WO1981001633A1

WO1981001633A1 - Motor system

Info

Publication number: WO1981001633A1
Application number: PCT/US1980/001614
Authority: WO
Inventors: K Bohacz
Original assignee: K Bohacz
Priority date: 1979-12-05
Filing date: 1980-12-03
Publication date: 1981-06-11
Also published as: EP0041988A1; JPS56501747A

Abstract

A motor system provides from a primary power source mechanical energy to an output shaft. The system has a plurality of electromagnetic devices (67A, 69A) mounted around a rotor for magnetically rotating it. A magnetic clutch (70, 72, 82, 89), is included which has a control signal input. The clutch is operable to couple the rotor to the output shaft by an amount determined by the magnitude of the control signal applied to the control signal input. The motor system has a control subsystem which is responsive to at least one operating parameter of the motor system. The control subsystem can apply the control signal to the control signal input. This control signal bears a predetermined relation to the operating parameter. Also included is a commutator (154) for applying the primary power source to successive ones of the plurality of electromagnetic device. The sequence and timing of such application is controlled by the control means.

Description

The present application is a continuation-in-part of copending U.S. Patent Application No. 06/096/826, filed December 5, 1979.

BACKGROUND^'OF THE INVENTION

The present invention relates to motor systems and, in particular, to systems having a rotor that is cou¬ pled to an output shaft by a magnetic clutch.

A great effort has been devoted to developing an electrical to mechanical motor system which is suffici¬ ently efficient to propel a vehicle over a range large enough to make it useful as a personal commuting vehicle. A current problem with existing electric motor vehicles is that their range and acceleration is limited since they employ a con¬ ventional electric motor.

It is known to provide a motive force from an elec- trie motor which operates through an eddy current magnetic clutch. However, such systems fail to precisely control the field around its rotor in such a manner that energy can be rapidly and efficiently^' obtained. In addition, these systems fail to continually operate the rotor at an appropriately high speed which allows the engine to provide high acceler¬ ation upon demmand. In addition, these known motor systems do not employ a rotor which can store significant energy from a relatively low power primary source.

SUMMARY OF THE INVENTION

In accordance with the illustrative embodiments demonstrating features and advantages of the present inven¬ tion, there is provided a motor system. This motor system applies from a primary power source mechanical energy to an output shaft. The motor system has a plurality of electro¬ magnetic devices mounted around a rotor for magnetically rotating it. The system also includes a magnetic clutch means having a control signal input. The magnetic clutch means is operable to couple the rotor to the output shaft

E SHEET by an amount determined by the magnitude of the control sig¬ nal applied to the control signal input. The system also has a control means which is responsive to at least one oper ating parameter of the motor system. Tlje control means applies the control signal to the control signal input. This control signal bears a predetermined relation to the above mentioned operating parameter. The system also has a commu- tation means for applying the primary power source to succes- sive ones of the plurality of electromagnetic devices. The control means establishes the sequence and timing of the commutation means.

In a preferred embodiment of the present invention a variable capacitance means is coupled to the plurality of electromagnetic devices. The variable capacitance means nulls the inductive effect of the stator field coils. In the preferred embodiment the capacitance is varied with speed by a microprocessor so that the inductive timing effects are effectively cancelled. Accordingly, the system operates with very high efficiency.

It is preferred that the rotor be relatively massiv have a high moment of inertia and be able to store a signif¬ icant amount of kinetic energy. It is anticipated that for some embodiments the rotor may be rated to operate at 20,000 revolutions per minute. By storing a large amount of kinetic energy the rotor itself is a source of energy that can pro¬ vide high acceleration upon demand. Furthermore, this high acceleration is available although the primary power source, such as a battery, can only supply relatively modest amounts of power. Accordingly, the rotor acts as a storage or inte¬ grating device which can be quickly released when high accel¬ eration is needed.

The system employs a clutch means which, preferably has a driven and driving member, each having an opposing plur ality of electromagnets. These electromagnets can be adjust¬ ably energized to act as a continuously variable transmission

In the preferred embodiment the rotor has on oppo¬ site sides a pair of rotor coils which cooperate with a plur- ality of stator coils. These electromagnetic devices have

' ^{O P} magnetic cores that are carefully machined and positioned so that a very small air gap remains, thereby producing rel- atively high torque. It is anticipated that the electromag¬ netic devices can be operated in either_%an attractive mode, a repulsion mode or an attractive/repulsion mode. The micro¬ processor, however, provides the timing and sequencing of the stator coils to ensure high'torque and efficient energy conversion.

In one embodiment the microprocessor receives data from various sensors. For example, an optical sensor can transmit incremental changes in the angular displacement of the rotor for controlling the commutation of the stator wind- ings. Also, an optical sensor may be placed on the output shaft of the magnetic clutch to determine its output speed. Furthermore, in some embodiments the microprocessor responds to environmental data such as air speed, ambient temperature and. internal operating parameters of the engine such as its vacuum etc. The processor can respond to the various operat¬ ing parameters to establish a proper setting of variable nulling capacitors that are coupled to the plurality of stator windings.

In the preferred embodiment, the battery system of the motor is replenished by independent energy sources such as a solar panel and generators which are driven by the drive train when the driver wishes to decelerate the vehicle.

Overall, the system can operate from a relatively low source of power such as a battery. This source is em- ployed to progressively accelerate the rotor to a relatively high speed. Once the rotor reaches its rated speed, it oper¬ ates efficiently and is able to provide high torque and accelerations upon demand through its magnetic clutch.

By employing equipment of the foregoing type, it is possible to provide a motor system for a vehicle that is capable of driving it well in excess of the ranges previously attainable. Moreover, the primary power source is electrical, a relatively plentiful energy source. BRIEF DESCRIPTION OF THE DRAWINGS

The above brief description as well as other objec features and advantages of the present invention will be more fully appreciated by reference to the following detailed de¬ scription of a presently preferred but nonetheless illustra¬ tive embodiment in accordance with the present invention when taken in conjunction with the accompanying drawings wherein: Fig. 1 is a sectional view along the axis of the motor and clutch mechanisms that are part of the present in¬ vention;

Fig. 2 is a reduced scale, non-section view of the apparatus of Fig. 1;

Fig. 3 is a reduced scale, sectional view along lines 3-3 of Fig. 1;

Fig. 4 is a reduced scale sectional view along lines 4-4 of Fig. 1; and Fig. 5 is a schematic illustration of the motor system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figs. 1 and 2, a rotor is shown here¬ in as hub 10 coaxially mounted on rotor shaft 12. Annular reinforcements 14 are employed between hub 10 and shaft 12. Hub 10 supports an annular band 16 on which is mounted a plurality of peripheral magnetic poles, shown herein as a pair of opposing cup shaped liners 18 and 20 which contain radially directed magnetic poles 22 and 24, respectively. Poles 22 and 24 are concentrically mounted within insulating liners 18 and 20 and are encircled by a plurality of windings 26 and 28, respectively. These windings can magnetize poles 22 and 24 and their concentric cylindrical forms 30 and 32. Windings 26 and 28 each comprise 10,000 turns of wire, 0.813 millimeters in diameter. Forms 30 and 32 are reinforced and held in their position in opposing circular apertures in cir¬ cular metallic band 34. A partially evacuated casing include upper plate 36 which is -% inch thick, 12% manganese Plate 36 supports a pair of conical roller bearings: outside bearing 38 and inside bearing 40, both being.-.located at the

5 upper end of shaft 12. Another pair of conical roller bear¬ ings are located on the opposite end of shaft 12 and is shown herein as inside bearing 42 and outside bearing 44. The above^' bearings are conventional and include an inside and an outside race having rollers contained therebetween. Bearings 38 and

10 40 are ^'located adjacent flange 46 of shaft 12 and are retained in place by it and bearing cup 48 which is held in place by bolt 50. Cup 48 also has on its outer surface electrical con¬ tacts which cooperate with carbon brushes 52. Brushes 52 conduct currents through wires (not shown) embedded in shaft

15 12, hub 10 and windings 26 and 28. Also, casing plate 36 has a concentric annular flange 54 which retains bearings 38 and 40 and also acts as a grease seal. Brushes 52 are mounted on suitable stanchions 56 on casing plate 36.

The casing has a peripheral frame portion 58 which

20 is essentially a cast aluminum channel, 1.5 inches thick, which is formed into an annulus and is mounted between plate 36 and lower circular plate 60. Lower plate 60, formed of 3/4 inch, 12% manganese steel, has an annular flange 62 which acts as a seal and retaining member for bearings 42 and 44.

25 in addition, shaft 12 has grease sealing flange 64 which retains bearing 42 while hat-shaped plate 66 holds and seals bearing 44. Plate 66 is held to shaft 12 by. olt 68. The rotor components of shaft 12 have a mass of approximately 360 kilograms and an overall diameter of about 18 inches.

30 A plurality of electromagnetic devices is shown herein as the equipment retained in cylindrical insulating liners 65A and 65D. These liners are formed of nylon, inch thick. In this embodiment there is contained in liner 65A a cylindrical metallic form 67A including pole 69Awhich 5 is concentrically mounted in and surrounded by a plurality of windings 71A. These windings are constructed the same as the rotor windings 26 and 28. It is to be appreciated that the contents of liner 65D is similar but is not in a position to be sectioned in this view. 0 Mounted below on plate 66 is a driving member of a agnetic clutch means, shown herein, as an electromagnetically attracting device having poles 70 and 72. Poles 70 and 72 are concentrically mounted in cylindrical retaining members 74 and 76, respectively. Poles 70 and 7£ are encircled by a plurality of windings 78 and 80, respectively. A driven member of the magnetic clutch means is shown herein as an electromagnetically attracting device including poles 82 and 84. Poles 82 and 84 are concentrically mounted in cylindri¬ cal retaining members, 86 and 88, respectively, which are mounted on a hub 90. ^' As illustrated subsequently, there are other poles in addition to those just discussed.

Hub 90 is supported on its inner end by ball bear- ing 92 which includes inner and outer races containing spher¬ ical rollers. Ball bearing 92 is retained within a cylindri¬ cal bore on the inner end of hub 90. Bearing 92 encircles a capstand 94 which is suitably attached to hub 66. The outer end of hub 90 is supported on a pair of conical roller bearings: inside bearings 96 and outside bearings 98. Bear¬ ings 96 are contained between hub 90 and flange 100 on outer plate 102. Plate 102, 3/4 inch thick, 12% manganese steel, is suitably mounted to annular side shell 104 (1.5 inches thick, cast aluminum) which is in turn suitably attached to plate 60. Bearing 98 is retained in place by bearing cup 106 which is bolted to hub 90 by bolt 108. An output shaft 110 is attached to cup 106. Carbon brushes 112 cooperate with contacts on cup 106 to supply electrical energy to wind¬ ings 114 and 116, which encircle poles 82 and 84, respectivel indings 78 and 80 are energized through brushes 52.

Referring to Fig. 3, the driven portion of the mag¬ netic clutch of Fig. 1 is shown (line 3-3- of that Figure.) Previously illustrated poles 82 and 84 and their respective retaining members 86 and 88 are shown with an annular inter- space between them illustrated as winding space 114 and 116. In addition, two other poles 120 and 122 are shown together with their retaining members 124 and 126, respectively. Their interspace also contain windings in interspaces 128 and 130. As shown herein the foregoing elements are mounted on hub 90 which has a central shaft portion 132. It will be appreciated that the sectional view of the driven member that cooperates with the apparatus of Fig. 3 is substantially identical.

Referring to Fig. 4, a sectional view along lines 4-4 of Fig. 1 is given. As shown herein annular frame 58 has mounted at equiangular positions seven electromagnetic devices such as the combination comprising pole 69A, its retaining member 67A and its windings 71A. Corresponding electromagnetic elements in frame 58 having identical structure but different position are labeled with the same numeric prefix but differ¬ ent alphabetic suffix. Also shown are insulating layers 140 and 142 which provide electrical and electromagnetic isola- tion of their associated electromagnets.

It will be observed that while magnetic poles 22 and 69A are in alignment, the opposite rotor pole 24 is not aligned with a matching pole. Accordingly, the rotor shaft 12 can always be electromagnetically rotated. For example, clockwise rotation may be obtained by energizing pole 69D to repel and pole.69E to attract pole 24.

It is to be understood that the magnetic circuitry of the foregoing Figures are dimensioned and formed of mater¬ ials to provide the following approximate performance figures: 5500 kilograms of force for a power input of 25 watts rms.

The foregoing assumes the following dimensions: the cross-sec¬ tional area of poles 22 and 24 is 270 cm²; the cross-sectional

2 areas of poles 69A-69G is 309 cm ,- and a working air gap of .

1.59 mm. The average magnetic circuit length is 88 cm. Referring to Fig. 5, a control means is shown here¬ in as microprocessor 150 and its associated memory 152. Microprocessor 150 is shown connected to the serial combina¬ tion of a commutator means 154 and the variable capacitor means 156. Transistor commutator 154 comprises a plurality of semiconductor power or other switches which are triggered by signals from processor 150. In this manner the processor controls the timing and sequence of energization of pairs of lines. The power commutated by commutator 154 is delivered from a battery means 158. The pairs of lines from commutator 154 pass through a variable capacitor bank 156 and connect

- OMPI to stator windings 71A-71G. The variable capacitor bank 156 employs an appropriate device such as a varactor or a conven- tional,mechanically variable capacitor adjusted by servo moto or other device.

Rotor 10 is illustrated in a simplified schematic form with a winding around it and mechanical linkage to angular position sensing means 160. In this embodiment senso 160 is an optical device which senses incremental changes in rotor position. Rotor 10 is also mechanically connected to magnetic clutch 162. Clutch 162 has output shaft .110 that drives output sensor 164 and solenoid-adjustable transmission 166. As illustrated herein the outputs of sensors 160 and 164 are transmitted to a system of digital to analog and analog to digital converters 168. These converters transmit and receive digital data from microprocessor 150. Also a parameter sensing means, shown herein as a block 170,' sends t converters 168 data corresponding to environmental and other conditions such as ambient temperatures, air speed, vacuum within the rotor housing, ground speed, curb weight, engine temperature, etc. Block 170 also contains the conventional accelerator pedal for the operator. Another parameter sensin means is shown herein as magnetic sensor 172 which transmits a signal to converters 168 signifying the strength of the fields being generated in the rotor housing by the various electromagnetic devices. As illustrated herein converters 168 supply control signals to regulate the performance of transmission 166, magnetic clutch 162 and power controller 174. Controller 174 is connected between ^*•" battery system

158 and the windings of rotor 10.

Battery system 158 contains 20 to 25 standard, heav duty, sealed automotive gel cells (not shown) , Battery syste

158 receives supplemental power from several additional source For example, solar panel 176 comprising a plurality of solar cells delivers powerto system 158. Similarly, a drive train generator 178 is mechanically connected to the output shaft of transmission 166 to derive power therefrom when the vehicl ought to be decelerating. Alternatively, generators may be mounted adjacent to each wheel of the vehicle. In addition,

/ ' . OM the battery system 158 receives supplemental power from an air turbine 180 which is mounted at the front of the vehicle to drive a generator to supply power to battery system 158. Also battery system 158 supplies power to an electrically operated vacuum pump 182 which maintains a partial vacuum within the rotor housing.

It will also be noted that microprocessor 150 has sufficient capacity to run certain auxiliary systems which are shown herein as auxiliary control subsystem 182. These auxiliary systems can be the vehicle climate control, power steering, power brakes, etc.

To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly discussed. Initially, the batteries of system 158 are charged by means of external charging terminals 184. Near the end of the charging cycle rotor 10 (Fig. 5) may be brought up to an operating speed of about 20,000 rpm. Since rotor 10 has a mass of 360 kg and an overall diameter of

18 inches, it can store at this operating speed a significant amount of kinetic energy. As previously mentioned the rotor/ stator reaction can provide 5500 kilograms of tangential force about rotor shaft 12 (Fig. 1) for a power input of 25 watts rms.

The sequence and timing of energization of the stator winding 71A-71G (Fig. 5) is controlled by microproc¬ essor 150 as previously mentioned. The angular position of rotor 10 is determined by sensor 160 which transmits this

^**_. information through converters 168 to microprocessor 150.

In response processor 150 commutates stator windings 71A---71G send¬ ingrotor 10 to its rated speed. While it is preferable during the initial charging interval before rotor 10 reaches full speed to operate windings 71A-71G in the aforementioned attrac- tive/repulsion mode, thereafter it is preferable to operate in only the attractive or only the repulsion mode for energy conservation purposes . When the accelerator pedal of sub¬ system 170 is depressed, that datum together with data indic¬ ating ambient temperature, road grade, vehicle curb weight, drive train gear ratio, relative air velocity,

» etc. are transmitted to microprocessor 150. Microprocessor 150 then applies the data to an appropriate formula or table to derive the proper amount of current to magnetic clutch 16 Accordingly, magnetic clutch 162 is actuated in response to control signal through converters 168. In the preferred em¬ bodiment the magnetic clutch is able to provide approximatel 22, 000 kilograms of tangential force at its pole faces for a power input of 100 watts. This magnetic reaction causes output shaft 110 to rotate which is sensed by sensor 164. A this time transmission 166 is in a low gear and provides hig acceleration and torque to the drive train thereby acceler¬ ating the vehicle. When the vehicle reaches a velocity consistent wit the accelerator pedal, microprocessor 150 reduces the curren to magnetic clutch 162 to a level sufficient to overcome frictional forces, inclination forces, and other losses. By this time the velocity of rotor 10 will have decreased below itr rated speed because of the work it performed. However, commutator 154 continues to supply power from battery system 158 to restore and eventually accelerate rotor 10 to full speed. Throughout this operation variable capacitor bank 156 is adjusted to minimize inductor timing effects and pro- vide an optimum power transfer to stator coil 71A-71G. This adjustment is based upon rotor speed and load, preferably. When the operator releases the accelerator pedal and/or depresses the brake, microprocessor 150 transmits an appropriate signal to battery system 158 so that drive train generator 178 transfers power to the batteries of system 158 This feature reduces brake wear and recaptures the kinetic energy of the vehicle by converting and storing it.

When the vehicle is parked and will remain parked for a considerable length of time, the operator may instruct processor 150 to recapture the kinetic energy in rotor 10. Under these circumstances processor 150 transmits an approp¬ riate signal to commutator 154 and controller 174 which reconnects the rotor and stator windings so they operate as a conventional pulse generator. This allows rotor energy to be returned to the batteries of system 158. Consequently, rotor 10 decelerates to a standstill, thereby reducing engine wear. Once the rotor speed is considerably reduced vacuum pump 182 is turned off. However, solar panel 176 continues to operate and replenish the batteries f system 158.

It is to be appreciated that various modifications may be implemented with respect to the above described pre¬ ferred embodiment. For example, the shapes and dimensions of the electrical motor and the magnetic clutch may be al¬ tered in some embodiments. In addition, the number of rotor and stator. magnetic poles may be increased or reduced. How¬ ever, it is preferableto have an odd number of stator poles if the number of rotor poles is even (or vice versa) . Further- more, various materials may be substituted depending upon the desired strength, weight, moment of inertia etc. In addition, the sequence and execution of various programming steps associated with microprocessor 150 may be altered depending upon the specific application. Also, it is to be understood that many of the non-essential accessories that are shown herein may be deleted in some embodiments. Obviously many other modifications and variations of the present invention are possible in light of the above teachings. It is there¬ fore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

^' *

Claims

WHAT IS CLAIMED IS:

1. A motor system for providing mechanical energy to an out put shaft from a primary power source, comprising: a rotor; a plurality of electromagnetic devices mounted around said rotor for magnetically rotating it; magnetic clutch means having a control signal input for coupling said rotor to said output shaft by an amount determined by the magnitude of the control signal applied to said control signal input; control means responsive to at least one operating parameter of said motor system for applying the control sign to said control signal input, said control signal bearing a predetermined relation to said operating parameter; and commutation means for applying* said primary power source to successive ones of said plurality of electromagnet devices with a sequence and timing controlled by said contro means.

2. A motor system according to claim 1 wherein said commuta¬ tion means comprises: variable capacitance means coupled to said electro¬ magnetic devices for reducing its inductive effect, said capa itance means being varied by said control means.

3. A motor system according to claim 1 wherein said system is mountable as a motive force on a vehicle weighing 2000 kilograms, said rotor having sufficient momentum at its rated speed to thereafter accelerate said vehicle to a vel¬ ocity in excess of 40 kilometers per hour.

4. A motor system according to claim 1 wherein said magnetic clutch means comprises: a driving and driven member, each having at least one electromagnetically attracting device.

5. A motor system according to claim 1 wherein said rotor

' includes : a peripheral magnetic pole.

6. A motor system according to claim ξ> wherein said rotor includes: a plurality of windings around said pole.

7: A motor ^'system according to claim 4 wherein said rotor indludes:

• a plurality of peripheral, magnetic poles, each encircled by a plurality of windings.

8. A motor system according to claim 7 wherein said plurality of poles contains an even number and wherein said plurality of electromagnetic devices contains an odd number.

9. A motor system according to claim 7 wherein said plur- ality of poles contains an odd number and wherein said plurality of electromagnetic devices contains an even number.

10. A motor system according to claim 5 wherein each of said plurality of electromagnetic devices is polarized prior to arrival of said pole in a direction to attract it.

11. A motor system according to claim5 or 10 wherein each of said plurality of electromagnetic devices is polarized subsequent to passage of said pole in a direction to repel it.

12. A motor system according to claim 1 comprising: an angular position sensing means coupled to said rotor for transmitting to said control means a signal signifying the position of said rotor.

13!. A motor system according to claim 12 further comprising: an output sensor responsive to the rotation of said output shaft and coupled to said control means.

14. A motor system according to claim 1 wherein said control means includes:

5 parameter sensing means responsive to a predeter¬ mined operating, parameter of said motor_* system for providing a parameter signal to said control means.

15. A motor system according to claim 14 wherein said

10 parameter sensing means is responsive to the ground speed of said motor system.

16. A motor system according to claim 15 wherein said parameter sensing means is responsive to ambient temperature

15

17. A motor system according to claim 14 wherein said parameter sensing means is responsive to the flux density at said plurality of electromagnetic devices.

20 18. A motor system according to claim 2 wherein said capacitance means is variable in. response to the rotational speed of said rotor.. ^•

19. A motor system according to claim 1 wherein said

25 plurality of electromagnetic devices each have a radially aligned stator pole.

20. A motor system according to claim 1 wherein said output shaft drives solenoid-shiftable transmission means. 0 -

21. A motor system according to claim 1 wherein said contro means operates to raise the angular velocity of said rotor i excess of a predetermined speed.

5 22. A motor system according to claim 21 comprising a partially evacuated casing for housing said rotor.

23. A mώtor system according to claim 5 wherein said periph eral pole and said commutation means are operable to generat 0 electricity, energy for generation of said electricity being de- rived from the kinetic energy of said rotor.

24. A motor system according to claim 23 wherein said primary power source includes: a battery means for supplying primary power to said plurality of electromagnetic devices.

25. A motor system^' according to claim 24 wherein said battery means is recharged by generation of said electricity by said peripheral pole and said commutation means.

26. A motor system according to claim 25 further comprising: a generator coupled to said output shaft for decel¬ erating it and recharging said battery means.

27. A motor system according to claim 26 further comprising: a solar cell for supplying energy to said battery system.

28. A motor system according to claim 1 wherein said rotor and said output shaft are coaxial.

29. A motor system according to claim 28 wherein said clutch means includes: a driving and driven member which are both coaxial with said rotor.

SUBSTITUTE -SHgE^j OMPI