Effects of Frictional Loss on Bicycle Chain Drive Efficiency

1999 ◽  
Vol 123 (4) ◽  
pp. 598-605 ◽  
Author(s):  
James B. Spicer ◽  
Christopher J. K. Richardson ◽  
Michael J. Ehrlich ◽  
Johanna R. Bernstein ◽  
Masahiko Fukuda ◽  
...  
Keyword(s):  
Energy Loss ◽  
Type Systems ◽  
Mechanical Efficiency ◽  
Chain Drive ◽  
Frictional Loss ◽  
Infrared Measurements ◽  
Drive Trains ◽  
Chain Drives ◽  
Lubrication Conditions ◽  
Loss Mechanisms

Chain drive efficiency has been studied to understand energy loss mechanisms in bicycle drive trains, primarily for derailleur-type systems. An analytical study of frictional energy loss mechanisms for chain drives is given along with a series of experimental measurements of chain drive efficiency under a range of power, speed and lubrication conditions. Measurements of mechanical efficiency are compared to infrared measurements indicating that frictional losses cannot account for the observed variations in efficiency. The results of this study indicate that chain tension and sprocket size primarily affect efficiency and that non-thermal loss mechanisms dominate overall chain drive efficiency.

Energy Recovery Methods in Adsorption Refrigeration Units

2017 ◽  
Author(s):  
Andrzej Grzebielec ◽  
Adam Szelągowski ◽  
Adam Ruciński
Keyword(s):  
Energy Loss ◽  
Thermal Wave ◽  
Energy Recovery ◽  
Type Systems ◽  
Adsorption Refrigeration ◽  
Wave Type ◽  
Recovery Processes ◽  
Refrigeration Unit ◽  
The One ◽  
Heat And Mass Recovery

Adsorption refrigeration systems, as opposed to absorption type operate in a cyclic manner. The result is that at the beginning of each process must be fed into the adsorber state in which they will adsorb or desorb a refrigerant. In the case of two adsorbers at the start of a cycle, the one of the adsorber must be refrigerated while the second has to be heated. These processes are causing unnecessary energy loss. The aim of the work is to show how these processes can be connected and the heat received from one adsorber is transported to another adsorber. As part of the study, the heat and mass recovery processes will be considered. It turns out that in the thermal wave type systems, it is possible to recover more than 25% of the energy lost to bring the adsorber to the states in which they will operate efficiently to desorb and adsorb refrigerant. That is, it is possible to improve the efficiency of the adsorption refrigeration unit using the proposed improvements.

Study of Energy Loss Mechanisms in AlN-Based Piezoelectric Length Extensional-Mode Resonators

2019 ◽  
Vol 28 (4) ◽  
pp. 619-627 ◽  
Author(s):  
Afzaal Qamar ◽  
Stewart Sherrit ◽  
Xu-Qian Zheng ◽  
Jaesung Lee ◽  
Philip X.-L. Feng ◽  
...  
Keyword(s):  
Energy Loss ◽  
Loss Mechanisms

Numerical Simulation on Dynamic Behavior of Intermittent Roller Chain Drives

2012 ◽  
Vol 155-156 ◽  
pp. 535-539 ◽  
Author(s):  
Li Xin Xu ◽  
Yong Gang Li
Keyword(s):  
Numerical Simulation ◽  
Dynamic Behavior ◽  
Simulation Analysis ◽  
Longitudinal Vibration ◽  
Three Dimension ◽  
Chain Drive ◽  
Rigid Body Dynamic ◽  
Analysis And Design ◽  
Roller Chain ◽  
Chain Drives

A detailed numerical simulation analysis on the dynamic response of intermittent roller chain drive has been carried out in this study. Instead of using analytical method, three dimension solid modeling software and multi-rigid body dynamic analysis software are utilized for modeling and simulating the dynamic behavior of chain drive. The longitudinal vibration response of the chain links is concentrated on, which aims to reveal the dynamic characteristics of the intermittent chain drive under varying motion laws such as the modified sinusoid (MS), the modified constant velocity (MCV) and the unsymmetrical modified trapezoid (UMT). The simulation results can enable designers to require information on the analysis and design of mechanisms with the intermittent roller chain drives.

Probability of Load-Carrying Ability of Two-Profile Chain Drives

2000 ◽  
Author(s):  
Petro D. Kryvyy ◽  
Ihor M. Bey ◽  
Oksana I. Shymanska ◽  
Petro P. Kryvyy
Keyword(s):  
Measurement Procedure ◽  
Chain Drive ◽  
Distribution Law ◽  
Drive Roller ◽  
Load Carrying ◽  
A Chain ◽  
Dimension Type ◽  
Chain Drives ◽  
Unit Pressure

Abstract The analysis of the available calculation methods of chain-drives load-carrying ability is given according to the criterion of the tolerance unit pressure in a single profile chain joint [p]0. It is shown, that the values of [p]0 were determined according to the deterministic ideas without consideration of the distribution law of both random varieties of contact step of inner and outer rings and lengths of drive strands of the first and second profile of the chain drive. Probability task of determination of the tolerance unit pressure in two profile chain joints [p0]q is solved, when the structural, technological and physical-mechanical characteristic of the chain, that is, the lengths of drive strand of a chain-drive, accuracy of contact steps and stiffness of a drive roller chain are considered. The measurement procedure and the empirical dependencies for determination of drive roller chains deformation and stiffness are presented. As a result, the dependencies for the determination of [p0]q as the basic criterion according to which selection of a chain dimension-type, as well as characteristics used for the comparative estimation of a drive chain quality of different manufacturers when certain probability estimations are taken into consideration, were obtained.

Toward a More Exact Kinematics of Roller Chain Drives

1988 ◽  
Vol 110 (3) ◽  
pp. 269-275 ◽  
Author(s):  
C.-K. Chen ◽  
F. Freudenstein
Keyword(s):  
Impact Velocity ◽  
Kinematic Analysis ◽  
Design Stage ◽  
Chain Drive ◽  
Slow Speed ◽  
Roller Chain ◽  
Remarkable Degree ◽  
Chain Drives ◽  
Center Distance

A kinematic analysis has been developed for the motion of roller chain drives, which is exact for relatively slow-speed chain drives with negligible wear. The results shed new light on chordal or polygonal action, and the associated impact velocity and motion fluctuation of the chain drive. The results have also revealed the existence of a remarkable degree of sensitivity of chain performance with respect to center distance including discontinuities in the motion derivatives. This in turn provides a new opportunity for the optimization of chain drives by optimizing center distance both in the design stage, as well as during installation and maintenance.

Effect of Pretension on the Dynamics of Chain Drives

2013 ◽  
Vol 365-366 ◽  
pp. 478-481
Author(s):  
Candida Pereira ◽  
Jorge Ambrósio ◽  
Amilcar Ramalho
Keyword(s):  
Dynamic Analysis ◽  
Multibody Systems ◽  
Chain Drive ◽  
Simulation Code ◽  
Revolute Joint ◽  
Marine Engines ◽  
Chain Drives

Suitable methodologies for the dynamic analysis of chain drive mechanisms, based on a multibody systems formulation in which clearance revolute joint formulation is extensively used, have been developed and implemented in a simulation code. The use of tightener systems has been recognized as the most effective way to improve the performance of chain drive mechanisms, since the occurrence of instabilities and vibration patterns of the free chain strands between sprockets can be largely reduced. As a result, these components have been extensively used in car and marine engines. Their influence on the dynamics of the system is analyzed in this article.

Energy-loss mechanisms of hot electrons in n-InSb

1981 ◽  
Vol 14 (33) ◽  
pp. 5151-5169 ◽  
Author(s):  
K Shimomae ◽  
Y Hirose ◽  
C Hamaguchi
Keyword(s):  
Energy Loss ◽  
Hot Electrons ◽  
Loss Mechanisms
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