The machining accuracy and surface roughness of worm and worm gear have a significant impact on their transmission performance, including the following:
1.*Machining Accuracy**:
Worms typically require high machining accuracy, including tooth profile accuracy (e.g., spiral rise angle, lead error), position accuracy (e.g., axial and radial runout), and dimensional accuracy (e.g., modulus, pressure angle). High precision can ensure a good meshing between the worm and the worm gear, reduce shock, vibration and noise, improve transmission efficiency and prolong service life.
Worm gears also require high-precision machining, especially for parameters such as tooth profile and indexing circle diameter to ensure proper engagement with the worm.
2.*Surface Roughness**:
The roughness of the contact surface of the worm and worm gear is critical to the transmission efficiency and life. Lower surface roughness can reduce the coefficient of friction, reduce wear and improve transmission efficiency. At the same time, the smooth surface reduces noise and improves lubrication conditions.
According to the working conditions and requirements, the surface roughness of the worm tooth surface is generally controlled at Ra08~0.4 m, while the surface roughness of the worm gear tooth surface is slightly larger, but also as low as possible, usually at Ra16~0.Within 8 m.
In order to achieve these precision and roughness requirements, precision gear hobbing machines are usually used for worm machining, while for worm gears, precision gear shaping machines, precision gear grinding machines, or precision casting molding may be used for finishing. Strict quality control and inspection are also required during the production process to ensure that the worm gear pair meets the design requirements.