scholarly journals Theoretical and Experimental Analysis of Dynamic Characteristics for a Valve Train System

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6328
Author(s):  
Bo Hu ◽  
Yunzhe Li ◽  
Lairong Yin
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Industrial Applications ◽  
Valve Train ◽  
Dynamic Responses ◽  
Engine Vibration ◽  
High Speeds ◽  
Proposed Model ◽  
Gyroscopic Effects ◽  
Train System

The valve train is one of the main sources of engine vibration, and its dynamic performance is crucial for output power and fuel consumption. The flexibilities of slender bars and beams should be emphasised in the design of valve trains to develop high-power and high-speed engines with industrial applications. A flexible dynamic model of a valve train system is proposed. In the proposed model, the components, except the cam and gear bodies, are modelled as flexible bodies with multidirectional deformations. The gyroscopic effects of the camshaft, cams and gear discs are also considered to predict dynamic responses at high speeds accurately. Gear meshing, the friction of the cam–tappet pair, the centrifugal force of the cams and valve clearance are also considered. Experiments on housing vibration and pushrod stress are conducted to validate the proposed model. Results show that the proposed model can predict the dynamic stress of the flexible components well and predict the trend shown by the housing vibration. The proposed model shows that excessive cam rotation speed and valve clearance will cause intense bounce and jump phenomena. The proposed model can be an important reference for designing engine work speed, adjusting valve clearance and improving component durability.

scholarly journals Modelling and analysis of vehicle crash system integrated with different VDCS under high speed impacts

2012 ◽  
Vol 2 (4) ◽  
Author(s):  
Mustafa Elkady ◽  
Ahmed Elmarakbi
Keyword(s):  
Control Systems ◽  
Vehicle Dynamics ◽  
High Speed ◽  
Dynamic Responses ◽  
High Speeds ◽  
Vehicle Crash ◽  
Proposed Model ◽  
High Speed Collision ◽  
Crash Characteristics ◽  
Vehicle Dynamics Control

AbstractThe behaviour of a vehicle at high-speed crashes is enhanced by using active vehicle dynamics control systems. A 6-Degree-of-Freedom (6-DOF) mathematical model is developed to carry out this study. In this model, vehicle dynamics is studied together with vehicle crash structural dynamics. Validation of the vehicle crash structure of the proposed model is achieved to ensure that the modelling of the crumble zone and the dynamic responses are reliable. Five different speeds are selected to investigate the robustness of control system and its effect on the vehicle crash characteristics at low and high speeds with full and offset collision scenarios. A great improvement of vehicle pitch and yaw angels and accelerations at high speed collision are obtained from this analysis.

scholarly journals Suspending force modeling based on nonlinear acoustics and high-speed running experiments for an ultrasonic journal bearing

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402094047
Author(s):  
He Li ◽  
Yu Wang ◽  
Deen Bai ◽  
Fuyan Lyu ◽  
Kuidong Gao ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Smart Materials ◽  
High Speed ◽  
Acoustic Radiation ◽  
Dynamic Performance ◽  
Force Model ◽  
Trajectory Data ◽  
Running Performance ◽  
High Speeds ◽  
Radiation Theory

As a kind of promising noncontact bearings, ultrasonic bearings actuated by smart materials such as lead zirconate titanate ceramics show a good application prospect in high-speed machines and precision-measuring devices. The suspending force is one of the most important parameters that play a dominated role on the bearing’s static and dynamic performance. A suspending force model based on acoustic radiation theory for cylindrical object near sound source is built to predict the radial carrying capacity of an ultrasonic bearing actuated by three piezoelectric transducers. To validate the model, an ultrasonic bearing prototype is developed and a testing system is established. For observing the bearing’s dynamic running performance at high speeds, the bearing’s running experiment is carried out and the rotor center’s trajectory data and frequency spectrum are acquired to analyze the bearing’s dynamic characteristics at high speeds. The suspending force model and running performance experiments will contribute to the design, detection, and test of this type of bearings.

Dynamics modeling and analysis of a four-wheel independent motor-drive virtual-track train

2020 ◽  
pp. 146441932096401
Author(s):  
Zhonghui Yin ◽  
Jiye Zhang ◽  
Haiying Lu ◽  
Weihua Zhang
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Spatial Dynamics ◽  
Dynamic Responses ◽  
Dynamics Modeling ◽  
Dynamics Model ◽  
Coupling Effects ◽  
Dynamic Interactions ◽  
Modeling And Analysis

Due to urbanisation and the economic challenges of traffic, it is urgently necessary to develop an environmentally friendly virtual-track train with suitable speed, high load capacity and low construction cost in China. To guide the design and evaluate this train’s dynamic behaviour, a spatial-dynamics model has been developed based on the dynamics theory and tyre-road interaction. The proposed dynamics model comprises mechanical vehicle systems, traction and braking characteristics and tyre-road dynamic interactions. The coupling effects amongst those systems of virtual track train are derived theoretically for the first time. The nonlinear characteristics of the tyre are modelled by the transit tyre-magic formula with consideration of road irregularities. Based on a designed PID controller and the comprehensive dynamics model, the dynamic performance of the system can be revealed considering motion coupling effects and complicated excitations, especially under traction and braking conditions. The dynamic responses of whole virtual track train can be obtained by numerical integration under different conditions. The vibration characteristics of such train are assessed under running at a constant speed and during the traction/braking process. The results show that the vibrations of the vehicle system are significantly influenced by road irregularities, especially at high speed ranges. The motions and vibrations of different components are intensive coupled, which should not to be neglected in the dynamics assessment of the virtual track train. Besides, the dynamics model can also be applied to dynamics-related assessment (fatigue, strength and some damage conditions, et al.) and parameter optimisation of the virtual-track train.

Dynamic Performance of Vehicle-Turnout-Bridge Coupling System in High-Speed Railway

2011 ◽  
Vol 50-51 ◽  
pp. 654-658
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Shun Xi Quan
Keyword(s):  
Relative Position ◽  
High Speed ◽  
Dynamic Performance ◽  
Dynamic Responses ◽  
Continuous Beam ◽  
Analysis Model ◽  
Wheel Load ◽  
System A ◽  
Coupling System ◽  
Contact Relation

In order to study dynamic behavior of vehicle-turnout-bridge coupling system, a vehicle-turnout-bridge dynamic analysis model is established by employing the dynamic finite element method (FEM). When No.18 crossover turnouts(with a speed of 350km/h) are laid symmetrically on the 6×32m continuous beam, influences of turnout/bridge relative position and wheel/rail contact relation in turnout zone on the system dynamic responses are analyzed. The result shows that: wheel/rail contact of turnout zone (especially the frog) has great effect on dynamic responses of turnout on bridge, thus the nose rail height of frog should be optimized to mitigate the wheel load transition and its longitudinal gradient. In terms of the 32m-span continuous beam, the best relative position is frog part of turnout arranged in the range of 1/8 and 1/4 of span.

Vibration Properties of High-Speed Planetary Gears With Gyroscopic Effects

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Christopher G. Cooley ◽  
Robert G. Parker
Keyword(s):  
High Speed ◽  
Eigenvalue Problems ◽  
Planetary Gear ◽  
Vibration Modes ◽  
Planetary Gears ◽  
High Speeds ◽  
Wide Range ◽  
Modal Property ◽  
Gyroscopic Effects ◽  
Complex Valued

This study investigates the modal property structure of high-speed planetary gears with gyroscopic effects. The vibration modes of these systems are complex-valued and speed-dependent. Equally-spaced and diametrically-opposed planet spacing are considered. Three mode types exist, and these are classified as planet, rotational, and translational modes. The properties of each mode type and that these three types are the only possible types are mathematically proven. Reduced eigenvalue problems are determined for each mode type. The eigenvalues for an example high-speed planetary gear are determined over a wide range of carrier speeds. Divergence and flutter instabilities are observed at extremely high speeds.

An Integrated Approach to the Design and Analysis of an Ultra-High Speed Air-Bearing Spindle

2012 ◽  
Vol 723 ◽  
pp. 227-232 ◽  
Author(s):  
Si Yu Gao ◽  
Hui Ding ◽  
Kai Cheng
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Integrated Approach ◽  
System Optimization ◽  
Air Bearing ◽  
Design Environment ◽  
Virtual Design ◽  
High Speeds ◽  
Ultra High Speed ◽  
Structural Behaviors

This paper presents an integrated approach to the design and analysis of an ultra-high speed air bearing spindle, by integrating the structural design, performance analysis and system optimization in a virtual design environment. Firstly, the ultra-high speed air bearing spindle is designed, including grooved hybrid air bearing, helical water cooling channel and built-in motor, etc; Subsequently, pneumatic hammer instability and whirl instability of air bearing are studied; The thermal-structural behaviors of the spindle system at ultra-high speeds are investigated by using structural FEA coupled CFD; Static and dynamic performance of spindle is studied to predict the stiffness, modes and natural frequencies of the spindle; Lastly, system optimizations are conducted to obtain optimal performance and dynamic behaviors of the spindle. The proposed integrated approach can be used to design an optimal ultra-high speed air bearing spindle.

Dynamic Synthesis of Cams Using Finite Trigonometric Series

1975 ◽  
Vol 97 (1) ◽  
pp. 287-293 ◽  
Author(s):  
J. L. Wiederrich ◽  
B. Roth
Keyword(s):  
Mathematical Model ◽  
Trigonometric Series ◽  
High Speed ◽  
Dynamic Performance ◽  
Design Rules ◽  
New Methods ◽  
Dynamic Synthesis ◽  
High Speeds ◽  
Rules Of Thumb ◽  
Empirical Design

New methods are presented for the design of high-speed cam profiles. These methods have the advantage of assuring the accuracy of the assumed mathematical model while at the same time providing for good dynamic performance. These methods do not rely on rules of thumb. In fact, it is shown that at high speeds low vibration motions exist which violate heretofore commonly accepted empirical design rules.

An Efficient Finite Element Procedure for Analysis of High-Speed Spiral Groove Gas Face Seals

2000 ◽  
Vol 123 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Marco Tulio C. Faria
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Dynamic Performance ◽  
Dynamic Force ◽  
Spiral Groove ◽  
Weighted Residual Method ◽  
New Class ◽  
High Speeds ◽  
Face Seals ◽  
Finite Element Procedure

An efficient and accurate finite element procedure is specially devised to analyze the performance of gas-lubricated spiral groove face seals operating at high speeds. The procedure is based on the Galerkin weighted residual method with a new class of high-order shape functions, which are derived from an approximate solution to the nonlinear Reynolds equation within an element. Static and dynamic performance characteristics, such as seal opening force, flow leakage and frequency-dependent dynamic force coefficients, are determined to study the effects of high speeds on the behavior of spiral groove gas face seals.

Interesting Eigenvalue Behavior in High-Speed Planetary Gears With Gyroscopic Effects

2013 ◽  
Author(s):  
Christopher G. Cooley ◽  
Robert G. Parker
Keyword(s):  
High Speed ◽  
Planetary Gear ◽  
Gyroscopic System ◽  
Critical Speeds ◽  
High Speeds ◽  
Lumped Parameter ◽  
Axially Moving ◽  
Gyroscopic Effects ◽  
Moving Media ◽  
Gyroscopic Systems

This study demonstrates interesting and unusual gyroscopic system eigenvalue behavior observed in a lumped-parameter planetary gear model. The focus of this work is on the eigenvalue phenomena that occur at especially high speeds rather than practical planetary gear behavior. The behaviors include calculation of exact trajectories across critical speeds, uncommon stability features near degenerate critical speeds, and unique stability transitions. These eigenvalue behaviors differ from those of other gyroscopic systems such as spinning disks, shafts, and rings, and axially-moving media.

Sign in / Sign up

Export Citation Format

Share Document