CN113928564B

CN113928564B - Rotor power system based on electrostatic driving

Info

Publication number: CN113928564B
Application number: CN202111411049.2A
Authority: CN
Inventors: 漆明净; 申威; 冷佳明; 刘志伟; 闫晓军
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-11-25
Filing date: 2021-11-25
Publication date: 2023-04-18
Anticipated expiration: 2041-11-25
Also published as: CN113928564A

Abstract

The invention provides a rotor wing power system based on electrostatic driving, which comprises a stator component, a rotor wing and a rotor wing, wherein the stator component comprises a positive electrode and a negative electrode which are connected with a high-voltage direct-current power supply; a rotor component at least partially located within the stator component; the invention provides an electrostatic drive rotor craft, and provides another possibility for a power system of the rotor craft.

Description

Rotor power system based on electrostatic driving

Technical Field

The invention relates to an aircraft, in particular to a rotor system based on electrostatic drive.

Background

The main power device of the existing micro aircraft is a propeller power device, and a micro electromagnetic motor is utilized to drive a propeller to rotate so as to generate lift force or thrust. The electromagnetic motor has the advantages of high rotating speed and high power, so that the electromagnetic motor is widely applied to the rotor craft.

The existing micro aircraft power device utilizes the traditional micro motor to drive the propeller to rotate, when the load of the propeller is increased, the interior of the micro motor can generate heat greatly due to the large increase of current, the energy conversion efficiency is greatly reduced, the power density can not be improved, even overheating and burnout occur, and in the process of further miniaturization, along with the reduction of the size, the output characteristic of the electromagnetic motor is obviously reduced, the energy density is reduced, the rotating speed is increased, the torque is reduced, a matched speed reducing and torque increasing device is needed, the structure is more complex, the reliability is reduced, and the safety is reduced. Taking several models of miniature electromagnetic machines manufactured by the company faulhaer (fuelhaber) as an example (as shown in table 1), the smaller the size of the electromagnetic machine, the faster the torque attenuation and the lower the maximum efficiency of the machine, so the electromagnetic machine has not been a good choice in order to meet smaller ultra-miniature aircraft and to meet long-endurance flight.

Product type	Size (mm)	Maximum efficiency%	Locked rotor torque mNm
				0308H003B	3	20	0.026
0515G006B	5	39	0.4
				0620K006B	6	50	0.73
0824K006B	8	70	3.34

TABLE 1 comparison of electromagnetic machine parameters at different sizes

Disclosure of Invention

The present invention has been made to solve at least one of the problems occurring in the prior art or the related art.

In order to achieve the above object, the present invention provides a rotor power system based on electrostatic driving, including:

the stator component comprises a positive electrode and a negative electrode which are connected with a high-voltage direct-current power supply, and an electrostatic field is formed between the positive electrode and the negative electrode;

the rotor part is positioned in the stator part and comprises a rotor wing assembly and a conducting strip;

the conducting strip of the rotor component can obtain electric charge from the positive electrode or the negative electrode of the stator component, so that the rotor component is driven by the stator component in a rotating mode; the positive electrode and the negative electrode are both multiple and are distributed in a crossed manner in the circumferential direction of the stator component.

The invention innovatively provides an electrostatic drive rotor craft, provides another possibility for a power system of the rotor craft, and particularly in the field of micro-rotor crafts, compared with an electromagnetic drive mode, the electrostatic drive mode has good performances, such as the advantages of easiness in miniaturization, low noise, high energy conversion efficiency and high power density, and the thrust-weight ratio of the power system is larger than 1, so that the first time of flight along a guide rail strip line by adopting the electrostatic drive rotor is realized.

Preferably, the stator member further comprises:

an upper support frame including an upper ring and an upper wire guide connected to the upper ring;

a lower support frame including a lower ring and a lower lead bar connected to the lower ring;

the upper supporting frame is connected with the lower supporting frame through a plurality of vertical beams arranged in the circumferential direction, the vertical beams are used as positive electrodes and negative electrodes and are distributed between the upper circular ring and the lower circular ring in the circumferential direction in a crossed mode, the positive electrodes are electrically connected with the positive electrode of the high-voltage direct-current power supply through the upper lead rods, and the negative electrodes are electrically connected with the negative electrode of the high-voltage direct-current power supply through the lower lead rods.

Preferably, the stator member further includes:

each positive electrode is correspondingly connected with an upper lead rod, the upper lead rods are radially arranged in the upper circular ring, all the upper lead rods are electrically connected together, and one positive electrode is electrically connected with the positive electrode of the high-voltage direct-current power supply through a positive electrode connecting wire;

each negative electrode is correspondingly connected with a lower lead rod, the lower lead rods are radially arranged in the lower circular ring, all the lower lead rods are electrically connected together, and one negative electrode is electrically connected with the negative electrode of the high-voltage direct-current power supply through a negative electrode connecting wire.

Preferably, the stator member further includes:

the positive electrode connecting wire and the negative electrode connecting wire are respectively connected to the adjacent positive electrode and the negative electrode.

Preferably, the rotor component further comprises:

a frame assembly rotatable and at least partially within the stator component;

the conducting strips are distributed on the circumferential outer side of the frame assembly and can pass through corona regions of the positive electrode and the negative electrode;

and the rotor assembly is fixedly connected with the frame assembly.

Preferably, the frame assembly further comprises:

the outer frame comprises a first annular outer frame and a second annular outer frame, and the conducting strip is positioned between the first outer frame and the second outer frame;

an inner frame including a ring-shaped first inner frame and a ring-shaped second inner frame;

the connecting rod is connected with the outer frame and the inner frame;

and a rotor assembly fixed between the outer frame and the inner frame.

Preferably, the method further comprises:

and the electric brush is positioned on the positive electrode, the negative electrode and/or the conducting sheet and can flexibly connect the electrode with the conducting sheet.

Preferably, the brush further includes:

the brush is a silver wire and is positioned on the electrode, and the cantilever end of the brush is radially inwards contacted with the conducting strip.

In addition, the invention also provides a motor.

An electrostatically driven motor comprising:

Has the beneficial effects that:

1) The invention innovatively provides an electrostatic drive rotor craft, the electrostatic drive mode has better performance than the electromagnetic drive mode, the electrostatic motor has simple structure, the electrostatic motor is widely applied in the MEMS field, the future further research and development prospect is very wide, the electrostatic motor is easy to micro-machine, the current is small (microampere level), the efficiency is high, almost no heat is generated, but the electromagnetic motor has low efficiency and serious heat generation under the micro size.

2) The invention can output larger torque by the electrostatic motor through the innovation of the electrostatic motor structure, and the side-driving type electrostatic driving mode can obtain larger torque, namely the force arm of the electrostatic driving is large, and larger distance can be obtained between the positive electrode and the negative electrode, so that larger voltage can be applied between the positive electrode and the negative electrode to generate larger electrostatic force. Moreover, the length of the conducting strip in the vertical direction can be increased continuously, so that larger electrostatic driving torque is obtained, and therefore, the invention has a large optimization space.

3) In the arrangement of the electric brush, a silver wire is extended out of the electrode to be used as the electric brush, so that soft contact between the rotor and the stator electrode is realized, and the gap between the rotor and the stator can be reduced to 0. The arrangement of the brush generates certain resistance, but larger electrostatic driving torque is obtained, and the electrostatic driving force is greatly improved.

4) The wiring mode of the invention ingeniously utilizes the structure itself to string all the electrodes into a whole (anode or cathode), and the upper lead rod and the lower lead rod are both a frame structure and a conductive structure, thereby simplifying the wiring structure and reducing the weight of the whole machine.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates a schematic structural diagram of a rotor power system based on electrostatic actuation according to an embodiment of the present invention;

figure 2 illustrates a perspective view of an electrostatic drive based rotor power system configuration according to an embodiment of the present disclosure;

figure 3 shows a schematic perspective view of a rotor component structure according to an embodiment of the invention;

FIG. 4 illustrates a perspective view of a stator component structure according to one embodiment of the present invention;

FIG. 5 is an enlarged view of the area A in the perspective view of the stator component structure of FIG. 4;

FIG. 6 shows a schematic diagram of a MEMS electrostatic motor (micron scale) architecture;

FIG. 7 shows a prior art electrostatic motor schematic;

FIG. 8 illustrates a prior art physical diagram of an electrostatic motor;

FIG. 9 illustrates an object made according to an embodiment of the invention.

The correspondence between the labels and the structures in fig. 1 to 9 is as follows:

the rotor power system 100, the rotor component 200, the first outer frame 21, the second outer frame 22, the connecting rod 23, the first inner frame 24, the second inner frame 25, the fan blade 26, the conducting strip 27, the bearing assembly 28, the stator component 300, the upper support frame 31, the lower support frame 32, the upper lead bar 33, the lower lead bar 34, the positive electrode 35, the negative electrode 36, the positive electrode connecting line 37, the negative electrode connecting line 38, the brush 39, the mems electrostatic motor 400, the rotor electrode 401, the bearing 402, and the stator electrode 403.

Detailed Description

So that the manner in which the above recited objects, features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

Some embodiments according to the invention are described below with reference to fig. 1 to 5.

Example 1:

the invention is based on the driving of an electrostatic motor, the working principle of the electrostatic motor is shown in figure 1, when direct-current high voltage is respectively applied to a positive electrode and a negative electrode, an electrostatic field is formed between the positive electrode and the negative electrode, and a corona zone is formed near the positive electrode and the negative electrode (the electric field near the electrodes is very strong, and the air near the electrodes can be ionized to form the corona zone, so that the air near the electrodes has the same charge as the polar plates of the electrodes); when conducting strip (can carry electric charge in the electric field) on the rotor part is through anodal (or negative pole), the conducting strip can take the electric charge the same with the polar plate, then can produce the repulsive force between conducting strip and electrode (anodal), promote the rotor part motion, the rotor that carries electric charge simultaneously can rush under the effect of electric field and reach next grade (negative pole), electric charge on the conducting strip is neutralized earlier and then is leading-in the electric charge the same with the negative pole, then can produce the repulsive force between conducting strip and electrode (negative pole), promote the rotor part motion, so the circulation is reciprocal and has formed a continuous driving force.

Therefore, based on the principle of fig. 1, the present embodiment first proposes an electrostatic motor.

An electrostatically driven motor comprising:

the rotor part is positioned in the stator part and comprises a rotor assembly and a conducting strip;

Figure 2 illustrates a perspective view of an electrostatic drive-based rotor power system 100 according to one embodiment of the present disclosure, including:

a stator part 300 including a positive electrode 35 and a negative electrode 36 connected to a high voltage dc power source, an electrostatic field being formed between the positive electrode 35 and the negative electrode 36;

a rotor component 200 located within the stator component 300, the rotor component 200 comprising a rotor assembly and a conductive strip 27;

wherein, the conducting strip 27 of the rotor component 200 can obtain the charge from the positive electrode 35 or the negative electrode 36 of the stator component 300, so that the rotor component 200 is driven by the stator component 300; each of the positive electrodes 35 and the negative electrodes 36 is plural and is distributed to intersect circumferentially in the stator member 300.

The electromagnetic motor has the beneficial effects that the electrostatic motor has small current (microampere level) and high efficiency, almost does not generate heat, but the electromagnetic motor has low efficiency and generates heat seriously under the condition of small size. The rotor power system based on electrostatic driving in fig. 2 has been verified and made into a finished product, as shown in fig. 9, the rotor power system based on electrostatic driving in fig. 9 is in a suspension state (because silver wires are used as positive and negative electrodes for supplying power, the silver wires are too fine and are not shown in fig. 9), the rotor power system based on electrostatic driving in the patent has the advantages of easy miniaturization, low noise, high energy conversion efficiency and high power density by adopting electrostatic driving, and the thrust-weight ratio of the power system is realized to be more than 1, in the test, the first time of flying along the guide rail strip line by adopting the electrostatic driving rotor is realized, and another possibility is provided for the power system of the rotor craft. Especially in the field of micro-rotor aircrafts, the electrostatic driving mode has a lot of good performance compared with the electromagnetic driving mode. In future research, the MEMS electrostatic motor can be further introduced, the structure is simple, the micro-processing is easy, and the application prospect is further expanded.

The invention is based on the core principle that the fan blades are driven by the electrostatic motor to generate lift force, and after the electrostatic driving force and the weight reduction are optimized, the lift-weight ratio is larger than 1, so that the whole aircraft can take off along the guide rail strip line. Theoretically, the configuration of the electrostatic motor drive can be multiple, and after configuration optimization and weight reduction optimization are completed, takeoff of the electrostatic drive rotor wing can be theoretically realized without the configuration in the embodiment of the invention.

Example 2:

in addition to the technical features of the above-mentioned embodiment, referring to fig. 3, the stator component 300 of the present embodiment further includes:

an upper support frame 31, which comprises an upper ring and an upper lead rod 33 connected to the upper ring, wherein the positive electrode 35 is electrically connected with the positive electrode of the high-voltage power supply through the upper lead rod 33;

a lower support frame 32 including a lower ring and a lower lead bar 34 connected to the lower ring, the negative electrode 36 being electrically connected to the negative electrode of the high voltage power supply through the lower lead bar 34;

wherein, the upper support frame 31 is connected with the lower support frame 32 through a plurality of vertical beams arranged along the circumferential direction, and the positive electrodes 35 and the negative electrodes 36 are distributed between the upper circular ring and the lower circular ring at intervals in the circumferential direction.

It should be noted that the upper ring and the lower ring are insulated, and the adjacent positive electrode and negative electrode are not fixed on the upper ring and the lower ring so that the charge transfer can not occur.

In fig. 1, the conductive sheet functions to carry charge to force movement between the electrodes, thereby imparting torque to the rotor member; as can be seen in fig. 3, the rotor assembly of the alternative rotor assembly may include a plurality of fan blades 26 as lift providing elements disposed within the electrostatic machine to provide increased structural efficiency, while the annular frame holding the conductive strips provides structural strength to the entire rotor, allowing the fan blades to be made very thin without significant deformation during movement. The upper and lower support frames are a part of the stator part 300, the vertical beam 8 supporting the upper and lower frames may be used as a positive electrode and a negative electrode, or a positive electrode and a negative electrode may be additionally provided, and the n pairs of electrodes are alternately arranged in a positive and negative direction or at intervals.

In the connection mode, as shown in fig. 3, taking the positive electrode connection as an example, a wire is embedded in the surface of the upper support frame 31 to connect the positive electrodes into a whole, and similarly, the negative electrodes on the lower support frame 32 are also connected together through a wire, so that 2n electrodes can be connected into a positive electrode connection port and a negative electrode connection port, then two wires are led out from the adjacent electrodes to be connected into a high-voltage direct-current power supply, and thus, the connection problem is solved.

Taking the wiring mode of fig. 4 as an example, the present embodiment has 12 pairs of electrodes, because high voltage of several kilovolts is input, and the conducting wire can only be exposed, so 12 electrodes (positive electrode or negative electrode) cannot be strung together by crossing electrodes (negative electrode is sandwiched between positive electrodes), and the conventional mode generally adopts independent power supply from the periphery to each electrode or wire insulation crossing electrode connection (as shown in fig. 6). The wiring mode of the invention skillfully utilizes the structure, and the internal upper lead rod 33 and the internal lower lead rod 34 are used for respectively stringing all the electrodes into an integral anode or cathode, and simultaneously, the upper lead rod 33 and the lower lead rod 34 are the force bearing structures of the frame.

Example 3:

in addition to the technical features of the above-described embodiment, referring to fig. 3, the rotor member 200 of the present embodiment further includes:

a frame assembly capable of rotation and located at least partially within the stator component 300;

the conducting strips 27 are distributed on the circumferential outer side of the frame assembly, and can pass through corona regions of the positive electrodes 35 and the negative electrodes 36;

and the rotor assembly is fixedly connected with the frame assembly.

In the embodiment, the electrostatic motor (the electrostatic driving part, which does not include the fan blades) is innovated to output larger torque. As shown in fig. 2-5, a side-driving electrostatic driving method is adopted, which can obtain a larger torque (a large force arm of electrostatic driving), and a larger distance can be obtained between the positive electrode and the negative electrode, so that a larger voltage can be applied between the positive electrode and the negative electrode to generate a larger electrostatic force. Most of the rotor parts of the traditional electrostatic motors adopt non-conductive insulators or semiconductors (as shown in fig. 7 and 8), while the rotor parts of the invention adopt conductive sheets which can carry more charges, the conductive sheets can be made of carbon fibers which can conduct electricity and have very high strength, so that the conductive sheets can be made to be very light. The length of the conducting strips in the vertical direction can be increased continuously, so that larger electrostatic driving torque is obtained, and a large optimization space is provided on the basis of the invention.

Example 4:

in addition to the technical features of the above embodiments, the frame assembly of the present embodiment further includes:

an outer frame including a first outer frame 21 and a second outer frame 22 in an annular shape, the conductive sheet 27 being located between the first outer frame 21 and the second outer frame 22;

an inner frame including a ring-shaped first inner frame 24 and a ring-shaped second inner frame 25;

the connecting rod 23 is connected with the outer frame and the inner frame;

and a rotor assembly fixed between the outer frame and the inner frame.

And a brush 39, wherein the brush 39 is positioned on the positive electrode 35, the negative electrode 36 and/or the conducting strip 27, and the brush can conduct electricity to the electrode and the conducting strip.

In the present embodiment, the magnitude of the electrostatic driving force of the electrostatic motor also depends on the gap between the rotor and the stator, and the smaller the gap, the closer the rotor is to the electrode (the closer the electrode, the stronger the corona field) and the more charge can be obtained. Because the invention has larger errors in processing and assembling, the clearance is between 0.6 and 1mm in order to avoid collision and abrasion, and thus large driving torque cannot be obtained. Taking the complete machine in FIG. 2 as an example, the weight is 960mg, the radius is 50mm, and the height is 14mm. Meanwhile, in order to obtain larger electrostatic driving torque, the clearance between the rotor component and the stator component must be reduced, but due to the precision problem of processing and assembling, the clearance cannot be made very small, a silver wire brush 39 is obliquely extended into the electrode in the radial direction, the soft contact between the rotor and the electrode is realized, the clearance between a rotor conducting strip and the electrode is 0, although the resistance of the rotor can be increased by adopting the brush, the improvement of the electrostatic force is larger than the increase of the resistance, and larger electrostatic driving torque is obtained. Through the arrangement of the electric brush, the electrostatic driving force is greatly improved, so that the takeoff is realized, which is the key of the invention.

In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless explicitly defined otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", "spatial horizontal", and "spatial longitudinal" and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or unit referred to must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotor power system (100) based on electrostatic actuation, comprising:

a stator component (300) comprising a positive electrode (35) and a negative electrode (36) connected to a high voltage direct current power supply, wherein an electrostatic field is formed between the positive electrode (35) and the negative electrode (36);

a rotor component (200) located within the stator component (300), the rotor component (200) comprising a rotor assembly and a conductive strip (27);

wherein the conducting strip (27) of the rotor component (200) can obtain electric charge from the positive electrode (35) or the negative electrode (36) of the stator component (300), so that the rotor component (200) is rotationally driven by the stator component (300); the positive electrodes (35) and the negative electrodes (36) are multiple and are distributed in the circumferential direction of the stator component (300) in a crossed manner;

the stator component (300) further comprises:

an upper support frame (31) including an upper ring and an upper wire guide (33) connected to the upper ring;

a lower support frame (32) including a lower ring and a lower wire bar (34) connected to the lower ring;

the upper support frame (31) is connected with the lower support frame (32) through a plurality of vertical beams which are arranged along the circumferential direction, the vertical beams are used as positive electrodes (35) and negative electrodes (36) and are distributed between the upper circular ring and the lower circular ring in the circumferential direction in a crossed manner, the positive electrodes (35) are electrically connected with the positive electrode of the high-voltage direct-current power supply through upper lead rods (33), and the negative electrodes (36) are electrically connected with the negative electrode of the high-voltage direct-current power supply through lower lead rods (34);

the rotor component (200) further comprises:

a frame assembly rotatable and at least partially within the stator component (300);

the conducting strips (27), the conducting strips (27) are multiple and distributed on the circumferential outer side of the frame assembly, and can pass through corona regions of the positive electrode (35) and the negative electrode (36);

and the rotor wing assembly is fixedly connected with the frame assembly.

2. The electrostatic drive-based rotary wing power system (100) of claim 1, wherein the stator component (300) further comprises:

each positive electrode (35) is correspondingly connected with an upper lead rod (33), the upper lead rods (33) are radially arranged in the upper circular ring, all the upper lead rods (33) are electrically connected together, and one positive electrode (35) is electrically connected with the positive electrode of the high-voltage direct-current power supply through a positive electrode connecting wire (37);

each negative electrode (36) is correspondingly connected with a lower lead rod (34), the lower lead rods (34) are radially arranged in the lower circular ring, all the lower lead rods (34) are electrically connected together, and one negative electrode (36) is electrically connected with the negative electrode of the high-voltage direct-current power supply through a negative electrode connecting wire (38).

3. The electrostatic drive-based rotary wing power system (100) of claim 2, wherein the stator component (300) further comprises:

the positive electrode connecting wire (37) and the negative electrode connecting wire (38) are respectively connected to the adjacent positive electrode (35) and negative electrode (36).

4. An electrostatic drive-based rotor power system (100) according to claim 1, wherein the frame assembly further comprises:

an outer frame including a first outer frame (21) and a second outer frame (22) in an annular shape, the conductive sheet (27) being located between the first outer frame (21) and the second outer frame (22);

an inner frame comprising an annular first inner frame (24) and an annular second inner frame (25);

the connecting rod (23) is connected with the outer frame and the inner frame;

and a rotor assembly fixed between the outer frame and the inner frame.

5. An electrostatic drive-based rotor power system (100) according to claim 4 further comprising:

and the electric brush (39), the electric brush (39) is positioned on the positive electrode (35), the negative electrode (36) and/or the conducting sheet (27), and the electrode and the conducting sheet (27) can be flexibly connected.

6. An electrostatic drive-based rotary wing power system (100) according to claim 5, wherein the brush (39) further comprises:

the brush (39) is a silver wire and is positioned on the electrode with its cantilevered end contacting the conducting strip (27) radially inwardly.