First, improve the shaft gear hobbing technology precis […]
First, improve the shaft gear hobbing technology precision method:
The shaft gear is the most important part in the gearbox, and its machining accuracy directly affects the overall quality of the gearbox. At present, the gear tooth processing method we use is hobbing and shaving. To produce high-precision gears through rolling and shaving processes, the level of rolling and shaving must be optimized. The shaving accuracy is largely dependent on the precision of the hobbing, so some of the error items in the hobbing must be strictly controlled in order to produce high quality gears. Hobbing is a commonly used method of gear machining. On precision hobbing machines, precision hobs can be used to produce gears with 4-5 precision. On an ordinary hobbing machine, using an ordinary precision hob, only 8-level precision gear teeth can be machined. Gearbox shaft gear tooth parts require an accuracy of 8-7-7, and the hobbing process is mainly based on the two center holes and end faces. Therefore, the error source of the gear hobbing is analyzed, and the method of ensuring and improving the machining accuracy is analyzed. Very important.
1 Hobbing precision analysis
The accuracy of shaft teeth is related to the accuracy of movement, accuracy of smoothness and contact accuracy. In the hobbing process, control the length of the normal line and the diameter of the ring gear
To ensure the accuracy of movement, control the tooth shape error and the base section deviation to ensure the accuracy of the work stability, and use the control tooth error to ensure the contact accuracy. The following are some of the error factors that tend to occur in hobbing:
1.1 radial runout error of the ring gear (ie, geometric eccentricity)
The radial runout of the ring gear refers to the maximum variation of the probe with respect to the axis of the gear tooth. It is also the eccentricity of the gear ring gear relative to the centerline of the shaft. This eccentricity is caused by the fact that the two center holes of the part are not coincident with the rotation center of the table or the deviation is too large when the parts are mounted. Or because of the top and top hole manufacturing problems, make the positioning surface contact is not good to cause eccentricity, so the ring gear diameter jump should be analyzed from the above reasons.