Microgeometrical tooth profile modification influencing efficiency of planetary hub gears

Fatourehchi, Ehsan; Mohammadpour, Mahdi; King, Paul D.; Rahnejat, Homer; Trimmer, G.; Williams, Alan

doi:10.1504/ijpt.2018.090374

Cited by 8 publications

(6 citation statements)

References 23 publications

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“…The effects of tooth surface roughness on RMIP in different working conditions are shown in Figure 13. It can be obviously found that the RMIP values of both sun–planet and ring–planet gear pairs yield increasing trend with the growth of surface roughness, which has a good agreement with the research results in Fatourehchi et al 20 And, the reason for this phenomenon relies on that the oil film is more easily broken as the roughness increases. The RMIP values has a maximum 3.187‰, 3.170‰, and 2.707‰ increments of the sun–planet gear pair as the roughness increasing from 0.1 to 0.4 at 1000, 1200, and 1400 r/min, respectively.…”

Section: Resultssupporting

confidence: 89%

“…Martins et al 19 investigated the influence of oil formulation on the protection against gear micropitting and also its influence on gear efficiency, and the results showed that the base oil, the additive package, as well as their combination have a significant influence on the efficiency and micropitting performance. Fatourehchi et al 20 studied the effect of tooth crowning and tip relief on system efficiency; the proposed method included an analytical elasto-hydrodynamic analysis of elliptical point contact of crowned spur gear teeth, and the results show that better surface finish with both crowning and tip relief modifications reduces the gear contact power loss. Nutakor et al 13 developed a composite power loss model combining a non-uniform load distribution model with a local friction coefficient at any point of contact and oil drag formulations, and the influence of design parameters of planetary gear sets and bearings and lubricant properties on power loss performance were investigated.…”

Section: Introductionmentioning

confidence: 99%

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Effect of roughness on meshing power loss of planetary gear set considering elasto-hydrodynamic lubrication

Wang

Chen

et al. 2020

Advances in Mechanical Engineering

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Meshing power loss is one of the most important parts in power loss calculation of planetary gear set. However, most of the conventional methods assumed the friction coefficient between gears as a constant value in the meshing power loss calculation, and most importantly, the influence of gear tooth surface geometry is usually ignored, for example, roughness. Therefore, a new meshing power loss calculation model for planetary gear set that considers tooth surface roughness is proposed on the basis of elasto-hydrodynamic lubrication method. With the proposed model, a planetary gear set dynamic model that considers friction force between gears is first established to study the time-varying meshing forces, sliding speeds, and curvature radii of the gear pairs. Then, an elasto-hydrodynamic lubrication model of the gear pair contact interface is constructed to investigate and modify the friction force distribution in the gear meshing process of the dynamic model iteratively until the meshing forces converge to stable values. Furthermore, the relationship between the tooth surface roughness and film thickness is studied in the elasto-hydrodynamic lubrication model. After that, the meshing power loss is calculated based on the obtained meshing forces, friction coefficients, sliding speeds, and so on. The results show that there is a sudden growth of the meshing power loss at the end of the meshing cycle, which has a good agreement with the meshing force impact. And, it is found that tooth surface roughness has a direct influence on the meshing power loss of sun–planet gear pair, which yields an increasing tendency as the surface roughness growing.

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Section: Resultssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Effect of roughness on meshing power loss of planetary gear set considering elasto-hydrodynamic lubrication

Wang

Chen

et al. 2020

Advances in Mechanical Engineering

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“…Finally, combined with an example, the influence on the quasi-static performance of spur gears of different kinds and amounts of flank and face width profile modifications was studied. Fatourehchi et al 24 studied the influence of tooth crowning and tip relief on the efficiency of planetary hub system, including the analytical elastohydrodynamic analysis of elliptical point contact of crowned spur gear teeth and the contact analysis of the relative meshing rough surface. Finally, they observed the influence of gear teeth crowning and tip relief on power loss of planetary hub under different surface finishes.…”

Section: Introductionmentioning

confidence: 99%

Study on nonlinear dynamic characteristics of power six-branch herringbone gear transmission system with 3D modification

Wang

2023

Proceedings of the Institution of Mechanical Engineers, Part K:

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The power six-branch herringbone gear transmission system has the advantages of large power transmission and transmission ratio. Because of its multi-way transmission and over-constraint structure, to prevent loaded tooth interference, there are large backlashes between teeth. The system shows complex nonlinear dynamic characteristics under the influence of backlashes, which seriously affects meshing performance. The modification technology can effectively improve gear meshing performance. Hence, on the basis of optimizing meshing performance of the active pair of the six-branch herringbone gear transmission system, this article will combine 3D modification with system nonlinear vibration characteristics and propose an analysis method of the system nonlinear vibration characteristics under 3D modification to reduce vibration and noise. First, the 3D modified tooth surface equation is determined by forming grinding, the loaded transmission error (LTE) of the system's active pair is obtained by tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA) technology, and the optimal modification parameters are obtained by Ant Lion Optimizer (ALO) with the minimum error amplitude as optimization objective. Then, the time-varying meshing stiffness of system under the optimal modification is calculated, and the pure torsional nonlinear dynamic model with backlashes, meshing stiffness, and static transmission error (STE) is established. Finally, the global vibration characteristics in parameter field are studied through time domain and bifurcation diagram of system. Results show that the 3D modification can eliminate edge contact of tooth and improve tooth contact performance. With the increase of input power, the root mean square (RMS) values of acceleration increase and the RMS values and jump decrease after 3D modification. With the increase of input speed, the RMS curves appear multiple resonance peaks and jumps at low input speed. After 3D modification, the RMS, jump, and resonance peak values decrease. Compared with level І, the backlashes and STEs of level II and phase difference ϛsII have great influence on system dynamic characteristics and easily make system in chaotic motion, while the 3D modification reduces their influence and makes system motion periodic.

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“…The effect of the microgeometrical form modification is widely studied by tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA). 25–27 Some other studies have further analysed the influence of microgeometry on the gear dynamics. 28–30 However, the above researchers ignore the presence of gear manufacturing errors.…”

Section: Introductionmentioning

confidence: 99%

The statistical analysis of the dynamic performance of a gear system considering random manufacturing errors under different levels of machining precision

Guo

Fang

2019

Proceedings of the Institution of Mechanical Engineers, Part K:

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Gear manufacturing error is one of the main sources of vibration and noise in gears; its influence on the dynamic transmission behaviour of gear systems is a research hotspot. In the current study on the effect of the manufacturing errors, the processing methods of the errors are mostly rough or hypothetical, so the analysis results cannot provide high reference value. This paper proposes a distinctive method to analyse the vibration response of helical gears in the presence of random manufacturing errors and modifications. The presented study performs tooth contact analysis (TCA) with the real tooth surface containing the random tooth profile error and the modification and performs loaded tooth contact analysis (LTCA) based on the superposition of the random pitch error and the initial gap between mating teeth obtained by TCA. Furthermore, the dynamic excitations, including time-varying mesh stiffness and meshing impact, are computed using the above-mentioned TCA and LTCA. The processing method for the manufacturing errors in this paper is reasonable and close to the actual situation of gear engagement. Using this proposed method, statistical analysis was carried out under machining accuracy grades 5, 6 and 7 to show the effect of the different distributions of random manufacturing errors on the gear vibration. The analysis results are of practical significance and provide references for the design and vibration control of gear drive systems.

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Microgeometrical tooth profile modification influencing efficiency of planetary hub gears

Cited by 8 publications

References 23 publications

Effect of roughness on meshing power loss of planetary gear set considering elasto-hydrodynamic lubrication

Effect of roughness on meshing power loss of planetary gear set considering elasto-hydrodynamic lubrication

Study on nonlinear dynamic characteristics of power six-branch herringbone gear transmission system with 3D modification

The statistical analysis of the dynamic performance of a gear system considering random manufacturing errors under different levels of machining precision

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