scholarly journals Simulation and Experimental Study on a New Successive Forming Process for Large Modulus Gears

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yao Lin ◽  
Tao Wu ◽  
Guangchun Wang
Keyword(s):  
New Technology ◽  
Spur Gears ◽  
Forming Process ◽  
Gear Teeth ◽  
Second Stage ◽  
Forming Load ◽  
Large Size ◽  
Single Tooth ◽  
Plastic Forming ◽  
Good Potential

AbstractA successive tooth forming process for producing large modulus spur gears (m>2.5 mm) is firstly proposed in this paper to break the restrictions of large forming load and large equipment structure of traditional plastic forming. It contains the preforming stage and the finishing stage. In the first stage, the die with a single-tooth preforms gear teeth one by one through several passes. In the second stage, the other die with multi-teeth refines the preformed teeth into required shape. The influence of total pressing depth and feed distribution in preforming stage on final forming quality is analyzed by numerical simulation, and the reasonable process parameters are presented. Successive tooth forming experiments are carried out on the self-designed gear forming device to verify the optimal simulation results. Gears without fold defects are well formed both in simulations and experiments, proving the feasibility of this method. Compared with the whole die forging process, the new technology has advantages of smaller load and simpler tooling, which shows a good potential for manufacturing large modulus and large size spur gears.

scholarly journals A New Successive Forming Process for Large Modulus Gears

2020 ◽  
Author(s):  
Yao Lin ◽  
Tao Wu ◽  
Guangchun Wang
Keyword(s):  
Spur Gears ◽  
Forming Process ◽  
Forming Quality ◽  
Gear Teeth ◽  
Second Stage ◽  
Forming Load ◽  
Single Tooth ◽  
New Process ◽  
Plastic Forming ◽  
Good Potential

Abstract A successive tooth forming process for producing large modulus spur gears (m＞2.5 mm) was firstly proposed in this paper to break the restrictions of large forming load and large equipment structure of traditional plastic forming. It contains the preforming stage and finishing stage. In the first stage, the die with a single-tooth preformed gear teeth one by one through several passes. In the second stage, the other die with multi-teeth refined the preformed teeth into required shape. The influence of total pressing depth and feed distribution in preforming stage on final forming quality was analyzed by numerical simulation and the reasonable process parameters had been presented. Gears without fold defects were well formed both in simulations and experiments, proving the feasibility of this method. The new process has advantages of smaller forming load and simpler tooling set, which shows a good potential for manufacturing large modulus spur gears.

A Review of Liquid Forging Process

2013 ◽  
Vol 690-693 ◽  
pp. 2275-2279 ◽  
Author(s):  
Xi Na Huang ◽  
Zhi Ping Zhong ◽  
Wei Wang ◽  
Feng Jiao Li ◽  
De Hua Qiu ◽  
...  
Keyword(s):  
Liquid Metal ◽  
New Technology ◽  
Die Casting ◽  
Die Design ◽  
Forming Process ◽  
High Quality ◽  
Simulation And Optimization ◽  
Forging Process ◽  
Bulk Forming ◽  
Plastic Forming

Liquid forging is a new technology of plastic forming. It is a kind of bulk forming process with liquid metal with high-quality and efficiency and it has the characteristics of both die casting and forging. This paper will discuss the liquid forging process, die design, simulation and optimization of liquid forging [1].

Determination of a Major Design Parameter for Forward Extrusion of Spur Gears

2004 ◽  
Vol 126 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Jong-Ho Song ◽  
Yong-Taek Im
Keyword(s):  
Design Parameter ◽  
Empirical Equation ◽  
Spur Gears ◽  
Cross Sectional ◽  
Equivalent Radius ◽  
Gear Teeth ◽  
Forming Load ◽  
Forward Extrusion ◽  
Symmetric Approximation

In this study, a major design parameter was identified for cold forward extrusion of solid or hollow spur gears by investigating the effect of gear geometries and forming variables on formation of gear teeth by finite element simulations. A limiting extrusion ratio was determined for reducing the likeliness of underfilling in the die cavity. An equivalent radius of the cross-sectional geometry of a gear was also determined to predict the forming load requirement from an axi-symmetric approximation. Based on this approximation, a modified empirical equation was determined for simple determination of forming loads required.

A Study on the Flow Behavior of 42CrMo Steel under Hot Compression by Thermal Physical Simulations

2010 ◽  
Vol 108-111 ◽  
pp. 494-499
Author(s):  
Ying Tong ◽  
Guo Zheng Quan ◽  
Gang Luo ◽  
Jie Zhou
Keyword(s):  
Strain Rate ◽  
Flow Behavior ◽  
Rate Sensitivity ◽  
Strain Hardening Exponent ◽  
Forming Process ◽  
Material Parameters ◽  
Basic Model ◽  
42Crmo Steel ◽  
Plastic Forming ◽  
Physical Simulations

This work was focused on the compressive deformation behavior of 42CrMo steel at temperatures from 1123K to 1348K and strain rates from 0.01s-1 to 10s-1 on a Gleeble-1500 thermo-simulation machine. The true stress-strain curves tested exhibit peak stresses at small strains, after them the flow stresses decrease monotonically until high strains, showing a dynamic flow softening. And the stress level decreases with increasing deformation temperature and decreasing strain rate. The values of strain hardening exponent n, and the strain rate sensitivity exponent m were calculated the method of multiple linear regression, the results show that the two material parameters are not constants, but changes with temperature and strain rate. Then the two variable material parameters were introduced into Fields-Backofen equation amended. Thus the constitutive mechanical discription of 42CrMo steel which can accurately describe the relationships among flow stress, temperature, strain rate, strain offers the basic model for plastic forming process simulation.

scholarly journals Plastic forming processes of transverse non-homogeneous composite metallic sheets

2021 ◽  
Vol 11 (1) ◽  
pp. 294-302
Author(s):  
Gal Davidi
Keyword(s):  
Inner Core ◽  
Plastic Material ◽  
Radial Solution ◽  
Algebraic Differential Equation ◽  
Forming Process ◽  
Perfectly Plastic ◽  
Plastic Forming ◽  
Validity Limit ◽  
Significant Achievement

Abstract In this work an analysis of the radial stress and velocity fields is performed according to the J 2 flow theory for a rigid/perfectly plastic material. The flow field is used to simulate the forming processes of sheets. The significant achievement of this paper is the generalization of the work by Nadai & Hill for homogenous material in the sense of its yield stress, to a material with general transverse non-homogeneity. In Addition, a special un-coupled form of the system of equations is obtained where the task of solving it reduces to the solution of a single non-linear algebraic differential equation for the shear stress. A semi-analytical solution is attained solving numerically this equation and the rest of the stresses term together with the velocity field is calculated analytically. As a case study a tri-layered symmetrical sheet is chosen for two configurations: soft inner core and hard coating, hard inner core and soft coating. The main practical outcome of this work is the derivation of the validity limit for radial solution by mapping the “state space” that encompasses all possible configurations of the forming process. This configuration mapping defines the “safe” range of configurations parameters in which flawless processes can be achieved. Several aspects are researched: the ratio of material's properties of two adjacent layers, the location of layers interface and friction coefficient with the walls of the dies.

scholarly journals Recent Developments in Coatings, Gratings, and Reflective Components

1984 ◽  
Vol 79 ◽  
pp. 607-616
Author(s):  
R. R. Shannon
Keyword(s):  
State Of The Art ◽  
New Technology ◽  
The State ◽  
Current Technology ◽  
Large Size ◽  
Incoming Radiation ◽  
Recent Developments ◽  
Electronic Sensors ◽  
Large Primary ◽  
Telescope System

The requirements on gratings and coatings for astronomical use differ from the general industrial requirements primarily in the scale of the components to be fabricated. Telescopes have large primary mirrors which require large coating plants to handle the components. Dispersive elements are driven by the requirement to be efficient in the presence of large working apertures, and usually optimize to large size in order to efficiently use the incoming radiation. Beyond this, there is a “new” technology of direct electronic sensors that places specific limits upon the image scale that can be used at the output of a telescope system, whether direct imagery or spectrally divided imagery is to be examined. This paper will examine the state of the art in these areas and suggest some actions and decisions that will be required in order to apply current technology to the predicted range of large new telescopes.

The Compliance of Solid, Wide-Faced Spur Gears

1990 ◽  
Vol 112 (4) ◽  
pp. 590-595 ◽  
Author(s):  
J. H. Steward
Keyword(s):  
Experimental Data ◽  
Contact Line ◽  
Load Distribution ◽  
3D Model ◽  
Spur Gear ◽  
Point Load ◽  
Spur Gears ◽  
Line Load ◽  
Gear Teeth ◽  
Theoretical Results

In this paper, the requirements for an accurate 3D model of the tooth contact-line load distribution in real spur gears are summarized. The theoretical results (obtained by F.E.M.) for the point load compliance of wide-faced spur gear teeth are set out. These values compare well with experimental data obtained from tests on a large spur gear (18 mm module, 18 teeth).

Coupled Thermo-Mechanical FEA of Three-Roll Cross Rolling Process for Rings with Small-Hole and Deep Groove

2012 ◽  
Vol 560-561 ◽  
pp. 846-852 ◽  
Author(s):  
Qi Ma ◽  
Lin Hua ◽  
Dong Sheng Qian
Keyword(s):  
Rolling Process ◽  
Small Hole ◽  
Fe Model ◽  
Forming Process ◽  
Software Environment ◽  
Cross Rolling ◽  
Design And Optimization ◽  
Forming Technology ◽  
Deep Groove ◽  
Plastic Forming

Ring parts with small-hole and deep groove such as duplicate gear and double-side flange, are widely used in various engineering machineries. Three-roll cross rolling (TRCR) is a new advanced plastic forming technology for the processing of rings with small-hole and deep groove. In this paper, a 3D coupled thermo-mechanical FE model for TRCR of ring with small-hole and deep groove is established under ABAQUS software environment. By simulation and analysis, the evolution and distribution laws of strain and temperature in the forming process are revealed, and the effects of the key process parameters on the deformation uniformity are explored. The results provide valuable guideline for the technological parameter design and optimization.

scholarly journals Simulation of plastic forming process of shells with minimal thickness fluctuations

2017 ◽  
Vol 201 ◽  
pp. 489-494
Author(s):  
E.G. Demyanenko ◽  
I.P. Popov ◽  
A.N. Epifanov
Keyword(s):  
Forming Process ◽  
Minimal Thickness ◽  
Plastic Forming

Querfließpressen und Verschieben*/Lateral extrusion and shifting

2017 ◽  
Vol 107 (10) ◽  
pp. 708-713
Author(s):  
M. Prof. Liewald ◽  
L. Pasler
Keyword(s):  
Numerical Simulation ◽  
New Technology ◽  
Cold Forging ◽  
Forming Process ◽  
Tensile Stresses ◽  
Lateral Extrusion

Mit dem neu entwickelten Verfahren, das Querfließpressen mit gleichzeitigem Verschieben kombiniert, lassen sich exzentrische Wellen oder kurbelwellenartige Bauteile durch Kaltfließpressen herstellen. Der Vorteil im Unterschied zur Verfahrenskombination von Stauchen und anschließendem Verschieben ist, dass das Querfließpressen ein Nachführen von Material während des Umformprozesses in die Umformzone ermöglicht. Aufgrund der verfahrensbedingten geringeren Zugspannungen in der Kurbelwange sind mit dem neuen Verfahren erweiterte Verfahrensgrenzen beim Versatz zu erwarten. Dieser Fachbeitrag beschreibt das Verfahrensprinzip, das Werkzeugkonzept und die numerische Auslegung des Prozesses.   The new technology of combined lateral extrusion and simultaneous shifting allows producing eccentric shafts or crankshaft-like components by cold forging. The advantage of lateral extrusion compared to an upsetting and subsequent shifting is the constant web thickness. For this, material is pushed into the forming zone during the forming process. It is expected that this will result in lower tensile stresses and thus lower damage in the crankshaft web. This paper describes the process, tooling concept and numerical simulation of the combined lateral extrusion and shifting process.

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