Second, the analysis and improvement of planetary gear processing technology
At present, the processing process of the differential planetary gear machine is roughly as follows:
1 qualified fine forging blanks→cold trimming→blasting→drilling→car hole→car surface, back cone→heat treatment→grinding hole→grinding surface.
The main process of Process 1 is shown in Figure 2.
Drilling--inside hole--car surface, back cone--grinding hole--grinding surface
2 qualified fine forging blanks → shot blasting → car back cone → cold cut edge drilling, car inner hole, spherical surface → heat treatment → fine car inner hole, spherical surface.
Car back cone--drilling, car inner hole, spherical surface--car hole, spherical surface
Comparing the hot and hot post-processing of the above two types of planetary gears, it is not difficult to see that there are many processes in the process flow 1, and the positioning reference occasionally changes or appears over the positioning between the tooth shape and the inner hole, resulting in the occupation of the machining process. More, more manpower and semi-finished products are installed many times, the quality is not easy to control, and the final positioning phenomenon occurs in the final finishing process, resulting in serious geometric tolerance.
In Process 2, there are fewer processes, and the individual processes are combined with one-shot cutting and forming, and the tooth shape of the net shape is always used as a positioning reference, and in the finishing process after heat treatment, the planetary gears are positioned in a tooth shape, and the back cone is pressed. The inner hole and the spherical surface are finished at one time, so that it is easy to control within 0.03 mm when the spherical surface is beaten based on the inner hole. In this way, under the premise of ensuring the accuracy of the bevel tooth shape of the forging process and the accuracy and alignment of the finished tooth profile locating body after the heat treatment, the inner hole and the spherical surface are machined to the size, and the bevel ring gear is beaten based on the inner hole, which can stably Control is within 0.04mm.
In this way, in combination with the assembly state of the aforementioned planetary gear in the differential assembly, and whether the planetary carrier revolves around the half shaft gear axis, or the planetary gear rotates around its own axis under the external force of the half shaft gear, the transmission can be stable. The noise is small, and the spherical gasket and the abnormal wear of the spherical surface SR in the casing are also eliminated, thereby improving the service life of the gear.
