EP0060298A4

EP0060298A4 - Multiple windings electrical motors controllers.

Info

Publication number: EP0060298A4
Application number: EP19810902699
Authority: EP
Inventors: John Thomas Richard Wilson
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-09-17
Filing date: 1981-09-17
Publication date: 1983-01-14
Also published as: WO1982001104A1; EP0060298A1; JPS57501559A; GB2094575A; AU558930B2; DE3152355C2; JPH0348751B2; DE3152355T1; GB2094575B; AU7642981A

Description

MULTIPLE WINDINGS ELECTRICAL MOTORS CONTROLLERS SUMMARY OF THE INVENTION

This invention is a controller for a multiple windings electrical motor such as is described in co-pending Inter national Application Number PCT/US80/00226 filed 03 March 1980 titled Multiple Windings Electrical Machines; this co pending application is incorporated herein by this reference. The present application provides for torque control of a multiple windings electrical motor by operating var ious numbers of electrical switches which energize various numbers of torque generating windings sets within the motor and by positioning a brushholder. The means of energizing and de-energizing these windings sets are individual electrical switches, which can be sequentially operated to preserve the advantages of a multiple windings electrical machine at all torque levels. The multiple windings electrical machine is uniquely controllable; the multiple windings electrical machine has multiple brushes in two groups contacting the commutator which provide multiple electrical control points. Each of these brushes can be energized, either directly or in series with a stator winding or portion thereof, through an electrical switch v/ith electrical energy derived from an electrical energy source. Thus, by operating these electrical switches the magnitude of torque generated by the multiple windings electrical motor can be controlled. Another aspect of the multiple windings electrical motor torque control is use of the position of the brushholder to control the positions of the groups of multiple brushes and thereby control the direction and magnitude of torque generation. This invention includes the sequential operation of individual electrical switches, singularly and cumulatively in a reversible sequence, to proceed in regular increments to any desired torque generation within the capability of the machine. Singular and cumulative operation of the electrical switches means they are operated one at a time and that once operated in an increasing torque sequence or a decreasing torque sequence the switch will remain in that position and the next switch in the sequence will be operated. This invention includes means for recovering electromagnetic energy from multiple windings electrical motor open circuit armature windings when interrupted while contacted through coupled commutator segments by brushes of the two groups. This energy recovery means includes a half bridge circuit composed of a plurality of diodes which are coupled between each group brufeh and the electrical energy source terminals. The diodes are arranged to be back-biased until an open circuit armature winding is interrupted as above and thereby induces voltage which forward-biases certain diodes of the half bridge circuits coupled to commutator segments coupled to the ends of the interrupted open circuit armature winding, and thereby electromagnetic energy associated with the interrupted open circuit armature winding is recovered and delivered to the electrical terminals.

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION: This application is related to motor speed and torque controllers for both positive and negative torques, and to motor starters, and power output controllers. This invention relates to such controllers for brush-type machines, and more particularly, to controllers for brush-type electrical machines of the type disclosed in the referenced co-pending application titled Multiple Windings Electrical Machines.

2. BACKGROUND ART: Previous brush-type electrical machine controllers have used series resistance to control speed and torque and current, especially the excessive currents caused during the startup of series motors. The control of these brush-type machines is very important in considering the application of these motors. There has been a lack of a reliably-operating, efficient controller for brush-type machines. The speed and torque of a series motor energized from a constant potential supply can be controlled by inserting resistance in series with the supply line. Speed control for shunt and compound motors can be obtained by inserting resistance in series with the armature circuit only. The stator field flux of shunt motors can be varied to control the speed these motors, although special care is required to prevent overspeeding of the motor is the shunt stator field flux becomes very weak. The speed of DC motors can be varied by varying the voltage applied to the motors; the Ward Leonard system of speed control is an example of varying the voltage applied to the DC motor. In the Ward Leonard system the adjustable output voltage from a motor-genera or set is applied to the motor. Electric vehicle motor controllers use semiconductor chopper controllers as well as electromechanical switches to connect resistors and batteries in various combinations to regulate electrical power input to the motor, which thereby control the motor output torque.

DISCLOSURE OF THE INVENTION

This invention provides control of the referenced multiple windings electrical motor by varying the number of torque generating winding sets of the motor which are energized. Each multiple windings electrical motor has a number of torque generating winding sets and the multiple windings electrical motor will operate efficiently with various numbers of the torque generating winding sets energized, as long as the torque generating winding sets are energized and de-energized in a certain sequence with respect to brush vacancies and the circumferential positions of the energized torque generating winding sets in the direction of armature movement, so as to maintain a rough mechanical balance of loads applied to the shaft bearings. Referring to Figure 1, a single multiple windings electrical motor torque generating winding set comprises a multiple windings electrical machine stator magnetomotive force means, such as split, stator winding 9-10 and 11-12, and a multiple windings electrical machine open circuit armature winding 60-61, which are positioned and interconnected using brushes 13 and 14 and brushholder 82 as in a multiple windings electrical motor described in the referenced application. Each torque generating winding set is energized by electrical current flow through a torque generating set current control means. This current control means may include any of a variety of electrical switches, such as switches 1, 2, 3, 4, 5, 6, 7, and 8 or may include a means to control the commutator contact of the first brushes group brushes, 13, 21, 27, 33, and second brushes group brushes, 14, 22, 28, 34, associated with individual torque generating winding sets by lifting brushes from the commutator.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a linear representation of a two-pole multiple windings electrical motor controller in which the multiple windings electrical motor has four torque generating winding sets and the torque may be varied between zero and maximum in four discrete steps by operating four, two-pole, single throw switches. The multiple windings electrical motor linear representation uses the same drawing simplifications used in the reference application and adds a brushholder. To simplify Figure 1 and represent the multiple windings electrical motor in one view, the commutator 88 with commutator segments 72 through 81 and brushes 14, 22, 28, 34, 15, 13, 21, 27, 33, and 16 and connecting circuits and brushholder 82 and brush springs, one designated 93, are shown in an enlarged air gap between the stator magnetic poles 70 and 71 and the magnetic armature 86. The preferred and practical electrical machine construction in accordance with the reference application and the present application is to remove these elements from this fictitious but simplifying air gap placement and place them adjacent to stator magnetic yoke 83 and armature magnetic member 86. Several figures showing the practical placement of the commutator and brushholder with brushes in a rotary multiple windings electrical machine are shown in the reference application. In Figure 1 dotted lines are used to represent stator or armature windings as they pass behind stator or armature magnetic mem- bers respectively.

Figure 2 shows a cam-operated controller for operatin the four switches of Figure 1 to provide torque control in a forward direction for the multiple windings electrical motor of Figure 1. Figure 3 is a representation of a portion of the multiple windings electrical motor of Figure 1 showing the brushholder shifted with respect to the stator poles to a neutral position in which the multiple windings electrical motor favors zero speed, and the multiple windings electrical motor does not generate either forward or reverse torque.

Figure 4 is a representation of a portion of the multiple windings electrical motor of Figure 1 showing the brushholder shifted with respect to the stator poles to cause torque generation in the reverse direction, or opposite direction from Figure 1.

Figure 5 shows a cam-operated controller for operating the four switches of Figure 1 to provide torque cont rol in either the forward direction, represented by the brushholder position in Figure 1, or the reverse direction represented by the brushholder position of Figure 4.

Figure 6 shows a linear representation of a four- pole multiple windings electrical motor controller in whi ch the multiple windings electrical motor has eight torque generating winding sets and the torque may be varied between zero and maximum in eight discrete steps by operating eight, three-pole, single throw switches. The multiple windings electrical motor linear representation uses the same type of drawing simplifications used in the reference application and Figure 1, except herein the commutator is designated 223, the commutator segments are designated 177 through 196, the brushholder is designated 222, the brushes are designated 157 through 176, and one brush spring is designated 226. In Figure 6 dotted lines are used to represent stator or armature windings as they pass behind stator or armature magnetic members respectively.

DETAILED DESCRIPTION OF THE INVENTION This detailed description will explain: (1) the forward torque controller for a two stator pole multiple windings electrical motor, (2) the recovery of energy from armature windings not energized as a torque generating set, (3) the reverse torque controller for a two stator pole multiple windings electrical motor (4) the forward torque controller for the general, multiple stator pole pair multiple windings electrical motor as represented by a two stator pole pair multiple windings electrical motor, and (5) the reverse torque controller for the general multiple windings electrical motor.

Consider a two-pole multiple windings electrical motor as represented in linear fashion in Figure 1 having two stator poles 70 and 71 with four split stator windings: 9- 10 and 11-12, 17-18 and 19-20, 23-24 and 25-26, and 29-30 and 31-32, and five open circuit armature windings: 60-61, 62-63, 64-65, 66-67, and 68-69. It will be recognized from the reference application that four stator windings is a number of stator windings chosen for the simplicity of presenting this multiple windings electrical motor controller and does not imply any multiple windings electrical motor or controller limitation at more or less than four stator windings; similarly, the five open circuit armature windings are chosen for simplicity of presenting this multiple windings electrical motor controller and does not imply any multiple windings electrical motor or controller limitation at more or less than five open circuit armature windings. Figure 1 also shows: stator magnetic yoke 83, structural support 84, key 85, brush spring 93, springloaded brushes 13, 14, 21, 22, 27, 28, 33, 34, brushholder 82, magnetic armature 86 with teeth one of which is 87, commutator 88 with conducting segments 72 through 81, mechanical energy coupling 89, key 90, and brush vacancies 15 and 16. In a rotary multiple windings electrical motor the structural support 84 is the stator housing and the mechanical energy coupling 89 is the shaft, and bearings position the shaft in the housing and allow the shaft to rotate within the housing; this construction is shown in the reference application. A brush vacancy is also defined in the reference application, but in general terms a brush vacancy is a gap in the brushes which allows the interruption and reversal of the open circuit armature windings currents. The brushes are divided at brush vacancies into two groups: first brushes group brushes and second brushes group brushes. The brushes 13, 21, 27, and 33 are of the first group, and brushes 14, 22, 28, and 34 are of the second group. The brushholder 82 is mechanically attached to the structural support 84, and the commutator 8 is mechanically attached to the mechanical energy coupling 89. Such a multiple windings electrical motor can be varied in torque in increments of approximately one- fourth of the maximum torque by energizing or de-energizing the split stator windings one set at a time in a four- step sequence.

In Figure 1, the first step of this sequence is to energize the stator windings 9-10 and 11-12 from unidirectional voltage source 51 by closing electrical switches 1 and 2. The stator windings 9-10 and 11-12 connect to first and second brushes group brushes 13 and 14 respectively, which connect through various segments of the com mutator 88 at various armature positions to energize open circuit armature windings once removed contrary to the direction of torque generation from the brush vacancies 15 and 16, and from which the armature and open circuit armature windings will move toward the brush vacancies in the forward direction of torque generation--armature movement to the left in Figure 1.

In Figure 1, the second step of this sequence is to continue the first step and additionally energize the stator windings 17-18 and 19-20 from the source 51 by closing electrical switches 3 and 4. The stator windings 17-18 and 19-20 connect to first and second brushes group brushes 21 and 22 respectively, which connect through various segments of the commutator 88 at various armature positions to energize open circuit armature windings twice removed from the brush vacancies contrary to the direction of torque generation.

In Figure 1, the third step of this sequence is to continue the second step and additionally energize the sta tor windings 23-24 and 25-26 from the source 51 by closing electrical switches 5 and 6. The stator windings 23-24 and 25-26 connect to first and second brushes group brushes 27 and 28 respectively, which connect through various segments of the commutator 88 at various armature positions to energize open circuit armature windings thrice removed from the brush vacancies contrary to the direction of torque generation.

In Figure 1, the fourth step of this sequence is to continue the third step and additionally energize the stator windings 29-30 and 31-32 from the source 51 by closing electrical switches 7 and 8. The stator windings 29-30 and 31-32 connect to first and second brushes group brushes 33 and 34 respectively which connect through various segώents of the commutator 88 at various armature positions to energize open circuit armature windings fourth removed from the brush vacancies contrary to the direction of torque generation.

Notice that these four steps energize first and second brushes group brushes at positions in a sequence with respect to the brush vacancies, which is a sequence dirrected contrary to the torque generation direction. The first step energizes the first and second brushes group brushes in the position once removed from the brush vacancies; the second step continues the first step and energizes the first and second brushes group brushes in the position twice removed from the brush vacancies; the third step continues the second step and energizes the first and second brushes group brushes in the position thrice removed from the brush vacancies; and, the fourth step continues the third step and energizes the first and second brush es group brushes in the position fourth removed from the brush vacancies. At each step of this energizing sequence of the stator windings and these open circuit armature win dings energizing first and second brushes group brushes positions, the previously energized steps are retained as a new step is energized. Thus, the multiple windings electrical motor configuration is retained at each energized step.

The de-energization sequence is the reverse of the energizing sequence. Thus, from the condition of having all four open circuit armature windings energizing first and second brushes group brushes positions energized, the electrical switches 7 and 8 are opened to reduce to the condition of having only three open circuit armature windings energizing first and second brushes group brushes positions energized; from the condition of having three open circuit armature windings energizing first and second brushes group brushes positions energized, the electrical switches 5 and 6 are opened to reduce to the condition of having only two open circuit armature windings energizing first and second brushes group brushes positions energized; from the condition of having two open circuit armature windings energizing first and second brushes group brushes positions energized, the electrical switches 3 and 4 are opened to reduce to the condition of having only one open circuit armature windings energizing first and second brushes group brushes position energized; and, to completely de-energize the multiple windings electrical motor, the electrical switches 1 and 2 are opened.

The recovery of electromagnetic energy from current interruption in open circuit armature windings while they are yet removed from the brush vacancies is done by diodes connected from each of brushes 13, 14, 21, 22, 27, 28, 33, and 34 to the positive and the negative terminals of the unidirectional voltage source 51. These diodes are desig nated 35 through 50 in Figure 1. Each diode connected to the unidirectional voltage source 51 positive terminal is connected to that terminal by its cathode and its anode is connected to the brush. Each diode connected to the unidirectional voltage source 51 negative terminal is connected to that terminal by its anode and its cathode is connected to the brush. A diode pair such as 35 and 36 is called a half bridge circuit. This recovery of electromagnetic energy takes place as follows under the following conditions. Assume the multiple windings electrical motor of Figure 1 is operating at the step-two torque level with two torque generating sets energized as described above; this will occur v/hen electrical switches 1, 2, 3, and 4 are closed. When the armature 87 with attached commutator 88 moves to the left from the Figure 1 shown position by one-half the commutator segments pitch, all the brushes

13, 14, 21, 22, 27, 28, 33, and 34 will straddle a gap between some of the commutator segments 72 through 81 and all the open circuit armature windings will more-or-less share in-parallel the energizing current flowing through the stator windings energized by the electrical switches 1, 2, 3, and 4. When the armature moves farther in the same direction, the parallel energizing current in the open circuit armature windings in the two un-energized open circuit armature windings energizing first and second brushes groups brushes positions thrice and fourth removed from the brush vacancies, will be interrupted by the commutator and commutator segments moving so the brushes no longer straddle the gaps between the commutator segments; this current interruption will induce a large inductive kick voltage in the open circuit armature windings at the two un-energized open circuit armature windings energizing first and second brushes groups brushes positions connected to brushes 27, 28, 33, and 34, which voltage is of opposite polarity to the voltage which caused the open circuit armature windings currents to flow; this opposite polarity voltage is conducted to the connected commutator segments and to the brushes 27, 28, 33, and 34 riding on these segments; through the diodes connected between these brushes and the unidirectional voltage source terminals, the electromagnetic energy is recovered for re-use or storage in a manner similar to that described in the referenced application. This same method of electromagnetic energy recovery from un-energized open circuit armature windings at energizing first and second brushes groups brushes positions applies to a multiple windings electrical motor with any number of stator pole pairs.

If the foregoing is defined as controlling forward torque, then the control of reverse torque can be achieved by shifting the brushholder 82 of Figure 1 by one stator pole pitch and operating the electrical switches in an inverted sequence. The reverse torque generation conditions are established by shifting the brushholder 82 to the position shown in Figure 3 and then to the position shown in Figure 4. To make the shift from the Figure 1 to the Figure 4 positions, the brushholder 82 has bearings between it and the structural support 84; the bearings are not shown in the Figures 1, 3, or 4. The brushholder 82 moves, shifts, so as to maintain the required operating brush spring loads between the brushes and the commutator segments. The control of reverse directed torque at four torque levels will be described by referring to Figures 1 4, and 5. The reverse torque generating sequence, the in verted sequence, starts with the brushholder 82 in the position shown in Figure 4 and with all the electrical swi tches 1, 2, 3, 4, 5, 6, 7, and 8 open, as shown in Figure 1.

In Figure 1 with brushholder 82 positioned as in Fig ure 4, the first step of the reverse sequence is to energize the stator windings 29-30 and 31-32 from the unidir ectional voltage source 51 by closing electrical switches 7 and 8. The stator windings 29-30 and 31-32 connect to first and second brushes groups brushes 35 and 34 respect ively, which connect through various segments of the commutator 88 at various armature positions to energize open circuit armature windings once removed from the brush vac ancies 15 and 16, and from which the armature and open circuit armature windings will move toward the brush vacancies in the reverse direction of torque generation--arm ature movement to the right in Figure 4. In Figure 1 with brushholder 82 positioned as in Figure 4, the second step of the reverse torque generating sequence is to continue the first step of this sequence and additionally energize the stator windings 23-24 and 25-26 from the source 51 by closing electrical switches 5 and 6. The stator windings 23-24 and 25-26 connect to first and second brushes groups brushes 27 and 28 respectively which connect through various segments of the commutator 88 at various armature positions to energize open circuit armature windings twice removed from the brush vacancies contrary to the direction of torque generation.

In Figure 1 with brushholder 82 positioned as in Figure 4, the third step of the reverse torque generating sequence is to continue the second step of this sequence and additionally energize the stator windings 17-18 and 19-20 from the source 51 by closing electrical switches 3 and 4. The stator windings 17-18 and 19-20 connect to first and second brushes groups brushes 21 and 22 respectively, which connect through various segments of the commutator 88 at various armature positions to energize open circuit armature windings thrice removed from the brush vacancies contrary to the direction of torque generation. In Figure 1 with brushholder 82 positioned as in Figure 4, the fourth step of the reverse torque generating sequence is to continue the third step of this sequence and additionally energize the stator windings 9-10 and 11-12 from the source 51 by closing electrical switches 1 and 2. The stator windings 9-10 and 11-12 connect to first and second brushes groups brushes 13 and 14 respectively, which connect through various segments of the commutator 88 at various armature positions to energize open circuit armature windings fourth removed from the brush vacancies contrary to the direction of torque generation.

In Figure 1 with brushholder 82 positioned as in Figure 4, the decrease in reverse torque generation level is the inverse, or backing-down the sequence, of the above sequence for increasing reverse torque generation level, or magnitude.

Torque direction control in a multiple windings electrical motor can be done by (1) a brushholder shift, as described above, wherein the brushholder is shifted by one or an odd number of stator pole pitches, or (2) by winding current reversal wherein currents through stator windings are reversed with respect to currents through armature windings. The preferred of these two methods of reversal for the multiple windings electrical motor is by shifting the brushholder by one, or an odd number, of stator pole pitches in the direction of commutator movement. The winding current reversal is more complex in requiring additional switchgear on a multiple windings electrical motor to effect the reversal. Shifting the brushholder requires bearings on the brushholder to maintain the brushholder concentric with the commutator and it requires flexible electrical connections to the brushes.

Figure 2 shows a push-knob operated cammed switch controller with a spring return for use in controlling the forward torque generated by a multiple windings electrical motor such as shown in Figure 1. The controller is shown in the zero torque position with all the electrical switches open, and the cam 91 held to the left against its stop by the compression spring 92. When it is desired to increase the multiple windings electrical motor forward torque, the knob 90 is pressed, moving cam 91 to the right, and compressing spring 92. The cam 91 is designed so the electrical switches operate in the sequence: 1 and 2, 3 and 4, 5 and 6, and 7 and 8, and that previously closed switches will continue closed as new ones are operated. Thus, pressing the knob 90 slowly until it causes the cam 91 to hit the right stop and slowly releasing knob 90 causes the forward torque of the multiple windings electri cal motor of Figure 1 to increase to the maximum torque in four steps and to decrease to zero torque through the same four steps in reverse order. Also notice that the torque may be increased to a less-than-maximum level and decreased from that level. Figure 5 shows a dual-cam switch controller operating one set of electrical switches with two cams 91 and 95 with separate push knobs to operate each cam and separate springs to return each cam; cam 91 is operated by knob 90 and returned by spring 92, and cam 95 is operated by knob 94 and returned by spring 96. The knob 90, cam 91, and spring 92 operate just as described for Figure 2 to control forward torque levels, when the brushholder 82 is in the position shown in Figure 1; the knob 94, cam 95, and spring 96 operate similarly to the knob 90, cam 91, and spring 92, but these control the reverse torque levels.

Before the knob 94, cam 95, and spring 96 can be operated efficiently in the multiple windings electrical motor fashion, the brushholder 82 must be shifted to the Figure 4 position. Once that has been done, pressing the knob 94 slowly to the cam 95 left stop and slowly releasing knob 94 causes the reverse torque of the multiple windings electrical motor of Figure 4 to increase to the maximum torque in four steps and to decrease to zero torque through the same four steps in reverse order. Operating the cam 95 in this manner causes the electrical switches to be operated in the inverted sequence described above for control of reverse torque.

Notice that the basic electrical switch required to switch each step of the torque varying sequence for the Figure 1 multiple windings electrical uotor with two sta tor poles, is a double-pole, single-throw (DPST) switch, such as switches 1 and 2 combined. The required basic electrical switch is different when the multiple windings electrical motor has more than two stator poles. When the multiple windings electrical motor has two or more pairs of stator poles, the basic electrical switch required at each step of the torque varying sequence is a three-pole, single-throw (3PST) switch. The controller for the multiple windings electrical motor with two or more pairs of stator poles will be described in the following section. The controllers for multiple windings electrical motors with two or more pairs of stator poles are described in the following by referring to Figure 6. A multiple windings electrical motor with two stator poles does not have the generality of a multiple windings electrical motor v/ith two or more pairs of stator poles when a controller is being described. To explain the more general multiple windings electrical motor controller, consider a multiple windings electrical motor consisting of two pair of stator poles with split-series stator windings as shown in Figure 6. The Figure 6 shows a multiple windings electrical motor with two stator pole pairs with four stator windings per pole pair and five open circuit armature windings per pole pair. This combination is representative of multiple windings electrical motors with largers numbers of pairs of stator poles and with different numbers of stator windings and armature windings per pole pair. This Figure 6 multiple windings electrical motor can be varied from zero torque to maximum torque in eight increments by closing eight three-pole single-throw electrical switches in sequence. These electrical switch poles are designated 101 through 124. These electrical switches switch both ends of the split-series stator windings. The reason for switching both ends of the split-series stator windings which connect to the unidirectional voltage source 51 is to allow electromagnetic energy recovery using diodes connected to the source 51 electrical terminals from the un- energized open circuit armature windings energizing first and second brushes groups brushes positions; since all the brush positions may be un-energized at some torque level in forward or reverse, this means that diodes are so connected to all the brush positions. This electromagnetic energy recovery occurs, as described above for a two-pole multiple windings electrical motor, when a commutator se gment or bar leaves a first or second brushes group brush while the commutator segment is yet removed from the brus vacancies. These segments are designated 177 through 196 in Figure 6. This electromagnetic energy recovery necessitates three electrical switch poles, because the negat ive-connected end of the split-series stator winding used in a two or more repeatable section multiple windings ele ctrical motor is sometimes in the same repeatable section as the positive-connected end and sometimes in an adjacent repeatable section; see the referenced application for a detailed description of a repeatable section. Briefly, a repeatable section is a one pole pair machine; in Figures 1, 3, 4, and 6, the double-dashed lines mark repeatable section boundaries; repeatable sections are joined at the stator structural support, stator magnetic yoke, mechanical energy coupling, magnetic armature, commutator, brushholder, and at the electrical terminals. To achieve electromagnetic energy recovery from the un-energized open circuit armature winding energizing first and second brushes groups brushes positions requires that a normally reverse-biased diode be connected, as described above for Figure 1, from each brush to each unidirectional voltage source 51 terminal. These diodes are not shown in Figure 6 to simplify and clarify the drawing; however, the diode brush connection points are indicated as unterminated wires along the brush-to-winding connections.

The Figure 6 controller torque-varying switches 101 through 124 are operated in groups of three by switch actuators, similar to those shown in Figures 2 and 5, in eight steps to produce eight torque levels. The Figure 6 multiple windings electrical motor can be varied in increments of about one-eighth of the maximum torque by energizing or de-energizing the torque generating winding sets of this motor one at a time in an eight step sequence. Figure 6 also shows: stator magnetic yoke 217, structural support 229, key 230, brush springs one designated 226, spring-loaded brushes 157 through 172, brushholder 222, magnetic armature 225 with teeth one of which is 224, commutator 223 with conducting segments 177 through 196, mechanical energy coupling 227, key 228, and brush vacancies 173 through 176. The brushholder 222 is mechanically attached to the structural support 229, and the commutator 223 is mechanically attached to the mechanical energy coupling 227.

In Figure 6, the first step of the eight-step sequenc is to energize the stator windings 125-126, 127-128, and 149-150 by closing electrical switches 101, 102, and 103. The stator winding 125—126 connects to first brushes group brush 157, and the stator windings 127-128 and 149-150 connect to second brushes group brushes 161 and 169 respectively; these brushes 157 with 161 or 157 with 169 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings once removed from the brush vacancies 175 and 174 or 175 and 176 contrary to the direction of torque generation In the Figure 1, the torque generating set position can be defined in relation to only two brush vacancies; however, in the more general multiple windings electrical motor of this Figure 6, the torque generating set position is defined in relation to three brush vacancies or two sets of brush vacancies; one brush vacancy is a central one and the other two are adjacent to the central one.

In Figure 6, the second step of this eight-step sequence is to continue the first step and additionally energize the stator windings 141-142, 149-150, and 127-128 by closing electrical switches 104, 105, and 106. The stator winding 141-142 connects to first brushes group brush 165 and the stator windings 149-150 and 127-128 connect to second brushes group brushes 169 and 161 respectively; these brushes 165 with 169 or 165 with 161 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings once removed from the brush vacancies 173 and 176 or 173 and 174 contrary to the direction of torque generation.

In Figure 6, the third step of this sequence is to continue the second step and additionally energize the the stator windings 129-130, 131-132, and 151-152 by clos ing electrical switches 107, 108, and 109. The stator winding 129-130 connects to first brushes group brush 158 and the stator windings 131-132 and 151-152 connect to second brushes group brushes 162 and 170 respectively; these brushes 158 with 162 or 158 with 170 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature v/indings twice removed from the brush vacancies 175 and 174 or 175 and 176 contrary to the direction of torque generation.

In Figure 6, the fourth step of this sequence is to continue the third step and additionally energize the stator windings 143-144, 151-152, and 131-132 by closing electrical switches 110, 111, and 112. The stator winding 143-144 connects to first brushes group brush 166, and the stator windings 151-152 and 131-132 connect to second brushes group brushes 170 and 162 respectively; these brushes 166 with 170 or 166 v/ith 162 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings tv/ice removed from the brush vacancies 173 and 176 or 173 and 174 contrary to the direction of torque generation.

In Figure 6, the fifth step of this sequence is to continue the fourth step and additionally energize the stator windings 133-134, 135-136, and 153-154 by closing electrical switches 113, 114, and 115. The stator winding 133-134 connects to first brushes group brush 159, and the stator windings 135-136 and 153-154 connect to second brushes group brushes 163 and 171 respectively; these brushes 159 with 163 or 159 with 171 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings thrice removed from the brush vacancies 175 and 174 or 175 and 176 contrary to the direction of torque generation. In Figure 6, the sixth step of this sequence is to continue the fifth step and additionally energize the stator windings 145-146, 153-154, and 135-136 by closing electrical switches 116, 117, and 118. The stator winding 145-146 connects to first brushes group brush 167, and the stator windings 153-154 and 135-136 connect to second bru shes group brushes 171 and 163 respectively; these brushes

167 with 171 or 167 with 163 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings thrice removed from the brush vacancies 175 and 176 or 173 and 174 contrary to the direction of torque generation.

In Figure 6, the seventh step of this sequence is to continue the sixth step and additionally energize the stator windings 137-138, 139-140, and 155-156 by closing electrical switches1l9, 120, and 121. The stator winding 137-138 connects to first brushes group brush 160, and the stator windings 139-140 and 155-156 connect to second brushes group brushes 164 and 172 respectively; these brushes 160 with 164 or 160 with 172 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings fourth removed from the brush vacancies 175 and 174 or 175 and 176 contrary to the direction of torque generation.

In Figure 6, the eighth step of this sequence is to continue the seventh step and additionally energize the stator windings 147-148, 155-156, and 139-140 by closing electrical switches 122, 123, and 124. The stator winding 147-148 connects to first brushes group brush 168, and the stator windings 155-156 and 139-140 connect to second brushes group brushes 172 and 164 respectively; these brushes

168 with 172 and 168 with 164 connect through various segments of the commutator 223 at various armature positions to energize open circuit armature windings fourth removed from the brush vacancies 173 and 176 or 173 and 174 contrary to the direction of torque generation. This complete the eight-step energizing sequence for the Figure 6 multiple windings electrical motor to reach its maximum torque generating level.

The de-energizing sequence to reach the zero torque level from the maximum torque level in the Figure 6 motor is the reverse of the energizing sequence described above.

The eight-step de-energizing sequence by step condition proceeds: eight, seven, six, five, four, three, two, one, and zero. Throughout all the above energizing and de-energizing steps, the multiple windings electrical motor configuration is retained at each energized step.

The control of reverse torque in the general multiple windings electrical motor as represented by the Figure 6 configured motor is done similarly to that control of rev erse torque described for the Figure 1 motor with the brushholder 82 shifted as in Figure 4. The brushholder 222 is shifted by one, or an odd number of, stator pole pitch(es), and the electrical switches are operated in an inverted eight step sequence to energize to maximum reverse torque as follows: step one: switches 124, 123, and 122; step two: switches 121, 120, and 119; step three: switches 118, 117, and 116; step four: switches 115, 114, and 113; step five: switches 112, 111, and 110; step six: switches 109, 108, and 107; step seven: switches 106, 105, and 104; step eight: switches 103, 102, and 101. To decrease to zero torque from the maximum reverse torque generation, just back-down the above eight step sequence.

Again notice that the torque in either reverse or forward generating sequences may be increased or decreased from any intermediate torque level.

Claims

AMENDED CLAIMS

(received by the International Bureau on 8 February 1982 (08.02.82))

1. A multiple windings electrical motor controller for incrementally controlling the torque generated by said mptor by operating a number of electrical switch means, wherein the improvement comprises said motor being a multiple windings electrical machine wherein the motor comprises an armature adapted for movement within the motor; a stator disposed adjacent the armature, said stator including an integral number of stator pole pairs, the stator poles being arranged in a side-by-side fashion in the direction of armature movement, adjacent stator poles being energized with opposite polarity magnetomotive force, the stator pole pairs being located adjacent the armature defining thereby an air gap there between; a plurality of open circuit armature windings disposed in the direction of armature movement; a commutator located on the armature and comprising a plurality of segments disposed singularly in the direction of armature movement and arranged in pairs, each segment of a pair being coupled to a corresponding open end of a respective one of the open circuit armature windings; a plurality of brushes arranged in first and second groups per stator pole pair, said brushes being singularly disposed within each group in the direction of armature movement, the first group of brushes containing one or more brushes, the second group of brushes containing one or more brushes, said groups being singularly disposed and alternating first and second in the direction of armature movement, each brush of a group for contacting a portion of said commutator wherein said portion includes at least one commutator segment as the armature moves relative to the stator, selected ones of said commutator segments coming out of contact with said brushes whereby respective ones of the open circuit armature windings Claim 1 continued . . . become electrically isolated from said brushes; and electrical terminal means coupled to said machine and adapted for receiving electrical energy for the machine and for delivering electrical energy from the machine, said machine generating torque from electrical current flow in open circuit armature windings whose respective commutator segment pairs are contacted by a brush in the first group of brushes on one segment and a brush in the second group of brushes on the corresponding segment, wherein said current flow in the open circuit armature windings is interrupted as the respective commutator segments move out of contact with said brushes and producing thereby induced voltage between the two commutator segments of pairs coupled to said interrupted open circuit armature windings; said machine including means for utilizing electrical energy recovered from the induced voltage produced from said interrupted armature windings current flow; said electrical switch means controlling electrical currents flow in said open circuit armature windings by applying electrical energy derived from the electrical terminal means to individual brushes within the first and second groups of brushes to thereby control the torque generated by said multiple windings electrical motor.

2. Apparatus according to claim 1 including means for operating the electrical switch means singularly and cumulatively in sequence to proceed stepwise to any desired torque generation between zero torque and maximum motor torque.

3. Apparatus according to claim 2 wherein said means for operating the electrical switch means in sequence comprises means for energizing brushes in the first Claim 3 continued . . . and second groups of brushes in positions once removed from central and adjacent brush vacancy means and contrary to the direction of torque generation in one pole pair repeatable section increments until all said once removed positions are energized.

4. Apparatus according to claim 3, further including means for thereafter energizing brushes in positions of the next increased level removed in said direction from said brush vacancy means in one pole pair repeatable section increments, and means for continuing in this manner until all said brush positions in all pole pairs and in all levels removed in said direction from said brush vacancy means are energized so as to generate maximum torque.

5. Apparatus according to claim 1 wherein said commutator segments are arranged in pairs with corre sponding segments one stator pole pitch apart.

6. A multiple windings electrical motor controller as in claim 1 wherein the electrical terminal means comprise positive and negative polarity terminals, and diodes in two groups connected between first group brushes and said terminals and between second group brushes and said terminals.

7. Apparatus according to claim 6 including connections of a first diode between each said group brush and said positive terminal, with first diode cathodes connected to said positive terminal; and connections of a second diode between each said group brush and said negative terminal, with second diode anodes connected Claim 7 continued . . . to said negative terminal, whereby the electromagnetic energy from interruptions of open circuit armature windings which are alternately energized and interrupted by multiple straddlings between comutator segments by first and second group brushes as the armature moves, is recovered at the electrical terminals as electrical energy.

8. A multiple windings electrical motor controller for controlling the magnitude and direction of torque generated by a motor by positioning brush holder means in the direction of armature movement with respect to stator pole means wherein the improvement comprises said motor being a multiple windings electrical machine wherein said machine comprises an armature adapted for movement within the machine; a stator disposed adjacent the armature, said stator including an integral number of stator pole pairs, the stator poles being arranged in a side-by-side fashion in the direction of armature movement, adjacent stator poles being energized with opposite polarity magnetomotive force, the stator pole pairs being located adjacent the armature defining thereby an air gap therebetween; a plurality of open circuit armature windings disposed in the direction of armature movement; a commutator located on the armature comprising a plurality of segments disposed singularly in the direction of armature movement and arranged in pairs, each segment of a pair being coupled to a corresponding open end of a respective one of the open circuit armature windings; said brush holder means holding a plurality of brushes arranged in first and second groups per stator pole pair; said brushes being singularly disposed within each group in the direction of armature movement, the first group of brushes containing one or more brushes, the second group of brushes containing one or more brushes, said groups being singularly disposed and alternating first and second in the direction of armature movement, each brush of a group for contacting a portion of said commutator and said portion including at least one commutator segment as the armature moves relative to the stator, and wherein, as the armature moves relative to the stator, selected ones of said commutator segments coming out of contact with said brushes whereby respective ones of the open circuit armature windings become electrically isolated from said brushes; electrical terminal means coupled to said machine and adapted for receiving electrical energy for the machine and for delivering electrical energy from the machine, said machine includ ing means for causing electrical current to flow in open circuit armature windings whose respective commutator segment pairs are contacted by a brush of the first group of brushes on one segment and a brush of the second group of brushes on the corresponding segment and wherein said current flow in the open circuit armature windings is interrupted as the respective commutator segments move out of contact with said brushes thereby producing induced voltage between the two commutator segments of pairs coupled to said interrupted open circuit armature windings; and means for utilizing electrical energy recovered from the induced voltage produced from said interrupted armature windings current flow.

9. Apparatus according to claim 8 wherein said commutator segments are arranged in pairs with corresponding segments one stator pole pitch apart; and wherein said brush holder means are positioned within one stator pole pitch to cause torque to vary between maximum in one direction to maximum in the opposite direction.

10. A multiple windings electrical motor controller for controlling the magnitude and direction of torque generated by said motor by operating a number of electrical switches to apply electrical energy to selected brushes within first and second groups of brushes and by positioning brush holder means in the direction of armature movement with respect to stator pole means, wherein the improvement comprises said motor being a multiple windings electrical machine, wherein said machine comprises an armature adapted for movement within the machine; a stator disposed adjacent the armature, said stator including an integral number of stator pole pairs, the stator poles being arranged in a side-by-side fashion in the direction of armature movement, adjacent stator poles being energized with opposite polarity magnetomotive force, the stator pole pairs being located adjacent the armature defining thereby an air gap therebetween; a plurality of open circuit armature windings disposed in the direction of armature movement; a commutator located on the armature comprising a plurality of segments disposed singularly in the direction of armature movement and arranged in pairs, each segment of a pair being coupled to a corresponding open end of a respective one of the open circuit armature windings; said brush holder means holding a plurality of brushes arranged in first and second groups per stator pole pair, said brushes being singularly disposed and alternating first and second in the direction of armature movement, the first brushes group containing one or more brushes, the second brushes group containing one or more brushes, said groups being singularly disposed and alternating first and second in the direction of armature movement, each brush of a group for contacting a portion of said commutator, said portion including at least one commutator segment Claim 10 continued . . . as the armature moves relative to the stator, and wherein, as the armature moves relative to the stator, selected ones of said commutator segments come out of contact with said brushes whereby respective ones of the open circuit armature windings become electrically isolated from said brushes; and electrical terminal means coupled to said machine and adapted for receiving electrical energy for the machine and for delivering electrical energy from the machine, said machine generating torque from electrical current flow in open circuit armature windings whose respective commutator segment pairs are contacted by a brush in the first group of brushes on one segment and a brush in the second group of brushes on the corresponding segment and by the positional relationship between energized brushes of the first and second groups of brushes and magnetically energized stator poles controlled by the position of said brush holder means, said current flow in the open circuit armature windings being interrupted as the respective commutator segments move out of contact with said brushes and producing thereby induced voltage between the two commutator segments of pairs coupled to said interrupted open circuit armature windings; said machine including means for utilizing electrical energy recovered from the induced voltage produced from said interrupted armature windings current flow; said electrical switch means controlling electrical current flow in said open circuit armature windings by applying electrical energy derived from the electrical terminal means to individual brushes within the first and second groups of brushes to thereby control the torque generated by said multiple windings electrical motor.

11. Apparatus according to claim 10 including means for operating the electrical switch means singularly and cumulatively in sequence to proceed stepwise to any desired torque generation between zero torque and maximum motor torque.

12. Apparatus according to claim 11 wherein said means for operating the electrical switch means in sequence comprises means for energizing brushes in the first and second groups of brushes means in positions once removed from central and adjacent brush vacancy means and contrary to the direction of torque generation in one pole pair repeatable section increments until all said once removed positions are energized, followed by energizing the said brush means positions of the next increased level removed in said direction from said brush vacancy means in one pole pair repeatable section increments, and continuing in this manner until all said brush means positions in all pole pairs and in all levels removed in said direction from said brush vacancy means are energized which causes maximum torque generation.

13. Apparatus according to claim 12 including means for operating the electrical switch means singularly and cumulatively in sequence to proceed stepwise to any desired torque generation between zero torque and maximum motor torque.

14. Apparatus according to claim 13 wherein said means for operating the electrical switch means in sequence comprises means for energizing brushes in the first and second groups of brushes in positions once removed from central and adjacent brush vacancy means and contrary to the direction of torque generation in one pole pair repeatable section increments until all said once removed positions are energized.

15. Apparatus according to claim 14, further including means for thereafter energizing brushes in positions of the next increased level removed in said direction from said brush vacancy means in one pole pair repeatable section increments, and means for continuing in this manner until all said brush positions in all pole pairs and in all levels removed in said direction from said brush vacancy means are energized so as to generate maximum torque.

16. Apparatus according to claim 10 wherein said commutator segments are arranged in pairs with corresponding segments one stator pole pitch apart.

17. Apparatus according to claim 10 wherein the electrical terminal means comprise positive and negative polarity terminals, and diodes in two groups connected between first group brushes and said terminals and between second group brushes and said terminals.

18. Apparatus according to claim 17 including connections of a first diode betv/een each said group brush and said positive terminal, with first diode cathodes connected to said positive terminal; and connections of a second diode between each said group brush and said negative terminal, with second diode anodes connected to said negative terminal, whereby the electromagnetic energy from interruptions of open circuit armature windings which are alternately energized and interrupted by multiple straddlings between commutator segments by first and second group brushes as the armature moves, is recovered at the electrical terminals.

19. A multiple windings electrical machine having a motor comprising an armature adapted for movement within the motor; a stator disposed adjacent the armature, said stator including an integral number of stator pole pairs, the stator poles arranged in a side-by-side fashion in the direction of armature movement, adjacent stator poles being energized with opposite polarity magnetomotive force, the stator pole pairs being located adjacent the armature defining thereby an air gap therebetween; a plurality of open circuit armature windings disposed in the direction of armature movement; a commutator located on the armature comprising a plurality of segments disposed singularly in the direction of armature movement and arranged in pairs, each segment of a pair being coupled to a corresponding open end of a respective one of the open circuit armature windings; a plurality of brushes arranged in first and second groups per stator pole pair, said brushes being singularly disposed within each group in the direction of armature movement, the first group of brushes containing one or more brushes, the second group of brushes containing one or more brushes, said groups being singularly disposed and alternating first and second in the direction of armature movement, each brush of a group for contacting a portion of said commutator, wherein said portion includes at least one commutator segment as the armature moves relative to the stator; and wherein, as the armature moves relative to the stator, commutator segments which are leaving one brush group and moving toward an adjacent brush group come out of contact with said group brushes whereby respective ones of the open circuit armature windings become electrically isolated from said group brushes; electrical terminal means coupled to said machine and adapted for receiving electrical energy coupled to said machine and adapted for receiving electrical energy for Claim 19 continued . . . the machine and for delivering electrical energy from the machine, said machine including means for causing electrical current to flow in open circuit armature wind ings whose respective commutator segment pairs are contacted by a brush in said first group of brushes on one segment and contacted by a brush in said second group of brushes on the corresponding segment, and wherein said current flow in the open circuit armature windings is interrupted as the respective commutator segments move out of contact with said brushes and produce thereby induced voltage between the two commutator segments of pairs coupled to said interrupted open circuit armature windings; a plurality of energy disposal brushes in which one energy disposal brush is located beween each adjacent group of brushes and adapted for contacting a commutator segment simultaneously with a brush of a group as the commutator segment comes out of contact with said brush of a group and for sole contact of said commutator segment for at least a portion of the movement of said segment between adjacent groups of brushes; and a plurality of half bridge circuits in which each half bridge circuit is coupled between one energy disposal brush and the electrical terminal means.

20. Apparatus according to claim 19 in which each of said half bridge circuits comprising a plurality of diodes arranged to be back-biased until the open circuit armature winding coupled to said commutator segment is interrupted and produces thereby induced voltage which forward-biases selected diodes of said half bridge circuit and of the half bridge circuit coupled to the adjacent energy disposal brush contacting the corresponding commutator segment coupled to said interrupted open circuit armature winding, whereby electromagnetic energy Claim 20 continued . . . contained in the open circuit armature windings interrupted by the movement of coupled commutator segment pairs between adjacent groups of brushes is recovered and delivered as electrical energy to the electrical terminal means.

21. Apparatus according to claim 20 wherein the machine includes a controller which includes electrical switch means connected to control the flow of electrical current to open circuit armature windings whose respective commutator segment pairs are contacted by a brush of the first group of brushes on one segment and contacted by a brush of the second group of brushes on the corresponding segment.

22. Apparatus according to claim 21 wherein said electrical switch means comprise a plurality of individual electrical switches which are operable singularly and cumulatively in a sequence to incrementally traverse the torque generating capability of said motor, wherein said individual electrical switch to control said current flow for one torque increment comprises multiple switch poles in which one switch pole is in series with the electrical connection between a brush of the first group of brushes and a positive terminal of said electrical terminal means and a second switch pole is in series with the electrical connection between a brush of the second group of brushes in the same stator pole pair with and one stator pole pitch removed from said first brushes group brush and a negative terminal of said electrical terminal means.

23. Apparatus according to claim 22 in which a third switch pole is used for motors of more than one stator pole pair and is in series with the electrical connection between said negative terminal and the brush in the second group of brushes in an adjacent stator pole pair and one stator pole pitch removed from the brush in the first group of brushes.

24. Apparatus according to claim 22 wherein said current flow is modulated by group brushes making straddling contacts between adjacent commutator segments and wherein said current flow in unenergized open circuit armature windings is interrupted as the commutator segments move to interrupt said straddling contacts and produce thereby induced voltage between the two commutator segments of pairs coupled to said unenergized interrupted open circuit armature windings.

25. Apparatus according to claim 19 including energy recovery means comprising a plurality of half bridge circuits in which each half bridge circuit is connected between only one group brush and the electrical terminal means and all group brushes are so connected, said half bridge circuit comprising a plurality of diodes arranged to be back-biased until the open circuit armature winding coupled to said commutator segment is interrupted and produces thereby induced voltage which forward-biases certain diodes of said half bridge circuit and of the half bridge circuit coupled to the alternate adjacent group brush contacting the corresponding commutator segment coupled to said interrupted open circuit armature winding, and thereby electromagnetic energy contained in the unenergized open circuit armature windings interrupted by the movement of coupled commutator segment pairs between adjacent group brushes is recovered and delivered Claim 25 continued . . . as electrical energy to the electrical terminal means.

26. An improved multiple windings electrical motor controller for incrementally controlling the torque generated by said motor for reducing energy dissipation within said controller by recovering electrical energy from interrupted unenergized open circuit armature windings, wherein the improvement comprises said motor being a multiple windings electrical machine wherein the motor comprises an armature adapted for movement within the motor; a stator disposed adjacent the armature, said stator including an integral number of stator pole pairs, the stator poles being arranged in a side-by-side fashion in the direction of armature movement, adjacent stator poles being energized with opposite polarity magnetomotive force, the stator pole pairs being located adjacent the armature defining thereby an air gap therebetween; a plurality of open circuit armature windings disposed in the direction of armature movement; a commutator located on the armature comprising a plurality of segments disposed singularly in the direction of armature movement and arranged in pairs, each segment of a pair being coupled to a corresponding open end of a respective one of the open circuit armature windings, a plurality of brushes arranged in first and second groups per stator pole pair, said brushes being singularly disposed within each group in the direction of armature movement, the first group of brushes containing one or more brushes, the second group of brushes containing one or more brushes, said groups being singularly disposed and alternating first and second in the direction of armature movement, each brush of a group for contacting a portion of said commutator and said portion including at least one commutator segment as the armature moves relative to the Claim 26 continued . . . stator; electrical terminal means coupled to said machine and adapted for receiving electrical energy for the machine and for delivering electrical energy from the machine, said machine including means for causing electrical current to flow in open circuit armature windings whose respective commutator segment pairs are contacted by a brush in the first group of brushes on one segment and contacted by a brush in the second group of brushes on the corresponding segment, and wherein said current flow in the open circuit armature windings is interrupted as the respective commutator segments move out of contact with said brushes and produce thereby induced voltage between the two commutator segments of pairs coupled to said interrupted open circuit armature windings; and energy recovery means comprising a plurality of half bridge circuits in which each half bridge circuit is connected between only one group brush and the electrical terminal means and all group brushes are so connected.

27. Apparatus according to claim 26 in which said half bridge circuit comprising a plurality of diodes arranged to be back-biased until the open circuit armature winding coupled to said commutator segment is interrupted and produces thereby induced voltage which forward-biases certain diodes of said half bridge circuit and of the half bridge circuit coupled to the alternate adjacent group brush contacting the corresponding commutator segment coupled to said interrupted open circuit armature winding, and thereby electromagnetic energy contained in the unenergized open circuit armature windings interrupted by the movement of coupled commutator segment pairs between adjacent group brushes is recovered and delivered as electrical energy to the electrical terminal means. EDITORIAL NOTE

The applicant failed to renumber the amended claims in accordance with Section 205 of the Aministrative Intructions.

Original claims 1 to 7 have been cancelled and, accordingly amended claims 1 to 27 are new.