INFLUENCE OF RIGIDITY OF ELASTIC ELEMENTS OF COUPLING COUPLINGS ON TORSIONAL VIBRATION OF SHUNTING LOCOMOTIVES DRIVES

2021 ◽  
pp. 30-35
Author(s):  
A. P. Evdokimov
Keyword(s):  
Torsional Vibration ◽  
Continued Fractions ◽  
Torsional Rigidity ◽  
Torsional Vibrations ◽  
Elastic Coupling ◽  
Elastic Elements

The results of calculations of torsional vibrations of elements of power drives of shunting locomotives with different torsional rigidity of rubbercord shells of elastic coupling couplings are presented. Based on the results obtained, the choice of rubbercord shells is justified depending on their torsional rigidity. The basis for the choice of shells is the obtained results of calculations of the resonant amplitudes of torsional vibrations by the method of continued fractions.

DRIVE COUPLING WITH SPLIT STEEL SLEEVES

2020 ◽  
pp. 32-34
Author(s):  
V. M. Zyablikov ◽  
B. V. Buketkin ◽  
V. F. Smirnov ◽  
A. A. Shirshov
Keyword(s):  
Torsional Rigidity ◽  
Gear Wheel ◽  
Dynamic Loads ◽  
Torsional Vibrations ◽  
Small Curvature ◽  
Elastic Elements

The main purpose of couplings with elastic elements is to reduce dynamic loads and reduce the level of dangerous vibration amplitudes. Sometimes it is necessary for this purpose to install such couplings directly in the units, since they have large amplitudes of torsional vibrations. Drive couplings with elastic elements – steel split sleevescan be installed inside the units. The design of the coupling, which is built into the gear wheel of the reducer, is shown. The main characteristic of drive clutches with elastic elements is torsional rigidity. A detailed output of the formula for calculating the stiffness of such couplings is given. The conclusion is based on determining the deformation of split sleeves taken as rods of small curvature.

Transient and Unstable Torsional Vibrations on a 4-Stroke Marine Diesel Engine

2003 ◽  
Author(s):  
D. C. Lee ◽  
J. D. Yu
Keyword(s):  
Diesel Engine ◽  
Torsional Vibration ◽  
Marine Diesel Engine ◽  
Torsional Vibrations ◽  
Steady State Condition ◽  
Marine Propulsion ◽  
Friction Clutch ◽  
Marine Diesel ◽  
Noise Measurements ◽  
Unstable Vibration

Under steady state condition, unstable torsional vibration normally does not occur in shafting systems using 4stroke diesel engine due to hysteresis damping of shafting system and relative damping of standard fitted damper. However, the unstable torsional vibration occurs on marine propulsion shafting systems due to slippage of a multi-friction clutch installed between increasing gear box and shaft generator. To identify this unstable vibration and make proper counter measure, the simulation for transient torsional vibration using the Newmark method is introduced in this paper. The mechanism of this unstable vibration is verified by vibration and noise measurements of the shafting system.

A Method of Reinforcement and Vibration Reduction of Girder Bridges Using Shape Memory Alloy Cables

2017 ◽  
Vol 17 (07) ◽  
pp. 1750076 ◽  
Author(s):  
Ai-Rong Liu ◽  
Chun-Hui Liu ◽  
Ji-Yang Fu ◽  
Yong-Lin Pi ◽  
Yong-Hui Huang ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Traffic Safety ◽  
Torsional Rigidity ◽  
Vibration Reduction ◽  
Torsional Vibrations ◽  
Moving Vehicle ◽  
Girder Bridges ◽  
Fe Simulations ◽  
Vehicle Loads

Bending and torsional vibrations caused by moving vehicle loads are likely to affect the traffic safety and comfort for girder bridges with limited torsional rigidity. This paper studies the use of cables made of shape memory alloy (SMA) as the devices of reinforcement and vibration reduction for girder bridges. The SMA cables are featured by their small volume, expedient installation. To investigate their effect on the vibration of girder bridges, theoretical analysis, numerical simulation and experimental study were conducted in this paper. For bending vibration, the governing equations of the girder with and without SMA cables subjected to moving vehicle loads were derived, while for torsional vibration, the finite element (FE) simulations were used instead. The results of bending and torsional vibrations obtained by the analytical approach and FE simulations, respectively, were compared with the experimental ones from model testing. It was confirmed that the SMA cables can restrain the vibration of the girder bridge effectively.

Effect of Axial and Torsional Vibrations on Tapping Performance

2016 ◽  
Vol 826 ◽  
pp. 88-92
Author(s):  
Swapnil Pawar ◽  
Sandip Patil ◽  
Pravin Pawar ◽  
Rajkumar Singh
Keyword(s):  
Titanium Alloys ◽  
Torsional Vibration ◽  
Torsional Vibrations ◽  
Taguchi Approach ◽  
Maximum Torque ◽  
Degree Of Reduction

Abrupt breakage of the taps is frequently encountered during tapping threads, especially when tapping on ‘difficult-to-cut’ material like titanium. This work therefore presents an extensive experimentation with the Taguchi approach to investigate maximum torque in tapping on titanium alloys while performing axial and, axial and torsional vibration-assisted tapping (AVAT and ATVAT). The experimentation shows that both AVAT and ATVAT reduce the tapping torqueduring tapping as compared to that of in conventional tapping process. However, ATVAT process had exhibited a higher degree of reduction in torque when compared to AVAT process.

Torsional Vibrations and Nonlinear Dynamic Characteristics of Drill Strings and Stick-Slip Reduction Mechanism

2019 ◽  
Vol 14 (8) ◽  
Author(s):  
Jialin Tian ◽  
Genyin Li ◽  
Liming Dai ◽  
Lin Yang ◽  
Hongzhi He ◽  
...  
Keyword(s):  
Torsional Vibration ◽  
Nonlinear Dynamic ◽  
Drill String ◽  
Drilling Process ◽  
Drill Bit ◽  
Torsional Vibrations ◽  
Reduction Mechanism ◽  
Nonlinear Dynamic Model ◽  
Stick Slip ◽  
Research Results

Torsional stick–slip vibrations easily occur when the drill bit encounters a hard or a hard-soft staggered formation during drilling process. Moreover, serious stick–slip vibrations of the drill string is the main factor leading to low drilling efficiency or even causing the downhole tools failure. Therefore, establishing the stick–slip theoretical model, which is more consistent with the actual field conditions, is the key point for new drilling technology. Based on this, a new torsional vibration tool is proposed in this paper, then the multidegree-of-freedom torsional vibrations model and nonlinear dynamic model of the drill string are established. Combined with the actual working conditions in the drilling process, the stick–slip reduction mechanism of the drill string is studied. The research results show that the higher rotational speed of the top drive, smaller viscous damping of the drill bit, and smaller WOB (weight on bit) will prevent the stick–slip vibration to happen. Moreover, the new torsional vibration tool has excellent stick–slip reduction effect. The research results and the model established in this paper can provide important references for reducing the stick–slip vibrations of the drill string and improving the rock-breaking efficiency.

Numerical Analysis of Coupled Lateral and Torsional Vibrations of a Vertical Unbalanced Rotor

2010 ◽  
Vol 20-23 ◽  
pp. 352-357
Author(s):  
Xue Li An ◽  
Dong Xiang Jiang ◽  
Ming Hao Zhao ◽  
Chao Liu
Keyword(s):  
Torsional Vibration ◽  
Coupling Effect ◽  
Torsional Vibrations ◽  
Lateral Vibration ◽  
Transient Vibration ◽  
Coupled Vibrations ◽  
Lateral Vibrations ◽  
Vertical Rotor ◽  
Unbalanced Rotor ◽  
Mass Eccentricity

A model for the coupled lateral and torsional vibrations of a vertical unbalanced rotor is developed. The equation of motion is obtained using Lagrangian dynamics without considering the external actuating forces and torque. The equation showed coupling and nonlinear interaction between the rotor lateral and torsional vibrations. Most of the earlier work on coupled vibrations has been done for the horizontal rotor model. The coupled vibrations for a vertical rotor have not been reported in the past. An attempt is made to reveal dynamic characteristics of vertical rotor. The results of the simulation showed the coupled between torsional and lateral vibrations is induced by mass eccentricity. Coupled vibrations have appeared in the start period of the vibration. After a transient vibration process, the vibrations are not coupling. The lateral vibration becomes equal amplitude with shafting speed. And the torsional vibration keeps on attenuating until it stops. When the vibration is coupled, the coupling effect on which torsional vibration to lateral vibration is evident. But there’s no coupling effect on the lateral to the torsional. It is also shown that for some operational parameters, the controlling action may excite large lateral vibrations due to coupling with the torsional motion.

Torsional Vibrations of Shells of Revolution

1961 ◽  
Vol 28 (4) ◽  
pp. 571-573 ◽  
Author(s):  
H. Garnet ◽  
M. A. Goldberg ◽  
V. L. Salerno
Keyword(s):  
Differential Equation ◽  
Governing Equation ◽  
Torsional Vibration ◽  
Conical Shell ◽  
Order Differential Equation ◽  
Annular Plate ◽  
Thin Shells ◽  
Torsional Vibrations ◽  
Vibration Modes ◽  
Shells Of Revolution

Torsional-vibration modes are uncoupled from the bending and extensional modes in thin shells of revolution. The solution for the uncoupled torsional modes then depends upon a linear second-order differential equation. The governing equation is subsequently solved for the frequencies of a conical shell. A tabulation of the first five frequencies for varying ratios of the terminal radii is presented. These frequencies are identical to those of an annular plate which has the same supports as the conical shell.

Torsional Vibration Suppression by a Centrifugal Pendulum Vibration Absorber

2005 ◽  
Author(s):  
Yukio Ishida ◽  
Tsuyoshi Inoue ◽  
Taishi Kagawa ◽  
Motohiko Ueda
Keyword(s):  
Torsional Vibration ◽  
Large Amplitude ◽  
Vibration Suppression ◽  
Torsional Vibrations ◽  
Vibration Absorbers ◽  
Harmonic Vibrations ◽  
Centrifugal Pendulum Vibration Absorbers ◽  
Automobile Engines ◽  
Large Amplitude Vibration ◽  
Driving Torque

Driving torque of rotating machinery, such as automobile engines, changes periodically. As a result, torsional vibrations occur and cause serious noise and vibration problems. In this study, the dynamic characteristics of centrifugal pendulum vibration absorbers restraining torsional vibration is investigated both theoretically and experimentally. In the theoretical analysis, the nonlinear characteristics are taken into consideration under the assumption of large amplitude vibration of pendulum. It is clarified that the centrifugal pendulum, although it has remarkable effects on suppressing harmonic vibration, induces large amplitude harmonic vibrations, the second and third superharmonic resonances, and unstable vibrations of harmonic type. We propose various methods to suppress these secondarily induced vibration and show that it is possible to suppress torsional vibrations to substancially zero amplitude in all through the rotational speed range.

Evaluation of a Vibration Damping Tool and of Drill Stem Torque Requirements From Data Recorded by an Instrumented Drill Stem Member

1968 ◽  
Vol 90 (2) ◽  
pp. 226-230
Author(s):  
C. E. Miller ◽  
H. M. Rollins
Keyword(s):  
Torsional Vibration ◽  
Axial Load ◽  
Vibration Damping ◽  
Torsional Vibrations ◽  
Bit Loading ◽  
Drill Stem ◽  
Torsional Load ◽  
Research Company ◽  
Production Research

An instrumented drill stem member was used by Esso Production Research Company to record drill stem axial load, torsional load, bending, and rates of changing in these three values. Interpretation of these data from selected runs is used to show variation in drill stem torque at the kelly, at the top of the collars, and near the bit. Data taken near the bit demonstrate erratic bit rotation and bit loading and suggest large torsional vibrations in the drill stem. Data recorded at the kelly and near the bit indicate substantial axial and torsional vibration damping by one type of vibration damping tool. Suggestions are made for further investigations.

Torsional Vibration Analysis of Drillstrings in Blasthole Drilling

2008 ◽  
Author(s):  
Omid Aminfar ◽  
Amir Khajepour
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Element Model ◽  
Drilling Process ◽  
Torsional Vibrations ◽  
Rotary Drilling ◽  
Well Drilling ◽  
State Response ◽  
Drilling Performance ◽  
Overall Performance

Reducing vibrations in well drilling has a significant effect on improving the overall performance of the drilling process. Vibrations may affect the drilling process in different ways, i.e., reducing durability of the drillstring’s elements, reducing the rate of penetration, and deviating the drilling direction. In rotary drilling, which is used to open mine and oil wells, torsional vibration of the drillstring is an important component of the overall system’s vibration that has received less attention in the literature. In this paper, we propose a finite element model for a sample blasthole drillstring used to open mine wells to investigate its torsional vibrations. Boundary conditions and elements’ specifications are applied to this model. In the model, the interaction between the insert and the rock is represented by a set of repetitive impulses according to the insert pattern. The steady-state response of the system to the repetitive impulses is found and natural frequencies, kinetic energy, and potential energy of the drillstring are calculated. The root mean square (RMS) of the total energy can be used as the measure for reducing the torsional vibration of the system. Finally, an optimum combination of inserts on the cone’s rows was found based on minimizing the total vibratory energy of the drillstring. The optimum design can reduce the torsional vibrations of the drillstring and improve the drilling performance.

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