A Study on the NVH Problems Caused by the Additional Excitation Force of Propeller Shaft

2017 ◽  
Author(s):  
Yong Xu
Keyword(s):  
Propeller Shaft ◽  
Excitation Force ◽  
Additional Excitation

FE Analysis of hollow propeller shaft using different composite material - A Review study

2012 ◽  
Vol 2 (5) ◽  
pp. 204-205
Author(s):  
Nimesh A Patel ◽  
◽  
Pradip M Patel ◽  
Prof. A. B. Patel Prof. A. B. Patel
Keyword(s):  
Composite Material ◽  
Fe Analysis ◽  
Propeller Shaft ◽  
Review Study

scholarly journals Research on the Fluid Excitation Force of Seal and Its Influencing Factors Based on CFD

2018 ◽  
Vol 1064 ◽  
pp. 012030
Author(s):  
Hao Cao ◽  
Weihua Zhou ◽  
Xiaowen Wu ◽  
Sheng Hu ◽  
Ling Lu ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Excitation Force

Vibration and sound radiation analysis of the final drive assembly considering the gear-shaft coupling dynamics

2016 ◽  
Vol 230 (7-8) ◽  
pp. 1258-1275 ◽  
Author(s):  
Yawen Wang ◽  
Junyi Yang ◽  
Dong Guo ◽  
Teik C Lim
Keyword(s):  
Dynamic Models ◽  
Acoustic Analysis ◽  
Bending Moment ◽  
Moment Of Inertia ◽  
System Dynamic ◽  
Dynamic Responses ◽  
Propeller Shaft ◽  
Hypoid Gear ◽  
Gyroscopic Effect ◽  
Gear Mesh

A generalized dynamic model of driveline system is formulated that includes the coupling effect and gyroscopic moments of the propeller shaft and hypoid gear rotor assembly. Firstly, the dynamic models with only gear-shaft coupling, with only gyroscopic effect, and with both gear-shaft coupling and gyroscopic effect are analyzed and compared. The results show that the combined effects of the gear-shaft interaction and gyroscopic behavior have considerable influence on the system dynamic responses surrounding gear bending resonances, especially for the bearing responses. However, the gear out-of-phase torsional modes still dominate the gear mesh frequency response. Secondly, the influence of pinion bending moment of inertia, propeller shaft stiffness and bearing stiffness on the system dynamic responses are examined. The system responses are then applied to perform further vibration and acoustic analysis for an axle housing structure. Computational results reveal that NVH (noise, vibration, and harshness) refinement can be achieved by tuning the pinion bearing rotational stiffness and pinion bending moment of inertia for the example considered. This study provides an understanding of the interaction between hypoid gear pair and propeller shaft, and can be employed to enhance driveline system design.

Economical Aspects of Cutting Speed Selection When Turning Stepped Parts

1971 ◽  
Vol 93 (4) ◽  
pp. 1113-1119 ◽  
Author(s):  
L. Kops
Keyword(s):  
Cutting Speed ◽  
Minimum Cost ◽  
Turbine Disk ◽  
Constant Speed ◽  
Graphical Form ◽  
Propeller Shaft ◽  
Analytical Comparison ◽  
Speed Selection ◽  
Time Required ◽  
Speed Method

The concept is developed of analytical comparison between two methods of cutting speed selection when cutting stepped parts: the constant rpm method and constant cutting speed method. Formulas for cost and time of machining stepped parts are derived and analyzed for two different examples of stepped parts: short ones with large differences in diameters (turbine disk) and long ones with small differences in diameters (propeller shaft). The results presented in graphical form show the advisable operating regions for the use of one of the two methods considered. The effect of time required to change the rpm on the effectiveness of the constant speed method is examined and the limit of applicability is determined. It is found that a reduction of as much as 1/3 in cost and time may be obtained when the constant speed method is applied in the case of the turbine disk. It is noted also that the minimum-cost speed and minimum-time speed depend on the choice of the method and on the shape of the machined part as well. The conclusions set out the conditions under which the use of the constant cutting speed method is justified.

scholarly journals Structural Damping with Friction Beams

2008 ◽  
Vol 15 (3-4) ◽  
pp. 291-298 ◽  
Author(s):  
L. Gaul ◽  
J. Roseira ◽  
J. Becker
Keyword(s):  
Linear Models ◽  
Natural Frequencies ◽  
Normal Force ◽  
Normal Pressure ◽  
Friction Model ◽  
Mode Shapes ◽  
Work Piece ◽  
Numerical Predictions ◽  
Double Beam ◽  
Excitation Force

In the last several years, there has been increasing interest in the use of friction joints for enhancing damping in structures. The joints themselves are responsible for the major part of the energy dissipation in assembled structures. The dissipated work in a joint depends on both the applied normal force and the excitation force. For the case of a constant amplitude excitation force, there is an optimal normal force which maximizes the damping. A ‘passive’ approach would be employed in this instance. In most cases however, the excitation force, as well as the interface parameters such as the friction coefficient, normal pressure distribution, etc., are not constant. In these cases, a ‘semi-active’ approach, which implements an active varying normal force, is necessary. For the ‘passive’ and ‘semi-active’ approaches, the normal force has to be measured. Interestingly, since the normal force in a friction joint influences the local stiffness, the natural frequencies of the assembled structure can be tuned by adjusting the normal force. Experiments and simulations are performed for a simple laboratory structure consisting of two superposed beams with friction in the interface. Numerical simulation of the friction interface requires non-linear models. The response of the double beam system is simulated using a numerical algorithm programmed inMATLABwhich models point-to-point friction with the Masing friction model. Numerical predictions and measurements of the double beam free vibration response are compared. A practical application is then described, in which a friction beam is used to damp the vibrations of the work piece table on a milling machine. The increased damping of the table reduces vibration amplitudes, which in turn results in enhanced surface quality of the machined parts, reduction in machine tool wear, and potentially higher feed rates. Optimal positioning of the friction beams is based on knowledge of the mode shapes, which are obtained from experimental modal analysis. The modal damping and the natural frequencies for the two dominant modes are measured for several combinations of excitation force and normal force.

Comparisons between Hullform and Propulsor Combinations for a High-Speed Sealift Ship

2009 ◽  
Author(s):  
Dominic S. Cusanelli ◽  
Michael B. Wilson
Keyword(s):  
High Speed ◽  
Propeller Shaft ◽  
Rotating Shaft ◽  
Mixed Flow ◽  
Scale Evaluation ◽  
Model Scale ◽  
Trade Offs

Designed ‘from the ground up’ for high speed, many trade-offs were made within the hullform parameters of this notional 298 m, 36,000 Long Ton, High Speed Sealift (HSS) ship, in an effort to optimize 39-knot performance. Resistance and powering comparisons are drawn between several hullform and propulsor combinations, considered the most applicable to HSS, which include: conventional 2-screw and 4-screw, open-propeller, shaft and strut; waterjet propulsion (axial and mixed-flow jet hulls); hybrid contra-rotating shaft-pod (twin shafts, twin pods) and dual-pods (twin sets of dual pods). This model-scale evaluation established that 39-knots was achievable by several candidate hullform and propulsor variations on this sealift ship, within the anticipated installed power levels.

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