What is the maximum torque that the Large Gear Frame can transmit?

The frame itself does not transmit torque; it supports the gear that does. However, the frame's load capacity and stiffness are designed to handle the reaction forces from a gear transmitting up to 250 kNm of torque. This is calculated based on a 1200mm gear with a tangential force of 416 kN at the pitch circle. The frame's deflection under this load is less than 0.1mm, ensuring proper gear meshing. For higher torque applications, consult our engineering team to verify the frame's suitability or consider a custom design.

How do I align the frame during installation to ensure proper gear meshing?

Alignment is critical for large gear frames. First, ensure the mounting surface is clean and flat within 0.05mm. Use a dial indicator to check the concentricity of the pilot diameter to the shaft; it should be within 0.05mm TIR. Then, check the face runout of the mounting flange; it should be within 0.03mm. Use shims under the frame feet to correct any angular misalignment. After bolting, recheck runout and adjust if necessary. Finally, verify gear backlash according to the gear manufacturer's specifications, typically 0.1-0.2mm for this size.

What maintenance is required for the Large Gear Frame?

The frame itself requires minimal maintenance, but regular inspections are recommended. Every 500 operating hours, check the mounting bolts for tightness using a torque wrench set to 1200 Nm for M36 bolts. Inspect the frame for cracks or corrosion, especially around weld seams and bolt holes. Clean any debris from the frame surfaces to prevent corrosion. Every 2000 hours, perform a dimensional check of the pilot diameter and mounting face to ensure they remain within tolerance. If the frame is exposed to harsh environments, apply a rust-preventive coating annually.

Can this frame be used with a gear of a different diameter?

The Large Gear Frame is specifically designed for gears with a 1200mm outer diameter and a 1100mm bolt circle. Using it with a different gear size may result in improper fit or inadequate support. However, if the gear has the same bolt circle and pilot diameter, it could be compatible, but the load capacity must be recalculated based on the new gear's weight and torque. We recommend consulting our engineering team before using this frame with any gear other than the intended 1200mm size to avoid safety risks.

Large Gear Frame

1200mm OD Large Gear Frame for Heavy-Duty Gearbox and Mill Drive Applications

The large gear frame is a precision-engineered structural component designed to support and align large-diameter gears in industrial power transmission systems. With a 1200mm outer diameter and a load capacity of 15 metric tons, this frame is built for continuous operation in gearboxes, ball mills, and rotary kilns.

Material Grade

42CrMo4 alloy steel

Gear Accuracy Grade

ISO 1328 Grade 6

Surface Hardness

280-320 HB

Mounting Bolt Circle

1100mm

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How Does the 1200mm Large Gear Frame Handle 15-Ton Loads in Continuous Operation?

The Large Gear Frame is a heavy-duty structural component specifically sized for gears with a 1200mm outer diameter, commonly found in industrial gearboxes and mill drives. Its core function is to maintain precise gear alignment under high torque and radial loads, preventing premature wear and tooth breakage. The frame is machined from 42CrMo4 alloy steel, a material chosen for its high tensile strength (≥1080 MPa) and fatigue resistance. With a maximum load capacity of 15 metric tons, it supports the gear and absorbs operational vibrations without deformation. The 1100mm bolt circle ensures compatibility with standard large gear mounting patterns, while the ISO 1328 Grade 6 accuracy guarantees low transmission error. This frame is not a generic support; it is engineered to meet the specific deflection limits required for gears above 1 meter in diameter.

Typical applications include ball mills in cement plants, rotary kilns in mining, and heavy-duty gearboxes in steel rolling mills. In these environments, gears face constant shock loads and abrasive dust. The Large Gear Frame's rigid construction and 280-320 HB surface hardness resist indentation and wear, extending maintenance intervals. For instance, in a ball mill drive, the frame keeps the girth gear aligned with the pinion, reducing vibration that would otherwise accelerate bearing failure. The 15-ton capacity allows it to handle the weight of the gear plus dynamic loads from material tumbling. Unlike smaller frames, this unit includes reinforced ribs and a thicker web section to distribute stress evenly, preventing crack initiation at bolt holes.

Compared to standard gear frames in the same series, the 1200mm model offers a 40% higher load capacity and a 25% increase in stiffness, thanks to its optimized rib pattern and larger cross-section. This makes it suitable for high-torque applications where standard frames would deflect excessively. The frame also features a machined pilot diameter for concentricity within 0.05mm, ensuring proper gear meshing. While smaller frames may suffice for light-duty conveyors, this large frame is necessary for applications where gear diameters exceed 1 meter and torque loads are continuous. Its design allows for shimming during installation to compensate for foundation settling, a common issue in heavy machinery.

42CrMo4 alloy steel with 280-320 HB hardness for wear resistance in abrasive environments.
ISO 1328 Grade 6 gear accuracy ensures low transmission error and quiet operation.
15-ton load capacity with safety factor of 2.5, tested under static and dynamic loads.
1100mm bolt circle with 24 M36 bolt holes for secure mounting and easy alignment.

Core Technical Features and Quantified Advantages

STEP 1

42CrMo4 Alloy Steel Construction with 280-320 HB Hardness

The frame is forged from 42CrMo4 alloy steel, which offers a tensile strength of at least 1080 MPa and a yield strength of 930 MPa. After quenching and tempering, the surface hardness reaches 280-320 HB, providing excellent resistance to abrasive wear and indentation. This material grade is commonly used in heavy-duty gears and shafts, ensuring the frame can withstand shock loads without cracking. The hardness range is verified using Brinell testing on every batch, and certificates are available upon request.

STEP 2

15-Metric-Ton Load Capacity with 2.5 Safety Factor

The frame is designed to support a maximum static load of 15 metric tons, with a safety factor of 2.5 against yield. This capacity accounts for the weight of the gear, shaft, and dynamic forces from torque transmission. Finite element analysis (FEA) was used to optimize rib placement, resulting in a maximum deflection of 0.08mm under full load. This ensures the gear remains properly aligned, reducing tooth contact stress and extending gear life. The load rating is based on continuous operation at 40°C ambient temperature.

STEP 3

ISO 1328 Grade 6 Accuracy for Minimal Transmission Error

The gear mounting surface and pilot diameter are machined to ISO 1328 Grade 6 tolerances, with a total composite error of less than 0.05mm. This precision ensures that the gear runs true, minimizing vibration and noise. The bolt holes are positioned within 0.1mm of the theoretical bolt circle, allowing for easy installation without binding. This level of accuracy is critical for gears with a diameter of 1200mm, where small misalignments can cause significant load concentrations and premature failure.

STEP 4

1100mm Bolt Circle with 24 M36 Mounting Holes

The frame features a 1100mm bolt circle with 24 evenly spaced M36 tapped holes, designed to match standard large gear hubs. The holes are drilled and tapped to a depth of 60mm, providing sufficient thread engagement for high-strength bolts. The mounting face is machined flat within 0.02mm to ensure full contact and uniform preload. This configuration allows the frame to be bolted directly to the gear hub without adapters, reducing assembly time and potential alignment errors.