The transmission error of the first stage reduction driving helical gear in the reducer of a pure electric vehicle is analyzed by using kissfot software.
1.Parameters and working conditions of the first reduction helical gear
| Pinion | Wheel | |
| Number of teeth | 14 | 70 |
| Modulus | 2.25 | 2.25 |
| Pressure angle | 20 | 20 |
| Helix angle | 12 | 12 |
| Tooth width | 35 | 35 |
Helical gear is adopted as the gear. See Table 1 and table 2 for the helical gear parameters and analysis conditions. The total degree of engagement is 3.103. The analysis condition is the rated output speed and torque of the motor:
| Input speed | Input torque |
| 3000rpm | 100 |
2.Transmission error analysis of the first reduction helical gear
The transmission error of the helical gear can be obtained by using the contact analysis module of kisssoft. The analysis is based on the meshing process of the first reduction helical gear pair, and the curve of the displacement of the actual meshing line versus the theoretical meshing line with the rolling angle is obtained. The maximum displacement of the first reduction helical gear pair along the meshing line is 24.7232 μ m. The minimum value is 22.2257 μ m. The difference between the maximum and minimum values is 2.4976 μ m. Here we focus on the stability of transmission, that is, the smaller the change of displacement along the meshing line, the more stable the transmission. The transmission error is the variation of displacement along the meshing line (maximum and minimum difference). The transmission error of the first stage reduction helical gear pair analyzed in this analysis is 2.4976 μ m. According to experience, the transmission error should be controlled within 1 μ m. The transmission error is too large and needs to be optimized. The following will specifically introduce how to reduce the transmission error through helical gear modification.