Multi site integrated parallel measurement technology for super large gears

The diameter of the oversize gear is large, the number of teeth is large, and the inertia is large. If the instrument starts, stops and reverses frequently in the measurement, it is not convenient, the measurement efficiency is low, and it may not meet the measurement accuracy requirements due to the torsional deformation of the shaft system. Therefore, the oversize gear measurement is suitable for completing the measurement of various error items in one-way rotation. Based on this idea, a multi site integrated parallel measurement scheme for super large gears is proposed.

Figure shows the scheme proposed by a German company for the measurement of 10 m gear. The gear is placed on a large rotating platform, two three-dimensional measuring platforms are symmetrically distributed around the turntable, and the measuring platform and the rotating platform are usually separated. The advantages of this scheme are as follows: (1) it is relatively easy to manufacture three-dimensional platform; (2) it has good adaptability to the change of gear size; (3) it can complete the measurement of left and right tooth surfaces at the same time when the gear rotates for one cycle, or it can complete the measurement of one-way tooth surfaces without rotating for one cycle, which improves the measurement efficiency and avoids the defects of the traditional scheme in measuring the super gear. The difficulties are as follows: (1) the performance requirements of the rotating platform are too high, including shafting accuracy, drive, bearing capacity, gear positioning and attitude adjustment, etc.; (2) the accuracy of the angle measuring circular grating is highly required; (3) the accuracy of the relative position of the two three-dimensional measuring platforms and the rotating platform is determined and the accuracy of the position is maintained; (4) the synchronous driving and synchronous measurement technology between the 3 platforms. It can be said that this measurement scheme is still a “large-scale measurement” scheme, and the realization of it will gather the highest level of German precision machinery.

As a case, for the same idea, Wenzel company of Germany developed this kind of double arm measuring machine lafd for liebher, a manufacturer of gear machine tools. The maximum diameter of measurable gear is 6m. The first two CMM arms need to be adjusted and positioned by special calibration tools. The probe adopts the sp80 scanning probe produced by Renishaw company, and the measurement efficiency is significantly improved.

According to ZHY gear, the vision measurement or optical measurement of the gear tooth surface is promising. If the above measurement technology is combined with the vision (Optics) measurement, the measurement efficiency of this scheme will be further improved, and the 3D measurement and global quality characterization of the super gear can be truly realized.