Development of a Modular Slotting Head With a Modified Rack-and-Pinion Transmission

The automated design issues of modular spindle heads for multi-operational metalcutting machines are considered.An option for expanding technological capabilities through the use of forming units with vertical and horizontal arrangement in the space of the machine working area is given.A 3D project for the drive of the machine's main movement with a built-in horizontal spindle head and replaceable vertical and slotting spindle heads has been developed.In the process of modelling complex drive housing parts and replaceable heads, Creo Parametric CAD functionality was developed.These functionalities with the procedure for interconnecting the three-dimensional design model and the manufactured casting mold are associated.The implementation of this procedure using the example of creating a structural element -a "Casting draft angle" in the housing part manufacturing of a slotting head is presented.The "Mechanism Design" module of the Creo Parametric CAD system models the rack-and-pinion transmission as the translationally moving link intended for processing grooves, blind-shaped surfaces, and internal cavities is used.Ways to improve the design of the rack-and-pinion gear are outlined.The main innovative idea of the rack tooth profile in the form of an arched shape is presentation.Primary analytical dependencies for a complex geometric-kinematic analysis of a rack-and-pinion transmission with arched teeth were obtained.The relationship between transmission parameters and the maximum size of the gear-cutting head has been established.A condition to guarantee the absence of secondary cutting using a gear-cutting head has been introduced.The value of the coefficient KL = 1.13 as an indicator of a decrease in bending stress and, as a consequence, an increase in the load capacity of arched teeth in comparison with straight rack and pinion teeth, all other things being equal is determined.