A Simple Thermal Correction for Large Spin Traction Curves

1981 ◽  
Vol 103 (2) ◽  
pp. 440-445 ◽  
Author(s):  
J. L. Tevaarwerk
Keyword(s):  
Rheological Behavior ◽  
Traction Force ◽  
Measured Data ◽  
Simple Design ◽  
Design Technique ◽  
Variable Speed ◽  
Thermal Correction ◽  
Energy Equivalence ◽  
Traction Drives ◽  
Large Spin

Presented in this paper is a simple design technique, based upon energy equivalence methods, to predict the thermally influenced large spin traction curves from a single nonspin large slip traction curve. The performance characteristics of variable speed traction drives is very closely linked to the rheological behavior of the fluid in the contact. At moderate values of spin the traction force can be predicted quite accurately from the Johnson and Tevaarwerk model. Their model is completely isothermal in nature. As the spin increases a definite discrepancy occurs between predicted and measured data and this discrepancy grows with increasing spin. Elastic effects in the fluid are negligible at these larger spin values and therefore the shearing is purely dissipative in nature. The observed discrepancy is thought to be caused by the heating of the material in the contact and the loss of limiting strength accompained by this. The model presented in this paper reduces the discrepancy between isothermally predicted spin traction and the thermally affected traction.

TRACTION DRIVE OF LOCOMOTIVES WITH HIGH MOMENTUM COLLECTOR TRACTION ELECTRIC MOTOR

2021 ◽  
Vol 2 ◽  
pp. 118-129
Author(s):  
O.V. DOROFEEV ◽  
V.I. VOROBYEV ◽  
M.I. BORZENKOV ◽  
O.V. IZMEROV ◽  
S.N. ZLOBIN
Keyword(s):  
Traction Force ◽  
Optimal Solution ◽  
Practical Implementation ◽  
Traction Drive ◽  
Traction Motors ◽  
Utility Models ◽  
High Torque ◽  
Traction Drives ◽  
Technical Solutions ◽  
Traction Electric Motor

The issues of development of traction drives of locomotives are considered. It was found that with the existing limitations of the traction force and the speed of continuous operation, asynchronous traction motors do not have clear advantages over collector motors. The possibility of creating collector motors for electric locomotives with a power equal to the used asynchronous ones has been proved, new technical solutions have been proposed for units that ensure the reliability of the latter when using high-torque motors (elastic gearwheel with chevron teeth, two-layer rubber-metal hinge, rubber-cord clutch options), as an optimal solution for the drive with collector motors, it is proposed to use a drive with a support frame motor and an axial gearbox. The directions of research necessary for the practical implementation of drives with a high-torque traction motor are determined, it is proposed to conduct research on the feasibility of creating diesel locomotives with bogies, unified with electric locomotives. The proposed solutions received two patents for inventions, eight patents for utility models, two patent applications were filed.

scholarly journals Kugel ball as an interesting application of designing the hydrosphere

2021 ◽  
Author(s):  
Ahmad Waguih Elescandarany
Keyword(s):  
Surface Roughness ◽  
Equilibrium Point ◽  
Analytical Solutions ◽  
Science Museum ◽  
Simple Design ◽  
Design Technique ◽  
Interesting Application ◽  
Natural Characteristic

Abstract Analytical solutions are not available for the partial hemispherical hydrosphere which called as the Kugel ball fountain or the Kugel ball. However, this study offers a comprehensive idea about this phenomenon presenting a design map that gives a panoramic sight enabling the designers to easily choose whatever specifications needed for their fountain. Through simplifying the author previous formulae for this type of bearings, this paper removes the mystery of the Kugel ball phenomenon and shows that no complicated mathematic or physics are needed, as believed, to be grasped for producing such fountains. A new simple design technique is used and the most two famous fountains (at the House of Science in Patras, Greece and the largest at the Science Museum of Virginia, Richmond, USA.) are checked as an application of this design. One of the most important side results of this study is finding the equilibrium point, discovered in the author previous papers, which was considered as the equilibrium point between the forces of centripetal inertia, viscosity and friction due to the surface roughness. It becomes clear that this point is a natural characteristic of this type of bearings.

scholarly journals Simple design technique for a triangular FBG filter based on a linearly chirped grating

2010 ◽  
Vol 283 (6) ◽  
pp. 985-992 ◽  
Author(s):  
Qiang Wu ◽  
Gerald Farrell ◽  
Yuliya Semenova
Keyword(s):  
Simple Design ◽  
Design Technique ◽  
Chirped Grating

scholarly journals A New Method of Flutter Boundary Prediction for Progressive Variable Speed Based on EM-KS Algorithm

2019 ◽  
Vol 37 (6) ◽  
pp. 1231-1237
Author(s):  
Junhao Liu ◽  
Hua Zheng ◽  
Shiqiang Duan ◽  
Chengming Pei
Keyword(s):  
Expectation Maximization ◽  
Prediction Method ◽  
Measured Data ◽  
New Method ◽  
Estimation Accuracy ◽  
Time Varying ◽  
Variable Speed ◽  
Smoothing Filter ◽  
Time Varying Parameter ◽  
Flutter Boundary

The flutter test with progression variable speed is actively explored in recent years. This paper proposes an improved Kalman smoothing filter (EM-KS) algorithm based on expectation maximization for the non-stationary characteristics of the signal in this type of experiment, which can effectively improve the estimation accuracy of time-varying parameter modeling. Combining with the flutter time domain criterion, a new method for flutter boundary prediction of flutter test with progression variable speed that can be recursively implemented is given. Finally, the reliability and engineering applicability of this method are validated by numerical simulation and measured data. The results show that the flutter boundary prediction method based on EM-KS does not depend on the assumption of stationary stochastic process, and the accuracy can meet the actual engineering needs.

Sign in / Sign up

Export Citation Format

Share Document