A Parametric Analysis of the Gear Surface Roughness After Hobbing

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Lars Vedmar
Keyword(s):  
Surface Roughness ◽  
Smooth Surface ◽  
Three Dimensional ◽  
Surface Topology ◽  
Roughness Parameters ◽  
Surface Geometry ◽  
Manufacturing Method ◽  
Differentiable Functions ◽  
Involute Gears ◽  
Dimensional Surface

Hobbing is a common manufacturing method when producing helical, involute gears. In order to give the manufactured gear a controlled surface smoothness, a method to, very accurately, determine the achieved surface geometry is needed. In this report, the cutting surfaces of the tool, of which the cutting edges are the boundaries, are assumed to be plane in arbitrary directions. They are mathematically described using parametric and analytically differentiable functions. These functions give the possibility to determine the geometry of the three-dimensional surface of the manufactured gear, without any additional numeric approximations. By comparing this surface with the smooth surface of an ideal gear, the roughness of the surface can be determined. An example is given in which the surface topology and the characteristic surface roughness parameters are determined.

Measurement Accuracy Problems of the Surface Texture Parameters

2017 ◽  
Vol 260 ◽  
pp. 227-234
Author(s):  
Natalija Bulaha ◽  
Janis Lungevics ◽  
Janis Rudzitis
Keyword(s):  
Surface Roughness ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Scientific Article ◽  
Roughness Parameters ◽  
Texture Parameters ◽  
Correlation Interval ◽  
Dimensional Surface

In this scientific article the recommendations for a three-dimensional surface roughness parameters determination of mechatronics elements are developed. First of all, the measurements for surface with irregular roughness were made, what led to the determination of a 3D roughness correlation function. On that basis correlation interval in two perpendicular treatment directions was calculated and associated with number of surface roughness uncorrelated points. Secondly, the surface roughness step parameters evaluation precision in two mutually perpendicular directions was analysed. Particular attention was paid to the roughness average step RSm in the treatment longitudinal direction. As a result, the recommendations for a 3D roughness parameters determination were prepared.

A Parametric Analysis of the Undeformed Chip Geometry in Gear Hobbing

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Lars Vedmar ◽  
Carin Andersson ◽  
Jan-Eric Ståhl
Keyword(s):  
Tool Life ◽  
Three Dimensional ◽  
Chip Thickness ◽  
Accurate Method ◽  
Manufacturing Method ◽  
Differentiable Functions ◽  
Cross Section Area ◽  
Involute Gears ◽  
Increase Tool Life ◽  
Chip Geometry

Hobbing is a common manufacturing method when producing helical, involute gears. In order to increase tool life and surface finish, an accurate method to determine chip geometry is needed. Although this accurateness may involve numeric solutions, the geometric description must, as far as possible, be analytic and give a description of the continuously changing chip geometry. In this report, the cutting edges of the tool are mathematically described using parametric and analytically differentiable functions. This gives the possibility to determine the geometry of the three-dimensional surface on the blank each cutting edge will cut with numeric approximations kept to a minimum. By comparing successively cut surfaces, the chip geometry is determined using the tool and process parameters. The mathematical description gives the possibility to calculate the required characteristic properties of the chips. These are needed for increasing the tool life in order to develop more efficient tools and processes. An example is given in which characteristics, as the maximum chip thickness, the chip cross-section area, and the mean chip thickness are calculated. The reported theory describes in detail how the chip geometry is determined.

The Many Faces of Turbine Surface Roughness

2001 ◽  
Vol 123 (4) ◽  
pp. 739-748 ◽  
Author(s):  
Jeffrey P. Bons ◽  
Robert P. Taylor ◽  
Stephen T. McClain ◽  
Richard B. Rivir
Keyword(s):  
Surface Roughness ◽  
Film Cooling ◽  
Smooth Surface ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Surface Conditions ◽  
The Many ◽  
Autocorrelation Length ◽  
Skewness And Kurtosis ◽  
Dimensional Surface

Results are presented for contact stylus measurements of surface roughness on in-service turbine blades and vanes. Nearly 100 turbine components were assembled from four land-based turbine manufacturers. Both coated and uncoated, cooled and uncooled components were measured, with part sizes varying from 2 to 20 cm. Spanwise and chordwise two-dimensional roughness profiles were taken on both pressure and suction surfaces. Statistical computations were performed on each trace to determine centerline averaged roughness, rms roughness, and peak to-valley height. In addition, skewness and kurtosis were calculated; as well as the autocorrelation length and dominant harmonics in each trace. Extensive three-dimensional surface maps made of deposits, pitting, erosion, and coating spallation expose unique features for each roughness type. Significant spatial variations are evidenced and transitions from rough to smooth surface conditions are shown to be remarkably abrupt in some cases. Film cooling sites are shown to be particularly prone to surface degradation.

Enhancement of Heat Transfer Performance in Nuclear Fuel Rod Using Nanofluids and Surface Roughness Technique

2015 ◽  
Author(s):  
Kang Liu ◽  
Titan C. Paul ◽  
Leo A. Carrilho ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Nuclear Fuel ◽  
Three Dimensional ◽  
Pressurized Water ◽  
Bulk Fluid ◽  
Fuel Rod ◽  
Dimensional Surface

The experimental investigations were carried out of a pressurized water nuclear reactor (PWR) with enhanced surface using different concentration (0.5 and 2.0 vol%) of ZnO/DI-water based nanofluids as a coolant. The experimental setup consisted of a flow loop with a nuclear fuel rod section that was heated by electrical current. The fuel rod surfaces were termed as two-dimensional surface roughness (square transverse ribbed surface) and three-dimensional surface roughness (diamond shaped blocks). The variation in temperature of nuclear fuel rod was measured along the length of a specified section. Heat transfer coefficient was calculated by measuring heat flux and temperature differences between surface and bulk fluid. The experimental results of nanofluids were compared with the coolant as a DI-water data. The maximum heat transfer coefficient enhancement was achieved 33% at Re = 1.15 × 105 for fuel rod with three-dimensional surface roughness using 2.0 vol% nanofluids compared to DI-water.

scholarly journals Properties of the Surface Layer After Trochoidal Milling and Brushing: Experimental Study and Artificial Neural Network Simulation

2019 ◽  
Vol 10 (1) ◽  
pp. 75
Author(s):  
Monika Kulisz ◽  
Ireneusz Zagórski ◽  
Jakub Matuszak ◽  
Mariusz Kłonica
Keyword(s):  
Neural Networks ◽  
Surface Roughness ◽  
Artificial Neural Networks ◽  
Cutting Speed ◽  
Mg Alloy ◽  
Polar Component ◽  
Maximum Height ◽  
Roughness Parameters ◽  
Surface Geometry ◽  
Artificial Neural

The aim of this study was to investigate the effect of milling and brushing cutting data settings on the surface geometry and energy parameters of two Mg alloy substrates: AZ91D and AZ31. In milling, the cutting speed and the trochoidal step were modified (vc = 400–1200 m/min and str = 5–30%) to investigate how they affect selected 2D (Rz, Rku, Rsk, RSm, Ra) and 3D (Sa, Sz, Sku, Ssk) roughness parameters. The brushing treatment was carried out at constant parameters: n = 5000 rev/min, vf = 300 mm/min, ap = 0.5 mm. The surface roughness of specimens was assessed with the Ra, Rz, and RSm parameters. The effects of the two treatments on the workpiece surface were analyzed comparatively. It was found that the roughness properties of the machined surface may be improved by the application of a carbide milling cutter and ceramic brush. The use of different machining data was also shown to impact the surface free energy and its polar component of Mg alloy specimens. Complementary to the results from the experimental part of the study, the investigated machining processes were modelled by means of statistical artificial neural networks (the radial basis function and multi-layered perceptron). The artificial neural networks (ANNs) were shown to perform well as a tool for the prediction of Mg alloy surface roughness parameters and the maximum height of the profile (Rz) after milling and brushing.

scholarly journals Multiscale three-dimensional surface reconstruction and surface roughness of porcine left anterior descending coronary arteries

2019 ◽  
Vol 6 (9) ◽  
pp. 190915 ◽  
Author(s):  
Hanna E. Burton ◽  
Rachael Cullinan ◽  
Kyle Jiang ◽  
Daniel M. Espino
Keyword(s):  
Surface Roughness ◽  
Coronary Arteries ◽  
Medical Devices ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Force Microscopy ◽  
Optical Scanning ◽  
Atomic Force ◽  
Reconstructed Surface ◽  
Dimensional Surface

The aim of this study was to investigate the multiscale surface roughness characteristics of coronary arteries, to aid in the development of novel biomaterials and bioinspired medical devices. Porcine left anterior descending coronary arteries were dissected ex vivo , and specimens were chemically fixed and dehydrated for testing. Surface roughness was calculated from three-dimensional reconstructed surface images obtained by optical, scanning electron and atomic force microscopy, ranging in magnification from 10× to 5500×. Circumferential surface roughness decreased with magnification, and microscopy type was found to influence surface roughness values. Longitudinal surface roughness was not affected by magnification or microscopy types within the parameters of this study. This study found that coronary arteries exhibit multiscale characteristics. It also highlights the importance of ensuring consistent microscopy parameters to provide comparable surface roughness values.

Sign in / Sign up

Export Citation Format

Share Document