JP6774205B2 - Motors, linear motor pumps, and water supply devices - Google Patents

Description

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

Aside from the underwater motor pump, which originally has a waterproof structure, to prevent droplets leaking from the pump due to damage to the shaft sealing device, etc., from entering the motor along the spindle. It is common to provide a drip-proof structure. As the drip-proof structure, for example, a rubber donut-shaped (hollow disk-shaped) draining ring is used. By fitting the drain ring into the main shaft between the pump and the motor, droplets that have traveled along the main shaft or come from the pump side are captured on the drain ring. The droplets trapped on the drain ring are blown outward by centrifugal force as the drain ring rotates with the spindle, and therefore do not enter the inside of the motor. An example of such a draining ring is described in, for example, Patent Document 1 below.

Japanese Unexamined Patent Publication No. 2014-109195

However, the draining ring having the conventional drip-proof structure as described above is not always sufficient to prevent the droplets from entering the motor. For example, if droplets adhere to the spindle between the drain ring and the motor for some reason, the droplets may enter the motor without being hindered by the drain ring. In addition, the drain ring is designed mainly for the operating state of the motor pump where centrifugal force acts, but there is a problem due to droplets even when the motor pump where centrifugal force does not act is stopped, 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. Further, for example, since the vane stop nut of the pump is arranged at the tip of the pump shaft on the opposite side of 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 the main shaft toward the motor during decomposition. The droplets that have flowed down can be captured by the drain ring, but since the motor pump is stopped, they are not blown outward by centrifugal force as described above. Therefore, droplets may flow down from the edge of the drain ring and enter the inside of the motor through a through hole for the motor shaft provided in the bracket that closes the internal space of the motor.

The present invention has been made in view of the above points. One object of the present invention is to provide a motor, a linear motor pump, and a water supply device capable of effectively preventing droplets from entering the motor in a linear motor pump. is there.

According to a certain aspect of the present invention, it is a motor that is connected to a pump by a spindle to form a linear motor pump, and the internal space of the motor is closed on the pump side and inserted into a bracket having a through hole and a through hole. The motor shaft, which forms at least a part of the main shaft, is attached to the motor shaft on the pump side of the bracket, and extends from the outer peripheral edge of the hollow disk-shaped portion surrounding the motor shaft to the bracket side. Provided are motors comprising a drip-proof member including a cylindrical portion whose tip extends outside the lip portion of the bracket projecting from the inlet of the through hole.
By reaching the outside of the lip portion of the bracket at the tip of the cylindrical portion of the drip-proof member, droplets are prevented from adhering to the spindle at the portion between the drip-proof member and the motor. Further, even when the motor pump in which centrifugal force does not work is stopped, it is possible to prevent the droplets that have flowed down from the drip-proof member from entering the inside of the motor through the through holes provided in the bracket.

In the above motor, the tip of the cylindrical portion may come into contact with 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, the effect of preventing the droplets from entering the inside of the motor can be improved as described above. For example, the bracket is formed of a casting by contacting the sliding plate arranged outside the lip portion of the bracket with the cylindrical portion of the drip-proof member, instead of directly contacting the drip-proof member and the bracket. In such a case, the adhesion can be improved and 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 with the motor shaft.
The contact between the drip-proof member and the sliding plate may increase the sliding resistance, for example, when the motor shaft rotates. At this time, if the tip of the cylindrical portion is separated from the sliding plate by the centrifugal force acting on the weight portion, the motor can be prevented from invading droplets while the motor pump is stopped as described above. The sliding resistance during operation of the pump can be reduced.

In the above motor, the tip of the cylindrical portion may be provided with an overhanging portion that projects inward toward the lip portion.
By providing the overhanging portion at the tip of the cylindrical portion of the drip-proof member, the effect of preventing the intrusion of droplets can be improved. At this time, the overhanging portion does not necessarily have to come into contact with the sliding plate arranged outside the lip portion of the bracket.

The motor may further include an open bearing that is provided in close proximity to the bracket and rotatably supports the motor shaft.
For example, when the drip-proof performance of a drip-proof structure such as a drain ring is not sufficient, it is necessary to provide a seal structure for preventing the intrusion of droplets in a bearing provided close to the bracket in the internal space of the motor. However, by installing a drip-proof member having improved drip-proof performance, it is possible to make the bearing an open type without a seal to reduce sliding resistance and reduce the cost of parts.

According to another aspect of the present invention, a linear motor pump including a motor, a pump, and a spindle connecting the motor and the pump, wherein the motor closes and penetrates the internal space of the motor on the pump side. A bracket with a hole, a motor shaft that is inserted through a through hole and forms at least a part of the main shaft, a hollow disk-shaped part that is attached to the motor shaft on the pump side of the bracket and surrounds the motor shaft, and a hollow disk. Provided is a linear motor pump including a drip-proof member including a cylindrical portion extending from the outer peripheral edge of the shaped portion toward the bracket and having a tip extending from the inlet of the through hole to the outside of the lip portion of the bracket.

In the above-mentioned linear motor pump, the tip of the cylindrical portion may come into contact with a sliding plate arranged outside the lip portion.

In the above-mentioned direct-acting 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 with the motor shaft.

In the above-mentioned direct-acting motor pump, the tip of the cylindrical portion may be provided with an overhanging portion that projects inward toward the lip portion.

In the linear motor pump described above, the motor may further include an open bearing that is provided in close proximity to the bracket and rotatably supports the motor shaft.

According to still another aspect of the present invention, there is provided a water supply device including the above-mentioned direct-acting motor pump.

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

It is a schematic vertical sectional view which shows the motor pump which concerns on one Embodiment of this invention. It is an enlarged sectional view which shows the drip-proof structure of the motor pump shown in FIG. It is a figure which shows the configuration example of the water supply device which includes the motor pump shown in FIG.

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

FIG. 1 is a schematic vertical 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 for driving the pump 100. In the illustrated example, the pump 100 is a multistage pump, comprising a plurality of impellers 120 attached to the pump shaft 110. The impeller 120 is housed in the casing 130, and the fluid is pumped by the rotation of the impeller 120 in the casing 130. A guide blade 140 for guiding the fluid between the impellers 120 is also provided in the casing 130. Further, in the illustrated example, the pump 100 is a vertical pump, and the fluid is sucked from the suction port 150 located on the opposite side of 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 non-load-side bearing 242 rotates together with the rotor 220 and transmits a rotational driving force to the pump shaft 110. In a linear motor pump as shown in the illustrated example, the motor shaft 210 and the pump shaft 110 are joined to form a main shaft. The rotor 220 and the stator 230 are housed in a space surrounded by a frame 250, load side brackets 261 and counterload side brackets 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) by using a retaining ring 243 and a screw 244. The bearing 241 is a bearing provided close to the bracket 261 and can be an open type bearing as described later. Further, a fan 270 for cooling the inside of the motor 200 by utilizing the rotational driving force is attached to the motor shaft 210.

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

A mechanical seal 310, which is a shaft sealing device, is arranged between the pump 100 and the motor 200. A shaft sealing device mounting portion 320 is provided on the spindle between the pump shaft 110 and the motor shaft 210. This portion may be, for example, a portion integrally formed with the pump shaft 110, or 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 on the pump 100 side of 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 toward the bracket 261. The tip of the cylindrical portion 334 reaches the outside of the lip portion 264 protruding 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, droplets flying from or from the side of the pump 100 or propagating through the motor shaft 210 pass through the through hole 263. It is effectively prevented from entering the inside of the motor 200 through the motor 200. As shown in the illustrated example, the effect of preventing the invasion of droplets by providing the overhanging portion 335 inwardly projecting toward the lip portion 264 of the bracket 261 at the tip of the cylindrical portion 334 of the drip-proof member 331. Can be further improved.

In the illustrated example, the overhanging portion 335 contacts the stainless steel plate 265 located outside the lip portion 264. Even by such contact, the effect of preventing the invasion of droplets can be further improved. Here, for example, when the bracket 261 is formed of a casting, if the overhanging portion 335 and the lip portion 264 are brought into direct contact with each other, the adhesion may not be sufficient due to the roughness of the surface of the casting. There is a possibility that the sliding resistance will increase. In such a case, by arranging the stainless steel plate 265 as a sliding plate on the outside of the lip portion 264, the adhesiveness can be improved and the sliding resistance can be reduced.

In another example, instead of the stainless steel plate 265, for example, another metal plate having corrosion resistance, a resin plate, or the like may be used. Further, when the bracket 261 is formed by using a casting, for example, by cation electrodeposition coating of an epoxy-based paint on the surface of the bracket 261, it is possible to prevent electrolytic corrosion from occurring between the bracket 261 and the stainless plate 265. .. When the tip of the cylindrical portion 334 is brought into contact with the stainless plate 265, the overhanging portion 335 does not necessarily have to be formed. For example, when the overhanging portion 335 is not formed, the tip of the cylindrical portion 334 may come into contact with the stainless steel plate 265 so as to be along the outside.

In this embodiment, the drip-proof member 331 is made of an elastic material such as rubber. As shown, by insert molding the core metal 336 into the elastic material, 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 be done. Further, when the drip-proof member 331 is made of an elastic material, for example, the overhanging portion 335 may be configured to function as a weight portion on which centrifugal force acts when the drip-proof member 331 rotates together with the motor shaft 210. It 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 generated by the centrifugal force acting during the rotation of the motor shaft 210. Can be separated from the stainless steel plate 265. When the drip-proof member 331 is rotating together 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 separates from the stainless steel plate 265 during the rotation of the motor shaft 210, that is, during the operation of the motor pump, it is unlikely that the droplets will enter the inside of the motor 200.

The weight portion of the drip-proof member 331 does not necessarily have to be formed as an overhanging portion 335. For example, a centrifugal force may be applied in place of or in combination with the overhanging portion 335 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 disk-shaped portion 332 on the pump 100 side. If the width of the groove is set appropriately, the capillary phenomenon can be utilized to promote the droplets to be blown outward by the centrifugal force. Further, for example, instead of the hollow disk-shaped portion 332, a portion having an inverted conical surface that opens toward the pump 100 side may be provided. The droplets on the surface of the inverted cone are blown outward and diagonally toward the pump 100, that is, away from the motor 200 by centrifugal force.

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, the sliding resistance between the overhanging portion 335 and the stainless steel plate 265. Further, the lubricant fills a gap that may occur between the overhanging portion 335 and the stainless plate 265 and / or between the hollow disk-shaped portion 332 and the motor shaft 210, and the drip-proof member 331 invades the droplets. The effect of prevention can be improved. Since the drip-proof member 331 has a cup-shaped shape as a whole, the applied grease and other lubricants are unlikely to flow out, especially 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 arranging the drip-proof member 331, the droplets that have flown from the pump 100 side or the side or have propagated through the motor shaft 210 are transmitted through the through hole 263. It is effectively prevented from entering the inside of the motor 200. Therefore, in the present embodiment, the bearing 241 provided in the vicinity of the bracket 261 can be an open type bearing.

Since the bearing 241 is the part most affected when droplets invade the inside of the motor 200, if the drip-proof structure does not have sufficient performance to prevent the invasion of droplets, the bearing 241 is moved into the bearing 241. It is necessary to separately provide a sealing structure to prevent the intrusion of droplets. The highly effective seal structure is a contact type structure in which the seal contacts the motor shaft 210 side, but when this structure is adopted, the sliding resistance during operation increases due to the contact of the seal. It is also possible, for example, to minimize the contact of the seals or to use ones with seals normally provided on both sides of the bearing on only one side, but such special bearings increase component costs. It may also complicate the assembly procedure of the motor 200. In the present embodiment, such a problem can be solved by using the bearing 241 as an open type bearing.

FIG. 3 is a diagram showing a configuration example of a water supply device including the motor pump shown in FIG. Referring to FIG. 3, the water supply device 10 includes two sets of motor pumps, a pump 100a and a motor 200a, and a pump 100b and a motor 200b. These motor pumps are incorporated into 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 has been. The water supply device 10 is a direct water supply type in which the suction port 11 is connected to the water main.
The water sucked from the suction port 11 is supplied to the pump 100a and the pump 100b from the suction header 14 via the suction pipe 12 and the backflow preventer 13, respectively.

In the water supply device 10, the pumps 100a and 100b are driven by the 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 to the demand destination through the bypass header 16 and the pipe connected to the discharge port 17. On the other hand, the pressure tank pipe 18 connected to the bypass header 16 supplies the water pressurized by the pumps 100a and 100b to the pressure tank 19. By holding (accumulating) the pressure of the supplied water, the pressure tank 19 makes it possible to supply the pressurized water 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 parts such as the cabinet 20 and the gantry 21, and electrical components such as the inverter 22 and the control panel 23. The water supply system may also include additional components such as strainers, ball valves, pressure sensors, check valves and the like. A detailed configuration of such a water supply device 10 can be appropriately designed by a person skilled in the art with reference to, for example, a known technique described in JP-A-2004-92089, and thus a detailed description thereof will be given here. Omit.

In the illustrated example, since the water supply device 10 is a direct 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. Further, since the pressure tank 19 is provided, the pumps 100a and 100b can be stopped even during normal operation when the water supply to the demand destination is low. Therefore, for example, if the mechanical seal 310 provided in any of the pumps 100a and 100b is damaged, high-pressure water will be 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 the draining ring having a conventional drip-proof structure, the droplets bypass the draining ring and reach the inside of the motor 200. there is a possibility. In such a case, the drip-proof member 331 according to the present embodiment is advantageous because it can effectively prevent the droplets from entering the inside of the motor 200 without using centrifugal force.

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

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 Overhanging part 336 Core metal 10 Water supply device

Claims (12)

A motor that is connected to a pump by a spindle to form a direct-acting motor pump.
A bracket that closes the internal space of the motor on the pump side and has a through hole,
A motor shaft that is inserted through the through hole and forms at least a part of the spindle,
A hollow disc-shaped portion that is attached to the motor shaft on the pump side of the bracket and surrounds the motor shaft, and extends from the outer peripheral edge of the hollow disc-shaped portion to the bracket side, and the tip thereof is an inlet of the through hole. A motor including a drip-proof member including a cylindrical portion extending from the outside of the lip portion of the bracket overhanging from. The motor according to claim 1, wherein the tip of the cylindrical portion contacts a sliding plate arranged outside the lip portion. The motor according to claim 2, wherein the 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 an overhanging portion protruding inward toward the lip portion is provided at the tip of the cylindrical portion. The motor according to any one of claims 1 to 4, further comprising an open bearing that is provided close to the bracket and rotatably supports the motor shaft. A linear motor pump including a motor, a pump, and a spindle connecting the motor and the pump.
The motor
A bracket that closes the internal space of the motor on the pump side and has a through hole,
A motor shaft that is inserted through the through hole and forms at least a part of the spindle,
A hollow disc-shaped portion that is attached to the motor shaft on the pump side of the bracket and surrounds the motor shaft, and extends from the outer peripheral edge of the hollow disc-shaped portion to the bracket side, and the tip thereof is an inlet of the through hole. A linear motor pump comprising a drip-proof member including a cylindrical portion extending from the outside of the lip portion of the bracket overhanging from. The linear motor pump according to claim 6, wherein the tip of the cylindrical portion contacts a sliding plate arranged outside the lip portion. The linear motion type according to claim 7, wherein the 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 linear motor pump according to any one of claims 6 to 8, wherein an overhanging portion that projects inward toward the lip portion is provided at the tip of the cylindrical portion. The linear motor pump according to any one of claims 6 to 9, wherein the motor is provided close to the bracket and further includes an open bearing that rotatably supports the motor shaft. A water supply device including the linear motor pump according to any one of claims 6 to 10. The water supply device according to claim 11, which is a direct water supply type.

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