JPH1162877A - Turbomachine with motor built-in - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turbomachine in which simplification of a sealing structure and improvement of sealing performance are achieved by eliminating a rotational part penetrating through a casing by making a motor to a built-in type, and the high efficient operation in a multiple stage impeller is realized. SOLUTION: A turbomachine with a motor built-in is constituted of an impeller 1 for improving energy of fluid by centrifugal force, casings 10, 11 provided with a suction port 16 and a discharge port 17 on the front surface side end and the rear surface side end, for surrounding the whole impeller 1 so that a shaft may not be projected, and for rotatably supporting it, magnetic bearings 4, 5, 6, 7 to be interposed among the impeller and the casings and for supporting the impeller 1 without lubricating to the front surface side and the back surface side, and a motor, composed of a rotor 2 provided on the impeller 1 side and a stator 3 provided on the casing 10 side so as to face the rotor and for driving the impeller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbo-type fluid machine which is a driven machine used in a gas compressor or the like, and more particularly to a motor-incorporated turbo machine in which a motor as a driving means is integrally built.

[0002]

2. Description of the Related Art A typical prior art relating to a centrifugal compressor which is a kind of turbo type fluid machine is disclosed in Japanese Patent Publication No. 7-6518.

The above-mentioned centrifugal compressor has the following configuration. That is, this centrifugal compressor has a shaft that can compress a gas body by the centrifugal force brought by it, an electromagnetic bearing that supports both ends of the shaft in a non-contact manner with the shaft, and a plurality of the shafts sequentially. And a coupling for connecting the shafts in series in the order in which the gas bodies can be compressed and to allow mutual misalignment of the axial centers, and a plurality of the connected shafts together with their electromagnetic bearings to integrally support the shafts. It has a case body having a gas inlet at one end and a discharge port at the other end, and a sealing means around the shaft provided on the side of the case body having the discharge port. .

[0004] In such a centrifugal compressor, since a compressor realizing a high head can be realized in one casing, only a portion where the seal device takes out the input shaft is required.
The danger of gas leakage is reduced and the reliability is high, and there is no need to worry about the core being out of order.

[0005]

In the above-mentioned centrifugal compressor, although only one sealing device is required, this is where the input shaft of the axle for connecting to the separately provided motor penetrates the casing. In addition, a shaft sealing device having a complicated structure corresponding to a high head is indispensable on the motor input shaft side, which raises manufacturing costs and requires a lot of trouble in maintenance.

[0006] In the case of a centrifugal compressor used for gas compression, as the gas is sequentially compressed by a multi-stage axle (impeller), the gas is reduced from the first stage to the last stage although the volume is reduced. Since each of the axles has a structure that is driven at a constant rotational speed, the specific speed of each stage fluctuates, so that the rear stage deviates from the optimum specific speed, and the efficiency may be reduced.

The present invention has been made to solve such problems, and an object of the present invention is to provide a motor built-in type by eliminating a rotating portion penetrating a casing. It is an object of the present invention to provide a turbomachine capable of simplifying a seal structure and improving sealing performance, and in particular, realizing high-efficiency operation in the case of a multi-stage impeller.

[0008]

The present invention has the following configuration to achieve the above object. That is, the present invention relates to a turbo-type fluid machine similar to a driven machine such as a pump or a compressor, which includes an impeller for increasing the energy of fluid by centrifugal force, and a fluid suction device for a front end and a rear end. A casing having a mouth and a discharge port, respectively, and entirely surrounding the impeller so that the shaft does not protrude and rotatably supporting the impeller; and an impeller on a front side and a back side of the impeller.
A magnetic bearing interposed between the casings to support the impeller without lubrication; an impeller driving motor including a rotor provided on the impeller side and a stator provided on the casing side opposed to the rotor; And a turbo machine with a built-in motor.

According to the present invention, there is also provided a turbo machine with a built-in motor as described in the preceding paragraph, wherein the impeller has a single-stage impeller structure having single-row or multi-row blades, and the casing comprises a front casing and a rear casing. And a fluid-tight integrated connection by face-to-face mating, and the impeller has at least two stages of single-row or multi-row blades, each having an independent rotating shaft. A multi-stage impeller structure, wherein the casing comprises at least one intermediate casing and a rear casing interposed between a front casing and an adjacent impeller, and are integrally joined in a fluid-tight manner by face-to-face mating; The motor is configured to be provided corresponding to each impeller.

According to the present invention, in the turbomachine with a built-in motor according to the preceding and second aspects, the magnetic bearings are provided corresponding to the center boss on the rear side of the impeller and the outer peripheral edge of the front side of the blade. That the magnetic bearings are provided respectively corresponding to the center boss portions on the front side and the back side of the impeller, the motor is provided corresponding to the front side inner peripheral edge of the blade in the impeller, and the motor is provided. The impeller is provided so as to correspond to the center boss on the back side, and the impeller has a hole formed by being deeply recessed in the center from the back side in the axial direction. And a motor is provided corresponding to the hole.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1A is a cross-sectional view showing a main structure of a centrifugal compressor according to the first embodiment of the present invention, and FIG. 1B is a side view taken along line AA in FIG. is there.

The centrifugal compressor shown in FIG. 1 is an example of a compressor having a single-stage impeller structure, in which a casing including a front casing 10 and a rear casing 11 and a shaft do not project into the casing. And an impeller 1 rotatably supported in the housing. The front side casing 10 is disposed so as to surround the front part of the impeller 1, has an inner wall provided close to and facing the front part of the impeller 1, and is located just before the center of the impeller 1 at the front end. A suction port 16 for sucking the gas to be compressed is opened at the end face located at the position. On the other hand, the rear casing 11
Is provided so as to surround the outer peripheral surface portion and the rear surface portion of the impeller 1, and is provided with a scroll 15 provided so as to be in contact with and surround the outer peripheral surface portion of the impeller 1, and close to and opposed to the rear surface portion. Discharge port 17 (see FIG. 1B)
) Is opened at an appropriate end face of the rear end,
The gas compressed by the rotating impeller 1 is led out of the discharge port 17 through the scroll 15.

The front casing 10 and the rear casing 11 are formed as a casing having a structure in which the rear face of the front casing 10 and the front face of the rear casing 11 can be integrally joined by face-to-face mating. The two casings 10 and 11 can be integrally connected in a fluid-tight (air-tight) manner by tightening the O-ring 12 with a plurality of bolts 13 with the O-ring 12 interposed between the mating surfaces.

In this centrifugal compressor, the impeller 1 is rotatably supported by the two casings 10, 11 via magnetic bearings without lubrication. The magnetic bearing for supporting the impeller 1 is provided at a position corresponding to a center boss on the back side of the impeller 1 and an outer peripheral edge on the front side of the blade. That is, the magnetic bearing stator 4 housed in a ring-shaped groove recessed in an inner wall portion of the front casing 10 which is close to and opposed to the front outer peripheral edge of the blade, and the impeller in the rear casing 11 1 and a magnetic bearing stator 6 housed in a ring-shaped groove recessed in an inner wall portion which is close to and opposed to the peripheral surface portion of the rear side center boss portion.
Is supported. The magnetic bearing stators 4 and 6 have the same structure, and are formed by an electromagnet formed by winding a coil around a core having a U-shaped cross section and a ring shape.

On the other hand, laminations 5 and 7 for magnetic bearings functioning to reduce eddy current loss are embedded in portions of the impeller 1 where the magnetic bearing stators 4 and 6 are close to and opposed to each other. , 6 and the corresponding magnetic bearing laminations 5, 7 constitute a pair of magnetic bearings. In this example, the radial sensor 8 and the thrust sensor 9 are combined with those magnetic bearings.
Are embedded in the opposing inner wall surface of the rear casing 11, and the impeller 1 is
-The magnetic force of each magnetic bearing stator 6, 4 is automatically controlled so that the gap length between the casings is kept constant. When a magnetic bearing having a sensorless structure is used, it goes without saying that the radial sensor 8 and the thrust sensor 9 are unnecessary.

The centrifugal compressor has a built-in motor as a drive source for driving the impeller 1. This motor includes a rotor 2 formed by lamination integrally attached to an outer surface portion of the impeller 1 that is close to and facing the casing, and windings attached to an inner surface portion of the casing that is close to and facing the rotor 2. And in the case of the example shown in FIG.
The impeller 1 is provided corresponding to a small-diameter peripheral portion on the front surface side of the blade. That is, by laminating a lamination formed by laminating a large number of thin steel plates such as an annular silicon steel plate at a position where the blade diameter is minimum at the front edge of the blades in the impeller 1, the lamination is formed. (Rotor) 2. On the other hand, an electromagnetic coil is wound around an annular core on the inner wall surface of the front side casing 10 at a position close to and facing the rotor 2. The windings are recessed to form a stator (stator) 3, and a rotating magnetic field generated when the stator 3 is energized and an induced electromotive force generated in the rotor 2 cause the impeller 1 to rotate in a predetermined rotation direction. Can be given.
Although only the lamination has been described as an example of the rotor 2, the present invention is not limited to this, and it is needless to say that the rotor 2 may function as a motor rotor.

In such a centrifugal compressor, since the stator 3 and the magnetic bearing stator 4 are mounted on the front casing 10 and the magnetic bearing stator 6 is mounted on the rear casing 11, the electric motor connected to each wire loop is provided. Cable 1
4 can be easily taken out from the casing surface via the inner layer portion, and the casing can be disassembled and the impeller 1 can be easily taken out without being affected by the rotating magnetic field and the motor. Furthermore, both casings 1
Reference numerals 0 and 11 designate a surface-matching structure, and an O-ring 1
2 is provided, the internal fluid is not leaked to the outside at all, and in addition to the structure in which the rotating shaft does not pass through the casing and is drawn out to the outside, the fluid tightness is very high. There are advantages.

FIG. 2 is a sectional view showing a main structure of a centrifugal compressor according to a second embodiment of the present invention. The centrifugal compressor shown in this figure has the same structure as the centrifugal compressor shown in FIG. 1 except that the arrangement of the motor is different. That is, the centrifugal compressor in the illustrated example is an impeller 1
Is provided with a hole 18 formed in the center thereof so as to be deeply recessed in the axial direction from the back side, while a motor including the rotor 2 and the stator 3 is provided corresponding to the hole 18. Is what you do. For example, a cylindrical hole 18 which is deeply recessed in the axial direction from the rear side at the axial center of the impeller 1 is provided with a rotor 2 made of an annular lamination on the peripheral wall of the hole 18 in a concentric relationship. While the impeller 1 is mounted on both casings 10 and 11.
The stator 3 is arranged so as to be fixed at the center of the shaft of the hole 18 and fixed to the rear casing 11 in a state of being incorporated therein.

Such a centrifugal compressor has an advantage that the rotor 2 is disposed at the center of the impeller 1 so that the impeller 1 having a characteristic that is light with respect to the rotational moment can be provided. There is also a feature that the connection on the electrical connection surface becomes very easy.

FIG. 3 is a sectional view showing a main structure of a centrifugal compressor according to a third embodiment of the present invention. The centrifugal compressor shown in this drawing has the same structure as the centrifugal compressor shown in FIG. 2 except that the arrangement of magnetic bearings provided on the rear casing 11 is different. That is, in the centrifugal compressor of the illustrated example, the ring-shaped magnetic bearing stator 6 has a ring formed by recessing the inner wall portion of the rear casing 11 which is close to and opposed to the end face of the rear center boss of the impeller 1. It is a structure that is housed in a groove. In the case of this example, the magnetic bearing stator 6 is provided on the inner wall portion of the back side casing 11 which is provided close to and opposed to the peripheral surface portion of the center boss portion on the back side of the impeller 1 as compared with the example shown in FIG. In this case, the difference is that the magnetic support force in the thrust direction is formed to be stronger than that in the radial direction, and such a modified example can be applied as needed. In each of the examples shown in FIGS. 1 to 3, since the axial distance between the magnetic bearing stator 4 and the magnetic bearing stator 6 is considerably large, a large moment for the magnetic supporting force is given, and stable shaft support can be achieved. Has advantages.

FIG. 4 is a sectional view showing a main structure of a centrifugal compressor according to a fourth embodiment of the present invention. The centrifugal compressor shown in this figure has the same structure as the centrifugal compressor shown in FIG. 2 except that the arrangement of the motor is different. That is, the centrifugal compressor of the illustrated example is characterized in that the motor is provided to correspond to a portion of the impeller 1 near the rear side outer periphery. The rotor 2 is formed by an annular lamination housed in a ring-shaped groove that is recessed in a portion of the impeller 1 that is closer to the outer periphery on the rear side, while the stator 3 is close to and opposed to the rotor 2 of the rear casing 11. It is formed by an annular winding which is recessed on the inner wall surface portion at the location where it is formed. Such a centrifugal compressor has an advantage that a large rotating torque can be obtained because the rotating magnetic field of the motor is located at a large radius in the impeller 1.

FIG. 5A is a sectional view showing the structure of a main part of a centrifugal compressor according to a fifth embodiment of the present invention, and FIG. A side view taken along arrow B is shown. The centrifugal compressor shown in FIG. 5 is an example of a compressor having a multi-stage impeller structure, and includes front casings 10, 1, and 1.
Or more intermediate casing 20 and rear casing 11
And a casing comprising a cylindrical wall body 21 which is collectively fitted to each of the casings and hermetically surrounds the periphery thereof;
A multi-stage impeller 1 is provided in the casing such that the shaft is not protruded, and the rotating shafts are individually and independently rotatably supported.

The front side casing 10 is disposed so as to surround the front part of the first stage impeller 1, and has an inner wall provided close to and facing the front part of the impeller 1.
A suction port 16 (not shown) for sucking the gas to be compressed is opened at an end face of the front end, which is located immediately before the center of the impeller 1. Each of the intermediate casings 20 is interposed between the adjacent impellers 1, and is close to an inner wall provided near and facing the outer peripheral surface portion and the rear surface portion of the front-stage impeller 1 and the front surface of the rear-stage impeller 1. -While having the inner wall provided facing, the rear side casing 11 is provided with the inner wall provided close to and facing the outer peripheral surface portion and the back surface of the impeller 1 at the last stage, and the end surface at an appropriate position at the rear end portion. A discharge port is opened in the portion.

In such a centrifugal compressor, the magnetic bearings and the motor are arranged in each impeller 1 as shown in FIG.
The proximity of the impeller 1 to a predetermined location of each casing corresponding to
They are provided at opposing locations. In this case, the manner of installation in the magnetic bearing and the motor is based on the same procedure as described in each example of FIGS. 1 to 4, and detailed description is omitted here. The electric cable 14 connected to a magnetic bearing disposed on the front side of the intermediate casing 20 to support the rear side of
As shown in (b), by inserting the return vane 19 provided in the compressed gas passage through a hole penetrating through the center of the return vane 19, the return vane 19 can easily pass through the intermediate casing 20 from the cylinder wall 21 to the outside. It is possible to take out.

FIG. 6 is a sectional view showing a main structure of a centrifugal compressor according to a sixth embodiment of the present invention. The centrifugal compressor shown in this figure is an example of a multi-stage open impeller system, and has the same structure as the centrifugal compressor shown in FIG. 5 except that the arrangement of magnetic bearings and motors is different. . In the centrifugal compressor shown in the drawing, the magnetic bearings are provided corresponding to the center boss portions on the front side and the rear side with respect to each impeller 1, respectively, and the motor is mounted on the center of the impeller 1 on the rear side. There is a feature in the structure provided for each boss.

In this centrifugal compressor, the magnetic bearings provided on the center bosses on the front side and the back side of each impeller 1 are provided so that the magnetic support force acts in both the thrust direction and the radial direction. Are arranged corresponding to the corners of
The gap support 22 installed on the inner wall portion of each casing that is close to and opposed to the impeller controls the magnetic bearing force of each magnetic bearing so that the gap between the casing and the impeller is kept constant. .

On the other hand, the respective motors composed of the rotor 2 and the stator 3 are provided on the peripheral surface of the center boss on the back side of the impeller 1 with the same structure as in the above-described embodiments. 1 can be independently driven to rotate. The connection of the electric cable 14 connected to the magnetic bearing and the stator disposed in relation to the intermediate casing 20 is provided in the compressed gas passage as in the fifth embodiment illustrated in FIG. The return vane 19 is inserted through a hole provided through the center of the return vane 19, so that the cylindrical wall 2 passes through the inside of the intermediate casing 20.
It is possible to easily take it out from the outside.

As described above, in the multi-stage centrifugal compressor illustrated in FIGS. 5 and 6, since each impeller is driven independently, each of the impellers has an optimum ratio by controlling the rotation of the motor. It is possible to drive at speed,
Highly efficient compression operation can be realized.

[0029]

The present invention is embodied in the form described above and has the following effects.

The turbomachine according to the present invention has a structure in which the casing entirely surrounds the impeller so that the rotating shaft does not protrude to the outside, and a motor is provided integrally with the impeller and housed in the casing. And a structure in which the impeller and the motor are supported by a magnetic bearing in a non-lubricated manner, whereby no casing penetrating portion for removing the rotating portion is required, and In addition, there is no danger area where the internal fluid such as a gas that gives energy may leak, and the reliability is greatly improved.

Further, by forming the casing integrally in a face-to-face manner by at least two casings including a front side and a rear side, it is possible to provide a casing with high sealing performance under a simple structure, By combining with a built-in motor type structure, it is possible to obtain a turbomachine with further improved fluid tightness at low cost.

According to the present invention, in a multi-stage turbomachine, each impeller is individually supported by a magnetic bearing, and a driving motor is integrally connected to each impeller so as to be built therein. Has a structure that can be operated individually, so that each impeller can be operated at an optimum specific speed, compared to a conventional turbo machine in which all the impellers are operated at the same rotation speed. Particularly, there is an advantage that a highly efficient operation can be achieved in the case of the gas compression operation. In addition, since an intermediate coupling is not required, compactness can be achieved.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing a main structure of a centrifugal compressor according to a first embodiment of the present invention, and FIG. 1B is a side view taken along line AA in FIG. 1A. is there.

FIG. 2 is a cross-sectional view illustrating a main structure of a centrifugal compressor according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a main structure of a centrifugal compressor according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a main structure of a centrifugal compressor according to a fourth embodiment of the present invention.

FIG. 5A is a cross-sectional view showing a main structure of a centrifugal compressor according to a fifth embodiment of the present invention, and FIG. 5B is a side view taken along line BB in FIG. 5A. is there.

FIG. 6 is a cross-sectional view illustrating a main structure of a centrifugal compressor according to a sixth embodiment of the present invention.

[Explanation of Signs] 1 ... Impeller, 2 ... Rotor, 3
... stator, 4 ... magnetic bearing stator, 5 ... lamination for magnetic bearing, 6 ... magnetic bearing stator, 7 ... lamination for magnetic bearing,
8 ... radial sensor, 9 ... thrust sensor,
Reference numeral 10: front side casing, 11: rear side casing, 12: O-ring, 13: bolt,
14 ... electric cable, 15 ... scroll, 16 ... suction port, 17 ... discharge port, 18 ... hole, 19 ... return vane, 20 ... intermediate casing, 21 ...
Cylindrical wall, 22 ... gap sensor,

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02K 21/14 H02K 21/14 M

Claims (8)

[Claims] 1. A turbo-type fluid machine similar to a driven machine such as a pump or a compressor, comprising: an impeller for increasing the energy of fluid by centrifugal force; and a fluid inlet at a front end and a rear end. And a casing that has a discharge port and surrounds the impeller entirely so that the shaft does not protrude and rotatably supports the impeller.
A magnetic bearing interposed between the casings to support the impeller without lubrication; an impeller driving motor including a rotor provided on the impeller side and a stator provided on the casing side opposed to the rotor; A turbo machine with a built-in motor. 2. The impeller according to claim 1, wherein the impeller has a single-stage or multi-row impeller structure, and the casing includes a front casing and a rear casing, and is integrally connected in a fluid-tight manner by face-to-face matching. Item 7. A turbo machine with a built-in motor according to Item 1. 3. The impeller has a multi-stage impeller structure having at least two stages of single-row or multi-row blades and independent rotation shafts, and a casing is interposed between the front-side casing and an adjacent impeller. 2. A turbomachine with a built-in motor according to claim 1, wherein the turbomachine is composed of at least one intermediate casing and a rear casing, and is integrally connected in a fluid-tight manner by face-to-face matching, and a magnetic bearing and a motor are provided for each impeller. . 4. The turbomachine with a built-in motor according to claim 1, wherein the magnetic bearings are provided corresponding to the center boss on the back side and the outer peripheral edge on the front side of the blade in the impeller. 5. The turbomachine with a built-in motor according to claim 1, wherein the magnetic bearings are provided corresponding to the center boss portions on the front side and the rear side of the impeller, respectively. 6. The turbomachine with a built-in motor according to claim 1, wherein the motor is provided corresponding to an inner peripheral edge of a front surface of the blade in the impeller. 7. The turbomachine with a built-in motor according to claim 1, wherein the motor is provided corresponding to the center boss on the rear side of the impeller. 8. The impeller according to claim 1, wherein the impeller is provided with a hole formed in the center thereof so as to be deeply recessed in the axial direction from the rear side, and a motor is provided corresponding to the hole. A turbo machine with a built-in motor according to the description.