Improvements in Hydraulic Speed Governors.
Year: 1891

page_text: Date of Application, 22nd Dec., 1891-Accepted, 23rd Jan., 1892
COMPLETE SPECIFICATION.
Improvements in Hydraulic Speed Governors.
THOMAS BLACKWOOD MURRAY Bachelor of Science, Electrical Engineer,
Heavyside, Biggar, Lanarkshire, N.B. do hereby declare the nature of this inven-
tion 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 to improvements in hydraulic governors for automatically
regulating the supply of fluid to any motor to which this governor is applied, so as
to maintain a constant speed under varying loads, and more particularly to the
government of turbine water wheels.
My invention consists in combining a high-speed centrifugal governor, driven by
the motor to be governed, which governor operates a four-way water valve
constructed according to my invention as herein described. This water valve
controls the position of a piston which traverses a cylinder, called the regulating
cylinder; the position of this piston regulating the flow of fluid into the motor.
This four way valve is a piston valve with supply & escape ports, and also ports
communicating with the top and also with the bottom of the regulating cylinder.
When the speed rises above, or falls below the normal, the piston in the four way
water valve falls or rises by the action of the centrifugal governor, and admits
fluid under pressure to the bottom or top of the regulating cylinder;
and opens the
top or bottom of the regulating cylinder to the escape ports for a time sufficient to
control the motor when the load varies; but when the load is constant, the four-
way valve shuts off the pressure, and opens both top & bottom of regulating
cylinder slightly to the escape ports.
The four way valve admits the fluid under pressure to the regulating cylinder,
and opens the escape from the said cylinder, without any mechanical shocks or
pressures on the said valve itself, so that there are no disturbing effects on the
centrifugal governor. This portion of my invention is effected by placing the inlet
ports of the four way valve diametrically opposite the ports communicating with
the top and bottom of the regulating cylinder, so that the fluid passes freely
through the valve with an even pressure, without acting on the valve; the passage
in the valve is an annular space cut in the piston of the valve, so that the fluid
flows in a plane perpendicular to the motion of the valve.
In order to enable others skilled in the art to which my invention relates, to
understand and put my improvements into practice I have appended hereunto
explanatory sheets of drawings.
Fig. I is a diametrical sectional elevation of the four-way valve through the
line 9. h. in Fig. IV.
Fig. II is a diametrical sectional elevation of the four way valve through the
line i. j. in Fig. IV.
Fig. III is a diametrical sectional elevation of the four way valve cylinder through
the line h. in Fig. IV, with the piston and the sleeve removed.
Fig. IV is a sectional plan of the four way valve through the line c. d. in
Fig. I.
Fig. V is a sectional plan of the four way valve through the line a. b. in
Fig. 1.
Fig. VI is a sectional plan of the four way valve through the line e. f. in
Fig. 1.
Fig. VII is a sketch of the whole combination.
A is a metal cylinder which forms the outer casing of the four way valve, and in
which are cut or cast the ports :-
S, the supply port.
E, the escape port.

page_text: T, the port communicating with the top of the regulating cylinder.
B, the port communicating with the bottom, of the regulating cylinder.
D is a sleeve accurately turned and bored, and fitted inside cylinder A, with
rectangular ports accurately cut in it; five of them forming the communication
between the supply port S and the annular passage C in the piston of the valve as
shown in Figs. T & IV. Five of them form the communication between the port T
and the inside of the valve, and other five form the communication between the
port B and the inside of the valve, as shown in Figs. I and V. Another port
forms the communication between the escape port E and the inside of the valve as
shown in Figs. I, II & VI.
P is a piston which is turned an easy fit for the sleeve D. Its length is a little
less than the distance between the outside edges of the top and bottom ports T
and B, as shown in Fig. 1. To the end of the piston rod is attached a beam M. by
means of two links L Fig. II. The one end of this beam is linked to the
centrifugal governor and the other end is pivoted to the rod R which can be
raised or lowered by the nuts N so as to adjust the position of the piston in the
four-way valve, as shown in Fig. 1. Four ports H, H, are bored through the
piston so as to allow free passage of fluid discharged above the piston to escape
port E as shown in Figs. I, II, IV & V. C is an annular passage turned in the
face of the piston (Figs. I, II & IV). Its breadth is a little less than the
distance between the inside edges of the top and bottom ports T & B so that when
the piston of the four way valve is in the central position, the top and bottom
ports T and B are closed to supply but opened slightly to escape; and also when
the piston is raised or lowered from this position the bottom or top ports are
opened freely to escape, before the top or bottom ports are opened to supply.
The annular passage C is made shallow so as to cause a uniform current, and
therefore a uniform distribution of pressure on its bounding surfaces. The four
holes H, H, in the piston P may be replaced by a port in the casing of the valve
connecting the top and bottom of the valve.
In Fig. VII G. is a high-speed centrifugal governor, driven by the motor to be
governed. As the speed rises, the rod F is pushed down. This rod F is linked
to the beam M so that when the speed rises, the piston in the four-way valve is
lowered. The supply port S is attached to some convenient head of water. Kis
the regulating cylinder from the top and bottom of which are pipes communicating
respectively with the ports T and B in the four way valve. V is the piston in
the regulating cylinder which decreases the supply of fluid to the motor when it is
raised in the cylinder and conversely.
The piston in the four way valve is so adjusted that when the speed is normal
it occupies a central position in the valve. When the speed rises the rod F is
depressed and this depresses the piston in the four way valve and opens port B
to the supply, and opens port T to the escape, thus causing piston V to rise and
cut off a part of the supply to the motor until the speed again becomes normal.
When the speed falls below the normal, T is opened to supply and B to escape
thus causing the piston V to fall and increase the supply to the motor until the
speed becomes normal.
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. The combination of a high speed centrifugal governor with a four-way valve
and a regulating cylinder, as and for the purposes herein described and illustrated
by the accompanying drawings.
2. In a four-way valve a piston, having an annular passage for the fluid under
pressure, and passages for the escape fluid, directing the fluid under pressure to the
top or bottom of a regulating cylinder, and controlling the escape of fluid from
the said cylinder, substantially as and for the purposes hereinbefore described and
illustrated on accompanying sheets of drawings.

page_text: 3. In a piston four-way valve as herein described an annular passage for the
fluid under pressure flowing therein without exerting any unbalanced pressures
parallel to the axis of the piston, as and for the purposes herein described and
illustrated by the accompanying sheets of drawings.
Dated this 19th day of December 1891.
THOMAS BLACKWOOD MURRAY.