Improvements in or relating to Hydraulic Motors.
Year: 1889

page_text: Date of Application, 31st Dec., 1889
Complete Specification Left. 30th Sept., 1890-Accepted, 27th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in or relating to Hydraulic Motors.
I, FRANÇOIS VAN RYSSELBERGHE, Electrical Engineer, of 37, rue Philippe-le-Bon,
Brussels, Belgium, do hereby declare the nature of my invention to be as follows:-
My invention relates to a method of construction for rotary hydraulic motors by
which a high efficiency can be obtained, even in case of high falls or high pressures;
and also to practical details ensuring the good working and regularity of the motors
constructed according to this method.
When, some time ago, for utilising a pressure of 50 atmospheres, I employed a
turbine (type Girard) in connection with a dynamo, I was astonished at the low
efficiency of the motor, although this one had been built according to the present
standard of construction.
The researches and experiments, which I made on this subject, have led me
to draw up different rules, which have resulted in a different method of con-
struction, hereafter described, which I believe to be new, and the ownership of which
I claim.
After the failure of a test with a Girard turbine, I first constructed an entirely
new type of motor. It consisted in a plain metallic cylinder, without buckets or
vanes which was struck tangentially on its plain inner surface by a water-jet.
I found, that this apparatus acquired the maximum of power and efficiency, when
the speed of the periphery was equal to half the speed of the water-jet which
strikes it.
The efficiency of this instrument for the high pressures with which I was dealing,
was greater than that of the Girard turbine and proves the following fact which
I consider very important. When the water moves along a curved surface, the effort
which takes effect on this surface is tangential and is in the same direction as the.
motion of the water.
I have next experimented with the well-known hydraulic reaction wheel, in which
the motion proceeds from simple reaction.
A straight tube revolves around a hollow axis placed in the centre of the tube
through which the water under pressure issues radially into the two branches of the
tube lateral openings made in the extremities of the tube allow a continuous flow
of water, which reacting on the opposite sides causes the tube to revolve. These efforts
are called efforts of reaction.
The principle. of this motor is well known, but I do not think that until now
the method for obtaining from the hydraulic reaction wheel, hereinafter called a
"turnpike," a very high efficiency was known, especially in cases of high pressure,
as for instance 50 atmospheres.
I have found, that, in order to obtain a high efficiency, it is necessary, that
there should be a well defined ratio between the flow of water due to the height
of the fall and the circumferential speed of the opening whilst the apparatus is
working.
When the instrument revolves, the pressure in the arms of the reaction wheel
becomes stronger, than that simply due to the height of the fall; it increases owing
to the compression caused by the centrifugal force, so that the speed of the flow is
greater, while revolving than while at rest; the effort of reaction increases at the
same time. But while this effort is directly proportional to the pressure that exists
in front of the opening, the flow is only proportional to the square root of this pressure,
so that, if increasing values be given to the circumferential speed of the openings, the
work increases more rapidly than the flow, or, in other words, the efficiency goes on

page_text: increasing continually, and I have found, that the ratio which connects these two
quantities is the following
Let V₁ be the speed due to the height of fall-V, the circumferential speed
imparted to the opening-n the ratio of these two speeds. Then the efficiency is
determined by the equation :-
"
To
The power of the apparatus also increases with n. The result is a method of
construction, for this sort of motor, which consists in increasing the circumferential
speed as a higher efficiency is required, and the ratio should be determined according
to the formula mentioned above.
I construct the turnpike in preference with tubes for radii or spokes. In all cases,
where the flow is small, but the height of fall is great, the turnpike with straight
tubes possesses numerous and considerable advantages over other hydraulic motors,
especially the one of being able to resist the very high pressures to which it is
subjected; a result which could hardly be obtained with any other shape except at
great expense.
The combination of this hydraulic turnpike with a dynamo is also very advan-
tageous, especially in the case of high pressures, for when a motor of small power
(1 to 10 horse power) is required in such circumstances, the construction of the usual
turbine becomes nearly impossible, unless one be satisfied with a very low efficiency.
I find, that all turbines constructed up to this day are a combination of the straight
branch turnpike working by simple reaction, with parts of a curved surface upon
which the liquid acts by shock and adhesion, and which I have discovered and
described heretofore in the cylindric motor.
My method of construction is applicable to all sorts of turbines. But as in all
water-wheels the effort of shocks and adhesions is in the same direction as the motion
of the water, whilst the reaction acts in the opposite one, it follows that these forces,
if utilised at the same time, in the same instrument, are always antagonistic.
And I find, that the hydraulic turnpike constructed according to the method I have
described is better than any other and presents over them very considerable economical
advantages.
The method of construction of a turnpike of high efficiency having been found,
some secondary points were yet to be solved, namely the admission of the water
from the axis by means of a good water-tight joint producing no unnecessary
friction.
The joint that has given me entire satisfaction, is made as follows:-
The vertical axle of the turnpike is hollow and made of steel. The open lower end
of this axle turns in and on an annular socket piece of bronze.
The sizes can be judiciously chosen, so that the weight bearing on the axle is slightly
superior to the pressure of the water.
In case of a horizontal axle, a coiled spring or a counter hydraulic pressure
supplies the power necessary for maintaining the joint watertight.
This joint maintains itself perfectly watertight, the two surfaces in contact.wearing
one another out, but it is necessary that the axle be harder than the socket.
A reliable governor regulating the flow of water according to the work required
and producing no waste of power was also needed.
For this purpose, I provide the orifice of the turnpike, and not the inlet tube, with
a movable plug or valve governed by the antagonism between the centrifugal force
and a counterweight, or between the centrifugal force and a spring having a so-called
initial tension.
invention :-
The following appear to be the features of novelty of my
1. A method of construction for hydraulic motors which consists in the

page_text: observance of the rules governing the ratio between the circumferential speed
of the single or several openings and the speed of the flow resulting from the
height of the fall, according to the degree of efficiency required, substantially as
described.
2. A system of hydraulic motors with curved smooth surface or surfaces such as
that of a cylinder, on which the water is projected tangentially and acts by impact
and adhesion without reaction, the characteristic of the system being, that the radius
of the curve acted upon by the jet is directed towards the axis of rotation, substantially
as described.
3. A system of hydraulic turnpikes with spokes formed of tubes, their tubular
shape opposing a great mechanical resistance to high pressures, and the straightness
of the spokes eliminating all other effects than those of reaction, substantially as
described.
4. In bydraulic motors with axial admission, the use of a rotary watertight joint,
obtained by superposing an axle on a socket piece, the joint keeping watertight (a) by
the excess of weight of the axle or the pressure exerted on it, over the pressure of the
liquid, (6) by the uniform wearing out of the parts of the joint, substantially as
described.
5. In hydraulic turnpikes, the use of a governor regulating the speed by closing
the outlet (and not the admission) of the water in the turnpike, the said governor
acting by the antagonism between the centrifugal force and a counterweight or a
spring having initial tension, substantially as described.
6. The combination on the same axle of the revolving part of a dynamo with a
hydraulic turnpike, substantially as described.
Dated the 20th 1
1000
COMPLETE SPECIFICATION.
Improvements in or relating to Hydraulic Motors.
I, FRANÇOIS VAN RYSSELBERGHE, Electrical Engineer, of 37, rue Philippe le Bon,
Bruxelles, Belgium, do hereby declare the nature of my 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 hydraulic motors suitable for the direct driving of
dynamos.
A hydro-electric generator embodying my invention is obtained by directly
coupling the revolving part of a dynamo with a hydraulic reaction wheel or turn-
stile constructed as hereinafter described and represented by the drawings annexed
to the present Specification.
In these drawings,
Fig. 1 is a vertical, and Fig. 2 a horizontal section of a hydro-electric generator,
while
Figs. 3 to 5 show certain details on a larger scale.
The motor comprises two straight tubes R¹ R2, each of which has at its extremity
a lateral aperture c' c³, through which the water escapes in exerting on the arms
a pressure in a direction opposite to the motion of the water itself. In other
words, it is a hydraulic reaction wheel with straight arms and vertical axis.
The water enters through the hollow pivot F, which is of hardened steel and
turns on a hollow step-bearing H made of gun metal. The bore of the step-
bearing is of such a diameter, that the upward pressure of the water will be
slightly less than the weight of the revolving part of the whole apparatus, so that
the joint may be kept tight (a task generally difficult to solve in this kind of
apparatus) by simply placing the pivot on this step-bearing. These two organs,
by their mutual wear, keep the joint tight without unnecessary friction. As the

page_text: weight of the apparatus is almost balanced by the pressure of the liquid, the
friction will be almost nil. This kind of joint is an essential part of the apparatus.
Another essential part is the cylindrical casing D E, which encloses the two arms
of the motor, in order to avoid, that the latter during their revolution, strike the air
perpendicularly, which would absorb considerable energy, because for securing a high
efficiency with water at high pressure, it is necessary to give to the discharge openings
a considerable circumferential speed.
By enclosing the arms in a cylindrical casing, I avoid the loss of energy caused by
impact with air, and substitute for it a frictional loss much less injurious.
The water discharged from the orifice c¹ c² spreads out in a receiving vessel OS. It
is important, that the water, after its impact with the walls of this vessel, should not
fall back upon the casing in motion, which would again produce a considerable waste
of energy. For this purpose, I have applied the shields K and L.
The most important part of the hydro-electric generator, however, is the speed
regulator.
The speed of dynamos must be kept as constant as possible, whatever the amount of
electric work required. Consequently, the motor should be governed by a regulator
of great precision.
My governor comprises two obturators illustrated separately on a larger scale
by Figs. 3, 4 and 5, Fig. 3 being a horizontal section through the left hand
obturator, Fig. 4 through the right hand one, and Fig. 5 a section along line A-B
of Fig. 4.
Cand C² are the obturators moveable around their respective axes B1 and B2 and
connected by a single rod A1 and A2, which forces them to work together, and
balances at the same time the lateral pressure of the water on the obturators. It was
necessary, to establish this equilibrium, which in this case results from a differential
action, because this lateral pressure, if not balanced, renders all exact regulation of
speed impossible. The centrifugal force of a mass M arranged on one side of the
connecting rod A' X A² exerts constantly a pull on the latter and tends to close the
obturators. But it meets with a counter effort in the action of the weight P, which
pivots on the axle Y and acts at X on the connecting rod in a direction opposite to
the centrifugal force of the mass M. The motion of the weight P is limited by a
pair of set screws, and the rod A¹ X A² is connected with the vertical arm of the
weight by a toggle or ball and socket joint. When the speed has become such, as to
establish equilibrium between these two antagonistic efforts, any increase of speed,
however small it may be, has for its consequence, to partly close the obturators and to
render the consumption of water exactly proportional to the work to be produced at
a constant speed.
Absolute isochronism of the governor, at the same time with its stability, is obtained
by means of a light spring T, which is essential to good working; because if the
speed tends to increase and the mass M is shifted, the centrifugal force of the latter
will increase in proportion to this small displacement; but then the tension of the
spring T increases also in proportion to the displacement, and it is easy to regulate
the force of the spring in such a manner, that there is again equilibrium, for the
same working speed, between the increase of the centrifugal force of the mass M and
the complementary tension of the spring T.
In this manner,
fulfilled.
the conditions of isochronism and stability are completely
It is evident, firstly, that the action of the weight P could be replaced by that of a
spring, and secondly, that the combined effect of the weight P and the spring T
could be replaced by that of a single spring, which would have to satisfy the following
conditions:-
a. The initial tension of the spring should be equal to the centrifugal force
which the mass M possesses in its starting position, and when the working speed is
attained.
b. Every displacement of the mass M should produce in the spring a complementary

page_text: compression, the amount of which should be equivalent to the increase of the centri-
fugal force of the mass M due to its displacement.
It is well known to experts that the first condition (a) determines the resistance of
each convolution of the spring and that the second condition (b) determines the number
of those convolutions.
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-
1. A high-speed reaction wheel, connected directly with the movable part of a
dynamo-machine, and having the characteristic feature, that the high-pressure water
passes upward into the wheel, through the vertical axis of the same, and that this
wheel carries directly the revolving part of the dynamo.
2. The combination of a reaction wheel or of a hydro-electric generator as
described, with an isochronous governor comprising obturators adapted to modify the
consumption of liquid, a rod which, besides revolving with the wheel, is also adapted
to move in a longitudinal direction and thereby to control the position of the said
obturator, a centrifugal mass M and a weight P adapted to act on the said rod in
opposite directions, and a light spring T adapted to counteract by its tension the
variations of the centrifugal force of the said mass M.
3. In a reaction wheel or a hydro-electric generator as described above, a pair of
obturators C¹ C² connected by a single rod A A2, in such a manner, that the said
obturators are simultaneously shifted in the same sense or direction, and that conse-
quently the lateral pressures of the out-flowing water balance each other as regards
their effect on the governor.
4. In the hydro-electric generator claimed above, a moveable hollow pivot resting
on a hollow, but fixed step-bearing, leakage being prevented by a slight excess of the
weight which presses on the pivot over the upward pressure of the liquid, and by the
mutual wear of the elements of the joint.
5. In the reaction wheel or hydro-electric generator described above, a casing D E
which encloses the arms of the reaction wheel and thus reduces the resistance opposed
by the air to the motion of the wheel.
6. In the reaction wheel or hydro-electric generator described above, the shields K
and L which prevent the discharge water from again coming into contact with the
moveable wheel.
Dated this 30th day of September 1890.