Case

A Polish industrial machinery manufacturer specializing in high-performance rotary transmission systems approached Hansheng Automation to manufacture a custom worm gear set. The client provided original engineering drawings based on GOST (East European/CIS) standards. They required a manufacturing partner who could interpret these specific standards and reliably execute tight dimensional tolerances and geometric accuracies.

Leveraging our ten-plus years of custom precision gear manufacturing experience and our specialized CNC gear hobbing setup, we successfully delivered the components to meet the client’s design criteria.

The Engineering Challenge & Tolerances

Worm gear transmissions require tight control over center distance, tooth contact patterns, and axial alignments. For this specific project, the critical technical requirements included:

• Standard Transition: The client’s drawings specified a GOST Grade 7 gear meshing accuracy (equivalent to ISO/DIN Grade 7).
• High-Precision Inner Bore: The matching inner bore of the worm gear demanded an IT7 (φ18H7) tolerance.
• Geometric Tolerances: A coaxiality of 0.01 mm and an inner bore roundness of 0.006 mm to ensure smooth, low-noise rotation.
• Surface Roughness: The finished working surfaces required a surface finish of Ra 1.6, while non-working surfaces were kept at Ra 3.2.

Our Manufacturing Solution

The custom worm gear features a bronze/brass alloy ring for low-friction meshing, while the worm shaft is made from high-tensile alloy steel. To cut the worm gear teeth to GOST Grade 7 precision, our utilized the Ningjiang YK3610 CNC Horizontal Gear Hobbing Machine.

The worm shaft has a splined end for torque transmission. The shaft and spline geometry were turned and milled, followed by precision cylindrical grinding between centers to control the critical 0.01 mm coaxiality between the shaft journals and the worm thread.

To meet the strict IT7 (φ18H7) inner bore tolerance and the 0.006 mm roundness specification, we performed precision internal grinding on the worm gear hub. This micro-honing and grinding process eliminated geometric distortions, ensuring a highly reliable fit on the client’s mating shaft.

Upon receiving the first batch, the Polish OEM confirmed that the assembly integrated seamlessly, exhibiting smooth operation, minimal backlash, and excellent noise-control properties.

About Hansheng Automation’s Gear Manufacturing Capabilities

At Hansheng Automation, we bring over a decade of experience to the production of custom precision gears, including spur gears, helical gears, bevel gears, racks, and gear shafts.

Our facility is equipped with a comprehensive range of advanced gear processing machinery, allowing us to select the most efficient and precise method for your specific design:

Need a Reliable Gear Sourcing Partner?

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