Axial Feed Research Articles

Machine-learning models to predict myopia in children and adolescents.

To explore machine-learning applications in myopia prediction and analyze the influencing factors of myopia. Stratified cluster random sampling was used to select elementary school students in Shenzhen, China for inclusion in this case-control study. Myopia screening, ocular biological parameter measurements, and questionnaires were conducted. Random forest (RF), decision tree (DT), extreme gradient boosting trees (XGBoost), support vector machine (SVM), and logistic regression (LR) algorithms were used to construct five myopia prediction models using R software (version 4.3.0). These myopia prediction models were used to investigate the relationship between ocular biological parameters, environmental factors, behavioral factors, genetic factors, and myopia. This study included 2,947 elementary school students, with a myopia prevalence rate of 47.2%. All five prediction models had an area under the receiver operating characteristic curve (AUC) above 0.75, with prediction accuracy and precision exceeding 0.70. The AUCs in the testing set were 0.846, 0.837, 0.833, and 0.815 for SVM, LR, RF, and XGBoost, respectively, indicating their superior predictive performance to that of DT (0.791). In the RF model, the five most important variables were axial length, age, sex, maternal myopia, and feeding pattern. LR identified axial length was the most significant risk factor for myopia [odds ratio (OR) =8.203], followed by sex (OR = 2.349), maternal myopia (OR = 1.437), Reading and writing posture (OR = 1.270), infant feeding pattern (OR = 1.207), and age (OR = 1.168); corneal radius (OR = 0.034) and anterior chamber depth (OR = 0.516) served as protective factors. Myopia prediction models based on machine learning demonstrated favorable predictive performance and accurately identified myopia risk factors, and may therefore aid in the implementation of myopia prevention and control measures among high-risk individuals.

Investigation of externally toothed parts forming using ballizing technique

Externally toothed parts such as gears, splined and coupling sleeves can be manufactured by machining, casting, and forming. The machining process is costly because of using a special tool, consuming power, and wasting material during the machining process. The casting processes usually need other finishing processes. In this study, a new forming tool based on the ballizing technique is suggested to perform the forming of the toothed parts with external splines in one stroke. The set is made up of six steel balls each having a 20 mm diameter. The process was performed on the lathe machine with data acquisition recording to record the process consumed load. Die with splines on the inner surface opposite the required splines was mounted in the lath check. The required tooth shape was obtained by forcing the forming tool into the hole by pushing the specimen into the die cavity. the mathematical model was formulated to calculate required force deformation. The model depends on the process dynamics and contact area between the tool and the specimen. The effect of process parameters on the load and the product properties was conducted. The study parameters were forming depths of 2, 3, 4, and 5 mm, the rotational speed of 50, 76, 120, and 150 rpm, axial feed 0.1, 0.15, 0.3, and 0.6 mm/rpm specimen inner diameter of 66, 64, 62 and 60 mm. A comparison was made between results of mathematical model and results of experimental. Rotational speed, axial feed, and cross-in feed were found to be the three factors that have the greatest impact on forming load and overall product quality. Also, it was found that deformation load increased with the increasing rotational speed, cross-in feed, and axial feed.

Research on the effect of grinding force on the axial ultrasonic vibration-assisted grinding of Ti-6Al-4V with multi-grain conical grinding head

A multi-grain conical grinding head capable of performing both peripheral and end-face grinding was created in Abaqus to simulate conventional grinding (CG) and axial ultrasonic-assisted vibration grinding (AUVAG) on Ti-6Al-4V alloy. A comparative analysis was conducted to examine the effects of key grinding parameters on the fluctuation amplitude and mean value of grinding forces in CG and AUVAG. The mechanism of ultrasonic vibration’s influence on grinding forces was analyzed, and a theoretical model for normal and tangential grinding forces in peripheral grinding of Ti-6Al-4V was established. Additionally, the surface morphology of CG and AUVAG was analyzed. The study found that the fluctuation amplitude of grinding forces in both AUVAG and CG increases with the axial grinding depth, feed rate, ultrasonic amplitude, and ultrasonic frequency, while it decreases with increasing spindle speed. However, the fluctuation amplitude in AUVAG is greater than that in CG. The average grinding forces in both CG and AUVAG increase with the grinding depth and feed rate, and decrease with the spindle speed. Compared to CG, the mean F x ([Formula: see text]) and F y ([Formula: see text]) are lower in AUVAG, while the mean F z ([Formula: see text]) is higher. Under different axial grinding depths, the maximum reduction in [Formula: see text] and [Formula: see text] for AUVAG is 4.70% and 5.18%, respectively, while the maximum increase in [Formula: see text] is 77.48%. At different feed rates, the maximum reduction in [Formula: see text] and [Formula: see text] for AUVAG is 3.02% and 21.01%, respectively, while the maximum increase in [Formula: see text] is 81.67%. Under different spindle speeds, the maximum reduction in [Formula: see text] and [Formula: see text] is 7.20% and 17.82%, respectively, and the maximum increase in [Formula: see text] is 281%. As the ultrasonic amplitude and frequency increase, [Formula: see text] significantly rises, but the effect on [Formula: see text] and [Formula: see text] is weak. AUVAG improves the surface quality of the specimen.

Study of non-stationary cutting processes in power skiving

The paper presents the results of the modelling and study of the cutting process in the cut-in phase during the machining of external gears by the power skiving. The studies were carried out on the basis of the previously developed graphical model of the cut layers and the model of the cutting force as a function of the chip cross-sectional area, the shear strength limit of the workpiece material, and the intensity of plastic deformation during cutting. The regularities of the cutting force in the cut-in phase of gear machining are shown for successive tool revolutions in four passes with a gradual increase in the depth of cut. It is shown that the peak values of the cutting force at the contact between the front face of the cutter and the face plane are two times higher than under the conditions of steady stationary cutting in a preformed gap. At the same time, the amplitude of the cutting force and its average value over the cut-in passes are 1.7–3.7 times and 1.2–1.5 times higher, respectively, than the corresponding values of these parameters for steady state cutting. It is these peak jumps in the cutting force that limit the maximum depth of the cut, number of passes, and axial feed. Based on the data obtained, recommendations were developed to modify the traditional gear cutting scheme in power skiving. It is proposed to use short tool strokes with a low cutting depth along the length of the cut-in path and, after forming a gap in this area, to cut at a full depth to the full height of the gear rim. The possibility of a significant reduction of gear machining time using the proposed scheme of technological operation is demonstrated.

Synchronous control method for the walking system of the dual forging manipulators based on triangular velocity planning

The primary function of the dual forging manipulators’ walking system is to precisely control the axial feeding of forgings. The stability and control accuracy of this system significantly impact forging quality and production efficiency. To achieve synchronized position control, a mathematical model was developed using two 20 kN forging manipulators as the research subjects. Subsequently, a triangular velocity trajectory planner was devised to examine the effects of acceleration, start–stop coefficient, and peak coefficient on the control behavior of the system. Lastly, the efficacy of this control method, which employing triangular velocity planning (TVP) for displacement–velocity composite control, was confirmed through equivalent experiments. The results indicate that this method can effectively regulate the response dynamics of two walking systems, with a displacement difference of less than 1 mm between the two manipulators.

Thermal and Mechanical Investigation of Friction Stir Welding with Disparate Materials AA6061 and AA7075

Background:: The primary objective of this study is to assess the impact of welding conditions on the mechanical properties of friction stir-welded butt joints created from two distinct aluminium alloys, namely, AA6061 and AA7075. Friction stir welding (FSW), known for its innovation and low-energy solid-state bonding technique, was employed in this research. Methods:: FSW experiments were carried out on both AA6061 and AA7075 alloys using a computer numerical control (CNC) machine. The selection and design of the tool geometry were meticulous, with an emphasis on new pin profiles that are nearly flat at the weld contact point. Precisely, four distinct tool geometries were machined from HC-HCr (High carbon, high chromium steel): Circular, Square, Tapered third, and Triangular. Critical process variables that significantly influence weld quality include rotation speed (800 rpm-1400 rpm) and traverse speed (12 to 25 mm/min). These variables were carefully optimized to achieve flawless welds. During the friction stir welding process, the nugget zone undergoes significant deformation, leading to the formation of a new microstructure that substantially impacts the mechanical properties of the joint. Results:: This study comprehensively investigates the thermal and mechanical properties of friction stir welding using aluminium alloys AA6061 and AA7075, considering various tool shapes. Among the four tool shapes employed, two were found to yield higher hardness values (referred to as BH). Notably, the square-shaped tool produced the highest temperature, reaching up to 690ºC, as determined by thermocouple readings. Based on the findings, the optimal FSW parameters for enhancing hardness involve an axial feed and spindle speed of 800 rpm combined with a feed rate of 15 mm/min. These parameters were identified as crucial for achieving the desired mechanical properties in the friction stir-welded joints. Conclusion:: This study presents new developments in FSW technology, which may have patent implications.

Performance Analysis of Helical Milling and Drilling Operations While Machining Carbon Fiber-Reinforced Aluminum Laminates

Being a difficult-to-cut material, Fiber Metal Laminates (FML) often pose challenges during conventional drilling and require judicious selection of machining parameters to ensure defect-free laminates that can serve reliably during their service lifetime. Helical milling is a promising technique for producing good-quality holes and is preferred over conventional drilling. The paper compares conventional drilling with the helical milling technique for producing holes in carbon fiber-reinforced aluminum laminates. The effect of machining parameters, such as cutting speed and axial feed, on the magnitude of cutting force and the machining temperature during conventional drilling as well as helical milling is studied. It was observed that the thrust force produced during machining reduces considerably during helical milling in comparison to conventional drilling at a constant axial feed rate. The highest machining temperature recorded for helical milling was much lower in comparison to the highest machining temperature measured during conventional drilling. The machining temperatures recorded during helical milling were well below the glass transition temperature of the epoxy used in carbon fiber prepreg, hence protecting the prepreg from thermal degradation during the hole-making process. The surface roughness of the holes produced by both techniques is measured, and the surface morphology of the drilled holes is analyzed using a scanning electron microscope. The surface roughness of the helical-milled holes was lower than that for holes produced by conventional drilling. Scanning electron microscope images provided insights into the interaction of the hole surface with the chips during the chip evacuation stage under different speeds and feed rates. The microhardness of the aluminum layers increased after processing holes using drilling and helical milling operations. The axial feed/axial pitch had minimal influence on the microhardness increase in comparison to the cutting speed.

Grinding Force Model and Experimental Study on Ultrasonic Assisted Spiral Grinding of Silicon Carbide Ceramic Materials

In order to reveal the mechanical properties of silicon carbide ceramic materials during the drilling process, based on the indentation fracture mechanics theory, a grinding force model of ultrasonic assisted spiral grinding for hole making was established, and the experimental results of ultrasonic assisted spiral grinding for hole making verified the mechanical model. The results showed that the experimental results had the same change trend as the predicted results of the established mechanical model, and the values were close to each other, indicating the accuracy of the established prediction model. The influence of different process parameters on the size accuracy of the hole inlet and outlet aperture after machining is analyzed. It is found that it should be selected as large rotation speed, moderate axial feed speed and small feed pitch to ensure the accuracy of the aperture and effectively suppress the aperture defects during ultrasonic assisted spiral grinding.

Исследование изменения геометрических параметров образцов, наплавленных методом GMAW при воздействии на электрическую дугу продольного магнитного поля

Introduction. The paper presents the results of research of additive manufacturing process by electric arc with axial feeding of steel filler wire in protective gas environment (GMAW technology) with additional influence of external longitudinal magnetic field on electric arc. Purpose of work: an experimental study of the effect of a longitudinal magnetic field during additive manufacturing by an electric arc with axial feed of filler wire made of structural steels in a protective gas environment on the change in the geometrical characteristics of the layers being surfaced. Research Methods. The manufacturing of specimens was carried out on a 5-axis additive machine based on a CNC machine. Surfacing was carried out in the following modes: voltage 17.5 V; current 55–65 A; wire diameter 1.2 mm; wire material Sv-08G2S; wire feed rate 2,267 mm/min; approximate roll diameter 3.0 mm; roll length 50 mm; number of wires per one roll 312.5 mm; number of layers when surfacing the wall 5; magnet operation mode: alternating current with frequency 50 Hz, voltage 30 V; measured magnetic induction 5.7 mTl; initial height of the magnet above the substrate 10 mm; electrode stickout 10 mm; shielding gas: welding mixture CO2-Ar; gas pressure (flow rate) 0.15 MPa. Results and discussion. The conducted experimental study showed that the effect of longitudinal magnetic field had a statistically significant effect on the change in the dimensions of the singular, namely an increase in the width of the layers being surfaced by 34.1 %, with a calculated significance index close to zero, and a decrease in height by 20.2 %, with a calculated significance index equal to 2.7105. The effect of longitudinal magnetic field had a statistically significant effect on the change of the overall dimensions of the specimens consisting of five layers, namely, the width of the specimens increased by 11.2 % with a calculated significance index of 4.3103, and the height of the specimens decreased by 10.3 % with a calculated significance index of 6.3105. The effect of longitudinal magnetic field had no statistically significant effect on the change of the vertical deviation from straightness for the side walls of the specimens, with a calculated significance index of 0.3277, and had no statistically significant effect on the change of the error of the width of the walls of the specimens, with a significance index of 0.098.

Influence of the laser-beam intensity distribution on the performance of directed energy deposition of an axially fed metal powder

This paper investigates the influence of laser-beam intensity distribution (LBID) on the performance of the annular laser-beam directed energy deposition (DED) process with axial powder delivery. Three different LBIDs: Gaussian-like (G-LBID), top-hat-like (TH-LBID) and ring (R-LBID) at two LBID diameters were used. The process performance was characterised qualitatively in terms of the melt-pool shape and the process stability and quantitatively by powder-catchment efficiency, selected geometrical and metallurgical properties of the clad. The observed influence of LBID on process performance, as determined by the relationship between LBID and powder stream density distribution (PSDD), decreased with increasing mean surface-energy density and was more significant at larger LBID diameter. The highest powder-catchment efficiencies (90% and 87%) were achieved with the G-LBID and TH-LBID, whose high-intensity centre is aligned with the peak of the Gaussian-like PSDD. A lower powder-catchment efficiency of 77% was achieved with the R-LBID, whose high-intensity region is located at the edge of the melt pool with minimum powder density. However, this also results in the highest and most uniform dilution, the highest metallurgical bond ratio and the lowest lack of fusion porosity at the clad-substrate interface. In addition, the process was stable at the lower values of mean surface-energy density with R-LBID, while balling instability was observed with G-LBID and TH-LBID. It can be concluded that the use of R-LBID at lower values of mean surface-energy density improves the performance of the DED process with axial powder feed in terms of process stability and metallurgical properties of the clad.

Features of using the power skiving method for multi-pass cutting of internal gears

The paper presents the results of a simulation on a 3D model of undeformed chips and cutting forces during three-pass gear cutting using the power skiving method. At the level of individual blades and teeth in successive angular cutting positions, the main component of the cutting force and the tangential force on the cutter axis are shown. The analysis of the forces acting on a single gear tooth and the continuous cutting forces allowed the development of a methodology for the selection of rational cutting modes – the value of the axial feed, the number of passes with different cutting depths in order to ensure the minimum time consumption and to achieve the required accuracy of the gears in terms of the parameter of the permissible angular deviation of the profile of the cut gear. It is shown that, provided the required machining accuracy is ensured, higher productivity is achieved by increasing the axial feed at a lower depth of cut and increasing the number of passes, rather than by reducing the feed and increasing the depth of cut.

Effect of process parameters of Al5083/SiC surface composites fabricated by FSP on microstructure, mechanical properties and wear behaviors

Friction stir process (FSP) applications in producing surface composites have become the focus of researchers' attention in recent years. Axial load, tool rotation, feed rate, tool geometry, tool size and reinforcement material strategy are the main factors affecting the properties of surface composites (SC). In this study, Al5083–H111/SiC surface composites (SC) were produced in a single pass by friction stir process (FSP), and the effects of axial load and tool rotation speed on the microstructure, mechanical properties and wear behaviour of SCs were investigated. Different axial loads (6000, 8000 and 10000 N) and tool rotation speeds (560, 710 and 900 rpm) were used in the study. Optimum results from the tests performed were obtained in sample number N8, produced at an axial load of 8000 N and a rotation speed of 900 rpm. Specimen N8 showed a 38 % improvement in hardness and a 42 % improvement in wear tests performed under a 15 N load compared to the base metal. In the maximum tensile strength, the closest results to the base material were seen in sample N8 with 97 % performance.

Parametric analysis of tooth surface characteristics of flexspline in harmonic reducer after hobbing

The accurate prediction of tooth surface morphology for the flexspline in harmonic reducers after hobbing is a crucial technology for achieving high-precision harmonic gearing. This study investigates the impact of process parameters on the tooth surface characteristics of the flexspline. Two models were established to study the formation of tooth surfaces using both continuous cutting with a hypothetical rack tool and interrupted cutting with a multi-cutting-edge hob. The resulting surface geometry of the models was compared, and the effect of hob axial feed, hob mounting angle deviation, and hob outer diameter size on tooth surface morphology was analyzed. The study findings indicate that the crowning of gear teeth results in overcutting on the flexspline tooth surface, which is directly proportional to the degree of crowning and hob outer diameter. Furthermore, a lower axial feed speed during the hobbing process reduces material residue, and hob mounting angle deviations can lead to overcutting on one end of the tooth surface and material residue on the other end.

Fusion model of weight on bit in horizontal exploration hole based on wavelet transform and machine learning

During the horizontal drilling of the development of energy and the geological exploration, the loss of axial feed pressure is serious due to the frictional resistance in horizontal hole. As the length of the drilling pipe increases, the problem of insufficient drilling pressure becomes increasingly prominent. It is imperative to master weight on bit (WOB) in time and accurately for the adjustment of drilling parameters. Limited by the long drilling pipe, it is difficult and costly to measure WOB directly. Therefore, a novel model of WOB prediction was established. The model realized the coupling of wavelet transform and neural network. Five easily available parameters, feed pressure, rotational speed, torque, pump pressure and drilling-fluid flow rate were selected as input to the model. The WOB was taken as the only output of model. First, Morlet wavelet was used to reform the structure of hidden layer and output layer of neural network. In the reformed model, the self-learning and adaptive ability of neural network and the ability for local information extraction of wavelet transform were fully stimulated. Then, embedded genetic algorithm (GA) was used to optimize the weights and wavelet parameters of the model, which improves the global optimization ability of the model. The established model was named GA-WNN, and the experimental results demonstrate that the R2 of prediction model reaches 0.9982. The mean absolute percentage error (MAPE) of GA-WNN prediction can yield as low as 6.22%, while the MAPE of standard neural network prediction can yield as high as 47.04%. Furthermore, the accuracy of the model was further verified by response surface methodology (RSM), and the results show that the predicted data of the model can meet the requirements of RSM for data quality. The RSM analysis of WOB based on predicted data was successfully carried out, and the interaction influence between drilling parameters on WOB were obtained, which provides reference for parameter adjustment. The high-quality algorithm of WOB prediction provides support for long-distance horizontal drilling.

Calculation of force parameters of workpiece machining process with end mill cutters

The aim is to develop and validate an operational methodology for calculating the force parameters and characteristics of the tool and the process of milling structural materials with end milling cutters. The structural schemes of machining and force models of oblique cutting processes in the modes of axial tool feed and continuous plastic deformation of the processed material were used when developing the method of preliminary calculation of the total axial force working on the cutting edge of end milling cutters. The rotating tool tests were conducted on a Hermle UWF 1202 H 3-axis machining center supplemented with a Kistler piezoelectric dynamometer (model 9272). Authors suggested, developed and tested the preliminary calculation method applied to the force characteristics of the machining process of workpieces by end milling cutters, considering how the energy power of ductile fracture of the machined material affects the process. Contact friction arising on the front and rear surfaces of the cutting tool does not reach the limiting value being subject to the Coulomb – Amonton law, that is, it is estimated by the dependence directly proportional to the normal pressure. After calculations, we defined the materials of the workpiece for milling, that is 45 steel (AISI 1045), and the end two-tooth cutter, uncoated T14K8 alloy, which was used to produce samples. The following milling modes were established: 4 mm boring depth; 50, 100 and 150 m/min cutting speeds; 0.05 and 0.1 mm/rev cutting tool feed. Deviation of the measured values of axial cutting force from the calculated values in the range of changing values of tool feed rate was found to be no more than 11%, and in the range of changing values of cutting speed no more than 15%. The developed calculation and analytical methodology for estimating force parameters of the machining process by end milling cutters provides an increase in the efficiency and reliability of the preliminary prognostic calculation of operating parameters and characteristics of cutting elements of end milling cutters.

A Study on the Effect of Gear Hobbing Process Parameters on the Residual Stress of the Tooth Root

The root residual stress during gear machining has a significant impact on the bending fatigue performance of the gear. The process parameters of gear hobbing (hob speed, axial feed speed, and radial cutting depth) directly affect the residual stress of the tooth root. To investigate the relationship between the process parameters of hobbing and the residual stress of the tooth root respectively, an analysis of an orthogonal and single factor was conducted in the hobbing experiment, taking into account the interactions among factors, which revealed the influence rule and primary–secondary relationship of the process parameters on the residual stress of the tooth root. The importance coefficients of the process parameters on the residual stress of the tooth root were calculated using the Least Absolute Shrinkage and Selection Operator (LASSO) method. The results indicate that the residual tensile stress at the tooth root increases with an increase in the hob speed and axial feed speed within the selected range but decreases with an increase in the radial cutting depth. The influence of the process parameters on the residual stress of the tooth root can be ranked as follows: hob speed (importance coefficient 0.460), axial feed speed (importance coefficient 0.278), and radial cutting depth (importance coefficient 0.262). This research provides a basis for improving the residual stress of the tooth root and enhancing the anti-fatigue manufacturing of gears, thus holding significant research value.

Numerical Analysis of Process Parameters and Tool Geometry in Friction Stir Back Extrusion of Pure Aluminum

Friction Stir Back Extrusion (FSBE) is an innovative process that offers efficient aluminum waste recycling and wire production. This process boasts economic and environmental advantages, as it requires minimal energy compared to traditional recycling casting methods. The objective of this study is to analyze the impact of process parameters using a Finite Element Method (FEM) model based on thermo-mechanical 3D Lagrangian. The study focuses on an AA1080 aluminum alloy and employs different geometric tools, including hole extrusion diameters of 4 mm and 8 mm, as well as a shoulder with two distinct angles of 10° and 15°. Furthermore, variations in several process parameters, such as a constant axial feed rate of 0.5 and 1 mm/min and a constant rotational speed of the die set at 100, 300, and 500 rpm, are considered. The simulation plan encompasses a total of 24 combinations of these parameters to identify the optimal conditions for chips extrusion. Subsequently, the obtained results were analyzed using Design of Experiments (DoE) analysis to assess the influence of each parameter on peak force, torque, and temperature during the process.

Features of using the over-skiving method for multi-pass cutting of external gears

Problem. There is a problem of determining the working parameters, including axial feed and cutting speed, as well as the helix angle of the teeth of the disc cutter and the tool spindle, the geometry of the cutting part, and the cutting depth per pass in Power skiving technology.Objective. It is necessary to investigate the cutting process using the Power Skiving method for generating external gears over multiple passes and develop recommendations for selecting its optimal parameters.Implementation methodology. The cutting force and its tangential component acting on the cutter are presented based on the fundamental principles of cutting theory, using the function of the cross-sectional area of the cut, the material strength limits of the workpiece for shear, and the intensity of plastic deformation of the chip. Calculations of the cut area are based on a graphoanalytical 3D model of the undeformed chip. The coefficient of shear intensity is determined depending on the thickness of the cut layers using the Deform 2D system. The study of the force factors is conducted in the initial stage for single-tooth cutting, considering the operation of a single tooth of the tool, and for multi-tooth cutting conditions, corresponding to real cutting and forming conditions in this method.Results. Analysis of harmonic vibrations with different frequencies of the investigated forces indicates that, under average loading, the maximum principal component of the cutting force occurs on the third pass, and the tangential force on the tool axis occurs on the first pass. The variation in the frequency of these signals is explained by changes in the contact angle between the tool and the gear wheel in the machine engagement and the different number of teeth involved in cutting.Conclusions. The obtained data allowed the development of a methodology for selecting rational parameters - axial feed values, the number of passes with different cutting depths to minimize time consumption, and achieve the desired accuracy of gears. It has been demonstrated that to reduce processing errors, it is most rational to decrease cutting force by increasing the number of passes, rather than reducing the axial feed.

MODELING OF THE TOOL LIFE FUNCTION OF A HOB MILLING TOOL USING GENETIC PROGRAMMING

The tool life of a hob milling tool and its cutting parameters have the greatest impact on gear cutting costs. The aim in this research was to model the tool life function of a hob milling tool, taking into account its impact on production costs. Experimental research of the tool life of a model single-tooth hob milling tool was carried out. On the basis of the obtained measurement results and by applying genetic programming, the tool life function of the hob milling tool was modelled. The paper presents a new model of the tool life function of the model single-tooth hob milling tool depending on the input cutting parameters, which include the cutting speed, axial feed and tangential feed.

Justification of the Choice of Parameters for the Gear Power Skiving Operation Based on Computer Simulation

Abstract The paper presents the results of modelling and investigation of the gear cutting process using the power skiving method. The investigations are based on the developed geometrical model of undeformed chips. The approach is based on the original method of forming an integral three-dimensional model on the basis of discrete cross-sections of tool tooth in their successive positions on the cutting path, taking into account the shape and size of the gap previously formed by this tooth. The formulae for calculating the cutting force and the forces acting on the work gear and tool are derived as a function of the angular position of the cutter. The dependence of this force on the angle of tool shaft setting and the angle of inclination of gear teeth is studied. The formulae take into account how the cutting intensity changes due to the peculiarities of the kinematics of power skiving technology and the influence of the actual geometric parameters of the tool on the cutting force. Based on the obtained dependencies, a methodology has been developed for the selection of the axial feed rate and spindle set angle to ensure a compromise between the required productivity and the accuracy of the gear profile.