The dynamic performance analysis of chevron
shape textured hydrodynamic bearings
Gourav Jamwal
School of Mechanical Engineering, Shri Mata Vaishno Devi University, Katra, India
Sanjay Sharma
Research Scholar, IKGPTU, Jalandhar, India and Faculty, School of Mechanical Engineering, Shri Mata Vaishno Devi University, Katra, India, and
R.K. Awasthi
Department of Mechanical Engineering, Beant College of Engineering and Technology, Gurdaspur, India
Abstract
Purpose – This paper aims to evaluate the various dynamic performance parameters of hydrodynamic journal bearings. For this, the bearing’s inner
surface is textured with chevron-shaped textures with different texture depths and number of textures in different regions/locations.
Design/methodology/approach – In the present study, the effect of chevron-shaped texture having different values of texture depths, locations
and number of textures has been numerically simulated. The dynamic performance characteristics have been calculated by solving the fluid flow
governing Reynolds equation using the finite element method, assuming iso-viscous and Newtonian fluid.
Findings – The obtained results indicate that the bearing stability can be improved with the help of surface texture. Among all the investigated texture
locations, the maximum increase in stability threshold speed is observed for fully textured distribution. Moreover, for the chevron-shaped texture considered
in the present study, the optimum values of texture depth and number of textures have also been determined for maximum bearing stability.
Practical implications – While designing, designers should focus on those optimum values of texture depth, texture location and number of
textures which lead to maximum enhancement in bearing stability.
Originality/value – This study is useful in the appropriate selection of chevron-shaped texture parameters on bearing surface for the maximum
bearing stability.
Keywords Finite element method, Hydrodynamic journal bearing, Dynamic characteristics, Surface texturing, Surface textures, Stiffness coefficient,
FEM, Damping coefficient, Stability threshold speed
Paper type Research paper
Nomenclature
Dimensional parameters
c = radial clearance, mm;
C
ij
= fluid-film damping coefficients (i, j = x, z), N.
mm
2
;
D = journal diameter, mm;
e = journal eccentricity, mm;
F = fluid-film reaction (@h/@t = 0), N;
F
x
, F
z
= fluid-film reaction components in X and Y
direction (@h/@t = 0), N;
F
o
= fluid-film reaction (@h/@t 0), N;
g = acceleration due to gravity, m.sec
2
;
h = nominal fluid-film thickness, mm;
L = bearing length, mm;
N = rotational speed, rpm;
p = pressure, N.mm
2
;
p
s
= supply pressure, N.mm
2
(hybrid journal bearing);
m
r
v
J
R
J
2
=c
2
(hydrodynamic journal bearing);
Q = lubricant flow, mm
3
.sec
1
;
r = radial coordinate;
R
J
, R
b
= radius of journal and bearing, mm;
S
ij
= fluid-film stiffness coefficients (i, j = x, z),
N.mm
1
;
k = ratio of inner to the outer side if the triangles
forming the chevron;
t = time, sec;
W
o
= external load, N;
x = circumferential coordinate;
y = axial coordinate;
X
J
, Z
J
= journal center coordinate; and
z = coordinate along film thickness.
Greek letters
d h = texture depth, mm;
m = lubricant viscosity, Pa. sec;
m
r
= reference viscosity of lubricant, Pa. sec;
v
th
= threshold speed, rad.sec
1
; and
v
j
= journal rotational speed, rad.sec
1
.
The current issue and full text archive of this journal is available on
Emerald Insight at: https://www.emerald.com/insight/0036-8792.htm
Industrial Lubrication and Tribology
72/1 (2020) 1–8
© Emerald Publishing Limited [ISSN 0036-8792]
[DOI 10.1108/ILT-05-2019-0172]
Received 6 May 2019
Revised 19 June 2019
21 June 2019
Accepted 21 June 2019
1