Investigation on fixture design and precision stability of new-type double collect chuck for machining of long ladder shaft gear

To solve the problems of poor positioning accuracy and non-automatic processing seen in the machining of long ladder shaft gears, a fixture structure scheme with a new type of double collect chuck (DCC) is proposed. The design rationality, clamping stability, and repeat clamping positioning accuracy of the proposed DCC were analyzed and investigated based on theory calculation, simulation analysis, and engineering application tests. First, the clamping performance of DCC was investigated through theory calculation and simulation analysis. The test results showed that the structure of DCC maintained effective clamping and the repeat clamping positioning accuracy was steadily controlled within 0.008 mm. Meanwhile, efficiently automated machining of long ladder shaft gear was realized based on extended design and engineering application of automatic up and down mechanism when the structure of DCC was applied. Furthermore, the machining accuracy of the gear was steadily controlled within DIN8 (DIN5480-2 standard). Additionally, based on extended design and engineering tests, the automatic up and down machining improves production efficiency and machining accuracy. Thus, the novel fixture structure scheme provides a new approach for automatic up and down machining of long ladder shaft gear.