JPH0350502B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a partition body of a magnetic coupling, and the present invention relates to a partition body of a magnetic coupling, which maintains thermal and mechanical strength while suppressing vortices generated by a rotating magnetic field. The present invention relates to a partition body that drastically reduces current loss and greatly improves the transmission efficiency of a magnetic coupling.

(Prior art) A magnetic coupling rotates a driving side magnet and applies its rotating magnetic field to a driven side rotor through a partition, thereby generating rotational torque on the rotor and transmitting power. It is a non-contact joint, and the partition body fluidly isolates the driving side and the driven side, so it handles fluids where leakage is averse and is used for power transmission in fluid machines such as pumps, blowers, and compressors. ing.

(Problems to be Solved by the Invention) By the way, it is desirable that the partition of the magnetic coupling satisfy the following five conditions.

(a) Since it is placed in a rotating magnetic field with high magnetic flux density,
It must be a non-magnetic material, not a magnetic material that causes magnetic short-circuiting or magnetic shielding.

(b) Since it is placed in a rotating magnetic field with high magnetic flux density,
It must be a high electrical resistance material with low eddy current loss caused by this rotating magnetic field.

(c) Must have the thermal and mechanical strength to withstand the temperature and pressure of the fluid being handled.

(d) It must have chemical strength (corrosion resistance) that can withstand the corrosion of the fluid to be handled.

(e) It must have a sealing property that prevents the fluid being handled from leaking.

Conventionally, most of the bulkheads of magnetic couplings are made of resin only, and of the above five conditions, (a), (b), (d), and (e) are completely satisfied. The thermal and mechanical strength of the object (c) is inferior.

Therefore, if the fluid to be handled is at high temperature or high pressure, or if the strength of the partition wall decreases due to an increase in the diameter of the partition due to an increase in the capacity of the magnetic coupling, the partition should be replaced with austenitic stainless steel, Inconel steel, etc. If the partition wall is made of a non-magnetic corrosion-resistant steel plate, or if a resin material is required for corrosion resistance, a reinforcing body made of the steel plate and having the same shape as the partition wall body is attached to the partition body made of a resin material to increase the strength. However, the use of the steel plate causes the eddy current loss described in (b) above.

This eddy current loss is caused by the lines of magnetic force of the rotating magnetic field generated by rotating the drive side magnet of the magnetic coupling, which cross the stationary partition at right angles, causing an induced current called an eddy current in the partition. , is the Joule heat loss generated in the partition body by this eddy current.

The value of this eddy current loss W _E is determined when the partition wall is filled with no defects in its constituent materials and is formed to a constant thickness in the magnetic gap where the driving side magnet and the driven side rotor face each other. If , then the following formula
It can be calculated using (1).

W _E = π/8D ³ · L · t · B ² · ω ² · σ (W) ... (1) Here, D (m): Diameter of the cylindrical partition.

L (m): Length of magnetic gap.

t(m): Thickness of partition wall.

B (Wb/m ² ): magnetic flux density of the magnetic gap.

ω (rad/sec): Angular velocity of rotating magnetic field.

σ (Ω ^-1 /m): Specific electrical conductivity of the partition wall.

Therefore, in the above equation (1), the partition wall is made of a high electrical resistance resin material, that is, only a resin material whose intrinsic conductivity σ (Ω ^-1 /m) is generally negligible compared to the non-magnetic corrosion-resistant steel plate. , the eddy current loss W _E
(W) does not substantially occur and is ideal in this respect, but since resin materials are inherently inferior in thermal and mechanical strength, they cannot be used with metal materials such as the above-mentioned steel plate, whose tensile strength changes extremely little with temperature. In comparison, the tensile strength at room temperature is more than an order of magnitude lower, and even for materials with relatively excellent heat resistance, the tensile strength is halved when the temperature rises to around 100°C. When strength is required, the occurrence of eddy current loss is unavoidable, so it is necessary to use a metal material such as the steel plate for the partition wall.

As a result, eddy current loss occurs, which accounts for approximately 10 to 20% of the power transmitted by the magnetic coupling, resulting in an extremely low transmission efficiency of the magnetic coupling, which causes the magnetic coupling and drive motor to become larger. However, there were problems in that it was expensive and the operating cost increased.

The present invention has been made to improve the above-mentioned problems, and the partition body of the conventional magnetic coupling can only be used independently due to its thermal and mechanical strength.
Alternatively, a metal material such as a non-magnetic corrosion-resistant steel plate used as a reinforcing material for a resin material is filled to a constant thickness without any defects in the magnetic gap where the driving side magnet and the driven side rotor face each other. We focused on the fact that excessive eddy current loss occurred due to the structure of the partition wall, and we added a cup-shaped sealing part to prevent fluid leakage, and a third part made of metal to increase the axial strength. The structure is composed of a first reinforcing part and a second reinforcing part made of a metal material to increase radial strength, and both the reinforcing parts are formed to suppress generation of eddy current. Thermal and
The present invention provides a magnetic coupling partition which has excellent mechanical strength, drastically reduces eddy current loss, and greatly improves transmission efficiency compared to partitions of conventional structure using the metal material.

[Structure of the invention]

(Means for solving the problem) The partition body of the magnetic coupling of the present invention is
a cup-shaped seal to prevent fluid leakage;
A first reinforcing portion for increasing the thermal and mechanical strength in the axial direction of the sealed portion and this first reinforcing portion are mutually insulated, and the thermal and mechanical strength in the radial direction of the sealed portion is and a second reinforcing part for increasing the temperature, and the first reinforcing part is made of a plurality of rod-shaped reinforcing pieces made of a metal material, which are made approximately parallel to the axial direction and concentric with the cylindrical part of the cup-shaped sealing part. The second reinforcing portion includes a cylindrical coil made of a metal material or a plurality of rings made of a metal material arranged sequentially in the axial direction and arranged concentrically on the cylindrical portion of the cup-shaped sealing portion. This is what happens.

(Function) The partition of the magnetic coupling of the present invention is
Compared to a partition made only of resin material with the same thickness,
Both reinforcing parts, which are constructed together with the sealing part made of a resin material, are made of the non-magnetic steel whose tensile strength at room temperature is generally one order of magnitude or more superior to that of the resin material, and whose tensile strength does not decrease as markedly as the resin material due to temperature rise. As a result, the thermal and mechanical strength against the temperature and pressure of the liquid handled by the pump is significantly improved.

Furthermore, the first reinforcing part and the second reinforcing part are insulated, and eddy current generation in both reinforcing parts is extremely suppressed. Eddy current loss is drastically reduced compared to the conventional partition wall structure.

(Example) Next, an example in which the present invention is applied to a magnetic coupling pump will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a magnetic coupling pump, which is constructed by integrally connecting a centrifugal pump 2, a magnetic coupling 3, and an electric motor 4.

A cup-shaped partition 6 is disposed within the frame 5 of the magnetic coupling 3, and its flange portion 6a is attached to a resin casing 8 disposed along the inner surface of the metal casing 7 of the pump 2. They are brought into contact with each other through a ring 9, and are sandwiched between the frame 5 and the metal casing 7 and fixed in a liquid-tight manner.

The driving side magnet 10 and the driven side magnet 11 of the magnetic coupling 3 are arranged opposite to each other via the cylindrical portion 6b of the partition wall body 6,
The driving side magnet 10 is a magnet mounting member 13 inserted and fixed onto the rotating shaft 12 of the electric motor 4.
A yoke 14 is closely attached to the inner diameter of the driven side magnet 11, and this yoke 14
and the driven side magnet 11 are integrally resin molded to form a driven side rotor 15,
This driven side rotor 15 has the resin casing 8
A resin impeller 16 disposed inside is screwed.

Further, slide bearings 17, 17 are mounted on the inner diameter part of the driven side rotor 15, and these slide bearings 17, 17 are connected to the stationary shaft supported between the bottom 6c of the partition wall 6 and the resin casing 8. 18, and the driven side rotor 15 is rotatably supported.

Next, the structure of the partition wall body 6 will be explained with reference to FIG.

The partition wall body 6, whose cylindrical portion 6b is disposed in the magnetic gap 19 between the driving side magnet 10 and the driven side magnet 11, includes a cup-shaped sealing portion 20 made of a resin material, and a cup-shaped sealing portion 20 made of a resin material. A first reinforcing portion 22 that is adhered to increase thermal and mechanical strength in the axial direction, and this first reinforcing portion 22
A second reinforcing portion 24 is attached to the reinforcing portion through an insulating layer 23 to increase thermal and mechanical strength in the radial direction.

In FIG. 3, the first reinforcing portion 22
A plurality of rod-shaped reinforcing pieces 25 made of non-magnetic steel such as austenitic stainless steel and having a rectangular cross section are arranged approximately parallel to each other in the axial direction, with gaps 26 provided between them, and adjacent to the outer peripheral surface of the cylindrical part 20b of the sealing part 20. The plurality of reinforcing pieces 25 are arranged in a concentric ring shape, and one end of the plurality of reinforcing pieces 25 is welded to the end plate 27 made of non-magnetic steel adjacent to the bottom part 20c of the sealing part 20, and the other end of the plurality of reinforcing pieces 25 is Flange portion 20 of sealing portion 20
They are bent outward on the a side and locked to a ring 28 made of a resin material so as not to come into contact with each other.

Further, the insulating layer 23 is formed on the outer peripheral surface of the first reinforcing portion 22 by wrapping an insulating tape or an insulating film, or by applying varnish treatment. A cylindrical coil 20 made of steel is wound with a gap 30 between each other so that adjacent parts do not contact each other, one end of the cylindrical coil 29 is welded to the end plate 27, and the other end is engaged with the ring 28. The second
A reinforcing portion 24 is formed.

A flange reinforcing body 31 made of a metal material is fitted into the flange part 20a of the sealing part 20, and a space surrounded by the reinforcing body 31 and the flange part 20a is filled with a resin curable filler 21. By doing so, the ring 28, the plurality of reinforcing pieces 25 locked to the ring 28, and the cylindrical coil 29 are fixed.

According to the embodiment configured in this way, in the first reinforcing portion 22, the rod-shaped reinforcing pieces 25 are arranged in an annular manner substantially parallel to the axial direction, and both ends thereof are connected to the flange portion 6a of the partition wall 6. Since it is fixed to the bottom part 6c, the sealing part 20 is sealed by the pressure of the liquid handled by the pump.
The second reinforcing part 24 receives an axial pressing force acting on the bottom part 20c of the partition wall 6, that is, the sealing part 20 supports the axially pulling force. Since it is fixed to the flange portion 6a and the bottom portion 6c, it receives a radial pressing force acting on the cylindrical portion 20b of the sealing portion 20 due to the pressure of the pump handling liquid, that is, the sealing portion 20 is pulled in the circumferential direction. This will support the ability to support people.

Therefore, the partition wall body 6 has both reinforcing portions 22 and 24 formed together with the sealing portion 20 made of a resin material, compared to a partition wall body made only of a resin material and having the same thickness.
However, since it is made of non-magnetic steel, which has tensile strength at room temperature that is generally one order of magnitude better than resin materials, and whose tensile strength does not decrease as much as resin materials do when temperature rises, the temperature and pressure of the liquid handled by the pump are physical and mechanical strength are significantly improved.

Furthermore, the first reinforcing part 22 and the second reinforcing part 24
are insulated from each other in the radial direction except for both ends through an insulating layer 23, and the first reinforcing portion 22 is such that each rod-shaped reinforcing piece 25 forming this reinforcing portion 22 is Gap 27 to avoid contact
are arranged substantially parallel to the axial direction, so
Electrical resistance in the circumferential direction against eddy currents is extremely high, and the second reinforcing portion 24 is also provided with a gap 30 to prevent adjacent portions of the cylindrical coils 29 forming this reinforcing portion 24 from coming into contact with each other. Since the winding is provided with The eddy current loss is drastically reduced compared to the conventional structure of the partition using the above-mentioned partition wall body using either alone or as a reinforcing material of the resin material.

In addition, in the embodiment, the first reinforcing portion 22
In this method, one end of each rod-shaped reinforcing piece 25 was welded to the end plate 27, and the other end was locked to a ring 28 and fixed with a resin curable filler 21, but as shown in FIG. The flange portion 20a and bottom portion 20c of the sealing portion 20 may be made thicker and integrally molded with resin so that the reinforcing pieces 25 having both ends bent are included in the sealing portion 20. In this case, the resin molding However, as in the embodiment described above, welding and locking of each reinforcing piece 25 and the filling material 21
In addition, since the outer diameter portion of the sealing portion 20 becomes the insulating layer 23, it is not necessary to wrap an insulating tape or an insulating film to form the insulating layer 23 as in the previous embodiment, or There is also no need for varnish treatment.

Further, as shown in FIG. 5, the first reinforcing portion 2
2, the second reinforcing part 24 is also added to the sealing part 20.
It is also possible to encapsulate it and mold it with resin.

Furthermore, if the wire of the cylindrical coil 29 of the second reinforcing section 24 is coated with an insulating coating, this insulating coating becomes the insulating layer 23 between the two reinforcing sections 22 and 24, and this insulating coating Therefore, a gap 30 is formed between the adjacent portions of the cylindrical coil 29, so that the cylindrical coil 29 can be tightly wound as shown in FIG.
The reinforcing effect can be increased.

Next, FIG. 8 shows that the cylindrical coil 29 is tightly wound without using an insulating coating on the wire as described above, that is, in the embodiment shown in FIG. 2, the cylindrical coil 29 The adjacent portions of the cylindrical coil 29 are closely wound in contact with each other without providing a gap 30 between the adjacent portions of the cylindrical coil 29. According to this embodiment, contact resistance occurs at the location where the adjacent portions of the cylindrical coil 29 are in contact with each other. However, since this contact resistance generally has a value several hundred to several thousand times as large as the specific resistance of the non-magnetic steel that constitutes both of the reinforcing parts 22 and 24, this contact resistance causes the second reinforcing part to 2
The electric resistance in the axial direction against the eddy current of No. 4 is considerably increased, and although not shown, the rod-shaped reinforcing pieces 25 forming the first reinforcing portion 22 are disposed in contact with each other without providing the gap 26. Similarly, the electrical resistance of the first reinforcing portion 22 in the circumferential direction against eddy current is considerably increased due to the contact resistance.
It is possible to exhibit the same eddy current reduction effect as in each of the above embodiments in which the 30 is provided. Furthermore, in these cases, since there are no gaps 26 and 30 in the reinforcing parts 22 and 24, the thermal and mechanical strength of the partition wall 6 is improved, albeit slightly, and the first reinforcing part 22
In this case, the rod-shaped reinforcing pieces 25 can be easily arranged, and the cylindrical coil 29 can be easily wound around the second reinforcing portion 24.

In each of the above embodiments, the second reinforcing portion 24 is formed of the cylindrical coil 29 over the entire cylindrical portion 6b of the partition wall 6, but as shown in FIG. A cylindrical coil 29 is used only for the part to be connected, and metal rings 32a,
32b, and in place of the cylindrical coil 29, as shown in FIG. A similar effect can be obtained even if adjacent portions are arranged in sequence in the axial direction with adjacent portions in contact with each other.

Furthermore, the cross-sectional shape of each rod-shaped reinforcing piece 25 of the first reinforcing portion 22 and the cross-sectional shape of the cylindrical coil 29 or each ring 33 of the second reinforcing portion 24 may be any shape other than the above embodiments. Can be used.

Further, as for the material of the sealing portion 20, in addition to resin, materials with high electrical resistance such as glass, ceramic, and rubber may be used depending on the type and temperature of the liquid handled by the pump. In addition, the thickness of the metal material, which is used in conventional barrier ribs made only of metal materials and is filled to a constant thickness without defective parts, is determined based on the need to maintain thermal and mechanical strength. However, if the thermal and mechanical strength is provided by both reinforcing parts 22 and 24, which are made of metal and have extremely low eddy current loss, as in the present invention, the sealing part 20 has no defects and has a constant thickness. Even if a metal material filled with water is used, the thickness of this metal material can be extremely thin compared to conventional ones, so the eddy current loss in the sealing part 20 can be calculated using the above equation (1). As shown in the figure, the thickness can be made extremely small in proportion to the thickness t. That is,
In the present invention, the sealing portion 20 is not limited to non-metallic materials, and it is also possible to use the same metal material as in the past, but with a thickness significantly smaller than that in the past. Also,
The positional relationship between the reinforcing parts 22 and 24 is not limited to the above embodiment, and the first reinforcing part 22 may be formed outside the second reinforcing part 24.

The embodiments in which the present invention is applied to pumps have been described above, but it can be similarly applied to magnetic couplings for other fluid machines such as blowers and compressors. In addition to synchronous type magnetic couplings that use magnets in the rotor, there are also hysteresis type magnetic couplings that use magnetic hysteresis material for the driven rotor, and highly conductive metal materials such as copper and aluminum for the driven rotor. Of course, the present invention can also be applied to eddy current type magnetic couplings using a squirrel cage rotor and magnetic couplings using DC excitation magnetic poles on the drive side magnet.

〔Effect of the invention〕

As described above, the magnetic coupling partition of the present invention includes a cup-shaped sealing portion for preventing fluid leakage, and a cup-shaped sealing portion for increasing the thermal and mechanical strength of the sealing portion in the axial direction. A first reinforcing part and a second reinforcing part which is insulated from each other and which increases the thermal and mechanical strength of the sealing part in the radial direction, The reinforcing portion is made of a plurality of bar-shaped reinforcing pieces made of a metal material that are arranged approximately parallel to the axial direction in a ring shape concentrically around the cylindrical portion of the cup-shaped sealing portion, and the second reinforcing portion is made of a metal material. A cylindrical coil made of or a plurality of rings made of metal material arranged sequentially in the axial direction are arranged concentrically on the cylindrical part of the cup-shaped sealing part, thereby creating a partition body made only of non-metallic materials such as resin material. The chemical strength (corrosion resistance) is the same as that of the conventional partition wall, and the thermal and mechanical strength is excellent, and the eddy current loss is drastically reduced compared to the conventional partition wall structure that uses metal material alone or as a reinforcing material for resin material. As a result, the transmission efficiency is greatly improved, and the magnetic coupling and drive motor can be miniaturized, which makes it possible to provide them at low cost and reduce operating costs, making them extremely useful in industry.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment in which the present invention is applied to a magnetic coupling pump, FIG. 2 is an enlarged sectional view of the partition body in FIG. 1, and FIG. The perspective views and FIGS. 4 to 8 are sectional views showing other embodiments of different partition bodies. 3...Magnetic coupling, 6...Cup-shaped partition, 10...Drive side magnet, 11...
Driven side magnet, 15... Driven side rotor, 19
. . . Magnetic gap, 20 .
...Cylindrical coil, 30...Gap, 32a, 32b,
33...Ring, 34...Gap.

Claims (1)

[Claims] 1. A cup-shaped sealing portion for preventing fluid leakage, a first reinforcing portion for increasing the thermal and mechanical strength of this sealing portion in the axial direction, and this first reinforcing portion. and a second reinforcing part which is insulated from the sealing part and increases the thermal and mechanical strength in the radial direction of the sealing part, and the first reinforcing part is made of a plurality of rod-shaped parts made of a metal material. The reinforcing pieces are arranged parallel to the axial direction and concentrically in a ring shape around the cylindrical part of the cup-shaped sealing part, and the second reinforcing part is made of a cylindrical coil made of a metal material or a metal material sequentially arranged in the axial direction. A partition body for a magnetic coupling, characterized in that a plurality of rings consisting of the above are arranged concentrically on the cylindrical part of the cup-shaped sealing part. 2. The magnetic cup according to claim 1, wherein the second reinforcing portion is formed by abutting adjacent portions of a cylindrical coil or a plurality of rings sequentially arranged in the axial direction. ring septum. 3. A partition wall body for a magnetic coupling according to claim 1 or 2, wherein the first reinforcing portion is formed by abutting adjacent portions of a plurality of rod-shaped reinforcing pieces.