Fault Analysis of Typical Structure of Helicopter Transmission System Based on Lumped-Parameter Modeling

2021 ◽  
Author(s):  
Jiao Hu ◽  
Niaoqing Hu ◽  
Zhe Cheng ◽  
Yi Yang ◽  
Yang Zhou
Keyword(s):  
Transmission System ◽  
Fault Analysis ◽  
Typical Structure ◽  
Lumped Parameter ◽  
Lumped Parameter Modeling ◽  
Helicopter Transmission

Lumped Parameter Modeling of a Magnetorheological Fluid Clutch

2006 ◽  
Author(s):  
John C. Ulicny ◽  
Daniel J. Klingenberg ◽  
Anthony L. Smith ◽  
Zongxuan Sun
Keyword(s):  
Mathematical Model ◽  
Physical Properties ◽  
Magnetorheological Fluid ◽  
Input Current ◽  
Fluid Composition ◽  
Fluid Temperature ◽  
Temperature Range ◽  
Lumped Parameter ◽  
Lumped Parameter Modeling ◽  
Fan Speed

A lumped-parameter mathematical model of an automotive magnetorheological (MR) fluid fan clutch was developed. This model is able to describe the average fluid temperature, average clutch temperature, and output fan speed as a function of time, input current, and fluid composition. The model also reproduces numerous features of fan operation observed experimentally and revealed a mechanism for some observed cases of hysteresis. However, it fails to capture certain other features which lead us to conclude that phenomena which are not included in the model, e.g., sedimentation and re-suspension, are important to the clutch behavior. In addition, the results indicate that certain physical properties need to be measured over a larger temperature range in order for the model to better predict the clutch behavior.

Prediction and test of stable transmission time of spiral bevel gear during a loss-of-lubrication event in helicopter transmission system

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanzhong Wang ◽  
Kai Yang ◽  
Wen Tang
Keyword(s):  
Transmission System ◽  
Bevel Gear ◽  
Transmission Time ◽  
Tooth Surface ◽  
Spiral Bevel Gear ◽  
Content Type ◽  
Surface Burn ◽  
Spiral Bevel ◽  
Helicopter Transmission ◽  
Stable Transmission

Purpose This paper aims to establish a prediction model of stable transmission time of spiral bevel gear during a loss-of-lubrication event in helicopter transmission system. Design/methodology/approach To observe the temperature change of spiral bevel gear during working condition, a test rig of spiral bevel gear was developed according to the requirements of experiments and carried out verification experiments. Findings The prediction is verified by the test of detecting the temperature of oil pool. The main damage form of helicopter spiral bevel gears under starved lubrication is tooth surface burn. The stable running time under oil-free lubrication is mainly determined by the degree of tooth surface burn control. Originality/value The experimental data of the spiral bevel gear oil-free lubrication process are basically consistent with the simulation prediction results. The results lay a foundation for the working life design of spiral bevel gear in helicopter transmission system under starved lubrication.

Lumped-Parameter Modeling of Visco-Elastically Coupled Rigid Bodies Using Clifford’s Biquaternions

2000 ◽  
Author(s):  
Ernest D. Fasse
Keyword(s):  
Computer Simulation ◽  
Rigid Bodies ◽  
Elastic Coupling ◽  
Potential Utility ◽  
Dual Quaternions ◽  
Lumped Parameter ◽  
Lumped Parameter Modeling

Abstract This work considers the problem of modeling visco-elastically coupled rigid bodies, with application to modeling and computer simulation of spatial, flexural mechanisms. A method of modeling visco-elastic coupling based on Clifford’s biquaternions (dual quaternions) is presented. The potential utility of the method is demonstrated by simulating the behavior of a complex spatial, flexural mechanism.

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