JP2011080477A - Vertical type centrifugal pump and air conditioner using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner incorporated with a drain pump excelling in silence. <P>SOLUTION: The vertical type centrifugal pump is equipped with: a casing 19 having an inlet port 24 and a discharge port 26; a cover 21 connected to the casing 19 and defining with the casing 19 a pump chamber 20 communicating with the inlet port 24 and the discharge port 26; and a rotor 22 rotatably contained in the pump chamber 20. The cover 21 is equipped with: a cylindrical boss part 30 projecting from its central part to the opposite side of the pump chamber and provided with a through-hole 30a through which the spindle 15a of a drive motor 15 connected to the rotor 22 passes; an inner cylindrical part 31 formed to enclose the boss part 30; and an outer cylindrical part 23 formed to enclose the inner cylindrical part 31. The inner cylindrical part 31 has an overflow passage 31a communicating with its inner peripheral side and outer peripheral side, and the outer cylindrical part 23 has an overflow port communicating with its inner peripheral side and outer peripheral side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vertical shaft centrifugal pump and an air conditioner incorporating the same, and is particularly suitable for application to a drainage pump that requires quietness.

  The vertical shaft centrifugal pump rotates the impeller to rotate the liquid intervening in the casing, and uses the centrifugal force generated thereby to discharge the liquid to the outside of the casing. For example, it is used as a drainage pump of an air conditioner.

  In an air conditioner, in order to discharge the condensed water in the air generated during cooling operation to the outside of the room, it is generally stored temporarily in a drain pan and then discharged to the outside using a drain pump. It has been broken. In recent years, there has been a demand for a reduction in operation noise in air conditioners, and it is also required to reduce the operating noise of the drainage pump incorporated in the air conditioner apparatus and the various types of noise generated therewith. Yes. For example, even a slight scratching sound generated by the operation of a drain pump is problematic.

  Patent Documents 1 to 3 are known as drainage pumps that deal with such problems. That is, in Patent Document 1, in order to reduce noise generated during pumping, a sound insulation case having an air inflow hole and an overflow hole is installed between the bearing portion of the drive motor that drives the rotary blade and the cover that covers the pump body. A fluid pump is disclosed. In addition, the drainage pump disclosed in Patent Document 2 is provided with a dust-proof cover between the lid and the motor that is fitted to the upper end of the main body, and the lid of the lid through the gap between the lid and the runner shaft. An open channel communicating with the flow outlet is provided in the upper part of the lid, and the upper edge of the opening of the discharge port inside the main body is positioned at the same height as or below the large diameter part of the runner. This is to prevent vibrations and noises that are generated when the gas is discharged. Further, in Patent Document 3, a lid body in which a silencer cover is erected is provided on the upper surface of a pump main body that houses blades therein, and an upper bracket and a lower bracket are provided above and below a stator of the motor, respectively. A drain water drainage pump is disclosed in which a gap is formed between the lower bracket and the sound of stirring the drain water while the blades are rotating.

Japanese Utility Model Publication No. 62-74187 Japanese Utility Model Publication No. 63-54883 JP-A-8-285306

  The conventional drainage pumps disclosed in Patent Document 1 and Patent Document 2 are provided with a sound insulation case and a dust cover between the motor and the pump body to reduce noise during operation. In addition to this, it is necessary to prepare a case and cover for separate parts, resulting in a decrease in assembling workability and an increase in part cost. In addition to the motor driving sound and drainage noise, noise generated by the resonance phenomenon, in particular, an annoying sound of 1 to 2 kHz has not been sounded, and improvement is desired.

  In Patent Document 3, an increase in the number of parts in Patent Documents 1 and 2 is suppressed by integrally forming a silencer cover on a lid provided on the upper surface of the pump body. Since it is formed inside, it is expected that water in the pump chamber will enter the inside of the motor. Therefore, a DC motor that needs to incorporate an electronic circuit or the like inside is more advantageous than an AC motor in terms of quietness, but has a drawback that it cannot be used for a pump having a configuration as in Patent Document 3. there were.

  An object of the present invention is to provide a vertical shaft centrifugal pump excellent in quietness by blocking unpleasant noise generated with rotation of a rotor, and an air conditioner incorporating this as a drainage pump.

  A first aspect of the present invention includes a casing having a suction port and a discharge port, a cover connected to the casing and defining a pump chamber communicating with the suction port and the discharge port with the casing, and the pump chamber A vertical-shaft centrifugal pump having a rotor rotatably accommodated therein, wherein the cover protrudes from the central portion to the opposite side of the pump chamber, and a spindle of a drive motor connected to the rotor passes therethrough A cylindrical boss portion having a through hole formed therein, an inner cylinder portion that is formed on the outer peripheral side of the boss portion and surrounds the boss portion, and an inner cylinder portion that is formed on the outer peripheral side of the inner cylinder portion The inner cylinder part has an overflow passage communicating with the inner peripheral side and the outer peripheral side, and the outer cylindrical part communicates with the inner peripheral side and the outer peripheral side. It is characterized in that it has a Poto.

  In the present invention, when the rotor is rotated by the drive motor, a liquid such as water intervening in the pump chamber is rotated, and the liquid is discharged from the pump chamber to the discharge port by the centrifugal force generated at the same time. Liquid is sucked into the pump chamber. At this time, when the noise generated with the rotation of the rotor and the liquid in the pump chamber leaks out of the pump chamber, it is blocked from the outside by the outer cylinder portion.

  In the vertical shaft centrifugal pump according to the first aspect of the present invention, it is preferable that the overflow port of the outer cylinder portion extends in a tangential direction perpendicular to the radial direction of the rotor.

  A plurality of reinforcing ribs can be provided on the outer cylinder portion of the cover.

It is preferable that the spindle drive moving the motor to place the overflow channel of the tubular part and the overflow port of the outer cylindrical portion in a different direction around the through-holes through. It is also effective to set the interval between the outer cylinder part and the inner cylinder part non-uniformly along these circumferential directions.

  The inner diameter of the through hole through which the spindle of the drive motor passes can be set larger than the outer diameter of the spindle of the drive motor and smaller than the shaft diameter of the rotor.

  One is engaged with the other with elastic deformation, and thereby a connecting means for integrally connecting the casing and the cover and a positioning means for defining a connecting position of the casing and the cover are provided on the casing and the cover. be able to. Further, the connecting means may use a snap-fastening mechanism, and the positioning means has a positioning pin protruding from the casing, and a positioning hole formed in the reinforcing rib of the outer cylinder portion so that the positioning pin fits. It may be a thing. A plurality of, for example, four sets of these connecting means and positioning means can be formed at equal intervals along the circumferential direction.

  The rotor is formed on the main plate, the rotor shaft, a circular main plate concentrically and integrally connected to the rotor shaft, a plurality of pins protruding substantially parallel to the axis of the rotor shaft from the main plate. You may have a pressure equalization part which connects the surface side and the back surface side. In this case, it is also effective to form a plurality of communication holes that connect the front surface side and the back surface side of the main plate, and to function these communication holes as a pressure equalizing portion, and the first plate substantially along the circumferential direction of the main plate. A first arrangement group in which pins and communication holes are arranged in a direction and a direction orthogonal thereto, and a second arrangement in which pins and communication holes are arranged in a direction inclined by 45 degrees with respect to the first direction and in a direction orthogonal thereto These arrangement groups can be arranged alternately along the circumferential direction.

  The area of each pin projected on a plane perpendicular to the rotation direction of the main plate can be set so that the pin located on the radially inner side of the rotor shaft becomes smaller. In this case, the protruding length of each pin is set shorter toward the inner side in the radial direction of the rotor shaft, or the width dimension of the tip portion along the radial direction of the rotor shaft of the pin located on the inner side in the radial direction of the rotor shaft is used. The same effect can be obtained by setting it to be smaller than that of the end portion or by making the interval between the pins located radially inside the rotor shaft larger than the interval between the pins located radially outside.

  As the cross-sectional shape of each pin in a plane perpendicular to the axis of the rotor shaft, a circular shape, an elliptical shape, a polygonal shape such as a rectangle, or an asymmetrical shape such as a wing shape can be appropriately employed. In this case, the maximum length of the pin along the rotation direction of the main plate can be set equal to or greater than the maximum width dimension of the pin along the radial direction of the rotor shaft.

  A stirring member protruding from one end of the rotor shaft along the axis of the rotor shaft can be disposed in the suction port, and the stirring member may be a plurality of blade members protruding radially from the axis of the rotor shaft.

  The cover has a partition wall that protrudes downward so as to surround the periphery of the rotor and forms an annular gap with the inner wall of the casing, and this partition wall of the cover faces the discharge port formed in the casing. It is preferable to arrange so as to block.

  A drive motor having a spindle connected to the rotor and driving the drive motor, and a bracket having an attachment part for attachment to an external fixing part, on which the drive motor is mounted and connected to the outer cylinder part be able to. In this case, a through hole through which the rotation shaft of the drive motor passes can be formed in the bracket, and the bracket can function as a partition wall that is interposed between the outer cylinder portion and the drive motor to partition them.

  The bracket can be formed of a nonmagnetic material having corrosion resistance.

  As a drive motor, a DC brushless motor that has less vibration than an AC motor, is small and light, and can be easily controlled can be employed.

  A joint portion that penetrates through the bracket and the mounting flange of the drive motor and integrally joins them can be formed in the outer cylinder portion. In this case, the joint portion may have a welded portion that engages with the mounting flange of the drive motor, and the welded portion can be formed by ultrasonic welding.

  The 2nd form of this invention exists in the air conditioning apparatus with which the vertical shaft centrifugal pump by the 1st form of this invention mentioned above was integrated as a drainage pump.

  According to the vertical centrifugal pump of the first aspect of the present invention, even if the noise generated in the pump chamber leaks to the outside of the pump chamber as the rotor rotates, the periphery of the boss portion is the inner cylindrical portion and the outer cylindrical portion. Since it is surrounded, it is possible to minimize the leakage of annoying noise particularly in the band of 1 kHz to 2 kHz. Further, when the rotation of the rotor stops, liquid such as water that flows backward in the pump chamber and leaks out of the pump chamber can be reliably discharged from the overflow port to the outside of the pump through the overflow passage, thereby avoiding adverse effects on the drive motor. It is possible.

  When the overflow port extends in the tangential direction perpendicular to the radial direction of the rotor, that is, in the tangential direction opposite to the rotational direction, the outside of the pump chamber is prevented from being scattered while minimizing the splash of liquid. The liquid overflowing into the cylindrical portion can be discharged more quickly and smoothly.

  When a plurality of reinforcing ribs are provided on the outer cylinder portion of the cover, the strength of the outer cylinder portion on which the drive motor is mounted can be improved.

  When the overflow port of the outer cylinder part and the overflow passage of the inner cylinder part are arranged in different directions centering on the through hole through which the spindle of the drive motor passes, leakage of noise generated in the pump chamber with the rotation of the rotor is prevented. It can be further suppressed by the labyrinth effect.

  When the interval between the outer cylinder part and the inner cylinder part is set non-uniformly along the circumferential direction, the noise generated in the pump chamber as the rotor rotates is affected by the inner peripheral surface of the outer cylinder part and the outer peripheral surface of the inner cylinder part. Can be further attenuated by internal reflection between the two.

  If the inner diameter of the through hole through which the drive motor spindle passes is larger than the outer diameter of the drive motor spindle and smaller than the rotor shaft diameter, the liquid from the gap between the through hole and the drive motor spindle Overflow is suppressed, thereby preventing liquid from entering the drive motor along the spindle.

  One of the casing and the cover is engaged with the other with elastic deformation, thereby providing a connecting means for integrally connecting the casing and the cover, and a positioning means for defining a connecting position between the casing and the cover. In this case, the assembly operation of the casing and the cover can be facilitated and speeded up. Further, since the relative rotation between the casing and the cover can be prevented by the connecting means, it is possible to improve workability when connecting the discharge pipe to the discharge port.

  The rotor is formed on the main plate, a rotor main shaft, a circular main plate concentrically connected to the rotor shaft, a plurality of pins projecting substantially parallel to the axis of the rotor shaft from the main plate, In the case of having a pressure equalizing section that communicates the front surface side and the back surface side, a pin swirling in the pump chamber about the rotor shaft center is located behind the liquid in the vicinity thereof in a laminar flow state. The pressure difference generated at the top and bottom of the main plate causes the flow of water to rise from multiple pressure equalization holes, resulting in the suppression of noise caused by cavitation and air entrainment around the pins. be able to.

  The cover has a partition wall that protrudes downward so as to surround the periphery of the rotor and forms an annular gap between the inner wall of the casing and the partition wall so as to face and block the discharge port formed in the casing In this case, it is possible to eliminate the noise generated when the bubbles move from the pump chamber to the discharge port by preventing the air intervening in the pump chamber from flowing into the discharge port.

  A drive motor having a spindle connected to the rotor and driving the drive motor, and a bracket having an attachment part for attachment to an external fixed part, on which the drive motor is mounted and connected to the outer cylinder part In this case, the relative position of the suction port and discharge port of the casing with respect to the external fixed part does not change unless the casing, cover or bracket is replaced with a different size. Therefore, it is not necessary to replace the bracket, and the bracket can be shared regardless of the ability of the drive motor.

  According to the air conditioner of the second aspect of the present invention, since the vertical centrifugal pump according to the present invention is incorporated as a drainage pump, the drainage treatment of the condensed water generated by the air conditioner can be performed extremely quietly.

It is a longitudinal cross-sectional view showing the schematic structure of one Embodiment which applied the vertical shaft type centrifugal pump by this invention to the drainage pump for air conditioning apparatuses. It is a longitudinal cross-sectional view showing the schematic structure of the drainage pump in embodiment shown in FIG. It is a top view of the drainage pump shown in FIG. It is a bottom view of the drainage pump shown in FIG. It is a side view of the part of the cover in the drainage pump shown in FIG. FIG. 6 is a bottom view of the cover shown in FIG. 5. FIG. 7 is a sectional view taken along arrow VII-VII in FIG. 2. It is a partially broken sectional view along the VIII-VIII arrow in FIG. It is a three-dimensional projection figure showing the external appearance of the rotor in the drainage pump shown in FIG. FIG. 10 is a rear view of the rotor shown in FIG. 9. FIG. 10 is a conceptual diagram schematically showing a fluid flow direction by a first arrangement group in the rotor shown in FIG. 9 together with FIG. 12. FIG. 10 is a conceptual diagram schematically showing a fluid flow direction by a second arrangement group in the rotor shown in FIG. 9 together with FIG. 11. It is a graph which shows the noise characteristic of the drainage pump shown in FIG. 2 with the comparative example, and the horizontal axis represents the measurement frequency logarithmically.

  An embodiment in which the vertical shaft centrifugal pump according to the present invention is incorporated in an air conditioner as a drainage pump will be described in detail with reference to FIGS. 1 to 13, but the present invention is not limited to such an embodiment, and is claimed. Any change or modification included in the concept of the present invention described in the scope of the present invention can be made, and can naturally be applied to any other technique belonging to the spirit of the present invention.

  The state of attachment of the drainage pump in this embodiment is shown in FIG. That is, the drainage pump 10 in the present embodiment is attached to a fixing portion 13 formed on the housing partition wall 12 of the air conditioner via the bracket 11. A gasket (not shown) having both an anti-vibration function and a sealing function is sandwiched between the fixing portion 13 and the plate-like bracket 11, and the attaching portion 11 a of the bracket 11 is attached to the housing by an attaching screw 14 screwed into the fixing portion 13. The fixing portion 13 of the partition wall 12 is screwed. The drive motor 15 is mounted on the connecting portion 11 b of the bracket 11 so that a drive motor 15 for driving a rotor, which will be described later, is positioned outside the housing partition wall 12. A control panel 16 for controlling the operation of the drive motor 15 is installed outside the housing partition wall 12, and the control panel 16 and a connector 17 attached to the drive motor 15 are connected via a cable 18. The connection between the control panel 16 and the drive motor 15 may be such that the cable 18 is directly pulled out from the drive motor 15 and connected to the control panel 16 without using the connector 17.

  In addition, the connector 17 of the drive motor 15 in this embodiment can also be arranged at a position as shown by a two-dot chain line in FIG. 3, so that the connection workability of the cable 18 and interference with other members are possible. Can be selected as appropriate. Moreover, since this connector 17 is arrange | positioned on the outer side of the housing partition 12 similarly to the drive motor 15, the thing of the cheap non-waterproof structure which does not need to consider water resistance is employable. Furthermore, the bracket 11 in the present embodiment is formed of a nonmagnetic material such as austenitic stainless steel or aluminum that does not adversely affect the operation of the drive motor 15 described later.

  The internal structure of the main part of the drainage pump 10 is shown in FIG. 2, the planar shape and the bottom shape are shown in FIGS. 3 and 4, respectively, and the side and bottom shapes of the cover part are shown in FIGS. 2 and FIG. 8 show cross-sectional structures taken along arrows VII-VII and VIII-VIII in FIG. 2, respectively, FIG. 9 shows the appearance of the rotor portion, and FIG. That is, the drainage pump 10 in the present embodiment is connected to the casing 19 having a cylindrical side wall portion 19a and a conical bottom wall portion 19b, and the upper end portion of the side wall portion 19a of the casing 19 to be connected to the casing 19. The cover 21 defining the pump chamber 20, the rotor 22 accommodated in the pump chamber 20, the drive motor 15 connected to the rotor 22 and rotating the rotor 22, and the drive motor 15 are mounted. The above-described bracket 11 to which the outer cylinder portion 23 integrated with the cover 21 is connected is provided. In the present embodiment, the bracket 11 is fixed to the housing partition wall 12 so as to partition the drive motor 15 disposed outside the housing partition wall 12 of the air conditioner and the cover 21 and the casing 19 disposed inside the housing partition wall 12. 13, there is no need to provide a draining plate for protecting the bearing portion of the drive motor 15 between the cover 21 and the drive motor 15, and a drive motor having a different capability is used. Even if it exists, it is only necessary to replace the drive motor 15 as the drainage pump 10, and there is an advantage that the bracket 11 and the like need not be replaced at all.

  In the present embodiment, a DC brushless motor is employed as the drive motor 15, which can be significantly reduced in size and weight as compared with an AC motor having a large vibration, and its drive control is also easy. The high-frequency vibration, which is a drawback of the DC motor, can be reliably blocked by interposing the above-described gasket between the housing partition wall 12 of the air conditioner and the mounting portion 11a of the bracket 11.

  In the present embodiment, the bottom wall portion 19b of the casing 19 is set in a conical shape with the central portion recessed downward, but there is no problem even if the bottom wall portion 19b is set in a so-called flat bottom shape parallel to the horizontal plane. . The casing 19 protrudes downward from the center of the bottom wall portion 19b and forms a suction pipe 25 that forms a suction port 24 communicating with the inside of the pump chamber 20, and protrudes radially outward of the rotor 22 from the side wall portion 19a. A discharge pipe 27 having a discharge port 26 facing the inside 20 is integrally formed. The suction pipe 25 is positioned in the drain pan 28 of the air conditioner indicated by a two-dot chain line in FIG. 2, and is almost immersed in the condensed water accumulated in the drain pan 28. The discharge pipe 27 is connected to the base end of a drain pipe 29 whose leading end is led out of the housing partition wall 12 of the air conditioner.

  In this embodiment, the inner diameter of the discharge pipe 27 is increased toward the downstream side so that the discharge port 26 facing the pump chamber 20 is narrowed, but the drain pipe 29 is fitted with the outer diameter of the discharge pipe 27 constant. Consideration has been given to ensure workability during sealing and sealing between them. For this reason, although the thickness of the discharge pipe 27 becomes thicker toward the base end side, in this embodiment, the outer peripheral portion of the discharge pipe 27 is subjected to a thinning process, thereby simultaneously achieving high rigidity and light weight of the discharge pipe 27. is doing. As long as the ease of fitting of the drain pipe 29 to the discharge pipe 27 and the sealing performance can be ensured, the hollowing formed on the outer periphery of the discharge pipe 27 may have any form and shape. .

  Note that, when the drainage pump 10 is at a low head, the connecting portion between the bottom wall portion 19b and the suction pipe 25 is formed by a two-dot chain line in FIG. 2 rather than forming a curved surface with a smooth convex cross section. When the concave curved portion 19c is formed, the water passing therethrough can flow more smoothly, and noise can be further reduced.

  A boss portion 30 having a cylindrical cross section whose upper surface is closed is formed upward at the center of the cover 21, and a circular inner cylinder portion 31 that surrounds the boss portion 30, and further, this inner cylinder portion 31 is surrounded. A substantially circular outer cylinder portion 23 projects upward from the cover 21, and these are all integrally formed of resin.

  The boss portion 30 is located at the center of the through hole 30a through which the spindle 15a of the drive motor 15 passes, and the boss portion 30 is located at the outer peripheral portion of the boss portion 30 so as to maintain the inside of the pump chamber 20 at atmospheric pressure (four in the illustrated example). ) Slit 30b. The inner diameter of the through hole 30a is set larger than the outer diameter of the spindle 15a of the drive motor 15 and smaller than the shaft diameter of the rotor 22 described later. Further, the slit 30b in the present embodiment has a groove shape from the upper end of the peripheral wall portion of the boss portion 30 to the upper surface of the cover, and the rotation direction of the rotor 22 (in FIG. Rotation direction) side. For this reason, when the drive motor 15 is stopped and the rotation of the rotor 22 is stopped, a part of the drainage flowing backward from the drain pipe 29 to the pump chamber 20 side through the discharge port 26 overflows from the slit 30 b to the outside of the pump chamber 20. However, in this embodiment, the slit 30b is formed in the peripheral wall portion of the boss portion 30 in the direction opposite to the rotation direction of the rotor 22 (left rotation direction in FIG. 7), that is, in the clockwise tangential direction in FIG. Since it is formed, the amount of drainage overflowing from the slit 30b can be reduced and the pump chamber 20 can overflow more smoothly from the cover 21. Moreover, the water overflowing outside the pump chamber 20 can be quickly returned into the pump chamber 20 from the slit 30b.

  A pair of slit-shaped overflow passages 31a facing each other at 180 degrees are formed in the inner cylindrical portion 31 whose upper end is in contact with the connecting portion 11b of the bracket 11, and the inner peripheral boss portion 30 side and the outer peripheral outer periphery 31a are formed. The cylinder part 23 side is communicated.

  The outer cylinder part 23 formed with a plurality of (four in the illustrated example) cylindrical cross-section reinforcing ribs 23a at equal intervals along the circumferential direction is formed on the outer peripheral part of the outer cylinder part 23 and the outside. A pair of overflow ports 23b communicating with each other is formed 180 degrees apart. The pair of overflow ports 23b are arranged so as to be substantially orthogonal to the opposing direction of the pair of overflow passages 31a of the inner cylinder portion 31, and are opposite to the rotation direction of the rotor 22 (counterclockwise in FIG. 7). Respectively extending in the tangential direction.

  A pair of overflow passages 31 a formed in the inner cylinder part 31 and an overflow port 23 b having a pair of labyrinth structures formed in the outer cylinder part 23 constitute an atmosphere communication path together with the slit 30 b of the boss part 30. In this embodiment, the pair of overflow passages 31a of the inner cylinder part 31 and the pair of overflow ports 23b of the outer cylinder part 23 are arranged in different directions, that is, their rotational phases so that they are not aligned in a straight line with the through hole 30a as a center. Is largely bent by 90 degrees, the air communication path that leads from the pump chamber 20 to the outside of the drainage pump 10 through the slit 30b, the overflow path 31a, and the overflow port 23b is greatly bent. Consideration is given so that a large silencing effect can be obtained against high frequency (1 to 2 kHz) noise. In addition, in the present embodiment, the outer cylinder portion 23 is greatly uneven in the radial direction so that the interval between the inner cylinder portion 31 and the outer cylinder portion 23 is non-uniform, which is generated in the pump chamber 20. As a result, the noise that has passed through the overflow passage 31a from the slit 30b is greatly attenuated while being reflected between the inner peripheral surface of the outer cylindrical portion 23 and the outer peripheral surface of the inner cylindrical portion 31, and as a result It can be almost eliminated.

  When a large amount of water temporarily overflows outside the pump chamber 20 from the slit 30b of the boss portion 30, a part of this water flows from the overflow passage 31a of the inner cylinder portion 31 to the overflow port 23b of the outer cylinder portion 23. It is discharged from outside the outer cylinder portion 23 and flows down to the drain pan 28.

  At the outer peripheral edge of the cover 21 facing the pump chamber 20 side, a cylindrical partition wall 33 that forms an annular gap 32 with the side wall 19 a of the casing 19 faces downward toward the bottom wall 19 b of the casing 19. Projected to Accordingly, the condensed water located at the upper peripheral edge of the pump chamber 20 flows downward due to the presence of the partition wall 33, passes through the gap 34 between the lower end of the partition wall 33 and the bottom wall portion 19 b of the casing 19, and the annular gap 32. As a result of being guided into the discharge port 26, it is possible to prevent the air bubbles present on the upper peripheral edge of the pump chamber 20 from flowing into the discharge port 26. That is, the partition wall 33 in the present embodiment is for suppressing air bubbles interposed in the upper peripheral edge of the pump chamber 20 from flowing into the discharge port 26 side. There is no need to form it. However, when the partition wall 33 is formed only at a position facing the discharge port 26, the upstream side of the partition wall 33 with respect to the discharge port 26 is made close to the inner peripheral surface of the side wall 19 a of the casing 19. It is necessary to prevent the condensed water containing bubbles flowing in the pump chamber 20 from directly flowing into the annular gap 32. Moreover, it is preferable that the cross-sectional shape is formed in curved surfaces, such as a semicircle shape, so that the lower end part of this partition wall 33 may not disturb the smooth flow of condensed water.

  An O-ring 35 is mounted between the casing 19 and the partition wall 33 of the cover 21 so that the condensed water does not leak out from the fitting portion of the casing 19 and the cover 21.

  At the upper end of the reinforcing rib 23a, a connecting pin 36 that protrudes through the connecting portion 11b of the bracket 11 and the mounting flange 15b formed on the drive motor 15 is projected, and the upper end of the connecting pin 36 is melted. By forming the caulking portion 36a, the cover 21 integrated with the outer cylinder portion 23, the connecting portion 11b of the bracket 11 and the drive motor 15 are integrally joined. The caulking portion 36a formed at the upper end of the connecting pin 36 can use a technique such as ultrasonic welding, and the shape is such that the drive motor 15 and the bracket 11 are not easily detached. Just do it.

  On the outer periphery of the lower portion of the cover 21, a plurality (four in the illustrated example) of locking claws 37 protruding upward in the radial direction are formed at equal intervals along the circumferential direction. Further, a claw holder 38 having a frame shape that can be elastically deformed in the radial direction and capable of locking the locking claws 37 is provided on the outer periphery of the side wall portion 19a of the casing 19, and the locking claw 37 and the claw holder 38 are provided. Constitutes the connecting means in the present invention. In this embodiment, the cover claw 37 is snapped to the claw holder 38 by pushing the cover 21 into the casing 19 from above. Can be integrated.

  As described above, in this embodiment, the claw holder 38 is formed in a frame shape and the return portion is formed on the locking claw 37, so that the casing 19 is locked in a state where the locking claw 37 is locked to the claw holder 38. The movement of separating the cover 21 in the direction parallel to the axis can be restrained, and when an external force acting to separate the casing 19 and the cover 21 is applied, the claw holder 38 is attached to the locking claw 37. It bites into the return part. Further, when the casing 19 and the claw holder 38 are formed of a hard composite resin material mixed with glass fibers or inorganic whiskers so that the claw holder 38 can be slightly elastically deformed in the radial direction, the casing 19 is made to have high strength. It becomes possible to design.

  A plurality of (four in the illustrated example) cylindrical positioning pins 39 projecting upward in the vicinity of each claw holder 38 project from the upper end of the side wall portion 19a of the casing 19 at equal intervals along the circumferential direction. The hollow hole 40 into which the tip end portion of the positioning pin 39 is fitted opens at the lower end surface of the reinforcing rib 23a of the outer cylinder portion 23. Therefore, in a state where these are fitted, the rotation of the cover 21 relative to the casing 19 can be restricted, and these constitute the positioning means in the present invention. Thus, by changing the fitting position of the hollow hole 40 of the reinforcing rib 23a with the positioning pin 39 of the casing 19, it is possible to select the relative rotational position of the casing 19 with respect to the cover 21, as shown in FIG. As shown by the two-dot chain line, the direction of the discharge pipe 27 can be changed to any of the four directions in accordance with the arrangement of other members.

  In the present embodiment, the rotor 22 includes a rotor shaft 41 having a cylindrical connection portion 41a to which the spindle 15a of the drive motor 15 is coupled at the upper end portion, and a plurality of four (4 in the illustrated example) projecting radially from the rotor shaft 41. The main plate 43 formed integrally with the rotor shaft 41 via the stays 42, and the surface of the main plate 43, that is, the axis of the rotor shaft 41 from the upper surface side. A large number of pins 44 projecting in parallel, a large number of communication holes 45 formed on the main plate 43 together with these pins 44 and communicating with the front surface side and the back surface, that is, the lower surface side, and the rotor from the lower end of the rotor shaft 41 A stirring member 46 is provided that protrudes along the axis of the shaft 41 and is located in the suction port 24.

  The main plate 43 is concentric with the rotor shaft 41, and a gap 47 that functions as a pressure equalizing portion of the present invention is formed between the inner peripheral surface of the main plate 43 and the outer peripheral surface of the rotor shaft 41 together with the communication hole 45 described above. Has been. The stay 42 described above crosses the gap 47 and connects the rotor shaft 41 and the main plate 43. In the present embodiment, the pins 44 and the communication holes 45 are alternately arranged in a first direction (left and right direction in FIG. 8) substantially along the circumferential direction of the main plate 43 and in a direction orthogonal thereto. The circumferential direction of the main plate 43 includes the array group A and the second array group B in which the pins 44 and the communication holes 45 are alternately arrayed in a direction inclined by 45 degrees with respect to the first direction and in a direction orthogonal thereto. 4 sets are formed alternately along the line. Each pin 44 has a regular quadrangular prism shape in which the cross-sectional shape cut by a plane perpendicular to the axis of the rotor shaft 41 is substantially square, and by rounding the ridges of the four corners, the water scraping sound is minimized. We are taking care to reduce it. Further, the stirring member 46 has four blades 46 a whose cross-sectional shape perpendicular to the axis of the rotor shaft 41 is a cross shape.

  When the drive motor 15 of the drainage pump 10 having such a configuration starts operating, the condensed water intervening in the suction port 24 is stirred by the rotation of the stirring member 46, and gradually in the suction port 24 together with the stirring member 46 due to its viscosity. Start turning at. Due to the centrifugal force generated with the swirling of the condensed water in the suction port 24, the water surface draws a concave three-dimensional paraboloid and passes over the upper end of the suction port 24 to the bottom wall portion 19b of the pump chamber 20. The main plate 43 and the pin 44 are further immersed in the condensed water. The condensed water entering the pump chamber 20 in this way is swirled at a higher speed by the main plate 43 and the pin 44 of the rotating rotor 22, and a part of the condensed water is in the bottom wall portion 19 b of the casing 19 and the cover 21. The gas is discharged from the annular gap 32 to the discharge port 26 through the gap with the lower end of the partition wall 33. As the condensed water is discharged, new condensed water in the drain pan 28 is sucked into the suction port 24, and the condensed water in the drain pan 28 is continuously discharged from the discharge port 26 to the outside through the drain pipe 29. . In this case, since the pressure difference between the radial center side and the radial outer end of the rotor 22 is determined by the rotational speed of the rotor 22 and its maximum diameter, that is, the outer diameter of the main plate 43, the cutoff lift of the drainage pump 10 is also naturally. However, the amount of drainage depends on the area of the pin 44 projected on a plane perpendicular to the rotation direction of the main plate 43.

  During the operation of the drainage pump 10, the pin 44 of the rotor 22 rotates at a higher speed than the swirling speed of the condensed water, so that the condensed water intervening around the pin 44 is not condensed with respect to the stationary pin 44. When it is considered that the inside of the pump chamber 20 is turning, the pin 44 is wound around the outer periphery of the pin 44 and flows backward relatively smoothly. That is, since a highly resistive blade plate having a wide surface substantially orthogonal to the rotation direction of the impeller is not used as in the prior art, even if the pin 44 is located on the outermost peripheral side of the rotor 22. The cavitation hardly occurs on the rear side in the turning direction, and the noise caused by the cavitation can be greatly reduced. In particular, in this embodiment, the flow direction of the condensed water formed by the first arrangement group A of the pins 44 and the communication holes 45 is as shown in FIG. 11 schematically showing the flow state with respect to the radial direction. The direction inclined approximately 45 degrees gives a relatively large kinetic energy to the condensed water, whereas the flow direction of the condensed water formed by the second array group B schematically represents the flow state. As shown in FIG. 12, it becomes substantially the circumferential direction of the main plate 43 to give relatively small kinetic energy to the condensed water, and the defoaming effect can be further enhanced by the flow of these two kinds of condensed water. Further, since the swirling circumferential speed of the condensed water in the suction pipe 25 is considerably slower than the swirling circumferential speed of the condensed water in the pump chamber 20, even if the stirring member 46 is a blade 46a having a large resistance, There is no problem that cavitation occurs. Further, even when the drainage pump 10 is started up and at a low head, the presence of the partition wall 33 formed on the cover 21 can prevent bubbles from being mixed into the condensed water discharged to the discharge port 26 side. Noise when discharged to the discharge port 26 side can be eliminated.

  In order to verify the noise characteristics of the drainage pump 10 according to this embodiment, the drainage pump 10 according to this embodiment is removed as a comparison by removing the outer cylinder portion 23 (all the same except for not having the outer cylinder portion 23). A noise level (dB) in the range of 100 to 10000 Hz when the drive motor 15 was operated so that the noise meter was separated from these drainage pumps by about 50 cm and the lift was 70 cm was obtained. The results are shown in FIG. A solid line indicates this embodiment, a broken line indicates a comparative example, and a two-dot chain line indicates a background noise value. As can be seen from FIG. 13, it can be recognized that the noise value is attenuated to a greater extent than the comparative example in the annoying 1000 Hz band, more specifically in the 630 to 1250 Hz band.

  The outer periphery of the main plate 43 does not have to be a complete circle centered on the axis of the rotor shaft 41, and the cross-sectional shape of the pin 44 cut by a plane perpendicular to the axis of the rotor shaft 41 is the above-described embodiment. Various shapes other than the substantially square shape as described above can be adopted.

  In the above-described embodiment, the height of the individual pins 44 is set so that the upper ends of the individual pins 44 are located on the same horizontal plane. However, the water level of the condensed water in the pump chamber 20 during the rotation of the rotor 22. Since the upper part of the pin 44 on the inner peripheral side near the rotor shaft 41 is exposed from the water surface and the condensed water cannot be stirred, the height of the swirling water surface of the condensed water formed in the pump chamber 20 is displaced. Accordingly, it is effective to set the height of the pin 44 farther from the rotor shaft 41 so that the function of the pins 44 arranged in the radial direction is maximized. Alternatively, in order to obtain the same effect, the area of the pin 44 projected onto a plane perpendicular to the rotation direction of the main plate 43 can be dealt with by setting the pin 44 located on the radially inner side of the rotor shaft 41 to be smaller. It is.

  In the embodiment described above, the pin 44 protrudes upward from the front surface side of the main plate 43, but the pin 44 may protrude downward from the back surface of the main plate 43. In this case, a larger rectifying effect can be obtained with respect to the condensed water sucked into the pump chamber 20 by the main plate 43 disposed in the vicinity of the cover 21. Further, the pin 44 closer to the rotor shaft 41 is formed with a step having a small diameter portion on the lower end side so that the outer diameter becomes smaller, and the thickness of the small diameter portion of the pin 44 protruding from the back surface of the main plate 43 is set to It is also effective to set the pin 44 thinner on the radially inner peripheral side.

  In addition, the pins 44 and the communication holes 45 are not aligned like the arrangement groups A and B as in the above-described embodiment, but are randomly formed on the main plate 43, or the pins 44 are protruded from both the front and back surfaces of the main plate 43. Is also possible. Similarly, the main plate 43 may be formed in a conical shape so as to be parallel to the conical bottom wall portion 19 b of the casing 19. Further, the rotor 22 itself can be a conventionally known one.

DESCRIPTION OF SYMBOLS 10 Drain pump 11 Bracket 11a Attachment part 11b Connection part 12 Body partition 13 Fixing part 14 Attachment screw 15 Drive motor 15a Spindle 15b Attachment flange 16 Control panel 17 Connector 18 Cable 19 Casing 19a Side wall part 19b Bottom wall part 19c Bending part 20 Pump chamber 21 Cover 22 Rotor 23 Outer cylinder part 23a Reinforcement rib 23b Overflow port 24 Suction port 25 Suction pipe 26 Discharge port 27 Discharge pipe 28 Drain pan 29 Drain pipe 30 Boss part 30a Through hole 30b Slit 31 Inner cylinder part 31a Overflow passage 32 Gap 33 Partition Wall 34 Clearance 35 O-ring 36 Connecting pin 36a Caulking portion 37 Locking claw 38 Claw holder 39 Positioning pin 40 Die-off hole 41 Rotor shaft 41a Connection portion 42 Step 43 main plate 44 pins 45 through hole 46 stirring member 46a vane 47 gaps A first sequence group B second sequence group

Claims (11)

A casing having a suction port and a discharge port;
A cover connected to the casing and defining a pump chamber communicating with the suction port and the discharge port with the casing;
A vertical shaft centrifugal pump comprising a rotor rotatably accommodated in the pump chamber, wherein the cover includes:
A cylindrical boss part that protrudes from the center part to the opposite side of the pump chamber and has a through hole through which a spindle of a drive motor connected to the rotor passes,
An inner cylinder part that is formed on the outer peripheral side of the boss part and surrounds the boss part,
And an outer cylinder part surrounding the inner cylinder part, the inner cylinder part having an overflow passage communicating with the inner circumference side and the outer circumference side, and the outer cylinder The vertical shaft centrifugal pump characterized in that the section has an overflow port communicating with the inner and outer peripheral sides thereof.   The vertical shaft centrifugal pump according to claim 1, wherein the overflow port of the outer cylinder portion extends in a tangential direction perpendicular to the radial direction of the rotor.   The vertical cylinder centrifugal pump according to claim 1 or 2, wherein the outer cylinder portion of the cover further includes a plurality of reinforcing ribs.   The vertical shaft according to any one of claims 1 to 3, wherein the overflow port of the outer cylinder part and the overflow passage of the inner cylinder part are arranged in different directions around the through hole. Centrifugal pump.   The vertical shaft centrifugal pump according to any one of claims 1 to 4, wherein an interval between the outer tube portion and the inner tube portion is set non-uniformly along the circumferential direction.   The vertical shaft according to any one of claims 1 to 5, wherein an inner diameter of the through hole is set to be larger than an outer diameter of a spindle of the drive motor and smaller than an axial diameter of the rotor. Shape centrifugal pump. A connecting means provided on the casing and the cover, one of which engages the other with elastic deformation, thereby integrally connecting the casing and the cover;
The vertical shaft centrifugal pump according to any one of claims 1 to 6, further comprising positioning means provided on the casing and the cover and defining a connection position between the casing and the cover. .   The rotor includes a rotor shaft, a circular main plate concentrically and integrally connected to the rotor shaft, a plurality of pins protruding substantially parallel to the axis of the rotor shaft from the main plate, and the main plate. The vertical shaft centrifugal pump according to any one of claims 1 to 7, further comprising a pressure equalizing portion that is formed and communicates the front surface side and the back surface side thereof.   The cover has a partition wall that protrudes downward so as to surround the rotor and forms an annular gap with the inner wall of the casing, and the partition wall includes a discharge port formed in the casing. The vertical-shaft centrifugal pump according to any one of claims 1 to 8, wherein the vertical-shaft centrifugal pump is arranged so as to oppose and oppose it. A drive motor having a spindle coupled to and driving the rotor;
10. The apparatus according to claim 1, further comprising: an attachment portion for attaching to an external fixing portion, wherein the drive motor is mounted and the bracket is connected to the outer cylinder portion. The vertical shaft centrifugal pump according to claim 1.   An air conditioner in which the vertical centrifugal pump according to any one of claims 1 to 10 is incorporated as a drainage pump.

Images