CN105305751A - Five-phase bearing-free brushless DC motor with two stators - Google Patents

Abstract

The invention discloses a double-stator bearingless five-phase brushless direct current motor. The outer stator yoke, the rotor iron core and the inner stator yoke are coaxially nested from the outside to the inside, and the inner peripheral surface of the outer stator yoke is along the circumferential direction. There are 10 armature teeth and 10 fault-tolerant teeth arranged in a staggered manner, and five-phase torque windings are wound on the armature teeth; 18 poles of permanent magnets are evenly distributed on the outer surface of the rotor iron core. 4-pole inner permanent magnets are evenly distributed on the surface, and 6 inner stator teeth are evenly fixed along the circumferential direction on the outer circumference of the inner stator yoke, and the suspension force windings are wound on the inner stator teeth; the torque winding, outer permanent magnets, and rotor work together Realize the rotation of the motor, the suspension force winding, the inner permanent magnet, and the rotor work together to realize the stable suspension of the rotor, the torque winding and the suspension force winding are controlled independently, and the suspension force winding and the torque winding have self-decoupling characteristics, which enhance the radial Suspension ability and improve the dynamic and static performance of suspension subsystem and torque subsystem.

Description

Dual Stator Bearingless Five-Phase Brushless DC Motor

technical field

The invention belongs to the field of motors, in particular to a double-stator bearingless five-phase brushless DC motor, which is suitable for application fields requiring high reliability such as aerospace, nuclear power plants, and electric vehicles.

Background technique

The bearingless brushless DC motor stacks the torque winding and the suspension force winding on the stator teeth. The torque winding realizes the rotation of the motor, and the suspension force winding generates radial suspension force to realize the stable suspension of the rotor. The motor has the functions of brushless DC motor and magnetic bearing at the same time, and has the advantages of high speed, high precision, long life, no need for lubrication and sealing, etc. of magnetic bearing. The main problems of this kind of bearingless brushless DC motor are: the magnetic field generated by the suspension force winding and the torque winding interacts, it is difficult to achieve effective decoupling between the suspension force and torque; since the motor current is a square wave DC , the coordinate transformation control method of the traditional motor is difficult to apply to the bearingless brushless DC motor.

The motor structure closest to the technology of the present invention is the traditional double-stator three-phase permanent magnet motor. Due to the inherent characteristics of the internal permanent magnets of the double-stator three-phase permanent magnet motor, its fault tolerance is limited, especially the fault caused by the winding short circuit fault. Problems such as temperature rise will cause serious systemic failure. Compared with ordinary three-phase motors, multi-phase motors have many advantages. First, multi-phase motors can provide greater output power, not only can have a smaller current at the same output power, but also have a large power capacity of Guaranteed operation during fault tolerance. Secondly, the harmonics of the space magnetomotive force generated by the fundamental current are reduced, which reduces the torque ripple of the motor, and the resulting noise is also reduced.

Contents of the invention

The purpose of the present invention is to further improve the working performance of the bearingless brushless DC motor, realize the automatic decoupling between the suspension force winding and the torque winding, and improve the fault tolerance of the motor. A double-stator bearingless five-phase brushless DC motor that is electrically, magnetically, thermally and physically isolated has the ability to ensure continuous operation of the remaining non-faulty phases when one or several phases fail.

In order to achieve the above object, the present invention adopts the following technical solutions: the present invention consists of an outer stator yoke, a fault-tolerant tooth, an armature tooth, an outer permanent magnet, a rotor core, a magnetic isolation aluminum ring, an inner permanent magnet, an inner stator tooth, an inner stator Composed of yoke, torque winding and suspension force winding, the outer stator yoke, rotor core and inner stator yoke are nested concentrically from the outside to the inside, and the inner circumference of the outer stator yoke is evenly fixed along the circumferential direction There are 10 armature teeth and 10 fault-tolerant teeth arranged in a staggered manner, and the five-phase torque windings of A, B, C, D, and E are wound on the armature teeth, and each phase winding is wound on one armature tooth; the rotor There are 18 poles of permanent magnets evenly distributed on the outer surface of the iron core. The 18 poles of the permanent magnets are fixed end to end and are magnetized in the radial direction. The N and S poles are arranged alternately. The middle of the rotor core is fixed with a spacer Magnetic aluminum ring; 4-pole internal permanent magnets are uniformly distributed on the inner surface of the rotor iron core, and the 4-pole internal permanent magnets are distributed in the clockwise direction in the order of N and S and are all magnetized in the radial direction. The outer circumferential surface of the inner stator yoke 6 inner stator teeth are evenly fixed along the circumferential direction, and suspension force windings are wound on the inner stator teeth; there is a radial outer air gap between the armature teeth, fault-tolerant teeth and the outer permanent magnet, and there is a radial air gap between the inner stator teeth and the inner permanent magnet. A radially inner air gap exists.

Further, the distance between two adjacent inner permanent magnets is 30°, and the arc occupied by the inner permanent magnets in each pole is 60°.

Further, each phase torque winding is composed of 2 coils, a total of 10 coils according to (A+)→(D-)→(B+)→(E-)→(C+)→(A-)→(D+)→ (B-)→(E+)→(C-) are distributed on the armature teeth in the counterclockwise direction in turn; the torque winding 4 adopts a star connection and adopts a five-phase H-bridge drive mode. When the motor is working normally, the rotor core 7 Rotate counterclockwise, at any moment, the four-phase torque winding 4 is energized at the same time, and the energization time of each phase is 144°: when the rotor angular position θ is -18°~18°, the B and C phases of the H bridge are turned on The upper bridge arm turns on the lower bridge arms of D and E phases; when θ is between 18°~54°, the upper bridge arms of B and C phases are turned on, and the lower bridge arms of phases A and E are turned on; when θ is between 54°~ When 90°, turn on the upper bridge arms of C and D phases, and turn on the lower bridge arms of A and E phases; when θ is between 90° and 126°, turn on the upper bridge arms of C and D phases, and turn on the A and B phases Lower bridge arm; when θ is 126°~162°, the upper bridge arm of phase D and E is turned on, and the lower bridge arm of phase A and B is turned on; when θ is 162°~198°, phase D and E are turned on The upper bridge arm turns on the lower bridge arms of phase B and C; when θ is between 198°~234°, the upper bridge arms of phase A and E are turned on, and the lower bridge arms of phase B and C are turned on; when θ is between 234°~ When 270°, turn on the upper bridge arms of A and E phases, and turn on the lower bridge arms of C and D phases; when θ is 270°~306°, turn on the upper bridge arms of A and B phases, and turn on the C and D phases Lower bridge arm; when θ is 306°~342°, the upper bridge arm of phase A and B is turned on, and the lower bridge arm of phase D and E is turned on.

The advantages of the present invention are:

1. In the present invention, the torque winding, the outer permanent magnet, and the rotor work together to realize the rotation of the motor, and the suspension force winding, the inner permanent magnet, and the rotor work together to realize the stable suspension of the rotor. The torque winding and the suspension force winding are controlled independently, respectively. Structurally, the suspension force winding and the torque winding have self-decoupling characteristics, and there is no mutual restriction, thereby enhancing the radial suspension capability and improving the dynamic and static performance of the suspension subsystem and the torque subsystem.

2. The outer stator torque winding adopts a multi-phase motor structure. The armature teeth and the fault-tolerant teeth are not equal in width, which is easy to realize the back EMF of 144° flat-top wave. The fault-tolerant teeth between the armature windings of each phase play an isolation role, not only can Make each phase form its own closed magnetic circuit through the fault-tolerant teeth, thereby realizing magnetic isolation, and also avoiding the heat exchange between phases to a certain extent, and realizing thermal isolation. When a short circuit or open circuit fault occurs in a phase winding , the adverse effects on other phase windings are reduced and normal rotation can be achieved through fault-tolerant control, while the fault-tolerant teeth without windings have the effect of isolating the instantaneous heat generated by them, realizing thermal isolation, improving the efficiency of the motor, and reducing the temperature. Lift.

3. The levitation force winding adopts a three-phase structure similar to that of ordinary motors, driven by a three-phase inverter, and the levitation force in the three-degree-of-freedom directions of a, b, and c phases can be adjusted, which can provide more accurate synthetic levitation force, and is compatible with power Compared with amplifiers, three-phase power inverters have the advantages of small size, low cost, and low power loss.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is the radial structure schematic diagram of double-stator bearingless five-phase brushless DC motor of the present invention;

Fig. 2 is the energization timing diagram of the five-phase torque winding in Fig. 1;

Fig. 3 is the magnetic potential diagram of the five-phase torque winding in Fig. 1;

Fig. 4 is a power-on sequence diagram of the three-phase suspension force winding of phase a, phase b and phase c in Fig. 1;

Fig. 5 is a schematic diagram of the magnetic field lines of the inner permanent magnet and the energized electromagnetic field lines of the three-phase suspension force winding in Fig. 1;

Figure 6(a), (b), and (c) are the phase diagrams of the levitation force generated when the a-phase, b-phase, and c-phase levitation force windings are energized, in which figure 6 (a) is a positive current for phase a, b, The levitation force phase diagram when phase c is negative current, Figure 6(b) is the levitation force phase when phase b is positive current, phase a and c are negative current, figure 6(c) is phase c is positive current, a, Phase b is the suspension force phase when the current is negative.

In the figure: 1—outer stator yoke; 2—fault-tolerant teeth; 3—armature teeth; 4—torque winding; 5—air gap A; 6—outer permanent magnet; 7—rotor core; 8—magnetic isolation aluminum Ring; 9—inner permanent magnet; 10—air gap B; 11—inner stator tooth; 12—suspension force winding; 13—inner stator yoke;

detailed description

Referring to Fig. 1, the dual-stator bearingless five-phase brushless DC motor of the present invention consists of an outer stator yoke 1, fault-tolerant teeth 2, armature teeth 3, an outer permanent magnet 6, a rotor core 7, a magnetic isolation aluminum ring 8, and an inner permanent magnet. The magnet 9, the inner stator teeth 11, the inner stator yoke 13, the torque winding 4 and the suspension force winding 12 are composed. The outer stator yoke 1, the rotor core 7 and the inner stator yoke 13 are nested concentrically from the outside to the inside, and 20 outer stator teeth are evenly fixed on the inner peripheral surface of the outer stator yoke 1 along the circumferential direction, 20 The outer stator teeth are composed of 10 armature teeth 3 and 10 fault-tolerant teeth 2, and there are independent fault-tolerant teeth 2 between the armature teeth 3 of each phase, and the armature teeth 3 and the fault-tolerant teeth 2 are arranged alternately. A torque winding 4 is wound around the armature tooth 3 .

The outer permanent magnet 6 has 18 poles, and the N and S poles are arranged alternately. They are all magnetized in the radial direction. On the outer surface of 7, there is a radial outer air gap 5 between the outer permanent magnet 6 and the 20 outer stator teeth, and the radial distance of the outer air gap 5 is 0.5 mm. The middle of the rotor iron core 7 is fixedly embedded with a magnetic isolation aluminum ring 8 , which divides the rotor iron core 7 into inner and outer parts, and is closely attached to the inner and outer rotor iron cores 7 . On the inner surface of the rotor iron core 7, 4 pole inner permanent magnets 9 are evenly distributed, and the inner permanent magnets 9 are all magnetized in the radial direction. The arc is 60°. Six inner stator teeth 11 are evenly fixed on the outer circumferential surface of the inner stator yoke 13 along the circumferential direction, and a levitation force winding 12 is wound on the inner stator teeth 11 . There is a radial inner air gap 10 between the inner stator teeth 11 and the inner permanent magnet 9, and the radial distance of the inner air gap 10 is 0.5 mm.

The torque winding 4, the outer permanent magnet 6 and the rotor core 7 work together to realize the rotation of the motor, and the suspension force winding 12, the inner permanent magnet 9 and the rotor core 7 work together to realize the stable suspension of the rotor.

The torque winding 4 adopts a fault-tolerant tooth structure with 20 slots and unequal tooth width. It is composed of five phases A, B, C, D, and E. It adopts fractional slot concentrated winding. The torque winding 4 of each phase is composed of 2 coils. 10 coils, coil press (A+)→(D-)→(B+)→(E-)→(C+)→(A-)→(D+)→(B-)→(E+)→(C-) Distributed on the armature teeth 3 in the counterclockwise direction in turn. The torque winding 4 is wound with concentrated spaced teeth, each phase winding is wound on one armature tooth 3, and each phase winding is separated by a fault-tolerant tooth 2, and the ends of the windings do not overlap each other to achieve thermal isolation.

The levitation force winding 12 is composed of a, b, and c three-phase levitation force windings, which are respectively spaced at 120° in space angle. Concentrated windings are used. Each phase levitation force winding 12 is composed of 2 coils, a total of 6 coils. The levitation force winding 12 is 2 poles. Among them, the a-phase suspension force winding is composed of coils a ₁ and a ₂ , the b-phase suspension force winding is composed of coils b ₁ and b ₂ , and the c-phase suspension force winding is composed of coils c ₁ and c ₂ . And the six coils are distributed on the inner stator teeth 11 along the counterclockwise direction in the order of coils a ₁ →c ₁ →b ₁ →a ₂ →c ₂ →b ₂ . Connect the coils a ₁ and a ₂ in series as the a-phase suspension force winding, connect the coils b ₁ and b ₂ in series as the b-phase suspension force winding, and connect the coils c ₁ and c ₂ in series as the c-phase suspension force winding.

The 18 outer permanent magnets 6 are attached to the outer surface of the rotor iron core 7 at intervals in the order of N and S, and the 18 outer permanent magnets 6 work together with the torque winding 4 to realize the rotation of the motor. The 4-pole inner permanent magnet 9 is magnetized in the radial direction, and is attached to the inner surface of the rotor core 7 in the clockwise direction in the order of N and S. The 4-pole inner permanent magnet 9 and the 2-pole suspension force winding 12 work together to realize Stable suspension of the motor.

In the existing double-stator motor structure, the torque winding basically adopts a three-phase permanent magnet motor. The torque of the brushless DC motor is greater than that of the permanent magnet motor, and the torque of the five-phase brushless DC motor is greater than that of the three-phase motor. The same current, The torque output of the five-phase brushless DC motor is greater, and in the 360° electrical angle that the motor rotor rotates, the three-phase brushless DC motor changes direction every 60° electrical angle, while the five-phase brushless DC motor The direction is changed every 36° electrical angle, so the torque ripple of its synthetic torque is smaller than that of the three-phase brushless DC motor, and the five-phase motor is easier to achieve fault-tolerant control. In the present invention, the five-phase torque winding 4 adopts a star connection and adopts a five-phase H-bridge drive mode. When the motor is working normally, the rotor rotates counterclockwise. At any moment, the four-phase torque winding 4 is energized at the same time. See Figure 2. The energization time of each phase is 144°, and the current phases of the phases A, B, C, D, and E are sequentially The difference is 72°, and the direction is changed every 36° electrical angle. Refer to Figure 3, where A, B, C, D, and E directions are the magnetic potential directions when each phase is energized separately, and F _AB/CD is the composite magnetic potential direction when the four phases A, B, C, and D are simultaneously turned on. And phases A and B are conducted by the upper bridge arm, and phases C and D are conducted by the lower bridge arm. The 10 combined conduction modes and synthetic magnetic potentials of the four-phase torque winding 4 are shown in Figure 3, which are the magnetic potentials F _{AB /DE} , F _BC/DE , F _{BC / AE} , F _CD/AE , F _CD/AB , F _DE/AB , F _DE/BC , F _AE/BC , F _AE/CD form a circle. The energization sequence of the torque winding 4 depends on the angular position θ of the rotor. According to the principle that the armature magnetic potential is perpendicular to the rotor magnetic field to generate the most effective torque, when the angular position θ of the rotor is -18°~18°, select the magnetic potential When F _BC/DE is valid, the upper bridge arm of phase B and C is turned on, and the lower bridge arm of phase D and E is turned on; when θ is between 18°~54°, the selected magnetic potential F _BC/AE is valid, and B is turned on , the upper bridge arm of phase C, conducts the lower bridge arm of phase A and E; when θ is between 54°~90°, selects the magnetic potential F _CD/AE to be effective, then conducts the upper bridge arm of phase C and D, and conducts A , the lower bridge arm of phase E; when θ is between 90° and 126°, the magnetic potential F _CD/AB is selected to be effective, then the upper bridge arm of phase C and D is turned on, and the lower bridge arm of phase A and B is turned on; when θ is at When 126°~162°, select the magnetic potential F _DE/AB to be effective, then turn on the upper bridge arms of D and E phases, and turn on the lower bridge arms of A and B phases; when θ is 162°~198°, select the magnetic potential When F _DE/BC is valid, the upper bridge arms of D and E phases are turned on, and the lower bridge arms of B and C phases are turned on; when θ is between 198°~234°, the selected magnetic potential F _AE/BC is valid, and A is turned on , the upper bridge arm of phase E, conducts the lower bridge arm of phase B and C; when θ is between 234°~270°, selects the magnetic potential F _AE/CD to be effective, then conducts the upper bridge arm of phase A and E, and conducts C , the lower bridge arm of phase D; when θ is between 270°~306°, the magnetic potential F _AB/CD is selected to be effective, then the upper bridge arm of phase A and B is turned on, and the lower bridge arm of phase C and D is turned on; when θ is at When 306°~342°, the magnetic potential F _AB/DE is selected to be effective, then the upper bridge arms of phase A and B are turned on, and the lower bridge arms of phase D and E are turned on. According to this conduction sequence, the synthetic magnetic potential of the torque winding 4 rotates counterclockwise to generate rotational torque to make the motor rotate. In order to form a trapezoidal back EMF with a flat top of 144°, the armature teeth 3 and the fault-tolerant teeth 2 are not equal in width, and the torque windings 4 of each phase are separated by the fault-tolerant teeth 2, which plays an isolation role. Each width of the pivot tooth 3 can easily form a trapezoidal wave back EMF with a flat top of 144°, which not only enables each phase to form its own closed magnetic circuit through the fault-tolerant tooth 2, thereby realizing magnetic isolation, but also avoids phase-to-phase contact to a certain extent. The heat exchange between them realizes thermal isolation and realizes the brushless DC motor structure. At the same time, the fault-tolerant tooth 2 can realize the complete isolation of magnetic field, heat, and physics. Each phase can be regarded as an independent part. When a phase winding fails, the phase is cut off, and the motor can be realized by compensating other phases. normal operation.

In the existing double-stator motor structure, the suspension force winding of the inner stator adopts a four-pole structure and is driven by two differential power amplifiers. In the present invention, the inner stator levitation force winding 12 adopts a three-phase structure similar to that of an ordinary motor, and is driven by an inverter. The levitation force in the three-degree-of-freedom direction of phase a, b, and c is adjustable, and can provide more accurate synthetic levitation force. When the rotor is suspended, the energization sequence of the three-phase suspension force winding 12 depends on the eccentric position of the rotor. If the center point of the rotor deviates to the negative direction of the x -axis, the levitation force current in the positive direction of the x -axis can be controlled to pull it back to the center position. The suspension force winding 12 and the torque winding 4 are controlled independently of each other, and the currents of the suspension force winding have a phase difference of 120° according to directions a, b, and c. Referring to Fig. 4, when the phase a current is the positive maximum u _a1 , the b and c phase currents are negative u _b1 and u _c1 respectively. When the suspension force winding of phase a is energized as shown in Figure 5, the current direction of phase b and c is opposite to that of Figure 5. a ₁ phase is in the same direction as the positive direction of the x -axis, let the b ₁ and c ₁ directions be the positive directions of the b and c phases respectively, the magnetic force line 14 of the suspension force winding and the magnetic force line 15 of the inner permanent magnet refer to the dotted line in Fig. 5, and the magnetic field in the negative direction of the x -axis increases , the magnetic field in the positive direction of the x -axis is weakened, while the magnetic field in the opposite direction of b and c is strengthened, and the magnetic field in the positive direction is weakened. Compared with the levitation force winding 12, the rotor is an outer rotor, so the levitation force F _a in the positive direction of the x -axis is generated, and the levitation forces F _b and F _c in the positive direction of b and c are generated. See Figure 6(a), the levitation force F _a is greater than F _b and F _c , by adjusting the a, b, c three-phase current to change the three-phase levitation force of F _a , F _b , F _c , the rotor that shifts to the negative direction of the x -axis will be pulled back to the center. See Figures 6(b) and 6(c) for the same reason. When the b-phase and c-phase levitation force windings pass through the positive maximum current respectively, the levitation forces generated are respectively F _b , F _c , distributed along the b and c axes, and the levitation The direction of the levitation force generated when the three phases of the force winding are turned on together determines a plane, changing the magnitude of the current of the corresponding levitation force winding can generate a levitation force with controllable size and direction in this plane, with three degrees of freedom a, b, and c The adjustable direction makes the output of the suspension force more accurate, thereby supporting the rotor to stabilize the suspension.

Claims (7)

1. a bimorph transducer bearing-free five-phase brushless DC motor, it is characterized in that: by external stator yoke (1), fault-tolerant teeth (2), armature tooth (3), outer permanent magnet (6), rotor core (7), every magnetic aluminium ring (8), interior permanent magnet (9), internal stator tooth (11), internal stator magnet yoke (13), torque winding (4) and levitation force winding (12) composition, external stator yoke (1), concentric is nested from outside to inside for rotor core (7) and internal stator magnet yoke (13) three, external stator yoke (1) inner peripheral surface is along the circumferential direction evenly fixed with 10 armature tooths (3) and 10 fault-tolerant teeths (2) of interlaced arrangement, (3) are wound with A to armature tooth, B, C, D, E five phase torque winding (4), every phase winding is around on 1 armature tooth (3), the outer surface of rotor core (7) is evenly distributed with 18 extremely outer permanent magnets (6), 18 extremely outer permanent magnet (6) head and the tail are fixedly connected, and all magnetize by radial direction and the extremely interlaced layout of N, S, the centre of rotor core (7) is fixedly embedded with every magnetic aluminium ring (8), rotor core (7) inner surface is uniformly distributed 4 extremely interior permanent magnets (9), 4 extremely interior permanent magnets (9) distribute along clockwise direction by the order of N, S and all magnetize by radial direction, internal stator magnet yoke (13) outer circumference surface is along the circumferential direction evenly fixed 6 internal stator teeth (11), internal stator tooth (11) is wound with levitation force winding (12), armature tooth (3), between fault-tolerant teeth (2) and outer permanent magnet (6), there is the outside air gap in footpath, between internal stator tooth (11) and interior permanent magnet (9), there is the inside air gap in footpath.

2. bimorph transducer bearing-free five-phase brushless DC motor according to claim 1, is characterized in that: be separated by 30 ° between adjacent two interior permanent magnets (9), often extremely in the shared radian of permanent magnet (9) be 60 °.

3. bimorph transducer bearing-free five-phase brushless DC motor according to claim 1, it is characterized in that: every phase torque winding (4) is made up of 2 coils, totally 10 coils are distributed on armature tooth (3) successively in the counterclockwise direction by (A+) → (D-) → (B+) → (E-) → (C+) → (A-) → (D+) → (B-) → (E+) → (C-).

4. bimorph transducer bearing-free five-phase brushless DC motor according to claim 3, it is characterized in that: described torque winding (4) adopts star link, adopt five phase H bridge type of drive, when motor normally works, rotor core (7) is rotated counterclockwise, all have four phase torque windings (4) to be energized at any one time, every phase conduction time is 144 ° simultaneously.

5. bimorph transducer bearing-free five-phase brushless DC motor according to claim 4, is characterized in that: work as rotor angle location θ-18 ° ~ 18 ° time, brachium pontis in B, C phase of conducting H bridge, the lower brachium pontis of conducting D, E phase; When θ18 ° ~ 54 ° time, brachium pontis in conducting B, C phase, the lower brachium pontis of conducting A, E phase; When θ54 ° ~ 90 ° time, brachium pontis in conducting C, D phase, the lower brachium pontis of conducting A, E phase; When θ90 ° ~ 126 ° time, brachium pontis in conducting C, D phase, the lower brachium pontis of conducting A, B phase; When θ126 ° ~ 162 ° time, brachium pontis in conducting D, E phase, the lower brachium pontis of conducting A, B phase; When θ162 ° ~ 198 ° time, brachium pontis in conducting D, E phase, the lower brachium pontis of conducting B, C phase; When θ198 ° ~ 234 ° time, brachium pontis in conducting A, E phase, the lower brachium pontis of conducting B, C phase; When θ234 ° ~ 270 ° time, brachium pontis in conducting A, E phase, the lower brachium pontis of conducting C, D phase; When θ270 ° ~ 306 ° time, brachium pontis in conducting A, B phase, the lower brachium pontis of conducting C, D phase; When θ306 ° ~ 342 ° time, brachium pontis in conducting A, B phase, the lower brachium pontis of conducting D, E phase.

6. bimorph transducer bearing-free five-phase brushless DC motor according to claim 1, is characterized in that: levitation force winding (12) is made up of a, b, c three-phase levitation force winding, respectively 120 °, interval space angle, and every phase levitation force winding (12) is made up of 2 coils.

7. bimorph transducer bearing-free five-phase brushless DC motor according to claim 1, is characterized in that: armature tooth (3) is not wide with fault-tolerant teeth (2).