Electronically switched reluctance motor

• US 6,262,510 B1
• Filed: 11/10/1998
• Issued: 07/17/2001
• Est. Priority Date: 09/22/1994
• Status: Expired due to Fees

• Current Assignee: Electric Drive Technology AG
• Original Assignee: Iancu Lungu
• Inventors: Lungu, Iancu
• Primary Examiner(s): TAMAI, KARL I
• Application Number:
  US08/809,238
• Time in Patent Office: 980 Days
• Field of Search: 310/166, 310/168, 310/254, 310/68.B, 310/216, 310/218, 310/214, 318/701, 318/254
• US Class Current: 310/216.023
• CPC Class Codes: H02K 1/143 of the horse-shoe type
• CPC Class Codes: H02K 19/103 Motors having windings on the stator and a variable reluctance soft-iron rotor without windings
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• CPC Class Codes: H02K 7/14 Structural association with mechanical loads, e.g. with hand-held machine tools or fans with fan or impeller for cooling the machine H02K9/06
• CPC Class Codes: H02P 25/089 Sensorless control direct torque control H02P23/30

Abstract

This motor has a special magnetic circuit which enables it to be powered by a very simple electronic circuitry. This motor has, according to the figure, four U-shaped Yokes (11, 112) with eight unevenly spaced poles (111) surrounding a rotating six-pole rotor (12). The motor is driven by two power semiconductor devices (21) controlled from a Hall sensor (31). The demagnetising energy being set free by switching off the main windings (112X) will be directed through the coupling diodes (22) as premagnetising energy to the secondary windings (113Y) of the following phase (Y). This motor with high speed capability which is inexpensive, simple and quietly running can be mainly used for pumps, fans and blowers for gases and fluids.

Claims

1. Electronically switched reluctance motor with wound yokes (11) magnetically separated from each other for the generation of a pulsating magnetic field and with a rotor (12) that is rotatable in relation to the yokes (11) with the rotor poles (121) which are attractable by the poles (111) of the yokes, in which case this atraction in dependence of the position of the rotor poles (121) relative to the poles (111) of the wound yokes (11) is electronically controllable, while at least one winding (112) of a yoke (11) is switchable by means of a power semiconductor (21) in series with a d.c. voltage source and the power conductor (21) is controllable in dependence of the position of the rotor poles (121) relative to the poles (111) of the yokes (11), the poles (111) of the wound yokes (11) as well as those of the rotor (121) are disposed in pairs and diametrically symmetrical relative to the rotating shaft (52) of the motor and wherein, between the rotor poles (121) of the rotor (12), non-magnetic gaps (122) exist and the rotor poles (121) are connected by a yoke (123),

characterized in that the yokes (11) are U-shaped and the number of U-shaped yokes (11) is four, the yokes (11) carry windings (112), which, on a circular circumference, form eight magnetic poles (111), the number of the rotor poles (121) of the rotor (12) is six and the distance between the external corners of the poles (111X,111Y) of adjacent yokes within the region of the air gap is smaller than the distance between the internal corners of the two poles of a yoke (11) within the region of the air gap.

2. Motor according to claim 1,

characterized in that it is an electronically commutated two phase (X, Y) motor.

3. Motor according to claim 1,

characterized in that the distance between the external corners of the poles (111X, 111Y) of adjacent yokes (11) within the region of the air gap is selected to be small that it is optimized with regard to the magnetic losses, while the distance is at least three times as large as the air gap.

4. Motor according to claim 1,

characterized in that the yokes (11X, 11Y), within the region between the windings (112) and the rotor (12) are reciprocally attached so as to be disposed in a radial arrangement.

5. Motor according to claim 1,

characterized in that the yokes (11) are provided with recessed or elevated points (116) which engage into corresponding recessed or raised points in counterparts (55) disposed between the windings (112) and the rotor (12) for the positive attachment of the yokes (111).

6. Motor according to claim 5,

characterized in that the counterparts (55) form component parts of mounting pieces (56) which are secured to a baseplate (57) of a rigid, non-magnetic frame (5), and in that the magnetically acting parts (11,12) of the frame are positioned relative to each other with the aid of the frame (5).

7. Motor according to claim 1,

characterized in that it possesses windings (112, 113) which are fabricated from at least one spirally wound metallic tape, while the windings are insulated from one another by an insulating sheeting or by means of an insulating layer applied to the tape.

8. Motor according to claim 7,

characterized in that the same possesses at least one main winding (112) with a secondary winding (113), said windings being comprised of metallic tapes and are wound at a distance next to each other and parallel to each other.

9. Motor according to claim 1,

characterized in that the same possesses a multipolar magnetic disk (32) secured to the rotor (12) and only one Hall sensor (31) having a digital or analog output, in front of which the magnetic disk (32) is rotatable relative to the motor windings for controlling the current supply.

10. Motor according to claim 1,

characterized in that a digital output of a rotor position detecting sensor (31) triggers direct the gate electrode of a power semiconductor (21Y) for selecting a winding and triggers indirect, by means of a switching semiconductor (28) supplying the complementary logical state, another power semiconductor (21Y) for another winding.

11. Motor according to claim 1,

characterized in that the power or speed control can be effected with the aid of a phase shift of the triggering signals from power semiconductors (21) for triggering the windings (112), whereas the phase shift can be effected with the aid of a local displacement of the position of a hall sensor (31) or by means of the action of a magnetic field.

12. Motor according to claim 1,

characterized in that the direction of rotation of the motor can be effected with the aid of the inversion of the logical signal of a Hall sensor (31) or with the aid of the changing over between two Hall sensors (31), that are disposed in different angular positions relative to the yokes (11).

13. Motor according to claim 1, characterized in that,

with the aid of logical comparison processes of the inductivity of the magnetic circuits (1) relative to the rotor (2), the rotor position is detectable and in that this electronic information can be utilized for controlling the running or the starting of the motor for the successive triggering of power semiconductors (21) for the triggering of the windings (112).

14. Motor according to claim 1,

characterized in that the control fo the semiconductors (21) for the triggering of the windings (112) takes place with the aid of an electronic circuit having a fixed program not comprising the detection of the rotor position.

15. Motor according to claim 1,

characterized in that the same possesses a rotor with a squirrel cage winding.

16. Motor according to claim 1,

characterized in that the same possesses a rotor chamber which is sealed to the outside with the aid of a thin shell (512) comprised of plastic, of a polymer or elastomer layer or of a metallic alloy possessing suitable magnetic or electrical properties, in which the shell is acted upon by compressive forces merely in small intermediate areas and, with the largest part of its surface area, is supported upon the external poles (111) or upon a non-magnetic filling disposed between the external poles (111).

17. Motor according to claim 1,

characterized in that the rotor (12) of the motor is positively connected to the pump rotor (62) of a motor-driven pump, in which the rotor (12) of the motor and the pump rotor (62) are mounted on a shaft (52), preferably comprised of ceramic material, which is rotatable between bearings (54) so that the shaft (52) does not transmit any torque stress of the pump rotor to the rotor (12) of the motor.

18. Motor according to any of the preceding claims,

characterized in that the same possesses lamellae that are secured to one another by means of an insulating adhesive agent possessing elastic properties.

19. Electronically commutated D.C. motor with at least two magnetically separated yokes (11) carrying windings (112) which are angularly disposed relative to each other in the direction of rotation of the motor, wherein the demagnetization energy which is produced when the windings (112) are disconnected, is reciprocally transmissible by the yokes (11) with the aid of coupling diodes (22), more particularly according to claim 1,

characterized in that the self-induction voltage (Ua), which comes from a winding (112), can be tapped at a joint between this winding and a power semiconductor (21) for triggering the winding (112) and, by means of a coupling diode (22), can be connected direct to the beginning of a winding (112) disposed on the functionally following yoke (11).

20. Motor according to claim 19,

characterized in that, in each case, not more than one power semiconductor (21) is connected in series with a winding (112).

21. Motor according to claim 19,

characterized in that, the yokes (11), in addition to the windings serving (113), and in that the self-induction voltage (Ua) coming from a main winding (112), can be tapped at a joint between this main winding and a power semiconductor (21) for triggering the main winding (112) and can be conducted through diodes (22) to the beginning of a secondary winding (113) mounted upon a functionally following yoke (11).

22. Motor according to the claim 21,

characterized in that the self-induction voltage (Ua) produced when a control semiconductor (21) is disconnected, during the period of time in which a rotor position sensor (31) does not change its logical state, can be returned with the aid of further, controllable semiconductors (211) to the main winding (112) wherein it originated.

23. Motor according to the claim 22,

characterized in that the power semiconductors (21,211) of a phase (X,Y) become simultaneously conductive, but the blocking of the further semiconductors (211) only takes place with the change in the logical state at the output of the rotor position sensor (31).

24. Motor according to the claim 1,

characterized in that the peak of the self-induction voltage (Ua) can be stored in a capacitor (25) for gaining the control voltage of a power semiconductor (21).

25. Electronically commutated motor according to claim 1,

characterized in that the rotor (12) and the external rotor comprising wound yokes (11) with a support (S) and in that the rotor (12) and the external rotor are rotatable in the opposite direction for the generation of, in each case, a part of the utilizable motor output.

26. Motor according to the claim 25,

characterized in that the support (S) possesses two bearings (541,542) for supporting a rotating shaft (52), while an external rotor support (5) for the external rotor (11) rotatable conjointly with the rotary shaft (52) is mounted on the rotary shaft (52) and in that the rotary shaft (52), on its extremities, possesses brushes (521+, 521−

) for the transmission of the energy required by the motor.

27. Motor according to the claim 26,

characterized in that the rotor is provided with fluidic displacement parts (641) and is insertable into the interior of the external rotor (11) or of the external rotor support (5) and is rotatable by means of a bearing (543) in relation to the latter.

28. Motor according to the claim 25,

characterized in that both the rotor (12) as well as the external rotor (11) drive fluidic displacement parts (64,641) of a counterrotating blower or of a counterrotating pump.

29. Motor according to the claim 25,

characterized in that the control of the motor output can be effected by a stationary part devoid of galvanic contact, more particularly with the aid of optoelectric means, or by the action of magnetic fields upon the electronic rotating modules of the motor.