(1) Influence of Helical Angle on Transmission Error of Helical Gear
Figure 1 shows the relationship curve between the helix angle and the transmission error of helical gears. When the helix angle changes in the range of 30 °~33 °, the transmission error first decreases and then increases with the increase of the helix angle. When the helix angle is equal to 31 °, the transmission error of the helical gear pair is the smallest, 0.109 μ m。
(2) Influence of Helical Angle on Hertz Contact Stress of Helical Gear
Figure 2 shows the relationship curve between helical angle and Hertz contact stress of helical gear. In the range of 30 °~31.5 °, the overall trend is that Hertz contact stress continues to decrease, that is, the strength of helical gear increases. However, in the range of 31.5 °~33 °, the Hertz contact stress increases first, then remains unchanged and finally decreases. When the helical angle of the helical gear pair is 31.5 ° and 33 ° respectively, the Hertz contact stress is the lowest, which is 550.645N/mm2.
(3) Influence of Helical Angle on Helical Gear Transmission Efficiency
Figure 3 shows the relationship curve between helical angle and helical gear transmission efficiency. When the helix angle is 30 °~31.5 °, the transmission efficiency of the helical gear pair remains unchanged; When the helix angle is 31.5 °~33 °, the transmission efficiency decreases with the increase of helix angle.
Therefore, except that the transmission efficiency of the helical gear will continue to decrease when the helix angle exceeds a certain range, that is, greater than 31.5 °, the magnitude of the helix angle has no obvious rule for the transmission error and Hertz contact stress of the helical gear pair. It is recommended to select the appropriate helix angle after comprehensively weighing the advantages and disadvantages of helical gear vibration noise and service life according to the specific working conditions in engineering practice.