Central Mixing Arm
Specifiche Tecniche
Key Attributes
| Product Name | Central Mixing Arm / Center Crossover Lever |
| Material Grade | GS700 / GGG70 Pearlitic Ductile Iron, Forged 42CrMo4 Steel |
| Tensile Strength | 700 – 750 MPa (Yield Strength 420–480 MPa) |
| Brinell Hardness | 260 – 320 HB (Matrix: Pearlitic Spheroidized Graphite) |
| Shaft Coupling Type | Square Shaft (90° Index), Hexagonal Shaft (60° Index), Round Keyway |
| Mixing Function | Central Crossover Shearing, Folding & 3D Homogenization |
| Machine Compatibility | BHS, SICOMA, Liebherr, Teka, SIMI, ELKON, MEKA, Linz |
| Casting Process | Computerized Mold Thermal Simulation & MagmaSoft NDT Testing |
| Brand Name | VOTNE |
| Place of Origin | China |
| SEO Keywords | central mixing arm, concrete mixer arm, twin shaft central arm, BHS central arm, SICOMA center arm, ductile iron mixer lever, concrete wear parts |
Product Overview
VOTNE Central Mixing Arms are heavy-duty structural levers engineered specifically to operate in the middle crossover zone of industrial twin-shaft concrete mixers, where opposing material streams meet under maximum fluid pressure.
Positioned at the center of counter-rotating mixing shafts, central mixing arms experience intense turbulent hydraulic shear as concrete slurry forced from the left and right side arms converges in the middle. Featuring a specialized transverse 0° / 90° mixing angle, central arms fold and shear opposing concrete flows, accelerating binder dispersion and achieving 98%+ mixture homogeneity in under 30 seconds. Because the central zone handles the highest volume of aggregate collisions, standard gray iron arms suffer severe bending fatigue and root cracking. VOTNE central mixing arms utilize high-strength GS700 pearlitic ductile iron (700 to 750 MPa tensile strength) with over 90% spherical graphite nodules, completely eliminating brittle fracture risks under aggregate wedging impacts.
Engineered with CNC-machined split clamping hubs and Grade 10.9/12.9 fastener hardware, VOTNE central mixing arms maintain a zero-backlash fit on square and hexagonal shafts, safeguarding drive gearboxes and lowering your total cost per cubic meter.
Material & Metallurgy Selection
| Material Grade | Tensile Strength | Yield Strength | Impact Toughness | Best Application |
|---|---|---|---|---|
| VOTNE Forged 42CrMo4 Steel | 850 - 1000 MPa | 650 - 750 MPa | Extreme (>35 J/cm²) | Heavy Dam Mass Concrete & 60mm Stone Drops |
| VOTNE GS700 Ductile Iron | 700 - 750 MPa | 420 - 480 MPa | High (10 - 14 J/cm²) | Commercial Ready-Mix & Precast Concrete Plants |
| Standard GGG40 Ductile Iron | 400 - 450 MPa | 250 - 310 MPa | Medium (8 - 10 J/cm²) | Light-Duty Mortar & Small Pan Mixers |
Technical Specifications & Dimensions
| Mixer Brand / Model | Shaft Profile Size | Clamp Bolt Spec | Arm Neck Cross-Section | Approx. Weight (kg) |
|---|---|---|---|---|
| BHS DKXS 2.0 / 3.0 | 80mm Square Shaft | M20 Grade 10.9 (2 Screws) | Heavy Diamond Section | 25.2 kg |
| SICOMA MAO 2250 / 3000 | 70mm Hexagonal Shaft | M18 Grade 10.9 (2 Screws) | Reinforced Oval Neck | 20.4 kg |
| Liebherr DW 2.25 / 3.0 | 90mm Square Shaft | M20 Grade 12.9 (2 Screws) | Extra-Duty Box Section | 29.0 kg |
| TEKA TPZ 1500 / 2250 | 60mm Round Keyway | M16 Grade 10.9 (Wedge Bolt) | Tapered Lever Arm | 17.1 kg |
| Custom OEM Drawings | Custom Shaft Profile | As Per CAD Drawing | Tailored Section | Custom |
Key Advantages for Plant Operators
Maximum Fluid Shear & Homogeneity
Transverse central arm design folds opposing concrete flows from both shafts, accelerating cement hydration and achieving 98%+ mix uniformity rapidly.
High Bending Fatigue Resistance
GS700 pearlitic ductile iron with 90%+ spherical graphite nodules stops fatigue crack growth under intense central turbulence.
Zero-Backlash Split-Hub Clamping
CNC-machined split hubs clamp onto square or hexagonal shafts with zero rotational play, eliminating keyway fretting and shaft damage.
Eliminates Central Arm Fractures
High yield strength (420–480 MPa) absorbs aggregate collision impacts in the central zone without snapping, protecting trough liners.
Standard & Custom OEM Stock
Direct replacement central mixing arms in stock for major European and Asian mixer brands, with rapid custom casting available.
Applications & Field Use Cases
VOTNE Central Mixing Arms are widely specified across high-volume industrial batching operations:
- Commercial Ready-Mix Concrete Batching Plants (Twin-Shaft Mixers 1.0m³ to 4.5m³)
- Precast Concrete Production Facilities (Planetary and Counter-Current Pan Mixers for pipe, beam, and precast slab casting)
- High-Impact Infrastructure & Dam Construction Projects (Mass concrete mixing with 40mm to 60mm aggregate)
- Cold Recycled Pavement & Road Base Mixing Plants
- Mining Paste Fill & Underground Backfill Preparation
- Heavy Refractory & Industrial Chemical Mixing Equipment
Frequently Asked Questions (FAQ)
1. How does a Central Mixing Arm differ from Side Mixing Arms?
Side mixing arms feature angled pitch profiles (+45° or -45°) designed to push material axially toward the center. Central mixing arms are positioned in the middle crossover zone with a neutral transverse orientation (0° or 90°), specifically designed to fold, shear, and intermix the opposing slurry streams coming from both ends.
2. Why is central arm fatigue resistance critical in twin-shaft mixers?
The central crossover zone experiences double the material volume and turbulent fluid pressure compared to end zones. VOTNE GS700 ductile iron (700–750 MPa tensile strength) provides the high yield strength and fatigue limits required to prevent central arm root cracking.
3. What clamp bolt torque should be applied during installation?
For M18 Grade 10.9 clamping screws, torque to 330–360 N·m. For M20 Grade 10.9/12.9 screws, torque to 480–520 N·m. Always apply medium-strength threadlocker (Loctite 243) to bolt threads and re-torque after the first 24 hours (500 m³) of batching operation.
4. Can VOTNE manufacture custom central mixing arms for non-standard shafts?
Yes. VOTNE produces custom central mixing arms based on customer sample castings or 2D/3D CAD drawings. We can customize square or hexagonal shaft hub dimensions, arm neck geometry, and blade mounting hole centers.
5. What are your lead times and trade terms for export orders?
Standard replacement central mixing arms for BHS, SICOMA, and Liebherr mixers are kept in stock for immediate shipment. Custom casting orders take 15 to 25 days. We support EXW, FOB, CIF, and DDP trade terms with global delivery.