scholarly journals Generation of a double-crowned involute helical gear with twist-free tooth flanks by a CNC hobbing machine with three synchronous axes

2017 ◽  
Vol 39 (2) ◽  
pp. 97-108
Author(s):  
Van-The Tran
Keyword(s):  
Computer Simulation ◽  
Rotation Angle ◽  
Computer Numerical Control ◽  
Helical Gear ◽  
Numerical Control ◽  
Production Costs ◽  
Parabolic Curve ◽  
Transmission Errors ◽  
Simulation Results ◽  
Center Distance

In the conventional hobbing process, a double-crowned involute helical gear is generated by the hob cutter with parabolic-curve tooth profiles for the cross-profile crowning and varied the center distance between the hob and work gear for the longitudinal crowning. Therefore, to cut a double-crowned helical gear not only requires at least four synchronous axes and hob cutter regrinding (which increases production costs) but also induces twisted tooth flanks on the generated work gear. In this paper, I propose a hobbing method by applying a modified work gear rotation angle that enables double-crowning of involute helical gear's tooth flanks using a standard hob cutter and a computer numerical control (CNC) hobbing machine with only three synchronous axes. The proposed method has also verified by using two computer simulation examples to compare the meshing-conditions, contact ellipses, and transmission errors of the double-crowned gear pairs with that produced by applying the conventional hobbing method. Computer simulation results reveal the advantages of the proposed novel hobbing method.

Tooth Contact Analysis for a Double-Crowned Involute Helical Gear With Twist-Free Tooth Flanks Generated by Dual-Lead Hob Cutters

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Van-The Tran ◽  
Ruei-Hung Hsu ◽  
Chung-Biau Tsay
Keyword(s):  
Computer Simulation ◽  
Longitudinal Direction ◽  
Helical Gear ◽  
Contact Analysis ◽  
Tooth Contact Analysis ◽  
Order Function ◽  
Transmission Errors ◽  
Gear Manufacturing ◽  
Simulation Results ◽  
Dual Lead

To double-crown an involute helical gear, a hobbing method is proposed by setting the hob's diagonal feed motion as a second-order function of hob's traverse movement and modifying the tooth profile of hob cutter into a dual-lead form with pressure angle changed in its longitudinal direction. Merits of the proposed double-crowning method are also verified by using three computer simulation examples to illustrate and compare the topographies of tooth flanks, contact ellipses, and transmission errors under various assembly errors of the double-crowned gear pairs with those produced by using the conventional modified hob cutter and dual-lead hob cutter. Computer simulation results reveal the advantages of the proposed hobbing method for involute helical gear manufacturing.

Generation of the Anti-Twist Crowned Helical Gear by Modifying the Gear Rotation Angle in the Hobbing Process

2017 ◽  
Vol 749 ◽  
pp. 161-170
Author(s):  
Ruei Hung Hsu ◽  
Yu Ren Wu ◽  
Shih Sheng Chen
Keyword(s):  
Rotation Angle ◽  
Gear Tooth ◽  
Helical Gear ◽  
Gear Hobbing ◽  
Tooth Flank ◽  
Center Distance

In the gear-hobbing process, the work gear tooth flank is usually longitudinally crowned by varying the center distance between the hob and the work gear. Without crossed angle compensation, however, this center distance variation produces a twisted tooth flank on the work gear. This paper therefore proposes a methodology to reduce this tooth flank twist and achieve anti-twist in longitudinal crowning by modifying the gear rotation angle in the hobbing process which is practiced using a CNC hobbing machine with three synchronous axes.

Gear Flank Modification Using a Variable Lead Grinding Worm Method on a Computer Numerical Control Gear Grinding Machine

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Zhang-Hua Fong ◽  
Gwan-Hon Chen
Keyword(s):  
Rotation Angle ◽  
Helical Gear ◽  
Numerical Control ◽  
Helical Gears ◽  
Numerical Examples ◽  
Gear Grinding ◽  
Helical Angle ◽  
Grinding Machines ◽  
Grinding Machine ◽  
Tooth Flank

Tooth crowning of a ground helical gear is usually done by adjusting the radial feed with respect to the axial feed of the grinding worm on the modern CNC gear grinding machine. However, when the amount of crowning and the helical angle of the gear are large, this method always results in a twisted tooth flank. Hence, in this paper, we propose a tooth flank crowning method for helical gears, which uses a diagonal (combined tangential and axial) feed on a grinding machine with a variable lead grinding worm (VLGW) obtained by adjusting the axial feed of the dressing disk with respect to the rotation angle of the grinding worm. Since all the required corrective motions for the proposed VLGW method are existing CNC controlled axes on modern gear grinding machines, it can easily be implemented without extra cost to modify the grinder hardware. Three numerical examples are presented to show the validation of the proposed method and its ability to reduce tooth flank twist even in the case of a large helical angle, with a particularly significant reduction on a crowned helical gear.

MODERNIZATION AND STUDY OF THE DRIVE SYSTEM OF A MACHINING CENTER WITH COMPUTER NUMERICAL CONTROL

2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Marin Zhilevski ◽  
Mikho Mikhov
Keyword(s):  
Computer Simulation ◽  
Electric Drive ◽  
Machine Tools ◽  
Computer Numerical Control ◽  
Drive System ◽  
Numerical Control ◽  
Tabular Form ◽  
Machining Center ◽  
Electric Drive System ◽  
Selection Of

A generalized algorithm for selection of the electric drive system for a class of machining centers with computer numerical control is presented in this paper. The successive steps for the calculation of feed and spindle drives in scraping operations are shown in tabular form. The electric drive system for the considered class of ma-chines has been studied through computer simulation and on the basis of practical implementations with developed ladder diagrams. Research carried out and the results obtained can be used in the modernization of such type of machine tools.

SIMULATION OF SOFT START OF SYNCHRONOUS ELECTRIC DRIVES

2019 ◽  
Author(s):  
Shakhboz Dadabaev
Keyword(s):  
Computer Simulation ◽  
Electric Drive ◽  
Water Supply Systems ◽  
Factors Affecting ◽  
Electric Drives ◽  
Soft Start ◽  
Simulation Results ◽  
Pumping Units ◽  
Negative Factors ◽  
Supply Systems

The main negative factors affecting the starting modes of synchronous electric drives of pumping units of irrigation water supply systems were identified, computer simulation of direct and soft start of synchronous electric drive was made, the simulation results are shown in graphs and a brief conclusion was made on the study.

Computer simulation to evaluate the economics of landfill gas recovery

1998 ◽  
Vol 38 (2) ◽  
pp. 201-208
Author(s):  
M. W. Milke
Keyword(s):  
Computer Simulation ◽  
Computer Program ◽  
Landfill Gas ◽  
Base Case ◽  
Simulation Tool ◽  
Hypothetical Case ◽  
Gas Recovery ◽  
Fixed Set ◽  
Key Variables ◽  
Simulation Results

A need exists for tools to improve evaluations of the economics of landfill gas recovery. A computer simulation tool is presented. It uses a spreadsheet computer program to calculate the economics for a fixed set of inputs, and a simulation program to consider variations in the inputs. The method calculates the methane generated each year, and estimates the costs and incomes associated with the recovery and sale of the gas. Base case results are presented for a city of 500,000. An uncertainty analysis for a hypothetical case is presented. The simulation results can help an analyst see the key variables affecting the economics of a project.

Computer numerical control of electron beam machining equipments

1977 ◽  
Vol 10 (16) ◽  
pp. 655-662
Author(s):  
A. Schuler ◽  
W. Oberreiter ◽  
H. Hoffmann
Keyword(s):  
Electron Beam ◽  
Computer Numerical Control ◽  
Numerical Control
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