Motor rotor structure

Abstract

A motor rotor structure comprises a silicon steel sheet main body, a magnet and an injection molding material. The silicon steel sheet body is composed of a plurality of silicon steel layers, each silicon steel layer is formed by stacking a plurality of silicon steel sheets and comprises a magnet groove and a corresponding slug hole, and the slug hole is closer to the axis of the silicon steel sheet body than the magnet groove. The magnet is located in the magnet groove and forms an air gap hole, and a flow channel groove is connected between the air gap hole and the slug hole. An injection molding material is filled into the slug hole, flows through the runner groove and the air gap hole, enters the magnet groove, and is cured to fix the magnet.

Description

Technical Field

[0001] The present invention relates to a motor rotor structure, and more particularly to a motor rotor structure in which magnets are fixed by an injection molding material. Background Art

[0002] In the application of a vehicle traction motor, when assembling a rotor assembly, in order to firmly fix the magnets in the magnet slots of the rotor silicon steel sheets, and to prevent the magnets from rubbing or colliding due to rotation, vibration and other factors during high-speed rotation, which may cause problems such as rust and cracking of the magnets, resulting in the risk of loss of motor performance. Therefore, the process of fixing the magnets on the rotor silicon steel sheets is very crucial.

[0003] It is known to use an injection molding material to fill the magnet slots of the rotor silicon steel sheets and cure it to fix the magnets. Since the injection molding air gap holes of the rotor silicon steel sheets are usually not designed too large, and when stacking the rotor silicon steel sheets, a staggered pole structure must be formed for magnetic performance, the cross-sectional area of the injection molding channel will be further limited, resulting in the risk that the injection molding material cannot fill the magnet slots. Summary of the Invention

[0004] The present invention provides a motor rotor structure to solve the problems of the prior art.

[0005] According to some embodiments of the present invention, a motor rotor structure includes a silicon steel sheet main body and an injection molding material. The silicon steel sheet main body is composed of multiple silicon steel layers, each silicon steel layer is stacked by a plurality of silicon steel thin sheets, and includes at least one magnet, at least one magnet slot and a corresponding at least one escape hole, wherein the escape hole is closer to an axis of the silicon steel sheet main body than the magnet slot. The magnet is located in the magnet slot and forms an air gap hole between the magnet and the magnet slot, wherein a flow channel groove is connected between the air gap hole and the escape hole. The injection molding material is filled into the escape hole and flows through the flow channel groove and the air gap hole into the magnet slot, and is cured to fix the magnet.

[0006] According to some embodiments of the present invention, for each silicon steel layer, the axial thickness of the injection molding material in the flow channel groove is less than the axial thickness of the injection molding material in the escape hole or the air gap hole.

[0007] According to some embodiments of the present invention, the axial thickness of the injection molding material in the flow channel groove is greater than or equal to the thickness of a single silicon steel thin sheet.

[0008] According to some embodiments of the present invention, the silicon steel layer includes two magnet slots arranged in a V shape, and the escape hole is connected to the two magnet slots by two flow channel grooves respectively.

[0009] According to some embodiments of the present invention, the flash hole has a partition strip with a thickness of a single silicon steel sheet, and the partition strip is connected to a partition wall between two of the flow channels.

[0010] According to some embodiments of the present invention, the silicon steel layer includes two larger first magnet grooves and two smaller second magnet grooves. The two first magnet grooves and the two second magnet grooves are respectively arranged in a V shape. The flash hole is connected to the two first magnet grooves through two first flow channels respectively, and each of the second magnet grooves is connected to the corresponding larger magnet groove through a second flow channel respectively.

[0011] According to some embodiments of the present invention, in each layer of the silicon steel layer, an axial thickness of the injection molding material in the first flow channel or the second flow channel is less than an axial thickness of the injection molding material in the flash hole.

[0012] According to some embodiments of the present invention, the air gap hole is closer to the axis of the silicon steel sheet body than the magnet.

[0013] According to some embodiments of the present invention, an opening area of the flash hole is greater than an opening area of the air gap hole.

[0014] According to some embodiments of the present invention, an axial thickness of the magnet is less than an axial thickness of each layer of the silicon steel layer.

[0015] In summary, the motor rotor structure of the present invention is designed for silicon steel sheets with very small air gap holes. A larger flash hole is used to replace the air gap hole as the plastic injection port and is connected to the magnet groove through the flow channel, which can effectively optimize the risk that the magnet groove cannot be filled with plastic due to the small cross-sectional area of the air hole flow channel after the silicon steel sheets are stacked with misalignment. In addition, using the flash hole with the flow channel can reduce the number of injection ports, greatly simplify the complexity of the flow channel mold, and optimize the plastic utilization rate. The double-layer V-shaped magnet groove can also increase the design of the flow channel between the large and small magnet grooves, and indeed achieve the purpose of filling the small magnet groove.

[0016] The following will describe the above description in detail with embodiments and provide further explanations for the technical solutions of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To make the above and other objects, features, advantages and embodiments of the present invention more obvious and understandable, the description of the drawings is as follows: Figure 1 A perspective view showing the motor rotor structure according to an embodiment of the present invention; Figure 2 A perspective view showing a single-layer silicon steel layer according to an embodiment of the present invention; Figure 3 Showing Figure 2 An exploded view of the single-layer silicon steel layer; Figure 4 Schematic diagram of injection molding of the motor rotor structure according to an embodiment of the present invention; Figure 5 Shows along Figure 4 The sectional view of the section line 5-5; Figure 6 Stereogram of a single-layer silicon steel layer according to another embodiment of the present invention; Figure 7 Shows Figure 6 The exploded view of the single-layer silicon steel layer; and Figure 8 Schematic diagram of injection molding of the motor rotor structure according to another embodiment of the present invention. Description of reference numerals 100: Motor rotor structure, 110: Silicon steel sheet body, 110a, 110b: Silicon steel layers, 110c: Axis, 112, 112c, 112d, 117: Flash holes, 112a, 112b: Openings of the flash holes, 113, 113a, 113b, 113c, 113d: Magnet slots, 114, 114a, 114b, 114c, 114d: Magnets, 115, 115a, 115b, 115c, 115d: Air gap holes, 116, 116a, 116b, 116c, 116d: Runner grooves, 118: Silicon steel sheet, 118a: Partition strip, 118b: Partition wall, 119: Flash hole, 120: Injection molding material, 130: Injection molding material, T1: Axial thickness, T2: Axial thickness, T3: Axial thickness. Detailed description of the specific embodiment

[0018] In order to make the description of the present invention more detailed and complete, reference may be made to the accompanying drawings and the following various embodiments, where the same numbers in the drawings represent the same or similar components. On the other hand, well-known components and steps are not described in the embodiments to avoid unnecessary limitations to the present invention. In the embodiments and the scope of the patent application, unless otherwise specifically defined in the text for the article, "a" and "the" may generally refer to a single or multiple.

[0019] Please refer toFigures 1 to 5 , Figure 1 A perspective view showing the motor rotor structure according to an embodiment of the present invention, Figure 2 A perspective view showing a single-layer silicon steel layer according to an embodiment of the present invention, Figure 3 Showing Figure 2 An exploded view of the single-layer silicon steel layer, Figure 4 A schematic injection molding view of the motor rotor structure according to an embodiment of the present invention, Figure 5 Showing a sectional view taken along the section line 5-5 of Figure 4 . The motor rotor structure 100 is composed of a silicon steel sheet main body 110 and a plurality of magnets 114 contained therein, etc. The silicon steel sheet main body 110 is composed of a multi-layer silicon steel layer 110a stacked in a staggered manner. Each layer of the silicon steel layer 110a is stacked by a plurality of silicon steel thin sheets 118 (refer to Figure 3 ).

[0020] In some embodiments of the present invention, each layer of the silicon steel layer 110a includes a plurality of magnet slots 113 and a plurality of flash holes 112, 117. The magnet slots 113 are used to accommodate the magnets 114, and the flash holes 112, 117 are used to reduce the overall weight of the silicon steel sheet main body 110. In some embodiments of the present invention, the flash holes 112, 117 are closer to the axis 110c of the silicon steel sheet main body than the magnet slots 113.

[0021] When the magnet 114 is placed in the magnet slot 113, the gap between the magnet slot 113 and the magnet 114 forms an air gap hole 115. In some embodiments of the present invention, the magnet 114 is generally a strip having a rectangular cross-section, and the air gap holes 115 are located at both ends in the longitudinal direction of the magnet slot 113. After the injection molding material 120 is filled into the air gap holes 115, it is cured to fix the magnet 114 located in the magnet slot 113. In the prior art, if only the air gap holes 115 at both ends of the magnet slot 113 are used as the inlets for filling the injection molding material 120, the number of runners designed by the mold needs to be very large. In addition, when the opening area of the air gap hole 115 is too small, after the multi-layer silicon steel layer 110a is stacked in a staggered manner, the cross-sectional area of the openings of the air gap holes 115 adjacent to each layer of the silicon steel layer is further reduced, which easily leads to the risk that the magnet slot 113 cannot be filled with the injection molding material.

[0022] In some embodiments of the present invention, a runner groove 116 is connected between the air gap hole 115 and the flash hole 112, and the flash hole 112 is used as the inlet for filling the injection molding material 120. After the injection molding material 120 is first injected into the flash hole 112, it then flows to the air gap hole 115 through the runner groove 116. This design helps to reduce the number of runners designed by the mold by half. Specifically, a runner groove 116a is connected between the flash hole 112 and the air gap hole 115a, and another runner groove 116b is connected between the flash hole 112 and the air gap hole 115b.

[0023] In some embodiments of the present invention, referring to Figure 5 , for each silicon steel layer 110a, the axial depth of the runner groove 116 is shallower than the axial depth of the flash hole 112 or the air gap hole 115. Therefore, the axial thickness T3 of the injection molding material 120 in the runner groove 116 is less than the axial thickness T1 of the injection molding material 120 in the flash hole 112 or the air gap hole 115. In some embodiments of the present invention, the axial depth of the runner groove 116 is equal to the stacked thickness of a single, two, or three silicon steel sheets. In other words, the axial thickness T3 of the injection molding material 120 in the runner groove 116 is equal to the stacked thickness of a single, two, or three silicon steel sheets, or the axial thickness T3 of the injection molding material 120 in the runner groove 116 is greater than or equal to the thickness of a single silicon steel sheet.

[0024] In some embodiments of the present invention, the opening of the flash hole 112 has a partition strip 118a with the thickness of a single silicon steel sheet, and the partition strip 118a is connected to the partition wall 118b between two runner grooves 116a, 116b. The partition wall 118b also has the thickness of a single silicon steel sheet 118. The partition strip 118a is connected to the partition wall 118b to prevent the partition wall 118b with the thickness of a single silicon steel sheet from warping due to external force. Therefore, the partition strip 118a only divides the flash hole 112 into two openings 112a, 112b, rather than dividing the flash hole 112 into two non - communicating regions.

[0025] Please refer to Figure 4 , Figure 5 , when using the flash hole 112 as the inlet for filling the injection molding material 120 (please refer to the arrow direction in Figure 5 ), it can be injected through either the opening 112a or the opening 112b, and can flow through the two runner grooves 116a, 116b to the two air gap holes 115a, 115b respectively, and then fill the two magnet grooves 113a, 113b respectively.

[0026] In some embodiments of the present invention, each silicon steel layer 110a includes multiple pairs of magnet grooves 113a, 113b, and each pair (i.e., every two) of magnet grooves 113a, 113b is arranged in a V - shape relative to the axis 110c. When using the flash hole 112 as the inlet for filling the injection molding material 120, each flash hole 112 can flow through the two runner grooves 116a, 116b to the two air gap holes 115a, 115b of the two magnet grooves 113a, 113b respectively.

[0027] In some embodiments of the present invention, the axial thickness T2 of the magnet 114 is less than the axial thickness T1 of each silicon steel layer 110a. Please refer to Figure 5In the direction of the arrow, when the injection molding material 120 flows into the air gap holes 115a and 115b of the magnet grooves 113a and 113b, it will then cross the magnets 114a and 114b to reach another air gap holes 115c and 115d, enabling the injection molding material to fill the magnet grooves 113a and 113b to encapsulate and fix the magnets 114a and 114b. In some embodiments of the present invention, the air gap holes 115a and 115b are closer to the axis 110c of the silicon steel sheet body than the magnets 114a and 114b, while the air gap holes 115c and 115d are farther from the axis 110c of the silicon steel sheet body than the magnets 114a and 114b.

[0028] In some embodiments of the present invention, the flash holes 112 are divided into two openings 112a and 112b with an area larger than that of a single air gap hole 115a, 115b, 115c or 115d, such that the flow resistance of the injection molding material in the flash holes 112 is smaller (compared with a single air gap hole).

[0029] Please also refer to Figure 6 、 Figure 7 , Figure 6 A perspective view of the single-layer silicon steel layer 110b showing another embodiment of the present invention, Figure 7 Showing Figure 6 An exploded view of the single-layer silicon steel layer 110b. In the embodiments of FIGS. 1-5, multiple pairs of magnet grooves 113a and 113b are arranged in multiple Vs, while Figure 6 、 Figure 7 In the embodiments of, multiple pairs of magnet grooves 113a, 113b, 113c and 113d are arranged in multiple double Vs. Each group (a total of four) of magnet grooves includes two larger magnet grooves 113a and 113b and two smaller magnet grooves 113c and 113d. The two larger magnet grooves 113a and 113b are arranged in a larger V and are closer to the axis 110c, and the two smaller magnet grooves 113c and 113d are arranged in a smaller V and are farther from the axis 110c, thus forming a radial inner and outer double-layer V-shaped magnet groove structure. In some embodiments of the present invention, the flash hole 112c is directly connected to the magnet groove 113a, and the flash hole 112d is directly connected to the magnet groove 113b. In other embodiments of the present invention, the embodiments of FIGS. 6 and 7 can also use the design of a single flash hole 112 in the embodiments of FIGS. 1-5, which is connected to the two magnet grooves 113a and 113b through two flow channel grooves 116a and 116b. The single-layer silicon steel layer 110b also has multiple flash holes 119 closer to the axis 110c, thereby reducing the overall weight of the silicon steel sheet body.

[0030] Please refer to Figure 8, which shows an injection molding schematic diagram of the motor rotor structure according to another embodiment of the present invention. In some embodiments of the present invention, two larger magnet slots 113a, 113b are respectively connected to two smaller magnet slots 113c, 113d via two runner slots 116c, 116d. Please refer to Figure 8 the arrow direction in. When the injection molding material 130 flows into the two larger magnet slots 113a, 113b from the flash holes 112c, 112d, it will then flow through the two runner slots 116c, 116d respectively to the two smaller magnet slots 113c, 113d, making it easier for the two smaller magnet slots 113c, 113d to be filled with the injection molding material. Similar to the embodiments of FIGS. 1-5 (for example, refer to Figure 5 ), the axial depths of the two runner slots 116c, 116d are shallower than those of the flash holes 112c, 112d. Therefore, the axial thickness of the injection molding material 130 in the two runner slots 116c, 116d (for example, refer to Figure 5 the axial thickness T3 of the runner slot) is less than the axial thickness of the injection molding material in the flash holes 112c, 112d (for example, refer to Figure 5 the axial thickness T1 of the flash hole). In some embodiments of the present invention, the axial depths of the two runner slots 116c, 116d are equal to the stacked thickness of a single, two, or three silicon steel sheets, for example, refer to Figure 5 the axial depth T3 of the runner slots 116a, 116b.

[0031] In some embodiments of the present invention, the axial thicknesses of the magnets 114a, 114b, 114c, 114d are all less than the axial thickness of each silicon steel layer 110b (for example Figure 5 the axial thickness T2 is less than the axial thickness T1). Therefore, when the injection molding material flows into the magnet slots 113a, 113b, 113c, 113d, it will then cross over the magnets 114a, 114b, 114c, 114d to the air gap holes at the other end, so that the injection molding material can fill the magnet slots 113a, 113b, 113c, 113d to coat and fix the magnets 114a, 114b, 114c, 114d.

[0032] The motor rotor structure of the present invention is designed for silicon steel sheets with very small air gap holes. Using larger flash holes instead of air gap holes as plastic injection inlets and matching runner slots can effectively optimize the risk that the magnet slots cannot be filled with plastic due to the small cross-sectional area of the air gap hole flow path after the silicon steel sheets are stacked with misalignment. In addition, using flash holes in combination with runner slots can reduce the number of injection inlets, greatly simplify the complexity of the runner mold, and optimize the plastic utilization rate. The double V magnet slots can also add the design of runner slots between the large and small magnet slots to truly achieve the purpose of filling the small magnet slots.

[0033] Although the present invention has been shown in the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to that defined by the appended patent application scope.

Claims

1. A motor rotor structure, wherein, Comprising: A silicon steel sheet body composed of multiple silicon steel layers, where each silicon steel layer is stacked by multiple silicon steel thin sheets and includes: At least one magnet groove and a corresponding at least one material escape hole, where the material escape hole is closer to an axis of the silicon steel sheet body than the magnet groove; and At least one magnet located in the at least one magnet groove and forming an air gap hole with the magnet groove, where a flow channel groove is connected between the air gap hole and the material escape hole; And An injection molding material is injected into the material escape hole, flows through the flow channel groove and the air gap hole, and enters the magnet groove, and is cured to fix the magnet.

2. The motor rotor structure according to claim 1, wherein, In each silicon steel layer, an axial thickness of the injection molding material in the flow channel groove is less than an axial thickness of the injection molding material in the material escape hole or the air gap hole.

3. The motor rotor structure according to claim 2, wherein, An axial thickness of the injection molding material in the flow channel groove is greater than or equal to a thickness of a single silicon steel thin sheet.

4. The motor rotor structure according to claim 1, wherein, The silicon steel layer includes two magnet grooves arranged in a V shape, and the material escape hole is connected to the two magnet grooves respectively by two flow channel grooves.

5. The motor rotor structure according to claim 4, wherein, The material escape hole has a partition strip with a thickness of a single silicon steel thin sheet, and the partition strip is connected to a partition wall between the two flow channel grooves.

6. The motor rotor structure according to claim 1, wherein, The silicon steel layer includes two larger first magnet grooves and two smaller second magnet grooves. The two first magnet grooves and the two second magnet grooves are respectively arranged in a V shape. The material escape hole is connected to the two first magnet grooves respectively by two first flow channel grooves, and each second magnet groove is connected to the corresponding first magnet groove by a second flow channel groove.

7. The motor rotor structure according to claim 6, wherein, In each silicon steel layer, an axial thickness of the injection molding material in the first flow channel groove or the second flow channel groove is less than an axial thickness of the injection molding material in the material escape hole.

8. The motor rotor structure according to claim 1, wherein, The air gap hole is closer to the axis of the silicon steel sheet body than the magnet.

9. The motor rotor structure according to claim 8, wherein, An opening area of the material escape hole is larger than an opening area of the air gap hole.

10. The motor rotor structure according to claim 1, wherein, An axial thickness of the magnet is less than an axial thickness of each silicon steel layer.

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