JP2009254025A - Cylindrical linear motor and its manufacturing method - Google Patents

Abstract

A linear motor with improved heat dissipation and a method for manufacturing the same are provided.
A linear motor 100 includes a cylindrical stator 110 and a movable element 130 that is disposed on the inner periphery of the stator 110 and that is movable in the axial direction of the cylindrical shape. The stator 110 is formed in an annular shape and a plurality of divided stator cores 114T in a direction perpendicular to the cylindrical axial direction, and is formed when a plurality of divided stator cores are combined. The stator coil 114C disposed in each of the plurality of slots is filled between the strands constituting the stator coil 114C, and one stator coil is formed into one divided stator core by pressure molding. And a thermally conductive insulating resin 114R that is filled and fixed.
[Selection] Figure 5

Description

  The present invention relates to a linear motor and a method for manufacturing the same, and more particularly to a cylindrical linear motor suitable for use as a suspension for railways, automobiles, and the like, and a method for manufacturing the same.

  In recent years, cylindrical motors are known among linear motors (see, for example, Patent Document 1 and Patent Document 2).

  On the other hand, in general rotating electrical machines, an insulation sheet (also called slot insulation, insulation film, liner, etc.), slots for bobbins, epoxy plates, adhesives, etc. are used between the winding and the stator core to ensure insulation performance. An insulator is disposed (see, for example, Patent Document 3).

JP 2006-87272 A JP 2003-158842 A JP 2004-376187 A

  Generally, an electric motor generates heat in a coil (winding, armature coil) portion when energized. The generated heat is conducted to the stator core (stator core) through the enamel coating, resin, slot insulator, etc., and is released to the outside on the surface of the stator core.

  Moreover, in a general rotary electric motor, since the coil is wound around the salient pole of the stator core, there is a coil end portion protruding from the end portion of the stator core. Therefore, it is possible to release the heat of the coil by cooling the coil end part with air or liquid.

  However, in a cylindrical linear motor, there is no coil end portion, and the coil is covered with a stator core. That is, it is a semi-closed cylindrical linear motor. Therefore, in the case of a cylindrical linear motor, the heat generated by the coil is only released from the surface of the stator core. Here, as described above, a slot insulator having low thermal conductivity exists between the coil and the stator core, so that there is a problem that heat dissipation characteristics are poor. When the heat dissipation characteristics are low, the energization current cannot be increased, and it is difficult to achieve high output and compactness.

  An object of the present invention is to provide a linear motor with improved heat dissipation and a method for manufacturing the same.

(1) In order to achieve the above object, the present invention provides a linear motor having a cylindrical stator and a movable element that is disposed on the inner periphery of the stator and that is movable in the axial direction of the cylindrical shape. The stator is formed into a plurality of divided stator cores and an annular shape in a direction perpendicular to the axial direction of the cylindrical shape, and the plurality of divided stator cores are combined. The stator coils respectively disposed in a plurality of slots formed at the time of filling and the strands constituting the stator coils are filled, and one stator coil is connected to one split stator. A heat conductive insulating resin that is filled and fixed to the core by pressure molding is provided.
With this configuration, the heat dissipation of the linear motor can be improved.

  (2) In the above (1), preferably, the thermally conductive insulating resin is obtained by kneading a non-magnetic powder in a resin.

  (3) In the above (1), preferably, the thermally conductive insulating resin includes a first thermally conductive insulating resin filled between strands constituting the stator coil, and one fixed It is made of a second heat conductive insulating resin for filling and fixing the child coil to one of the divided stator cores by pressure molding.

  (4) In the above (3), preferably, a convex portion is formed on the surface of the first thermally conductive insulating resin that faces the one divided stator core. is there.

  (5) In the above (1), preferably, the one stator coil is bonded to another one of the divided stator cores with an adhesive or is in close contact with a heat conductive sheet.

  (6) In the above (1), preferably, the heat conductive insulating resin constitutes a heat transfer path from a strand forming the armature coil to the split stator core on one side. .

(7) In order to achieve the above object, the present invention includes a cylindrical stator, and a movable element that is disposed on the inner periphery of the stator and that is movable in the axial direction of the cylindrical shape. A method for manufacturing a stator core in a linear motor, wherein the stator is formed in an annular shape with a plurality of divided stator cores divided in a direction perpendicular to the axial direction of the cylindrical shape, and The stator coils are arranged in a plurality of slots formed when a plurality of divided stator cores are combined, and the wires constituting the stator coils are impregnated with a heat conductive insulating resin. And a second step of filling and fixing one stator coil to one of the divided stator cores by pressure molding using a heat conductive insulating resin. .
With this configuration, the heat dissipation of the linear motor can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the heat dissipation of a linear motor can be improved.

  Hereinafter, the configuration and manufacturing method of a cylindrical linear motor according to an embodiment of the present invention will be described with reference to FIGS. Here, as a cylindrical linear motor, an electromagnetic suspension used for railways, automobiles, and the like will be described as an example.

First, the configuration of the cylindrical linear motor according to the present embodiment will be described with reference to FIGS.
FIG. 1 is a cross-sectional view showing a configuration of a cylindrical linear motor according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line AA in FIG.

  The cylindrical linear motor 100 according to the present embodiment is a permanent magnet type three-phase linear motor. The linear motor 100 includes a cylindrical stator 110 and a cylindrical movable element 130 slidably held inside the stator 110.

  The stator 110 includes a stator case 112, a stator core 114, a coil 114C, and a stator inner case 118. The stator case 112 has a bottomed cylindrical shape, and a mounting portion 150W is fixed to the outer end surface on the bottom side. In addition, an uneven portion (not shown) is formed on the outer periphery of the stator case 112 for heat dissipation. A stator core 114 is fixed on the inner peripheral side of the stator case 112. The stator case 112 has a cylindrical shape obtained by dividing a cylindrical shape with a bottom into two in the axial direction, and combining them at the dividing surface. Each component of the stator (a divided stator core 114T having a tooth portion (stator salient pole) described later, a coil 114C, and an auxiliary salient pole 114P) is disposed in one half of the stator case 112. Then, the stator is constructed by covering the remaining half of the stator case.

  The stator core 114 includes a split stator core 114T (114T1, 114T2,..., 114T10) having ten ring-shaped teeth (stator salient poles) and two ring-shaped auxiliary salient poles 114P (114P1). 114P2). The split stator core 114T and the auxiliary salient pole 114P are both made of iron.

  The divided stator core 114T is divided into a plurality of parts in a direction perpendicular to the axial direction of the cylindrical stator core 114. An auxiliary salient pole 114P1 is disposed on the surface opposite to the surface where the divided stator core 114T1 is in contact with the divided stator core 114T2. An auxiliary salient pole 114P2 is disposed on the surface opposite to the surface where the split stator core 114T10 contacts the split stator core 114T9. The auxiliary salient poles 114P1 and 114P2 are provided on both sides of the stator core, and smooth the change in magnetic flux at both ends of the stator core.

  Nine coils 114C (114C (U1 +), 114C (U2-), 114C (U3 +), 114C (V1 +), 114C (V2−) are included in nine slots formed by the adjacent divided stator cores 114T. ), 114V (V3 +), 114C (W1 +), 114C (W2-), 114C (W3 +)). For example, the coil 114C1 is disposed in a slot formed by the adjacent divided stator core 114T1 and the divided stator core 114T2.

The configuration between the 114C coil and 114 core will be described below.
Coils 114C (U1 +), 114C (U2-), 114C (U3 +) constitute a U-phase stator coil, and coils 114C (V1 +), 114C (V2-), 114V (V3 +) are V-phase stator coils. The coils 114C (W1 +), 114C (W2-), and 114C (W3 +) constitute a W-phase stator coil. Looking at the U-phase coil, the coil 114C (U1 +) and the coil 114C (U3 +) are wound in the same direction, current flows in the same direction, and the coil 114C (U2-) is opposite to the coil 114C (U1 +). Winding in the direction, current flows in the opposite direction.

  Further, a convex portion protruding in the direction of the arrow X is provided on the innermost peripheral side of the stator core tooth portion 114T, and the width of the slot entrance is shorter than the width of the coil 114C.

  Next, the mover 130 includes a mover case 132, a mover iron core 134, and eleven permanent magnets 136. The mover case 132 has a bottomed cylindrical shape, and the inner diameter thereof is larger than the outer diameter of the stator case 112. A mounting portion 150 </ b> B is fixed to the outer end surface on the bottom side of the mover case 132. The mover iron core 134 is fixed to the bottom of the mover case 132 and has a cylindrical shape. The eleven permanent magnets 136 have a ring shape and are attached to the outer peripheral side of the mover iron core 134 at regular intervals while being spaced apart from each other.

  In addition, magnetic pole position sensors 170W and 170B each including three Hall elements are provided in the vicinity of the outer periphery of the permanent magnet positioned on both ends of the mover 130. The three Hall elements detect the U-phase, V-phase, and W-phase magnetic pole positions, respectively. A stroke sensor stator 192 is provided at the end of the stator inner case 118 on the mover side, and a rod-shaped stroke sensor mover 194 is provided at the bottom of the mover case 132 of the mover 130. . The stroke sensor 190 is constituted by the stroke sensor stator 192 and the stroke sensor mover 194. The stroke sensor 190 is a linear sensor that detects the amount of movement of the mover 130 with respect to the stator 110 in the x direction. For example, the stroke sensor 190 detects the amount of movement (stroke) by a potentiometer method. The stroke sensor may be a non-contact sensor using reluctance. Furthermore, the stroke sensor can be substituted for the magnetic pole position sensor, and can also be used as an acceleration sensor.

  In the cylindrical linear motor including the stator 110 and the mover 130 described above, an electromagnetic suspension is configured by further including a control device that controls the current flowing through the coil 114C to control the generated thrust. The electromagnetic suspension is used for automobiles, railway vehicles, and the like, the attachment portion 150B is attached to the vehicle body side, and the attachment portion 150W is attached to the wheel side.

Here, the specific dimension of each part is demonstrated using FIG.
FIG. 3 is an enlarged view of a main part of FIG. The same reference numerals as those in FIG. 1 denote the same parts.

  The dimension of each part demonstrated below is a case of the electromagnetic suspension used for a motor vehicle. Stator 110 outer diameter R1, stator case 112 thickness T1, split stator core 114T tooth thickness radial direction T2, stator core teeth (stator salient pole) 114T2 axial direction (FIG. 1) , 114T9, the width of the tooth portions (stator salient poles) of the divided stator cores 114T1, 14T3,..., 114T9 is also L1. The axial length L2 of the tooth portion (stator salient pole) of the stator core 114T1 is half of the tooth portion of the stator core 114T2.

  When the axial length L3 of the yoke portion of the divided stator core 114T2 is assumed, the axial lengths of the yoke portions of the other divided stator cores 114T1, ..., 114T9 are also L3. When the axial length L4 of the auxiliary salient pole 114P1 is assumed, the axial length of the auxiliary salient pole 114P2 is also L4. The auxiliary salient poles 114P1 and 114P2 have a truncated cone shape, and the side in contact with the divided stator cores 114T1 and 114T10 has a cylindrical shape, the axial length L6 of the cylindrical portion, and the inner salient side of the auxiliary salient pole 114P1. The angle θ1 that the surface makes with the axial direction is 20 °. Assuming that the interval L5 between the adjacent convex portions 114TT1 and 114TT2 on the innermost peripheral side of the divided stator core 114T is the same, the interval between the other convex portions is also L5.

  The distance (gap length) G between the inner peripheral surface of the tooth portion of the split stator core 114T and the outer peripheral surface of the permanent magnet 136 of the mover 130 is 0.5 mm.

Next, the winding method of the 114C coil of the cylindrical linear motor used for the electromagnetic suspension of the present embodiment will be described with reference to FIG.
FIG. 4 is a plan view showing a configuration of a coil used in the cylindrical linear motor according to the embodiment of the present invention. Here, the U-phase coil will be described, but the same applies to other V-phase and W-phase coils.

  The U-phase coil includes coils 114C (U1 +), 114C (U2-), and 114C (U3 +). The coil 114C (U1 +) and the coil 114C (U3 +) are wound in the same direction, current flows in the same direction, and the coil 114C (U2-) is wound in the opposite direction to the coil 114C (U1 +). Current flows in the direction. Here, these three coils 114C (U1 +), 114C (U2-), 114C (U3 +) are continuously wound. In this way, by making the in-phase 114C coil continuously wound, the connection work of the 114C coil can be reduced, so that the productivity is improved. Further, the U-phase, V-phase, and W-phase three-phase windings are star (Y) connected. The above is the basic structure of the target cylindrical linear motor.

Next, the structure and manufacturing method of the stator in the cylindrical linear motor of this embodiment will be described with reference to FIGS.
Initially, the detailed structure of the stator in the cylindrical linear motor of this embodiment is demonstrated using FIG.
FIG. 5 is a cross-sectional view showing a detailed configuration of the stator in the cylindrical linear motor according to the embodiment of the present invention. FIG. 5A shows the configuration of the stator according to the present embodiment, and FIG. 5B shows the configuration of the stator of the comparative example.

  5A and 5B show the configuration in the vicinity of the split stator cores 114T2 and 114T3 and the stator coil 114C2 in the configuration shown in FIG. The configurations of 114T1 and 114T3 to 114T10 and the stator coils 114C1 and 114C3 to 114C9 are the same.

  The stator coil 114C2 is resin-molded with a heat conductive insulating resin 114R. The stator coil 114C2 is fixed to the split stator core 114T3 by a two-stage mold. The stator coil 114C2 and the split stator core 114T2 are fixed by an adhesive 114AD. Note that a gap 114a1 is formed in the outer peripheral surface of the stator coil 114C2 at a position facing the split stator core 114T2. The reason for this will be described later. The gap 114a1 has a thickness of about 0.1 mm.

  The thermally conductive resin 114R is a resin in which alumina powder is kneaded with an epoxy resin. The epoxy resin has an insulating property. Alumina is a non-magnetic material, is an insulator, and has a higher thermal conductivity than resin. The thermal conductivity of a general epoxy resin is 0.2 to 0.6 W / mK, whereas the thermal conductivity of the thermally conductive insulating resin 114R in which alumina powder is kneaded is 1 W / mK or more, An example is 5 W / mK.

  Zirconia or silica can be used instead of alumina as a non-magnetic material, an insulator, and a material having a higher thermal conductivity than that of the resin. A combination of these can also be used. Further, as the resin, an unsaturated polyester resin (BDC) can be used instead of the epoxy resin.

  FIG. 5B shows a configuration of a stator prototyped by the present inventors as a comparative example. The stator coil 114C2 is fixed by an adhesive 114d1. The shape of the stator coil 114C2 formed by the adhesive 114d1 is a ring shape. Epoxy plates 114d1, 114d2, and 114d3 are respectively secured to the inner peripheral surface and both end surfaces of the stator coil 114C2 by an adhesive 114d1. In addition, an insulating sheet 114s is fixed to the outer peripheral surface of the stator coil 114C2 with an adhesive 114d1. One end surface of the stator coil 114C2 whose outer surface is covered with the epoxy plates 114d1, 114d2, 114d3 and the insulating sheet 114s is fixed to the inner peripheral surface of the divided stator core 114T2 by an adhesive 114d2. The other end surface of the stator coil 114C2 is fixed to the inner peripheral surface of the split stator core 114T3 by an adhesive 114d3. At this time, a gap 114a2 is formed between the outer periphery of the insulating sheet 114s and the inner periphery of the divided stator cores 114T2 and 114T3. This is because if the outer diameter of the stator coil 114C2 is larger than the inner diameter of the split stator cores 114T2 and 114T3, the stator coil 114C2 cannot be accommodated inside the split stator cores 114T2 and 114T3. This is because the outer diameter is slightly smaller than the inner diameter of the split stator cores 114T2 and 114T3. The thickness of the gap 114a2 is about 0.2 mm.

  In the case of the configuration of the stator of the comparative example shown in FIG. 5B, the heat conduction path for heat generation from the stator coil 114C2 is as follows: 1) Adhesive 114d1-epoxy plate 114p2-adhesive 114p2-split stator core 114T2, 2) Adhesive 114d1-epoxy plate 114p3-adhesive 114p3-split stator core 114T3, 3) Adhesive 114d1-insulating sheet 114s-gap 114a2-split stator core 114T2, 114T3.

  Here, the third path has a gap 114a2 in the middle, and therefore has a lower heat transfer property than the other paths. Looking at the first and second paths, the thermal conductivity of the epoxy plates 114p2 and 114p3 is as low as 0.2 to 0.6 W / mK as described above. Further, the adhesives 114p1, 114p2, and 114p3 are smaller than the thermal conductivity of the epoxy plate when epoxy-based adhesive is used. The reason is that voids are generated in the cured adhesive. The void generation rate of the adhesive was found to be 13 to 60% as a result of the test. Accordingly, the thermal conductivity of the adhesives 114p1, 114p2, 114p3 is significantly lower than 0.2 W / mK.

  On the other hand, in the case of the present embodiment shown in FIG. 5A, the heat conduction path of heat generated from the stator coil 114C2 is 1) resin 114R-adhesive 114AD-divided stator core 114T2, 2) resin 114R- There are divided stator cores 114T3, 3) resin 114R, gap 114a and divided stator core 114T2.

  Here, the thermal conductivity of the first path is much lower than 0.2 W / mK because the adhesive 114AD is present in the middle. On the other hand, the thermal conductivity of the second path is 1 W / mK or higher because the resin 114R is in direct contact with the split stator core 114T3, and is, for example, 5 W / mK, which is higher than that of the first path. Also, it can be made larger than the comparative example shown in FIG.

  With the above configuration, in this embodiment, it is possible to provide a continuous path from the coil 114C to the split stator core 114T by the heat conductive resin 114R. As a result, the minute gaps at the boundary of the insulator and the contact thermal resistance can be reduced as much as possible and the heat dissipation can be improved.

Next, the manufacturing process of the stator in the cylindrical linear motor of this embodiment is demonstrated using FIGS.
6-8 is process drawing which shows the manufacturing method of the stator in the cylindrical linear motor of one Embodiment of this invention. The same reference numerals as those in FIG. 5 indicate the same parts.

  First, a method for forming the stator coil 114C2 will be described with reference to FIG.

  First, a copper wire having an enamel coating on its surface is wound around a bobbin or the like to form a solenoidal coil 114C2. The strand (copper wire) used for the coil 114C2 may be a round wire or a flat wire. Note that a self-bonding wire may be used as the element wire and self-bonding may be performed by energization heating. Thereby, the shape loss at the time of shaping | molding of coil 114C2 can be prevented. However, some voids may be generated during self-bonding by the self-bonding line. Therefore, it is better not to use the self-bonding wire when it is desired to increase the energization current. On the other hand, by using the self-bonding wire, it is possible to prevent the deformation of the coil 114C2 when it is formed, so that formability is improved and assembly workability is improved.

  Next, in order to ensure insulation between the armature coil 114C2 and the stator core 114, an insulating film 602 made of a heat conductive resin is formed on the surface of the armature coil 114C2. Moreover, the convex part 601 is formed in two surfaces facing the division | segmentation stator core 114T2 shown in FIG. The insulating coating 602 and the convex portion 601 are integrally formed. This is the primary impregnation.

  The primary impregnation method is pressure molding such as transfer molding or injection molding, and a heat conductive resin is infiltrated between the coils 114C2. Thereby, generation | occurrence | production of a void is eliminated, the contact thermal resistance between the coil 114C2 and a stator core can be reduced, a micro space | gap can also be decreased, and heat dissipation can be improved.

  Note that the convex portion 601 has a cylindrical shape. The dimensions of the convex portion 601 are, for example, a diameter of 1.0 mm and a height t1 of about 0.1 mm. In addition, it is good also considering the shape of a convex part as a rectangular parallelepiped shape. The dimensions at that time are, for example, about 1 × 1 × 0.1 mm. The thickness t2 of the insulating coating 602 on the surface of the stator coil 114C2 is about 0.4 mm including the height of the convex portion 601. Since the thickness t2 of the insulating coating 602 and the convex portion 601 is an insulation distance between the armature winding and the stator core, insulation can be ensured according to the applied voltage. When the interval between the convex portions 601 is set as large as possible, it is difficult for impregnation defects to occur during main impregnation between the coil core described later.

  Although the insulating coating 602 and the convex portion 601 are formed of the heat conductive resin on the coil 114C2, the insulating coating 602 and the convex portion 601 may be formed on the stator core.

  In order to secure another insulating property, a spacer or the like may be attached to the coil 114C2 without securing the primary impregnation for the purpose of emphasizing workability, thereby securing an insulating distance. However, since a contact thermal resistance corresponding to the contact area of the spacer is generated, it should be made as small as possible to ensure heat dissipation.

  Next, a fixing process between the stator coil 114C2 and the divided stator core 114T3 will be described with reference to FIG.

  The stator coil 114C2 with an insulating coating manufactured in the primary impregnation step described with reference to FIG. 6 is placed in the recess of the split stator core 114T3. A mold mold (a mold designed so as to be molded between the cores on one side of the coil; here referred to as “main impregnation mold” or “secondary mold”) is prepared. The stator core 114 in which the coil 114C2 is housed in the secondary mold is fitted, and the entire coil-one-side core is impregnated with the heat conductive resin 114R again. Also at this time, a high pressure impregnation method such as transfer molding or injection molding is employed. Thereby, insulation defects such as voids can be prevented and the contact thermal resistance can be reduced.

  The path of resin impregnation during secondary molding is as shown by the arrows in FIG. Note that the direction of the arrow may be reversed. In this method, since resin impregnation is performed only on one side of the stator core 114, resin impregnation is possible from the axial direction as shown in FIG.

  Generally, when resin impregnation is performed after the split stator cores 114T on both sides are assembled, resin impregnation is performed in the radial direction from the inside. However, when the motor diameter is large, impregnation defects often occur. Also, in an ordinary mold motor (open in the other direction), since the insulator and the stator core are impregnated with resin, they often become obstacles during resin impregnation and the resin is not impregnated up to the gap between the coils 114C2. is there. As a result, voids and peeling are likely to occur, and heat dissipation characteristics and insulation characteristics are degraded.

  On the other hand, as in this embodiment, if the impregnation process is made into two stages and the resin impregnation is applied only to the winding coil by primary impregnation, it depends on the structure of the rotating electric machine (other-direction open type) or linear motor. In addition, the resin 114R can be impregnated up to the gap between the stator coils 114C2 to reduce voids. In addition, since the work of winding the insulating sheet 114R or the like is eliminated, the work time can be shortened and mass production is possible.

  However, an insulating sheet 503 as shown in FIG. 5 (B) is partially wound around a portion where the electric field is high and high insulation is required, such as a lead portion of a linear motor, to ensure a necessary insulation distance. Is also good.

  Next, the manufacturing process of the stator core 114T will be described with reference to FIG.

  A set in which the stator coil 114C2 is fixed to one side of the stator core 114T3 as described in FIG. In the example shown in FIG. 8, a stator coil 114C2 fixed to one side of the stator core 114T3 constitutes one set.

  In the example shown in FIG. 8, a first set consisting of a stator coil 114C2 fixed to one side of a stator core 114T3 and a second set consisting of a stator coil 114C1 fixed to one side of a stator core 114T2. A set is shown.

  In the second set of the stator coil 114C1 and the stator core 114T2, the stator coil 114C2 and the stator coil 114T3 are formed on the inner surface of the stator core 114T2 where the stator coil 114C1 is not fixed. The first set of stator coils 114C2 is bonded by an adhesive 114AD.

  The adhesive 114AD used at this time is selected to be excellent in fixing. Since the heat conductivity is ensured by the resin impregnated on the opposite side, the thermal conductivity of the adhesive 114AD may be low.

  In place of the adhesive 114AD, a heat conductive sheet may be interposed between the stator core 114T2 and the stator coil 114C2. Thereby, the heat generated by the stator coil 114C1 can be radiated not only from the stator core 114T3 but also from the stator core 114T2 side. As described with reference to FIG. 1, the stator core 114 </ b> T is housed in the stator case 112. Therefore, the stator core 114T2 and the stator coil 114C2 are fixed to each other by being housed in the stator course 112 with the heat conductive sheet sandwiched between the stator core 114T2 and the stator coil 114C2. It can be adhered.

Next, the relationship between the temperature of the stator coil and the resin thermal conductivity in the cylindrical linear motor of this embodiment will be described with reference to FIG.
FIG. 9 is an explanatory diagram of the relationship between the temperature of the stator coil and the resin thermal conductivity in the cylindrical linear motor of one embodiment of the present invention.

  In FIG. 9, the horizontal axis indicates the thermal conductivity of the resin used for fixing the stator coil, and the vertical axis indicates the temperature increase rate of the stator coil.

In order for the output density of the linear motor to be 5 W / cm ³ , the resin thermal conductivity needs to be 1 W / mK or more. In this embodiment, as the heat conductive resin impregnated in the primary impregnation and the secondary impregnation, those having a thermal conductivity of 5 W / mK are used. As a result, the temperature rise reduction rate was 23%.

  The resin used for the primary impregnation and the secondary impregnation may be different. For example, it is possible to easily fill the resin between the coils 114C2 by applying a resin having a good spiral flow for the primary impregnation, and it is also possible to apply a resin that places importance on thermal conductivity for the secondary impregnation.

  With the above configuration, according to the present embodiment, heat dissipation can be improved by providing a continuous heat transfer path of the heat conductive resin from the stator coil to the stator core. As a result, the output density can be improved by 10% compared to the conventional case.

  Next, the configuration and manufacturing method of a cylindrical linear motor according to another embodiment of the present invention will be described with reference to FIG. Here, as a cylindrical linear motor, an electromagnetic suspension used for railways, automobiles, and the like will be described as an example. The basic configuration of the cylindrical linear motor according to the present embodiment is the same as that described with reference to FIGS. However, the shape of the split stator core is different from that shown in FIGS. Moreover, the manufacturing method of the stator in the cylindrical linear motor of this embodiment is the same as what was demonstrated in FIGS.

  FIG. 10 is a process diagram showing a method for manufacturing a stator in a cylindrical linear motor according to another embodiment of the present invention. In addition, the process demonstrated in FIG. 6 is the same also in this embodiment.

  In the present embodiment, the stator core is divided into a larger shape on the side impregnated with resin. That is, for example, the split stator core that houses the stator coil 114C2 includes a split stator core 114T ′ and a split stator core 114T ″. The split stator core 114T ″ is substantially L-shaped. The two surfaces of the stator coil 114C2 are impregnated with the resin so as to come into contact with the divided stator core 114T ″. As a result, the area in contact with the resin is increased, so that the heat dissipation can be improved. It should be noted that the impregnation failure is likely to occur because the impregnation path is long, and the division dimension is not limited to the example shown in the figure, and may be set to be long or short.

According to this embodiment, heat dissipation can be improved by providing a continuous heat transfer path of the heat conductive resin from the stator coil to the stator core.

1 is a cross-sectional view illustrating a configuration of a cylindrical linear motor according to an embodiment of the present invention. It is AA sectional drawing of FIG. It is a principal part enlarged view of FIG. It is a top view which shows the structure of the coil used for the cylindrical linear motor by one Embodiment of this invention. It is sectional drawing which shows the detailed structure of the stator in the cylindrical linear motor of one Embodiment of this invention. It is process drawing which shows the manufacturing method of the stator in the cylindrical linear motor of one Embodiment of this invention. It is process drawing which shows the manufacturing method of the stator in the cylindrical linear motor of one Embodiment of this invention. It is process drawing which shows the manufacturing method of the stator in the cylindrical linear motor of one Embodiment of this invention. It is explanatory drawing of the relationship between the temperature of the stator coil and resin thermal conductivity in the cylindrical linear motor of one Embodiment of this invention. It is process drawing which shows the manufacturing method of the stator in the cylindrical linear motor by other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Cylindrical linear motor 110 ... Stator 112 ... Stator case 114 ... Stator core 114C ... Coil 114P ... Auxiliary salient pole 114R ... Thermal conductive insulating resin 114T ... Split stator core 118 ... Stator inner case 130 ... Movement Child

Claims (7)

A linear motor having a cylindrical stator and a movable element arranged on the inner periphery of the stator and movable in the axial direction of the cylindrical shape,
The stator is
A split stator core divided into a plurality of parts in a direction perpendicular to the axial direction of the cylindrical shape;
A stator coil formed in an annular shape and disposed in a plurality of slots formed when the plurality of divided stator cores are combined; and
A heat conductive insulating resin that is filled between the strands constituting the stator coil and that fixes and fixes one of the stator coils to one of the divided stator cores by pressure molding. Features a linear motor. The linear motor according to claim 1,
The linear motor according to claim 1, wherein the heat conductive insulating resin is obtained by kneading a non-magnetic powder in a resin. The linear motor according to claim 1,
The thermally conductive insulating resin is
A first thermally conductive insulating resin filled between the strands constituting the stator coil;
A linear motor comprising a second thermally conductive insulating resin that fills and fixes one stator coil to one divided stator core by pressure molding. The linear motor according to claim 3,
A convex portion is formed on a surface of the surface of the first thermally conductive insulating resin that faces the one divided stator core. The linear motor according to claim 1,
The linear motor according to claim 1, wherein the one stator coil is adhered to another one of the divided stator cores with an adhesive or in close contact with a heat conductive sheet. The linear motor according to claim 1,
The linear conductive motor characterized in that the heat conductive insulating resin forms a heat transfer path from a strand forming the armature coil to the split stator core on one side. A method for manufacturing a stator core in a linear motor having a cylindrical stator and a movable element that is arranged on an inner periphery of the stator and is movable in the axial direction of the cylindrical shape,
The stator is
A split stator core divided into a plurality of parts in a direction perpendicular to the axial direction of the cylindrical shape;
A stator coil formed in an annular shape and disposed in a plurality of slots formed when the plurality of divided stator cores are combined,
A first step of impregnating between the strands constituting the stator coil with a heat conductive insulating resin;
And a second step of filling and fixing one of the stator coils to one of the divided stator cores by pressure molding using a heat conductive insulating resin.

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