Magnet-embedded motor and rotary compressor having same

Abstract

The present invention provides a magnet-embedded motor and a rotary compressor having same. The magnet-embedded motor comprises: a stator core; a rotor core; a permanent magnet accommodated inside the rotor core; and a rotation shaft provided inside the rotor core and rotating together with the rotor core, wherein the rotation shaft includes an upper portion and a lower portion, a plurality of magnet accommodating portions are provided inside the rotor core, the permanent magnet is inserted into the magnet accommodating portion, the permanent magnet includes a top end, a bottom end, and side ends, the top end includes a rounded portion formed to be rounded, and the bottom end and the two side ends are formed as straight lines.

Description

Magnet insertion motor and rotary compressor having the same

[0001] The present invention relates to a magnet insertion motor and a rotary compressor having the same, and more particularly, to a magnet insertion motor that reduces noise and vibration and a rotary compressor having the same.

[0002] Typically, a motor transmits the rotational force of a rotor to a rotating shaft, which then drives a load. For example, a rotating shaft connected to a washing machine drum can drive the drum, or connected to a refrigerator fan to drive the fan, supplying cool air to the required space.

[0003] In these motors, the rotor rotates through electromagnetic interaction with the stator. To achieve this, coils are wound around the stator, and when current is applied to the coils, the rotor rotates relative to the stator.

[0004] Compressors can be categorized into reciprocating compressors, rotary compressors, and scroll compressors depending on how they compress the refrigerant. Reciprocating compressors compress fluid by forming a compression space between a piston and a cylinder and allowing the piston to reciprocate linearly. Rotary compressors compress fluid by means of rollers that rotate eccentrically within the cylinder. Scroll compressors compress fluid by interlocking and rotating a pair of spiral scrolls.

[0005] Among these, rotary compressors can be classified according to the way the rollers rotate relative to the cylinder. For example, rotary compressors can be classified into eccentric rotary compressors in which the rollers rotate eccentrically relative to the cylinder, and concentric rotary compressors in which the rollers rotate concentrically relative to the cylinder.

[0006] Patent Document 1 (Japanese Application No. 2014-110660, June 12, 2014) discloses a magnet insertion motor in which the stator is configured in multiple stages and the inner diameter of the stator increases toward the upper part to create a larger gap. Through this, the problem of torque reduction caused by magnetic flux concentration on the rotor side in the prior patent can be improved, and vibration noise caused by shaking of the rotor can be suppressed.

[0007] As in patent document 1, when the motor stator is manufactured by dividing it into multiple stages, the number of stator cores and the number of molds for manufacturing them increase, the stamping and assembly time during production increase, which increases the manufacturing cost, and there is a problem that the average gap between the stator and the rotor in the direction of the lamination length increases, which deteriorates the motor performance.

[0008] A rotary compressor has a shaft supported on one side, and the opposite side of the support is spaced from the rotation axis and moves eccentrically.

[0009] In the motor of a rotary compressor, eccentric rotation of the rotor and shaft causes shaking of the upper rotor and causes noise and vibration.

[0010] To solve the problems of the prior art, it was proposed to make the outer diameter of the rotor or the inner diameter of the stator two-dimensional, but this has the problem that the production process becomes complicated, which lowers productivity, and the average gap increases, which lowers the motor efficiency.

[0011] It is required to develop an electric motor with a structure that minimizes eccentric rotation of the rotor and shaft and upper rotor shaking, which are causes of noise and vibration.

[0012] Additionally, the development of an electric motor that maintains high productivity and minimizes the decrease in motor efficiency is required.

[0013] The present invention has been devised to solve the above problems, and the first object of the present invention is to provide a magnet insertion motor having a structure that minimizes eccentric rotation of the rotor and shaft and upper rotor shaking, which are causes of noise and vibration.

[0014] A second object of the present invention is to provide a magnet insertion motor having a magnet shape and arrangement to maintain high productivity and minimize reduction in motor efficiency.

[0015] A third object of the present invention is to provide a magnet insertion motor in which the magnetic force (MPF) on the upper side of the stator facing the magnet is reduced, thereby reducing rotor wobble and reducing vibration and noise.

[0016] The fourth object of the present invention is to provide a magnet insertion motor having a magnet of an optimized shape, which has a simple production process and high productivity compared to laminating by dualizing the core shape, and which can reduce material costs.

[0017] In order to solve the above problem, the magnet insertion motor of the present invention includes a stator core, a rotor core provided inside the stator core and rotatably provided, a permanent magnet accommodated inside the rotor core, and a rotational shaft provided inside the rotor core and rotating together with the rotor core, the rotational shaft including an upper portion coupled with the rotor core and a lower portion coupled with a load that receives the rotational force of the rotor core, and a plurality of magnet receiving portions spaced apart from each other along a circumferential direction inside the rotor core, the permanent magnet being inserted into the magnet receiving portion, the permanent magnet including an upper end facing an end of an upper portion of the rotational shaft based on a surface on which polarity acts, a lower end facing the upper end and facing a end of a lower portion of the rotational shaft, and two side ends connecting the upper end and the lower end, the upper end including a rounded portion formed to be rounded, and the lower end and the two side ends being formed in a straight line.

[0018] Due to this, the upper side of the stator core facing the upper side of the magnet has a reduced maximum force (MPF), which reduces the shaking of the rotor core and reduces vibration and noise. In addition, since the upper and lower parts form an asymmetrical structure, the upper side of the stator core facing the upper side of the magnet has a reduced maximum force (MPF), which reduces the shaking of the rotor core and reduces vibration and noise.

[0019] Each of the plurality of magnet receiving portions is configured with a pair of magnet receiving portions that are inserted in a V shape and spaced apart from each other as they go outward in the radial direction, and the pair of magnet receiving portions includes a first magnet receiving portion and a second magnet receiving portion, and the permanent magnet may include a first permanent magnet inserted into the first magnet receiving portion and a second permanent magnet inserted into the second magnet receiving portion.

[0020] Preferably, the lower portion of the rotational axis may include a crankshaft that rotates eccentrically.

[0021] This reduces cogging torque while minimizing the loss of motor efficiency. Furthermore, by reducing the amount of magnets used, material costs can be reduced, and the optimized shape allows for increased magnet utilization. Furthermore, cogging torque can be reduced while minimizing the loss of motor efficiency.

[0022] The first and second permanent magnets may each have a rounded portion on each side adjacent to each other at each end.

[0023] This configuration reduces material costs by reducing the amount of magnets used, and increases magnet utilization through an optimized shape. Furthermore, it minimizes the loss of motor efficiency while reducing electromagnetic excitation.

[0024] The first permanent magnet may have a rounded portion on one side adjacent to the second permanent magnet, and the second permanent magnet may have a rounded portion on a portion provided between the side adjacent to the first permanent magnet and the other side on the opposite side.

[0025] This allows for a reduction in electromagnetic excitation while minimizing the reduction in motor efficiency.

[0026] The first permanent magnet may have a rounded portion on one side adjacent to the second permanent magnet, and the second permanent magnet may have a rounded portion on the other side opposite to the side adjacent to the first permanent magnet.

[0027] Due to this, the upper side of the stator core facing the upper side of the magnet has a reduced maximum force (MPF), which reduces the shaking of the rotor core and reduces vibration and noise.

[0028] The first permanent magnet may have a rounded portion at a portion provided between one side adjacent to the second permanent magnet and the other side on the opposite side, and the second permanent magnet may have a rounded portion at one side adjacent to the first permanent magnet.

[0029] Since the first permanent magnet has a rounded portion in the middle portion and the second permanent magnet has a rounded portion on one side adjacent to the first permanent magnet, cogging torque can be reduced while minimizing the decrease in motor efficiency.

[0030] The first permanent magnet may have a rounded portion at a portion provided between one side adjacent to the second permanent magnet and the other side on the opposite side, and the second permanent magnet may have a rounded portion at a portion provided between one side adjacent to the first permanent magnet and the other side on the opposite side.

[0031] This allows for a reduction in cogging torque while minimizing the loss of motor efficiency.

[0032] The first permanent magnet may have a rounded portion at a portion provided between one side adjacent to the second permanent magnet and the other side on the opposite side, and the second permanent magnet may have a rounded portion at the other side provided on the opposite side of the one side adjacent to the first permanent magnet.

[0033] This reduces material costs by reducing the amount of magnets used, and increases magnet utilization through optimized geometry. Furthermore, cogging torque can be reduced while minimizing any loss of motor efficiency.

[0034] Preferably, the first and second magnet receiving portions may be alternately provided in the circumferential direction on the outside of the rotor core.

[0035] The rounded portions of the first and second permanent magnets may each be provided with a curved portion on one side and the other side.

[0036] A corner removal area may be provided between both sides of the above-mentioned rounding portion, the first and second magnet receiving portions, and the side walls of the first and second magnet receiving portions.

[0037] This reduces material costs by reducing the amount of magnets used, and increases magnet utilization through optimized geometry. Furthermore, cogging torque can be reduced while minimizing any loss of motor efficiency.

[0038] The above stator core has teeth that extend radially to form a gap with the outer periphery of the rotor core, and the edge removal area can overlap the teeth in the circumferential direction.

[0039] According to this configuration, the upper side of the stator core facing the upper side of the magnet has a reduced electromagnetic excitation force, so that the shaking of the rotor core is reduced and vibration and noise can be reduced.

[0040] A protruding bridge may be provided that protrudes from a surface between the first magnet receiving portion and the second magnet receiving portion to define one side of the corner removal area between the first magnet receiving portion and the second magnet receiving portion.

[0041] The above-mentioned protruding bridge has a predetermined width and extends axially to support the side surfaces of the first and second permanent magnets.

[0042] The curvature of one side of the rounded portion adjacent to each other of the first and second permanent magnets may be smaller than the curvature of the other side of the rounded portion opposite to each other.

[0043] The first permanent magnet may have a curvature on one side adjacent to the second permanent magnet of the rounded portion that is smaller than the curvature on the other side of the opposite portion, and the second permanent magnet may have the same curvature on one side adjacent to the first permanent magnet of the rounded portion and the same curvature on the other side of the opposite portion.

[0044] The first permanent magnet may have a curvature on one side of the rounded portion adjacent to the second permanent magnet that is smaller than the curvature on the other side of the opposite portion, and the second permanent magnet may have a curvature on one side of the rounded portion adjacent to the first permanent magnet that is larger than the curvature on the other side of the opposite portion.

[0045] The first permanent magnet may have the same curvature on one side adjacent to the second permanent magnet of the rounded portion and on the opposite side, and the second permanent magnet may have the curvature on one side adjacent to the first permanent magnet of the rounded portion smaller than the curvature on the opposite side.

[0046] The rotary compressor of the present invention may include a casing forming an exterior, a cylinder installed inside the casing, having a compression space on an inner surface, and having a suction port connected to the compression space to enable suction of refrigerant, a roller rotatably provided in the compression space of the cylinder, and the magnet insertion type motor.

[0047] In the magnet insertion motor of the present invention, the first and second permanent magnets are provided with a rounded portion formed to be rounded at one end, so that the upper side of the stator core facing the upper side of the permanent magnets has a reduced excitation force, thereby reducing the shaking of the rotor core, thereby reducing vibration and noise.

[0048] In addition, the magnet insertion motor of the present invention has a simple production process and high productivity because the shape of the rotor core is not divided into two and laminated.

[0049] In addition, the magnet insertion motor of the present invention can reduce material costs by reducing the amount of magnets used and increase the magnet usage rate with an optimized shape.

[0050] Fig. 1 is a cross-sectional view showing a rotary compressor of the present invention.

[0051] Fig. 2 is a perspective view of the magnet insertion motor of the present invention viewed from one side.

[0052] Fig. 3 is a plan view showing a part of the magnet insertion type motor of the present invention.

[0053] Fig. 4 is a front view showing an example of a permanent magnet of the present invention.

[0054] Fig. 5 is a front view showing another example of a permanent magnet of the present invention.

[0055] Fig. 6 is a front view showing another example of a permanent magnet of the present invention.

[0056] Figure 7 is a plan view showing the arrangement of the first and second permanent magnets of Case 2.

[0057] Figure 8 is a plan view showing the arrangement of the first and second permanent magnets of Case 3.

[0058] Figure 9 is a plan view showing the arrangement of the first and second permanent magnets of Case 4.

[0059] Figure 10 is a plan view showing the arrangement of the first and second permanent magnets of Case 5.

[0060] Fig. 11 is a plan view showing the arrangement of the first and second permanent magnets of Case 6.

[0061] Figure 12 is a plan view showing the arrangement of the first and second permanent magnets of Case 7.

[0062] Figure 13 is a plan view showing the arrangement of the first and second permanent magnets of Case 8.

[0063] Figure 14 is a plan view showing the arrangement of the first and second permanent magnets of Case 9.

[0064] Figure 15 is a graph showing the electromagnetic force (MPF) and motor efficiency for each case.

[0065] Figure 16 is a graph showing cogging torque and motor efficiency for each case.

[0066] Hereinafter, a magnet insertion motor according to the present invention and a rotary compressor equipped with the same will be described in detail based on an embodiment illustrated in the attached drawings. In the following description, descriptions of some components may be omitted to clarify the features of the present invention.

[0067] In addition, the term "upper side" used in the following description means a direction away from a support surface that supports a magnet insertion motor and a rotary compressor according to an embodiment of the present invention, that is, when looking at the electric motor (120) and the compression unit as the center, the compression unit side is the upper side. The term "lower side" means a direction approaching the support surface, that is, when looking at the electric motor (120) and the compression unit as the center, the electric motor (120) side is the lower side.

[0068] Additionally, the term "axial" used in the following description refers to the longitudinal direction of the rotation axis (125). "Axial" can be understood as an up-down direction. "Radial" refers to a direction intersecting the rotation axis (125).

[0069] Figure 1 shows an example of a rotary compressor.

[0070] Referring to FIG. 1, a rotary compressor may include a casing (110) forming an exterior, a cylinder (133) installed inside the casing (110) and having a compression space (V) on an inner surface, and having a suction port connected to the compression space (V) to enable suction of refrigerant, a roller (134) rotatably provided in the compression space of the cylinder (133), and a magnet insertion motor (120) described below.

[0071] A magnet insertion motor may include, for example, a stator (121) coupled to the inner surface of a casing (110) and a rotor (122) rotatably installed on the inner surface of the stator (121) and having a rotational shaft (125) provided on the inner surface.

[0072] The casing (110) is a part that forms the exterior of the compressor, and can be classified into a vertical type or a horizontal type depending on the installation method of the compressor. The vertical type has a structure in which a magnet insertion motor (120) and a compression unit (130) are arranged on both upper and lower sides along the axial direction, and the horizontal type has a structure in which a magnet insertion motor (120) and a compression unit (130) are arranged on both left and right sides. The casing (110) according to the present embodiment is described focusing on the vertical type, but it is not excluded that it can also be applied to the horizontal type.

[0073] The casing (110) may include a cylindrical intermediate shell (111), a lower shell (112) covering the lower part of the intermediate shell (111), and an upper shell (113) covering the upper part of the intermediate shell (111).

[0074] The cylinder (133) has an inner circumferential surface formed in an annular shape to form a compression space (V). In addition, the cylinder (133) has a suction port (1331), and the suction port (1331) is formed to be connected to the compression space (V) so as to suck in refrigerant and provide it to the compression space (V).

[0075] The inner surface of the cylinder (133) may be formed into an oval shape. For example, the inner surface of the cylinder (133) may be formed into an asymmetrical oval shape by combining multiple ovals.

[0076] A roller (134) is rotatably provided in a compression space (V) of a cylinder (133). In addition, a plurality of vane slots (not shown) are formed along the outer circumference of the roller (134) at preset intervals. In addition, a compression space (V) is formed between the inner circumference of the cylinder (133) and the outer circumference of the roller (134).

[0077] The lower portion (125b) of the rotation shaft (125) may include a crank shaft (125c) that rotates eccentrically. The crank shaft (125c) may be a portion inserted into the inner circumference of the roller (134).

[0078] That is, the compression space (V) is a space formed between the inner surface of the cylinder (133) and the outer surface of the roller (134). In addition, the compression space (V) is divided into spaces equal to the number of vanes by a plurality of vanes (not shown).

[0079] The vane (not shown) is configured to be slidably inserted into the vane slot and rotated together with the roller (134). In addition, a back pressure is provided at the rear end of the vane so that the front end of the vane comes into contact with the inner circumference of the cylinder (133).

[0080] The magnet insertion motor (120) can be installed in the upper internal space (110a) of the casing (110), and the compression unit (130) can be installed in the lower internal space (110a) of the casing (110), and the magnet insertion motor (120) and the compression unit (130) can be connected by a rotation shaft (125).

[0081] The magnet insertion motor (120) is a part of the electric motor and provides power to drive the compression unit (130). The magnet insertion motor (120) includes a stator (121), a rotor (122), and a rotation shaft (125).

[0082] The stator (121) can be fixedly installed inside the casing (110), and can be fixed by being press-fitted onto the inner surface of the casing (110) by heat-fitting, etc. For example, the stator (121) can be fixed by being press-fitted onto the inner surface of the intermediate shell (111). The stator (121) can be equipped with a stator core (121a), which will be described later. A coil can be wound around the stator core (121a).

[0083] The rotor (122) is rotatably inserted into the interior of the stator (121), and a rotational shaft (125) is press-fitted and coupled to the center of the rotor (122). Accordingly, the rotational shaft (125) rotates together with the rotor (122). The rotor (122) may include a rotor core (122a), which will be described later.

[0084] As described below, the rotation shaft (125) includes an upper portion (125a) coupled with a rotor core (122a) and a lower portion (125b) coupled with a load that receives the rotational force of the rotor core (122a).

[0085] The upper part (125a) may be a rotor or rotor core side part. The lower part (125b) may be a part to which a load or compression part is coupled.

[0086] In the present invention, as the compression member moves eccentrically, the load side (lower side) of the rotor may have greater shaking than the upper side.

[0087] When an external power source is applied to the coil of the stator core (121a), a magnetic field can be formed around the coil of the stator. The rotor (122) and the rotation shaft (125) coupled thereto can rotate through electromagnetic interaction with the stator (121).

[0088] The rotor (122) may be provided with vent holes (122a) formed through the upper and lower sides. The airflow of the refrigerant discharged from the compression section can flow upward through the vent holes (122a).

[0089] An oil passage can be formed in the shape of a hollow hole at the center of the rotation axis (125).

[0090] An oil pickup (not shown) may be installed in the middle or bottom of the oil passage so that oil from the oil storage space can be sucked up and supplied to the wetted part.

[0091] Additionally, the rotation shaft (125) may be formed integrally with the roller (134) or may be post-assembled by press-fitting the roller (134).

[0092] The rotary compressor of the present invention may further include a main bearing (131) and a sub-bearing (132). The main bearing (131) and the sub-bearing (132) may be installed at each end of the cylinder (133). The main bearing (131) and the sub-bearing (132) are arranged to be spaced apart from each other to form each side of the compression space (V) described above.

[0093] In the present invention, the rotary shaft (125) of the magnet-inserted motor in the rotary compressor is assembled in a structure in which it is supported on one side at the lower end of the mechanism, so that when the rotary compressor is operated, the opposite side of the one-side support of the rotary shaft (125) is spaced from the rotary shaft (125) and rotates eccentrically. At this time, due to the eccentricity of the rotary shaft (125) that occurs, the upper gap (121c) of the stator and the rotor of the motor becomes uneven, and an electromagnetic excitation force is generated in the direction in which the eccentricity of the rotary shaft (125) increases, which causes a problem in that it increases the vibration and noise of the compressor.

[0094] The present invention proposes a magnet structure and arrangement having asymmetrical shapes at the upper and lower portions, which can reduce vibration and noise of a rotary compressor by improving eccentric rotation characteristics generated from a one-sided support structure of a rotary shaft (125).

[0095] The magnet insertion motor of the present invention includes a stator core (121a), a rotor core (122a) provided on the inside of the stator core (121a) and rotatable, a permanent magnet (123, 124) accommodated inside the rotor core (122a), and a rotation shaft (125) having one side provided on the inside of the rotor core (122a) and rotating together with the rotor core (122a).

[0096] The rotation shaft (125) includes an upper portion (125a) coupled with a rotor core (122a) and a lower portion (125b) coupled with a load that receives the rotational force of the rotor core (122a).

[0097] A plurality of magnet receiving portions (122b, 122c) spaced apart along the circumferential direction are provided inside the rotor core (122a).

[0098] Permanent magnets (123, 124) are inserted into magnet receiving portions (122b, 122c).

[0099] The permanent magnet (123, 124) includes an upper end facing the end of the upper side (125a) of the rotation axis (125) based on the surface where the polarity acts, a lower end (123f, 124f) facing the upper end and facing the end of the lower side (125b) of the rotation axis (125), and two side ends (123k, 124k) connecting the upper and lower ends (123f, 124f).

[0100] The upper part includes a rounded portion (123a, 124a) formed to be rounded, and the lower part (123f, 124f) and two side ends (123k, 124k) are formed in a straight line.

[0101] For example, the motor of the present invention may be a single-phase IPM type motor.

[0102] The present invention can minimize eccentric rotation of the rotor and rotation shaft (125) and shaking of the upper rotor core (122a), which are causes of noise and vibration. In particular, it can minimize reduction in motor efficiency while maintaining high productivity.

[0103] The present invention provides rounding portions (123a, 124a) at the upper ends of the first and second permanent magnets (123, 124), thereby minimizing shaking at the upper portion of the rotor.

[0104] In addition, the present invention can reduce noise and vibration sources generated during eccentric driving.

[0105] For example, each of the plurality of magnet receiving portions (122b, 122c) may be configured as a pair of magnet receiving portions (122b, 122c) that are inserted in a V shape so that they are spaced apart from each other as they go outward in the radial direction.

[0106] A pair of magnet receiving portions (122b, 122c) may include a first magnet receiving portion (122b) and a second magnet receiving portion (122c).

[0107] The permanent magnets (123, 124) may include a first permanent magnet (123) inserted into a first magnet receiving portion (122b) and a second permanent magnet (124) inserted into a second magnet receiving portion (122c).

[0108] The lower part (125b) of the rotation shaft (125) may include a crank shaft (125c) that rotates eccentrically.

[0109] For example, the motor of the present invention may be a V-shaped IPM type motor.

[0110] One side of the rotor core (122a) may be provided with a first magnet receiving portion (122b) and a second magnet receiving portion (122c) that are formed to be able to intersect with each other.

[0111] The permanent magnets (123, 124) may include a first permanent magnet (123, 124) accommodated in a first magnet receiving portion (122b) and a second permanent magnet (123, 124) accommodated in a second magnet receiving portion (122c).

[0112] The first and second permanent magnets (123, 124) may have rounded portions (123a, 124a) formed to be rounded at the top.

[0113] Fig. 2 is a perspective view of the magnet insertion motor of the present invention as viewed from one side. Fig. 3 is a plan view showing a part of the magnet insertion motor of the present invention.

[0114] An example in which the first and second permanent magnets (123, 124) in the present invention are installed in the rotor core (122a) is shown in FIG. 2.

[0115] The first and second permanent magnets (123, 124) are accommodated in the first and second magnet accommodation portions (122b, 122c), respectively.

[0116] The first magnet receiving portion (122b) and the second magnet receiving portion (122c) can be arranged to cross each other while forming a predetermined angle on one side of the rotor core (122a).

[0117] A protruding bridge (122d) may be provided between the first magnet receiving portion (122b) and the second magnet receiving portion (122c). The protruding bridge (122d) may be placed between the first and second permanent magnets (123, 124).

[0118] The protruding bridge (122d) may be formed to protrude from the surface between the first magnet receiving portion (122b) and the second magnet receiving portion (122c). The protruding bridge (122d) may have a predetermined width. The protruding bridge (122d) may be formed to extend in the axial direction, which is the direction in which the rotation axis (125) extends.

[0119] By this structure, the protruding bridge (122d) can define one side of the corner removal area.

[0120] Additionally, the protruding bridge (122d) can support the first and second permanent magnets (123, 124) between the first and second permanent magnets (123, 124).

[0121] In the present invention, for convenience, in order to refer to the formation positions of the rounding portions (123a, 124a) as left, right, or middle positions, the left, right, or middle positions are designated based on the part where the rotational axis (125), which is the center of the rotor core (122a), is installed, when looking at the first and second permanent magnets (123, 124). In other words, the left and right are determined based on the inside of the rotor core (122a) or when looking outward from the center where the rotational axis (125) is installed.

[0122] Fig. 4 is a front view showing an example of a permanent magnet (123, 124) of the present invention.

[0123] Referring to Fig. 4, an example is shown in which a rounding portion (123a, 124a) is provided on the left side of the top of the permanent magnet (123, 124).

[0124] A first curved portion (123b) may be provided on one side of the rounding portion (123a, 124a), and a second curved portion (123c) may be provided on the other side.

[0125] The first curved portion (123b) and the second curved portion (123c) can be distinguished based on the end of the rounded portion (123a).

[0126] In Fig. 4, a first curved portion (123b) may be provided on the left end of the rounding portions (123a, 124a), and a second curved portion (123c) may be provided on the right end. The first curved portion (123b) and the second curved portion (123c) may each have different predetermined curvatures. For example, the curvature of the first curved portion (123b) may be smaller than the curvature of the second curved portion (123c). The curvature and the radius of curvature are inversely proportional or reciprocal. That is, the radius of curvature of the first curved portion (123b) may be larger than the radius of curvature of the second curved portion (123c).

[0127] First and second corner removal areas (123d, 123e) may be provided on both sides of the rounding portion (123a, 124a), respectively.

[0128] The first and second corner removal areas (123d, 123e) may be areas defined by both sides of the rounding portion (123a, 124a), the first and second magnet receiving portions (122b, 122c), and side walls or bridges connected between the first and second magnet receiving portions (122b, 122c), respectively.

[0129] For example, the first curved portion (123b) may have a first corner removal area (123d), and the second curved portion (123c) may have a second corner removal area (123e).

[0130] The first and second corner removal areas (123d, 123e) are areas where no magnet portion is provided around the rounded portions (123a, 124a) of the permanent magnets (123, 124). That is, if the permanent magnets (123, 124) are formed in a square shape, these areas are areas where corners are formed, and can be understood as the surrounding space as the rounded portions (123a, 124a) are formed.

[0131] As the first and second corner removal areas (123d, 123e) are provided, the driving force on the upper side of the tooth (121b) portion on the stator core (121a) side is reduced, thereby reducing the shaking of the rotor core (122a) and reducing vibration and noise.

[0132] Additionally, the material cost can be reduced by reducing the amount of magnets used, and the magnet usage rate can be increased by optimizing the shape.

[0133] The permanent magnet (123, 124) can have a width (W) and a height (H).

[0134] The width of the permanent magnet (123, 124) may be the distance from the left end to the right end. In addition, the height of the permanent magnet (123, 124) may be the shortest distance from the bottom to the end of the rounded portion (123a, 124a).

[0135] For example, the width (W) of the permanent magnet (123, 124) may be 5 mm or more and 10 mm or less.

[0136] For example, the height (H) of the permanent magnet (123, 124) may be 25 mm or more and 60 mm or less.

[0137] The vertical distance (X11) from the top of the rounding portion (123a, 124a) to the bottom of the first curved portion (123b) may be less than half the height (H) of the permanent magnet (123, 124).

[0138] For example, the vertical distance (X11) from the top of the rounding portion (123a, 124a) to the bottom of the first curved portion (123b) may be 12.5 mm or more and 30 mm or less.

[0139] The vertical distance (X12) from the top of the rounding portion (123a, 124a) to the bottom of the second curved portion (123c) may be less than half the height (H) of the permanent magnet (123, 124).

[0140] For example, the vertical distance (X12) from the top of the rounding portion (123a, 124a) to the bottom of the second curved portion (123c) may be 12.5 mm or more and 30 mm or less.

[0141] The distance of the first curved portion (123b) may be greater than half the width (W) of the permanent magnet (123, 124). The distance of the first curved portion (123b) may be the distance along an arc passing between both ends of the first curved portion (123b). For example, the distance of the first curved portion (123b) may be 5 mm or more.

[0142] The distance of the second curved portion (123c) may be greater than half the width (W) of the permanent magnet (123, 124). The distance of the second curved portion (123c) may be the distance along an arc passing between the two ends of the second curved portion (123c). For example, the distance of the second curved portion (123c) may be 5 mm or more.

[0143] Fig. 5 is a front view showing another example of a permanent magnet of the present invention.

[0144] Referring to FIG. 5, an example is shown in which a rounded portion (123a, 124a) is provided in the middle between the left and right sides at the top of a permanent magnet (123, 124).

[0145] A third curved portion (123g) may be provided on one side of the rounding portion (123a, 124a), and a fourth curved portion (123h) may be provided on the other side.

[0146] In Fig. 5, a third curvature portion (123g) may be provided on the left end of the rounding portion (123a, 124a), and a fourth curvature portion (123h) may be provided on the right end. For example, the third curvature portion (123g) and the fourth curvature portion (123h) may each have the same predetermined curvature so as to be symmetrical to each other.

[0147] The third curved portion (123g) may have a third corner removal area (123d), and the fourth curved portion (123h) may have a fourth corner removal area (123e).

[0148] As the third and fourth corner removal areas (123d, 123e) are provided, the driving force on the upper side of the tooth (121b) portion on the stator core (121a) side is reduced, thereby reducing the shaking of the rotor core (122a) and reducing vibration and noise.

[0149] Additionally, the material cost can be reduced by reducing the amount of magnets used, and the magnet usage rate can be increased by optimizing the shape.

[0150] The permanent magnet (123, 124) can have a width (W) and a height (H).

[0151] The width of the permanent magnet (123, 124) may be the distance from the left end to the right end. In addition, the height of the permanent magnet (123, 124) may be the shortest distance from the bottom to the end of the rounded portion (123a, 124a).

[0152] For example, the width (W) of the permanent magnet (123, 124) may be 5 mm or more and 10 mm or less.

[0153] For example, the height (H) of the permanent magnet (123, 124) may be 25 mm or more and 60 mm or less.

[0154] The vertical distance (X11) from the top of the rounding portion (123a, 124a) to the bottom of the third curved portion (123g) or the fourth curved portion (123h) may be less than half the height (H) of the permanent magnet (123, 124).

[0155] For example, the vertical distance (X11) from the top of the rounding portion (123a, 124a) to the bottom of the third curved portion (123g) or the fourth curved portion (123h) may be 12.5 mm or more and 30 mm or less.

[0156] The distance of the third curvature portion (123g) or the fourth curvature portion (123h) may be greater than half the width (W) of the permanent magnet (123, 124). The distance of the third curvature portion (123g) or the fourth curvature portion (123h) may be the distance on an arc passing between the two ends of the third curvature portion (123g) or the fourth curvature portion (123h). For example, the distance of the third curvature portion (123g) or the fourth curvature portion (123h) may be 5 mm or more.

[0157] Fig. 6 is a front view showing another example of a permanent magnet of the present invention.

[0158] Another example of the first and second permanent magnets (123, 124) in the present invention is shown in Fig. 6.

[0159] As described above, in the present invention, for convenience, in order to refer to the formation position of the rounding portion (123a, 124a) as the left, right, or middle position, the left, right, or middle position is named based on the direction in which the first and second permanent magnets (123, 124) are viewed from the part where the rotation axis (125), which is the center of the rotor core (122a), is installed.

[0160] Referring to Fig. 6, an example is shown in which a rounding portion (123a, 124a) is provided on the right side of the upper portion of the permanent magnet (123, 124).

[0161] A fifth curvature portion (123i) may be provided on one side of the rounding portion (123a, 124a), and a sixth curvature portion (123j) may be provided on the other side.

[0162] In Fig. 6, a fifth curvature portion (123i) may be provided on the left end of the rounding portions (123a, 124a), and a sixth curvature portion (123j) may be provided on the right end. The fifth curvature portion (123i) and the sixth curvature portion (123j) may each have different predetermined curvatures. For example, the curvature of the fifth curvature portion (123i) may be greater than the curvature of the sixth curvature portion (123j). The curvature and the radius of curvature are inversely proportional or reciprocal. That is, the radius of curvature of the fifth curvature portion (123i) may be smaller than the radius of curvature of the sixth curvature portion (123j).

[0163] The fifth curvature portion (123i) may have a fifth corner removal area (123d), and the sixth curvature portion (123j) may have a sixth corner removal area (123e).

[0164] As the fifth and sixth corner removal areas (123d, 123e) are provided, the driving force on the upper side of the tooth (121b) portion on the stator core (121a) side is reduced, thereby reducing the shaking of the rotor core (122a) and reducing vibration and noise.

[0165] Additionally, the material cost can be reduced by reducing the amount of magnets used, and the magnet usage rate can be increased by optimizing the shape.

[0166] The permanent magnet (123, 124) can have a width (W) and a height (H).

[0167] The width of the permanent magnet (123, 124) may be the distance from the left end to the right end. In addition, the height of the permanent magnet (123, 124) may be the shortest distance from the bottom to the end of the rounded portion (123a, 124a).

[0168] For example, the width (W) of the permanent magnet (123, 124) may be 5 mm or more and 10 mm or less.

[0169] For example, the height (H) of the permanent magnet (123, 124) may be 25 mm or more and 60 mm or less.

[0170] The vertical distance (X31) from the top of the rounding portion (123a, 124a) to the bottom of the fifth curvature portion (123i) may be less than half the height (H) of the permanent magnet (123, 124).

[0171] For example, the vertical distance (X31) from the top of the rounding portion (123a, 124a) to the bottom of the fifth curved portion (123i) may be 12.5 mm or more and 30 mm or less.

[0172] The vertical distance (X32) from the top of the rounding portion (123a, 124a) to the bottom of the sixth curvature portion (123j) may be less than half the height (H) of the permanent magnet (123, 124).

[0173] For example, the vertical distance (X32) from the top of the rounding portion (123a, 124a) to the bottom of the sixth curvature portion (123j) may be 12.5 mm or more and 30 mm or less.

[0174] The distance of the fifth curvature (123i) may be greater than half the width (W) of the permanent magnet (123, 124). The distance of the fifth curvature (123i) may be the distance along an arc passing between the two ends of the fifth curvature (123i). For example, the distance of the fifth curvature (123i) may be 5 mm or more.

[0175] The distance of the sixth curvature (123j) may be greater than half the width (W) of the permanent magnets (123, 124). The distance of the sixth curvature (123j) may be the distance along an arc passing between the two ends of the sixth curvature (123j). For example, the distance of the sixth curvature (123j) may be 5 mm or more.

[0176] Below, the arrangement of permanent magnets (123, 124) to reduce electromagnetic pull force (MPF) or cogging torque is described.

[0177] The electromagnetic force (MPF) in a magnet insertion motor is a force that the permanent magnets (123, 124) pull radially on the teeth (121b) of the stator core (121a). When the upper gap (121c) of the magnet insertion motor becomes smaller as the rotation axis (125) inside the rotor becomes eccentric to the compression section, vibration and noise increase due to the increase in the electromagnetic force (MPF).

[0178] In the present invention, in order to reduce the shaking of the upper portion of the rotor core (122a), the shape of the permanent magnets (123, 124) is changed to have rounded portions (123a, 124a), thereby reducing the electromagnetic force (MPF) and thus reducing the shaking of the rotor core (122a), thereby reducing vibration and noise.

[0179] In Fig. 15, the electromagnetic excitation force (MPF) characteristics according to the gap (121c) between the rotor core (122a) and the stator core (121a) are shown in a graph. It can be confirmed that the smaller the gap (121c), the larger the electromagnetic excitation force (MPF), and conversely, the larger the gap (121c), the smaller the electromagnetic excitation force (MPF), an inversely proportional pattern can be observed.

[0180] First, we will describe cases 1 to 3, which are arrangements advantageous for reducing electromagnetic excitation.

[0181] In case 1, the first and second permanent magnets (123, 124) have rounded portions (123a, 124a) on each of their respective upper sides adjacent to each other.

[0182] In case 1, the rounding portions (123a, 124a) of the first permanent magnet (123, 124) and the rounding portions (123a, 124a) of the second permanent magnet (123, 124) are arranged as close as possible to each other compared to other cases.

[0183] In FIGS. 2 and 3, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) are formed to intersect each other on one side of the rotor core (122a). In addition, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) may form a pair and be alternately arranged on the outside of the rotor core (122a), and the two pairs are arranged continuously.

[0184] When viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0185] A rounded portion (123a, 124a) is formed on the upper right side of the first permanent magnet (123, 124) accommodated in the first magnet accommodation portion (122b), and a rounded portion (123a, 124a) is formed on the upper left side of the second permanent magnet (123, 124) accommodated in the second magnet accommodation portion (122c).

[0186] In this way, the first and second permanent magnets (123, 124) have rounded portions (123a, 124a) formed on each of the upper ends and on each side adjacent to each other.

[0187] As shown in FIGS. 2 and 3, the curvature of the adjacent sides (124b, 123j) of the rounded portions (123a, 124a) of the first and second permanent magnets (123, 124) may be smaller than the curvature of the opposite sides (123i, 124c) of the rounded portions (123a, 124a).

[0188] This allows for a reduction in electromagnetic excitation while minimizing the reduction in motor efficiency.

[0189] In case 2, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) on one side adjacent to the second permanent magnet (123, 124) at the top. The second permanent magnet (123, 124) has a rounded portion (123a, 124a) on the part provided between the side adjacent to the first permanent magnet (123, 124) at the top and the other side on the opposite side.

[0190] Figure 7 is a plan view showing the arrangement of the first and second permanent magnets of Case 2.

[0191] In Fig. 7, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) are formed to intersect each other on one side of the rotor core (122a). In addition, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) may form a pair and be alternately arranged on the outside of the rotor core (122a), and a portion where the two pairs are arranged continuously is illustrated.

[0192] When viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0193] A rounded portion (123a, 124a) is formed on the upper right side of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounded portion (123a, 124a) is formed at a mid-position between the upper right and left sides of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0194] In this way, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) on one side adjacent to the second permanent magnet (123, 124) at the top. The second permanent magnet (123, 124) has a rounded portion (123a, 124a) at the center portion provided between the side adjacent to the first permanent magnet (123, 124) at the top and the other side on the opposite side.

[0195] For example, referring to FIGS. 5 to 7, the curvature of one side (123j) adjacent to the second permanent magnet (124) of the rounding portion (123a) of the first permanent magnet (123) may be smaller than the curvature of the other side (123i) on the opposite side, and the curvature of one side (124d) adjacent to the first permanent magnet (123) of the rounding portion (124a) of the second permanent magnet (124) and the other side (123h) on the opposite side may be equal to each other.

[0196] This allows for a reduction in electromagnetic excitation while minimizing the reduction in motor efficiency.

[0197] In case 3, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) on one side adjacent to the second permanent magnet (123, 124) at the top. The second permanent magnet (123, 124) has a rounded portion (123a, 124a) on the other side opposite to the side adjacent to the first permanent magnet (123, 124) at the top.

[0198] Figure 8 is a plan view showing the arrangement of the first and second permanent magnets of Case 3.

[0199] In Fig. 8, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) are formed to intersect each other on one side of the rotor core (122a). In addition, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) may form a pair and be alternately arranged on the outside of the rotor core (122a), but only the portion of the rotor core (122a) where the two pairs (the first magnet receiving portion (122b) and the second magnet receiving portion (122c)) are arranged continuously is shown cut away.

[0200] When viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0201] A rounded portion (123a, 124a) is formed on the upper right side of the first permanent magnet (123, 124) accommodated in the first magnet accommodation portion (122b), and a rounded portion (123a, 124a) is formed on the upper right side of the second permanent magnet (123, 124) accommodated in the second magnet accommodation portion (122c).

[0202] In this way, in case 3, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) on one side adjacent to the second permanent magnet (123, 124) at the top. The second permanent magnet (123, 124) has a rounded portion (123a, 124a) on the other side opposite to the side adjacent to the first permanent magnet (123, 124) at the top.

[0203] Referring to FIGS. 6 and 8, the curvature of one side (123j) adjacent to the second permanent magnet (124) of the rounding portion (123a) of the first permanent magnet (123) may be smaller than the curvature of the other side (123i) of the opposite side, and the curvature of one side (124i) adjacent to the first permanent magnet (123) of the rounding portion (124a) of the second permanent magnet (124) may be larger than the curvature of the other side (124j) of the opposite side.

[0204] This allows for a reduction in electromagnetic excitation while minimizing the reduction in motor efficiency.

[0205] Figure 15 is a graph showing the electromagnetic force (MPF) and motor efficiency for each case.

[0206] Referring to Figure 15, the degree to which the electromagnetic force (MPF) is reduced and the motor efficiency is reduced can be confirmed for each case.

[0207] In cases 1 to 3, the electromagnetic force (MPF) was reduced by 27% and the motor efficiency was reduced by approximately 17 to 18%.

[0208] The arrangement of the permanent magnets (123, 124) in cases 1 to 3, described below, minimizes the reduction in motor efficiency compared to the arrangement of the permanent magnets (123, 124) in cases 4 to 9 while maximally reducing the electromagnetic force (MPF).

[0209] In case 4, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the second permanent magnet (123, 124) at the top and the other side on the opposite side.

[0210] The second permanent magnet (123, 124) has a rounded portion (123a, 124a) on one side adjacent to the first permanent magnet (123, 124) at the top.

[0211] Figure 9 is a plan view showing the arrangement of the first and second permanent magnets of Case 4.

[0212] In Fig. 9, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) are formed to intersect each other on one side of the rotor core (122a). In addition, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) may form a pair and be alternately arranged on the outside of the rotor core (122a), and a portion where the two pairs are arranged continuously is illustrated.

[0213] When viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0214] A rounding portion (123a, 124a) is formed at a mid-position between the upper right and left sides of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounding portion (123a, 124a) is formed at the upper left side of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0215] In this way, in case 4, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the second permanent magnet (123, 124) at the top and the other side on the opposite side, and the second permanent magnet (123, 124) has a rounded portion (123a, 124a) at a side adjacent to the first permanent magnet (123, 124) at the top.

[0216] Referring to FIGS. 4, 5 and 9, the curvature of the first permanent magnet (123) on one side (123h) adjacent to the second permanent magnet (124) of the rounding portion (123a) and the curvature of the opposite side (123g) are the same, and the curvature of the second permanent magnet (124) on one side (124b) adjacent to the first permanent magnet (123) of the rounding portion (124a) may be smaller than the curvature of the opposite side (124c).

[0217] This allows for a reduction in cogging torque while minimizing the loss of motor efficiency.

[0218] In case 5, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the second permanent magnet (123, 124) and the other side on the opposite side at the top. The second permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the first permanent magnet (123, 124) and the other side on the opposite side at the top.

[0219] Figure 10 is a plan view showing the arrangement of the first and second permanent magnets of Case 5.

[0220] In Fig. 10, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) are formed to intersect each other on one side of the rotor core (122a). In addition, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) may form a pair and be alternately arranged on the outside of the rotor core (122a), and a portion where the two pairs are arranged continuously is illustrated.

[0221] When viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0222] A rounding portion (123a, 124a) is formed at a mid-position between the upper right and left sides of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounding portion (123a, 124a) is formed at a mid-position between the upper right and left sides of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0223] In this way, in case 5, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the second permanent magnet (123, 124) at the top and the other side on the opposite side. The second permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the first permanent magnet (123, 124) at the top and the other side on the opposite side.

[0224] This allows for a reduction in cogging torque while minimizing the loss of motor efficiency.

[0225] In case 6, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the second permanent magnet (123, 124) at the top and the other side on the opposite side.

[0226] The second permanent magnet (123, 124) has a rounded portion (123a, 124a) on the other side opposite to the side adjacent to the first permanent magnet (123, 124) at the top.

[0227] Fig. 11 is a plan view showing the arrangement of the first and second permanent magnets of Case 6.

[0228] In Fig. 11, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) are formed to intersect each other on one side of the rotor core (122a). In addition, the first magnet receiving portion (122b) and the second magnet receiving portion (122c) may form a pair and be alternately arranged on the outside of the rotor core (122a), and a portion where the two pairs are arranged continuously is illustrated.

[0229] When viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0230] A rounding portion (123a, 124a) is formed at a mid-position between the upper right and left sides of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounding portion (123a, 124a) is formed at a upper right position of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0231] In this way, in case 6, the first permanent magnet (123, 124) has a rounded portion (123a, 124a) at a portion provided between one side adjacent to the second permanent magnet (123, 124) at the top and the other side on the opposite side.

[0232] The second permanent magnet (123, 124) has a rounded portion (123a, 124a) on the other side opposite to the side adjacent to the first permanent magnet (123, 124) at the top.

[0233] This allows for a reduction in cogging torque while minimizing the loss of motor efficiency.

[0234] Figure 16 is a graph showing cogging torque and motor efficiency for each case.

[0235] Referring to Figure 16, the degree to which cogging torque is reduced and motor efficiency is reduced can be confirmed for each case.

[0236] In cases 4 to 6, the cogging torque was reduced by about 60% and the motor efficiency was reduced by about 0.5%.

[0237] The arrangement of permanent magnets (123, 124) in cases 4 to 6 is advantageous in terms of reducing cogging torque compared to the arrangement of permanent magnets (123, 124) in cases 1 to 3 (there is a difference in reducing cogging torque of about 70%).

[0238] The arrangement of permanent magnets (123, 124) in cases 4 to 6 is advantageous in that it can reduce the reduction in motor efficiency compared to the arrangement of permanent magnets (123, 124) in cases 7 to 9 (there is a difference in that the reduction in motor efficiency is about 0.05%).

[0239] The arrangement of permanent magnets (123, 124) in cases 4 to 6 is advantageous in that it can reduce cogging torque and minimize reduction in motor efficiency compared to the arrangement of permanent magnets (123, 124) in other cases.

[0240] Fig. 12 is a plan view illustrating the arrangement of the first and second permanent magnets in case 7, and Fig. 13 is a plan view illustrating the arrangement of the first and second permanent magnets in case 8. In addition, Fig. 14 is a plan view illustrating the arrangement of the first and second permanent magnets in case 9.

[0241] Referring to FIGS. 12 to 14, cases 7 to 9 of the present invention will be described.

[0242] In cases 7 to 9, when viewed from the point where the rotation axis (125), which is the center of the rotor core (122a), is installed, the first magnet receiving portion (122b) is placed on the left, and the second magnet receiving portion (122c) is placed on the right. The first magnet receiving portion (122b) and the second magnet receiving portion (122c) are connected so as to be able to intersect with each other.

[0243] In case 7, a rounded portion (123a, 124a) is formed on the upper left side of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounded portion (123a, 124a) is formed on the upper left side of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0244] In case 8, a rounded portion (123a, 124a) is formed on the upper left side of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounded portion (123a, 124a) is formed at a mid-position between the upper left and right sides of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0245] In case 9, a rounded portion (123a, 124a) is formed on the upper left side of the first permanent magnet (123, 124) accommodated in the first magnet receiving portion (122b), and a rounded portion (123a, 124a) is formed on the upper right side of the second permanent magnet (123, 124) accommodated in the second magnet receiving portion (122c).

[0246] The magnet insertion motor and the rotary compressor having the same described above are not limited to the configuration and method of the embodiments described above, and the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

[0247] It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential characteristics thereof. Therefore, the detailed description of the present invention should not be construed in any way as limiting, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0248] The present invention can be used in a magnet insertion motor that reduces noise and vibration and a rotary compressor having the same.

Claims

1. Stator core; A rotor core provided on the inside of the stator core and capable of rotation; A permanent magnet accommodated inside the rotor core; It includes a rotating shaft provided on the inside of the rotor core and rotating together with the rotor core, The above rotational axis includes an upper part coupled with the rotor core and a lower part coupled with a load that receives the rotational force of the rotor core, A plurality of magnet receiving portions are provided spaced apart along the circumference inside the rotor core, The above permanent magnet is inserted into the magnet receiving portion, The above permanent magnet includes an upper end facing the upper end of the rotational axis based on the surface where the polarity acts, a lower end facing the upper end and facing the lower end of the rotational axis, and two side ends connecting the upper end and the lower end. A magnet insertion motor in which the upper part includes a rounded portion formed to be rounded, and the lower part and the two side ends are formed in a straight line.

2. In paragraph 1, Each of the plurality of magnet receiving portions is composed of a pair of magnet receiving portions that are inserted in a V shape so that they are spaced apart from each other as they go outward in the radial direction. The above pair of magnet receiving portions comprises a first magnet receiving portion and a second magnet receiving portion, The above permanent magnet is a magnet insertion type motor including a first permanent magnet inserted into the first magnet receiving portion and a second permanent magnet inserted into the second magnet receiving portion.

3. In paragraph 1, A magnet insertion motor including a crankshaft that rotates eccentrically at the lower part of the above rotational axis.

4. In paragraph 2, The above first and second permanent magnets are magnet insertion type motors having rounded portions on each of their respective upper sides adjacent to each other.

5. In paragraph 2, The above first permanent magnet has a rounded portion on one side adjacent to the second permanent magnet at the top, The above second permanent magnet is a magnet insertion motor having a rounded portion at a portion provided between one side adjacent to the first permanent magnet and the other side on the opposite side at the top.

6. In paragraph 2, The above first permanent magnet has a rounded portion on one side adjacent to the second permanent magnet at the top, The above second permanent magnet is a magnet insertion motor having a rounded portion on the other side opposite to the side adjacent to the first permanent magnet at the top.

7. In paragraph 2, The above first permanent magnet has a rounded portion at the upper portion, between one side adjacent to the second permanent magnet and the other side on the opposite side, The above second permanent magnet is a magnet insertion motor having a rounded portion on one side adjacent to the first permanent magnet at the top.

8. In paragraph 2, The above first permanent magnet has a rounded portion at the upper portion, between one side adjacent to the second permanent magnet and the other side on the opposite side, The above second permanent magnet is a magnet insertion motor having a rounded portion at a portion provided between one side adjacent to the first permanent magnet and the other side on the opposite side at the top.

9. In paragraph 2, The above first permanent magnet has a rounded portion at the upper portion, between one side adjacent to the second permanent magnet and the other side on the opposite side, The above second permanent magnet is a magnet insertion motor having a rounded portion on the other side opposite to the side adjacent to the first permanent magnet at the top.

10. In paragraph 2, A magnet insertion type motor in which the first and second magnet receiving sections are alternately provided in a circumferential direction on the outside of the rotor core.

11. In paragraph 2, A magnet insertion motor in which the rounding portions of the first and second permanent magnets are provided with curved portions on one side and the other side, respectively.

12. In paragraph 2, A magnet insertion motor having a corner removal area provided between both sides of the above-mentioned rounding portion, the first and second magnet receiving portions, and the side walls of the first and second magnet receiving portions.

13. In paragraph 12, The above stator core has teeth that extend radially to form a gap with the outer periphery of the rotor core, The above corner removal area is a magnet insertion motor that overlaps the above tee in the circumferential direction.

14. In paragraph 12, A magnet insertion motor having a protruding bridge formed protruding from a surface between the first magnet receiving portion and the second magnet receiving portion to define one side of the corner removal area between the first magnet receiving portion and the second magnet receiving portion.

15. In paragraph 14, The above protruding bridge is a magnet insertion motor having a predetermined width and extending in the axial direction to support the side surfaces of the first and second permanent magnets.

16. In paragraph 4, The above first and second permanent magnets are magnet insertion motors in which the curvature of one side of the rounding portion adjacent to each other is smaller than the curvature of the other side of the rounding portion opposite to each other.

17. In paragraph 5, The above first permanent magnet has a curvature on one side adjacent to the second permanent magnet of the rounded portion that is smaller than the curvature on the other side of the opposite side, The above second permanent magnet is a magnet insertion motor in which the curvature of one side adjacent to the first permanent magnet of the rounding part and the other side on the opposite side are the same.

18. In paragraph 6, The above first permanent magnet has a curvature on one side adjacent to the second permanent magnet of the rounded portion that is smaller than the curvature on the other side of the opposite side, The above second permanent magnet is a magnet insertion motor in which the curvature of one side adjacent to the first permanent magnet of the rounding part is greater than the curvature of the opposite side.

19. In paragraph 7, The first permanent magnet has the same curvature on one side adjacent to the second permanent magnet of the rounded portion and on the opposite side, The above second permanent magnet is a magnet insertion motor in which the curvature of one side adjacent to the first permanent magnet of the rounding part is smaller than the curvature of the opposite side.

20. The casing that forms the exterior, A cylinder installed inside a casing, having a compression space on the inner surface, and having a suction port connected to the compression space to enable suction of refrigerant; A roller that is rotatably provided in the compression space of the cylinder, A rotary compressor comprising a magnet insertion motor according to any one of claims 1 to 19.

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