Kontinuierliches Wälzschleifen*/Continuous gear grinding. Thermal and mechanical loads during continuous gear grinding with cBN grinding tools

2019 ◽  
Vol 109 (06) ◽  
pp. 473-478
Author(s):  
B. Denkena ◽  
T. Grove ◽  
P. Dzierzawa ◽  
F.L. Kempf
Keyword(s):  
Service Life ◽  
Thermal Damage ◽  
Gear Train ◽  
Measuring System ◽  
Grinding Process ◽  
Mechanical Loads ◽  
Gear Teeth ◽  
Gear Grinding ◽  
Grinding Tool ◽  
Thermische Schädigungen

Für die Leistung und die Standzeit der Zahnräder im Getriebe sind die Oberflächen- und Randzoneneigenschaften der Zähne entscheidend. Die Kenntnis der durch den Schleifprozess erzeugten Temperaturen ist von besonderem Interesse, da thermische Schädigungen ein Bauteil für den Einsatz unbrauchbar machen. Die Messung von Temperaturen nahe der Kontaktzone ist aufgrund der gekoppelten Rotation von Werkstück und Schleifwerkzeug aufwendig. Eine werkstückseitige Messung bietet eine einfachere Lösung dafür, die auch die Untersuchung unterschiedlicher Werkzeuge erlaubt.   Surface and subsurface properties of the gear teeth are crucial for the performance and service life of gears inside the gear train. The knowledge of temperatures generated by the grinding process is of particular interest, as thermal damage causes the gear to be unusable. The measurement of temperatures near the contact zone in this case is not trivial, due to the coupled rotation of workpiece and grinding tool. A measuring system attached to the workpiece offers a less complicated solution for this, and allows the examination of different tools.

scholarly journals Strength Analysis of a PTO (Power Take-Off) Gear-Train of a Multi-Purpose Cultivator during a Rotary Ditching Operation

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1100 ◽  
Author(s):  
Yeon-Soo Kim ◽  
Pa-Ul Lee ◽  
Wan-Soo Kim ◽  
Oh-Won Kwon ◽  
Chang-Won Kim ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Safety Factor ◽  
Gear Train ◽  
Measuring System ◽  
Soil Conditions ◽  
Strength Analysis ◽  
Actual Measurement ◽  
Simulation Results ◽  
Fatigue Life Analysis

Optimal design of transmission gears is important to ensure product durability and reliability. This study measured a multi-purpose cultivator during a rotary ditching operation and analyzed the strength of the power take off (PTO) gear-train for the cultivator using analysis software (KISSsoft, KISSsoft AG—A Gleason Company, Bubikon, Switzerland) based on ISO 6336 standards and a modified Miner’s rule. A load measurement system was installed on the cultivator to measure the load on the PTO shaft. To measure the load on the PTO shaft, the load measuring system consisting of a data acquisition board (NI USB-6212, National Instruments, Austin, TX, USA) and a torque sensor was installed on the cultivator. Rotary ditching operations were conducted at two ground speeds and two PTO rotational speeds on a field with the same soil conditions. The measured load data were constructed using the rainflow-counting algorithm and the Smith-Watson-Topper equation. When the ground speed or PTO rotational speed increased, the average and maximum PTO torque increased significantly. The average measured torque ratio to rated torque of the PTO input shaft (19.6 Nm) was in the range of 50.1–105.9%. The simulation results using the actual measurement load indicated that the strength of the PTO gear-train tended to decrease with higher transmission gear stage and lower PTO gear stage except for the G2 and G3 gears. The simulation results of the safety factor for contact stress were lower than the minimum safety factor of ‘1.0’ at the T2P1 gear stage (G4 and G2). The simulation results of the fatigue life analysis showed fatigue life of less than service life (1000 h) at T2P2 (G2) and T2P1 (G2, G3, and G4). The simulation results indicate that there is a possibility of gear failure before service life at the T2P1 (G2, G3, and G4) and T2P2 (G2). It is known that the weak parts (G2, G3, and G4) should be the focus of design optimization through gear strength simulation to meet upward of a 1.0 safety factor and service life.

Development of a Methodology for Analyzation of the Influence of Pitch Diameter Shift on the Generating Gear Grinding Process

2016 ◽  
Vol 1140 ◽  
pp. 149-156
Author(s):  
Marco Kampka ◽  
Christoph Löpenhaus ◽  
Fritz Klocke
Keyword(s):  
Process Efficiency ◽  
Test Case ◽  
Grinding Process ◽  
Contact Conditions ◽  
Contact Points ◽  
Gear Grinding ◽  
Load Carrying ◽  
Grinding Tool ◽  
Hard Finishing ◽  
Gear Profile

In order to improve load carrying capacity and noise behaviour, case hardened gears are usually hard finished. One possible process for hard finishing of gears is generating gear grinding, which has replaced other grinding processes in batch production of small and middle sized gears due to high process efficiency. Especially generating gear grinding of large module gears with a module higher than mn > 8 mm can be challenging due to high process forces and the resulting excitation, which can influence gear quality negatively. TÜRICH suggested applying a pitch diameter shift during generating gear grinding to equal out the number of contact points between the left and right flanks of the gear with the grinding tool [1]. This qualitative approach is not sufficient to predict the process behaviour because it does not take the changing radii of the curvature of the involute into account and, therefore, the changing contact conditions along the gear profile. In this paper a methodology to quantify the influence of pitch diameter shift on the generating gear grinding process using a manufacturing simulation is introduced. Additionally this methodology is validated for one manufacturing test case.

scholarly journals Study on the Effect of Grinding Pressure on Material Removal Behavior Performed on a Self-Designed Passive Grinding Simulator

2021 ◽  
Vol 11 (9) ◽  
pp. 4128
Author(s):  
Peng-Zhan Liu ◽  
Wen-Jun Zou ◽  
Jin Peng ◽  
Xu-Dong Song ◽  
Fu-Ren Xiao
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Service Life ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Force ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Temperature ◽  
Grinding Efficiency

Passive grinding is a new rail grinding strategy. In this work, the influence of grinding pressure on the removal behaviors of rail material in passive grinding was investigated by using a self-designed passive grinding simulator. Meanwhile, the surface morphology of the rail and grinding wheel were observed, and the grinding force and temperature were measured during the experiment. Results show that the increase of grinding pressure leads to the rise of rail removal rate, i.e., grinding efficiency, surface roughness, residual stress, grinding force and grinding temperature. Inversely, the enhancement of grinding pressure and grinding force will reduce the grinding ratio, which indicates that service life of grinding wheel decreases. The debris presents dissimilar morphology under different grinding pressure, which reflects the distinction in grinding process. Therefore, for rail passive grinding, the appropriate grinding pressure should be selected to balance the grinding quality and the use of grinding wheel.

scholarly journals Potentials of Vitrified and Elastic Bonded Fine Grinding Worms in Continuous Generating Gear Grinding

2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Maximilian Schrank ◽  
Jens Brimmers ◽  
Thomas Bergs
Keyword(s):  
High Performance ◽  
Manufacturing Processes ◽  
Fine Grinding ◽  
Gear Grinding ◽  
Profile Line ◽  
Grinding Tool ◽  
Process Behavior ◽  
Hard Finishing ◽  
Tooth Flank ◽  
Process Strategy

Continuous generating gear grinding with vitrified grinding worms is an established process for the hard finishing of gears for high-performance transmissions. Due to the increasing requirements for gears in terms of power density, the required surface roughness is continuously decreasing. In order to meet the required tooth flank roughness, common manufacturing processes are polish grinding with elastic bonded grinding tools and fine grinding with vitrified grinding tools. The process behavior and potential of the different bonds for producing super fine surfaces in generating gear grinding have not been sufficiently scientifically investigated yet. Therefore, the objective of this report is to evaluate these potentials. Part of the investigations are the generating gear grinding process with elastic bonded, as well as vitrified grinding worms with comparable grit sizes. The potential of the different tool specifications is empirically investigated independent of the grain size, focusing on the influence of the bond. One result of the investigations was that the tooth flank roughness could be reduced to nearly the same values with the polish and the fine grinding tool. Furthermore, a dependence of the roughness on the selected grinding parameters could not be determined. However, it was found out that the profile line after polish grinding is significantly dependent on the process strategy used.

Influence of Dressing Tool Specification on Dressing Tool Wear for Generating Gear Grinding

2016 ◽  
Vol 1140 ◽  
pp. 228-235
Author(s):  
Matthias Ophey ◽  
Christoph Löpenhaus ◽  
Fritz Klocke
Keyword(s):  
Tool Wear ◽  
Economic Efficiency ◽  
Grinding Process ◽  
Gear Grinding ◽  
Dressing Tool ◽  
Best Fitting ◽  
Efficiency And Productivity

One research objective for generating gear grinding is to increase economic efficiency and productivity of the process. Furthermore, the gear quality must be equal or higher compared to the non optimised process. In addition to the grinding process and the grinding tools, the dressing process can be suitable to lead to an increase of efficiency of generating gear grinding. Due to the variety of dressing tool specifications process users have the problem of selecting the best fitting dressing tool for their demands. Therefore, it is necessary to know the interactions of dressing tool specification and dressing tool wear. But the influence of the dressing tool specification onto dressing tool wear has yet not been sufficiently investigated for generating gear grinding.

Experimental Investigation on the Rubbing Process of Labyrinth Seals Against Honeycomb Liners

2020 ◽  
Author(s):  
Oliver Munz ◽  
Lisa Hühn ◽  
Corina Schwitzke ◽  
Hans-Jörg Bauer ◽  
Tim Fischer ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Service Life ◽  
Wear Mechanism ◽  
Relative Velocity ◽  
Labyrinth Seal ◽  
Honeycomb Structure ◽  
Labyrinth Seals ◽  
Mechanical Loads ◽  
Low Leakage ◽  
Mass Flows

Abstract Sealing systems contribute significantly to the efficiency of turbomachinery. Small gap widths, which are important for low leakage mass flows in labyrinth seals, combined with thermal and mechanical expansion of the rotor can lead to contact with the stator. During these so-called rubbing processes, it is necessary to make an accurate prediction with respect to the performance and service life of the seal. For this purpose, the influence of relative velocity in the contact (up to 165ms−1) and incursion rate (up to 0.5 mms−1) on the resulting thermal and mechanical loads as well as wear mechanisms are studied for the rubbing process between an inclined labyrinth seal fin and a honeycomb segment. Furthermore, different axial configurations of the seal fin with respect to the honeycomb structure are considered. The system reacts very sensitively to a change of the seal fin position relative to the honeycomb structure. The incursion per revolution reflects a change of the wear mechanism from abrasive to plastic for a certain value. The results of this study contribute to the optimization of labyrinth seals and the development of new types of liner materials as well as geometries.

Reverse on the Spiral Bevel Gear’s Teeth Profile Line

2011 ◽  
Vol 308-310 ◽  
pp. 1596-1599
Author(s):  
Chun Xiang Wang ◽  
Jing Qiang Zhang ◽  
Zhi Jun Liu
Keyword(s):  
Gear Tooth ◽  
Bevel Gear ◽  
Measuring System ◽  
Gear Teeth ◽  
Bevel Gears ◽  
Profile Line ◽  
Simple Processing ◽  
Base Circle ◽  
Spiral Bevel ◽  
Reverse Method

For the purposes of spiral bevel gears of cycloid gear is more and more extensive, the research on the reverse are rare phenomenon, this paper puts forward a reverse method: It’s based on three coordinates measuring system for prolate epicycloids’ bevel gear teeth profile. This method according to the forming principle of the spiral bevel gear tooth profile, with the back cone expanding the measured data of a group of good quality after simple processing, according to the involutes’ parameter equation for theoretical analysis, reverse out the base circle radius and modulus, make the bevel gear tooth profiles to reverse.

Modeling of the Grinding Wheel Topography Depending on the Recipe-Dependent Volumetric Composition

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Sebastian Barth ◽  
Michael Rom ◽  
Christian Wrobel ◽  
Fritz Klocke
Keyword(s):  
Research Work ◽  
Distribution Functions ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Edge Zone ◽  
Application Behavior ◽  
Wheel Topography ◽  
Grinding Wheel Topography ◽  
Grinding Tool

The prediction of the grinding process result, such as the workpiece surface quality or the state of the edge zone depending on the used grinding wheel is still a great challenge for today's manufacturers and users of grinding tools. This is mainly caused by an inadequate predictability of force and temperature affecting the process. The force and the temperature strongly depend on the topography of the grinding wheel, which comes into contact with the workpiece during the grinding process. The topography of a grinding wheel mainly depends on the structure of the grinding wheel, which is determined by the recipe-dependent volumetric composition of the tool. So, the structure of a grinding tool determines its application behavior strongly. As result, the knowledge-based prediction of the grinding wheel topography and its influence on the machining behavior will only be possible if the recipe-dependent grinding wheel structure is known. This paper presents an innovative approach for modeling the grinding wheel structure and the resultant grinding wheel topography. The overall objective of the underlying research work was to create a mathematical-generic grinding tool model in which the spatial arrangement of the components, grains, bond, and pores, is simulated in a realistic manner starting from the recipe-dependent volumetric composition of a grinding wheel. This model enables the user to determine the resulting grinding wheel structure and the grinding wheel topography of vitrified and synthetic resin-bonded cubic boron nitride (CBN) grinding wheels depending on their specification and thus to predict their application behavior. The originality of the present research results is a generic approach for the modeling of grinding tools, which takes into account the entire grinding wheel structure to build up the topography. Therefore, original mathematical methods are used. The components of grinding wheels are analyzed, and distribution functions of the component's positions in the tools are determined. Thus, the statistical character of the grinding wheel structure is taken into account in the developed model. In future, the presented model opens new perspectives in order to optimize and to increase the productivity of grinding processes.

Adaptive Grinding Process—Prevention of Thermal Damage Using OPC-UA Technique and In Situ Metrology

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Matthias Steffan ◽  
Franz Haas ◽  
Alexander Pierer ◽  
Gentzen Jens
Keyword(s):  
Thermal Damage ◽  
Control Variable ◽  
Safety Margin ◽  
Value Added ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Production Chain ◽  
Process Step ◽  
Edge Zone ◽  
Control Concept

The production process grinding deals with finishing of hardened workpieces and is one of the last stages of the value-added production chain. Up to this process step, considerable costs and energy have been spent on the workpieces. In order to avoid production rejects, significant safety reserves are calculated according to the present state of the art. The authors introduce two approaches to minimize the safety margin, thus optimizing the process’ economic efficiency. Both control concepts use the feed rate override of the machining operation as regulating variable to eliminate thermal damage of the edge zone. The first control concept is developed to avoid thermal damage in cylindrical plunge grinding by controlling the cutting forces. Therefore, the industrial standard Open Platform Communications Unified Architecture (OPC-UA) is used for the communication between a proportional–integral–derivative (PID) controller and the SINUMERIK grinding machine tool control system. For noncircular workpieces, grinding conditions change over the circumference. Therefore, thermal damage cannot be ruled out at any time during the grinding process. The authors introduce a second novel control approach, which uses a micromagnetic measure that correlates with thermal damage as the main control variable. Hence, the cutting ability of the grinding wheel and thermal damage to the workpiece edge zone is quantified in the process. The result is a control concept for grinding of noncircular workpieces, which opens up fields for major efficiency enhancement. With these two approaches, grinding processes are raised on higher economic level, independently of circular and noncircular workpiece geometries.

scholarly journals Stress Assessment of Gear Teeth in Epicyclic Gear Train for Radial Sedimentation Tank

2020 ◽  
Vol 14 (3) ◽  
pp. 121-127
Author(s):  
Grzegorz Budzik ◽  
Tadeusz Markowski ◽  
Michał Batsch ◽  
Jadwiga Pisula ◽  
Jacek Pacana ◽  
...  
Keyword(s):  
Planetary Gear ◽  
Gear Train ◽  
Load Factor ◽  
The Finite Element Method ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Sedimentation Tank ◽  
Epicyclic Gear ◽  
Comparison Of The Results ◽  
Root Stress

Abstract The paper presents the strength evaluation of planetary gear teeth designed for a radial sedimentation tank drive. A novel type of gear drive, composed of a closed epicyclic gear train and an open gear train with internal cycloidal gear mesh is proposed. Contact stress and root stress in the planetary gear train were determined by the finite element method and according to ISO 6336. The influence of the mesh load factor at planet gears on stress values was also established. A comparison of the results followed. It was observed that the mesh load factor on satellites depends mainly on the way the satellites and central wheels are mounted, the positioning accuracy in the carrier and the accuracy of teeth. Subsequently, a material was selected for the particular design of planetary gear and the assumed load. The analysis of the obtained results allowed assuming that in case of gears in class 7 and the rigid mounting of satellites and central wheels, gears should be made of steel for carburizing and hardening. In case of flexible satellites or flexible couplings in the central wheels and gears in class 4, gears can be made of nitriding steel.

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