Square Shaft Mixing Arm
Technical Specifications
Key Attributes
| Product Name | Square Shaft Mixing Arm / 90° Square Bore Mixing 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 | Precision 90° Square Bore (70x70mm, 80x80mm, 90x90mm) |
| Torque Transmission | 4-Surface Equal Stress Distribution (Eliminates Keyway Shear) |
| Machine Compatibility | BHS DKXS, Liebherr DW, SIMI, ELKON, MEKA, Linz |
| Casting Process | Vacuum Sand Casting, MagmaSoft Thermal Simulation & Ultrasonic NDT |
| Brand Name | VOTNE |
| Place of Origin | China |
| SEO Keywords | square shaft mixing arm, square bore mixer arm, BHS square shaft arm, Liebherr mixer arm, ductile iron mixer lever, concrete wear parts |
Product Overview
VOTNE Square Shaft Mixing Arms are precision-engineered structural levers featuring CNC 4-sided square bore couplings, designed specifically for heavy-duty twin-shaft concrete batching mixers (such as BHS DKXS and Liebherr DW models).
Unlike conventional round keyway shafts that concentrate motor torque onto a single narrow drive key, square drive shafts distribute rotational torque evenly across four broad flat contact faces. This design completely eliminates keyway fretting, key deformation, and shaft rotational play. Operating at 90° radial indexing angles, square shaft mixing arms propel concrete slurry into a high-intensity 3D figure-8 turbulent flow. Under extreme aggregate wedging conditions (40mm to 60mm stone drops), peak shock loads are absorbed evenly across the square hub section. VOTNE square shaft mixing arms utilize high-density GS700 pearlitic ductile iron (700 to 750 MPa tensile strength) with 90%+ spherical graphite nodularity, ensuring high bending fatigue resistance and zero internal porosity.
Equipped with CNC-machined split clamping hubs and Grade 10.9/12.9 fasteners, VOTNE square shaft mixing arms provide a rock-solid, zero-backlash fit that protects drive gearboxes and lowers your total wear 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 | Square Shaft Dimension | Clamp Bolt Spec | Radial Indexing Angle | Approx. Weight (kg) |
|---|---|---|---|---|
| BHS DKXS 2.0 / 3.0 | 80mm x 80mm Square | M20 Grade 10.9 (2 Screws) | 90° Precision Index | 25.0 kg |
| Liebherr DW 2.25 / 3.0 | 90mm x 90mm Square | M20 Grade 12.9 (2 Screws) | 90° Precision Index | 28.8 kg |
| SIMI Twin-Shaft 2.0 | 70mm x 70mm Square | M18 Grade 10.9 (2 Screws) | 90° Precision Index | 21.2 kg |
| ELKON / MEKA 2.25 | 80mm x 80mm Square | M20 Grade 10.9 (2 Screws) | 90° Precision Index | 24.6 kg |
| Custom OEM Drawings | Custom Square Size | As Per CAD Drawing | Tailored Angle | Custom |
Key Advantages for Plant Operators
4-Surface Equal Torque Distribution
Square bore hub design distributes high motor torque evenly across four flat drive surfaces, eliminating localized stress concentrations.
Eliminates Keyway Shearing
Flat square contact surfaces prevent single-key shear failures, key deformation, and rotational fretting under heavy aggregate shock.
90° Precision Radial Indexing
CNC-broached square bore corners ensure exact 90° angular alignment along the mixing shaft, maintaining optimal blade clearance.
Zero-Backlash Clamping
Split-hub design with Grade 10.9/12.9 clamping screws secures the arm firmly to the square shaft with zero axial or rotational play.
Standard & Custom OEM Stock
Direct replacement square shaft mixing arms in stock for BHS, Liebherr, and SIMI mixers, with custom square sizes cast to order.
Applications & Field Use Cases
VOTNE Square Shaft Mixing Arms are widely specified across heavy-duty industrial concrete 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. What is the main technical advantage of a Square Shaft Mixing Arm over a round keyway arm?
A square shaft arm transmits torque across four wide flat faces, lowering contact pressure by over 60% compared to a single round keyway. This prevents key shearing, eliminates rotational play (backlash), and protects drive gearboxes from shock loads.
2. How do I measure my square shaft to ensure a correct fit?
Measure the flat-to-flat distance of your drive shaft across two opposing parallel faces using a precision vernier caliper (e.g., exactly 70.0mm, 80.0mm, or 90.0mm). VOTNE square bore hubs are CNC-machined to +0.1mm/-0.0mm tolerance for a snug fit.
3. What clamp bolt torque should be applied when installing square shaft arms?
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) and re-torque after the first 24 hours (500 m³) of operation.
4. Can VOTNE manufacture custom square bore mixing arms for non-standard square sizes?
Yes. VOTNE produces custom square shaft mixing arms based on customer sample castings or 2D/3D CAD drawings. We can customize square bore dimensions (e.g., 65x65mm, 75x75mm, 100x100mm), arm length, pitch angle, and blade mounting hole centers.
5. What are your lead times and trade terms for export orders?
Standard replacement square shaft mixing arms for BHS 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.