Rotating electric machine and washing machine equipped with the same

Abstract

To provide a rotary electric machine that has high productivity at low cost and can achieve lower noise by reduction of pulse torque, and a washing machine including the same.SOLUTION: A dynamo-electric motor as a rotary electric machine comprises: a stator having a stator iron core with a plurality of steel plates laminated; and a rotator provided so as to rotate with respect to the stator. The stator iron core has teeth 120 on which an armature coil is wound. A tip end surface 121 of the teeth 120 exhibits a non-concentric convex shape on the rotator side. In a tip end part of the teeth 120, a plurality of holes 123 arranged in a width direction of the teeth 120 are provided.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a rotating electric machine and a washing machine equipped with the same. [Background technology]

[0002] Current drum-type washer-dryers are increasing their high-speed spin rotation speeds to improve drying performance. Furthermore, as laundry capacity increases, motors must be designed to be low-speed, high-torque without changing their size. Furthermore, noise must be reduced in both the high-speed, low-torque and low-speed, high-torque ranges.

[0003] Background of the present invention is Japanese Patent Application Laid-Open No. 2013-009541 (Patent Document 1). This publication states that "In a magnet motor 1 equipped with a stator 10 having a plurality of slots 14 formed in a stator core 13 and teeth 12 on which concentrated armature windings 15 are wound, and a rotor 30 configured by radially arranging permanent magnets that form magnetic poles, the inner surfaces of the teeth 12 are formed into a non-concentric shape 17 that is convex toward the rotor 30, and beveling 16 is applied to the circumferential ends of this non-concentric shape 17" (see abstract). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-009541 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 describes that it is possible to provide a magnet motor (rotating electric machine) that can reduce noise while maintaining characteristics even when using ferrite magnets (see paragraph

[0011] of Patent Document 1). On the other hand, there is also a challenge to develop low-cost, high-performance motors to meet potential needs. Furthermore, improving productivity is important for mass-produced products. Here, increasing the thickness of the steel plate used for the stator core not only reduces costs, but also improves productivity by reducing the number of times the die is punched.

[0006] However, when the thickness of a steel sheet is increased, a beveled shape such as that described in Patent Document 1 may result in the formation of thin-walled portions that are thinner than the sheet thickness. This may cause damage to dies such as punches. On the other hand, while it is possible to reduce dies damage by minimizing the beveling and eliminating such thin-walled portions, this presents a problem in that the effect of suppressing pulsating torque is reduced.

[0007] Therefore, an object of the present invention is to provide a rotating electric machine that is low cost, has good productivity, and can achieve low noise by reducing pulsating torque, and a washing machine equipped with the same. [Means for solving the problem]

[0008] In order to achieve the above object, the rotating electric machine according to the present invention has a stator core in which a plurality of steel plates are laminated. , and a resin insulating base and a rotor arranged to rotate relative to the stator. 、 The stator core has an armature winding Through the insulating substrate With teeth to be wound the insulating base has a first inclined portion and a second inclined portion in a portion where the armature winding is wound, the first inclined portion is inclined so that the width of the first inclined portion on the inner diameter side is shorter than the width of the outer diameter side in a cross section obtained by cutting the insulating base along a plane perpendicular to the central axis of the stator core, and the second inclined portion is inclined so that the width of the second inclined portion on the inner diameter side is longer than the width of the outer diameter side in a cross section obtained by cutting the insulating base along the central axis of the stator core, The tip surfaces of the teeth have a non-concentric shape that is convex toward the rotor. 、 A plurality of holes are formed at the tip end of each tooth and aligned in the width direction of the tooth. A washing machine according to the present invention is configured using the rotating electric machine. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a rotating electric machine that is low cost, has good productivity, and can achieve low noise by reducing pulsating torque, and a washing machine equipped with the same. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an external perspective view of a drum-type washer / dryer as a washing machine according to an embodiment of the present invention. [Figure 2] 1 is a longitudinal cross-sectional view taken along a rotation shaft of an electric motor according to an embodiment of the present invention. [Figure 3] FIG. 3 is a partially enlarged cross-sectional view taken along line AA in FIG. 2. [Figure 4] 3A and 3B are an enlarged longitudinal sectional view and an enlarged front view of a rotor. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] 6 is a partially enlarged view seen from the direction of arrow B in FIG. 5. [Figure 8] FIG. 8 is a partial cross-sectional view taken along line CC in FIG. 7. [Figure 9] FIG. 8 is a partial cross-sectional view taken along line DD in FIG. 7. [Figure 10] 4 is an enlarged view of the vicinity of the tip of the tooth shown in FIG. 3. [Figure 11] 10 is a graph showing the analysis results showing the relationship between each parameter of hole pitch ratio, hole length ratio, hole width ratio, and hole arrangement height ratio and the sensitivity of pulsating torque during washing operation. [Figure 12] 10 is a graph showing torque waveforms when analyses are performed with and without holes. [Figure 13] FIG. 2 is an enlarged view of the vicinity of the tip of a tooth having a flat portion. [Figure 14] 10 is a graph showing an analysis result showing the relationship between the flat portion length ratio and the pulsating torque. [Figure 15] 10 is a graph showing torque waveforms analyzed when a flat portion is provided and when a flat portion is not provided. [Figure 16] FIG. 4 is an enlarged view of the teeth shown in FIG. 3. [Figure 17]10 is a graph showing analysis results illustrating the relationship between the sensitivity of pulsating torque and each of the parameters of the outer diameter side angle ratio, the inner diameter side angle ratio, the tip angle ratio, and the inner diameter side corner radius. [Figure 18] 17 is a graph showing torque waveforms analyzed in the case of the present embodiment shown in FIG. 16 and in the case of a comparative example in which no hole is formed and beveling is performed. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. In each drawing, common components or components of the same type are denoted by the same reference numerals, and redundant explanations thereof will be omitted as appropriate.

[0012] FIG. 1 is a perspective view showing the appearance of a drum-type washer / dryer 400 as a washing machine according to an embodiment of the present invention. First, the overall configuration of the washer / dryer 400 according to this embodiment will be described, and then the electric motor 1 as a rotating electric machine mounted in the washer / dryer 400 will be described.

[0013] The washer-dryer 400 includes a substantially box-shaped housing 401 that forms the outer shell of the washer-dryer 400. The housing 401 is attached to a synthetic resin base 402 that supports the housing 401. In FIG. 1, a top cover (not shown), a front cover (not shown), and a lower front cover (not shown) that constitute the housing 401 are shown removed in order to show the internal structure of the housing 401 of the washer-dryer 400. In FIG. 1, reference numeral 406 denotes a side panel that constitutes the housing 401, and reference numeral 407 denotes a rear cover.

[0014] In this washer-dryer 400, laundry such as clothes is loaded into and unloaded from drum 404 through opening 408 provided in the approximate center of the front surface. Opening 408 can be opened and closed by door 403 that rotates around a hinge (not shown).

[0015] Drum 404 is a rotatably supported cylindrical drum with a bottom, and has a number of through-holes in its outer peripheral wall and bottom wall for water and ventilation. The rotation axis of drum 404 is horizontal or inclined so that the opening 408 side is higher.

[0016] The outer tub 405 is formed in a cylindrical shape and contains the drum 404 coaxially therewith. The drum 404 contained within the outer tub 405 functions as a washing chamber, a spin-drying chamber, and a drying chamber. An outer tub cover (not shown) made of synthetic resin is provided over the opening in the front of the outer tub 405, allowing water to be stored in the outer tub 405. A drain outlet (not shown) is provided on the bottom of the outer tub 405.

[0017] The outer tub 405 is supported in a vibration-isolating manner by a suspension 409 (comprising a coil spring and a damper) fixed to the base 402 at its lower side. The upper side of the outer tub 405 is supported by an auxiliary spring (not shown) attached to an upper reinforcing member 410, and this auxiliary spring prevents the outer tub 405 from tipping over in the front-to-rear direction.

[0018] In such a washer-dryer 400, wash water is stored in outer tub 405, and drum 404 is rotationally driven by motor 1, which will be described next, to wash laundry. After washing is completed, in washer-dryer 400, motor 1 rotationally drives drum 404 when rinsing, spin-drying, and drying are performed.

[0019] Next, the electric motor 1 according to this embodiment will be described in more detail. As shown in Fig. 1, the electric motor 1 is disposed at the outer center of the rear end face of the outer tub 405. In Fig. 1, the outline (contour) of the electric motor 1 as viewed from the direction of its rotational axis (extension direction of the rotational axis) is shown by a hidden line (dashed line). The rotational axis of the electric motor 1 passes through the outer tub 405 and is connected to the drum 404.

[0020] FIG. 2 is a vertical cross-sectional view taken along a rotation shaft 320 of the electric motor 1 according to the embodiment of the present invention. As shown in FIG. 2, the electric motor 1 is attached to the bottom (outer tub base) side of the outer tub 405 (see FIG. 1) via a stator base 300 using fasteners such as screws (not shown). The stator base 300 is mainly composed of a flange portion 300a attached to the outer tub 405 and a body portion 300b in which the rotary shaft 320 of the electric motor 1 is housed.

[0021] A water seal 311 is press-fitted into the inside of a boss 310 provided on the body 300b on the side that penetrates the bottom of the outer tub 405 (see FIG. 1). This water seal 311 prevents cleaning water in the outer tub 405 from leaking out of the outer tub 405 via the electric motor 1.

[0022] Bearings 313a and 313b that support the rotation of rotating shaft 320 are housed inside body portion 300b. Rotating shaft 320 extends within body portion 300b away from outer tank 405 (see FIG. 1), and the tip of rotating shaft 320 protruding from body portion 300b is inserted into rotor 200, which will be described later. A threaded portion is formed at the tip of rotating shaft 320, and rotor 200 is attached to rotating shaft 320 by nut 314 that screws into this threaded portion.

[0023] As will be described later, the stator 100, which will be disposed radially outside the rotor 200, is fixed to the flange portion 300a with screws 315. Attached to the stator 100 are a Hall IC holder 101 (see FIG. 5) for detecting the magnetic pole position of the rotor 200 and a thermal protector holder (not shown) equipped with a thermal protector that detects heat generation in the windings. The Hall IC holder detects the magnetic flux on the end face of the rotor 200 to detect the polarity and position. The thermal protector holder is configured to cut off the power supply to the windings when the motor 1 is overloaded. A flange 316 for mounting the drum 404 is fitted and fixed to the rotating shaft 320 .

[0024] Fig. 3 is a partially enlarged cross-sectional view taken along line AA in Fig. 2. Fig. 4 is an enlarged longitudinal cross-sectional view and an enlarged front view of rotor 200. In Fig. 4, reference numeral 4A indicates an enlarged longitudinal cross-sectional view of rotor 200, and reference numeral 4B indicates an enlarged front view of rotor 200 (an enlarged view seen from the right side of Fig. 2). As shown in FIG. 3, rotor 200 fixed to rotating shaft 320 (see FIG. 2) is disposed inside stator 100.

[0025] The stator 100 includes a stator core 140 formed by laminating multiple electromagnetic steel plates. The stator core 140 has an annular back yoke 130 and multiple teeth 120 serving as fixed magnetic poles provided on the back yoke 130. Armature windings (stator coils) 110 are wound around the teeth 120. The stator core 140 is formed by bending the multiple straight teeth 120 and back yoke 130 into an arc shape, and is fitted into a metal stator flange 160. The armature windings 110, which are three-phase windings (concentrated windings), are wound in multiple slots 141 formed in the stator core 140.

[0026] Tip surfaces 121 of teeth 120 have a non-concentric shape that protrudes toward rotor 200. A non-concentric shape refers to a shape that is not an arc shape centered on rotation shaft 320 of electric motor 1. Tips of teeth 120 are provided with protruding portions 122 that protrude in the circumferential direction.

[0027] The rotor 200 is arranged to rotate relative to the stator 100. The rotor 200 has a rotor core 210 and a plurality of permanent magnet pieces 220 arranged alternately to form a ring shape radially from the center of the rotation shaft 320 (see FIG. 2). Because the radially extending permanent magnet pieces 220 are long, the required torque characteristics can be obtained even when using, for example, a ferrite magnet.

[0028] Rotor core 210 is formed by laminating multiple electromagnetic steel plates. Tip surface 211 of rotor core 210 has a non-concentric shape that is convex toward stator 100. By making tip surfaces 121 of teeth 120 and tip surface 211 of rotor core 210 have a non-concentric shape that is convex toward each other, noise is reduced.

[0029] The number of teeth 120 serving as fixed magnetic poles in the stator 100 in this embodiment is 42. The number of permanent magnet pieces 220 and rotor cores 210 serving as rotating magnetic poles in the rotor 200 in this embodiment is 56. Reference numeral 275 denotes a molding resin that is filled when the rotor 200 is insert-molded in a predetermined mold.

[0030] Here, the permanent magnet piece 220 uses a magnet element in an unmagnetized state, and the permanent magnet piece 220 is not magnetized when it is assembled. This prevents overlooking the magnetization direction of the permanent magnet piece 220 or making an incorrect insertion, and there is no risk of the permanent magnet piece 220 being assembled with the wrong magnetization direction.

[0031] The permanent magnet pieces 220 use ferrite as the magnetic elements, achieving a thin, lightweight, and high torque. The permanent magnet pieces 220 are sandwiched between the rotor core 210 to form a ring shape, and then the rotor core 210 and the permanent magnet pieces 220 are molded with resin 270 to form an integrated unit. A hole 230 is provided in the center of the rotor core 210. The resin 270 is filled into this hole 230 and fused.

[0032] 4, boss portion 261 and core support base 262 are also molded with resin 275 to integrate rotor 200. Note that a keyhole-shaped recess 235 is provided at the end of rotor core 210. Resin 275 is filled into recess 235 and fused thereto.

[0033] 3, between adjacent rotor cores 210, an air gap 240 is formed on the outer diameter side of the permanent magnet pieces 220 (the side facing the stator), and an air gap 250 is formed on the inner diameter side of the permanent magnet pieces 220. In other words, each permanent magnet piece 220 is structured so that both the outer diameter side and the inner diameter side do not come into contact with the rotor core 210. These air gaps 240 and 250 act to reduce leakage magnetic flux of the permanent magnet pieces 220.

[0034] Resin 270 is filled and fused into these gaps 240 and 250. In other words, the permanent magnet pieces 220 are sandwiched between the rotor core 210 on both sides in the rotation direction, and are also supported in the radial direction by the resin 270.

[0035] FIG. 5 is an enlarged front view of the stator 100, and FIG. 6 is an enlarged rear view of the stator 100. As shown in FIG. 5 and 6, the stator 100 includes a metal stator flange 160 that houses the stator core 140 (see FIG. 3), and a resin insulating base 150 that is provided on the radially inner side (one side) of the stator flange 160. The insulating base 150 is formed for winding the armature winding 110, and covers the periphery of the stator core 140 (see FIG. 3).

[0036] The stator 100 also includes a mounting base forming portion 170 provided on the radially outer side (the other side) of the stator flange 160. The mounting base forming portion 170 has a fastening portion 171 for fastening to another member. The mounting base forming portion 170 is formed of the same resin as the insulating base 150. The fastening portion 171 is formed with an insertion portion 172 and an insertion portion 173. A screw 315 (see FIG. 2) used to fasten the stator 100 to a stator base 300 (see FIG. 2) is inserted into the insertion portion 172. A screw (not shown) used to fasten a motor cover (not shown) to the stator 100 is inserted into the insertion portion 173. The fastening portion 171 also includes a mounting seat surface 174 for mounting to the stator base 300 (see FIG. 2).

[0037] The mounting base forming portion 170 is separated from the insulating base 150. In other words, the insulating base 150 and the mounting base forming portion 170 are molded physically separate and do not contact each other. In this case, the insulating base 150 and the mounting base forming portion may be formed in a single molding operation, or may be formed by molding in two separate operations.

[0038] The mounting base forming portion 170 may have an annular portion 175 having an annular shape. In this case, the fastening portions 171 are provided at a plurality of locations on the annular portion 175. That is, the fastening portions 171 are connected to each other by the annular portions 175 along the stator flange 160. The annular portion 175 between the plurality of fastening portions 171 is provided with recesses 176 formed so as to be partially recessed radially inward.

[0039] In addition to the Hall IC holder 101, a power terminal block 102 and a neutral terminal block 103 are attached to the stator 100.

[0040] FIG. 7 is a partially enlarged view seen from the direction of arrow B in FIG. 5. FIG. 8 is a partial cross-sectional view taken along line CC in FIG. 7. In FIG. 8, reference numeral 8A indicates a state before the armature winding 110 is wound, reference numeral 8B indicates a state in which the first layer of the armature winding 110 is wound, and reference numeral 8C indicates a state in which the second layer of the armature winding 110 is wound. FIG. 9 is a partial cross-sectional view taken along line DD in FIG. 7. In FIG. 9, reference numeral 9A indicates a state before the armature winding 110 is wound, reference numeral 9B indicates a state in which the first layer of the armature winding 110 is wound, and reference numeral 9C indicates a state in which the second layer of the armature winding 110 is wound.

[0041] As shown in FIGS. 7 to 9, an insulating substrate 150 made of resin is provided on the teeth 120 of the stator 100 so as to cover the teeth 120. As shown in FIG. 8, in a cross section when the insulating substrate 150 is cut by a plane perpendicular to the central axis of the stator core 140, the insulating substrate 150 has a first inclined portion 151 whose width dimension changes in a portion where the armature winding 110 is wound. Further, as shown in FIG. 9, in a cross section when the insulating substrate 150 is cut by a plane along the central axis of the stator core 140, the insulating substrate 150 has a second inclined portion 152 whose width dimension changes in a portion where the armature winding 110 is wound.

[0042] Here, as shown by reference numeral 8A in FIG. 8, let the width on the outer diameter side of the first inclined portion 151 be W1, and the width on the inner diameter side of the first inclined portion 151 be W2. Further, as shown by reference numeral 9A in FIG. 9, let the width on the outer diameter side of the second inclined portion 152 be H1, and the width on the inner diameter side of the second inclined portion 152 be H2. At this time, in the present embodiment, it is set such that W1 > W2 and H1 < H2.

[0043] FIG. 10 is an enlarged view of the vicinity of the tip of the tooth 120 shown in FIG. 3. In the present embodiment, as shown in FIG. 10, a plurality of holes 123 arranged in the width direction of the tooth 120 are provided at the tip of the tooth 120.

[0044] When the motor 1 of the washing and drying machine 400 operates in a high load region, if there are no holes 123, the pulsating torque tends to increase. This is because as the load torque increases, the current value increases and the amount of change in the magnetic flux density increases, so that a steep change in the magnetic flux density occurs, resulting in an increase in the pulsating torque. Here, by adding the holes 123 for magnetic flux suppression as shown in FIG. 10, the flow of the magnetic flux is restricted and the maximum value of the electromagnetic force of each tooth 120 is restricted, so that the pulsating torque generated by the sum thereof can be suppressed. Furthermore, because there is no need to bevel the tips of teeth 120 as in the past, even if the thickness of the electromagnetic steel sheet is increased, there is no risk of thin-walled portions that are thinner than the sheet thickness. As a result, by increasing the thickness of the electromagnetic steel sheet used for stator core 140, costs can be reduced and productivity can be improved by reducing the number of times a die is punched. Therefore, according to this embodiment, it is possible to achieve low cost, good productivity, and low noise due to reduced pulsating torque.

[0045] In this embodiment, a pair of holes 123 are provided. Here, the pitch between the pair of holes 123 is defined as L1, the length of the holes 123 in the radial direction of the stator 100 (see FIG. 3) is defined as L2, and the width (length) of the holes 123 in the width direction of the teeth 120 is defined as L3. Also, the shortest distance from the tip surfaces 121 of the teeth 120 to the inner surfaces of the holes 123 is defined as L4, the width of the tips of the teeth 120 is defined as L, and the thickness of one of the multiple electromagnetic steel sheets that make up the stator core 140 is defined as t.

[0046] Figure 11 is a graph of the analysis results showing the relationship between each parameter, i.e., hole pitch ratio (L1 / L), hole length ratio (L2 / t), hole width ratio (L3 / t), and hole arrangement height ratio (L4 / t), and the sensitivity (dB) of pulsating torque during washing operation. The larger the sensitivity (dB) value, the larger the pulsating torque. The "average value" shown in Figure 11 indicates the average value for all cases in this analysis. Note that a reduction in pulsating torque was achieved in all cases in this analysis. Figure 11 shows the degree of influence of each parameter on the sensitivity (dB) of pulsating torque.

[0047] It is preferable to set each parameter within the following range depending on the mold structure and productivity. As shown in Figure 11, the analysis results showed that the pulsating torque is reduced as the hole pitch ratio (L1 / L) is reduced. The optimal value of the hole pitch ratio (L1 / L) can be selected within the range of 0.19 to 0.39. The hole length ratio (L2 / t) can be selected within the range of 2 to 3 to reduce the pulsating torque. The hole width ratio (L3 / t) can be specified within the range of 1.5 to 2.5 to reduce the pulsating torque. The analysis results showed that the pulsating torque is reduced as the hole arrangement height ratio (L4 / t) is increased. Selecting the optimal hole arrangement height ratio (L4 / t) within the range of 1 to 1.4 is highly effective in reducing the pulsating torque.

[0048] In this embodiment, the hole pitch ratio (L1 / L) is set within the range of 0.19 to 0.39, the hole length ratio (L2 / t) is set within the range of 2 to 3, the hole width ratio (L3 / t) is set within the range of 1.5 to 2.5, and the hole arrangement height ratio (L4 / t) is set within the range of 1 to 1.4. In the present invention, P to Q (P and Q are numerical values) mean P or more and Q or less.

[0049] 12 is a graph showing torque waveforms obtained by performing an analysis with and without holes 123. When holes 123 are provided, each parameter is set within the ranges described above. The vertical axis represents the normalized torque during the wash operation. The horizontal axis represents the rotation angle (mechanical angle) when rotor 200 (see FIG. 3) rotates. 12, by arranging holes 123 within the above-mentioned range, it is possible to suppress excessive magnetic flux flow and reduce the peak torque value under high load. Furthermore, by setting each parameter according to the thickness of the electromagnetic steel sheet used in stator core 140, it is possible to reduce costs and improve productivity.

[0050] Next, a method for reducing pulsating torque in the high speed rotation region will be described. FIG. 13 is an enlarged view of the vicinity of the tip of the tooth 120 having the flat portion 124. 13, a flat portion 124 is formed on a tip surface 121 of each tooth 120. Here, the width of the tip of each tooth 120 is L, and the length of the flat portion of each tooth 120 in the width direction is X1.

[0051] In this embodiment, the flat portion length ratio (X1 / L) is set to a range greater than 0 and equal to or less than 0.37. The flat portion 124 is formed by cutting the tip surface 121 of the tooth 120, which has a convex, non-concentric shape, flat. Here, the gap 201 (see FIG. 3) between the flat portion 124 and the rotor 200 is kept within a predetermined range. The predetermined range is set to, for example, 0.55 to 0.65 mm from the viewpoints of preventing contact and ensuring the required torque.

[0052] Fig. 14 is a graph of the analysis results showing the relationship between the flat portion length ratio (X1 / L) and pulsating torque. Fig. 14 shows the effect of reducing pulsating torque by providing flat portions 124 on the tip surfaces 121 of the teeth 120. The pulsating torque is the difference between the maximum and minimum values ​​of the torque waveform. As shown in Fig. 14, it can be seen that the pulsating torque is smaller when flat portions 124 are provided than when the tip surfaces 121 of the teeth 120 are simply made non-concentrically convex, i.e., when the flat portion length ratio (X1 / L) = 0.

[0053] Fig. 15 is a graph showing the torque waveforms analyzed when the flat portion 124 is provided and when the flat portion 124 is not provided. When the flat portion 124 is provided, the flat portion length ratio (X1 / L) is set within the range described above. The vertical axis represents the result of normalizing the torque during dehydration operation. The horizontal axis represents the rotation angle (mechanical angle) when the rotor 200 (see Fig. 3) rotates.

[0054] As shown in FIG. 15, by widening the air gap by cutting the tip end surfaces 121 of the teeth 120 flat, the peak value of the torque generated by the non-concentric convex shape is suppressed, and pulsating torque is reduced.

[0055] This analysis was performed on a shape in which there are no holes 123 at the tips of the teeth 120 and the protruding portions 122 are beveled 125, as shown in Fig. 13. However, a similar effect can be expected even in the case of a shape in which the tips of the teeth 120 have holes 123, as shown in Fig. 10.

[0056] FIG. 16 is an enlarged view of the tooth 120 shown in FIG. Next, in order to reduce pulsating torque during high-speed spin-drying, optimization of the shape of the tip of the teeth 120 was investigated. The electromagnetic steel sheets that make up the stator core 140 having the teeth 120 are formed by punching using a die including a punch. However, due to the structure of the die, if there are thin portions at the tips of the teeth 120, this could lead to damage to the die. For this reason, it is desirable to design the shape of the tips of the teeth 120 so that performance can be achieved regardless of the shape of the die.

[0057] In this embodiment, the protruding portions 122 provided at the tips of the teeth 120 and protruding in the circumferential direction are made thick. As a result, the shape of the tips of the teeth 120 that reduces pulsation torque is optimized by analysis using experimental design, regardless of the shape of the mold.

[0058] Here, the pitch angle of the stator 100 (teeth 120) is θ, and the circumferential angle of the tip end of the tooth 120 including the protruding portion 122 is θ3. Also, the circumferential angle on the outer diameter side corresponding to the portion of the tooth 120 where the armature winding 110 (see FIG. 3) is wound is θ1, and the circumferential angle on the inner diameter side corresponding to the portion of the tooth 120 where the armature winding 110 is wound is θ2. Also, the radius of curvature of the corner on the inner diameter side of the tooth 120 located at the base of the protruding portion 122 is R.

[0059] Figure 17 is a graph of the analysis results showing the relationship between each parameter, namely the outer diameter side angle ratio (θ1 / θ), inner diameter side angle ratio (θ2 / θ), tip end angle ratio (θ3 / θ), and inner diameter side corner radius (R), and the sensitivity (dB) to pulsating torque. The larger the sensitivity (dB) value, the larger the pulsating torque will be. The "average value" shown in Figure 17 indicates the average value for all cases in this analysis. Note that a reduction in pulsating torque was achieved in all cases in this analysis. Figure 17 shows the degree of influence that each parameter has on the sensitivity (dB) to pulsating torque.

[0060] It can be seen that changes in the outer diameter side angle ratio (θ1 / θ), inner diameter side angle ratio (θ2 / θ), and inner diameter side corner radius (R) do not significantly affect pulsating torque. The tip side angle ratio (θ3 / θ) can be selected to an optimum value within the range of 1.10 to 1.33. Therefore, in this embodiment, the tip angle ratio (θ3 / θ) is set within the range of 1.10 to 1.33.

[0061] FIG. 18 is a graph showing the torque waveforms analyzed for the present embodiment shown in FIG. 16 and a comparative example in which there are no holes 123 and beveling 125 (see FIG. 13). In the present embodiment shown in FIG. 16, the tip angle ratio (θ3 / θ) is set within the above range. The vertical axis represents the result of normalizing the torque during dehydration operation. The horizontal axis represents the rotation angle (mechanical angle) when rotor 200 (see FIG. 3) rotates.

[0062] In the comparative example, the pulsating components of the magnet torque and reluctance torque are in phase, but in the present embodiment, the provision of holes 123 causes the magnet torque and reluctance torque to be in opposite phase in the region where the magnetic flux density is saturated. For this reason, as shown in Fig. 18, in the present embodiment, it is possible to reduce the pulsating torque more than in the comparative example.

[0063] Also, in the present embodiment, as shown in FIGS. 7 and 8, in the cross section when the insulating substrate 150 is cut along a plane perpendicular to the central axis of the stator core 140, the insulating substrate 150 has a first inclined portion 151. Further, as shown in FIGS. 7 and 9, in the cross section when the insulating substrate 150 is cut along a plane along the central axis of the stator core 140, the insulating substrate 150 has a second inclined portion 152. When the width on the outer diameter side of the first inclined portion 151 is W1, the width on the inner diameter side of the first inclined portion 151 is W2, the width on the outer diameter side of the second inclined portion 152 is H1, and the width on the inner diameter side of the second inclined portion 152 is H2, it is set such that W1>W2 and H1<H2.

[0064] In this configuration, the directions in which the armature winding 110 is likely to shift during winding are opposite between the first inclined portion 151 and the second inclined portion 152 and cancel each other out. As a result, the position of the armature winding 110 can be stabilized and the armature winding 110 is aligned. Therefore, spillage of the armature winding 110 can be easily prevented.

[0065] Also, since the ratio (occupation ratio) of the armature winding 110 with respect to the slot 141 (see FIG. 3) can be improved, the loss due to the armature winding 110 is reduced, and a highly efficient motor 1 can be provided. Also, excessive stress during winding required to align the armature winding 110 can be alleviated. For this reason, insulation failure due to damage to the insulating substrate 150 on the surface of the armature winding 110 and elongation of the conductor portion can be suppressed, and a high-quality motor 1 with high reliability can be provided. Furthermore, in this configuration, the same effect can be obtained even if the wire diameter of the armature winding 110 used is different. For this reason, by standardizing the insulating substrate 150 and winding armature windings with different wire diameters, motors of a plurality of specifications with different performances can be provided at low cost.

[0066] In the above-described embodiment, W1>W2 and H1<H2 are set, but W1<W2 and H1>H2 may also be set. Even with such a configuration, similar effects can be obtained. Further, in the above-described embodiment, the insulating substrate 150 is integrally formed with the stator core 140, but it is not limited thereto. The insulating substrate 150 may be configured to be fitted as a pair of parts divided in the axial direction of the stator core 140.

[0067] Also, in the present embodiment, the electric motor 1 includes a stator flange 160, an insulating substrate 150, and a mounting substrate forming portion 170. The stator flange 160 is made of metal and houses the stator core 140. The insulating substrate 150 is made of resin and is provided on the inner side in the radial direction of the stator flange 160. The mounting substrate forming portion 170 is made of resin and is provided on the outer side in the radial direction of the stator flange 160 and has a fastening portion 171 for fastening to other members. And the mounting substrate forming portion 170 is separated from the insulating substrate 150.

[0068] When the insulating substrate 150 and the mounting substrate forming portion 170 are integrally formed and connected, the stress due to the molding shrinkage applied to the stator core 140 is unevenly applied at the number of locations (six locations in this embodiment) where the fastening portion 171 is arranged. However, in the present embodiment, since the mounting substrate forming portion 170 is separated, a stress due to uniform molding shrinkage (forty-two locations, which is the number of locations where the teeth 120 are arranged in this embodiment) is applied to the insulating substrate 150. As a result, the mounting substrate forming portion 170 can be provided while maintaining the high-precision inner diameter dimension of the stator core 140 in a state where the stator core 140 is press-fitted and housed in the stator flange 160. Therefore, the roundness of the stator core 140 can be improved. And by improving the roundness of the stator core 140, an electric motor 1 with low vibration and low noise can be provided.

[0069] In this embodiment, the mounting base forming portion 170 has an annular portion 175, the fastening portions 171 are provided at a plurality of locations on the annular portion 175, and recesses 176 are provided in the annular portion 175 between the plurality of fastening portions 171. With this configuration, it is possible to protect the stator flange 160 and improve formability, and the recesses 176 can also relieve stress caused by molding shrinkage of the mounting base forming portion 170.

[0070] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to add, delete, or replace part of the configuration of the above-described embodiments with other configurations.

[0071] For example, in the above embodiment, the electric motor 1 is described as being arranged such that the stator 100 is disposed radially outside the rotor 200, but the present invention is not limited to this. The present invention is also applicable to the case where the rotor 200 is disposed radially outside the stator 100. In the above embodiment, the rotating electric machine is the electric motor 1, but the present invention is not limited to this. The present invention is also applicable to a case where the rotating electric machine is a generator. [Explanation of symbols]

[0072] 1. Electric motor (rotating electric motor) 100 stator 110 Armature Winding 120 Teeth 121 Tip surface 122 Protruding shape part 123 holes 124 Plane section 130 Back Yoke 140 Stator core 150 Insulating substrate 151 1st slope 152 2nd slope part 160 Stator flange 170 Mounting base forming section 171 Fastening part 175 Annular part 176 Recess 200 rotors 210 Rotor core 211 Tip surface 220 Permanent magnet piece 270 Resin 275 Resin 320 Rotational Axis 300 Stator base (other parts) 400 Washer / Dryer (Washing Machine)

Claims

1. a stator having a stator core made of a plurality of laminated steel plates and an insulating base made of resin; a rotor configured to rotate relative to the stator, the stator core has a plurality of teeth around which an armature winding is wound via the insulating base; the insulating base has a first inclined portion and a second inclined portion at a portion where the armature winding is wound, the first inclined portion is inclined such that a width of the first inclined portion on an inner diameter side is shorter than a width of the first inclined portion on an outer diameter side in a cross section obtained by cutting the insulating base along a plane perpendicular to a central axis of the stator core, the second inclined portion is inclined such that a width on an inner diameter side of the second inclined portion is longer than a width on an outer diameter side of the second inclined portion in a cross section obtained by cutting the insulating base along a plane along a central axis of the stator core, The tip surfaces of the teeth have a non-concentric shape that is convex toward the rotor, A rotating electric machine characterized in that a plurality of holes are provided at the tip portions of the teeth and aligned in the width direction of the teeth.

2. The holes are provided in pairs, The pitch of the pair of holes is L1, The length of the hole in the radial direction of the stator is L2, The width of the hole in the width direction of the teeth is L3, The shortest distance from the tip surface of the tooth to the inner surface of the hole is L4. The width of the tip of the teeth is L, When the thickness of one steel plate is t, L1 / L is 0.19 to 0.39, L2 / t is 2 to 3, L3 / t is 1.5 to 2.5, L4 / t is 1 to 1.4, 2. The rotating electric machine according to claim 1, wherein the respective values ​​are set within the ranges of .

3. A flat portion is formed on the tip surface of the tooth, The width of the tip of the teeth is L, When the length of the flat portion in the width direction of the tooth is X1, The gap between the flat portion and the rotor is maintained within a predetermined range, 2. The rotating electric machine according to claim 1, wherein X1 / L is set within a range greater than 0 and equal to or less than 0.

37.

4. The pitch angle of the stator is θ, When the circumferential angle of the tip of the tooth is θ3, 2. The rotating electric machine according to claim 1, wherein θ3 / θ is set within a range of 1.10 to 1.

33.

5. The rotor is configured such that a plurality of rotor cores and permanent magnet pieces are alternately arranged radially from the center of the rotation shaft to form a ring shape, 2. The rotating electric machine according to claim 1, wherein a tip end surface of the rotor core has a non-concentric shape that is convex toward the stator side.

6. The rotor is configured such that a plurality of rotor cores and permanent magnet pieces are alternately arranged radially from the center of the rotation shaft to form a ring shape, 2. The rotating electric machine according to claim 1, wherein the rotor core and the permanent magnet pieces are integrally formed by molding with resin.

7. A washing machine using the rotating electric machine according to any one of claims 1 to 6.

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