In the overhaul project of large-scale mechanical press produced, due to the long service time of the press, when checking the transmission mechanism, it is found that the left and right intermediate gears and helical cylindrical gears are seriously worn and can no longer be used, so they must be replaced. However, because the press is an early product of a company, the reference materials and drawing parameters are incomplete, It is necessary to map the middle passing wheel and helical cylindrical gear of the press in order to process new parts.
It is known that the diameter of the steel ball is 28.96 mm. By measuring the distance h of the steel ball along the axial direction of the helical cylindrical gear is 128.68 mm and the cross ball distance m is 1490.95 mm, which can be obtained through calculation θ The radian of the angle is 0.021. It is also known that the end face modulus of the helical cylindrical gear shaft is 16mm and the number of teeth is 32. The helix angle can be calculated by substituting it into the formula β It is 30 ° 2 ′ 38 ″.
Using this method, we successively tested the helical angle of involute cylindrical helical gear of press helical gear, left and right intermediate gear and flywheel transmission gear. During the inspection, it is found that there are certain errors in the smoothness of the tooth surface, the flatness of the platform, the parallelism of the equal height sizing block and the measurement of the span tooth pitch, which will affect the measurement results. Therefore, it is necessary to optimize and adjust the measured surveying and mapping spiral angle according to the actual assembly meshing of the press helical cylindrical gear and the left and right intermediate helical cylindrical gear respectively β After the deviation is corrected manually, the complete tooth parameters are finally obtained.
According to the obtained tooth parameters, the helical cylindrical gear and the left and right intermediate gears of the overhaul press are processed. Finally, after installation, grinding and testing, the meshing contact between the helical cylindrical gear and the left and right intermediate gears in the length direction is greater than 85%, and the meshing contact surface in the height direction of the teeth is greater than 65%, which meets the user’s requirements, restores the performance of the press, and successfully completes the overhaul project of large mechanical press.