scholarly journals Study on Dynamic Characteristics of the Disc Spring System in Vibration Screen

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Jiacheng Zhou ◽  
Chuzhe Zhang ◽  
Ziqiu Wang ◽  
Kuanmin Mao
Keyword(s):  
Natural Frequency ◽  
Vertical Direction ◽  
Maximum Amplitude ◽  
Exciting Force ◽  
Third Order ◽  
The Third ◽  
Simulation And Experiment ◽  
Exciting Forces ◽  
Spring System ◽  
Disc Spring

To avoid too large exciting force in traditional linear vibrating screen and unstable working state in resonance screen, the disc spring system is applied in the linear vibration screen. The model of the disc spring system in vibration screen is established by simulation and experiment. The characteristics of modal and amplitude of the disc spring system in vibration screen are studied. We found that the disc spring system vibrates in vertical direction at the third-order natural frequency, which is consistent with the direction of the vibration screen when screening particles. Moreover, the third-order natural frequencies in simulation and experiment are basically consistent. Furthermore, the maximum amplitude of the disc spring system appears at 960 r/min (16 Hz), which is in accord with the third-order natural frequency. Meanwhile, the amplitude increases proportionally with the increase of exciting force, while the amplification factors are the same under three different exciting forces. This indicates that the disc spring system has excellent linearity. The results of research provide guidance for design and application of elastic components on the vibration screen.

scholarly journals Study on dynamic characteristics of leaf spring system in vibration screen

2021 ◽  
pp. 146134842110229
Author(s):  
Jiacheng Zhou ◽  
Chao Hu ◽  
Ziqiu Wang ◽  
Zhengfa Ren ◽  
Xiaoyu Wang ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Vertical Direction ◽  
Maximum Amplitude ◽  
Exciting Force ◽  
Mode Shapes ◽  
Leaf Spring ◽  
Amplification Factors ◽  
Simulation And Experiment ◽  
Exciting Forces ◽  
Spring System

By studying dynamic characteristics of the leaf spring system, a new elastic component is designed to reduce the working load and to a certain extent to ensure the linearity as well as increase the amplitude in the vertical and horizontal directions in vibration screen. The modal parameters, amplitudes, and amplification factors of the leaf spring system are studied by simulation and experiment. The modal results show that the leaf spring system vibrates in horizontal and vertical directions in first and second mode shapes, respectively. It is conducive to loosening and moving the particles on the vibration screen. In addition, it is found that the maximum amplitude and amplification factor in the horizontal direction appear at 300 r/min (5 Hz) while those in the vertical direction appear at 480 r/min (8 Hz), which are higher than those in the disc spring system. Moreover, the amplitude of the leaf spring system increases proportionally with the increase of exciting force while the amplification factors are basically the same under different exciting forces, indicating the good linearity of the leaf spring system. Furthermore, the minimum exciting force occurs in the leaf spring system under the same amplitude by comparing the exciting force among different elastic components. The above works can provide guidance for the industrial production in vibration screen.

scholarly journals A Study on the Influence of Different Constraint Modes and Number of Disc Springs on the Dynamics of Disc Spring System

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jiacheng Zhou ◽  
Chuzhe Zhang ◽  
Ziqiu Wang ◽  
Kuanmin Mao ◽  
Xiaoyu Wang
Keyword(s):  
Amplification Factor ◽  
Maximum Amplitude ◽  
Assembly Process ◽  
Good Consistency ◽  
Before And After ◽  
Simulation And Experiment ◽  
Spring System ◽  
The Relationship ◽  
Maximum Amplification ◽  
Disc Spring

In this work, the influences of constraint modes and the number of disc springs on the dynamic characteristics of the disc spring system are studied by simulation and experiment. The amplitudes and amplification factors of the disc spring system under different constraint modes and different numbers of disc springs are obtained. The results show that the maximum amplitude and amplification factor both appear at the constraint modes of locking and no preloading, which indicates that the locking and no preloading is the best constraint mode among the four different constraint modes. Moreover, the amplitude of the disc spring system first increases and then decreases with the number of disc springs increasing, while the amplification factor increases with the number of disc springs increasing. The maximum amplification factor (10.21 in experiment) of the disc spring system appears at 10 disc springs. By studying the relationship between the number of disc springs and amplification factor and damping, we find that the damping of the disc spring system can be reduced by increasing the disc spring numbers, and thus, the corresponding amplification factor can be improved. Furthermore, as the number of disc spring increases, the height differences of disc springs before and after locking are all close to 3 mm, which indicates that the amount of locking compression in the assembly process has a good consistency when the number of disc springs changes. The aforementioned works can provide guidance for the industrial production in screen vibration.

Vertical Vibration Characteristics Analysis of Stand Rolls System in Six-Roll Cold Tandem Mill

2013 ◽  
Vol 470 ◽  
pp. 572-576 ◽  
Author(s):  
Ying Zhang ◽  
Li Liu ◽  
Pei Ming Shi ◽  
Bin Liu
Keyword(s):  
Cold Rolling ◽  
Natural Frequency ◽  
Rolling Mill ◽  
Rolling Process ◽  
Vertical Vibration ◽  
Vibration System ◽  
Cold Rolling Mill ◽  
Third Order ◽  
The Third ◽  
Characteristics Analysis

A dynamic model of seven degree of freedom for the vertical vibration of stand rolls system in a cold tandem mill is developed by Kinematics Theory. According to the actual parameters of a factory six-roll cold rolling mill, the influence of natural frequency and modes for rolling process is analyzed. It finds that the third-order and the six-order natural frequency play a role key in vertical vibration system. Combined with energy distribution of each part and flexibility of the modes analysis for vertical vibration system, it can avoid resonance of rolling process and optimize the parameters of stand rolls system by adjusting structural size appropriately. The above mentioned results have provided a reference for further research on Kinematics and structural optimization of six-roll cold tandem mill.

Modal Analysis about Direct-Drive Bi-Rotary Milling Head

2010 ◽  
Vol 154-155 ◽  
pp. 299-303 ◽  
Author(s):  
Ming Yan ◽  
Le Tang ◽  
Peng Zheng ◽  
Ming Yuan Zhang
Keyword(s):  
Natural Frequency ◽  
Natural Frequencies ◽  
Vibration Modes ◽  
Vibration Characteristic ◽  
Direct Drive ◽  
Third Order ◽  
Technological Support ◽  
First Order ◽  
Swing Angle ◽  
The Third

Vibration characteristic of direct drive A/C bi-rotary milling head is been analyzed by finite element method (FEM), former four order vibration modes of the milling’s structure are given. The influence of the swing angle of the A-axis to the natural frequency of the milling head is analyzed. The natural frequencies when the milling head is working are interval values, the first order natural frequency is [120.48, 122.91], the second order natural frequency is [139.68, 142.08], the third order natural frequency is [328.68, 331.9], the fourth order natural frequency is [369.68, 372.45]. This computing provides technological support for design and improvement of this type of milling head.

scholarly journals Subharmonic oscillation in third order non-linear systems

1979 ◽  
Vol 1 (3-4) ◽  
pp. 12-20
Author(s):  
Nguyen Van Dao
Keyword(s):  
Order Equation ◽  
Exciting Force ◽  
Order System ◽  
Subharmonic Solution ◽  
Third Order ◽  
The Third ◽  
The Family ◽  
Subharmonic Oscillation ◽  
Non Linear Systems ◽  
The Stability

In this paper the subharmonic oscillation with frequency n times smaller than that of exciting force is considered. The first paragraph is devoted to the formulation of problem. Here an example of third order equation in which there exists pure subharmonic solution is given. In the second paragraph the condition (2.5), (2.7) for the existence of pure odd subharmonic oscillation in the dynamical system governed by equation (2.1) are derived. The mixed subharmonic oscillation is studied in the third paragraph. The family of tow parameters solutions (3.2) of equation (3.1) with subharmonic term is found by means of asymptotic method. The stationary oscillations are given by formulae (3.14)-(3.16). The stability of subharmonic is oscillation is studied by Liapunov-Routh-Hurwitz criterium in the fourth paragraph. In general, the stability conditions (4.5) lead to the results which are different from those in second order system. To illustrate the presented method a concrete example has been analysed in the fifth paragraph.

Probe size and 5th-order aberration

1987 ◽  
Vol 45 ◽  
pp. 134-135 ◽  
Author(s):  
Zhifeng Shao
Keyword(s):  
Electron Probe ◽  
Spherical Aberration ◽  
Wave Length ◽  
Cylindrical Symmetry ◽  
Electron Wave ◽  
Third Order ◽  
The Third ◽  
Probe Radius ◽  
Small Probe ◽  
Probe Size

A small electron probe has many applications in many fields and in the case of the STEM, the probe size essentially determines the ultimate resolution. However, there are many difficulties in obtaining a very small probe.Spherical aberration is one of them and all existing probe forming systems have non-zero spherical aberration. The ultimate probe radius is given byδ = 0.43Csl/4ƛ3/4where ƛ is the electron wave length and it is apparent that δ decreases only slowly with decreasing Cs. Scherzer pointed out that the third order aberration coefficient always has the same sign regardless of the field distribution, provided only that the fields have cylindrical symmetry, are independent of time and no space charge is present. To overcome this problem, he proposed a corrector consisting of octupoles and quadrupoles.

Children’s Recall of Approximations to English

1973 ◽  
Vol 16 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Elizabeth Carrow ◽  
Michael Mauldin
Keyword(s):  
Language Development ◽  
Fourth Order ◽  
Third Order ◽  
Memory Processes ◽  
The Third ◽  
General Index ◽  
General Linguistic

As a general index of language development, the recall of first through fourth order approximations to English was examined in four, five, six, and seven year olds and adults. Data suggested that recall improved with age, and increases in approximation to English were accompanied by increases in recall for six and seven year olds and adults. Recall improved for four and five year olds through the third order but declined at the fourth. The latter finding was attributed to deficits in semantic structures and memory processes in four and five year olds. The former finding was interpreted as an index of the development of general linguistic processes.

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