Rotor assembly and motor

Abstract

The invention provides a rotor assembly and a motor. The rotor assembly comprises an outer rotor and an inner rotor, wherein the outer rotor comprises a straight-barrel-shaped rotor body; at least one of the two ends of the rotor body is provided with a bending part, the bending part is made of a conductor material, and the extending direction of the bending part is crossed with the axial direction of the rotor body. According to the invention, at least one of the two ends of the rotor body of the outer rotor is provided with the bending part, so that the tangential current on the outer rotor is located on the bending part, the tangential current on the rotor body is reduced, and the power density and the force energy index of the motor are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of electric motors, and in particular relates to a rotor assembly and an electric motor. Background Art

[0002] The working principle of the solid rotor induction motor is the same as that of the ordinary induction motor. When the current is passed through the multi-phase winding of the motor stator, a synthetic rotating magnetic field is generated, and an induced electromotive force and current are generated in the solid rotor. The interaction generates electromagnetic force and electromagnetic torque, which makes the rotor rotate and converts electrical energy into mechanical energy. The stator structure of the solid rotor induction motor is the same as that of the ordinary induction motor. The rotor is a solid ferromagnetic cylinder or cylinder. It is both the core part of the magnetic circuit and the winding of the circuit. The two are integrated into one. This is the key difference between the solid rotor induction motor and the ordinary induction motor.

[0003] The solid rotor has a simple structure, high mechanical reliability, large starting torque and small starting current, that is, a high starting quality factor. It is suitable for working conditions such as frequent starting under heavy loads and harsh conditions. It has low vibration and electromagnetic noise during operation and has a wide range of application prospects. However, its disadvantages are also obvious. Because the solid rotor is in a changing magnetic field, a closed current loop will be generated inside it. These currents are called eddy currents. When the eddy currents flow in the solid rotor, they will encounter resistance, thereby generating heat energy. This part of the energy is lost in the form of heat, reducing the efficiency of the motor. An important factor affecting the size of the rotor impedance is that the induced eddy currents in the rotor close themselves within the rotor body, such as Fig.14 As shown, there is a strong tangential current component, and its utilization coefficient is not high. The solid rotor induction motor can only reach about 50% of the cage rotor induction motor, and its efficiency and power factor are low, which greatly affects its application and development.

[0004] In summary, how to improve the efficiency of solid rotor induction motors and overcome the shortcomings of existing technologies needs to be solved urgently. Summary of the invention

[0005] Therefore, the present application provides a rotor assembly and a motor, which can solve the problems of the solid rotor in the prior art having a tangential current component and low efficiency and power factor.

[0006] In order to solve the above problems, the present application provides a rotor assembly, comprising:

[0007] The outer rotor comprises a straight cylindrical rotor body;

[0008] At least one end of the rotor body is provided with a bending portion, the bending portion is made of a conductive material, and an extending direction of the bending portion is arranged to intersect with an axial direction of the rotor body.

[0009] In some embodiments,

[0010] The bending portion includes a first bending portion bent toward a direction away from the axis of the rotor body, and a second bending portion bent toward the axis of the rotor body; the first bending portion and the second bending portion are respectively arranged at two ends of the rotor body.

[0011] In some embodiments,

[0012] The outer rotor also includes a mounting portion, the second bending portion is connected to the mounting portion by injection molding, and one end of the rotating shaft of the outer rotor is mounted on the mounting portion.

[0013] In some embodiments,

[0014] A groove is provided on the inner peripheral wall of the rotor body, and the extending direction of the groove is the same as the axial direction of the rotor body.

[0015] In some embodiments,

[0016] There are a plurality of grooves, which are evenly arranged along the circumference of the rotor body.

[0017] In some embodiments,

[0018] The depth of the groove is greater than the opening width of the groove.

[0019] According to another aspect of the present application, a motor is provided, comprising the rotor assembly as described above.

[0020] In some embodiments,

[0021] The motor also includes a stator assembly, which includes an annular slot body and a stator. The boss at the center of the slot body is set to be a straight cylinder; the stator is sleeved on the outer periphery of the boss, and the rotor body is sleeved on the outer periphery of the stator and is located in the slot body.

[0022] In some embodiments,

[0023] The rotating shaft of the outer rotor passes through the boss, and the two are axially connected via a bearing.

[0024] In some embodiments,

[0025] The stator assembly also includes a terminal block and a stator winding. The terminal block is arranged at the slot bottom of the slot body and is electrically connected to the stator winding.

[0026] A rotor assembly provided in the present application includes: an outer rotor, including a straight cylindrical rotor body; a bending portion is provided at at least one end of the rotor body, the bending portion is made of a conductive material, and an extension direction of the bending portion is cross-set with an axial direction of the rotor body.

[0027] This application has the following beneficial effects:

[0028] By providing a bending portion at at least one end of the rotor body of the outer rotor, the tangential current on the outer rotor is located on the bending portion, reducing the tangential current on the rotor body, thereby improving the power density and power energy index of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the implementation methods or the prior art descriptions. The drawings described below are merely exemplary, and for those of ordinary skill in the art, other implementation drawings can be derived from the provided drawings without creative work.

[0030] Figure 1 This is a schematic structural diagram of a rotor assembly according to an embodiment of the present application;

[0031] Figure 2 A cross-sectional view of a rotor assembly according to an embodiment of the present application;

[0032] Figure 3 A schematic diagram of the internal eddy current distribution of the rotor assembly according to an embodiment of the present application;

[0033] Figure 4 A partial isometric view of a rotor assembly according to an embodiment of the present application;

[0034] Figure 5 A partial cross-sectional view of a rotor assembly according to an embodiment of the present application;

[0035] Figure 6 A front view of a rotor assembly according to an embodiment of the present application;

[0036] Figure 7 For the embodiment of this application Figure 6 A partial enlarged view of

[0037] Figure 8 For the embodiment of this application Figure 7 Schematic diagram of the internal vortex distribution;

[0038] Fig. 9 A schematic diagram of the structure of a motor according to an embodiment of the present application;

[0039] Fig.10 A cross-sectional view of a motor according to an embodiment of the present application;

[0040] Fig.11 A cross-sectional view of a stator assembly according to an embodiment of the present application;

[0041] Fig.12 This is a schematic structural diagram of a stator core according to an embodiment of the present application;

[0042] Fig.13 This is a schematic diagram of the structure of the tank body according to an embodiment of the present application;

[0043] Fig.14 Schematic diagram of the structure of a traditional outer rotor.

[0044] The reference numerals are as follows:

[0045] 1. rotor assembly; 11. rotating shaft; 12. rotor body; 13. first bending portion; 14. second bending portion; 15. mounting portion; 16. groove;

[0046] 2. stator assembly; 21. slot body; 22. stator; 221. stator winding; 222. stator core; 223. frame; 224. terminal pin; 23. terminal board; 24. bearing; 25. boss. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0049] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0050] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0051] See also Figures 1 to 13 As shown, according to an embodiment of the present application, in order to solve the above problems, the present application provides a rotor assembly 1, comprising:

[0052] The outer rotor includes a straight cylindrical rotor body 12;

[0053] At least one end of the rotor body 12 is provided with a bending portion, the bending portion is made of a conductive material, and an extending direction of the bending portion is arranged to intersect with an axial direction of the rotor body 12 .

[0054] The present application provides a bending portion at at least one point at both ends of the rotor body 12 of the outer rotor so that the tangential current on the outer rotor is located on the bending portion, thereby reducing the tangential current on the rotor body 12 and improving the power density and power energy index of the motor.

[0055] In the magnetic field formed by the stator winding 221, a closed current loop is formed inside the outer rotor, which is an eddy current. When the body of the conventional outer rotor is cylindrical, this eddy current has axial flow and circumferential flow. The circumferential flow is a tangential current, which flows in the cylindrical body to form a closed loop. The utilization rate of the circumferential flow in the magnetic field of the stator 22 is very low.

[0056] In the present application, a bending portion is provided at the end of the rotor body 12, so that the current cross-section is increased, and at the same time, the eddy current inside the outer rotor flows in the rotor body 12 and the bending portion. At this time, part of the circumferential flow is in the bending portion, thereby reducing the tangential current inside part of the rotor body 12, and the end reactance of the rotor body 12 is reduced, thereby improving the power density and force energy index of the motor.

[0057] The bent portion and the rotor body 12 are arranged to cross each other axially, so that when the rotor body 12 rotates, the current inside the bent portion does not interact with the magnetic field, thereby reducing energy consumption.

[0058] The rotor body 12 and the bent portion may be made of the same ferromagnetic material.

[0059] In some embodiments,

[0060] The bending portion includes a first bending portion 13 bent toward a direction away from the axis of the rotor body 12 , and a second bending portion 14 bent toward the axis of the rotor body 12 ; the first bending portion 13 and the second bending portion 14 are respectively disposed at two ends of the rotor body 12 .

[0061] The bending portion is provided with two parts: a first bending portion 13 and a second bending portion 14, which are respectively provided at the two axial ends of the rotor body 12 and are integrally structured with the rotor body 12 and are both made of conductive materials, so that the tangential flow in the vortex formed inside the outer rotor is in the bending portions at both ends, ensuring that most of the flow inside the rotor body 12 is axial. Figure 3 As shown, this can improve the power density of the motor.

[0062] In some embodiments,

[0063] The outer rotor further includes a mounting portion 15 , the second bending portion 14 and the mounting portion 15 are connected by injection molding, and one end of the rotating shaft 11 of the outer rotor is mounted on the mounting portion 15 .

[0064] The outer rotor shaft 11 is mounted on the mounting portion 15 . Since the second bending portion 14 is bent toward the axis of the rotor body 12 , the mounting portion 15 and the second bending portion 14 are connected by injection molding to improve the overall structural stability.

[0065] In some embodiments,

[0066] A groove 16 is formed on the inner peripheral wall of the rotor body 12 , and the extending direction of the groove 16 is the same as the axial direction of the rotor body 12 .

[0067] In the present application, an axially extending groove 16 is arranged on the inner circumferential wall of the rotor body 12. Due to the skin effect characteristics, the magnetic lines of force inside the rotor body 12 are concentrated on the inner surface of the rotor body 12. At this time, due to the presence of the groove 16, the effective area of ​​the inner surface of the rotor body 12 is increased, and the rotor impedance is reduced, thereby improving the output power of the motor.

[0068] In some embodiments,

[0069] There are a plurality of grooves 16 , which are evenly arranged along the circumference of the rotor body 12 .

[0070] In some embodiments,

[0071] The depth of the groove 16 is greater than the opening width of the groove 16 .

[0072] As for the setting of the grooves 16, multiple grooves are evenly arranged, and the depth of the grooves 16 is greater than the opening width, which can effectively increase the area of ​​the inner surface and reduce the impedance of the rotor, thereby improving the output power of the motor.

[0073] To summarize, when the outer rotor of the present application is provided with bending portions at both ends of the rotor body 12, it is an integrally formed "flat-top hat" structure, and the rotor body 12 is axially perpendicular to the first bending portion 13 and the second bending portion 14 at both ends. In order to meet the logical assembly size requirements, it is defined that a>b>c>0, wherein a is the inner radius of the slot body 21 where the outer rotor is installed, b is the radius of the first bending portion 13, and c is the radius of the second bending portion 14; in addition, the axis of the mounting portion 15 is arranged to coincide with the center line of the rotor body 12.

[0074] According to another aspect of the present application, a motor is provided, comprising the rotor assembly 1 as described above.

[0075] In some embodiments,

[0076] The motor also includes a stator assembly 2, which includes an annular slot body 21 and a stator 22. The boss 25 at the center of the slot body 21 is set to be a straight cylinder; the stator 22 is sleeved on the outer periphery of the boss 25, and the rotor body 12 is sleeved on the outer periphery of the stator 22 and is located in the slot body 21.

[0077] The structure of the stator assembly 2 of the motor is adapted to the above-mentioned rotor assembly 1. The stator 22 is arranged in an annular slot body 21. Specifically, the stator 22 is sleeved on the boss 25 in the slot body 21, and then the outer rotor is sleeved on the outer periphery of the stator 22, thus forming an outer rotor motor structure.

[0078] The rotor body 12 is located in the slot body 21 , and the outer wall of the slot body 21 covers the rotor to provide protection.

[0079] In some embodiments,

[0080] The rotating shaft 11 of the outer rotor passes through the boss 25 , and the two are axially connected via a bearing 24 .

[0081] The rotating shaft 11 on the outer rotor is inserted into the center hole of the boss 25, and is connected to the center hole of the boss 25 by a bearing 24. The rotating shaft 11 is stably arranged on the stator assembly 2 through the bearing 24; at this time, the slot body 21 of the stator assembly 2 is in a stationary state, and the magnetic field is generated by power, driving the outer rotor to rotate, thereby completing the kinetic energy output of the motor.

[0082] In some embodiments,

[0083] The stator assembly 2 further includes a terminal block 23 and a stator winding 221 . The terminal block 23 is disposed at the slot bottom of the slot body 21 and is electrically connected to the stator winding 221 .

[0084] The terminal block 23 and the stator winding 221 in the stator assembly 2 are structures such as the terminal block 23 being arranged at the bottom of the slot body 21 to form a point connection with the stator winding 221 to reduce the exposure of the wiring.

[0085] like Fig. 9 As shown, the induction motor using the above-mentioned outer rotor is structured by a stator assembly 2 and a rotor assembly 1; wherein the stator assembly 2 is composed of a stator 22, a terminal block 23, a slot body 21, a bearing 24 and other components, and the outer periphery of the slot body 21 is characterized by a mounting hole for assembling the rotating shaft 11, forming a boss 25 structure, and the bearing 24 is arranged in the inner hole of the boss 25 and fits tightly with the boss 25; the stator 22 is composed of a stator core 222, an insulating frame 223, a stator winding 221, a terminal pin 224 and other components; the stator winding 221 is composed of a multi-turn coil, and its wire ends are wound around the terminal pins 224 on the frame 223 and are welded and fixed to the terminal block 23.

[0086] The rotor assembly 1 mainly includes an outer rotor, and the rotating shaft 11 is placed in the mounting portion 15 of the outer rotor. The central axes of the two coincide and the assembly method is interference fit; the rotor assembly 1 passes through the inner hole of the bearing 24 of the stator assembly 2 through its rotating shaft 11, thereby forming an outer rotor motor structure.

[0087] It is easy for those skilled in the art to understand that the above-mentioned implementation modes can be freely combined and superimposed without conflict.

[0088] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A rotor assembly, characterized in that: include: The outer rotor comprises a straight cylindrical rotor body (12); At least one end of the rotor body (12) is provided with a bending portion, the bending portion is made of a conductive material, and the extending direction of the bending portion is arranged to intersect with the axial direction of the rotor body (12).

2. The rotor assembly according to claim 1, characterized in that: The bending portion comprises a first bending portion (13) bent in a direction away from the axis of the rotor body (12), and a second bending portion (14) bent towards the axis of the rotor body (12); the first bending portion (13) and the second bending portion (14) are respectively arranged at two ends of the rotor body (12).

3. The rotor assembly according to claim 2, characterized in that: The outer rotor further comprises a mounting portion (15), the second bent portion (14) and the mounting portion (15) are connected by injection molding, and one end of the rotating shaft (11) of the outer rotor is mounted on the mounting portion (15).

4. The rotor assembly according to any one of claims 1 to 3, characterized in that: A groove (16) is provided on the inner peripheral wall of the rotor body (12), and the extending direction of the groove (16) is the same as the axial direction of the rotor body (12).

5. The rotor assembly according to claim 4, characterized in that: A plurality of grooves (16) are provided, and are evenly arranged along the circumference of the rotor body (12).

6. The rotor assembly according to claim 5, characterized in that: The depth of the groove (16) is greater than the opening width of the groove (16).

7. A motor, characterized in that: Comprising a rotor assembly as described in any one of claims 1-6.

8. The motor according to claim 7, characterized in that: The motor further comprises a stator assembly (2), the stator assembly (2) comprising an annular slot body (21) and a stator (22), the boss (25) at the center of the slot body (21) being arranged in a straight cylindrical shape; the stator (22) being sleeved on the outer periphery of the boss (25), the rotor body (12) being sleeved on the outer periphery of the stator (22) and being located in the slot body (21).

9. The motor according to claim 8, characterized in that: The rotating shaft (11) of the outer rotor is inserted into the boss (25), and the two are axially connected via a bearing (24).

10. The motor according to any one of claims 8 to 9, characterized in that: The stator assembly (2) further comprises a terminal block (23) and a stator winding (221); the terminal block (23) is arranged at the slot bottom of the slot body (21) and is electrically connected to the stator winding (221).

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