JPH07117060B2 - Fluid transfer device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fluid transfer device that rotates in a non-contact state with a pump blade that transfers a fluid (a liquid or a gas).

[Prior Art] As a pump motor having a structure similar to that of the present invention, the present inventor has known a slurry pump motor 10 as shown in FIG. 16 previously proposed.
10 is a levitation stator 1 symmetrically on both sides of a stator 11 of an ordinary general-purpose three-phase motor (hereinafter referred to as the main motor) that can be operated in liquid as the main power for driving the pump.
2 and 13 are provided, and levitation rotors 14 and 15 made of a conductor tube are provided corresponding to the levitation stators 12 and 13, and the levitation stators 12 and 13 and the levitation rotors 14 and 15 pump one end. Bearing the pump drive shaft 18 with the blades 17 fixed 1
It had a structure that floated from 9 and 20.

[Problems to be solved by the invention]

However, in the slurry pump motor 10,
In order to increase the repulsive force, it is necessary to increase the slip (S) of the levitation rotors 14 and 15, so the levitation stators 15 and 16 are excited in the direction opposite to the rotation direction of the main motor, and the frequency is changed. Since it is controlled to be low, the drive shaft
18 is barely in contact with the bearings 19 and 20, which makes it difficult to say that it is levitation. Also, the rotation speed of the main motor is extremely reduced and the exciting current of the levitation stator has a large leakage. It was found to be too large and practically useless.

The present invention has been made in view of such circumstances, and it is possible to maintain an appropriate gap between the drive shaft and the bearing, suppress the exciting current of the stator, and further facilitate the removal of the rotating portion. An object of the present invention is to provide a simple fluid transfer device.

[Means for solving problems]

The fluid transfer device according to claim 1, which is in line with the above object, has a stator disposed outside a cylindrical main casing for generating a rotating magnetic field, a pump blade disposed inside the casing, and fixed to the pump blade. A rotor made of a non-magnetic conductor cylinder having an outer diameter slightly smaller than the inner diameter of the main casing, and a magnetic cylinder made of a magnetic material having an outer diameter slightly smaller than the inner diameter of the rotor and fixed to the side casing. Is configured.

The fluid transfer device according to claim 2 is a pump having a symmetrical structure arranged inside the stator, the stator being arranged on both outer sides of a cylindrical main casing to generate a rotating magnetic field in the same direction. A blade, a rotor made of a non-magnetic material having an outer diameter slightly smaller than the inner diameter of the main casing fixed to the pump blade, and a conductor cylinder corresponding to each of the stators, and an outer diameter slightly smaller than the inner diameter of each rotor. And a magnetic cylinder made of a magnetic material and fixed to the side casing.

The fluid transfer device according to claim 3 is the fluid transfer device according to claim 1 or 2, wherein an outer casing is provided outside the cylindrical main casing, and the stator has a closed structure.

The fluid transfer device according to claim 4 is the fluid transfer device according to claim 3, wherein the inlet of the fluid transferred by the pump blade is provided in the axial direction, and the outlet is formed at a plurality of locations around the pump blade. It is configured.

Here, in the fluid transfer device according to any one of claims 1 to 4, it is necessary to levitate the rotating portion to some extent in order to bring the rotating portion out of contact with its surroundings, and it is preferable to make the rotating portion slight, For this reason, it is preferable to use blades, rotors, and the like made of a material having a small specific gravity to reduce the weight.

Further, in the fluid transfer device, when a magnetic material is present in the rotating portion, the rotational force increases, but the suction force also increases more than the rotational force. Therefore, the magnetic material is not provided in this portion.
However, if there is no magnetic body on the secondary side, the magnetic flux crossing the non-magnetic conductor in the rotating portion of the magnetic flux from the stator is reduced, resulting in a decrease in rotational force and an increase in the exciting current on the stator side. Is preferably fixed to the side casing or the like with a gap between the conductor cylinder made of a non-magnetic material that constitutes the rotor and the conductor cylinder, and this can reduce the exciting current that causes the reactive current, As a result, the conductor cylinder rotates in the gap between the magnetic body and the stator.

When a spiral type is used as the pump blade, as in the fluid transfer device according to claim 2, the liquid is sucked in from both sides and discharged in the circumferential direction, that is, the double suction type is used to balance the left and right blades. Make sure there is no thrust on the shaft.

And when it is used as a rotating part as a pump, especially as a stirrer, it is necessary to have a structure that allows the rotating part and its auxiliary equipment to be taken out easily.
For example, if the pump cylinder power generating conductor cylinder is free from the casing and the magnetic cylinder is attached to the side casing to remove the side casing, the equipment inside the inner casing can be easily removed to the outside. It is also possible to make the inside of the inner cylinder casing completely hollow.

[Action]

The operation of the fluid transfer device according to any one of claims 1 to 4 will be described in more detail. Generally, the basic condition for generating a repulsive force between the rotor and the stator to levitate the rotor from the inner lower surface of the stator is Rm × s> 1. Is to be.

Here, Rm (Rm ₁ , Rm ₂ , and Rm ₃ described below are the same) is the number of magnetic Reynolds, and Rm is the magnetic field as the magnetic gap between the stator and rotor is smaller, and the pole gap of the stator is larger. The higher the rotational speed of (that is, the smaller the number of poles and the higher the frequency), the larger the rotational speed and the repulsive force are. Therefore, the rotational speed of the magnetic field should be an appropriate value (for example, maximum value). It is selected.

If Rm is constant, the larger the rotor current and the larger the corresponding area between the rotor and the stator core, the larger the repulsive force and the rotational force.

In FIG. 5, the suction force between the stator and the rotor is + F (vertical axis upward), and the repulsive force is −F (vertical axis downward), and the slip S
(Horizontal axis) and a graph showing these relationships are shown.
P ₁ indicates slip S = 1, that is, the rotor is stopped, and P ₂ indicates that the rotor speed is the same as the synchronous speed of the stator, that is, slip S
= 0.

In curve A, Rm ₁ is small and the slippage is S ₂ point, which repels from suction and S
_It shows the case where the rotor current becomes saturated and the repulsive force becomes constant at _one point.

Curve B shows the case where Rm ₂ > Rm ₁ and the repulsive force becomes constant at the slip S ₃ point.

In curve C, the repulsive force is constant at the same slip S ₃ point as in curve B when Rm ₃ > Rm ₂ , but the saturation current of the rotor at that time is larger than that in case of curve B, and therefore the repulsive force is larger than curve B. Indicates.

In each of the A, B, and C curves, when the rotor is made of a non-magnetic conductor material and the rotor contains non-magnetic material, the attractive force is strong and almost no repulsive force appears overall.

Based on these conditions, in the present invention, if the power supply voltage and frequency are the same, the inner diameter of the stator is made larger than the inner diameter of the stator of a general-purpose motor of the same capacity, and the number of poles is appropriately reduced. There is.

However, even if the rotor is a completely non-magnetic conductor, an attractive force is generated when the rotation speed of the rotor approaches the synchronous speed. Therefore, in the present invention, the pump blades are connected and a load is exerted on the pump blades, so that a slip S is generated and a repulsive force is generated between the rotor and the stator.
This allows the rotor, which is a conductor cylinder, to rotate in a floating state.

In order to improve the efficiency, the maximum effect is to reduce the gap between the stator core and the fixed magnetic body on the secondary side. Therefore, if the thickness of the conductor cylinder as the rotor is reduced, the saturation current will decrease and the repulsive force will decrease. Is reduced.

Therefore, in the fluid transfer device according to claims 1 to 4,
Since the rotor made of a conductor cylinder is arranged inside the stator that generates a rotating magnetic field, a rotating force is generated in the rotor, and a fixed magnetic cylinder made of a magnetic material is arranged inside the rotor. In the magnetic flux generated from the stator, since the magnetic cylinder serves as a magnetic path, the magnetic flux intersecting with the rotor increases and the leakage magnetic flux decreases.

Particularly, in the fluid transfer device according to the second aspect, since the pump blade has a symmetrical structure, it is possible to cancel the thrust load generated thereby.

In the fluid transfer device according to the third aspect, since the stator has a closed structure, it is possible to use the fluid transfer device by, for example, submerging it in a liquid.

In the fluid transfer device according to claim 4, since a plurality of outlets for the fluid transferred by the pump blades are formed in the periphery, the fluid sucked from the axial direction is discharged from the outlet and again sucked from the inlet. Therefore, it can be used as an efficient stirrer.

〔Example〕

Next, as an example for explaining the basic structure of the present invention, which embodies the present invention, with reference to the attached drawings, a description will be given of one using a spiral double suction type pump blade.

First, FIGS. 1 and 2 show an example in which the fluid transfer device of the present invention is applied to a spiral double suction type pump 23 having suction ports in both directions. FIG. 1 is an overall sectional view thereof and FIG. It is an AA sectional view of FIG.

The outer casing 24 of the main body of the pump 23 is made strong,
There is no particular limitation on the material. Stator mount
The inner surface of the stator core 28 is brought into close contact with the outer circumference of an inner cylindrical casing 27, which is an example of a casing that fixes the stator 25 to the mounting base 25. The inner cylinder casing 27 is made of a non-magnetic material having high electric resistance, and is thinned within a range in which strength is allowed. This is because the magnetic gap between the inner cylinder casing 27 and the later-described magnetic cylinders 48 and 49 is made as small as possible.

The inner cylinder casing 27 is provided with appropriate numbers of liquid circulation holes 30 and 31 with filters at appropriate places, and the inner cylinder and outer cylinder casing 2
This is because a part of the liquid conveyed by the pump is circulated between 7 and 24, the stator 26 is immersed in the liquid, the stator is cooled, and the stator is excluded from the explosion-proof test. Therefore, the winding of the stator coil is coated with a special material so that sufficient insulation can be obtained, and its thickness is several times or more that of a general-purpose motor so as to withstand abrasion and the like.

When the carrier liquid cannot be used for cooling the stator 26, the liquid circulation holes 30 and 31 with a filter are not provided and the cooling liquid is supplied from the outside between the inner cylinder and the outer cylinder casings 27 and 24. A cooling liquid inlet pipe 32 and an outlet pipe 33 for circulation are provided. And between the inner cylinder casing 27 and the inner cylinder outer cylinder casing
Always keep the fluid pressure of 24 equal.

The stator 26 is installed symmetrically in a centrally distributed manner, and a spiral double suction type pump blade 34 having a structure in which two symmetrically formed pump blades are superposed is installed in the center of the inner cylinder casing 27.

The outer diameter of the pump vanes 34 is made slightly smaller than the inner diameter of the inner cylinder casing 27.

A conductor cylinder 3 that has the same outer diameter as the pump blade 34 and is made of a hollow non-magnetic material having an appropriate thickness to form a rotor.
5 and 36 are fixed to this pump blade 34 symmetrically. Its length corresponds completely to the stator core 28.

Rotational force and repulsive force are generated by the conductor cylinders 35 and 36.

Both side surfaces of the outer casing 24 are closed by side casings 37 and 38. The side casings 37 and 38 are the outer casing 24
And bolts 37a and 38a to connect them and make them removable.

A cylinder in which bearings 39, 40 are provided in the center of the side casings 37, 38 and ring-shaped permanent magnets 41, 42 are fixed to the inner surfaces thereof, and poles are aligned so as to repel the permanent magnets 41, 42, respectively. -Shaped permanent magnets 43 and 44 are fixed to the ends of the rotation center shaft 45, and suction pipes 46 and 47 for sucking liquid into the casing from the outside are attached to the side casings 37 and 38, respectively.

Magnetic cylinders 48, 49 are fixed inside the side casings 37, 38 with their axes aligned, the outer diameter of which is slightly smaller than the inner diameters of the conductor cylinders 35, 36, and the thickness saturates the magnetic flux from the stator. The thickness is set so as not to be applied, and the length is set so as to be completely compatible with the stator core, and the material thereof has a high magnetic permeability and suppresses the generation of eddy current.

The pump blade 34 and the conductor cylinders 35, 36 are made as light as possible, and a rotation center shaft 45 is passed through the center of the blade to fix the pump blade 34 thereto.

The rotation center shaft 45 is sufficient to support the weight of the pump blades 34 when the rotation of the pump blades 34 is stopped, and may be hollow so that buoyancy is generated in the liquid in order to reduce the weight. .

The repulsive force generated by the permanent magnets 41, 42 and the permanent magnets 43, 44 may be a repulsive force sufficient to keep them in a non-contact state with a minute gap therebetween.

With such a structure, when the pump blade 34 rotates, the conductor cylinder 3
Reference numerals 5 and 36 respectively rotate in the center of the inner cylinder casing 27 with a slight gap between the inner cylinder casing 27 and the magnetic cylinders 48 and 49, and when stopped, the repulsive force between the permanent magnets 41 and 42 and the permanent magnets 43 and 44. Is supported by the bearings 39, 40 in a non-contact manner.

In this stopped state, the conductor cylinders 35 and 36 and the magnetic cylinders 48 and 49 are in the upper part, and the pump blades are in the lower part.
It is assumed that the inner diameter and the diameter of each of the conductor cylinders 35, 36 and the inner cylinder casing 27 are determined so as not to contact each other.

Next, an experimental example of the pump 23 configured as described above will be described.

The stator has an inner diameter of 82 mm, the power supply is AC220V3Φ60Hz, and two 0.75Kw2P symmetrically converted two general-purpose motors are used. The pump blade is a spiral single suction type.

Conductor cylinder −3 mm thickness Al cylinder Magnetic cylinder −5 mm thickness Magnetic steel sheet lamination And, assuming that the rotation center axis is at the center of the entire device,
Each gap was set as follows.

Blade shaft-bearing clearance 0.9mm (bearing is pentagonal) Inner cylinder casing-conductor cylinder approx. 1.2mm Conductor cylinder-magnetic material cylinder approx. 1.2mm Also, the center of rotation is stainless solid shaft and the total weight of rotating part Since it was about 6 kg and the reaction force to the pump blade was about 1.5 kg, a total load of 7.51 kg would be applied.

Next, in order to measure the levitation of the rotation center axis, use a differential transformer type measuring instrument with an accuracy of 1 μm, operate with water at room temperature as the fluid, and the rotation center axis contacts the bearing parts at both ends when stopped. As it is (so no permanent magnet is used)
The gap at that time was set to 0.

When the operation is started under the above conditions, the center axis of rotation is about
It floats up to 450 μm, the shaking at that time is 10 μm or less, and the rotation speed is 2
It was 500 RRM (slip about 30% or more).

And the efficiency as a pump was about 60%. This experimental example is the result of testing by modifying a general-purpose motor, but it was confirmed that the rotor floated and rotated without contact. As a result of examination, it seems that the weight of the rotating part can be reduced to about 3 kg, and if the design of the stator is optimized, the flying height will be further increased.

3 and 4 show a state in which the skew grooves 50 are provided in the conductor cylinders 35 and 36 shown in FIG. 1, respectively.

The skew groove 50 serves to rectify the current flowing in the conductor cylinder 35 (36 is the same), and it is possible to expect an increase in rotational force and repulsive force. The skew groove 50 allows the conductor cylinders 35 and 36 to penetrate therethrough. Is necessary, and it is advisable to fill the gap with a synthetic resin or the like which is a non-magnetic electric non-conductor.

In FIG. 1, 51 is a discharge pipe, 52 is a stator core end, and 53 is a supply wire for the stator.

Next, a case where the fluid transfer device according to the present invention is applied to the axial flow type pump 54 will be described with reference to FIGS. 6, 7, and 8.

The basic technique is exactly the same as that of the pump 23 shown in FIG. 1, except that an axial flow blade 55 is used as a pump blade and a stator 56,
The conductor cylinder 57 and the magnetic cylinder 58 are one set.

In this embodiment, one or several units of a flange are inserted in series in the middle of a transport pipe for the target liquid (hereinafter referred to as the main pipe), and the target liquid is continuously stirred while transporting the target liquid.

Since one side of the outer casing 59 is the suction side (IN) and the other side is the discharge side (OUT), the rotation center shaft 60 receives the thrust, so that the thrust is not contacted inside the bearing portion 61 as shown in FIG. Attach a disk-shaped permanent magnet 62 to receive the rotation center axis
In addition to utilizing the repulsive force with the permanent magnet 63 attached to the end portion of 60, as described above, when the rotation of the axial flow vane 55 is stopped, the whole is supported in a non-contact manner. A cylindrical permanent magnet 64 is attached to the bearing 61 (and the other is the same), and a permanent magnet 65 that generates a corresponding repulsive force is attached.

The bearings 61, 66 are mounted on central bosses 71, 72 which are respectively supported by several arms 69, 70 extending from side casings 67, 68.

Since the target liquid passes between the arms 69 and 70, the cross section of the arm has a shape with little resistance to the flow direction, for example, as shown by the arrow P in FIG.

Incidentally, FIG. 9 shows an example in which the pump 54 is inserted in series in the middle of the main pipe 73. Here, 73a and 73b show flanges for connection.

FIG. 10 and FIG. 11 show that in the pump 23 or 54, when the target liquid contains a mixture of slurry or the like, the liquid smoothly passes through the bearing portion and the bearing portion 39 (same for 40) or
The means for reducing the wear of 61 (same as 66) are shown respectively.

As shown in FIG. 10, the bypass pipe 74 is shown in FIG.
In the figure, a bypass hole 75 is provided to allow the target liquid to flow inside the bearing portions 39 and 61.

Next, FIGS. 12 to 15 explain an example in which the fluid transfer device of the present invention is applied to the stirring device 76.

FIG. 12 is an overall vertical cross-sectional view of the stirring device 76. As the pump blade 77, the same spiral double suction type as that shown in FIG. 1 is used.

A stirrer, which is an example of a suspension supporting member, is obtained by reinforcing a stirrer body 78 including a fluid transfer device with a reinforcing frame 79, and combining a connecting shaft 80, a reinforcing ring 81, a suspending boss 82, and a suspending arm 83. The main body 78 is suspended from the ceiling of the tank by the lowering shaft 84, and the fluid transfer device is used as an agitator in the target liquid.

A shaft bearing / sealing device 85 is installed at a portion where the suspension shaft 84 penetrates the ceiling of the stirring tank. Since the suspension shaft 84 only moves up and down and does not need to be rotated, sealing is easy.

The power supply line 87 to the stator 86 of the stirrer main body 78 goes out of the stator, reaches the hanging shaft 84 along the reinforcing frame 79, passes through the shaft, goes out of the tank, and is connected to the power supply.

Discharge ports 88 from the pump blades 77 are provided at several places around the outer casing 89 as shown in FIG.

That is, in this apparatus, the target liquid is sucked from above and below the agitator body 78 and discharged from the center in all directions.

Here, FIG. 13 is a view taken along the line DD of FIG. 12, and FIG.
EE sectional view of the figure (however, the cross section of the pump blade is not shown)
Fig. 15 shows a sectional view of the apparatus installed in a stirring tank,
In the figure, 90 is an inner casing, 91 is a side casing, 92 is a bearing portion, 93 is a bearing support arm, 94 is a boss, 95 is a rotation center axis, 96 is a conductor cylinder, and 97 is a magnetic body. A cylinder, 98 is a stirring tank ceiling plate, 99 is a rack attached to the suspension shaft 84, 100 is a pinion that meshes with the rack 99, 101 is a drive device for the pinion, and 102 is a bearing and sealing device. Indicates.

In each figure, the arrow indicates the flow direction of the liquid. Arrow R
Indicates the target liquid, and the arrow r indicates the flow direction of the cooling liquid.

Although each of the above-mentioned embodiments shows the case where the liquid is used as the fluid, the present invention is also applied to the case where the gas is used as the fluid.

〔The invention's effect〕

In the fluid transfer device according to any one of claims 1 to 4, as is apparent from the above description, it is possible to rotate the rotor blades in a non-contact manner, non-seal, and have a structure capable of removing the rotating portion. Therefore, it has a long life and, in some cases, can be maintenance-free.

Therefore, it can be used as a chemical industrial pump that does not leak, a nuclear power pump that must absolutely prevent leaks, a stirrer for pharmaceuticals and biotechnology, or a slurry liquid pump, but it does not have sliding parts, so it can be used for a long time. Hold the life of
It can exert excellent effects.

[Brief description of drawings]

FIG. 1 is an overall sectional view when the fluid transfer device of the present invention is applied to a spiral double suction type pump, and FIG.
Fig. 3 is a sectional view taken along the line A-A in the drawing, Fig. 3 is a side view in which the conductor cylinder of the fluid transfer device is provided with a skew groove, Fig. 4 is a sectional view taken along the line BB in Fig. 3, and Fig. 5 is shown. FIG. 6 is a graph showing the relationship between the suction force and the repulsive force between the stator and the rotor and the slip, FIG. 6 is an overall sectional view when the fluid transfer device of the present invention is applied to an axial flow type pump, and FIG. 7 is FIG. 8 is a sectional view taken along line CC in FIG. 8, FIG. 8 is a side view showing a usage state of the pump, and FIG. 9 is a side view showing a usage state of the pump.
10 is a partial sectional view showing another example of the bearing portion of the pump shown in FIG. 1, FIG. 11 is a sectional view showing another example of the bearing portion of the pump shown in FIG. 6, and FIG. 12 is the present invention. FIG. 13 is an overall sectional view when the fluid transfer device of FIG. 11 is applied to an agitator, FIG. 13 is a sectional view taken along the line DD in FIG. 12, and FIG. 14 is a sectional view taken along the line EE in FIG. FIG. 16 is a schematic sectional view of the stirring device attached to a stirring tank, and FIG. 16 is a sectional view for a slurry pump according to a conventional example. [Explanation of symbols] 23 …… pump, 24 …… outer casing, 25 …… mounting base, 26 …… stator, 27 …… cylindrical casing, 28 ……
Stator core, 29 …… Magnetic cylinder, 30,31 …… Liquid circulation hole, 32 …… Coolant inlet, 33 …… Coolant outlet, 34 …… Pump blade, 35,36 …… Conductor cylinder, 37,38 ...... Side casings, 39, 40 …… Bearing parts, 41 to 44 …… Permanent magnets, 45 …… Rotation center shafts, 46,47 …… Suction pipes, 48,49 …… Magnetic cylinders, 50
...... Skew groove, 51 …… Discharge pipe, 52 …… Stator core end, 53 …… Supply electric wire, 54 …… Pump, 55 …… Axial flow vane (pump wing), 56 …… Stator, 57 …… Conductor cylinder , 58
...... Magnetic cylinder, 59 …… Outer casing, 60 …… Rotation center shaft, 61 …… Bearing part, 62 to 65 permanent magnets, 66 …… Bearing part, 6
7, 68 …… Side casing, 69, 70 …… Arm, 71, 72
...... Boss, 73 …… Main pipe, 74 …… Bypass pipe, 75 …… Bypass hole, 76 …… Stirring device, 77 …… Pump blade, 78 …… Agitator body, 79 …… Reinforcing frame, 80 …… Coupling Axis, 81 …… Reinforcing ring, 82 …… Suspension boss, 83 …… Suspension arm, 84
...... Suspension shaft, 85 …… Bearing part and sealing device, 86 …… Stator, 87 …… Power supply part, 88 …… Discharge port, 89 …… Outer casing, 90 …… Inner casing, 91 …… Side casing, 92 …… Bearing part, 93 …… Bearing support arm, 94 …… Boss, 95 …… Rotation center shaft, 96 …… Conductor cylinder, 97 …… Magnetic cylinder, 98 …… Stirring tank ceiling plate, 99 …… Rack, 100 …… pinion, 101 …… driving device, 102 …… bearing and sealing device

Claims (4)

[Claims] 1. A stator for generating a rotating magnetic field arranged outside a cylindrical main casing, a pump blade arranged inside the casing, and fixed to the pump blade,
A rotor made of a non-magnetic conductor cylinder having an outer diameter slightly smaller than the inner diameter of the main casing, and a magnetic cylinder made of a magnetic material having an outer diameter slightly smaller than the inner diameter of the rotor and fixed to the side casing. A fluid transfer device comprising: 2. A stator for generating a rotating magnetic field in the same direction, which is arranged on both sides of a cylindrical main casing so as to face each other, a pump blade having a symmetrical structure arranged inside the stator, and the pump blade. A rotor made of a non-magnetic material having an outer diameter slightly smaller than the inner diameter of the fixed main casing, and the conductor cylinders respectively corresponding to the stators;
A fluid transfer device having an outer diameter slightly smaller than the inner diameter of each rotor and a magnetic cylinder made of a magnetic material fixed to the side casing. 3. The fluid transfer device according to claim 1, wherein an outer casing is provided outside the cylindrical main casing, and the stator has a closed structure. 4. A fluid transfer device used as an agitator according to claim 3, wherein an inlet for the fluid transferred by the pump blade is provided in the axial direction, and outlets are formed at a plurality of locations around the pump blade.