Gear micropitting initiation of ground and superfinished gears: Wrought versus pressed and sintered steel

Bergstedt, Edwin; Lin, Jiachun; Andersson, Michael; Olofsson, Ulf

doi:10.1016/j.triboint.2021.107062

Cited by 19 publications

(13 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Discussionmentioning

confidence: 99%

“…Once the tip comes into contact with the flank of the mating gear, the meshing becomes uncontrolled. Micropitting onset and its relation to the tip coming into mesh is treated by Bergstedt et al 24 Therefore, the threshold torque serves as a break point between normal contact and tip contact. Torque above the threshold should be avoided completely.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Reducing scrapping of gears by assessment of tip contact threshold torque

Hjelm

Ahadi

Wahlström

2021

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

While striving for more competitive products as well as reaching the Global Sustainable Development Goals, automotive powertrain manufacturers increase the demands on gears, which translates to decreased manufacturing error tolerances. Too tight tolerances may, however, counteract the goal if it leads to increased material and energy consumption due to unjustified scrapping. This paper presents a method to prevent unjustified scrapping by comparing the severity of different manufacturing error tolerances by means of the tip contact threshold torque. Curve fits are shown to be accurate and helpful to assess the outcome of a produced batch of gears. A case study is made where the method is used with measured data from the industry. It can be concluded from the investigation that considerable amounts of scrapping can be avoided by consideration of the threshold torque.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Reducing scrapping of gears by assessment of tip contact threshold torque

Hjelm

Ahadi

Wahlström

2021

Proceedings of the Institution of Mechanical Engineers, Part J:

View full text Add to dashboard Cite

show abstract

“…Studies have focused on producing gears with low roughness to raise gear life [3]. In order to delay the nucleation of cracks, causing micropitting, or gray staining, recent studies have been able to advance the reduction of roughness using superfinishing process [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

“…Liu et al [9,10] seek to find manufacturing process conditions that reduce the occurrence of micropitting. The residual stress gradient produced during the superfinishing process can be a solution to explore the competitive process between micropitting and pitting [5]. Care with the surface finish of gear affects the durability of this component and its efficiency [11].…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical study of contact fatigue for 18CrNiMo7-6 and 20MnCr5 carburized gear tooth

Calabokis¹,

Rosa²,

Moraes³

et al. 2022

Surf. Topogr.: Metrol. Prop.

View full text Add to dashboard Cite

Gear manufacturers must make decisions about the manufacturing materials and superficial treatments. The best performance as to a type of failure should be evaluated. However, it is a time-demanding and costly process. The present work proposes a methodology for a comprehensive assessment (experimental and computational) of contact fatigue of gears in FZG test rig. The materials investigated were 18CrNiMo7-6 and 20MnCr5 alloy steels, widely used in industrial and automotive transmission systems, but with very different raw material costs, which can exceed twice the first compared to the second. The study evaluated the contact analysis between gears from the macroscopic point of view and the microscopic (inclusion of roughness). At the same time, the evolution of roughness and pit-damaged area after each test stage was monitored. The approach determined the stress field after each loading cycle and thus correlating the regions of higher stresses with surface and subsurface fatigue (micropitting and pitting). In addition, Weibull's statistical analysis and SEM-EDS observations were executed. In many cases, the methodology correlated the increased roughness and pitting affected area with the regions submitted to the higher contact stress. Observations by SEM-EDS revealed that the occurrence of plastic deformation as a mechanism of wear should be considered in the equations of microscopic stress analysis. The similar fatigue life of such different materials may be correlated to the competitive mechanisms of higher mechanical strength of 18CrNiMo7-6 and better crack propagation characteristics of 20MnCr5. The methodology proved to be consistent for fatigue failure analysis of gears in FZG test rig.

show abstract

“…Various tests and applications have verified the potential and superiority of mass finishing in improving the performance of gear parts, such as increased gear mesh efficiency [4] and load-carrying capacity and pitting/micropitting life [5], improved noise and vibration behavior, and contact fatigue [6].…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of a novel bidirectional composite vibratory finishing

Yang¹,

Wang³

et al. 2022

Preprint

View full text Add to dashboard Cite

Given the poor accessibility of the current finishing process for parts with complicated geometries, a novel bidirectional composite vibratory finishing (BCVF) approach is presented, which combines the power actions on abrasive particles and processed workpieces. The discrete element method (DEM) was used to obtain a fundamental understanding of the BCVF process. By comparing different processes, it has been demonstrated that the BCVF promotes the mobility of abrasive particles to improve the finishing results and efficiency further. The characteristics of normal and tangential contact on the surface of the workpiece involved in the BCVF process were analyzed. Meanwhile, the effects of container size (or wall effects), media amount, workpiece position, and vibration parameters (including vibration amplitude and frequency) on the media-component interactions were systematically studied. The results show that the distance between the workpiece and the container wall in the y-direction can be reduced to 4d (d is the abrasive particle diameter) without affecting the finishing effect. In addition, with the enhancing vibration in the x-direction, particle impact and shear effects are subsequently strengthened. In contrast, the media amount above the workpiece and the z-directional vibration is mainly effective for the shear effect. Overall, the process can enhance the impact and shear effects simultaneously through composite vibration.

show abstract

Gear micropitting initiation of ground and superfinished gears: Wrought versus pressed and sintered steel

Cited by 19 publications

References 19 publications

Reducing scrapping of gears by assessment of tip contact threshold torque

Reducing scrapping of gears by assessment of tip contact threshold torque

Experimental and numerical study of contact fatigue for 18CrNiMo7-6 and 20MnCr5 carburized gear tooth

Numerical investigation of a novel bidirectional composite vibratory finishing

Contact Info

Product

Resources

About