JP4158269B2 - Externally driven line pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a small, high-lift externally driven line pump having a rotor with a driving magnet disposed around and a rotor provided with a blade portion for boosting.
[0002]
[Prior art]
  In recent years, in particular, pumps built into devices are required to be reduced in size and weight in the trend of reducing the size and weight of devices. As one of the means, an externally driven axial flow pump having an impeller in which a drive magnet for driving with a stator is disposed around and an axial flow vane is provided is disclosed in, for example, US Pat. No. 2,697, No. 986 is known.
[0003]
  Hereinafter, the prior art will be described using description examples of patents already filed. FIG. 2 is a structural view of a conventional externally driven axial flow pump. Reference numeral 101 denotes a partition wall, 102 denotes a pump suction flange, 103 denotes an axial flow blade for pressurizing a fluid, 104 denotes a pump discharge flange, 105 denotes a shaft for rotatably supporting the axial flow blade 103, and 106 denotes a boss of the axial flow blade 103 The bearing plate 107 is provided on the suction flange 102 and the discharge flange 104, 107 is a bearing plate that contacts the bearing 106 and supports the thrust load when the axial flow blade 103 moves to the suction side by the axial thrust during operation. A shaft holder that supports the shaft 105, 109 is a rib that connects the suction flange 102 and the discharge flange 104 and the shaft holder 108, 110 is a driving magnet that is provided on the outer periphery of the axial flow blade 103 and is driven by an external magnetic field, 111 Is a rotor incorporating the drive magnet 110 and the axial flow blade 103, and 112 is provided around the drive magnet 110. A stator forming a rotating magnetic field for rotating the rotor 111 by. The partition wall 101 has a structure in which the stator 112 is held outside and the rotor 111 is incorporated to partition the rotor 111 and the stator 112. The axial flow pump is connected to a pipe (not shown) by an annular suction flange 102 and a discharge flange 104, and is structured to be incorporated into the pipe on the line.
[0004]
  The operation of the conventional externally driven axial flow pump configured as described above will be described with reference to FIG. When a control current is applied to the stator 112 to form a rotating magnetic field, the driving magnet 110 receives torque around the shaft 105 due to the rotating magnetic field, and the rotor 111 starts rotating around the shaft 105 in the partition wall 101. At this time, if water is introduced into the partition wall 101, the water is pushed out by the action of the axial flow blade 103 provided in the rotor 111, and the pressure is increased. At this time, the discharge pressure and the flow rate vary depending on the number of rotations of the rotor 111. Since this pump boosts pressure only by the blade action of the axial flow blade 103, it can discharge a relatively large amount of flow, but the discharge pressure is not so high. It did not rise. While the rotational speed is low, the pressure and flow rate tend to increase in proportion to the rotational speed. However, if the rotational speed is further increased, the efficiency deviates from the design point of the cavitation and the axial flow blade 103. It had the problem of being greatly lowered.
[0005]
[Problems to be solved by the invention]
  The conventional externally driven axial flow pump described above can realize a line-type pump and has characteristics not found in other pumps, such as reducing the number of parts because the rotor and impeller of the drive motor are shared. However, in order to realize a line-type pump, axial flow blades have to be adopted, and it has been essentially difficult to realize a high-lift pump. Here, the high head is not a general pump head that has a high head of over 400 W, but a head that is necessary to supply tap water and circulate the water built into the equipment. Specifically, this is a case where the total lift is higher than about 4 m. Therefore, when the pressure is increased by increasing the rotation speed, there is a problem that the pump becomes inefficient as described above. In addition, when the rotational speed is increased and the head is increased, the thrust load due to the differential pressure before and after the blades increases, and the mechanical loss due to the sliding between the bearing and the bearing plate is significantly affected by both the increase in the rotational speed and the increase in the thrust load. Increasing and raising the rotational speed by raising the rotational speed has a problem of remarkably deteriorating the efficiency.
[0006]
  If this externally driven axial flow pump is to be miniaturized, it cannot be scaled down to a small size while maintaining the normal pump characteristics. This is because even if the pump size can be reduced in size, the loss cannot be scaled down in proportion to the physical size. For example, mechanical loss, fluid loss, leakage loss, etc. cannot be made relatively small. In addition, if this pump is downsized to further increase the head, it is necessary to increase the number of revolutions. In addition to these various losses, the above-described reduction in efficiency due to the increase in speed occurs, resulting in an extremely inefficient pump. It was something that would end up. Miniaturization here means that the physical size at the same output is small, and that the pump has a small output (for example, a water pump for home use or a circulation pump incorporated in equipment, the output is 400 W or less). This is especially true for pumps with low output, high head (4 m or more) and small flow rate (20 L / min or less). And when the speed is increased, cavitation occurs on the suction side of the rotor, and the amount of retention of air generated due to the difference in specific gravity with water also has a relatively large effect on the contrary to downsizing, and the efficiency is impaired. The machine life was shortened. For example, the bearing life is significantly reduced as the speed increases. This was particularly remarkable when the pressurized water was at a high temperature (for example, 85 ° C.).
[0007]
  Then, in order to increase the head, simply abandoning the point of the axial flow type pump and making it a centrifugal type pump would increase the size in the radial direction and increase the size at the same time. It was something that had to be abandoned to the point of a pump. Further, in order to maintain the external drive type, there are restrictions from the drive system side, and there is a problem that the arrangement of the drive magnet and the structure as the impeller have to be troublesome. In order to manufacture a small pump, it was difficult to prepare and assemble many small parts in terms of assembly and manufacturing. If this is manufactured with an integral pump, the thickness of the rotor is inevitably uneven because the drive magnet is molded, and it is difficult to manufacture a high-quality one. Although dimensional accuracy should be necessary to prevent contact, there is a problem that accuracy is lost. If the accuracy is not good, the loss increases due to contact or leakage, and if one is improved, a vicious circle will occur.
[0008]
  As explained above, when trying to realize a small-sized, high-lift line-type pump with a conventional externally driven axial flow pump, many contradictions arise and it is practically difficult to realize this type of pump. Met.
[0009]
  SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and an object thereof is to provide an externally driven line pump that is compact, has a high head, is highly efficient, and can ensure dimensional accuracy with a simple structure.
[0010]
[Means for Solving the Problems]
  In order to solve this problem, an externally driven line pump according to the present invention includes a partition wall in which a stator is attached to the periphery and a holding portion of a fixed shaft that rotatably supports a rotor is provided in the center portion. Is integrally formed and disposed between the stator and the rotor.The discharge edge of the blade portion coincides with the outer shape of the mouth ring portion of the rotor, the rear shroud of the blade portion has a conical shape, the central portion of the volute has a conical convex portion, and Are arranged facing each other with a gap ofIt is characterized by that.
[0011]
  With the above structure, it is possible to provide an externally driven line pump that is compact, has a high head, is highly efficient, and can ensure dimensional accuracy with a simple structure.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
  According to the first aspect of the present invention, a drive magnet is disposed around, a rotor provided with a blade portion for boosting therein, and a rotating magnetic field for rotating the rotor is formed. An external drive type line pump including a stator, the stator being mounted around the stator, and a partition having a fixed shaft holding portion for rotatably supporting the rotor provided in the center, the partition being integrated Since it is an externally driven line pump that is molded and disposed between the stator and the rotor, the assembly tolerance of the fixed shaft can be reduced because it is assembled on the basis of the integrally formed partition wall. In addition, the gap between the rotor and the partition can also be set narrow, reducing the reduction in motor efficiency due to the axial displacement of the rotor and stator, and leaking back through the gap between the rotor and the partition. Loss can be reduced.Further, since the discharge edge of the blade portion matches the outer peripheral shape of the mouth ring portion of the rotor, the blade can be reduced in size, and the rear shroud of the blade portion has a conical shape, and the central portion of the volute Is provided with conical convex portions and opposed to each other with a predetermined gap, so that the inertia of the rotor can be reduced, the responsiveness and weight can be reduced, and the strength of the holding portion of the volute shaft is increased. Further, by reducing the secondary flow on the rear surface of the rear shroud, the noise is reduced, and the fluid loss between the volute and the rear shroud is also reduced, so that the pump efficiency can be improved.
[0013]
  The invention described in claim 2 is characterized in that a volute is provided on the discharge side of the rotor, and a holding portion for a fixed shaft is provided in the center of the volute. Therefore, the fixed shaft can be fixed to the holding part by the assembly tolerance of the partition wall and volute, so that the deviation between the center of the rotor and the stator can be reduced, the vibration caused by the deviation of the magnetic balance and the sliding of the bearing and the shaft accompanying it. It is possible to provide an externally driven line pump that suppresses an increase in resistance, is small and efficient, and has little vibration noise.
[0014]
  According to a third aspect of the present invention, a circumferential rib concentric with the fixed shaft is provided on the outlet side of the partition wall, the outer periphery of the volute is concentric with the fixed shaft, and the outer periphery of the circumferential rib and the volute is formed. 3. The external drive type line pump according to claim 1 or 2, wherein the fixed shaft holding portion and the circumferential rib, and the fixed shaft and the outer circumference of the volute are concentric circular gold on the same axis. Since it can be molded with a mold and is circular, the processing accuracy in manufacturing the mold can be improved, and the accuracy is easily obtained because it is circular during molding.
[0015]
  Since the invention described in claim 4 is the externally driven line pump according to any one of claims 1 to 3, wherein the volute is fixed by being sandwiched between the discharge housing and the partition wall, It is possible to provide an externally driven line pump that can be assembled, is small and efficient, and has low vibration and noise.
[0016]
  The invention described in claim 5 is provided with a flow path in which the volute circulates in the circumferential direction and the amount of axial protrusion gradually increases, and the flow discharged from the outlet guides the back surface of the volute in the centripetal direction. The externally driven line pump according to any one of claims 1 to 4, wherein there is no need to enlarge the radius of the volute, and the size is small, and the fluid discharged from the volute is discharged at a short distance. Can lead to the exit.
[0017]
  According to a sixth aspect of the present invention, a discharge port is provided in the center of the discharge side housing, and a guide rib that guides the fluid discharged from the volute to the discharge port protrudes from the discharge housing toward the volute. Since it is an external drive type line pump according to any one of claims 1 to 5, fluid can be guided by a guide rib provided inside the discharge housing, and a flow path can be configured with a simple configuration. It is possible to improve the strength of the discharge housing, to provide an externally driven line pump that is easy to assemble and has high reliability..
[0018]
Claim7The invention described in claim 1 is characterized in that the internal flow path of the blade portion is bent from the axial direction to the expanding direction.1-6Therefore, it is possible to achieve a high head by utilizing centrifugal force at the blade portion of the line structure.
[0019]
  Claim8The invention described in claim 2 is characterized in that the cross-sectional area of the internal flow path of the blade portion is constant from the inlet to the outlet.7Since it is an externally driven line pump as described, the pressure is not increased in the rotor, air is discharged smoothly, and the flow in the internal passage is reduced to a complicated flow due to deceleration, and the efficiency is less likely to be reduced..
[0020]
Claim9The invention described in claim 1 is characterized in that a reflux hole is provided in the vicinity of the bearing end of the rear shroud.1-8Because it is an externally driven line pump as described, air that accumulates in the vicinity of the bearing end at the center of the rear shroud is discharged from the return hole of the rear shroud, and water lubrication to the bearing is improved, improving the bearing life and the machine. Loss can be reduced.
[0021]
  Claim10The invention described in claim 1 is characterized in that the volute is provided with a water channel communicating between the discharge side and the vicinity of the holding hole of the fixed shaft.1-9Therefore, the air accumulated in the center of the rear shroud is pushed away by the fluid that flows back through the water channel of the volute, and the water lubrication of the bearing is improved to improve the life of the bearing. Mechanical loss can be reduced.
[0022]
  Claim11Since the discharge edge of the blade portion is disposed so as to protrude from the volute contact surface of the partition wall to the volute side, the externally driven line pump according to claim 1 is provided. The volute can be attached on the outside and assembly is easy, the rotor can be mounted slowly on the partition during assembly, and the stator and rotor are attracted by magnetic force and the bearing and bearing plate are shocked during assembly. The rotor can be prevented from being damaged, and the rotor can be easily replaced during maintenance.
[0023]
  (Embodiment)
  Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a structural diagram of an externally driven line pump according to an embodiment of the present invention.
[0024]
  In FIG. 1, 1 is a partition wall, 2 is a pump suction port, 3 is a rectifying plate that rectifies fluid, 4 is a blade portion that pressurizes fluid, which will be described in detail later, and 5 is a rotation direction given to water from the blade portion 4 The volute which converts the flow energy into pressure energy and discharges in the line (axial) direction, 6 is the discharge port of the pump, 7 is fixed with the volute 5 sandwiched between the partition wall 1 and guides the fluid to the discharge port 6 inside. A discharge housing provided with ribs 26, 8 is a fixed shaft fixed to the partition wall 1 and the volute 5 so as not to rotate, 9 is a bearing plate fixed by the partition wall 1 and the fixed shaft 8, and 10 is described later on the blade portion 4. A bearing fixed to the boss 21 and rotatably supporting the blades, 11 is a drive magnet, 12 is a rotor in which the drive magnet 11 is arranged around and has a blade portion 4 and a bearing 10 inside, and 13 is a rotor 1 that is energized. , A stator configured with a stator winding for rotating the stator 14, a control unit 14 for controlling a current supplied to the stator 13, and a plurality of fins 15 for radiating heat from the heat-generating components mounted on the control unit 14 and radiating the stator 13. 16 is a holding portion for holding the fixed shaft 8 provided at the center of the partition wall 1, 17 is an inlet side housing, and 18 is a mouth ring portion of the rotor 12 around which the drive magnet 11 is provided in a cylindrical shape. , 19 is an inner cylindrical portion which is a groove wall surface on the inner peripheral side constituting an annular mouth ring receiving groove for receiving the mouth ring portion 18 formed in the partition wall 1, and 20 is an annular mouth ring paired with the inner cylindrical portion 19. An outer cylindrical portion that is a groove wall surface on the outer peripheral side constituting the housing groove, 21 is a boss of the rotor 12 that supports the blades and the like of the blade portion 4 at the center, and 22 holds a fixed shaft 8 provided in the volute 5. A holding hole, 23 is a reflux hole provided in the vicinity of the end of the bearing 10 provided in the boss 21, 24 is a water channel communicating the discharge side of the volute 5 and the vicinity of the holding hole 22, and 25 projects from the outer periphery of the partition wall 1. Circumferential ribs 26 that fit into the discharge housing 7 and fix the outer periphery of the volute 5, and 26 are guide ribs that extend to the back surface of the volute 5 and guide fluid to the discharge port 6.
[0025]
  The drive magnet 11 is accommodated in the mouth ring portion 18 of the rotor 12 extending in the axial direction from the side surface of the blade portion 4 in the axial direction. Further, the partition wall 1 is provided with an annular mouth ring accommodating groove that can accommodate the mouth ring portion 18 through a minute gap, a rectifying plate 3 provided in an inner cylinder of the annular mouth ring accommodating groove, and further provided therein. A holding portion 16 for holding the fixed shaft 8 is integrally formed and integrally provided. A stator 13 is provided around the outer cylindrical portion 20 of the partition wall 1 and is disposed at a position facing the drive magnet 11 when the mouth ring portion 18 is inserted into the annular mouth ring receiving groove of the partition wall 1. . The inner cylinder, the holding part 16 and the rectifying plate 3 constitute a pump suction port.
[0026]
  In the rotor 12, the vicinity of the center of the blade portion 4 provided inside is a boss 21 of the rotor 12, and the boss 21 holds the bearing 10 inside. The bearing 10 passes through the center of the rotor 12, and both ends of the bearing 10 are rotatably attached to a fixed shaft 8 held by the partition wall 1 and the volute 5.
[0027]
  Since the stator 13 and the rotor 12 have the above-described configuration, the rotor 12 and the stator 13 constitute a motor. That is, the control current flowing through the stator 13 is switched by switching a commuter element provided on a control board (not shown), and the rotor 12 is rotated. The control unit 1 may be configured as software using a microcomputer or the like, or may be configured as hardware.
[0028]
  When the control unit 14 energizes the stator 13, a rotating magnetic field is generated in the stator 13, the driving magnet 11 receives torque around the axis due to the magnetic field, and the rotor 12 rotates. Since the blade portion 4 is provided in the rotor 12 in which the drive magnet 11 is housed, the blade also rotates when the rotor 12 rotates. At this time, if the fluid is filled in the partition wall 1, the fluid is given momentum from the rotor 12 by the action of the blades. In this embodiment, since the rectifying plate 3 is provided, when a flow is formed in the rotor 12, the fluid that is subsequently sucked by the negative pressure is pre-swiveled by the rectifying plate 3, It flows into the blade in the blade portion 4 at the incident angle. While passing through the blade 4 passage, the fluid is given kinetic energy by the blade 4 and discharged from the blade 4 outlet provided around the rotor 12.
[0029]
  The discharged fluid converts the kinetic energy just given by the volute 5 provided behind the rotor 12 into pressure energy and recovers the pressure. The flow after the discharge is directed from the outlet of the volute 5 in the centripetal direction, and discharged from the discharge port 6 in the axial direction through the return flow path.
[0030]
  The externally driven line pump of the present embodiment basically performs the operation as described above, and details of each part will be described below. First, the rotor 12 of the present embodiment will be described. A blade portion 4 is provided in the rotor 12. In order to make the blade portion 4 a small head pump with a high head, an axial flow blade is provided on the inlet side, and a mixed flow blade is continuously formed. The axial flow vane may be of a screw type. Further, instead of the mixed flow blade, a centrifugal blade slightly higher than the thickness of the drive magnet 11 may be used. That is, in the blade portion 4, the internal flow path is bent from the axial direction to the expanding direction (diagonal flow direction or centrifugal direction). Thereby, in addition to the pressure increase due to the blade action of the blade portion 4, a higher pressure increase is possible by the centrifugal action caused by the rotation of the rotor 12. The axial blade is an inducer for smoothly introducing the flow. The action of this inducer prevents cavitation that is likely to occur under the conditions of small size, high head and high rotation, and prevents long life and cavitation noise. This is especially the case with pumps when handling hot water. In addition, since the discharge edge of the mixed flow blade (spreading direction blade) has a shape that coincides with the outer peripheral surface of the mouth ring portion 18, the flow velocity distribution of the discharge flow is slightly biased toward the rear shroud, and after discharge The flow direction can be easily changed, and the volute 5 can be smoothly flowed. Since the discharge edge of the blade portion 4 is disposed so as to protrude from the volute contact surface of the partition wall 1 to the volute 5 side, the volute 5 can be easily attached and maintenance can be easily performed. The rotor 12 can be prevented from being pulled by the magnetic force, and the bearing 10 and the bearing plate 9 can be damaged by receiving an impact. The blade section 4 is configured such that the cross-sectional area of the flow path to the rotor 12 is constant from the inlet to the outlet, so that the air flowing into the blade section 4 is also preloaded by the inducer and at the same time in the rotor 12 In this case, the air is discharged without a pressure increase at a relatively large internal flow velocity, and the air is smoothly discharged and is less likely to stay. In addition, the flow in the internal passage is slowed down to become a complicated flow, and the efficiency is hardly lowered.
[0031]
  Since the drive magnet 11 is provided on the mouth ring portion 18 on the side of the mixed flow blade, the cylindrical space can be used without waste, and the drive magnet 11 can be easily mounted. The side surface shape of the rear shroud side of the rotor 12 is a conical depression because the blades are provided with mixed flow and have a uniform thickness. If this dent is not formed, inertia will increase and the response will be poor, and it will be easy to produce a sink in manufacture, and if possible, a dent should be formed. However, although the bearing 10 is provided in the boss 21 of the rotor 12, air tends to accumulate in the conical recess due to the difference in specific gravity with the fluid, and if the air stays, the bearing 10 becomes an underwater bearing. It is easy to be seized. Therefore, in order to discharge this air, a reflux hole 23 that communicates the inside and outside of the rear shroud is provided. Thereby, air is discharged by the flow recirculated from the high pressure side. However, since the pump efficiency is deteriorated by refluxing, it is better not to provide the reflux hole 23 from this aspect. Therefore, the reflux amount and the hole diameter should be appropriately selected from the viewpoint of preventing seizure and pump efficiency.
[0032]
  Next, the volute 5 will be described. The volute 5 recovers pressure by converting kinetic energy given by the rotor 12 into pressure energy. As the pressure recovery device, a vortex is usually used. However, in this embodiment, when the vortex casing is used, the outer diameter of the pump is enlarged. Therefore, a circle that circulates 360 ° from the inlet provided near the outlet of the rotor 1. It is a circumferential groove. However, the flow passage cross-sectional area has a shape that expands by increasing the axial depth of the groove so that pressure recovery can be achieved. After flowing around the volute 5 by 360 °, the flow directs the flow in the centripetal direction from the outlet of the volute 5, passes through a return flow path formed by the guide rib 26 protruding from the discharge housing 7 toward the back of the volute 5, and passes through the discharge port 6. It becomes the structure discharged from an axial direction. A holding hole 22 for holding the fixed shaft 8 is provided in the center of the volute 5. The rear shroud described above has a cylindrical depression, but if it is left as it is, a secondary flow that circulates greatly is formed on the rear surface of the shroud, resulting in a large fluid loss and air retention. Therefore, a conical convex portion is formed at the center of the volute 5, and is arranged opposite to the rear shroud with a predetermined gap. This significantly reduces fluid loss. Further, it is appropriate to provide the volute 5 with a water channel 24 that communicates between the discharge side and the vicinity of the holding portion 16 of the fixed shaft 8. By this water channel 24, the fluid on the discharge side is recirculated from the discharge side, and the remaining air is washed away, so that the water-lubricating fluid can be supplied to the bearing 10.
[0033]
  Subsequently, the assembly of the rotor 12, the partition wall 1, the volute 5, the discharge housing 7, the inlet housing 17, and the externally driven pump using them will be described. The partition wall 1 includes an annular mouth ring housing groove for housing the inlet side of the mouth ring portion 18, a rectifying plate 3 provided in an inner cylinder of the annular mouth ring housing groove, and a holding portion 16 provided therein. It is provided as a unit. The rectifying plate 3 also has a character as a support member that integrally connects the holding portion 16 and the inner cylinder of the partition wall 1. A stator 13 is provided around the outer cylindrical portion 20 of the partition wall 1 so that when the mouth ring portion 18 is inserted into the annular mouth ring receiving groove of the partition wall 1, the stator 13 is positioned so as to face the drive magnet 11 in the radial direction. It is arranged. The stator 13 is fixed by incorporating the suction port 2 into the partition wall 1 and tightening the inlet housing.
[0034]
  The fixed shaft 8 is fitted or molded via a bearing plate 9 in the hole of the holding portion 16 at the center of the partition wall 1 to be integrated. The bearing 10 of the rotor 12 is press-fitted into the fixed shaft 8, and the mouth ring portion 18 is inserted into the annular mouth ring receiving groove of the partition wall 1. In this state, the other end side of the fixed shaft 8 is inserted and held in a holding hole 22 provided at the center of the volute 5. At the same time, a circumferential outer surface concentric with the fixed shaft 8 of the volute 5 is fitted inside the circumferential rib 25 concentric with the fixed shaft 8 protruding from the discharge side end surface of the partition wall 1. It pushes in until it contacts the volute contact surface, and is sandwiched and fixed by the discharge housing 7 from the outside to complete the assembly of the external drive type line pump.
[0035]
  By the way, in the partition wall 1, an annular mouth ring accommodating groove for accommodating the mouth ring portion 18, and further, an inner cylindrical portion 19 and an outer cylindrical portion 20 for constituting the annular mouth ring accommodating groove are all integrally formed of resin. . For this reason, the rotor 12 and the stator 13 can be positioned inside and outside with respect to the bulkhead 1 which is the same component, and the gap management which is the main cause of the efficiency deterioration when the size is reduced can be extremely accurate. An efficient pump can be obtained. Compared with the case where the fixed shaft 8 is manufactured as a separate part from the partition wall 1 and is inserted later, there is no shaft misalignment (assembly tolerance) due to assembly, and the positions of the rotor 12 and the partition wall 1 are uniquely ensured. As a result, the gap between the rotor 12 and the partition wall 1 can be narrowed, and the amount of leakage returning from the discharge side of the rotor 12 to the suction side can be reduced. At the same time, the gap between the drive magnet 11 and the stator 13 can be narrowed, the motor efficiency can be improved, and a small and highly efficient pump can be realized. Furthermore, since the partition wall 1 is integrally formed and the circumferential rib 25 is also integrated, the positioning of the volute 5 is ensured. As a result, the positions of the drive magnet 11 and the stator 13 and all the gaps can be reliably controlled.
[0036]
  As described above, since the partition wall 1 and the volute 5 can be formed by the same mold, the accuracy of individual parts is high, and the assembly accuracy is increased by the above-described configuration, so that extremely high gap management can be realized as a whole pump. . Furthermore, there is no problem of dynamic balance and magnetic balance, and vibration and noise due to these deviations can be remarkably reduced. Further, since the volute 5 is sandwiched and fixed between the partition wall 1 and the discharge housing 7, when assembling, the rotor 12 is first inserted into the fixed shaft 8 in the partition wall 1, and then the volute 5 is assembled, and the discharge housing 7 is further fixed. What is necessary is just to pile up and to fix by screwing or caulking. Since it is only assembled in order, the assembly can be performed easily and the accuracy can be ensured.
[0037]
  Further, by controlling the gap between the mouth ring portion 18 of the rotor 12 and the annular mouth ring receiving groove of the partition wall 1 as follows, the external drive type line pump of the present embodiment minimizes leakage loss and mechanical loss. To improve the stability during operation. That is, the inner gap formed between the mouth ring portion 18 and the inner cylindrical portion 19 is made smaller than the outer gap formed between the mouth ring portion 18 and the outer cylindrical portion 20, so Leakage loss is reduced by the inner gap and becomes smaller. Furthermore, since this leakage flow forms a liquid film between the rotor 12 and the partition wall 1 to form a kind of underwater bearing, the stability during operation of the rotor 12 can be increased, and the inlet side and the outlet side of the rotor 12 can be improved. By reducing the thrust load applied to the bearing 10 by the axial thrust caused by the pressure difference, the mechanical loss due to the sliding of the bearing plate 9 can be reduced, and the leakage loss from the bearing 10 can be reduced. Since the friction between the bearing 10 and the bearing plate 9 is reduced, the rotor 12 can be rotated at a high speed, and a higher head, a smaller size, and an improved efficiency can be achieved at the same time. Instead of making the inner gap formed between the mouth ring portion 18 and the inner cylindrical portion 19 smaller than the outer gap formed between the mouth ring portion 18 and the outer cylindrical portion 20, the inner cylinder A part of the gap between the part 19 and the mouth ring part 18 may be narrowed. Even in this case, the fluid recirculated from the discharge side of the rotor 12 can be restricted by the narrowed gap portion, leakage loss can be reduced, and the liquid formed in the gap between the partition wall 1 and the rotor 12 can be reduced. The action of the underwater bearing can be given by the membrane.
[0038]
【The invention's effect】
  As described above, according to the invention described in claim 1 of the present invention, since it is assembled with the integrally formed partition wall as a reference, the assembly tolerance of the fixed shaft can be reduced, and the gap between the rotor and the partition wall is set narrow. In addition, it is possible to reduce the reduction in motor efficiency due to the axial deviation between the rotor and the stator, and it is possible to reduce the leakage loss that flows back through the gap between the rotor and the partition wall.Furthermore, since the discharge edge of the blade portion matches the outer peripheral shape of the mouth ring portion of the rotor, the size can be reduced, the inertia of the previous rotor can be reduced, the responsiveness can be reduced and the weight can be reduced, and the volute By increasing the strength of the shaft holding part and reducing the secondary flow on the back of the rear shroud, noise is reduced, and fluid loss between the volute and rear shroud is reduced, improving pump efficiency. be able to.
[0039]
  According to the second aspect of the present invention, since the fixed shaft can be fixed to the holding portion by the assembly tolerance of the partition wall and the volute, it is possible to reduce the deviation of the center of the rotor and the stator, and to reduce the vibration caused by the deviation of the magnetic balance. Accordingly, it is possible to provide an externally driven line pump that suppresses the increase in sliding resistance between the bearing and the shaft, and that is small and efficient, and that has little vibration noise.
[0040]
  According to the third aspect of the invention, the holding portion of the fixed shaft and the circumferential rib, and the fixed shaft and the outer circumference of the volute can be molded with a concentric circular mold on the same axis. The processing accuracy in manufacturing can be improved, and the accuracy is easily obtained due to the circular shape at the time of molding. The accuracy of the fixed shaft can be achieved with a simple configuration.
[0041]
  According to the fourth aspect of the present invention, it is possible to provide an externally driven line pump that can be easily assembled, is small and efficient, and has little vibration noise.
[0042]
  According to the fifth aspect of the present invention, it is not necessary to enlarge the radius of the volute, and it is small in size, and the fluid discharged from the volute can be guided to the discharge port at a short distance.
[0043]
  According to the sixth aspect of the present invention, the fluid can be guided by the guide rib provided inside the discharge housing, the flow path can be configured with a simple configuration, the strength of the discharge housing is improved, and the assembly is easy. Highly reliable externally driven line pump can be provided.
[0044]
Claim7According to the invention described in (4), it is possible to achieve a high head by basically utilizing centrifugal force at the blade portion of the line structure.
[0045]
  Claim8According to the invention described in the above, the pressure is not increased in the rotor, the air is smoothly discharged, and the flow in the internal passage is reduced to a complicated flow due to deceleration, and the efficiency is less likely to be reduced..
[0046]
Claim9According to the invention described in the above, air accumulated in the vicinity of the bearing end portion in the center portion of the rear shroud is discharged from the reflux hole of the rear shroud, and water lubrication to the bearing is performed satisfactorily, improving the life of the bearing and reducing mechanical loss. Reduction can be performed.
[0047]
  Claim10According to the invention described in the above, the air accumulated in the central portion of the rear shroud is pushed away by the fluid that flows back through the water channel of the volute, and the water lubrication of the bearing is improved, the life of the bearing is improved and the mechanical loss is reduced. be able to.
[0048]
  Claim11According to the invention described in the above, the volute can be attached outside the partition wall, and the assembly is easy, and the rotor can be mounted slowly by placing it on the partition wall at the time of assembly. As a result, the bearing and the bearing plate can be prevented from being damaged by an impact during assembly, and the rotor can be easily replaced during maintenance.
[Brief description of the drawings]
FIG. 1 is a structural diagram of an externally driven line pump according to an embodiment of the present invention.
FIG. 2 is a structural diagram of a prior art externally driven axial flow pump.
[Explanation of symbols]
  1,101 Bulkhead
  2 Suction port
  3 Current plate
  4 feathers
  5 Volute
  6 Discharge port
  7 Discharge housing
  8 Fixed shaft
  9,107 Bearing plate
  10,106 Bearing
  11,110 Drive magnet
  12,111 rotor
  13,112 stator
  14 Control unit
  15 Heat sink
  16 Holding part
  17 Inlet housing
  18 Mouse ring
  19 Inner cylinder
  20 Outer cylindrical part
  21 Boss
  22 Holding hole
  Reflux hole
  24 waterways
  25 circumferential ribs
  26 Guide rib
  102 Suction flange
  103 Axial flow blade
  104 Discharge flange
  105 axes
  108 Shaft holder
  109 ribs

Claims (11)

An externally driven line pump including a rotor having a driving magnet disposed around, a rotor provided with a blade portion for boosting therein, and a stator that forms a rotating magnetic field for rotating the rotor; The stator is attached to the periphery, and a fixed shaft holding portion that rotatably supports the rotor is provided at a central portion. The partition is integrally formed, and is disposed between the stator and the rotor. And the discharge edge of the blade portion coincides with the outer shape of the mouth ring portion of the rotor, the rear surface shroud of the blade portion has a conical shape, and the central portion of the volute has a conical convex portion, An externally driven line pump, wherein the externally driven line pumps are arranged to face each other with a predetermined gap . 2. The external drive type line pump according to claim 1, wherein a volute is provided on a discharge side of the rotor, and a holding portion for a fixed shaft is provided in a central portion of the volute. A circumferential rib concentric with the fixed shaft is provided on the outlet side of the partition wall, the outer periphery of the volute is concentric with the fixed shaft, and the circumferential rib and the outer periphery of the volute are fitted. The externally driven line pump according to 1 or 2. The external drive type line pump according to any one of claims 1 to 3, wherein the volute is fixed between the discharge housing and the partition wall. The volute rotates in a circumferential direction and includes a flow path in which an axial bulge amount gradually increases, and the flow discharged from the outlet is guided in the centripetal direction on the back surface of the volute. 5. An externally driven line pump according to any one of 4 above. 6. A discharge port is provided in the center of the discharge side housing, and a guide rib for guiding fluid discharged from the volute to the discharge port is projected from the discharge housing toward the volute. An externally driven line pump according to the above. The externally driven line pump according to any one of claims 1 to 6, wherein the internal flow path of the blade portion is bent from the axial direction to the expanding direction. 8. The externally driven line pump according to claim 7, wherein the cross-sectional area of the internal flow path of the blade portion is constant from the inlet to the discharge port. The externally driven line pump according to claim 1, wherein a reflux hole is provided in the vicinity of the bearing end of the rear shroud. The external drive type line pump according to any one of claims 1 to 9, wherein the volute is provided with a water channel that communicates between the discharge side and the vicinity of the holding hole of the fixed shaft. 2. The externally driven line pump according to claim 1, wherein the discharge edge of the blade portion is disposed so as to protrude from the volute contact surface of the partition wall toward the volute side.

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