JP2019037118A - Water-sealed motor and submersible pump - Google Patents

Abstract

To provide a water-sealed motor and a submersible motor capable of maintaining water-resistant insulation performance for high efficiency and for long term.SOLUTION: A water-sealed motor 1 includes: a motor shaft; a rotor and a stator 4 for rotating the motor shaft; and a cylindrical casing 5 for housing the rotor and the stator 4. An interior of the casing 5 is filled with enclosed water. A mold resin 30 which covers the stator 4 and rubber ring 40 arranged in the opposed part A of the mold resin 30 and the casing 5 are included.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a water ring motor and a submersible pump.

  As a motor used for driving a deep well submersible pump or the like, a so-called water-sealed motor is used in which the casing is filled with sealed water in order to keep the pressure inside and outside the motor casing constant. The sealed water generally consists of a harmless and water-soluble antifreeze composed of water or an aqueous solution of propylene glycol so that it can leak to outside water. The charging parts such as the stator core of the motor, the coil, and the connection portion between the lead wire and the coil are covered with a metal member (frame, side plate, can, etc.) so that the sealed water is not directly touched, and the stator is hermetically sealed. In general, the stator structure is such that sealed water does not enter. As such a water-sealed motor, for example, a canned motor described in Patent Document 1 below is known.

Japanese Patent Laid-Open No. 9-103042

By the way, the can inserted between the inner peripheral surface of the stator core and the outer peripheral surface of the rotor is generally made of a non-magnetic material such as thin stainless steel, but the rotating magnetic field generated in the stator passes through the can. When propagating to the rotor, an eddy current is generated inside the can, and this eddy current causes an electric resistance loss (can loss), resulting in a problem that efficiency is deteriorated.
Therefore, the inventor of the present application has considered to provide water resistance by molding the stator and the rotor with resin without inserting the can as a method for preventing such a can loss. However, the linear expansion coefficient of the mold resin is greatly different from several times to several tens of times with respect to the linear expansion coefficient of the metal members such as the stator, the core of the rotor, the casing, and the motor shaft. For this reason, when the motor is warmed or cooled with the operation / stop of the motor, a minute gap is generated between the metal member and the mold resin due to the difference in the linear expansion coefficient described above. There is a possibility that the enclosed water may enter the mold resin. As a result, in the stator, the insulation is lowered due to the proximity of the coil and the sealed water, and in the rotor, the permanent magnet may react with the sealed water and the activity and corrode and collapse. In addition, even if an adhesive or the like is previously interposed at the interface between the metal member and the mold resin, it is peeled off by a long-term thermal cycle, and it is difficult to prevent the ingress of enclosed water.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a water-sealed motor and a submersible motor that are highly efficient and can maintain water-resistant insulation performance for a long period of time.

  (1) A water-sealed motor according to an aspect of the present invention includes a motor shaft, a rotor and a stator that rotate the motor shaft, and a cylindrical casing that houses the rotor and the stator. Is a water-sealed motor filled with sealed water, and includes a mold resin that covers the stator, and a rubber ring that is disposed at a facing portion of the mold resin and the casing.

(2) In the water-sealed motor described in (1) above, the stator has a stator core fixed to the inner peripheral surface of the casing, and the rubber ring is formed between the casing and the stator core. You may arrange | position at the corner | angular part.
(3) In the water-sealed motor described in (2) above, the rubber ring has a right-angled portion in contact with a corner of the casing and the stator core, and a hypotenuse on the opposite side of the right-angled portion. You may have the cross-sectional shape of the right triangle which has.
(4) In the water-sealed motor described in (1) to (3) above, the rubber ring may be formed of a water-expandable rubber.
(5) The water-sealed motor described in the above (1) to (4), wherein the second mold resin that covers the rotor, and the second mold resin and the motor shaft are arranged at opposing portions. A second rubber ring.
(6) The water-sealed motor described in (5) above, wherein the rotor has a rotor core fixed to an outer peripheral surface of the motor shaft, and the second rubber ring is connected to the motor shaft. You may arrange | position at the corner | angular part with the said rotor core.
(7) The water-sealed motor according to (6), wherein the second rubber ring has a right-angled portion in contact with a corner between the motor shaft and the rotor core, and the opposite side of the right-angled portion May have a cross-sectional shape of a right triangle having a hypotenuse.
(8) In the water-sealed motor described in (5) to (7) above, the second rubber ring may be made of water-expandable rubber.

  (9) The submersible pump which concerns on 1 aspect of this invention has the water-sealed motor described in said (1)-(8), and the pump part driven by the said water-sealed motor.

  According to the above aspect of the present invention, water-resistant insulation performance can be maintained with high efficiency over a long period of time.

It is a whole block diagram of a submersible pump provided with a water ring type motor concerning a 1st embodiment. It is sectional drawing of the water ring type motor which concerns on 1st Embodiment. It is an enlarged view of the stator covered with the mold resin according to the first embodiment. It is explanatory drawing which shows the mode during (a) driving | operation stop of the water ring motor which has a rubber ring which concerns on 1st Embodiment, and (b) driving | operation. It is explanatory drawing which shows the mode in (b) operation | movement at the time of (a) operation stop of the water-sealed motor which does not have a rubber ring as a comparative example. It is an enlarged view which shows the rubber ring provided in the water ring motor which concerns on another form of 1st Embodiment. It is a figure which shows the rotor covered with the mold resin which concerns on 2nd Embodiment. It is explanatory drawing which shows the mode in (b) operation | movement at the time of (a) operation stop of the rotor which has a rubber ring which concerns on 2nd Embodiment. It is an enlarged view which shows the rubber ring provided in the rotor which concerns on another form of 2nd Embodiment. It is an enlarged view which shows the rubber ring provided in the rotor which concerns on another form of 2nd Embodiment. It is an enlarged view which shows the rubber ring provided in the rotor which concerns on another form of 2nd Embodiment.

  Hereinafter, a water ring motor and a submersible pump according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is an overall configuration diagram of a submersible pump 100 including a water ring motor 1 according to the first embodiment.
As shown in FIG. 1, the submersible pump 100 includes a water ring motor 1 and a pump unit 101 that is driven by the water ring motor 1. This submersible pump 100 is installed in a deep well, for example, and discharges groundwater.

  The pump unit 101 is attached to the upper part of the water ring motor 1. The pump unit 101 includes a cylindrical casing 102 and a pump shaft 103 accommodated in the casing 102. The casing 102 has a configuration in which a suction casing 104, an intermediate casing 105, an upper casing 106, a valve casing 107, and a discharge casing 108 are connected along a rotation center axis B of the pump shaft 103 in order from the bottom.

  The pump shaft 103 includes a main shaft 109 connected to the motor shaft 2 of the water ring motor 1 and a plurality of impellers 110 attached to the main shaft 109. A lower portion of the main shaft 109 is connected to the motor shaft 2 via a socket coupling 111. An intermediate portion of the main shaft 109 is rotatably supported via an intermediate bearing 112. Further, the upper portion of the main shaft 109 is rotatably supported via an upper bearing 113. The impeller 110 is attached to the main shaft 109 in a multistage manner between the intermediate bearing 112 and the upper bearing 113, and rotates integrally with the main shaft 109.

  A plurality of suction ports 114 are formed on the peripheral surface of the suction casing 104. When the pump shaft 103 rotates, the liquid outside the casing 102 is sucked into the casing 102 through the plurality of suction ports 114. The intermediate casing 105 forms a spiral flow path that guides the liquid sucked into the casing 102 to the multistage impeller 110. A guide vane 115 that guides the liquid discharged from the impeller 110 in the radial direction to the next stage is attached to the intermediate casing 105.

  The upper casing 106 forms a flow path that guides the liquid discharged from the intermediate casing 105 upward. The upper casing 106 supports the upper bearing 113. The valve casing 107 houses a valve mechanism 117 that can close the flow path of the upper casing 106. The valve mechanism 117 includes a valve stem 118 disposed along the rotation center axis B, a valve body 119 movable along the valve stem 118, and a spring 120 that biases the valve body 119 toward the valve seat 121. Have.

  The valve seat 121 is sandwiched between the upper casing 106 and the valve casing 107. When the pump shaft 103 is not rotating, the valve body 119 is moved downward by the spring 120 and comes into contact with the valve seat 121. When the valve body 119 contacts the valve seat 121, the flow path of the upper casing 106 is closed. A discharge port 122 is formed at the top of the discharge casing 108. The discharge port 122 communicates with a flow path formed around the valve mechanism 117 of the valve casing 107 and discharges the liquid upward, and a pipe (not shown) can be connected to the surrounding flange portion.

FIG. 2 is a cross-sectional view of the water ring motor 1 according to the first embodiment.
As shown in FIG. 2, the water ring motor 1 includes a motor shaft 2, a rotor 3 and a stator 4 that rotate the motor shaft 2, and a casing 5 that houses the rotor 3 and the stator 4. The motor shaft 2 is disposed along the rotation center axis B. The motor shaft 2 is rotatably supported by a plurality of bearings 6 and 7. A rotor 3 having a magnet is fixed around the motor shaft 2.

  The casing 5 is formed in a cylindrical shape, and side plates 14 and 15 are fixed to upper and lower ends thereof. The casing 5 is made of stainless steel, for example, and the internal space 11 is filled with sealed water. A lower portion of the internal space 11 is formed by a diaphragm 13 stretched by a spring 12. The diaphragm 13 is deformed according to the pressure difference between the internal space 11 and the outside of the casing 5 to relieve the pressure difference. The sealed water contacts the motor shaft 2, the rotor 3, and the plurality of bearings 6 and 7, and cools and lubricates them. Further, the sealed water filled in the casing 5 is sealed by the shaft seal device 8.

  The stator 4 includes a stator core 17 fixed to the inner peripheral surface 5 a of the casing 5, and a coil 18 wound around the stator core 17. A lead wire 20 is connected to the coil 18, and the lead wire 20 is connected to a power cable 21 outside the casing 5 via a terminal member 22. The stator 4 is covered with a mold resin 30. The mold resin 30 covers the stator core 17, the coil 18, and the connection portion between the coil 18 and the lead wire 20.

FIG. 3 is an enlarged view of the stator 4 covered with the mold resin 30 according to the first embodiment.
As shown in FIG. 3, the stator core 17 is formed in an annular shape along the inner peripheral surface 5 a of the casing 5. The stator core 17 is formed by laminating a plurality of electromagnetic steel plates in the axial direction extending in parallel with the motor shaft 2, and a slot (not shown) through which the coil 18 is inserted in both end surfaces 17 a in the axial direction. (Space) is open. The outer peripheral surface 17 b of the stator core 17 is in contact with the inner peripheral surface 5 a of the casing 5.

  The mold resin 30 covers both end surfaces 17a of the stator core 17 and covers the inner peripheral surface 17c of the stator core 17 with a thickness T in order to prevent intrusion of sealed water from the inner peripheral surface 17c of the stator core 17. The thickness T depends on the strength of the mold resin 30 and the convenience of molding, but is about 1 to 2 mm, for example. For example, the mold resin 30 is cast by making the core metal of the mold metal smaller than the inner diameter of the stator core 17 so that a gap is formed between the core metal and the inner peripheral surface 17c of the stator core 17. Can be molded.

  For the mold resin 30, for example, a two-component curable epoxy resin or the like can be used. After pouring this liquid resin into the mold, the resin is solidified. In addition, in order to solidify resin quickly, it is good to hold | maintain and harden about 80-120 degreeC high temperature. After the resin is cured, the stator is taken out from the casting mold and cooled to form a thin film of the mold resin 30 on the inner peripheral surface 17c of the stator core 17. This mold resin 30 integrally covers the connecting portion between the stator core 17, the coil 18, the coil 18 and the lead wire 20 excluding the outer peripheral surface 17 b so as to be in contact with the inner peripheral surface 5 a of the casing 5.

  As shown in FIG. 3, a rubber ring 40 is disposed at a facing portion A between the mold resin 30 and the casing 5. The rubber ring 40 is an annular seal member (for example, an O-ring) and has a circular cross-sectional shape. The rubber ring 40 is disposed at the corner 10 between the casing 5 and the stator core 17. The corner 10 is formed by the inner peripheral surface 5 a of the casing 5 and the end surface 17 a of the stator core 17, and is formed at both ends in the axial direction of the stator core 17. The rubber ring 40 disposed in the corner portion 10 is in contact with the inner peripheral surface 5 a of the casing 5 and the end surface 17 a of the stator core 17.

  The rubber ring 40 is preferably formed from water-expandable rubber. The water-expandable rubber is a rubber that swells (expands) about 1.5 to 10 times in volume when contacted with water, and is made of a base material such as butyl rubber, chloroprene rubber, or urethane rubber. The rubber ring 40 can be easily disposed in the facing portion A by being attached to the corner portion 10 of the casing 5 and the stator core 17 in advance before the molding resin 30 is cast. It is preferable that the outer diameter of the rubber ring 40 is slightly larger than the inner peripheral surface 5a (inner diameter) of the casing 5, whereby a pressure accumulation state is obtained when the rubber ring 40 is attached to the corner portion 10, and positioning of the rubber ring 40 is facilitated. .

Then, with reference to FIG.4 and FIG.5, the effect | action of the water-sealed motor 1 of the said structure is demonstrated.
FIGS. 4A and 4B are explanatory views showing a state of the water-sealed motor 1 having the rubber ring 40 according to the first embodiment during (a) operation stop and (b) operation. FIG. 5 is an explanatory view showing a state during (a) operation stop and (b) operation of a water-sealed motor 1 ′ that does not have the rubber ring 40 as a comparative example.

In the case of the water-sealed motor 1 ′ of the comparative example, as shown in FIG. 5A, when the operation is stopped and cooled, the mold resin 30 contracts more in the radial direction than the casing 5, and the mold resin 30 and the casing A gap S <b> 1 is formed in a portion A facing the A 5. This casing 5 and the linear expansion coefficient of the metal material or the like of the stator core 17, to which the for example 10 to 18 × ^{10 -6,} the coefficient of linear expansion of the mold resin 30, for example 60-80 × 10 ^{- The} reason is that it is greatly different from about ⁶ . For this reason, even if the mold resin 30 is molded so as to be in contact with the inner peripheral surface 5a of the casing 5, a gap S1 is formed between the mold resin 30 and the casing 5, so that the sealed water enters the gap S1. End up.

  Next, as shown in FIG. 5 (b), when the operation is resumed and the water-sealed motor 1 'is warmed, the gap S1 disappears due to the radial expansion of the mold resin 30, but a gap S2 is formed instead. The That is, the mold resin 30 covering both end faces 17a of the stator core 17 is connected through a slot (not shown) of the stator core 17, and the mold resin 30 expands more in the axial direction than the stator core 17, thereby A gap S <b> 2 is formed between the resin 30 and the end surface 17 a of the stator core 17. Since the sealed water that has entered the gap S1 enters the gap S2 from the gap S1, there is a possibility that it will come into contact with the coil 18. Thus, it is difficult to prevent intrusion of the enclosed water only by covering the stator 4 with the mold resin 30.

  As shown in FIG. 4A, the water ring motor 1 according to the present embodiment has a rubber ring 40 disposed at a facing portion A between the mold resin 30 and the casing 5. According to this configuration, as shown in FIG. 4A, the operation is stopped and the water-sealed motor 1 is cooled, and the mold resin 30 is contracted more in the radial direction than the casing 5 to form the gap S1. In addition, since the rubber ring 40 is disposed in the facing portion A, it is possible to prevent the intrusion of sealed water through the gap S1. Further, as shown in FIG. 4B, even if the operation is resumed and the water-sealed motor 1 is warmed to form the gap S2, the sealed water is less likely to enter the gap S2, so that it can be used for a long time. The water resistance of the stator 4 can be maintained.

  That is, in the present embodiment, the rubber ring 40 is disposed at the corner 10 between the casing 5 and the stator core 17. According to this configuration, as shown in FIG. 4A, when the water-sealed motor 1 is cooled and the mold resin 30 contracts in the axial direction, the rubber ring 40 is located between the mold resin 30 and the end face 17 a of the stator core 17. The rubber ring 40 extends in the radial direction and comes into close contact with the inner peripheral surface 5a of the casing 5, thereby improving the sealing performance. Also, as shown in FIG. 4B, when the water-sealed motor 1 is warmed and the mold resin 30 expands in the radial direction, the rubber ring 40 is pressed against the inner peripheral surface 5a of the casing 5 so that the seal is sealed. Improves.

  Furthermore, in this embodiment, the rubber ring 40 is formed from water-expandable rubber. As shown in FIG. 4A, the sealed water that has entered the gap S <b> 1 formed in the facing portion A between the mold resin 30 and the casing 5 comes into contact with the rubber ring 40 before reaching the end surface 17 a of the stator core 17. Therefore, the rubber ring 40 is expanded by water, and the water stop performance between the mold resin 30 and the inner peripheral surface 5a of the casing 5 and the end surface 17a of the stator core 17 is further improved. Accordingly, since the sealed water is less likely to enter the stator 4, the water resistance of the stator 4 can be maintained over a long period of time.

  Thus, according to the above-described embodiment, the motor shaft 2, the rotor 3 and the stator 4 that rotate the motor shaft 2, and the cylindrical casing 5 that houses the rotor 3 and the stator 4 are provided. A water-sealed motor 1 in which the inside of the casing 5 is filled with sealed water, the mold resin 30 covering the stator 4, and the rubber ring 40 disposed in the facing portion A between the mold resin 30 and the casing 5; Since the sealed water is prevented from entering the inside of the mold resin 30 by adopting the configuration of having the above, the water-resistant insulation performance of the stator 4 can be maintained for a long time. Moreover, since the water-sealed motor 1 of this embodiment does not have a metal can, a can loss does not generate | occur | produce and becomes high efficiency. Furthermore, the water-sealed motor 1 of the present embodiment has a simpler structure and is less expensive than conventional canned and water-resistant insulated wire submersible motors.

In the first embodiment, the following other forms can be adopted.
FIG. 6 is an enlarged view showing a rubber ring 40A provided in a water-sealed motor 1A according to another form of the first embodiment.
As shown in FIG. 6, the rubber ring 40 </ b> A disposed at the corner portion 10 between the casing 5 and the stator core 17 has a right angle portion 41 in contact with the corner portion 10, and has an oblique side portion 42 on the opposite side of the right angle portion 41. It has a right triangle cross section. According to this configuration, for example, as shown in FIG. 4A, when the water-sealed motor 1 is cooled and the mold resin 30 contracts in the axial direction, a force is applied to the oblique side portion 42 of the rubber ring 40A, and the rubber ring Since 40A is pressed by both the inner peripheral surface 5a of the casing 5 and the end surface 17a of the stator core 17, the sealing performance is further improved.

(Second Embodiment)
Next, a water ring motor according to a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

FIG. 7 is a view showing the rotor 3 covered with the mold resin 50 according to the second embodiment.
As shown in FIG. 7, the water-sealed motor 1 </ b> B of the second embodiment is different from the above-described embodiment in that the rotor 3 is covered with a mold resin 50 (second mold resin).

  The rotor 3 includes a rotor core 61 fixed to the outer peripheral surface 2 b of the motor shaft 2 and a permanent magnet 62 inserted into the rotor core 61. The rotor core 61 is formed by laminating a plurality of disc-shaped electromagnetic steel plates in the axial direction extending in parallel with the motor shaft 2, and the permanent magnet 62 is inserted into both end surfaces 61 a in the axial direction. A slot (space) (not shown) is opened. The inner peripheral surface 61 c of the rotor core 61 is in contact with the outer peripheral surface 2 b of the motor shaft 2. The permanent magnet 62 is made of, for example, a general rare earth element having low corrosion resistance against the sealed water.

  The mold resin 50 covers the rotor core 61 and the permanent magnet 62. Specifically, the mold resin 50 covers both the end surfaces 61a of the rotor core 61, and covers the outer peripheral surface 61b of the rotor core 61 with a thickness T1 in order to prevent intrusion of enclosed water from the outer peripheral surface 61b of the rotor core 61. . The thickness T1 depends on the strength of the mold resin 50 and the convenience of molding, but is about 1 to 2 mm, for example. Such a mold resin 50 is cast, for example, by making the mold die larger than the outer diameter of the rotor core 61 and forming a gap between the mold die and the outer peripheral surface 61 b of the rotor core 61. Can be molded.

  For the mold resin 50, for example, a two-component curable epoxy resin or the like can be used. After pouring this liquid resin into the mold, the resin is solidified. In addition, in order to solidify resin quickly, it is good to hold | maintain and harden about 80-120 degreeC high temperature. After the resin is cured, the stator is taken out from the casting mold and cooled to form a thin film of the mold resin 50 on the outer peripheral surface 61b of the rotor core 61. The mold resin 50 integrally covers the rotor core 61 and the permanent magnet 62 excluding the inner peripheral surface 61c so as to be in contact with the outer peripheral surface 2b of the motor shaft 2.

  As shown in FIG. 7, a rubber ring 70 (second rubber ring) is disposed at a facing portion C between the mold resin 50 and the motor shaft 2. The rubber ring 70 is an annular seal member (for example, an O-ring) and has a circular cross-sectional shape. The rubber ring 70 is disposed at the corner 10 </ b> A between the motor shaft 2 and the rotor core 61. 10 A of corner | angular parts are formed of the outer peripheral surface 2b of the motor shaft 2, and the end surface 61a of the rotor core 61, and are formed in the both ends in the axial direction of the rotor core 61. As shown in FIG. The rubber ring 70 disposed at the corner 10 </ b> A is in contact with the outer peripheral surface 2 b of the motor shaft 2 and the end surface 61 a of the rotor core 61.

  The rubber ring 70 is preferably formed from water-expandable rubber, like the rubber ring 40 of the first embodiment described above. The water-expandable rubber is a rubber that swells (expands) about 1.5 to 10 times in volume when contacted with water, and is made of a base material such as butyl rubber, chloroprene rubber, or urethane rubber. The rubber ring 70 can be easily disposed in the facing portion C by mounting the rubber ring 70 on the corner portion 10A of the motor shaft 2 and the rotor core 61 in advance before the molding resin 50 is cast. It is preferable that the inner diameter of the rubber ring 70 is slightly smaller than the outer peripheral surface 2b (outer diameter) of the motor shaft 2 at the mounting portion of the rotor core 61, whereby a pressure accumulation state is obtained when the rubber ring 70 is attached to the corner portion 10A. It becomes easy to position.

Then, with reference to FIG. 8, the effect | action of the water-sealed motor 1B of the said structure is demonstrated.
FIG. 8 is an explanatory diagram showing a state of (a) when the operation of the rotor 3 having the rubber ring 70 according to the second embodiment is stopped and (b) during operation.

  As shown in FIG. 8A, the water-sealed motor 1 </ b> B of the second embodiment has a rubber ring 70 disposed at a facing portion C between the mold resin 50 and the motor shaft 2. According to this configuration, as shown in FIG. 8A, when the operation is stopped and the water-sealed motor 1B is cooled (further due to the pressure during the injection molding of the mold resin 50), and the mold resin 50 contracts, For example, in the radial direction, the rubber ring 70 is compressed between the mold resin 50 and the outer peripheral surface 2 b of the motor shaft 2. As a result, the rubber ring 40 and the mold resin 50 are brought into close contact with each other, and the rubber ring 40 and the outer peripheral surface 2b of the motor shaft 2 are brought into close contact with each other. .

  Further, since the rubber ring 70 is arranged at the corner 10A between the motor shaft 2 and the rotor core 61, the rubber ring 70 is contracted when the mold resin 50 contracts in the axial direction due to thermal contraction (and pressure at the time of injection molding). Is compressed between the mold resin 50 and the end surface 61 a of the rotor core 61. As a result, the rubber ring 70 and the rotor core 61 are in close contact with each other, and the close contact portion P3 is formed. If it does so, since the three contact | adherence parts P1-P3 of the outer peripheral surface 2b of the motor shaft 2, the mold resin 50, and the end surface 61a of the rotor core 61 are formed, water stop performance improves. Accordingly, the sealed water is less likely to enter the rotor 3, so that the water resistance of the rotor 3 can be maintained over a long period of time.

  Further, as shown in FIG. 8B, when the operation is resumed and the water-sealed motor 1B is warmed, the mold resin 50 expands in the radial direction from the motor shaft 2, and the mold resin 50 and the motor shaft 2 There may be a gap S3 between them. Further, the mold resin 50 expands more in the axial direction than the rotor core 61, and a gap S <b> 4 can be generated between the mold resin 50 and the end surface 61 a of the rotor core 61. Here, the rubber ring 70 is pre-compressed by the mold resin 50, and expands (restores and deforms) when a part of the accumulated pressure is released, and maintains the water stop performance at the contact portions P1 to P3. Further, the rubber ring 70 is made of water-expandable rubber, and the sealed water that has entered the gap S3 comes into contact with the rubber ring 70 before reaching the end surface 61a of the rotor core 61. By doing so, the water stop performance is further improved. Accordingly, the sealed water is less likely to enter the rotor 3, so that the water resistance of the rotor 3 can be maintained over a long period of time.

  Thus, according to the second embodiment described above, the motor shaft 2, the rotor 3 and the stator 4 that rotate the motor shaft 2, and the casing 5 that houses the rotor 3 and the stator 4 are provided. A water-sealed motor 1B filled with sealed water, and a mold resin 50 that covers the rotor 3, and a rubber ring 70 that is disposed at a facing portion C between the mold resin 50 and the motor shaft 2. By adopting the configuration of having, it is possible to prevent the sealed water from entering the inside of the mold resin 50, so that the water resistant insulation performance of the rotor 3 can be maintained for a long time. Moreover, since the water-sealed motor 1B of the second embodiment has no metal can, no can loss occurs and the efficiency is high. Furthermore, the water-sealed motor 1B of the second embodiment has a simpler structure and is less expensive than the conventional canned and water-resistant insulated wire submersible motors.

Note that the second embodiment may adopt another form as follows.
FIG. 9 is an enlarged view showing a rubber ring 70 </ b> C provided in the rotor 3 according to another form of the second embodiment.
As shown in FIG. 9, the rubber ring 70 </ b> C disposed at the corner portion 10 </ b> A between the motor shaft 2 and the rotor core 61 has a right angle portion 71 in contact with the corner portion 10 </ b> A, and an oblique side portion 72 on the opposite side of the right angle portion 71. It has a right-angled triangular cross-sectional shape. According to this configuration, for example, when the rubber ring 70 </ b> C expands in the radial direction (water expansion), the upper end portion of the rubber ring 70 </ b> C enters a wedge shape in the gap between the mold resin 50 and the rotor core 61. Since it is pressed by both of the end surfaces 61a, the sealing performance at the contact portions P2 and P3 is further improved.

FIG. 10 is an enlarged view showing rubber rings 70D1 and D2 provided in the rotor 3 according to another form of the second embodiment.
As shown in FIG. 10, a plurality of rubber rings 70 </ b> D <b> 1 and D <b> 2 are arranged at the corner 10 </ b> A between the motor shaft 2 and the rotor core 61. The inner diameter of the rubber ring 70D1 is slightly smaller than the outer peripheral surface 2b (outer diameter) of the motor shaft 2, and is attached to the motor shaft 2 in a pressure accumulation state to form a close contact portion P1. The rubber ring 70 </ b> D <b> 2 is in close contact with the mold resin 50 and the end surface 61 a of the rotor core 61 to form the close contact portions P <b> 2 and P <b> 3, and is supported by a ring member 73 having a rectangular shape in sectional view attached to the outer peripheral surface 2 b of the motor shaft 2. ing. The rubber ring 70D1 is in close contact with the side surface of the ring member 73 and forms a close contact portion P4.

The ring member 73 is a resin member having a larger linear expansion coefficient than the mold resin 50. For example, when the mold resin 50 is a PPS (polyphenylene sulfide) resin, the linear expansion coefficient is about 20 to 30 × 10 ^−6. Therefore, the ring member 73 is made of EP (epoxy) resin and the linear expansion coefficient is 40 × 10. It should be about ^-6 . According to this configuration, even if the mold resin 50 is thermally expanded in the radial direction and a gap is formed between the rubber ring 70 </ b> D <b> 1 and the mold resin 50, the ring member 73 is heated more greatly in the radial direction than the mold resin 50. Since it expands, the rubber ring 70D2 is lifted, and the water stopping performance (at the contact portion P2) with the mold resin 50 is maintained. That is, the water stopping performance is maintained even if the rubber rings 70D1 and D2 are not water-expandable rubber. In addition, if the rubber rings 70D1 and D2 are water-expandable rubbers, the water stop performance is further improved.

FIG. 11 is an enlarged view showing rubber rings 70E1 and E2 provided in the rotor 3 according to another form of the second embodiment.
The form shown in FIG. 11 is a combination of the form shown in FIG. 9 and the form shown in FIG. That is, a plurality of rubber rings 70E1 and E2 having a right-angled triangular cross-sectional shape are arranged at the corner 10A between the motor shaft 2 and the rotor core 61, and the rubber ring 70E2 has a larger linear expansion coefficient than the mold resin 50. 73. According to this configuration, the wedge effect by the rubber ring 70E2 and the pressing (pushing up) effect by the ring member 73 are obtained, and the water stop performance is further improved. The rubber rings 70E1 and E2 may be integrated. That is, the upper and lower ends of the rubber rings 70E1 and E2 are connected to form a right triangle as a whole, but a form in which a groove for arranging the ring member 73 is formed at the right angle may be adopted.

  Although preferred embodiments of the present invention have been described and described above, it should be understood that these are exemplary of the present invention and should not be considered as limiting. Additions, omissions, substitutions, and other changes can be made without departing from the scope of the invention. Accordingly, the invention is not to be seen as limited by the foregoing description, but is limited by the scope of the claims.

For example, in the first embodiment, the configuration in which the rubber ring 40 is disposed at the corner portion 10 of the casing 5 and the stator core 17 has been described. However, the rubber ring 40 may be disposed away from the corner portion 10. If the mold resin 30 and the casing 5 are disposed at the facing portion A, the water-resistant insulation performance is improved as compared with the conventional case.
Also in the second embodiment, the rubber ring 70 may be disposed away from the corner portion 10A as long as it is the facing portion C.

Further, for example, in the above-described embodiment, the rubber rings 40 and 70 are arranged one by one at both ends in the axial direction of the stator core 17, but a plurality of rubber rings 40 and 70 may be arranged at each of both ends.
Further, for example, when one end portion in the axial direction of the stator core 17 is poorer in water-stopping than the other end portion, the rubber rings 40 and 70 may be arranged at one end portion more than the other end portion. However, the rubber rings 40 and 70 that are wider at one end portion along the facing portion A than at the other end portion may be disposed.
For example, the cross-sectional shape of the rubber rings 40 and 70 is not limited to a circle or a right triangle, but may be a quadrangle, other polygons, an ellipse, or other irregular shapes.

  Further, for example, the form in which the mold resins 30 and 50 are formed and the rubber rings 40 and 70 are disposed may be at least one of the rotor 3 and the stator 4.

1 Water-sealed motor 1A Water-sealed motor 1B Water-sealed motor 2 Motor shaft 2b Outer peripheral surface 3 Rotor 4 Stator 5 Casing 5a Inner peripheral surface 10 Corner 17 Stator core 30 Mold resin 40 Rubber ring 40A Rubber ring 41 Right angle 42 Inclined side Part 50 Mold resin 61 Rotor core 62 Permanent magnet 70 Rubber ring 70C Rubber ring 70D1 Rubber ring 70D2 Rubber ring 70E1 Rubber ring 70E2 Rubber ring 71 Right angle part 72 Slanted side part 73 Ring member 100 Underwater pump 101 Pump part A Opposing part C Opposing part S1 Crevice S2 Gap S3 Gap S4 Gap

Claims (9)

The water-sealed motor has a motor shaft, a rotor and a stator that rotate the motor shaft, and a cylindrical casing that houses the rotor and the stator, and the casing is filled with sealed water. And
A mold resin covering the stator;
A water ring motor, comprising: a rubber ring disposed at a facing portion between the mold resin and the casing. The stator has a stator core fixed to the inner peripheral surface of the casing,
The water ring motor according to claim 1, wherein the rubber ring is disposed at a corner between the casing and the stator core.   3. The rubber ring according to claim 2, wherein the rubber ring has a right-angled portion in contact with a corner of the casing and the stator core, and has a right-angled triangular cross-sectional shape having a hypotenuse on the opposite side of the right-angled portion. Water-sealed motor.   The water ring motor according to any one of claims 1 to 3, wherein the rubber ring is formed from a water-expandable rubber. A second mold resin covering the rotor;
The water-sealed motor according to any one of claims 1 to 4, further comprising a second rubber ring disposed at a facing portion between the second mold resin and the motor shaft. . The rotor has a rotor core fixed to the outer peripheral surface of the motor shaft,
The water-sealed motor according to claim 5, wherein the second rubber ring is disposed at a corner portion between the motor shaft and the rotor core.   The second rubber ring has a right-angled triangular cross-sectional shape having a right-angled portion in contact with a corner of the motor shaft and the rotor core and having a hypotenuse on the opposite side of the right-angled portion. Item 7. A water ring motor according to item 6.   The water-sealed motor according to any one of claims 5 to 7, wherein the second rubber ring is formed of water-expandable rubber. The water ring motor according to any one of claims 1 to 8,
A submersible pump comprising: a pump unit driven by the water ring motor.

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