A Variable-Speed Method for Improving Motion Characteristics of Cam-Follower Systems

1996 ◽  
Vol 118 (2) ◽  
pp. 250-258 ◽  
Author(s):  
Hong-Sen Yan ◽  
Mi-Ching Tsai ◽  
Meng-Hui Hsu

A cam is often assumed to be operated at a constant speed in designing a cam-follower system. The motion characteristics of the follower are determined once the cam displacement curve is designed. The traditional design method for improving the motion characteristics is to find a new displacement curve which has better motion characteristics. This paper, however, presents an alternative approach by varying the speed of the cam to reduce the peak values of the follower output motion characteristics. Constraints and design criteria for selecting suitable cam speed trajectories are then developed. Finally, examples are given to illustrate the design procedure and also to show its feasibility.

Author(s):  
Hong-Sen Yan ◽  
M. C. Tsai ◽  
M. H. Hsu ◽  
M. K. Fong ◽  
W. H. Hsieh

Abstract A cam is often assumed to be operated at a constant speed in designing a cam-follower system. And, to improve the motion characteristics is to do a new design by finding an appropriate cam-profile. From the kinematic point of view, this paper presents an alternative approach to improve the motion characteristics by varying the speed of the cam. Design criteria for selecting suitable cam speed trajectories are provided. Examples are given to illustrate the design procedure and also to show the feasibility.


2003 ◽  
Vol 125 (3) ◽  
pp. 593-601 ◽  
Author(s):  
B. Demeulenaere ◽  
J. De Schutter

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.


1998 ◽  
Vol 37 (11) ◽  
pp. 105-111 ◽  
Author(s):  
Jasna Petrovic ◽  
Jovan Despotovic

Traditional design method for urban drainage systems is based on design storms and its major drawback is that frequencies of peak flows in the system are considered equal to frequencies of design storms. An alternative is to use historical storms with rainfall-runoff models to produce a series of possible flows in the system and their frequencies. The latter approach involves more computations and can be laborious for larger catchments. This paper considers ways to reduce the set of historical storms to be involved in design procedure and yet to lead to realistic flow frequencies. Frequencies obtained by rainfall-runoff simulation at an experimental catchment are compared with frequencies of observed peak flows in the system.


2003 ◽  
Vol 125 (3) ◽  
pp. 480-482 ◽  
Author(s):  
Yan-An Yao ◽  
Hong-Sen Yan ◽  
Ce Zhang

This paper applies the concept of variable speeds to vibration control of elastic cam-follower systems. A multi-design-point approach, based on optimal control theory, is developed for selecting suitable input speed functions of the cam that can reduce both primary and residual vibrations of the output in elastic cam-follower systems despite parameter variations. A design example is given to verify the feasibility of the approach.


2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.


1991 ◽  
Vol 18 (6) ◽  
pp. 926-932 ◽  
Author(s):  
Seshu Madhava Rao Adluri ◽  
Murty K. S. Madugula

The concept of schifflerization of 90° equal-leg angle is presented and its application in triangular-base latticed steel towers is explained. The similarities and differences between schifflerized angles and regular 90° angles are discussed. The current design practice for schifflerized angles is reviewed and its limitation is highlighted. A design method which includes the effect of the torsional-flexural buckling mode of failure is proposed. For ready use of designers, the factored axial compressive resistances of schifflerized angles are tabulated for both the present and proposed design methods. Key words: buckling, compressive resistance, design criteria, schifflerized angles, stability, standards, steel, struts, towers, guyed towers.


2014 ◽  
Vol 716-717 ◽  
pp. 1518-1521
Author(s):  
Shu Fang ◽  
Yan Xu ◽  
Fei Dong

The manufacture of fire robot has characteristics such as different types and piece production, and flexible manufacture and cost control of the fire robot must be considered due to these characteristics. In this paper, the similarity of fire robot’s working environment was analyzed, The demand of chassis’s adaptability and the method using general technical platform were discussed with the thinking of modular design, and new series fire robots which composed of the general platform and different function modules were proposed, and the manufacture cost of traditional design method and modular design method were compared in using the activity-based costing method, and under the new design method the manufacture cost were decreased extremely.


2007 ◽  
Vol 31 (2) ◽  
pp. 167-190 ◽  
Author(s):  
Zhang Ying ◽  
Yao Yan-An ◽  
Cha Jian-Zhong

This paper proposed a novel concept of active balancer for dynamic balancing of planar mechanisms. Somewhat similar to a vibration absorber, the active balancer is designed as an independent device, which is placed outside of the mechanism to be balanced and can be installed easily. It consists of a two degree-of-freedom (DOF) linkage with two input shafts, one of which is connected to the output shaft of the mechanism to be balanced by a joint coupling, and the other one is driven by a controllable motor. Flexible dynamic balancing adapted to different working conditions can be achieved by varying speed trajectories of the control motor actively. A design method is developed for selecting suitable speed trajectories and link parameters of the two DOF linkage of the balancer to meet various design requirements and constraints. Numerical examples are given to demonstrate the design procedure and to verify the feasibility of the proposed concept.


ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Suyong Wu ◽  
Xingwu Long ◽  
Kaiyong Yang

We present a novel fast robust design method of multilayer optical coatings. The sensitivity of optical films to production errors is controlled in the whole optimization design procedure. We derive an analytical calculation model for fast robust design of multilayer optical coatings. We demonstrate its effectiveness by successful application of the robust design method to a neutral beam splitter. It is showed that the novel robust design method owns an inherent fast computation characteristic and the designed film is insensitive to the monitoring thickness errors in deposition process. This method is especially of practical significance to improve the mass production yields and repetitive production of high-quality optical coatings.


Author(s):  
G D Gosain ◽  
R Sharma ◽  
Tae-wan Kim

In the modern era of design governed by economics and efficiency, the preliminary design of a semi-submersible is critically important because in an evolutionary design environment new designs evolve from the basic preliminary designs and the basic dimensions and configurations affect almost all the parameters related to the economics and efficiency (e.g. hydrodynamic response, stability, deck load and structural steel weight of the structure, etc.). The present paper is focused on exploring an optimum design method that aims not only at optimum motion characteristics but also optimum stability, manufacturing and operational efficiency. Our proposed method determines the most preferable optimum principal dimensions of a semi-submersible that satisfies the desired requirements for motion performance and stability at the preliminary stage of design. Our proposed design approach interlinks the mathematical design model with the global optimization techniques and this paper presents the preliminary design approach, the mathematical model of optimization. Finally, a real world design example of a semi-submersible is presented to show the applicability and efficiency of the proposed design optimization model at the preliminary stage of design.


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