The non-circular gear pair in the reversing device of the non-circular gear pumping unit (as shown in the figure) can realize forward and reverse movement through its specific pitch curve equation. The existence of the backlash between the two will lead to a large difference between them. In order to improve its transmission accuracy, it is necessary to analyze the transmission error distribution law at different turns.
| Name | Numerical value |
| Modulus m/mm | 3 |
| Center distance a/mm | 150 |
| Top clearance coefficient C* | 0.25 |
| Eccentricity k | 0.2 |
| Number of teeth Z | 47 |
| Addendum height coefficient ha* | 1 |
| Tooth width B/mm | 30 |
| Nodal curve equation r | r=64.667/1+-0.3278cosθ |
According to the formula, the main factors affecting the transmission error and backlash of non-circular gears are eccentricity k, eccentricity error e and initial phase φ， In the subsequent analysis process, the influence of the above parameters on the transmission error and backlash of non-circular gears will be studied respectively. The parameters of non-circular gear are shown in the table.