Nonlinear simulation of speed variation of variable-speed unit under large disturbance by Simulink

Traditionally, cam-follower systems are designed by assuming a constant camshaft speed. Nevertheless, all cam-follower systems, especially high-speed systems, exhibit some camshaft speed fluctuation (despite the presence of a flywheel) which causes the follower motions to be inaccurate. This paper therefore proposes a novel design procedure that explicitly takes into account the camshaft speed variation. The design procedure assumes that (i) the cam-follower system is conservative and (ii) all forces are inertial. The design procedure is based on a single design choice, i.e., the amount of camshaft speed variation, and yields (i) cams that compensate for the inertial dynamics for any period of motion and (ii) a camshaft flywheel whose (small) inertia is independent of the period of motion. A design example shows that the cams designed in this way offer the following advantages, even for non-conservative, non-purely inertial cam-follower systems: (i) more accurate camshaft motion despite a smaller flywheel, (ii) lower motor torques, (iii) more accurate follower motions, with fewer undesired harmonics, and (iv) a camshaft motion spectrum that is easily and robustly predictable.

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The Influence of Variable-Speed Waveforms on Vibration Suppression in Time-Varying Speed Cutting

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.2514 ◽

2013 ◽

Vol 690-693 ◽

pp. 2514-2518

Author(s):

Juan Cong ◽

Yun Wang ◽

Wei Na Yu

Keyword(s):

Wave Speed ◽

Vibration Suppression ◽

Sine Wave ◽

Time Varying ◽

Variable Speed ◽

Suppression Effect ◽

Speed Variation ◽

Input And Output ◽

System Input ◽

Better Than

Through the research on the change of system input and output energy in time-varying speed cutting, the influence of variable-speed waveforms on vibration suppression effect in time-varying speed cutting is quantitatively analyzed in this paper. A conclusion can be drawn that sine wave speed variation is better than triangle wave speed variation in vibration suppression.

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The impact of speed variation on the stability of variable speed axial compressors at efficient operating points

2012 American Control Conference (ACC) ◽

10.1109/acc.2012.6314785 ◽

2012 ◽

Cited By ~ 3

Author(s):

G. Sari ◽

O. Akhrif ◽

L. Saydy

Keyword(s):

Variable Speed ◽

Axial Compressors ◽

Speed Variation ◽

The Stability ◽

The Impact ◽

Operating Points

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The Antivibration of Deeper Solt Milling System Experiment Research

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.121-126.468 ◽

2011 ◽

Vol 121-126 ◽

pp. 468-472

Author(s):

Zhi Jian Gou

Keyword(s):

Surface Finish ◽

Cutting Tool ◽

Spindle Speed ◽

Variable Speed ◽

Experiment Research ◽

Trajectory Parameter ◽

Slot Milling ◽

Speed Variation ◽

System Experiment ◽

Cutting Vibration

The cutting vibration is a very harmful phenomenon, which destroys the surface finish and dimensional integrity of workpieces and quickens the wear of cutting tool. The cutting vibration can be suppressed or reduced by applying the variable spindle speed cutting. In order to investigate the effect of variable spindle speed parameters and cutting conditions on suppressing the vibration, the deeper slot milling tests have been conducted. The results have shown that the vibration occurring in deeper slot milling can be reduced by applying the method of variable spindle speed milling, as long as the variable speed parameters are elected suitably. The values of speed variation amplitude Δn/n0 and speed variation frequency fn of spindle speed trajectory parameter have a great effect on antivibration. Under this article test condition, the amplitude Δn/n0 of variable spindle speed is 20% and frequency fn of variable spindle speed is 0.3Hz.

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Performance and Loads Investigation of Optimum Speed Rotors

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.607.500 ◽

2014 ◽

Vol 607 ◽

pp. 500-506

Author(s):

Shi Ming Liu ◽

Wei Dong Yang ◽

Ling Hua Dong ◽

Jie Wu

Keyword(s):

Power Reduction ◽

Comprehensive Model ◽

Variable Speed ◽

Rotor Speed ◽

Rotating Speed ◽

Speed Variation ◽

Optimum Speed ◽

Blade Loads

Performance of helicopters can be significantly influenced by rotor speed variation. A comprehensive model is built to exam the influences of rotating speed on performance and blade loads of a variable speed rotor. The results indicate that for a 2,200kg gross weight helicopter, power reduction is up to 30% at 100km/h by slowing the rotor properly. For lower gross weights, the reductions in rotor rotating speed and power savings are more apparent. The optimum rotating speed may cause a 20.5% increase in endurance and 8.5% in range by thoroughly consuming 400kg of fuel. Rotor RPM variation has an important effect on blade loads. For 100km/h and 2,200kg gross weight, amplitudes for most of the harmonic loads decrease with reduced rotor RPM.

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Transient Analysis of Converter-Fed Variable-Speed Generator-Motor for Pumped Storage Power Plant: Relationship between Fault Current and Speed Variation

IEEJ Transactions on Power and Energy ◽

10.1541/ieejpes1990.115.12_1406 ◽

1995 ◽

Vol 115 (12) ◽

pp. 1406-1411

Author(s):

Tadshiro Yanagisawa ◽

Tadashi Taguchi ◽

Michiyuki Abe ◽

Hirokazu Kaneko ◽

Takahisa Kageyama ◽

...

Keyword(s):

Power Plant ◽

Transient Analysis ◽

Fault Current ◽

Variable Speed ◽

Speed Variation ◽

Pumped Storage

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The Trial Research on Suppressing the Chatter by Variable Speed Milling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.2010 ◽

2011 ◽

Vol 291-294 ◽

pp. 2010-2013 ◽

Cited By ~ 1

Author(s):

Zhi Jian Gou

Keyword(s):

Cutting Tool ◽

Face Milling ◽

Spindle Speed ◽

Cutting Process ◽

Variable Speed ◽

Trajectory Parameter ◽

Speed Variation ◽

Cutting Chatter ◽

Speed Parameter ◽

Tool Cutting

The vibration occurring in cutting process is a very harmful phenomenon, which destroys the surface finish and dimensional integrity of workpieces and quickens the wear of cutting tool. Cutting chatter can be suppressed or reduced by applying the method of suppressing chatter by variable speed cutting. In order to investigate the effect of variable speed parameters and cutting conditions on suppressing the chatter in face milling, the tests have been conducted.The results have shown that cutting with variable spindle speed cutting in face milling will suppress the development of chatter. If chatter occurs in cutting process, the vibration amplitude of variable speed cutting can reduce by 3-6 times lower than that of constant speed cutting, as long as the variable speed parameter are selected suitably.The values of speed variation amplitude Δn/no and speed variation frequency fn of spindle speed trajectory parameter have great effect on suppressing chatter, Δn/no = 15- 20% and fn = 0.4 - 0.5Hz are suitable.

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