Abstract

The lubrication regimes of a contact pair escapement-ruby pallet of a Swiss lever escapement have been investigated combining the theory of fluid lubrication with a well-established kinematic and inverse dynamic multibody model. The kinematic analytical results have been confronted with experimental measurements. The developed model allows to easily obtain, for the three operating phases of the Swiss lever escapement, the relative speed and the contact forces and, by considering a hydrodynamic lubrication regime, the lubricant minimum film thickness and the coefficient of friction. The presented formulation allows to study the influence of crucial technical parameters in the Swiss lever escapement lubrication. The spout radii of curvature have been identified as the optimal parameters to control the lubrication regimes in the pallet/escapement contacts. In that sense, an interesting result is that the lubrication regime moves away from the boundary lubrication by increasing these radii.

References

References
1.
Roup
,
A. V.
, and
Bernstein
,
D. S.
,
1999
, “
On the Dynamics of the Escapement Mechanism of a Mechanical Clock
,”
Proceedings of 38th Conference on Decision & Control, WeP11
,
Phoenix, AZ
,
December
, pp.
2599
2604
.
2.
Vermot
,
M.
,
Bovay
,
P.
,
Prongué
,
D.
, and
Winkler
,
P.
,
2011
,
Traité de Construction Horlogère
,
Presses Polytechniques et Universitaires Romandes
,
Lausanne
.
3.
Reymondin
,
C.-A.
,
Monnier
,
G.
,
Jeanneret
,
D.
, and
Pelaratti
,
U.
,
2011
,
Théorie d'horlogerie
,
Fédération des Ecoles Techniques
,
Le Locle, Switzerland
.
4.
Duncan
,
H. E.
,
1895
, “
Mechanism of the Pocket Watch
,”
J. Franklin Inst.
,
139
(
2
), pp.
81
100
.
5.
Headrick
,
M. V.
,
2002
, “
Origin and Evolution of the Anchor Clock Escapement
,”
IEEE Control Syst.
,
22
(
2
), pp.
41
52
. 10.1109/37.993314
6.
Hoyng
,
P.
,
2014
, “
Dynamics and Performance of Clock Pendulums
,”
Am. J. Phys.
,
82
(
11
), pp.
1053
1061
. 10.1119/1.4891667
7.
Moline
,
D.
,
Wagner
,
J.
, and
Volk
,
E.
,
2012
, “
Model of a Mechanical Clock Escapement
,”
Am. J. Phys.
,
80
(
7
), pp.
599
606
. 10.1119/1.4705517
8.
Patel
,
S.
,
Moline
,
D.
, and
Wagner
,
J.
,
2013
, “
Modeling and Analysis of an Atmospheric Driven Atmos Clock With Mechanical Escapement Control
,”
European Control Conference
,
Zurich, Switzerland
,
July 17–19
, pp.
281
287
.
9.
Blumenthal
,
A. S.
, and
Nosonovsky
,
M.
,
2020
, “
Friction and Dynamics of Verge and Foliot: How the Invention of the Pendulum Made Clocks Much More Accurate
,”
Appl. Mech.
,
1
(
2
), pp.
111
122
. 10.3390/applmech1020008
10.
Rolland
,
J.
,
Berre
,
H. W.-L.
,
Saulot
,
A.
, and
Berthier
,
Y.
,
2017
, “
Instrumentation of a Contact With the Finite Element Method and Experimental Coupling: The Case of the Swiss Lever Escapement Mechanism
,”
Tribol. Int.
,
111
, pp.
176
183
. 10.1016/j.triboint.2017.03.012
11.
Rolland
,
J.
,
Saulot
,
A.
, and
Berthier
,
Y.
,
2017
, “
Experimental Tribological Analysis of the Swiss Lever Escapement
,”
Wear
,
376–377
, pp.
1418
1428
. 10.1016/j.wear.2016.12.032
12.
Hutchings
,
I. M.
,
1992
,
Tribology: Friction and Wear of Engineering Materials
, 1st ed.,
Edward Arnold
,
London
.
13.
Czichos
,
H.
,
1978
,
Tribology: A Systems Approach to the Science and Technology of Friction, Lubrication, and Wear
,
Elsevier Scientific Pub. Co.
,
Amsterdam
.
14.
Johnson
,
K. L.
,
1985
,
Contact Mechanics
,
Cambridge University Press
,
New York
.
15.
SYNTESCAP 941. Technical Data
,
2019
, http://www.moebius-lubricants.ch, Accessed November 2019.
16.
Ditisheim
,
P.
,
1931
, “
Etat Actuel de la Question du Graissage en Horlogerie
,”
Ann. Fr. Chronom.
,
1
, pp.
104
110
.
17.
Ditisheim
,
P.
,
1938
, “
Sur L’emploi des Huiles D’horlogerie Naturelles et Artificielles
,”
Ann. Fr. Chronom.
,
8
, pp.
101
112
.
18.
Rymuza
,
Z.
,
1989
,
Tribology of Miniature Systems. Tribology Series: 13
,
Elsevier
,
Amsterdam
.
19.
Semenov
,
A. P.
,
2010
, “
The Role of Epilames in Tribology
,”
J. Frict. Wear
,
31
(
6
), pp.
469
480
. 10.3103/S1068366610060103
20.
Tosatti
,
S.
, and
Zurcher
,
S.
,
2010
,
“Ultra-Thin Hydrophobic and Oleophobic Layer, Method of Manufacture and Use in Watchmaking as an Epilam.” US PATENT 2010/0075138 A1
.
21.
Pan
,
J.
,
Fu
,
Y.
, and
Du
,
R. X.
,
2014
, “
Kinematic Analysis of Swiss Lever Escapement
,”
Adv. Mater. Res.
,
945–949
, pp.
684
689
. 10.4028/www.scientific.net/AMR.945-949.684
22.
Vermot
,
M.
,
2002
, “
Tests Tribologiques Horlogers
,”
Journée Technologique Pour L’Industrie Horlogère, SSC 40
,
Lausanne, Switzerland
,
May 22
, pp.
17
23
.
23.
Magnin
,
V. A. M.
,
2020
, “
Tribological Approach to the Watch Movements
,”
Ph.D. thesis
,
Ecole Polytehcnique Federale de Lausanne
,
Switzerland
.
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