Improved Apparatus for Measuring the Pressure of Shafts on their Bearings.
Year: 1898

page_text: Date of Application, 28th Apr., 1898-Accepted, 27th Aug., 1898
COMPLETE SPECIFICATION.
Improved Apparatus for Measuring the Pressure of Shafts on their
Bearings.
I, HENRI BOURON, of No. 20, Avenue de Gigant, Nantes, in the Republic of
France, 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:―
This invention relates more particularly to pedestal, plummer block and other
bearings, designed to transmit the motion or pressure due to the thrust of the
shafts.
In order to measure the pressures or thrusts transmitted or received by trans-
mitting shafts in motion, either in a direction parallel to their axes or in a
direction perpendicular thereto, it has heretofore been usual to employ balances
with springs or counter weights. These various devices are inconvenient in so
far that it is necessary to give to the different parts a very large amount of
play" or mobility which entails great intricacy in order to cause the displace-
ment to be as slight as possible, and leads to errors in the indication of the
power transmitted."
<<
To obviate this inconvenience, I, according to this invention, substitute for
the aforesaid balance hydraulic balances, the slight compressibility of water
allowing considerable difference in the pressures or thrusts to be measured without
apparent displacement of the parts under observance.
The power transmitted is indicated by the pointer of a manometer, the variations
of which may be very great for relatively slight differences of power.
These balances may be of various types, as for example, that shown in Figure 2
of the drawings, which consists of a cylinder D sliding in a stuffing box E and
resting on the water contained in the space or chamber A. The water tight
packing compressed in the stuffing box may be replaced by a leather packing or
cup, as used in hydraulic presses.
I prefer however to employ the device shown in Figure 1, comprising a chamber
or container A filled with water and communicating with a manometer M. This
container is closed by an elastic and impermeable web or diaphragm B, attached
to it by means of a socketted flange C, in which may slide a block D adapted to
bear exactly on the whole of the surface of the web left free in the interior of
the flange. Other arrangements may however be employed.
Any pressure exerted on the block D will be transmitted to the liquid, and will
be indicated by the manometer with great exactitude, without apparent displace-
ment of the block, by reason of the small quantity of water contained in the
container, and by reason of its small compressibility. Thus for example suppose
the block to be of 138 millimeters diameter, which gives a surface of 70 square
centimeters, and the container to be of 7 mm. depth, the coefficient of the com-
pressibility of water being 0.000049 per atmosphere, if the thrust is 3000 kilo-
0 grammes, or 20 kgs. per square centimeter, the displacement of the block will be
only three hundredths of a mm., that is to say the layer of water of 7 mm. will be

page_text: reduced by 0.01407. The expansion of the liquid due to rise of temperature is
only six hundredths of a mm. per degree. As it is not absolutely necessary to
give the layer of water a thickness of 7 mm., particularly if the depth of the
container is uniform, the above figures might be further reduced, although under
such conditions the bearing might very well be considered as having its axis
absolutely fixed.
To facilitate the displacement, rather theoretical than actual, which is produced,
and to prevent the sliding of the bearing on the frame or support from causing a
sensible difference in the indication of the power transmitted, I may, instead of
making the bearing simply slide, place a series of rollers between it and the
frame, as shown in Figures 3, 4 and 6, which convert the sliding into rolling
friction. For bearings mounted on levers, as those shown in Figures 7, 8, 9
and 10, rollers may also be put between the axles and the holes in the levers
or the frames.
This improved bearing will be applicable to all industries, and more particularly
to the direct measurement of loads which are transmitted to the axles of vehicles:
and also in navigation, to measure the thrusts of propellers on ships.
In certain cases only one balance, or one series, would be sufficient, if it be
desired to measure the thrust in only one direction; but if it be desired to measure
this thrust in two opposite directions, as in the forward and rearward movement of
a ship, it will be convenient to employ two balances, or two series, according as
the load is distributed on one or more blocks.
Figures 3, 4 and 6 show different arrangements of bearings transmitting their
thrusts directly on to the balances Figures 7, 8, 9 and 10 show others transmitting
their thrusts through levers.
The bearings Figures 3, 4 and 5, and those shown in Figures 8, 9 and 10 are
designed to measure a thrust parallel to the axis of the shaft, as in screw shafts
for example; that shown in Figure 6 is designed to measure a perpendicular
thrust or pressure at the axis of the shaft, as in the paddle-wheel shafts of steamers.
The manometer recording or registering apparatus, shown at M in Figures 1
to 10, are assumed to have their diagram rollers worked by a clock movement;
that shown at M, Figure 3 has its roller in direct connection with the shaft.
Rollers might likewise be employed on which would be indicated the time and
the movement of the shaft.
It will be understood that, with this arrangement of bearing it is easy to
remove the diagrams indicating the different thrusts for longer or shorter periods
of time, according to the arrangement of the rollers of the manometers. On a
ship, for example, there might be registered mechanically all the phases of a
voyage, which would enable an account to be kept of the different resistances
of the ship for any parts of this voyage, and, by combining the diagrams thus
produced with the speed of the ship, to give account of the use and effectiveness
of the motive apparatus and propellers."
Figures 11, 12, 13 and 14 represent a thrust block for a screw shaft, measuring
the thrust only in the forward direction and arranged for a cargo of a weight
ranging to 4000 tons. This thrust bearing is composed of a main frame or support
secured to the ship by the bolts E, and with which are cast two supports FG
intended to bear the weight of the shaft; the part of the frame connecting the
two supports serves to carry the box H which receives the discs or collars I
on which the thrust of the shaft is exerted. This box rests on rollers J in such
a way as to have ample movement in the longitudinal direction. To prevent
upward displacement, which might cause friction of the shaft on the discs or
collars, the box H is held by the pieces L, fixed to the supports of the shaft and
joining them to one another. Between the box H and the pieces L there are
rollers, as between the box and the frame, so as to convert the sliding into rolling
friction. The pieces K close the cases or races of the rollers.
The discs or collars I are all formed of two principal pieces, the lower of which
enters a circular groove arranged in the lower part of the box, and the upper of

page_text: which enters, on each side, the extension of the circular groove. These discs or
collars are held in place by bolts O.
In one of the supports of the shaft are arranged the two containers intended to
receive the liquid to indicate the thrust, these containers communicating with
each other by means of the pipe P, on which the manometer is placed. This
manometer may well be placed much further off, in the watch room of the ship,
for example, but in this case it is necessary to take account in the indications of
the pressure of the height of the column of water between the manometer and the
containers.
To insure the efficient working of the whole, all the wedges U, X, between the
box H and the principal frame, and also between the box and the pieces L,
are first tightened, then the wedges S are adjusted on the blocks D, so that these
are quite ready to simultaneously exert the thrust transmitted by the box on the .
liquid of the containers, and this without damaging the webs or diaphragms
closing said containers. The wedges being properly adjusted they are fixed by
means of screws and then the wedges X, X, serving as the abutment for the forward
motion, are slightly loosened.
If for any reason whatever it is desired to temporarily suspend the effect of the
thrust of the shaft on the liquid of the containers it is only necessary to re-tighten
the wedges X so that there is no play between the box H and the frame secured
to the ship.
I wish it to be understood that I do not limit myself only to the forms and
constructions shown in the accompanying drawings but that I may give to the
balances any suitable shapes and directions, and also that I may employ such
a number of them as I deem necessary, according to requirements; and may give
to the bearing such shapes and dimensions as may be convenient; and finally that
I may construct the whole of any suitable material.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
The combination of hydraulic balances with transmission bearings, to measure
the thrust of the shafts on the bearings, substantially as described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.