Study on the cutting time of the hypoid gear tooth flank

Hypoid-gear cutting is a highly specified and complicated metal cutting process. The degree of freedom (DOF) of a six-axis computer numerical control (CNC) machine tools is sufficiently high to emulate the complex generating motion of conventional hypoid-gear cutting. This study presents a proposal for a constant material removal rate (CMRR) cutting process for hypoid gears with the aid of CNC flexibility. The relative spatial relationship between the cutter and the workpiece is kept strictly identical to the machine settings of the conventional hypoid generator. A hypoid gear cutting plan is developed to implement the CMRR concept by varying the feed rate and cradle roll velocity (CRV) to retain the cutting torque within a certain range during the cutting process. A CRV function can be numerically obtained to provide a material-removal polynomial (MRP) curve. The validation of the proposed CMRR process is experimentally verified on a six-axis CNC hypoid-gear generator by measuring the electrical current of the cutter spindle motor, which is proportional to the cutting torque. Machining time is reduced to 38%, and the maximum cutting torques is not exceeded. (C) 2014 Elsevier Ltd. All rights reserved.