The Step Bearing Set (Part 18564932) is the complete upper thrust bearing assembly engineered for the ThyssenKrupp Kubria F210 Cone Crusher. The set includes the step bearing, retainer, dust seal, and mounting hardware required to restore main shaft support and axial positioning during the crushing cycle — a direct-fit replacement for OEM part 18564932.
1. What Is a Step Bearing Set in a Cone Crusher?
In a cone crusher, the step bearing sits at the top of the main shaft (between the shaft head and the spider arm). It performs three critical functions simultaneously:
- Supports the main shaft vertically — absorbs the entire weight of the shaft plus crushing forces during the crushing cycle.
- Provides axial positioning — prevents the shaft from moving up or down inside the crushing chamber, keeping CSS (closed side setting) stable.
- Allows controlled rotation — the polished bearing surface lets the shaft rotate at low speed (typically 400-600 RPM) with minimum friction.
The step bearing set is the complete service assembly — the bearing itself, the retainer cover that holds it in place, the dust seal that keeps contamination out of the oil film, and the mounting hardware. When the step bearing fails (spalling, brinelling, overheating from oil starvation, or seal contamination), the whole set is normally replaced together during a planned shutdown.
2. Components in This Set
| Composant | Function | Matériau |
|---|---|---|
| Step Bearing (Main Disc) | Main shaft support surface; carries vertical + impact load | Alloy steel (forged/rolled), hardened to 58-62 HRC on contact face |
| Retainer Cover | Clamps the bearing to the frame; locates the seal housing | Ductile iron / cast steel, epoxy-coated for corrosion resistance |
| Joint anti-poussière | Prevents dust, fines and water ingress into the oil film | NBR rubber + polyurethane + steel insert (labyrinth + lip combination) |
| Backing Ring | Distributes clamping load evenly; allows axial float tolerance | Bronze or brass (low-friction interface) |
| Mounting Bolts & Washers | Secures retainer cover to crusher frame | Grade 10.9 high-tensile steel, zinc-flake coated |
| Hot-dipped tungsten steel overlay | Bearing contact face treated with hot-dipped tungsten-steel overlay; surface hardness ≥ 65 HRC equivalent, metallurgic
loy-steel substrate for superior abrasion resistance under cyclic impact loads.
|
3. Compatible Equipment
This step bearing set is engineered specifically for the following ThyssenKrupp Kubria cone crusher models:
| OEM Brand | Model Series | Crusher Type | Recommended Application |
|---|---|---|---|
| ThyssenKrupp (Kubria) | F210 (primary fit) | Cone crusher, coarse/medium chamber | Hard rock, iron ore, copper ore, gold ore, granite, basalt |
| ThyssenKrupp (Kubria) | F-series (cross-reference) | Cone crusher | Verify with crusher serial number before ordering |
Cross-reference numbers: 18564932 (primary) · ThyssenKrupp drawing reference available on request.
4. Working Principle
During Crushing (Loaded Cycle)
As the mantle compresses rock against the bowl liner, the main shaft experiences a downward impact force. The step bearing on top of the shaft bears this load and transfers it to the crusher frame via the retainer cover. The bearing surface floats on a thin hydrodynamic oil film (~0.05 mm), preventing metal-to-metal contact.
During Idle Rotation (Unloaded)
Between crushing strokes, the eccentric rotates the main shaft slowly. The step bearing surface allows low-friction rotation while the dust seal keeps oil clean and contamination-free. Stable oil temperature (40-55°C) is the key health indicator.
5. Key Features & Advantages
- Direct OEM replacement — engineered to match Kubria F210 original part 18564932 dimensions, tolerances and load rating. No frame modification required.
- High-grade alloy steel — through-hardened bearing surface (58-62 HRC) resists brinelling, spalling and fatigue under cyclic impact loads.
- Concentric ring pattern — precision-machined grooves on the bearing face ensure uniform oil film distribution and reduce localized hot spots.
- Bronze backing ring — accommodates minor axial float without galling, extending bearing life during start-up and shutdown.
- Labyrinth + lip dust seal — double protection against dust ingress; critical in crushing environments where fines contaminate lubricant.
- Pre-assembled kit — saves 6-8 hours of downtime vs. sourcing components separately; everything fits together out of the box.
- Serial-number traced QC — every set is dimensionally inspected, hardness-tested and run-out checked before packing.
- Stock available — lead time typically 5-10 working days from stock; expedited options for emergency breakdowns.
6. Typical Applications
The Kubria F210 cone crusher is widely deployed across the mining and aggregate industries. The 18564932 step bearing set supports the following operations:
- Iron ore mining — secondary and tertiary crushing of magnetite and hematite ore.
- Copper ore processing — medium-hard ore crushing in concentrator plants.
- Gold ore crushing circuits — hard rock gold operations in Africa, South America and Australia.
- Granite and basalt quarries — aggregate production for construction and infrastructure.
- Cement plant raw material preparation — limestone and clinker crushing.
- Industrial mineral processing — quartz, feldspar, andalusite and similar abrasive feedstocks.
7. Material & Manufacturing Process
| Stage | Process Detail |
|---|---|
| Material selection | Alloy steel (42CrMo / 50Mn equivalent) for bearing disc; ductile iron (GGG60) for retainer cover; NBR + PU for dust seal |
| Forging / Casting | Bearing disc: open-die forged for grain-flow continuity. Retainer: sand-cast with riser design to avoid shrinkage porosity. |
| Rough turning | All critical surfaces rough-machined with 3-5 mm allowance for finish. |
| Heat treatment | Bearing disc: quenched and tempered (Q&T) to achieve 58-62 HRC surface hardness with tough core. |
| Finish machining | CNC turning + grinding to achieve Ra ≤ 0.4 µm on the bearing contact face; concentricity within 0.02 mm. |
| Concentric ring machining | Concentric grooves precision-cut for hydrodynamic oil film distribution. |
| Surface treatment | Retainer cover: sand-blasted, anti-rust primer, epoxy top-coat. Hardware: zinc-flake coating (240h salt spray). |
| Final assembly | Step bearing + backing ring + hardware pre-assembled; dust seal installed in groove. Each set serial-numbered and shipped in matched pair packaging. |
8. Quality Control & Inspection
Every 18564932 step bearing set undergoes the following inspection protocol before shipment:
- Dimensional inspection — critical diameters, heights and bolt-circle patterns verified with CMM.
- Hardness testing — surface and core hardness checked on bearing disc (target 58-62 HRC surface).
- Surface finish — bearing contact face roughness Ra measured (target ≤ 0.4 µm).
- Run-out test — axial and radial run-out checked against drawing tolerance.
- Ultrasonic testing (UT) — bearing disc inspected for internal defects per ASTM A388.
- Magnetic particle inspection (MPI) — surface crack detection on critical load-bearing surfaces.
- Visual & packaging check — final QC before export crating; matching components verified.
9. Packaging & Shipping
- Individual wrapping — each component wrapped in VCI anti-rust film + bubble wrap.
- Inner packing — foam-fitted wooden crate with cardboard separators.
- Outer packing — ISPM-15 compliant fumigated plywood export crate, heat-treated and stamped.
- Marking — crate labeled with part number 18564932, quantity, net/gross weight, and “Fragile / Heavy” handling marks.
- Shipping options — sea freight (FCL / LCL), air freight, or courier (DHL / FedEx / UPS) for emergency orders.
- Documents — commercial invoice, packing list, material certificate (EN 10204 3.1), heat-treatment certificate, QC report.
10. Specification Table
| Objet | Detail |
|---|---|
| Product Name / Part Name | Step Bearing Set (Upper Thrust Bearing Assembly) |
| Numéro de pièce | 18564932 |
| Compatible Crusher | ThyssenKrupp Kubria F210 Cone Crusher |
| Set Components | Step Bearing, Retainer Cover, Dust Seal, Backing Ring, Mounting Hardware |
| Bearing Material | High-Grade Alloy Steel (42CrMo equivalent), Q&T |
| Bearing Surface Hardness | 58-62 HRC |
| Retainer Material | Ductile Iron (GGG60), Epoxy-Coated |
| Dust Seal Material | NBR + Polyurethane + Steel Insert |
| Backing Ring Material | Bronze / Brass |
| Bearing Surface Finish | Ra ≤ 0.4 µm, concentric grooves for oil distribution |
| Approx. Net Weight (full set) | Contact us for the latest weight per your serial number |
| Operating Temperature | -20°C to +80°C (continuous duty); oil temp target 40-55°C |
| Lubrication | Oil bath / flood lubrication (per OEM specification) |
| Recommended Service Life | 4,000-8,000 operating hours (depends on duty cycle, feed hardness, oil cleanliness) |
| Manufacturing Standards | OEM-equivalent tolerances, ISO 9001 quality system |
| Inspection Standards | CMM dimensional, hardness per ASTM E18, UT per ASTM A388, MPI per ASTM E709 |
| Country of Origin | China |
| HS Code | 8474.90 (parts of machinery for sorting, screening, separating, washing or otherwise treating earth, stone, ores or other mineral substances) |
| MOQ | 1 Set |
| Lead Time | 5-10 working days from stock (expedited options for breakdowns) |
| Packaging | VCI film + foam-fitted ISPM-15 plywood export crate |
| Shipping Terms | EXW / FOB / CIF / DDP (negotiable) |
| Warranty | 12 months against manufacturing defects |
11. Why Buy From MiningSpares
- Specialized in crusher wear parts — our core focus is cone crusher replacement parts for ThyssenKrupp Kubria, Trio, Sandvik, Metso, Symons, Telsmith and other major brands.
- Direct factory pricing — we manufacture in-house with foundry partners, eliminating middleman markups.
- Large inventory — common parts ready to ship; emergency breakdown orders prioritized.
- Engineering support — we help you cross-reference part numbers and confirm fitment by crusher serial number.
- Global export experience — we ship to 60+ countries with full export documentation.
- Quality guaranteed — every part comes with material certificate and dimensional QC report.
Need a quote or want to confirm fitment for your serial number?
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