US2951189A - Control device - Google Patents
Control device Download PDFInfo
- Publication number
- US2951189A US2951189A US621703A US62170356A US2951189A US 2951189 A US2951189 A US 2951189A US 621703 A US621703 A US 621703A US 62170356 A US62170356 A US 62170356A US 2951189 A US2951189 A US 2951189A
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- Prior art keywords
- rotor
- air gap
- winding
- flux
- movement
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- Expired - Lifetime
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- 238000004804 winding Methods 0.000 description 70
- 230000004907 flux Effects 0.000 description 52
- 230000005291 magnetic effect Effects 0.000 description 28
- 239000004020 conductor Substances 0.000 description 15
- 230000008859 change Effects 0.000 description 7
- 239000012530 fluid Substances 0.000 description 5
- 230000004044 response Effects 0.000 description 5
- 230000001965 increasing effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002730 additional effect Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K31/00—Actuating devices; Operating means; Releasing devices
- F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
- F16K31/04—Actuating devices; Operating means; Releasing devices electric; magnetic using a motor
- F16K31/041—Actuating devices; Operating means; Releasing devices electric; magnetic using a motor for rotating valves
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/06—Electromagnets; Actuators including electromagnets
- H01F7/08—Electromagnets; Actuators including electromagnets with armatures
- H01F7/14—Pivoting armatures
- H01F7/145—Rotary electromagnets with variable gap
Definitions
- This invention relates in general to electromagnetic control devices and more particularly to electromagnetic devices, for example, fluid fuel valves, requiring a high initial or starting torque.
- One of the main objects of the present invention is to provide an improved form of electromagnetic control device wherein the operating force obtained is at a maximum at the beginning of the operating movement, as distinguished from devices in which the force exerted initially is a minimum.
- This is advantageous, particularly in a valve or switch operator, since it provides a large initial or starting force to overcome the inertia and friction of moving parts and also toovercome the strong initial resistance to valve opening movement caused by fluid pressures tending to hold the valve closed or spring biasing tending to hold the switch closed.
- Another object is to provide a device of the aforementioned character which is quiet andefiicient in operation and which affords increased efficiency in the transformation from electrical to mechanical energy, for example, in providing for a given sized valve unit substantially increased capacity as compared to known devices of similar character.
- Another and more specific object of this invention is to provide a device of the aforementioned characteristics having means therein for increasing the starting torque of an already normally high starting torque type electromagnetic device without a corresponding increase in the size of the device and without an increase in the heat losses thereof.
- Another object of the invention is to provide a device as characterized having therein an electromagnetic operator comprising coil means, rotor means associated with said coil means for movement upon energization of the coil means and means associated with the rotor means for changing the number of effective turns in the coil means to provide both a high starting torque and a low running-power loss.
- Another object of the invention is to provide the abovedescribed device with means associated with the rotor means to change the number of turns in the winding means in response to movement of the rotor means from a first to a second position, thereby providing a high starting torque and reducing the power required by the device when the rotor is in its second position and high torque is no longer needed.
- Anotherspecific object of the invention is to provide a device of the class described having two windings initially energized by line power and opposing each other to produce high torque actuation of the rotor, and having means for disconnecting one of said windings from said source and short circuiting said winding to permit induction of a current therein for continuation of flux flow in said core means and rotor to maintain the latter in actuated position.
- Another specific object of the invention is to provide an electromagnetic device wherein the power unit takes the form of a current limiting step-down transformer ice having a primary winding energizable by line power, and a low-voltage secondary winding including condition responsive means or other apparatus for controlling said unit, the low voltage of said secondary winding making it unnecessary to provide the secondary circuit with the type of insulation and the conduits required for line voltage.
- a further object of the invention is to provide a device of the above general type that is sturdy and easily constructed and is otherwise well adapted for the purposes for which it is designed.
- FIG. 1 is an axial sectional view of one form of the device embodying the present invention showing in schematic form thermostatic means for controlling the secondary circuit thereof;
- Figure 2 is a schematic plan view of the device depicted in Figure 1 showing the rotor armature in retracted relation;
- Figure 3 is a view similar to Figure 2 showing the armature in attracted relation
- Figure 4 is a schematic plan view of a modified form of the invention.
- Figure 5 is a perspective view of a rotor armature of the type used in the devices depicted in Figures 1 to 3;
- Figure 6 is an enlarged fractional sectional plan view taken through the contact ring of the rotor shown in Figures 1, 2 and 5 and indicating the cooperation of the fixed contacts with said contact ring when the rotor is in retracted position.
- control selected for illustration comprises an electromagnetically operated valve which is of the general type or class shown in the copending application of Floyd J. Bydalek and Russell B. Matthews, Serial No. 270,666, filed February 8, 1952, now Patent No. 2,833,565, and as shown in the issued patent of Eugene E. Meusy, No. 2,756,370, dated July 24, 1956. It is to be understood that While the invention is shown and described as an improved form of a particular type or class of electromagnetic device as aforementioned, the invention is not so limited in its application and its apphcability to other electromagnetic devices will become apparent.
- control apparatus comprises a valve body 10 having an inlet 11 and outlet 12.
- a valve member 13 cooperates with a valve seat 14 to control the flow of fluid through the valve body. It will be noted that the pressure of the controlled fluid tends to hold valve member 13 closed agamst seat 14.
- the valve body 10 has an opening 15 covered by control casing 16 of non-magnetic material for housing an electromagnetic power unit or operator to be hereinafter described.
- the bottom wall 16a of the casing 16 affords a base plate for the power unit and a plate-like cover for opening 15, said wall being sealingly secured by suitable means (not shown) to the body 10.
- the upper side of base plate 16a is provided with a pair of integrally 3, formed upstanding arms 16b which form a partial enclosure for a rotor or rotary armature 17 hereinafter described.
- a core 19 of laminated, or of any other suitable form is disposed within casing 16 and may be formed of any suitable magnetically permeable material such as iron.
- the particular core 19 selected for illustration is of generally rectangular configuration, and comprises a pair of parallel side legs 20 and 21 which are magnetically connected by parallel end legs 22 and 23 as best shown in Figures 2 and 3.
- the core side legs 2%; and 21 have spaced pole pieces 24 and 25 formed, for example, as integral parts of the core laminations, said pole pieces having the configuration shown in Figures 2 and 3 including arcuate pole faces defining with arms 16b of the base plate 16a, a well including an air gap in which the rotor 17 is adapted to turn.
- the rotor 17 is of magnetic material, such as steel, and is of the form best illustrated in the perspective view of Figure 5.
- the rotor 17 is of solid form and is fixedly mounted on a shaft 31 which is positioned for turning movement and is provided with suitable bearings.
- the illustrated bearings include balls 26 and a sleeve 27 carried by and projecting through the cover 16a, and also include a spring loaded ball-type thrust bearing 28.
- the rotor shaft 31 extends downwardly through the sleeve 27 for connection with a crank member 40.
- a resilient ring 41 surrounds shaft 31 within the sleeve 27 to provide a gas-tight seal therebetween.
- the crank member is formed with an off-center pin 43 which is adapted to engage a yoke or spool member 44 connected at one end, as by a stem 45, to valve member 13.
- the aforementioned yoke and valve member may be suspended in the valve body by a pair of spiral springs 47 which are fixedly attached to a portion 160 of the base plate 16a.
- the springs 47 serve both to support the valve member .13 assembly in alignment with the valve seat GM and to bias the rotor 17 and valve member 13 in a valve closing direction as will hereinafter become apparent.
- the electrical system comprises a primary winding 33 which is wound on coil leg 23.
- the primary winding 33 is adapted to be connected to a suitable source 60 of A.-C. line power by conductors 56 and 57 through circuitry which will be described hereinafter.
- a secondary coil or winding 34 is wound around the coil leg 22 and the circuit thereof includes condition responsive means such as a thermostat illustrated schematically at 38 in Figures 1, and 2 and 3 for opening and closing said circuit.
- the primary winding 33 may be provided with end taps 33b and 330 and with a tap 33a intermediate its length.
- the portion of winding 33 between end tap 33c and tap 3301 which, of course, is less than total number of turns of said winding is referred to as winding portion 33d.
- the center tap 33a is connected by a suitable conductor 54 to a fixed contact 51
- the end tap 33b is connected to a fixed contact 52 by conductor 55
- the end tap 33c is connected to conductor 57 which is also connected to one side of the source 60.
- the other side of source 60 is connected to a fixed contact 50 by a suitable conductor 56.
- Means for alternatively connecting the entire winding 33 or the portion 33d thereof across the source 6! is provided by suitable contact means such as a contact sleeve 32 ( Figures Sand 6) which is carried by the rotor 17 and cooperable with the contacts 50, 5'1 and 52.
- the electrically conductive contact sleeve 32 may be molded into an insulating bushing 31a fixedly mounted on the rotor stem 31 and is preferably formed with side wall openings 32c and 32d separated by wall portions 320 and 32b. Wall portion 32b is continuously engaged by contact 50, and wall portion 32d is positioned for engagement by the contact 51 as shown in Figures 2 and 6 when the rotor 17 is in retracted position, to complete the circuit between contacts 50 and 51.
- the wall portion 32d of sleeve 32 moves out of engagement with contact 51 and into engagement with contact 52 to thereby complete the circuit between contacts 50 and 52.
- the entire coil or winding 33 is energized through the following circuitry: from source 60, through conductor 56, contact 50, sleeve 32, contact 52, conductor 55, end tap 33b, entire coil '33, end tap 33c, and conductor 57 back to source 60.
- the improved starting torque is obtained for the following reasons:
- the impedance oifered by the less than total number of turns in portion 33d of the winding is less than the impedance offered by the total winding 33 (the latter being substantially the same as the primary windings in devices heretofore except for the intermediate tap 33a).
- the improved device is, however, constructed in a manner to prevent such overheating,.there being means operable upon partial opening of the valve 13 to cause the entire Winding 33 to be energiZBd. This reduces the NI produced in the primary winding as well as the heat generated therein, and it also reduces the armature torque. Since there is need for the high armature torque only during initial cracking of the valve 13, however, the reduced armature torque available after partial opening of said valve is adequate for movement of said valve to its full open position.
- Another desirable feature of the aforedescribed device is that it is inherently more efficient than known electromagnetic operators as, for example, the power requirement is about one-sixth that of a conventional solenoid operator, and substantially less than that of the devices of the same class disclosed in the aforementioned patent and copending application.
- Figure 4 is a View similar to Figure 2 and showing a modified form of the invention. It is to be understood that Figure 4 is a schematic presentation of a device of the same general type shown in Figure l. The primed numerals in Figure 4 indicate parts which are similar to the parts indicated in the other figures by the same numerals unprirned. It is to be noted that the thermostat 38' is located in the primary winding circuit and affords a complete shut off of power to said winding when the circuit is broken at said thermostat.
- the secondary winding 34' is connected in parallel circuit with the primary winding 33 through normally closed con tacts 70 and 71, whereby upon closure of thermostat contacts, both coils become energized directly from source 60' in such a manner that the magnetic flux generated by one of said windings tends to flow in the core side legs 20' and 21' in a direction opposite to the direction in which the flux generated by the other winding tends to flow in said side legs.
- flux is shunted across the air gap defined by the pole faces 24' and 25', producing a high counterclockwise torque in the armature 17'.
- a cam of insulating material is fixed on rotor stem 31' and rotates with the rotor 17' to engage contact leaves 70 and 71 and disengage the latter from each other to open the circuit between conductors 82 and 84 leading to source 60'.
- Cam 90 simultaneously causes contact 71 to engage a contact '72 to afford, through contacts 71 and 72 and conductors 82 and 83, a short circuit for the portion of winding 34 between the terminal thereof connected to conductor 82 and a suitable tap 75 (which may be placed anywhere along its length as desired) to which the conductor 83 is connected.
- the coil 34' is now a shorted secondary which operates in a manner similar to that of the coil 34 in the other figures, i.e., the current induced therein maintaining the flux created by the primary 33' diverted across the air gap to maintain the rotor in attracted position and the valve open.
- the structure shown in Figure 4 also affords high starting torque and a very low running power requirement.
- the device depicted in Figure 4 is also particularly adaptable to a multiple valve application wherein it is desired to have a single thermostat control several valves simultaneously.
- An electromagnetic device comprising a permeable core having an air gap, a rotor having its axis of rotation within said air gap, magnetic flux source means comprising first and second windings for producing a magnetic flux in said core and through said air gap, said rotor being rotatable from a first to a second position in response to said flux flow in said air gap, a control member operatively associated with'said rotor for actuation thereby and requiring"a first force to initiate movement from a first controlling position and a second force to continue said movement once initiated toward a second controlling position, means associated with said rotor and said mag netic flux source means comprising contact means normally connecting said windings in parallel circuit relation and actuated by the rotor to interrupt said connection and short circuit at least a portion of said secondary Winding to thereby afford a first amount of flux in said air gap when said control member is in its first controlling position and therefore requires said first force for movement thereof and affording a second amount of flux in said air gap for continuing movement of said control'member
- An electromagnetic device comprising a permeable core having an air gap, a rotor having its axis of rotation within said air gap, magnetic source means comprising a primary and a secondary winding for producing a magnetic flux in said core and through said air gap, said rotor being rotatable from a first to a second position in response to said flux flow in said air gap, a control member operatively associated with said rotor for actuation thereby and requiring a first force to initiate movement from a first controlling position and a second force to continue said movement once initiated toward a second controlling position, means associated with said rotor and said magnetic flux source means comprising contact means in circuit with the primary winding and actuated by the rotor for changing the number of effective turns therein to vary the inductive reactance and hence the flux produced thereby to aiford a first amount of flux in said air gap when.
- said control member is in its first controlling position and therefore requires said first force for moveprimary and a secondary winding for producing a magnetic flux in said core and through said air gap, said rotor being rotatable from a first to a second position in response to said flux flow in said air gap, a control member operatively associated with said rotor for actuation thereby and requiring a first force to initiate movement from a first controlling position and a second force to continue said movement once initiated toward a second controlling position, means associated with said rotor and said magnetic flux source means comprising contact means in circuit with said secondary winding and actuated by the rotor to change the number of effective turns therein to vary the inductive reactance and hence the flux produced thereby to afford a first amount of flux in said air gap when said control member is in its first controlling position and therefore requires said first force for movement thereof and to afford a second amount of flux in said air gap for continuing movement of said control member once movement thereof toward said second controlling position is initiated.
- An electromagnetic operator comprising a permeable core affording a closed magnetic circuit and also having pole pieces defining an air gap, magnetic flux source means comprising a primary and a secondary winding on said core for producing a magnetic flux in said core, first and second control means for varying the amount of flux at said pole pieces, said first control means being connected to a source of electrical energy and to both of said windings and operable upon actuation thereof to effect energization of both of said windings and initiate flux flow through said air gap, a rotor having its axis of rotation in said air gap having surfaces adapted to be drawn into said air gap by said flux flow therethrough, said second control means being connected in circuit with both of said windings, and said rotor being associated with said second control means for actuation thereof to disconnect said secondary winding from said source: of electric energy and short circuit a portion of said winding, whereby actuation of said first control means initiates sufficient rotary motion to said rotor with maximum force at the beginning of its movement to satisfy the inherent tendency of said
- An electromagnetic operator comprising a magnetically permeable core having an air gap, an armature mounted for movement in said air gap and adapted for connection to a control member to be actuated, magnetic flux source means comprising first and second windings for producing magnetic flux in said core and through said air gap, said armature being movable from a first to a second position in response to fiux flow in said air gap, means associated with said armature and said magnetic flux source means comprising contact means connecting said windings in parallel circuit relation when saidartnature is in its first position and actuated by movement of said armature toward its second position to interrupt said connection and short circuit at least a portion of said secondary winding to thereby afford a first amount of flux in said air gap when said armature is in its first position and a second smaller amount of flux in said air gap when said armature is in its second position.
- An electromagnetic operator comprising a magnetically permeable core affording a closed magnetic circuit and also having pole pieces defining an air gap, magnetic flux source means comprising a primary and a secondary winding on said core for producing opposing magnetic flux flows in said core and thereby flux flow across said air gap, first and second control means for varying the amount of flux in said air gap, said first con trol means being connected to a source of electrical energy and to both of said windings and operable upon actuation thereof to effect energization of both of said windings and initiate flux flow through said air gap at a first rate, an armature movable from a first toward a second position by flux flow through said air gap, said second controlmeans being connected in circuit with both windings, and said rotor being associated with said second control means for actuation thereof to disconnect said secondary winding from said source of electric energy and short circuit at least a portion of said winding, whereby actuation of said first control means initiates motion of said armature from its first toward its second position, and
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Power Engineering (AREA)
- Magnetically Actuated Valves (AREA)
Description
Aug. 30, 1960 Q HAJNY' 2,951,189
CONTROL DEVICE Filed Nov 15, 1956 2 Sheets-Sheet 1 i5 INVENTOR.
' C zar-les E. )Z'gjn Aug. 30, 1960 c E HAJNY 2,951,189
CONTROL DEVICE Filed Nov. 13,- 1956 2 Sheets-Sheet 2 INVENTOR. 82 Charles E.
my QM United States Patent CONTROL DEVICE Charles E. Hajny, Milwaukee, Wis., assignor to lSaso Inc., Milwaukee, Wis., a corporation of Wisconsin Filed Nov. 13, 1956, Ser. No. 621,703
6 Claims. (Cl. 317156) This invention relates in general to electromagnetic control devices and more particularly to electromagnetic devices, for example, fluid fuel valves, requiring a high initial or starting torque.
One of the main objects of the present invention is to provide an improved form of electromagnetic control device wherein the operating force obtained is at a maximum at the beginning of the operating movement, as distinguished from devices in which the force exerted initially is a minimum. This is advantageous, particularly in a valve or switch operator, since it provides a large initial or starting force to overcome the inertia and friction of moving parts and also toovercome the strong initial resistance to valve opening movement caused by fluid pressures tending to hold the valve closed or spring biasing tending to hold the switch closed.
Another object is to provide a device of the aforementioned character which is quiet andefiicient in operation and which affords increased efficiency in the transformation from electrical to mechanical energy, for example, in providing for a given sized valve unit substantially increased capacity as compared to known devices of similar character.
Another and more specific object of this invention is to provide a device of the aforementioned characteristics having means therein for increasing the starting torque of an already normally high starting torque type electromagnetic device without a corresponding increase in the size of the device and without an increase in the heat losses thereof.
Another object of the invention is to provide a device as characterized having therein an electromagnetic operator comprising coil means, rotor means associated with said coil means for movement upon energization of the coil means and means associated with the rotor means for changing the number of effective turns in the coil means to provide both a high starting torque and a low running-power loss.
Another object of the invention is to provide the abovedescribed device with means associated with the rotor means to change the number of turns in the winding means in response to movement of the rotor means from a first to a second position, thereby providing a high starting torque and reducing the power required by the device when the rotor is in its second position and high torque is no longer needed.
Anotherspecific object of the invention is to provide a device of the class described having two windings initially energized by line power and opposing each other to produce high torque actuation of the rotor, and having means for disconnecting one of said windings from said source and short circuiting said winding to permit induction of a current therein for continuation of flux flow in said core means and rotor to maintain the latter in actuated position.
Another specific object of the invention is to provide an electromagnetic device wherein the power unit takes the form of a current limiting step-down transformer ice having a primary winding energizable by line power, and a low-voltage secondary winding including condition responsive means or other apparatus for controlling said unit, the low voltage of said secondary winding making it unnecessary to provide the secondary circuit with the type of insulation and the conduits required for line voltage.
A further object of the invention is to provide a device of the above general type that is sturdy and easily constructed and is otherwise well adapted for the purposes for which it is designed.
The novel features which are characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will thus be better understood by the following description of the specific embodiments when read in connection with the accompanying drawings, in which:
Figure 1 is an axial sectional view of one form of the device embodying the present invention showing in schematic form thermostatic means for controlling the secondary circuit thereof;
Figure 2 is a schematic plan view of the device depicted in Figure 1 showing the rotor armature in retracted relation;
Figure 3 is a view similar to Figure 2 showing the armature in attracted relation;
Figure 4 is a schematic plan view of a modified form of the invention; I
Figure 5 is a perspective view of a rotor armature of the type used in the devices depicted in Figures 1 to 3; and
Figure 6 is an enlarged fractional sectional plan view taken through the contact ring of the rotor shown in Figures 1, 2 and 5 and indicating the cooperation of the fixed contacts with said contact ring when the rotor is in retracted position.
Referring to the drawings, and more particularly to Figure 1 thereof, the control selected for illustration comprises an electromagnetically operated valve which is of the general type or class shown in the copending application of Floyd J. Bydalek and Russell B. Matthews, Serial No. 270,666, filed February 8, 1952, now Patent No. 2,833,565, and as shown in the issued patent of Eugene E. Meusy, No. 2,756,370, dated July 24, 1956. It is to be understood that While the invention is shown and described as an improved form of a particular type or class of electromagnetic device as aforementioned, the invention is not so limited in its application and its apphcability to other electromagnetic devices will become apparent.
The details of the electromagnetic device shown in Figure 1 may be ascertained by referring to the aforementioned copending application and patent.
For properly setting forth sufficient background to readily understand the present invention, however, it should be pointed out that the illustrated form of control apparatus comprises a valve body 10 having an inlet 11 and outlet 12. A valve member 13 cooperates with a valve seat 14 to control the flow of fluid through the valve body. It will be noted that the pressure of the controlled fluid tends to hold valve member 13 closed agamst seat 14.
The valve body 10 has an opening 15 covered by control casing 16 of non-magnetic material for housing an electromagnetic power unit or operator to be hereinafter described. The bottom wall 16a of the casing 16 affords a base plate for the power unit and a plate-like cover for opening 15, said wall being sealingly secured by suitable means (not shown) to the body 10. The upper side of base plate 16a is provided with a pair of integrally 3, formed upstanding arms 16b which form a partial enclosure for a rotor or rotary armature 17 hereinafter described.
A core 19 of laminated, or of any other suitable form is disposed within casing 16 and may be formed of any suitable magnetically permeable material such as iron. The particular core 19 selected for illustration is of generally rectangular configuration, and comprises a pair of parallel side legs 20 and 21 which are magnetically connected by parallel end legs 22 and 23 as best shown in Figures 2 and 3. The core side legs 2%; and 21 have spaced pole pieces 24 and 25 formed, for example, as integral parts of the core laminations, said pole pieces having the configuration shown in Figures 2 and 3 including arcuate pole faces defining with arms 16b of the base plate 16a, a well including an air gap in which the rotor 17 is adapted to turn.
The rotor 17 is of magnetic material, such as steel, and is of the form best illustrated in the perspective view of Figure 5. In general the rotor 17 is of solid form and is fixedly mounted on a shaft 31 which is positioned for turning movement and is provided with suitable bearings. The illustrated bearings include balls 26 and a sleeve 27 carried by and projecting through the cover 16a, and also include a spring loaded ball-type thrust bearing 28.
As shown in Figlre l, the rotor shaft 31 extends downwardly through the sleeve 27 for connection with a crank member 40. A resilient ring 41 surrounds shaft 31 within the sleeve 27 to provide a gas-tight seal therebetween. The crank member is formed with an off-center pin 43 which is adapted to engage a yoke or spool member 44 connected at one end, as by a stem 45, to valve member 13.
The aforementioned yoke and valve member may be suspended in the valve body by a pair of spiral springs 47 which are fixedly attached to a portion 160 of the base plate 16a. The springs 47 serve both to support the valve member .13 assembly in alignment with the valve seat GM and to bias the rotor 17 and valve member 13 in a valve closing direction as will hereinafter become apparent.
Referring back to the power unit of the device, the electrical system comprises a primary winding 33 which is wound on coil leg 23. The primary winding 33 is adapted to be connected to a suitable source 60 of A.-C. line power by conductors 56 and 57 through circuitry which will be described hereinafter. A secondary coil or winding 34 is wound around the coil leg 22 and the circuit thereof includes condition responsive means such as a thermostat illustrated schematically at 38 in Figures 1, and 2 and 3 for opening and closing said circuit.
Devices having the general structure thus far described are shown and described in the aforementioned copending application and patent. The operation of the instant device is, however, substantially improved over that of prior art devices by virtue of additional structural features and modifications which will now be described.
As shown in Figure 2, the primary winding 33 may be provided with end taps 33b and 330 and with a tap 33a intermediate its length. For sake of convenience in reference, the portion of winding 33 between end tap 33c and tap 3301 which, of course, is less than total number of turns of said winding is referred to as winding portion 33d. The center tap 33a is connected by a suitable conductor 54 to a fixed contact 51, the end tap 33b is connected to a fixed contact 52 by conductor 55, and the end tap 33c is connected to conductor 57 which is also connected to one side of the source 60. The other side of source 60 is connected to a fixed contact 50 by a suitable conductor 56.
Means for alternatively connecting the entire winding 33 or the portion 33d thereof across the source 6! is provided by suitable contact means such as a contact sleeve 32 (Figures Sand 6) which is carried by the rotor 17 and cooperable with the contacts 50, 5'1 and 52. The electrically conductive contact sleeve 32 may be molded into an insulating bushing 31a fixedly mounted on the rotor stem 31 and is preferably formed with side wall openings 32c and 32d separated by wall portions 320 and 32b. Wall portion 32b is continuously engaged by contact 50, and wall portion 32d is positioned for engagement by the contact 51 as shown in Figures 2 and 6 when the rotor 17 is in retracted position, to complete the circuit between contacts 50 and 51. On rotation of the rotor to the attracted position of Figure 2, the wall portion 32d of sleeve 32 moves out of engagement with contact 51 and into engagement with contact 52 to thereby complete the circuit between contacts 50 and 52.
From the aforedescribed circuitry, it is apparent that when the rotor is in the retracted position shown in Figures 2 and 6, only portion 33d of winding 33 is energized as follows: from source 60, through conductor 56, contact 50, sleeve 32, contact 51, conductor 54, tap 33a, portion 33d of coil 33, end tap 33c, and conductor 57 back to source 60. On the other hand, when the rotor is in the attracted position shown in Figure 3 of the drawings, the entire coil or winding 33 is energized through the following circuitry: from source 60, through conductor 56, contact 50, sleeve 32, contact 52, conductor 55, end tap 33b, entire coil '33, end tap 33c, and conductor 57 back to source 60.
The operation of the improved device shown in Figures 2, 3 and 6 will now be described. With the parts of the device disposed as shown in Figures 2 and 6, the portion 33d of winding 33 is energized to create a magnetic flux in the core 19 that flows, during one half of the alternation current cycle, in a clockwise direction and during the other half cycle in the opposite direction through side leg 20, end leg 22, side leg 21 and leg 23. The majority of this flux tends to flow through leg 22 of core 19 only so long as the circuit of the secondary winding 34 remains open.
When the thermostat '38 calls for heat, the contacts thereof close the circuit of the secondary winding 34 and a current is thereupon induced into said winding. A major portion of the magnetic flux in the core 1 9 will now no longer flow through end leg 22, but will be diverted across the air gap afforded by the pole pieces 24 and 25. The flux flowing across the air gap tends to rotate the rotor from its retracted position of Figure 2 to its attracted position of Figure 3 with a very high starting torque which is effective to open the valve 14 against fluid pressure and against the bias of springs 47. It is to be understood that the torque thus developed is susbtantial- 1y higher than that developed in other devices of the same class due to the fact that less than the total number of turns in winding 33 are energized to effect such movement.
The improved starting torque is obtained for the following reasons: The impedance oifered by the less than total number of turns in portion 33d of the winding is less than the impedance offered by the total winding 33 (the latter being substantially the same as the primary windings in devices heretofore except for the intermediate tap 33a). Thus, when a load is impressed on the portion 33d of the primary winding by the closure of the secondary circuit, a relative and abnormally high amount of current will flow in said winding portion as compared with amount that would fiow if the entire winding 33 were energized. This current flow produces a very high Ni and consequently a high magnetic flux which is shunted through the poles 24- 25 and rotor 17. Since flux crosses an air gap at the point of minimum air gap, and since the minimum air gap occurs at the point where the leading edges of the rotor 17 are presented to the pole pieces, the magnetic flux is concentrated at those points, imparting a very high counter-clockwise torque to the rotor 17.
Extremely high starting torque is thus occasioned both by the concentration of magnetic'flux into a limited area of rotor and pole face surface presented to each other and by the large amount of magnetic flux available due to the increased NI occasioned by energization of only a portion of the total number of turns in the primary winding 33.
The inherent tendency of the device is to tend toward a condition of minimum effective air gap. Hence, the rotor '17 will be rotated into the air gap until the arms 17a and 17b thereof are in substantial registry with the pole faces 24 and 25 respectively to define the attracted position of said 'rotor shown in Figure 3. Further counterclockwise rotation of the rotor =17 will not occur since suchmovement would tend to increase the air gap, setting up magnetic forces creating a torque in the opposite direction. The rotor 17 is thereby afforded a magnetic stop limiting its rotation in counterclockwise direction.
If the aforementioned abnormally high current is permitted to continue flowing through the winding portion 33d, as distinguished, from the entire winding 33, the primary would soon overheat. The improved device is, however, constructed in a manner to prevent such overheating,.there being means operable upon partial opening of the valve 13 to cause the entire Winding 33 to be energiZBd. This reduces the NI produced in the primary winding as well as the heat generated therein, and it also reduces the armature torque. Since there is need for the high armature torque only during initial cracking of the valve 13, however, the reduced armature torque available after partial opening of said valve is adequate for movement of said valve to its full open position. The aforementioned change in the number of energized turns of the winding 33 is effected by movement of the wall portion 32a of contact sleeve 32 out of engagement with contact 51 and into engagement with contact 52 upon rotation of the contact sleeve 32 with the rotor 17 toward the attracted position of the latter.
The reason for the reduced heat losses and NI produced by the energization of the entire winding 33 shall now be explained. If arbitrarily the center tap 33a is disposed at the midpoint of the winding 33, then when the turns. are doubled by movement of the rotor contact sleeve 32, the primary impedance more than doubles. This obtains because the reactance part of the primary impedanceis a function of the square of the number of turns of said winding. Since the primary turns are doubled and the primary current goes to less than half of the initial current because of the impedance change, the effective NI available at the pole faces 24 and 25 decreases to correspondingly reduce the armature torque.
The reduction in. heat losses is obtained because heat losses are a function of PR, and although the resistance of the primary doubles by doubling the turns thereof, the current flow drops to less than half due to the additional effect of the impedance change aforenoted. Thus, the PR heat losses occurring when the entire winding 33 is energized are less than one half of the heat losses occurringwhen only one half of the winding is energized.
Another factor that affects the amount of current flow in the primary winding 33, and hence the NI, is the change in reluctance in the magnetic path due to the change in the air gap. Inasmuch as the reluctance is high, initially due to. the very small amount of rotor area presented to the pole faces, a low impedance is obtained in the primary which permits a very high initial current flow affording. a high starting torque. The aforementioned reluctance becomes lower as the rotor presents more and more area to the pole faces, and the current flow, therefore, drops correspondingly. Thus it is observed that the device will have an extremely low operating loss because of both the decrease in reluctance in the magnetic path and the increase in the number of energizedturns in the winding resulting in a lower current flow.
It is, of course, understood that the rotation of the rotor 17 and consequent movement of the valve member 13 through the linkage of shaft 31, crank member 40 and yoke 44 is against the bias of springs 47 which return both the valve member 13 and the rotor 17 to their initial positions upon cessation of flux flow across the air gap between pole faces 24 and 25 effected, for example, by reopening of the thermostat 38. It should further be noted that such return will be prompt and without dangerous sticking, since the rotor 17 never seals against the pole faces 24 and 25; that is, the air gap therebetween, although minimized by registration of the rotor arm to the pole pieces, is never completely eliminated and said minimum air gap remains constant throughout the life of the device. The device is not, therefore, subject to residual magnetism of the core 19, the differential of the flux value required to pull in the rotor, and that at which it will drop out is thereby greatly minimized, rendering the control extremely sensitive and fast-acting.
Another desirable feature of the aforedescribed device is that it is inherently more efficient than known electromagnetic operators as, for example, the power requirement is about one-sixth that of a conventional solenoid operator, and substantially less than that of the devices of the same class disclosed in the aforementioned patent and copending application.
Figure 4 is a View similar to Figure 2 and showing a modified form of the invention. It is to be understood that Figure 4 is a schematic presentation of a device of the same general type shown in Figure l. The primed numerals in Figure 4 indicate parts which are similar to the parts indicated in the other figures by the same numerals unprirned. It is to be noted that the thermostat 38' is located in the primary winding circuit and affords a complete shut off of power to said winding when the circuit is broken at said thermostat. As shown, the secondary winding 34' is connected in parallel circuit with the primary winding 33 through normally closed con tacts 70 and 71, whereby upon closure of thermostat contacts, both coils become energized directly from source 60' in such a manner that the magnetic flux generated by one of said windings tends to flow in the core side legs 20' and 21' in a direction opposite to the direction in which the flux generated by the other winding tends to flow in said side legs. As a result, flux is shunted across the air gap defined by the pole faces 24' and 25', producing a high counterclockwise torque in the armature 17'. A cam of insulating material is fixed on rotor stem 31' and rotates with the rotor 17' to engage contact leaves 70 and 71 and disengage the latter from each other to open the circuit between conductors 82 and 84 leading to source 60'. Cam 90 simultaneously causes contact 71 to engage a contact '72 to afford, through contacts 71 and 72 and conductors 82 and 83, a short circuit for the portion of winding 34 between the terminal thereof connected to conductor 82 and a suitable tap 75 (which may be placed anywhere along its length as desired) to which the conductor 83 is connected. The coil 34' is now a shorted secondary which operates in a manner similar to that of the coil 34 in the other figures, i.e., the current induced therein maintaining the flux created by the primary 33' diverted across the air gap to maintain the rotor in attracted position and the valve open.
The structure shown in Figure 4 also affords high starting torque and a very low running power requirement. The device depicted in Figure 4 is also particularly adaptable to a multiple valve application wherein it is desired to have a single thermostat control several valves simultaneously.
Although certain specific embodiments of the invention have been shown and described, it is with full awareness that many modifications thereof are possible within the inventive concept.
The invention, therefore, is not to "7 be restricted except insofar as is necessitated by the prior art and by the appended claims.
What is claimed by the invention is: V.
1. An electromagnetic device comprising a permeable core having an air gap, a rotor having its axis of rotation within said air gap, magnetic flux source means comprising first and second windings for producing a magnetic flux in said core and through said air gap, said rotor being rotatable from a first to a second position in response to said flux flow in said air gap, a control member operatively associated with'said rotor for actuation thereby and requiring"a first force to initiate movement from a first controlling position and a second force to continue said movement once initiated toward a second controlling position, means associated with said rotor and said mag netic flux source means comprising contact means normally connecting said windings in parallel circuit relation and actuated by the rotor to interrupt said connection and short circuit at least a portion of said secondary Winding to thereby afford a first amount of flux in said air gap when said control member is in its first controlling position and therefore requires said first force for movement thereof and affording a second amount of flux in said air gap for continuing movement of said control'member once movement thereof toward said second controlling position is initiated.
2. An electromagnetic device comprising a permeable core having an air gap, a rotor having its axis of rotation within said air gap, magnetic source means comprising a primary and a secondary winding for producing a magnetic flux in said core and through said air gap, said rotor being rotatable from a first to a second position in response to said flux flow in said air gap, a control member operatively associated with said rotor for actuation thereby and requiring a first force to initiate movement from a first controlling position and a second force to continue said movement once initiated toward a second controlling position, means associated with said rotor and said magnetic flux source means comprising contact means in circuit with the primary winding and actuated by the rotor for changing the number of effective turns therein to vary the inductive reactance and hence the flux produced thereby to aiford a first amount of flux in said air gap when. said control member is in its first controlling position and therefore requires said first force for moveprimary and a secondary winding for producing a magnetic flux in said core and through said air gap, said rotor being rotatable from a first to a second position in response to said flux flow in said air gap, a control member operatively associated with said rotor for actuation thereby and requiring a first force to initiate movement from a first controlling position and a second force to continue said movement once initiated toward a second controlling position, means associated with said rotor and said magnetic flux source means comprising contact means in circuit with said secondary winding and actuated by the rotor to change the number of effective turns therein to vary the inductive reactance and hence the flux produced thereby to afford a first amount of flux in said air gap when said control member is in its first controlling position and therefore requires said first force for movement thereof and to afford a second amount of flux in said air gap for continuing movement of said control member once movement thereof toward said second controlling position is initiated.
4. An electromagnetic operator comprising a permeable core affording a closed magnetic circuit and also having pole pieces defining an air gap, magnetic flux source means comprising a primary and a secondary winding on said core for producing a magnetic flux in said core, first and second control means for varying the amount of flux at said pole pieces, said first control means being connected to a source of electrical energy and to both of said windings and operable upon actuation thereof to effect energization of both of said windings and initiate flux flow through said air gap, a rotor having its axis of rotation in said air gap having surfaces adapted to be drawn into said air gap by said flux flow therethrough, said second control means being connected in circuit with both of said windings, and said rotor being associated with said second control means for actuation thereof to disconnect said secondary winding from said source: of electric energy and short circuit a portion of said winding, whereby actuation of said first control means initiates sufficient rotary motion to said rotor with maximum force at the beginning of its movement to satisfy the inherent tendency of said flux to minimize the air gap through which it is forced to flow, and further movement of said rotor aifords actuations of said second control means to afford a reduction in the flux flow through said air gap.
5. An electromagnetic operator comprising a magnetically permeable core having an air gap, an armature mounted for movement in said air gap and adapted for connection to a control member to be actuated, magnetic flux source means comprising first and second windings for producing magnetic flux in said core and through said air gap, said armature being movable from a first to a second position in response to fiux flow in said air gap, means associated with said armature and said magnetic flux source means comprising contact means connecting said windings in parallel circuit relation when saidartnature is in its first position and actuated by movement of said armature toward its second position to interrupt said connection and short circuit at least a portion of said secondary winding to thereby afford a first amount of flux in said air gap when said armature is in its first position and a second smaller amount of flux in said air gap when said armature is in its second position.
6. An electromagnetic operator comprising a magnetically permeable core affording a closed magnetic circuit and also having pole pieces defining an air gap, magnetic flux source means comprising a primary and a secondary winding on said core for producing opposing magnetic flux flows in said core and thereby flux flow across said air gap, first and second control means for varying the amount of flux in said air gap, said first con trol means being connected to a source of electrical energy and to both of said windings and operable upon actuation thereof to effect energization of both of said windings and initiate flux flow through said air gap at a first rate, an armature movable from a first toward a second position by flux flow through said air gap, said second controlmeans being connected in circuit with both windings, and said rotor being associated with said second control means for actuation thereof to disconnect said secondary winding from said source of electric energy and short circuit at least a portion of said winding, whereby actuation of said first control means initiates motion of said armature from its first toward its second position, and such movement of said armature affords actuation of said second control means to afford a reduction in the flux flow through said air gap.
References Cited in the file of this patent UNITED STATES PATENTS 954,745 Larsen Apr. 12, 1910 2,115,748 Reisner May 3, 1938 2,344,178 Sparrow Mar. 14, 1944 2,687,870 Matthews Aug. 31, 1954 2,756,370 .Meusy July 24, 1956
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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US621703A US2951189A (en) | 1956-11-13 | 1956-11-13 | Control device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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US621703A US2951189A (en) | 1956-11-13 | 1956-11-13 | Control device |
Publications (1)
Publication Number | Publication Date |
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US2951189A true US2951189A (en) | 1960-08-30 |
Family
ID=24491274
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US621703A Expired - Lifetime US2951189A (en) | 1956-11-13 | 1956-11-13 | Control device |
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US (1) | US2951189A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3059094A (en) * | 1960-09-23 | 1962-10-16 | Anna Vang | Pressure transformer |
DE1903014B1 (en) * | 1969-01-22 | 1970-08-20 | Danfoss As | Rotary armature magnet, especially for valve actuation, with damping chambers |
US4609965A (en) * | 1984-11-09 | 1986-09-02 | Pt Components, Inc. | Magnetic clutch |
US4734817A (en) * | 1984-11-09 | 1988-03-29 | Pt Components, Inc. | Magnetic clutch |
US11976742B1 (en) * | 2023-01-12 | 2024-05-07 | Magdrive Technologies, Inc. | Electromagnetically activated pipe valve |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US954745A (en) * | 1907-05-25 | 1910-04-12 | Louis Larsen | Alternating-current electromagnet. |
US2115748A (en) * | 1935-03-09 | 1938-05-03 | W H Reisner Mfg Company | Electromagnetic control apparatus |
US2344178A (en) * | 1941-11-06 | 1944-03-14 | Honeywell Regulator Co | Electromagnetic device |
US2687870A (en) * | 1950-09-14 | 1954-08-31 | Milwaukee Gas Specialty Co | Electromagnetic control device |
US2756370A (en) * | 1952-10-28 | 1956-07-24 | Milwaukee Gas Specialty Co | Electromagnetic control device with manual operator and electroresponsive release |
-
1956
- 1956-11-13 US US621703A patent/US2951189A/en not_active Expired - Lifetime
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US954745A (en) * | 1907-05-25 | 1910-04-12 | Louis Larsen | Alternating-current electromagnet. |
US2115748A (en) * | 1935-03-09 | 1938-05-03 | W H Reisner Mfg Company | Electromagnetic control apparatus |
US2344178A (en) * | 1941-11-06 | 1944-03-14 | Honeywell Regulator Co | Electromagnetic device |
US2687870A (en) * | 1950-09-14 | 1954-08-31 | Milwaukee Gas Specialty Co | Electromagnetic control device |
US2756370A (en) * | 1952-10-28 | 1956-07-24 | Milwaukee Gas Specialty Co | Electromagnetic control device with manual operator and electroresponsive release |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3059094A (en) * | 1960-09-23 | 1962-10-16 | Anna Vang | Pressure transformer |
DE1903014B1 (en) * | 1969-01-22 | 1970-08-20 | Danfoss As | Rotary armature magnet, especially for valve actuation, with damping chambers |
US4609965A (en) * | 1984-11-09 | 1986-09-02 | Pt Components, Inc. | Magnetic clutch |
US4734817A (en) * | 1984-11-09 | 1988-03-29 | Pt Components, Inc. | Magnetic clutch |
US11976742B1 (en) * | 2023-01-12 | 2024-05-07 | Magdrive Technologies, Inc. | Electromagnetically activated pipe valve |
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