Stator Comprising High Density Multiple Row Armature Winding

Abstract

The present invention relates to a stator winding structure comprising: a stator core formed by stacking a plurality of steel plates including slots arranged in an annular and double row around a rotation axis; conductive rods disposed in each of the slots; a first partition electrically shielding between conductive rods arranged adjacently in the radial direction; a second partition electrically shielding between conductive rods arranged adjacently in the circumferential direction; and a pair of end-turn members disposed at both ends of the stator core in the axial direction and coupled to a plurality of winding bars, wherein the conductive rods are formed to be disposed within the stator core by a casting process including die casting.

Description

Technology Field

[0001] The present invention relates to a stator comprising a high-density double-row armature winding. Background Technology

[0002] The content described in this section merely provides background information regarding the present embodiment and does not constitute prior art.

[0003] Drive motors used in electric vehicles require high output and high efficiency. To meet this demand, power semiconductors in the control unit are also being developed to allow for high temperatures and high currents so that higher currents can flow through the stator windings. To generate higher magnetic flux within a limited motor size, it is necessary to maximize the fill factor of the stator windings.

[0004] In an asynchronous induction motor, the rotor's magnetic field is not synchronized with the rotor's mechanical rotational speed, and the slip value between the magnetic field speed and the rotor speed varies depending on the rotational speed. In other words, the frequency of the rotor core is different from the frequency of the stator core.

[0005] When an induction motor is driven, heat is generated as high-density current flows through the resistors, and in particular, the armature windings and rotor conductor bars heat up to high temperatures due to copper loss. The rise in temperature of the conductor bars leads to an increase in resistivity, and consequently, motor efficiency decreases due to the increase in copper loss. To produce high output power, a high current must be applied to the induction motor, and the armature windings must be able to withstand low or high temperature increases.

[0006] While circular coil windings are the most common type for stator windings, they are disadvantageous for securing the required fill factor due to the empty spaces between the coils. Consequently, supplying higher current to the stator windings leads to heat generation becoming a problem.

[0007] This can be resolved by installing a cooling system adjacent to the heat source to forcibly cool the heat generated by the stator windings, but it has the disadvantage of requiring an additional cooling system.

[0008] Alternatively, a hairpin-shaped conductor as exemplified in FIG. 1 (b) or a square cross-section coil (not shown) may be used. By using a conductor with a larger cross-sectional area compared to the coil-shaped winding as exemplified in FIG. 1 (a), armature resistance is reduced, thereby reducing heat generation. However, for hairpins, assembly and fixing the ends exposed at both ends of the stator as shown in FIG. 1 (c) is difficult, and although equipment exists to automate this, the associated costs are excessively high. In the case of square cross-section coils, significant manufacturing costs are required for assembly and inter-coil connection, and it is still not easy to secure the maximum fill factor. Since this type of concentrated winding method must be assembled into a divided core, the manufacturing cost increases.

[0009] In other words, to improve the output density of the drive motor, manufacturing technology for stator armature windings with a high fill factor and low manufacturing cost is required. The problem to be solved

[0010] The present disclosure provides a stator winding structure for an induction motor in which the armature windings are arranged in double rows with a high density and are easy to manufacture. means of solving the problem

[0011] To solve the above problem, the stator winding structure according to the present disclosure comprises: a stator core formed by laminating a plurality of steel plates including slots arranged in an annular and double row around a rotation axis; a conductive rod disposed in each slot; a first partition electrically shielding between conductive rods arranged adjacently in the radial direction; a second partition electrically shielding between conductive rods arranged adjacently in the circumferential direction; and a pair of end turn members disposed at both ends of the stator core in the axial direction and coupled to the plurality of conductive rods, wherein the conductive rods are formed to be disposed within the stator core by a casting process including die casting.

[0012] Additionally, the end turn member includes a connecting member that provides an electrical connection between conductive rods, and the connecting member is formed to provide multiple windings wound on a stator core by connecting a pair of circumferentially adjacent double-row conductive rods.

[0013] In addition, the conductive rod includes a longitudinal structure at both ends in the longitudinal direction, the longitudinal structure is formed by post-processing after the casting process, and the end turn member is characterized by including a plurality of pockets formed to accommodate the longitudinal structure in the stator core side area.

[0014] In addition, the pocket is characterized by being formed with at least a portion penetrating in the thickness direction of the end turn member.

[0015] In addition, at least a portion of the area between the pocket and the end structure is formed to have a gap, and the pocket and the end structure are joined by a tapered pin or tapered member or a tapered structure formed on a part of the connecting member being pressed into the gap in a wedge shape.

[0016] In addition, the connecting member includes through holes at both ends that accommodate the end structure of the conductive rod, and is characterized by the end structure and the connecting member being joined by caulking the end structure.

[0017] In addition, the pocket and the end structure are joined by press-fitting, and then current is applied to a conductive rod so that the press-fit contact area is resistance welded by contact resistance.

[0018] In addition, the current is characterized by being greater than the operating current at which the stator will be used.

[0019] In addition, the conductive rod is formed in the shape of a cartridge to form a slot arranged in a double row in the radial direction, including a first partition and a second partition, and is characterized by being pre-placed in the slot and assembled, after which the cartridge is inserted into the stator core. Effects of the invention

[0020] The stator winding structure according to the present disclosure includes a double row slot arranged in the axial direction of the motor surrounding the stator core, and includes a conductor bar formed by die casting in the double row slot and an end-turn member coupled to both ends of the conductor bar to provide an electrical connection between the conductor bars, thereby providing a high-output and high-efficiency motor by providing a high-density winding to the stator while being easy to manufacture. Brief explanation of the drawing

[0021] Figure 1 illustrates a typical armature winding configuration of a stator. FIG. 2 is a cross-sectional view showing a stator according to one embodiment of the present invention. FIG. 3 is a perspective view showing a stator core and a conductive rod of a stator according to one embodiment of the present invention. FIG. 4 is a perspective view showing a stator core according to one embodiment of the present invention. FIG. 5 is a perspective view showing a conductive rod and an end turn member according to one embodiment of the present invention. Specific details for implementing the invention

[0022] Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present invention, if it is determined that a detailed description of related known components or functions could obscure the essence of the invention, such detailed description is omitted.

[0023] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the present invention. These terms are intended merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by such terms. Throughout the specification, when a part is described as 'comprising' or 'equipped' with a certain component, unless specifically stated otherwise, this means that it may include additional components rather than excluding other components. Furthermore, terms such as 'part' or 'module' described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software.

[0024] FIG. 2 is a cross-sectional view showing a stator according to one embodiment of the present invention.

[0025] Referring to FIG. 2, a stator (10) according to one embodiment includes a conductive rod (120) formed by a casting process including die casting in a slot (110) of a stacked stator core (100), and an end-turn member (130) that connects each conductive rod (120) to form a plurality of windings.

[0026] The stator core (100) has slots (110) that accommodate conductive rods (120) arranged in an annular and double row around a rotation axis. The unit steel plates (e.g., silicon steel plates) constituting the stator core (100) may include an insulating film (not shown) coated with a phosphate or ceramic-based material, either individually or after lamination, to ensure insulation. On both sides of the laminated stator core (100), a mold member (not shown) may be provided to form a conductive rod (120) protruding from both sides of the stator core (100). After the casting of the conductive rod (120) is completed, the mold member may be separated to form the conductive rod (120) in a shape where the end portions protrude from both sides of the stator core (100). The conductive rod (120) may be made of aluminum or copper material.

[0027] The end (122) region of the conductive rod (120) can be post-processed to have a suitable shape, tolerance, and surface roughness so as to be easily combined with an end turn member (130) that includes a connecting member for winding connection between the conductive rods (120).

[0028] The ends (122) of the conductive rods (120) can be connected in an alternating manner in the double-row arrangement direction by a connection structure (not shown) inside the end turn member (130) so that the conductive rods (120) facing each other in the double-row arrangement direction wrap around each tooth of the stator core (100) and form a pair and are electrically connected to form multiple windings.

[0029] FIG. 3 is a perspective view showing a stator core and a conductive rod of a stator according to one embodiment of the present invention.

[0030] Referring to FIG. 3, a conductive rod (120) in a state where casting and end processing have been post-processed is shown assembled in a stator core (100).

[0031] FIG. 4 is a perspective view showing a stator core according to one embodiment of the present invention.

[0032] Referring to FIG. 4, the stator slot (110) is formed within the unit steel plate constituting the stator core (100) by a first partition (160) that electrically shields between conductive rods (120) arranged adjacently in the radial direction of the stator (10) and a second partition (170) that electrically shields between conductive rods (120) arranged adjacently in the circumferential direction of the stator (10).

[0033] According to one embodiment, the winding of the stator (10) is formed by casting to fill the stator slot (110), thereby providing a high packing ratio. Additionally, since the cross-sectional area of ​​the conductive rod (120) is formed larger than in the conventional case, a higher current can be allowed, and due to the low resistivity, heat generation under high current flow can also be small. Furthermore, due to these features, the resistance welding embodiment between the end turn member (130) and the end of the conductive rod (120), which will be described later, can also be easily implemented.

[0034] FIG. 5 is a perspective view showing a conductive rod and an end turn member according to one embodiment of the present invention.

[0035] Referring to FIG. 5, the end (122) of the conductive rod (120) is inserted into a plurality of pockets (132) on one side of the end turn member (130). The end turn member (130) may have a multilayer structure in the longitudinal direction of the stator (10). It may include a layer comprising a connecting member that enables proper electrical connection between the ends (122) while the end (122) of the conductive rod (120) is coupled to the pocket (132), and a protective layer that protects the connecting member and the end (122) from the outside. The end turn member (130) may be formed entirely of a non-conductive material and may have a conductive connecting member disposed inside. Alternatively, it may have a structure in which the body is formed of a non-conductive material such as ceramic and a conductive material identical to the conductive rod (120) material is coated on the inner surface of each pocket (132) by metallizing.

[0036] The structure of the end turn member (130) that connects the end (122) of the conduction rod (120) and seals both sides of the stator (10) can be any form that provides the necessary winding structure and provides a reliable electrical and physical connection.

[0037] As an exemplary embodiment, a pocket (132) in which at least a portion of the end turn member (130) penetrates to the other side of the end turn member (130) and the end (122) of the conductive rod (120) may be set to a loose fit. Additionally, the gap between the pocket (132) and the end (122) may include a groove formed in at least a portion so that the pocket (132) and the end (122) can be physically compressed and electrically attached, and a tapered pin or tapered member made of the same material as the conductive rod (120) may be inserted and pressed into the groove in a wedge shape after the pocket (132) and the end (122) are pre-assembled. A person skilled in the art would be able to easily derive the assembly structure necessary to automate this process. According to an exemplary embodiment, a tapered pin or tapered member may be plastically deformed by press-fitting to provide a rigid connection between the inner surface of the pocket (132) and the outer surface of the end (122). Meanwhile, a form may also be included in which through holes are formed at both ends of the connecting member to accommodate the end (122), and the end surface of the end (122) is plastically deformed by pressing, for example, using a caulking process.

[0038] Additionally, according to an exemplary additional embodiment, a larger gap may be formed in at least a portion of the pocket (132) and the end (122) to accommodate the winding of the conductive rod (120). After the pre-assembly of the pocket (132) and the end (122), a connecting member included in the end turn member (130) for winding may be provided in a form that is pressed into a gap provided adjacent to the end (122) of the conductive rod (120) to be connected to each other. That is, after the end turn member (130) and the conductive rod (12) are pre-assembled, assembly and winding may be completed by pressing a plurality of connecting members from the other side of the end turn member (130) by an automated mechanism.

[0039] Additionally, according to an exemplary additional embodiment, although not separately illustrated, the pocket (132) of the end turn member (130) and the end (122) of the conductive rod (120) may be pressed by a connecting member including a tapered pin, a tapered member, or a tapered structure to achieve physical contact, and then locally melted and joined using the principle of resistance welding. In one embodiment, the conductive rod (120) has a large cross-sectional area to allow for a high current. On the other hand, the contact portion between the end (122) and the pocket (132) may have a relatively very high contact resistance compared to the body of the conductive rod (120). Taking this into account, the assembly may be completed by locally welding the contact portion by allowing a high current—e.g., a current higher than the allowable current of a motor applied to a stator—to flow between one end and the other end of the conductive rod (120) for an appropriate amount of time, thereby heating the contact portion to a high temperature higher than the melting temperature of the material. In addition, to ensure that welding of the contact area is securely performed, the wedge structure including the tapered pin during resistance welding can form an assembly structure such that additional pressure is applied from both sides in the direction of the stator core (100).

[0040] A stator structure according to embodiments of the present invention is formed and assembled in a batch process by casting including die casting on a stator core (100) and the connection for winding between the conductive rods (120) is completed in a manner advantageous for automation by an end turn member (130), thereby providing an armature winding with a high density to allow for a high current, while simultaneously having high manufacturing productivity.

[0041] Meanwhile, the stator (10) according to one embodiment may also include a form in which a conductive rod (120) in a double row direction is assembled in a cartridge form in a frame in which a first partition (160) and a second partition (170) are integrally formed, and a plurality of pre-formed conductive rods (120) are subsequently assembled into a stator core (100).

[0042] The above description is merely an illustrative explanation of the technical concept of the present embodiment, and a person skilled in the art to which the present embodiment belongs would be able to make various modifications and variations within the scope of the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain, not limit, the technical concept of the present embodiment, and the scope of the technical concept of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present embodiment.

Claims

Claim 1 A stator core formed by stacking a plurality of steel plates including slots arranged in an annular and double-row configuration around a rotation axis; conductive rods disposed in each of the slots; a first partition electrically shielding the conductive rods arranged adjacently in the radial direction; and a second partition electrically shielding the conductive rods arranged adjacently in the circumferential direction. The stator comprises a pair of end-turn members disposed at both axial ends of the stator core and coupled to a plurality of conductive rods, wherein the conductive rods are formed to be disposed within the stator core by a casting process including die casting, and the end-turn members include a connecting member that provides an electrical connection between the conductive rods, and the connecting member is formed to provide a plurality of windings wound on the stator core by connecting a pair of circumferentially adjacent double-row conductive rods, and the conductive rods include a terminal structure at both longitudinal ends, wherein the terminal structure is formed by post-processing after the casting process, and the end-turn members include a plurality of pockets formed to accommodate the terminal structure in the stator core side region, wherein at least a portion of the pocket is formed to penetrate in the thickness direction of the end-turn member, and at least a portion of the region between the pocket and the terminal structure is formed to have a gap, and the pocket and the terminal structure are coupled by a tapered pin or a tapered member, or a tapered structure formed on a part of the connecting member, being pressed into the gap in a wedge shape. Winding structure. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A stator winding structure according to claim 1, wherein the connecting member includes through holes at both ends for receiving the end structure of the conductive rod, and the end structure and the connecting member are joined by caulking the end structure. Claim 7 A stator winding structure according to claim 1, wherein after the pocket and the terminal structure are joined by press-fitting, current is applied to the conductive rod so that the press-fit contact portion is resistance welded by contact resistance. Claim 8 In claim 7, the stator winding structure wherein the current is of a magnitude greater than the operating current in which the stator is used. Claim 9 A stator winding structure according to claim 1, wherein the conductive rod is formed in a cartridge shape to form a slot arranged in a double row in a radial direction including the first partition and the second partition, and after being pre-placed and assembled in the slot, the cartridge is inserted into the stator core.

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