US20020063484A1

US20020063484A1 - Single-stator-double-rotor rotating motor

Info

Publication number: US20020063484A1
Application number: US09/751,980
Authority: US
Inventors: Ping-Ho Chen
Original assignee: National Chung Shan Institute of Science and Technology NCSIST
Current assignee: National Chung Shan Institute of Science and Technology NCSIST
Priority date: 2000-10-06
Filing date: 2000-12-29
Publication date: 2002-05-30
Anticipated expiration: 2020-12-29
Also published as: JP2002186230A; DE10060825A1; US6455969B1

Abstract

The present invention discloses a single-stator-double-rotor rotating motor, mainly comprises at least one upper-layer rotor, at least one intermediate-layer armature and at least one lower-layer rotor. The upper-layer rotor and lower-layer rotor are embedded with the same number of magnets to form a “magneto type” magnetic pole, stator electrodes of the same number as the number of magnets are disposed on the intermediate-layer armature to form a “electro type” magnetic pole. The characteristic of the present invention is that a skew symmetry exists between an upper-layer rotor and a corresponding lower-layer rotor, and the at least one upper-layer rotor and at least one lower-layer rotor are rotated in opposite directions by changing the direction of the current flowing through exciting coils every T/N of time, wherein T is a rotation cycle of the upper-layer rotor, and N is the number of the magnets.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rotating motor, and particularly to a single-stator-double-rotor (SIR 2) rotating motor.

2. Description of Related Art

In a prior motor structure, a rotor is rotated in one direction, but a Gyro effect will be induced and thus it is difficult to control the rotating direction of the motor's shaft.

Another prior rotating motor includes two totors rotating in opposite directions, and in general has three structures as follows:

(1) a reduction and reverse mechanism of a gasoline engine;

(2) two mutually independent motors rotating in opposite directions; and

(3) a single motor, whose rotating rotors and stators are rotated in opposite directions.

Disadvantages of the first structure include a big noise, a high frequency to refill the engine with gasoline, and a need for a reduction and reverse mechanism. Besides, to drive a gasoline engine is less convenient, as compared with an electronically or electro magnetically controlled engine.

Disadvantages of the second structure include a high cost, high loading and a need for two sets of driving circuits.

A disadvantage of the third structure is difficult to control the rotating speed between a rotor and a stator.

SUMMARY OF THE INVENTION

A first object of the present invention is to provide a rotating motor with a large energy efficiency to directly transform an electrical power to a mechanic power.

A second object of the present invention is to provide a rotating motor with a simple structure, which performs a high efficient power with a low weight.

A third object of the present invention is to provide a rotating motor with a low noise, which can directly drive a motor without a speed-reducing mechanism.

A fourth object of the present invention is to provide a rotating motor with a brushless form to reduce a maintenance fee.

A fifth object of the present invention is to provide a rotating motor which is free from a Gyro effect to enhance the controllability of rotation direction.

The present invention can be applied to a rotating motor in a military torpedo for controlling the thrust of the torpedo. In addition to generating a thrust to overcome water resistances, the rotating motor of the present invention also balances the thrust in the axis of the rotating motor to avoid generating a torque. The present invention can be farther applied to a military double-rotor Gyro equipment, whose speed could be improved by changing angular momentum during rotation. The third application of the present invention is a mower, which could be directly driven without a speed-reducing and reverse mechanism. Since a brushless form is adopted, there will be no sparkle generated by the rotating motor.

The present invention mainly comprises at least one upper-layer rotor, at least one intermediate-layer armature and at least one lower-layer rotor. The upper-layer rotor and lower-layer rotor are embedded with the same number of magnets to form a “magneto type” magnetic pole, stator electrodes of the same number as the number of magnets are disposed on the intermediate-layer armature to form an “electro type” magnetic pole. The characteristic of the present invention is that a skew symmetry exists between an upper-layer rotor and a corresponding lower-layer rotor, and the at least one upper-layer rotor and at least one lower-layer rotor are rotated in opposite directions by changing the direction of the current flowing through exciting coils every T/N of time, wherein T is a rotation cycle of the upper-layer rotor, and N is the number of the magnets.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described according to the appended drawings in which: [0019]
FIG. 1 shows a cross-sectional view of the single-stator-double-rotor rotating motor according to an embodiment of the present invention; [0020]
FIG. 2 shows a schematic diagram of upper-layer motors, the armature layer and lower-layer motors of the single-stator-double-rotor rotating motor according to the present invention; [0021]
FIG. 3 shows a schematic diagram of forming a magnetic torque of the single-stator-double-rotor rotating motor according to the present invention; [0022]
FIG. 4 shows another schematic diagram of forming a magnetic torque of the single-stator-double-rotor rotating motor according to the present invention; [0023]
FIG. 5 shows a schematic diagram of an armature winding of the stator electrodes according to the present invention; [0024]
FIG. 6 shows a schematic diagram of magnetic torque distributions of starting coils when starting and kicking according to the present invention; [0025]
FIG. 7 shows a timing diagram of current phases of a stator electrode and voltage phases of Hall components according to the present invention, and [0026]
FIG. 8 shows a current-driving circuit according to the present invention.[0027]

PREFERRED EMBODIMENT OF THE PRESENT INVENTION

FIG. 1 shows a cross-sectional view of an embodiment of the single-stator-double-rotor (SIR[0028] 2) rotating motor according to the present invention.
The [0029] SIR2 rotating motor 10 comprises at least one upper-layer rotor 11, at least one lower-layer rotor 12 and an armature layer 13. The motor 10 is formed as a ring structure. Magnets 14, 15 are attached to the upper-layer is rotor 11 and lower-layer rotor 12. The armature 13 is winded. Both ends of the SIR2 rotating motor 10 have their applications, such as a scissor 16 of a mower. With the torque generated by the upper-layer rotor 11 and lower-layer rotor 12, the scissor 16 will be continuously opened and closed to execute its job.
FIG. 2 shows a schematic diagram of the upper-layer motors, the armature layer and the lower-layer motors of the single-stator-double-rotor rotating motor according to the present invention. In FIG. 2, the upper-[0030] layer rotor 11 and lower-layer rotor 12 are embedded with a plurality of magnets respectively, and the ring structures of the upper-layer rotor 11 and lower-layer rotor 12 are spread. In other words, a magnet 21 of the upper-layer rotor 11 is neighboring to magnets 22 and 23 of he upper-layer rotor 11 in the ring structures, and a magnet 24 of the lower-layer rotor 12 is neighboring to magnets 25 and 26 of the lower-layer structures. Besides, the neighboring magnets of the upper-layer rotor 11 and the lower-layer rotor 12 have opposite polarities. In FIG. 2, it can be found that the magnetism distributions of the plurality of magnets are symmetrical. For example, the magnet 21 of the upper-layer rotor 11 corresponds to the magnet 24 of the lower-layer rotor 12, the magnet 22 of the upper-layer rotor 11 corresponds to the magnet 25 of the lower-layer rotor 12. The symmetry phenomenon is called as “skew symmetry effect.” Since the distributions of the torques, the upper-layer rotors will move to the right, and the lower-layer rotors will move to the left. If the SIR2 rotating motor (not shown) is viewed from the top, the upper-layer rotors will rotate clockwise, and the lower-layer rotors will rotate counterclockwise.
FIG. 3 shows a schematic diagram of forming a magnetic torque of the single-stator-double-rotor rotating motor according to the present invention, wherein the rotating motor has 6 electrodes and 6 slots. A symbol {circle over (X)} represents a current flowing inward to the paper, and a symbol ⊙ represents a current flowing outward from the paper. The [0031] stator armature 13 is stacked by a plurality of laminated silicon steel sheets, to reduce the eddy current loss, and is divided into 6 groups of armatures. Each armature is winded with exciting coils U_A, U_B, V_A, V_B, W_A, and W_B. The notation “X” represents its loop torque direction. The exciting coils of the neighboring stator electrodes have opposite flowing directions of current. Therefore, 3 sets of magnetic flux loops are formed counterclockwise. For example, a loop is formed by a magnet 26 of the lower-layer rotors, an exciting coil V_Bof the stator electrodes, a magnet 21 of the upper-layer rotors, an upper yoke 31, a magnet 22 of the upper-layer rotors, an exciting coil V_Aof the stator electrode, a magnet 27 of the lower-layer rotors and a lower yoke 32. Besides, a first Hall component H1, a second Hall component H2 and a third Hall component H3 are placed beside the body of the exciting coil U_Aof the stator electrode, the body of the exciting coil U_Bof the stator electrode and a stator flange of the coil U_Ato convert a magnetic flux into a voltage signal. The magnetic torque τ is formed by a loop of a distorted magnetic flux to keep the upper-layer rotor rotating counterclockwise when viewed from the top. (i.e. moving to the right in a cross-sectional view), and keep the lower-layer rotor rotating clockwise when viewed from the top (i.e. moving to the left in a cross-sectional view).
FIG. 4 shows another schematic diagram of forming a magnetic torque of the single-stator-double-rotor rotating motor according to the present invention. The directions of current flow of the exciting coils U[0032] _A, U_B, V_A, V_B, W_Aand W_Bof 6 stator electrodes are opposite to those of the structure of FIG. 3, and the opposition is called as current commutation. Besides, since the directions of current flowing in the exciting coils of the neighboring stators are opposite, 3 sets of clockwise magnetic loops are formed. For example, a loop is formed by a magnet 24 of the lower-layer, a lower yoke 32, a magnet 26 of the lower-layer, an exciting coil V_Aof the stator electrode, a magnet 28 of the upper-layer rotor, upper yoke 31, a magnet 22 of the upper-layer rotor and an exciting coil V_Bof the stator electrode. The purpose of the brushless current commutation is to continuously drive the upper-layer rotor to rotate counterclockwise when viewed from top (i.e. moving to the right in a cross-sectional view), and continuously drive the lower-layer rotor to rotate clockwise viewed from the top (i.e. moving to the left in a cross-sectional view).
FIG. 5 shows a schematic diagram of an armature winding of the stator electrode according to the present invention. The structure of the stator electrode comprises a [0033] body 53, a left-top flange and a right-bottom flange. Start/kick coils 51, 52 are placed beside the left-top flange and right-bottom flange. For averaging the start torque in every cycle, a set of start/kick coils is winded on every stator electrode.
FIG. 6 shows a schematic diagram of magnetic torque distributions of starting coils when starting and kicking according to the present invention. When the magnets of the upper-layer rotor, stator electrodes and the magnets of the lower-layer rotor are in a straight line, strength of the magnetic torque is not generated by a flux distortion. At this moment, in a region, the magnets of the upper-layer and lower-layer rotors are rotated due to an inertia property. The region is called as a dead space or a neutral position. Besides, a current commutation will be performed in the dead space; therefore, an action of start and kick must be executed to force the SIR[0034] 2 rotating motor to switch the direction of current flow. The action of start and kick is performed by the start/kick coils 51, 52 winded on the left-top flange and right-bottom flange of the stator electrode in FIG. 5. Similar to the phenomenon of the magnetic torques in FIG. 3 and FIG. 4, the magnetic torque of the start/kick coils still has a skew symmetry effect. The magnetic torque τ is clockwise to force the upper-layer rotor to rotate counterclockwise when viewed from the top (i.e. moving to the right in a cross-sectional view), and force the lower-layer rotor to rotate clockwise when viewed from the top (i.e. moving to the left in a cross-sectional view). 3 sets of clockwise magnetic flux loop will be formed. For example, a loop is formed by a magnet 24 of the lower-layer rotor, lower yoke 32, a magnet 26 of the lower-layer rotor, a start/kick coil KVA of the stator electrode, a magnet 28 of the upper-layer rotor, an upper yoke 31, a magnet 22 of the upper-layer rotor and a start/kick coil KVB of the stator electrode. Besides, when starting, the directions of current flowing in the start/kick coils of the neighboring electrodes are opposite.
FIG. 7 shows a timing diagram of current phases of the stator electrode and voltage phases of the Hall components according to the present invention. Since the [0035] SIR2 rotating motor 10 has 6 electrodes and 6 slots in one mechanical cycle T, the directions of current flowing through the exciting coils U_A, U_B, V_A, V_B, W_Aand W_Bof the stator electrodes will change 6 times. During the period of current commutation of the exciting coils U_A, U_B, V_A, V_B, W_Aand W_Bof the stator electrodes, a kick action is activated by the start/kick coils, thereby alleviating the problem of instant huge voltage induced by the exciting coils when a current commutation happens. The leading edge and trailing edge of the waveform generated by the Hall component H3 are corresponding to a pulse D (H3) for generating a kick signal and commutation signal of the exciting coils U_A, U_B, V_A, V_B, W_Aand W_Bof the stator electrodes. In other words, every non-continuous point of a voltage curve outputted from the third Hall component H3 corresponds to a pulse signal for driving the plurality of start/kick coils winded around the stator electrodes. The Hall components H1 and H2 can form a close loop to monitor and control the speed of the SIR2 rotating motor.
FIG. 8 shows a current-driven circuit according to the present invention. One end of a [0036] speed controller 81 is connected to the Hall components H1, H2 and H3, and uses a fussy algorithm to control the phase and magnitude of an output voltage V_i. Another end of the speed controller 81 is connected to a transformation circuit 82, such as a well-known Darlington circuit. The exciting coils U_A, U_B, V_A, V_B, W_Aand W_Bof the stator electrodes are connected in series to form an exciting series coil 84. The start/kick coils KU_A, KU_B, KV_A, KV_B, KW_Aand KW_Bare connected in series to form a start/kick series coil 83. The exciting series coil and start/kick series coil are connected to one end of the transformation circuit 82. The exciting series coil 84 is, in a feedback form connected to the speed controller 81 through resistors R1 and R2 so as to feed back an end voltage through a resistor R11. The output voltage V_i, is proportional to a motor current I_m. Therefore, the current flowing into the exciting coil and start/kick coil of the stator electrodes can be adjusted automatically. The relationship of I_m, R1, R1, R11 and Vi is denoted by equation 1: $\begin{matrix} I_{m} = - \frac{R2 \times R11}{R1} \times V_{i} & (1) \end{matrix}$
When a current commutation of the exciting coils U[0037] _A, U_B, V_A, V_B, W_Aand W_Bof the stator electrodes happens, the instant current after the current commutation will flow into the start/kick series coil 83 to keep the continuity of current variance. Besides, a suitable time constant is obtained by adjusting the inductance and resistance of the start/kick series coil 83 to decide the period of the transient time of the start/kick action.
The above-described embodiments of the present invention are intended to be illustrated only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims. [0038]

Claims

What is claimed is:

1. A single-stator-double-rotor rotating motor, comprising at least one upper-layer rotor, at least one intermediate-layer armature and at least one lower-layer rotor; wherein said upper-layer rotor and lower-layer rotor are embedded with the same number of magnets, stator electrodes of the same number as the number of magnets are disposed on said intermediate-layer armature; characterized in that a skew symmetry exists between an upper-layer rotor and a corresponding lower-layer rotor, and the at least one upper-layer rotor and at least one lower-layer rotor are rotated in opposite directions by changing the direction of the current flowing through exciting coils every TIN of time, wherein T is a rotation cycle of the upper-layer rotor, and N is the number of the magnets.

2. The single-stator-double-rotor rotating motor of Claim 1, wherein the neighboring magnets on the at least one upper-layer rotor and the neighboring magnets on the at least one lower-layer rotor have opposite polarities, and the currents flowing through the exciting coils of the neighboring stator electrodes have opposite directions.

3. The single-stator-double-rotor rotating motor of claim 1, wherein each of said stator electrodes has flanges respectively on its top and bottom sides for use in winding start/kick coils, each of said start/kick coils is triggered when the at least one upper-layer rotor, the at least one intermediate-layer armature and the at least one lower-layer rotor are situated in a dead space for keeping the continuation of current variations when the directions of currents flowing through the exciting coils of the stator electrodes are changed.

4. The single-stator-double-rotor rotating motor of claim 3, wherein a first Hall component is situated beside a body of the stator electrode to transfer a magnetic flux passing the body of the stator electrode into a voltage signal; a third Hall component is situated beside the flange of another neighboring stator electrode to transfer a magnetic flux passing the body of the stator electrode into a voltage signal; and a second Hall component is situated beside the body of the neighboring stator electrode to transfer a magnetic flux passing the body of the stator electrodes into a voltage signal.

5. The single-stator-double-rotor rotating motor of claim 4, wherein every non-continuous point of a voltage curve outputted from the third Hall component corresponds to a pulse signal for driving the plurality of start/kick coils winded around the stator electrodes.

6. The single-stator-double-rotor rotating motor of claim 1, wherein the first and second Hall components are used to monitor and control the rotating speed of the rotating motor.

7. The single-stator-double-rotor rotating motor of claim 4, further comprising a driving circuit for controlling the current flowing through the exciting coils of the stator electrodes and start/kick coils, said driving circuit comprising:

a speed controller connected to the plurality of Hall components for generating an output voltage V_i;

a transformation circuit for generating an output current I_m;

an exciting series coil connected in series to the plurality of exciting coils winded around the bodies of the stator electrodes;

a start/kick series coil connected in series to the plurality of start/kick coils winded around the flanges of the stator electrodes; and

a feedback circuit connected to the exciting series coil, the speed controller and the transformation circuit.

8. The single-stator-double-rotor rotating motor of claim 7, wherein the feedback circuit is connected to the transformation circuit and speed controller with a resistor R1, then connected to the exciting series coil R2 with a resistor R2, and then connected to the ground with a resistor R11, wherein

I_{m} = - \frac{R2 \times R11}{R1} \times V_{i} .

9. The single-stator-double-rotor rotating motor of claim 7, wherein the transformation circuit is a Darlington circuit.

10. The single-stator-double-rotor rotating motor of claim 7, wherein in the dead space, the current flowing through the exciting series coil will flow into the power end of the start/kick coil to keep the continuity of current flowing through the exciting series coil when flowing directions are changed.