Deformation of Flexspline under Transmission Force in Harmonic Drive

2010 ◽  
Vol 97-101 ◽  
pp. 3536-3539 ◽  
Author(s):  
Xiao Xia Chen ◽  
Shu Zhong Lin ◽  
Jing Zhong Xing
Keyword(s):  
Elastic Deformation ◽  
Shell Element ◽  
Beam Element ◽  
Tangential Displacement ◽  
Harmonic Drive ◽  
Ansys Software ◽  
Neutral Layer ◽  
Experimental Distribution ◽  
Wave Generator ◽  
Tangential Forces

Method to investigate the elastic deformation of a flexspline in harmonic driver was developed under assembly force from wave generator and transmission force. Shell element and tapered beam element were applied to model the flexspline cone and the teeth on the flexspline respectively. Forced displacement of the flexspline in assembly state was imposed by contact analysis between the flexspline and wave generator. According to experimental distribution of tangential forces in transmission state, applying forces at the teeth tips on the flexspline in mesh state, deformation distribution under transmission torque loading was obtained. Simulations of assembly state and transmission state were realized in ANSYS software. In three sections of tooth ring vertical to the axis, the deformation distributions of the flexspline under specified displacement in assembly state were compared with the theory results. Deformation between tip of tooth and neutral layer in assembly state and in transmission state were compared respectively. The deformation results agreed well with the theory results in assembly state, while difference was found in tangential displacement on tooth tips in transmission state, which may influence mesh property evidently under transmission loading.

Modeling of Flexspline and Contact Analyses of Harmonic Drive

2009 ◽  
Vol 419-420 ◽  
pp. 597-600 ◽  
Author(s):  
Xiao Xia Chen ◽  
Shu Zhong Lin ◽  
Jing Zhong Xing
Keyword(s):  
High Performance ◽  
Shell Element ◽  
Harmonic Drive ◽  
Element Analysis ◽  
Experimental Distribution ◽  
Compact Size ◽  
Wave Generator ◽  
High Reduction ◽  
And Performance ◽  
Contact Relation

Harmonic drive has widespread applications for its compact size and high reduction ratios. It is often favored for electro-mechanical systems with space and weight limitation. In order to minimize the volume and improve its transmission capacity, more and more aborative design technologies are adopted. For structural analyses in assembly state and in transmission stage, Finite Element Analysis (FEA) can be widely applied to get proper parameters and performance. Flexspline usually endures large deformation under assembly force from wave generator. In transmission state, driving force leads to multiple tooth mesh contact between flexspline and circular spline teeth. In this paper, shell element is applied to build flexspline cone, and tapered beam element is used to model the teeth on the flexspline. Contact relation between flexspline and wave generator is simulated by contact element. Forced displacement of flexspline is imposed by contact analysis. Transmission forces are acted at the teeth tips on the flexspline in mesh state, whose values are determined according to experimental distribution. Simulations of assembly state and transmission state are computed in ANSYS. Deformation and stress distribution in assembly state are compared with that in transmission state. Some suggestions for long life and high performance design are present.

Deformation of Harmonic Drive in Transmission State Based on Contact Analysis with Shell Element Tooth

2011 ◽  
Vol 86 ◽  
pp. 771-774 ◽  
Author(s):  
Xiao Xia Chen ◽  
Shu Zhong Lin ◽  
Jing Zhong Xing ◽  
Yu Sheng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Shell Element ◽  
Element Model ◽  
Contact Analysis ◽  
Contact Element ◽  
Harmonic Drive ◽  
Wave Generator ◽  
Nonlinear Contact ◽  
Deformation Distribution

The displacement of tooth and the deformation of flexspline of harmonic drive in transmission state were studied by finite element model with shell element. A finite element model of flexspline based on shell element was built with taper teeth on the flexspline, and the contact relationship was defined by contact element between the flexspline and wave generator. The deformation distribution of the flexspline and the deformed position of the teeth on the flexspline were obtained by nonlinear contact analysis in ANSYS environment under the transmission forces according to the loading distribution in the reference. The position of teeth tip and teeth root in front, middle and back plane along teeth length were given by the deformation results. The research shows that the positions and orientations of the teeth in the planes have quite different distributions, which may influence mesh property evidently. The deformation in transmission state in the paper is of importance in heavy loading harmonic drive design because there is no theory results for flexspline in transmission state.

The study of the elastic deformation of a flexible wheel by a cam wave generator

2020 ◽  
Vol 65 (1) ◽  
pp. 51-58
Author(s):  
Sava Ianici
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Elastic Deformation ◽  
Theoretical Study ◽  
Elastic Field ◽  
The Finite Element Method ◽  
Elastic Deformations ◽  
Wave Generator ◽  
Two Stages

The paper presents the results of research on the study of the elastic deformation of a flexible wheel from a double harmonic transmission, under the action of a cam wave generator. Knowing exactly how the flexible wheel is deformed is important in correctly establishing the geometric parameters of the wheels teeth, allowing a better understanding and appreciation of the specific conditions of harmonic gearings in the two stages of the transmission. The veracity of the results of this theoretical study on the calculation of elastic deformations and displacements of points located on the average fiber of the flexible wheel was subsequently verified and confirmed by numerical simulation of the flexible wheel, in the elastic field, using the finite element method from SolidWorks Simulation.

Contrastive Study on Finite Element Models of High-Strength Pipelines Crossing Active Faults

2016 ◽  
Vol 850 ◽  
pp. 957-964
Author(s):  
Wei Zheng ◽  
Hong Zhang ◽  
Xiao Ben Liu ◽  
Le Cai Liang ◽  
Yin Shan Han
Keyword(s):  
Finite Element ◽  
Design Method ◽  
Active Faults ◽  
Shell Element ◽  
High Strength ◽  
Element Model ◽  
Beam Element ◽  
Finite Element Models ◽  
Fixed Boundary ◽  
Equivalent Boundary

There is a potential for major damage to the pipelines crossing faults, therefore the strain-based design method is essential for the design of buried pipelines. Finite element models based on soil springs which are able to accurately predict pipelines’ responses to such faulting are recommended by some international guidelines. In this paper, a comparative analysis was carried out among four widely used models (beam element model; shell element model with fixed boundary; shell element model with beam coupled; shell element model with equivalent boundary) in two aspects: differences of results and the efficiency of calculation. The results show that the maximum and minimum strains of models coincided with each other under allowable strain and the calculation efficiency of beam element model was the highest. Besides, the shell element model with beam coupled or equivalent boundary provided the reasonable results and the calculation efficiency of them were higher than the one with fixed boundary. In addition, shell element model with beam coupled had a broader applicability.

A Wave Generator of New Concept for Flex Gear of Harmonic Drive With Pure Involute Tooth Gear Pairs

2000 ◽  
Author(s):  
R. Maiti ◽  
A. K. Roy
Keyword(s):  
New Wave ◽  
Harmonic Drive ◽  
Tooth Gear ◽  
Circular Arcs ◽  
Wave Generator ◽  
Accurate Performance ◽  
Involute Gears ◽  
Cam Profile ◽  
Engagement And Disengagement ◽  
Made In

Abstract A new wave generator (or cam) is proposed (Maiti, Patent 1995) to drive the flex gear of strain wave gearing i.e., harmonic drives with gear pairs of pure involute profiles. The cam profile is made of circular arcs at the two contact zones and shifted elliptical curves for the other zones. The geometric constniction is made in such a way that tip interference is properly avoided for both engagement and disengagement with nominally stubbed or full depth involute gears. The theories are established to verify other geometric and gearing conditions. Evidently, in the existing products (all are patented design) the profiles are non-involute and none of them offers ideal gear kinematics. It is expected that this new harmonic drive will offer the best gearing kinematics and will have desired accurate performance.

Locking Behavior of Isoparametric Curved Beam Finite Elements

1995 ◽  
Vol 48 (11S) ◽  
pp. S25-S29 ◽  
Author(s):  
Miguel Luiz Bucalem ◽  
Klaus-Ju¨rgen Bathe
Keyword(s):  
Shell Element ◽  
Beam Element ◽  
Curved Beam ◽  
Shear Locking ◽  
Shell Elements ◽  
One Dimensional ◽  
Curved Beam Element ◽  
The One ◽  
Insight Into ◽  
The Continuum

We present a study of the membrane and shear locking behavior in an isoparametric curved beam element. The objective is to gain insight into the locking phenomenon, specially membrane locking, of continuum based degenerated shell elements. This is possible since the isobeam element is the one-dimensional analogue of the continuum based shell element. In this context, reduced integration and mixed interpolation schemes are briefly examined. Such a study can be a valuable aid when developing new shell elements.

scholarly journals Study on Lubrication Characteristics of Novel Forced Wave Generator of Harmonic Drive without Flexible Bearing

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 215
Author(s):  
Hongli Jia ◽  
Hongbing Xin
Keyword(s):  
The Novel ◽  
Harmonic Drive ◽  
Design And Optimization ◽  
Forced Wave ◽  
Gap Ratio ◽  
Optimal Value ◽  
Wave Generator ◽  
Computational Fluid Dynamics Cfd ◽  
Lubrication Characteristics ◽  
Cfd Method

In contrast to the conventional forced wave generator which consists of cam and flexible bearing in harmonic drive, the novel forced wave generator retains cam but cancels flexible bearing. In this article, the lubrication characteristics of the novel forced wave generator in harmonic drive is studied. First, an elliptical sliding bearing (ESB) model of simplified structure between the novel forced wave generator and the flex spline is established. Further, the computational fluid dynamics (CFD) method is employed to study the effect of some factors on the lubrication characteristics of the ESB model including elliptical gap ratio, width, and rotational speed. According to the analysis, the elliptical gap ratio has a great impact and its optimal value is 3, which is used in the design of the novel forced wave generator. Last, the practical design of the novel forced wave generator in harmonic drive is given, which can provide a basis for design and optimization of a forced wave generator without flexible bearing of the harmonic drive.

scholarly journals Kinematic error of a harmonic drive

2018 ◽  
Vol 224 ◽  
pp. 01039 ◽  
Author(s):  
Igor Lyuminarsky ◽  
Stanislav Lyuminarsky
Keyword(s):  
Mathematical Model ◽  
Kinematic Error ◽  
Harmonic Drive ◽  
Elastic Interactions ◽  
Wave Generator ◽  
Flexible Gear

The article deals with the causes for kinematic error of harmonic drives. The error was determined theoretically using a mathematical model of a drive accounting elastic interactions of the drive elements. The paper identifies the main cause for the inherent kinematic error of a harmonic drive featuring a cam wave generator: a variation in a flexible gear deformation at rolling of flexible bearing balls. It was established that the highest kinematic error of a drive is significantly lower than the first harmonic of a flexible gear generating error. There is obtained a cam displacement dependence of the highest kinematic error for VZP-80 drive.

scholarly journals Two nodes cusp geometry beam element by using condensed IGA

2019 ◽  
Vol 258 ◽  
pp. 05031
Author(s):  
Buntara Sthenly Gan ◽  
Ay Lie Han
Keyword(s):  
Timoshenko Beam ◽  
Single Point ◽  
Beam Element ◽  
Vertical Shear ◽  
Tangential Displacement ◽  
Control Points ◽  
Element Analysis ◽  
Inertia Effects ◽  
Condensation Method ◽  
Straight Beam

A cusp is a curve which is made by projecting a smooth curve in the 3D Euclidean space on a plane. Such a projection results in a curve whose singularities are self-crossing points or ordinary cusps. Self-crossing points created when two different points of the curves have the same projection at a point. Ordinary cusps created when the tangent to the curve is parallel to the direction of projection on a single point. The study of a cusp geometry beam is more complex than that of a straight beam because the structural deformations of the cusp geometry beam depend also on the coupled tangential displacement caused by the singular geometry. The Isogeometric Approach (IGA) is a computational geometry based on a series of polynomial basis functions used to represent the exact geometry. In IGA, the cusp geometry of the beam element can be modeled exactly. A thick cusp geometry beam element can be developed based on the Timoshenko beam theory, which allows the vertical shear deformation and rotatory inertia effects. The shape of the beam geometry and the shape functions formulation of the element can be obtained from IGA. However, in IGA, the number of equations will increase according to the number of degree of freedom (DOF) at the control points. A new condensation method is adopted to reduce the number of equations at the control points so that it becomes a standard two-node 6-DOF beam element. This paper highlights the application of IGA of a cusp geometry Timoshenko beam element in the context of finite element analysis and proposes a new condensation method to eliminate the drawbacks elevated by the conventional IGA. Examples are given to verify the effectiveness of the condensation method in static and free vibration problems.

An Efficient Finite Element Modeling of Composite Stiffened Shells

2014 ◽  
Vol 553 ◽  
pp. 673-678
Author(s):  
Hamid Sheikh ◽  
Liang Huang
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Degrees Of Freedom ◽  
Torsional Rigidity ◽  
Shell Element ◽  
Beam Element ◽  
Shell Elements ◽  
Element Modeling ◽  
Stiffened Shells ◽  
Element Technique

This paper presents an efficient finite element modeling technique for stiffened composite shells having different stiffening arrangements. The laminated shell skin is modeled with a triangular degenerated curved shell element having 3 corner nodes and 3 mid-side nodes. An efficient curved beam element compatible with the shell element is developed for the modeling of stiffeners which may have different lamination schemes. The formulation of the 3 nod degenerated beam element may be considered as one of the major contributions. The deformation of the beam element is completely defined in terms of the degrees of freedom of shell elements and it does not require any additional degrees of freedom. As the usual formulation of degenerated beam elements overestimates their torsional rigidity, a torsion correction factor is introduced for different lamination schemes. Numerical examples are solved by the proposed finite element technique to assess its performance.

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