Three-degree-of-freedom spherical actuator based on hybrid winding and t-shaped stator

Abstract

The application relates to the motor technical field, in particular to a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-shaped stator, which comprises a frame, a rotating stator, a deflection rotor and a deflection stator; the rotating stator is rotationally connected to the frame; the deflection rotor is fixedly connected to the rotating stator; the deflection stator is fixedly connected to the frame; the rotating stator and the deflection stator are both annularly arranged at the middle part of the rotating stator; the distance between the deflection stator and the rotating stator is greater than the distance between the deflection rotor and the rotating stator; the deflection rotor is provided with magnetic poles; and the deflection stator is provided with windings; the application enables the motor to realize constant deflection torque and wide deflection range movement, and improves the movement precision and stability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electric machines, in particular to a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-shaped stator. BACKGROUND

[0002] Multi-degree-of-freedom actuators are widely used in industrial automation, robots, vector propulsion and other fields, and the main function is to provide flexible operation capability through the movement of multiple degrees of freedom. Traditional multi-degree-of-freedom actuators usually adopt a series structure, which often leads to a large volume and a complex structure, limiting their application in compact spaces. As an innovative actuator, the spherical motor (SpM) can realize multi-degree-of-freedom movement in a single joint, and in particular, the permanent magnet spherical motor has a wide application prospect in the industrial field due to its large torque characteristics.

[0003] The existing spherical motor adopts a combined structure of multiple layers of stators and multiple layers of permanent magnets, and in order to maintain the linear characteristics of the torque output, an iron-core-free stator is adopted. However, due to the large magnetic loop resistance, the deflection torque is relatively small, which is difficult to meet the demand for large torque in industrial applications. Directly using an iron core or soft magnetic material in the conventional structure can increase the torque density, but the coupling relationship between the deflection torque and the deflection angle still exists, which limits the deflection range and accuracy of the motor, and it is difficult to realize high torque output under large deflection angle. The above problems need to be solved. SUMMARY

[0004] In order to make the motor realize constant deflection torque and wide deflection range movement, and improve the movement accuracy and stability, the application provides a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-shaped stator, which adopts the following technical scheme:

[0005] The application provides a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-shaped stator, which comprises a frame, a rotating stator, a deflection rotor and a deflection stator.

[0006] The rotating stator is rotationally connected to the frame, the deflection rotor is fixedly connected to the rotating stator, and the deflection stator is fixedly connected to the frame. The rotating stator and the deflection stator are both annularly arranged at the middle part of the rotating stator, the distance between the deflection stator and the rotating stator is greater than the distance between the deflection rotor and the rotating stator. The deflection rotor is provided with magnetic poles, and the deflection stator is provided with windings.

[0007] Preferably, the frame comprises a bottom frame and a support, the support is annularly arranged at the side edge of the bottom frame, and the deflection stator is mounted on the support.

[0008] Preferably, the magnetic poles comprise positive poles and negative poles, and the positive poles and the negative poles of a plurality of magnetic poles are alternately arranged along the length of the deflection rotor.

[0009] Preferably, the deflection stator comprises a stator tooth fixedly connected to the support and a stator arm, one end of the stator arm being fixedly connected to the stator tooth, and the stator tooth and the stator arm are both provided with a winding.

[0010] Preferably, each stator tooth is fixedly connected with two stator arms, one end of one of the stator arms being fixedly connected to one side of the stator tooth, and one end of the other stator arm being fixedly connected to the other side of the stator tooth.

[0011] Preferably, the deflection stator further comprises a stator yoke, and the other end of the stator arm is fixedly connected to the stator yoke.

[0012] Preferably, the cross-sectional area of the stator arm is half of the cross-sectional area of the stator tooth.

[0013] Preferably, the two stator teeth corresponding to a pair of magnetic poles are arranged at the same horizontal height.

[0014] Preferably, one of the stator teeth is arranged at the same horizontal height as one of the positive poles, and the other stator tooth is arranged at the same horizontal height as one of the negative poles.

[0015] Preferably, the winding is arranged along the length direction of the stator tooth on the side wall of the stator tooth, and the winding is arranged along the length direction of the stator arm on the side wall of the stator arm.

[0016] In summary, compared with the prior art, the technical scheme provided by the present application has at least the following beneficial effects:

[0017] In the present application, the rotating stator is installed with the deflection rotor, so that the relative position of the deflection rotor and the deflection stator changes during the operation of the motor, thereby driving the output shaft of the rotating stator to rotate and drive the external structure to move. The deflection stator is provided with more windings, so that the stator magnetic field is three-dimensionally distributed, the space utilization rate of the winding is higher, the input current is reduced, the output torque is improved, the motor realizes constant deflection torque and wide deflection range movement, and the movement precision and stability are improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic diagram of a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-shaped stator according to an embodiment of the present application.

[0019] Figure 2 is a structural schematic diagram of a deflection rotor and a deflection stator according to an embodiment of the present application.

[0020] Figure 3 is a structural schematic diagram of a stator block according to an embodiment of the present application.

[0021] Figure 4 This is a schematic diagram of the single-pole equivalent magnetic circuit model described in the embodiments of this application.

[0022] Figure 5 This is a simplified equivalent magnetic circuit model schematic diagram as described in the embodiments of this application.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Frame; 11. Base frame; 12. Support component; 2. Rotating stator; 3. Deflecting rotor; 4. Deflecting stator; 41. Stator teeth; 42. Stator arm; 43. Stator yoke; 5. Magnetic pole; 6. Winding. Detailed Implementation

[0025] The following combination Figures 1-5 The present application will be described in further detail below. The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0026] Reference Figure 1 and Figure 2 The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator involved in this application includes a frame 1, a rotating stator 2, a deflecting rotor 3 and a deflecting stator 4;

[0027] The rotating stator 2 is rotatably connected to the frame 1, the deflecting rotor 3 is fixedly connected to the rotating stator 2, and the deflecting stator 4 is fixedly connected to the frame 1; the rotating stator and the deflecting stator 4 are both arranged around the middle of the rotating stator 2, and the distance between the deflecting stator 4 and the rotating stator 2 is greater than the distance between the deflecting rotor 3 and the rotating stator 2; the deflecting rotor 3 is provided with magnetic poles 5, and the deflecting stator 4 is provided with windings 6.

[0028] Specifically, the spherical motor of this application mounts a rotating stator 2 and a deflecting stator 4 via a frame 1. The rotating stator 2 is equipped with a deflecting rotor 3, so that during motor operation, the relative positions of the deflecting rotor 3 and the deflecting stator 4 change, thereby causing the output shaft of the rotating stator 2 to rotate and drive the external structure. The deflecting stator 4 is T-shaped, allowing for more windings 6, resulting in a three-dimensional distribution of the stator magnetic field. This improves the space utilization of the windings 6, reduces the input current, and increases the output torque, enabling the motor to achieve constant deflection torque and a wide deflection range, thus improving motion accuracy and stability.

[0029] When the rotor outer diameter of the three-degree-of-freedom ball actuator with hybrid winding and T-type stator is 149mm, the rated tilting torque is 3Nm, and the maximum deflection angle is ±30°, the three-degree-of-freedom motion of this ball motor is completely decoupled. Compared with other ball motors, it can achieve constant deflection torque and a wide deflection range. Therefore, this ball motor has the advantage of simple control.

[0030] As one of the embodiments, the frame 1 comprises a bottom frame 11 and support members 12, the support members 12 are arranged at the side edges of the bottom frame 11 in equal intervals, and the deflection stator 4 is mounted on the support members 12.

[0031] Specifically, the frame 1 of the ball motor of the embodiment of the application comprises a bottom frame 11 and support members 12, the bottom frame 11 is used to fix and position the support members 12, the number of the support members 12 depends on the number of the deflection stators 4 and the deflection rotors 3 of the ball motor, the ball motor of the embodiment of the application has four deflection stators 4 and four deflection rotors 3, each set of the deflection stator 4 and the deflection rotor 3 arranged at a corresponding position forms a deflection unit, and the support members 12 are arranged according to the use requirements of the deflection stators 4, one end of each support member 12 is fixedly mounted on the side edge of the bottom frame 11 in equal intervals, and the other end of the support member 12 stands up to the side of the bottom frame 11 and is used to mount the deflection stator 4.

[0032] As one of the embodiments, the magnetic poles 5 comprise positive poles and negative poles, and the positive poles and the negative poles of the plurality of magnetic poles 5 are arranged alternately along the length of the deflection rotor 3.

[0033] Specifically, the magnetic pole 5 of the embodiment of the application is composed of a pair of positive poles and negative poles, and the plurality of magnetic poles 5 are arranged along the length direction of the deflection rotor 3 and are arranged towards the deflection stator 4. The deflection rotor 3 and the rotating stator 2 facing each other are connected through bearings to realize synchronous deflection movement, when the deflection unit is in motion, the rotating shaft always remains vertical, which makes the decoupling of the two deflection degrees of freedom, and realizes the relative motion of the deflection rotor 3 and the deflection stator 4.

[0034] As one of the embodiments, two stator teeth 41 corresponding to a pair of magnetic poles 5 are arranged at the same horizontal height.

[0035] One of the stator teeth 41 is arranged at the same horizontal height as one of the positive poles, and the other stator tooth 41 is arranged at the same horizontal height as one of the negative poles.

[0036] Specifically, two stator teeth 41 and one pair of magnetic poles 5 of the embodiment of the application are arranged at the same horizontal height, the two stator teeth 41 are two adjacent stator teeth 41 arranged above and below, and the one pair of magnetic poles 5 comprises positive poles and negative poles, one of the stator teeth 41 is arranged at the same horizontal height as one of the positive poles, and the other stator tooth 41 is arranged at the same horizontal height as one of the negative poles, so that the magnetic poles 5 and the windings 6 can be coupled under the working condition of the motor.

[0037] Among the four deflection rotors 3, the magnetic poles 5 mounted on the adjacent two deflection rotors 3 are in reverse order, which can reduce the reverse torque to a certain extent, improve the stability of the motor, enhance the balance and stability, and reduce the vibration.

[0038] As one of the embodiments, the deflection stator 4 comprises a stator tooth 41 fixedly connected to the support 12 and a stator arm 42, one end of the stator arm 42 being fixedly connected to the stator tooth 41, and the stator tooth 41 and the stator arm 42 are both provided with the winding 6.

[0039] Each stator tooth 41 is fixedly connected with two stator arms 42, one end of one stator arm 42 being fixedly connected to one side of the stator tooth 41, and one end of the other stator arm 42 being fixedly connected to the other side of the stator tooth 41.

[0040] Referring to Figure 3 , specifically, the deflection stator 4 of the embodiment of the application is composed of the stator tooth 41 and the stator arm 42, the stator tooth 41 and the stator arm 42 are both provided with the winding 6, and the stator tooth 41 and the stator arm 42 form a T-shaped stator block.

[0041] The embodiment of the application further optimizes the ball motor, each deflection stator 4 is composed of a plurality of T-shaped stator blocks, the winding 6 is wound on the tangential extension arm and the radial stator tooth 41 of the T-shaped stator block, the multi-directional winding 6 structure makes the stator magnetic field present three-dimensional distribution, the space utilization rate of the winding 6 is higher, thereby reducing the input current by arranging more turns of the winding 6, and improving the output torque.

[0042] As one of the embodiments, the deflection stator 4 further comprises a stator yoke 43, the other end of the stator arm 42 being fixedly connected to the stator yoke 43.

[0043] Specifically, the winding 6 of the embodiment of the application is wound on the stator extension arm and the stator tooth 41, and the stator yoke 43 is fixed on the extension arm, the advantage of this structure is that the number of turns of the winding 6 can be increased in the limited ball space, thereby higher stator magnetomotive force can be brought under small current, the complete decoupling of the stator magnetic load and the electric load is realized, and the stator yoke 43 can limit the position of the winding 6 on the stator arm 42 to a certain extent, thereby playing a role in stabilizing the winding.

[0044] As one of the embodiments, the cross-sectional area of the stator arm 42 is half of the cross-sectional area of the stator tooth 41.

[0045] Specifically, in order to improve the utilization rate of the soft magnetic material, it is necessary to ensure that the magnetic field strength of each position in the soft magnetic material remains consistent to prevent local saturation. Therefore, it is known from the formula magnetic flux equals magnetic field density multiplied by cross-sectional area that the cross-sectional area of the extension arm must be half of the cross-sectional area of the stator tooth 41.

[0046] As one of the embodiments, the winding 6 is provided on the side wall of the stator tooth 41 along the length direction of the stator tooth 41, and the winding 6 is provided on the side wall of the stator arm 42 along the length direction of the stator arm 42.

[0047] Specifically, the stator tooth 41 is a metal block fixed to the side of the support 12 toward the center of the ball, and the stator arm 42 is fixed to the two sides of the stator tooth 41. In this case, the stator tooth 41 still has a part protruding toward the center of the ball, that is, the stator arm 42 is not fixed to the end of the two sides of the stator tooth 41, but to the middle part, and the protruding end of the stator tooth 41 is used to wind the winding 6.

[0048] The motion principle of the embodiment of the application is that since the rotation axes of the x deflection rotor 3 and the y deflection rotor 3 remain constant at 90 degrees, the deflection motions of the two degrees of freedom do not interfere with each other. The detas and detam respectively represent the angles from the center of the six permanent magnets to the center of the last stator tooth 41 and to the center of the last permanent magnet. Therefore, when the y deflection rotor 3 rotates by a degree of detay, ignoring the slotting effect and the end effect, the torque remains constant within detas-detam at most, that is, the maximum deflection range of the x deflection rotor 3 part can be represented as detas-detam, and when detay=0, the deflection x part is similar to a part. The output shaft vector position of the two degrees of freedom control is represented as:

[0049]

[0050] wherein E pn is the coordinate of the deflected output shaft, E P1 is the initial vector, represented as (0, 0, z).

[0051] The embodiment of the application considers the three-dimensional characteristics of the deflection stator 4 of the ball motor, which is difficult to model by using the traditional method, so the equivalent magnetic circuit method is used to simplify the complex T-shaped stator, and then the inclined torque part is analytically modeled to obtain appropriate parameters.

[0052] The h m of the embodiment of the application is the thickness of the permanent magnet, R m is the outer diameter of the permanent magnet, L is the thickness of the back iron along the Z axis direction, l s is the length of the stator tooth 41, l a is the length of the stator arm 42, l t is the length of the stator yoke 43, l g is the length of the air gap, b1 is the width of the stator tooth 41, b2 is the width of the stator arm 42, b3 is the width of the stator yoke 43, and b4 is the span at the middle position between adjacent two stator arms 42, used to measure the leakage magnetic flux between the stator arms 42, b o is the length of the stator slot opening. The magnetic circuit mainly includes three parts, the main magnetic flux Φ through the permanent magnet and the stator, the leakage magnetic flux Φ l1 through the stator arm 42 and the stator tooth 41, and the leakage magnetic flux Φ l2 between the poles of the permanent magnet.

[0053] Referring to Figure 4 , an equivalent magnetic circuit model of a pair of stator teeth 41 is given, Φ Iron , s t1 , s t2 and yoke represent the magnetic fluxes passing through the rotor back iron, the stator teeth 41, the stator arm 42 and the stator yoke 43, R iron , R st1 , R st2 and R yoke represent the magnetic resistances thereof. Generally, the magnetic resistance of the soft magnetic material can be ignored when the soft magnetic material is not saturated. However, in order to improve the deflection torque of the spherical motor, the working state of the iron core is set to be close to saturation, so the magnetic resistance of the soft magnetic material must be involved in the calculation of the magnetic circuit model, R pm , R air , R l1 and R l2 are the magnetic resistances caused by the magnetic steel, the air gap and the leakage magnetic region respectively. F S1 and F S2 are the magnetomotive forces caused by the windings 6. The above parameters are calculated as follows:

[0054] F r = H r h m

[0055] B r = H r μ0μ r

[0056]

[0057] wherein μ0 is the magnetic permeability of vacuum, μ r is the relative magnetic permeability of the magnetic body, and μ r can be regarded as 1 since the magnetic permeability of the magnetic body is similar to that of air.

[0058] Referring to Figure 5 , the magnetic circuit is simplified into a two-dimensional form, which means that the complex T-shaped stator can be converted into a simple model. Among them, R st3 is the equivalent stator magnetic resistance, R l1 ’ is the stator magnetic resistance, and R yoke ’ is the magnetic resistance of the stator yoke 43. The elements before and after the simplification satisfy the conditions: R st3 = R st1 + R st2 ; F3 = F1 + F2; R l1 ’ = R l1 / 2 * R l3 / (R l1 / 2 + R l3 ); Ryoke ’=R yoke / 2。

[0059] In order to ensure that the B-H curve of the simplified stator material is consistent, the model size satisfies the following relationship: b'2=b2; l's=ls+la; l't=ltN=N1+N2.

[0060] Wherein N is the equivalent number of turns, N1 and N1 are the number of turns of the tangential winding 6 and the radial winding 6 before the equivalent. The proposed T-shaped stator is equivalent to greatly increasing the number of turns of the winding 6 without changing the wire gauge of the winding 6 and the outer diameter of the stator, that is, under the same input current, the torque of the motor will be correspondingly increased.

[0061] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described device and product can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0062] In several embodiments provided in the present application, it should be understood that the disclosed method, system, device and program product can be implemented in other ways.

[0063] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator, characterized in that, Includes a frame, a rotating stator, a deflecting rotor, and a deflecting stator; The deflection stator includes stator teeth and stator arms. The stator teeth are fixedly connected to the support member, and one end of the stator arms is fixedly connected to the stator teeth. Both the stator teeth and the stator arms are wound with windings. The deflection stator also includes a stator yoke, and the other end of the stator arm is fixedly connected to the stator yoke; The rotating stator is rotatably connected to the frame, the deflecting rotor is fixedly connected to the rotating stator, and the deflecting stator is fixedly connected to the frame. Both the rotating stator and the deflecting stator are arranged in a ring around the middle of the rotating stator, and the distance between the deflecting stator and the rotating stator is greater than the distance between the deflecting rotor and the rotating stator; The deflecting rotor is provided with magnetic poles, and the deflecting stator is provided with windings; The winding is wound along the length of the stator teeth on the side wall of the stator teeth, and the winding is wound along the length of the stator arm on the side wall of the stator arm.

2. The three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator according to claim 1, characterized in that, The frame includes a base frame and a support member, with the support member spaced around the side of the base frame and the deflection stator mounted on the support member.

3. The three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator according to claim 2, characterized in that, The magnetic poles include positive and negative poles, and the positive and negative poles of several magnetic poles are arranged alternately along the length of the deflecting rotor.

4. The three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator according to claim 3, characterized in that, Each stator tooth is fixedly connected to two stator arms, one end of which is fixedly connected to one side of the stator tooth, and the other end of which is fixedly connected to the other side of the stator tooth.

5. The three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator according to claim 3, characterized in that, The cross-sectional area of ​​the stator arm is half the cross-sectional area of ​​the stator tooth.

6. The three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator according to claim 4, characterized in that, The two stator teeth correspond to a pair of magnetic poles and are set at the same horizontal height.

7. The three-degree-of-freedom spherical actuator based on hybrid windings and a T-type stator according to claim 6, characterized in that, One of the stator teeth is positioned at the same horizontal height as one of the positive terminals, and the other stator tooth is positioned at the same horizontal height as one of the negative terminals.

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