Source: https://patents.google.com/patent/DE102007036692A1/en
Timestamp: 2020-07-11 06:25:59
Document Index: 439204817

Matched Legal Cases: ['art 72', 'art 105', 'art 105', 'art 105', 'art 105', 'art 27', 'art 308', 'art 46']

DE102007036692A1 - Fan - Google Patents
DE102007036692A1
DE102007036692A1 DE102007036692A DE102007036692A DE102007036692A1 DE 102007036692 A1 DE102007036692 A1 DE 102007036692A1 DE 102007036692 A DE102007036692 A DE 102007036692A DE 102007036692 A DE102007036692 A DE 102007036692A DE 102007036692 A1 DE102007036692 A1 DE 102007036692A1
DE102007036692A
Wolfgang Dr. Amrhein
2006-09-22 Priority to DE102006046434 priority Critical
2006-09-22 Priority to DE102006046434.6 priority
2007-08-03 Application filed by Ebm Papst St Georgen GmbH and Co KG filed Critical Ebm Papst St Georgen GmbH and Co KG
2008-03-27 Publication of DE102007036692A1 publication Critical patent/DE102007036692A1/en
A fan (100) has an electronically commutated drive motor (52) for driving fan blades (26). This drive motor (52) has a stator (50) connected to a bearing tube (54) and a rotor (22) provided with a shaft (34). The shaft (34) is mounted radially non-contact in the bearing tube (54) by means of passive radial magnetic bearings (16, 18). It is axially displaceable relative to the bearing tube (54) and is in drive connection with a rotor magnet (44), which has a first magnetic yoke (46). Also provided is a second magnetic yoke (27) connected to the shaft (34), which is approximately bell-shaped and in which the inner side (59) of the outer rim (28) forms an outer boundary for a substantially cylindrical air gap (57) in which in operation a radial magnetic flux (55 ') extends in a predetermined direction. Furthermore, a plunger coil (64) is provided, which dips into the cylindrical air gap (57) and is mechanically connected to the bearing tube (54), so that upon axial displacement of the plunger coil (64) relative to the cylindrical air gap (57) the position the shaft (34) relative to the bearing tube (54) changes.
The The invention relates to a fan with an electronically commutated drive motor for driving Fan blades. One such drive motor has a stator and one with a shaft provided rotor, and its shaft is mounted on the stator.
Become a fan Today mostly driven by electronically commutated motors. These are, especially for reasons the life, but also because of the bearing noise, a bearing of the fan desired without mechanical bearings. This especially with high-speed fans, such as for ventilation of Servers are used.
Arrangements with permanent magnets are known for storage without mechanical bearings. This is also referred to as "non-contact storage" or as "magnetically supported drives." There are two types of so-called passive bearings, ie bearings that work without external energy supply:
• Magnetic bearings that are axially stable but radially unstable.
• Magnetic bearings that are radially stable but axially unstable.
It It is an object of the invention to provide a new fan.
To the invention, this object is achieved by the subject of the Claim 1. This allows a squat and mechanically robust construction, as a fan anyway a fan needs that through the rotor of the electronically commutated motor is driven. In the invention, the space within the impeller used to create a cylindrical air gap. In this an approximately radial magnetic field is generated in which a plunger is located, which mechanically connects to the stator of the motor connected is. Dependent From the current in this plunger coil, the axial position of the fan wheel and thus the rotor are actively controlled relative to the stator, whereby one actively controlled magnetic thrust bearing of simple construction receives. This minimizes friction and noise while of operation and increased the life. Here it is possible to control the flow through the To keep the plunger coil low and thus an impairment the fan efficiency to reduce.
On this way succeeds in fans with any mounting position (horizontal, vertical, etc.) a frictionless and non-contact Ensure the rotor is running. Because the fan wheel is free floats, the life of the fan is increased and its noise reduced. Such an arrangement may also be the weight of the rotor and other, acting in the axial direction forces, for. B. flow forces, electromagnetic forces Vibratory forces Shock forces. This will also be apparent from the description below. By the Elimination of the bearing friction can also improve the efficiency.
1 a longitudinal section through the rotor of a fan, in which on the rotor shaft 34 annular permanent magnets are arranged, which components of passive magnetic radial bearings 16 and 18 are,
2 a longitudinal section through the 1 associated stator including a arranged on this plunger coil 64 , which forms part of an actively controllable magnetic thrust bearing,
3 a representation of the fan after the 1 and 2 in the assembled state; the fan is shown in a state in which the active thrust bearing is activated, ie that the rotor "floats",
4 the course of the magnetic flux in the rotor of 1 as used in the active magnetic thrust bearing,
5 an exploded view of the fan of 3 .
6 a representation analog 4 which shows in a highly schematic representation the operation of a fan according to a preferred embodiment of the invention,
7 a representation of the basic structure of an eddy current sensor 33 as it can be used in one embodiment of the invention,
8th a schematic representation of the evaluation of the electrical signals of the eddy current sensor 33 .
9 a representation of the output signal of the eddy current sensor 33 depending on a distance size d,
10 a circuit which shows how the current i in a plunger coil 64 depending on Output signal of the eddy current sensor 33 and other sizes,
11 a representation showing four basic types of non-contact magnetic radial bearings,
12 a detailed description of the bearing design 262 of the 11 .
13 a representation of the field line course in the bearing design 262 of the 11 and 12 .
14 a detailed description of the bearing design 254 of the 11 .
15 a representation of the field line course in the bearing design 254 of the 11 and 14 .
16 a variant of the bearing design 254 of the 14 ; In this variant, the risk is reduced that demagnetize the magnetic rings of the radial bearing,
17 a representation of the bearing design 214 to 12 and 13 in three different axial positions,
18 a representation which for the bearing design 254 to 17 for different axial positions of the bearing, the bottom in 18 are drawn, the generated axial force F Z and the bearing stiffness S r ,
19 an enlarged view of detail XIX the 18 .
20 the representation of a preferred control arrangement 198 as with the fan after the 1 to 6 can be used to store this contactless and with low energy consumption,
21 a representation analog 3 , but in the de-energized state of the fan, in which the rotor shaft 34 with magnetically generated bias against a disc 72 is applied,
22 an excerpt from 21 showing the location of the lower radial bearing 18 in the de-energized state of the fan shows
23 The representation of a start routine, as it runs after switching on a fan to bring the non-contact bearing in an operating position,
24 the representation of a first variant, which serves in operation to change the axial position of the fan shaft,
25 a second variant, and
26 a third variant of an arrangement for changing the axial position of the rotor shaft.
In The following description will be the same or the same Parts are designated by the same reference numerals and usually only once described. spatial Terms such as above, below, left, right refer to the respective one Figure.
1 shows the rotor 22 a fan 100 , The rotor 22 has a rotor bell 24 with a floor 30 in which an upper shaft end 32 a rotor shaft 34 in an aluminum hub 31 is attached. The lower end of the rotor shaft 34 is with 35 designated. The aluminum hub 31 belongs to an eddy current sensor 33 ( 7 . 8th ), which also includes a sensor coil 66 ( 2 ) belongs. It is powered by a high frequency current 230 fed and thus generates a high-frequency magnetic field, for example, with a frequency of 1 MHz. When changing the distance d ( 7 ) between the coil 66 and the aluminum hub 31 the damping of the coil changes 66 , and this can be used as an electrical signal U m ( 9 ). This signal provides a measure of the distance d between the sensor coil 66 and the hub 31 It can be used with a reference value Z soll ( 20 , Comparator 214 ). By a position controller 216 This position signal, there called Z, is controlled to an optimized setpoint Z soll to the rotor 22 in an optimal axial position relative to the stator 50 to keep. This will be described below.
The lower end 35 the wave 34 is approximately dome-shaped and serves in an emergency, or after switching off the fan 100 , in cooperation with a part 72 as a mechanical thrust bearing or as a so-called fishing camp.
For passive radial bearing of the shaft 34 are two passive magnetic radial bearings 16 ( 3 , above) and 18 ( 3 , Below), which are constructed identically in the embodiment. The upper radial bearing 18 has two magnet rings 38 at the upper end 32 the wave 34 , and about this two stationary magnetic rings lying opposite 56 in a bearing tube 54 , see. 2 , The lower radial bearing 18 has two magnet rings 40 at the bottom 35 the wave 34 , and about this two stationary magnetic rings lying opposite 58 in a bearing tube 54 , see. 2 , All of these rings are magnetized in the axial direction and consist of permanent magnetic material, eg SmCo or NdFeB. The magnet rings 38 and 40 be through a spacer sleeve 42 at a defined distance from each other the held. Likewise, the magnet rings 56 and 58 through a spacer sleeve 60 ( 2 ) held in this defined distance from each other. In this type of repulsive radial bearings 16 . 18 , as below 11 . 14 . 17 . 18 and 19 is described in all details and there with 254 is called, the spacers should 42 and 60 have exactly the same length and preferably be electrically conductive, for example made of aluminum.
2 shows a longitudinal section through a fan housing 51 , as well as through the stator 50 a pancake motor 52 that drives the fan 100 serves. (Instead of a pancake motor 52 For example, an internal or external rotor motor can also be used.) The housing 51 is preferably integral with the bearing tube 54 formed in its interior, in this embodiment, the two upper magnetic rings 56 and the two lower magnet rings 58 are located. The spacers 42 . 60 consist of the same material and have an identical length. They are chosen so that the greatest possible distance between the upper magnetic rings 38 . 56 on the one hand and the lower magnet rings 40 . 58 guaranteed on the other hand. This achieves that the tilting stiffness of the radial bearing assembly is increased, which is formed by these magnetic rings, as is known per se. Also put the spacers 42 . 60 sure that when the upper radial bearing 16 is in its axialkraftfreien center position, the same for the lower radial bearing 18 applies. (For the topic of axial forces, see the comments at 6 .)
The top magnetic ring 56 lies with its upper end 62 against a paragraph 74 ( 2 ) of the bearing tube 54 at. To support the lower end of the bottom magnet ring 58 serves a plant disc 72 ( 3 ), which are in a recess 70 of the bearing tube 54 is attached. The magnetic rings can be attached eg by gluing.
The pancake motor 52 is in this embodiment on the outside of the bearing tube 54 attached. He has a flat (flat) air gap 101 that goes up through the bottom 107 a rotor magnet 44 is limited. According to 5 can the rotor magnet 44 be four-pole. The motor 52 has a so-called ironless stator 102 , which in the embodiment four sector-shaped ironless coils 103 ( 5 ) that has in a carrier part 105 are made of plastic. Below the carrier part 105 can be a magnetic inference 109 be provided from a weichferromagnetischen material which in 3 indicated by dashed lines. Optimal is when this inference 109 together with the rotor magnet 44 rotates. A soft iron ring 46 serves as a magnetic return for the rotor magnet 44 , and also serves as a flux guide for an actively controllable non-contact thrust bearing.
To the fan 100 heard a circuit board 73 on the electronic components 75 are arranged, including a digital signal processor (DSP) 76 which shows both the axial position of the rotor 22 relative to the stator 50 regulates, as well as the commutation of the currents in the electronically commutated motor 52 controls, cf. 10 , At the top of the carrier part 105 is a plunger coil 64 fixed, which in a cylindrical air gap 57 ( 3 ) dips and serves the position of the rotor 22 relative to the bearing tube 54 to stabilize in an optimized position. This is not a fixed position, but a position Z soll , which depends on the forces that are in operation on the shaft 34 act in the axial direction. This will be included below 20 explained.
The sensor coil 66 of the eddy current sensor 33 is frontally on a heel 63 ( 2 ) at the upper end 62 of the bearing tube 54 arranged. At the lower end 68 has the bearing tube 54 a recess 70 in which the investment disc 72 ( 3 ), eg by screwing. During normal running of the fan 100 the wave is floating 34 free, ie without the contact washer 72 to touch. At standstill, and with large axial disturbance forces, the contact washer serves 72 as so called catch camp, ie the wave 34 then lies with her knoll 36 against the disc 72 on, cf. 21 , which also runflat properties arise. In the same way, such a fishing camp also at the upper end of the bearing tube 54 be provided. Likewise, at least one radial fishing camp can be provided, in which the mechanical gap of the radial slide bearing is smaller than the gap of the adjacent magnetic radial bearing 16 respectively. 18 , This ensures that in case of a possible tilting of the rotor 22 the radial fishing camp is mechanically stressed first. The radial magnetic bearings 16 . 18 therefore remain intact in such a case.
The tracking tip 36 the wave 34 is preferably formed as a smooth, rounded end, which together with the contact disk 72 forms a thrust bearing, which is also referred to as a thrust bearing. The radial fishing camp is not shown.
It becomes advantageous between the track tip 36 and the washer 72 a thin (preferably 0.2 to 0.3 mm) layer of a plastic with a low coefficient of friction inserted, for example made of PTFE, so that the toe 36 during start-up, run-out, and in emergencies, forms an emergency bearing with this thin layer.
3 shows a longitudinal section through the overall structure of a fan 100 who from the Schei benläufermotor 52 is driven. In 3 has the rotor 22 in operation no point of contact with the stator 50 , Rather, the rotor 22 Non-contact in the radial direction through the passive radial bearings 16 . 18 stored. Axial it is contactless by the actively controllable thrust bearing 57 . 64 and those of the two radial bearings 16 . 18 generated axial force F Z ( 6 ; 18 ) stored. The components of the active thrust bearing are an axially magnetized magnet ring 48 , a soft ferromagnetic ring 46 , a second magnetic inference 27 on the rotor 22 , the cylindrical air gap 57 , as well as the ironless plunger coil 64 on the support part 105 So at the stator 50 ,
On the outer circumference of the rotor 22 , whose rotor bell 24 partially formed of plastic and in which the magnetic return 27 embedded, there are fan blades 26 , in operation, and depending on the direction of rotation, an axial force on the rotor 22 up or down, based on 1 to exercise. These wings 26 dampen the movements of the rotor 22 , which proves to be very advantageous for the required control processes and causes great stability of these processes.
The rotor 22 with its rotor shaft 34 and the magnetic rings attached to it 38 . 40 is so in the case 51 positioned that the magnetic rings 56 . 58 and the magnet rings 38 . 40 with the engine running 52 approximately opposite, but are very slightly offset from each other in most operating conditions. Relatively rarely, however, operating states may occur in which such an offset does not occur.
4 shows in a simplified representation of the course of the magnetic flux lines 55 , which symbolize the flow, that of the axially magnetized magnet ring 48 is produced. This flow goes in an approximately radial direction through the cylindrical air gap 57 that is between the inside 59 the inference 27 and the outside 47 of soft iron ring 46 extends. The river 55 ' in the air gap 57 runs in the radial direction and is largely homogeneous due to the nature of the design of the magnetic circuit. The plunger coil 64 is located as in 3 represented, in the region of this homogeneous air gap flux 55 ' , Will the plunger coil 64 energized, it generates an axial force on the rotor 22 , The direction of this force is from the direction of current i in the plunger coil 64 dependent. This allows the rotor 22 to keep in a desired axial position so that it does not require a mechanical thrust bearing during operation.
The location of the magnet ring 48 to generate the river 55 can also be chosen differently, eg on the inside 59 of the border section 28 of the second return part 27 , see. the arrangements according to 25 and 26 , Of course, the magnetic ring 48 particularly easy to manufacture and assemble.
5 shows the structure of the fan 100 in an exploded view. The fan 100 has a fan housing 51 , which is about the shape of a pipe 104 has, at both ends mounting flanges 106 . 108 are provided in the usual way. The flow direction of the air is at 110 shown. The inflow side of the fan 100 is with 112 , its outflow side with 114 designated. The motor 52 drives a fan 25 at. There are fan blades on it 26 on, of which only two are shown schematically.
The shape of the wings 26 is due to the conical shape of the inside of the tube 104 customized. On its outside is the fan 25 preferably formed frusto-conical and forms together with the pipe 104 of the fan housing 51 an air passage opening. This has preferred on the air inlet side 112 a smaller diameter than on the air outlet side 114 , Likewise, the fan has 25 on the air inlet side 112 a smaller diameter, which is towards the air outlet side 114 increases. Naturally, the described construction of the fan is suitable 100 as well for a conventional axial fan, a diagonal fan or a radial fan, since the type of storage for all fan types, and also for other devices with similar properties, is suitable, especially because the fan blades 26 a natural damping for the rotor 22 represent.
6 shows the working principle of optimized axial bearing in a highly simplified and schematic representation. The DSP 76 different values are supplied, namely the actual position Z, which is determined by means of the eddy current sensor 33 is measured in 6 not shown, further, the target position Z is intended (this is in DSP 76 calculated internally, but is shown as an external signal for clarity), and also the actual current i in the plunger coil 64 using a in 10 shown current sensor 339 is measured indirectly and can be positive or negative, and that of the donor 208 ( 20 ) preset target voltage U soll = 0, the actual voltage U (this is also internal in the DSP 76 calculated, but is shown as external value), and the setpoint current i soll for the subordinate current controller 202 ( 20 ), which stream i should also internally in the DSP 76 is calculated.
There are mainly two forces here, on the one hand a force F w , which - with a vertical rotor axis 34 - By the weight of the rotor 22 is caused and acts downward, and a bearing force F z , generated by the two radial bearings 16 . 18 which acts upwards and whose size depends on the axial displacement Z between the inner magnetic rings ( 14 : 274 . 276 ) and the outer magnetic rings ( 14 : 270 . 272 ) depends.
In 6 is instead of the actually existing two radial bearings 16 . 18 only a single radial bearing 254 represented, whose force F z is twice as large as the axial force of one of the radial bearings 16 . 18 , This is done to make the presentation more understandable.
Controlled by the DSP 76 becomes the plunger coil 64 as long as a current is supplied until the rotor 22 is located in a situation where applies F w - F z = 0 (1)
This location Z must be through the DSP 76 be constantly readjusted because it is unstable, but for readjustment only small values of the current i are required, so that the active axial position control (by the ironless plunger coil 64 ) has only a low energy consumption and the efficiency of the fan 100 not significantly affected.
If you have the 6 turns upside down, the weight F w of the rotor acts 22 in the opposite direction, and consequently the direction of the bearing force F z must also be reversed, which is done by reversing the sign of the value Z soll . The bearing force F z then acts in the opposite direction.
In the 20 illustrated control arrangement 198 naturally compensates not only the weight F w , so the weight of the rotor 22 but all axial forces acting on the rotor 22 act, such as the flow forces from the fan blades 26 be generated, any forces as a result of shocks on the fan 100 act, and any axial forces from the engine 52 be generated. It is favorable, if by the engine 52 no oscillating forces are generated, as this is a constant readjustment of the position of the rotor 22 would require. In practice, it has been shown that with good design of the regulator 198 The size Z can be kept constant down to about 1 μm, so that a very quiet running of the fan 100 results. This is also helped by the damping by the fan blades 26 at.
7 shows schematically the structure of the eddy current sensor 33 , In this is the coil 66 according to 9 from an oscillator, not shown, with a high-frequency current 230 is fed. Parallel to the coil 66 is a capacitor 232 who can be chosen so that he is together with the coil 66 a resonant circuit 234 that forms with the frequency of the signal 230 is in resonance or works on a side arm of its resonance curve.
The voltage 236 on this resonant circuit 234 is a function of the distance d ( 7 ) between the coil 66 and the hub 31 , The reason is that the hub 31 the resonant circuit 234 the more dampens, the smaller the distance d. The hub 31 is made of aluminum or another good conductive metal, eg copper.
The voltage 236 is in a rectifier 238 rectified and then in an amplifier 240 amplified, so that at the output of the amplifier 240 receives a measuring voltage U m , which in 9 is shown schematically as a function of the distance d. This analog voltage is applied to an input ADC of the DSP 76 fed and converted there into a digital value, which in 20 Z is denoted and in the digital control arrangement 198 is further processed to the rotor 22 to keep in a levitating state.
10 shows how the current i through the plunger coil 64 from the DSP 76 is controlled.
The DSP 76 controls the commutation of the electronically commutated motor (ECM) 52 , which is connected as usual to a direct current network and its commutation and possibly speed control from the DSP 76 what is controlled by a bidirectional bus 320 is hinted about the also the rotor position signals from the ECM 52 to the DSP 76 flow and are processed there to the commutation of the engine 52 to control and, if necessary, to regulate its speed.
Further, the DSP controls 76 over a bus 322 the commutation in an H-bridge 324 , which eg below two npn MOSFETs 328 . 330 and above two pnp MOSFETs 332 . 334 Has. In the diagonal of this H-bridge 324 lies between a connection point 336 (between the transistors 328 and 332 ) and a connection point 338 (between the transistors 330 and 334 ) the plunger coil 64 , If through the DSP 76 the two transistors 330 and 332 be controlled conductively, the current i flows from the terminal 336 to the connection 338 , and if through the DSP 76 the transistors 328 and 334 are controlled conductively, the current i flows from the point 338 to the point 336 , The magnitude of the current i is at a measuring resistor 339 measured between mass 340 and the lower transistors 328 and 330 and the magnitude of the current i can be controlled by changing the duty cycle of PWM signals sent over the bus 322 the H bridge 324 be supplied. The direction of the measured current i results from whether the two transistors 330 . 332 are conductive, or the transistors 328 . 334 ,
When the current i in the plunger coil 64 from the connection 336 to the connection 338 flows, shifts through the plunger coil 64 Lorentz force generated the rotor 22 up, like that in 6 is shown, ie the value Z ( 19 ) becomes positive, and if the current i is from the terminal 338 to the connection 336 flows, shifts the plunger coil 64 the rotor 22 down, ie the value Z becomes negative. Such shifts depend on the position of the fan 100 must work and cause a corresponding change in size and possibly direction of the force F.
11 shows in a schematic overview four different basic types of passive non-contact magnetic radial bearings, as they can be used in the present invention. These are each between a wave 34 and a stator 50 arranged. In principle, the force effect of the magnet rings can be repulsive or attractive (attractive).
The magnetic rings can be stacked. As a result, the ratio of radial stiffness to magnetic volume can be increased. Any number of stack numbers are possible. 11 shows as examples stack numbers of n = 1 and n = 2. Also, the passive radial bearing can be realized in the invention by permanent magnets with radial direction of the magnetization.
In the upper row is left a single ring bearing 250 represented on the principle of repulsion (magnetic repulsion poles of the same name), and right is a so-called stacking warehouse 254 represented by n = 2 magnetic rings, which is also based on the principle of repulsion.
In the lower row is left a single ring bearing 258 based on the principle of attraction, that is on the principle of magnetic attraction between the North and South Pole, and on the right is a stack bearing 262 which is also based on the principle of magnetic attraction.
All four storage types can be used in the context of the present invention. The illustrated embodiment uses as an example stacking bearings with n = 2 rings, which after the Principle of the repulsion work and magnetized in the axial direction are.
The warehouse 250 of the 11 uses a stationary magnetic ring 264 which is axially magnetized, and it uses a rotating magnetic ring 266 which is also magnetized axially. Between the rings 264 . 266 there is a (magnetic) air gap 268 , As you can see, the north pole of the ring lies in each case 264 the north pole of the ring 266 opposite, as well as the south pole of the ring 264 the south pole of the ring 266 , The repulsion between the poles produces the effect as a magnetic radial bearing. The instability of the warehouse 250 in the axial direction is evident, ie the position of the shaft 34 in the axial direction must be determined by a corresponding thrust bearing.
The warehouse 254 of the 11 uses two stationary, axially polarized magnetic rings 270 . 272 , which lie against each other with their northern poles and are stacked on top of each other. It also uses two rotating, axially polarized magnet rings 274 . 276 , which are stacked on top of each other and abut each other with their north poles. The mode of action is described below with reference to 14 and 15 explains and rests like the camp 250 on the radial repulsion of poles of the same name. The air gap is at the warehouse 254 With 278 designated.
The warehouse 258 of the 11 has a stationary, axially magnetized magnet ring 280 which has a north pole above and a south pole below. Likewise, it has one on the shaft 34 attached and with this rotating, axially magnetized magnetic ring 282 which has a south pole at the bottom and a north pole at the top, which is the south pole of the magnet ring 280 opposite and from this through an air gap 284 is disconnected.
Moves the ring 282 in the radial direction, so the attraction between the rings decreases 280 . 282 too and strives to the wave 34 to move into a position concentric with the magnet ring 280 is. The instability in the axial direction is obvious as the rings 280 . 282 tighten each other in the axial direction. However, this instability can be mitigated by the fact that the other radial bearing mirror image of the radial bearing 258 is trained.
The warehouse 262 of the 11 has an outer, stationary, axially magnetized magnet ring 288 with the south pole at the top and concentric in the ring 288 has the warehouse 262 an inner, stationary, axially magnetized magnet ring 290 with the North Pole up. The Rings 288 . 290 are therefore stacked in the radial direction.
On the wave 34 Inside is an axially magnetized magnet ring 292 with the North Pole up, and this ring 292 is surrounded by an axially magnetized magnet ring 294 where the south pole is up. A flat (flat) air gap 296 separates the stationary ring pair 288 . 290 from the rotating ring pair 292 . 294 , Consequently, there is a south pole of the stationary ring 290 a north pole of the rotating ring 292 opposite, and a north pole of the stationary ring 288 lies a south pole of the rotating ring 294 across from. This mating acts a radial displacement of the shaft 34 opposite. Further explanations follow at 12 and 16 ,
12 put the warehouse again 262 to 11 dar., and 13 shows the associated flow line course. As there are poles of unlike poles, there are very short field lines. For example, if the north pole of the rotating magnet ring 292 shifted in the radial direction to the left, he comes increasingly in a position opposite the north pole of the magnet ring 288 and is repelled by this, and at the same time the attraction between this north pole of the rotating magnet ring 292 and the south pole of the stationary magnet ring 290 is reduced, whereby the effect is produced as a non-contact radial bearing, if a thrust bearing is present, which counteracts an axial displacement between the rotating and stationary rings.
14 shows again the stacking warehouse 254 according to 11 , which works according to the repulsion principle. Its advantage is the symmetrical structure in the axial direction. Both stationary magnetic rings 270 . 272 are identical, and everyone has the height a. Likewise, the two rotating magnetic rings 274 . 276 identical, and everyone has the height a.
15 shows the field line course at the stack warehouse 254 , The reference numbers are the same as in 11 , Here are each the same pole adjacent, ie in the air gap 278 occurs a strong repulsion, which generates the radial bearing effect.
As in the configuration after 15 the same pole in the axial direction are opposite, there is the risk that the magnetic rings demagnetize each other in the long run. For this reason, it may be advantageous, according to
16 between the stationary magnetic rings 270 . 272 a soft ferromagnetic ring 300 to arrange, as well as between the rotating magnetic rings 274 . 276 a soft ferromagnetic ring 302 , These counteract such demagnetization and are particularly favorable when operating at higher temperatures. Alternatively, the rings 300 . 302 also be non-magnetic material, such as a plastic.
16 So sets a variant 15 and can also be used with advantage in the invention.
17 shows the radial bearing 254 as in the embodiment of the radial bearings 16 and 18 is used in different axial positions. In practice, the inner part of the radial bearing leads 254 only small axial movements through, in addition to the security by stops as well as by value limits in the program of the rule arrangement 198 are limited, ie the values of certain parameters are automatically limited by the program.
The representation B) of 17 shows the radial bearing 254 in its zero position (Z = 0). In this position produces the camp 254 no axial force, but is in axial equilibrium, ie F z = 0. The radial stiffness S r of the bearing 254 has its maximum, ie the fan 100 should be operated so that its two radial bearings 16 . 18 simultaneously close to Z = 0 and move synchronously in the axial direction. If due to the location of the shaft 34 the one radial bearing 16 the value Z = 0 should be the other, identical radial bearing 18 also have the value Z = 0. However, there are also cases conceivable where a first force from the radial bearing 16 a second force from the radial bearing 18 superimposed and these two forces are different in size.
The representation A) of 17 shows a state where the shaft 34 relative to representation B) is shifted upwards by a distance which is smaller than a / 2, that is, less than half the thickness a of a magnet ring. This results in a force F Z upwards, and the rigidity S r is reduced.
The representation C) of 17 shows a state where the shaft 34 relative to representation B) is shifted downwards by a distance which is smaller than a / 2.
This results in a force F z down, and the radial stiffness S r is also reduced.
18 shows at A) as an example the course of the axial force F z of the bearing 254 as a function of the axial displacement Z.
When Z = 0, in 18 F z = 0. If Z becomes negative, F z increases to a positive maximum 255 to, which is about at -a / 2 and then decreases again. When Z becomes positive, F z decreases to a minimum 257 which is at + a / 2, and then increases again.
The representation B) of 18 shows the course of the radial stiffness Sr of the bearing 254 , The stiffness Sr has its maximum at Z = 0 and decreases from there in both directions. The rigid area is hatched and is approximately between -a / 2 and + a / 2. In practice, this area is not used fully, but usually only a small part thereof, in which the stiffness Sr is particularly high, as is desirable for a good storage. The mechanical stops 261 . 263 ( 19 ) are arranged in this radially stable region.
19 schematically shows an enlargement of the section XIX of 18 , You realize that for the camp 254 a first stop 261 at the location -Z 0 is provided, ie in 14 below the camp 254 , and that a second stop 263 is provided at the point + Z 0 , ie in 14 above the camp 254 , (For a fan with a stationary mounting position, which does not change during operation, the upper stationary stop could 263 omitted.)
19 also shows that the radial bearing 254 at the point -Z 0 generates an axial force + F z0 , which, according to the representation C) of 17 acting downwards, and that it generates an axial force F z0 upwards at the position + Z 0 , according to the illustration A) of FIG 17 ,
The workspace within which the fan 100 working in the company is with 265 for example, this range could be between about -a / 4 and about + a / 4. The working point within the range 265 Depends on the various forces in operation on the rotor 22 Act. A typical operating point 273 is drawn.
In 19 is also a curve 267 shown, which shows the course of the axial force F z as a function of the displacement Z, also a straight line 269 , which at zero point tangential to the curve 267 runs and which in the work area 265 has the same course as the curve 267 ,
If the fan 100 a general orientation accordingly 3 has, is the wave 34 at start in position -Z 0 ( 19 ), wherein the value of Z 0 may be about 0.3 mm, and is located with a force F z0 against the stop 261 at. This position of the shaft 34 is in 21 and 22 shown. It can be seen that the force F Z0 acts downward, ie in the "wrong" direction, provided the fan 100 the orientation 21 Has. 22 is an excerpt from 21 and shows greatly enlarged the radial bearing 18 in the idle state of the fan 100 ,
The start will be in 19 through an arrow 271 symbolizes. In this case, a corresponding starting current i through the plunger coil 64 sent, so the rotor 22 is moved upwards, based on 3 or 21 , and the two radial bearings 16 . 18 in their workspace 265 ( 19 ) and to the working point 273 moves, leaving the rotor 22 floats.
This state shows 6 , for reasons of clarity the engine 52 not shown, since this usually has only a small influence on the contactless storage.
24 shows a variant of the coil arrangement for an active magnetic thrust bearing.
This arrangement has a carrier part 308 made of a soft ferromagnetic material. At this is a stationary pole core 310 attached, and this is through an air gap 312 separated from a movable pole core 314 connected to the upper end of the shaft (not shown) 34 connected is.
Stationary Polkern 310 and movable pole core 314 are from a stationary actuator coil 64 ' surround. When a current i is applied to this coil, it generates a magnetic field 316 the illustrated form, which seeks the air gap 312 to shrink, eliminating the movable pole core 314 with a force Fz is pulled up.
The disadvantage is that such an arrangement can only generate an upward force, which is a corresponding invariable orientation of the fan 100 presupposes. If a force is to be generated in both directions, a corresponding arrangement must also be arranged at the lower end of the shaft.
The arrangement after 24 is based on the so-called Maxwell force, ie on the force effect at interfaces. In contrast, the force is based on a plunger coil 64 (like the 1 to 23 ) on the so-called Lorentz force, ie on the force on a conductor through which current flows, which is located in a magnetic field. At present, controlled thrust bearings based on the Lorentz force are preferred, because in these, the direction of the generated force can be controlled by the direction of the current i, and because the magnitude of the force can be controlled by the magnitude of the current, so that thrust bearings, the work with a Lorentz force, are more versatile in their application. In addition, the plunger has 64 a low inductance, because it has no parts made of ferromagnetic materials. It can therefore very quickly change the current through the current regulator 202 ( 20 ), so that oscillations are avoided. The 25 and 26 show therefore other embodiments of thrust bearings with plunger coil.
25 shows a first variant of the rotor assembly according to 1 to 5 , The wave 34 , the eddy current sensor 33 , the radial bearings 16 and 18 , the motor 52 and the fan blades 26 are not shown and can be structured the same as in 1 ,
The cup-shaped second magnetic yoke 27 carries on the inside of its outer edge 28 a ring 334 made of permanent magnetic material, which is radially magnetized, ie at 25 he has consistently on his inside 336 a north pole and on its outside 338 a south pole. Naturally, alternatively, the inside could 236 a south pole and the outside 338 have a north pole.
The inside 336 is through a cylindrical air gap 57 '' separated from the outside of a magnetic return part 46 ' ,
In the cylindrical air gap 57 '' protrudes the ironless immersion coil 64 as well as at 2 on the stator-fixed support member 105 is attached.
The advantage over 1 is that the zone in which a homogeneous radial magnetic field 55 '' is present, may be greater than in the embodiment according to 1 and 4 ,
26 shows a second variant in which as well as in 25 the wave 34 , the position sensor 33 , the radial bearings 16 and 18 , the motor 52 and the fan blades 26 are not shown. These can be structured the same as at 1 ,
The bell-shaped second magnetic yoke with the first ring magnet 334 is the same education as at 25 , as well as the plunger coil 64 ,
On the outer periphery 47 of the first magnetic conclusion 46 '' here is a second, inner magnet ring 342 arranged, its outer periphery 344 the cylindrical air gap 57 ''' is facing and whose flow is the flow of the first ring magnet 334 amplified, leaving you in the air gap 57 ''' a very homogeneous, radial magnetic flux 55 ''' with a high magnetic flux density.
The second magnetic ring 342 is also radially magnetized and has in this example inside a north pole and on its outer periphery 344 a south pole.
A homogeneous magnetic field 55 ''' facilitates the control of the axial position Z of the rotor 22 and also facilitates the generation of the axial force required at start-up to the rotor 22 into its equilibrium position.
Of course you could also according to the rotor training 1 combine with an outer ring magnet 334 as he is in 25 is shown. It seems important that the cylindrical air gap 57 . 57 '' . 57 ''' good with the motor elements of the fan 100 can be combined without significantly increasing the volume of the fan.
20 shows a preferred structure for the control arrangement used 198 , For each controller, which is supposed to effect a so-called levitation, a high control speed is important, ie the axial position Z of the rotor 22 must be detected as often as possible in a digital controller, for example, at intervals of 100 microseconds, and the current i, by the immersion coil 64 should also be measured at close intervals to obtain a good control result.
At a comparator 200 is the desired current i soll in the plunger coil 64 compared with the actual current i. The latter becomes indirect with the current sensor 339 of the 10 measured. (The sign of the current i results from the commutation signals of the H-bridge 324 .)
From the difference between i and i should result in a control deviation, called i dev (current deviation), and this is a current regulator 202 fed to the current in the plunger coil 64 regulates. The regulator 202 is a so-called "lower-level current controller", ie it works with a setpoint i soll , that of a position controller 216 is delivered. At its output, it generates a voltage U, which is required to a certain current i soll in the plunger coil 64 to effect. This voltage U is in the controller 202 which is usually a proportional controller (P-controller). The output voltage U is the same U = k · i dev (2) ie equal to the product of current deviation i dev and a constant factor k.
The subordinate current regulation 202 can be omitted if for the stabilization of the axial position Z of the fan wheel 25 a power electronics with current injection is used, so a constant current regulator.
The position control is based on the fact that the time integral over the voltage (∫Udt) or alternatively the time integral over the current (∫idt) becomes 0 when the fan wheel 25 is in an axial position Z, in which the forces F w and F z ( 6 ) cancel each other out. In this case, flows in the plunger coil 64 no current, with the exception of small correction currents, which are necessary to maintain this position Z is constantly.
At the exit 204 of the current controller 202 So you get the actual voltage U. This becomes a comparator 206 supplied there and there with the target voltage U soll = 0 from a setpoint generator 208 compared. This setpoint voltage therefore has the value 0, because it allows a favorable energy balance of the fan 100 can achieve. From the difference between the setpoint voltage U soll and the actual voltage U results in a voltage deviation U dev , and this is a controller 210 fed, which can be referred to as "superimposed position tracking".
The purpose of the regulator 210 is it the "force-free" position according to 6 to determine where the downward force F w (weight of the rotor 22 , etc.) is exactly balanced by the upward acting total force F z of the two radial bearings 16 . 18 ,
In this balanced state, the time average of the voltage U (or the current i) has the value 0. Therefore, the controller 210 preferably designed as an integral controller.
At the initialization of the arrangement 198 after switching on, the value Z is set at the output 211 set to zero. Subsequently, in each sampling step of the digital controller, the current voltage U at the output 204 multiplied by a factor k and added to the value Z soll of the previous sampling step, provided that the amount of Z soll then does not exceed a limit Z soll, max .
When switching is so Z soll0 = 0 (3)
After the first scanning step applies Z set1 = Z soll0 + k · U 1 (4)
After the second scanning step applies Z soll2 = Z set1 + k · U 2 (5)
After the n-th sampling step applies Z solln = Z to (n-1) + k · U n (6)
In this way, the digital integration is constantly being continued. In this case, U 1 , U 2 , U 3 , U n, etc. are the voltage values at the output 204 during the relevant scanning step 1, 2, 3, n ...
This integration by the controller 210 is continued continuously, and you get in operation at rated speed a very stable value for Z soll , ie between stator 50 and rotor 22 then only extremely small axial movements take place.
The value Z soll becomes a comparator 214 supplied and compared there with the value Z for the actual position, which value with the eddy current sensor 33 (or any other position sensor) is measured. The difference between Z and Z will be referred to as Z dev and a position controller 216 (PD controller) supplied, at the output one receives the value i soll for the desired current, the already described comparator 200 is supplied.
The value i should be at initialization of the fan 100 set to zero. (In operation, the value i soll may be positive or negative.)
In every sampling step of the digital controller 198 is in the PD controller 216 the current setpoint current i soll1 is calculated as a weighted sum of the setpoint current i soll0 of the preceding sampling step, the current position error Z dev1 and the position error Z dev0 of the preceding sampling step, ie i set1 = k1 · i soll0 + k2 · Z dev1 + k3 · Z dev0 (7)
Here, k1, k2 and k3 are constants which serve to weight the values i soll0 , Z dev0 and Z dev1 and which must be determined when designing a new fan by means of corresponding control loop simulators .
The function of position tracking (controller 210 ) is the following:
The passive radial bearings 16 . 18 Although form a stable, non-contact storage in the radial direction, but are unstable in the axial direction, ie they pull the rotor 22 depending on their axial position in one or the other axial direction, cf. Picture A) in 18 where the axial force F z is shown as a function of Z.
Likewise, other forces act in the axial direction, eg the weight of the rotor 22 , Air forces, etc. The force passing through the plunger coil 64 is generated, also acts in the axial direction.
For this force system is used by the position tracking controller 210 an optimum value Z is intended for the position of the rotor 22 calculated, in which this force system can be kept in equilibrium with a minimum of energy. This is achieved by the value U soll = 0 from the setpoint adjuster 208 , 19 shows an example conceivable working point 273 , which is defined by such a value Z is defined.
This "balancing" of the rotor 22 acting forces takes place by very small changes in the value Z soll , ie the relative position of stator 50 and rotor 22 ie when the rotor 22 able after 6 its position is slightly shifted upwards, for example, by 0.05 mm, and when the fan 100 is turned upside down, the target position of the rotor 22 shifted in the reverse direction by a similar path. You can also put it that way from the radial bearings 16 . 18 In the axial direction generated magnetic forces are exploited to the rotor 22 With minimal energy expenditure in a power-saving position Z is designed to hold, in which the forces acting on the rotor 22 act, be in balance and the rotor 22 consequently "floats" without any appreciable current through the plunger coil 64 must flow. That's like one Surfer, who is held in balance by the wave and carried as long as he performs the necessary minimum control movements correctly.
This axial position Z is the rotor 22 is unstable in nature and therefore has to be constantly readjusted, but are sufficient for this purpose very small correction currents in the plunger coil 64 , where the integral of these correction currents over time has approximately the value 0, if the value Z soll has its optimum.
21 and 22 show a picture of the fan 100 analogous 3 , While, though 3 shows the fan in its operating state at which the shaft 34 hovers, show 21 and 22 the fan 100 in the de-energized state, at which the lower end of the shaft 34 against the disc 72 is supported. It can be seen that the inner rings of the two radial bearings 16 . 18 by about a / 4 ( 18 ) are offset down, so that there is a significant magnetic force F Z , which acts downward and at start by the force of the plunger coil 64 must be overcome, so the fan 100 can get into the state of hovering before turning its rotation. If possible, this offset should be smaller than a / 2, otherwise the force F Z0 will become very large and at start a large current i in the plunger coil 64 is required to overcome the sum of the forces (F w + F Z0 ).
The starting point is the de-energized state, in which the rotor 22 stands still. The radial bearings 16 . 18 together generate an axial force Fz0 ( 21 ), which is the wave 34 presses against a mechanical stop, for example, the stop 72 , as in 21 shown. The radial bearings 16 . 18 cause a non-contact radial centering of the shaft 34 but do not have their operating position yet. In 21 you can tell by the fact that the force Fz0 is acting in the wrong direction.
By applying a supply voltage to the fan 100 begins the digital signal electronics DSP 76 with the execution of a startup routine S310, the in 23 is shown. This first causes the values Zsoll and isoll to be set to zero in S312 and the voltage setpoint Usoll to be polled, which is preferably 0 V. According to equation (6), in step S314, the stepwise (iterative) process of optimizing Z soll begins. In S316, according to equation (7), a first value i soll is calculated, and in S318, according to equation (2), a value U is calculated, that is, the voltage applied to the plunger coil 64 should be created.
In S320, U is applied to the plunger coil by applying this voltage 64 an axial position Z is set. In S322, the current i in the plunger coil 64 is measured, and the measured value is returned to step S318. In step S324, the current value Z of the axial position is detected by the sensor 33 measured.
The calculated value U is returned to step S314 where it is used according to equation (6) to calculate a new value for Z soll . The measured value Z is returned to step S316 where it is used to calculate a new value for isoll. The measured current i is returned to step S318 where it is used to calculate a new voltage U.
On in this way, the current i and thus the position Z become so long changed until the axial forces be in balance.
Subsequently, the fan 100 switched on, ie the fan 25 is with the engine 52 driven, the control arrangement 198 necessary corrections of Z are automatically made when the axial forces change due to the operation of the fan. The rotor 22 So now touch the stator 50 no more, and the storage of the entire system is non-contact by magnetic forces. Through the active thrust bearing 57 . 64 and the passive radial bearings 16 . 18 becomes the fan wheel 25 held in this floating position. The magnet rings of the first and second thrust bearings 16 respectively. 18 are here in each case in close proximity to an associated level of alignment, as the 3 and 6 show particularly well. In 6 is the distance from the associated plane of alignment denoted by Z.
From the time of activation of the active thrust bearing, in step S324 (FIG. 22 ) the distance Z between the stator 50 and rotor 22 measured at close intervals, for. B. every 100 μs. According to the described method (position tracking 210 , Position controller 216 and current regulator 202 in 20 ) is connected to the plunger coil 64 to be applied voltage U calculated. The value for this voltage U is transmitted to a power electronics, which provides the power for the plunger coil 64 is needed. Alternatively, if this power electronics itself contains a current control, the power electronics directly transmits a value for an instantaneously required desired current i soll . The control of the current i can be done with clocked transistors, that is, with transistors that are alternately completely off and completely turned on, see. 10 , or z. B. with an analog amplifier. However, it is not bound by the previously mentioned principles, so more Modifications and modifications are possible.
In operation, different forces can occur in the axial direction:
Permanent magnetic forces; dynamic axial forces (due to mass inertia); Weight forces with vertical rotor axis; electromagnetic forces; possibly flow forces; other disturbing forces. The stationary forces are compensated by a corresponding change in the force F Z , by the size Z by the actively controllable magnetic thrust bearing (plunger 64 ) is changed, cf. 18 ,
In the radial direction also different forces can occur:
Static and dynamic unbalance forces; dynamic radial forces due to inertia and gyroscopic effects; Radial forces of the drive; Weight forces with horizontal rotor axis; other disturbing forces.
These forces are due to the passive radial bearings 16 . 18 added. Also too strong tilting of the fan 25 gets through the radial bearings 16 . 18 prevented. At very high disturbance forces catch bearings (emergency bearing) temporarily take over the radial and axial guidance of the rotor 22 ,
in the Operation, the state of the system is continuously checked. To counts the surveillance the active magnetic bearing, the drive and the electronics, so that the value Z adaptively adapts to the respective operating conditions.
An example is the monitoring of the temperature of the plunger coil 64 to protect them from overheating. One possible implementation is to estimate the current coil temperature using a thermal model located in the signal electronics. Such thermal models are known from motor protection switches and are therefore not described further.
So in the invention has a fan 100 an electronically commutated drive motor 52 for driving fan blades 26 , This drive motor 52 has one with a bearing tube 54 connected stator 50 and one with a wave 34 provided rotor 22 , The wave 34 is in the bearing tube 54 by means of passive radial magnetic bearings 16 . 18 mounted radially non-contact. It is relative to the bearing tube 54 axially displaceable and communicates with a rotor magnet 44 in drive connection, which has a first magnetic return 46 having. Also is one with the wave 34 connected second magnetic inference 27 provided, which is approximately bell-shaped and in which the inside 59 the outer edge 28 an outer boundary for a substantially cylindrical air gap 57 forms, in which in operation a radial magnetic flux 55 ' in a given direction. Furthermore, a plunger coil 64 provided, which in the cylindrical air gap 57 dips in and with the bearing tube 54 is mechanically connected, so that at an axial displacement of the plunger coil 64 relative to the cylindrical air gap 57 the location of the shaft 34 relative to the bearing tube 54 changes. This makes it possible to bring the magnetic storage virtually powerless in a limbo, ie in a state of levitation.
Naturally, many modifications and modifications are possible within the scope of the present invention. Thus, in the context of the invention, other types of motors can be used, for example, internal or external rotor motors, and especially those motors that generate no or only small radial forces at a displacement of the rotor from the center of the stator bore. Also, the magnetic flux can 55 ' . 55 '' . 55 ''' in the cylindrical air gap 57 . 57 '' . 57 ''' are produced by various arrangements of permanent magnets, the illustrated examples are not exhaustive.
Fan with an electronically commutated drive motor ( 52 ) for driving fan blades ( 26 ), which drive motor ( 52 ) a stator ( 50 ) and one with a wave ( 34 ) provided rotor ( 22 ), which shaft ( 34 ) on the stator ( 50 ) by means of permanent magnets ( 38 . 56 ; 40 . 58 ) Radially mounted without contact and relative to the stator ( 50 ) is axially displaceable, and with the rotor ( 22 ) is in drive connection, which rotor ( 22 ) in turn with a fan ( 25 ) is in drive connection, in which a cylindrical air gap ( 57 . 57 '' . 57 ''' ) is formed, in which in operation a substantially radial magnetic flux ( 55 ' . 55 '' . 55 ''' ) in a predetermined direction, further comprising a plunger coil ( 64 ), which in the cylindrical air gap ( 57 . 57 '' . 57 ''' ) and with the stator ( 50 ) is mechanically connected, so that when an axial displacement of the shaft ( 34 ) relative to the stator ( 50 ) the position of the plunger ( 64 ) relative to the cylindrical air gap ( 57 . 57 '' . 57 ''' ) changes.
Fan according to claim 1, in which for quantitative detection of the relative position (Z) of the stator ( 50 ) relative to the shaft ( 34 ) a contactless position sensor ( 33 ) is provided.
Fan according to claim 2, wherein the position sensor as eddy current sensor ( 33 ) is trained.
Fan according to claim 3, wherein the eddy current sensor ( 33 ) a sensor coil ( 66 ), which in operation a high-frequency signal ( 230 ), and the electrically good conducting part ( 31 ) whose distance (d) from the sensor coil ( 66 ) a function of the position of the shaft ( 34 ) relative to the stator ( 50 ).
Fan according to claim 4, wherein the sensor coil ( 66 ) on the stator ( 50 ) is arranged.
Fan according to claim 4 or 5, wherein the electrically good conductive part as a hub ( 31 ) of the rotor ( 22 ) is formed and in interaction with the sensor coil ( 66 ), so that the damping of the sensor coil ( 66 ) through the electrically good conductive part ( 31 ) a function of the position of the shaft ( 34 ) relative to stature ( 50 ).
Fan according to one of the preceding claims, in which for generating the magnetic flux ( 55 ' . 55 '' . 55 ''' ) in the cylindrical air gap ( 57 . 57 '' . 57 ''' ) an axially magnetized permanent magnet ( 48 ) is provided, which is a flux guide ( 46 ), which has an approximately circular-cylindrical outer circumference ( 47 ) having a radially inner boundary of the cylindrical air gap ( 57 ).
Fan according to claim 7, wherein the axially magnetized permanent magnet ( 48 ) is continuously magnetized at its one axial end as a north pole and at its other axial end as a south pole.
Fan according to Claim 8, in which the axially magnetised permanent magnet ( 48 ) between two magnetic return parts ( 27 . 46 ) is arranged.
Fan according to Claim 9, in which the axially magnetised permanent magnet is in the form of a ring magnet ( 48 ) is trained.
Fan according to claim 9 or 10, wherein one in the rotor ( 22 ) arranged soft ferromagnetic part ( 46 ) both as a flux guide as well as the first magnetic yoke for the rotor magnet ( 44 ) of the electronically commutated motor ( 52 ) is trained.
Fan according to one of the preceding claims, in which the electronically commutated motor ( 52 ) a rotor magnet ( 44 ), and this rotor magnet ( 44 ), the soft ferromagnetic part ( 46 ), and for the generation of the river ( 55 ' . 55 '' . 55 ''' ) in the air gap ( 57 . 57 '' . 57 ''' ) serving permanent magnet ( 48 ) are sandwiched.
Fan according to one of the preceding claims, in which the electronically commutated motor has a shallow air gap ( 101 ) having.
Fan according to claim 13, wherein in the flat air gap ( 101 ) a so-called ironless winding ( 102 ) is arranged.
Fan according to claim 14, wherein the ironless winding ( 102 ) with the bearing tube ( 54 ) is mechanically connected in a rotationally fixed manner.
Fan according to Claim 15, in which the plunger coil ( 64 ) on a carrier element ( 105 ) for the ironless winding ( 102 ) is attached.
Fan according to Claim 16, in which the support element ( 105 ) for the ironless winding ( 102 ) with the bearing tube ( 54 ) is mechanically connected.
Fan according to one of the preceding claims, in which a position controller ( 20 : 216 ) for automatically controlling the position of the shaft ( 34 ) relative to the stator ( 50 ) is provided.
Fan according to claim 18, in which for controlling the position of the shaft ( 34 ) relative to the stator ( 50 ) a current regulator ( 202 ) for the current in the exchange coil ( 64 ), which depends on the difference between the actual position (Z) and the desired position (Zsoll) of the shaft ( 34 ) a desired current (i soll ) is specified.
Fan according to Claim 19, in which, when the actual position (Z) of the plunger coil coincides ( 64 ) and the desired position (Zsoll) of the plunger coil ( 64 ) the nominal current (i soll ) has essentially the value zero.
Fan according to claim 19 or 20, wherein a superposed position tracking ( 210 ) regulating the position of the shaft ( 34 ) relative to the stator ( 50 ) is provided.
Fan according to Claim 21, in which, depending on the difference (i dev ) between the nominal current (i soll ) and the actual value (i) of the current in the plunger coil ( 64 Calculated) a voltage (U) and (with a predetermined target voltage V set) is compared with the difference of these voltages is summed and depending to the instantaneous magnitude of the sum to calculate a target position (Z) (for the position controller 216 ) serves.
Fan according to claim 22, wherein the value for the target current is about 0 A.
Fan according to one of claims 18 to 23, in which the controller comprises a digital signal processor ( 76 ) having.
Fan according to Claim 24, in which the digital signal processor ( 76 ) also to control the Commutation of the electronically commutated motor ( 52 ) serves.
Fan according to one of the preceding claims, in which a passive bearing arrangement ( 16 . 18 ) is provided with permanent magnets, which is adapted to the rotor in currentless plunger coil ( 64 ) into a desired nominal position ( 21 ) to move.
Fan according to claim 26, in which on the shaft ( 34 ) two passive magnetic radial bearings ( 16 . 18 ) are provided, each having four axially magnetized rings, two of which adjacent to each other on the shaft ( 34 ) are arranged, and two other adjacent rings opposite to this on the stator ( 50 ) of the fan ( 100 ) are arranged.
Fan according to claim 27, wherein two adjacent axially magnetized rings are each arranged so that poles of the same name are opposite one another and a repulsive magnetic radial bearing ( 254 ) form.
Fan according to claim 27 or 28, wherein at the on the shaft ( 34 ) arranged adjacent magnetized rings and on the stator ( 50 ) of the fan ( 100 ) arranged rings of the same radial bearing ( 254 ) the pole sequence is the same.
Fan according to one of claims 27 to 29, wherein between on the shaft ( 34 ) arranged magnetized rings of the first and the second magnetic bearing ( 16 . 18 ) a spacer ( 42 ) is provided.
Fan according to one of the preceding claims, in which in the region of the shaft ( 34 ) is provided at least one run flat slide bearing.
Fan according to one of the preceding claims, in which, in the case of an emergency operation or in the case of the switched-off state, the shaft ( 34 ) with at least one mechanical safety bearing ( 72 ) is provided.
Fan according to claim 32, wherein the mechanical safety bearing as a wear-resistant sliding bearing ( 36 ) is trained.
Fan according to claim 32 or 33, wherein a mechanical safety bearing designed as a thrust bearing and at the free end ( 35 ) the wave ( 34 ) is provided.
Fan according to claim 34, in which the free end ( 35 ) the wave ( 34 ) in the manner of a dome ( 36 ) is trained.
A fan with a rotor, a stator, furthermore with at least one passive radial magnetic bearing and with at least one actively controllable axial magnetic bearing system, characterized by: a first magnetic bearing arrangement, which on the rotor ( 22 ) of the fan ( 100 ), which at least one magnet ( 38 ) having; a second magnetic bearing assembly ( 56 ) on the stator ( 50 ) of the fan is arranged and at least one magnet ( 56 ) having; an electromagnetic arrangement (inside the fan) 57 . 64 ) for controlling the axial position (Z) of the rotor ( 22 ) relative to the stator ( 50 ).
Fan according to claim 36, characterized in that the first magnetic bearing arrangement ( 38 ) has a plurality of mutually adjacent magnetic rings, which are arranged so that the polarities of adjacent magnetic rings ( 38 ) are the same.
Fan according to claim 36 or 37, characterized in that the second magnetic bearing arrangement ( 56 ) has a plurality of mutually adjacent magnetic rings, which are arranged so that the polarities of mutually adjacent magnetic rings are equal.
Fan according to claim 36, characterized in that the first magnetic bearing arrangement ( 38 ) has a plurality of mutually adjacent magnetic rings, which are arranged so that the polarities of mutually adjacent magnetic rings are unequal.
Fan according to claim 36, characterized in that the second magnetic bearing arrangement ( 56 ) has a plurality of mutually adjacent magnetic rings, which are arranged so that the polarities of mutually adjacent magnetic rings are unequal.
Fan according to one of the claims 36 to 40, characterized in that between the magnetic rings a non-ferromagnetic intermediate layer is introduced.
Fan according to one of the claims 36 to 41, characterized in that between the magnetic rings a soft ferromagnetic intermediate layer is introduced.
Fan according to one of claims 36 to 42, characterized in that juxtaposed magnets of the first magnetic bearing assembly ( 38 ) relative to the juxtaposed magnets of the second magnetic bearing assembly ( 56 ) are arranged so that the magnets of both bearing assembly are aligned with each other in the same axial position.
Fan according to one of claims 36 to 43, characterized in that the magnets of the first magnetic bearing assembly and the magnets of the second magnetic fan assembly ( 56 ) are at least partially formed as axially magnetized magnetic rings.
Fan according to one of claims 36 to 44, characterized in that magnets of the first magnetic arrangement ( 38 ) and magnets of the second magnetic arrangement ( 56 ) have an uneven thickness.
Fan according to one of claims 36 to 45, characterized in that magnets of the first magnetic arrangement ( 38 ) and magnets of the second magnetic arrangement ( 56 ) have the same thickness (a).
Fan according to one of claims 36 to 46, characterized in that the rotor ( 22 ) a position control magnet ( 48 ), a magnetic inference ( 46 ), and a motor magnet ( 44 ), and that for this arrangement a common magnetic inference ( 46 ) is provided.
Fan according to claim 45, characterized in that between the magnetic return ( 46 ) and the rotor bell ( 27 . 28 ) a radial air gap ( 57 . 57 '' . 57 ''' ), in which the magnetic coil ( 64 ) of the position controller protrudes into it.
Fan according to one of claims 36 to 48, characterized in that at least one end of the shaft ( 34 ) in the event of an emergency operation or in the case of the off state, a low-wear formation ( 36 ), which has an emergency running surface ( 72 ) assigned.
Fan according to claim 49, characterized in that at least one end of the shaft ( 34 ) a rounded, parabolic, elliptical, convex or flat surface ( 36 ) having.
Fans with at least one passive radial magnetic bearing ( 16 . 18 ) and with at least one actively controllable thrust bearing ( 57 . 64 ), characterized by: a first magnetic arrangement ( 38 ), which on the rotor ( 22 ) of the fan ( 100 ), and has at least one or a plurality of juxtaposed magnets; a second magnetic arrangement ( 56 ) on the stator ( 50 ) of the fan ( 100 ), and has at least one or a plurality of juxtaposed magnets; an electromagnetic arrangement ( 57 . 64 ) for influencing the axial position of the rotor ( 22 ) relative to the stator ( 50 ), which arrangement within the fan ( 100 ), wherein the first magnetic arrangement ( 38 ) and the second magnetic arrangement ( 56 ) in magnetic interaction to the rotor ( 22 ) radially supported by magnetic forces, and the electromagnetic arrangement ( 57 . 64 ) is adapted to the axial position of the rotor ( 22 ) relative to the stator ( 50 ) in order to influence the storage system ( 16 . 18 ) of the fan forces to compensate and the fan ( 25 ) in a predetermined nominal position (Z soll ) relative to the stator ( 50 ) to keep.
Fan according to claim 51, characterized in that the electromagnetic Thrust bearing is designed to compensate for internal and external forces.
Fan according to claim 52, characterized in that the compensation of internal and external forces the axial forces the passive radial bearing system takes place, the size of these axial personnel by a corresponding displacement of the rotor relative to the stator is regulated.
Fan according to claim 51, characterized in that a sensor system ( 33 ) for measuring the axial position of the rotor ( 22 ) relative to the stator ( 50 ) is provided
Fan according to claim 51, characterized in that a supporting part ( 31 ) of the rotor ( 22 ) a component of the sensor system ( 33 ).
Fan according to claim 54, characterized in that for controlling the axial rotor position, a digital processor ( 76 ) is provided.
Fan according to claim 56, characterized in that for the regulation of axial rotor position an analog circuit is provided.
Fan according to one of claims 36 to 57, characterized in that for its drive a brushless disc rotor motor ( 52 ), an internal rotor motor or an external rotor motor is provided, in particular a drive which has no or only small occurring radial forces, in particular when the rotor axis is deflected from its center.
Fan according to one of claims 36 to 58, characterized in that a device for temporarily changing the relative position of rotor ( 22 ) and stator ( 50 ) is provided to the radial stiffness (S r ) of the permanent magnetic passive radial bearing (S 16 . 18 ) and thus to change the resonant frequency of the fan during startup or when passing through a critical speed range.
Fan according to one of claims 36 to 59, characterized in that for detecting the axial rotor position (Z) a contactless measuring system ( 33 ) is provided.
Fan according to one of the claims 36 to 60, characterized in that for detecting the axial Rotor position (Z) an evaluation device for electrical quantities of the Axiallagersystems, in particular of voltages or currents, is provided.
Fan according to one of claims 36 to 61, characterized in that for position control of the electromagnetic arrangement ( 57 . 64 ) a control principle with a position tracking ( 210 ), a position controller ( 216 ) and a current regulator ( 202 ) is implemented.
Fan according to one of claims 36 to 62, characterized in that the electromagnetic arrangement ( 57 . 64 ) via a magnetic circuit ( 55 ), which is designed such that the axial forces on at least one electrical conductor ( 64 ), and thus a change in the position of the rotor ( 22 ) relative to the stator ( 50 ) cause.
Fan according to one of claims 36 to 63, characterized in that the electromagnetic arrangement ( 24 ) a magnetic circuit ( 316 ), which is designed such that the axial forces acting on at least one ferromagnetic interface, and thus a change in the position of the rotor ( 22 ) cause.
Fan according to one of claims 36 to 64, characterized in that at least one of the passive magnetic radial bearings ( 16 . 18 ) is designed as a repulsive or attractive magnetic bearing.
Fan according to one of claims 36 to 65, characterized in that at least one damping member ( 26 ) for mechanical or electrodynamic damping of vibrations in the fan ( 100 ) is provided.
DE102007036692A 2006-09-22 2007-08-03 Fan Withdrawn DE102007036692A1 (en)
DE102006046434 2006-09-22
DE102006046434.6 2006-09-22
DE102007036692A1 true DE102007036692A1 (en) 2008-03-27
ID=38875007
DE102007036692A Withdrawn DE102007036692A1 (en) 2006-09-22 2007-08-03 Fan
US (1) US7825558B2 (en)
EP (1) EP2064450B1 (en)
DE (1) DE102007036692A1 (en)
WO (1) WO2008034542A1 (en)
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