What is the maximum torque this 800mm gear set can transmit, and how does the 20:1 ratio affect it?

The gear set is rated for a maximum output torque of 12,000 Nm, based on a input torque of 600 Nm and a 20:1 reduction ratio. The torque capacity is determined by the bending strength of the gear teeth (AGMA 2001) and the surface durability (AGMA 2101). The 20:1 ratio multiplies the input torque by 20, but it also reduces the output speed proportionally. For continuous operation, we recommend a safety factor of 1.5, so the continuous torque should not exceed 8,000 Nm. The hardened teeth (45-50 HRC) and 42CrMo4 core provide resistance to tooth breakage under shock loads up to 200% of rated torque. Always ensure proper lubrication and alignment to achieve full torque capacity.

How do I align the large gear set during installation to prevent premature wear?

Proper alignment is critical for gear life. First, ensure the mounting surfaces are clean and flat within 0.05 mm. Use a dial indicator to check the runout of the main gear on its shaft; total runout should not exceed 0.10 mm. For the pinion, check parallelism between the pinion shaft and main gear shaft; misalignment should be less than 0.05 mm per 100 mm of face width. Set the backlash to 0.10-0.15 mm using a feeler gauge at the tightest point. After installation, apply a light coat of marking compound and run the set under light load to check tooth contact pattern; the contact should cover at least 70% of the tooth face and be centered. Recheck alignment after 100 hours of operation and tighten bolts if necessary.

What lubrication method is recommended for this gear set in a dusty mining environment?

For dusty environments, we recommend a forced lubrication system with filtered oil (ISO VG 220 or 320) delivered directly to the meshing zone. The oil should be filtered to 10 microns and cooled to maintain a sump temperature of 40-50°C. Use a splash lubrication only if the gear is enclosed in a sealed housing; in open setups, use a grease with EP additives (NLGI 2) applied weekly. Inspect the oil every 500 hours for contamination and change every 2,000 hours or annually. In severe dust, increase inspection frequency to every 250 hours. Ensure breathers are equipped with dust filters to prevent ingress. Proper lubrication reduces wear and extends gear life by up to 50% compared to inadequate lubrication.

Large Gear Set

800mm OD, 20:1 Ratio, 45HRC – Built for Continuous Heavy-Duty Service

The Large Gear Set is a precision-engineered power transmission assembly designed for industrial machinery operating under high torque and continuous load. With an 800 mm outer diameter, module 8 mm, and a 20:1 reduction ratio, this set delivers reliable torque multiplication for applications such as mining ball mills, rotary kilns, and heavy-duty conveyors.

Number of Teeth

100 (main gear)

Gear Ratio

20:1

Material

42CrMo4 alloy steel

Surface Hardness

45-50 HRC

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How Does the 800mm Large Gear Set Handle High-Torque Industrial Drives?

The large gear set is a complete power transmission package built around an 800 mm outer diameter main gear and a matching pinion. The main gear features 100 teeth with a module of 8 mm, providing a 20:1 reduction ratio that multiplies torque by a factor of 20 while reducing speed accordingly. Manufactured from 42CrMo4 alloy steel, the gear set undergoes precision hobbing and grinding to achieve AGMA 10 quality, ensuring uniform tooth contact and minimal backlash. The teeth are case-hardened to 45-50 HRC, offering excellent resistance to wear and pitting under high loads. The set is designed for direct mounting on shafts with a maximum diameter of 120 mm and includes a keyed pinion shaft for secure torque transfer. This gear set is not a generic catalog item; it is specifically engineered for drives requiring an 800 mm center distance, making it a direct replacement for many OEM configurations in heavy machinery.

Typical applications include mining ball mills, rotary kilns, and heavy-duty belt conveyors where continuous operation and high torque are standard. In these environments, the gear set must withstand shock loads from material crushing or uneven feed, as well as abrasive dust and temperature fluctuations. The 20:1 ratio is optimized for motor speeds of 1000-1500 rpm, delivering output speeds of 50-75 rpm, which is ideal for slowly rotating drums and mills. The large diameter and hardened teeth distribute load across multiple teeth in contact, reducing stress and extending service life. Compared to smaller gear sets, this 800 mm unit offers a higher torque capacity—up to 12,000 Nm—without the need for additional reduction stages, simplifying drivetrain design and reducing maintenance points. The set is also compatible with forced lubrication systems, with oil nozzles positioned to deliver lubricant directly to the meshing zone.

Within the Large Gear Set family, this 800 mm variant sits between the 600 mm and 1000 mm models, offering a balance of torque capacity and installation space. It is 30% lighter than the 1000 mm version, making it easier to handle during installation and reducing bearing loads. The 20:1 ratio is steeper than the 15:1 ratio of the 600 mm model, providing higher torque multiplication for demanding applications without increasing the gear diameter. This makes the 800 mm set particularly suitable for retrofitting existing drives where space is limited but higher torque is needed. The set is supplied with a precision-machined pinion shaft, mounting bolts, and an installation guide, ensuring a complete solution. All gears are inspected for runout, tooth thickness, and hardness, and a test report is included with each set.

AGMA 10 quality gears with 45-50 HRC surface hardness for wear resistance and long life in abrasive environments.
20:1 reduction ratio and 12,000 Nm torque capacity, eliminating the need for additional reduction stages in many heavy-duty drives.
Direct replacement for 800 mm center-distance drives, with keyed pinion shaft and mounting hardware included for fast installation.

Core Technical Features and Quantified Advantages

STEP 1

42CrMo4 Alloy Steel with 45-50 HRC Case Hardness

The gear set is forged from 42CrMo4 alloy steel, known for its high tensile strength (≥1080 MPa) and toughness. Teeth are case-hardened to 45-50 HRC, providing a hard wear-resistant surface while maintaining a tough core to absorb shock loads. This combination is ideal for continuous operation in abrasive environments such as mining and cement plants, where pitting and wear are primary failure modes. The hardened depth of 2-3 mm ensures longevity even after minor regrinding.

STEP 2

20:1 Reduction Ratio with 12,000 Nm Torque Capacity

The 20:1 ratio is achieved through a 100-tooth main gear and a 5-tooth pinion (module 8 mm). This ratio provides a torque multiplication of 20, allowing a 600 Nm input to deliver 12,000 Nm output, suitable for driving heavy drums and mills. The ratio is optimized for input speeds of 1000-1500 rpm, producing output speeds of 50-75 rpm. This eliminates the need for secondary reduction stages in many applications, reducing complexity and maintenance.

STEP 3

AGMA 10 Precision for Smooth and Quiet Operation

Gears are manufactured to AGMA 10 quality standards, with tooth profile and lead tolerances within 0.02 mm. This precision ensures uniform load distribution across teeth, minimizing vibration and noise. The resulting low backlash (≤0.15 mm) improves positioning accuracy in reversing drives and reduces impact loads during start-stop cycles. Each set is tested for runout and tooth contact pattern, and a inspection report is provided.

STEP 4

Complete Set with Keyed Pinion Shaft and Mounting Hardware

The set includes the main gear, pinion, keyed pinion shaft (max diameter 120 mm), and all necessary mounting bolts and keys. The pinion shaft is machined from the same 42CrMo4 steel and hardened to 45-50 HRC. The keyed connection ensures reliable torque transfer without slippage. The set is packaged with an installation guide and a test certificate, allowing for quick and correct assembly. This complete package reduces procurement time and ensures compatibility.