How to Improve the Service Life of Large Helical Gears?

I. In Terms of Design

Reasonable Parameter Selection

Determine appropriate parameters such as module, number of teeth, and helix angle. The larger the module, the higher the strength of the gear, but it will also increase the weight and cost. The selection of the number of teeth should consider the transmission ratio and contact ratio. The greater the contact ratio, the more stable the transmission, and the service life of the gear will also be correspondingly improved. The size of the helix angle will affect the axial force and transmission efficiency of the gear, and it needs to be optimized according to the actual working conditions.

Optimize the tooth width coefficient. If the tooth width coefficient is too large, it is easy to cause uneven load distribution and lead to eccentric load; if the tooth width coefficient is too small, it will reduce the bearing capacity of the gear. Therefore, according to the force condition of the gear and the installation space, an appropriate tooth width coefficient should be selected.

Precise Geometric Shape Design

Adopt technologies such as tooth profile modification and crowning. Tooth profile modification can reduce the impact when the gear meshes in and out, reducing noise and vibration; crowning can improve the contact condition of the tooth surface and make the load distribution more uniform, improving the bearing capacity and service life of the gear.

Ensure the accuracy of the tooth profile and tooth trace. High-precision tooth profile and tooth trace can reduce meshing errors and reduce the risk of tooth surface wear and fatigue damage.

II. In Terms of Material Selection

Select the Appropriate Gear Material

For large helical gears that bear heavy loads, high speeds, and harsh working conditions, high-strength alloy steels such as 20CrMnTi and 42CrMo can be selected. After appropriate heat treatment (such as carburizing and quenching, quenching and tempering, etc.), these materials have high strength, hardness, and toughness and can meet the use requirements of gears.

In some special occasions, such as environments requiring corrosion resistance, high temperature resistance, or non-magnetic properties, stainless steels, high-temperature alloys, or non-ferromagnetic materials can be selected.

Ensure Material Quality

Strictly control the chemical composition, metallographic structure, and mechanical properties of the material. Defects such as impurities, pores, and inclusions in the raw material will reduce the strength and toughness of the material and increase the risk of gear failure. Therefore, when purchasing materials, reliable suppliers should be selected and strict material inspections should be carried out.

III. In Terms of Manufacturing Process

Precision Machining

Use high-precision gear processing equipment and processes to ensure the dimensional accuracy and surface quality of the gear. For example, use CNC hobbing machines, gear grinding machines and other equipment for processing, and control the tooth profile error, pitch error, and tooth trace error of the gear within a small range.

Improve the tooth surface roughness. A rough tooth surface will increase the friction coefficient and accelerate tooth surface wear. By using finishing processes such as grinding and honing, the tooth surface roughness can be controlled at a low level to improve the anti-wear ability of the gear.

Appropriate Heat Treatment

Perform appropriate heat treatment on the gear, such as carburizing and quenching, quenching and tempering, normalizing, etc., which can improve the material's 组织结构 and improve the hardness, strength, and toughness of the gear. Carburizing and quenching can make the gear surface obtain high hardness and wear resistance, while the core maintains good toughness; quenching and tempering treatment can improve the comprehensive mechanical properties of the gear.

Strictly control the heat treatment process parameters, such as heating temperature, holding time, cooling speed, etc., to ensure the stability and consistency of the heat treatment quality. Defects such as overheating, overburning, and decarburization during the heat treatment process will seriously affect the performance and life of the gear.

IV. In Terms of Lubrication and Maintenance

Reasonable Lubrication

Select the appropriate lubricant. According to the working speed, load, temperature and other conditions of the gear, select the appropriate lubricating oil or grease. Lubricating oil has good cooling and cleaning effects and is suitable for high-speed and heavy-load gear transmissions; lubricating grease has good sealing and adhesion properties and is suitable for low-speed and intermittent gear transmissions.

Ensure the reliability of the lubrication system. Regularly check the working status of the lubrication system, such as whether the oil pump, filter, oil pipe, etc. are normal, and ensure that the lubricant can reach the gear mesh