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Publication numberUS2704334 A
Publication typeGrant
Publication dateMar 15, 1955
Filing dateNov 18, 1952
Priority dateNov 18, 1952
Publication numberUS 2704334 A, US 2704334A, US-A-2704334, US2704334 A, US2704334A
InventorsBrailsford Harrison D
Original AssigneeBrailsford Harrison D
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Dynamotor
US 2704334 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

March 15, 1955 Filed Nov. 18, 1952 H. D. BRAlLsl-ORD 2,704,334

DYNAMoToR 2 Sheets-Sheet l Fgg; l@ rml@ 56 j@ @mfgw March l5, 1955 H, D, BRAlLsFORD 2,704,334

DYNAMOTOR Filed Nov. 18, 1952 2 Sheets-Sheet 2 ILC'.\ K

A1%.@ Sja @L IAAAA l United States Patent O DYNAMOTOR Harrison D. Brailsford, Rye, N. Y.

Application November 18, 1952, Serial No. 321,131

9 Claims. (Cl. 310-68) The present invention relates to dynamotors and particularly to a device which is small and compact and which is capable of generating alternating current of up to approximately 1500 volts from an input operating at 4.5 volts at 30 milliamperes. In one form of the invenvention, a motor portion of the device is a structure similar to that shown in my Patent No. 2,457,637, issued December 2S, 1948.

in a modified form of the invention the motor rotor, instead of rotating, oscillates and the controlling contacts are arranged to produce this type of operation. The output is, as in the first form mentioned, a high voltage A. C. output.

lt is an object of my invention to provide a dynamotor which is extremely small and compact and which is capable of an output voltage many times that of the input.

It is another object of my invention to provide such a device utilizing the motor structure of my prior patent above-identified.

It is another object ofthe invention to provide a dynamotor having an oscillating rotor member and which generates an alternating current of high voltage.

Other objects and features of the invention will be apparent when the following description is considered in connection with the annexed drawings, in which,

Figure l is a top plan view of the dynamotor of my invention;

Figure 2 is a side elevation of the motor structure of Figure 1;

Figure 3 is a top plan View of the field pieces and rotor with the rotor supports removed. In this figure the motor circuit is shown in diagrammatic form;

Figure 4 is a top plan view of a dynamotor similar to that of Figures 1 through 3, the device being modified to provide an oscillating rather than a rotating rotor; and

Figure 5 is a top plan view of a device of the same type as that shown in Figure 4 but slightly modified in that the rotor is of rectangular shape and extends between the pole pieces.

Referring now to the drawings, there is shown therein a laminated field core having the two pole pieces 11 and 12 and a winding 13 which winding has a common center tap thus providing effectively two field windings designated 14 and 1S. A battery 17 (see Figure 3) is connected to the center tap and the other ends of the coils 14 and 15 are connected by suitable conductors to the flexible contact members and 21. Members 20 and 21 are suitably supported intermediate upper and lower frame members 22 and 23 on aninsulating support 19 as shown in Figures l and 2.

A rotor 26 of disk shape is mounted on a shaft 28 which is journalled at its upper and lower ends in the corresponding frame members 22 and 23.

Shaft 28 is provided with a cam 29 which is located between the free end portions of the contacts 20 and 21. Cooperating with the contacts 20 and 21 are fixed contacts 20a and 21./z respectively, the arrangement being such that the opening and closing of the contact pairs is controlled by the cam 29. The arcuate extent of the cam 29 is approximately 260 with the result that during each complete rotation of the shaft 2S the contact pair 21, 21a is closed for 100 and open for 260, the contact pair 20, 20a is closed for 100 and open for 260, and during two periods of 80 each, both contact pairs are open.

The rotor 26 is formed of highly magnetizable material such as Alnico and is permanently magnetized in a diametrical band to provide magnetic poles at the armature periphery, these poles being marked N and S in Figure 3. The magnetic effect of the poles is strongest at the two indicated pole portions, but the magnetism spreads out with decreasing strength from each polar region toward areas indicated generally, but not precisely, by the boundary lines N and S. Within the boundary lines N and S the armature is not magnetized or at least not appreciably magnetized.

The field poles 11 and 12 are provided with pole faces 11a and 12a respectively which are eccentric with respect to the axis of rotation of rotor 26. Thus the pole faces are spaced from the armature periphery by a gap which decreases in a counterclockwise direction as viewed in Figure 3.

Referring to Figure 3, the magnetic poles of the armature are shown in a position corresponding to the shortest possible magnetic path between diametrical portions 11a and 12a of the pole faces 11 and 12. The cam 29 is in contact with the contact member 21 and out of contact with 20, that is, contacts 20, 20a are closed and 21, 21a open. Upon closing of the circuit through the field winding, as for example by means of switch 32, the coil 15 will be energized. This coil is so wound and the current so poled that the field pole 11 will be north and the field pole 12 will be south. The north field pole 11 will, at its upper portion as viewed in Figure 3, repel the north pole of the armature in a counterclockwise direction. The south field pole 12 at its lower portion will similarly repel the south pole of the armature. Concurrently with the repelling action of each field pole on the armature poles of like polarity, the upper portion of the south field pole 12 will attract the north pole of the armature while the lower' portion of the north field pole 11 will attract the south tieid pole of the armature, these forces acting in a direction to produce counterclockwise rotation of the rotor.

When the cam 29 has moved through an arc of approximately 50 from the position shown in Figure 3, the field circuit for winding 14 is broken by separation of the contacts 20, 20a and the field poles thereupon become nonmagnetic. However, the permanent magnetic poles of the armature, due to the attraction of the same to the faces of the field poles, continue to exert rotative force on the rotor by reason of the decreasing air gap between the permanent magnet poles of the rotor and the faces of the field pole.

The rotor will, of course, tend to come to rest in a position approximately 180 from the position indicated in Figure 3. However, prior to this time and when the rotor has advanced through approximately 130 of arc from the position shown in Figure 3 contacts 21, 21a will have closed thereby effecting energization of coil 15. This results in energization of the field winding and magnetic reenergization of the field poles but with the polarity reversed with respect to that of the prior half-cycle. Field pole 11 will now be a south pole and field pole 12 a north pole and they will cooperate as described above each to repel the rotor pole of like polarity.

After a further rotation of approximately the field poles will again be de-energized by movement of the cam 29 out of contact with both contacts 20 and 21. During the subsequent 80 rotative force is applied by the attractive force existing between the permanent rotor poles and the non-magnetized eld pole faces through the gap that constantly decreases in the direction of rotor rotation. When the rotor arrives at the position shown in 'Figure 3 the cam 29 will again permit closure of contacts 20, 20a and the cycle will repeat.

A winding 50 is wound on the field structure comprising the pole pieces 11 and 12, this field winding being placed on the same core portion 51 on which windings 14 and 15 are placed. As will be` clear the magnetic flux threading the winding 50 will be the same as that which threads the windings 14 and 15.

At the instant that switch 32 is closed and assuming the starting conditions above described in connection with Figure 3, current flows through the right half 14 of the motor field winding 13. The winding 14 is so proportioned that the fiux produced in the core 51 is equal and andasse opposite to the fiux produced in that core by the permanently magnetized rotor, the net flux in the core 51 being zero.

As a result of the repulsion action above described, the motor revolves in a counterclockwise direction. As soon as the rotor has reached a vvertical position with respect to its axis of magnetization, the flux threading the field as a result of the permanent magnetization of the rotor is modified and a portion thereof threads the core in a direction opposite to that of the remainder. As rotation continues all of the flux due to the permanently magnetized rotor threads the core in the direction opposite to that at starting. Since the winding 14 remains energized there will now be a fiux threading the windings 14 and 5t) which is twice that due to the winding 14 or to the permanent magnetization of the rotor 26 alone.

Shortly thereafter the contacts 21, 21a open and the electromagnetic field consequently collapses. There is thus the additive effect of reversal of the fiux threading winding 14 resulting from the permanent magnetization of the rotor and collapse of the electrically induced flux in that same core 51. This results in a sharp peak in the wave form of the alternating flux, the sequence being repeated during following half revolutions by operation of the contacts 20, a and 21, 21a alternately.

The winding 50, being threaded by the alternating flux mentioned, has generated therein a corresponding voltage. This voltage may be utilized as an alternating current voltage or may be rectified to produce a D. C. output by means of the simple circuit shown and comprising half wave rectifiers 52 and S3 together with the condensers 54 and 55. The rectified current appears at terminals 56.

This arrangement generates voltages substantially higher than are possible from rotating mechanisms of comparable size and conventional design. A typical unit of the type described weighs less than six ounces. It operates on an input voltage of 41/2 volts at 30 milliamperes and delivers up to 1500 volts D. C.

Referring now to Figure 4, there is shown therein a device generally sirnilar to that of Figures 1 and 3 and therefore having parts designated by the same reference characters as are applied to those figures. In this arrangement the permanent magnet member 26 is generally rectangular in shape rather than round as in the foregoing figures and is mounted on a shaft 28 which may be in turn mounted in the same manner as in the arrangement first described. A single set of contacts 60, 61 is provided which contacts are normally closed but may be caused to open by means of the member 62 fixed to the shaft 28. In place of the center tapped winding 13 of Figures l through 3 the contacts 60 and 61 are in this instance connected through the battery 17 and switch 32 to a winding 63. A second winding is connected through the rectifier 64 to the output terminals 65, a condenser 66 being shunted across the terminals as clearly shown in Figure 4.

At rest fiux from the permanently magnetized rotor 26 passes through the pole piece 11, through core 51 and through pole piece 12 to the opposite pole of the rotor. When the switch 32 is closed current from the battery 17 passes through the operating winding 63 in a direction causing the upper pole face 11a to become a north pole and lower pole face 12a to become a south pole which is the reverse of the polarity of the upper and lower ends of the rotor 26 respectively. As in the form first described the winding here designated 63 is so proportioned that the flux produced in the core 51 is equal and opposite to the fiux produced in that core by the permanently magnetized rotor 26 and consequently the net fiux in the core is zero.

However, as a result of the like poles being adjacent Vthe rotor tends to move in a counterclockwise direction.

When the rotor 26 has turned far enough for its flux to add to the electromagnet field, that is, when the rotor has turned far enough so that the fiux path is through the upper portion of pole face 12a and lower portion of pole face 12a, the contact member 62 raises the Contact spring 60 thus causing contacts and 61 to open interrupting the current to the winding 62 and causing a collapse of the electromagnetic field. The rotor then returns to its original position due to the attraction of its field on the pole faces 11a and 12a. This collapse of the electromagnetic .field together with the mechanical reversal of the magnetic field set up by the rotor causes an inductive peak which generates a high voltage in the generating winding 50. This high Vvoltage current may be rectified by the half-wave rectifier 64 cooperating with the condenser 66 in a well-known manner or the full wave rectifying circuit shown in Figure 3 may be utilized.

In Figure 5 there is shown a slight modification of the Figure 4 arrangement wherein the shape of the rotor and the pole pieces is changed since in the Figure 4 form the rotor simply oscillates and therefore it is unnecessary to have it mounted for continuous rotation. Therefore in the Figure 5 form the rotor ends extend between the pole faces 11a, 12a. In this form of the invention, of course, the same contact operator 62 is employed as was employed in the Figure 4 form and the adjustment is such that the contacts 66 and 61 open before the ends of rotor 26 can come into contact with the pole faces 11a and 12a. In fact, the contacts 60 and 61 open just prior to the time when the rotor 26 would arrive at the vertical position as shown in Figure 5 which assures the return of the rotor to the position indicated. Were the rotor to pass beyond a position slightly inclined clockwise from the vertical, it might then move against the pole faces 12a and 11a and render the device thereafter operative.

Considerable modification of the above devices may be made. For example, the shape of the field may be altered for convenience in manufacture, the contact design may be changed, etc. In addition, it is entirely possible to eliminate the second winding 50 and take alternating current directly from the outer terminals of the center tapped coil 13, although it is generally preferable to separate the high and low voltage circuits in the manner shown in the drawing.

While I have described preferred embodiments of my invention, it will be understood that many modifications may be made within the scope thereof. Consequently, l wish to be limited not by the foregoing description, but solely by the claims granted to me.

What is claimed is:

l. A dynamotor Acomprising in combination a pair of field poles having a core portion integral therewith, a winding on said core for electromagnetically energizing said field poles, a rotor member positioned between the field poles and within the electromagnetic field, said rotor being of magnetizable material and being magnetized to form permanent north and south poles at diametrically opposite points of its periphery, contact means operable by the rotor for supplying energizing current to the field winding, said energizing current and winding being proportioned so that the magnetic flux in said core portion caused by current flow in said winding is equal to the fiux in said core portion resulting from said permanently magnetized rotor, said contact means being positioned relative to said rotor so that said-electromagnetic field and permanently magnetic field together and said permanent magnet field alone are alternately effective to produce movement of said rotor, the fiux in the said core varying with each rotor movement from a minimum to a maximum value, and means for applying a current derived from said build up and decay of fiux to an external circuit.

2. A dynamotor comprising, in combination, a pair of field poles having a core portion integral therewith, a winding on said core for electromagnetically energizing said field poles, a rotor member positioned between the field poles and within the electromagnetic field, said rotor being of magnetizable material and being magnetized to form permanent north and south poles at diametrically opposite points of its periphery, Contact means operable by the rotor for supplying energizing current to the field Winding, said energizing current and winding being proportioned so that the magnetic flux in said core portion caused by current fiow in said winding is equal to the flux in said core portion resulting from said permamently magnetized rotor, said contact means being positioned relative to said rotor so that said electromagnetic field and permanently magnetic field together and said permanently magnetic field alone are alternately effective to produce movement of said rotor, the linx in the said core varying with each rotor movement from a minimum to a maximum value, and a second winding on said core the built up and decay of flux in said core generating an electrical current in said winding.

3. A dynamotor comprising an electromagnetic field Ahaving a core, a pairof field poles and a pair of windings alternately energizable for effecting reversal of polarity of said field poles, at rotor positioned between said field poles and within the magnetic field thereof, said rotor being of disk form and being permanently magnetized along a diameter thereof to provide permanent north and south poles, said iield poles having arcuate pole faces positioned adjacent the periphery of the rotor and spaced therefrom to provide air gaps which decrease in width in the direction of rotation of the rotor, means operable by the rotor for supplying energizing current to the winding in opposite directions for effecting reversal of polarity of said field poles during portions of each cycle of rotation of the rotor for producing both attractive and repelling forces which act on said rotor during each energization of the winding to produce rotation of the rotor, the current through said Winding and the winding itself being so proportioned that the magnetic ux in said core portion caused by said electric current is equal to the flux in said core portion resulting from said permanently magnetized rotor whereby as the rotor rotates the flux in said core portion varies from substantially zero to a maximum value, and means for applying a current derived from said flux variation in said core to an external circuit.

4. A dynamotor comprising an electromagnetic field having a core portion, a pair of ield poles and a pair of windings alternately energizable for effecting reversal of polarity of said eld poles, a rotor positioned between said field poles and within the magnetic field thereof, said rotor being of disk form and being permanently magnetized along a diameter thereof to provide permanent north and south poles, said field poles having arcuate pole faces positioned adjacent the periphery of the rotor and spaced therefrom to provide air gaps which decrease in width in the direction of rotation of the rotor, means operable by the rotor for supplying energizing current to the winding in opposite directions for effecting reversal of polarity of said field poles during portions of each cycle of rotation of the rotor for produring both attractive and repelling forces which act on said rotor during each energization of the winding tol produce rotation of the rotor, the current through said winding and the winding itself being so proportioned that the magnetic iux in said core portion caused by said electric current is equal to the ilux in said core portion resulting from said permanently magnetized rotor whereby as the rotor rotates the flux in said core portion varies from substantially zero to a maximum value, and a second winding on said core the build up and decay of flux in said core generating an electrical current in said winding.

5. A dynamotor comprising a core portion having a pair of eld poles integral therewith, a winding on said core for electromagnetically energizing said field poles, a rotor member positioned between the eld poles and within the electromagnetic field, said rotor member being permanently magnetized to form permanent north and south poles adjacent the ends thereof, contact means operated by the rotor for alternately making and breaking a supply circuit to said field winding, said rotor being urged in one direction when said eld winding is energized, and being returned to a normal position on de-energization of said eld winding, said eld winding being so proportioned with respect to the current supplied thereto that the flux resulting in said core from electrical energization of said winding is substantially equal to the flux flowing in said core due to said permanent magnetization of said rotor, the flux in said core varying with each oscillatory cycle of said rotor from a minimum to a maximum value, and means for applying a current derived from said varying iiux to an external circuit.

6. A dynamotor comprising a core portion having a pair of eld poles integral therewith, a winding on said core for electromagnetically energizing said eld poles, a rotor member positioned between the field poles and within the electromagnetic eld, said rotor member being permanently magnetized to form permanent north and south poles adjacent the ends thereof, contact means operated by the rotor for alternately making and breaking a supply circuit to said field winding, said rotor being urged in one direction when said iield winding is energized, and being returned to a normal position on deenergization of said field winding, said eld winding being so proportioned with respect to the current supplied thereto that the iiux resulting in said core from electrical energization of said winding is substantially equal to the ilux flowing in said core due to said permanent magnetization of said rotor, the flux in said core varying with each oscillatory cycle of said rotor from a minimum to a maximum value, and a second winding on said core the build up and decay of flux generating an electrical current in said winding.

7. A dynamotor comprising, in combination, an electromagnetic iield having a pair of field poles and a winding alternately energizable and de-energizable for polarizing said iield poles, a rotor positioned between said field poles and Within the magnetic iield thereof, said rotor being of disk form and being permanently magnetized along a diameter thereof to provide permanent north and south poles, said iield poles having arcuate pole faces positioned adjacent the periphery of the rotor and spaced therefrom to provide air gaps which decrease in width in the direction in which the rotor moves when said iield poles are energized, means operable by the rotor for supplying energizing current to the winding for producing repelling forces which act on said rotor to produce movement in said one direction, said permanent magnetization of said rotor producing a restoring force to move the rotor in the opposite direction, the magnetic iiux in the core portion of the electromagnetic field varying as said ield winding is energized and de-energized whereby as the rotor oscillates the ux in said core portion varies from a minimum to a maximum value, and means for applying the current derived from said flux Variation in said core to an external circuit.

8. A dynamotor comprising, in combination, an electromagnetic field having a pair of field poles and a winding alternately energizable and de-energizable foi' polarizing said iield poles, a rotor positioned between said field poles and within the magnetic eld thereof, said rotor being of disk form and being permanently magnetized along a diameter thereof to provide permanent north and south poles, said eld poles having arcuate pole faces positioned adjacent the periphery of the rotor and spaced therefrom to provide air gaps which decrease in width in the direction in which the rotor moves when said eld poles are energized, means operable by the rotor for supplying energizing current to the winding for producing repelling forces which act on said rotor to produce movement in said one direction, said permanent magnetization of said rotor producing a restoring force to move the rotor in the opposite direction, the magnetic ux in the core portion of the electromagnetic eld varying as said field winding is energized and de-energized whereby as the rotor oscillates the ux in said core portion varies from a minimum to a maximum value, and a second winding on said core portion the build up and decay of ux in said core portion generating an electrical current at high voltage in said winding.

9. A dynamotor comprising an electromagnetic field having a core portion, a winding thereon and a pair of eld poles, said field poles being alternately energizable f or effecting reversal of polarity thereon, a rotor positioned between said field poles and within the magnetic field thereof, said rotor comprising a permanently magnetized bar mounted for oscillatory movement, means operable by the rotor for making and breaking a circuit to said field winding for producing attractive and repelling forces ac ting on said rotor during each energization of the winding to produce movement away from a normal rest position, said permanently magnetized rotor providing a restoring force for restoring the rotor to the normal rest position upon the de-energization of said eld windin g, .said flux resulting from energization of said field winding aswell as from permanent magnetization of said rotor passing through said core whereby as the rotor oscillates the flux in said core varies from a minimum to a maximum value, and means for applying a current derived from said flux variation in said core to an external circuit, said current being at a voltage many times that of the direct current input to said energizing winding.

References Cited in the le of this patent UNITED STATES PATENTS 2,278,061 Dalkowitz Mai'. 31, 1942 2,457,637 Brailsford Dec. 28, 1948

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2278061 *Apr 25, 1938Mar 31, 1942American Safety Razor CorpIlluminating dry shaver
US2457637 *Aug 17, 1945Dec 28, 1948Brailsford Harrison DElectrical motor
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2932733 *Nov 18, 1957Apr 12, 1960Barber Colman CoTransmitter for a remote control system
US3028532 *Jun 21, 1957Apr 3, 1962Movado MontresArrangement for electro-magnetically sustaining the movement of a spiral balance spring
US3264538 *Dec 6, 1961Aug 2, 1966Harrison D BrailsfordBrushless transistor commutated motor
US3969642 *Jul 17, 1974Jul 13, 1976Kabushiki Kaisha Suwa SeikoshaStep motor for electronic timepiece
US4214181 *Aug 8, 1977Jul 22, 1980Jeco Co., Ltd.Self-starting miniature synchronous motors
US4600864 *Jan 23, 1985Jul 15, 1986Sanyo Electric Co., Ltd.Easily restarted brushless DC motor
US4968921 *Oct 23, 1989Nov 6, 1990G & E Engineering LimitedElectromagnetic motor with secondary stator coils
US6479959 *Dec 7, 2000Nov 12, 2002Samsung Kwangju Electronics Co., Ltd.Self-excited reluctance motor
DE2314259A1 *Mar 22, 1973Sep 26, 1974Papst Motoren KgKollektorloser gleichstrommotor
DE3044056A1 *Nov 22, 1980Jun 19, 1981Papst Motoren KgZweipulsiger kollektorloser gleichstrommotor
Classifications
U.S. Classification310/68.00D, 310/68.00R, 310/39, 310/46, 318/400.26, 310/40.0MM
International ClassificationH02M7/58, H02M7/42
Cooperative ClassificationH02M7/58
European ClassificationH02M7/58