scholarly journals Numerical Simulation of Gear Heat Distribution in Meshing Process Based on Thermal-structural Coupling

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Peixiang Xu
Keyword(s):  
Heat Conduction ◽  
High Speed ◽  
Element Model ◽  
Simulation Method ◽  
Spur Gear ◽  
Gear Transmission ◽  
Heat Distribution ◽  
Heavy Load ◽  
Structural Coupling ◽  
Meshing Process

The thermal balance state of high-speed and heavy-load gear transmission system has an important influence on the performance and failure of gear transmission and the design of gear lubrication system. Excessive surface temperature of gear teeth is the main cause of gluing failure of gear contact surface. To investigate the gear heat distribution in meshing process and discuss the effect of thermal conduction on heat distribution,a finite element model of spur gear is presented in the paper which can represent general involute spur gears. And a simulation approach is use to calculate gear heat distribution in meshing process. By comparing with theoretical calculation, the correctness of the simulation method is verified, and the heat distribution of spur gear under the condition of heat conduction is further analyzed. The difference between the calculation results with heat conduction and without heat conduction is compared. The research has certain reference significance for dry gear hobbing and the same type of thermal-structural coupling analysis.

Effect of Gear Tooth Crack on Spur Gear Dynamic Response by Simulation

2011 ◽  
Author(s):  
Yimin Shao ◽  
Xi Wang ◽  
Zaigang Chen ◽  
Teik C. Lim
Keyword(s):  
Dynamic Response ◽  
Gear Tooth ◽  
Sudden Change ◽  
Element Model ◽  
Spur Gear ◽  
Operating Conditions ◽  
Lumped Parameter Model ◽  
Mesh Stiffness ◽  
Heavy Load ◽  
High Rotational Speed

Geared transmission systems are widely applied to transmit power, torque and high rotational speed, and as well as change the direction of rotational motion. Their performances and efficiencies depend greatly on the integrity of the gear structure. Hence, health monitoring and fault detection in geared systems have gained much attention. Often, as a result of inappropriate operating conditions, application of heavy load beyond the designed capacity or end of fatigue life, gear faults frequently occur in practice. When fault happens, gear meshing characteristics, including mesh stiffness that is one of the important dynamic parameters, can be affected. This sudden change in mesh stiffness can induce shock vibration as the faulty gear tooth passes through the engagement zone. In this study, a finite element model representing the crack at the tooth root of a spur gear is developed. The theory is applied to investigate the effect of different crack sizes and the corresponding change in mesh stiffness. In addition, a lumped parameter model is formulated to examine the effect of tooth fault on gear dynamic response.

The Stress Analysis on Spur Gear Meshing Simulation

2013 ◽  
Vol 392 ◽  
pp. 151-155
Author(s):  
Zheng Li ◽  
Yang Chen
Keyword(s):  
Gear Tooth ◽  
Nonlinear Behavior ◽  
Element Model ◽  
Spur Gear ◽  
Contact Analysis ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Reliable Model ◽  
Nonlinear Behaviors ◽  
Meshing Process

The gear meshing is a very complicated process due to the nonlinear behaviors during the teeth contact. It is necessary to build a reliable model to simulate gear meshing process which can consider geometry and boundary conditions nonlinear behavior in gear tooth contact analysis. This paper propose a 3D finite element model to simulate the meshing process of a pair of spur gears, and then carry out the gear tooth contact analysis with the consideration of nonlinear behaviors. The results and relevant discussions will indicate and explain some significant phenomena of the gear tooth contact characteristics in gear meshing process.

Multiple Influencing Factors Analysis for Non-Conformal Contact Characteristics of Ball Screw

2011 ◽  
Vol 199-200 ◽  
pp. 707-714
Author(s):  
Fu Ji Wang ◽  
Jian Wei Ma ◽  
Zhen Yuan Jia ◽  
Jiang Yuan Yang ◽  
Di Song
Keyword(s):  
High Speed ◽  
Contact Stiffness ◽  
Simulation Method ◽  
Transmission Efficiency ◽  
Ball Screw ◽  
Design Parameters ◽  
Heavy Load ◽  
Theoretical Support ◽  
Element Simulation ◽  
Conformal Contact

The contact between balls and screw races or nut races is a kind of typical non-conformal contact. The study of contact characteristics of ball screw will provide theoretical bases for improving transmission efficiency and working properties of ball screw. In this study, hertz contact theory was adopted to construct the solution formula of ball screw’s contact stiffness, ball screw’s contact characteristics in terms of axial load, design parameters and material properties was analyzed, and the contact deformation value of the contact between ball and screw races was got using finite element simulation method. The simulation result is close to the theoretic value, which proves the correctness of the theory analysis. The present study offers theoretical support for the design and application of high speed, heavy load and precision ball screws.

scholarly journals Research on matching conditions of coaxial six-branch split-torsion herringbone gear transmission system

2021 ◽  
Vol 39 (2) ◽  
pp. 341-349
Author(s):  
Zhibin Li ◽  
Sanmin Wang ◽  
Fei Li ◽  
Qi'an Peng ◽  
Jianfeng Li
Keyword(s):  
Calculation Method ◽  
High Speed ◽  
High Reliability ◽  
Three Dimensional ◽  
Matching Condition ◽  
Transmission System ◽  
Gear Transmission ◽  
Heavy Load ◽  
Gear Transmission System ◽  
Herringbone Gear

Compared with traditional gear transmission, the multi-branch split-torsion gear transmission system has the advantages of large transmission power, small size and high reliability, so it is more and more used in high-speed heavy load occasions such as ships and aircraft. Since the transmission system of multi-branch split torsional gears belongs to over-constrained configuration, it is necessary to meet strict tooth matching condition in the design process in order to realize the correct synchronous meshing of each branch, which is of great significance to ensure its uniform installation and motion synchronization.Aiming at the coaxial six-branch twisted herringbone gear transmission system, this paper establishes a calculation method for the proper meshing conditions of each branch on the basis of considering the movement synchronization of each branch and preventing geometric interference.In addition, the calculation of gear allocation was carried out for a ship's power transmission system, and a parameter scheme that satisfies the requirements of transmission ratio, concentricity and synchronous meshing was obtained.The correctness of the calculation method of tooth matching in this paper is verified by three-dimensional modeling. This method has universal application value to the tooth matching design of other coaxial multi-branch gear transmissions.

Design principle and modeling method of asymmetric involute internal helical gears

2018 ◽  
Vol 233 (1) ◽  
pp. 244-255 ◽  
Author(s):  
Mo Shuai ◽  
Ma Shuai ◽  
Jin Guoguang ◽  
Gong Jiabei ◽  
Zhang Ting ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Planetary Gear ◽  
High Strength ◽  
Spur Gear ◽  
Low Noise ◽  
Gear Transmission ◽  
Contact Ratio ◽  
Transmission Systems ◽  
Helical Gears

In the field of mechanical engineering, involute helical gears are widely used. Compared with the involute spur gear, helical gears have a high bearing strength, more smooth transmission, less impact and less noise. The internal gear pairs have the features of large transmission ratio, low vibration, low noise and low wear and hence are widely used in planetary gear transmission systems. In order to meet the requirements of high strength, high speed of the modern gear transmission systems, a new type of asymmetric involute internal helical gears is designed based on conventional involute gears. This paper discusses the gear shaper cutter modeling for machining this new gear, analyzes the formation principle of asymmetric tooth profile and establishes a three-dimensional modeling by SolidWorks. Through MATLAB simulation, pressure angle, tooth number, coefficient of displacement and contact ratio of conventional and asymmetric gear are compared and analyzed. Using ANSYS, two types of gears are compared on strength in order to demonstrate superiority of asymmetric tooth and further study about the asymmetric internal helical gears.

scholarly journals Multicriteria Optimization Design for End Effector Mounting Bracket of a High Speed and Heavy Load Palletizing Robot

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Ying He ◽  
Jiangping Mei ◽  
Jiawei Zang ◽  
Shenglong Xie ◽  
Fan Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Natural Frequency ◽  
Multicriteria Optimization ◽  
High Speed ◽  
Optimization Design ◽  
Element Model ◽  
Contrastive Analysis ◽  
Heavy Load ◽  
End Effector

End effector mounting bracket is an important load bearing part of high speed and heavy load palletizing robot, which is located at the most distant point in robot rotation radius and frequently works in complex conditions such as start-stop, switch direction, and acceleration and deceleration motion; therefore, optimizing design for its structure is beneficial to improve the dynamic performance of robotic system and reduce energy consumption. Firstly, finite element model of end effector mounting bracket was established, and its accuracy was verified by contrastive analysis of modal test result and finite element model. Secondly, through modal analysis, vibration response test, frequency response analysis, and the static analysis, taking inertia into account, the mass is minimized, the maximal stress is minimized, the maximal deformation is minimized, and the first natural frequency is maximized as the optimization objectives are determined; the design variables were selected by sensitivity analysis, taking their value range as the constraint conditions; approximation models of objective functions were established by the Box-Behnken design and the response surface methodology, and their reliability was validated; to determine weighting factor of each optimization objective, an analytic hierarchy process based on finite element analysis (FEA + AHP) method was put forward to improve the objectivity of comparison matrix; subsequently, the multicriteria optimization mathematical model was established by the methods mentioned above. Thirdly, the multicriteria optimization problem was solved by the NSGA-II algorithms and optimization results were obtained. Finally, the contrastive analysis results between optimized model and initial model showed that, in the case of the maximum stress and deformation within allowable values range, the mass reduction was 17.8%; meanwhile, the first natural frequency was increased, and vibration response characteristics of the entire structure were improved significantly. The validity of this optimization design method was verified.

Tool-Chip Friction and Two-Dimensional Numerical Simulation Analysis of High-Speed Milling AISI304

2015 ◽  
Vol 1089 ◽  
pp. 377-380
Author(s):  
Lin Lin Guo ◽  
Guang Hui Li ◽  
Ning Xia Yin ◽  
Guang Yu Tan
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Simulation Analysis ◽  
Chip Morphology ◽  
Element Model ◽  
Simulation Method ◽  
State Theory ◽  
Friction Model ◽  
Two Dimensional ◽  
High Speed Milling

The physical friction system model was established between the tool and the chip based on the analysis of tri-bological behavior of high speed milling process of the end mill. The finite element simulation method was employed to study the tool-chip friction model, and the two-dimensional(2D) finite element model of milling was created. The numerical results revealed the chip morphology, stress and temperature distribution of the tool-chip contact surface. The tool temperature field distribution provided supports for tool-chip friction state theory and the 3D milling model.

Analysis and Simulation of Air Flow Field Surrounding Grinding Wheel

2014 ◽  
Vol 1027 ◽  
pp. 12-15 ◽  
Author(s):  
Chun Yu Wang ◽  
Lei Zhang ◽  
Chun Feng Yang
Keyword(s):  
Flow Field ◽  
Contact Zone ◽  
High Speed ◽  
Thermal Damage ◽  
Air Flow ◽  
Element Model ◽  
Simulation Method ◽  
Grinding Wheel ◽  
Speed Increase ◽  
Conventional Grinding

In grinding, high specific heat is generated and hence it is very important for the fluid to remove heat from the grinding contact zone to avoid thermal damage to the workpiece surface and/or sub-surface layers. In conventional grinding, a stiff air layer is generated due to the rotation of the porous grinding wheel at high speed. Hence, most of fluid isn’t penetrated into the grinding contact zone because of the stiff air layer around the grinding wheel. To improve grinding fluid cooling effection and avoid thermal damage, it is necessary to analyze the air flow and stiff air layer around the grinding wheel. Based on fluid dynamics and mathematical simulation method, the 3D finite element model of the air flow field around the grinding wheel is developed. The air flow pressure field and flow velocity near the grinding zone are analyzed. In results, the pressure and the velocity of the air flow near the grinding zone increase with the wheel speed increase, and the pressure and the velocity of the air flow near the grinding zone increase with the minimum gap between the grinding wheel and the workpiece reducing. After the air is drived by the grinding wheel into the high pressure area near the grinding zone, the air flows around both sides of the grinding wheel and there are no obvious returning air flow phenomena.

Strength Evaluation of Polymer Composite Spur Gear by Finite Element Analysis

2008 ◽  
Author(s):  
Mohammad Robiul Hossan ◽  
Zhong Hu
Keyword(s):  
Finite Element ◽  
Polymer Composite ◽  
Volume Fraction ◽  
Gear Tooth ◽  
Axial Stress ◽  
High Stress ◽  
Element Model ◽  
Simulation Method ◽  
Spur Gear ◽  
Element Analysis

Modern advanced polymer composite materials have opened a new level of noiseless, lubricant free, high resilience and precision gearing in power and motion transmission. The proper understanding and evaluation of gear strength and performance is an important prerequisite for any reliable application. In this paper, a 20% short glass fiber reinforced nylon66 spur gear fabricated by injection molding has been carefully investigated. A three-dimensional finite element model was used to simulate the multi-axial stress-strain behaviors of a gear tooth under the dynamic load for a complete working cycle with a special geometry, operating condition, fiber orientation and volume fraction. The strength of composite gears has been compared with isotropic un-reinforced nylon66 and steel gears. The tooth root region of a gear which usually experiences high stress and potential to failure has been carefully investigated. This computer simulation method can be used as a useful tool for evaluating strength and predicting failure of the polymer composite gears.

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