Hollow shaft motor rotor with rotor core of novel structure

Abstract

The hollow shaft motor rotor according to the present invention comprises a rotor core in which a plurality of thin plate members are laminated, and is characterized by comprising: a core body in which the plurality of thin plate members are laminated; and a plurality of magnets provided in the core body, the core body being composed of an inner body and an outer frame, the inner body and the outer frame being connected by a plurality of connecting ribs spaced at predetermined intervals, the magnets being inserted into magnet insertion portions, the magnet insertion part is formed by the inner side body, the outer side frame and the connecting rib.

Description

Technical Field

[0001] This invention relates to hollow shaft motors. More specifically, this invention relates to hollow shaft motor rotors having a structure suitable for die casting. Background Technology

[0002] Typically, in braking systems, the force acting on the brakes comes from the pressure generated by the master cylinder. To generate pressure in the master cylinder of such braking systems, the technology of utilizing an electric motor is widely used. This electric motor includes: a ball screw that engages with a hollow shaft by rotating the internal hollow shaft, rotating together within the hollow shaft; and a ball nut that moves up and down due to the rotation of the ball screw; therefore, it is commonly referred to as a hollow shaft motor.

[0003] As disclosed in Korean Patent No. 10-2190270, a conventional hollow shaft motor rotor includes: a hollow shaft housing, which is a hollow cylindrical shape; and a rotor core disposed on the outer circumferential surface of the hollow shaft, having multiple magnets. The hollow shaft is mostly made of stamped metal material, and in most cases, the rotor core is press-fitted into the hollow shaft, which is a stamped material.

[0004] In cases like this, where a rotor core is pressed into a hollow shaft or bonded using adhesives or other methods, the bonding process requires precise numerical accuracy. If assembly tolerances fall within a precise range, it becomes difficult to maintain the concentricity of the hollow shaft's rotation, thus compromising the proper functioning of the braking system.

[0005] Furthermore, Korean Patent No. 10-2634721 discloses a technique of attaching a rotor shielding sleeve around the magnet to prevent the magnet attached to the outer circumference of the rotor core from falling off.

[0006] According to the prior art, since individual components need to be placed on the outer circumferential surface of the rotor core, in addition to the assembly tolerance and concentricity issues mentioned above, there is a problem of reduced productivity due to the increase in the number of manufacturing processes.

[0007] Therefore, the present invention provides a hollow shaft motor rotor that solves the above problems by die casting without the need for non-stamping processing. Summary of the Invention

[0008] The object of the present invention is to provide a hollow shaft motor rotor that simplifies the manufacturing process and eliminates assembly tolerances when manufacturing the hollow shaft motor rotor.

[0009] Another object of the present invention is to provide a hollow shaft motor rotor in which the magnets are mounted on the rotor core in a way that makes the connection simple and secure.

[0010] Another object of the present invention is to provide a hollow shaft motor rotor that can improve productivity and reduce manufacturing costs by simplifying the assembly process.

[0011] The above-mentioned and other inherent objectives of the present invention can be easily achieved by the present invention as described below.

[0012] The hollow shaft motor rotor of the present invention includes a rotor core 110 formed by stacking multiple thin plate components 111'. The hollow shaft motor rotor is characterized in that it includes: a core body 111, which is formed by stacking the multiple thin plate components 111'; and a plurality of magnets 130 disposed on the core body 111. The core body is composed of an inner body 111-1 and an outer frame 111-2. The inner body 111-1 and the outer frame 111-2 are connected by a plurality of connecting ribs 111-3 spaced apart at predetermined intervals. The magnets 130 are inserted into magnet insertion portions 111A, which are formed by the inner body 111-1, the outer frame 111-2 and the connecting ribs 111-3.

[0013] In this invention, preferably, a pair of magnet fixing protrusions 111B are formed in each magnet insertion portion 111A of the inner body 111-1 to support the circumferential sides of the magnet 130 inserted in the magnet insertion portion 111A.

[0014] In this invention, preferably, when the magnet 130 is inserted into the magnet insertion part 111A, the inner side of the magnet 130 is in contact with the outer side of the inner body 111-1, and the two ends of the magnet 130 in the circumferential direction are supported by the magnet fixing protrusion 111B.

[0015] In this invention, preferably, a gap 111A' is formed between the outer side of the magnet 130 provided in the magnet insertion part 111A and the inner side of the outer frame 111-2.

[0016] In this invention, preferably, a two-sided passageway 111A is formed between the two sides of the magnet 130 in the circumferential direction and the connecting rib 111-3.

[0017] In this invention, preferably, a plurality of rotor fixing holes 111C are formed in the inner body 111-1 along the vertical direction.

[0018] In this invention, preferably, a plurality of outer surface grooves 111D formed along the vertical direction are formed on the outer side of the outer frame 111-2 of the core body 111.

[0019] In this invention, preferably, the hollow shaft motor rotor further includes a lower cover component 112 and an upper cover component 113. By changing the outer frames 112-2 and 113-2 of the thin plate components 111' at the upper and lower ends of the core body 111, the outer frames 112-2 and 113-2 cover a part of the magnet insertion portion 111A.

[0020] The hollow shaft motor rotor provided by the present invention has the following effect: when assembling the hollow shaft housing and the rotor core, a more precise structure can be obtained and optimal concentricity can be ensured by eliminating the resulting assembly tolerances.

[0021] Furthermore, the present invention simplifies and strengthens the connection of magnets to the rotor core while eliminating magnet assembly tolerances.

[0022] Furthermore, this invention not only improves productivity and reduces manufacturing costs by simplifying the assembly process, but also provides a high-quality hollow shaft motor rotor. Attached Figure Description

[0023] Figure 1 A perspective view of a hollow shaft motor using the rotor of the present invention, viewed from above.

[0024] Figure 2 A perspective view of a hollow shaft motor in which the rotor of the present invention is applied, viewed from below.

[0025] Figure 3 A perspective view of the rotor of the present invention viewed from above.

[0026] Figure 4 A perspective view of the rotor of the present invention, viewed from below.

[0027] Figure 5 An exploded perspective view of the rotor core and die-cast portion used in the rotor of the present invention.

[0028] Figure 6 An exploded perspective view of the rotor core and die-cast portion used in the rotor of the present invention, viewed from below.

[0029] Figure 7 A top view showing the rotor core of the rotor of the present invention.

[0030] Figure 8 An exploded perspective view of the rotor core of the rotor of the present invention is shown.

[0031] Figure 9 An exploded perspective view of the rotor core and magnet of the rotor of the present invention is shown.

[0032] Figure 10 A top view showing the core body of the rotor core in the rotor of the present invention.

[0033] Figure 11 A top view is shown of the lower or upper cover component in the rotor of the present invention.

[0034] The present invention will now be described in detail with reference to the accompanying drawings. Detailed Implementation

[0035] Figure 1 To view the hollow shaft motor 1 using the rotor 10 of the present invention from above, Figure 2 This is a perspective view of the hollow shaft motor 1 viewed from below.

[0036] like Figure 1 and Figure 2 As shown, the rotor 10 and the motor housing 20 of the present invention together constitute the hollow shaft motor 1. That is, the hollow shaft motor 1 is composed of the rotor 10 and the motor housing 20. The rotor 10 is located inside the motor housing 20 and is rotatably attached to the inside of the motor housing 20.

[0037] The motor housing 20 includes: a housing body 21; a flange 22 extending outward and formed on the upper part of the housing body 21; a bus body 23 attached to the upper part of the housing body 21; and a terminal cover 24 attached to one side of the bus body 23 for connecting to an external power source.

[0038] A stator (not shown) is provided in the housing body 21, and the rotor 10 is located inside the housing body 21. When power is applied to the stator, the rotor 10 rotates due to the changing magnetic field generated by the stator affecting the magnet 130 provided in the rotor 10. The upper and lower parts of the rotor 10 rotate via the busbar body 23 and / or bearings (not shown) provided in the housing body 21. A lower protrusion 211 is formed at the lower end of the housing body 21, and the lower part of the rotor 10 is exposed inside the lower protrusion 211. A cover (not shown) covering this exposed part can be combined with the lower protrusion 211.

[0039] Figure 3 To view the rotor 10 of the present invention from above, Figure 4 A perspective view of the rotor 10 of the present invention is shown below. Figure 5 An exploded perspective view of the rotor core 110 and hollow shaft housing 120 used in the rotor of the present invention is shown above. Figure 6 An exploded perspective view of the rotor core 110 and the hollow shaft housing 120 from below.

[0040] Reference Figures 3 to 6The hollow shaft motor rotor 10 of the present invention includes: a rotor core 110; and a hollow shaft housing 120 formed around the rotor core 110. The inner space of the rotor core 110 and the hollow shaft housing 120 is a hollow portion C, which refers to the space used for positioning the ball screw (not shown) and the ball nut (not shown).

[0041] The rotor core 110 includes: a core body 111, which is formed by stacking multiple thin plate components 111', which are made of thin electrical steel plates by stamping; and multiple magnets 130, which are disposed in the core body 111. The specific structure of the rotor core 110 will be described again below.

[0042] The hollow shaft housing 120 is manufactured by positioning the rotor core 110 in a die-casting mold and then injecting molten metal into the mold to form the housing. The molten metal used as the die-casting material can be an alloy of copper, zinc, aluminum, tin, magnesium, etc.

[0043] As described above, the hollow shaft housing 120 formed in the rotor core 110 by die casting includes: an upper core cover portion 121, which is annular and formed on the upper surface of the rotor core 110; an upper support portion 122, which is cylindrical and extends from the upper core cover portion 121 along the upper part; and an upper bearing support portion 123, which is cylindrical and extends along the upper part of the upper support portion 122.

[0044] Furthermore, the hollow shaft housing 120 includes: a lower core cover portion 124, which is annular and formed on the lower surface of the rotor core 110; a lower support portion 125, which extends from the lower core cover portion 124 along the lower part and has a shape in which the diameter gradually decreases towards the lower part; and a lower bearing support portion 126, which is cylindrical and extends along the lower part of the lower support portion 125. A ball screw engagement portion 126A is formed at the lower end of the lower bearing support portion 126 and engages with a ball screw (not shown).

[0045] The outer core support portion 127 is formed along the outer surface grooves 111D, 112D, and 113D formed on the outer peripheral surface of the rotor core 110. The outer core support portion 127 connects the upper core cover portion 121 and the lower core cover portion 124 in the vertical direction.

[0046] The magnet support portion 128 supports the outer diameter surface of the magnet 130 inserted into the rotor core 110, providing a bonding force between the magnet 130 and the rotor core 110. Magnet end support portions 128A are also formed at both ends of the magnet support portion 128 to support the ends of the magnet 130 and provide a bonding force with the rotor core 110. An inner core support portion 129 is formed on the inner circumferential surface of the rotor core. The magnet support portion 128, magnet end support portions 128A, inner core support portion 129, and outer core support portion 127 together connect the upper core cover portion 121 and the lower core cover portion 124 along the vertical direction.

[0047] Multiple upper fixing points 121A are formed in the upper core cover portion 121. Multiple lower fixing points 124A and rotor core fixing holes 124B are formed in the lower core cover portion 124.

[0048] The upper fixing point 121A is hole-shaped to expose a portion of the connecting rib 113-3 constituting the upper cover component 113 of the rotor core 110. As the molten material smoothly fills around the connecting rib 113-3 via the upper fixing point 121A, it can be visually confirmed whether the magnet support portion 128 and the magnet end support portions 128A have been successfully formed. Similarly, the lower fixing point 124A is hole-shaped to expose a portion of the connecting rib 112-3 constituting the lower cover component 112 of the rotor core 110. As the molten material smoothly fills around the connecting rib 112-3 via the lower fixing point 124A, it can be visually confirmed whether the magnet support portion 128 and the magnet end support portions 128A have been successfully formed.

[0049] The rotor fixing hole 124B communicates with the rotor core fixing holes 111C and 112C of the rotor core 110. This is because, as the pin of the die-casting mold is inserted into the rotor core fixing holes 111C and 112C, the rotor core 110 can be fixed in the mold. The rotor fixing hole 124B is formed in the lower core cover portion 124 and communicates with the rotor core fixing holes 111C and 112C. All parts of this hollow shaft housing 120 can be integrally formed into a single component from the die-casting material.

[0050] Figure 7 To show a top view of the rotor core 110 of the rotor 10 of the present invention, Figure 8 To show an exploded perspective view of the rotor core 110 of the rotor 10 of the present invention, Figure 9 An exploded perspective view of the rotor core 110 and magnet 130 of the rotor 10 of the present invention is shown.

[0051] like Figures 7 to 9 As shown, the rotor core 110 of the present invention includes a core body 111, a lower cover component 112, an upper cover component 113, and a magnet 130.

[0052] The core body 111 is formed by stacking multiple thin plate components 111' formed by stamping. The core body 111 consists of an inner body 111-1 and an outer frame 111-2, and the inner body 111-1 and the outer frame 111-2 are connected by multiple connecting ribs 111-3 formed at specified intervals.

[0053] The space formed by the inner body 111-1, the outer frame 111-2 and the connecting rib 111-3 constitutes a magnet insertion part 111A that runs vertically through the space.

[0054] Each magnet 130 is inserted into the magnet insertion portion 111A and attached to the outer surface of the inner body 111-1. In the inner body 111-1, to support the circumferential sides of the magnet 130 within the magnet insertion portion 111A, each magnet insertion portion 111A may have a pair of magnet fixing protrusions 111B. Therefore, when the magnet 130 is inserted into the magnet insertion portion 111A, the inner surface of the magnet 130 is in contact with the outer surface of the inner body 111-1, and both circumferential ends of the magnet 130 are supported by the magnet fixing protrusions 111B.

[0055] A gap 111A' is formed between the outer surface of the magnet 130, which is disposed in the magnet insertion part 111A, and the inner surface of the outer frame 111-2 at a predetermined interval. Furthermore, a two-sided passage 111A' is formed between the magnet 130 and the connecting rib 111-3 on both sides in the circumferential direction. When the hollow shaft shell 120 is formed, molten metal, which is a die-casting material, fills the gap 111A', thereby forming the magnet support part 128. As the molten metal fills the two-sided passage 111A', the magnet end support parts 128A are formed.

[0056] Multiple rotor fixing holes 111C are formed along the vertical direction on the inner side of the core body 111-1. During the die-casting process, a mold pin is inserted into the rotor fixing hole 111C to fix the rotor core 110. Figure 7 Although the rotor fixing holes 111C are formed at four symmetrical positions at 90-degree intervals relative to the central axis of the rotor core 110, there is no particular limitation on the number or position of the rotor fixing holes 111C. Preferably, at least three or more are formed at mutually symmetrical positions. Furthermore, the rotor fixing holes 111C can be formed through the vertical direction, and can be formed only along the lower side as needed, or can be formed on the lower side and the upper side respectively according to a specified depth.

[0057] The outer side groove 111D refers to a groove formed along the vertical direction on the outer side of the outer frame 111-2 of the core body 111. If the molten metal used as the die-casting material fills the outer side groove 111D, the outer support portion 127 of the core is formed.

[0058] Embossing 111E is used for lamination bonding between sheet metal parts 111'. Embossing 111E can be omitted as needed, and the bonding between sheet metal parts can also be achieved by adhesives or adhesive coatings. In particular, as the substrate for manufacturing sheet metal parts 111', self-bonding electrical steel sheets with a pre-formed coating layer on the surface can also be used. In this case, since the die-casting mold provides a high-temperature environment, the adhesive coating layer can have the effect of curing a specified portion during the die-casting process.

[0059] The inner surface groove 111F is a groove used to increase the bonding force and prevent the die-cast portion from detaching during the rotation of the rotor 10 when the molten metal, as the die-casting material, forms the inner core support portion 129 on the inner circumferential surface of the rotor core 110. The molten metal fills the inner surface groove 111F, and simultaneously forms the inner core support portion 129 on the inner circumferential surface of the rotor core 110. That is, the inner core support portion 129 can surround the inner surface groove 111F and the inner circumferential surface of the rotor core 110 as a whole. Therefore, the inner space of the inner core support portion 129 constitutes a hollow portion C. This inner core support portion 129 can increase the bonding force between the rotor core 110 of the rotating rotor 10 and the hollow shaft housing 120.

[0060] Figure 10 To show a top view of the core body 111 of the rotor core in the rotor of the present invention, Figure 11 A top view is shown for illustrating the lower cover member 112 or the upper cover member 113 in the rotor of the present invention.

[0061] Reference Figures 10 to 11 The rotor core 110 of the present invention includes a lower cover component 112; a core body 111, which is formed by stacking a plurality of thin plate components 111'; and an upper cover component 113.

[0062] The aforementioned lower cover component 112, multiple thin plate components 111', and upper cover component 113 can be manufactured by a stamping device using progressive dies to process electrical steel plates.

[0063] Multiple thin plate components 111' are stacked to form the core body 111. Each thin plate component 111' includes an inner body 111-1 and an outer frame 111-2, with multiple connecting ribs 111-3 spaced at predetermined intervals connecting the inner body 111-1 to the outer frame 111-2. A magnet insertion portion 111A is formed in the space between the inner body 111-1, the outer frame 111-2, and the connecting ribs 111-3. Multiple magnet fixing protrusions 111B are provided on the outer surface of the inner body 111-1 to fix a magnet 130.

[0064] Multiple rotor core fixing holes 111C are formed at predetermined intervals on the inner body 111-1. Although the rotor core fixing holes 111C can be formed on the entire thin plate component 111' constituting the core body 111, they can also be formed only on a portion of the thin plate component 111'. Multiple outer surface grooves 111D are formed on the outer frame.

[0065] For bonding between sheet metal components, embossing 111E can be formed by stamping, having a downwardly projecting shape while providing a bonding groove on top. Thus, the embossing 111E of one sheet metal component 111' is bonded to the embossing 111E of the sheet metal component 111' below it. When the bonding between sheet metal components is achieved by adhesives or other methods, embossing 111E can be omitted.

[0066] Inside the inner body 111-1 of the thin plate component 111', the inner side groove 111F is stacked with multiple thin plate components 111' so that the inner side groove 111F is formed on the inner side of the rotor core 110 in the vertical direction.

[0067] The lower cover component 112 and the upper cover component 113 can be made using the same stamping die as the sheet metal component 111'. The lower cover component 112 and the upper cover component 113 can be manufactured by pressing the outer frame 112-2 of the die-formed sheet metal component 111' using a tool such as a side press to form the outer frames 111-2 and 113-2 to cover a portion of the magnet insertion portion 111A of the sheet metal component 111'. Therefore, during die casting, the outer frames 111-2 and 113-2 prevent the magnet inserted into the magnet insertion portion 111A of the rotor core 110 from detaching from the upper or lower part.

[0068] The lower cover component 112, formed by a stamping die, is located at the bottom, and the core body 111, composed of multiple thin plate components 111', is located above it. The upper cover component 113 is stacked and bonded to the upper part of the core body 111. With the magnet 133 inserted into the magnet insertion part 111A, the outer frames 112-2 and 113-2 of the lower cover component 112 and the upper cover component 113 can be pressed by tools such as a side press to bend and deform the outer frames 112-2 and 113-2 along the inner body 112-1 and 113-1, thereby completing the shape of the lower cover body 112 and the upper cover body 113.

[0069] An embossed bonding hole 112E is formed in the lower cover member 112 at a position corresponding to the embossing 111E of the thin plate member 111'. Therefore, the thin plate member 111' can be stacked on the upper part of the lower cover member 112. An embossed pattern 113E is formed in the upper cover member 112 at a position corresponding to the embossing 111E of the thin plate member 111'. Therefore, the embossing 111E of the thin plate member 111' located at the uppermost part of the core body 111 can be combined with the embossing 113E of the upper cover member 113. However, if the structure is not suitable for the application of the lower cover member 112 and the upper cover member 113, the embossing 111E of the lowermost thin plate member 111' can be formed as an embossed bonding hole through perforation molding.

[0070] The above description of the invention is merely illustrative to help understand the invention and should not be construed as limiting the scope of protection of the invention. It should be understood that the scope of the invention should be defined based on the scope of the claims, and any simple modifications or alterations made to the invention within this scope fall within the protection scope of the invention.

Claims

1. A hollow shaft motor rotor, characterized in that, include: The core body is composed of multiple thin-plate components stacked together; and Multiple magnets are disposed in the aforementioned core body. The aforementioned sheet metal components are manufactured from self-adhesive steel sheets through stamping. The aforementioned core body consists of an inner body and an outer frame, wherein the inner body and the outer frame are connected by a plurality of connecting ribs spaced at predetermined intervals. The magnet is inserted into the magnet insertion part, which is formed by the inner body, the outer frame and the connecting rib.

2. The hollow shaft motor rotor according to claim 1, characterized in that, Each magnet insertion portion of the inner body is provided with a pair of magnet fixing protrusions to support the magnet inserted into the magnet insertion portion on both sides in the circumferential direction.

3. The hollow shaft motor rotor according to claim 2, characterized in that, With the magnet inserted in the magnet insertion part, the inner side of the magnet is in contact with the outer side of the inner body, and the two ends of the magnet in the circumferential direction are supported by the magnet fixing protrusion.

4. The hollow shaft motor rotor according to claim 1, characterized in that, A gap is formed between the outer surface of the magnet located in the magnet insertion part and the inner surface of the outer frame.

5. The hollow shaft motor rotor according to claim 1, characterized in that, Two-sided passages are formed between the magnet and the connecting rib on both sides of the circumference.

6. The hollow shaft motor rotor according to claim 1, characterized in that, The inner body has multiple rotor fixing holes formed along the vertical direction.

7. The hollow shaft motor rotor according to claim 1, characterized in that, Multiple outer surface grooves are formed on the outer side of the outer frame of the core body along the vertical direction.

8. The hollow shaft motor rotor according to claim 1, characterized in that, It also includes a lower cover component and an upper cover component, and the outer frame of the thin plate component at the upper and lower ends of the core body is changed so that the outer frame covers a part of the magnet insertion part.

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