Improvements in Self-oiling Pulleys.
Year: 1898

page_text: Date of Application, 27th June, 1898-Accepted, 10th Sept.,
1898
Improvements in Self-oiling Pulleys.
I, FRED HAZELTON SPEAR, of 63, South Champlain Street, Burlington, County of
Chittenden, State of Vermont, United States of America, Gentleman, do hereby
declare the nature of my invention for Improvements in Self-oiling Pulleys,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My invention relates to self-oiling pulleys, meaning thereby pulleys that require
to be charged with oil only at long intervals of time.
My invention has for its object to effect a thorough circulation of the oil carried
in the chamber of the pulley in such manner as to constantly and freely lubricate
all the wearing surfaces of the device. This results in greatly lessening the friction,
and resistance to rotation offered by the pulley.
wear,
In carrying my invention into effect I avail myself of the principle of centrifugal
force, by constructing the oil carrying chamber of the pulley so that one portion of
it is further from the axis of rotation than the other portion, with the result that
the oil tends to collect in the first mentioned portion with a greater pressure than
With the first
in the portion of the chamber which is not so far from said axis.
mentioned portion of the oil chamber communicates a duct or ducts formed in the
stationary portion of the pulley and leading thence to the surfaces to be lubricated,
and finally back to the oil chamber at that portion of the same which is nearer the
axis of rotation. It results from the above described construction and arrangement
of parts that the oil pressure in the first mentioned portion of the oil chamber
causes the oil to enter the said ducts, while at their delivery end the ducts are
relieved of pressure and induced to deliver their oil into the chamber of the pulley,
said pressure and exhausting tendency at the entrance and delivery ends of the
ducts resulting in the above-mentioned desirable circulation of the lubricating
fluid.
Such being the general nature of the invention it consists in the parts and
combinations thereof hereinafter set forth and claimed.
In order to make my invention more clearly understood I have shown in the
accompanying drawings means for carrying the same into practical effect, without
limiting my improvements, in their useful applications, to the particular construction
which, for the sake of illustration, I have delineated.
In said drawings:
Figure 1 is a longitudinal section of a pulley embodying my invention, shown as
mounted upon a portion of a shaft, the said section being taken on line I, Fig. 2.
Fig. 2 is an end view with the parts removed on line II, Fig. 1.
Fig. 3 is a transverse sectional view, the outer portion of the pulley being broken
away, taken upon line III, Fig. 1.
Fig. 4 is an end view of the head or covering plate of the pulley hub.
Referring to the drawings 1 indicates a portion of a shaft on which is mounted a
bushing A fixed in place upon the shaft, so as to be stationary or rotate therewith,
by means of a set screw M, or other suitable device.

page_text: 2 is the pulley, comprising a rib or flange L, a radial web K and a hollow hub C
adapted to fit and have a rotary bearing upon the bushing A and interiorly
shaped to form an annular oil chamber D, one portion of which chamber, the right
hand portion in Fig. 1, is of somewhat greater radius than the other (left hand)
portion. I do not restrict my invention to any particular shape of the interior of
the chamber to produce the above mentioned result, but find the construction
illustrated to be practical and convenient, in which the outer wall of the pulley-
hub is frusto-conical in contour the interior of the annular oil chamber tapering or
flaring outwardly (from left to right in Fig. 1).
B is a disk or flange formed upon one end of the bushing A and adapted to be
enclosed within the hub of the pulley at that end of the same which is of larger
diameter.
Tindicates one or more oiling grooves or ducts formed in the periphery of the
bushing A and running longitudinally thereof. The oil in these ducts is in direct
communication with the interior bearing surface of the hub C and is freely
delivered thereto for the purpose of lubrication. At the smaller side of the hub
is a circular groove J extending around the bushing and communicating with the
ends of the groove T. This circular groovo may be formed in either one of the
contiguous parts A C, or preferably as shown partly in each of said parts. From
the groove J oil distributing holes H load to the smaller end of the oil chamber D.
With the other ends of the groove T communicate ducts G which lead from said
grooves through the bushing and radially outward through the disk B, opening
from the periphery of the latter into the larger portion of the oil chamber.
The outer portion of the disk B is shaped to fit lightly within the oil chamber,
while its inner portion is bevelled, as indicated at i, to give a clearance for the
ends of the ducts G.
When the pulley is in operation, properly charged with oil, the course of the
latter is, for the reasons already described, from the larger end of the oil chamber
into and through the ducts G, thence through the grooves T through which the
oil is distributed to the pulley bearing, thence into the groove J, and thence
through the holes H into the smaller end of the oil chamber from which it circulates
again to the larger end. This course of the oil is indicated in Fig. 1 by the
arrows.
At one side of the bushing A is formed a shoulder a which is engaged by a
corresponding shoulder S on the pulley hub, to prevent longitudinal movement of
the pulley upon the bushing in one direction. E is a ring engaging the outer
face of the disk B and covering the ends of the horizontal portions of the ducts G
which are bored directly inward from the outer face of the disk. F is a cap
enclosing the oil chamber and the parts above described at one end of the hub
and secured in place by screws N. The cap F fits around a portion of the
bushing A and fits closely against the ring E thus holding the pulley from any
longitudinal movement to the left hand (Fig. 1). Around the ring E and between
the cap F and disk B is left an annular chamber O which serves as the original
filling and oil distributing space. From this space holes (Fig. 2) communicate
with the oil chamber D. The periphery of the ring E is dished as shown at e
to throw the oil inward to the holes P.
V is a filling aperture provided with a screw cap W and formed in the outer
face of the disk F. The oil chamber must not be filled above the inner diameter
of the cap F, and the filling aperture V is placed in such position and direction (see
Fig. 4) that the proper amount of oil will not be exceeded.
That portion of the ducts G which is formed in the disk E is preferably at an
angle to a true radial line, as seen in Fig. 2, and I also prefer to form two of such
inwardly extending duct portions, inclined in opposite directions and communicating
with the same horizontal duct portion, as also shown in said figure. The entrance
of the oil into the ducts is thus promoted whichever be the direction of the rotation
of the pulley.

page_text: A pulley constructed according to my invention will not drip when standing still,
or throw oil when in motion, as is the case with ordinary loose pulleys. It will run
for months, after having been filled, without any attention. It is simple and easy
of construction, and can be made of any width or diameter desired. It is impossible
for any dust or foreign matter to enter the oil chamber or bearings, and the latter
are absolutely dust proof. There is, therefore, very little friction or wear upon the
running surfaces. The use of this pulley prevents the saturation of pulley belts
with oil and their consequent rotting, and damage to goods from oil thrown by the
pulley is entirely avoided.
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. A self-oiling pulley, comprising a hub having therein an oil chamber of
greater diameter at one end than at the other, and having a bearing surface, and
a separate bushing or sleeve within said surface and adapted to be fixed on a shaft
or support, one of said parts having a longitudinal duct along said bearing surface,
and said parts having at the inner portion of the smaller end of the chamber a
communication with one end of said duct and at the outer portion of the larger end
of the chamber a communication with the other end of said duct.
2. In a self-oiling pulley, the combination with a bushing having a disk formed
with inwardly extending ducts leading from its periphery, and transverse ducts or
grooves leading longitudinally across its bearing face, of a pulley having a hub
fitting on said bushing, an oil chamber of larger diameter at one end than at the
other enclosing said disk at its larger end, the smaller end of said chamber
communicating with the rear ends of the said ducts in the bashing, substantially
as set forth.
3. In a self-oiling pulley, the combination of a bushing having the disk B and
formed with the ducts G, the grooves T, and the annular chamber J, the pulley
fitting on said bushing and having the oil chamber D of greater diameter at one
end than at the other and formed with the openings H by which said chamber
communicates at its smaller end with said groove J, and an enclosing cap engaging
the bushing and secured to the hub of the pulley, substantially as set forth.
4. The combination with the pulley having the oil chamber D, of the bushing
having the disc B, inclined ducts G formed in the disk, transverse grooves leading
from the inner ends of said ducts across the hub and bushing between their
bearing surfaces, and means whereby the rear ends of said grooves communicate
with the smaller end of the oil chamber D, substantially as set forth.
5. In a self-oiling pulley, the combination of the bushing having the disk B
formed on its outer face with the chamber O, ducts formed in the bushing and
extending from the outer portion of the disk inwardly and across the bushing
and communicating with the rear end of the oil chamber, the ring E situated at
the outer side of the dish and serving to cover the ends of the ducts, holes P
formed in the disk and leading from the chamber O to the chamber D and an
enclosing cap F secured to the hub of the pulley and having the filling aperture,
substantially as set forth.
6. The general construction, arrangement and combination of the several and
respective parts together forming my invention of improvements in self-oiling
pulleys, substantially as hereinbefore described, and illustrated by the drawings.
'000 Ong to lon BALO SU DODG
For the Applicant,
J. G. LORRAIN, M.I.E.E., M.I. Mech. E.,
Chartered Patent Agent.