In order to meet the requirements of the gear processing industry for manufacturing precision, production efficiency, clean production, and quality improvement, the following development trends have emerged in gear machine tools and gear technology. Due to the CNC control of each movement axis of the machine tool and the linkage between some axes, it has the following advantages:
(1) The functions of the machine tool have been increased, such as hobbing small taper and drum gears, etc. have become extremely simple.
(2) The transmission chain is shortened, and at the same time, after semi-closed-loop or full-closed-loop control is adopted, the positioning fine gear machining degree and repeat positioning accuracy of each axis can be improved through numerical control compensation, thereby improving the machining accuracy and Cp value of the machine tool, and increasing the machine tool. reliability.
(3) When changing the type, the time for calculating and changing the split gear and differential gear, feed and spindle shifting is saved, and the gear shaping machine also saves the time for changing the inclined guide rail, thereby reducing auxiliary processing time, increasing the flexibility of the machine tool.
(4) Since the mechanical structure becomes simpler, it can be designed to be more conducive to improving the rigidity of the machine tool and minimizing thermal deformation.
(5) There is no mechanical connection between the axes, and the structural design becomes typical, which is more conducive to the implementation of modular design and manufacturing.
Requirements for grinding parts in gear grinding
1. Only the involute tooth shape is allowed to be ground in the grinding gear
In the grinding of modern hard-toothed heavy-duty gears, only the involute tooth profile above the involute start circle and below the involute end circle is allowed to be ground.
2. It is not allowed to grind the circular alveolar part of the tooth root in the grinding process
For the teeth of the inner ring gear, no matter whether it is intermediate frequency quenching or carburizing quenching, whether it is internal gear or external gear processing teeth, the remarkable feature that the grinding of the tooth root round tooth groove is not allowed in the grinding gear has become a contemporary hardening tool. The most important symbol and bright spot in tooth grinding of heavy-duty gears.
3. When grinding teeth, it is not allowed to produce bosses, steps and sharp points at the root of the tooth
A step is ground at the root of the tooth. Due to the concentration of stress at the step and the high temperature generated by the grinding wheel when grinding the teeth, the hardness and strength of the step are reduced. Therefore, when the gear with steps is under load, fatigue cracks will occur at the step. And gradually expanded, eventually leading to tooth root fracture and failure.