WO2009013204A1

WO2009013204A1 - Electrical driver with integrated fan

Info

Publication number: WO2009013204A1
Application number: PCT/EP2008/059302
Authority: WO
Inventors: Richard Brune; Norbert WÖHNER
Original assignee: Siemens Aktiengesellschaft
Priority date: 2007-07-20
Filing date: 2008-07-16
Publication date: 2009-01-29
Also published as: DE102007033882A1

Abstract

The invention relates to an electrical driver (10) with a cylindrical primary part (2) which has a single-phase or polyphase winding and permanent magnets, and having a cylindrical secondary part (3), which is arranged within the primary part (2) and has means for guiding a magnetic flux, wherein the cylindrical secondary part (3) is in the form of a fan.

Description

description

Electric drive with integrated fan

The invention relates to an electric drive having a cylindrical primary part, which has a single- or multi-phase winding and permanent magnets, and having a cylindrical secondary part which is arranged within the primary part and has means for guiding a magnetic flux.

Rotary electric drives have a primary part and a secondary part, which are referred to as stator and rotor. In this case, electric drives can be built up in such a way that the stator and / or the rotor can have permanent magnets. The stator is the part which has electrically energizable windings. The stator is designed in particular as a fixed part and the rotor as a moving part.

Stator and rotor for electrical machines generally have a laminated core, consisting of individual electric sheets, wherein the winding or permanent magnets for generating magnetic fields are arranged on the laminated core. In order to guide the main magnetic flux between the stator and the rotor, toothed plates are usually used in winding-carrying stators and / or rotors. In the grooves of the laminated core, the winding is arranged.

From DE 10 2004 045 992 Al an electric machine is known whose secondary part has no active means, such as energizable windings or permanent magnets, for generating electric fields. In a permanent-magnet synchronous motor with a permanent magnet-free secondary part, the primary part has energizable windings and permanent magnets, wherein the secondary part has only a tooth structure of, for example, an iron-containing material. Furthermore, an electric drive has a bearing system comprising a plurality of bearings, since the components, ie in particular rotor and stator, must be stored. The storage system is designed for example by means of ball bearings or plain bearings.

If electric drives for smoke and heat exhaust systems, such as fans, fans, fans and combustion gas engines, used, the fans or fans also have bearings.

Conventional bearings, such as ball bearings or bearings, are very maintenance intensive. Especially in fans for fire gas smoke, the electric drive is exposed to high temperatures. The requirements are that such a combustion gas engine, ie an electric drive with blower, with storage system at about 400 ⁰ C ambient temperature must be functional for two hours. But the bearings are extremely heat resistant.

In fluidic applications, the electric drive i. d. R. arranged in the region of the cooling air flow, which means that the drive motor is located practically in the flow channel and thus reduces the possible cross section for the cooling air flow. Especially with fans for

Fire gas smoke removal unnecessarily limits the need for entrainment in case of fire.

In order to reduce the cross section of the electric drive in the region of the cooling air flow and thus to improve the flow characteristics, it is possible to carry out the electric drive, for example, without terminal box.

For higher speeds and to reduce maintenance, it is also possible to use magnetic bearing systems, but which require a high level of control engineering effort. In addition, magnetic bearings can only be used with low impact forces on the rotor. A disadvantage of such a magic netlagersystem is that control technology two systems, namely drive motor and magnetic bearings must be mastered.

The object of the invention is to provide an electric drive for particular heat and smoke extraction systems, the fan or fan has improved flow characteristics.

This object is solved by the features of claims 1 and 21. Advantageous developments can be found in the dependent claims.

The electric drive according to the invention is an internal rotor machine with a cylindrical primary part, d. H. a stator, and a cylindrical secondary part, d. H. a rotor formed. The cylindrical stator has a single-phase or multi-phase winding and permanent magnets. The stator thus has several means for generating and guiding magnetic fields and fluxes.

The secondary part is free of means for generating magnetic fields and has only means for guiding magnetic fluxes and fields. According to the invention, the cylinder-shaped secondary part, i. H. the cylindrical rotor, at the same time designed as a fan.

The secondary part is formed as a hollow cylinder and has an outer circumferential surface and an inner lateral surface. In this case, the outer lateral surface has the means for guiding magnetic fluxes and fields.

Preferably, the outer surface of the secondary part has a tooth structure with a plurality of teeth. In particular, the teeth of the secondary part are arranged offset axially relative to one another and / or in the circumferential direction of the secondary part, so as to reduce cogging torques of the secondary part. On an inner circumferential surface of the hollow cylindrical secondary part, a fan wheel is arranged. Advantageously, the secondary part is mechanically fixedly connected to the fan wheel, so that a secondary part with integrated fan wheel is formed. The fan practically acts as a secondary part or the secondary part as a fan. The fan wheel is enclosed, for example, by an outer rim, wherein the outer rim forms the secondary part with a tooth structure.

In a further embodiment, the primary part is subdivided into at least two primary sub-segments, wherein each primary sub-segment is formed as a self-standing functional component with a single- or multi-phase winding and permanent magnets. In particular, the primary part is divided in its circumferential direction and / or axial direction into a plurality of primary part segments. By means of primary sub-segments of the electric drive can be built modular, wherein depending on the desired size or power of the electric drive, the corresponding number of primary sub-segments can be arranged.

The primary part segments are preferably arc-shaped and arranged in a circle around the secondary part in the circumferential direction. Characterized in that the primary part segments are arcuate, a uniform cylindrical air gap between the primary part and the secondary part is formed. All primary segment segments together form the primary part.

In a further advantageous embodiment of the invention, two primary subsegments are arranged axially one behind the other and arranged in pairs in a circular manner in the circumferential direction around the secondary part. This results in the possibility of extending the secondary part with integrated fan wheel a- xial and thus to generate a larger cooling air flow.

In a further advantageous embodiment, the secondary part is arranged bearingless with fan. A stockless Order is possible because in the primary part or the individual primary part segments in addition to a winding and permanent magnets are arranged, whereby a positioning, ie a bearingless arrangement of the secondary part on the magnetic forces of the permanent magnets of the primary part is possible.

In particular, the position of the secondary part can be determined and regulated by means of electromagnetic force flows between primary part and secondary part. For this purpose, the primary part or the primary part segments advantageously means for monitoring the air gap between the primary part and the secondary part. Such means serve to detect a radial distance to the secondary part. Such means are for example designed as sensors which determine or measure the radial distance between primary part or primary part segment and secondary part.

In a further embodiment, a frequency converter is associated with each primary sub-segment, wherein a radial positioning of the secondary part takes place by means of the frequency converter. Preferably, in each case a frequency converter is integrated in a primary part segment or a frequency converter in the primary part.

Furthermore, a higher-level control and / or regulating unit is provided for regulating the position of the secondary part.

The provided electric drive according to the invention with a fan improves the flow characteristics of a fan driven directly in this manner, since the cross section for the air flow is no longer reduced by a drive motor installed in the air flow. In particular, in the case of fire gas smoke extraction can be achieved by the arrangement of the primary part or stator outside the air duct, a much higher air flow. Because the secondary part is operated without bearings, there are no measures and also no bearing components necessary, thereby saving costs and time.

In order to make the operation of the secondary part, in particular of the fan wheel, safe, the secondary part has at least one safety bearing. As a safety device in case of failure or unforeseen instabilities catch bearings are used. A safety bearing is an additional bearing that is ineffective in normal operation. In fast-running, supercritically operated secondary parts or rotors, large rotor deflections often occur. If the rotor deflection exceeds the bearing clearance, the rotor attaches itself to the safety bearing. The contact force from the backup bearing to the rotor limits the rotor deflection.

The design of the electric drive according to the invention with the described Lüfterradsystem is scalable under various aspects. Thus, when dispensing with the magnetic bearing functionality, the secondary part, which is then arranged on a shaft, can be used with only one primary part segment. In this case, the force input acts only in a sub-segment of the secondary part. For larger power requirements then further primary sub-segments and thus force entry points can be placed. In this way, redundant or highly available drive concepts can be realized.

In a further embodiment, the cooling of the primary part, in particular of the primary part segments with integrated frequency converters, can take place by means of a cooling system. For this purpose, the primary part to a cooling system, which acts as a central cooling system, for example, based on a liquid cooling. Alternatively, each primary section segment can have its own cooling unit, wherein the cooling units are either coupled over an entire cooling circuit and form a cooling system, or operate autonomously. Additional cooling systems or cooling units, such as special thermal insulation or special cooling drive, such. As water cooling, an almost unlimited operation, even at much higher temperatures of the electric drive with fan can be guaranteed.

The load distribution of the frequency converter can be further improved with known torque or force compensation regulations. This coordinating task may also be performed by the equally central instance, i. the higher-level control and regulation unit, the magnetic bearing control are taken over. It is also possible to transfer the task of the central instance to a single frequency converter or to distribute this to all frequency converters. Redundancy groups can be formed that increase the availability of the entire system.

In the following description of further features and details of the invention in conjunction with the accompanying drawings using exemplary embodiments are explained in more detail. In this case, features and relationships described in individual variants can in principle be applied to all exemplary embodiments. In the drawings show:

1 shows a permanent-magnet synchronous linear motor according to the prior art,

2 shows a permanent-magnet electric drive in rotatory design,

3 shows an electric drive according to the invention with integrated fan wheel,

4 shows the electric drive according to the invention according to FIG. 3 in a side view,

5 shows an electric drive according to the invention with a first control concept,

6 shows an electric drive according to the invention with a second control concept, and

7 shows a further embodiment of an electric drive according to the invention with integrated fan. 1 shows a permanent-magnet electric drive 1, which is designed as a synchronous linear motor, according to the prior art, as it is known for example from DE 10 2004 045 992 Al.

The synchronous linear motor 1 has the primary part 2 and the secondary part 3. The secondary part 3 has no active means for generating magnetic fields, but is constructed only as a tooth structure of, for example, iron-containing material. In contrast, the primary part 2 has several means for generating magnetic fields. These means for generating magnetic fields are the polyphase, in particular three-phase, winding 4 and the permanent magnets. 5

2 shows a permanent-magnet electric drive 1 in rotary design. The linear embodiment according to FIG. 1 is now converted into a rotary embodiment. The electric drive 1 is designed as a permanent-magnet synchronous motor. The primary part 2 is designed as a stator and has a single-phase or multi-phase, in particular three-phase, winding and permanent magnets. The winding and the permanent magnets are not shown.

The primary part 2, also referred to as stator, is subdivided into four primary subsegments, or stator segments, 2a to 2d, each stator segment 2a to 2d being designed as a stand-alone stator component with winding and permanent magnets.

Furthermore, the secondary part 3, which is designed as a rotor, shown, which has a tooth structure with the teeth 6. The secondary part 3, also referred to as rotor, is formed as a hollow cylinder. Likewise, the primary part 2 is cylindrical, in particular hollow cylindrical, formed. This results in a cylindrical air gap 7 between the primary part 2 and secondary part. 3 The primary part segments 2a to 2d are configured arcuate and arranged circumferentially in the circumferential direction around the secondary part 3. In this case, the four segments 2a to 2d are arranged uniformly, ie at the same distance from one another. Because the segments 2a to 2d are arc-shaped, a uniform air gap 7 is formed.

FIG. 3 shows an electric drive 10 according to the invention with integrated fan wheel 8. The secondary part 3 has a hollow-cylindrical design, the teeth 6 being arranged on its outer circumferential surface for forming a tooth structure. By means of this tooth structure, the main magnetic flux is conducted between primary part 2 and secondary part 3.

On the inner circumferential surface of the secondary part 3, the fan 8 is arranged. The secondary part 3 and the fan 8 are mechanically firmly connected to each other, so that a secondary part 3 is formed with integrated fan 8. The secondary part 3 thus assumes two functions; on the one hand the function of a fan and on the other hand the function of an electrical / magnetic component. For example, the region of the secondary part 3 which has the electrical / magnetic function, which are essentially the teeth 6, is made of iron-containing material. The fan 8 is made for example of plastic.

The secondary part 3 with integrated fan 8 may also be formed as a one-piece component, for example as a casting.

It can be clearly seen in FIG. 3 that an optimum flow cross-section for the fan wheel 8 is present, since the electric drive 10 with primary part 2 and secondary part 3 are not located in the cross-section of the air flow, but outside.

4 shows the electric drive 10 according to the invention according to FIG. 3 in a side view. It is only the two segments 2 a and 2 b of the primary part 2 and the secondary part 3 are shown.

FIG. 5 shows the electric drive 10 according to the invention in a first control concept. Each primary part segment 2 a to 2 d is assigned a means for detecting the radial distance of a primary part segment 2 a to 2 d to the secondary part 3. The segment 2a is associated with a distance meter IIa, wherein the distance meter IIa is formed, for example, as a sensor. The segment 2b is a distance meter

IIb, the segment 2c associated with a distance meter 11c and the segment 2d a distance meter Hd. The distance meters Ha to Hd designed as sensors measure the distance between the respective primary part segment 2a to 2d to the secondary part 3.

Furthermore, a frequency converter 12a to 12d is assigned to each primary sub-segment 2a to 2d. The primary section 2a is associated with the frequency converter 12a, the primary section 2b of the frequency converter 12b, the primary section 2c of the frequency converter 12c and the primary section 2d of the frequency converter 12d. Each primary sub-segment 2a to 2d is fed in each case via its associated frequency converter 12a to 12d. The frequency converter 12a to 12d in turn are connected to a power supply network 13, which is formed for example as a three-phase network.

The position of the secondary part 3 can now be controlled by means of the frequency inverters 12a to 12d via the electromagnetic forces acting between the primary part 2 and the secondary part 3. Depending on which frequency or current feeds a primary sub-segment 2a to 2d, corresponding electromagnetic forces occur between the primary sub-segments 2a to 2d and the secondary part 3, the distance being adjustable in accordance with frequency or current. 6 shows the electric drive 10 according to the invention in accordance with a second control concept. The control concept according to FIG. 6 essentially corresponds to the concept according to FIG. 5, a control and regulation unit 14 now being arranged as a higher-level instance for monitoring or regulating (or also controlling) the developing magnetic bearing system. The distance meter IIa to Hd are each connected to the control and regulation unit 14. The control unit 14, in turn, is also connected to the frequency converters 12a to 12d.

The distance meters Ha to Hd measure the distance between a primary sub-segment 2a to 2d and the secondary part 3. The measured or determined values are forwarded to the control and regulation unit 14. For this purpose, a specific value or a specific interval of values is stored in the control and regulation unit 14 in which the distance between primary sub-segments 2a to 2d and secondary part 3 should move. The values determined by the distance meters Ha to Hd are compared with the stored value in the control and regulation device 14 and a possible deviation by a feedback 15, which includes a drive to the frequency converter 12a to 12d corrected. Thus, the position of the secondary part 3 with integrated fan wheel 8 can be continuously monitored and regulated accordingly.

7 shows a further embodiment of the electric drive 10 according to the invention. According to this embodiment, two primary part segments are arranged axially one behind the other and arranged in pairs around the secondary part 3 in a circle. In FIG. 7 it can be seen that an axially arranged primary subsegment 2e is provided in addition to the primary subsegment 2a. Also, adjacent to the primary sub-segment 2b, a neighboring primary sub-segment 2f is arranged. Overall, eight secondary sub-segments 2a to 2h are arranged around the secondary part 3, wherein not all primary sub-segments are shown. Furthermore, it can be seen in FIG 7 that the secondary part 3 with integrated fan (not shown) is arranged on a shaft 9. Due to the now axially enlarged secondary part 3 and thus an axially enlarged fan 8, an arrangement on a shaft 9 for stabilization makes sense.

The embodiment according to FIG. 7 offers the advantage that a greater cooling capacity can be achieved on account of the enlarged fan wheel 8. The arrangement of axially adjacent stator segments 2a to 2h also offers the possibility of making an axial position position control in addition to a radial position control of the secondary part 3.

Claims

claims

1. Electric drive (10) with a cylindrical primary part (2), which has a single- or multi-phase winding and permanent magnets, and with a within the Pri ^¬ märteils (2) arranged cylindrical secondary part (3), which means for guiding a magnetic Flow on ^¬ points, characterized in that the cylindrical secondary part (3) is designed as a fan.

2. Electric drive (10) according to claim 1, characterized in that the secondary part (3) is formed as a hollow cylinder and on an outer circumferential surface, the means for guiding a magnetic flux on ^¬ and on an inner circumferential surface of a fan (8) ^¬ ordered.

3. Electric drive (10) according to claim 2, characterized in that the secondary part (3) me ^¬ chanically fixed to the fan wheel (8) is connected, so that a secondary part (3) with integrated fan wheel (8) is ^{ausgebil ¬} det.

4. Electric drive (10) according to claim 2 or 3, characterized in that the outer circumferential surface of the secondary part (3) has a tooth structure with Tough ^¬ NEN (6).

5. Electric drive (10) according to claim 4, characterized in that the teeth (6) of Sekun ^¬ därteils (3) axially and / or circumferentially of the secondary part (3) offset from one another to reduce cogging moments are arranged.

6. Electric drive (10) according to any one of the preceding claims, characterized in that the primary part (2) in at least two primary sub-segments (2a, 2b, 2c, 2d, 2e, 2f) is divided, each primary ^¬ subsegment (2a, 2b, 2c, 2d, 2e, 2f) formed as a stand-alone func ^¬ onsfähiges component with a single- or multi-phase winding and permanent magnets is.

7. Electric drive (10) according to claim 6, characterized in that the primary part (2) is divided in its circumferential direction and / or axial direction into a plurality of primary part segments (2a, 2b, 2c, 2d, 2e, 2f).

8. Electric drive (10) according to claim 6 or 7, characterized in that the primary ^¬ partial segments (2 a, 2 b, 2 c, 2 d, 2 e, 2 f) are arcuate and circular in the circumferential direction around the secondary part (3) to form a uniform Air gap (7) are arranged.

9. An electrical drive (10) according to any one of claims 6 to 8, characterized in that in each case two primary part segments (2a, 2b, 2c, 2d, 2e, 2f) are axially toward ^¬ behind the other are provided and in each case in pairs circular circumferentially around the Secondary part (3) are arranged.

10. Electric drive (10) according to one of the preceding claims, characterized in that the secondary part (3) can be arranged without bearing.

11. Electric drive (10) according to one of the preceding claims, characterized in that a position of the secondary part (3) via magnetic

Power flows between primary part (2) and secondary part (3) he ^¬ mediate and controllable.

12. Electric drive (10) according to one of the preceding claims, characterized in that the primary part (2) comprises means for monitoring the Luftspal ^¬ tes (7) between the primary part (2) and the secondary part (3) on ^¬ has.

13. Electric drive (10) according to claim 12, characterized in that the primary ^¬ part (2) comprises means for detecting a radial distance to Se ^¬ kundärteil (3).

14. Electric drive (10) according to one of claims 6 to

13, characterized in that each primary part segment (2a, 2b, 2c, 2d, 2e, 2f) is associated with each ^¬ tel for detecting a radial distance to the secondary part (3).

15. Electric drive (10) according to one of claims 6 to

14, characterized in that each Primärteilsegment (2a, 2b, 2c, 2d, 2e, 2f) a Frequenzum- (12a, 12b, 12c, 12d) is assigned, wherein a radial positioning of the secondary part (3) by means of the frequency converter (12a 12b, 12c, 12d).

16. Electric drive (10) according to claim 15, wherein a frequency converter (12a, 12b, 12c, 12d) is integrated into a primary subsegment (2a, 2b, 2c, 2d, 2e, 2f).

17. Electric drive (10) according to one of the preceding claims, characterized in that a higher-order control and / or regulating unit (14) is provided for positioning the secondary part (3).

18. Electric drive (10) according to one of the preceding claims, characterized in that the primary part (2) has a cooling system.

19. The electric drive (10) of claim 18, wherein: each primary segment (2a, 2b, 2c, 2d, 2e, 2f) comprises a cooling unit.

20. Electric drive (10) according to one of the preceding claims, characterized the secondary part (3), in particular the fan wheel (8), has at least one safety bearing.

21. Electric drive (10), dadurchgek nzeichnet that the electric drive (10) is designed according to one or more of the preceding claims 1 to 20 and for use in smoke and Wärmeeab ^¬ zugsanlagen, in particular fire gas engines, is provided.