The plant manager at an aggregate quarry in Poland had been chasing unexplained bearing failures on their Metso LT300GP cone crusher for two seasons. The bearings were OEM-specified, properly lubricated, and within load ratings — yet they were failing at 40% of their expected service life. A vibration analysis consultant identified the problem within three hours of on-site testing: the four anti-vibration mounts isolating the crusher base from the plant frame had hardened from 45 Shore A to 68 Shore A due to sustained exposure to crusher heat and crushing oil mist. The hardened mounts were transmitting crusher vibration directly to the frame and — more critically — reflecting vibration back into the crusher mechanism, creating resonance that multiplied bearing load by an estimated factor of 2.3. Replacing the four mounts ($280 total) ended the bearing failures immediately.
Crushing and screening plants generate some of the most intense vibration environments in industrial machinery. Jaw crushers hammering rock at 200-400 rpm, cone crushers gyrating under 1,000+ kN crushing force, and vibrating screens oscillating at 900-1,800 rpm with 6-10 mm amplitude — all of these systems require rubber components to protect structure, bearings, and operators from vibration levels that would otherwise cause rapid fatigue failure.
This guide covers the rubber parts inventory for mobile and stationary crushing and screening equipment from the major manufacturers: Sandvik, Metso (Outotec), Kleemann (WIRTGEN Group), and Terex Finlay.
Need crushing and screening rubber isolation components? Request a quote from Babacan Group — we stock anti-vibration mounts for all major crusher and screener makes.
Screen Rubber Components: The Highest-Volume Wear Items
Vibrating screens process thousands of tonnes of aggregate daily. The screen itself — a rectangular metal deck that vibrates to separate particles by size — incorporates rubber throughout.
Screen Panels and Modular Screen Media
The aperture panels through which aggregate passes are the primary wear items on any screening plant. Most modern screens use polyurethane or rubber modular panels rather than woven wire mesh:
Rubber screen panels:
– Natural rubber or SBR compound, Shore A 45-65 depending on aperture size
– Higher open area than polyurethane for the same particle size (rubber deflects under load, momentarily increasing effective aperture)
– Better performance in wet and sticky applications — rubber releases material rather than clogging
– Noisier than polyurethane panels (rubber amplifies the impact sound from falling aggregate)
Selection guide:
– Dry aggregate screening: Either rubber or polyurethane
– Wet or clay-contaminated material: Rubber preferred
– Noise-sensitive sites: Polyurethane preferred
– Very fine screening (<10 mm): Rubber preferred for its flexibility
Screen panels are high-volume consumables, not structural rubber components. On a large three-deck screen processing 600 tph, full panel replacement may occur every 2,000-6,000 tonnes of processed material depending on feed hardness.
Vibrating Screen Mounting Isolators
The screen body vibrates at high amplitude and must be isolated from the plant structure to prevent fatigue cracking of the support steelwork. Screen mounting rubber isolators:
- Support the complete screen body weight (2,000-15,000 kg for heavy-duty screens)
- Must maintain isolation efficiency at the exciter operating frequency (typically 900-1,500 rpm = 15-25 Hz)
- Work in an environment of rock dust, process water, and vibration-induced accelerations up to 5g
For a detailed treatment of vibration isolation principles including the critical isolator-to-excitation frequency ratio, see our anti-vibration mount selection guide.
Screen mount stiffness must be tuned to the screen body mass and exciter frequency:
– If mount natural frequency > exciter frequency: The mount amplifies rather than isolates vibration (resonance zone)
– Target: Mount natural frequency ≤ exciter frequency / √2 (typically requires mount natural frequency 5-10 Hz)
Common screen mount types:
– Coil spring with rubber bump stops: Most common; spring provides compliance, rubber stops limit overtravel
– Rubber shear mounts: Lower isolation efficiency but simpler design; used on lighter screens
– Air spring with rubber bellows: Best isolation performance; higher cost and maintenance
Exciter Bearing Seals
The screen exciter shaft bearings are exposed to fine rock dust and must be sealed against contamination while allowing continuous high-speed rotation. Rubber lip seals and felt exclusion seals protect these bearings:
– Specification: Must maintain sealing performance while accommodating 6-10 mm exciter amplitude
– Temperature: Bearing temperature can reach 80-90°C under continuous heavy load
– Compound: FKM or NBR; FKM required above 80°C sustained temperature
Jaw Crusher Rubber Components
Jaw Crusher Frame Isolation Mounts
Jaw crushers generate extremely high peak impact forces — the jaw plate mechanism creates impulse loads that can reach 10× the average crushing force as large rocks break. The isolation mounts supporting the crusher on its base or trailer frame must:
- Handle the high peak-to-mean force ratio (5-15:1 in typical jaw crusher operation)
- Not “bottom out” during peak load events (would transmit full impact to frame)
- Maintain isolation for the continuous vibration at jaw operating frequency
High-dynamic-range anti-vibration mounts with progressive stiffness are typically specified for jaw crusher applications. These use a rubber element design that becomes progressively stiffer as deflection increases, providing soft compliance during normal operation and high stiffness during peak impacts.
Toggle Plate and Seat Cushions
The jaw crusher toggle plate — the element that transmits crushing force from the eccentric shaft to the movable jaw — seats against rubber or polyurethane cushions at both ends. These cushions:
- Distribute the contact stress across the toggle plate contact area
- Absorb slight misalignment and thermal expansion
- Provide a “fusible” element: an oversized tramp metal piece that would otherwise damage the crusher causes the cushion to compress completely (warning sign) before structural damage occurs
Toggle seat cushion durometer: 60-75 Shore A (must be firm enough to support the crushing force without excessive compression, but compliant enough to distribute contact stress).
Cone Crusher Rubber Systems
Cone Crusher Anti-Vibration Base Mounts
Cone crushers generate the highest average crushing forces of any crusher type. The gyrating mantle processes material continuously, creating a rotating eccentric load. The isolation mounts must handle both vertical crushing force and the horizontal component of the eccentric gyration.
Anti-vibration mounts for cone crushers are typically designed for:
– Vertical capacity: 15,000-80,000 kg depending on crusher size
– Horizontal stiffness: Must be high enough to prevent excessive horizontal movement (which would cause oil seal leakage from the crusher mainshaft assembly)
– Isolation efficiency: Natural frequency 4-7 Hz to isolate the primary gyration frequency (typically 15-20 Hz at operating speed)
The Metso HP series (HP4, HP5, HP6) and Sandvik CS/CH series are the most widely deployed cone crushers globally. Their base mount specifications are model-specific — the larger HP6 crusher requires significantly higher-capacity mounts than the HP4 despite similar external appearance.
Mantle and Bowl Liner Seating Rubber
The crushing chamber liners (mantle on the cone, bowl liner on the concave) are held in place by zinc or epite backing material. However, the initial seating of these liners against the crusher head uses rubber seal rings that:
- Prevent backing material from leaking during the liner installation process
- Provide a cushioned bed for the liner during initial break-in
Screener Feed Rubber: Apron Feeders and Vibrating Grizzlies
Apron Feeder Rubber Skirting
Apron feeders are the primary feed conveyor for most crushing plants, transferring blasted rock from the receiving hopper to the primary crusher. The sides of the apron feeder trough use rubber skirting to:
- Seal the gap between the moving apron and the stationary trough sides
- Prevent rock spillage that would create housekeeping and safety hazards
- Allow slight movement of the feeder under heavy rock drop impacts
Apron feeder skirting is a wear item, typically replaced every 3-12 months depending on feed rock size and sharpness. The compound should be a high-abrasion natural rubber (NR) or styrene-butadiene (SBR) blend — avoiding polyurethane in wet or muddy applications where polyurethane sticks to feed material.
Vibrating Grizzly Rubber Suspensions
Vibrating grizzlies (scalping screens before the primary crusher) use rubber suspension mounts similar to screening plant mounts. Given their position before the primary crusher, they receive the largest and most impactful pieces of blasted rock — requiring robust, high-capacity rubber mounts that survive direct impact loading beyond their rated continuous capacity.
For context on mining equipment vibration isolation principles, see our mining equipment vibration isolation guide.
Mobile Crushing Plant Rubber Components
Mobile crushing and screening plants (tracked or wheeled) add transport-related rubber demands to the crushing-operation requirements:
Track Frame Rubber Components
Tracked mobile crushers (Kleemann MC, Sandvik QJ series, Metso Lokotrack) use rubber track systems:
– Final drive seals — same Duo-Cone design as excavators
– Track carrier roller rubber surfaces — abrasion-resistant compound
– Front idler cushion springs — track tension regulation
Transport Anti-Vibration Mounts
Wheeled mobile plants travel on public roads between quarry sites. The crusher and screen components must be isolated during road transport to prevent fatigue from road vibration — which has a completely different frequency spectrum from crushing operation vibration. Transport isolators for mobile plants are often designed for lower natural frequency than operational mounts to provide better isolation across the road vibration spectrum (2-20 Hz).
For more on hydraulic rock breaking equipment rubber parts, see our hydraulic breaker rubber parts guide.
Quality Specifications for Crushing Plant Rubber
Crushing plant rubber components operate in continuous high-duty environments. Quality requirements:
- Shore A verification: Screen mounts and crusher base mounts should be tested per Shore durometer methods — a mount that looks intact but has hardened 20 Shore A above specification provides significantly degraded isolation
- Dynamic stiffness testing: For screen mounts, static stiffness testing is insufficient; dynamic stiffness at operating frequency should be verified
- Compound chemical resistance: Process water, oils, and rock dust accelerate some rubber compounds — specify the site chemical environment to the supplier
Babacan Group manufactures crushing and screening rubber mounts under ISO 9001:2015 quality management. Our range covers screen vibration isolators (coil spring + rubber type and pure rubber type), jaw crusher frame mounts, cone crusher base mounts, and apron feeder skirting. Browse our rubber mounts catalog or request a technical quote.
Replacement Intervals
| Component | Service Life | Key Failure Indicator |
|---|---|---|
| Screen rubber panels | 2,000-6,000 t processed | Hole diameter >2× aperture specification |
| Screen vibration mounts | 10,000-20,000 hrs | Shore A hardening >+15, resonance onset |
| Jaw crusher frame mounts | 5,000-10,000 hrs | Increased frame vibration measurement |
| Cone crusher base mounts | 8,000-15,000 hrs | Horizontal crusher movement, oil seal weepage |
| Toggle seat cushions | 3,000-6,000 hrs | Visible compression set >40% |
| Apron feeder skirting | 3-12 months | Material spillage, visible gap at skirting face |
Conclusion
Crusher and screener rubber parts protect machinery worth hundreds of thousands to millions of dollars from the vibration generated in their own operation. A $70 screen mount set that hardens prematurely can cause bearing failures worth $15,000. A $280 cone crusher base mount set that degrades creates resonance that multiplies bearing loads — as demonstrated in the Polish quarry case above.
Key takeaways for plant managers and maintenance engineers:
– Crusher base mount hardening (Shore A increase) is a silent failure mode that causes bearing damage before visual symptoms appear
– Screen mount natural frequency must be well below exciter frequency — verify by calculation or measurement, not just visual inspection
– Toggle seat cushions are “fusible” indicators — severe compression set signals an oversized tramp metal event that needs investigation
– Mobile plant transport mounts need lower natural frequency than operational mounts
Babacan Group ships crushing and screening rubber parts to quarry operators and aggregate producers in 84+ countries. Request a technical quote for your plant model and configuration.