Specification for propeller shaft ends and bosses for inboard-engined pleasure craft

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.

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Economical Aspects of Cutting Speed Selection When Turning Stepped Parts

Journal of Engineering for Industry ◽

10.1115/1.3428050 ◽

1971 ◽

Vol 93 (4) ◽

pp. 1113-1119 ◽

Cited By ~ 1

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.

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Sea trial researches on extraction of propeller shaft frequency

Proceedings 2013 International Conference on Mechatronic Sciences, Electric Engineering and Computer (MEC) ◽

10.1109/mec.2013.6885269 ◽

2013 ◽

Author(s):

Niu Fang ◽

Hui Juan ◽

Cui Huachao ◽

Duan Haixu ◽

Yu Mengxiao

Keyword(s):

Propeller Shaft ◽

Sea Trial

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

10.5957/smc-2009-058 ◽

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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