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Патент USA US2125055

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July 26, 1938.
Filed April 24, 1935
3 Sheets-Sheet l
Jul)’ 26, 1938.
2,125,055‘ ‘
Filed April 24, 1955
3 She_ets-Sheet 2
4M, ‘M/44M”00mM
July 26, l938w
Filed April ‘24, 1935
3 Sheets-Sheet 3
Patented July 26, 1938
William R. Taliaferro, Pittsburgh, Pa., assignor _
to Westinghouse Electric
& Manufacturing '
Company, East Pittsburgh, Pa", a corporation _
of Pennsylvania
Application April 24, 1935, Serial No. 17,969‘
_ 3 Claims.
(01. 171-229) '
My’ invention relates, generally, to control sys- copper or other non-magnetic material. The cup
terns, and, more particularly, to systems for con- \I5 is concentric with the magnet l0, and is car
trolling the operation of electric motors.
ried by a short shaft l6 which is mounted in
An object of my invention, generally stated, is‘ bearings l1 and IS. The bearing I8 is sup
5 to provide a motor control system- which shall be ported by a frame member 2|, which is secured
simple and e?icient in operation. and which may to the frame member l3 by screws 22, and the\
.be economicallyjmanufactured and installed.
. end bearing 11 is supported by a bracket 23, se
A more specific object of my invention is to
provide a relay for controlling the operation of
10 an electric motor which shall be responsive to the
speed of the motor.
cured to the frame member 2| by screws 24. A
laminated steel ring 25, which surrounds the ,
magnet lo and the cup I5, is clamped between 10
the frame members 13 and 2|, thereby prodiding
Another object of my‘ invention is to provide
for remotely varying the setting of a speed-re-
a magnetic circuit for the flux of the magnet IO.
As will be readily .understood, eddy currents
sponsive relay.
are produced in the cup 15 and the rotation of
A further object of my invention is to provide v the magnet l0 produces/a magnetic drag or 15
a‘ system for regulating the speed of an electric torque on the cup, the torque being approxi
mately proportional to the speed of rotation of
A still further object of my invention is to pre-
the magnet IU-
However, eomplete rotation of
vent hunting of a speed regulating system.
the cup‘ [5 is prevented by a contact arm 26,
"other objects of my invention will be explained
fully hereinafter or' will be ‘apparent to those
which is carried by a contact block 21 secured to
the shaft IS. ,The contact arm 26 is disposed be
skilled in the art.
tween ?xed contact members 28 and 29, which
For a fuller understanding of the nature and
objects of ,my invention, reference may be hadw
‘15 to the following detailed description taken in
v conjunction-with the accompanying drawingsin
' which:
Figure 1 is a view, in elevation, of a speed-responsive relay constructed in accordance with
rm my invention; .
to overcome the force of the spring 3|, the, con- 30.
tact arm 26 is ‘actuated. into engagement with
Fig. 3 is another view, in elevation, of the relay illustrated in Figs. 1.. and 2;
3-, r Fig. 4 is a view, partly in section and partly in
elevation, of a modi?cation of the relay shown in
Figs. 1, 2 and 3;
28 when the rotating magnet 10 is driven below
a/predetermine'd speed. When the torque pro
duced by the magnet to on the cup 15 is su?icient
Fig. 2 is a view, in section, of the relay shown
.in Fig. 1;
are mounted on the stationary frame members.
A calibrating spring 3| is disposed to Oppose the
torque on the _cup 15, thereby biasing the\con—:g, '
tact arm 26 against the upper contact member‘
the contact member 29.
Therefore, it will be
seen that the device is responsive to the» speed
of the apparatus driving the rotating magnet l0
and that it may be utilized as a speed relay and 35
also as a speed regulator, as Will he more fully
explained hereinafter.
Fig. 5 is a view, in section, taken along the line
In the modi?catieh 0f the relay Shown in Figs, V-V of Fig. 4; and
4 and 5, the laminated ring 25 is omitted and a
Figs. 6, 7 and 8 are diagrammatic views of con- _ cup 35 composed of a‘magnetic'material. such as .10
trol systems embodying my invention.
a Steel, is utilized, thereby providing a path for the
Referring 'now to the drawings and ‘partieularly to Figs. 1, 2 and‘ 3, the speed-responsive re-
magnetie?ux produced by the rotating magnet
10: A thin layer 35 of copper, or other non- '
lay shown therein is of the magnetic drag type magnetic material, 18 disposed on the inside of
45 and comprises a' rotating magnet II) which is the rim of the 011D 35- Thus the laminated ring 45
mounted on the end of a ‘shaft H by means of 15 and 011D “.111 the Structure shown in Figs: 1.
stud bolts l2.- The shaft ,l,l isrotatably supported
2 and 3, are combined into 35111818 member.
in a frame member H! by a sleeve bearing l4 and
thereby Simplifying the. structure.
'the shaft may be either directly connected or
50' geared to an electric motor, locomotive axle or
other rotating apparatus, whose speed it is de-
. The 011p 35 is carried bythe shaft '5. rot?tably
mounted in a supporting frame 31, which may be 50
bolted onto an end bracket 38 of an électricmo
sired to regulate or utilize as a means of con- ' tor by stud bolts 39. The magnet It! may be se
trolling the operation of other equipment.‘
As shown, the magnet I0 is disposed inside‘of
55 .a cup l5, which may be composed‘ of aluminum,-
cured to the end of the motor shaft (not shown).
by stud bolts 40, the ‘magnet shaft ll being dis- posed at the center of the motor shaft. , In this 55
‘ manner the relay may be rigidly secured to an
electric motor, or other apparatus having a ro
scribed in Patent No. 1,922,724, issued August 15,
tating shaft, the relay magnet being "driven at
The shunt 1| includes a reactor 14 and resistors
the same speed as the shaft of the motor.
43 and 44 are normally biased by a compression
10 spring 45 into engagement with contact members
relation with the reactor 14. -As shown, an elec- 5
tlcally-operated switch 11 is provided for‘ short
circuiting the reactor 14 when the switch 11 is
in the‘ deenergized position. When the actuating
coil‘ 18 of the switch 11' is ener'gized,'the reactor
14 is connected in the shunt circuit, and the V10
resistor 15 is short circuited from the interpole
46, 41, 48 and 49, respectively, which are resil
iently mounted on‘ the stationary frame 31.
The spring 45 functions similarly to the spring
shunt 1|, thereby varying the relative values of
3| to oppose the torque on the ‘cup 35 and bias
interpole winding 12.
the contact vmembers of the relay to predeter
mined positions. The spring may be calibrated
by means of an adjusting screw 5|, thereby vary
ing the speed at which the rotating magnet I6
, must revolve in order to produce su?icient torque
to'overcome the spring and operate the cup 35. A
stop member 52 is provided for limiting the travel
of the cup 35. The, relay is totally'enclosed by’
a cover 53 for protection against moisture, and
dirt. Further protection is ‘aiior‘ded by a felt
liner 54.
_ 15 and 16, which are connected in series circuit
As shown in Fig. 4, the contact members 4|, 42,
43 and 44 are carried by the contact block 21,
which is secured to the shaft N5 of the cup 35 and
actuated thereby. The contact members 4|, 42,
1933, to S. H. Cowin and L. J. Hibbard.
resistance and reactance in the shunt for the
Assuming that the motor 13 is operating at a 15
relatively low speed, the contact members 26 and
29 of the speed relay are ‘separated by the spring ‘3| and the actuating coil 18 of the switch 11 is
deenergized. When the motor- "attains a pre
determined speed, the contact members 26 and 29 20
are closed by the torque producedby the rotating ‘
magnet ‘of the relay, as herein described, and the
actuating-coil." is connected across a battery
19, thereby energizing-the coil and actuating the
Qswitch 11 to itsuppermost position to change the 25 ' ‘
As illustrated in Fig.‘ 6, the speed-responsive
relay herein described may be utilized to open the
circuit through the starting winding of a single
phase induction motor 66 when the motor has
relative valuesof resistance and reactance in the
the actuating coil 61 of the starting switch 64 is
the motor 13 than when the solenoid 8| is de
interpole shunt 1|.
. '
In order that the speed at which the relay op
erates may be remotely controlled a solenoid BI
attained a predetermined speed. The motor 66 is ' is provided on the relay to oppose the spring 3|, 30
provided with a starting winding 6| which may as shown in Fig. 7. It will be understood that
be connected across the} power conductors 62 when the solenoid -B| is energized, less torque
and 63 by means ofv a starting switch 64 to start will be required to overcome the force of the
the motor. ’When the line switches 65 and 66 are spring 3| and permit the contact members 26
closed to connect the conductors 62 and 63 to .and 29 to close. Therefore, the-relay will func- 35
any suitable source of alternating-current power, tion to operate ‘the switch 11 at a lower speed of '
energized through a circuit established by con
tact members 26 and 28 of‘the relay, which are
40 biased to their closed position by the spring 3|
on the speed-responsive relay.
As described hereinbefore, when the motor at- '
tains a predetermined speed, the torque developed
by the relay is sumcient to overcome the force of
energized. , The solenoid 8| may be energized by
closing a switch 82, which may be located at
,any suitable point, thereby permitting the speed‘ 40
setting. of the relay to be remotely controlled.
-‘ 'In the motor control system illustrated in Fig.
8, the relay herein described is utilized as a speed
regulating device for controlling the operation of
the spring 3| and the contact members 26 and 2B ‘ a shunt motor 85, which is provided with- an 45
armature winding 86 and a shunt ?eld winding
61. A'sis well known in the vart, the speed of an
the switchto open and disconnect the starting 'electric motor may be controlled by varying the
current in the motor ?eld winding.‘ The relay is ‘
winding 6| of the motor 60. '
‘Centrifugally-operated switches have been uti-' driven by the motor shaft, in the manner herein- 50
lized for vthis purpose and are fairly'satisfactory before described, and the contact members of the '
on small motors. However, in view of mechanical relay are so connected in vthe motor circuit that
di?iculties encountered and the cost involved in the current‘ in the shunt ?eld winding 81 is de
building a satisfactory centrifugal switch for creased wheh the contact members 26 and 28
are closed by the spring 3|,,thereby' causing the 55
55 larger-sized motors, centrifugal switches have not
been developed which are suitable for use on speed of the motor 85 to increase. Referring to
large motors. It is apparent that the speed-re; ‘ Fig. 8, it .will be seen that a ‘resistor 88 is con
sponsive relay herein disclosed may be utilized nected in series \circuit relation with the ?eld
' with a motor of any size, and that it may be built , winding 81, and a resistor 89 is connected par
are opened, thereby deenergizing the actuating
coil 61 of the starting switch 64, which permits
V60 at a ‘comparatively small cost. Furthermore, the
speed setting of the relay may be readily adjusted
by means of the calibrating spring 3|, thereby
permitting the relay to becalibrated to dee'ner
gize the starting“ winding at the'most-suitable
speed for the particular motor being controlled
by the relay.
allel to the field winding 81 when thecontaot 60
members 26 and 28 of the relay are closed, which‘
causes a minimum amount of current to ?ow
through the ?eld winding 81..
When the motor 85 attains a speed which will
producesu?icient torque in the relay, in the man- 65
ner hereinbefore described, to overcome the force
As shown in Fig. 7, the speed relay may also be > of the spring 3| and open the contact members
utilized to control the relative values of resistance 26 and 28 and close .the contact members 26 and
and reactance 'in a shunt 1| for the interpole 29, the resistor 88 is shunted and resistor 69 is
70. winding 12 of an alternating-current motor 13, disconnected from the shunt ?eld circuit and the v70 '
winding 81 is connected directly across the power
of the commutating type. In order that satisfac
conductors SI and 32, thereby causing maximum
tory commutation of the motor 13 may be ob
tained at various operating speeds, it is necessary current to ?ow through the shunt ?eld winding, _
to vary the relative values of resistanceand re
75 actance in the-interpole shunt 1|, as is fullyv de
which will ‘decrease the motor speed.
The con- .
tact members 26 and 26 remain closed until 75 ‘
opened by the spring 8|, which will decrease the
the relay within a predetermined time after the
motor ?eld current and cause the motor speed to
increase when the cycle of operation is again
cup starts to rotate, thereby providing a time ele
ment after a certain speed is reached.
repeated._ In this manner, the relay may be
utilized as a speed regulator to control the speed
While I have illustrated the manner in whichv
the speed-responsive device may be connected
of the motor 88.
to and utilized with various electrical devices, it
In order to prevent hunting or surging of the
regulating system, the solenoid coil 8| may be
will be understood that it may be readily utilized
in connection with mechanical apparatus, as well
connected either in series with or parallel to the
Thus the coil 8| is ener
as electrical.
10 resistor 88,v as shown.
gized when the contact members 28 and 28 are
closed by the spring 8|. The circuit through the
coil 8| may be‘ traced from the power conductor
8| through the resistor 88, conductor 92, contact
members 28 and 28, conductors 84 and 88, the‘coil
8| and conductor 88 to the power conductor 92.
As the solenoid 8| opposes the spring 3| when
energized, it will be seen that the solenoid .8| tends
to prevent overshooting oi'.'the regulator, since it
20 will cause the contact members 28 and 28 to open
slightly before the motor has attained the maxi
mum speed normally permitted by the regulator.
Since the solenoid 8| is- deenergized when the
contact members 26 and 28 are opened by the
25 torque produced in the relay as a result of the
increased speed of the motor, the spring 8| i‘s
Since many modi?cations may be made in the
apparatus and arrangement of parts without de
parting from' the spirit of my invention, I do not
wish to be limited other than by the scope of the
appended claims.
I claim as my invention:
1. Ina motor control system, in combination,
an electric motor, a ?eld winding for said motor,
a speed-responsive relay having a rotating mem
ber driven by said motor, a rotatablemember
magnetically actuated by the rotating member, _
spring means for governing the movement of the‘
rotatable member to control the current in the 1
motor ?eld winding, thereby regulating the speed
of the motor, and electro-magnetic means con
trolled by said rotatable member to _vary the 25
‘effect of said spring means.
2. In a-motor control system, in combination,
relay without having to overcome the force of the .an' electric motor, a ?eld winding for said motor,
a speed-responsive relay having a rotating mem
solenoid 8|.
30v In this manner, the speed of the motor 88 is ‘ber driven by said motor, a rotatable member
regulated by controlling the current in the ?eld magnetically actuated by therotating member,
winding 81 by means ,0! the resistors 88 and 88,‘ ' spring .means for biasing the rotatable member to
which are alternately connected in and discon-_ shunt the motor ?eld, thereby regulating the
nected from the field winding circuit by means ‘of speed of the motor, electro-magnetic means dis
contact members on the speed regulating re-, posed to vary the e?ect of said spring means, and
35 the
lay, and hunting of the regulating system is re
means actuated‘ by said rotatable member-‘for
. enabled to again close the contact members of the
duced by the action of the electrically energized
controlling the energization of said electro-mag
solenoid 8|.
netic means.
From the foregoing description, it is apparent
3. In a motor control system, in combination,
40 that I have provided a speed-repsonsive device
which may be economically constructed and may
be readily utilized as a speed relay to control
the operation for numerouselectrical or mechan
‘magnetically actuated by the rotating member to
ical devices, and may also be utilized, as a speed
increase the'motor ?eld current, spring means for
an electric motor, a ?eld winding for the motor, 40
a speed-responsive relay} having a rotating mem
ber driven by said motor, a rotatable member.
45 regulatorlto control» the speed or electric motors biasing the rotatable member to decreasethe ?eld
of various types. ,
I! desired, the relay may be modi?ed to con
stitute ‘a speed-responsive device having a time
delay characteristic by permitting the cup mem
ber 01 the relay to rotate and drive a gear ‘train
loaded with a spring or friction load. In this
manner contact members or‘ mechanical trip de
vices may beoperated in sequential relation by
current, thereby regulating ‘the motor speed, elec
trically-energized means disposed, to, oppose the
‘spring means to prevent hunting of the regulat- '
ing system, and means actuated by said rotatable
member for controlling the energization of said '
electrically energised means.
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