Product introduction

Precision shaft is a key component used in mechanical structures to support rotating parts and transmit motion and power. Its design needs to take into account material properties, structural rationality, and machining accuracy, and has the characteristics of high precision and high reliability. It is widely used in various fields such as aerospace, automobiles, ships, energy and power.

Material selection and heat treatment

The selection of materials for precision shafts must meet the mechanical performance requirements, and commonly used materials include:
Carbon steel: such as 45 steel, with a hardness of HRC28-32 after heat treatment, suitable for general transmission scenarios.
Alloy steel, such as 40Cr, can achieve higher strength and toughness through quenching and tempering treatment, making it suitable for heavy-duty or high-speed transmission.
Special materials: such as stainless steel (used in corrosion-resistant environments), bearing steel GCr15 (used for high-precision bearing shafts), etc.
Heat treatment process is a key step in improving the performance of precision shafts, such as:
Quenching and tempering treatment: By quenching and high-temperature tempering, the shaft obtains good comprehensive mechanical properties.
Surface quenching: such as high-frequency induction quenching, can significantly improve the hardness and wear resistance of the journal surface, while maintaining the toughness of the core.
Carburizing treatment: Suitable for low carbon steel shafts, the surface obtains high hardness (HRC58-62) through carburizing and quenching, and the core maintains good toughness.

Processing accuracy and surface quality

The machining of precision shafts requires strict control of the following indicators:
Dimensional accuracy: The dimensional accuracy of the supporting shaft neck usually requires IT5-IT7 levels to ensure precise fit with the bearing.
The dimensional accuracy of the transmission shaft neck can be appropriately relaxed to IT6-IT9 levels.
Geometric accuracy: The roundness and cylindricity errors of the journal should generally be limited within the dimensional tolerance range, and the roundness error of high-precision shafts (such as the main shaft) should be controlled within 1 μ m.
The straightness error of the axis must meet the design requirements to avoid vibration or noise caused by bending.
Surface roughness: The surface roughness of the journal that matches with the bearing is usually required to be Ra0.16-0.63 μ m, and high-precision shafts can reach Ra0.04 μ m.
The roughness of the mating surface of the transmission components can be appropriately relaxed to Ra2.5-6.3 μ m.