Rotor assembly and motor

Abstract

The utility model discloses a rotor assembly and a motor, and the rotor assembly comprises a shaft body with a first connecting part, a rotor iron core, and a plastic-coated body. The first connecting part is provided with a spiral groove which spirally extends along the axis direction of the shaft body, and the rotor iron core comprises a plurality of magnetic conductive blocks which are arranged at intervals along the circumferential direction of the shaft body; a radial groove is formed between every two adjacent magnetic conductive blocks, the permanent magnets are embedded in the radial grooves, the rotor iron core, the permanent magnets and the shaft body are plastically packaged into a whole by the plastic-coated body, and at least part of the plastic-coated body is filled in the spiral groove. According to the utility model, the binding force between the rotor iron core and the shaft body of the rotor assembly is strong, and the overall strength and reliability of the rotor assembly are higher.

Description

Technical Field

[0001] The utility model relates to the field of motor technology, in particular to a rotor assembly and a motor. Background Art

[0002] Existing motors generally include a rotor assembly and a stator assembly. Among them, the rotor assembly mainly includes a shaft, a rotor core, a permanent magnet, etc. When the rotor core is assembled with the shaft, the rotor core and the shaft are combined by a plastic coating to achieve the connection between the rotor core and the shaft.

[0003] At present, the bonding force between the rotor core and the shaft body is generally improved by providing an annular groove on the shaft body. The annular groove extends circumferentially along the axis of the shaft body. When the rotor core and the shaft body are assembled, a part of the plastic body is stuck in the annular groove. However, this bonding method does not have enough friction, and relative rotation is easily generated between the rotor core and the shaft body, resulting in insufficient torque of the rotor assembly, which ultimately leads to insufficient strength and reliability of the rotor assembly. Utility Model Content

[0004] One purpose of an embodiment of the utility model is to provide a rotor assembly, in which the rotor core and the shaft body have a strong bonding force, and the overall strength and reliability of the rotor assembly are higher.

[0005] Another purpose of the embodiment of the utility model is to provide a motor, which improves the overall strength and reliability of the motor by improving the bonding force between the rotor core and the shaft.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] In one aspect, a rotor assembly is provided, comprising:

[0008] The shaft body has a first connecting portion; the first connecting portion is provided with a spiral groove extending spirally along the axial direction of the shaft body;

[0009] The rotor core comprises a plurality of magnetic conductive blocks arranged at intervals along the circumference of the shaft body; a radial groove is formed between two adjacent magnetic conductive blocks;

[0010] A permanent magnet is embedded in the radial groove;

[0011] as well as

[0012] A plastic encapsulation body, which encapsulates the rotor core, the permanent magnet and the shaft into one body;

[0013] At least a portion of the plastic-encapsulated body fills the spiral groove.

[0014] Optionally, the spiral groove has multiple turns.

[0015] Optionally, a plurality of protruding teeth are provided on the first connecting portion, and the plurality of protruding teeth are sequentially arranged at intervals along the extension path of the spiral groove.

[0016] Optionally, the plurality of protruding teeth are all located outside the spiral groove and extend along the axial direction of the shaft body.

[0017] Optionally, the shaft body further comprises a second connection portion and a third connection portion connected to two ends of the first connection portion; the axis of the first connection portion, the axis of the second connection portion and the axis of the third connection portion coincide with each other;

[0018] Each of the convex teeth has a tooth bottom connected to the outer circumferential side of the first connecting part and a tooth top extending radially along the first connecting part; the radius of the second connecting part and the radius of the third connecting part are both smaller than the distance between the tooth top and the axis of the first connecting part.

[0019] Optionally, the radius of the second connection portion is equal to the radius of the third connection portion and is smaller than the radius of the first connection portion.

[0020] Optionally, the overmolded body is filled into the spiral groove by injection molding.

[0021] Optionally, the shaft body further has a mounting portion, the mounting portion has a first end connected to the first connecting portion and a second end extending in a direction away from the first connecting portion, and an edge of the second end is provided with a groove extending in a direction close to the first end.

[0022] Optionally, an external thread column is provided on the second end, and the axis of the external thread column coincides with the axis of the mounting portion.

[0023] On the other hand, a motor is provided, comprising the above-mentioned rotor assembly.

[0024] The beneficial effects of the utility model are as follows: a spiral groove is provided on the shaft body of the rotor assembly, and the spiral groove extends along the axial direction of the shaft body. When the rotor core is combined with the shaft body through the plastic-encapsulated body, a part of the plastic-encapsulated body is stuck in and fills the spiral groove. When the rotor core and the shaft body rotate, the friction force is increased by the abutment between the plastic-encapsulated body and the side wall of the spiral groove, so that relative rotation will not occur between the rotor core and the shaft body, the torsional force of the rotor assembly is stronger, and the strength and reliability of the rotor assembly are higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The utility model is further described in detail below based on the drawings and embodiments.

[0026] Figure 1 It is the transfer diagram of the rotor assembly;

[0027] Figure 2is an exploded view of the rotor assembly;

[0028] Figure 3 It is a half-section view of the rotor assembly, and the section lines are hidden in the figure;

[0029] Figure 4 A side view of the shaft.

[0030] Description of the accompanying drawings:

[0031] 11. Shaft body; 12. Rotor core; 13. Plastic-coated body; 15. Permanent magnet;

[0032] 110, first connection part; 111, second connection part; 112, third connection part; 113, mounting part; 114, spiral groove; 115, convex tooth; 116, first end; 117, second end; 118, cut groove; 119, external thread column;

[0033] 120. Magnetic block. DETAILED DESCRIPTION

[0034] In order to make the technical problems solved by the utility model, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the utility model will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0035] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "fixed", "connected", "communicated", "abutted", "clamped" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] In the description of this article, it should be understood that the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0038] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0039] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0040] Unless specifically stated or defined otherwise, the term “and / or” used in the present invention includes any and all combinations of one or more of the associated listed items.

[0041] For the convenience of description, unless otherwise specified, the axis direction of the shaft body and the center line direction of the first helix mentioned below are the same as Figure 1 The up and down directions of the shaft are consistent, and the radial direction of the shaft is consistent with Figure 1 The horizontal direction itself is consistent.

[0042] like Figures 1 to 4As shown, a rotor assembly includes a shaft body 11, a rotor core 12, a permanent magnet 15, and a plastic overmolding body 13. The shaft body 11 has a first connecting portion 110, and the first connecting portion 110 is a section of a cylinder of the shaft body 11. The rotor core 12 is annular, and includes a plurality of completely isolated magnetic conductive blocks 120, and the plurality of magnetic conductive blocks 120 are arranged at intervals along the circumference of the shaft body, and radial grooves are formed between two adjacent magnetic conductive blocks. The plastic overmolding body 13 is plastic, and the plastic overmolding body 13 is used to connect the rotor core 12 and the first connecting portion 110 of the shaft body 11. There are a plurality of permanent magnets 15, and a plurality of radial grooves 122 correspond to a plurality of permanent magnets 15 one by one, and the permanent magnets 15 are embedded in the radial grooves 122.

[0043] In order to improve the connecting force between the rotor core 12 and the shaft body 11, a spiral groove 114 is opened in the first connecting portion 110 of the shaft body 11. The spiral groove 114 extends spirally along the axial direction of the shaft body 11. The spiral groove 114 has a first spiral line. The center line of the first spiral line coincides with the axis of the shaft body 11. The spiral groove 114 is integrally formed in the first connecting portion 110 of the shaft body 11.

[0044] During installation, the rotor core 12 and the shaft body 11 are first placed in a mold, the magnetic conductive blocks of the rotor core are arranged at intervals along the circumference of the first connecting portion 110 of the shaft body 11, and then the permanent magnets are embedded in the radial grooves, the spiral grooves 114 are located in the area enclosed by the rotor core and the permanent magnets 15, and finally the plastic-encapsulating body 13 is arranged to connect the rotor core 12 with the shaft body 11. After the plastic-encapsulating body 13 is arranged, at least part of the plastic-encapsulating body 13 fills the spiral grooves 114, and at least part of the plastic-encapsulating body 13 is connected to the rotor core 12 and the permanent magnets 15, so as to realize the connection between the rotor core 12, the permanent magnets 15 and the shaft body 11. Specifically, a part of the plastic-encapsulating body 13 is connected to the rotor core 12 and the permanent magnets 15, and a part of the plastic-encapsulating body 13 is inserted into the spiral grooves 114, so as to realize that the plastic-encapsulating body 13 connects the shaft body 11 with the rotor core 12, and the rotor core 12 can rotate together with the shaft body 11.

[0045] The conventional plastic-encapsulated body 13 is inserted into the annular groove of the shaft body 11. When the rotor core 12 rotates, the side wall of the annular groove is perpendicular to the axis of the shaft body 11. There is no obstruction of the side wall of the annular groove along the circumference of the shaft body 11. The part of the plastic-encapsulated body 13 inserted into the annular groove will easily slide relative to the inner wall of the annular groove along the circumference of the shaft body 11, making the binding force between the shaft body 11 and the rotor core 12 not strong enough. The shaft body 11 of the present application is provided with a spiral groove 114, and a part of the plastic-encapsulated body 13 is inserted into the spiral groove 114. The side wall of the spiral groove 114 is located on the moving path of the rotor core 12 along the circumferential direction of the shaft body 11. When the shaft body 11 and the rotor core 12 rotate, the part of the plastic body 13 that is stuck in the spiral groove 114 abuts against the side wall of the spiral groove 114, and the plastic body 13 and the shaft body 11 will not slide relative to each other, thereby improving the bonding force between the shaft body 11 and the rotor core 12, thereby making the rotor assembly have stronger torque, higher strength and higher reliability.

[0046] Optionally, the spiral groove 114 is formed by lathe processing, and the shaft body 11 is provided with a tool-retracting groove. The spiral groove 114 is formed by one-time processing, and the processing is convenient. The spiral groove 114 has at least one circle, and specifically, the spiral groove 114 has multiple circles. The spiral groove has multiple circles means that the first spiral line rotates more than 360 degrees around its axis in three-dimensional space. The number of circles of the first spiral line around the cylinder can be expressed by an integer, such as 1 circle, 2 circles, 3 circles, etc.

[0047] It can be understood that permanent magnets 15 are mounted on the rotor core 12 .

[0048] In some embodiments, a plurality of convex teeth 115 are provided on the first connection portion 110. The plurality of convex teeth 115 are arranged in sequence along the extension path of the spiral groove 114. The plurality of convex teeth 115 are arranged along the second spiral line at intervals, the second spiral line is arranged at intervals with the first spiral line, the center line of the second spiral track coincides with the center line of the first spiral track, and the plurality of convex teeth 115 are formed between the pitches of the first spiral line. By adding a plurality of convex teeth 115 to the first connection portion 110, tooth grooves are formed between adjacent convex teeth 115, and the convex teeth 115 and the tooth grooves are used to improve the friction and bonding force between the plastic package 13 and the shaft body 11, thereby further improving the strength and reliability of the rotor assembly.

[0049] Furthermore, the protruding teeth 115 are integrally formed with the outer circumferential side surface of the first connecting portion 110. Optionally, the protruding teeth 115 are knurled teeth.

[0050] In addition, the protruding teeth may also be arranged on the inner wall of the spiral groove. Alternatively, a part of the protruding teeth 115 may be located on the outer circumferential side of the first connecting portion 110, and a part of the protruding teeth 115 may be located on the inner wall of the spiral groove.

[0051] Optionally, the plurality of protruding teeth 115 are all located outside the spiral groove 114 and extend along the axial direction of the shaft body 11. The protruding teeth 115 are strip-shaped, and both ends of the protruding teeth 115 extend to the edge of the spiral groove 114. The plurality of protruding teeth 115 are arranged at intervals along the axial direction of the shaft body 11, and a portion of the overmolded body 13 is inserted into and fills the tooth grooves formed between adjacent protruding teeth 115.

[0052] In some embodiments, the overmolded body 13 is filled in the spiral groove 114 by injection molding. The overmolded body 13 is formed by injection molding plastic. Specifically, a portion of the overmolded body 13 is inserted into the spiral groove 114, a portion of the overmolded body 13 is inserted into the tooth groove, and another portion of the overmolded body 13 wraps the rotor core 12 and the permanent magnet 15.

[0053] In some embodiments, the shaft body 11 further has a second connection portion 111 and a third connection portion 112. The shaft body 11 further has a second connection portion 111 and a third connection portion 112 connected to both ends of the first connection portion 110. The second connection portion 111 and the third connection portion 112 are both cylindrical, and the second connection portion 111 and the third connection portion 112 are both adjacent to the first connection portion 110. The first connection portion 110 is located between the second connection portion 111 and the third connection portion 112. One end of the first connection portion 110 is connected to the second connection portion 111, and the other end of the first connection portion 110 is connected to the third connection portion 112. The first connection portion 110, the second connection portion 111, and the third connection portion 112 are integrally formed. The axis of the first connection portion 110, the axis of the second connection portion 111, and the axis of the third connection portion 112 coincide.

[0054] Each convex tooth 115 has a tooth bottom connected to the outer circumferential side of the first connecting portion 110 and a tooth top extending radially along the first connecting portion 110. Along the direction away from the outer circumferential side of the first connecting portion 110, the cross section of the convex tooth 115 gradually decreases, that is, the cross section of the tooth top is smaller than the cross section of the tooth bottom, so that the plastic package 13 is conveniently inserted into the tooth groove.

[0055] The radius of the second connection part 111 and the radius of the third connection part 112 are both smaller than the distance between the tooth top and the axis of the first connection part 110, which further improves the bonding force between the plastic package 13 and the first connection part 110, and facilitates the processing of the first connection part 110 to form the convex tooth 115. Specifically, the diameter of the second connection part 111 and the diameter of the third connection part 112 are both D1, the radius of the second connection part 111 and the radius of the third connection part 112 are R1=0.5×D1, the diameter of the first connection part 110 is D2, the radius of the first connection part 110 is R2=0.5×D2, and the distance between the tooth top of the convex tooth 115 and the tooth bottom of the convex tooth 115 is H, wherein R2>R1, preferably R2-R1=H / 2. After the overmolded body 13 is injection molded on the shaft body 11, it wraps the entire first connecting part 110, part of the second connecting part 111, and part of the third connecting part 112. The convex teeth 115 protrude from the surfaces of the second connecting part 111 and the third connecting part 112 along the radial direction of the shaft body 11, and can produce axial and radial bite with the overmolded body 13 along the shaft body 11, thereby avoiding relative sliding between the overmolded body 13 and the shaft body 11 along the axial and radial directions of the shaft body 11, thereby improving the bonding strength.

[0056] Furthermore, the radius of the second connection portion 111 and the radius of the third connection portion 112 are equal and smaller than the radius of the first connection portion 110. The diameter of the first connection portion 110 is larger than the diameter of the second connection portion 111 and the diameter of the third connection portion 112, so it is easier to process the convex teeth 115, and more convex teeth 115 can be formed on the outer side of the first connection portion 110, thereby increasing the friction between the plastic-encapsulating body 13 and the first connection portion 110.

[0057] Optionally, each convex tooth 115 extends in a wave shape along the axial direction of the shaft body 11 to increase the side surface area of ​​each convex tooth 115, thereby increasing the contact area between the overmolded body 13 and each convex tooth 115, and further improving the bonding force between the overmolded body 13, the shaft body 11, and the rotor core 12.

[0058] In some embodiments, the spiral groove 114 is entirely located in the area enclosed by the rotor core 12 and the permanent magnet 15, and the length of the spiral groove 114 extending along the axis of the shaft body 11 is less than the length of the rotor core 12 extending along the axis of the shaft body 11, thereby reducing the process and saving the processing cost. When the shaft body 11 and the rotor core 12 are assembled, the entire spiral groove 114 is located in the area enclosed by the rotor core 12 and the permanent magnet 15. When the overmolded body 13 is formed by injection molding, part of the overmolded body 13 can be directly filled in the spiral groove 114 after filling the area enclosed by the rotor core 12 and the permanent magnet 15, thereby ensuring that part of the overmolded body 13 can fill the spiral groove 114, and facilitating the arrangement of the overmolded body 13.

[0059] In some embodiments, the shaft body 11 further has a mounting portion 113, the mounting portion 113 has a first end 116 connected to the first connecting portion 110 and a second end 117 extending in a direction away from the first connecting portion 110, and the first end 116 of the mounting portion 113 is indirectly connected to the first connecting portion 110. The second end 117 is the end of the shaft body 11. The edge of the second end 117 is provided with a groove 118 extending in a direction close to the first end 116. The groove 118 forms a flat position on the shaft body 11, and the flat position can prevent slipping when used to assemble components such as a wind wheel. The bottom wall of the groove 118 is a plane parallel to the axis of the shaft body 11, the depth of the groove 118 along the radial direction of the shaft body 11 is 0.4±0.1mm, and the length of the groove 118 along the axial direction of the shaft body 11 is 37.4±0.2mm. The shaft body 11 is phosphating treated, and chamfers are provided at both ends of the shaft body 11.

[0060] In some embodiments, an external thread column 119 is disposed on the second end 117, and the axis of the external thread column 119 coincides with the axis of the mounting portion 113. The external thread column 119 can meet the installation requirements of the shaft body 11.

[0061] In some embodiments, the radial cross-section of the spiral groove 114 along the shaft body 11 is semicircular, and the inner wall of the spiral groove 114 is provided with anti-slip grooves, which can be convex strips formed on the inner wall of the spiral groove 114, or anti-slip grooves formed on the inner wall of the spiral groove 114.

[0062] Specifically, the anti-skid pattern is an X-shaped convex strip formed on the inner wall of the spiral groove 114. The anti-skid pattern further improves the bonding force between the overmolded body 13 and the shaft body 11, thereby improving the strength and reliability of the rotor assembly.

[0063] It is understandable that the anti-skid pattern may also be a column hole or an anti-skid groove formed on the inner wall of the spiral groove 114 , and part of the overmolded body 13 flows into the column hole or the anti-skid groove when the overmolded body 13 is injection molded.

[0064] This embodiment also provides a motor, comprising the rotor assembly as described above.

[0065] Specifically, the motor further includes a housing, an output shaft, and a stator assembly. The stator assembly matches the rotor assembly, both the stator assembly and the rotor assembly are installed in the housing, the rotor assembly rotates relative to the stator assembly, and the output shaft is drivingly connected to the rotor assembly.

[0066] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementation methods of the present invention without creative work, and these methods will fall within the protection scope of the present invention.

Claims

1. A rotor assembly, characterized in that: include: The shaft body (11) has a first connection portion (110); the first connection portion (110) is provided with a spiral groove (114) extending spirally along the axial direction of the shaft body (11); The rotor core (12) comprises a plurality of magnetic conductive blocks (121) arranged at intervals along the circumference of the shaft (11); a radial groove (122) is formed between two adjacent magnetic conductive blocks (121); A permanent magnet (15) is embedded in the radial groove (122); as well as A plastic encapsulation body (13) is used to encapsulate the rotor core (12), the permanent magnet (15) and the shaft body (11) into one body; At least a portion of the plastic-encapsulated body (13) fills the spiral groove (114).

2. The rotor assembly according to claim 1, characterized in that The spiral groove (114) has multiple turns.

3. The rotor assembly according to claim 1, characterized in that: The first connecting portion (110) is provided with a plurality of protruding teeth (115), and the plurality of protruding teeth (115) are sequentially arranged at intervals along the extension path of the spiral groove (114).

4. The rotor assembly according to claim 3, characterized in that: The plurality of protruding teeth (115) are all located outside the spiral groove (114) and extend along the axial direction of the shaft body (11).

5. The rotor assembly according to claim 3, characterized in that: The shaft body (11) further comprises a second connecting portion (111) and a third connecting portion (112) connected to two ends of the first connecting portion (110); the axis of the first connecting portion (110), the axis of the second connecting portion (111) and the axis of the third connecting portion (112) coincide with each other; Each of the convex teeth (115) has a tooth bottom connected to the outer circumferential side surface of the first connecting part (110) and a tooth top extending radially along the first connecting part (110); the radius of the second connecting part (111) and the radius of the third connecting part (112) are both smaller than the distance between the tooth top and the axis of the first connecting part (110).

6. The rotor assembly according to claim 5, characterized in that The radius of the second connection portion (111) and the radius of the third connection portion (112) are equal and are both smaller than the radius of the first connection portion (110).

7. The rotor assembly according to any one of claims 1 to 6, characterized in that: The overmolded body (13) is filled into the spiral groove (114) by injection molding.

8. The rotor assembly according to any one of claims 1 to 6, characterized in that: The shaft body (11) further comprises a mounting portion (113), wherein the mounting portion (113) comprises a first end (116) connected to the first connecting portion (110) and a second end (117) extending in a direction away from the first connecting portion (110), wherein an edge of the second end (117) is provided with a cutting groove (118) extending in a direction close to the first end (116).

9. The rotor assembly according to claim 8, characterized in that An external thread column (119) is provided on the second end (117), and the axis of the external thread column (119) coincides with the axis of the mounting portion (113).

10. A motor, characterized in that: Comprising a rotor assembly as claimed in any one of claims 1 to 9.

Images