Study on simulation for the tooth surface fatigue strength analysis of conical gear

2019 ◽  
Vol 2019 (0) ◽  
pp. S11118
Author(s):  
Sota UENO ◽  
Naoki MIYAZAKI ◽  
Tatsuya OHMACHI
Author(s):  
Tatsuya Ohmachi ◽  
Koji Iizuka ◽  
Hidenori Komatsubara ◽  
Ken-ichi Mitome

Abstract The tooth surface fatigue strength of the conical involute gear is evaluated in this paper. Test gears are straight intersecting-axis conical gears. The material of the test gear is normalized steel. The power circulating testing machine is used in this experiment. The circulating torque is kept constant and the number of times of contact is 107. The tooth surface life is evaluated by the pitting area rate. The critical value of the circulating torque is found between 147 N·m and 157 N·m. For critical torque, the pitting area rate does not progress over 4%. The Hertzian contact stress of the test gear is calculated at the circulating torque. The contact stress should be evaluated in consideration of the wearing effects.


Author(s):  
Gang Deng ◽  
Tsutomu Nakanishi ◽  
Hironori Ikeda

Abstract Surface temperature is resulted by not only the load and dimension at the contact point but also the sliding velocity, rolling velocity, surface roughness, lubrication condition and etc. So, the surface fatigue strength of such as roller and gear may be evaluated more exactly and simply by use of the surface temperature or an index including the surface temperature than the Hertzian stress. In this research, the surface temperatures of rollers in different rolling and sliding conditions were measured with a thermocouple. The effects of the load P, mean velocity Vm and sliding velocity Vs on the surface temperature are clarified. An experimental formula, which expresses a linear relationship between the surface temperature and the P0.86Vs1.31Vm−0.83 value, is presented to calculate the surface temperature. This formula is also confirmed available for the gear tooth surface temperature calculation by comparison of calculated temperature and the measured temperature on the gear tooth surface. The relationship between the surface temperature and the number of load cycles of rollers are investigated, the necessity and rationality of the surface fatigue strength evaluation considering the surface temperature are discussed.


2020 ◽  
Vol 10 (1) ◽  
pp. 394-400 ◽  
Author(s):  
I. M. W. Ekaputra ◽  
Rando Tungga Dewa ◽  
Gunawan Dwi Haryadi ◽  
Seon Jin Kim

AbstractThis paper presents the reliability estimation of fatigue strength of the material used for crank throw components. The material used for crank throw components is forged S34MnV steel and subsequently heat-treated by normalising and tempering. High cycle fatigue testing under fully reversed cycling (R = −1) was performed to determine the fatigue limit of the material. The staircase test method is used to obtain accurate values of the mean fatigue limit stress until a number of cycles up to 1E7 cycles. Subsequently, the fatigue test results depend strongly on the stress step and are evaluated by the Dixon-Mood formula. The values of mean fatigue strength and standard deviation predicted by the staircase method are 282 MPa and 10.6MPa, respectively. Finally, the reliability of the design fatigue strength in some selected probability of failure is calculated. Results indicate that the fatigue strength determined from accelerated staircase test is consistent with conventional fatigue testing. Furthermore, the proposed method can be applied for the determination of fatigue strength and standard deviation for design optimisation of S34MnV steel.


Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 847 ◽  
Author(s):  
Ryoichi Saito ◽  
Nao-Aki Noda ◽  
Yoshikazu Sano ◽  
Jian Song ◽  
Takeru Minami ◽  
...  

This paper deals with the roller chain commonly used for transmission of mechanical power on many kinds of industrial machinery, including conveyors, cars, motorcycles, bicycles, and so forth. It consists of a series of four components called a pin, a bush, a plate, and a roller, which are driven by a sprocket. To clarify the fatigue damage, in this paper, the finite element method (FEM) is applied to those components under three different types of states, that is, the press-fitting state, the static tensile state, and the sprocket-engaging state. By comparing those states, the stress amplitude and the average stress of each component are calculated and plotted on the fatigue limit diagram. The effect of the plastic zone on the fatigue strength is also discussed. The results show that the fatigue crack initiation may start around the middle inner surface of the bush. As am example, the FEM results show that the fatigue crack of the inner plate may start from a certain point at the hole edge. The results agree with the actual fractured position in roller chains used in industry.


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