JP2016178750A - Liquid encapsulated motor, and manufacturing method of liquid encapsulated motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid encapsulated motor which makes a liquid encapsulated within the liquid encapsulated motor harmless, improves efficiency and recyclability and can be manufactured at low cost, the liquid encapsulated motor being configured by encapsulating the liquid within a motor.SOLUTION: Since an entire outer surface of a portion of a stator 50 in contact with the liquid is coated by a non-conductive thermoplastic resin, even if water or a harmless aqueous solution is used as an encapsulation liquid, a water resistant insulation performance is secured. Since not an oil of high viscosity like an oil encapsulated type but water or an aqueous solution of low viscosity can be encapsulated, a stirring loss with rotations of a rotor core 40 is reduced, thereby providing a high-efficiency liquid encapsulated motor 20. Further, since the coating is the thermoplastic resin, by heating the thermoplastic resin as high as or higher than its melting point, the coating can be easily removed. Therefore, re-winding of a winding wire can be performed in contrast to a canned type, and recyclability is also improved.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid ring motor in which a liquid is sealed.

  A motor (so-called deep well motor) used for a deep well submersible pump for taking drinking water or the like from a deep well is installed in a well having a deep water depth, so that a high water pressure is applied to the motor. For this reason, a liquid ring motor that encloses a liquid inside the motor has been used as a deep well motor. Such liquid ring type deep well motors are roughly classified into three types. The first is an oil seal type, the second is a cand type, and the third is a water-resistant insulated wire type. In any of these methods, liquid is sealed inside the motor, and the pressure inside and outside the motor is kept approximately equal by a pressure regulating mechanism called a diaphragm. In any of these methods, the bearing is lubricated by a liquid sealed in the motor (hereinafter also referred to as a sealed liquid).

  In the oil-sealed motor, a normal enameled wire is used for the winding wound around the stator core. When enameled wire is in contact with water for a long period of time, the insulation is destroyed. Therefore, a liquid having insulating properties such as mineral oil is used as the sealing liquid. In the canned motor, a can formed of a thin metal plate is inserted between the rotor outer peripheral surface and the stator core inner peripheral surface. Stator with stator core and windings, and lead-out wires connected to the windings are welded and sealed using motor frames, side plates and cans, and the parts where voltage is applied Water is prevented from entering. In a water-resistant insulated wire motor, a water-resistant insulated wire is used as a winding. In this water-resistant insulated electric wire, a normal enameled wire is covered with a polyolefin resin (for example, polyethylene, cross-linked polyethylene, or polypropylene) having excellent water-resistant insulating performance. In addition, in a water-resistant insulated electric wire motor, a structure in which a winding and a connection portion between the winding and the lead wire are molded with a rubber material is adopted in order to provide a water-stopping structure for all parts to which voltage is applied. ing. Techniques for molding the periphery of the winding with resin are described in, for example, Patent Documents 1 to 3 below.

JP 2002-78276 A JP 2004-166414 A Japanese Patent Laid-Open No. 2001-231212

  However, in the oil-sealed motor, even if a liquid having insulating properties such as mineral oil is used as the sealing liquid, if well water outside the motor enters the motor through the shaft seal, the insulation is lowered. In addition, since a part of the sealing liquid flows out into the well water outside the motor through the shaft seal, a harmless antifreeze such as water or a propylene glycol aqueous solution is used as the sealing liquid from the viewpoint of well water quality. It is inherently desirable. Such a harmless antifreeze can be used in a canned motor and a water-resistant insulated electric wire motor. On the other hand, in an oil-sealed motor, insulation is lowered when water or an aqueous solution enters the motor, so it is impossible to use water or a harmless antifreeze.

In the canned motor, the rotating magnetic flux generated from the stator toward the rotor passes through a can located between them, so an eddy current is generated in the can and a loss (referred to as can loss) occurs. Due to the occurrence of the can loss, the motor efficiency is lowered. Further, in the canned motor, the entire stator is hermetically sealed, so that the winding cannot be repaired after a long period of use. For this reason, a canned motor is often disposable and has poor recyclability.

  In a water-resistant insulated electric wire motor, the polyolefin coating for maintaining the water-resistant voltage resistance performance usually requires a coating thickness of 0.2 to 0.4 mm in the case of a 600V class electric wire. That is, the cross-sectional area of the water-resistant insulated electric wire is larger than that of the enameled wire by this coating thickness. For this reason, when inserting the same number of windings into a stator core having the same slot area, the conductor cross-sectional area in the water-resistant insulated wire must be reduced as compared with the enameled wire winding. Therefore, the winding resistance is increased, and as a result, the Joule heat loss is increased and the motor efficiency is decreased. Moreover, since the water-resistant insulated wire is a special wire and winding work by an automatic winding machine is difficult, it is necessary to perform winding work manually. This also increases the cost. The various problems described above are not limited to deep well motors but are common to various liquid ring motors.

  For this reason, it is required to improve at least one of the above-described drawbacks of the conventional system in a liquid ring motor in which a liquid is sealed inside the motor. For example, it is desirable that the liquid sealed in the liquid ring motor is harmless. Alternatively, the liquid ring motor is desirably highly efficient. Alternatively, the liquid ring motor is desirably excellent in recyclability. Alternatively, it is desirable that the liquid ring motor can be manufactured easily and inexpensively.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

  According to the first aspect of the present invention, a liquid ring motor in which a liquid is sealed is provided. The liquid ring motor includes a stator having a stator core and windings. All the outer surfaces of the portions of the stator that come into contact with the liquid are coated with a non-conductive thermoplastic resin.

  According to such a liquid ring motor, since all the outer surfaces of the portions of the stator that come into contact with the liquid are coated with a non-conductive thermoplastic resin, water or a harmless aqueous solution is used as the sealing liquid. Even if it is a case, water-proof insulation performance is ensured. Moreover, since a normal enameled wire can be used for the winding, the conductor cross-sectional area of the winding can be increased as compared with the water-resistant insulated wire type. Furthermore, since it is not necessary to use a can, no can loss occurs. Furthermore, since the oil or the aqueous solution having a low viscosity can be enclosed instead of the oil having a high viscosity as in the oil seal type, the stirring loss accompanying the rotation of the rotor is small. From these things, a highly efficient liquid ring motor can be provided. Moreover, since the film is a thermoplastic resin, it can be easily removed by heating to the melting point or higher. Therefore, in contrast to the canned type, the winding can be rewinded and the recyclability is excellent.

  According to the second aspect of the present invention, in the first aspect, the liquid ring motor is a motor frame in which a through hole is further formed, the stator being inserted into the through hole, and the stator being a motor frame. A motor frame fitted to the housing. The outer surface and the inner peripheral surface of the motor frame are integrally coated with a thermoplastic resin. According to this form, there exists an effect similar to the 6th form mentioned later.

  According to the third aspect of the present invention, in the first or second aspect, the liquid ring motor further includes a lead wire connected to the winding. The outer surface and the lead wire are integrally coated with a thermoplastic resin. According to this form, there exists an effect similar to the 7th form mentioned later.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the thermoplastic resin is a polyolefin-based thermoplastic resin having a melting point of 100 ° C. or higher and 170 ° C. or lower, or The polyolefin-based thermoplastic resin is contained as a main ingredient. According to this embodiment, sufficient water resistance insulation can be obtained. In particular, since the polyolefin-based thermoplastic resin has a melting point of about 100 ° C. or higher, it is not affected even when the temperature of the encapsulating liquid rises as the motor is operated.

  According to the fifth aspect of the present invention, a method for manufacturing a liquid ring motor is provided. In this liquid ring motor manufacturing method, a stator having a stator core and a winding is immersed in a melted non-conductive thermoplastic resin to form a thermoplastic resin coating on the outer surface of the stator. A process is provided. According to this method for manufacturing a liquid ring motor, the liquid ring motor of the first embodiment can be manufactured by a simple process.

  According to a sixth aspect of the present invention, in the fifth aspect, the method for manufacturing a liquid ring motor includes: inserting a stator into a through hole formed in the motor frame before the dipping step; A step of fitting the frame; The dipping step includes a step of dipping together the stator fitted to the motor frame and the motor frame in the molten thermoplastic resin. According to this mode, since the coating is performed after the fitting operation, the coating is not damaged by the fitting operation. Therefore, the reliability of the water resistant insulation performance is improved.

  According to a seventh aspect of the present invention, in the fifth or sixth aspect, the method for manufacturing a liquid ring motor includes a step of connecting a lead wire to the winding before the dipping step. The dipping step includes a step of dipping the stator and the lead wire together in the molten thermoplastic resin. According to such a form, the water-proof insulation performance can be imparted to both the stator and the lead wire and their connecting portions only by the dipping process, so that the manufacturing process can be simplified. In addition, a liquid ring motor can be manufactured at a low cost.

It is a fragmentary sectional view showing a schematic structure of a liquid ring motor as one example of the present invention. It is an enlarged view of the stator core of FIG. It is an enlarged view of the coil | winding and connector of FIG.

A. Example:
FIG. 1 is a partial cross-sectional view showing a schematic configuration of a liquid ring motor 20 as one embodiment of the present invention. In the present embodiment, the liquid ring motor 20 is a deep well motor used for a deep well submersible pump or the like. However, the liquid ring motor 20 may be any liquid ring motor in which liquid is sealed. The liquid ring motor 20 is connected to a deep well submersible pump (not shown) and used as a rotational drive source of the pump. As illustrated, the liquid ring motor 20 includes a shaft 30, a rotor core 40, a stator 50, a stator frame 60, and a connector 80. The shaft 30 is supported by bearings 31 and 32 so as to be rotatable about the axis AL.

Around the shaft 30, a rotor core 40 around which a winding is wound is mounted concentrically with the axis AL. A stator 50 is disposed on the outer side in the radial direction of the rotor core 40 so as to surround the rotor core 40 in the circumferential direction concentrically with the axis AL. A predetermined clearance is provided between the rotor core 40 and the stator 50 so that the rotor core 40 does not contact the stator 50 when the rotor core 40 rotates. The stator 50 includes a stator core 51, windings 52, and slot insulating paper 53. Stator core 51 is formed by laminating electromagnetic steel plates (for example, silicon steel plates). A plurality of slots (not shown) are formed along the circumferential direction on the radially inner side of the stator core 51. In each slot, a winding 52 is wound between the stator core 51 and the winding 52 via a slot insulating paper 53. The winding 52 is electrically connected to a connector 80 for electrically connecting the external power source and the liquid ring motor 20 (details will be described later). In this embodiment, the winding 52 is an enameled wire.

  The stator frame 60 has a substantially cylindrical shape extending in the direction of the axis AL. Inside the stator frame 60, a through hole 65 (see FIG. 2) is formed through the stator frame 60 in the direction of the axis AL. The stator 50 is fitted into the stator frame 60 by being inserted into the through hole 65. As a result, the stator 50 is accommodated inside the stator frame 60. Frame side plates 63 and 64 are attached to both ends of the stator frame 60 in the direction of the axis AL so as to be fitted inside the stator frame 60.

  A liquid (filled liquid) is sealed in the internal space 66 of the liquid ring motor 20 surrounded by the stator frame 60 and the frame side plates 63 and 64. This sealed liquid is sealed in the internal space 66 in order to make the pressures inside and outside the liquid ring motor 20 substantially equal. The pressure of the sealing liquid is controlled by a pressure adjusting mechanism (not shown). The sealed liquid also has a role of lubricating the bearings 31 and 32. For example, any liquid (for example, propylene glycol, paraffin oil, etc.) can be used as the sealing liquid. However, water or a harmless aqueous solution may be used as the sealing liquid. In this way, even if the liquid filling liquid leaks from the shaft seal part to the outside of the liquid ring motor 20, the surrounding environment is not adversely affected.

  FIG. 2 is an enlarged view of the stator 50 shown in FIG. In FIG. 2, the shaft 30 and the rotor core 40 are not shown. As shown in the figure, a coating 70 is formed on all outer surfaces of portions of the stator 50 (that is, the stator core 51, the winding 52, and the slot insulating paper 53) that come into contact with the sealing liquid. Although not shown, a coating 70 is also formed on the outer surface of the portion of the winding 52 and the slot insulating paper 53 that is accommodated in the slot formed in the stator core 51. The thickness of the coating 70 may be, for example, a minimum of 0.2 mm or a maximum of 0.8 mm in the 600V class liquid ring motor 20.

  In the present embodiment, the coating 70 is also formed on the inner peripheral surface 61 of the stator frame 60. The outer surface and the inner peripheral surface 61 of the stator 50 are coated integrally (that is, continuously) by the coating 70. The coating 70 provides the stator 50 with a water-stop structure (that is, water-resistant insulation performance). The formation of the coating 70 on the surface of the inner peripheral surface 61 is due to the manufacturing method of the liquid ring motor 20 described later. A method for manufacturing the liquid ring motor 20 will be described later. In the present embodiment, the coating 70 is also formed on the outer peripheral surface of the stator frame 60 (not shown).

The film 70 is formed of a non-conductive thermoplastic resin. As such a thermoplastic resin, an arbitrary material may be selected in consideration of the following conditions.
(1) Excellent water-resistant insulation performance.
(2) Do not violate the enamel coating of the winding 52 chemically.
(3) Flexible and strong (4) The liquid enclosed in the motor absorbs the heat generated by the liquid ring motor 20 during operation, and is usually about 60 to 70 ° C. Therefore, the coating 70 should be able to withstand hot water at this temperature.
Further, since the heat resistant temperature of the enamel layer of the winding 52 is about 180 ° C., the winding 52 is damaged when the liquid ring motor 20 is manufactured by the manufacturing method described later in the manufacturing stage of the liquid ring motor 20. In order to avoid this, it is desirable to select a thermoplastic resin that will be in a molten state at least below 180 ° C. In this embodiment, in consideration of such temperature conditions, a thermoplastic resin having a melting point of 100 ° C. or higher and 170 ° C. or lower is selected as the material of the film 70.

  As such a thermoplastic resin, for example, a polyolefin-based thermoplastic resin can be selected. More specifically, the thermoplastic resin may be, for example, polyethylene (melting point: 100 to 140 ° C.), crosslinked polyethylene, polypropylene (melting point: about 160 ° C.), or the like. Further, the thermoplastic resin may contain a polyolefin-based thermoplastic resin as a main ingredient and other components. As other components, for example, a colorant or another kind of resin for enhancing the flexibility of the coating 70 may be used.

  FIG. 3 is an enlarged view of the winding 52 and the connector 80 shown in FIG. As shown in the figure, the connector 80 includes a terminal block 81, a connector pin 82, and a lead wire 83. The connector 80 is provided to electrically connect the inside and the outside of the liquid ring motor 20 in a liquid-tight manner. A portion of the terminal block 81 is inserted into a through hole formed in the frame side plate 63, and the space between the terminal block 81 and the frame side plate 63 is sealed. The connector pin 82 protrudes from the terminal block 81 toward the outside of the liquid ring motor 20. The connector pin 82 is connected to a terminal of a cable connected to an external power source. A lead wire 83 extends from the terminal block 81 on the side of the connector 80 opposite to the connector pin 82, that is, on the inner side of the liquid ring motor 20. The lead wire 83 is connected to the winding 52. In the deep well motor, since the distance from the power supply inlet of the liquid ring motor 20 to the ground where the external power source is installed is very long, the cable connecting the liquid ring motor 20 and the external power source also becomes long. By providing the connector 80 as described above so that the cable can be disconnected from the liquid ring motor 20, the handleability at the time of installation of the liquid ring motor 20 is improved.

  In this embodiment, as shown in FIG. 3, the coating 70 is formed on a part of the terminal block 81 and the lead wire 83 of the connector 80 in addition to the outer surface of the stator 50 and the inner peripheral surface 61 of the stator frame 60. A film 70 is formed on the surface of the portion (that is, the portion disposed in the internal space 66). The outer surface of the stator 50, the inner peripheral surface 61, and the portion of the connector 80 that is disposed in the internal space 66 are integrally (that is, continuously) coated with the coating 70.

  The liquid ring motor 20 described above can be manufactured as follows, for example. First, a stator 50 in which a winding 52 is wound around a stator core 51 via a slot insulating paper 53 is prepared. Next, the lead wire 83 of the connector 80 is connected to the prepared winding 52 of the stator 50. For this connection, for example, a crimp terminal is used. Next, the stator 50 is fitted into the stator frame 60 by inserting the prepared stator 50 into the through hole 65 of the stator frame 60. At this time, the stator 50 and the stator frame 60 are completely fixed to each other by a method such as shrink fitting. The stator 50, the stator frame 60, and the connector 80 obtained thereby are also referred to as subassemblies below. Next, the subassembly is immersed in a container containing a molten thermoplastic resin (here, a polyolefin resin) without being varnished. The temperature of the polyolefin resin is maintained above the melting point of the resin and below the heat resistant temperature of the enameled wire. During the immersion, a part of the terminal block 81 and the connector pin 82 (that is, a part not disposed in the internal space 66) are masked so that the molten resin does not adhere.

The container is evacuated after the subassembly is received so that voids do not occur in the polyolefin resin coating, ie, the coating 70. When the inside of the container is evacuated, the air adhering to the surface of the subassembly is discarded, so that the polyolefin resin is uniformly coated. After maintaining the temperature and degree of vacuum of the container for a certain period of time until no bubbles are generated, the container is opened to the atmosphere and the subassembly is lifted from the container. When the subassembly is withdrawn from the container, the outer surface of the subassembly is coated with the polyolefin resin following the shape of the outer surface by the surface tension of the resin. At this time, depending on the viscosity of the melted polyolefin resin, the polyolefin resin melted by capillary action may enter the inside of the winding 52, that is, the gap between the windings 52. However, since the thickness of the resin that has entered depends on the gap between the windings 52, it is very small compared to the thickness of the coating film 70 that is finally obtained. Thereafter, the polyolefin resin is solidified by being cooled, and the stator 50, the stator frame 60, and the connector 80 on which the film 70 is formed are obtained.

  The thickness of the coating 70 depends on the melting temperature and viscosity of the resin used. For this reason, the process from the above immersion to drying is repeated a predetermined number of times (for example, twice) until the target coating thickness of the film 70 (for example, in the case of 600 V class, 0.2 mm or more and 0.8 mm or less). It is. Thus, the subassembly in which the film 70 is formed is assembled with other members, and the liquid ring motor 20 is completed.

  According to the liquid ring motor 20 described above, the non-conductive thermoplastic resin coating 70 is formed on all the outer surfaces of the portion of the stator 50 that contacts the sealed liquid. Therefore, even when water or a harmless aqueous solution is used as the sealing liquid, water-resistant insulation performance is ensured. Since the coating film 70 is also formed on the outer surface of the stator core 51 having a laminated structure, it is possible to prevent the sealing liquid from entering the slot from the stator core 51. Moreover, since the film 70 is a thermoplastic resin, it can be easily removed by heating to the melting point or higher. Therefore, in contrast to the cand type, the winding 52 can be rewinded and is excellent in recyclability.

  Further, enameled wire can be used for the winding 52, and the coating 70 is formed on the outer surface of the assembly of the windings 52. Therefore, it is necessary that the coating is formed over the entire length of the winding 52. Absent. For this reason, when winding a winding in a slot having the same area, the conductor cross-sectional area of the winding is larger than that of a water-resistant insulated wire type in which an insulating water-stopping structure is applied over the entire length of the winding. it can. Furthermore, since it is not necessary to use a can, no can loss occurs. Furthermore, water or an aqueous solution having a low viscosity can be sealed in the internal space 66 instead of an oil having a high viscosity as in the oil seal type, so that the stirring loss associated with the rotation of the shaft 30 and the rotor core 40 is small. From these things, the highly efficient liquid ring motor 20 can be provided.

  Further, since the water-resistant insulation performance is maintained by the coating 70, an enameled wire can be used for the winding 52. Since the enameled wire can be wound around the stator core 51 using an automatic winding machine, the manufacturing process is easy and inexpensive.

  Moreover, according to the manufacturing method of the liquid ring motor 20 described above, the coating film 70 can be formed by a simple process. Further, according to this manufacturing method, since the coating 50 is formed after the stator 50 is fitted and fixed to the stator frame 60, the coating 70 is not damaged by the fitting / fixing operation. Therefore, the reliability of the water resistant insulation performance of the liquid ring motor 20 is improved.

  Further, according to this manufacturing method, since the water-resistant insulation performance can be imparted to both the stator 50 and the connector 80 (part of the terminal number 81 and the lead wire 83) only by the dipping process, the manufacturing process can be simplified. In other words, unlike the prior art, after connecting the winding 52 and the lead wire 83, it is not necessary to cover them with a heat shrinkable tube or the like to form an insulating structure. In addition, the liquid ring motor 20 can be manufactured at a low cost.

Furthermore, the above-described liquid ring motor 20 has a great advantage over the above-mentioned Patent Document 1. Specifically, Patent Document 1 discloses a submerged motor that can be insulated by casting a mold resin around windings and lead wires without using a can-sealing structure or a water-resistant insulated wire. Disclosure. This submerged motor employs a double insulation structure in which a liquid-proof coating layer is formed on a mold resin layer. For molding the first mold resin layer, it is necessary to incorporate a lower receiving jig and a mandrel, and the jig needs to be coated with a release agent for removal. Silicone rubber with good electrical insulation is used as the mold resin, but silicone rubber is expensive, and since the entire stator winding is cast, the amount of silicone rubber used increases. It becomes expensive. In addition, if the thickness of the mold resin is thin, the sealed water penetrates into the resin and causes a decrease in insulation, so it is necessary to form a second layer of liquid-proof coating.

  On the other hand, according to the liquid ring motor 20 described above, a polyolefin-based resin that is less expensive than silicone rubber is used as the material of the coating 70. Further, unlike the casting method in which a jig is attached and the entire winding 52 is buried with a resin as in the prior art, in this embodiment, the above-described subassembly is subjected to a vacuum dipping treatment, whereby the winding is performed. A film 70 is formed at a site to which a voltage is applied such as the wire 52 and the lead wire 83. For this reason, the amount of thermoplastic resin used can be reduced. Further, the cost can be reduced and the resource saving is excellent because the amount of the thermoplastic resin used is small. In addition, since the formation of the coating 70 does not require attachment of a jig, application of a release agent, and removal of the jig as in the casting method, the liquid ring motor 20 is advantageous in terms of workability and cost. It has a much better structure than the prior art. In addition, since the polyolefin-based resin is excellent in water resistance and insulation, even if the coating 70 is formed as a thin film having a thickness of 0.8 mm or less, for example, a second liquid-proof coating as in the prior art is required. do not do. Therefore, the number of work steps is less than that of the prior art, and it is possible to contribute to cost reduction.

B. Variations:
B-1. Modification 1:
In the manufacturing process of the liquid ring motor 20, instead of the method of immersing the subassembly of the stator 50, the stator frame 60 and the connector 80 in the molten thermoplastic resin, only the stator 50 or the stator 50 and the connector 80 Only the subassembly may be immersed. For example, after the subassembly of the stator 50 and the connector 80 is immersed and the coating 70 is formed on the stator 50 and a part of the connector 80 (including the lead wire 83), the stator 50 and the connector 80 are It may be attached to the frame 60. In this case, in the manufactured liquid ring motor 20, the coating 70 is not formed on the inner peripheral surface 61. Alternatively, the stator 50 may be attached to the stator frame 60 after the stator 50 is immersed alone and the coating 70 is formed on the outer surface of the stator 50. Also in this case, the coating 70 is not formed on the inner peripheral surface 61. In this case, as in the prior art, after the winding 52 and the lead wire 83 are connected, an insulating structure may be formed by covering them with a heat-shrinkable tube or the like.

B-2. Modification 2:
The liquid ring motor 20 may not include the connector 80. In this case, a cable connected to an external power supply may be liquid-tightly inserted into the liquid-sealed motor 20, and a lead wire formed at the tip thereof may be connected to the coating 70. In this case, in the manufacturing process of the liquid ring motor 20, after the winding 52 and the lead wire are connected, an insulating structure may be formed by covering them with a heat shrinkable tube or the like.

The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof. In addition, any combination or omission of each constituent element described in the claims and the specification is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect is achieved. It is.

DESCRIPTION OF SYMBOLS 20 ... Liquid seal motor 30 ... Shaft 31, 32 ... Bearing 40 ... Rotor core 50 ... Stator 51 ... Stator core 52 ... Winding 53 ... Slot insulating paper 60 ... Stator frame 61 ... Inner peripheral surface 63, 64 ... Frame side plate 65 ... Through Hole 66 ... Internal space 70 ... Coating 80 ... Connector 81 ... Terminal block 82 ... Connector pin 83 ... Lead wire AL ... Axis line

Claims (7)

A liquid ring motor in which liquid is enclosed,
A stator having a stator core and a winding;
All the outer surfaces of the portions of the stator that come into contact with the liquid are coated with a non-conductive thermoplastic resin. The liquid ring motor according to claim 1,
And a motor frame having a through hole, the stator being inserted into the through hole, and the stator being fitted to the motor frame.
The liquid seal motor, wherein the outer surface and the inner peripheral surface of the motor frame are integrally coated with the thermoplastic resin. A liquid ring motor according to claim 1 or 2,
Furthermore, a lead wire connected to the winding is provided,
The liquid seal motor, wherein the outer surface and the lead wire are integrally coated with the thermoplastic resin. A liquid ring motor according to any one of claims 1 to 3,
The thermoplastic resin is a polyolefin-based thermoplastic resin having a melting point of 100 ° C. or more and 170 ° C. or less, or contains the polyolefin-based thermoplastic resin as a main agent. A method for manufacturing a liquid ring motor,
A liquid-sealed motor comprising a dipping step of immersing a stator having a stator core and windings in a melted non-conductive thermoplastic resin to form a film of the thermoplastic resin on the outer surface of the stator Production method. It is a manufacturing method of the liquid ring motor according to claim 5,
Before the dipping step, the step of inserting the stator into a through hole formed in the motor frame and fitting the stator to the motor frame,
The immersion step includes a step of immersing the stator fitted to the motor frame and the motor frame together in the melted thermoplastic resin. It is a manufacturing method of the liquid ring motor according to claim 5 or 6,
Before the immersion step, comprising a step of connecting a lead wire to the winding,
The dipping step includes a step of dipping the stator and the lead wire together in the melted thermoplastic resin. A method for manufacturing a liquid ring motor.

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