An internal gear is a cylindrical gear with its teeth located on the inner surface of its rim. It meshes with an external gear, rotating in the same direction, which enables compact designs. Internal gears are widely used in planetary gear systems, industrial clutches, automotive transmissions, and aerospace drives, offering high reduction ratios, high torque capacity, and precise power transmission.
Low carbon steel, mid-carbon steel, mid-carbon alloy steel, case hardened alloy steel including 20CrMnTi, 20CrMnMo, 20CrNiMo, 18CrNiMo7-6, 17CrNiMo6, 20Cr2Ni4A, 20CrNi2MoA, 18Cr2Ni4WA, 20Cr, 35CrMo, 40Cr, 42CrMo, 40CrNiMo, 40CrNi2MoA, 38CrMoAI, 9310, etc.
Products designed for aerospace applications. The primary manufacturing challenge lies in grinding the internal teeth within a blind hole. This requires a very small relief distance, placing extremely high demands on the internal grinding arm and grinding wheel size. For internal teeth ground with dressable grinding wheels, the minimum wheel diameter is 30mm, and the maximum grinding depth is 150mm. When using CBN grinding wheels, the minimum grinding module is 0.5, and the minimum wheel diameter is 13mm. These capabilities allow us to resolve small module internal tooth grinding issues across virtually all fields.
These are high-precision planetary internal ring gears. The main processing challenge for these products is controlling deformation and maintaining precision. Kean employs various special processing methods, such as gravity-free grinding processes and tempering processes, to eliminate internal stress in parts before deformation occurs. As a result, for thin-walled internal ring gears that undergo carburizing and quenching, we have established highly stable and reliable processing methods to ensure product accuracy and all required parameters.
Internal gears are ideal for applications where space is limited and a compact design is required. They are commonly used in planetary gear systems, such as the automatic transmissions found in vehicles, where multiple gears are arranged around a central sun gear. Internal gears are also utilized in lifting mechanisms, aircraft engines, and marine propulsion systems.
Compared to external gears of a similar size, internal gears offer a larger contact area between meshing teeth. This increased contact allows internal gears to transmit higher torque and withstand greater loads. Internal gears typically have a load-bearing capacity that is 20-50% higher than that of equivalent external gears.
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Our gear transmission parts are used in a wide range of mechanical assemblies
Leveraging 23 years of high-precision gear manufacturing experience, Kean specializes in high-volume custom gear solutions. Backed by globally leading equipment, over 30 patented technologies, and a scalable production capacity exceeding 35,000 non-standard parts annually, we provide clients with high-precision, cost-effective custom gears that meet the most stringent transmission requirements.
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