Permanent magnet embedded motor and pump device

Abstract

To provide a permanent magnet embedded motor in which a permanent magnet can be firmly attached with a small amount of an adhesive agent while an unnecessary amount of an adhesive agent is eliminated.SOLUTION: A permanent magnet embedded motor includes: an annular stator St; and a rotor Rt that includes a rotor core 50 disposed inside the stator and having an insertion hole 51 arranged in a circumferential direction and a fill portion 54 disposed adjacent to the insertion hole to be filled with an adhesive agent, and a permanent magnet 60 inserted in the insertion hole and rotating about a prescribed axis S. The insertion hole 51 includes a wall surface 51a to which the permanent magnet is attached. The fill portion 54 is formed such that an inner edge region Ie of the insertion hole 51 corresponding to the wall surface 51a is stepped down to be thinned at one side open end of the insertion hole 51.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] The present invention relates to an embedded permanent magnet motor including a stator around which a coil is wound and a rotor in which a permanent magnet is embedded, and to a pump device using the same as a drive source. [Background technology]

[0002] A known conventional embedded permanent magnet motor includes an annular stator core having circumferentially arranged teeth and slots, coils wound around the teeth, a rotor core arranged opposite the stator teeth and having circumferentially arranged insertion holes and filling holes for filling with adhesive, and permanent magnets inserted into the insertion holes, with the stator core and coils forming a stator and the rotor formed by the rotor core and permanent magnets (for example, Patent Document 1).

[0003] In this permanent magnet embedded motor, the filling hole is formed with a narrow width that is radially inward from the insertion hole and communicates with the central region of the insertion hole, and a depth that covers almost the entire depth of the insertion hole. When this filling hole is filled with adhesive, the adhesive is only present between the rotor core and the permanent magnet within the width range that communicates with the central region of the insertion hole, and the adhesive layer tends to be thick. Therefore, there is room for improvement in the adhesive filling technique in order to increase the adhesive strength of the adhesive and avoid cohesive failure of the adhesive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-116563 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an embedded permanent magnet motor that can firmly bond permanent magnets with a small amount of adhesive, eliminating waste of adhesive, and a pump device that uses the same as a drive source, in view of the problems with the conventional technology. [Means for solving the problem]

[0006] The permanent magnet embedded motor of the present invention comprises an annular stator, a rotor core arranged inside the stator and having insertion holes arranged in the circumferential direction and filling portions provided adjacent to the insertion holes for filling with adhesive, and a rotor including permanent magnets inserted into the insertion holes and rotating about a predetermined axis, wherein the insertion holes include wall surfaces to which the permanent magnets are adhered, and the filling portion is configured such that at one opening end of the insertion hole, the inner edge region of the insertion hole corresponding to the wall surface of the insertion hole is stepped down and hollowed out.

[0007] In the above-mentioned permanent magnet embedded motor, a configuration may be adopted in which the insertion hole has a rectangular cross section perpendicular to the axis that includes long sides and short sides, the permanent magnet has a rectangular flat plate shape that includes long sides and short sides that includes a cross section perpendicular to the axis, and the filling portion has an inner edge region along the long side of the insertion hole that is stepped down and hollowed out.

[0008] In the above-mentioned permanent magnet embedded motor, a configuration may be adopted in which the insertion hole has a cross-sectional shape that is elongated in a direction perpendicular to the radial direction of the rotor, the permanent magnet has a cross-sectional shape that is elongated in the vertical direction, and the filling portion includes a bottom surface that is elongated in the vertical direction and is flat in a direction perpendicular to the axis.

[0009] In the above-described embedded permanent magnet motor, a configuration may be employed in which the filling portion is formed adjacent to the insertion hole on a radially inner side of the insertion hole.

[0010] In the above-mentioned permanent magnet embedded motor, when the depth dimension of the filling portion in the axial direction is Gd and the thickness dimension of the rotor core in the axial direction is RT, 0.05≦Gd / RT≦0.06, A configuration may be adopted in which the insulating film is formed so as to satisfy the above.

[0011] In the above-mentioned embedded permanent magnet motor, when the thickness dimension of the permanent magnet in the short side direction is Mt, the hole dimension of the insertion hole in the short side direction is Ht, and the gap dimension between the permanent magnet and the insertion hole is Cf=Ht-Mt, 0.1mm≦Cf≦0.2mm, A configuration may be adopted in which the insulating film is formed so as to satisfy the above.

[0012] In the above-mentioned permanent magnet embedded motor, when the axial depth of the filling portion is Gd, the axial thickness of the rotor core is RT, the thickness of the permanent magnet in the short side direction is Mt, the hole dimension of the insertion hole in the short side direction is Ht, and the gap dimension between the permanent magnet and the insertion hole is Cf=Ht-Mt, 0.05≦Gd / RT≦0.06, 0.1mm≦Cf≦0.2mm, A configuration may be adopted in which the insulating film is formed so as to satisfy the above.

[0013] In the above-mentioned permanent magnet embedded motor, a configuration may be adopted in which the insertion hole has a long cross-sectional shape in a direction perpendicular to the radial direction of the rotor, the permanent magnet has a long cross-sectional shape in the vertical direction, the filling portion includes a bottom surface that is long in the vertical direction and is flat in a direction perpendicular to the axis, and the rotor core includes a gap that is continuous with both ends of the insertion hole in the vertical direction.

[0014] In the above-described embedded permanent magnet motor, the rotor core may have a configuration including isolation walls near both ends of the long side of the insertion hole that separate the filling portion from the wall surfaces that define the short sides of the insertion hole.

[0015] In the above-described embedded permanent magnet motor, the rotor core may include a receiving portion at the other open end of the insertion hole that abuts against and receives the permanent magnet inserted into the insertion hole.

[0016] In the above-described embedded permanent magnet motor, a configuration may be adopted in which the adhesive filled in the filling portion is in a paste form.

[0017] In the above-described embedded permanent magnet motor, a configuration may be adopted that includes a housing that fixes the stator and rotatably supports the rotor.

[0018] The pump device of the present invention is a pump device comprising a pump unit that sucks in and discharges a fluid, a rotating shaft connected to the pump unit, and a driving source that exerts a driving force on the rotating shaft, and is configured to employ, as the driving source, a permanent magnet embedded motor that includes the above-mentioned housing and has any of the above-mentioned configurations.

[0019] In the above pump device, the pump unit may be a trochoid pump including an inner rotor to which the rotating shaft is connected, and an outer rotor that meshes with the inner rotor. Effect of the Invention

[0020] With the embedded permanent magnet motor having the above configuration, it is possible to obtain an embedded permanent magnet motor with excellent durability, which can firmly attach the permanent magnets with a small amount of adhesive without wasting the adhesive used to secure the permanent magnets. Furthermore, by using such an embedded permanent magnet motor as a drive source, it is possible to obtain a highly reliable pump device. [Brief description of the drawings]

[0021] [Figure 1] 1 is an external perspective view showing a pump device including a permanent magnet embedded motor according to the present invention; [Diagram 2] FIG. 2 is a cross-sectional view of the pump device shown in FIG. [Diagram 3] FIG. 2 is an exploded perspective view of the pump device shown in FIG. [Figure 4] 2 is a cross-sectional view showing a fluid intake port and a fluid discharge port in the pump device shown in FIG. 1, taken along a plane perpendicular to the axis which is the center line of rotation of the rotor. [Diagram 5] 2 is an external perspective view showing a stator and a rotor of a permanent magnet embedded motor serving as a driving source included in the pump device shown in FIG. 1. [Figure 6] 6 is an exploded perspective view of the stator and rotor of the embedded permanent magnet motor shown in FIG. 5. [Figure 7] 1 is a cross-sectional view taken along a plane perpendicular to the axis of the rotor, showing the internal structure of a stator and a rotor of a permanent magnet embedded motor. FIG. [Figure 8] FIG. 2 is an external perspective view of a rotor that constitutes a part of a permanent magnet embedded motor, as viewed from one end side. [Figure 9] 2 is an external perspective view of a rotor that constitutes a part of a permanent magnet embedded motor, as viewed from the other end side. FIG. [Figure 10] FIG. 2 is an exploded perspective view of a rotor that constitutes a part of a permanent magnet embedded motor, in which a rotor core and permanent magnets are disassembled. [Figure 11] 2 is a plan view of a rotor core that constitutes a part of a permanent magnet embedded motor, as viewed from one end side in the axial direction. FIG. [Figure 12] 4 is a partial enlarged view showing the relationship between insertion holes and permanent magnets in a rotor that is a part of a permanent magnet embedded motor. FIG. [Figure 13] 4 is a partially enlarged view showing the dimensional relationship between insertion holes and permanent magnets in a rotor core that constitutes a part of a permanent magnet embedded motor. FIG. [Figure 14] 1 is a perspective cross-sectional view partially showing the areas of an insertion hole and a filling portion in a rotor core that constitutes a part of a permanent magnet embedded motor. FIG. [Figure 15] 1 is a partial cross-sectional view showing the dimensional relationship of an insertion hole and a filling portion in a rotor core that constitutes a part of a permanent magnet embedded motor, the cross-sectional view being cut along a plane including an axis. [Figure 16] 10A to 10C are process diagrams showing the operation of fitting a permanent magnet into an insertion hole of a rotor core which is a part of a permanent magnet embedded motor. [Figure 17] 10A to 10C are process diagrams showing the operation of fitting permanent magnets into insertion holes in a rotor core that is part of a permanent magnet embedded motor. [Figure 18] 10A to 10C are process diagrams showing the operation of fitting permanent magnets into insertion holes in a rotor core that is part of a permanent magnet embedded motor. [Figure 19]19 is a schematic diagram showing the state of adhesive adhesion on the wall surface of a permanent magnet bonded through the steps shown in FIGS. 16 to 18. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in Figures 1 to 3, a pump device equipped with an embedded permanent magnet motor in one embodiment includes a housing body 1, a pump cover 2, a motor cover 3, a board cover 4, a rotating shaft 5, a pump unit U, an embedded permanent magnet motor M as a driving source, a circuit board CB, etc.

[0023] The pump unit U is a trochoid pump that sucks in and discharges a fluid (here, oil), and includes an inner rotor 11 and an outer rotor 12. As shown in Figures 2, 5, and 6, the embedded permanent magnet motor M is a three-phase brushless motor having nine slots and eight magnetic poles, and includes a stator St including a stator core 20, a bobbin 30, and a coil 40, a rotor Rt including a rotor core 50 and a permanent magnet 60 and rotating around an axis S, and a housing (housing body 1, motor cover 3). Here, the housing body 1 and the motor cover 3 function as part of the housing of the pump device and also as a housing for the permanent magnet embedded motor M, fixing the stator St and supporting the rotor Rt so as to be freely rotatable.

[0024] The housing body 1 is formed from an aluminum material or the like, and, as shown in Figures 2 and 3, is provided with an accommodating recess 1a for accommodating the pump unit U, an accommodating recess 1b for fitting and accommodating the stator St, a communicating passage 1c connecting the accommodating recess 1a and the accommodating recess 1b, an annular recess 1d, an annular recess 1e, end faces 1f and 1g. The communication passage 1c is formed in a cylindrical shape centered on the axis S, which is the rotation center line of the rotor Rt, and the rotating shaft 5 is inserted therethrough with a predetermined gap. The annular recess 1d is formed in an annular shape centered on the axis S so that the lip seal LS can be fitted into it. The annular recess 1e is formed in an annular shape centered on the axis S so that a bearing B1 that rotatably supports the rotating shaft 5 is fitted into the annular recess 1e with a washer W interposed between the lip seal LS and the bearing B1.

[0025] The pump cover 2 is formed from an aluminum material or the like, and as shown in Figures 2 and 3, is joined to the end face 1f of the housing body 1 to cover the accommodating recess 1a, and is provided with an intake port 2a for sucking in fluid and an exhaust port 2b for discharging pressurized fluid. With the pump unit U accommodated in the accommodation recess 1a, the pump cover 2 is joined to the end surface 1f of the housing body 1 and fastened and fixed by screws b1.

[0026] The motor cover 3 is formed from a resin material and joined to the end face 1g of the housing body 1 to cover the accommodating recess 1b. As shown in Figures 2 and 3, the motor cover 3 has a through hole 3a centered on the axis S, an annular recess 3b, a fixing portion 3c for fixing the circuit board CB, and a connector 3d for accommodating terminals for connection to the outside. The through hole 3a is formed so that a detection target unit 5b fixed to the end of the rotating shaft 5 can be inserted therethrough. The annular recess 3b is formed in an annular shape centered on the axis S so that a cylindrical metal holder 3e can be fitted and fixed in place. The metal holder 3e fits and holds a bearing B2 that rotatably supports the rotating shaft 5. The motor cover 3 is joined to the end surface 1g of the housing body 1, and the board cover 4 is joined from the outside and fastened therebetween by screws b2.

[0027] The board cover 4 is formed of a metal plate, a resin material, or the like, and is fastened and fixed to the end surface 1g of the housing body 1 by screws b2 with the motor cover 3 sandwiched therebetween to cover the circuit board CB.

[0028] The rotating shaft 5 is made of a metal material and formed into a cylindrical shape centered on the axis S. As shown in Figures 2, 3, and 11, the rotating shaft 5 is provided with a connecting portion 5a having a two-face width at one end, a detectable unit 5b fixed to the other end, and a key groove portion 5c on the outer periphery. The rotating shaft 5 has a key groove portion 5c fitted into an axial hole 57 of a rotor core 50 included in a permanent magnet embedded motor M, and a connecting portion 5a connected to an inner rotor 11 of a pump unit U. In addition, the outer periphery is sealed by a lip-type seal LS, and the rotating shaft 5 is rotatably supported by bearings B1 and B2 so as to transmit the rotational force of the rotor Rt to the inner rotor 11.

[0029] The detectable unit 5b is an annular holder in which a permanent magnet is fitted so that its north and south poles alternate around the axis S, and is positioned opposite the detection sensor C1 mounted on the circuit board CB, as shown in FIG. 2. The detected unit 5b functions as a detection target of the detection sensor C1 that detects the rotational angle position of the rotating shaft 5, that is, the rotor Rt.

[0030] As shown in FIGS. 2 and 3, the pump unit U includes an inner rotor 11 and an outer rotor 12. The inner rotor 11 is made of a material such as steel or sintered steel and is formed into a roughly star shape that defines an end face that slides on the bottom wall surface of the accommodating recess 1a of the housing body 1 and the inner wall surface of the pump cover 2. The inner rotor 11 is formed as an external gear having a tooth profile based on a trochoid curve, with a fitting hole 11a, seven protrusions (peaks) and seven recesses (valleys). The fitting hole 11a is formed so that the connecting portion 5a of the rotating shaft 5 is fitted therein. The inner rotor 11 is rotated by the rotary shaft 5 around the axis line S as the center of rotation in the direction of the arrow A in FIGS.

[0031] The outer rotor 12 is made of a material such as steel or sintered steel and is formed into an annular shape that defines an end face that slides on the bottom wall surface of the accommodating recess 1a of the housing body 1 and the inner wall surface of the pump cover 2. The outer rotor 12 has a circular outer circumferential surface 12a, eight protrusions and eight recesses, and is formed as an internal gear with teeth that can mesh with the inner rotor 11. The outer circumferential surface 12a is in contact with the inner circumferential surface of the installation recess 1a and is supported so as to be rotatable about an axis deviated from the axis S. The outer rotor 12 rotates at a slower speed than the inner rotor 11 while being linked to the rotation of the inner rotor 11 which rotates about the axis S. By the rotation of the inner rotor 11 and the outer rotor 12, the fluid is sucked into the pump chamber from the suction port 2a, pressurized, and discharged from the discharge port 2b.

[0032] The circuit board CB is equipped with components that control the drive of the permanent magnet embedded motor M, and has wiring printed thereon and various electronic components that constitute the control circuit mounted thereon.In addition, as shown in Figure 2, a detection sensor C1 that faces the detected unit 5b is also mounted on the circuit board CB. The detection sensor C1 is made up of a plurality of Hall elements arranged in an arc shape centered on the axis S. The detection sensor C1 is adapted to detect the magnetic pole position (rotational angle position) in the rotation direction of the rotating shaft 5, i.e., the rotor Rt.

[0033] As shown in FIGS. 5 and 6, the embedded permanent magnet motor M includes a stator St including a stator core 20, a bobbin 30, and a coil 40, a rotor Rt including a rotor core 50 and a permanent magnet 60, and a housing. Here, the housing body 1 and the motor cover 3 function as a housing for the permanent magnet embedded motor M as described above.

[0034] The stator core 20 is formed as a laminated body by press-molding steel plates made of a magnetic material and then laminating them, and as shown in Figures 6 and 7, it has an annular portion 21, nine teeth 22 as salient poles that protrude from the annular portion 21 toward the center (axis S) and are arranged at equal intervals in the circumferential direction, and nine slots 23 arranged at equal intervals in the circumferential direction. The nine teeth 22 are formed in the same shape and are rotationally symmetrical about the axis S, and each has a tip end surface 22a that defines a circular arc surface. The nine tip faces 22a are arranged on a cylindrical surface having a predetermined diameter, and are disposed so as to face the outer peripheral contour 50a (outer peripheral magnetic pole surface 53b) of the rotor core 50 with a predetermined gap therebetween. The nine slots 23 are formed in the same shape and are rotationally symmetric about the axis S, and each has an opening 23a having a predetermined width between the teeth 22 on both sides.

[0035] The bobbin 30 is formed in a two-piece structure using an electrically insulating resin material, and is assembled so as to sandwich the stator core 20 in the direction of the axis S. The coil 40 adopts a concentrated winding structure in which it is wound around each of the nine teeth 22 via the bobbin 30, and is electrically connected in three separate phases.

[0036] The rotor core 50 is made of a laminated body that is press-molded using steel plates made of a magnetic material and then laminated, and is formed so as to define a cylindrical outer peripheral contour 50a that faces the teeth 22 (tip surfaces 22a) of the stator core 20 with a predetermined gap therebetween, as shown in FIG. 7. As shown in Figures 7 to 11, the rotor core 50 has eight insertion holes 51 arranged at equal intervals in the circumferential direction, eight through holes 52 arranged at equal intervals in the circumferential direction, eight outer peripheral magnetic pole portions 53 arranged at equal intervals in the circumferential direction, eight filling portions 54 arranged at equal intervals in the circumferential direction, isolation walls 55 located on both sides of each filling portion 54, receiving portions 56 formed corresponding to each filling portion 54, a shaft hole 57 into which the rotating shaft 5 is fitted, and eight trapezoidal holes 58 arranged at equal intervals in the circumferential direction.

[0037] Here, the eight insertion holes 51, the eight through holes 52, the eight outer magnetic pole portions 53, the eight filling portions 54, the eight receiving portions 56, and the eight trapezoidal holes 58 are each formed rotationally symmetrically around the axis S, and also formed linearly symmetrically with respect to the radial straight line DL, so only one of each will be described below.

[0038] The insertion hole 51 is an area where the permanent magnet 60 is inserted and fixed, i.e., an embedding area for the permanent magnet 60, and as shown in FIG. 11, has a rectangular shape including a long side Ls and a short side Ss in a cross section perpendicular to the axis S, and here is formed so as to have an elongated cross-sectional shape in the direction Pd perpendicular to the radial straight line DL of the rotor Rt. Specifically, the insertion hole 51 is formed to include two wall surfaces 51a, 51b parallel to the vertical direction Pd and two wall surfaces 51c, 51c perpendicular to the vertical direction Pd, as shown in Figures 12 to 14. The wall surface 51a functions as a wall surface to which the permanent magnet 60 is adhered. Here, the edge regions of the wall surfaces 51a, 51b define the long side Ls of the insertion hole 51, and the edge region including the wall surfaces 51c, 51c defines the short side Ss of the insertion hole 51.

[0039] As described above, since the insertion hole 51 has two wall surfaces 51c, 51c, when the permanent magnet 60 is inserted into the insertion hole 51, it is possible to suppress or prevent the permanent magnet 60 from shifting in the vertical direction Pd while providing a gap G at both ends of the insertion hole 51. Here, since a continuous gap G is formed at both ends of the insertion hole 51 in the direction of the long side Ls, it is possible to prevent the permanent magnet 60 from short-circuiting the magnetic field lines.

[0040] As shown in Figs. 11 and 12, the through holes 52 are formed in a plane perpendicular to the axis S between the insertion holes 51, 51 in the circumferential direction and radially inward to form gaps with circular cross sections. The through hole 52 functions as a flux barrier that suppresses or prevents leakage and short circuits of magnetic lines, and also serves as a positioning portion into which a jig for positioning the rotor core 50 is inserted when assembling the permanent magnet 60 into the insertion hole 51.

[0041] The outer peripheral magnetic pole portion 53 is a region that generates a magnetic pole corresponding to the permanent magnet 60 inserted into the insertion hole 51, and as shown in Figure 11, has a shape that is line-symmetrical with respect to a radial line DL, and has an outer peripheral magnetic pole surface 53b between a pair of recesses 53a, 53a. The pair of recesses 53a, 53a are symmetrical with respect to the straight line DL, and are formed in a V-groove shape extending in the direction of the axis S, as shown in FIGS. The outer magnetic pole surface 53b is an area sandwiched between a pair of recesses 53a, 53a in the circumferential direction, and forms a cylindrical curved surface that defines the outer peripheral contour 50a, that is, a curved surface having a curvature of 2 / D when the outer diameter dimension of the outer peripheral contour 50a is D, and faces the tip surface 22a of the tooth 22 with a predetermined gap between them.

[0042] The filled portion 54 is a region to be filled with adhesive for fixing the permanent magnet 60, and is formed adjacent to the insertion hole 51 on the radially inner side than the insertion hole 51. That is, as shown in Figures 10, 12, and 14, the filling portion 54 has a shape in which the inner edge region Ie of the insertion hole 51 corresponding to the wall surface 51a, i.e., the inner edge region Ie along the long side Ls of the insertion hole 51, is stepped down and hollowed out at one opening end of the insertion hole 51. Specifically, the filling portion 54 has a side surface 54a that is long in the vertical direction Pd, and a bottom surface 54b that is long in the vertical direction Pd and is flat in a direction perpendicular to the axis S.

[0043] As shown in FIG. 16, in the filling portion 54, the side surface 54a acts as a dam to prevent the filled adhesive Gr from flowing away from the insertion hole 51, and the bottom surface 54b acts to retain the filled adhesive Gr before the permanent magnet 60 is inserted.

[0044] That is, after the filling portion 54 is filled with adhesive, the permanent magnet 60 is inserted into the insertion hole 51, so that the adhesive Gr is stretched and applied between the wall surface 61a defining the long side Ls of the permanent magnet 60 and the wall surface 51a defining the long side Ls of the insertion hole 51. Here, since the filling portion 54 is formed adjacent to and radially inward (in the direction of straight line DL) of the insertion hole 51, the area outside the insertion hole 51 can be effectively used as the outer circumferential magnetic pole portion 53.

[0045] 12, the partition walls 55 are formed near both ends of the long side Ls direction of the insertion hole 51 so as to separate the filling portion 54 from the wall surface 51c that defines the short side Ss of the insertion hole 51. In other words, the partition walls 55 block the filling portion 54 from communicating with the area facing the wall surface 51c. This prevents the adhesive Gr filled in the filling portion 54 from flowing out toward the wall surface 61b that defines the short side Ss of the permanent magnet 60, and allows the adhesive Gr to be retained on the wall surface 61a that defines the long side Ls of the permanent magnet 60, so that a small amount of adhesive Gr can be effectively used to bond the wall surface 61a and the wall surface 51a.

[0046] As shown in Figures 9, 14, and 18, the receiving portion 56 is formed as a protruding piece that protrudes inward at the other opening end of the insertion hole 51, and receives the end face 62 of the permanent magnet 60 inserted into the insertion hole 51, thereby positioning the permanent magnet 60 in the direction of the axis S. According to this, after the adhesive Gr is filled in the filling portion 54, the positioning and bonding work can be completed simply by inserting the permanent magnet 60 into the insertion hole 51.

[0047] As shown in FIG. 11, the shaft hole 57 is for fitting the rotating shaft 5 therein, and has eight projections 57a which fit into the key grooves 5c of the rotating shaft 5. As shown in FIG. The trapezoidal holes 58 are formed to be arranged at equal intervals in the circumferential direction on the radial outside of the shaft hole 57. The trapezoidal holes 58 contribute to reducing the weight of the rotor core 50 and allow elastic deformation of the peripheral region of the protrusion 57a ​​when the rotating shaft 5 is fitted into the shaft hole 57. This allows the fitting operation of the rotating shaft 5 to be performed smoothly.

[0048] 7, 10 and 12, the eight permanent magnets 60 are formed in the same shape and are fitted and fixed in the respective insertion holes 51. That is, the permanent magnets 60 have a rectangular flat plate shape including long sides Ls and short sides Ss in a cross section perpendicular to the axis S, and here, are formed to have a cross-sectional shape that is elongated in the vertical direction Pd.

[0049] 10 and 12, the permanent magnet 60 is formed to include two wall surfaces 61a, 61a parallel to the vertical direction Pd, two wall surfaces 61b, 61b perpendicular to the vertical direction Pd, and two end surfaces 62, 62 extending in the direction of the axis S. Here, the wall surfaces 61a, 61a define the long side Ls of the permanent magnet 60, and the wall surfaces 61b, 61b define the short side Ss of the permanent magnet 60.

[0050] 8 and 9, the eight permanent magnets 60 are oriented so that their N poles and S poles face each other in the radial direction (direction of straight line DL) of the rotor core 50, and are inserted at equal intervals in the circumferential direction about the axis S so that the poles facing outward alternate. When the permanent magnets 60 are inserted in the insertion holes 51, air gaps G are defined at both ends of the permanent magnets 60 in the vertical direction Pd.

[0051] Here, since the gap G is provided on both sides of the permanent magnet 60, it is possible to prevent the magnetic field lines from short-circuiting themselves from the north pole to the south pole of the permanent magnet 60. Furthermore, since one permanent magnet 60 having a simple flat plate-like shape is arranged in correspondence with one outer peripheral magnetic pole portion 53, it is possible to achieve a simplified structure and reduced costs compared to a configuration in which a permanent magnet having a curved shape is arranged in correspondence with one outer peripheral magnetic pole portion 53, or a configuration in which multiple permanent magnets are arranged in correspondence with one outer peripheral magnetic pole portion 53.

[0052] 15, when the depth dimension of filled portion 54 of rotor core 50 in the direction of axis S is Gd and the thickness dimension of rotor core 50 in the direction of axis S is RT, the rotor core 50 is preferably formed to satisfy 0.05≦Gd / RT≦0.06. Specifically, the dimensions are set, for example, such that RT is about 20 mm to 30 mm and Gd is about 1.0 mm to 1.8 mm. The value of Gd / RT is not limited to the above range. As described above, by setting the ratio of the depth dimension Gd of the filling portion 54 to the thickness dimension RT of the rotor core 50, a small amount of adhesive Gr can be filled into the filling portion 54 and the adhesive Gr can be applied to the wall surface 61a of the permanent magnet 60.

[0053] Furthermore, as shown in FIG. 13, when the thickness dimension of the permanent magnet 60 in the direction of the short side Ss is Mt, the hole dimension of the insertion hole 51 in the direction of the short side Ss is Ht, and the gap dimension between the permanent magnet 60 and the insertion hole 51 is Cf=Ht-Mt, the magnet is preferably formed so as to satisfy 0.1 mm≦Cf≦0.2 mm. By setting the gap dimension Cf as described above, the adhesive Gr filled in the filling portion 54 can be spread and applied in a thin film between both wall surfaces 61a, 51a as the permanent magnet 60 is inserted into the insertion hole 51, preventing cohesive failure and the like that may occur when the layer of adhesive Gr is thick. This allows the permanent magnet 60 to be firmly bonded and fixed, improving the durability of the rotor Rt. The value of Cf is not limited to the above-mentioned range.

[0054] Next, the operation of assembling the permanent magnets 60 into the insertion holes 51 of the rotor core 50 will be described with reference to FIGS. 16, a small amount of adhesive Gr is filled into the filled portion 54 of the rotor core 50 using a nozzle Nz. As the adhesive Gr, a non-fluid adhesive having a relatively high viscosity, i.e., a paste-like adhesive, such as a one-part epoxy adhesive, is used.

[0055] 17, the permanent magnet 60 is inserted into the insertion hole 51 of the rotor core 50. At this time, the adhesive Gr of the filling portion 54 is stretched while adhering to the wall surface 61a of the permanent magnet 60 in the gap formed between the wall surface 61a and the wall surface 51a. 18, the permanent magnet 60 is completely inserted into the insertion hole 51, and its end face 62 abuts against the receiving portion 56, so that it is positioned in the direction of the axis S.

[0056] During this insertion process, a thin film layer Tf of adhesive Gr is formed between the wall surface 61a of the permanent magnet 60 and the wall surface 51a of the insertion hole 51, as shown in FIG. During the insertion operation, the separation wall 55 prevents the adhesive Gr filled in the filling portion 54 from flowing out to the wall surface 61b that defines the short side Ss of the permanent magnet 60. Therefore, the adhesive Gr is retained on the wall surface 61a that defines the long side Ls of the permanent magnet 60, and is effectively used to bond the wall surface 61a and the wall surface 51a.

[0057] As described above, in the permanent magnet embedded motor M configured as above, the filling portion 54 has a shape in which the inner edge region Ie of the insertion hole 51 corresponding to the wall surface 51a to which the permanent magnet 60 is adhered is stepped down at one open end of the insertion hole 51, and in this embodiment more specifically, the inner edge region Ie along the long side Ls of the insertion hole 51 has a stepped down shape at one open end of the insertion hole 51, so that waste of the adhesive Gr that fixes the permanent magnet 60 is eliminated, and the permanent magnet 60 can be firmly adhered with a small amount of adhesive Gr. This improves the durability of the rotor Rt. Furthermore, according to the pump device to which the embedded permanent magnet motor M having the above-mentioned configuration is applied, the drive source to which the permanent magnet 60 is firmly fixed can improve the reliability of the pump operation.

[0058] The operation of the embedded permanent magnet motor M having the above configuration is similar to that of a conventional embedded permanent magnet motor, so a description thereof will be omitted here.

[0059] In the above embodiment, the insertion hole is an insertion hole 51 having a rectangular cross section perpendicular to the axis S including a long side Ls and a short side Ss, the permanent magnet is a permanent magnet 60 having a rectangular flat plate shape having a long side Ls and a short side Ss in cross section perpendicular to the axis S, and the filling portion is a filling portion 54 having an inner edge region Ie along the long side Ls of the insertion hole 51 with a stepped hollowed-out shape, but this is not limited to this. For example, if the insertion hole includes a wall surface to which a permanent magnet is adhered, and the filling portion has a shape in which the inner edge region of the insertion hole corresponding to the wall surface of the insertion hole at one opening end of the insertion hole is stepped down and hollowed out, it is possible to use a bow-shaped insertion hole and a corresponding bow-shaped permanent magnet.

[0060] In the above embodiment, the insertion hole 51 has a cross-sectional shape that is elongated in the direction Pd perpendicular to the radial direction (direction of the straight line DL) of the rotor core 50. However, an insertion hole having a cross-sectional shape that is elongated in another direction may also be used.

[0061] In the above embodiment, the filling portion is shown as filling portion 54, which is adjacent to the insertion hole 51 radially inward from the insertion hole 51, but this is not limited to this, and a filling portion adjacent to the insertion hole 51 radially outward from the insertion hole 51 may be used, or two filling portions adjacent to the inside and outside of the insertion hole 51 in the radial direction may be used. In this case, two walls 51a and 51b can be used as the wall surfaces of the insertion hole 51 to which the permanent magnet 60 is attached.

[0062] In the above embodiment, a permanent magnet embedded motor M was shown that includes a stator St including nine teeth 22 and slots 23, and a rotor Rt including eight insertion holes 51 (i.e., eight permanent magnets 60), i.e., the rotor Rt has eight magnetic poles and the stator St has nine teeth and slots. However, the present invention is not limited to the above configuration, and can be similarly applied to a general permanent magnet embedded motor that satisfies the condition that the number of magnetic poles of the rotor is 2n (n is a natural number) and the number of teeth and slots of the stator is 3n (n is a natural number), or to a permanent magnet embedded motor having other numbers.

[0063] In the above embodiment, a trochoid pump is used as the pump unit in a pump device driven by a permanent magnet embedded motor M, but this is not limited to this and a vane pump or other type of pump may also be used.

[0064] As described above, the embedded permanent magnet motor of the present invention eliminates waste of adhesive used to secure the permanent magnets and is able to firmly bond the permanent magnets with a small amount of adhesive, making it useful not only as a drive source for pump equipment, but also as a drive source for a variety of other devices. [Explanation of symbols]

[0065] 1 Housing body (housing) 2 Pump cover 2a Inlet 2b Outlet 3 Motor cover (housing) 4 Circuit Board Cover 5 Rotation Axis U Pump Unit (Trochoid Pump) 11 Inner rotor (trochoid pump) 12 Outer rotor (trochoid pump) M Permanent magnet embedded motor (drive source) S axis St stator 20 Stator core 22 Teeth 23 Slots 40 Coil Rt Rotor 50 Rotor core DL Linear (radial direction) Pd Perpendicular to the radial direction of the rotor 51 Insertion hole Ls Long side Ss Short side 51a Wall surface to which permanent magnets are attached Ie The inner edge area of ​​the mounting hole that corresponds to the wall surface to which the permanent magnet is attached 51b, 51c Wall G void 52 Through hole 53 Outer magnetic pole part 53a Depression 53b Outer magnetic pole surface 54 Filling section 54a Side 54b Bottom Gr adhesive Tf Thin layer of adhesive 55 Isolation Wall 56 Receiving part 57 Shaft hole 60 Permanent Magnets 61a, 61b Wall 62 End face Gd Depth dimension of the filling part in the axial direction RT Thickness dimension in the axial direction of the rotor core Mt Thickness dimension of the permanent magnet in the short side direction Ht: Hole size in the short side direction of the insertion hole Cf: Gap between the permanent magnet and the mounting hole

Claims

1. An annular stator; a rotor core disposed inside the stator, the rotor core having circumferentially arranged insertion holes and filling portions provided adjacent to the insertion holes for filling with adhesive; and a rotor including permanent magnets inserted into the insertion holes and rotating about a predetermined axis; the insertion hole includes a wall surface to which the permanent magnet is attached, the filling portion has a shape in which an inner edge region of the insertion hole corresponding to the wall surface is stepped down at one opening end of the insertion hole, A permanent magnet embedded motor.

2. The insertion hole has a rectangular cross section perpendicular to the axis, the cross section including long sides and short sides, The permanent magnet has a rectangular plate shape in a cross section perpendicular to the axis, the rectangular plate shape including long sides and short sides. The filling portion has an inner edge region along the long side of the insertion hole, the inner edge region being recessed to form a stepped shape.

2. The permanent magnet embedded motor according to claim 1 .

3. the insertion hole has a cross-sectional shape that is elongated in a direction perpendicular to a radial direction of the rotor, The permanent magnet has a cross-sectional shape that is elongated in the vertical direction, The filling portion includes a bottom surface that is elongated in the vertical direction and flat in a direction perpendicular to the axis.

3. The permanent magnet embedded motor according to claim 2.

4. The filling portion is formed adjacent to the insertion hole on a radially inner side of the insertion hole.

3. The permanent magnet embedded motor according to claim 2.

5. When a depth dimension of the filling portion in the axial direction is Gd and a thickness dimension of the rotor core in the axial direction is RT, 0.05≦Gd / RT≦0.06 The present invention is formed so as to satisfy the following:

3. The permanent magnet embedded motor according to claim 2.

6. When the thickness dimension of the permanent magnet in the short side direction is Mt, the hole dimension of the insertion hole in the short side direction is Ht, and the gap dimension between the permanent magnet and the insertion hole is Cf = Ht - Mt, 0.1mm≦Cf≦0.2mm, The present invention is formed so as to satisfy the following:

3. The permanent magnet embedded motor according to claim 2.

7. When the depth dimension of the filling portion in the axial direction is Gd, the thickness dimension of the rotor core in the axial direction is RT, the thickness dimension of the permanent magnet in the short side direction is Mt, the hole dimension of the insertion hole in the short side direction is Ht, and the gap dimension between the permanent magnet and the insertion hole is Cf=Ht-Mt, 0.05≦Gd / RT≦0.06, 0.1mm≦Cf≦0.2mm, The present invention is formed so as to satisfy the following:

3. The permanent magnet embedded motor according to claim 2.

8. the insertion hole has a cross-sectional shape that is elongated in a direction perpendicular to a radial direction of the rotor, The permanent magnet has a cross-sectional shape that is elongated in the vertical direction, The filling portion includes a bottom surface that is elongated in the vertical direction and is flat in a direction perpendicular to the axis, The rotor core includes a gap continuous to both ends of the insertion hole in the vertical direction.

3. The permanent magnet embedded motor according to claim 2.

9. the rotor core includes a partition wall that separates the filling portion from a wall surface that defines the short side of the insertion hole, near both ends of the insertion hole in the long side direction, 3. The permanent magnet embedded motor according to claim 2.

10. the rotor core includes a receiving portion at the other open end of the insertion hole for receiving the permanent magnet inserted into the insertion hole by contacting the receiving portion, 3. The permanent magnet embedded motor according to claim 2.

11. The adhesive filled in the filling portion is in a paste form.

3. The permanent magnet embedded motor according to claim 2.

12. a housing for fixing the stator and for rotatably supporting the rotor; 12. The permanent magnet embedded motor according to claim 1, wherein the rotor is a rotor having a first end and a second end.

13. A pump unit that draws in and discharges a fluid; A rotating shaft connected to the pump unit; A pump device including: The driving source is a permanent magnet embedded motor according to claim 12. A pump device characterized in that

14. The pump unit is a trochoid pump including an inner rotor to which the rotating shaft is connected and an outer rotor that meshes with the inner rotor.

13. The pump device according to claim 12.

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