Gear assembly errors are an important contributor to premature gearbox failure. As part of the master's thesis, we will discuss the impact of centre distance deviation on the service life of polymer gears. Spur gears with involute gear profile type were investigated. The main focus in studying the effect of centre distance error was the influence on the stress state of the gear. For the ideal centre distance, the stress was determined analytically according to the DIN 3990 standard and the VDI2736 guideline and numerically by employing the finite element method. The stress was also numerically analysed for cases with a centre distance error. It has been found that by increasing the centre distance, due to the reduction in the contact ratio, tooth root stress will increase. The effect of centre distance error was also characterized with mechanical tests. Several tests were performed for the steel/PA6 gear combination, at two load levels and at different centre distances. We measured the time to failure and the temperature of the gears in the steady state. It has been shown that increasing the centre distance does not significantly affect the temperature of the gears, however it can reduce the number of cycles to failure.
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