Two gear-grinding techniques to improve pitch deviations of ultra-precision gears

Abstract

The ultra-precision master gear with high pitch accuracy has important applications in the calibration of high-precision gear measuring instruments or coordinate measuring machines and in military industries. In order to improve pitch deviations of ultra-precision gear, two gear-grinding techniques to improve pitch deviations of ultra-precision gear were proposed. First, based on the indexing plate system, the working principle of indexing plate and error transferring rules were discussed, and the technical approaches of decreasing the geometric eccentricity were proposed. Then according to the error interference principle, the offset-compensated technique and the neighbour-tooth translocation technique were proposed to improve the pitch machining accuracy of ultra-precision master gear. Finally, precision gear-grinding experiments were conducted by adopting the neighbour-tooth translocation technique based on offset-compensated technique. And the single pitch deviation fp of the test specimen is reduced from 1.06 to 0.63μm and the total cumulative pitch deviation Fp is reduced from 3.11 to 1.98μm with measurement uncertainty U95 = 0.33μm, which both reach the highest class (class 1 defining in ISO 1328-1:2013). The results show the efficiency and practicability of the two gear-grinding techniques to machine ultra-precision master gear.

Formation mechanism study on tooth surface of two gear finishing processes: combined theoretical and experimental approaches

“…, and such transformation matrix of gear honing and gear grinding can be differentiated by the tags M O1 (H) and M O1 (G), which can be expressed by Eqs. (6) and (7).…”

“…Generally, a measuring equipment requires higher precision than a manufacturing equipment. Ling [6] put forward two ultra-precision master gear grinding methods which decreased the gear total cumulative pitch deviation from 3.11 to 1.98 (lm) with measurement uncertainty U 95 = 0.33. Wang [7] used a compensation coefficient to correct the motion error of each axis, and built a closed loop error compensation model which improved the precision of gear form grinding process.…”

Manufacturing helical gears with double-crowning and twist-free tooth flanks using a variable pressure angle shaving cutter

“…To localize the gear tooth contact pattern and to allow perfect transmission errors, a novel double-crowned tooth geometry is used ease-off topography for a spiroid gear that was manufactured using a precision casting process. 18 Ling et al 19 proposed two gear-grinding techniques to improve pitch deviations in ultra-precision gears: the offset-compensated technique and the neighbour-tooth translocation technique. Recently, Tran et al 20,21 proposed a methodology for finish-hobbing of twist-free tooth flank of helical gears for longitudinal tooth crowning by setting the hob’s diagonal feed motion as a second-order function of the hob’s traverse movement and using a dual-lead hob cutter wherein the pressure angle changes in its longitudinal direction.…”