{"title":"Evaluation of friction calculation methods for rolling bearings","authors":"M. Zander, M. Otto, T. Lohner, K. Stahl","doi":"10.1007/s10010-023-00715-1","DOIUrl":"https://doi.org/10.1007/s10010-023-00715-1","url":null,"abstract":"Abstract In gearboxes, rolling bearing power losses often make up a large amount of the total gearbox power losses. Therefore, an exact calculation of rolling bearing power losses is very important for resource and energy efficient gearbox design. The state of the art offers numerous friction calculation methods with different levels of detail to calculate power losses of rolling bearings. Bearing manufacturers like SKF and Schaeffler offer popular bearing-based/global calculation methods for standard rolling bearings. Contact-based/local calculation methods can consider a wider application field by generalization of tribological relations, which enables its application to e.g. hybrid bearings or non-standard bearings. The different methods may yield widely differing results. For its validation, measurement results are required. In this study, a broad comparison of calculation results with substantial measurement results is shown. Based on the validation a classification of the calculation methods is derived, which provides guidance for the design engineer to choose the appropriate method for the respective application. Contact-based/local calculation methods have the potential to predict friction in rolling bearings precisely.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135884954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlos M. C. G. Fernandes, Rui Ferreira, Jorge H. O. Seabra, João M. Cruz, Ricardo Bernardes
{"title":"Testing and modelling of a 2.5 MW wind turbine gearbox: Influence of lubricant formulation","authors":"Carlos M. C. G. Fernandes, Rui Ferreira, Jorge H. O. Seabra, João M. Cruz, Ricardo Bernardes","doi":"10.1007/s10010-023-00716-0","DOIUrl":"https://doi.org/10.1007/s10010-023-00716-0","url":null,"abstract":"Abstract This study aimed to evaluate the efficiency of different ISO VG 320 oil formulations used in a 2.5 MW wind turbine gearbox. Two commercially available lubricants, a mineral oil and a polyalphaolefin (PAO) lubricant, were tested under realistic operating conditions using a customized test rig. Measurements showed that the overall efficiency of the mineral lubricant was higher than that of the PAO lubricant, but the difference was only 0.1% in degree of efficiency. Detailed oil analysis revealed that the mineral lubricant generated more wear particles. A power loss model was also implemented to predict the efficiency of the gearbox, and the results of the model were found to be in agreement with the experimental results. The study concluded that the mineral oil presented higher efficiency than the PAO oil due to its lower viscosity within the narrow operating temperature range imposed on the gearbox. Nevertheless, it is important to note that the observed differences in efficiency may be attributed, in part, to measurement uncertainties and the fact that the mineral lubricant has 10% lower viscosity at the operating temperature compared to the PAO lubricant.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136295359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ulrike Cihak-Bayr, Thomas Wopelka, Christoph Wintersteiger
{"title":"Untersuchung von Reibung und Fressneigung bei Verlust der Schmierung auf einem Zweischeiben Teststand","authors":"Ulrike Cihak-Bayr, Thomas Wopelka, Christoph Wintersteiger","doi":"10.1007/s10010-023-00717-z","DOIUrl":"https://doi.org/10.1007/s10010-023-00717-z","url":null,"abstract":"Abstract Increasing demands on gear components such as high-pressure and high speeds are aggravated by weight saving strategies eliminating an optional secondary lubrication system during negative g operations or windmilling, which result in loss of lubrication conditions (LOL) and scuffing. In order to understand gear design options able to withstand LOL at high velocities, systematic, fundamental studies on model test-rigs, e.g. twin-disc rigs, are required. For this purpose, a twin-disc rig was designed which is able to perform test at high entrainment velocities of up to 80 m/s and high lubricant injection temperatures. Systematic studies have been carried out in continuous lubrication and LOL condition and evaluated in terms of friction and time-of failure (TOF). A mixed EHL model complemented the experimental matrix for wider range of temperatures and additionally compared the influence of the grinding direction on the lubricant gap. Entrainment velocity showed to have the most prominent influence on friction in continuous mode, mostly for the increase from 8 m/s to 23 m/s, followed by minor changes upon further increase to 30 m/s. The influence of injection temperature was mostly prominent at high entrainment velocities. Contact pressure had the strongest influence on TOF. Comparisons with superfinished disc surfaces exhibited a high increase in TOF and significantly less scuffing damage fractures on the runway.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136295659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Niklas Blech, Constantin Paschold, Luc Amar, Thomas Lohner, Thomas Tobie, Karsten Stahl
{"title":"Überblick über verschiedene Berechnungsansätze für die mittlere Verzahnungsreibungszahl nach ISO 6336","authors":"Niklas Blech, Constantin Paschold, Luc Amar, Thomas Lohner, Thomas Tobie, Karsten Stahl","doi":"10.1007/s10010-023-00718-y","DOIUrl":"https://doi.org/10.1007/s10010-023-00718-y","url":null,"abstract":"Abstract Important goals in gear design are high load carrying capacity, good noise, vibration, and harshness (NVH) performance and high efficiency. Regarding the load carrying capacity, the international series of standards ISO 6336 [13–15] is the state of the art for its calculation. To ensure reliable calculation of the load carrying capacity of gears and the temperatures occurring during operation, knowledge of the friction in the gear mesh is crucial. Currently, various approaches exist in the literature for calculating the mean coefficient of friction, which weight the influencing variables to varying degrees. In this publication, the empirical approaches for calculating the mean coefficient of friction given in the international series of standards ISO 6336 [13–15] are to be analyzed in terms of their origin and validated ranges, systematically compared, and contrasted. These calculation approaches are mainly covered in the parts ISO/TS 6336-20 [14], ISO/TS 6336-21 [15], and ISO/TS 6336-22 [13], which address the calculation of the scuffing load carrying capacity according to the flash and integral temperature method and the calculation of the micropitting load carrying capacity, respectively. Additionally, ISO/TR 14179‑2 [12] which describes a calculation approach for the thermal load carrying capacity will be included in this review. Besides the analysis of their origin, exemplary comparative calculations for various applications are intended to show possible differences between the various calculation approaches and enable a quantitative evaluation. The overall, long-term goal is to merge and standardize the various calculation approaches for the mean coefficient of friction in the international series of standards ISO 6336.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135591009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A non-restrictive approach of gear geometry calculation for plastic gears","authors":"Florian Eigner, Stephan Oberle, Maik Berger","doi":"10.1007/s10010-023-00708-0","DOIUrl":"https://doi.org/10.1007/s10010-023-00708-0","url":null,"abstract":"Abstract For the unrestricted calculation of gearboxes with a constant transmission ratio, a parameter radius ratio is developed. For this purpose, a parameter radius ratio is introduced that has a piecewise continuous and differentiable domain of definition. Thus, the parameter can be used efficiently in the algorithmic implementation for the optimisation of a contact point of two gears. Furthermore, the data processing of the surface intersection is shown. Through direct surface conjugation, two paired gears can always achieve a line contact, therefore an optimal power transmission can be achieved regarding the technical properties. The procedure is demonstrated with a practical example of a planetary gear with skewed planet.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135193846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marco Arndt, Martin Dazer, Wolfram Raither, Bernd Bertsche
{"title":"Gezielte Bestimmung relevanter Einflussparameter für die Zuverlässigkeitsmodellierung von Maschinenkomponenten durch heuristisches Screening","authors":"Marco Arndt, Martin Dazer, Wolfram Raither, Bernd Bertsche","doi":"10.1007/s10010-023-00711-5","DOIUrl":"https://doi.org/10.1007/s10010-023-00711-5","url":null,"abstract":"Abstract For the investigation of influence of various parameters on properties and outputs of components or systems, Design of Experiments (DOE) offers the most efficient approach to create a comprehensive empirical insight into product performance. However, especially if product lifetime is treated as the investigation objective, the main focus of attention must be placed on the efficiency of testing—if only to comply with the principle of DOE, even before testing begins. Without actual test runs, a pre-selection of relevant factors influencing the target quantity can be performed here and strategically adjusted in scale compared to the subsequent method. In this work, common heuristic tools and methods are analyzed and evaluated with respect to a deliberate preselection of influencing factors versus the challenges in lifetime testing and degradation behaviors. Several factors as well as their interactions are taken into account to achieve this. For this purpose, these methods are partially extended and adapted in their focus in order to finally be made applicable in a suitable procedure. An illustration of this is also provided in a selected use case with limited empirical and experimental prior-knowledge, in which a sample of relevant influences is identified through qualitative heuristic decision making with respect to parameters that influence product lifetime.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135814821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Verbesserung der Übertragungseffizienz in Elektrofahrzeugen durch den Einsatz von doppelt versetzten Schrägverzahnungen mit verkürzten Zähnen","authors":"Ignacio Gonzalez-Perez, Alfonso Fuentes-Aznar","doi":"10.1007/s10010-023-00707-1","DOIUrl":"https://doi.org/10.1007/s10010-023-00707-1","url":null,"abstract":"Abstract The application of double staggered helical gears with shortened teeth is proposed to increase the efficiency of gear reducers applied in electric vehicles. The staggered helical gears are designed with short addendum and dedendum as well as a phase angle between their two parts. Reduction of power losses is achieved by avoiding contact between tooth surfaces where the sliding velocities are larger, since the meshing occurs in areas close to the pitch circle during a longer period of the cycle of meshing. The calculation of the efficiency is based on the application of the finite element method through two algorithms for post-processing the obtained results. The first one is based on the use of tangential forces and sliding velocities to compute the power losses along the cycle of meshing. The second one is based on the determination of the input and output powers through the torques and velocities at the pinion and gear reference nodes of the finite element model. A constant friction coefficient is being considered between the contacting tooth surfaces for all the geometries. Several two-stage gear transmissions are analyzed and compared, considering standard helical gears and their counterpart double staggered helical gears with shortened teeth, different facewidth-to-module ratios, and different helix angles. The results show an improvement in the efficiency about 1.8 percentile points among the compared geometries.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135740339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christian Westphal, Jens Brimmers, Christian Brecher
{"title":"Influence of axis misalignments in stepped planetary gear stages on the excitation behavior—test rig development and simulative analysis","authors":"Christian Westphal, Jens Brimmers, Christian Brecher","doi":"10.1007/s10010-023-00709-z","DOIUrl":"https://doi.org/10.1007/s10010-023-00709-z","url":null,"abstract":"Abstract One challenge in the design of automotive gearboxes is the combination of high power density, high efficiency and low noise emission. With the electrification of the powertrain, the requirements in terms of noise emission and efficiency increase additionally. Stepped planetary gear stages are a potential topology to solve the current challenges in gearbox technology. Current research shows the pronounced misalignment behavior of planetary gear stages, especially with manufacturing or assembly deviations. However, the effects of dynamic misalignment behavior on tooth contacts in stepped planetary gear stages have not been adequately investigated. This paper presents a test rig that allows the investigation of the excitation and displacement behavior of stepped planetary gear stages taking into account adjustable axis misalignments. The axis misalignment of the stepped planetary shafts is introduced with eccentric bushings in this test rig concept. To evaluate the excitation and displacement behavior the transmission error and the displacements of different components can be measured. The test rig is modeled in the dynamic multibody simulation. The tooth contact is modeled using the force module GearForce6D. The axis misalignment is varied in the simulation model and the influence on the excitation and displacement behavior is evaluated. The simulation results show that planet pin position errors have the highest influence on the sun trajectory and the load sharing. The misalignments occurring in the tooth contacts due to inclination and skew of the stepped planetary shaft lead to higher tooth flank pressures and an increase in the total transmission error.","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135734700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Christian Sax, A. Stroh, Robin Leister, C. Denda, Patrick Bürk, Maximilian Dreisbach, J. Kriegseis
{"title":"Strömungsmechanische Bewertung verschiedener Kupplungsgeometrien anhand von experimentellen und numerischen Untersuchungen","authors":"Christian Sax, A. Stroh, Robin Leister, C. Denda, Patrick Bürk, Maximilian Dreisbach, J. Kriegseis","doi":"10.1007/s10010-023-00703-5","DOIUrl":"https://doi.org/10.1007/s10010-023-00703-5","url":null,"abstract":"","PeriodicalId":50431,"journal":{"name":"Forschung Im Ingenieurwesen-Engineering Research","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48128733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}