IMPROVEMENT IN PADS FOR COUNTERACTING THE ENDTHRUST AND THE WEIGHT OF PROPELLER AND OTHER SHAFTS
Year: 1885

page_text: I, ALEXANDER HENRY REED, of Suffolk House, Laurence Pountney Hill, Cannon
Street in the county of Middlesex, Engineer, do hereby declare the nature of the
said invention for an IMPROVEMENT IN PADS FOR COUNTERACTING THE ENDTHRUST
AND THE WEIGHT OF PROPELLER AND OTHER SHAFTS and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The object of this invention is to counteract the endthrust and the weight of
propeller and other shafts, and it consists in the novel construction of the parts as
is fully pointed out in the following specification and claims and illustrated in the
accompanying drawing in which:
Fig. 1 represents a side view of the pad applied to counteract the endthrust of
a shaft.
"
Fig. 2 is a transverse section of the same in the plane ax fig. 1.
Fig. 3. is a section of one of the endthrust pads on a larger scale than the
previous figures.
Fig. 4 is a side view of the pad applied to support the weight of the shaft.
Fig. 5 is a transverse section on the plane y y fig. 4. of the supporting pad and
the shaft on a larger scale.
.
Similar letters indicate corresponding parts.
In this drawing, referring for the present more especially to figures 1. 2 and 3,
the letter A designates a shaft such for instance as a propeller shaft and B is a
pillow block which forms one of the bearings for this shaft. On the face of
this pillow block are secured a series of pads C which bear against a flange D
fastened on the shaft. In the example represented by figs. 1. 2, 3 of the drawings
four pads are shown, but the number may be decreased or increased according to
circumstances. The pads shown in the drawing are provided with dovetailed
ribs a a which engage with corresponding grooves in the face of the pillow block
(best seen in fig. 3) but other means may be used for retaining the pads in position
on the pillow block, and the inventors do not restrict themselves to the exact

page_text: means shown. Each of the pads consists of two cylinders b, c, the cylinder b being
bored out to receive the cylinder c. In the circumference of the cylinder c is a
groove or recess d into which is placed the leather packing e and a ring f serves to
retain this packing in the recess. When the pad is charged with water under
pressure, the outer section of the packing e is forced against the inner surface of the
cylinder b, by the pressure of the water and leakage at that point is prevented.
The head g, of the cylinder c is provided with holes h, and with a recess i which
contains the leather packing, j, said packing being constructed like the packing e
and being retained in position by the ring . When the pad is charged with water
under pressure, the outer face of the head. g is forced up against the face of the
flange D on the shaft, and leakage is prevented by the packing j, while at the same
time comparatively little friction is produced between the pads and the flange. In
order to keep the head g in contact with the flange D, when the pad is not charged
with water, a spring is placed into each pad. The pads are supplied with water
by means of a force pump E which connects by means of a pipe F with the supply
openings m of all the pads. The pump E is provided with an air chamber n, and
with a safety valve p which is set to the maximum pressure required in the pads.
When the pump is set in operation, all the pads are charged with water and when
the pressure reaches the desired limit the water blows off through the safety valve.
At the same time the air in the upper portion of the air chamber becomes com
pressed and acts as an elastic cushion, whereby the pressure in the pads is rendered
yielding to some extent, and the friction between the pads and the flange D is reduced
to a minimum. By these means the endthrust of the shaft A is sustained by the
water packed pads C and a large percentage of power is saved. If desired, an
additional set of pads may be applied to counteract the endthrust of the shaft in
the opposite direction.
•
When the pad is to be used to sustain the weight of the shaft figs 4 and 5 so as
to relieve the bearings or journal boxes of the effect of the weight of the shaft, the
same is applied to the shaft between the pillow blocks B, B. Instead of having
the head g of the cylinder c flat, it is made concave so as to fit the convex surface
of the shaft. When the pad is charged with water under pressure, the concave
face of the head is forced up toward the shaft, and leakage is prevented by the
packing, while at the same time comparatively little friction is produced between
the pad and the shaft.
: The pad. C rests upon a screw T which is tapped' into a suitable base U. When
the screw T is turned so as to screw into the base a sufficient distance, the pad
can be removed from the shaft and when the screw T is screwed up or out of
the base U, the pad is pressed up against the shaft. The screw can be turned
by applying a wrench to its polygonal head, or it may be turned by any suitable
means.
The pad in this case as before is supplied with water by a force pump E which
connects by means of a pipe F with the supply opening m of the pad. The pump
is also provided with an air chamber n and with a safety valve p which is set to
the maximum pressure required in the pad. When the pump is set in operation
the pad is charged with water, and when the pressure reaches the desired limit the
water blows off through the safety valve. At the same time the air in the air
chamber becomes compressed and acts as an elastic cushion whereby the pressure
in the pad is rendered yielding to some extent and the friction between the pad
and the shaft is reduced to a minimum. At the same time, the wear of the journal
boxes is materially reduced since they are released of the pressure usually produced
by the weight of the shaft.
In the foregoing description of the pad, it has been stated that the head of the
cylinder c of the pad. is provided with a leather packing j, but if desired this
packing may be left out, and a ground joint may be produced between the head
of the pad, and the shaft, and in order to render the joint tight, a suitable material
such as a solution of rubber, or leather may be injected into the pad at the
beginning of the operation and subsequently, whenever such becomes desirable.

page_text: Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination, substantially as herein described, with the shaft A and the
pillow block B, of a series of waterpacked pads C, secured to the pillow block and
the flange D which is securely fastened on the shaft in position to bear against
the pad.
.
2. The combination, substantially as herein described, with the shaft A and the
pillow block B, the pads C and the flange D, of the force pump E for injecting into
all the pads the required supply of water.
3. The combination, substantially as herein described, with the shaft A, the
pillow block B, the pads C and the flange D, of the force pump E, its air chamber n
and safety valve p.
4. The combination with the the shaft A. and with the pillow blocks or journal
boxes in which said shaft revolves, of a water packed supporting pad substantially
as shown and described.
5. The combination with the shaft A, its pillow blocks or journal boxes B B and
with the water packed supporting pads C of the force pump E, its air chamber n
and a safety valve p, substantially as described.
6. The combination with the shaft A, its pillow block or journal boxes B B and
with the water packed supporting pad C of the adjusting screw T and base U
substantially as described.