Technical Specifications
- Manufacturing Process: Forged, Cast
- Forged Materials: 42CrMo, 34CrNiMo6
- Cast Materials: ZG42CrMo, ZG55
- Diameter: Custom – up to 800mm (forged); Custom – up to 1,200mm (cast)
- Length: Custom – up to 4,000mm
- Heat Treatment: Quenching + tempering, normalizing
- Surface Hardness: HB 200 – 280 (depending on material)
- NDT Methods: UT (ultrasonic), MT (magnetic particle)
- Applications: Cement rotary kilns, lime kilns, rotary dryers, chemical rotary kilns, metallurgical kilns
- Customization: Yes, according to customer drawings
Rotary Kiln Support Roller Shaft – Engineered for Reliability Under Heavy Loads
In the rotary kiln support system, the support roller shaft is the component that connects the support roller to the bearing system. It transmits the load from the roller to the foundation and enables smooth rotation of the entire assembly.
The support roller shaft works in combination with the support roller, bearing housing, and bearings. Together, these components form the support roller set that carries the full weight of the rotating kiln — which can be hundreds of tons.
AGICO manufactures support roller shafts for cement plants, lime kilns, and other rotary processing systems. We offer both forged and cast shafts in a range of alloy steel grades. Every shaft is custom-made to the customer’s drawing and operating requirements.
The Support Roller Shaft in the Kiln Support System
The support roller shaft is one part of a four-component support system:
| Component | Function |
|---|---|
| Kiln Tyre | Mounted on the kiln shell; transfers load to the roller |
| Support Roller | Rotates against the tyre; bears the weight of the kiln |
| Support Roller Shaft | Connects the roller to the bearings; transmits torque and load |
| Bearing Assembly | Supports the shaft; enables smooth rotation |
The shaft must transfer both the radial load (downward weight of the kiln) and the axial load (side thrust from the kiln’s slope). It must also resist the bending moment created by the weight distribution along the kiln.
This is why the shaft is not just a simple cylinder. It is a precisely engineered component with specific diameter, length, surface finish, and heat treatment requirements — all designed to handle the stresses of continuous operation.
Manufacturing Processes – Forged and Cast Support Roller Shaft
AGICO offers support roller shafts in two manufacturing processes: forged and cast. The choice depends on the kiln size, load, and application.
Forged Shafts
Forged shafts are produced by heating a steel ingot and shaping it under high pressure. This process refines the grain structure of the steel, resulting in higher strength and better fatigue resistance.
Key characteristics:
- Higher tensile and yield strength
- Superior fatigue resistance
- Better impact toughness
- Suitable for high-load and high-speed applications
Material options: 42CrMo, 34CrNiMo6
Cast Shafts
Cast shafts are produced by pouring molten steel into a mold. This process is suitable for large diameters and complex shapes that are difficult to forge.
Key characteristics:
- Can achieve larger diameters
- Suitable for complex shapes
- Cost-effective for large sizes
- Good for the replacement of existing cast shafts
Material options: ZG42CrMo, ZG55
How to Choose
| Condition | Recommended Process |
|---|---|
| Heavy-load kiln (large cement kiln) | Forged |
| Large diameter (over 600mm) | Cast |
| Complex shape | Cast |
| High fatigue risk | Forged |
| Replacing an existing shaft | Same as original |
AGICO can advise on the best process for your specific kiln. Contact us with your drawing and operating parameters.
Advantages of AGICO Rotary Kiln Support Roller Shaft
Certified Materials – Full Traceability
AGICO uses certified steel ingots from approved mills. Each heat of steel is tested with a spectrometer to verify chemical composition. Material certificates are provided with every shaft.
Heat Treatment – Balanced Strength and Toughness
Support roller shafts require both high surface hardness and good core toughness. AGICO uses quenching and tempering (or normalizing) to achieve this balance. The heat treatment process is controlled to ensure consistent results across the entire shaft cross-section.
Precision Machining – Proper Fit with Roller and Bearings
The shaft must fit the roller bore and the bearings within tight tolerances. AGICO uses large CNC lathes to achieve the required dimensional accuracy and surface finish. This ensures proper fit, reduces vibration, and extends bearing life.
Hot Assembly – A More Reliable Fit
For shafts that are assembled into the roller body, AGICO uses hot assembly (shrink fit). The roller is heated to expand, the shaft is inserted, and the assembly is cooled to create a uniform interference fit. This method is more reliable than cold pressing and reduces the risk of shaft slipping.
100% NDT – No Hidden Defects
Every AGICO shaft undergoes ultrasonic testing (UT) for internal flaws and magnetic particle testing (MT) for surface defects. This ensures that no shaft leaves our factory with hidden cracks, porosity, or inclusions.
Custom Manufacturing – Forged, Cast, or Your Specification
We manufacture both forged and cast shafts, and every shaft is produced according to customer drawings. We can also reverse-engineer a worn shaft from your kiln if drawings are not available. This gives you full flexibility — choose the process, size, and design that fits your kiln.
Quality Assurance and Manufacturing Control
AGICO operates a comprehensive quality control system for support roller shaft production. The following controls are applied at each stage.
| Stage | Control |
|---|---|
| Raw material receiving | Spectrometer analysis of chemical composition |
| Forging or casting | Process control, temperature monitoring |
| Heat treatment | Controlled heating and cooling cycles |
| Rough machining | Dimensional inspection |
| NDT | UT (100%) + MT (100%) |
| Finishing machining | Precision dimensional inspection |
| Final inspection | Full dimensional + hardness + visual inspection |
| Documentation | Material Test Report + NDT Report |
All test reports are provided with the shipment. This gives you full visibility into the quality of the shaft you receive.
FAQ about Rotary Kiln Support Roller Shaft
Q1: What is the function of the support roller shaft?
A: The support roller shaft connects the support roller to the bearings. It transmits the kiln weight from the roller to the bearing system and enables smooth rotation.
Q2: What is the difference between forged and cast shafts?
A: Forged shafts are shaped under high pressure, resulting in higher strength and fatigue resistance. Cast shafts are made by pouring molten steel into a mold, which allows for larger diameters and complex shapes.
Q3: What material does AGICO use for support roller shafts?
A: For forged shafts, we use 42CrMo and 34CrNiMo6. For cast shafts, we use ZG42CrMo and ZG55. We can also use customer-specified materials.
Q4: Can AGICO manufacture a shaft according to my drawing?
A: Yes. All AGICO shafts are custom-made. Please provide your drawing in CAD or PDF format.
Q5: What is the typical lead time for a support roller shaft?
A: Typical lead time is 30–60 days, depending on size and material. Contact us for a specific lead time for your requirement.
Q6: What causes support roller shaft failure?
A: The most common causes are excessive interference fit (stress concentration), fatigue cracks, and hidden casting defects. AGICO shafts are designed to prevent these through proper fit design, material selection, and 100% NDT.
Q7: How to maintain a support roller shaft?
A: Regular maintenance includes checking shaft temperature, maintaining bearing lubrication, monitoring vibration, and inspecting the shaft surface for scratches during scheduled maintenance.
Q8: Does AGICO supply other rotary kiln spare parts?
A: Yes. AGICO supplies kiln tyres, support rollers, thrust rollers, girth gears, kiln shells, and sealing devices.
