A Novel Approach for Computation of Constraints on Parameters of Modification of the Tooth Addendum of Precision Involute Hobs

2005 ◽  
Vol 128 (4) ◽  
pp. 803-811 ◽  
Author(s):  
Stephen P. Radzevich
Keyword(s):  
Computer Aided Design ◽  
Normal Pressure ◽  
Surface Generation ◽  
Surface Machining ◽  
Novel Approach ◽  
Part Surface ◽  
Involute Gears ◽  
Computer Representation ◽  
To Come ◽  
Aided Design

In this paper a novel modified scheme and effective computer representation for hobbing operation of precision involute gears is presented. The specific goals of the paper are as follows: (a) to provide a comprehensive understanding of the principal features of addendum modification of an involute gear hob tooth, (b) to come up with a novel approach for the computation of parameters of modification of the hob tooth addendum, (c) to determine the applicability and advantages of the application of the developed approach. The key concept in this paper is satisfaction of the necessary conditions of proper part surface generation (Radzevich, S. P., 2002, Computer Aided Design, 34, pp. 727–740) in gear hobbing operation. The research is performed with the application of the novel DG∕K approach of surface machining earlier developed by the author. The DG∕K approach of surface generation is based on fundamental results obtained in differential geometry of surfaces, and in kinematics of multiparametric motion of a rigid body in E3 space. The interested reader may wish to go to the monographs (Radzevich, S. P., 2001, Monograph Kiev, Rastan; 1991, Monograph, Kiev, Vishcha Shkola Publishing) for details. Both of the monographs are available from The Library of Congress. A novel approach for the computation of constraints on the actual values of addendum modification of an involute hob is reported in this paper. The advantages of the developed approach are threefold. It yields the computation: (a) of the minimum and the maximum allowed value of the normal pressure angle; (b) of the maximum allowed value of addendum modification of an involute hob, and (c) of the maximum allowed reduction of addendum of a gear hob. In the way of implementation is also described.

Computation of Parameters of a Form Grinding Wheel for Grinding of Shaving Cutter for Plunge Shaving of Topologically Modified Involute Pinion

2005 ◽  
Vol 127 (4) ◽  
pp. 819-828 ◽  
Author(s):  
Stephen P. Radzevich
Keyword(s):  
Transmission Error ◽  
Low Noise ◽  
Tooth Surface ◽  
Grinding Wheel ◽  
Cnc Machine ◽  
Surface Machining ◽  
Form Grinding ◽  
Novel Approach ◽  
Light Trucks ◽  
Part Surface

The paper is targeting on the finishing of precision gears for low-noise/noiseless transmission for cars and light trucks. Transmission error is the predominant cause of gear noise. The application of a topologically modified pinion results in reduction of transmission error up to two times. The required modification of the pinion tooth surface is provided on a plunge shaving operation with application of a shaving cutter of an appropriate design. A novel approach for computation of parameters of a form grinding wheel for grinding of the shaving cutter for plunge shaving of a precision involute pinion with topologically modified tooth surface is reported in the paper. The developed approach for computation of parameters of the form grinding wheel is focused on application of the shaving cutter grinder with a lack of CNC articulation. The problem under consideration is solved using the DG/K-based approach of part surface machining earlier developed by the author. (The DG/K-approach is based on fundamental results obtained in differential geometry of surfaces, and in kinematics of multi-parametric motion of a rigid body in E3 space (See Radzevich, S.P., Sculptured Surface Machining on Multi-Axis CNC Machine. Monograph, 1991, Vishcha Shkola Publishers, Kiev (in Russian). See also Radzevich, S.P., 2001, Fundamentals of Surface Machining. Monograph, Rastan, Kiev (in Russian).) An analytical solution to the problem is discussed in the paper. The solution has been used for developing software for the Mitsubishi ZA30CNC shaving cutter grinder for the needs of the automotive industry. Computer simulation reveals high accuracy of the ground shaving cutter.

On Satisfaction of the Fifth Necessary Condition of Proper Part Surface Generation in Design of Plunge Shaving Cutter for Finishing of Precision Involute Gears

2006 ◽  
Vol 129 (9) ◽  
pp. 969-980 ◽  
Author(s):  
Stephen P. Radzevich
Keyword(s):  
Gear Tooth ◽  
Numerical Control ◽  
Proper Part ◽  
Surface Generation ◽  
Tooth Surface ◽  
Necessary Condition ◽  
Analytical Mechanics ◽  
Part Surface ◽  
Involute Gears ◽  
Novel Design

In this paper, a novel modified scheme and effective computer representation for design of a plunge shaving cutter is presented. The paper aims to develop a novel design of shaving cutter for plunge shaving of precision involute gears. The study is carried out on the premise of satisfaction of the fifth necessary condition of proper part surface generation (PSG) when designing the plunge shaving cutter. In the current study, the author’s earlier developed DG/K method of surface generation is used together with the principal elements of analytical mechanics of gears. (The DG/K method is based on fundamental results obtained in differential geometry of surfaces, and on kinematics of multi-parametric motion of a rigid body in the E3 space. The interested reader may wish to go for details to the monograph: Radzevich, S.P., Fundamentals of Surface Generation, Monograph, Kiev, Rastan, 2001, 592 pp., and to: Radzevich, S.P., Sculptured Surface Machining on Multi-Axis NC Machine, Monograph, Kiev, Vishcha Schola, 1991, 192 pp.) In the particular case under consideration, the method employs (a) an analytical description of the gear tooth surface to be machined, (b) configuration of the plunge shaving cutter relative to the involute gear, (c) analytical representation of the coordinate systems transformations, and (d) the fifth condition of proper PSG that is adapted to finishing of precision involute gears. The fifth condition of proper PSG is investigated in the paper. On the premise of the obtained results of the investigation, a novel design of plunge shaving cutter for finishing of precision involute gears is proposed. The developed novel design of plunge shaving cutter can be used on shaving machines available on the market, e.g. on Gleason’s new Genesis™ 130SV computer numerical control (CNC) shaving machine.

Numerical Simulation for Optimizing Tooth Profile Using Bezier Curve

2019 ◽  
Author(s):  
Kevin Qiu ◽  
Reza Samadi
Keyword(s):  
Numerical Simulation ◽  
Stress Reduction ◽  
Computer Aided Design ◽  
Bézier Curve ◽  
Bezier Curve ◽  
Bending Stress ◽  
Novel Approach ◽  
Design Variables ◽  
Numeric Simulation ◽  
Aided Design

Abstract The research hereby introduces a novel approach to reduce tooth bending stress using a parametric numeric simulation. This Finite Element Method (FEM) is used to determine optimal design variables for an asymmetric root profile of a helical gear defined by a rational cubic Bezier curve. The gear is first modelled using a machine design software and later implemented into a 3D computer aided design (CAD) package to modify the root spline geometry using a script. A nonlinear relationship exists between the design variables and tooth bending stress. Additionally, certain trends exist between the design variables to exhibit a more optimal root profile. The simulation results show that the proposed method is feasible as the general optimization process results in significant bending stress reduction. The numerical simulation demonstrates that bending stress can be reduced by as much as 10.75% by the proposed approach.

Novel Approach for the Implementation of 3D-MID Compatible Routing Functionalities into Computer-Aided Design Tools

2014 ◽  
Vol 1038 ◽  
pp. 11-17 ◽  
Author(s):  
Jochen Zeitler ◽  
Bernhard Götze ◽  
Christian Fischer ◽  
Jörg Franke
Keyword(s):  
Computer Aided Design ◽  
Routing Algorithms ◽  
Cad Tools ◽  
Novel Approach ◽  
Attractive Option ◽  
High Standards ◽  
Aided Design ◽  
Electrical Components ◽  
Development Methods ◽  
Molded Interconnect Devices

Molded Interconnect Devices can be considered as attractive option for the integration of electronic functions into mechanical systems. While development methods and procedures reached high standards, CAD tools still drag behind. This paper focusses the necessary software structure for implementing of automated routing algorithms or other MID specific extensions into CAD tools. An innovative three-layer model will be introduced and explained in detail. This paper also describes a method for mapping electrical components on unfolded surfaces for the further implementation of the automated routing algorithms.

Interference-free tool orientation determination by a virtual enveloping element for five-axis machining of a freeform surface

2001 ◽  
Vol 215 (12) ◽  
pp. 1683-1693 ◽  
Author(s):  
R S Lee ◽  
J N Lee
Keyword(s):  
Computer Aided Design ◽  
Cutting Tool ◽  
Contact Length ◽  
Freeform Surface ◽  
Tool Orientation ◽  
Surface Machining ◽  
Cad Cam ◽  
Rear Gouging ◽  
Aided Design ◽  
Five Axis

In machining freeform surfaces on five-axis machine tools, it is very important to determine the location of the cutting tool. The commercial computer aided design/manufacturing (CAD/CAM) software for five-axis machining often lacks flexibility to specify the appropriate tool orientation and toolpath for surface machining. This paper presents a new methodology for determining feasible tool orientation of a toroidal milling cutter with collision and gouging avoidance in five-axis machining of a freeform surface. To avoid collision and rear gouging, a virtual enveloping element is proposed that is derived from the properties of the local and global surfaces. The set of tool orientations can be found first by confining the cutting tool within the virtual enveloping element. Then, the principal induced normal curvatures between the freeform surface and the cutting tool need to be evaluated to offer the criterion of gouging detection. To achieve the best combination of scallop height and machining efficiency, the contact length is also calculated for various tool orientations. The toolpaths generated by the proposed method are verified through solid cutting simulation and a trial cut on a five-axis machine.

Offset Surface Generation and Contouring in Computer-Aided Design

1987 ◽  
Vol 109 (1) ◽  
pp. 133-142 ◽  
Author(s):  
Y. J. Chen ◽  
B. Ravani
Keyword(s):  
Computer Aided Design ◽  
Numerical Control ◽  
Surface Generation ◽  
Computational Techniques ◽  
Computational Technique ◽  
Contour Lines ◽  
Computer Aided ◽  
Offset Surfaces ◽  
Aided Design ◽  
Offset Surface

Two computational techniques are presented for Computer-Aided Design (CAD) and Machining (CAM) of parametrically defined surfaces. One technique deals with construction of offset surfaces. An algorithm is presented that would allow detection and removal of the closed loop on the offset surface due to its self-intersection. The second computational technique presented deals with contouring of parametric surfaces. The technique presented allows for optimal generation of planar contour lines. The results are applied to Numerical Control (NC) machining of surfaces.

CAD-Based Calculation of Cutting Force Components in Gear Hobbing

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Tapoglou Nikolaos ◽  
Antoniadis Aristomenis
Keyword(s):  
Cutting Forces ◽  
Computer Aided Design ◽  
Simulation Code ◽  
Gear Hobbing ◽  
Involute Gears ◽  
Cutting Force Components ◽  
Force Components ◽  
The Cost ◽  
Aided Design

Gear hobbing is a common method of manufacturing high precision involute gears. The thorough knowledge of the developed cutting forces and the wear of the cutting tool are of great importance in order to produce helical and spur gears as they influence the cost of the manufacturing process and the quality of the produced gear. A novel simulation code called HOB3D was created in accordance with the above. This code can simulate the complex movements involved in gear hobbing with the best available accuracy, which is achieved by embedding the developed algorithm in a commercial computer aided design (CAD) environment. The simulation code calculates and exports the total cutting forces as well as the cutting forces in every cutting edge involved in the cutting process.

scholarly journals Design of complex surface machining on NC lathes in Esprit CAD system

2018 ◽  
Vol 2018 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Владимир Гусев ◽  
Vladimir Gusev ◽  
Елена Савина ◽  
Elena Savina
Keyword(s):  
Computer Aided Design ◽  
High Performance ◽  
Control Program ◽  
Complex Surface ◽  
Surface Machining ◽  
Cad Systems ◽  
Cad System ◽  
Computer Aided ◽  
Simultaneous Use ◽  
Aided Design

A high-performance and accurate machining of complex special surfaces with the aid of NC equipment at the simultaneous use of four and more controlled coordinate axes is impossible without application of modern CAD systems and post-processors. Functional potentialities and a methodology for the design of complex surface machining in a "flange" part in modern CAD Esprit system are considered. Control commands are described the realization of which ensures a procedure for a computer aided design of technology, the development of a control program and simulation of operation motions of working units in a lathe. The simulation of profile surface turning is described in an intelligible way which is particularly significant for the comprehension and use of material presented.

scholarly journals A Novel Approach for Design and Investigation of Dual Material Stack Gate Oxide TFET using Oxide Strip Layer Mechanism

2021 ◽  
Author(s):  
Kaushal Nigam ◽  
Dharmender Nishad
Keyword(s):  
Computer Aided Design ◽  
Gate Oxide ◽  
Subthreshold Swing ◽  
Power Switching ◽  
Novel Approach ◽  
Drain Side ◽  
Work Functions ◽  
Oxide Tunnel ◽  
Aided Design ◽  
Dual Material

Abstract In this paper, for the first time, we use a distinctive approach based on oxide strip layer in dual material stack gate oxide-tunnel field-effect transistor (DMSGO-OSL-TFET) to improve the DC, analog/RF, and linearity performance. For this, a stack gate oxide with workfunction is considered to enhance the ONstate current (ION ) and reduce the ambipolar current (Iamb). For this case, the gate electrode is tri-segmented, named as tunnel gate (M1), control gate (M2) and auxiliary gate (M3) with different gate lengths (L1, L2, L3) and work functions (φ1, φ2, φ3), respectively. To maintain dual-work functionality, the possible combinations of these work functions are considered. Technology computer-aided design (TCAD) simulations are performed and noted that the workfunction combination (φ1 = φ3 < φ2) outperforms compared to other structures. Where φ1 on the source side is used to enhance the ION , while φ3 (equal to φ1) is used on the drain side to minimize the Iamb. To further enhance the device performance, a high-K oxide strip layer is considered on the drain side to suppress the (Iamb) whereas, a low-K oxide strip layer is used at the source junction to maximize the ION . Moreover, length of gate segments, oxide strip layer height, and thickness are optimized to achieve a better ION , switching ratio, subthreshold swing (SS) and reduce the (Iamb) which helps in the gain of device and design of analog/RF circuits. The proposed device as compared to dual material control gate-oxide strip layer-TFET (DMCG-OSL-TFET) shows improvement in ION /IOF F (∼ 4.23 times), 84 % increase in transconductance (gm), 136 % increase in cut-off frequency (fT ), 126 % increase in gain bandwidth product (GBP), point subthreshold swing (15.8 mV/decade) and other significant improvements in linearity performance parameters such as gm3, VIP3, IIP3, IMD3 making the proposed device useful for low power switching, analog/RF and linearity applications.

scholarly journals USING A PROJECT ON ASSISTIVE TECHNOLOGY TO TEACH CAD AND RAPID PROTOTYPING

2018 ◽  
Author(s):  
Shalaleh Rismani ◽  
Peter Ostafichuk ◽  
Carol Jaeger ◽  
Jonathan Nakane
Keyword(s):  
Rapid Prototyping ◽  
Assistive Technology ◽  
Stakeholder Engagement ◽  
Computer Aided Design ◽  
First Year ◽  
Design Decision ◽  
Formal Instruction ◽  
Novel Approach ◽  
Design Competition ◽  
Aided Design

Abstract - This paper describes a novel approach used in a first year engineering at UBC to teach computer-aided design (CAD) and rapid prototyping as part of a real-world design project. It is centred on the design of an assistive technology device for a real client who is a quadriplegic and has limited use of his hands.  Notably, students were able to create their designs in CAD without receiving any formal instruction on the use of the tool. In addition to CAD and rapid prototyping,the project integrated elements of stakeholder engagement, design, decision-making, and communication. By the end of the three-week module, students submitted a technical memorandum recommending their design, and they were able to submit their CAD files for 3D printing and for entry into an inaugural assistive technology design competition.

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