Research Papers: Design of Mechanisms and Robotic Systems

Avoiding Early Failures in Conjugate Cam Mechanism by Means of Different Design Strategies

[+] Author and Article Information
Pau Català

Department of Mechanical Engineering,
Universitat Politècnica de Catalunya,
Avda. Diagonal 647,
Barcelona 08028, Spain
e-mail: pau.catala@upc.edu

Maria Antònia De los Santos, Joaquim M. Veciana, Salvador Cardona

Department of Mechanical Engineering,
Universitat Politècnica de Catalunya,
Avda. Diagonal 647,
Barcelona 08028, Spain

Contributed by the Mechanisms and Robotics Committee of ASME for publication in the JOURNAL OF MECHANICAL DESIGN. Manuscript received May 30, 2015; final manuscript received September 30, 2015; published online November 16, 2015. Assoc. Editor: Ettore Pennestri.

J. Mech. Des 138(1), 012302 (Nov 16, 2015) (9 pages) Paper No: MD-15-1401; doi: 10.1115/1.4031805 History: Received May 30, 2015; Revised September 30, 2015

To solve the indetermination of forces existing in a form-closed cam mechanism formed by conjugate cams, where the contact between the cams and the follower rollers is constantly ensured by only the geometry of the elements, dynamic models that consider the elasticity of the elements must be proposed. Because the stiffness of the main elements is associated with the elasticity of the solids, tight variations in manufacturing and assembly errors modify the effective interference fit, which significantly affects the expected fatigue life of the mechanism, leading to a premature failure of the elements due to surface fatigue. Based on a real industrial application of a conjugate cam mechanism and using lumped-parameter models, the objectives of this paper are: first, to show that it is difficult to achieve a pure form-closed conjugate cam mechanism, with the expected fatigue life of the mechanism, by using only standard tolerance specifications; second, to compare the expected fatigue life and motor torque with other cam mechanism design strategies such as force-closed and the combination of force-closed and form-closed strategies, known as force-closed conjugate cam strategy. This paper based on simulation results demonstrates that this latest strategy can, thanks to a better control of the preload, easily achieve results very similar to the theoretical ones of a form-closed conjugate cam mechanism. A prototype of the mechanism of the force-closed conjugate cam strategy is also built.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.


Cardona, S. , Zayas, E. E. , Jordi, L. , and Català, P. , 2013, “ Synthesis of Displacement Functions by Bézier Curves in Constant-Breadth Cams With Parallel Flat-Faced Double Translating and Oscillating Followers,” Mech. Mach. Theory, 62, pp. 51–62. [CrossRef]
Cardona, S. , Zayas, E. E. , and Jordi, L. , 2014, “ Radius of Curvature and Sliding Velocity in Constant-Breadth Cam Mechanism,” Mech. Mach. Theory, 81, pp. 181–192. [CrossRef]
Lee, T.-M. , Lee, D.-Y. , Lee, H.-C. , and Yang, M.-Y. , 2009, “ Design of Cam-Type Transfer Unit Assisted With Conjugate Cam and Torque Control Cam,” Mech. Mach. Theory, 44(6), pp. 1144–1155. [CrossRef]
Flocker, F. W. , 2012, “ A Versatile Cam Profile for Controlling Interface Force in Multiple-Dwell Cam-Follower Systems,” ASME J. Mech. Des., 134(9), p. 094501. [CrossRef]
Chavan, U. , and Joshi, S. , 2011, “ Synthesis of Cam Profile Using Classical Splines and the Effect of Knot Locations on the Acceleration, Jump, and Interface Force of Cam Follower System,” Proc. Inst. Mech. Eng. Part C, 225(12), pp. 3019–3030. [CrossRef]
Pastorelli, S. , Almondo, A. , and Sorli, M. , 2010, “ Mechanical Spring Replacement With Pneumatic Return Device in a Valve Train: Effects on Dynamics and Preload Tuning,” ASME J. Mech. Des., 132(1), p. 011008. [CrossRef]
Alzate, R. , Di Bernardo, M. , Montanaro, U. , and Santini, S. , 2007, “ Experimental and Numerical Verification of Bifurcations and Chaos in Cam-Follower Impacting Systems,” Nonlinear Dyn., 50(3), pp. 409–429. [CrossRef]
Özgür, K. , and Pasin, F. , 1996, “ Separation Phenomena in Force Closed Cam Mechanisms,” Mech. Mach. Theory, 31(4), pp. 487–499. [CrossRef]
Dalpiaz, G. , and Rivola, A. , 2000, “ Non-Linear Elastodynamic Model of a Desmodromic Valve Train,” Mech. Mach. Theory, 35(11), pp. 1551–1562. [CrossRef]
Norton, R. L. , 2002, Cam Design and Manufacturing Handbook, Industrial Press, New York, pp. 263–314, 522–523.
Rothbart, H. A. , 2004, Cam Design Handbook, McGraw-Hill, New York, pp. 251–260, 311–312.
Chang, W.-T. , and Wu, L.-I. , 2013, “ Tolerance Analysis and Synthesis of Cam-Modulated Linkages,” Math. Comput. Model., 57(3–4), pp. 641–660. [CrossRef]
Demeulenaere, B. , Spaepen, P. , Masselis, S. , Cornelissen, P. , Pinte, G. , Hemelsoen, J. , Boonen, R. , Roelstraete, K. , Desmet, W. , Swevers, J. , and De Schutter, J. , 2008, “ Experimental Validation of Input Torque Balancing Applied to Weaving Machinery,” ASME J. Mech. Des., 130(2), p. 022307. [CrossRef]
Català, P. , De Los Santos, M. A. , Veciana, J. M. , and Cardona, S. , 2013, “ Evaluation of the Influence of a Planned Interference Fit on the Expected Fatigue Life of a Conjugate Cam Mechanism—A Case Study,” ASME J. Mech. Des., 135(8), p. 081002. [CrossRef]
Chang, W.-T. , Wu, L.-L. , Fuh, K.-H. , and Lin, C.-C. , 2008, “ Inspecting Profile Errors of Conjugate Disk Cams With Coordinate Measurement,” ASME J. Manuf. Sci. Eng., 130(1), p. 110099. [CrossRef]
Chang, W.-T. , and Wu, L.-L. , 2008, “ A Simplified Method for Examining Profile Deviations of Conjugate Disk Cams,” ASME J. Mech. Des., 130(5), p. 052601. [CrossRef]
Johnson, K. L. , 1985, Contact Mechanics, Cambridge University Press, Cambridge, UK, pp. 84–99.
Gatti, G. , and Mundo, D. , 2010, “ On the Direct Control of Follower Vibrations in Cam-Follower Mechanisms,” Mech. Mach. Theory, 45(1), pp. 23–35. [CrossRef]
Demeulenaere, B. , and De Schutter, J. , 2005, “ Input Torque Balancing Using an Inverted Cam Mechanism,” ASME J. Mech. Des., 127(5), pp. 887–900. [CrossRef]
Kim, H. R. , 1977, “ Stochastic Analysis of Manufacturing Errors in Cam Mechanisms,” Open Access Dissertations and Theses, Paper No. 2692.


Grahic Jump Location
Fig. 1

Current form-closed conjugate cam mechanism

Grahic Jump Location
Fig. 2

Scheme of the dynamic model for pure form-closed

Grahic Jump Location
Fig. 3

Linear displacement functions imposed on the roller centers

Grahic Jump Location
Fig. 4

Free-body diagram of conjugate cams

Grahic Jump Location
Fig. 5

Form-closed contact forces

Grahic Jump Location
Fig. 6

Form-closed motor torque

Grahic Jump Location
Fig. 7

Form-closed contact pressures

Grahic Jump Location
Fig. 8

Scheme of the dynamic model for force-closed strategy

Grahic Jump Location
Fig. 9

Free-body diagram of cam

Grahic Jump Location
Fig. 10

CAD model with a feasible constructive solution

Grahic Jump Location
Fig. 11

Force-closed conjugate cam strategy prototype

Grahic Jump Location
Fig. 12

Scheme of the dynamic model for force-closed conjugate cam strategy

Grahic Jump Location
Fig. 13

Force-closed strategy forces

Grahic Jump Location
Fig. 14

Bottom follower accelerations for different springs for the force-closed conjugate cam mechanism

Grahic Jump Location
Fig. 15

Comparison of spring forces for the force-closed conjugate cam mechanism

Grahic Jump Location
Fig. 16

Forces for the force-closed conjugate cam strategy

Grahic Jump Location
Fig. 17

Contact pressures for new alternatives design strategies

Grahic Jump Location
Fig. 18

Motor torque for new alternatives design strategies



Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In