0
Technical Briefs

A Parameter Investigation Into the Thompson Constant-Velocity Coupling

[+] Author and Article Information
I. T. Watson, J. Olsen

School of Mechanical and Manufacturing Engineering, University of New South Wales, UNSW, Sydney, NSW 2052, Australia

B. Gangadhara Prusty1

School of Mechanical and Manufacturing Engineering, University of New South Wales, UNSW, Sydney, NSW 2052, AustraliaG.Prusty@unsw.edu.au

D. Farrell

Director of Engineering, Thompson Couplings Limited, 30 Lords Place, Orange, NSW 2800, Australia

1

Corresponding author.

J. Mech. Des 133(12), 124501 (Dec 09, 2011) (7 pages) doi:10.1115/1.4005229 History: Received November 19, 2009; Revised September 14, 2011; Published December 09, 2011; Online December 09, 2011

The Thompson coupling is a relatively recent design of constant-velocity coupling, that is, principally based on the double Cardan mechanism. An extra mechanism comprising a spherical pantograph serves to align the intermediate shaft of this coupling and so maintains the constant velocity of the double Cardan mechanism, in a modular fashion. This technical note serves to introduce basic closed form expressions for the coupling’s geometry—which may then be used to derive linkage accelerations and dynamic forces. The expressions are derived using standard identities in spherical geometry. The resulting dynamic model then informs a basic conceptual design optimization, which object is intended to reduce induced driveline vibrations, when the coupling is articulated at nonzero angles of torque transmission.

FIGURES IN THIS ARTICLE
<>
Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The Thompson coupling detailing the double Cardan mechanism for the transmission of torque. (1) The complete assembled coupling, (2) the double Cardan components in the coupling, (3) the cee-ring, (4) the input shaft, (5) the inner ring, (6) the outer ring, and (7) the output flange

Grahic Jump Location
Figure 2

The Thompson coupling detailing the centering mechanism used to align the intermediate shaft. Note that for the purposes of later analysis, the spherical pantograph is split over two radii, r1  = 65 mm and r2  = 85 mm.

Grahic Jump Location
Figure 3

Completely general spherical pantograph projected onto a two-dimensional plane

Grahic Jump Location
Figure 4

Four-bar spherical linkage WXYZ, note that WZ comprises the “ground” link

Grahic Jump Location
Figure 5

Schematic representation of the double Cardan mechanism in global x-y-z coordinate system, at articulation of α and at rotation corresponding to ψ = 0, and DE, BC lying on the homokinetic plane

Grahic Jump Location
Figure 6

Full schematic of spherical pantograph orbits

Grahic Jump Location
Figure 7

Summary schematic of one symmetric half of the spherical pantograph

Grahic Jump Location
Figure 8

Local (and moving) coordinate system for a spherical rigid link between A and B

Grahic Jump Location
Figure 9

A mass m orbiting periodically within some spherical envelope, subjected to forces L and M, used as parameters in nondimensionalization

Grahic Jump Location
Figure 10

Folding of pantograph corresponding to the constraint in Eq. 29

Grahic Jump Location
Figure 11

Total reaction force applied at the sphere center for the idealized pantograph corresponding to K2

Grahic Jump Location
Figure 12

Total reaction moment applied at the sphere center for the idealized pantograph corresponding to K2

Grahic Jump Location
Figure 13

Total reaction force and moment applied at sphere center for a physical double Cardan and spherical pantograph, nondimensionalized by RS  = 115.74 mm and m = 9.006 kg, φ = 1 rad/s

Tables

Errata

Discussions

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