An approach to design a pair of similar square gears and manufacture by laser cutting process

Non-circular gears for their ability to create cyclic changes in the velocity and torque of the gears in each revolution employed for various purposes such as robotics, textile, and packaging industries. In this paper, the design methodology of a similar pair of plastic square gears is investigated. The design of gear profiles was performed according to complex mathematical calculations and the three-dimensional model of the gears was designed. Then the assembly of the gears was performed in CAD software and their motion was simulated. The laser cutting process was utilized to manufacture square gears. Examination of the results and the absence of special errors such as the gear's inappropriate meshing during rotation, improper backlash, or the impossibility of assembly due to incorrect dimensions design, indicate the accuracy of the design methodology. Moreover, the use of thin plastic sheets as raw material in the laser cutting process has prevented the laser beam from diverging and technical faults of gear samples. Comparing the angular speed of the driver gear with the lobe number also shows the accuracy of the square gear simulation process.