Dynamic force transmissibility in helical gear pairs

1995 ◽  
Vol 30 (3) ◽  
pp. 323-339 ◽  
Author(s):  
G. Wesley Blankenship ◽  
Rajendra Singh
1994 ◽  
Vol 22 (1) ◽  
pp. 60-74 ◽  
Author(s):  
J. T. Tielking

Abstract A laboratory study of force transmission in radial truck tires is described. The experiments are conducted with the tire-wheel assembly attached to a fixed, nonrotating axle. Contact with the tire is provided by a flat surface. Single frequency displacement cycles are applied to the loaded tire footprint, and the dynamic force transmitted through the tire is measured at the fixed axle. Fourier transform signal analysis is used to extract the cyclic displacement and force amplitudes. The amplitude ratio force/displacement is defined as the force transmissibility. The experiments show inflation pressure and tire load to have little effect on force transmissibility. A single degree of freedom tire model for force transmissibility is described. The model uses easily measured tire parameters and is intended for use in vehicle models to include the effect of tire dynamics.


2021 ◽  
Vol 103 (3) ◽  
pp. 2273-2286
Author(s):  
Duzhou Zhang ◽  
Dengyun Wu ◽  
Qinkai Han ◽  
Hong Wang

Author(s):  
Wei Xu ◽  
Lin He ◽  
Zhi-Qiang Lv

To reduce the vibration and noise level in ships, marine propulsion engines are conventionally supported by rubber mounts. But the design of a rubber mounting system for medium- and low-speed propulsion engines could be very complicated due to the large stiffness and rubber creep of rubber mounts. Air spring, which is superior in many respects to rubber mount, can be used as the propulsion engine mounting system. The superiority and potential of pneumatic mounting system is discussed in this paper. The pneumatic system’s loading and stiffness characteristics, which are distinct from rubber system, are analyzed. And an optimized air pressure distribution among air springs is given. The system natural frequencies and force transmissibility are calculated based on a fictitious propulsion engine model. The results show that the pneumatic mounting system can effectively attenuate the dynamic force transmitted to the ship floor, and the system characteristics are not apparently affected by the air pressure distribution.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1365-1372
Author(s):  
Xiaohui Mao ◽  
Liping Fei ◽  
Xianping Shang ◽  
Jie Chen ◽  
Zhihao Zhao

The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.


1957 ◽  
Vol 13 (5) ◽  
pp. 71-72
Author(s):  
M.H. Earp
Keyword(s):  

Author(s):  
В. М. Мойсишин ◽  
M. V. Lyskanych ◽  
R. A. Zhovniruk ◽  
Ye. P. Majkovych

The purpose of the proposed article is to establish the causes of oscillations of drilling tool and the basic laws of the distribution of the total energy of the process of changing the axial dynamic force over frequencies of spectrum. Variable factors during experiments on the classical plan were the rigidity of drilling tool and the hardness of the rock. According to the results of research, the main power of the process of change of axial dynamic force during drilling of three roller cone bits is in the frequency range 0-32 Hz in which three harmonic frequency components are allocated which correspond to the theoretical values of low-frequency and gear oscillations of the chisel and proper oscillations of the bit. The experimental values of frequencies of harmonic components of energy and normalized spectrum as well as the magnitude of the dispersion of the axial dynamic force and its normalized values at these frequencies are presented. It has been found that with decreasing rigidity of the drilling tool maximum energy of axial dynamic force moves from the low-frequency oscillation region to the tooth oscillation area, intensifying the process of rock destruction and, at the same time, protecting the tool from the harmful effects of the vibrations of the bit. Reducing the rigidity of the drilling tool protects the bit from the harmful effects of the vibrations generated by the stand. The energy reductions in these fluctuations range from 47 to 77%.


2020 ◽  
Vol 68 (1) ◽  
pp. 48-58
Author(s):  
Chao Liu ◽  
Zongde Fang ◽  
Fang Guo ◽  
Long Xiang ◽  
Yabin Guan ◽  
...  

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.


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