Improvements in Bearings for Crank Shafts.
Year: 1892

page_text: Date of Application, 28th Apr., 1892-Accepted, 28th May, 1892
OMLETE SPECIFICATION.
Improvements in Bearings for Crank Shafts.
We, JOHN HENRY HARGREAVES, and GEORGE FREDERICK HILL, of Soho
Iron Works, Bolton, in the County of Lancaster, Engineers, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement, that is
to say :—
This invention relates to bearings for such crank shafts as from their arrange-
ment in connection with other parts of a steam engine or other motor or machine,
are liable to strains tending to give them a slight inclination in the bearings in
planes passing through the axes of the shafts but at right angles to the planes in
which the piston rods or reciprocating parts connected to the cranks, work. The
improved bearings are advantageously applicable to horizontal steam engines having
horizontal cylinders and the crank shafts of which carry heavy flywheels, with the
bearings between such flywheels and the cranks.
The invention consists in constructing the bearings in a special manner allowing
of automatic adjustment to suit the slight inclination which the shaft may assume
without causing increased strain and friction. On an accompanying sheet of
explanatory drawings three modifications are delineated.
Figure, 1, is a sectional plan, and Figures, 2, and 3, are vertical sections as at
right angles to each other.
Figures, 4, and 5, are vertical sections as at right angles to each other of the
second modification.
Figure, 6, is a vertical section of the third modification.
In these drawings the same reference letters are used to mark the same or like
parts wherever they are repeated.
In Figure, 1, to the right of the vertical centre plane the bearing cap or cover, A,
is supposed to be removed, and the lateral bearing brass, B, and its bolsters, C, are
shown in horizontal section. At the left of the vertical centre plane a part of the
cap, A, is shown in plan at the lower part, but at the upper part the cap is supposed
to be removed. In Figure, 2, the right-hand part is sectioned as by a plane passing
through one of the bolsters, C, and other parts, and the left-hand part is sectioned
as by a plane passing through the middle of the bearing. In Figures 4, and 5, the
section planes pass through the middle of the hearing.
The essential feature of our improved bearing is the shaping of the bottom, D,
of the recess for the bearing in the main casting or bedframe, E, with a concave
cylindrical surface, together with the shaping of the bottom bolster, F, of the
bearing with a convex cylindrical bottom surface which is a counterpart of the
recess bottom, D, and is fitted to move thereon. The axis or centre line of
the cylindrical surfaces of the bolster, F, and recess bottom, D, is in the modification
now being described, at a level a little higher than the top of the cap, A, and is at
right angles to the axis of the crank shaft, G. The cap, A, is secured to the bed-
frame, E, by two bolts, H, the screw nuts of which have inserted under them
washers, J, which are convexly spherical on their undersides and fit concavely
spherical seats in the cap, the centres of the spherical surfaces of the washers being
in the axis of the cylindrical surface of the bottom bolster, F. With this
construction, and the bolt holes and other parts being shaped to allow of a small
movement, the bearing is free to move to a limited but sufficient extent about the
axis of the cylindrical surfaces.
As shown in Figures, 2, and 3, the bottom bolster, F, has upon it a bottom
bearing brass, K, above which and resting partly on it and partly on the bottom
bolster, F, there are the side bearing brasses, B, the bearing surfaces of which

page_text: however do not extend across the middle of the bearing. On the left-hand side of
the bearing as seen in Figures, 1, and 2, the bolsters, L, of the side brass, B, are in
the form of wedges which can be adjusted by means of screw bolts, M, to tighten
the brass to compensate for wear. The bottom bolster, F, together with the bottom
and side brasses, K, B, B, are connected and bound to the cap, A, by T-ended
bolts, N, the cap being made with internal projections bearing on the tops of the
side brasses, B, B, and these several parts move together as one piece when
inclination of the shaft takes place.
The smaller bearings shown in Figures, 4, and 5, is substantially the same as the
one already described, some minor parts being simplified or omitted.
The position of the axis of the cylindrical surfaces of the brasses or bolsters may
be varied in different cases as may be found desirable in practice, and when placed
in or near the axial plane of the shaft, as shown in the third modification, Figure, 6,
there may be a top brass and a bolster, P, having a convex cylindrical surface
co-axial with that of the bottom bolster, F, the cap A, being made with a counter-
part concave surface to fit it, and being secured by ordinary bolts.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is :
The improved construction of crank-shaft bearings with parts shaped to allow of
a small inclination in a plane passing through the axis of the shaft and at right
angles to the plane in which piston rods or reciprocating parts connected to the
shaft work, the parts of the bearings being made and combined substantially as
hereinbefore described and as shown in the accompanying drawings.
Dated this Twenty-seventh day of April 1892.
EDMUND HUNT,
Applicants' Agent.