A Kinematic Method for Improving Motion Characteristics of Cam-Follower Systems

1994 ◽  
Author(s):  
Hong-Sen Yan ◽  
M. C. Tsai ◽  
M. H. Hsu ◽  
M. K. Fong ◽  
W. H. Hsieh
Keyword(s):  
Design Procedure ◽  
Point Of View ◽  
Cam Design ◽  
Alternative Approach ◽  
Kinematic Method ◽  
Cam Follower ◽  
Cam Profile ◽  
Motion Characteristics ◽  
Kinematic Point ◽  
Provided Examples

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.

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
Keyword(s):  
Design Method ◽  
Design Procedure ◽  
Design Criteria ◽  
Displacement Curve ◽  
Variable Speed ◽  
Traditional Design ◽  
Alternative Approach ◽  
Cam Follower ◽  
Motion Characteristics ◽  
Speed Method

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.

Spline Based Design of Cam Contours for Improved Dynamic Performance

1993 ◽  
Author(s):  
Holly K. Ault ◽  
James C. Wilkinson
Keyword(s):  
Dynamic Performance ◽  
Integrated Design ◽  
Polynomial Functions ◽  
Piecewise Polynomial ◽  
Cam Design ◽  
Piecewise Polynomial Functions ◽  
Cam Follower ◽  
Cam Profile ◽  
Pitch Curve ◽  
Design And Manufacture

Abstract A method for the integrated design and manufacture of radial plate cams is discussed. Currently, a cam-follower system is designed by specifying constraints on the motion of the follower. The physical cam contour or cam pitch curve are not mathematically defined. The cam is manufactured from the discretized follower motion program. A new method for cam design is proposed which will produce a smooth, mathematically defined cam pitch curve while maintaining the proper constraints on the follower motion. Piecewise polynomial functions in the form of rational and/or non-rational splines may be used. Cams will be manufactured using smoothed profiles and tested for improved dynamic performance. The results of initial investigations of cam profile design for this research are presented.

Valve Gear Refinement

2000 ◽  
Vol 124 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Jurij Avsec ◽  
Milan Marcic ◽  
Maks Oblak
Keyword(s):  
Mathematical Model ◽  
Cam Design ◽  
Cam Follower ◽  
New Type ◽  
Cam Profile ◽  
Profile Design ◽  
Comparison Of The Results ◽  
The Mathematical Model ◽  
Valve Gear ◽  
Lubrication Properties

This paper describes a new type of valve gear cam—MULTICAM—which consists of seven curves and allows an optimum cam profile design. In order to calculate the cinematic and dynamic values and to assess the minimum oil film thickness in the valve gear, the mathematical model of an ideal valve gear was used. In addition, the comparison of the results between the polysine cam and the new MULTICAM cam design was made. By means of the new cam design the Hertz pressures were reduced at the point of contact between the cam and the cam follower and the lubrication properties at the top of the cam improved.

Synthesis of Inertially Compensated Variable-Speed Cams

2003 ◽  
Vol 125 (3) ◽  
pp. 593-601 ◽  
Author(s):  
B. Demeulenaere ◽  
J. De Schutter
Keyword(s):  
High Speed ◽  
Design Procedure ◽  
Variable Speed ◽  
Speed Variation ◽  
Design Choice ◽  
Cam Follower ◽  
Speed Fluctuation ◽  
Novel Design

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.

Target Optimization Design of Cam Curve in Zoom System

2013 ◽  
Vol 552 ◽  
pp. 44-51
Author(s):  
Chen Wei Ning ◽  
Cao Jian Zhong ◽  
Yang Hong Tao ◽  
Zhang Jian ◽  
Fan Zhe Yuan ◽  
...  
Keyword(s):  
Optimization Design ◽  
Rotation Angle ◽  
Optical Design ◽  
Zoom Lens ◽  
Pressure Angle ◽  
Cam Design ◽  
System A ◽  
Cam Follower ◽  
Optimization Function ◽  
The Stability

Zoom lens has been widely applied in all kinds of fields, and its cam optimization is the key to actualizing the performance of its optical design and the zooming process, while the smoothness and speediness of zooming movement must be considered for military and civilian use. With the incremental use of environmental requirements, it puts forward higher requests to the cam performance of lens. In order to guarantee that the cam has good stiffness in the case of vibration and shock environment, in the process of cam design, it not only requires curve optimal, but also needs to consider influence on the performance which is caused by reduced cam stiffness of the zoom system. A fine curve can ensure that the cam pressure angle α is smaller, and to ensure the cam follower maintains the uniform velocity and smaller acceleration in zooming process, and make the zoom system produce little impact, and whole zooming process smooth and fluent, it can reduce the zoom systems driving moment M, and can ensure the stability imaging of the zoom system. Good cam stiffness K can make the zoom lens have good stability in vibration environment, and make sure that the image quality. M and K respectively up to the pressure angle α of zoom curve and the rotation angle θ of zoom curve in cam. In the new cam design process, considering the whole influence on the performance that is caused by K and M to cam, we construct the function expressions K = f (α, θ) and M = f (α, θ), and then, build target optimization function with K and M, optimize the relationship between pressure angle α of zoom curve and rotation angle θ, looking for the optimal value for the stiffness K and the cam system driving moment M , and improve overall performance of the zoom cam .

scholarly journals An Unified Design Procedure for Flying Machining Operations

2012 ◽  
Author(s):  
Roberto Strada ◽  
Bruno Zappa ◽  
Hermes Giberti
Keyword(s):  
Design Procedure ◽  
Point Of View ◽  
Drive System ◽  
General Validity ◽  
The Subject ◽  
Machining Operations ◽  
Selection Of ◽  
Unified Design

“Flying machining” represents synchronization of an axis (slave) with a master axis in motion. One of the most important aspects of the design of “flying machining” operation is the choice of the proper law of motion of the slave axis. In literature, technical reports and papers can be found concerning this subject, but they deal with specific problems and the solutions or suggestions proposed are specific as well, suitable for those cases. In order to try to overcome this limitation, in this paper we analyze the subject of the flying machining operations from a wider point of view. We propose a unified design procedure with general validity, suitable for the choice of the slave axis’ law of motion for whatever “flying machining” operation. Furthermore methodologies for the selection of the drive system will be proposed. The procedure is described applying it on a cross sealing operation, typical of wrapping machine.

scholarly journals Influence of Functional Classification on Skill Tests in Elite Female Wheelchair Basketball Athletes

Medicina ◽  
2019 ◽  
Vol 55 (11) ◽  
pp. 740 ◽  
Author(s):  
Kaori Tachibana ◽  
Hirotaka Mutsuzaki ◽  
Yukiyo Shimizu ◽  
Takashi Doi ◽  
Kazushi Hotta ◽  
...  
Keyword(s):  
Point Of View ◽  
Functional Classification ◽  
Wheelchair Basketball ◽  
Basketball Players ◽  
National Team ◽  
Test Items ◽  
Skill Test ◽  
Functional Classes ◽  
Kinematic Point ◽  
Ball Test

Background and objectives: Wheelchair basketball players are classified into four functional classes according to the player’s “volume of action”, characterized by trunk movement and stability. As this classification is based on a kinematic point of view, test items might be differentially affected by the functional classification level. We aimed to clarify field-based skill test items closely related to the functional classification level. Materials and Methods: Twenty-six female wheelchair basketball athletes (Japan National Team candidates) completed seven field-based skill tests (20 m sprint, agility T-test, figure-eight with a ball test, the Yo-Yo 10 m recovery test, and three types of maximal passes), and anthropometric measurements were applied. Results: Significant differences among the classification levels were found for one-hand maximal passes (baseball and hook passes) and the figure-eight with a ball test. Furthermore, performance in the 20 m sprint and 10 m Yo-Yo recovery tests significantly differed between classes 1 and 4. Conclusions: The test items most influenced by the classification levels were one-hand passes, which require trunk stability and balance not only in the horizontal plane, but also in the sagittal and frontal planes. Coaches should consider which test items are strongly affected by the functional classification level when assessing a player’s performance.

AN INDEPENDENT ACTIVE TORQUE BALANCER USING A SERVO-CONTROLLED DIFFERENTIAL GEAR TRAIN

2009 ◽  
Vol 33 (2) ◽  
pp. 329-348 ◽  
Author(s):  
Sun Jing ◽  
Yao Yan-An
Keyword(s):  
Control Function ◽  
Design Procedure ◽  
Point Of View ◽  
Gear Train ◽  
Optimization Approach ◽  
Integrated Method ◽  
Control Functions ◽  
Differential Gear ◽  
Novel Concept ◽  
Input Torque

This paper proposes a novel concept of active balancer for reducing the input torque fluctuations of mechanisms. A differential gear train is used in this active balancer and one of its two input shafts is driven and controlled by a servomotor. From the structural point of view, it is designed as an independent device that can be assembled and disassembled easily; from the functional point of view, it can minimize the torque fluctuations in a variety of working conditions. At first, an exact control function of the servomotor that can totally eliminate the input torque fluctuations of the mechanism is gained by an analytical method; in what follows, an optimization approach is developed to select appropriate control functions for the servomotor to balance the input torque of the working mechanism with consideration of the servomotor’s own input torque minimization; finally, an integrated method is presented for optimizing both the control function of the servomotor and the structure parameters of the differential gear train. Two numerical examples are given to illustrate the design procedure and to show its feasibility.

Improving the B-Spline Method of Dynamically-Compensated Cam Design by Minimizing or Restricting Vibrations in High-Speed Cam-Follower Systems

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
J. K. Jiang ◽  
Y. R. Iwai
Keyword(s):  
High Speed ◽  
Design Method ◽  
Damping Ratio ◽  
Radius Of Curvature ◽  
Spline Method ◽  
Application Process ◽  
B Spline ◽  
Cam Design ◽  
Cam Follower ◽  
Design Values

This paper presents an improved method for dynamically-compensated (tuned) cam design by minimizing or restricting vibrations in high-speed cam-follower systems. Using this approach, cams can be synthesized with a variety of design requirements and reduced residual vibrations. An example of the dynamically-compensated B-spline method illustrates the application process and demonstrates the improvement effect. While preserving the features of the B-spline method, the improved design method allows the cams to satisfy requirements, such as pressure angle, radius of curvature, and contact stress, and also reduces the residual vibrations caused by deviations in actual cam speed or system damping ratio from their design values.

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