Research On Cylindrical Gear Transmission Accuracy Measurement Theory And Application Technology

As the basic part of mechanical transmission in industrial products,the gear has always been deeply appreciated in industry because of its important function,complicated shape and technical matters.The processing quality and machining efficiency of the gear reflect the overall level of a country's mechanical industry to a larger extent.With the continuous improvement of the electric drive technology,the reduced production of gear may occur in future;nevertheless,requirements of the processing quality and transmission accuracy will be greatly improved.Taking the most important user of gear transmission,the automobile industry as an example,the majority of gears in automobile gearboxes is required to grind gear after quenching.However,the measurement method of the gear precision index falls behind the requirement in gear manufacturing technology.Whether the current international ISO standard?1328-2₁997 ISO?or the national standard?GB/T10095.1?2-2008?,the measurement precision of transmission accuracy cannot be so high.For example,the measurement accuracy of total tangential composite deviation?Fi'?and total radial composite deviation?Fi"?depend on the measurement accuracy of gear.And total cumulative pitch error?Fp?and radial runout?Fr?are fuzzy position measurement by definition in the middle of depth of tooth.From the existing theoretical method that evaluates the gear precision on the basis of gear measuring instrument,this article attempts to carry out a new research on the measuring method of gear precision.It explores the analytical evaluation method by measuring the gear's geometrical shape that correspondingly guarantees transmission accuracy requirement.The method can fundamentally improve the measuring accuracy of gear,and then enhance the manufacturing quality of gear.The geometric eccentricity in essence is the resulting eccentricity which occurs between the center of base circle and its center of rotation-that is the radial offset of the tooth profile center,thus the gear rotation angle error is called as the radial error.As for the radial run-out of gear,the existing measuring method is to prop up the gear by two live centers in the radial run-out tester,where the rotation axis of the gear is embodied by the top of live centers.But actually at the completion of assembly,for the journal axis works as the axis of rotation,once geometric eccentricity and motion eccentricity appear in the gear processing,the original measuring method is not convenient to measure the radial run-out at working hours of gear.The article proposes a measurement evaluation method that is based on the least square method.Via the mathematical model that fits datum axis,thereby the variation from the measured points to the fitting axis is calculated.Furthermore,the validity of the proposed analytical evaluation method is demonstrated by the numerical simulation and experimental results.