Cutting Performance of Randomly Distributed Active Abrasive Grains in Gear Honing Process

In power gear honing, the random distribution of abrasive grains on the tooth surface of the honing wheel is the main factor that influences the machining performance of high-quality hardened gears. In order to investigate the micro-edge cutting performance of the active abrasive grains on the workpiece gear, the real honing process is simplified into a micro-edge cutting model with random distribution of active abrasive grains in the cells of the meshing area by obtaining the random distribution states such as the position, orientation and quantity of the honing wheel teeth. The results show that although the active abrasive grains are distributed at different locations, they all experience three types of material removal—slip rubbing, plowing and cutting—allowing the gear honing process to have the combined machining characteristics of grinding, lapping and polishing. The active abrasive grains in first contact produce high honing force, high material removal efficiency and poor surface roughness on the machined workpiece, while the latter ones have the opposite effects. The dislocation angle affects the chip shape and chip discharging direction, and the highest honing force and material removal efficiency is achieved with a dislocation angle of 135°. The higher the number of active abrasive grains in a given contact area, the higher the material removal efficiency.

Research on the Mechanisms of Internal Gear Honing by use of Cone-shape Honing Wheel with Tool Tilt Angle

Ring gear is an important transmission component, but restricted by its ring-shape structure, the tooth surfaces are pretty hard to be finished after heat treatment. Honing is the most commonly used finishing technique for external gear, but for ring gear, it is inconvenient. In this paper, a new type of cone-shape honing wheel is proposed and the honing mechanism is studied for improving the honing performance of ring gear. First of all, the mathematical model of the honing technology by use of cone-shape honing wheel is built, and the merits of the new honing method are discussed. Then, the contact conditions between the honing wheel and the work gear are analyzed, and it is found that the tool tilt angle of the honing wheel has good influences on the honing mark distribution of the work gear. Finally, the honing simulations for ring gear by use of cone-shape honing wheel are carried out, by which the feasibility of the new honing technique are verified.

A 3D Free Vibration Analysis of the Horn-Gear System through Chebyshev–Ritz Method in Ultrasonic Gear Honing

Applying the ultrasonic machining in gear honing can improve honing speed, reduce cutting force, and avoid blocking. There are two problems leading to the decrease of calculation accuracy in the traditional nonresonant theory of the ultrasonic gear honing. One is that one-dimensional longitudinal vibration theory and two-dimensional theory cannot reflect the vibration characteristics of ultrasonic horn and gear comprehensively. And, the other one is that the difference of the analysis dimension between the two theories leads to mismatch of the coupling condition dimension between ultrasonic horn and gear. A free vibration analysis through Chebyshev–Ritz method based on three-dimensional elasticity theory was presented to analyze the eigenfrequencies of the horn-gear system in ultrasonic gear honing. In the method, the model of the horn-gear system was divided into four parts: a solid circular plate, an annular plate, a solid cylinder, and a cone with hole. The eigenvalue equations were derived by using displacement coupling condition between each part under completely free boundary condition. It was found that the eigenfrequencies were highly convergent through convergence study. The hammering method for a modal experiment was used to test the horn-gear systems’ eigenfrequencies. And, the finite element method was also applied to solve the eigenfrequencies. Through a comparative analysis of the frequencies obtained by these three methods, it showed that the results achieved by the Chebyshev–Ritz method were close to those obtained from the experiment and finite element method. Thus, it was feasible to use the Chebyshev–Ritz method to solve the eigenfrequencies of the horn-gear system in ultrasonic gear honing.

Investigation of the influence of the process of gear honing by diamond worm honing tools on the roughness factor of gear wheels

In the presented article, a new method of finishing is considered in more detail - gear honing of cylindrical gears. Analysis of literature sources shows that the most problematic technological operation is the finishing of gear wheels and gear honing in particular. The difference between the traditional honing of cylindrical gears with disc abrasive honing and the new method of processing with diamond worm honing is shown. The main advantage of this method is that it can be implemented on milling machines. New tools are proposed - diamond worm gears and the technology of their manufacture is described. The modes of processing cylindrical gears with various diamond worm gears are given and the processing method itself is described. The gear wheels that were processed are used in hydraulic pumps and in hydraulic motors. Roughness parameters Rmax (total height of profile), Rz (irregularity height at 10 points), Rq (root mean square deviation of the assessed profile), which correspond to the Ukrainian and European DSTU ISO 4287 standard, were used as a criterion for assessing the quality of gear processing: 2012. As you know, the strength, wear resistance, durability and other parameters depend on the roughness of the working surfaces of the teeth of the gear wheels. Roughness affects the wear of contact surfaces and noise during operation when running in gears, as well as at the time of their starting. The surfaces were compared before and after treatment. Distribution curves were plotted to visualize the experimental data. When using the new processing method, the correction of defects of the previous processing methods is shown. Based on the results of the studies carried out, it can be concluded that the roughness parameters Rmax, Rz, Rq improve on average by 1.5-2 times. This method can be recommended for the finishing of cylindrical gears, as effective and not requiring new equipment, replacing the traditional methods of honing gears, which can be implemented without significant costs at most Ukrainian enterprises.

TECHNOLOGICAL CAPACITY UPDATING OF CONTINUOUS RUN-IN GEAR GRINDING METHOD

The work purpose consists in the technological capacity updating of the method for cog-wheel continuous run-in gear grinding based on the purpose of efficient modes and characteristics of the worm disk. The investigation methods are based on mathematical modeling and planning experiments. Machining aircraft cylindrical cog-wheels and special samples was carried out on modern NC machines, benches and plants with the use of up-to-date test equipment: coordinate inspection machine KIM R-100 “Klingelnberg”, profile meter MarSurf M300S “Mahr”, optical microscope Axiovert 400MAT “Zeiss”, electronic scanning microscope Tescan Mira3 “Tescan”, micro-hardness gage Micro Met 5104 “Buehler”, X-ray diffractometer Xstress Robot “Stresstech OY”, Barkhausen digital nose analyzer Rollscan 350 “StresstechOY”, plant APOON on the well-known and developed techniques. The research results and novelty. Special strategy and cutting modes at the required characteristics of the combined polish-grinding worm allow ensuring gear profile roughness Ra=0.089 mkm keeping high accuracy of a ring gear (gear profile error Fa=1.6mkm) without gear honing thereby increasing productivity. The quality researches of gear surface layer give grounds for the application of the method for aircraft cog wheels.

Prozess-Maschine-Interaktion des Verzahnungshonens/Process-machine-interaction for gear honing

Für die Endbearbeitung von Zahnrädern wird unter anderem das Verzahnungshonen eingesetzt. Die theoretisch erreichbare Maschinenleistung kann aufgrund auftretender Schwingungen eingeschränkt sein. In einem aktuellen Forschungsprojekt zur Abbildung der Prozess-Maschine-Interaktion beim Verzahnungshonen werden die Eigenschaften der Maschine und die Prozesskräfte berücksichtigt. In diesem Beitrag wird ein gekoppeltes Prozess-Maschine-Modell für das Verzahnungshonen vorgestellt.   One of the processes used for finishing gears is gear honing. The theoretically achievable machine performance can be limited due to occurring vibrations. A current research project for modelling the process-machine interaction in gear honing considers the characteristics of the machine and the process forces. This article presents a coupled process-machine model for gear honing.

Capacity of globoidal gear-honing

A capacity is characterized by a value of material removal per time unit. A globoidal gear-honing capacity was defined by general normal changing before and after processing. In the course of an experimental part fulfillment the removals were defined depending on the properties of material worked, the abrasive layer characteristics of a globoidal hone and working modes. The experimental results are presented in a graphical form.