JP2000314390A - Pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump which shows high efficiency, even if rotational speed is varied during operation, and can crush mixed foreign materials, downsize itself and attain high lifting. SOLUTION: This pump has a rectifying plate 9 which is arranged on a suctioning part has an arcuate rear edge with a prescribed radius of curvature, a rotor 1 arranged with specified spacing from the arcuate rear edge, rotated in a rotor chamber and has blade lines therein set so as to be an optimum inflow angle in rated operation, a volute casing 10 arranged for recovering pressure of fluid flow discharged from the rotor 1, and a blade 12 formed an acute front edge contained in the blade lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a pump with a high efficiency even when a pre-swirl is provided by a current plate and the rotational speed is varied around a rated rotational speed, in particular, a rotor is provided with a drive magnet. The present invention relates to an externally driven pump.

[0002]

2. Description of the Related Art Conventionally, turbo-type pumps do not give a pre-swirl to the fluid flowing into the impeller, and a rectifying plate or front stationary blade is provided to pre-swirl the fluid flowing into the impeller. There are types that give. A pump that does not give a pre-swirl changes its flow rate to an appropriate inflow angle within a range that does not cause separation when the rotation speed of the impeller changes. As long as the blade is designed so as to have the maximum inflow angle in (1), the reduction in efficiency can be relatively suppressed even if the rotational speed changes. However, this type of pump has the disadvantage that the efficiency at the rated point is inherently worse than that without pre-swirl because no pre-swirl is given.

On the other hand, a pump of the type in which a straightening vane or a front stationary vane is provided to give a pre-swirl to the fluid flowing into the impeller, the fluid is forced to a predetermined inflow angle by the straightening vane or the front stationary vane. Therefore, if this angle is set to the optimum inflow angle at the rated point, the peripheral speed changes and the blade deviates from the optimum inflow angle for the blade when the pump speed changes from the rated point. The actual inflow angle and the designed inflow angle do not match. Therefore, this type of pump causes a considerable loss of efficiency when it goes out of the rated point. However, this type of pump exhibits higher efficiency than a pump that does not provide pre-swirl when operated at a rated point where the inflow angle matches the designed inflow angle.

[0004] As described above, these two types of pumps have advantages and disadvantages, and the two are in a rather contradictory relationship, and it is difficult to realize a pump that is highly efficient and resistant to fluctuations in rotation speed. there were.

[0005] In addition, recent fluid devices tend to be smaller and lighter, and there is a strong demand for smaller and lighter pumps to be incorporated therein. In addition, such a fluid device is often used in close contact with daily life, a pump that is easy to maintain, consumes low power, and has low noise is desired.

If the size of a turbo-type pump is simply reduced in order to meet such needs, the specific gravity of the loss due to flow separation or backflow exerted on the pump efficiency increases, conversely with the size. Conversely, a change in the number of revolutions greatly affects efficiency.

Therefore, a flow loss is unavoidable at a rotational speed outside the rated point, and it is practically difficult to realize a high-efficiency, small-sized and high-head pump. In particular, a pump of the type that does not provide a pre-swirl is still closer to practical use, although the pump that does not provide a pre-swirl is still slightly more practical at this point, because if the size is reduced, the loss becomes larger than expected at points other than the rated point.
However, pumps that do not provide this pre-swirl were originally inefficient at the rated point and were far from practical in this respect.

Therefore, a conventional small pump that does not give a pre-swirl, especially an externally driven axial flow type line pump will be described with reference to US Pat. No. 2,697,986. FIG. 3 is a structural view of a conventional externally driven axial flow type line pump, and FIG. 4 is a sectional view of a blade of the conventional externally driven axial flow type line pump. In FIG. 3, reference numeral 51 denotes a housing;
Is the suction flange of the pump, 53 is the axial flow blade for pressurizing the fluid, 54 is the discharge flange of the pump, 55 is the axial flow blade 53
, A bearing that holds the rotating shaft 55, 57 is a bearing holder that supports the bearing 56,
Reference numeral 8 denotes a rib connecting the housing 51 and the bearing holder 57, 59 denotes a permanent magnet, 60 denotes a rotor having a built-in permanent magnet 59, 111 denotes a stator that rotates the rotor 60 when energized, and is a driving unit of this conventional pump. is there. The axial flow type line pump is connected to a pipe (not shown) by a suction flange 52 and a discharge flange 54, and has a structure that can be incorporated into the pipe in a line shape. In the connected state, the line pump pressurizes the fluid sucked from the suction flange 52 by rotating the fluid with the axial flow blade 53, and discharges the fluid from the discharge flange 54. The axial flow blade 53 is attached to a rotating shaft 55, and the outer periphery is attached to a rotor 60, and the whole is rotatable about the rotating shaft 55. The rotation shaft 55 is provided on the housing 51 with the rib 5.
8 and is supported by a bearing 56 in a bearing holder 57 attached.

Further, a permanent magnet 59 is built in the rotor 60, and when the stator 111 is energized, the rotor 60 starts rotating, and the axial flow blade 5 inside the rotor 60 is rotated.
3 rotates and pushes out the fluid. Operation control of the axial flow line pump is performed by a control unit (not shown). Regarding the blade shape, a screw blade having an axial flow blade 53 has also been proposed.

As described above, in the externally driven axial flow type line pump according to the prior art, as shown in FIG. 3, the axial flow blades 53 are provided in the rotor 60, and the rotor 60 and the impeller serving as the rotor 60 are rotated. Because of the structure, a small pump can be realized as compared with an axial flow pump having the same capacity (flow rate and head). Then, as shown in FIG. 4, at the set inflow angle α ₀ ′, the leading edge of the axial flow blade 53 is an arc-shaped leading edge having a radius of curvature. It was able to respond flexibly. However, due to the low head, this line pump was suitable for a blower that pumped gas rather than using liquid. Further, since this conventional pump is not of a type that provides a pre-swirl provided with a straightening vane or a stationary vane at the front, a pump efficiency is low and power consumption is large as described above. When the conventional pump is incorporated in a fluid device used in a circulating system such as a circulating warm water bath, foreign matter such as hair is caught on the axial flow blade, which hinders maintenance.

[0011]

As described above,
Conventional pumps that do not give a pre-swirl can respond flexibly without a decrease in efficiency when the rotation speed of the impeller changes, but the efficiency is not very good at the rated point where the efficiency should be high Was something. Also, a pump of the type that provides a pre-swirl to a fluid by providing a straightening vane or a pre-stationary vane, forcibly applies a predetermined inflow angle to the flow in the pre-swirl, and is therefore higher than a pump that does not provide a pre-swirl at the rated point Although the efficiency is shown, when the rotational speed changes from the rated point, the inflow angle to the blade changes, causing a large decrease in efficiency.

In addition, with the recent miniaturization of fluid equipment, a pump having a small size and a high head is desired, and the pump is often used in close contact with daily life. There is a need for a pump that requires no maintenance, consumes low power, and has low noise.

Therefore, the present invention solves the above-mentioned conventional problems, and the efficiency is high even when the operation is performed while changing the rotation speed.
It is an object of the present invention to provide a pump that can be crushed even if foreign matter is mixed therein, and that can be reduced in size and height.

[0014]

In order to solve the above-mentioned problems, a pump according to the present invention is provided with a straightening plate provided at a suction portion and having an arc-shaped rear edge having a predetermined radius of curvature, and a predetermined flow from the arc-shaped rear edge. A rotor provided with a gap, rotating in the rotor chamber, and having therein a row of blades set to have an optimum inflow angle during rated operation, and a volute casing for recovering the pressure discharged from the rotor by pressure. Wherein the blade row is provided with a blade having a sharp edge-shaped leading edge.

[0015] With this, even if the operation is performed while changing the rotation speed, the efficiency is high, and even if foreign matter is mixed, it can be crushed.
Higher head is possible.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that a straightening plate provided on a suction portion and having an arc-shaped rear edge having a predetermined radius of curvature is formed, and a predetermined gap is formed from the arc-shaped rear edge. A rotor provided with a row of blades that is set in the rotor chamber and rotates so as to have an optimum inflow angle at the time of rated operation, and a volute casing that recovers pressure discharged from the rotor, The pump is characterized in that the blade row is provided with a blade having a sharp edge-shaped leading edge, so that at the rated speed, the flow pre-swirled by the rectifying plate is an edge-shaped leading edge. Kinetic energy is given as the optimal flow, and when the rated rotation speed changes, the inconsistency of the inflow angle of the blade and the flow can be absorbed by the arc-shaped trailing edge and the gap of the straightening plate of a predetermined radius of curvature, Edge Foreign matter can be crushed or cut by the trailing edge of the leading edge and the rectifying plate.

According to a second aspect of the present invention, there is provided a rectifying plate provided on the suction portion and having an arc-shaped trailing edge having a first radius of curvature, and provided at a predetermined gap from the arc-shaped trailing edge. A rotor provided inside the rotor chamber and provided with a row of blades set to have an optimum inflow angle at the time of rated operation, and a volute casing for recovering pressure discharged from the rotor, wherein the row of blades is provided. Is a pump characterized in that a blade having an arc-shaped leading edge having a second radius of curvature and a blade having a sharp edge-shaped leading edge are arranged in a regular order. At the rotation speed, the flow pre-swirled by the rectifier plate is optimized by the edge-shaped leading edge and kinetic energy is given.When the rated rotation speed changes, the arc-shaped leading edge of the blade and the rectifier plate First
The inflow angle mismatch between the vane and the flow is absorbed by the arc-shaped trailing edge and the gap having the radius of curvature, and the inflow angle mismatch is absorbed by the arc-shaped trailing edge and the gap having the first radius of curvature of the current plate. The foreign matter can be crushed or cut by the edge-shaped leading edge and the trailing edge of the current plate.

According to a third aspect of the present invention, the edge-shaped leading edge blade is deformed into an arc-shaped leading edge blade having a second radius of curvature on the outer peripheral side. According to the pump described in 1 or 2, on the outer peripheral side of the blade, the peripheral velocity is high, and a backflow area attached to the leading edge of the blade tip is formed. There is, however, an arc-shaped leading edge that can better absorb discrepancies.

According to a fourth aspect of the present invention, there is provided the pump according to any one of the first to third aspects, wherein the edge-shaped leading edge is symmetrical with respect to the blade center line. The inflow angle mismatch can be well absorbed at both upper and lower rated speeds, and a leading edge excellent in crushing and cutting foreign matter can be obtained.

According to a fifth aspect of the present invention, there is provided a pump according to any one of the first to fourth aspects, wherein a driving magnet is provided inside a mouth ring portion of the rotor. Therefore, the size of the externally driven pump that rotates the rotor by the stator provided around the rotor chamber can be reduced.

(Embodiment 1) Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a structural view of a pump according to an embodiment of the present invention in an external drive type, and FIG. 2A is a rectifier plate and a blade having an edge-like front edge of the pump according to the embodiment of the present invention. FIG. 2B is a conceptual cross-sectional view of a vane having a current plate and an edge-shaped and arc-shaped front edge of a pump according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a rotor which gives kinetic energy to the liquid passing therethrough by the action of a blade 12 provided inside by rotating in the liquid, and 2 denotes a plurality of rotors on the outer periphery of the rotor 1 at predetermined intervals. The driving magnet is a permanent magnet disposed and rotated by a rotating magnetic field formed outside. The rotor 1 is provided with a mouth ring portion, the drive magnet 2 is arranged around the periphery, and the blade portion 12 is bent in the expanding direction (centrifugal direction or diagonal flow direction). In the case of the first embodiment, the blade portion 12 provided in the rotor 1
Is constituted by a blade row of a combination of an axial flow blade 121 on the inlet side and a mixed flow blade 122 connected thereto. The axial flow blade 121 is provided so as to realize a smooth suction without generating cavitation even at high speed rotation in order to realize a small-sized, high-lift externally driven line pump. When sending hot water, cavitation tends to occur easily, so it is better to provide this inducer for a pump that sends hot water. The inducer also contributes to the discharge of air accumulated in the rotor 1, which has been relatively affected by downsizing. Even if the pump is rotated at high speed to increase the head, vibrations and the like are likely to occur in the case of a small pump, and there is a limit to speeding up. Therefore, the first embodiment
In this case, the diagonal flow vanes 122 are provided in order to apply a centrifugal action to pressurize the peripheral velocity component and at the same time facilitate discharge in the line direction. Needless to say, even if centrifugal blades having a height slightly exceeding the thickness of the axial flow blade 121 and the drive magnet 2 are used, sufficient miniaturization and high head can be achieved.

The sectional shape of the axial flow blade 121 is shown in FIG.
(A) As shown in FIG.
It is now 4. The designed inflow angle of the axial flow blade 121 is set to be the optimum inflow angle α ₀ during the rated operation. The edge-shaped leading edge 104 is formed symmetrically at an angle of θ / 2 with respect to the blade center line. In FIG. 2A, the blade is bent from the edge portion and connected to the blade body. However, it is preferable that the blade be connected with a smooth curve without bending. In this way, the mismatch between the inflow angles can be effectively absorbed at both the rated speed and the non-rated speed. In the case of water containing foreign matter such as hair, the shape is suitable for crushing and cutting. As will be described in detail later, the leading edge 10
Regarding the four shapes, as shown in FIG. 2B, it is not necessary to form all the leading edges 104 into sharp edges, and a row of blades constituting the blade portion 12 (the axial flow blade 121 in the first embodiment).
Of some of the blades are arc-shaped leading edges 104 having a predetermined radius of curvature.
And the remaining blades are sharp edge-like leading edges 1
04 may be provided. When the arc-shaped leading edge 104 and the edge-shaped leading edge 104 are combined to form one blade row as a whole, it is preferable to arrange the two types of leading edges 104 alternately or in a fixed regular order. .

Further, although not shown in FIG. 2B, an edge-shaped front edge 104 is formed on the inner peripheral side of the blade portion 12, and an arc-shaped front edge having a radius of curvature from a predetermined radial position to the outer peripheral side. It is good to transform it into 104. The reason is that the axial flow blade 121 having the edge-shaped leading edge 104 has good efficiency when the rated operation is performed, but the efficiency is deteriorated if the rated point is deviated.
This is because when the rotational speed changes largely, the arc-shaped leading edge 104 is more resistant to the change. The axial flow blade 121 often has a flow pattern in which a backflow area adheres to the tip of the outer periphery on the inlet side of the blade. However, the backflow twists the main flow three-dimensionally, thereby further emphasizing a shift in rotation speed. This is because that. Therefore, the inner peripheral side of the blade section 12 is formed into an edge-shaped front edge 104, and the outer peripheral side is formed into an arc-shaped front edge 104 having a predetermined radius of curvature. be able to. In the present invention, not only the shape of the front edge 104 of the blade portion 12 but also the arc-shaped rear edge 105 of the current plate 9 described later and the gap between the arc-shaped rear edge 105 and the axial flow blade 121 are opened by a predetermined size. ,
By providing the rectifying plate 9, it is possible to prevent a decrease in efficiency due to a change in the number of revolutions caused by giving the pre-swing, which will be described later.

Next, the drive magnet 2 will be described.
The driving magnet 2 includes a plurality of rotors
May be formed by fitting into the receiving groove of the above, or may be molded with resin or the like. In the case of the first embodiment, a taper is provided at the discharge-side end of the drive magnet 2 along the mixed flow blade 122. Also, the rotor 1 is molded with a plastic magnet in which magnetic powder is mixed in resin, and when the magnetic powder is still flowing during molding, a magnetic field is applied from outside to magnetize the rotor 1, thereby forming the drive magnet 2. You may do it. According to this manufacturing method, the rotor 1 can be manufactured very easily. As described above, since the configuration of the blade portion is a combination of the axial flow blade 121 and the oblique flow blade 122, the mouth ring portion of the outer diameter difference between the outer diameter of the flow path on the inlet side and the outer diameter of the flow path on the outlet side of the rotor 1. The drive magnet 2 can be accommodated in parallel with the axis, and the space can be effectively used.

Reference numeral 3 denotes a cover for attaching and holding the drive magnet 2 to the outer periphery of the rotor 1. Reference numeral 4 denotes a bearing press-fitted into the boss of the rotor 1. When the rotor 1 is constituted by the above-described plastic magnet, the cover 3 is unnecessary.
When a brittle ferrite magnet or the like is used as the drive magnet 2, a cover 3 is required to prevent breakage or diffusion at the time of breakage. In a small-sized, high-lift pump as in the present invention, the leakage from the high-pressure side and the fluid loss are relatively larger than those of a normal-sized pump, so that the gap can be finely adjusted by the cover 3. With the cover 3 attached, the outer diameters of the cover 3 and the blade outlet of the rotor 1 form a flush cylindrical surface, and the rotor outer periphery is made a cylindrical surface to reduce fluid loss and leakage. it can. Also, since the bearing 4 is used in a liquid, an underwater bearing is suitable. An externally driven line pump having the least amount of leakage, the least vibration, and the least contact can be obtained by comprehensively considering the bearing action due to the leakage flow on the outer periphery of the rotor 1 and the bearing action of the bearing 4.

Reference numeral 5 denotes a stator which is provided at a position facing the drive magnet 1 and comprises a stator winding which forms a rotating magnetic field for rotating the rotor 1 when energized. In the first embodiment, the rotor 1 and the stator 5 constitute a brushless DC motor. The drive current flowing through the stator winding is switched by switching a commutator element provided on a control board (not shown), and the rotor 1 is rotated. Reference numeral 6 denotes a fixed shaft which is located at the center of the bearing 4 and supports the rotor 1. Reference numeral 7 denotes a thrust contact with the end face of the bearing 4 when the rotor 1 moves in the axial direction by axial thrust generated around the rotor 1 during pump operation. A bearing plate that supports loads. When the pressure is increased by rotating the rotor 1, the pressure after the pressure acts on the back surface of the rotor 1, and the rotor 1
Since the pressure before the pressure rise acts on the front surface of this, the difference becomes the axial thrust and gives the thrust load during operation. Of course, the higher the lift, the greater the axial thrust.

Numeral 8 denotes a partition wall provided between the rotor 1 and the stator 5 to form a rotor chamber. Numeral 9 is provided in a suction portion on the inlet side of the rotor chamber to rectify the flow flowing into the blade section 12 in the rotor 1. It is a current plate. When operating at the rated point, the flow straightening plate 9 gives a pre-rotation so that the inflow angle of the fluid flowing into the axial flow blade 121 and the designed inflow angle (optimal inflow angle α ₀ ) of the axial flow blade 121 match. In this case, the collision loss can be reduced. An arc-shaped trailing edge 105 having a predetermined radius of curvature is formed on the rectifying plate 9 of the present invention, and the rotation speed varies with the action of a gap provided between the rectifying plate 9 and the axial flow blade 121. Even in this case, the outflow angle from the flow straightening plate 9 is slightly changed to prevent the efficiency from decreasing. That is,
When operating at the rated point, the efficiency of the flow straightening plate 9 increases,
When the rotation speed is reduced from the rated point, the interval and the arc-shaped trailing edge 10
The effect of 5 prevents a decrease in efficiency. The gap between the flow straightening plate 9 and the leading edge 104 of the axial flow blade 121 is suitably set to an interval of 0.1 to 2 times the product of the blade height and the hub ratio. When hair or other foreign matter enters the gap, it can be crushed or cut by the edge-shaped front edge 104 of the axial flow blade 121.

Reference numeral 10 denotes a volute casing provided downstream of the rotor 1 for converting kinetic energy given by rotation of the rotor 1 into pressure energy. Reference numeral 11 denotes a shaft support for supporting the fixed shaft 6. Volute casing 10
Is for recovering pressure in order to convert kinetic energy given by the rotor 1 to pressure energy, and usually has a spiral shape. However, since the volute casing 10 of the present invention is a pressure recovery device for a small external drive line pump and has a limited outer diameter, the volute casing 10 is a circumferential groove for rotating the liquid discharged from the rotor 1 in the circumferential direction. At the same time, the overhang is increased in the direction of the fixed shaft 6 so as to gradually increase the cross-sectional area of the groove. After rotating 360 ° in the circumferential groove to the winding start portion, the pressure is recovered and the liquid is discharged in the axial direction. In the case of a pump that operates near the rated point where the discharge flow rate is almost constant, if the guide vanes are provided in the volute casing 10, the pressure recovery becomes smooth, and a more efficient pump can be realized.

Since the externally driven line pump according to the first embodiment is a combination of the axial flow blade 121 and the mixed flow blade 122, the side surface (shroud) of the discharge-side rotor 1 has the shape of the mixed flow blade 122. If a predetermined thickness is taken along the shape, a conical concave portion is formed as shown in FIG. If the thickness is increased without forming the concave portion, the weight of the rotor 1 increases, and the stator 5 has to be made large, and the pump becomes large. Inertia increases,
Response also gets worse. Although the concave portion is formed for such a reason, if the concave portion is left as it is, a secondary flow occurs with the rotation of the rotor 1, which causes a large loss. Further, it becomes difficult to discharge the air accumulated near the rear of the bearing 4. Therefore, in the first embodiment, one of the fixed shafts 6 is supported by the shaft support portion 11, and the other is supported by the volute casing 10, and a cone portion that fills the recess is provided in the volute casing 10. This prevents a large secondary flow from being formed behind the rotor 1, reduces fluid loss, and prevents seizure of the bearing 4 due to air accumulated near the bearing.

Next, the operation of the externally driven line pump according to the first embodiment will be described. When the stator 5 is energized with the liquid, a rotating magnetic field is formed and the rotor 1
Starts rotating around the fixed axis 6. When the liquid is introduced into the rotor 1 by the action of the axial flow blade 121, kinetic energy is given to the liquid by imparting centrifugal action in addition to the action of the blade by the mixed flow blade 122, and the liquid is discharged from the rotor 1 at the outer peripheral position. With this configuration, a small-sized, high-lift externally driven pump can be realized. The liquid discharged from the rotor 1 is gradually recovered in pressure while rotating by the volute casing 10, and is discharged in the axial direction. An axial thrust is generated due to a pressure difference between the front and rear of the rotor 1, but the rotor 1 moves to the inlet side, and the thrust load is supported by the bearing plate 7. The gap between the outer periphery of the rotor 1 and the partition 8 is small, and leakage is small. Then, a liquid film is formed in the gap, and stably supports the rotor 1 together with the bearing 4 which is an underwater bearing. Moreover, due to the cone behind the rotor 1, 2
Subsequent flow is prevented and fluid loss can be prevented. When the rotor 1 is small and has a high head, the rotor 1 is inevitably unstable and generates vibrations. However, in the first embodiment, the rotor 1 is stabilized by such an action, and the drive magnet 2 is disposed around the rotor 1 to move. Balancing is easy, and a pump with low vibration and noise can be realized.

As described above, according to the externally driven line pump of the first embodiment, the fluid passage is bent in the expanding direction by the diagonal blade 122 on the back side of the discharge side end of the driving magnet 2, and the externally driven line pump is formed. The rotor 1 can be miniaturized, and a high head, high efficiency, and a line can be realized. Further, since the axial flow blade 121 is provided as an inducer,
Smooth inflow into the rotor 1 and cavitation can be prevented. Then, since the discharge side end of the drive magnet is arranged at the axial position where the transition from the axial flow blade 121 to the diagonal flow blade 122 starts to expand, the positioning of the drive magnet 2 can be performed simply and accurately. Furthermore, a cover for holding the drive magnet is provided around the mouth ring part, and the outer peripheral surface of the rotor including the cover is made a cylindrical surface,
Holds the drive magnet and simplifies its installation,
The clearance between the rotor outer periphery and the partition wall can be finely adjusted, and the function of the underwater bearing can be exhibited by the clearance.

An arc-shaped trailing edge 105 having a predetermined radius of curvature is provided.
And a rotor 1 provided at a predetermined gap from the arc-shaped trailing edge 105 and provided with an axial flow blade 121 having an optimum inflow angle α ₀ during rated operation. Has a sharp edge-shaped front edge 104, the flow pre-turned by the rectifying plate 9 at the rated rotation speed becomes an optimal flow by the edge-shaped front edge 104 and kinetic energy is given. When the rotation speed is changed, the inflow angle mismatch can be absorbed by the arc-shaped trailing edge 105 of the current plate 9 and the gap.
Foreign matter can be crushed or cut by the arc-shaped trailing edge 105 of the current plate 4 and the current plate 9.

An arc-shaped leading edge 104 having a predetermined radius of curvature is formed at a part of the axial flow blade 121 constituting the blade row, and a sharp edge-shaped leading edge 104 is formed at the remaining axial flow blade 121. Even more effectively, the mismatch between the inflow angles of the blade and the flow can be absorbed. When the edge-shaped front edge 104 is deformed into an arc-shaped front edge 104 on the outer peripheral side, the front edge 104
Although the main flow tends to be twisted due to the backflow area attached to the surface, the inconsistency of the inflow angle tends to be large. However, this configuration can further absorb the inconsistency. When the edge-shaped leading edge 104 is symmetrical with respect to the wing center line, the inflow angle mismatch can be well absorbed at both the upper and lower rated points, and the leading edge 104 can be excellent in crushing and cutting of foreign matter. .

[0035]

According to the first aspect of the present invention, at the rated rotation speed, the flow pre-swirled by the rectifying plate becomes the optimum flow by the edge-like leading edge, and the kinetic energy is given. When the rated rotation speed changes, the gap between the vane and the flow inflow angle can be absorbed by the arc-shaped trailing edge and the gap of the predetermined radius of curvature of the current plate, and the edge-shaped front edge and the rear edge of the current plate can be absorbed. Can crush or cut foreign matter.

According to the invention described in claim 2 of the present invention,
At the rated rotation speed, the flow pre-swirled by the rectifier plate is optimized by the edge-shaped leading edge and given kinetic energy, and when the rated rotation speed changes, the arc-shaped leading edge of the blade and the rectifier plate The gap of the inflow angle between the blade and the flow is absorbed by the arc-shaped trailing edge of the first radius of curvature and the gap, and the inflow angle of the edge-shaped leading edge is also mismatched by the arc-shaped rear edge of the first radius of curvature and the gap. And foreign matter can be crushed or cut by the edge-shaped leading edge and the trailing edge of the current plate.

According to the third aspect of the present invention,
On the outer peripheral side of the blade, the peripheral velocity is high, and a reverse flow area attached to the leading edge of the blade tip is formed, and the mismatch of the inflow angle tends to increase at the edge-shaped leading edge, but it becomes an arc-shaped leading edge Can better absorb discrepancies.

According to the invention described in claim 4 of the present invention, the inflow angle mismatch can be well absorbed at both upper and lower rated speeds, and a leading edge excellent in crushing and cutting of foreign matter can be obtained. it can.

According to the invention described in claim 5 of the present invention, it is possible to reduce the size of the externally driven pump in which the rotor is rotated by the stator provided around the rotor chamber.

[Brief description of the drawings]

FIG. 1 is a configuration diagram when an externally driven pump according to an embodiment of the present invention is used.

FIG. 2A is a conceptual view of a cross section of a vane having a flow straightening plate and an edge-shaped leading edge of a pump according to an embodiment of the present invention; and FIG. Conceptual diagram of blade cross section with arc-shaped leading edge

FIG. 3 is a structural diagram of a conventional externally driven axial flow type line pump.

FIG. 4 is a sectional view of a blade of a conventional externally driven axial flow type line pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2 Drive magnet 3 Cover 4 Bearing 5 Stator 6 Fixed shaft 7 Bearing plate 8 Partition wall 9 Rectifier plate 10 Volute casing 11 Shaft support part 12 Blade part 104 Front edge 105 Arc-shaped trailing edge 121 Axial blade 122

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F04D 29/22 F04D 29/22 A 29/44 29/44 BE 29/54 29/54 A 29/70 29/70 G F term (reference) 3H033 AA01 AA11 BB01 BB07 BB08 CC01 CC03 DD03 DD06 DD23 EE04 EE06 EE07 EE19 3H034 AA01 AA11 BB01 BB07 BB08 CC01 CC03 DD04 DD08 DD12 EE04 EE06 EE07 EE12 EE18

Claims (5)

[Claims] 1. A current plate provided in a suction portion and having an arc-shaped trailing edge having a predetermined radius of curvature, and a predetermined gap from the arc-shaped rear edge. The current plate rotates in a rotor chamber and has a rated operation inside. A rotor provided with a row of blades set to sometimes have an optimum inflow angle, and a volute casing for recovering pressure discharged from the rotor, wherein the row of blades has a sharp edge-shaped leading edge. A pump characterized by having wings provided. 2. A rectifying plate provided in the suction portion and having an arc-shaped trailing edge having a first radius of curvature, and provided at a predetermined gap from the arc-shaped trailing edge. A rotor provided with a row of blades set to an optimum inflow angle during operation, and a volute casing for recovering pressure discharged from the rotor, wherein the row of blades has an arc shape having a second radius of curvature. A pump wherein a blade having a leading edge and a blade having a sharp edge-like leading edge are arranged in a regular order. 3. The pump according to claim 1, wherein the edge-shaped leading edge blade is deformed into an arc-shaped leading edge blade having a second radius of curvature on the outer peripheral side. 4. The pump according to claim 1, wherein the edge-like leading edge is symmetrical with respect to the blade center line. 5. A rotor according to claim 1, wherein a driving magnet is provided inside the mouth ring portion of the rotor.
The pump according to any one of the above.