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

Abstract

The invention relates to the technical field of motors, 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, and the deflection stator is fixedly connected to the frame; the rotating stator and the deflection stator are annularly arranged in the middle of the rotating stator, and the distance between the deflection stator and the rotating stator is larger than that between the deflection rotor and the rotating stator; according to the motor, the motor can move in a constant deflection torque and a wide deflection range, and the movement precision and stability are improved.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-type stator. Background Art

[0002] Multi-DOF actuators are widely used in industrial automation, robotics, vector propulsion and other fields. Their main function is to provide flexible operation through multiple degrees of freedom. Traditional multi-DOF actuators usually adopt a series structure, which often leads to large size and complex structure, limiting their application in compact spaces. Spherical motors, SpM, as an innovative actuator, can achieve multi-DOF motion in a single joint, especially permanent magnet spherical motors, which have broad application prospects in the industrial field due to their large torque characteristics.

[0003] The existing spherical motor adopts a combined structure of multi-layer stators and multi-layer permanent magnets, and in order to maintain the linear characteristics of the torque output, a coreless stator is used. However, due to the large magnetic resistance of the magnetic circuit, its deflection torque is relatively small, which is difficult to meet the demand for large torque in industrial applications. The conventional structure directly uses an iron core or soft magnetic material to 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 makes it difficult to achieve high torque output at a large deflection angle. The above problems need to be solved. Summary of the invention

[0004] In order to enable the motor to achieve a constant deflection torque and a wide deflection range of motion, and to improve motion accuracy and stability, the present application provides a three-degree-of-freedom spherical actuator based on a hybrid winding and a T-type stator, which adopts the following technical solutions:

[0005] The present application provides a three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator, comprising a frame, a rotating stator, a deflecting rotor and a deflecting stator;

[0006] The rotating stator is rotatably 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 arranged in a ring in the middle of the rotating stator, and 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 member, the support member spacer ring is arranged on a side of the bottom frame, and the deflection stator is installed on the support member.

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

[0009] Preferably, the deflection stator comprises stator teeth and stator arms, the stator teeth are fixedly connected to the support, one end of the stator arm is fixedly connected to the stator teeth, and the stator teeth and the stator arms are both wound with windings.

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

[0011] Preferably, the deflection stator further includes 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 and one of the positive poles are arranged at the same horizontal height, and another of the stator teeth and one of the negative poles are arranged at the same horizontal height.

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

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

[0017] The present application installs a rotating stator and a deflection stator through a frame. The rotating stator is installed with a deflection rotor, so that during the operation of the motor, the relative positions of the deflection rotor and the deflection stator change, thereby causing the output shaft of the rotating stator to rotate, driving the external structure to move. The deflection stator is wound with more windings, so that the stator magnetic field presents a three-dimensional distribution, the space utilization rate of the winding is higher, the input current is reduced, the output torque is increased, the motor can achieve a constant deflection torque and a wide deflection range of movement, and the movement accuracy and stability are improved. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 2 It is a schematic diagram of the structure of the deflection rotor and the deflection stator described in the embodiment of the present application.

[0020] Figure 3 It is a schematic diagram of the structure of the stator block described in the embodiment of the present application.

[0021] Figure 4 It is a schematic diagram of a single-pole equivalent magnetic circuit model described in an embodiment of the present application.

[0022] Figure 5 It is a schematic diagram of a simplified equivalent magnetic circuit model described in an embodiment of the present application.

[0023] Description of reference numerals:

[0024] 1. Frame; 11. Bottom frame; 12. Support; 2. Rotating stator; 3. Deflection rotor; 4. Deflection stator; 41. Stator teeth; 42. Stator arm; 43. Stator yoke; 5. Magnetic pole; 6. Winding. DETAILED DESCRIPTION

[0025] The following combination Figure 1-Figure 5 The present application is described in further detail. The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are 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 the present application comprises a frame 1, a rotating stator 2, a deflection rotor 3 and a deflection stator 4;

[0027] The rotating stator 2 is rotatably connected to the frame 1, the deflection rotor 3 is fixedly connected to the rotating stator 2, and the deflection stator 4 is fixedly connected to the frame 1; the rotating stator and the deflection stator 4 are both arranged in a ring in the middle of the rotating stator 2, and the distance between the deflection stator 4 and the rotating stator 2 is greater than the distance between the deflection rotor 3 and the rotating stator 2; the deflection rotor 3 is provided with a magnetic pole 5, and the deflection stator 4 is provided with a winding 6.

[0028] Specifically, the spherical motor of the present application installs the rotating stator 2 and the deflection stator 4 through the frame 1, and the rotating stator 2 is installed with the deflection rotor 3, so that during the operation of the motor, the deflection rotor 3 and the deflection stator 4 change their relative positions, thereby causing the output shaft of the rotating stator 2 to rotate, driving the external structure to move. The deflection stator 4 is set in a T shape, so that more windings 6 are wound, so that the stator magnetic field presents a three-dimensional distribution, the space utilization rate of the winding 6 is higher, the input current is reduced, the output torque is increased, and the motor can achieve a constant deflection torque and a wide deflection range of movement, thereby improving the movement accuracy and stability.

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

[0030] As one embodiment, the frame 1 includes a bottom frame 11 and a support member 12 . The support member 12 is disposed at a side of the bottom frame 11 in a spaced ring manner, and the deflection stator 4 is installed on the support member 12 .

[0031] Specifically, the frame 1 of the ball motor in the embodiment of the present application includes a bottom frame 11 and a support member 12. The bottom frame 11 is used to fix the support member 12 and limit its position. 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 deflection stators 4 and the deflection rotors 3 of the ball motor in the embodiment of the present application are 4, and the deflection stators 4 and the deflection rotors 3 arranged at each corresponding position form a deflection unit, and the support member 12 is arranged according to the use requirements of the deflection stator 4. One end of the support member 12 is fixedly installed on the side of the bottom frame 11 at equidistant intervals, and the other end of the support member 12 stands up toward a side surface of the bottom frame 11 for installing the deflection stator 4.

[0032] As one implementation manner, the magnetic pole 5 includes a positive pole and a negative pole, and the positive poles and the negative poles of a plurality of magnetic poles 5 are alternately arranged along the length of the deflection rotor 3 .

[0033] Specifically, the magnetic pole 5 of the embodiment of the present application is composed of a pair of positive poles and negative poles, and a plurality of magnetic poles 5 are installed along the length direction of the deflection rotor 3 toward the deflection stator 4. The face-to-face deflection rotor 3 and the rotating stator 2 are connected through bearings to achieve synchronous deflection movement. When the deflection unit is moving, the rotation axis always remains vertical, which decouples the two deflection degrees of freedom and realizes the relative movement of the deflection rotor 3 and the deflection stator 4.

[0034] As one implementation manner, 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 and one of the positive poles are arranged at the same level, and the other stator tooth 41 and one of the negative poles are arranged at the same level.

[0036] Specifically, two of the stator teeth 41 and one of the pairs of magnetic poles 5 in the embodiment of the present application are set at the same horizontal height, and the two stator teeth 41 are two stator teeth 41 adjacent to each other up and down, and one of the pairs of magnetic poles 5 includes a positive pole and a negative pole, and one of the stator teeth 41 is set at the same horizontal height as one of the positive poles, and the other stator tooth 41 is set at the same horizontal height as one of the negative poles, so that the magnetic pole 5 and the winding 6 can be coupled when the motor is working.

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

[0038] As one embodiment, the deflection stator 4 includes a stator tooth 41 and a stator arm 42 . The stator tooth 41 is fixedly connected to the support 12 . One end of the stator arm 42 is fixedly connected to the stator tooth 41 . The stator tooth 41 and the stator arm 42 are both wound with a winding 6 .

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

[0040] Reference Figure 3 Specifically, the deflection stator 4 of the embodiment of the present application is composed of stator teeth 41 and stator arms 42, windings 6 are wound around the stator teeth 41 and the stator arms 42, and the stator teeth 41 and the stator arms 42 form a T-shaped stator block.

[0041] The embodiment of the present 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 extending arms and radial stator teeth 41 of the T-shaped stator block. The multi-directional winding 6 structure makes the stator magnetic field present a three-dimensional distribution, and the space utilization rate of the winding 6 is higher, thereby reducing the input current and improving the output torque by arranging more turns of the winding 6.

[0042] As one implementation manner, the deflection stator 4 further includes a stator yoke 43 , and the other end of the stator arm 42 is fixedly connected to the stator yoke 43 .

[0043] Specifically, the winding 6 of the embodiment of the present application is wound on the stator protruding arm and the stator teeth 41, and the stator yoke 43 is fixed on the protruding arm. The advantage of this structure is that the number of turns of the winding 6 can be increased within a limited spherical space, thereby bringing a higher stator magnetomotive force under a small current, achieving complete decoupling of the stator magnetic load and the electric load, 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 implementation manner, 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 soft magnetic materials, the embodiment of the present application must ensure that the magnetic field strength at each position in the soft magnetic material remains consistent to prevent local saturation. Therefore, from the formula that magnetic flux is equal to magnetic field density multiplied by cross-sectional area, it can be seen that the cross-sectional area of ​​the extended arm must be half of the cross-sectional area of ​​the stator tooth 41.

[0046] As one implementation manner, the winding 6 is wound around the side wall of the stator tooth 41 along the length direction of the stator tooth 41 , and the winding 6 is wound around the side wall of the stator arm 42 along the length direction of the stator arm 42 .

[0047] Specifically, the stator tooth 41 of the embodiment of the present application is a metal block fixed to the support member 12 on the side toward the center of the ball, and the stator arm 42 is fixed on both sides of the stator tooth 41. In this case, the stator tooth 41 still has some protrusions protruding toward the center of the ball, that is, the stator arm 42 is not fixed at the ends on both sides of the stator tooth 41, but in the middle, and the protruding end of the stator tooth 41 is used for winding the winding 6.

[0048] The motion principle of the embodiment of the present application is that since the rotation axes of the x deflection rotor 3 and the y deflection rotor 3 are kept at a constant 90 degrees, the deflection motions of the two degrees of freedom do not interfere with each other. In the embodiment of the present application, detas and detam are respectively expressed as the angle from the center of the 6 permanent magnets to the center of the last stator tooth 41 and the angle to the center of the last permanent magnet. Therefore, when the y deflection rotor 3 part rotates detay degrees, ignoring the slotting effect and the end effect, the torque is at most consistent within detas-detam, that is, the maximum deflection range of the deflection rotor 3 part can be expressed as detas-detam. When detay=0, the deflection x part is similar to the one part. The vector position of the two-degree-of-freedom control output axis is expressed as:

[0049]

[0050] Where E pn is the coordinate of the output shaft after deflection, E P1 is the initial vector, expressed as (0, 0, z).

[0051] The embodiment of the present application takes into account the three-dimensional characteristics of the magnetic circuit of the deflection stator 4 of the ball motor, which is difficult to model using traditional methods. Therefore, the equivalent magnetic circuit method is used to simplify the complex T-type stator, and then the tilt torque part is analytically modeled to obtain appropriate parameters.

[0052] Embodiment of the present application m 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, l s is the length of 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 between the middle positions of two adjacent stator arms 42, which is used to measure the leakage flux between the stator arms 42. o is the length of the stator slot opening. The magnetic circuit is mainly divided into three parts: the main magnetic flux Φ passing through the permanent magnet and the stator, the leakage magnetic flux Φ passing through the stator arm 42 and the stator tooth 41 l1 And the leakage flux between the permanent magnet poles Φ l2 .

[0053] Reference 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 flux passing through the rotor back iron, stator teeth 41, stator arms 42 and stator yoke 43, R iron , R st1 , R st2 and R yoke Represents its magnetic resistance. In general, when the magnetic material is not saturated, the corresponding magnetic resistance can be ignored. However, in order to increase the deflection torque of the ball motor, the core working state is set to near 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 They are the magnetic resistance caused by the magnetic steel, air gap and leakage magnetic area. S1 and F S2 is the magnetomotive force brought by winding 6. Calculate the above parameters:

[0054] F r =H r h m

[0055] B r =H r μ0μ r

[0056]

[0057] Where μ0 is the vacuum magnetic permeability, μ r is the relative magnetic permeability of the magnet. Since the magnetic permeability of the magnet is similar to that of air, μ r Can be considered as 1.

[0058] Reference Figure 5 , simplifying the magnetic circuit into a two-dimensional form means that the complex T-type stator can be converted into a simple model. Among them, the simplified stator model R st3 is the equivalent stator reluctance, R l1 ' is the stator magnetic resistance, R yoke ' is the magnetic resistance of the stator yoke 43. The elements before and after simplification meet 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 the consistency of the BH curve of the simplified stator material, the model size satisfies the following relationship: b'2 = b2; l's = ls + la; l't = ltN = N1 + N2.

[0060] Where N is the equivalent number of turns, N1 and N2 are the equivalent number of turns of the tangential winding 6 and the radial winding 6 respectively. The proposed T-type 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 improved.

[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 aforementioned method embodiment, and will not be repeated here.

[0062] In several embodiments provided in this application, it should be understood that the disclosed methods, systems, devices and program products may be implemented in other ways.

[0063] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0064] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 winding and T-type stator, characterized in that: including a frame, a rotating stator, a deflecting rotor and a deflecting stator; The rotating stator is rotatably 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 arranged in a ring in the middle of the rotating stator, and 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.

2. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 1, characterized in that: The frame comprises a bottom frame and a support member, wherein the support member spacing ring is arranged on the side of the bottom frame, and the deflection stator is installed on the support member.

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

4. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 3, characterized in that: The deflection stator comprises stator teeth and stator arms, wherein the stator teeth are fixedly connected to the support member, one end of the stator arm is fixedly connected to the stator teeth, and windings are wound around the stator teeth and the stator arms.

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

6. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 5, characterized in that: The deflection stator further includes a stator yoke, and the other end of the stator arm is fixedly connected to the stator yoke.

7. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 4, characterized in that: The cross-sectional area of ​​the stator arm is half the cross-sectional area of ​​the stator tooth.

8. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 5, characterized in that: The two stator teeth correspond to a pair of magnetic poles and are arranged at the same horizontal height.

9. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 8, characterized in that: One of the stator teeth is correspondingly arranged at the same level as one of the positive poles, and the other stator tooth is correspondingly arranged at the same level as one of the negative poles.

10. The three-degree-of-freedom spherical actuator based on hybrid winding and T-type stator according to claim 6, characterized in that: The winding is wound around the side wall of the stator tooth along the length direction of the stator tooth, and the winding is wound around the side wall of the stator arm along the length direction of the stator arm.

Images