Year: 1886

page_text: I, JOHN BROUGH FYFE, of 33 Cumberland Street, West, Glasgow, in the County
of Lanark, North Britain, Engineer, do hereby declare the nature of this Invention
to be as follows, that is to say :-
My said Invention has for its object to improve the construction of thrust
apparatus for screw-propeller shafts and to render the same suitable for high
rotatory velocities.
In carrying out my Invention I employ balls of steel or other suitable hard
metal or alloy and I place one or more annular sets of the balls between an enlarge-
ment or disk on the shaft and a fixed annular abutment disk or block. There may
be one set of balls in front of the shaft disk for the thrust when going ahead and
another set at the back of the shaft disk for the thrust when going astern. Each
set of balls is placed between a flat surface at right angles to the shaft and an
annular concave surface which in radial section has the form of an arc of a circle
of somewhat larger radius than the radius of the balls, the flat surface being by
preference on the shaft. This conformation of the bearing surfaces not only keeps
the balls in their place but also insures their preserving a true spherical form if
any wear takes place. The said bearing surfaces are made of steel or other suitable
hard metal or alloy, and either or both may be fixed on a layer of cork or wood to
impart a slight elasticity. The stationary bearing surface for the ahead thrust is
fixed to a massive thrust casting which is made in halves, the joint being in a
horizontal plane passing through the axis of the shaft. The lower part or base is
made with a broad bottom flange and which is of considerable length and extends
under and abaft of the enlargement or disk on the shaft, so that it can be secured
by a number of bolts to suitable plates fixed to the floors of the ship in order that
the strain may be well distributed. The top part or cover is bolted to the base
by flanges at the sides, and the front ends of the flanges are made to fit up
against projections on the flanges of the base so as to transmit thrust to the base
independently of the bolts. The bearing disks or annular plates are made in halves
and the stationary ones are by preference fixed with their joint vertical or at right
angles to the joint of the thrust casting.
7
The part for receiving the astern thrust may be similar to that for the ahead
thrust, or it may consist of comparatively narrow parts connected by tie bolts or
rods to the parts for the ahead thrust.
D
A1 100G
EDMUND HUNT,
Applicant's Agent.

page_text: •
Improvements in Thrust Apparatus for Screw-propeller Shafts.
I, JOHN. BROUGH FYFE, of 33 Cumberland Street, West, Glasgow, in the County
of Lanark, North Britain, Engineer, 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:-
My said Invention has for its object to improve the construction of thrust
apparatus for screw-propeller shafts and to render the same suitable for high
rotatory velocities.
In carrying out my Invention I employ balls of steel or other suitable hard
metal or alloy and I place an annular set of the balls on each side of an enlarge-
ment or disk on the shaft and between it and fixed annular abutment disks or
thrust blocks. There may be two or more sets of balls in front of the shaft disk
for the thrust when going ahead but in general one set placed at the back of the
The thrust blocks
shaft disk will be sufficient for the thrust when going astern.
and other parts are of an improved construction.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append two sheets of explanatory
drawings to be hereinafter referred to and showing my improved arrangement of
thrust apparatus for screw-propeller shafts.
Figure, 1, on sheet, 1, of the accompanying drawings is a plan partly in section.
Figure, 2, on sheet, 2, is a transverse vertical section. Figure; 3, is a side elevation
partly in section and figures, 4, 5, 6, and 7, are separate views of details. In these
drawings the saine reference numerals are used to mark the same or like parts
wherever they are repeated.
Ai
In the modification shown in the drawings I employ two sets of balls, 8; each
set of balls being placed between a flat surface formed on an annular plate or flat
ring; 9, (shown, separate in figures, 6, and 7,) which is attached to an enlargement or
disc, 10, formed on the shaft, 11, by means of screws and a concave surface formed
on an annular plate or ring, 12, (shown separate in figures, 4, and 5,) and which
surface has in radial section, the form of an arc of a circle of somewhat larger
radius than the radius of the balls, 8. This conformation of the surfaces of the
bearing plates, 9, 12, not only keeps the balls, 8, in their places but also insures
their preserving a true spherical form if any wear takes place. The said bearing
plates, 9, 12, are made of steel or other suitable hard metal or alloy and they are
made in halves the stationary plates, 12, being by preference fixed with their joint
vertical or at right angles to the joint of the thrust casting hereinafter described.
Both of the stationary bearing plates, 12, are by preference fixed on a layer of cork
or wood, 13, so as to have a slight elasticity. The annular bearing plates, 9, are
made each with a dovetailed opening a little larger than the diameter of the
balls, 8, to admit of the insertion of the balls between the bearing plates, 9, 12,
when they are fixed in position; and sector plates, 14, with dovetailed edges, are
then inserted in the openings and fixed in position by screws.
The stationary bearing plate, 12, for the ahead thrust is fixed by means of
screws, to a massive thrust casting which is made in halves, 15, 16, the joint being

page_text: In a horizontal plane passing through the axis of the shaft, 11. The lower part or
base, 16, is made with a broad bottom flange, 18, which is of considerable length
and extends under and abaft of the disk, 10, on the shaft, 11, so that it can be
Becured by a number of bolts (not shown) to suitable plates, 19, fixed to the floors
of the ship in order that the strain may be well distributed.. The top part or
cover, 15, is bolted to the base, 16, by flanges, 20, at the sides, and the front ends
of the flanges on the cover, 15, are made to fit up against projections on the flanges
of the base, 16, so as to transmit thrust to the base independently of the bolts.
A comparatively narrow part, 21, is formed on the after end of the base of the
main thrust casting, 16, 18, for receiving the astern thrust, this part, 21, with its
cover, 17, being connected by tie bolts or rods, 22, to the main part, 15, 16, which
receives the ahead thrust.
Where shafts of extra large diameter are used two of my improved thrust blocks
may be used and they can be on one base or on separate bases as preferred; also
the part for receiving the astern thrust may be similar in construction to that for
the ahead thrust.
I prefer to use a single circular series of balls at each part of the shaft at which.
they are applied, but two or more concentric sets of balls may be used at each part,
provided that the sizes of the outer set or sets be made much larger in proportion
to the greater distance or distances from the centre of the shaft, the several bearing
surfaces being made to correspond.
If after long use the balls, -8, should become worn the defect arising therefrom
can be easily remedied by inserting liners between the back of the bearing plates, 9,
and the disc, 10, on the shaft, 11, but the use of these liners will very seldom be
called for. The action of the concave surfaces of the stationary plates, 12, on the
balls will cause the balls to be continually changing their points of contact, in
all directions, in consequence of which the balls will retain their sphericity even as
they wear.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
1. The improved combination of parts constituting thrust apparatus for screw-
propeller shafts, and consisting of metal balls placed round the shaft and between
an enlargement or disk on the shaft and stationary thrust blocks, each set of balls
being between a flat bearing surface and a concave-annular bearing surface; and
the thrust blocks being constructed and combined substantially in the improved..
manner herein before described.
2. The fixing of the bearing plates or any of them on layers of cork or wood
substantially as and for the purposes hereinbefore described.
Dated this tanth dân of Natambay 1000
EDMUND HUNT,
Applicant's Agent.