Hollow shaft motor

Abstract

To provide a hollow shaft motor that can simplify the manufacturing process. The hollow shaft motor (1) includes a stator assembly and a motor housing formed by resin molding around the stator assembly, with a hollow shaft rotor positioned inside the stator assembly and rotatably coupled to the motor housing. The motor housing has a main body (21) with an open inner space to accommodate the hollow shaft rotor, and a flange (22) formed on the top of the main body (21) and extending outward.

Description

[Technical Field]

[0001] The present invention relates to a hollow shaft motor, and more particularly to a hollow shaft motor having a structure suitable for integrally manufacturing a motor housing by insert injection molding when manufacturing the hollow shaft motor. [Background technology]

[0002] Generally, the force acting on the brakes in a braking system is derived from the pressure generated in a master cylinder. A widely used technology uses an electric motor to generate pressure in the master cylinder of such a braking system. Such electric motors are usually called hollow shaft motors because they include a ball screw that rotates a hollow shaft, a ball nut that moves up and down as the ball screw rotates, and a ball screw that is connected to the hollow shaft and rotates together inside the hollow shaft.

[0003] As disclosed in Korean Patent Registration No. 10-2123180, a conventional hollow shaft motor has a structure in which a stator assembly, which combines a stator core wound with a coil and a bus bar housing, is combined with a motor housing made of a pressed metal, a hollow shaft rotor is positioned inside the stator assembly, and a separate upper cover is combined with the bus bar housing.

[0004] In this hollow shaft motor structure, when the stator assembly is coupled to the motor housing, work tolerances may occur, making it possible for the concentricity of the hollow shaft to be compromised during rotation. In particular, a bearing insertion space must be formed by post-processing to press-fit the bearing into the hollow shaft housing, which increases the number of processes. Such work tolerances or post-processing may result in noise and vibration during motor operation. Furthermore, moisture or foreign matter may penetrate the stator assembly, adversely affecting the durability and reliability of the motor. This may result in the brake system not operating properly.

[0005] Therefore, the present invention proposes a hollow shaft motor that can simplify the manufacturing process and solve the above-mentioned problems by enabling the motor housing containing the stator assembly to be manufactured by insert injection. Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a hollow shaft motor that can simplify the manufacturing process.

[0007] Another object of the present invention is to provide a hollow shaft motor that can eliminate assembly tolerances and ensure concentricity.

[0008] It is yet another object of the present invention to provide a hollow shaft motor that can prevent noise and vibration from occurring during operation of the hollow shaft motor.

[0009] It is still another object of the present invention to provide a hollow shaft motor that can prevent moisture from penetrating into a stator assembly of the hollow shaft motor.

[0010] The above objects and other inherent objects of the present invention are all readily attained by the invention as described below. [Means for solving the problem]

[0011] The hollow shaft motor according to the present invention comprises: a stator assembly 10; The motor includes a motor housing 20 formed by resin molding around the stator assembly 10, and a hollow shaft rotor is positioned inside the stator assembly 10, and the hollow shaft rotor is rotatably coupled to the motor housing.

[0012] In the present invention, the stator assembly 10 may include a stator 11 and a busbar unit 12 coupled to an upper portion of the stator.

[0013] In the present invention, the motor housing 20 includes a main body 21 having an inner space so that the hollow shaft rotor can be positioned in the inner space. It is preferable that the main body 21 has a flange 22 formed on the upper portion thereof and extending outward.

[0014] In the present invention, a bus bar cover 23 in which the bus bar unit 12 is molded with resin may be formed inside the flange 22 .

[0015] In the present invention, a lower protrusion 24 having a ring shape and protruding downward may be formed at the lower part of the main body 21 .

[0016] In the present invention, the bus bar unit 12 may include a plurality of bus bars 120 and a free mold 121 to which the bus bars 120 are fixed.

[0017] In the present invention, a terminal cover 13 may be formed on one side of the motor housing 20 so as to protrude upward. [Effects of the Invention]

[0018] The present invention has the advantages of providing a hollow shaft motor that can simplify the manufacturing process by forming the motor housing by injection molding while the stator assembly is positioned in an insert injection mold, eliminates assembly tolerances of the hollow shaft motor, ensures concentricity, minimizes noise and vibration generated during motor operation, and effectively prevents moisture from penetrating into the hollow shaft motor. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view of a hollow shaft motor according to the present invention, seen from above; [Figure 2] FIG. 1 is a perspective view of a hollow shaft motor according to the present invention, seen from below. [Figure 3] 1 is an exploded perspective view of a stator assembly and a motor housing of a hollow shaft motor according to the present invention; FIG. [Figure 4] 1 is a cross-sectional perspective view of a hollow shaft motor according to the present invention, with a portion cut away; [Figure 5] FIG. 2 is a perspective view of a stator assembly of a hollow shaft motor according to the present invention, seen from above. [Figure 6] FIG. 2 is a perspective view of a stator assembly of a hollow shaft motor according to the present invention, seen from below. [Figure 7] 1 is an exploded perspective view of a stator of a hollow shaft motor according to the present invention, viewed from above. FIG. [Figure 8] FIG. 2 is an exploded perspective view of the stator of the hollow shaft motor according to the present invention, seen from below. [Figure 9] 1 is an exploded perspective view of a stator and a busbar unit in a stator assembly of a hollow shaft motor according to the present invention; FIG. [Figure 10] FIG. 2 is a perspective view of a busbar unit of the hollow shaft motor according to the present invention, seen from below. [Figure 11] 1 is an exploded perspective view of a bus bar and a free mold in a bus bar unit of a hollow shaft motor according to the present invention, viewed from above; FIG. [Figure 12] 1 is a perspective view showing an exploded bottom view of a bus bar and a free mold in a bus bar unit of a hollow shaft motor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] FIG. 1 is a perspective view of a hollow shaft motor 1 according to the present invention as seen from above, FIG. 2 is a perspective view of the hollow shaft motor 1 according to the present invention as seen from below, FIG. 3 is a perspective view of an exploded view of a stator assembly 10 and a motor housing 20 in the hollow shaft motor 1 according to the present invention, and FIG. 4 is a cross-sectional perspective view of a portion of the hollow shaft motor 1 according to the present invention as seen from above.

[0021] As shown in FIGS. 1 to 4, a hollow shaft motor 1 according to the present invention includes a stator assembly 10 and a motor housing 20 formed around the stator assembly 10 by resin molding.

[0022] The stator assembly 10 includes a stator 11 and a busbar unit 12 coupled to an upper portion of the stator 11. The motor housing 20 is integrally formed around the stator assembly 10 by injection molding, i.e., insert injection molding, in which the stator assembly 10 is placed in an insert injection mold and then a plastic resin melt is injected into the mold. A hollow shaft rotor (not shown) is located in the internal space of the stator assembly 10, and the hollow shaft rotor is rotatably coupled to the motor housing 20.

[0023] The stator 11 includes a stator core 110, an upper insulator 111 coupled to the upper part of the stator core 110, a lower insulator 112 coupled to the lower part of the stator core 110, and coils 113 wound around the teeth of the stator 11.

[0024] Stator core 110 is manufactured by stacking a large number of thin core sheets made from electrical steel plates. Stator core 110 includes a circular core base 110A and a plurality of teeth 110B formed by protruding from core base 110A in the axial direction of the hollow interior of stator core 110. The space formed by two adjacent teeth 110B forms slot 110C.

[0025] A plurality of core outer grooves 110A-1 are formed at regular intervals in the vertical direction on the outer surface of the core base 110A. When the motor housing 20 is insert-molded into the stator assembly 10, a molten resin is injected into the core outer grooves 110A-1, thereby increasing the bonding strength between the motor housing 20 and the stator core 110.

[0026] The axial ends of the teeth 110B are tooth end portions 110B-1, which protrude on both circumferential sides. Teeth end inner grooves 110B-1' are formed at the center of the tooth end portions 110B-1, one above the other. Resin is also injected into the tooth end inner grooves 110B-1', forming part of the motor housing 20. In this specification, the term "axial direction" refers to the direction toward the center of the circle when viewed from the plane of the core base 110A. Coil windings 113A wound around the teeth 110B are located in the slots 110C.

[0027] The upper insulator 111 coupled to the upper part of the stator core 110 includes a ring-shaped upper base insulating portion 111A coupled to the upper part of the core base 110A, an upper tooth insulating portion 111B coupled to the upper part of the teeth 110B, and an upper slot insulating portion 111C for insulating the upper side of the inner surface of the slot 110C.

[0028] Lower insulator 112 coupled to the lower part of stator core 110 includes ring-shaped lower base insulating part 112A coupled to the lower part of core base 110A, lower tooth insulating part 112B coupled to the lower part of teeth 110B, and lower slot insulating part 112C for insulating the lower side of the inner surface of slot 110C. Lower slot insulating part 112C is assembled in contact with upper slot insulating part 111C to insulate the inner surface of slot 110C.

[0029] The busbar unit 12 is coupled to the upper part of the stator 11. Specifically, it is coupled to the upper insulator 111 of the stator 11. The detailed coupling structure between the busbar unit 12 and the upper insulator 111 will be described again below.

[0030] The busbar unit 12 includes a plurality of busbars 120 and a free mold 121 coupled to the busbars 120. The number of busbars 120 is not particularly limited, but in the case of a three-phase BLDC motor, it is preferable to use three busbars to connect the U, V, and W phases. The attached drawings show a case where three busbars 120 are used. Each busbar 120 includes a circular busbar body 120A, a plurality of coil connection portions 120B formed in the outer diameter direction of the busbar body 120A, and a terminal 120C extending upward from an end of the busbar body 120A.

[0031] The terminal cover 13 covers the terminals 120C and protects them. The terminal cover 13 is attached to the free mold 121 and protrudes above the busbar cover 23 to be attached to the busbar unit 12. Preferably, the terminal cover 13 may be formed by insert injection molding after the stator 11 and the busbar unit 12 are attached together. In this case, resin is injected through the through-holes 120C' formed in the terminals 120C, firmly attaching the terminals 120C to the resin molding. More preferably, the terminal cover 13 may be formed together with the motor housing 20 when the motor housing 20 is formed by insert injection molding. As another embodiment, the terminal cover 13 may be attached to one side of the motor housing 20 as a separate member after the motor housing 20 is molded by insert injection molding. As another embodiment, the terminal cover 13 may be omitted, and the terminal guide 121D of the free mold 121 may be formed to cover the entire terminals 120C except for the upper portions thereof to protect the terminals 120C.

[0032] The motor housing 20 includes a main body 21, a flange 22, a bus bar cover 23, a lower protrusion 24, an upper bearing press-fit portion 25, and a lower bearing press-fit portion 26. Because the motor housing 20 is formed by resin injection molding, all of the components of the motor housing 20 are formed as a single, integrally formed member.

[0033] The main body 21 has an open inner space in which the hollow shaft rotor can be positioned, and the stator assembly 10 is embedded inside the main body 21. The main body 21 has an upper portion formed with a flange 22 extending outward. A busbar cover 23 in which the busbar unit 12 is molded with resin is formed inside the flange 22. The main body 21 has a lower portion 24 formed with a ring shape and protruding downward from the lower portion.

[0034] An upper bearing press-fitting portion 25 into which an upper bearing (not shown) is press-fitted is formed on the inner surface of bus bar cover 23, and a lower bearing press-fitting portion 26 into which a lower bearing (not shown) is press-fitted is formed on the inner surface of lower protrusion 24. A lower step portion 26A is formed along the outer periphery of lower bearing press-fitting portion 26 to prevent the lower bearing from coming off. A lower cover coupling portion 24A into which a lower cover (not shown) is coupled is formed at the bottom of lower protrusion 24.

[0035] A plurality of central coupling teeth 23A protruding upward are formed on the upper periphery of the inner space of the busbar cover 23. The central coupling teeth 23A provide a structure for coupling a piston mechanism (not shown) of a master cylinder to the hollow shaft motor 1. A boundary groove 23B is formed along the periphery on the top of the busbar cover 23. A sealing member (not shown), such as rubber or silicone, is coupled to the boundary groove 23B when the hollow shaft motor 1 is coupled to the master cylinder.

[0036] A plurality of confirmation holes 23C may be formed in the upper portion of the bus bar cover 23. These confirmation holes 23C allow confirmation of whether the resin molding has sufficiently flowed around the bus bar 120, and in some cases may communicate with the internal see-through holes 121A-4 formed in the annular ring portion 121A of the free mold 121, allowing confirmation through these holes 23C, 121A-4 of whether the resin molding has sufficiently flowed around the coil winding 113A. In an actual commercial hollow shaft motor, these holes 23C, 121A-4 may not be formed.

[0037] In the prior art, the busbar and coil ends are connected after a separate busbar cover is attached to the motor housing and stator assembly, which increases the number of work steps, makes the work more difficult, and takes more time. In the hollow shaft motor 1 according to the present invention, the busbar cover 23 is integrally formed with the motor housing 20 by resin molding with the stator assembly 10 placed in an insert injection mold, which simplifies the process of connecting the busbar and coils and shortens the assembly process, thereby reducing costs and improving productivity.

[0038] Fig. 5 is a perspective view of the stator assembly 10 of the hollow shaft motor 1 according to the present invention as seen from above, and Fig. 6 is a perspective view of the stator assembly 10 as seen from below. Referring to Figs. 5 and 6, the stator assembly 10 according to the present invention includes a stator 11, a busbar unit 12, and a terminal cover 13.

[0039] The stator 11 includes a stator core 110, an upper insulator 111 coupled to the upper part of the stator core 110, a lower insulator 112 coupled to the lower part of the stator core 110, and a coil 113 wound around a tooth 110B when the upper insulator 111 and the lower insulator 112 are coupled to the stator core 110.

[0040] An upper end portion 111B-1 is formed at the axial end of the upper tooth insulating portion 111B of the upper insulator 111, protruding from and coupled to the upper portion of the tooth end portion 110B-1. An upper end groove 111B-1' is formed in the center of the axial end surface of the upper end portion 111B-1 in the vertical direction so as to communicate with the tooth end inner groove 110B-1'. Therefore, when forming the motor housing 20, resin is also injected into the upper end groove 111B-1', and the injected resin becomes part of the motor housing 20.

[0041] The axial end of the lower tooth insulating portion 112B is formed with a lower end portion 112B-1 that protrudes from and is coupled to the lower part of the tooth end portion 110B-1. A lower end groove 112B-1' is formed in the center of the axial end surface of the lower end portion 112B-1 so as to be connected to the tooth end inner groove 110B-1' in the vertical direction. Therefore, when forming the motor housing 20, resin is also injected into the lower end groove 112B-1', and the injected resin becomes part of the motor housing 20.

[0042] The coils 113 wound around the teeth form coil windings 113A, and resin molding is formed by insert injection in the empty space other than the space occupied by the coil windings 113A in the slots. Therefore, when the motor housing 20 is molded, the axial surfaces of the tooth end portions 110B-1 are exposed to the internal space of the motor housing 20, as shown in Figure 4.

[0043] Fig. 7 is an exploded perspective view of the stator 11 of the hollow shaft motor 1 according to the present invention, viewed from above, and Fig. 8 is an exploded perspective view of the stator 11, viewed from below. As shown in Figs. 7 and 8, the stator 11 according to the present invention includes a stator core 110, an upper insulator 111, a lower insulator 112, and a coil 113.

[0044] Stator core 110 includes a circular core base 110A, a plurality of teeth 110B formed to protrude from core base 110A in the hollow axial direction inside stator core 110, and slots 110C which are spaces formed by two adjacent teeth 110B.

[0045] The upper insulator 111 is coupled to the upper part of the stator core 110 and includes a ring-shaped upper base insulating part 111A coupled to the upper part of the core base 110A, an upper tooth insulating part 111B coupled to the upper part of the teeth 110B, and an upper slot insulating part 111C for insulating the upper side of the inner surface of the slot 110C. An upper pleat part 111B' is formed on the upper surface of the upper tooth insulating part 111B to allow the coil winding 113A to be wound smoothly. An upper tooth inner groove 111B" is formed on the lower surface of the upper tooth insulating part 111B to allow resin molding to be injected into this part.

[0046] The lower insulator 112 is coupled to the lower part of the stator core 110 and includes a ring-shaped lower base insulating part 112A coupled to the lower part of the core base 110A, a lower tooth insulating part 112B coupled to the lower part of the teeth 110B, and a lower slot insulating part 112C for insulating the lower side of the inner surface of the slot 110C. The lower slot insulating part 112C is assembled by abutting against the upper slot insulating part 111C to insulate the inner surface of the slot 110C. A lower pleat part 112B' is formed on the lower surface of the lower tooth insulating part 112B to allow the coil winding 113A to be wound smoothly. A lower tooth inner groove 112B" is formed on the upper surface of the lower tooth insulating part 112B to allow resin molding to be injected into this part.

[0047] Coils 113 are wound around each tooth 110B, and each coil wound around tooth 110B includes a coil winding 113A, coil end portions 113B that are the ends of the coil protruding upward, and lower coil connecting portions 113C for connecting the coil windings 113A together. The coil end portions 113B are electrically connected to bus bars 120 that connect the coil windings 113A of the same phase. The lower coil connecting portions 113C connect the coil windings 113A of the same phase to each other at the bottom of stator 11, and are guided and fixed by a plurality of lower coil guides 112A-1 that are formed by protruding from the bottom of lower base insulating portion 112A of lower insulator 112.

[0048] The upper base insulating portion 111A of the upper insulator 111 has a plurality of coil support pieces 111A-1 protruding upward. Each coil support piece 111A-1 has at least one coil coupling portion 111A-2 at its upper portion. The coil end portion 113B is coupled to the coil coupling portion 111A-2 to fix the coil end portion 113B. The number of coil support pieces 111A-1 and coil coupling portions 111A-2 is not particularly limited, and various numbers can be used depending on design factors such as the number of slots or the size of the stator.

[0049] A coil support piece hole 111A-1' is formed in the lower part of the coil end portion 113B of the coil support piece 111A-1, penetrating the coil support piece hole 111A-1' in the axial direction. The resin mold passes through the coil support piece hole 111A-1' to ensure that the resin molding is properly formed around the coil end portion 113B.

[0050] A coil support piece groove 111A-1'' is formed on the outer surface of the coil support piece 111A-1, and a resin mold is filled into this coil support piece groove 111A-1'' so that the coil support piece 111A-1 is firmly connected to the motor housing 20.

[0051] At least one first block coupling protrusion 111A-3 protruding upward is formed on a portion of the upper base insulating portion 111A. A first block inserting protrusion 111A-4 is formed on one side of the first block coupling protrusion 111A-3. Although two first block coupling protrusions 111A-3 and two first block inserting protrusions 111A-4 are shown in the drawings, the number is not limited to two and may vary depending on design needs.

[0052] At least one second block coupling protrusion 111A-5 is formed at a position facing the first block coupling protrusion 111A-3 on the upper base insulating portion 111A. A first block inserting protrusion 111A-6 is formed on one side of the second block coupling protrusion 111A-5. Although the number of second block coupling protrusions 111A-5 and second block inserting protrusions 111A-6 is shown as two each in the drawings, this is not limited to two and various numbers may be used depending on design needs.

[0053] The first block coupling protrusion 111A-3 and the second block coupling protrusion 111A-5 are formed facing each other on the circular upper base insulating part 111A, so that the coil support piece 111A-1 is disposed between the first block coupling protrusion 111A-3 and the second block coupling protrusion 111A-5. That is, when viewed from above, if the first block coupling protrusion 111A-3 is positioned at 12 o'clock and the second block coupling protrusion 111A-5 is positioned at 6 o'clock, the coil support piece 111A-1 is positioned approximately between 2 and 4 o'clock and between 8 and 10 o'clock. This facilitates the coil connection between the coil end portion 113B and the coil connection portion 120B, and also allows the coil end portion 113B and the coil connection portion 120B to be aligned and gathered on both sides.

[0054] Figure 9 is an exploded perspective view of the stator 11 and busbar unit 12 in the stator assembly 10 of the hollow shaft motor 1 according to the present invention, Figure 10 is a perspective view of the busbar unit 12 of the hollow shaft motor 1 according to the present invention viewed from below, Figure 11 is a perspective view of the busbar 120 and free mold 121 in the busbar unit 12 of the hollow shaft motor 1 according to the present invention viewed from above, and Figure 12 is a perspective view of the busbar 120 and free mold 121 viewed from below.

[0055] 9 to 12, the busbar unit 12 of the hollow shaft motor 1 according to the present invention includes a busbar 120 and a free mold 121.

[0056] The bus bars 120 are conductors for electrically connecting the coil end portions 113B of the coil windings 113A of the same phase to each other. The number of bus bars 120 is not particularly limited, and an appropriate number of bus bars 120 can be used as needed. In the case of a three-phase BLDC motor, three bus bars 120 are used to connect the U phase, V phase, and W phase.

[0057] The free mold 121 serves to fix the bus bar 120 to the upper part of the stator 11. To this end, the free mold 121 is coupled to the upper insulator 111 of the stator 11.

[0058] The busbar 120 includes a circular busbar body 120A, a plurality of coil connection portions 120B protruding from one side of the busbar body 120A, and terminals 120C protruding upward from one side of the busbar body 120A. In the drawings, three busbars 120 are used, and therefore three busbar bodies 120A-1, 120A-2, and 120A-3 are shown with a plurality of coil connection portions 120B-1, 120B-2, and 120B-3 and terminals 120C-1, 120C-2, and 120C-3, respectively.

[0059] The coil connection portion 120B is electrically connected to the coil end portion 113B. The coil end portion 113B can be connected to the coil connection portion 120B by a method such as fusing or welding. For this purpose, the coil connection portion 120B can be bent to the coil end portion 113B. Assuming that the position of the terminal 120C is at 12 o'clock on a plane referenced to the bus bar 120 viewed from above, the coil connection portions 120B are arranged at approximately 2 to 4 o'clock and 8 to 10 o'clock.

[0060] Free mold 121 is a structure made of a polymer resin compound, and serves to guide the position of bus bar 120, fix the position of bus bar 120 to the upper part of stator 11, and guide terminal 120C.

[0061] The free mold 121 includes an annular ring portion 121A, a first connecting block 121B formed on one side of the annular ring portion 121A, a second connecting block 121C formed on the other side of the annular ring portion 121A, and a terminal guide 121D formed on the other side of the annular ring portion 121A and protruding upward.

[0062] The annular ring portion 121A is coupled to the top of the circular busbar body 120A of the busbar 120. A plurality of first exposure holes 121A-1 are formed in the annular ring portion 121A. The busbar 120 is exposed from above through the first exposure holes 121A-1, and molten resin is injected through the first exposure holes 121A-1 to mold the resin between the busbars 120.

[0063] The first bus bar guides 121A-2 are formed in a plurality of pieces protruding from the lower part of the annular ring part 121A and coupled between the plurality of bus bars 120 to guide the positions of the bus bars 120. The second bus bar guides 121A-3 are formed in a plurality of pieces protruding from the lower part of the annular ring part 121A and coupled between the plurality of bus bars 120 to guide the positions of the bus bars 120 separately from the first bus bar guides 121A-2. The second bus bar guides 121A-3 may be omitted depending on design needs.

[0064] The second exposure holes 121A-2' may be formed in a plurality of pieces penetrating the annular ring portion 121A in the vertical direction. The second exposure holes 121A-2' are formed to communicate with positions corresponding to the confirmation holes 23C of the bus bar cover 23, and allow the state of resin molding between the bus bars 120 to be confirmed from the outside through the confirmation holes 23C. If necessary, the second exposure holes 121A-2' may be omitted.

[0065] The side guide groove 121A-2″ is formed on the outer surface of the outermost corner of the first bus bar guide 121A-2, and the bonding force between the outer peripheral surface of the outermost corner bus bar main body 120A-3 and the first bus bar guide 121A-2 can be increased by filling the side guide groove 121A-2″ with resin molding.

[0066] A plurality of internal viewing holes 121A-4 are formed penetrating the annular ring portion 121A from top to bottom, and the joining state of the busbar body 120A can be seen through the internal viewing holes 121A-4 before the insert is injected. The internal viewing holes 121A-4 can be used for quality testing of the finished product, and do not necessarily have to be used in actual mass-produced products.

[0067] The first coupling block 121B is formed on one side of the annular ring portion 121A of the busbar body 120A at a position corresponding to the first block coupling protrusion 111A-3 of the upper insulator 111. The second coupling block 121C is formed on the other side of the annular ring portion 121A of the busbar body 120A at a position corresponding to the second block coupling protrusion 111A-5 of the upper insulator 111. Preferably, the first coupling block 121B and the second coupling block 121C are formed at positions facing each other as shown in FIGS. 10 to 12.

[0068] The first and second coupling blocks 121B and 121C serve to fix the busbar unit 12 to the upper portion of the stator 11. To this end, the first coupling block 121B has at least one first coupling hole 121B-1 formed therein. FIG. 10 illustrates a pair of first coupling holes 121B-1 formed therein to provide a stable coupling. A first fixing protrusion 121B-1' is formed protruding downward from the first coupling hole 121B-1. The first block coupling protrusion 111A-3 of the upper insulator 111 is inserted into the first coupling hole 121B-1, and the first fixing protrusion 121B-1' is inserted into the first block coupling protrusion outer groove 111A-3' to provide a stable coupling.

[0069] Similarly, at least one second coupling hole 121C-1 is formed in the second coupling block 121C. In FIG. 10, a pair of second coupling holes 121C-1 are formed to provide a stable coupling. A second fixing protrusion 121C-1' is formed protruding downward from the second coupling hole 121C-1. The second block coupling protrusion 111A-5 of the upper insulator 111 is inserted into the second coupling hole 121C-1, and the second fixing protrusion 111C-1' is inserted into the second block coupling protrusion outer groove 111A-5', providing a stable coupling.

[0070] At least one first insertion hole 121B-2 is formed on one side of the first coupling hole 121B-1 of the first coupling block 121B. In Fig. 10, two first insertion holes 121B-2 are formed, one on each side of the first coupling hole 121B-1. First block insertion protrusion 111A-4 of upper insulator 111 is coupled to first insertion hole 121B-2 to guide the coupling of busbar unit 2.

[0071] At least one second insertion hole 121C-2 is formed on one side of the second coupling hole 121C-1 of the second coupling block 121C. In Fig. 10, two second insertion holes 121C-2 are formed, one on each side of the second coupling hole 121C-1. The second block insertion protrusion 111A-6 of the upper insulator 111 is coupled to the second insertion hole 121C-2 to guide it to an accurate position.

[0072] The terminal guide 121D serves to guide and fix the position of the terminal 120C, thereby preventing the position of the terminal from being changed by injection pressure during insert injection.

[0073] It should be understood that the above description of the present invention is merely an example for understanding the present invention and is not intended to define the scope of the present invention. The scope of the present invention is defined by the appended claims, and it should be understood that any mere modification or change of the present invention within this scope falls within the scope of protection of the present invention. [Explanation of symbols]

[0074] 1: Hollow shaft motor 10: Stator assembly 11: Stator 12: Busbar unit 13: Terminal cover 20: Motor housing 21: Main body 22: Flange 23: Busbar cover 23A: Central fused tooth 23B: Boundary groove 23C: Check hole 24: Lower protrusion 24A: Lower cover joint 25: Upper bearing press-fit part 26: Lower bearing press-fit part 26A: Lower step 110: Stator core 110A: Core base 110A-1: Core outer groove 110B: Teeth 110B-1: Teeth end 110B-1': inner groove at the end of teeth 110C: Slot 111: Upper insulator 111A: Upper base insulation part 111A-1: Coil support piece 111A-1': Coil support piece hole 111A-1": Coil support groove 111A-2: Coil joint 111A-3: First block connecting protrusion 111A-4: First block insertion protrusion 111A-5: Second block connecting protrusion 111A-6: Second block insertion protrusion 111B: Upper teeth insulation part 111B': Upper pleats 111B": Upper teeth inner groove 111B-1: Upper end 111B-1': Upper end groove 111C: Upper slot insulation 112: Lower insulator 112A: Lower base insulation part 112A-1: Lower coil guide 112B: Lower teeth insulation part 112B': Lower pleats 112B": Lower teeth inner groove 112B-1: Lower end 112B-1': Lower end groove 112C: Lower slot insulation 113: Coil 113A: Coil winding 113B: Coil end 113C: Coil lower connection part 120: Busbar 120A: Busbar body 120B: Coil connection part 120C: Terminal terminal 121:Free mold 121A: Annular ring part 121A-1: 1st exposure hole 121A-2: First bus bar guide 121A-2': 2nd exposure hole 121A-2": Side guide groove 121A-3: Second bus bar guide 121A-4: Internal transparent hole 121B: First bond block 121B-1: 1st binding hole 121B-1': 1st fixed protrusion 121B-2: First insertion hole 121C: Second bond block 121C-1: 2nd binding hole 121C-1': 1st fixed protrusion 121C-2: Second insertion hole 121D: Terminal Guide

Claims

1. A hollow shaft motor, a stator assembly (10); a motor housing (20) formed by resin molding around the stator assembly (10); A hollow shaft rotor is located inside the stator assembly (10), and the hollow shaft rotor is rotatably connected to the motor housing. Hollow shaft motor.

2. The stator assembly (10) includes a stator (11) and a busbar unit (12) coupled to an upper portion of the stator.

2. The hollow shaft motor according to claim 1.

3. The motor housing (20) a main body (21) having an inner space so that the hollow shaft rotor can be positioned in the inner space; The main body (21) has a flange (22) formed on the top thereof and extending outward.

3. The hollow shaft motor according to claim 2.

4. The bus bar unit (12) is molded with resin to form a bus bar cover (23) inside the flange (22).

4. The hollow shaft motor according to claim 3.

5. The lower part of the body (21) is provided with a ring-shaped lower protrusion (24) that protrudes downward.

4. The hollow shaft motor according to claim 3.

6. The busbar unit (12) includes a plurality of busbars (120) and a free mold (121) to which the busbars (120) are fixed.

3. The hollow shaft motor according to claim 2.

7. A terminal cover (13) is formed on one side of the motor housing (20) so as to protrude upward.

2. The hollow shaft motor according to claim 1.

8. A hollow shaft motor, a stator assembly (10); a motor housing (20) formed by resin molding around the stator assembly (10); The bus bar cover (23) formed on the upper inside of the motor housing (20) is formed integrally. Hollow shaft motor.

Images