Effect of extended tooth contact on the modeling of spur gear transmissions



Publisher: National Aeronautics and Space Administration, Publisher: U.S. Army Research Laboratory, Publisher: National Technical Information Service, distributor in [Washington, DC, Adelphi, MD?], [Springfield, Va

Written in English
Published: Downloads: 399
Share This

Subjects:

  • Gearing, Spur.

Edition Notes

StatementHsiang Hsi Lin ... [et al.].
SeriesArmy research laboratory ARL-TR -- 159., NASA technical memorandum -- 106174., Army research laboratory ARL-TR -- 159., NASA technical memorandum -- 106174.
ContributionsLin, Hsiang Hsi., United States. National Aeronautics and Space Administration., U.S. Army Research Laboratory.
The Physical Object
FormatMicroform
Pagination1 v.
ID Numbers
Open LibraryOL14701037M

In this study, the separate benefits of an HCR gear and asymmetric teeth are unified into a spur gear with asymmetric teeth. In this case, the effect of the gear contact ratio, addendum factor. Maximum life spur gear design. M. SAVAGE, B. MACKULIN, H. COE and J. COY; 27th Joint Propulsion Conference August Effect of extended tooth contact on the modeling of spur gear transmissions. In this study a large scale digitized approach is used for an uninterrupted static and dynamic analysis of spur gearing. An interactive method was developed to calculate directly the variable gear mesh stiffness as a function of transmitted load, gear profile errors, gear tooth deflections and gear hub torsional deformation, and position of contacting profile points. This model is circular and is geometrically different from the rectilinear gear model of Azar and Crossley. By taking advantage of involute tooth profile, we are able to take material compliance and energy dissipation into account. Furthermore, the complicated phenomenon of contact tooth pairs alternation between one and two during meshing is.

  Considering the effects of profile shift and tooth crack, Time-varying mesh stiffness (TVMS) is determined based on an analytical model and the result accuracy is also verified by Finite element (FE) model. Then, by introducing TVMS into the FE model of a gear rotor system, the combined effects of profile shifted gear pair under positive, negative and zero gear transmission conditions and. 68 Gurumani R. et al.: Modeling and Contact Analysis of Crowned Spur Gear Teeth It is more suitable to use 3D modeling, because of tooth height, tooth thickness and tooth face width of a gear tooth in three mutually perpendicular directions are comparable with each other. Further, an elliptical contact area formed when two three-dimensional. A reduced-order dynamic model, based on three-dimensional (3D) finite element model (FEM) and component modal synthesis technique (CMS), was presented for simulating the dynamic behavior of the spur gear system. The gear shaft and gear body were established via 3D elements to simulate bending and torsion of the gear system. The CMS technique was used to generate a reduced-order model of a spur. A model of a simple parallel-shaft, spur-gear transmission is presented. The model is developed to simulate dynamic loads in power transmissions. Factors affecting these loads are identified. Included are shaft stiffness and inertia, load and power source inertia, tooth geometry, tooth stiffness, local compliance due to contact stress, load.

did include spur gear defects. Parey etc. [3] developed a six DOF nonlinear model for a pair of spur gears on two shafts, calculated the Hertzian stiffness for the tooth surface contact, and implemented the empirical mode decomposition (EMD) method to simulate the different defect widths. The above research is based on fix-axis gears.   In this work, a nonlinear dynamic model of an FZG-A10 spur gear was investigated by taking into account for the actual time-varying gear mesh stiffness and the frictional effects between meshing gear teeth to evaluate the influence of the dynamic effects on frictional gear .   The estimation of gear stiffness is an important parameter for determining loads between the gear teeth when two sets of teeth are in contact. In this paper, a 2-D tooth model is developed for finite elements analysis. Gear friction occurs at the interface of lubricated tooth contacts that are subject to combined sliding and rolling motions. Engineered gear tooth surfaces that are not smooth experience diverse lubrication conditions, ranging from full-film to mixed elastohydrodynamic lubrication (EHL) or boundary lubrication conditions, depending on surface and operating conditions and lubricant characteristics.

Effect of extended tooth contact on the modeling of spur gear transmissions Download PDF EPUB FB2

The article "Effect of Extended Tooth Contact on the Modeling of Spur Gear Transmissions " appeared in the July/August issue of Gear Technology. Summary In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact.

Effect of extended tooth contact on the modeling of spur gear transmissions. Dynamic stress prediction for spur gears compared to gear rig measurements. OZKUL; 23rd Joint Propulsion Conference August 29th Joint Propulsion Conference and Exhibit.

28 June - 30 June   In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved.

This means the zone of tooth contact and average tooth meshing stiffness are underestimated and the individual tooth load is overstated, especially for heavily-loaded Cited by: Effect of extended tooth contact on the modeling of spur gear transmissions.

By Jifeng Wang, Hsiang Hsi Lin, Fred B. Oswald and John J. Coy. Abstract. In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the. During meshing of a gear pair, the total load is shared between different teeth.

Generally in standard spur gear transmissions, a contact ratio between one and two is found, meaning that for a certain part of the meshing cycle, a single tooth carries the load, while for the remaining time of the meshing cycle, two teeth share the load.

21 Effect of Extended Tooth Contact on the Modeling of Spur Gear Transmissions (July/August ) In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved.

3 Effect of Extended Tooth Contact on the Modeling of Spur Gear Transmissions (July/August ) In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact.

Deflection of loaded teeth is not introduced until the equations of motion are solved. Energy efficiency and functional reliability are the two key requirements in the design of high-performance transmissions.

Therefore, a representative analysis replicating real operating conditions is essential. This paper presents the thermoelastohydrodynamic lubrication (TEHL) of meshing spur gear teeth of high-performance racing transmission systems, where high generated contact pressures.

In high precision and heavily loaded spur gears the effect of gear errors is negligible, so the periodic variation of tooth stiffness is the principal cause of noise and vibration. High contact ratio spur gears could be used to exclude or reduce the variation of tooth stiffness.

A model is presented which enables the simulation of the three-dimensional static and dynamic behavior of planetary/epicyclic spur and helical gears with deformable parts. The contributions of the deflections of the ring gear and the carrier are introduced via substructures derived from 3D finite element models.

Link to Article: Effect of Extended Tooth Contact on the Modeling of Spur Gear Transmissions. Tell your friends and customers you were featured in the article Effect of Extended Tooth Contact on the Modeling of Spur Gear copy one of the highlighted code examples below and paste it into your website's HTML.

Simple Link. The second effect of the teeth deflection is an earlier start of contact. As seen in Fig. 1, due to the delay interval, the base of the driving tooth hits the tip of the driven one at point I, before the theoretical start of contact -i.e., point e– and outside the pressure line [35,36].This hit induces a shock, which is source of noise and vibrations.

[3] [4] [5][6][7][8][9] By using a finite element model (FEM) of a spur gear pair, Tharmakulasingam et al. 4 studied the effect of tip relief on contact stress distributions, analyzed LSTE. In the proposed scheme, a dynamic model of a spur gear system is firstly developed to generate realistic vibrations, which allows a quantitative study of the effects of gear tooth surface wear on.

ence of extended tooth contact on the static and dynamic loads of a low-contact-ratio spur gear transmission. The findings may form the basis:for improvements in the spur gear dynamic analysis code [)ANST (Dynamic ANalysis of Spur gear Transmissions).

Theory and Analysis Two sets of low-contact-ratio gears were considered for an analytical. A model is presented taking into account off line-of-action, non-linear wheel stiffness by using the finite element method, and elasticity coupling between the gear teeth.

The contact points are determined by searching the common normal using the undeformed, but otherwise true theoretical, tooth shapes where the teeth have a tip rounding to.

Get this from a library. Effect of extended tooth contact on the modeling of spur gear transmissions. [Hsiang Hsi Lin; United States. National Aeronautics and Space Administration.; U.S.

Army Research Laboratory.;]. Tooth Profile Modification and its Effect on Spur Gear Pair Vibration in Presence of Localized Tooth Defect - Volume 28 Issue 2 - M. Divandari, B. Aghdam, R. Barzamini.

The effects of the shape of tooth profile modifications on the transmission error, bending, and contact stress of spur gears Y A Tesfahunegn, F Rosa, and C Gorla Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 8, A spur gear having 14 numbers of teeth was modelled in CATIA V5 and a single spur gear tooth was considered for Finite Element Analysis as per the Lewis Model for investigating bending stress in.

First, experimental and numerical results at low speeds are compared and confirmed that the proposed tooth mesh interface model is valid. Comparisons were then extended to dynamic fillet stresses on both spur and helical gears between 50– rpm on pinion shaft. Considering the effects of the extended tooth contact and tooth root crack on the time-varying mesh stiffness (TVMS), a finite element (FE) model of a spur gear pair in mesh is established by ANSYS software.

TVMS under different crack depths at constant rated torque (60 Nm) are calculated based on the FE model. But in actual practice, extended tooth contact (ETC) occurs due to gear tooth deflection under load.

Considering the effect of ETC, the mesh stiffness in the pre-mature and post-mature contact regions is gradually rather than abruptly varying with time, which would influence the parametric stability of the geared system significantly.

In this research, we consider the standard spur gear tooth with a module m whose profile is generated by a standard rack (f = 1, c =α = 20°) with double rounded tooth tip at each side as shown in Fig.␣ generation of spur gear tooth shape during the cutting process is equivalent to the pure rolling of the pitch line of the rack against the pitch circle of a gear blank.

Considering the effects of the extended tooth contact, a finite element (FE) model of a gear pair is established based on ANSYS software. TVMS of the perforated gear with crack propagating through tooth and rim are calculated by using the FE model.

2 Asymmetric spur gear teeth The two profiles (sides) of a gear tooth are functionally different for many gears. The workload on one profile is significantly higher and is applied for longer periods of time than for the opposite one.

The design of the asym-metric tooth shape reflects this functional difference. Fig. 2: Asymmetric spur gear. This paper presents a planar spur gear planetary transmission model, describing in great detail aspects such as the geometric definition of geometric overlaps and the contact forces calculation, thus facilitating the reproducibility of results by fellow researchers.

The planetary model is based on a mesh model already used by the authors in the study of external gear ordinary transmissions. Effect of extended tooth contact on the modeling of spur gear transmissions. HSIANG LIN, JIFENG WANG, FRED OSWALD and JOHN COY; 29th Joint Propulsion Conference and Exhibit August Finite-element analysis of ring gear/casing spline contact.

NASA Contractor Report Flexibility Effects on Tooth Contact Location in Spiral Bevel Gear Transmissions P. Altidis and M. Savage The University of Akron. On the spur-gear dynamic tooth-load under consideration of system elasticity and tooth involute profile.

Mechanisms, Transmissions, and Automn in Des.,(September), –. Effect of extended tooth contact on the modeling of spur gear transmissions. J. COY; 27th Joint Propulsion Conference August Bending strength model for internal spur gear teeth. The determination of the mesh stiffness and the load sharing of tooth gears is critical to predict the dynamic behavior or the load capacity of spur gear transmissions.

Several models for the meshing stiffness and studies on the load distribution along the line of contact .Gearbox dynamics are characterized by a periodically changing stiffness due to multiple teeth contacts. In real gear systems, a backlash also exists that can lead to a loss in contact between the teeth.

Due to this loss of contact, the gear has piecewise linear stiffness characteristics. This paper examines the effect of backlash in the two-stage gear system.