Optimization of Torsional Dynamic Properties of Hydraulic Excavator Slewing Transmission Mechanism

2012 ◽  
Vol 538-541 ◽  
pp. 2536-2542
Author(s):  
Zhao Jun Li ◽  
Yu Ling Zhang ◽  
Tao Mao ◽  
Xu Juan Yang
Keyword(s):  
Mathematical Model ◽  
Torsional Vibration ◽  
Dynamic Properties ◽  
Optimization Theory ◽  
Moment Of Inertia ◽  
Transmission Mechanism ◽  
Hydraulic Excavator ◽  
Vibration Equation ◽  
Working Device ◽  
The Mathematical Model

A hydraulic excavator is taken as the object to study. Considering the characteristics of slewing transmission mechanism of hydraulic excavator, the torsional vibration equation is established by the finite element method. According to the torsional vibration equation, the effects of the equivalent moment of inertia of working device on the torsional dynamic properties of slewing transmission mechanism are analyzed. Using the optimization theory, the mathematical model is built, which is by means of the equivalent moment of inertia of working device as objective function and by means of the position parameters of the working device as design variables. Based on the mathematical model, the optimization of torsional dynamic properties of slewing transmission mechanism is studied. Finally, a numerical example is presented.

Dynamic Modeling of the Torsional Vibration of the Slewing Mechanism of a Hydraulic Excavator

2012 ◽  
Vol 253-255 ◽  
pp. 2102-2106 ◽  
Author(s):  
Xu Juan Yang ◽  
Zong Hua Wu ◽  
Zhao Jun Li ◽  
Gan Wei Cai
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Moment Of Inertia ◽  
Hydraulic Excavator ◽  
Planetary Gear Trains ◽  
Vibration Model ◽  
Gear Trains ◽  
The Moment ◽  
Relationship Of

A torsional vibration model of the slewing mechanism of a hydraulic excavator is developed to predict its free vibration characteristics with consideration of many fundamental factors, such as the mesh stiffness of gear pairs, the coupling relationship of a two stage planetary gear trains and the variety of moment of inertia of the input end caused by the motion of work equipment. The natural frequencies are solved using the corresponding eigenvalue problem. Taking the moment of inertia of the input end for example to illustrate the relationship between the natural frequencies of the slewing mechanism and its parameters, based on the simulation results, just the first order frequency varies significantly with the moment of inertia of the input end of the slewing mechanism.

Stability of Car Trailer Systems With Special Regard to Trailer Design

1974 ◽  
Vol 96 (2) ◽  
pp. 236-243 ◽  
Author(s):  
R. L. Collins ◽  
J. P. Wong
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Moment Of Inertia ◽  
Tire Pressure ◽  
Special Regard ◽  
Articulated Vehicle ◽  
The Mathematical Model ◽  
Solution Techniques

A linear stability analysis is performed on the articulated vehicle to provide information on the effects that various trailer parameters and variations in tire pressure have on the inherent towing stability of the typical car-trailer combination. Although certain portions of the mathematical model and solution techniques are similar to some previous efforts, the results are generalized to include a much larger class of vehicles than previously presented. The results indicate that hitch loading, trailer length, mass and moment of inertia, and fairly small variations in the car tire pressures can influence trailer towing stability.

scholarly journals A Novel Method for Changing the Dynamics of Slender Elements Using Sponge Particles Structures

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4874
Author(s):  
Mateusz Żurawski ◽  
Bogumił Chiliński ◽  
Robert Zalewski
Keyword(s):  
Mathematical Model ◽  
Dynamic Properties ◽  
Experimental Studies ◽  
Continuous Model ◽  
Particle Structure ◽  
System Parameters ◽  
Mass Redistribution ◽  
Novel Method ◽  
The Mathematical Model ◽  
Theoretical Considerations

The paper concerns problems related to controlling the dynamic properties of beam-like elements. The parameters of the investigated system can be changed by external factors, resulting in partial changes in the system mass redistribution. It is assumed that it is possible to control the system dynamics by shaping the object frequency structure. The paper introduces the mathematical model of the investigated cantilever beam filled with a Sponge Particle Structure. The continuous model has been simplified to a discrete multi-degree of freedom system. The influence of the system parameters on its behavior is discussed in details. The possible applications of the presented concept are proposed. The spectral vibration analyses were carried out. Theoretical considerations enabled the use of the preliminary semi-active method for controlling the vibration frequencies through a mass redistribution. Experimental studies were carried out to verify the proposed mathematical model.

scholarly journals Mathematical model and geometrical design method of noncircular face gear with intersecting axes

2021 ◽  
pp. 095440622199070
Author(s):  
Dawei Liu ◽  
Zhenzhen Lv ◽  
Bingbing Li
Keyword(s):  
Mathematical Model ◽  
Fourier Series ◽  
Design Method ◽  
Experimental Results ◽  
Transmission Mechanism ◽  
Design Parameters ◽  
Cnc Milling ◽  
Face Gear ◽  
Pitch Curve ◽  
The Mathematical Model

In order to establish the design method of a noncircular face gear (NFG) with intersecting axes, the meshing theory of this gear is investigated based on the principle of space gear meshing. A generalized approach for designing closed pitch curve of the NFG with intersecting axes was proposed based on Fourier series. The mathematical model of the NFG generated by a shaper cutter was established. The fundamental design parameters of the gears were defined, with the principle for determining their values discussed. The prototype of a NFG was machined by 5-axis CNC milling and the motion rule was tested. Experimental results verify the feasibility of the innovative transmission mechanism and the correctness of the mathematical model of NFG with intersecting axes.

scholarly journals Dewaxing models digitalization in the mathematical model of winter diesel fuel production

2021 ◽  
Vol 258 ◽  
pp. 11004
Author(s):  
Valentin Nikonorov ◽  
Andrei Kutuzov ◽  
Viktor Nikonorov ◽  
Irina Bagaeva ◽  
Anna Letta
Keyword(s):  
Mathematical Model ◽  
Diesel Fuel ◽  
Optimization Theory ◽  
Oil Refining ◽  
The Arctic ◽  
Fuel Production ◽  
Main Research ◽  
Retrospective Data Analysis ◽  
The Subject ◽  
The Mathematical Model

The climatic features of Russia, as well as the need for the development of the Arctic and the Great Northern Sea Route, require an increase in the production of winter diesel fuel. The object of the study is obtaining winter diesel fuel. The subject of the study is digitalizing oil-refining processes by building the mathematical model of winter diesel fuel production for the case of combining dewaxing regimes taking into account the logistical aspect. Main research methods: retrospective data analysis, synthesis, comparison, optimization theory methods. A literary review was carried out, the main methods for improving the low-temperature properties of winter diesel fuel were revealed. Study hypothesis: a combination of dewaxing regimes will increase the yield of denormalizate and, accordingly, winter diesel fuel. The authors for each mode of dewaxing compiled a mathematical model. Then, the authors constructed a mathematical model of obtaining winter diesel fuel for a combination of dewaxing regimes and taking into account the logistical aspect. The obtained mathematical model can be used to obtain the required amount of winter diesel fuel with compliance with quality requirements and taking into account the logistical aspect.

Study on Torsional Vibration Characteristics of Cross Shaft Universal Coupling

2020 ◽  
pp. 1-11
Author(s):  
Nengqi Xiao ◽  
Xiang Xu ◽  
Ruiping Zhou ◽  
Baojia Chen
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Torsional Vibration ◽  
Vibration Characteristics ◽  
Mass Point ◽  
Parameter Method ◽  
System Matrix ◽  
Ship Propulsion ◽  
Universal Coupling ◽  
The Mathematical Model

In this work, the ship propulsion shaft system with cruciform universal coupling is studied. First, based on the analysis of the structure and characteristics of the cross-axis universal coupling, the motion relations and expressions between the components of the universal coupling are established by using the coordinate transformation method. Second, the characteristics of the four submodels of the head mass point element, the end mass point element, the universal coupling mass point element, and other mass point elements are discussed, and the corresponding torsional vibration differential equations of the four submodels are established. On this basis, the mathematical model of the propulsion shafting system and the differential equations of torsional vibration are established by using the modularization method and lumped parameter method. Finally, the torsional vibration modes and response characteristics of the shafts are calculated and analyzed by using the system matrix method when the external load driving torques of the universal coupling, propeller, and diesel engine are considered. At the same time, the correctness of the mathematical model and calculation method is verified by the test and comparative analysis of ship propulsion shafts. It lays a theoretical foundation for further research on torsional vibration characteristics and mechanisms of the ship propulsion shafting system based on universal coupling.

Characterization of Automotive Shock Absorbers Using Random Excitation

1995 ◽  
Vol 209 (4) ◽  
pp. 239-248 ◽  
Author(s):  
S Cafferty ◽  
K Worden ◽  
G Tomlinson
Keyword(s):  
Mathematical Model ◽  
Dynamic Properties ◽  
Test Procedure ◽  
Random Excitation ◽  
Fixed Frequency ◽  
Restoring Force ◽  
Shock Absorbers ◽  
The Mathematical Model ◽  
Clear Method

In a previous paper [see reference (4)], it was shown that the restoring force surface (RFS) procedure provides a direct and clear method for characterizing the dynamic properties of automotive shock absorbers or dampers. The procedure was based on repetitive harmonic testing of the absorbers at fixed frequency but with varying amplitude. The current paper describes how the surfaces can be obtained from tests using random excitation. The merits and demerits are discussed relative to the harmonic test procedure. It is shown that the random excitation approach offers a useful alternative but produces force surfaces which are corrupted by small stochastic components; an explanation of the distortion is given in terms of the mathematical model proposed in the previous paper. The implications for identification of shock absorbers are discussed

scholarly journals Analysis of the Torque Loss of High-Speed Transmission Mechanism with a Stacked Roller Set

Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 140
Author(s):  
Ke Zhu ◽  
Chuantan Ruan ◽  
Heyuan Wang ◽  
Sheng Li ◽  
Jian Ruan
Keyword(s):  
Mathematical Model ◽  
Rotational Speed ◽  
High Speed ◽  
Theoretical Data ◽  
Transmission Mechanism ◽  
Inertia Force ◽  
Load Pressure ◽  
Enveloping Surface ◽  
Torque Loss ◽  
The Mathematical Model

Two-dimensional pumps have broad application prospects in aerospace. However, the performance of the pump is degraded because of the clearance problem of the current 2D transmission mechanism. In order to eliminate the clearance between the cam rail and the rollers, a high-speed transmission mechanism with a stacked roller set is proposed. The stacked roller set is compressed by the load pressure. The axial inertia force is balanced when the transmission mechanism works at high speed, via the equal acceleration and reverse movement of two cam rail sets. Thus, the transmission mechanism meets the high-speed demand. In this paper, the mathematical model of the transmission mechanism is established based on the enveloping surface theory and the differential geometry principle. Afterwards, numerical analysis of the mathematical model is performed based on MATLAB, combined with the experiment, to study the influence of load pressure and rotational speed on the torque loss. Then, the torque characteristics of the transmission mechanism is obtained. According to a test, the deviation between theoretical data and experimental data is 11.9%; therefore, the mathematical model can predict the torque of the transmission mechanism effectively. It is concluded that the torque loss of the transmission mechanism increases linearly with the load pressure, and the rotational speed has a slight effect on the torque loss.

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