Numerical and Experimental Study of the Loaded Transmission Error of a Worm Gear With a Plastic Wheel

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Jean-Pierre de Vaujany ◽  
Michèle Guingand ◽  
Didier Remond
Keyword(s):  
Experimental Study ◽  
Transmission Error ◽  
Original Method ◽  
Worm Gear ◽  
Experimental Measurements ◽  
Structural Damping ◽  
Kelvin Model ◽  
Worm Gears ◽  
History Of ◽  
Generalized Kelvin Model

Nowadays, the wheels of worm gears with a low module can be made of plastic; thus, classical modeling can no longer be used satisfactorily. The present paper describes an original method for studying the quasistatic loaded behavior of a worm gear, with a steel worm and a nylon wheel. A generalized Kelvin model is proposed, and the computation of load sharing is described by using an equation of displacement compatibility. The history of previous deformation and the effect of the nylon’s structural damping are also taken into account. Experimental measurements of the loaded transmission error are performed with the help of optical encoders rigidly connected to the worm and gear shafts, giving access to their instantaneous angular positions. The numerical simulations fit quite well with the experimental results.

Numerical and Experimental Study of Loaded Transmission Error of Worm Gear With a Plastic Wheel

2007 ◽  
Author(s):  
Jean-Pierre de Vaujany ◽  
Miche`le Guingand ◽  
Didier Remond
Keyword(s):  
Experimental Study ◽  
Transmission Error ◽  
Original Method ◽  
Worm Gear ◽  
Experimental Measurements ◽  
Structural Damping ◽  
Kelvin Model ◽  
Worm Gears ◽  
History Of ◽  
Generalized Kelvin Model

Nowadays, the wheels of worm gears with a low module can be made of plastic, thus classical modeling can no longer be used satisfactorily. The present paper describes an original method for studying the quasi-static loaded behavior of a worm gear, with a steel worm and a nylon wheel. A generalized Kelvin model is proposed and the computation of load sharing is described by using an equation of displacement compatibility. The history of previous deformation and the effect of the nylon’s structural damping are also taken into account. Experimental measurements of the Loaded Transmission Error are performed with the help of optical encoders rigidly connected to the worm and gear shafts, giving access to their instantaneous angular positions. The numerical simulations fit quite well with the experimental results.

Load Sharing of Worm Gear With a Plastic Wheel

2006 ◽  
Vol 129 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Yann Hiltcher ◽  
Michèle Guingand ◽  
Jean-Pierre de Vaujany
Keyword(s):  
Experimental Tests ◽  
Load Sharing ◽  
Transmission Error ◽  
Original Method ◽  
Worm Gear ◽  
Structural Damping ◽  
Meshing Stiffness ◽  
History Of ◽  
Driving Torque ◽  
Very High

The material of the wheel in a worm gear has to be nonrigid due to very high sliding velocity. Such gears are currently made of plastic in the case of a small module. The present paper describes an original method for studying the quasi-static loaded behavior of a worm gear, with a steel worm and a nylon wheel. Plastics are viscoelastic materials and do not obey Hooke’s law. This paper describes an elaborated method that is a generalization of Kelvin’s model. The computation also uses experimental tests to obtain data relating to the plastic. The computation of the load sharing is described and uses the equation of displacement compatibility. The history of previous deformation and the effect of the nylon’s structural damping are taken into account. At a given constant temperature, the load sharing, meshing stiffness, and loaded transmission error depend on the driving torque and time, that is to say speed of rotation.

Load Distribution in Cylindrical Worm Gears

2000 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Point Contact ◽  
Transmission Error ◽  
Worm Gear ◽  
Gear Teeth ◽  
Total Transmission ◽  
Transmission Errors ◽  
Gear Drive ◽  
Worm Gears

Abstract A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases — that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.

Load Distribution in Cylindrical Worm Gears

2003 ◽  
Vol 125 (2) ◽  
pp. 356-364 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Point Contact ◽  
Transmission Error ◽  
Worm Gear ◽  
Gear Teeth ◽  
Total Transmission ◽  
Transmission Errors ◽  
Gear Drive ◽  
Worm Gears

A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases—that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.

Predictions of Wear and Transmission Errors of Cylindrical Worm Gears

2003 ◽  
Author(s):  
X. Wang ◽  
L. Morrish
Keyword(s):  
Transmission Error ◽  
Wear Intensity ◽  
Worm Gear ◽  
Tooth Surface ◽  
Initial Shape ◽  
Gear Design ◽  
Transmission Errors ◽  
Meshing Stiffness ◽  
Contact Patterns ◽  
Worm Gears

Transmission error (TE) is an important transmission parameter for precision worm gears. Modern cutting methods in conjunction with modern software allow manufacturers to deliver worm gear products of high accuracy to the highly competitive market. However, the initial shape of a bronze wheel tooth changes dramatically due to bedding-in and wear when gears mesh under load, and hence transmission characteristics change. A computer program is being developed to predict wear during bedding-in and constant wear rate stages for involute worm gears. A progressive wear over given number of tooth engagements is estimated using both the available experimental wear data and theoretical considerations. Being subtracted from an “as-cut” geometry, a new shape of worm wheel tooth surface can be predicted. The calculations can be executed iteratively for as many wear steps as necessary. The model takes load sharing and contact stress distribution into account to estimate the lubrication oil film thickness and wear intensity. Contact patterns, TE, load cycles and meshing stiffness are also modeled. A comparison between theoretical wear predictions and experimental wear data is made. Predictions of wear and transmission errors are useful for optimization of existing worm gear design and for development of worm gears of new designs.

Finite Element Modelling and Analysis for Involute Worm Gears With Localised Tooth Contact

2000 ◽  
Author(s):  
D. Su ◽  
F. Yang ◽  
C. R. Gentle
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Transmission Error ◽  
Worm Gear ◽  
Tooth Contact ◽  
Element Modelling ◽  
Meshing Stiffness ◽  
Modelling Method ◽  
Worm Gears ◽  
Root Stress

Abstract A general approach is reported in this paper for finite element modelling and analysis of involute worm gear with localised tooth contact. The process of finite element modelling is based on the modified tooth geometry which was presented in a previous paper. The finite element analyses were conducted using commercially available software. The following topics have been investigated in this study: (1) geometric modelling method for involute worm gears, (2) tooth elastic deformation and tooth root stress of worm gear under different loads, and (3) instantaneous tooth meshing stiffness and loaded transmission error of the involute worm gear. Although this study is aimed at involute worm gears, the method developed is applicable for other worm gear types.

scholarly journals Numerical and experimental study of the dynamic factor of the dynamic load on the urban railway

2020 ◽  
Vol 29 (1) ◽  
pp. 195-202
Author(s):  
Tran Anh Dung ◽  
Mai Van Tham ◽  
Do Xuan Quy ◽  
Tran The Truyen ◽  
Pham Van Ky ◽  
...  
Keyword(s):  
Experimental Study ◽  
Dynamic Load ◽  
Dynamic Measurement ◽  
Experimental Results ◽  
Load Factor ◽  
Dynamic Factor ◽  
Experimental Measurements ◽  
Train Speed ◽  
Dynamic Load Factor

AbstractThis paper presents simulation calculations and experimental measurements to determine the dynamic load factor (DLF) of train on the urban railway in Vietnam. Simulation calculations are performed by SIMPACK software. Dynamic measurement experiments were conducted on Cat Linh – Ha Dong line. The simulation and experimental results provide the DLF values with the largest difference of 2.46% when the train speed varies from 0 km/h to 80 km/h

An Experimental Study of Free Corrective Heat Transfer in a Parallelogrammic Enclosure

1983 ◽  
Vol 105 (3) ◽  
pp. 433-439 ◽  
Author(s):  
N. Seki ◽  
S. Fukusako ◽  
A. Yamaguchi
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Nusselt Number ◽  
Correlation Equation ◽  
Transformer Oil ◽  
Experimental Measurements ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Prandtl Numbers ◽  
Rayleigh Numbers

Experimental measurements are presented for free convective heat transfer across a parallelogrammic enclosure with the various tilt angles of parallel upper and lower walls insulated. The experiments covered a range of Rayleigh numbers between 3.4 × 104 and 8.6 × 107, and Prandtl numbers between 0.70 and 480. Those also covered the tilt angles of the parallel insulated walls with respect to the horizontal, φ, of 0, ±25, ±45, ±60, and ±70 deg under an aspect ratio of H/W = 1.44. The fluids used were air, transformer oil, and water. It was found that the heat transfer coefficients for φ = −70 deg were decreased to be about 1/18 times those for φ = 0 deg. Experimental results are given as plots of the Nusselt number versus the Rayleigh number. A correlation equation is given for the Nusselt number, Nu, as a function of φ, Pr, and Ra.

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