Tooth Surface Contact Stress Research Articles

182 調質コニカルギヤの歯面接触応力解析に関する研究(機素潤滑設計I,一般講演)

182 調質コニカルギヤの歯面接触応力解析に関する研究(機素潤滑設計I,一般講演)

The Comparative Study on Less Tooth Differenced Teeth Profile of High Precision FA Pin-Cycloid Gear Transmission

In High precision FA type pin-cycloid gear transmission, carrying capacity has always been sacrificed by using one tooth differenced of "Arch Back Teeth Profile" to achieve high precision transmission. Compared with one tooth differenced transmission, two teeth differenced transmission can have more teeth meshing at the same time, namely can have better carrying capacity than one tooth differenced. In order to simultaneously satisfy high-precision transmission and high bearing capacity, this paper do a comparative study on two kinds of less teeth differenced FA pin-cycloidtransmission.Through theoretical analysis, programming one type model calculated two kinds of teeth differenced cases geometric relative rotated angle, the tooth surface contact force and contact stress. Then do a comparative study and analysisaccording to the calculated results.

The Method of Analyzing the Reliability of Tooth Surface Contact Strength Based on Finite Element Method and Weibull Distribution

In this paper, a method of analyzing the reliability of tooth surface contact strength was presented and several kinds of errors of tooth shape were taken into consideration. In the method, experimental design method and Finite Element Method (FEM) were used to get the samples of tooth surface contact stress, and then Weibull distribution was used to fit these samples. On the basis of both stress and strength obeying to Weibull distribution, the reliability of tooth surface contact strength was calculated. The result of the calculation example indicates that the method is correct and effective.

Centrifugal load and its effects on bending strength and contact strength of a high speed thin-walled spur gear with offset web

Abstract This paper discusses effects of centrifugal load on bending strength and contact strength of a thin-walled spur gear used at high speed. A three-dimensional (3D), finite element method (FEM) is presented in this paper for analyzing centrifugal deformations and centrifugal stresses of the thin-walled gear at high speed and the responsive FEM software are developed through many years’ efforts. It is verified that the developed FEM software can calculate correct centrifugal deformations and centrifugal stresses of the thin-walled gear by a cantilever model. Then centrifugal deformations and centrifugal stresses of a thin-walled spur gear with offset web are analyzed with the FEM software at speed range 5000–40,000 rpm. It is found that effects of centrifugal load on deformations and stresses of the thin-walled gear can be neglected when gear speed is below 10,000 rpm. But it is necessary to consider the effects of centrifugal stresses on strength design of the thin-walled gear when the gear speed exceeds 10,000 rpm. Effects of the centrifugal load-deformed thin-walled spur gear on tooth contact pattern, surface contact stress, root bending stress and tooth load-sharing ratio of the gear are also investigated through performing loaded tooth contact analyses of the gear when it is engaged with a solid mating gear under a torque. It is found that centrifugal deformation of the gear at high speed has greater effects on tooth contact pattern, tooth surface contact stress, root bending stress and tooth load-sharing ratio of the pair of gears. Finally it is pointed out that strength calculation methods of a thin-walled gear are quite different from a solid gear. Methods for exact bending strength and contact strength calculations of a thin-walled gear at high speed are presented in this paper.

Modified pitch cone method in the hypoid gear design and tooth-cutting experiment

In order to improve the strength and endurance of hypoid gear,and extend the lifetime of hypoid gear,the modi- fied pitch cone method is firstly introduced.On the condition of the invariant mean working tooth depth,invariant outer diame- ter of gear and the gear addendum coefficient f_a≤0,the new pitch cone parameters are derived.The new pitch cone is coin- cident to face cone or out of the gear solid.The meshing be- havior,the tooth surface contact stress,the maximum tensile bending stress and the maximum compressive bending stress are researched by using tooth contact analysis (TCA),loaded tooth contact analysis (LTCA) and finite element method (FEM).The computer simulation results show that the tooth surface contact stress,the maximum tensile bending stress and the maximum compressive bending stress of the pinion to hy- poid gear pair designed by new method are markedly reduced. The results of the experiment show that the new type hypoid gear can be processed by the general cutter,and doesn't need other special tools.

The modified pitch cone design of the hypoid gear: Manufacture, stress analysis and experimental tests

Abstract In order to improve the strength and endurance of hypoid gear, and extend the lifetime of hypoid gear, the modified pitch cone method is firstly introduced. On the condition of the invariant mean working tooth depth, invariant outer diameter of gear and the gear addendum coefficient f a ⩽ 0, the new pitch cone parameters are derived. The new pitch cone is coincident to face cone or out of the gear solid. The meshing behavior, tooth surface contact stress, maximum tensile bending stress and maximum compressive bending stress are researched by using tooth contact analysis, loaded tooth contact analysis and finite element method. The computer simulation results show that the tooth surface contact stress, the maximum tensile bending stress and the maximum compressive bending stress of the pinion to hypoid gear pair designed by new method are markedly reduced. From the experiment, the new type hypoid gear pair can be processed by the general cutter, and the other special tool is unnecessary. In this paper, the approach of derivation for the pinion rough-machining machine tool settings designed by the modified pitch cone method is presented, and has been verified in the gear research center of Dong Feng Vehicle-bridge Co., Ltd.

Effects of machining errors, assembly errors and tooth modifications on loading capacity, load-sharing ratio and transmission error of a pair of spur gears

Abstract This paper quantitatively investigates effects of machining errors (ME), assembly errors (AE) and tooth modifications (TM) on loading capacity, load-sharing ratio (LSR) and transmission error (TE) of a pair of spur gears by using special-developed finite element method (FEM) software in a personal computer. Tooth surface contact stress (TSCS) and tooth root bending stress (TRBS) of a pair of spur gears with ME, AE and TM are analyzed by the FEM software. Effects of ME, AE and TM on TSCS and TRBS are also defined as “Influence factors” and the influence factors of ME, AE and TM on TSCS and TRBS are calculated quantitatively. It is found that misalignment error of gear shafts on the plane of action of the spur gears exerts great effects on TSCS and TRBS while misalignment error of gear shafts on the vertical plane of the plane of action almost exerts no effects on TSCS and TRBS. It is also found that ME and lead crowning have greater effects on TSCS and TRBS. When the maximum tooth surface machining error is 40 μm, influence factor of ME on TSCS and TRBS are about 2.2 and 1.5. When quantity of lead crowning is 40 μm, influence factor of lead crowning on TSCS and TRBS are about 2.0 and 1.4. These influence factors can be used as references when ISO standards are used for tooth surface contact strength and root bending strength calculations of a pair of spur gears with ME, AE and TM. Methods for LSR calculation of a pair of spur gears with ME, AE and TM are also presented in this paper. Effects of ME, AE and TM on LSR are analyzed quantitatively. It is found that ME has greater effect on LSR. When the maximum tooth surface machining error is greater than 10 μm, double pair tooth-contact shall become single pair tooth-contact for sake of the effect of ME. This means that when ME on tooth surface is large, outer limit of the single pair tooth-contact area can not be used as the so-called “worst load position”. It is safe and reasonable to use tooth tip as the “worst load position” when to perform tooth bending strength calculation. Methods for TE calculation of a pair of spur gears with ME, AE and TM are also presented in this paper. Effects of ME, AE and TM on TE of the gears are analyzed quantitatively. It is found that ME not only changes waveform of TE easily, but also makes TE greater and greater when ME is increased. AE and TM also make TE greater and greater when they are increased, but do not change waveform of TE.

706 有限要素法によるコニカルギヤ歯面の接触応力解析(GS-13 歯車,CVT)

706 有限要素法によるコニカルギヤ歯面の接触応力解析(GS-13 歯車,CVT)