The design of spiral bevel gears is still very complex because tooth geometry and thus kinematics performance depend on the manufacturing process of this type of gear. The cutting process is dominated by two major manufacturers: Gleason and Klingelnberg. The shape of the teeth surfaces are governed by a large number of programmed machine settings, so they cannot be optimized intuitively. Due to the progress made during the last decade by CNC machines and CAM (Computer Aided Manufacturing) softwares, it is now possible to manufacture spiral bevel gears with quite good quality on a 5-axis milling machine.
In a previous study, the authors presented a numerical model for calculating the quasi-static load sharing of spiral bevel gears. Two kinds of geometries were developed: a simplified Gleason type, and a geometry based on classical spherical involutes combined with a logarithmic spiral. After being generated using a CAD (Computer-Aided Design) software, these two geometries were manufactured with a 5-axis milling machine controlled by CAM software. A metrological study showed that manufacturing by a 5-axis milling machine can be an alternative to conventional cutting methods.
The aim of the present paper is to validate the numerical model. To reach this goal, a test bench was designed to measure the loaded transmission error and visualize the contact patterns. The test bench is integrated inside a numerical 3-axis milling machine: the pinion is mounted on the spindle, while the base of the bench is clamped on its plate. Thus assembly errors can be imposed easily and accurately. Measured and simulated transmission errors are then compared for different axis misalignments cases.