JP5602615B2 - Resin mold rotor, canned motor, and canned motor pump - Google Patents

Description

The present invention relates to a resin mold rotor having a structure in which a rotor core and a magnet and a main shaft are integrally molded with a resin, a canned motor using the resin molded rotor, and a canned motor pump in which the canned motor and a pump are integrated.
About.

  The canned motor pump's canned motor has a structure in which the rotor chamber containing the rotor is isolated by a stator can without sealing the rotating shaft of the rotor with a mechanical seal. It is safe and has a long life.

  On the other hand, since the motor rotor is exposed to the pump handling liquid, if the pump handling liquid is corrosive, the main shaft, the rotor core, the permanent magnet, and the like constituting the motor rotor must take corrosion resistance into consideration. FIG. 1 is a diagram showing a configuration example of a conventional motor rotor, FIG. 1 (a) is a front sectional view, and FIG. 1 (b) is a left side view. Corrosion-resistant materials can be used for the main shaft 101 of the motor rotor, but the rotor core 102 is generally made of an electromagnetic steel plate and the permanent magnet 103 is made of a rare earth element or the like, and has low corrosion resistance. As shown in the drawing, the rotor core 102 and the permanent magnet 103 are made of a rotor can 104, a load side rotor can side plate 106-1 and a counter load side rotor can side plate 106-2 made of a material equivalent to the material of the main shaft 101, for example, stainless steel. Cover, joint portion 105-1 between rotor can 104 and load side rotor can side plate 106-1, joint portion 105-2 between rotor can 104 and anti-load side rotor can side plate 106-2, joint portion between main shaft 101 and load side rotor can side plate 106-1 107-1, and the main shaft 101 and the anti-load side rotor can side plate 106-2 It was sealed by welding the joint portion 107-2. A through hole 101 a is formed at the center of the main shaft 101.

The manufacturing process of the conventional motor rotor is as follows.
(1) The rotor core 102 is fitted into the main shaft 101 (shrink fit, press fit, etc.).
(2) The permanent magnet 103 is inserted into the rotor core 102 and fixed by adhesion.
(3) The same stainless steel load side rotor can side plate 106-1 and counter load side rotor can side plate 106-2 as the main shaft 101 are abutted against both side surfaces of the rotor core 102 and circumferentially welded to the main shaft 7, respectively.
(4) A rotor can 104 made of stainless steel is placed on the rotor core 102, and both end faces are circumferentially welded to the load side rotor can side plate 106-1 and the anti-load side rotor can side plate 106-2, respectively.
(5) The completed motor rotor is inserted into the magnetizing yoke and magnetized.

The configuration and manufacturing process of the conventional motor rotor have the following problems (a) to (d).
(A) Expensive members are required for the rotor can 104, the load side rotor can side plate 106-1, and the anti-load side rotor can side plate 106-2.
(B) Since a lot of bonding and welding are used for fixing the parts, the manufacturing process takes a very long time and the manufacturing cost increases.
(C) The adhesive used for bonding and fixing the permanent magnet 103 and the rotor core 102 in the manufacturing step (2) is vaporized by heat input during welding, and the soundness of bonding and the swelling of the rotor can 104 due to gas generation. Likely to happen.
(D) Since the material constituting the rotor can 104 is a metal material, an eddy current is generated due to the passage of a magnetic field generated by a permanent magnet and a change in magnetic flux during rotation, and heat is generated by the flow of the eddy current. The motor efficiency was reduced.

  In order to solve the above problem, there is known a structure in which a rotor including a permanent magnet and a shaft material are integrally formed as a main shaft by a resin molding (see Patent Document 1).

Japanese Patent Laid-Open No. 7-312852

  However, as shown in FIGS. 2 and 3, in the conventional example in which the rotor core 102 including the permanent magnet 103 and the main shaft 101 are integrated with the resin mold layer 110 and configured as the main shaft 101, centrifugal force at high speed is obtained. It is possible to obtain a strong mechanical strength that can withstand torque at high torque, but from airtightness, especially from the gap generated between the metal member having a different linear expansion coefficient and the resin due to resin shrinkage when the resin is cured. No consideration is given to leakage. In particular, the resin mold layer 110 is destroyed due to leakage into the gap between the metal material constituting the main shaft 101 and the resin material constituting the resin mold layer 110, expansion due to heat of the handling liquid, and the like. There is a problem that the permanent magnet 103 comes into contact with the liquid and the motor is damaged.

  The present invention has been made in view of the above-described conventional problems, and has a simple configuration, a low-cost resin mold rotor that can reliably maintain airtightness, a cand motor using the resin mold rotor, and the cand motor. It aims at providing the canned motor pump which integrated the pump.

In order to solve the above problems, the present invention includes a magnet, a rotor configured by laminating a plurality of steel plates, and the main shaft that transmits the power to the outside by mounting the rotor. forming one or more grooves from the rotor both end surfaces of the main shaft on the load side and the outer periphery of the position spaced axially a predetermined dimension of the anti-load side, from the outer periphery and the rotor of the rotor to the portion where the grooves are formed in the main shaft outer resin mold layer of molten resin is formed on the periphery, in the course of cooling the molten resin, contractile force of the resin mold layer due to the difference in linear expansion coefficient of the material of the linear expansion coefficient and the rotor of the resin mold layer The resin mold rotor is characterized in that the resin mold layer is brought into close contact with the side surface of the groove .

As described above, the outer resin mold layer of molten resin is formed in the periphery, the cooling process of the molten resin from the outer periphery and the rotor of the rotor to the portion where the grooves are formed in the main shaft, the linear expansion coefficient of the resin mold layer Because the resin mold layer is brought into close contact with the side surface of the groove by utilizing the shrinkage force of the resin mold layer due to the difference in linear expansion coefficient between the rotor and the constituent material of the rotor , it is strong enough to withstand centrifugal force at high speed and torque at high torque Even if it is a resin mold rotor with an integral structure consisting only of a resin mold, it is possible to reliably maintain airtightness at low cost. In addition, since one or more grooves are provided on both the load side and the counter-load side from the rotor of the main shaft, deformation due to “sink” between the groove portions can be offset and a stable resin molded shape can be obtained.

Further, the present invention is characterized in that the resin mold rotor is provided with a through hole through which a pump handling liquid flows in a central portion of the main shaft .

In the resin mold rotor according to the present invention, at least a surface of the groove on the side close to the rotor is inclined from a surface orthogonal to the main shaft to the side opposite to the rotor .

  In addition, the present invention includes the resin mold rotor, a bearing that rotatably supports a main shaft of the resin mold rotor, and a canned stator that surrounds the rotor and applies a rotating magnetic field to the rotor. It is in the canned motor.

  The present invention also provides a canned motor pump comprising the above canned motor, an impeller fixed to the main shaft, and a pump casing surrounding the impeller.

The present invention is to form one or more grooves from the rotor both end surfaces of the main shaft on the load side and the outer periphery of the position spaced axially a predetermined dimension of the anti-load side, the outer periphery and the grooves of the spindle from the rotor of the rotor is formed to form a resin mold layer outside circumference to the molten resin up portion, in the course of cooling the molten resin, the contractile force of the resin mold layer due to the difference in linear expansion coefficient and the linear expansion coefficient of the rotor of the constituent material of the resin mold layer By utilizing the resin mold layer in close contact with the side surface of the groove, a resin mold rotor capable of maintaining a good sealed state between the resin mold, the rotor, and the main shaft can be provided with a simple configuration.

  In addition, by using the resin mold rotor for the can motor, the can motor can be configured to provide a long-life can motor with a simple configuration and at a low cost.

  In addition, by forming a canned motor pump with a canned motor, an impeller fixed to the main shaft, and a pump casing surrounding the impeller, a long-life canned motor pump can be provided with a simple configuration and at low cost.

It is a figure which shows the schematic structure of the canned rotor of the conventional canned motor. It is a figure which shows the general | schematic structure of the conventional general resin mold rotor. It is a figure which shows the general | schematic structure of the conventional general resin mold rotor. It is sectional drawing which shows the schematic structure of the canned motor pump which concerns on this invention. It is a figure showing the outline structure of the resin mold rotor concerning the present invention. It is a figure which shows the example of a partial outline structure of the resin mold rotor which concerns on this invention. It is a figure which shows the example of a partial outline structure of the resin mold rotor which concerns on this invention. It is a figure which shows the example of a partial outline structure of the resin mold rotor which concerns on this invention. It is a figure which shows the example of a partial outline structure of the resin mold rotor which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent member in each drawing.

  FIG. 4 is a cross-sectional view showing a schematic structure of a canned motor pump according to the present invention. As shown in the figure, the canned motor pump includes a stator 14 fixed to the inner peripheral surface of the motor frame 13 by shrink fitting, the rotor 10 rotatably disposed in the stator 14, and the tip of the main shaft 7 of the rotor 10. It is the structure provided with the impeller 1 mounted and fixed to the part. The stator 14 includes a stator core 15 in which a magnetic plate material having a circular hole formed in the center is stacked and a through space having a substantially cylindrical inner periphery formed therein, and a conductor (winding) wound around the stator core 15. ) 16 and a substantially cylindrical stator can 18 made of, for example, stainless steel, fixed to the inner peripheral surface of the stator core 15. The rotor 10 includes a rotor core 12 having a permanent magnet 9 embedded therein, and a load-side groove portion 7 that is a portion in which grooves are formed on the outer peripheral surface of the rotor core 12 and the outer periphery of both shaft ends outside the mounting range of the rotor core 12 of the main shaft 7. -1 and the anti-load side groove 7-2 are covered with the rotor resin mold 11. A uniform gap δ is formed between the surface of the rotor resin mold 11 formed on the outer periphery of the rotor core 12 and the inner periphery of the stator can 18.

  In this embodiment, an example in which an IPM (Internal Permanent Magnet) having a permanent magnet 9 inside the rotor 10 is applied to a motor is shown. However, an SPM (Surface Permanent Magnet) having a permanent magnet on the surface of the rotor 10 is shown. Of course, the present invention can also be applied to a motor having an electromagnet in a motor or a rotor to which the above is applied.

  The end 18-2 on the side opposite to the load of the stator can 18 (left side in FIG. 1) is brought into contact with the motor frame 13 and fixed by welding the contact portions of both. Further, a load side stator can side plate 19 provided with a through hole at the center of a disk-shaped plate material is provided at an end portion 18-1 on the load side (right side in FIG. 1) of the stator can 18. The end portion 18-1 of the stator can 18 is fitted into the 19 through holes, and the contact portions of both are fixed by welding from the end face side.

  The motor frame 13 is formed in a bottomed cylindrical shape in which the anti-load side end bracket is closed by the anti-load side bearing bracket 4 and the load side end is opened. The anti-load side bearing bracket 4 includes the main shaft 7. A cylindrical projecting portion 4a projecting in a cylindrical shape inward along the axial direction is provided, and an anti-load side bearing 6 for rotatably supporting the main shaft 7 is provided on the cylindrical projecting portion 4a. The motor frame 13 and the anti-load side bearing bracket 4 are hermetically sealed. For example, a sealing member 20-3 made of, for example, a rubber O-ring is interposed to prevent the pump handling liquid from leaking to the outside. The bearing bracket 4 is configured to be fixed to the motor frame 13 by tightening bolts 22. Further, an anti-load side thrust disk 8-2 is fixed to the main shaft 7 between the anti-load side bearing 6 and the rotor 10.

  On the other hand, a load side bearing bracket 3 is disposed at the load side end of the motor frame 13, and is disposed on the load side bearing bracket 3 on the output side of the main shaft 7 (right side in FIG. 1) to rotate the main shaft 7. A load-side bearing 5 that is freely supported is fixed. Further, a load side thrust disk 8-1 is fixed to the main shaft 7 between the load side bearing 5 and the rotor 10.

  A space is formed between the motor frame 13 and the load-side bearing bracket 3, and the outer peripheral portion of the load-side stay can side plate 19 is sandwiched in this space, and the bolt 21 for fixing the pump casing 2 is tightened, whereby the load side The stator can side plate 19 is configured such that its outer peripheral portion is sandwiched and fixed between the motor frame 13 and the load side bearing bracket 3. Furthermore, the load side bearing bracket 3 is configured such that its outer peripheral portion is sandwiched and fixed between the motor frame 13 and the pump casing 2.

  Between the load side bearing bracket 3 and the load side stator can side plate 19, a sealing member 20-2 made of, for example, a rubber O-ring or the like is interposed, and the load side bearing bracket 3 and the load side stator can side plate 19 are A sealing member 20-1 made of, for example, a rubber O-ring or the like is interposed between the load side bearing bracket 3 and the pump casing 2 so as to seal between the load side bearing bracket 3 and the pump. The space between the casings 2 is sealed.

  By interposing the sealing members 20-2 and 20-1 between the load side stator can side plate 19 and the load side bearing bracket 3 and between the load side bearing bracket 3 and the pump casing 2 as described above, the pump The handling liquid can be prevented from leaking outside.

  5A and 5B are views showing the entire configuration of the resin mold rotor in which the rotor resin mold 11 is formed. FIG. 5A is a front sectional view and FIG. 5B is a left side view. FIG. 6 is a partially enlarged sectional view of the rotor 10 and the main shaft. As described above, the rotor 10 arranged with the uniform gap δ (see FIG. 4) between the inner peripheral surface and the outer peripheral surface of the stator can 18 has a rotor core in which a permanent magnet 9 is embedded. 12 and the outer peripheral surface of the rotor core 12 and the load side groove portion 7-1 and the anti-load side groove portion 7-2 provided on the outer periphery of both shaft ends outside the mounting range of the rotor 10 of the main shaft 7 are covered with the rotor resin mold 11. It becomes the composition.

  The rotor resin mold 11 is made of a material having high corrosion resistance (PPS material, fluororesin PFA, etc.). Although the resin film thickness of the rotor resin mold 11 corresponding to the rotor can is approximately 0.5 mm to 1.0 mm, it is possible to improve mechanical strength, corrosion resistance, and liquid resistance, but more than necessary. Therefore, there is a problem from another point of view, such as a decrease in economic efficiency due to the use of materials, and a change in shape due to “sinking” of the materials, which impairs productivity.

  Further, both shaft end sides 11-1, 11- of the rotor resin mold 11 corresponding to the conventional rotor can side plate portion (see the load side rotor scan side plate 106-1 and the anti-load side rotor scan side plate 106-2 in FIG. 1). The thickness of 2 is suitably about 2 to 3 mm in consideration of the positioning accuracy in the axial direction. This is because the axial positioning accuracy dimension of the rotor core 12 when the rotor core 12 is mounted on the main shaft 7 in addition to the mechanical dimensions of the resin film thickness of the rotor resin mold 11 corresponding to the rotor can and the corrosion resistance and liquid resistance. Determined by taking into account tolerances.

  Further, the main shaft 7 is provided with a load-side groove portion 7-1 and a non-load-side groove portion 7-2 in which grooves are formed on the outer periphery of both shaft ends outside the mounting range of the rotor 10, and the rotor resin mold 11 is The load side groove portion 7-1 and the anti-load side groove portion 7-2 provided on both shaft end sides outside the mounting range are covered. Each of the groove portions 7-1 and 7-2 is an annular groove provided so as to go around the outer peripheral surface of the main shaft 7 in the circumferential direction.

  As described above, the rotor resin mold 11 is configured to cover the load side groove portion 7-1 and the anti-load side groove portion 7-2 so that the rotor resin mold 11 is in close contact with the main shaft 7, and the resin mold is molded. Even after natural cooling, the adhesion and sealing action can be maintained. Moreover, about the cross-sectional shape of the groove | channel of the load side groove part 7-1 and anti-load side groove part 7-2 provided in the outer periphery of the main axis | shaft 7, it is made into a wedge shape as shown in FIG. 7, and an inclined groove shape as shown in FIG. As shown in FIG. 9, the close contact / sealing action can be improved by providing a plurality of grooves.

  The conventional resin mold rotor shown in FIGS. 2 and 3 is not formed with the load-side groove portion 7-1 and the anti-load-side groove portion 7-2 having the structures shown in FIGS. 7, 8, and 9, or the corresponding groove portions. . Therefore, the resin mold layer 110 formed by injecting a molten resin material has a linear expansion coefficient larger than that of the rotor core 102 and the main shaft 101 made of a metal material, and the rotor core 102 is used as a reference in the process of being naturally cooled after injection molding. The rotor core 102 contracts toward the outer diameter side. For this reason, a force for contracting the outer diameter side of the contact portion of the resin mold layer 110 to the main shaft 101 also acts, and the contact force is reduced. As a result, it is not possible to obtain a sufficient sealing effect such as exposure of the inner diameter side of the rotor core 102 and a gap with the main shaft 101.

  Since the resin mold rotor according to the present invention has the load-side groove 7-1 and the anti-load-side groove 7-2 as shown in FIGS. 7, 8, and 9, the rotor resin mold 11 is injection-molded in the mold. Has a linear expansion coefficient larger than that of the rotor core 12 and the main shaft 7 made of a metal material, and utilizes contraction in the longitudinal direction by the load side groove 7-1 and the anti-load side groove 7-2 in the process of natural cooling after injection. Then, the rotor resin mold 11 is brought into close contact with the side surface of the groove, whereby the outer diameter of the rotor core 12 and the permanent magnet 9 are sealed without being exposed to the outside. Specifically, it can be shown in the following (1) to (4).

(1) In the case of one groove: As shown in FIG. 6, when one groove is formed in the load side groove 7-1 and the anti-load side groove 7-2, the rotor resin mold 11 as shown by an arrow A By utilizing the shrinkage change in the longitudinal direction, the rotor resin mold 11 is pressed against the side surface of the groove to improve the sealing performance.

(2) In the case of wedge-shaped grooves: As shown in FIG. 7, when the cross-sectional shape of the grooves formed in the load-side groove portion 7-1 and the anti-load-side groove portion 7-2 is wedge-shaped, as indicated by an arrow A Not only the shrinkage change in the longitudinal direction of the rotor resin mold 11 but also the shrinkage change in the outer diameter direction as shown by the arrow B, the rotor resin mold 11 is pressed against the taper-shaped surface of the groove side surface to improve the sealing performance. Can be improved.

(3) In the case of an inclined groove shape: As shown in FIG. 8, the groove forming the wedge-shaped groove formed in the load side groove portion 7-1 and the anti-load side groove portion 7-2 is complicated. When an inclined groove shape is formed by machining the main shaft 7 at an angle, the rotor resin mold 11 is contracted in the longitudinal direction and the contraction change in the outer diameter direction in the same manner as in (2). Sealing performance is improved by pressing the resin mold 11 against the tapered surface of the groove side surface.

  (4) In the case of a plurality of grooves: As shown in FIG. 9, when a plurality of grooves (two grooves in the figure) are formed in the load side groove 7-1 and the anti-load side groove 7-2, the arrow C, As shown in D, the sealing property is improved by pressing the rotor resin mold 11 against the side surface of the groove by utilizing the contraction in the longitudinal direction of the resin of the rotor resin mold 11 connecting the adjacent grooves. In this case, the reliability of the sealing performance is improved by increasing the number of groove side surfaces for pressing the resin.

  In addition, although illustration is abbreviate | omitted, of course, it is good also as a structure which each combined said (1) thru | or (4).

By adopting the above configuration in the resin mold rotor, the manufacturing process can be simplified as follows by the resin mold rotor having the conventional configuration shown in FIG.
(A) The rotor core 10 is inserted into the main shaft 7.
(B) The rotor obtained in the manufacturing step (a) is positioned in the injection mold using the main shaft as a guide.
(C) The permanent magnet 9 is mounted on the rotor core 10.
(D) A resin material is molded (injection molding) so that the rotor core 10 and the permanent magnet 9 are not exposed.
(E) The completed motor rotor is inserted into the magnetizing yoke and magnetized.

In this embodiment, the temperature control was performed at the following temperature.
-Melting temperature of resin: about 300 ° C
-Mold: about 100-200 ° C

  As described above, in the canned motor, the rotor can is made of a rotor resin mold made of a resin material having good corrosion resistance without using a metal material such as a stainless steel material for the rotor can, thereby preventing the rotor core and the magnet material, which are originally intended, from being corroded. Can do. In addition to being inexpensive, it is possible to prevent the generation of eddy current during operation like a can from a conventional metal material, and to provide an efficient canned motor.

  Next, the operation of the canned motor pump shown in FIG. 4 will be described. By connecting a three-phase AC power source to the outlet line 17 and energizing the conductor (winding) 16 of the stator 14 with a three-phase AC, the generated rotating magnetic field acts on the rotor 10 and the impeller 1 rotates. The pump handling liquid sucked from the suction port 2a of the pump casing 2 by the rotation of the impeller 1 flows into the pump casing 2, is discharged from the discharge port (not shown) through the discharge volute 24, and partly It flows into the rotor chamber surrounded by the stator can 18 through the hole 3 a provided in the load side bearing bracket 3. The pump handling liquid that has flowed into the rotor chamber passes through the gap δ between the rotor resin mold 11 and the stator can 18 and flows into the bottomed cylindrical cylindrical protrusion 4a of the anti-load side bearing bracket 4 and from here. It flows into the impeller 1 through a through hole 7a provided in the center of the main shaft 7, and merges with the sucked pump handling liquid.

  As described above, the pump-handed liquid flows into the rotor chamber surrounded by the stator can 18 and flows through the gap δ between the rotor resin mold 11 and the stator can 18, but the outer periphery of the rotor 10 and the rotor 10 of the main shaft 7. Since the rotor resin mold 11 is formed from the end surface to the load side groove 7-1 and the anti-load side groove 7-2, the rotor resin mold 11, the rotor 10 and the main shaft 7 are kept in a good sealed state, and the rotor No contact with the pump handling liquid. Therefore, the life of the resin mold rotor can be extended.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible.

  The present invention includes a magnet, a rotor configured by laminating a plurality of steel plates, and a main shaft that mounts the rotor and transmits power to the outside, and is located at a predetermined axial distance from the rotor end surface of the main shaft. A groove is formed on the outer periphery of the rotor, and a resin mold is formed on the outer periphery of the rotor and the outer periphery of the main shaft from the rotor to the portion where the groove is formed. It can be used as a motor rotor of a can motor or a canned motor pump as a long-life resin mold rotor capable of maintaining a good sealed state.

DESCRIPTION OF SYMBOLS 1 Impeller 2 Pump casing 3 Load side bearing bracket 4 Anti load side bearing bracket 5 Load side bearing 6 Anti load side bearing 7 Main shaft 7-1 Load side groove 7-2 Anti load side groove 8-1 Load side slide disk 8- 2 Non-load side slide disk 9 Permanent magnet 10 Rotor 11 Rotor resin mold 12 Rotor core 13 Motor frame 14 Stator 15 Stator core 16 Conductor (winding)
17 Exit line 18 Stator can 19 Load side stator can side plate 20-1 Sealing member 20-2 Sealing member 20-3 Sealing member 21 Bolt 22 Bolt 23 Blade stop nut δ Clearance

Claims (5)

Magnets,
A rotor comprising a plurality of steel plates and provided with the magnet;
A main shaft that mounts the rotor and transmits power to the outside;
Forming one or more grooves in the outer periphery of the position spaced axially a predetermined dimension on the load side and counter load side from the rotor both end faces of the main spindle,
The rotor outer periphery and to form a resin mold layer outside circumference to the molten resin from the rotor to the portion where the grooves are formed in the main axis of, in the course of cooling the molten resin, the linear expansion coefficient of the resin mold layer A resin mold rotor, wherein the resin mold layer is brought into close contact with a side surface of the groove by utilizing a contraction force of the resin mold layer due to a difference in linear expansion coefficient of a constituent material of the rotor. In the resin mold rotor according to claim 1,
A resin-molded rotor characterized in that a through-hole through which a pump handling liquid flows is provided at the center of the main shaft . In the resin mold rotor according to claim 1 or 2,
The resin mold rotor characterized in that at least a surface of the groove on the side close to the rotor is inclined to a side opposite to the rotor from a surface orthogonal to the main axis. The resin mold rotor according to any one of claims 1 to 3,
A bearing that rotatably supports the main shaft of the resin mold rotor;
A canned motor comprising: a canned stator that surrounds the rotor and applies a rotating magnetic field to the rotor. A canned motor according to claim 4;
An impeller fixed to the main shaft;
A canned motor pump comprising: a pump casing surrounding the impeller.

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