Improvements in Shaft-governors.
Year: 1899

page_text: Date of Application, 7th Sept., 1899-Accepted, 11th Nov., 1899
Improvements in Shaft-governors.
1, JOHANN STUMPF, of 27, Rankestrasse, Berlin, in the German Empire, Pro-
fessor at the Koniglich Technische Hochschule, 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 this invention is to produce a shaft-governor which permits
adjustment or regulation of the speed within wide limits without materially
interfering with the displacing force, i.e., the force produced during or by a
definite temporary alteration in speed. Shaft-governors of this kind are very
advantageous for use with pumps or compressing engines, in which it is required
to regulate the amount of water or air delivered by the engine, in accordance
with the consumption, by varying the speed.
Governors of this kind heretofore known present great disadvantages which
result from the circumstance that they are made highly static, that is to say, wherein
cach position of the rotating mass or masses corresponds to a definite velocity. If
the steam pressure alters, the velocity must alter, since the supply of steam and
therefore the position of the adjusting member of the valve gearing is altered,
and this altered position must correspond to an altered position of the governor
and consequently to an altered speed. This takes place if the vacuum alters in
a condensing engine or if the resistance varies in the pump or compressor. If,
for example, the governor, and therefore the engine, has been set to the highest
or approximately the highest speed, and the load suddenly removed from the
engine (by breakage of the delivery pipe, or setting fast of any solid parts in the
suction valve or delivery-valve), the engine must run on uncontrolled, since there.
is no longer room for displacement. The governors heretofore known, accord-
ingly do not even fulfil the most ordinary requirements of a governor; their value
sinks moreover below that of an ordinary adjusting device.
All the above mentioned disadvantages are completely obviated by the present
invention. If the steam pressure, the vacuum, or the resistance alter, it has no
influence on the improved governor. If the delivery-pipe break or if anything
be caught between the valves, whereby the latter are prevented from closing, it
has likewise no influence. The governor will moreover always keep the engine at
an approximately constant speed.
This is attained by the following arrangement:-A shaft-governor is provided
with tension springs of such length that the difference in tension, in combination
with the difference in length of the connection between the driving-eccentric
controlled by the governor and the expansion-regulator or other adjusting member
of the valve-gearing held in a fixed position for all velocities, is used for altering
the velocity. The alteration in the position of the eccentric and the consequent
alteration in the length of the connection between the eccentric and the adjusting
member of the valve-gearing, alters the tension of the moderately short loading-
spring of the governor within wide limits. This altered tension of the spring
must correspond to an altered velocity, since the turning moment exerted by the
tension of the spring must always counterbalance the moment exerted by the

page_text: centrifugal force. Since the lever-arms remain approximately the same in both
moments, or only alter slightly, the tension of the spring altered by the adjust-
ment of the length of the eccentric rod must correspond approximately to the
alteration in the centrifugal force. The alteration of centrifugal force now
corresponds to a suitable alteration in speed, the change in the number of revolu-
tions per minute being thus obtained. At any suitable position between the
driving-eccentric and the adjusting member of the valve-gearing, is introduced
an adjusting device. The position of the eccentric can thus be altered so that
either lead or travel or both can be altered. This depends upon the nature of
the valve-gearing actuated by the eccentric.
I preferably employ for this purpose an inertia shaft-governor, which removes
by far the greater part of the displacing force from the inertia. If the same
percentage variation in velocity be allowed at all speeds, it results that, for all
speeds, the same contribution to the whole amount of the displacing force must
result from the inertia. In other words, the magnitude of the contribution to
the whole displacing force, which is obtained from the inertia, remains constant
for all speeds. Naturally the displacing force which is obtained from the centri-
fugal force alters, since the absolute amount of the centrifugal force alters with
the number of revolutions per minute. With the absolute value of the speed,
the amount of the contribution from the centrifugal force for the total displacing
force must obviously alter if the same percentage variation in velocity be assumed
for all speeds. If now, from this result, the contribution to the total displacing
force, of the contrifugal force, be made quite small (in proportion to the contribu-
tion of the inertia), the total displacing force will accordingly alter little for all
speeds.
The form of governor shown in the accompanying drawing is designed in
accordance with the above considerations.
Figure 1 shows in front elevation an inertia governor arranged on a fly-wheel.
Figure 2 is a section on the line A-B, Figure 1.
Figure 3 shows in front elevation, the governor removed from the fly-wheel.
Figure 4 illustrates the connection of the eccentric rod with the adjusting mem-
ber of the valve-gearing and the adjusting device introduced into the eccentric
rod.
The governor a is provided at one end with a ring b, which is mounted over the
hub c eccentrically to the fly-wheel-shaft d and bears the driving eccentric strap
which is connected to the rod r. By means of a stud k, the governor is pivotally
connected to an arm m of the fly-wheel and the governor bears at its outer end a
weight f, which is provided with a projection g, the travel whereof is limited by
two stops i, i mounted on the rim h of the fly-wheel. Between a pin n on the
governor and an arm of the fly-wheel, is arranged a moderately short spring o,
the tension of which can be adjusted by means of an adjusting-nut p. The
eccentric rod is connected at its other end to the adjusting members of a Rider
valve-gear, Figure 4. Between the governor and the adjusting members an
adjusting device is introduced into the eccentric rod. This merely consists of a
sleeve t, which is provided with internal screw-threads and engages with the
ends u and of the two parts of the eccentric rod which ends are provided with
right and left-handed screw-threads, respectively. By turning the sleeve to the
right or to the left, the eccentric rod can thus be lengthened or shortened as
desired.
"
The manipulation and method of operation of the improved governor are as
follows-If it is desired to alter, for example, to increase the number of revolu-
tions per minute made by the engine, the sleeve t is turned in such a manner that
the eccentric rod is lengthened. In this manner, in the first place, the adjusting
members of the valve-gear and therefore also the valve-gear is so actuated that
the supply of steam to the engine is increased. The direct result of this is an
increased angular velocity of the fly-wheel, an adjustment or movement, of the
At the same time,
governor a and an alteration of the tension of the spring o.

page_text: the eccentric rod r is displaced and the adjusting member of the valve-gear is
actuated. The increased number of revolutions per minute will however be
maintained by reason of the altered tension of the spring o.
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. A shaft-governor, substantially as described, in which the position of the
driving eccentric of the valve-gearing controlled by the governor, is altered by
altering the length of the connection between this eccentric and the adjusting
member of the valve-gearing, whereby the tension of the loading spring or springs
of the governor is altered and thus an adjustment in speed of the governor is
effected.
2. A shaft-governor of the kind claimed in the preceding claiming clause, in
which the inertia provides a contribution to the total displacing force of such
amount that, by this combination, the total displacing force remains approximately
constant for all angular velocities.
D. YOUNG & Co.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.