Improvements in Governing Apparatus for Impulse Water Motors.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Governing Apparatus for Impulse Water Motors.
We, SAMUEL CLELAND DAVIDSON, of Sirocco Engineering Works, Belfast, Ire-
land, Merchant, and ALEXANDER BASIL WILSON, of Holywood, County Down,
Ireland, Engineer, do hereby declare the nature of this invention to be as
follows:
--
The object of the apparatus which forms the subject of the present invention
is to govern or regulate the speed of impulse water motors, such as what are
known as Pelton wheels, in which the impingement of a jet of water under pres-
sure against a succession of buckets or their equivalent secured to the rim of a
wheel, is the means employed for transferring the energy of the water into the
rotation of a shaft, so that under varying conditions of resistance of the aforesaid
buckets, the speed at which the buckets recede from the jet may be maintained
effectively constant.
In motors of the type above referred to it is necessary in order to obtain the
best efficiency in the transfer of energy from the water to the wheel, that the speed
of the issuing jet should bear a constant definite relation to the receding speed
of the buckets, such speeds being constant for all changes of resistance to the
torque of the wheel.
It is further desirable that under all conditions of resistance, within the limits
of the power of the apparatus, the speed of the wheel should be uniform, and that
the consumption of water issuing from the jet should bear direct relation to the
resistance offered by the wheel.
It has been customary to maintain the speed of efflux of the water through the
jet by reducing the area of the jet opening by the insertion of a conical pin into
the centre of the jet, such pin being so arranged by screws or other device that
it could be advanced or withdrawn as the quantity of water issuing from the jet
was required to be reduced or increased; the maintenance of consequent relation
between the speed of the jet and that of the buckets under varying resistance of
same, hereinafter called the governing, has been thus attained.
The movement of such conical pin whether determined by a screw, lever or
other device and actuated by a governor, of any of the well known types has hitherto
involved a difference of resistance to such movement of the pin at its different
positions within the jet, such variation of resistance rendering it impossible for a
governor to deal with it in practice efficiently.
Similar means have been adopted to obtain effective governing of such motors
by the use of a fixed central pin, the variation in section of jet being attained
by moving the cone used for determining the shape of jet closer to or further
from the pin by means and with results as aforesaid.
Now in our invention we make use of either a movable central pin with a fixed
cone, or a movable cone with a fixed pin, the position of the pin within the cone
determining the effective area of the jet issuing from the conc. The amount of
such area is regulated by the advance of the pin with respect to the end of the
cone, and the correspondingly reduced area of the annular space through which
the fluid issues between the pin and the cone.

page_text: According to our invention we regulate the position of the pin with respect to
the cone in the manner hereinafter described by the following means which is
equally applicable to a moving pin and a fixed cone or to a moving cone and a
fixed pin. The particular arrangement described is that of a moving pin and a
fixed cone.
It is necessary for the perfect working of the apparatus, that the advance
of the pin within the cone which may be called its stroke should correspond with the
position of the governor balls, or the equivalent of governor balls in any governor
or governing apparatus which may be attached to the motor, that is to say, if the
governor balls hereinafter called balls, are at their inmost position correspond-
ing to the slowest speed at which the motor is desired to work, the pin with rela-
tion to the cone must be at the outward end of its stroke and permit the largest
possible flow of water through the cone. With the balls at their outmost posi-
tion due to the pre-arranged higher speed of the motor, the pin must be at the
inward end of its stroke corresponding to the smallest admission of water to the
motor, and each intermediate position of the balls must be followed by a corres-
ponding position of the pin throughout its stroke. The balls and the pin therefore
move in unison and the orifice of the jet varies in direct relation to the position
of the balls.
In our invention we actuate the pin by a piston working in a cylinder, or other
equivalent device. The position and movement of the piston is controlled and
actuated by fluid taken from the supply to the jet, or from other source, acting
on one or both sides of it and the regulation of the volume of fluid thus admitted
or maintained to one or both sides of the said piston is determined by the rela-
tive position of two valves having ports and passages connected therewith as
follows.
One of these valves is actuated direct by the governor and is hereinafter for
distinction called the A valve, and its motion corresponds, and is determined
by the position of the balls. The other valve hereinafter called the B valve is
connected to, and its motion determined by the position of the aforesaid piston.
The A valve is so arranged that it admits the fluid to either end of the aforesaid
cylinder, or to one end only, and exhausts the fluid from either end or from one
end through ports in the B valve.
The A valve is constructed similarly to the ordinary D valve of a steam engine.
so that while by its position, fluid is admitted to one end of the cylinder, fluid
is likewise and at the same time exhausted from the other end,
The B valve has ports therein which correspond to the ports on the A valve
in the same manner as the valve face of an ordinary engine cylinder corresponds
with the ordinary D valve working upon it, that is to say there are two ports in
the B valve, one connected to each end of the aforesaid cylinder. The ports on
the valve are so disposed in relation to the ports in the B valve, that at the
mid-position of the stroke of each, all the ports are closed. If however, the
A valve be moved through a fraction of its stroke thereby uncovering a port in
the B valve, and admitting the fluid thereby into one end of the cylinder, the
motion of the piston connected as aforesaid to the B valve moves it in such a
manner as to close the port between the A valve and the B valve, which had been
opened by the change of position of the A valve.
The result of the arrangement is that whatever position the A valve may be
moved to, by the action of the governor in relation to its stroke, the B valve,
the piston, and the pin which are all connected together assume the same relative
positions as to their stroke, and the motion of the pin therefore corresponds to the
motion of the balls.

page_text: Improvements in Governing Apparatus for Impulse Water Motors.
We, SAMUEL CLELAND DAVIDSON, of Sirocco Engineering Works, Belfast, Ire-
land, Merchant, and ALEXANDER BASIL WILSON, of Holywood, County Down,
Ireland, 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:-
The object of the apparatus which forms the subject of the present invention
is to govern or regulate the speed of impulse water motors, such as what are
known as Pelton wheels, in which the impingement of a jet of water under pres-
sure against a succession of buckets or their equivalent secured to the rim of a
wheel, is the means employed for transferring the energy of the water into the
rotation of a shaft, so that under varying conditions of resistance of the aforesaid
buckets, the speed at which the buckets recede from the jet may be maintained
effecavely constant.
In motors of the type above referred to it is necessary in order to obtain the
best efficiency in the transfer of energy from the water to the wheel, that the speed
of the issuing jet should bear a constant definite relation to the receding speed
of the buckets, such speeds being constant for all changes of resistance to the
torque of the wheel.
It is further desirable that under all conditions of resistance, within the limits
of the power of the apparatus, the speed of the wheel should be uniform, and that
the consumption of water issuing from the jet should bear direct relation to the
resistance offered by the wheel.
It has been customary to maintain the speed of efflux of the water through the
jet by reducing the area of the jet opening by the insertion of a conical pin into
the centre of the jet, such pin being so arranged by screws or other device that
it could be advanced or withdrawn as the quantity of water issuing from the jet
was required to be reduced or increased; the maintenance of consequent relation
between the speed of the jet and that of the buckets under varying resistance of
same, hereinafter called the governing, has been thus attained.
The movement of such conical pin whether determined by a screw, lever or
other device and actuated by a governor, of any of the well known types has hitherto
involved a difference of resistance to such movement of the pin at its different
positions within the jet, such variation of resistance rendering it impossible for a
governor to deal with it in practice efficiently.
Similar means have been adopted to obtain effective governing of such motors
by the use of a fixed central pin, the variation in section of jet being attained
by moving the cone used for determining the shape of jet closer to or further
from the pin by means and with results as aforesaid.
Now in our invention we make use of either a movable central pin with a fixed
cone, or a movable cone with a fixed pin, the position of the pin within the cone
determining the effective area of the jet issuing from the cone.
The amount of
such area is regulated by the advance of the pin with respect to the end of the
cone, and the correspondingly reduced area of the annular space through which
the fluid issues between the pin and the cone.
According to our invention we regulate the position of the pin with respect to
the cone in the manner hereinafter described by the following means which is
equally applicable to a moving pin and a fixed cone or to a moving cone and a
fixed pin. The particular arrangement described is that of a moving pin and a
fixed nano

page_text: It is necessary for the perfect working of the apparatus, that the advance
of the pin within the cone which may be called its stroke should correspond with the
position of the governor balls, or the equivalent of governor balls in any governor
or governing apparatus which may be attached to the motor, that is to say, if the
governor balls hereinafter called balls, are at their inmost position correspond-
ing to the slowest speed at which the motor is desired to work, the pin with rela-
tion to the cone must be at the maximum distance from the nozzle and permit
the largest possible flow of water through the cone. With the balls at their
outmost position due to the pre-arranged higher speed of the motor, the pin
must be at the nearest point to the nozzle corresponding to the smallest admission
of water to the motor, and each intermediate position of the balls must be followed
by a corresponding position of the pin throughout its stroke. The balls and the
pin therefore move in unison and the orifice of the jet varies in direct relation to
the position of the balls.
In our invention we actuate the pin by a piston working in a cylinder, or other
equivalent device. The position and movement of the piston are controlled and
actuated by fluid taken from the supply to the jet, or from other source, acting
on one or both sides of it and the regulation of the volume of fluid thus admitted
ór maintained to one or both sides of the said piston is determined by the rela-
tive position of two valves having ports and passages connected therewith as
follows:-
One of these valves is actuated direct by the governor and is hereinafter for
distinction called the A valve, and its motion corresponds with and is determined
by the position of the balls. The other valve hereinafter called the B valve is
connected to; and its motion determined by the position of, the aforesaid piston.
The A valve is so arranged that it admits fluid to either end of the aforesaid
cylinder if the cylinder is made separated from the nozzle, in which case the posi-
tion of the piston is determined by the amount of fluid admitted on the one side
thereof, and exhausted from the other, or the A valve may be so arranged to
admit to one end only, in which case one side of the piston is always subject to the
fluid pressure supplying the nozzle, and the other side of the piston is connected
to the fluid supply or to the waste by the motion of the A valve admitting fluid
to or from that end of the cylinder and through the ports of the B valve.
The A valve is constructed similarly to the ordinary D valve of a steam engine,
so that while by its position, fluid is admitted to one end of the cylinder, fluid
is likewise and at the same time exhausted from the other end,
The B valve has ports therein which correspond to the ports on the A valve
in the same manner as the valve face of an ordinary engine cylinder corresponds
with the ordinary D valve working upon it, that is to say there are two ports in
the B valve, one connected to each end of the aforesaid cylinder. The ports on
the A valve are so disposed in relation to the ports in the B valve, that at the
mid-position of the stroke of each, all the ports are closed. If however, the
A valve be moved through a fraction of its stroke thereby uncovering a port in
the B valve, and admitting the fluid thereby into one end of the cylinder, the
motion of the piston connected as aforesaid to the B valve moves it in such a
manner as to close the port between the A valve and the B valve, which had been
opened by the change of position of the A valve.
The result of the arrangement is that whatever position the A valve may be
moved to, by the action of the governor in relation to its stroke, the B valve,
the piston, and the pin which are all connected together assume the same relative
positions as to their stroke, and the motion of the pin therefore corresponds to the
motion of the balls.
The accompanying drawings illustrate a practical form of construction of the
arrangement of our governing apparatus in which the cone is fixed and the pin is
adapted to move and each motion of the pin is determined by the constant pres-
sure on the nozzle side of the piston and by a varying admission and discharge
of fluid into that end of the cylinder which is away from the nozzle.

page_text: Figure 1 is a longitudinal vertical section of the apparatus.
Figure 2 is a developed plan of the spindle.
Figure 3 is a cross section of the apparatus on the line A-B of Figure 1, and
Figure 4 is a cross section of the pin on the line C-D) of Figure 1.
1 is the nozzle which is supplied with the motive fluid from a pipe 2. The
nozzle body is extended rearwardly in the form of a cylindrical chamber or cylin
der 3 which is closed at its rear end by a head 4. The area of the jet of fluid
issuing from the nozzle is arranged to be regulated that is to say, diminished and
increased respectively by means of the advance and the withdrawal of the coni-
cally headed pin 5, the rear portion of which works fluid-tight longitudinally in
the head 4. The pin 5 is formed with a circular enlargement or piston 6 adapted
to work fluid-tight longitudinally in the cylinder 3. The pin is prevented from
rotating by means of a stop or rod 7 which is fixed in the piston and works in a
recess 8 formed in the head 4.
The pin 5 is pierced from end to end by a central hole 9 which is of comparatively
small-sectional area in the forward portion of the pin and which expands towards
the rear portion of the pin in the form of a central chamber 10 extending to the
rear end of the pin.
A spindle 11, capable of rotation, but not of longitudinal movement, is arranged
to work fluid-tight in the chamber 10; it extends through a space 12 formed in
the head 4, to the outside of the latter where it is formed with a square portion 13
adapted to receive a lever (not shown) connected with the movable collar of a
centrifugal governor by any suitable gearing in such a manner that the spindle 11
will be rotated in one direction (indicated by the arrow a in Figure 3) by the
outward movement of the governor balls, and in the opposite direction (indicated
by the arrow b in Figure 3) by the inward movement of the said balls, and always
to an extent proportional to the extent of the corresponding movement of the balls.
On one side of a central longitudinal plane passing through the spindle 11
when the latter is in the position corresponding to the mid-position of the gover-
nor balls, there is provided in the wall of the hollow pin 5, a port 14 opening
into the space 15 behind the piston G in the cylinder 3. A similar port 16 also
opening into the space 15 is provided in the pin 5 on the other side of the said
central plane.
To the outer side of the port 14 in the pin 5, there is formed or cut in the
spindle 11 an inclined passage or groove 17 which is in constant communication
by means of a rearward extension 18 with the space 12 in the head 4.
To the outer side of the port 16 there is also formed in the spindle 11, an in-
clined groove 19 which is in constant communication by means of a forward
extension 20 with the chamber 10, and through the hole 9 with the nozzle 1.
The space 12 is in constant communication through a pipe 21 with the supply
pipe 2, and the space 22 in front of the piston G in the cylinder
is perma-
nently open to the fluid supply from the pipe 2.
When the governor balls are in the mid-position, the several parts of the
apparatus are in the position shown in Figure 1. The positions of the ports 14
and 16 in relation to the grooves 17 and 19 respectively are shown in Figures 2
and 3. In the former figure the ports 14 and 16 are indicated in dotted lines.
On the rotation of the spindle 11 by the governor in the direction of the
arrow in Figures 2 and 3, the port 14 is opened to the groove 17 which is in
communication with the fluid supply from the pipe 21, the fluid thereby enters
the space 15 and forces the piston 6 forward and introduces the pin 5 further
into the nozzle 1 and thereby reduces the flow of motive fluid through it.
By the advance of the piston G the port 14 has changed its position with regard
to the
groove 17 and cut off thereby the supply from the pipe 21 so that to what-
ever degree the spindle 11 is rotated by the governor in the direction of arrow a,
the piston 6 and the pin 5 will advance and reduce the flow to the nozzle 1 to an
equivalent degree.
If on the other hand the governor rotates the spindle 11 in the direction of

page_text: the arrow b in Figures 2 and 3 the port 19 is opened to the port 16 and the pres-
sure in the space 15 being reduced by the flow of fluid therein through these ports
and out by the hole 9, the piston 6 moves back and withdraws the pin 5 from the
nozzle and increases the jet through the latter. The extent of rotation of the
spindle 11 is followed by a corresponding movement of the piston 6. so that the
ports 16 and 19 are closed by the backward motion of the piston as before.
From the foregoing it will be perceived that each motion of the
governor balls
is followed by a corresponding motion of the pin 5, the motion of the balls and
the pin coinciding in extent, and that the power required to produce the motion
of the pin 5 is derived from the fluid and not from the governor, the governor
having only to rotate the spindle 11.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is:-
1. In governing apparatus for impulse water motors in which the motor is
governed by regulating the water jet by means of a device under the influence
of a governor, the operating of the said device by the pressure of the water, the
governor controlling the distribution of the water pressure to the said device
in such manner as to effect the requisite regulation, substantially as described.
2. In governing apparatus for impulse water motors of the kind referred to in
the preceding claim, the combination with a fixed jet nozzle and a movable part
for varying the effective area of the jet, or a movable nozzle and a fixed part for
effecting such variation, of a piston working in a cylinder and connected to the
said movable part or to the movable nozzle of a valve or valves for distributing
the pressure water to and from said cylinder, and of a governor for operating
said valve or valves, the whole arranged and operating substantially as described
and for the purpose specified.
3. Governing apparatus for impulse water motors constructed, arranged and
operating, substantially as hereinbefore described with reference to the accom-
panying drawings.
THIS 17th day of November 1899.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Chartered Patent Agents.