Dual-drive rolling mill speed reducer

HANI DualDrive Dual-Drive Rolling Mill Speed Reducer: A Reliable Power Transmission Solution for the Metallurgical Industry

The HANI DualDrive dual-drive rolling mill speed reducer is specifically engineered to meet the modern metallurgical industry’s demanding requirements for high precision, high reliability, and high-efficiency transmission systems. As a core power transmission component in steel rolling lines, this speed reducer accurately converts the high-speed rotation of motors into the low-speed, high-torque output required by rolling mills, ensuring process stability and product quality. HANI’s DualDrive technology employs an innovative power-split architecture that enables synchronized dual-motor drive and built-in redundancy—delivering a safe, efficient, and resilient transmission solution for rolling mill operators.

Product Overview

The HANI DualDrive rolling mill speed reducer is a high-performance speed reducer designed exclusively for the harsh operating conditions of metallurgical environments—characterized by heavy loads, frequent shock impacts, and elevated temperatures. Featuring a dual-input shaft configuration and a proprietary power-split mechanism, it evenly distributes input power across two independent transmission paths, significantly enhancing system load capacity and operational reliability.

Compared to conventional single-drive speed reducers, the DualDrive system offers a critical advantage: if one drive unit fails, the other continues operating normally, preventing unplanned mill shutdowns—a crucial benefit in metallurgy, where unexpected downtime translates into massive production losses and financial costs.

Built with a modular architecture, the HANI DualDrive speed reducer can be customized to suit various mill types and process requirements—whether for hot strip mills, bar mills, or other rolling applications. Through advanced manufacturing techniques and stringent quality control, it achieves high precision, minimal vibration, and extended service life, providing metallurgical enterprises with a dependable transmission backbone.

Technical Specifications

Parameter Category	Value	Parameter Category	Value
Model	ZJ-Dual Series	Gear Material	Alloy Steel (Deep Carburized)
Rated Power	550 kW – 6 MW	Gear Accuracy Grade	Grade 6 (ISO 2815)
Input Speed	750–1500 rpm	Tooth Surface Hardness	58–62 HRC
Output Speed	30–300 rpm (adjustable)	Reduction Ratio Range	Single-stage: 3–10; Multi-stage: up to 1:1000
Transmission Efficiency	≥96%	Bearing Configuration	Self-aligning Roller Bearings (20–30% increased clearance)
Allowable Overload	300% instantaneous	Lubrication Method	Forced Circulation Lubrication System
Operating Temp. Range	-20°C to +80°C	Protection Class	IP54
Mounting Type	Horizontal	Weight	1500–6000 kg (model-dependent)
Bearing Life	≥50,000 hours	Noise Level	≤75 dB(A)
Vibration Amplitude	≤0.04 mm	Manufacturer	HANI

Key Features & Advantages

The core strength of the HANI DualDrive dual-drive rolling mill speed reducer lies in its unique dual-drive architecture and power-split technology. This design not only boosts load capacity but also dramatically improves system reliability. In the event of a motor failure, the second motor independently carries the full load, ensuring uninterrupted mill operation. Real-world applications show this redundancy reduces transmission system failure rates by over 60%.

High-precision, hardened gear surfaces—carburized to 58–62 HRC—greatly enhance wear resistance and fatigue life. Precision tooth profile modification further minimizes meshing noise and vibration, improving efficiency and longevity. HANI’s patented power-split structure evenly distributes torque between two transmission paths, reducing stress on individual components and extending overall system life.

Equipped with an advanced forced circulation lubrication system, the speed reducer maintains oil temperature within ±2°C, ensuring optimal lubrication for gears and bearings. Integrated smart oil monitoring continuously assesses lubricant condition, enabling predictive maintenance. Moreover, HANI’s intelligent synchronizing controller uses cross-coupled feedforward control to maintain dual-motor synchronization within 8 μm—critical for high-precision rolling operations.

The welded steel housing delivers exceptional rigidity and vibration damping, compliant with JB/T14244-2022 standards. Input shafts connect to motors via drum-type gear couplings, while output ends feature mechanical seals. Select models support horizontal/vertical (H/V) interchangeability to accommodate diverse mill layouts.

Application Scenarios & Case Studies

The HANI DualDrive speed reducer is widely deployed across metallurgical production lines—including hot strip mills, bar mills, and section mills—where it endures low-speed, high-torque, and shock-loaded conditions demanding extreme reliability.

In roughing stands, the speed reducer demonstrates outstanding load-bearing and impact resistance. For example, a φ750 mm mill gearbox maintained stable operation even under a 15% increase in rolling load. Thanks to DualDrive’s power-split design, gear shaft strength improved by 30%, effectively mitigating bending and wear issues caused by overload.

In finishing stands, ultra-low vibration ensures micron-level surface accuracy in rolled strips—meeting stringent quality demands of high-end manufacturing.

For vertical mills, HANI’s innovative return-oil pipe design solves chronic leakage at the output shaft. By optimizing oil return paths and adding sealing隔 rings, lubricant consumption and environmental contamination are reduced while seal life is extended. Additionally, HANI’s cold-weld sealing process enhances high-temperature sealing performance, ensuring stable operation even during 950–1050°C hot rolling.

In high-speed wire rod lines, the intelligent synchronizing controller and low-vibration structure maintain precision at high speeds. Field data shows a 15–20% improvement in rolling accuracy, significantly boosting product quality and market competitiveness.

Detailed Product Advantages

1. Redundant Drive Architecture: Ensures continuous operation during single-motor failure—reducing unplanned downtime by ~200 hours/year and cutting transmission failure rates by over 60%.
2. Enhanced Torque Density: Power-split technology increases torque density by 30% (≥300 Nm/kg), meeting heavy-duty rolling demands.
3. Extended Gear Life: Deep-carburized, precision-modified gears last 40% longer, lowering maintenance costs.
4. Smart Lubrication Management: Oil change intervals of 6–12 months; real-time oil condition monitoring prevents lubrication-related failures.
5. Superior Structural Rigidity: Enlarged bearing clearance (20–30%) accommodates shaft deflection; patented housing design reduces vibration by 30%.

Structure & Working Principle

The HANI DualDrive speed reducer integrates a high-rigidity split housing, dual input/output shafts, power-split gear trains, bearings, seals, and standard components. Two motors drive dual input shafts, and internal power-split gears distribute torque equally across two parallel transmission paths—each typically comprising 3–5 reduction stages.

The power-split gear system uses optimized helical gear arrangements to enable mutual compensation between paths, enhancing dynamic stability. HANI’s patented design maintains synchronization error below 8 μm at frequencies <10 Hz, satisfying ultra-precise rolling requirements.

The forced circulation lubrication system delivers precisely calculated oil flow and pressure. Coupled with ±2°C temperature control and adaptive flow regulation based on load/temperature, it ensures long-term reliability under extreme conditions.

Installation & Commissioning

Proper installation is critical:

• Foundation flatness: ≤0.04/1000
• Input shaft-to-motor coaxiality: ≤Ø0.040 mm
• Use dedicated lifting fixtures to maintain horizontal alignment

Installation steps:

1. Verify dimensional compatibility between motor and reducer (e.g., locating bosses, shaft grooves).
2. Align clamp ring side holes with dust caps and secure with hex screws.
3. Connect motor and reducer naturally—ensuring output/input shaft concentricity and flange parallelism.
4. Conduct no-load test run to verify noise, vibration, and operational status.

Commissioning requires HANI’s proprietary tools and software to calibrate synchronization, efficiency, and vibration. Final validation includes full-load testing across operational ranges.

Maintenance & Care Guidelines

Follow the 10-point maintenance principle: safety first, regular inspection, cleaning, lubrication, wear-part replacement, cooling/electrical checks, logkeeping, manufacturer compliance, and staff training.

Daily tasks: Monitor noise/vibration, check oil level/seals, inspect fasteners and cooling systems.
Periodic tasks (quarterly/half-yearly): Inspect gear/bearing wear, perform oil analysis, recalibrate performance metrics.
Oil change schedule: First change at 300 hours; thereafter every 2500 hours or 6–12 months. Use only high-quality, manufacturer-approved lubricants.

Market Applications & Customer Value

Deployed at major steel plants, the HANI DualDrive speed reducer delivers measurable ROI:

• 60%+ reduction in transmission failures
• 10–15% energy savings
• 15–20% improvement in rolling accuracy

At Lianyuan Steel’s CSP line, it resolved high-temperature sealing/lubrication issues. At Taiyuan Iron & Steel’s 2250 hot strip mill, its redundancy prevented production loss during motor faults.

Technical Support & After-Sales Service

HANI provides end-to-end support:

• Customized selection guidance
• On-site installation/commissioning assistance
• Operator/maintenance training
• 24/7 emergency response
• Genuine spare parts supply
• Remote diagnostics & predictive maintenance

All units come with a minimum 5-year warranty, backed by lifelong technical support.

Future Outlook

Aligned with metallurgy’s shift toward smart, green manufacturing, HANI continues advancing DualDrive technology—focusing on higher efficiency, greater torque capacity, AI-enabled predictive maintenance, eco-friendly materials, and expanded applications beyond steel rolling.

Frequently Asked Questions (FAQ)

Q: How is synchronization accuracy ensured?
A: Cross-coupled feedforward control maintains dual-motor sync within 8 μm. The power-split gear system further compensates for dynamic imbalances.

Q: Does dual-drive require more maintenance?
A: No. Modular design and redundancy actually reduce unplanned maintenance. Routine checks mirror single-drive units.

Q: What is the power range?
A: 550 kW to 6 MW—customizable for any mill size.

Q: How does redundancy prevent downtime?
A: Upon motor failure, the system disengages the faulty unit’s brake, allowing the healthy motor to carry full load while the failed motor freewheels.

Q: How is high-temperature sealing achieved?
A: Cold-weld sealing + dual-lip oil seals + O-ring-equipped隔 rings + optimized return-oil paths prevent leakage at >1000°C.

Q: How is lubricant volume calculated?
A: Total flow = Gear cooling (Q₁ = 60×P×(1−η)ⁿ/(Y×C×Δt)) + Bearing lubrication (Q₂ = 0.5×D×B). Typically rounded to ~100 L/min.

Q: What are alignment tolerances?
A: Coaxiality ≤Ø0.040 mm; foundation flatness ≤0.04/1000. Post-installation dial indicator checks are mandatory.

Q: When to change oil?
A: Replace if water >0.5%, acid number rises, or metal particles surge. Scheduled changes every 6–12 months.

Q: What fault diagnosis methods are used?
A: Acoustic monitoring, vibration analysis, thermal imaging, and oil spectrometry enable early failure detection.

Q: Dual-drive vs. single-drive—key differences?
A: Dual-drive offers redundancy, 30% higher torque density, better shock absorption, and longer life—critical for continuous metallurgical processes.

Q: How does the synchronizing controller work?
A: Real-time sensor feedback adjusts motor outputs via advanced algorithms, maintaining sub-10μm sync under varying loads.

Q: What makes the lubrication system special?
A: ±2°C temperature control, adaptive flow regulation, and real-time oil health monitoring ensure peak performance in harsh environments.

Conclusion

The HANI DualDrive dual-drive rolling mill speed reducer redefines reliability in metallurgical power transmission. By combining redundant dual-motor architecture, precision-hardened gears, intelligent synchronization, and robust sealing, it delivers unmatched uptime, efficiency, and product quality.

As the industry advances toward intelligent, sustainable manufacturing, HANI remains committed to evolving DualDrive technology—empowering steelmakers with future-ready solutions. Whether for new installations or retrofits, the HANI DualDrive speed reducer stands as the optimal choice for mission-critical rolling applications.

Partner with HANI—where engineering excellence meets industrial resilience