Improvements in Bearings for Shafts and Means of Cooling the same.
Year: 1889

page_text: Improvements in Bearings for Shafts and Means of Cooling
the same.
I, CHARLES E. HYDE, of Bath, in the County of Sagadahoc, and State of Maine,
United States of America, Mechanical 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 :-
My invention relates to engineering, and more especially to marine steam engines.
Its object, primarily is to obviate the practical difficulties heretofore experienced with
the journal bearings of marine engine shafts, but it is applicable, also, to bearings for
all kinds of shafts and shafting.
The weight of a shaft is carried by the lower brass in the bearing, which consequently
wears faster than the upper brass, and lets the shaft settle out of line. Moreover, in
marine engines, the bearings of the crank shaft wear faster than those of the line shaft
and stern shaft, which increases the difficulty of preserving their alignment. It is
therefore necessary to frequently examine the lower brasses, especially those near the
cranks, and to adjust them vertically, or scrape or re-babbitt them to make up for
the wear and re-align the shaft. In the modern triple expansion engine, and other
forms of multiple crank engine, it is in many cases impossible to remove the lower
brasses without taking down the connecting rods and hoisting the shaft out of the
pillow blocks. This is a tedious and laborious operation, and, when done at sea, a
dangerous one. The brass is usually square on the outside to fit the recess in the
pillow block, which prevents it from being removed by turning it around on the shaft:
and the close proximity of the cranks and pillow blocks prevents the brasses from
being slid out end wise from the pillow blocks. It is necessary, however, to retain the
square shape of the brass to enable it to be readily adjusted vertically by means of
shims inserted between the bottom of the brass and the bottom of its seat in the pillow
block while the necessity for economizing room, and other reasons, forbid placing
the cranks far enough away from the bearings to permit the end wise removal of the
brasses.
My invention obviates all these difficulties, and enables any one or more of the
brasses to be readily removed for re-babbitting or scraping without disturbing the
shaft, and yet provides for their vertical adjustment by means of shims.
In the drawings, fig. 1 is a plan view of a part of the bed of a triple expansion
engine, showing the relative location of the cranks and pillow blocks, the cap and
upper brass being removed from one of the latter. Fig. 2 is a half cross section,
half elevation of one of the pillow blocks, embodying my invention. Fig. 3 is a
longitudinal section, and fig. 4 is an underside perspective view of the lower brass.
The same letters refer to the same parts in all the figures.
This
The bed-plate A is provided with pillow blocks B for the crank shaft C, the
bearings being located close to the cranks, as shown, for well known reasons.
construction, as already pointed out, prevents the endwise removal of the brasses.
My improved bearing consists of the ordinary pillow block B, provided with the
usual flat seat band parallel faced jaws 61 forming a recess to, receive the brasses.
Instead of a solid brass, I provide a cast iron chair D, fitted into the pillow block,
I employ any convenient means of adjusting the chair vertically, but prefer to use
ordinary shims, and consequently make the chair with a flat bottom, to fit the seat b,
so that shims can be introduced beneath it, the same as when an ordinary square brass
is used. The upper face of the chair has a semi-cylindrical hollow to receive the lower
brass E, which is a semi-cylindrical bushing, fitted smoothly to its place in the chair,
and having a flange e at each end to prevent it from accidental displacement in a
lengthwise direction.

page_text: The cap F of the bearing, may be fitted with an ordinary brass, or with a semi-
cylindrical upper brass E', similar to the lower brass E, the two brasses together
forming the cylindrical bearing for the journal of the shaft. The brasses are
kept from turning in their seats in the chair D and cap F by means of metal
liners G inserted between the meeting faces of the brasses, chair and cap. Bolts H
pass through the flanges of the cap and down through the pillow block, being
let half into the block, and half into the cap, liners and chair, as shown. This
prevents the liners and chair from moving endwise in the pillow block, but does
not interfere with their vertical adjustment.
Whenever it is desired to examine the lower brass, the nuts h are removed, the
cap F and its brass E¹ lifted out, and the liners G taken up. The lower brass E
can then be revolved around the shaft C, by means of a spanner applied to the
notches e in the flange e. When the brass has come up on top of the shaft, it is
free from the chair D and can be lifted out of the pillow block, either by hand, or
if large and heavy, by suitable hoisting tackle attached to an eye I screwed into a
threaded hole in the brass.
The same brass, or a new one, can be inserted into the chair by reversing the
operation for its removal, slipping it around the shaft until its edges are even with
the top of the chair, and then replacing the liners G, the brass E¹ and the cap F.
In order to cool the brasses, it has been customary to core them out and pump
water through them. Such a construction would be impracticable with my improved
bearing, and I have accordingly devised another mode of accomplishing the same
purpose. In the outer face of the lower brass E is formed a groove e², preferably
zigzag, as shown, coursing back and forth along the brass from one end to the
other, and back again. When the brass is placed in the chair, the groove forms with the
adjacent face of the chair a continuous passage way. A pipe K is inserted loosely
through a hole in the lower part of the pillow block and through the chair D,
terminating at a point opposite the groove e², and preferably near one end thereof.
The pipe K is connected with a supply of water, which is forced to traverse the
groove e, and escapes through a pipe K', inserted into the chair in the same way
as pipe K. Both pipes, being loose in the pillow block, can rise with the chair Ď
when it is adjusted vertically.
This mode of cooling the bearing is applicable to the upper brass E': and also
to connecting-rod and other bearings, giving excellent results in practice. It will be
seen that my bearing possesses marked advantages in the facility with which it can
be examined and repaired. It necessitates some extra work in fitting it up, but
the worth of the composition saved by using a semi-cylindrical brass instead of a
square one more than compensates for the additional time and labor required.
My bearing is of service not only for marine engine-shafts, but for shafting of
all kinds, and is especially valuable where the presence of cranks, collars, couplings,
gear-wheels, belt-pulleys, or other parts renders it impossible to remove the ordinary
style of brasses without unshipping the shaft.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what 1
claim is :-
1. A bearing for shafts, provided with a vertically movable chair having a semi-
cylindrical seat formed in its upper face, and a semi-cylindrical brass fitted into said
seat, substantially as described.
2. The combination with a pillow block, of a chair fitted to move vertically therein,
a semi-cylindrical lower brass seated in a semi-cylindrical hollow in the top of said
chair, and a cap provided with an upper brass, substantially as described.
3. The combination with a pillow block having a square recess, of a flat bottomed
chair fitted therein, a semi-cylindrical brass seated in a semi-cylindrical hollow in said
chair and provided with notched end flanges, a cap extending down towards the
chair, and liners inserted between the chair and the cap, substantially as described.

page_text: 4. A bearing provided with a semi-cylindrical brass having a groove formed in its
outer face, and means for supplying water to said groove, substantially as described.
5. The combination with the chair D of the brass E provided with the groove e³,
and the pipes K, K', inserted through the chair and terminating adjacent to said
groove, substantially as described.
ALLISON BROS.,
Agents for the Applicant.