Answer: When designing and processing parallel-axis helical cylindrical gears, the parameters on the normal surface are generally used as standard values. Because when cutting the number of teeth of a helical gear, the cutting direction of the tool is generally perpendicular to its normal surface, so its normal surface parameters are the same as those of the tool and are taken as standard values.
When designing and processing parallel-axis helical cylindrical gears, the parameters on the normal surface are generally used as standard values. Because when cutting the number of teeth of a helical gear, the cutting direction of the tool is generally perpendicular to its normal surface, so its normal surface parameters are the same as those of the tool and are taken as standard values.