JP2018117491A - Canned motor, pump device, and maintenance method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a canned motor that is easy to maintain, a pump device, and an easy maintenance method for the canned motor.SOLUTION: A canned motor includes a cylindrical motor frame, a stator disposed inside the motor frame, a cylindrical can disposed inside the stator, and a first frame side plate and a second frame side plate individually disposed at outer peripheral sides of both ends of a can in the cylindrical axis direction. The canned motor includes a sealing member disposed between an inner peripheral surface of the first frame side plate and an outer peripheral surface of the can to seal the first frame side plate and the can, and a reinforcing member having a shape corresponding to the inner peripheral surface of the first frame side plate and being fitted to an inside of the can so as to be positioned at an inner peripheral side of the sealing member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a canned motor, a pump device, and a maintenance method.

  Conventionally, a canned motor is sometimes used to drive a rotating device such as a pump or a fan. The canned motor is used, for example, in applications where it is not preferable that the fluid (liquid or gas) to be handled leaks to the outside. In addition, the canned motor is used in applications where it is not preferable for an external fluid to enter the pump or the motor, such as a submersible motor pump or a vacuum pump.

  In a canned motor, the rotor and stator of the motor are separated by a can. The can usually has a cylindrical shape and is fixed to a stator core or the like in a state where a gap is generated between the can and the outer peripheral surface of the rotor. In general, a space in which a stator (stator core and stator coil) and the like are accommodated is sealed as a stator chamber by a motor frame, a frame side plate, and a can.

  Generally, the motor frame, the frame side plate, and the can are welded together to seal the stator chamber. For this reason, it is difficult to maintain a stator coil or the like in the stator chamber even if a defect such as insulation failure occurs, and the stator including the motor frame or the canned motor itself has been replaced.

  On the other hand, there has conventionally been proposed a technique in which the motor frame and the frame side plate are sealed with a sealing material such as an O-ring or a gasket without welding the motor frame and the frame side plate (see, for example, Patent Document 1). In this canned motor, an operator can perform maintenance by releasing the sealing of the stator chamber by removing the welded portion between the frame side plate on one side and the can.

Japanese Patent Laid-Open No. 7-231600

  In the canned motor described in Patent Document 1, the welded portion is scraped when the welded portion between the frame side plate and the can is removed, and this operation takes time. Moreover, since the frame side plate and the can are welded again after the maintenance work is completed, the maintenance work is complicated, such as requiring a welding machine.

  In order to facilitate maintenance work of the canned motor, it is conceivable to seal the frame side plate and the can with a sealing material such as an O-ring or a gasket without welding the frame side plate and the can. However, in the canned motor, it is desirable to reduce the separation distance between the stator and the rotor from the viewpoint of improving the motor characteristics, and the can thickness is minimized. For this reason, the mechanical strength of the can is small, and the can easily distorts. Therefore, a gap is generated between the can and the sealing material, and the frame side plate and the can may not be sufficiently sealed.

SUMMARY An advantage of some aspects of the invention is to provide a canned motor and a pump device that can be easily maintained. Furthermore, an object of the present invention is to provide a simple maintenance method for a canned motor.

[Embodiment 1] According to Embodiment 1, a canned motor is proposed, a cylindrical motor frame, a stator that is disposed inside the motor frame and has a stator core and a stator coil wound around the stator core, and inside the stator. A cylindrical can that is disposed, a first frame side plate and a second frame side plate that are respectively disposed on the outer peripheral sides of the cylindrical axial ends of the can and that define a stator chamber in which the stator is disposed together with the motor frame and the can; A sealing member disposed between the inner peripheral surface of the one frame side plate and the outer peripheral surface of the can and having a shape corresponding to the inner peripheral surface of the first frame side plate; And a reinforcing member fitted inside the can so as to be positioned on the inner peripheral side of the sealing member.
According to the first aspect, since the first frame side plate and the can are not fixed to each other by welding or the like and are sealed by the sealing member, the stator chamber can be easily maintained. Further, since the reinforcing member is fitted inside the can so as to be located on the inner peripheral side of the sealing member, it is possible to suppress a gap between the can and the sealing member, and the first frame side plate and The can can be more reliably sealed.

[Mode 2] According to Mode 2, in the canned motor of Mode 1, the reinforcing member is cylindrical.
According to the second aspect, a space can be secured inside the reinforcing member, and the rotating shaft of the canned motor can be arranged in the space.

[Embodiment 3] According to Embodiment 3, in the canned motor of Embodiment 2, the reinforcing member has a tapered shape that gradually decreases in diameter toward one end in the cylindrical axis direction.
According to the third aspect, the reinforcing member can be easily fitted inside the can.

[Mode 4] According to mode 4, in the canned motor of mode 2 or 3, the reinforcing member has a slit extending from one end to the other end in the cylindrical axis direction.
According to the fourth aspect, the reinforcing member can be easily fitted inside the can. Further, the can can be urged toward the first frame side plate by the reinforcing member, and the first frame side plate and the can can be more reliably sealed.

[Embodiment 5] According to Embodiment 5, in any one of the canned motors of Embodiments 1 to 4, the second frame side plate and the can are fixed.
According to the fifth aspect, the second frame side plate and the can can be more reliably sealed.

[Mode 6] According to mode 6, in any one of the canned motors of modes 1 to 5, the motor frame, the first frame side plate, and the second frame side plate are sealed by the second sealing member.
According to the sixth aspect, the first frame side plate and the second frame side plate can be easily detached from the motor frame, and the stator chamber can be easily maintained.

[Mode 7] According to mode 7, a pump device is proposed, and the pump device includes any one of the canned motors of modes 1 to 6.
According to the form 7, there exists an effect similar to an above-described canned motor.

[Embodiment 8] According to Embodiment 8, a method for maintaining any one of the canned motors of Embodiments 1 to 6 or the pump device of Embodiment 7 is proposed, which includes a step of removing the reinforcing member from the can, Removing from the inside of the stator.
According to the eighth aspect, the stator chamber of the above canned motor can be easily maintained.

It is a figure which shows the external appearance of the pump apparatus of this embodiment. It is a figure which shows schematic structure of the canned motor of this embodiment. It is the figure which looked at the reinforcement member of this embodiment from the cylindrical-axis direction. It is sectional drawing which shows a reinforcement member from the AA direction in FIG. It is the figure which looked at the reinforcement member of the modification from the cylindrical axis direction.

  Hereinafter, a canned motor according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted. This embodiment demonstrates the case where a canned motor is applied to a submersible pump. However, the canned motor may be used to drive other rotating equipment, for example, to drive a vacuum pump. In the present embodiment, the output shaft of the canned motor is arranged along the vertical direction. However, the present invention is not limited to this example. For example, the output shaft of the canned motor may be arranged along the horizontal direction.

  FIG. 1 is a diagram illustrating an appearance of the pump device according to the present embodiment. As shown in FIG. 1, the pump device 500 includes a liquid ring type canned motor 100 and a submersible pump 200 connected to the canned motor 100. The pump device 500 is used for pumping up deep well water as an example.

  The submersible pump 200 has a drive shaft 202 connected to the output shaft 110 of the canned motor 100 and a plurality of blades 204 attached to the drive shaft 202. In the submersible pump 200, the drive shaft 202 and the blades 204 rotate as the output shaft 110 of the canned motor 100 rotates, thereby pumping up water.

  FIG. 2 is a view showing a cross section of the canned motor of the present embodiment. As shown in FIG. 2, the canned motor 100 includes a rotor 107 that rotates integrally with the output shaft 110, and a stator 104 that is disposed on the outer peripheral side of the rotor 107. The canned motor 100 includes a motor frame 116, a can 118, frame side plates 120 and 130, a reinforcing member 160, and brackets 122 and 132.

  The motor frame 116 is cylindrical and defines the outer surface of the canned motor 100. A stator 104 is fixed to the inner peripheral side of the motor frame 116. A thin cylindrical can 118 is arranged on the inner peripheral side of the stator 104. The motor frame 116 and the can 118 are arranged concentrically around the same cylindrical axis CA. On both sides of the stator 104 in the direction of the cylindrical axis CA, load side (right side in FIG. 2) and counter load side (left side in FIG. 2) frame side plates (first frame side plate, second frame side plate) 120, 130 is arranged. The load-side and anti-load-side frame side plates 120 and 130 have a thin cylindrical shape with a low height, and when viewed along the cylindrical axis CA, a substantially perfect outer circumference and a substantially perfect inner circumference are shown. Have. The frame side plates 120 and 130 are disposed so as to be sandwiched between the inner peripheral surface of the motor frame 116 and the outer peripheral surface of the can 118. In other words, the frame side plates 120 and 130 are disposed on the outer peripheral side of both ends of the can 118 in the cylindrical axis CA direction. The motor frame 116, the can 118, and the frame side plates 120 and 130 define a stator chamber 140 in which the stator 104 is disposed.

  In the present embodiment, O-rings (second sealing members) 124 and 134 are provided between the frame side plates 120 and 130 and the motor frame 116. That is, the frame side plates 120 and 130 and the motor frame 116 are sealed by the O-rings 124 and 134 without being welded to each other. In this embodiment, the O-rings 124 and 134 are used as the second sealing member. However, the second sealing member only needs to be able to seal the frame side plates 120 and 130 and the motor frame 116. Instead of or in addition to the O-rings 124, 134, other mechanisms may be used.

  In the present embodiment, the load-side frame side plate 120 and the can 118 are welded to each other by the welded portion Wp. On the other hand, the frame side plate 130 and the can 118 on the anti-load side are sealed by an O-ring (sealing member) 138 without being welded to each other. Specifically, the O-ring 138 is disposed between the inner peripheral surface of the frame side plate 130 on the anti-load side and the outer peripheral surface of the can 118. In this embodiment, the O-ring 138 is used as a sealing member, but the sealing member may be any member that can seal the frame side plate 130 and the motor frame 116. Or in addition, other mechanisms may be used.

  As shown in FIG. 2, a reinforcing member 160 is fitted inside the can 118 so as to be positioned on the inner peripheral side of the O-ring 138. The reinforcing member 160 is formed of a metal such as stainless steel as an example. 3 is a view of the reinforcing member of the present embodiment as seen from the cylindrical axis direction, and FIG. 4 is a cross-sectional view showing the reinforcing member from the AA direction in FIG. As shown in FIGS. 3 and 4, the reinforcing member 160 is substantially cylindrical and has a thickness (for example, several mm) larger than the thickness of the can 118. Here, the outer shape of the reinforcing member 160 corresponds to the shape of the inner peripheral surface of the frame side plate 130 on the anti-load side. Specifically, the reinforcing member 160 has an outer peripheral surface that takes into account the thickness of the can 118, the gap for the O-ring 138, and a predetermined margin with respect to the shape of the inner peripheral surface of the frame side plate 130 on the anti-load side. 162. In other words, in the present embodiment, the reinforcing member 160 reduces the inner diameter of the frame side plate 130 by twice the thickness of the can 118, the gap for the O-ring 138, and a margin that takes into account manufacturing errors and the like. The outer peripheral surface 162 has an outer diameter.

  Generally, in the canned motor 100, the thickness of the can 118 is made as small as possible from the viewpoint of improving the motor characteristics. For this reason, the mechanical strength of the can 118 is small, and the can 118 is likely to be distorted. If the can 118 is distorted and a gap is formed between the can 118 and the O-ring 138, the sealing of the frame side plate 130 and the can 118 by the O-ring 138 will not function sufficiently. For this reason, in this embodiment, the reinforcing member 160 is fitted inside the can 118 so as to be positioned on the inner peripheral side of the O-ring 138. Thereby, it is possible to suppress a gap from being generated between the can 118 and the O-ring 138, and the frame side plate 130 and the can 118 can be more reliably sealed.

  As shown in FIGS. 3 and 4, the reinforcing member 160 has a slit 168 along the cylindrical axis CA direction. That is, the reinforcing member 160 has a split shape in which a part in the circumferential direction is missing. Since the reinforcing member 160 has the slit 168 as described above, the reinforcing member 160 can be easily fitted inside the can 118. Further, the reinforcing member 160 can be urged toward the frame side plate 130 by making the reinforcing member 160 a shape slightly larger than the inner peripheral surface of the can 118 when the slit 168 is open. Thereby, the frame side plate 130 and the can 118 can be more reliably sealed.

  Further, particularly as shown in FIG. 4, the reinforcing member 160 has a tapered shape 164 that gradually decreases in diameter toward one end in the cylindrical axis CA direction. For this reason, as shown in FIG. 2, the reinforcing member 160 can be easily fitted inside the can 118 by inserting the reinforcing member 160 from the tapered shape 164 side.

  As described above, in this embodiment, the inner peripheral surface of the frame side plate 130 on the anti-load side and the outer peripheral surface of the can 118 are not fixed to each other by welding or the like, and are sealed by the O-ring 138. For this reason, it is possible to easily maintain the interior of the stator chamber 140 by releasing the seal between the frame side plate 130 and the can 118. Further, the reinforcing member 160 is fitted inside the can 118 so as to be positioned on the inner peripheral side of the O-ring 138, and the can 118 is pressed toward the O-ring 138 by the reinforcing member 160. Therefore, it is possible to suppress the generation of a gap between the can 118 and the O-ring 138, and the sealing performance of the stator chamber 140 can be ensured.

  In this embodiment, the load-side frame side plate 120 and the can 118 are welded, but the load-side frame side plate 120 and the can 118 may be fixed to each other with an adhesive or the like. Further, instead of or in addition to the frame side plate 130 and the can 118 on the anti-load side being sealed by the O-ring 138, the frame side plate 120 and the can 118 on the load side are sealed by the O-ring 138. Also good. At this time, the reinforcing member 160 may be fitted inside the can 118 so as to be positioned on the inner peripheral side of the O-ring 138 of the frame side plate 120 on the load side. Of the frame side plates 120 and 130, the frame side plates 120 and 130 that are sealed with the can 118 by the O-ring 138 are replaced with the second sealing members (O-rings 124 and 134). Further, it may be fixed to the motor frame 116 by welding or an adhesive.

  Returning to FIG. The stator 104 is disposed in the stator chamber 140 defined on the outer peripheral side of the can 118. Stator 104 has a stator core 105 formed by laminating electromagnetic steel plates, and a stator coil 106 wound around stator core 105. A connector cable 112 for supplying electric power to the stator coil 106 is connected to the stator coil 106. The connector cable 112 is connected to an external power source (not shown) through a through hole formed in the motor frame 116. A gap between the through hole of the motor frame 116 and the connector cable 112 is sealed with a cable packing 113. In the present embodiment, the stator chamber 140 is filled with an insulating coolant in order to cool the heat generated from the stator 104 and the like. However, a predetermined gas may be sealed in the stator chamber 140.

  On the outer side of the frame side plates 120 and 130 in the direction of the cylindrical axis CA, brackets 122 and 132 on the load side (right side in FIG. 2) and the anti-load side (left side in FIG. 2) are respectively attached. These brackets 122 and 132 and the can 118 define a rotor chamber 142 in which the rotor 107 is disposed inside the can 118. In the present embodiment, the brackets 122 and 132 are fixed to the motor frame 116 with bolts.

  The load-side bracket 122 is provided with a bearing 126 for supporting the output shaft 110. The load side bracket 122 is formed with a through hole through which the output shaft 110 can pass. The through hole is provided with a shaft sealing mechanism 128 that prevents the sealed liquid from leaking to the outside or water outside the canned motor 100 from entering the inside of the canned motor 100. The output shaft 110 protrudes to the outside of the canned motor 100 through the through hole and is connected to the drive shaft 202 of the submersible pump 200. The output shaft 110 is formed with a spline or key for connecting to the drive shaft 202 of the submersible pump 200.

  A bearing 136 for supporting the output shaft 110 is provided on the bracket 132 on the non-load side of the canned motor 100. The bracket 132 on the non-load side may be provided with a pressure adjusting mechanism (not shown) that absorbs pressure fluctuations in the rotor chamber 142. As the pressure adjusting mechanism, for example, a diaphragm that absorbs the pressure fluctuation between the rotor chamber 142 and the external pressure of the canned motor 100 by displacing the film in accordance with the pressure fluctuation in the rotor chamber 142 can be used.

  In the rotor chamber 142, the rotor 107 attached to the output shaft 110 is disposed. The rotor 107 is supported by the output shaft 110 being pivotally supported by the brackets 122 and 132. The rotor 107 is composed of a rotor core 108 formed by laminating electromagnetic steel plates, a secondary conductor 109 configured by inserting a plurality of copper, aluminum, or the like by a rod or die cast, and a short circuit connecting the secondary conductor 109. And a ring 109a. In the present embodiment, the canned motor 100 is configured as an induction motor having the secondary conductor 109 or the like, but other methods such as a synchronous motor may be adopted. The rotor 107 is disposed at a position corresponding to the inner peripheral surface of the stator 104, and rotates integrally with the output shaft 110 by a magnetic force applied from the stator 104. In the present embodiment, the rotor chamber 142 is filled with a sealing liquid. By filling the filled liquid, it is possible to take measures against an external pressure caused by the canned motor 100 itself being submerged in the liquid, and it is possible to lubricate and cool the bearings 126 and 136. However, a predetermined gas may be sealed in the rotor chamber 142.

  Next, a method for maintaining the inside of the stator chamber 140 when a failure of insulation failure or the like occurs in the canned motor 100 of the present embodiment will be described. First, the operator removes the brackets 122 and 132 from the motor frame 116, and removes the output shaft 110 and the rotor 107 supported by the brackets 122 and 132 from the inside of the motor frame 116. Subsequently, the operator removes the reinforcing member 160 from the inside of the can 118. At this time, a jig or the like may be used. Next, the operator removes the can 118 from the inside of the stator 104. In this embodiment, since the can 118 is welded to the frame side plate 120 on the load side, the operator moves the can 118 to the load side (the right side in FIG. 2), and the can 118 and the frame side plate 120 on the load side. May be removed from the motor frame 116. Thereby, the sealing of the stator chamber 140 is released, and an operator can maintain the interior of the stator chamber 140.

  When the maintenance in the stator chamber 140 is completed, first, the worker places the can 118 inside the motor frame 116. At this time, the operator may move the can 118 and the frame side plate 120 from the load side (right side in FIG. 2) to the non-load side (left side in FIG. 2) with respect to the motor frame 116. Then, the operator fits the reinforcing member 160 inside the can 118 so as to be located inside the O-ring 138. Thereby, the sealing performance between the can 118 and the frame side plate 130 is ensured. Then, the operator can complete the maintenance of the canned motor 100 by attaching the output shaft 110, the rotor 107, the brackets 122, 132, and the like to the motor frame 116. Thus, in the canned motor 100 of the present embodiment, the interior of the stator chamber 140 can be easily maintained.

[Modification 1]
FIG. 5 is a view showing a reinforcing member 160 of a modified example. The modified reinforcing member 160 is different from the reinforcing member 160 shown in FIG. 2 in that a grip 169 is provided, and the rest is the same as the reinforcing member 160 shown in FIG. As shown in FIG. 5, the grip portion 169 is provided on the inner peripheral surface of the reinforcing member 160 in the vicinity of the slit 168. In the present embodiment, one set of gripping portions 169 is provided at both ends of the slit 168 when viewed in the direction of the cylindrical axis CA. Note that the gripping portion 169 may be provided at the inner end (right side in FIG. 2) or the outer end (left side in FIG. 2) in the cylindrical axis CA direction when the reinforcing member 160 is fitted inside the can 118. Alternatively, it may be provided at a center position in the direction of the cylindrical axis CA. Further, the reinforcing member 160 may be provided with two or more sets of gripping portions 169. The grip 169 is provided for the user to grip the reinforcing member 160 when the reinforcing member 160 is attached to or detached from the can 118. The gripping part 169 may be gripped using a predetermined jig such as a pliers. By providing such a gripping portion 169, particularly when the reinforcing member 160 has the slit 168, the reinforcing member 160 can be attached to and detached from the can 118 while gripping the gripping portion 169 and making the slit 168 small. Can do.

[Modification 2]
The reinforcing member 160 of the above-described embodiment or modification 1 has a slit 168 along the cylindrical axis CA direction, that is, a split shape in which a part in the circumferential direction is missing. However, the slit 168 only needs to extend from one end to the other end in the cylindrical axis CA direction, and may be inclined with respect to the cylindrical axis CA direction, for example. Further, the reinforcing member 160 may not have such a slit 168. In this case, the reinforcing member 160 may be attached to and detached from the can 118 using a hammer or the like. Similarly, the reinforcing member 160 described above has a tapered shape 164 that gradually decreases in diameter toward one end in the direction of the cylindrical axis CA. However, the reinforcing member 160 may not have such a tapered shape 164. Further, instead of or in addition to the tapered shape 164, one end or both ends in the direction of the cylindrical axis CA may be rounded and chamfered.

[Modification 3]
The reinforcing member 160 of the above-described embodiment is made of a metal such as stainless steel. However, the reinforcing member 160 may be formed of a highly rigid resin or the like. Further, the reinforcing member 160 may be formed entirely or partly on the outer peripheral side with an elastic member such as rubber or resin. In the above-described embodiment, the reinforcing member 160 is a mechanically independent member. However, the reinforcing member 160 may be integrally formed with other members, for example, integrally formed with the bracket 132.

  Although the embodiments of the present invention have been described above, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and are not intended to limit the present invention. 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 of the embodiment and the modified example 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 can be achieved, and is described in the claims and the specification. Any combination or omission of each component is possible.

100 canned motor 104 stator 107 rotor 110 output shaft 116 motor frame 118 can 120 load side frame side plate 122 load side bracket 124 O ring 126 bearing 128 shaft seal mechanism 130 anti load side frame side plate 132 anti load side bracket 134 O Ring 136 Bearing 138 O-ring 140 Stator chamber 142 Rotor chamber 160 Reinforcement member 162 Outer peripheral surface 164 Tapered shape 168 Slit 169 Grasping part 200 Submersible pump 500 Pump device CA Cylindrical shaft Wp Welding part

Claims (8)

A cylindrical motor frame;
A stator disposed inside the motor frame and having a stator core and a stator coil wound around the stator core;
A cylindrical can disposed inside the stator;
A first frame side plate and a second frame side plate, which are respectively disposed on the outer peripheral sides of both ends in the cylindrical axial direction of the can, and define a stator chamber in which the stator is disposed together with the motor frame and the can;
A sealing member disposed between an inner peripheral surface of the first frame side plate and an outer peripheral surface of the can and sealing the first frame side plate and the can;
A reinforcing member that has a shape corresponding to the inner peripheral surface of the first frame side plate and is fitted inside the can so as to be positioned on the inner peripheral side of the sealing member;
A canned motor. The canned motor according to claim 1,
The canned motor, wherein the reinforcing member is cylindrical. The canned motor according to claim 2,
The reinforcing member has a tapered shape that gradually decreases in diameter toward one end in the cylindrical axis direction.
Canned motor. The canned motor according to claim 2 or 3,
The reinforcing member has a slit extending from one end to the other end in the cylindrical axial direction.
Canned motor. A canned motor according to any one of claims 1 to 4,
The second frame side plate and the can are fixed,
Canned motor. A canned motor according to any one of claims 1 to 5,
The motor frame, the first frame side plate, and the second frame side plate are sealed by a second sealing member,
Canned motor.   The pump apparatus provided with the canned motor of any one of Claims 1 thru | or 6. A method for maintaining the canned motor according to any one of claims 1 to 6, or the pump device according to claim 7.
Removing the reinforcing member from the can;
Removing the can from the inside of the stator;
Having a method.

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