lower production costs and higher total output.
Tell us about your material and your crusher
With a roller screen, the feed material and the crusher behind it decide the configuration. The more precisely we know both, the more precisely we can size the machine. Only your contact details are required.