Motor for vehicle

Abstract

The present invention relates to a motor for a vehicle, comprising: a shaft provided to be rotatable; a rotor fixed to the shaft; a stator disposed around the rotor; and a housing accommodating the stator, wherein the rotor comprises: a first rotor and a second rotor arranged side by side; a plurality of permanent magnets provided on each of the first rotor and the second rotor; and a coupling plate interposed between the first rotor and the second rotor and having a first hole and a second hole, wherein a first protrusion formed on the lower surface of the first rotor and a second protrusion formed on the upper surface of the second rotor are inserted into the first hole and the second hole of the coupling plate, respectively, so that the first rotor and the second rotor may be arranged to be skewed by a predetermined skew angle.

Description

Vehicle motor

[0001] The present invention relates to a motor for vehicles.

[0002] A motor is a device that converts electrical energy into mechanical energy to generate rotational force, and it is widely used in vehicles, household electronics, industrial equipment, and more.

[0003] The motor may include a housing, a shaft, a stator disposed inside the housing, and a rotor installed on the outer surface of the shaft. Here, the stator induces the rotation of the rotor by causing electromagnetic interaction with the rotor. Consequently, the shaft also rotates together with the rotor due to the rotation of the rotor.

[0004] Motors are used in various devices in vehicles, such as the power train, steering system, brake system, and suspension system.

[0005] For example, a vehicle motor can be used as an Electric Power Steering System (EPS) to ensure the steering stability of a vehicle.

[0006] The motor can also be used in the clutch actuator. The transmission of an automobile is a transmission device that is manually operated according to the driver's clutch operation or automatically operated according to speed by the transmission, and can be configured to include a motor.

[0007] Among automotive motors, there are skewed type motors. Skewed type motors are composed of a skewed stator or a skewed rotor to facilitate improvements in key output qualities, such as cogging torque and torque ripple. A skewed rotor is formed by varying the tilt or installation angle of the rotor's permanent magnets. The skewed structure acts to reduce variations in magnetic resistance during motor rotation by mitigating cogging torque and torque ripple, which are uneven torque phenomena caused by non-uniform magnetic flux density in the air gap. Additionally, the skewed structure improves back EMF harmonics.

[0008] Skew-type motors offer many advantages, but they are subject to various manufacturing constraints. When forming a skew structure in the rotor, it is configured into two stages with different installation angles to impart a skew angle corresponding to that difference. However, in the process of matching the skew angle of two semi-assemblies relying on the precision of the equipment and jig, it is difficult to achieve a precise skew angle due to deviations between the jig and the semi-assemblies. Therefore, the development of rotor technology capable of resolving these difficulties is necessary.

[0009] The present invention is intended to provide a skew-type rotor for a vehicle motor having a skew structure, wherein the manufacturing process is simple and a precise skew angle is secured.

[0010] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below.

[0011] The present invention relates to a motor for a vehicle, comprising a rotatable shaft, a rotor fixed to the shaft, a stator disposed around the rotor, and a housing that accommodates the stator. The rotor comprises a first rotor and a second rotor arranged side by side, a plurality of permanent magnets provided on each of the first rotor and the second rotor, and a coupling plate interposed between the first rotor and the second rotor and having a first hole and a second hole formed therein. A first protrusion formed on the lower surface of the first rotor and a second protrusion formed on the upper surface of the second rotor are each inserted into the first hole and the second hole of the coupling plate, respectively, so that the first rotor and the second rotor are arranged to be twisted by a predetermined skew angle.

[0012] In some embodiments of the present invention, the first rotor and the second rotor may be formed by stacking a plurality of core plates along the height direction.

[0013] In some embodiments of the present invention, the first protrusion and the second protrusion may be formed on the core plate by pressing in a stamping process.

[0014] In some embodiments of the present invention, the outer diameter of the coupling plate may be larger than the outer diameter of the rotor plus a length of 1 / 10 of the thickness of the permanent magnet.

[0015] In some embodiments of the present invention, the outer diameter of the coupling plate may be smaller than the outer diameter of the rotor plus 2 / 5 of the thickness of the permanent magnet.

[0016] In some embodiments of the present invention, the first hole and the second hole of the coupling plate may each be provided in a range of 1 to 10.

[0017] In some embodiments of the present invention, the skew angle at which the first hole and the second hole of the coupling plate are spaced apart in the circumferential direction may be in the range of 1 to 15 degrees.

[0018] In some embodiments of the present invention, the coupling plate may be formed of an electrical steel plate.

[0019] In some embodiments of the present invention, a guide projection for arranging a permanent magnet may be formed to protrude outwardly from the outer surface of the first rotor and the second rotor.

[0020] In some embodiments of the present invention, the height of the guide jaw may be smaller than the thickness of the permanent magnet.

[0021] In the vehicle motor of the present invention, when applying a skew structure to the rotor, the manufacturing process of the motor can be simplified and a precise skew angle can be realized by inserting a protrusion, which is precisely formed in a stamping process in which a core plate is formed, laminated, and joined, into a hole of a joining plate.

[0022] Figure 1 is a cross-sectional view illustrating a vehicle motor.

[0023] Figure 2 is a perspective view of the rotor illustrated in Figure 1.

[0024] Figure 3 is an exploded perspective view of the rotor illustrated in Figure 2.

[0025] Figure 4 is a drawing showing that the first rotor illustrated in Figure 3 is made of a laminated core.

[0026] Figure 5 is a cross-sectional view along line II' of Figure 4.

[0027] Figure 6 is a plan view of the coupling plate shown in Figure 2.

[0028] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0029] "And / or" includes each of the mentioned items and all combinations of one or more.

[0030] The terms used herein are for describing embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprising" and / or "comprising" does not exclude the presence or addition of one or more other components, steps, actions, and / or elements to the mentioned components, steps, actions, and / or elements.

[0031] Furthermore, throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly" or "electrically connected" with other members or elements interposed between them.

[0032] Additionally, throughout the specification, the description that each layer (film), region, pattern, or structure is formed "on" or "under" the substrate, each layer (film), region, pad, or pattern includes both direct formation and formation through another layer. The criteria for "on" or "under" each layer are described based on the drawings.

[0033] Furthermore, expressions such as 'first, second,' etc., are used solely to distinguish multiple compositions and do not limit the order or other characteristics between the compositions.

[0034] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0035] FIG. 1 is a cross-sectional view illustrating a vehicle motor (10).

[0036] The X direction shown in FIG. 1 may be the radial direction (first direction), and the Y direction may be the axial direction (second direction). Also, the axial direction and the radial direction may be perpendicular to each other. Here, the axial direction is the longitudinal direction of the shaft (3), and in the drawing, the positive Y direction may be the upper side and the negative Y direction may be the lower side.

[0037] In addition, the symbol 'C' shown in FIG. 1 indicates the center of rotation (axis center). And, the direction along a circle having a radial radius with respect to the axis center 'C' can be called the circumferential direction.

[0038] Referring to FIG. 1, a vehicle motor (10) may include a housing (2), a shaft (3), a stator (4) disposed inside the housing (2), a rotor (5) installed on the outer surface of the shaft (3), etc.

[0039] The shaft (3) is configured to be rotatable relative to the housing (2), and a stator (4) is positioned around a rotor (5) fixed to the shaft (3). A coil (6) is wound around the stator (4), and a magnetic material, such as a permanent magnet (7), may be provided on the rotor (5). Accordingly, when power is supplied to the coil (6) of the stator (4), the stator (4) induces electromagnetic interaction with the rotor (5), thereby inducing rotation of the rotor (5). Then, the shaft (3) also rotates together with the rotation of the rotor (5).

[0040] The vehicle motor (10) of the present invention may form a rotor (5) in a two-stage structure of a first rotor (201) and a second rotor (202), and may arrange the first rotor (201) and the second rotor (202) to have a skewed structure using a connecting plate (230).

[0041] FIG. 2 is a perspective view of a rotor according to the present invention, and FIG. 3 is an exploded perspective view of the rotor shown in FIG. 2.

[0042] Referring to FIG. 2 and FIG. 3, the rotor (5) according to the embodiment includes a first rotor (201) provided on the upper side, a second rotor (202) provided on the lower side, and a coupling plate (230) inserted between the first rotor (201) and the second rotor (202). A first protrusion (211) formed on the lower surface of the first rotor (201) and a second protrusion (212) formed on the upper surface of the second rotor (202) are inserted into the first hole (231) and the second hole (232) of the coupling plate (230), respectively, so that the first rotor (201) and the second rotor (202) can be positioned with a predetermined skew angle (SA).

[0043] The first rotor (201) and the second rotor (202) may be provided with a guide projection (220) formed in the axial direction to serve as a reference for the circumferential position when attaching a permanent magnet (7) to the outer surface. The guide projection (220) may protrude from the outer surface of the first rotor (201) and the second rotor (202) of the rotor core (310) to guide the permanent magnet (7) so that it does not go beyond a predetermined area. By this guide projection (220), the permanent magnet (7) can be fixed at a predetermined position in the circumferential direction.

[0044] At this time, the height of the guide jaw (220) is formed to be smaller than the thickness of the permanent magnet (7), so that the rotor (5) can rotate without interference with the stator (4).

[0045] The guide jaws (220) of the first rotor (201) and the second rotor (202) can be arranged so that their circumferential phases are offset by a skew angle (SA) with respect to the center of the rotor (5), i.e., the center (C) of the rotation axis. Accordingly, the permanent magnets (7) attached to the first rotor (201) and the second rotor (202), respectively, can form a skewed structure offset by a skew angle (SA).

[0046] The rotor core forming the body of the rotor (5) can be manufactured in a structure such as a solid core or a laminated core. A solid core is a rotor core made by cutting a steel material into a single block, which has the advantage of having good strength and durability, but has the disadvantage of high eddy current loss and requiring high-precision machining.

[0047] In contrast, a laminated core is a rotor core made by stacking dozens or more core plates of electrical steel material. It is widely used because it has the advantage of minimizing eddy current losses, resulting in high electrical efficiency and easy thermal management.

[0048] A first rotor (201) and a second rotor (202) according to one embodiment of the present invention may be formed of a laminated core. However, the first rotor (201) and the second rotor (202) provided by the present invention may also be composed of a solid core instead of a laminated core.

[0049] FIG. 4 is a drawing showing the first rotor illustrated in FIG. 3 as a laminated core, and FIG. 5 is a cross-sectional view along line II' of FIG. 4. The cross-section along line II' of FIG. 5 shows that a plurality of core plates (209) are joined by forming a first protrusion (211) by pressing in a stamping process and simultaneously caulking.

[0050] Referring to FIG. 4, the first rotor (201) can be formed by stacking a plurality of core plates (209) along the axial direction.

[0051] A first protrusion (211) protruding downward is formed on the core plate (209). A plurality of core plates (209) equipped with the first protrusion (211) can be stacked in the axial direction to form a first rotor (201).

[0052] When a steel plate for forming a core plate (209) is fed into a stamping process, a core plate (209) including an outer shape and an inner hole can be formed through operations such as blanking and piercing.

[0053] Next, in an in-line press process, a first protrusion (211) is formed by applying high pressure with a press tip (300) at the location of the first protrusion (211). A new core plate (209) is stacked on the core plate (209) on which the first protrusion (211) is formed, and by applying high pressure with the press tip (300) at the same location, they can be caulked and joined together. By repeating this process, a first rotor (201) can be formed in which a predetermined number of core plates (209) are stacked and joined.

[0054] The second rotor (202) can also be formed in the same stamping process.

[0055] The first rotor (201) has a first protrusion (211) formed in the stamping process facing downward, but the second protrusion (212) of the second rotor (202) can be positioned to face upward.

[0056] As such, the first rotor (201) and the second rotor (202) have the same configuration and shape as each other, and the second rotor (202) is positioned opposite the lower surface of the first rotor (201) with the upper and lower surfaces of the first rotor (201) reversed, and a connecting plate (230) can be inserted between the first rotor (201) and the second rotor (202). Therefore, when producing a product, the first rotor (201) and the second rotor (202) can be produced identically without distinction.

[0057] In this way, the first rotor (201) and the second rotor (202) can be machined with high precision in the stamping process, and the position of the protrusions (211, 212) formed at this time can also be precisely controlled with a small error. That is, since the protrusions (211, 212) formed in the process of caulking a plurality of core plates (209) can be applied as a standard for forming a skew angle (SA), difficult work to secure precision during the manufacturing process can be avoided, and at the same time, precision of the skew angle (SA) can be secured.

[0058] The first protrusion (211) formed on the lower surface of the first rotor (201) and the second protrusion (212) formed on the upper surface of the second rotor (202) can each be inserted into the first hole (231) and the second hole (232) of the coupling plate (230).

[0059] In order for the first rotor (201) and the second rotor (202) to be twisted by a predetermined skew angle (SA), the first hole (231) and the second hole (232) of the coupling plate (230) may be spaced apart by the skew angle (SA).

[0060] Figure 6 is a plan view of the coupling plate shown in Figure 2.

[0061] The connecting plate (230) according to the embodiment can be formed of an electrical steel plate.

[0062] Preferably, cold-rolled non-oriented electrical steel having the same magnetic properties in all directions can be used.

[0063] The coupling plate (230) may include a first hole (231) and a second hole (232), and the first hole (231) and the second hole (232) may each be provided in a range of 1 to 10.

[0064] Even if at least one is formed, it can serve as a reference for the skew angle (SA) of the first rotor (201) and the second rotor (202). If there are more than 10, it becomes difficult to work when assembling the first rotor (201) and the second rotor (202) to the coupling plate (230), so it is limited to a range of 1 to 10.

[0065] The skewed angle (SA) of the first hole (231) and the second hole (232) of the coupling plate (230) being spaced apart in the circumferential direction may be 1 to 15 degrees.

[0066] To improve cogging torque and torque ripple, a skew angle (SA) of at least 1 degree is required, and since exceeding 15 degrees causes a decrease in the driving force of the motor, the range of the skew angle is limited as above.

[0067] The coupling plate (230) according to the embodiment can serve as a reference for the axial position when attaching permanent magnets (7) to the outer surface of the first rotor (201) and the second rotor (202).

[0068] Therefore, the permanent magnet (7) can be aligned axially with the coupling plate (230) without being twisted in the vertical direction.

[0069] The outer diameter of the above-mentioned coupling plate (230) may be larger than the outer diameter of the rotor (201, 202) plus a length equal to 1 / 10 of the thickness of the permanent magnet (7). It is preferable that the coupling plate (230) protrude more than 1 / 20 of the thickness of the permanent magnet (7) from the outer surface of the rotor (201, 202) so that it can serve as a reference for alignment during assembly. Accordingly, it must be formed to be larger than the length obtained by adding 1 / 10 of the thickness of the permanent magnet (7) (1 / 20 of the length at each end of the diameter) to the diameter of the rotor (201, 202).

[0070] Since the permanent magnet (7) according to the embodiment is formed with a thickness of 3 mm or more, the protrusion amount is 1 / 20 of the length of 3 mm, i.e., 0.15 mm, so that the permanent magnet (7) can be attached in the correct position without being twisted.

[0071] Additionally, the outer diameter of the coupling plate (230) may be smaller than the outer diameter of the rotor (201, 202) plus the length of 2 / 5 of the thickness of the permanent magnet (7). When the length of 2 / 5 of the thickness of the permanent magnet (7) is added to the diameter of the rotor (201, 202), the coupling plate (230) protrudes from the outer surface of the rotor (201, 202) by the length of 1 / 5 of the thickness of the permanent magnet (7).

[0072] If the protrusion amount is excessive, there are side effects such as the magnetic flux of the permanent magnet (7) causing interference with the stator (4), so it is preferable to form it with a length smaller than 1 / 5 of the thickness of the permanent magnet (7).

[0073] Since the permanent magnet (7) according to the embodiment is formed with a thickness of 3 mm or more, the protrusion amount may be smaller than 1 / 5 of the length of 3 mm, i.e., 0.5 mm.

[0074] The rotor of a vehicle motor according to the present invention simplifies the manufacturing process and enables the realization of a precise skew angle by inserting a protrusion, which is precisely formed during a stamping process for forming and laminating a core plate, into a hole of a coupling plate.

[0075] Although the present invention has been described above, those skilled in the art will recognize that the invention may be implemented in other forms while maintaining the technical concept and essential features of the invention.

[0076] The scope of the present invention shall be defined by the claims, but all modifications or variations derived from configurations directly derived from the descriptions in the claims, as well as configurations equivalent thereto, shall be interpreted as being included within the scope of the present invention.

Claims

1. Rotatable shaft; A rotor fixed to the above shaft; A stator disposed around the rotor; and A housing for accommodating the above stator; comprising The above rotor comprises a first rotor and a second rotor arranged side by side, a plurality of permanent magnets provided on each of the first rotor and the second rotor, and a coupling plate interposed between the first rotor and the second rotor and having a first hole and a second hole formed therein. A vehicle motor in which a first protrusion formed on the lower surface of the first rotor and a second protrusion formed on the upper surface of the second rotor are respectively inserted into a first hole and a second hole of the coupling plate, so that the first rotor and the second rotor are arranged to be twisted by a predetermined skew angle.

2. In Paragraph 1, A vehicle motor in which the first rotor and the second rotor are formed by stacking a plurality of core plates along the height direction.

3. In Paragraph 2, A vehicle motor in which the first protrusion and the second protrusion are formed on the core plate by pressing in a stamping process.

4. In Paragraph 1, A vehicle motor in which the outer diameter of the above coupling plate is greater than the value obtained by adding 1 / 10 the thickness of the permanent magnet to the outer diameter of the above rotor.

5. In Paragraph 1, A vehicle motor in which the outer diameter of the above coupling plate is smaller than the value obtained by adding 2 / 5 of the thickness of the permanent magnet to the outer diameter of the above rotor.

6. In Paragraph 1, A vehicle motor, wherein the first hole and the second hole of the above-mentioned coupling plate are each provided in a range of 1 to 10.

7. In Paragraph 1, A vehicle motor in which the first hole and the second hole of the above-mentioned coupling plate are spaced apart in the circumferential direction at a skew angle ranging from 1 to 15 degrees.

8. In Paragraph 1, The above-mentioned coupling plate is a vehicle motor formed of an electrical steel plate.

9. In Paragraph 1, A vehicle motor having a guide projection for arranging a permanent magnet formed to protrude outwardly from the outer surface of the first rotor and the second rotor.

10. In Paragraph 9, A vehicle motor in which the height of the above guide jaw is smaller than the thickness of the above permanent magnet.

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