JP2017184570A - Motor, linear motion type motor pump, and water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent a droplet to be immersed into an inner part of a liner motion type motor pump.SOLUTION: A motor constructs a liner motion type motor pump coupled to a pump by a main axis. The motor comprises: a bracket that closes an inner part space of the motor on the pump side and includes a penetration hole; a motor axis that is penetrated to the penetration hole and constructs at least one part of the main axis; a hollow discoid part that is mounted to the motor axis on the pump side from the bracket and surrounds the motor axis; and a drip-proof member that is extended to the bracket side from an outer periphery of the hollow discoid part and includes a discoid part reached to an outer side of a lip part of the bracket in which a tip end is expanded from an inlet port of the penetration hole.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor, a direct acting motor pump, and a water supply device.

  In motor pumps, except for water-proof ones that are inherently waterproof, it is possible to prevent droplets leaking from the pump from entering the motor along the main shaft due to damage to the shaft seal device. It is common to provide a drip-proof structure. As a drip-proof structure, for example, a rubber donut-shaped (hollow disk-shaped) draining ring is used. By fitting a draining ring on the main shaft between the pump and the motor, droplets that have traveled along the main shaft or have come from the pump side are captured on the draining ring. The droplet trapped on the draining ring is blown outward by centrifugal force when the draining ring rotates with the main shaft, and therefore does not enter the motor. The example of such a draining ring is described in the following patent document 1, for example.

JP 2014-109195 A

  However, the conventional draining ring having the conventional drip-proof structure as described above is not necessarily sufficient to prevent the droplets from entering the motor. For example, when a droplet adheres to the main shaft between the draining ring and the motor for some reason, the droplet may enter the motor without being blocked by the draining ring. In addition, the draining ring is designed assuming that the motor pump in which centrifugal force is applied is operating, but there is no problem with droplets even while the motor pump is not operating, for example, during maintenance. Can occur.

  For example, in a direct acting motor pump in which a motor shaft and a pump shaft are joined to form a main shaft, the motor remains attached to the main shaft even when the pump is disassembled for maintenance. Furthermore, for example, since a pump blade retaining nut is disposed at the tip of the pump shaft opposite to the motor, maintenance is often performed with the motor down and the pump up. As a result, droplets of residual water inside the pump may flow down toward the motor along the main shaft during decomposition. The dropped liquid can be captured by the draining ring, but since the motor pump is stopped, it is not blown outside by the centrifugal force as described above. Accordingly, there is a possibility that the droplets flow down from the edge of the draining ring and enter the motor through a through hole for the motor shaft provided in the bracket that closes the inner space of the motor.

  The present invention has been made in view of the above points. One of the objects of the present invention is to provide a motor, a direct-acting motor pump, and a water supply device that can effectively prevent droplets from entering the motor in the direct-acting motor pump. is there.

According to an aspect of the present invention, a motor that is connected to a pump by a main shaft and constitutes a direct-acting motor pump, closes the internal space of the motor on the pump side, is inserted into the bracket having a through hole, and the through hole. A motor shaft that forms at least a part of the main shaft, and is attached to the motor shaft on the pump side from the bracket, and extends from the outer periphery of the hollow disk-shaped portion to the bracket side. And a drip-proof member including a cylindrical portion whose tip extends outside the lip portion of the bracket protruding from the entrance of the through hole.
When the tip of the cylindrical portion of the drip-proof member reaches the outside of the lip portion of the bracket, it is possible to prevent droplets from adhering to the main shaft at a portion between the drip-proof member and the motor. In addition, even when the motor pump is stopped where centrifugal force does not work, it is possible to prevent the liquid droplets that have flowed down from the drip-proof member from entering the motor through the through hole provided in the bracket.

In the motor described above, the tip of the cylindrical portion may contact a sliding plate arranged outside the lip portion.
By bringing the tip of the cylindrical portion of the drip-proof member into contact with the lip portion, it is possible to improve the effect of preventing droplets from entering the motor as described above. Rather than bringing the drip-proof member and the bracket into direct contact, the bracket is formed, for example, by casting by bringing the sliding plate placed outside the lip portion of the bracket into contact with the cylindrical portion of the drip-proof member. In such a case, the adhesion can be improved or the sliding resistance can be reduced.

In the above motor, the tip of the cylindrical portion may have a weight portion configured to be separated from the sliding plate by centrifugal force when the drip-proof member rotates together with the motor shaft.
The contact between the drip-proof member and the sliding plate may increase the sliding resistance when the motor shaft rotates, for example. At this time, if the tip of the cylindrical part is separated from the sliding plate by the centrifugal force acting on the weight part, the effect of preventing the intrusion of liquid droplets while the motor pump is stopped as described above can be obtained. The sliding resistance during the operation of the pump can be reduced.

In the motor described above, a protruding portion that protrudes inward toward the lip portion may be provided at the tip of the cylindrical portion.
By providing the protruding portion at the tip of the cylindrical portion of the drip-proof member, the effect of preventing the intrusion of the droplet can be improved. At this time, the overhanging portion does not necessarily need to contact the sliding plate arranged outside the lip portion of the bracket.

The motor may further include an open type bearing that is provided close to the bracket and rotatably supports the motor shaft.
For example, when the drip-proof performance of a drip-proof structure such as a draining ring is not sufficient, it is necessary to provide a seal structure that prevents intrusion of liquid droplets in a bearing provided in the inner space of the motor in the vicinity of the bracket. However, by installing a drip-proof member with improved drip-proof performance, it is possible to reduce the sliding resistance and reduce the component cost by making the bearing an open type without a seal.

  According to another aspect of the present invention, a direct acting motor pump including a motor, a pump, and a main shaft that connects the motor and the pump, the motor closes the internal space of the motor on the pump side, and passes therethrough. A bracket having a hole, a motor shaft inserted through the through-hole and constituting at least a part of the main shaft, a hollow disk-shaped portion that is attached to the motor shaft on the pump side of the bracket and surrounds the motor shaft, and a hollow disk A drip-proof motor pump is provided that includes a drip-proof member that includes a cylindrical portion that extends from the outer peripheral edge of the shaped portion toward the bracket side and that reaches the outside of the lip portion of the bracket protruding from the inlet of the through hole.

  In the above-described direct acting motor pump, the tip of the cylindrical portion may contact a sliding plate arranged outside the lip portion.

  In the above linear motion motor pump, the tip of the cylindrical portion may have a weight portion configured to be separated from the sliding plate by centrifugal force when the drip-proof member rotates together with the motor shaft.

  In the above-described direct acting motor pump, a protruding portion that protrudes inward toward the lip portion may be provided at the tip of the cylindrical portion.

  In the above-described direct-acting motor pump, the motor may further include an open type bearing that is provided close to the bracket and rotatably supports the motor shaft.

  According to another viewpoint of this invention, a water supply apparatus provided with said direct-acting motor pump is provided.

  The water supply device may be a direct water supply type.

1 is a schematic longitudinal sectional view showing a motor pump according to an embodiment of the present invention. It is an expanded sectional view which shows the drip-proof structure of the motor pump shown in FIG. It is a figure which shows the structural example of a water supply apparatus provided with the motor pump shown in FIG.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic longitudinal sectional view showing a motor pump according to an embodiment of the present invention. Referring to FIG. 1, the motor pump includes a pump 100 and a motor 200 that drives the pump 100. In the illustrated example, the pump 100 is a multistage pump and includes a plurality of impellers 120 attached to a pump shaft 110. The impeller 120 is accommodated in the casing 130, and the fluid is pumped by the rotation of the impeller 120 in the casing 130. Guide vanes 140 for guiding fluid between the impellers 120 are also provided in the casing 130. In the illustrated example, the pump 100 is a vertical shaft pump, and the fluid is sucked from the suction port 150 located on the side opposite to the motor 200 and discharged from the discharge port 160 on the side close to the motor 200.

  On the other hand, in the illustrated example, the motor 200 is a permanent magnet type electric motor, and includes a rotor 220 attached to the motor shaft 210 and a stator 230 corresponding to the rotor 220. The motor shaft 210 rotatably supported by the load side bearing 241 and the anti-load side bearing 242 rotates together with the rotor 220 and transmits a rotational driving force to the pump shaft 110. In a direct acting motor pump such as the illustrated example, a motor shaft 210 and a pump shaft 110 are joined to form a main shaft. The rotor 220 and the stator 230 are accommodated in a space surrounded by the frame 250, the load side bracket 261, and the anti-load side bracket 262. A load side bearing 241 (hereinafter also simply referred to as a bearing 241) is fixed to the load side bracket 261 (hereinafter also simply referred to as a bracket 261) using a retaining ring 243 and a screw 244. The bearing 241 is a bearing provided in the vicinity of the bracket 261 and can be an open type bearing as will be described later. In addition, a fan 270 for cooling the inside of the motor 200 using a rotational driving force is attached to the motor shaft 210.

Note that the configurations of the pump 100 and the motor 200 (for example, portions other than the motor shaft 210, the bearing 241 and the bracket 261) are examples, and various configurations are possible without being limited to the illustrated examples. For example, in the illustrated example, the pump 100 is a multi-stage vertical pump, but in other examples it may be any type of pump, such as a vortex pump, a gear pump, or a cascade pump. Similarly, the motor 200 is a permanent magnet type electric motor in the illustrated example, but in other examples, any type of motor such as an induction motor or a synchronous motor other than a permanent magnet type may be used. Good. The motor pump according to the present embodiment is not for underwater use, and the motor 200 is not provided with a waterproof structure.

  Between the pump 100 and the motor 200, a mechanical seal 310 that is a shaft seal device is disposed. On the main shaft between the pump shaft 110 and the motor shaft 210, a mounting portion 320 of the shaft seal device is provided. This portion may be a portion formed integrally with the pump shaft 110, for example, or may be a portion formed separately from the pump shaft 110 and the motor shaft 210 and joined to these shafts. Further, a drip-proof structure 330 is provided between the pump 100 and the motor 200. Hereinafter, the drip-proof structure 330 will be further described.

  FIG. 2 is an enlarged cross-sectional view showing a drip-proof structure of the motor pump shown in FIG. Referring to FIG. 2, the drip-proof structure 330 includes a drip-proof member 331. The drip-proof member 331 is attached to the motor shaft 210 closer to the pump 100 than the bracket 261 that closes the internal space of the motor 200. In the present embodiment, the drip-proof member 331 includes a hollow disk-shaped portion 332 that surrounds the motor shaft, and a cylindrical portion 334 that extends from the outer peripheral edge 333 of the hollow disk-shaped portion 332 to the bracket 261 side. The tip of the cylindrical portion 334 reaches the outside of the lip portion 264 that protrudes from the entrance of the through hole 263 provided in the bracket 261. The motor shaft 210 is inserted through the through hole 263.

  By arranging the drip-proof member 331 as described above, in the motor pump according to the present embodiment, the liquid droplets flying from the side of the pump 100 or from the side or transmitted through the motor shaft 210 pass through the through hole 263. Thus, it is possible to effectively prevent the motor 200 from entering. As shown in the illustrated example, by providing a protruding portion 335 that protrudes inward toward the lip portion 264 of the bracket 261 at the tip of the cylindrical portion 334 of the drip-proof member 331, an effect of preventing the intrusion of liquid droplets. Can be further improved.

  In the illustrated example, the overhang portion 335 contacts a stainless plate 265 disposed outside the lip portion 264. Even by such contact, the effect of preventing the intrusion of the liquid droplets can be further improved. Here, for example, when the bracket 261 is formed of a casting, if the projecting portion 335 and the lip portion 264 are brought into direct contact, the adhesion is not sufficient due to the roughness of the surface of the casting, The sliding resistance may increase. In such a case, by arranging the stainless steel plate 265 as a sliding plate outside the lip portion 264, the adhesion can be improved or the sliding resistance can be reduced.

  In another example, instead of the stainless steel plate 265, for example, another metal plate having corrosion resistance or a resin plate may be used. Further, when the bracket 261 is formed using a casting, it is possible to prevent the occurrence of electrolytic corrosion between the bracket 261 and the stainless steel plate 265 by applying, for example, an epoxy paint on the surface of the bracket 261 by cationic electrodeposition. . When the tip of the cylindrical portion 334 is brought into contact with the stainless steel plate 265, the protruding portion 335 is not necessarily formed. For example, when the protruding portion 335 is not formed, the tip of the cylindrical portion 334 may come into contact with the stainless steel plate 265 so that the tip is along the outside.

  In the present embodiment, the drip-proof member 331 is formed of an elastic material such as rubber, for example. As shown in the figure, the core metal 336 is insert-molded into the elastic material, so that the shape is maintained even if the elastic material deteriorates due to long-term use, and the adhesion with the motor shaft 210 is maintained. Can do. When the drip-proof member 331 is formed of an elastic material, for example, the overhanging portion 335 may be configured to function as a weight portion to which centrifugal force acts when the drip-proof member 331 rotates with the motor shaft 210. Is possible.

  More specifically, for example, by appropriately setting the mass of the overhanging portion 335 and the rigidity of the cylindrical portion 334 that supports the overhanging portion 335, the overhanging portion 335 is caused by the centrifugal force that acts when the motor shaft 210 rotates. Can be separated from the stainless steel plate 265. In addition, when the drip-proof member 331 rotates with the motor shaft 210, the droplets adhering to the surface of the drip-proof member 331 are blown outward by centrifugal force. Therefore, even if the overhanging portion 335 moves away from the stainless steel plate 265 during the rotation of the motor shaft 210, that is, during the operation of the motor pump, there is a low possibility that the droplets enter the inside of the motor 200.

  Note that the weight portion of the drip-proof member 331 is not necessarily formed as the protruding portion 335. For example, instead of or together with the overhanging portion 335, a centrifugal force may be applied by attaching a weight such as metal to the tip of the cylindrical portion 334.

  As another additional configuration, for example, a radial groove may be formed on the surface of the hollow disc portion 332 on the pump 100 side. If the width of the groove is appropriately set, it is possible to promote the use of capillary action to cause the droplets to fly outward by centrifugal force. Further, for example, instead of the hollow disk-shaped portion 332, a portion having an inverted conical surface opened toward the pump 100 may be provided. The droplet on the surface having the inverted conical shape is blown away in an oblique direction toward the pump 100 side by the centrifugal force, that is, away from the motor 200.

  Further, a lubricant such as grease may be applied to the inside of the drip-proof member 331, that is, the side surrounding the lip portion 264. The lubricant reduces, for example, sliding resistance between the overhang portion 335 and the stainless steel plate 265. Further, the lubricant fills a gap that may be formed between the overhanging portion 335 and the stainless steel plate 265 and / or between the hollow disk-shaped portion 332 and the motor shaft 210, and the drip-proof member 331 prevents the intrusion of the liquid droplets. The effect of preventing can be improved. Since the drip-proof member 331 has a cup-like shape as a whole, the lubricant such as applied grease is unlikely to flow out, particularly while the motor pump is operated with the motor 200 on the top and the pump 100 on the bottom. .

  As described above, in the present embodiment, by providing the drip-proof member 331, the liquid droplets flying from the side of the pump 100 or from the side or transmitted through the motor shaft 210 via the through-hole 263. Intrusion into the motor 200 is effectively prevented. Therefore, in the present embodiment, the bearing 241 provided close to the bracket 261 can be an open type bearing.

  Since the bearing 241 is a part that is most affected when a droplet enters the motor 200, if the drip-proof structure does not have sufficient performance to prevent the droplet from entering, the bearing 241 enters the bearing 241. It is necessary to separately provide a seal structure for preventing intrusion of liquid droplets. A highly effective seal structure is a contact type structure in which the seal contacts the motor shaft 210 side. However, when this structure is employed, sliding resistance during operation increases due to the contact of the seal. Also, for example, it is possible to minimize the contact of the seal or to use a seal that is normally provided on both sides of the bearing only on one side, but such special bearings increase the part cost In addition, the assembly procedure of the motor 200 may be complicated. In the present embodiment, such a problem can be solved by making the bearing 241 an open type bearing.

FIG. 3 is a diagram illustrating a configuration example of a water supply apparatus including the motor pump illustrated in FIG. 1. Referring to FIG. 3, water supply apparatus 10 includes two sets of motor pumps, pump 100a and motor 200a, and pump 100b and motor 200b. These motor pumps are incorporated in a water supply system including a suction port 11, a suction pipe 12, a backflow preventer 13, a suction header 14, a discharge pipe 15, a bypass header 16, a discharge port 17, a pressure tank pipe 18, and a pressure tank 19. It is. The water supply apparatus 10 is a directly connected water supply type in which the suction port 11 is connected to a water main.
The water sucked from the suction port 11 is supplied from the suction header 14 to the pump 100a and the pump 100b through the suction pipe 12 and the backflow preventer 13, respectively.

  In the water supply apparatus 10, the pumps 100a and 100b are driven by motors 200a and 200b, respectively, and function as booster pumps that pressurize the supplied water. The water discharged from each of the pump 100a and the pump 100b merges and is supplied from the discharge pipe 15 through the bypass header 16 to the customer from the pipe connected to the discharge port 17. On the other hand, the pressure tank pipe 18 connected to the bypass header 16 supplies water pressurized by the pumps 100 a and 100 b to the pressure tank 19. The pressure tank 19 maintains the pressure of the supplied water (accumulating pressure), thereby enabling the pressurized water to be supplied to the demand destination even when the pumps 100a and 100b are stopped.

  In addition to the water supply system as described above, the water supply device 10 includes structural components such as a cabinet 20 and a gantry 21 and electrical components such as an inverter 22 and a control panel 23. The water supply system can also include additional components such as strainers, ball valves, pressure sensors, check valves and the like. In addition, about the detailed structure of such a water supply apparatus 10, since those skilled in the art can design suitably with reference to the well-known technique described, for example in Unexamined-Japanese-Patent No. 2004-92089 etc., detailed description is carried out here. Omitted.

  In the illustrated example, since the water supply apparatus 10 is a directly connected water supply type, the pressure of the water main is applied to the water supply system even when the pumps 100a and 100b are stopped. In addition, since the pressure tank 19 is provided, the pumps 100a and 100b can be stopped at a time when the supply of water to the demand destination is low even during normal operation. Therefore, for example, when the mechanical seal 310 provided in any of the pumps 100a and 100b is broken, high-pressure water is ejected from the pump 100 side toward the motor 200 while the motor pump is stopped. Since the centrifugal force due to the rotation of the motor shaft 210 does not act while the motor pump is stopped, for example, in a draining ring having a conventional drip-proof structure, the droplet bypasses the draining ring and reaches the inside of the motor 200. there is a possibility. In such a case, the drip-proof member 331 according to this embodiment is advantageous because it can effectively prevent the liquid droplets from entering the motor 200 regardless of the centrifugal force.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the technical scope of the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field of the present invention can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that it belongs to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Pump 110 Pump shaft 120 Impeller 130 Casing 200 Motor 210 Motor shaft 220 Rotor 230 Stator 241 Bearing 261 Bracket 263 Through-hole 264 Lip part 265 Stainless steel plate 310 Mechanical seal 331 Drip-proof member 332 Hollow disk-shaped part 334 Cylindrical part 335 Overhang portion 336 Core 10 Water supply device

Claims (12)

A motor that is connected to a pump by a main shaft to constitute a direct acting motor pump,
A bracket having a through hole that closes the internal space of the motor on the pump side;
A motor shaft inserted through the through-hole and constituting at least a part of the main shaft;
A hollow disk-shaped portion that is attached to the motor shaft on the pump side with respect to the bracket and that surrounds the motor shaft, and extends from the outer peripheral edge of the hollow disk-shaped portion to the bracket side, with the tip at the inlet of the through hole And a drip-proof member including a cylindrical portion that reaches the outside of the lip portion of the bracket protruding from the motor.   The motor according to claim 1, wherein a tip of the cylindrical portion contacts a sliding plate disposed outside the lip portion.   The motor according to claim 2, wherein a tip of the cylindrical portion has a weight portion configured to be separated from the sliding plate by centrifugal force when the drip-proof member rotates together with the motor shaft.   The motor according to any one of claims 1 to 3, wherein a protruding portion that protrudes inward toward the lip portion is provided at a tip of the cylindrical portion.   5. The motor according to claim 1, further comprising an open-type bearing provided in proximity to the bracket and rotatably supporting the motor shaft. A direct-acting motor pump including a motor, a pump, and a main shaft connecting the motor and the pump,
The motor is
A bracket having a through hole that closes the internal space of the motor on the pump side;
A motor shaft inserted through the through-hole and constituting at least a part of the main shaft;
A hollow disk-shaped portion that is attached to the motor shaft on the pump side with respect to the bracket and that surrounds the motor shaft, and extends from the outer peripheral edge of the hollow disk-shaped portion to the bracket side, with the tip at the inlet of the through hole And a drip-proof member including a cylindrical portion reaching the outside of the lip portion of the bracket projecting from the bracket.   The direct acting motor pump according to claim 6, wherein a tip of the cylindrical portion contacts a sliding plate disposed outside the lip portion.   The linear motion type according to claim 7, wherein a tip of the cylindrical portion has a weight portion configured to be separated from the sliding plate by centrifugal force when the drip-proof member rotates together with the motor shaft. Motor pump.   The direct acting motor pump according to any one of claims 6 to 8, wherein a protruding portion that protrudes inward toward the lip portion is provided at a tip of the cylindrical portion.   10. The direct acting motor pump according to claim 6, wherein the motor is further provided with an open type bearing that is provided in the vicinity of the bracket and rotatably supports the motor shaft.   A water supply apparatus provided with the direct acting motor pump of any one of Claims 6-10.   The water supply apparatus of Claim 11 which is a direct connection water supply type.

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