Electric disc motor with media separation in the motor gap

Abstract

An electric disc motor with the following features: a rotor (10) having a moving element (105); a stator (20) wherein the stator is arranged relative to the rotor (10) such that a motor gap (30) is provided between the rotor and the stator, wherein the rotor (10) has a recess (40) in which the stator (20) is arranged, wherein the rotor (10) is arranged in a first region (50) with a first pressure, wherein the stator (20) is arranged in a second region (60) with a second pressure, the second pressure being different from the first pressure, and wherein an encapsulation material (70) is arranged in the motor gap (30) by which the first region (50) is separated from the second region (60).wherein the electric disc motor further comprises the following features: a motor housing (110) to which the encapsulation material (70) is directly or indirectly connected, such that inside the motor housing the first region is formed with the first pressure and outside the motor housing the second region is formed with the second pressure.

Description

[0001] The present invention relates to electric motors and in particular to electric disc motors.

[0002] EP 2 549 113 A2 discloses a magnetic rotor and a rotary pump with a magnetic rotor. The rotor is magnetically driven and mounted within a pump housing inside a stator of the rotary pump for pumping a fluid without physical contact. The rotor is also encapsulated by an outer encapsulation containing a fluorinated hydrocarbon. Inside the encapsulation, the rotor comprises a permanent magnet encased in a metal shell. The rotary pump includes a pump housing with an inlet for supplying a fluid and an outlet for discharging the fluid. The fluid is, for example, a chemically aggressive acid containing a gas, such as sulfuric acid with ozone. For pumping the fluid, a magnetic rotor is magnetically mounted within the pump housing without physical contact. The rotor is further equipped with a magnetic drive comprising electrical coils.The stator is made of laminated iron, which is magnetically connected to the rotor's permanent magnet. The drive is a bearingless motor, in which the stator serves simultaneously as both the bearing and drive stator. The rotor is a disc rotor, with its axial height being less than or equal to half its diameter.

[0003] The ETH dissertation No. 12870, "The Bearingless Disc Motor," by N. Barletta, 1998, discloses magnetically levitated disc motors. These magnetic bearings operate completely without contact, wear, maintenance, or lubrication. Two controllable electromagnets, including electronic control, are required for the active stabilization of one degree of freedom. The bearingless disc motor is used within a bearingless blood pump as a bearingless disc motor with an active axial bearing, as a miniature disc motor, or as a bearingless bioreactor. A combination of passive reluctance magnetic bearings and a bearingless motor makes it possible to fully support a disc rotor with only two actively stabilized radial degrees of freedom. The requirement for a large air gap, necessary in hermetic systems, is met by using a bearingless permanent magnet synchronous motor.A bearingless disc motor suitable for driving an axial pump for cardiac support is designed for speeds of 30,000 revolutions per minute, resulting in a smaller size.

[0004] Commercial electric disc motors are also known as "pancake motors." The motor concept described in the two preceding references is characterized by the fact that the stator extends around the rotor. Such motors are also called internal rotor motors.

[0005] The problem with the internal rotor design is that the stator must always be larger than the rotor, meaning that the size and design of the rotor are always limited by the stator housing, or rather, that the rotor dominates the design of the stator. This limits the application range of such a disc motor designed as an internal rotor.

[0006] Furthermore, disc motors inherently suffer from the problem that the rotor, regardless of whether it is designed as an internal or external rotor, is subjected to pressure differentials or pressures in certain directions. These pressures cause a bearing to be loaded in the direction of the pressure acting on the rotor, thus increasing wear. Alternatively, if rotor deflection is permitted, the rotor will deflect in this direction, necessitating the provision of clearance for this deflection. Particularly when the pump is used to transfer a medium from a pressure zone with a lower pressure to a pressure zone with a lower pressure, or even to generate such a pressure differential in the first place, complex design measures must be implemented to either achieve the required wear resistance or to provide sufficient clearance for the resulting deflection.

[0007] All of this leads to an increase in the design complexity of the disc motor, and thus also an increase in its susceptibility to errors, while at the same time restricting its area of ​​application.

[0008] The object of the present invention is to create a flexible disc motor concept.

[0009] This problem is solved by an electric disc motor according to claim 1, a heat pump according to claim 23 or a method for manufacturing an electric disc motor according to claim 25.

[0010] In one respect, the electric disc motor is designed as an external rotor. This means that the rotor has a recess in which the stator is located. The rotor then rotates around the stator. This allows the rotor design to be defined directly by its application, rather than always requiring, as with an internal rotor motor, the addition of a stator housing with corresponding magnetic coils. Furthermore, the disc motor is media- and pressure-separated by encapsulating the stator within the motor gap between the rotor and stator, thus completely isolating the stator from the surrounding media and pressure.This allows all coil connections for the motor coils in the stator to be routed out of the motor without any problems, because the entire stator area is at ambient pressure and / or in the ambient medium, and not in the pumping zone where the rotor is located. This also avoids overvoltage problems and similar effects that occur when high voltages are used in low-pressure areas, because the adjacent stator coils are all separated from the low-pressure area by the encapsulation material located in the motor gap. This is particularly important when the rotor operates in a low-pressure area, such as below 100 mbar, which occurs when the rotor is used as a compressor element in a heat pump that uses water as the working medium. However, even when the rotor operates at a higher pressure than the stator, the media / fluid is protected.Pressure separation through an encapsulation material in the engine gap is of particular advantage.

[0011] By using an external rotor in conjunction with media / pressure separation through an encapsulation material in the motor gap, an electric disc motor is created that can be manufactured with minimal structural complexity, avoids the problems associated with overvoltage effects that would occur when coils are subjected to relatively high voltage in low-pressure areas, and is particularly well-suited for high speeds. This latter advantage arises from the fact that the permanent magnets attached to the rotor, which define the magnetic gap on the rotor side, are supported "outwardly" by the rotor material itself. This is especially important at high speeds, such as those exceeding 50,000 revolutions per minute, because the centrifugal forces occurring at these speeds can be problematic, particularly in internal rotor motors, requiring the permanent magnets to be secured with considerable effort.

[0012] On the other hand, the larger rotor diameter, due to the rotor being arranged around the stator, is particularly advantageous at speeds above 50,000 revolutions per minute, because, as with a gyroscope, it further stabilizes the rotation of the rotor itself and its axis of rotation. This effect is less pronounced or absent in electric disc motors with relatively small rotor diameters, such as those used in internal rotor motors.

[0013] In another aspect, the electric disc motor is used as either an external or internal rotor motor. It has a rotor, which contains a moving element, and a stator, which is positioned relative to the rotor such that a motor gap is formed between the rotor and the stator. The electric disc motor is designed to convey a medium from a source area to a target area through the moving element, where the target pressure in the target area is higher than the source pressure in the source area. According to this aspect, the pressure acting on the rotor due to the pressure difference is reduced by a pressure reducer, such that the pressure in the motor gap, i.e., where the magnetic interaction between the rotor and stator takes place, is lower than the target pressure and greater than or equal to the source pressure.This ensures that the rotor is no longer, or at least less, stressed in a certain direction due to the pressure difference between source pressure and target pressure, which would otherwise lead to a resulting pressure and thus to a deflection or increased wear of the bearing.

[0014] This means that while the rotor can generate the required pressure difference between the inlet and outlet, i.e., between the source and target areas, no such pressure difference, or only a reduced one, exists in the motor gap and thus in the area of ​​interaction between the rotor and stator. Using the example of a bearingless motor that is only passively supported axially, for example by a magnetic bearing, this reduces or even eliminates axial deflection due to the operation of the electric disc motor.

[0015] However, even in the case of a contact-mounted rotor, i.e., a rotor supported by a ball bearing, pressure reduction prevents the pressure from being transferred to the bearing and increasing bearing wear. Pressure reduction in the motor gap thus leads to a reduction in motor and bearing wear. In the case of wear-free bearings, i.e., non-contact bearings, the necessary clearances for rotor deflection due to the resulting pressure on the rotor in a specific direction, either axial or radial, can be reduced because, due to the rotor's operation, such deflections either do not occur or are very small compared to a situation where no specific mechanical pressure reduction is applied.

[0016] Pressure reduction in the motor gap is equally beneficial for both external and internal rotor motors. Even with an internal rotor, it is advantageous that the rotor does not experience significantly greater deflection during operation than when stationary. This allows for a reduction in clearances, i.e., clearances between the rotor and a guide element that limits the fluid flow area in which the rotor operates.

[0017] In preferred embodiments, the pressure reduction is achieved by two flow resistances: a first flow resistance located between the target area and the engine gap, and a second flow resistance located between the engine gap and the source area. In particular, the flow resistance between the engine gap and the target area is designed to be greater than the flow resistance between the engine gap and the source area, so that the flow resistance between the engine gap and the target area reduces the pressure short circuit, while the flow resistance between the engine gap and the source area ensures that the lower pressure acting in the engine gap is the same as that acting in the source area.Particularly when the motor is designed as an external rotor, such that the stator is arranged in a recess of the rotor, it is preferred to position the flux resistance between the target area and the motor gap as far out on the rotor as possible, so that as large a portion of the rotor surface as possible, opposite the stator, is located in an area exposed to the low source pressure or a pressure lower than the target pressure. Conversely, it is preferred to position the second flux resistance between the motor gap and the source area as centrally as possible, i.e., relatively in the middle of the rotor, to achieve conditions as uniform as possible around the circumference of the motor gap.

[0018] In preferred embodiments, the pressure reducer comprises a labyrinth seal between the target area and the motor gap, which creates a defined and relatively high flux resistance, and alternatively or additionally a bore in the rotor between the motor gap and the source area, which creates a relatively low flux resistance. Even the use of either only a labyrinth seal or only a bore, i.e., the use of only one flux resistance between the source area and the motor gap or the target area and the motor gap, already leads to a pressure reduction in the motor gap and thus to a reduced deflection of the rotor relative to the stator during operation in the case of a non-contact magnetic bearing, and especially in the case of an axially passive bearing, or to a reduction in wear in the case of a contact bearing, such as a ball bearing, due to the reduced load during operation.

[0019] The first aspect of the encapsulation material in the motor gap and the second aspect of the pressure reducer can preferably be combined, such that an external rotor disc motor incorporates both the encapsulation in the motor gap and the pressure reducer. However, the two aspects can also be used interchangeably and, with regard to the pressure reducer, not only for external rotors but also for internal rotors. Furthermore, both aspects can be used separately or together for contact bearings, although the use of magnetically levitated rotors is preferred, and in particular axially passive bearings, i.e., axially unregulated bearings and radially actively regulated magnetic bearings.

[0020] Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings. These show:

[0021] Fig. 1A an outrunner according to a first aspect;

[0022] Fig. 1B an electric disc motor according to a second aspect, designed as an external rotor or internal rotor;

[0023] Fig. 1C an internal runner according to the second aspect;

[0024] Fig. 1D a preferred implementation of the second aspect with two series-connected flux resistors;

[0025] Fig. 2A a cross-section through an electric disc motor according to the first aspect;

[0026] Fig. 2B a cross-section through an electric disc motor according to the second aspect in which the first aspect is also realized;

[0027] Fig. 3 a cross-section through a detailed representation of an implementation of flow resistance using a labyrinth seal;

[0028] Fig. 4 a schematic representation of a rotor and the forces acting on it with regard to the second aspect;

[0029] Fig. 5 a schematic representation of a magnetic bearing using the example of an internal rotor;

[0030] Fig. 6 a cross-sectional view of an outer rotor with an increased return element; and

[0031] Fig. 7 a schematic cross-section through a heat pump with the electric disc motor according to the first or second aspect.

[0032] Fig. 1A shows a cross-section through a schematically represented electric disc motor with a rotor 10 , which has an element to be moved. Furthermore, a stator is 20 present, whereby the stator 20 so regarding the rotor 10 is arranged so that there is an engine gap 30 between the rotor and the stator. The rotor 10also includes an exclusion 40 , in which the stator 20 is arranged.

[0033] Furthermore, the rotor 10 in a first area 50 with a first pressure p1. Furthermore, the stator is located in a second area. 60 , which has a second pressure p3, arranged in a manner that differs from the first pressure p1. In the case of the Fig. In the embodiment shown in 1A, the first pressure is, for example, the pressure inside the electric disc motor of Fig. 1A. In contrast, the second pressure is, for example, ambient pressure or atmospheric pressure if the disc motor is located in the atmosphere, or a pressure different from atmospheric pressure if the disc motor is located in an area with a pressure different from atmospheric pressure. Furthermore, in the motor gap 30 an encapsulation material 70arranged by which the first area 50 from the second area 60 is separated. The separation occurs, for example, when the encapsulation material is separated in the Fig. In the embodiment shown in 1A, the stator is completely enclosed, and connecting leads 80 for the coils that are attached to the stator and that are in Fig. 1A are not shown, to supply the coils with electrical power, through the encapsulation material to the outside, i.e. into the second area 60 The electric disc motor is designed as a conveyor motor and includes an inlet. 90 for a working medium and an outlet 100 for the working fluid conveyed by the disc motor. As it is in Fig. As shown in Figure 1A, the pressure inside the disc motor, p1, differs from the pressure outside the disc motor, p3. Preferably, the pressure p1 inside the disc motor is lower than the pressure outside the disc motor. Likewise, the pressure outside the disc motor can be lower than the pressure inside, i.e., within the motor housing.

[0034] In particular, in Fig. 1A further shows that the rotor and stator are housed in a motor casing 110 are arranged, wherein the motor housing has an opening through which the encapsulation material can pass. 70 extends. The encapsulation material, or an element to which the encapsulation material is connected, is attached to the motor housing. 110 by a schematically represented sealing ring 120 attached so that a pressure-tight connection between the encapsulation material 70 and the engine housing 110about the sealing ring 120 , which could be, for example, an O-ring, is present. This means that in Fig. 1A An external rotor is implemented as an exemplary electric disc motor in which the rotor moves within a motor housing, while the stator coils, and in particular the area of ​​the stator located at the motor gap, do not communicate with the internal pressure p1 of the disc motor, but rather with the external pressure. This is particularly advantageous with regard to the electrical supply of the coils typically located in the stator. Especially when the internal pressure p1 is lower than the external pressure p3, it offers significant advantages with regard to coil flashovers and other effects that the coils are not located in the low-pressure region, but are encapsulated from it.

[0035] Furthermore, encapsulating the coils in relation to the interior of the disc motor has advantages in that the coils do not come into contact with the medium being conveyed and are therefore not exposed to corrosion due to the medium being conveyed, which can be, for example, water or steam. Fig. 1A further shows that the rotor 10 with permanent magnets 130 is provided with, which are opposite the stator-side area, which typically has stator-side poles on which magnetic coils are wound, to close the motor gap 30 to define.

[0036] Fig. 1B shows an electric disc motor according to a second aspect, which also has a rotor. 10 features a stator 20 opposite, to close the engine gap 30 to define. In particular, the second aspect, which is in Fig. As shown in 1B, the electric disc motor is designed to move the element to be moved, which is connected to the rotor. 10 is connected, and that with Fig. 1B together with the rotor 10 shown is a medium of an inlet 90 or a source area 90 , in which there is less pressure, into a target area 100 or to an outlet 100 to promote pressure in areas where the target area has high pressure, or more generally, higher pressure than the source area. Furthermore, the electric switching motor is designed to act as a pressure reducer. 140 to have a design that reduces the pressure acting on the rotor due to the pressure differences in the source and target areas. In particular, the pressure reducer is designed such that a pressure in the motor gap 30The pressure is lower than the target pressure or the high pressure, but greater than or equal to the source pressure. The pressure reducer 140 It is therefore designed to reduce the pressure in the engine gap compared to a situation where the pressure reducer is not present. 30 to reduce the pressure compared to the higher pressure in the target area and ideally to equalize the pressure in the source area or to bring it between the target pressure and the source pressure.

[0037] Fig. Figure 1D shows an alternative implementation of the electric disc motor from Fig. 1B where in turn a stator 20 is present, which is now part of the engine housing 110 forms. The stator is further equipped with coils. 150 equipped with permanent magnets 130 of the rotor 10 opposite each other to close the engine gap again 30 to form. Furthermore, the rotor 10with a movable element formed here above the rotor and connected to the rotor 105 connected. The pressure reducer 140 is in turn intended to be located in the engine gap 30 to reduce the pressure, specifically the pressure in the target area, i.e., the pressure at the outlet. 100 .

[0038] As it is in Fig. As shown in 1D, the pressure reducer includes 140 for example, a first flow resistance 140a between the target area 100 and the engine gap 30 as well as a second flux resistance 140b between the engine gap 30 and the source area 90 or the entrance 90 The two flux resistances 140a , 140bPreferably, both are present. However, depending on the implementation, it may be sufficient to reduce the pressure acting on the rotor due to the operation of the disc rotor by reducing only the first flux resistance between the target area and the motor gap, or, alternatively, the second flux resistance. 140b to be provided between the engine gap and the source area. Preferably, the first flow resistance has 140a , if both flux resistances 140a , 140b are intended to have a higher value than the second flow resistance 140b This means that the pressure in the engine gap 30 preferably more of the high pressure in the target area 100 The pressure in the engine gap differs from the pressure in the engine gap. 30 differs from the pressure in the source area when the electric disc motor is operated.

[0039] Fig. Figure 2A shows a preferred embodiment of the electric disc motor according to the first aspect by way of an embodiment for a radial wheel compressor which can be used at high speeds above 50,000 revolutions per minute and up to, for example, 90,000 revolutions per minute within a heat pump which can be operated with, for example, water as the working medium.

[0040] Fig. Figure 2A shows an implementation of the disc motor according to the first aspect, where the stator 20 with the encapsulation material 70 is encapsulated, so that the media separation between the high and low pressure areas is achieved via the engine gap. 40 takes place. The stator 20 is equipped with coils that are in Fig. 2A are not shown, but are accessible via the access lines. 80 , which are characterized by the encapsulation material 70extend or, if the encapsulation material only encapsulates the motor gap and parts of the stator, already in the surrounding area 60 condition.

[0041] The rotor, which is driven by the permanent magnets 130 , a feedback element encompassing the permanent magnets 160 as well as bandaging applied as an additional safety measure 170 is formed, is furthermore connected to the element to be moved 105 connected, which in Fig. Figure 2A is shown schematically as a radial wheel with blades. In particular, the electric disc motor is designed to drive the radial wheel. 105 and the rotor 10 within a guide element 180 to turn that has a range 190 from the respective blade ends of the radial wheel 105The radial wheel is spaced apart. It is designed to typically bring steam from an evaporator, where a lower pressure p0 prevails, to a first pressure p1. This first pressure p1 typically exists at an outlet of the radial wheel, also called an impeller, as seen in Fig. 2A is shown schematically. Typically, the guide element is coupled to a guide chamber, so that the steam accelerated by the rotation of the radial wheel is brought into the guide chamber, and there, due to the continuous demand for steam by the radial wheel, is brought to a higher target pressure p2, which prevails during the condensation of the heat pump, as described in Fig. Figure 2A is shown. In the case of the external rotor, the height of the electrically effective stator is... 20 smaller than the diameter of the stator and preferably smaller than half the diameter of the stator. If, on the other hand, the internal rotor is considered, then in this case, if Fig. 1C is taken as a reference, the height of the electrically effective rotor is preferably smaller than the diameter of the electrically effective rotor and preferably even smaller than half the diameter of the rotor.

[0042] Fig. Figure 2B shows an embodiment of the electric disc motor according to the second aspect, in connection with an application for a radial wheel of a compressor of a heat pump, as shown by Fig. 2A has been shown. In addition to the ones in Fig. The elements shown in 2A are present in the Fig. In the embodiment shown in 2B, the two flux resistances are also shown. 140a , 140b , which are based on Fig. The pressure reducer, as described in 1D, is formed. In particular, it includes... 140 at the in Fig. 2B shown as an exemplary second flux resistance 140b a bore 200 in the rotor 105, which is trained to create a media passage from the engine gap 40 to the source area or inlet 90 to allow into the compressor. This makes it possible for a media to pass through the element being moved. 105 , which is connected to the rotor.

[0043] Furthermore, in the Fig. 2B shown embodiment of the pressure reducer 140 trained to handle a variety of construction elements 210a , 210b , 210c to have, which between the target area or the outlet from the radial wheel, which is also with 100 in Fig. 2B is shown, and the engine gap 140 are present. This results from the interaction of the majority of construction elements. 210a – 210c a pressure drop from the target area 100, which has a pressure p1, reaches the motor gap, which only has a pressure p1', which is smaller than the pressure p1 and greater than or equal to the pressure p0 in the source area, i.e. at the inlet 90 is. In particular, a first design element of the plurality of design elements is attached to the rotor. This design element is located in the Fig. In the embodiment shown in 2B, the construction element 210b Furthermore, a design element is one of the multiple design elements on an engine housing, such as the engine housing. 110 attached, with this structural element serving as a structural element 210a or 210c is designated. Furthermore, the two structural elements, which are described as protruding rings, which have a cross-section of Fig. The elements shown in 2B are designed and arranged in such a way that their interaction causes a pressure drop. In particular, the design elements form 210a – 210c a labyrinth seal. In the Fig. In the embodiment shown in 2B, the structural elements are each designed as protruding rings. However, they can also be designed as alternative structural elements that extend from a surface of the motor housing. 110 on the one hand and of the rotor or the element to be moved on the other hand, in order to interact in such a way that the rotor can be rotated relative to the motor housing, and in such a way that, due to the close proximity of the structural elements to each other, a pressure drop occurs, so that the pressure p1' within the labyrinth seal with the structural elements 210a – 210c is smaller than the pressure p1 outside the labyrinth seal.

[0044] Fig. Figure 3 shows an alternative, enlarged-scale representation of the embodiment of Fig. 2B. Furthermore, there are other construction elements 212a – 212d formed, whereby the construction elements are again 212a , 212c on the case 210 are arranged, and the construction elements 212b , 212d on the case 210 or the moving element 105 are arranged. In contrast to the structural elements 210a until 210c or 210d from Fig. The 3, which extend radially with respect to a rotation of the rotor, are the construction elements. 212a – 212d axial with respect to a rotation of the rotor 10 arranged. In one implementation, radial, axial, or alternatively oriented design elements can be provided as labyrinth seals, or only radial design elements. 210a – 210dor only axial structural elements 212a – 212d or only construction elements designed in other directions.

[0045] Furthermore, it is not necessarily required that only a relatively small number of construction elements, such as in Fig. Figure 2B shows that the components do not necessarily interact with each other; rather, more or even fewer components can interact, for example, only two components or four or more. Furthermore, it is also possible that more components are attached to the rotor than to the housing, or vice versa.

[0046] In one implementation, the structural elements could also be placed between the rotor and stator, outside the motor gap. However, this is not the case in the application in Fig. 2B or, in general, preferably, to place the structural elements between the rotor / moving element and the motor housing, since then the structural elements or the associated flux resistance R1 140a between the target area 100 and the engine gap 30 is placed as far out as possible with respect to the rotor, while at the same time the second flux resistance, i.e. the bore 200 through the rotor, ideally mounted as far inside as possible and preferably even directly axially within the rotor. This ensures that the largest possible area of ​​the rotor, specifically at the top where it is located, is exposed. Fig. The orientation shown in 2B, which is also a preferred orientation for this disc motor in a heat pump compressor application, is not subjected to the target pressure p1, but only to the reduced pressure p1'. Therefore, the operation of the rotor, which ultimately creates the different pressures p1 and p0, will not cause any downward deflection of the rotor, or only a very small deflection. Thus, the clearance can 190 between the guide element 180 and the radial wheel 105 They can be made very small, so that a compressor with good efficiency is obtained.

[0047] On the other hand, the small deflection of the radial wheel in the axial direction, i.e., when in Fig. As shown in example 2B below, the rotor can be magnetically supported, and in particular with a magnetic bearing that is passive in the axial direction, i.e., not controlled in this direction, but only in the radial direction. Thus, control is only required in one direction, namely the radial direction. This results in an electric disc motor which, despite the considerable speeds it is capable of achieving, has a simple bearing control concept, since axial bearing control is not necessary, while the rotor still has a small clearance relative to the guide element. 180 can be operated to achieve high efficiency.

[0048] Fig. Figure 4 shows a schematic representation of the forces acting on the rotor. The rotor 10 or the element to be moved 105The rotor is again schematically represented as a cross-sectional view of a radial wheel, although the individual blades are not shown in detail for clarity, although they are immediately obvious to experts. When the rotor is operating, a low evaporation pressure p0 exists in the source region, while a higher pressure p1 is present at the outlet of the radial wheel in the target region. This higher pressure is increased to the even higher condenser pressure by the guide chamber to which the radial wheel borders. The outlet pressure p1 exerts a force F1 on the relatively large upper surface of the radial wheel, which is equal to the product of p1 and the area A1, i.e., the area shown in the top view of the rotor. 10 from above.

[0049] In addition, a small pressure F0 acts on the rotor from below, which is equal to the product of the low source pressure p0 and the relatively small area A0.

[0050] In addition, a weight force F acts gon the rotor, which is equal to the mass of the rotor m R times the acceleration due to gravity g. In addition, a force F also acts on it. M again upwards, which is equal to the change in mass over time multiplied by the velocity of the mass flow that the radial wheel draws in from bottom to top. The weight force and the force due to the mass flow are externally determined. The same applies to the dimensions of areas A0 and A1. However, the pressure reducer 140According to the present invention, the pressure p1 is reduced. This minimizes the difference between p0·A0 and p1·A1 through the pressure reducer. As a result, the total force acting on the rotor or the moving element due to rotor operation is reduced as much as possible, which in turn leads to reduced rotor deflection when the rotor is in operation. If no deflection is permitted due to an existing contact bearing, such as a ball bearing, the pressure on the bearing is reduced.

[0051] Preferably, the rotor is supported relative to the stator by a magnetic bearing, as exemplified in Fig. 5 is shown. Fig. 5 are the two axial directions 250 and radial 260 shown. There is also a motor with a motor gap. 40The rotor is held axially relative to the stator by the permanent magnets on the rotor side and the electrical coils on the stator side, and is not specifically controlled. In contrast, a radial sensing device... 270 as well as a radial control / regulating device 280 planned. The radial detection device 270 Detects the position of the rotor relative to the stator, or vice versa, via detection lines. 271 The result of the radial measurement 270 is via a sensor line 272 the radial control / regulating device 280 communicated. This generates corresponding actuator signals via actuator signal lines. 273 at the rotor or the stator, depending on the implementation. However, it is preferred to control only the rotor in order to control its position relative to the stator based on the actuator signal. 273 to position it in such a way that the engine gap 40the rotor is of a similar size all around and the rotor does not touch the stator.

[0052] At the in Fig. In the embodiment shown in Figure 5, the rotor can be on the inside and the stator on the outside. In this case, it is an internal rotor. However, the inner element can also be the stator and the outer element the rotor, making it an external rotor. In principle, the magnetic bearing is similar in both cases in that axial control does not occur, while radial control is achieved by the radial sensing device. 270 and the radial control / regulating device 280 takes place.

[0053] Fig. Figure 6 shows a cross-section through a preferred rotor, which is designed in multiple sections. In particular, the rotor comprises the moving element. 105, which in preferred embodiments of the present invention is made of a non-ferromagnetic material, such as plastic or aluminum. The moving element is, for example, a paddle wheel or impeller of a turbo compressor, such as those used in a heat pump.

[0054] In contrast, the rotor 10 , which contains the permanent magnets 130 , the ring-shaped permanent magnets 130 surrounding backstop element and the bandage arranged above it 170 The retaining element is made of a different material than the moving element. In particular, the permanent magnets are made of a specific material suitable for permanent magnets. The return element is ring-shaped and made of a ferromagnetic material, and the bandage... 170 is preferably made of carbon material.

[0055] At the in Fig. In the embodiment shown in 6, the permanent magnets are 130 partly over a first flat side 105a before, in which the recess 40 is formed. The element to be moved 105 It also has a second "flat" side 105b , which, however, has a smaller diameter than the first side 105a , which can also be seen as a "flat" side if the recess is used for presentation purposes 40 is considered non-existent, and furthermore, if the board is in the form of a circumferential spring 276 is also disregarded. Preferably, however, the spring takes hold. 276 in one in the inference element 160 provided ring-shaped groove 278 one, so that the lead 276 and the groove 278 Intervene. Depending on the design, however, a spring may also be incorporated into the return element and into the element to be moved. 105 or in the first “flat” side 105aThe groove must be provided. This gives the connection between the return element, permanent magnet, and bandage structural stability with the element to be moved. 105 , creating a stable overall structure that retains its shape and structure even at high speeds. In particular, the recess ensures this. 40 Furthermore, it is ensured that the permanent magnets and the return element press against the rotor material due to centrifugal forces, so that the connection between the return element on the one hand and the rotor material on the other hand becomes stronger the higher the rotational speed.

[0056] Regarding the dimensions, it is preferred that the engine gap 40 is less than 1.5 mm, wherein, in the case of encapsulation in the motor gap, the distance between the encapsulation material and the permanent magnets is less than 1.5 mm. Furthermore, it is preferred that the stator diameter be less than 1.5 mm. 20between 3 cm and 7 cm, or that the stator height is less than 4 cm. Furthermore, the electric disc motor is designed to run at a speed greater than 50,000 revolutions per minute. Furthermore, the bore 200 a diameter preferably between 1 and 4 mm. Furthermore, a tolerance is required. 190 between the guide element 180 and the paddle wheel 105 preferably smaller than 1.5 mm.

[0057] Furthermore, as is particularly evident in Fig. As shown in 6, preferably the element to be moved 105 the first “flat” side 105a has, which the stator 20 opposite, and the second flat side 105b has, which is from the stator 20 is turned away, with the diameter of the first flat side being larger than the diameter of the second flat side. Furthermore, as mentioned, the recess 40 in the first flat side 105aarranged, wherein the permanent magnets 130 at least partially in the recess 40 are localized. Furthermore, in preferred embodiments, it is advantageous that the return element has a more trapezoidal cross-sectional shape, as shown in Fig. 6 is drawn, so that an upper edge of the inference element 160 is arranged higher in the axial direction than the upper edge of the permanent magnets 130 This means the permanent magnets 130 positioned as deep as possible in the recess, while the return element is held in place by the permanent magnets. 130 regarding his side, which is covered with a bandage 170 is connected, presides over.

[0058] Furthermore, as is more clearly stated, for example, in Fig. 2B shows the encapsulation material 70 not only in the engine gap 40 at the stator 20 attached, but also on the underside of the stator 20 in Fig. 2B, i.e., the side of the stator that has the recess 40 opposite. The stator 20 The stator is preferably disc-shaped and has a normal that is parallel to or coincides with the axis of rotation. The flat side of the stator lies over the recess. 40 opposite a corresponding side of the element to be moved, and the encapsulation material 70 It is also applied to the flat side of the stator, in addition to the corresponding sides of the permanent magnets. However, it is not necessary for the encapsulation material to cover the entire area above the stator. 20 fills. Instead, it is sufficient that the encapsulation material of the stator seals against the interior of the electric disc motor.

[0059] Fig. Figure 7 shows a preferred application of the electric disc motor using the example of a heat pump. The heat pump includes an evaporator. 300, a compressor 400 and a liquefaction 500 , where the compressor 400 the electric disc motor, which refers to the Fig. 1A to Fig. 6 has been described. In addition to the elements of the disc motor, which, for example, refer to Fig. As shown in 2A, the compressor also includes a guide chamber. 510 , which is arranged radially to deflect the element to be moved 105 The working steam produced by the evaporator 300 has been drawn in, to be conveyed further and ultimately to increase the pressure to the required pressure in the condensation zone in the condenser. 500 to increase.

[0060] The liquid to be cooled flows through an evaporator inlet. 302 into the evaporator. Cooled working fluid flows through an evaporator outlet. 304 again from the evaporator. To ensure that the radial wheel 105It only draws in steam and not water droplets; it also has a droplet separator. 306 Provided. Due to the low pressure in the evaporator. 300 A portion of the water is drawn via the evaporator inlet. 302 into the evaporator 300 The introduced working fluid evaporates and passes through the droplet separator. 306 through across the second side 105b of the radial wheel 105 sucked in and pumped upwards and then into the control chamber 510 handed in. From the control room 510 Compressed working steam is introduced into the condensation zone. 510 brought to the condensation zone. 510 Furthermore, it is connected via a condenser inlet. 512 The working fluid to be heated is supplied, which is heated by condensation with the heated steam and flows through a condenser outlet. 514is discharged. Preferably, the condenser is designed as a condenser in the form of a "shower", so that via a distribution device 516 a liquid distribution in the condensation zone 510 This is achieved so that the compressed working steam is condensed as efficiently as possible and the heat contained in it is transferred to the liquid in the condenser.

[0061] At the in Fig. In the embodiment shown in 7, the motor housing forms 110 at the same time also the upper housing part of the condenser or liquefier 500 Furthermore, as is further explained in Fig. As shown in section 7, the connecting cable 80 for the stator coils 20 with a control 600 connected to perform the corresponding speed controls and simultaneously also the active bearing via a preferably used magnetic bearing, as shown by the Fig. As described in section 5. The control system also provides the functions of radial detection. 270 and the radial control / regulation 280 ready.

[0062] Although certain elements are described as device elements, it should be noted that this description can equally be seen as a description of steps in a process and vice versa.

[0063] Furthermore, it should be noted that the control is, for example, by the element 600 in Fig. 7 or 280 in Fig.5. The control system can be implemented as software or hardware. The control system can be implemented on a non-volatile storage medium, a digital or other storage medium, in particular a floppy disk or CD with electronically readable control signals that can interact with a programmable computer system to execute the corresponding method for pumping heat or operating a heat pump. In general, the invention thus also includes a computer program product with program code stored on a machine-readable medium for carrying out the method, provided the computer program product runs on a computer. In other words, the invention can also be realized as a computer program with program code for carrying out the method, provided the computer program runs on a computer. Reference symbol list 10 Rotor 20 Stator 30 engine gap 40 Exclusion 50 first area 60 second area 70 Encapsulation material 80 connecting lines 90 Inlet / Source area 100 Exit / Destination area 105 element to be moved 105a first page 105b second page 110 engine housings 120 seals 130 permanent magnets 140 pressure reducers 140a first flow resistance 140b second flux resistance 150 stator coils 160 Inference element 170 Bandage 180 guide element 190 leeway 200 bore 210A-210d structural elements 212a–212d construction elements 250 Axial direction 260 Radial direction 270 Radial detection device 271 Recording line 272 Control line 273 Actuator line 276 lead 278 Nut 280 Radial control / regulation 300 evaporators 302 Evaporator inlet 304 Evaporator drain 306 droplet separators 400 compressor 410 Route 500 condensers 510 Condensation zone 512 Condenser inlet 514 Condenser outlet 516 Condenser distributor 600 control QUOTES INCLUDED IN THE DESCRIPTION

[0064] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0065] EP 2549113 A2

[0002] Cited non-patent literature

[0066] Dissertation ETH No. 12870, “The Bearingless Disc Motor”, N. Barletta, 1998

[0003]

Claims

[1] Electric disc motor with the following features: a rotor ( 10 ), which is an element to be moved ( 105 ) exhibits; a stator ( 10 ), wherein the stator is positioned relative to the rotor ( 20 ) is arranged so that an engine gap ( 30 ) between the rotor and the stator, where the rotor ( 10 ) an exception ( 40 ) has, in which the stator ( 20 ) is arranged, where the rotor ( 10 ) in a first area ( 50 ) is arranged with a first pressure, where the stator ( 20 ) in a second area ( 60 ) is arranged with a second pressure, wherein the second pressure differs from the first pressure, and where in the engine gap ( 30 ) an encapsulation material ( 70 ) is arranged through which the first area ( 50 ) from the second area ( 60) is separated. [2] Electric disc motor according to claim 1, further comprising the following features: a motor housing ( 110 ), with which the encapsulation material ( 70 ) is connected directly or indirectly, so that inside the motor housing the first area is formed with the first pressure and outside the motor housing the second area is formed with the second pressure. [3] Electric disc motor according to claim 1 or 2, wherein the stator ( 20 ) a plurality of coils ( 150 ) has which are connected to ( 80 ) are provided, and which are applied to poles, the encapsulation material being ( 70 ) the coils ( 150 ) and surrounds the poles, and wherein the connecting lines ( 80 ) from the encapsulation material ( 70 ) into the second area ( 60 ) stand before. [4] Electric disc motor according to one of the preceding claims, which can be operated such that the first pressure is less than the second pressure. [5] Electric disc motor according to one of the preceding claims, wherein the rotor is actively magnetically supported radially with respect to an axis of rotation of the rotor ( 270 , 280 ). [6] Electric disc motor according to one of the preceding claims, wherein the rotor is axially oriented with respect to an axis of rotation of the rotor ( 10 ) is magnetically passively mounted. [7] Electric disc motor according to one of the preceding claims, wherein the rotor ( 10 ) on an interior area of ​​the recess ( 40 ) a plurality of permanent magnets ( 130 ) having a ring-shaped magnetic return element ( 160 ) the permanent magnets ( 130 ) surrounds, so that the permanent magnets between the return element and the motor gap ( 30are arranged. [8] Electric disc motor according to claim 7, in which the annular return element ( 160 ) a bandage ( 170 ) on the side of the inference element ( 160 ) is attached, which is held by the permanent magnet ( 130 ) is turned away. [9] Electric disc motor according to any one of the preceding claims, in which the stator ( 20 ) is disc-shaped and has a flat side whose normal is parallel to or coincides with an axis of rotation, where the flat side of the stator forms one side of the element to be moved ( 150 ) opposite, and where the encapsulation material ( 70 ) on the flat side of the stator ( 20 ) and on one end face of the stator, the permanent magnets ( 130 ) of the rotor ( 10 ) opposite, is arranged. [10] Electric disc motor according to one of the preceding claims, wherein the element to be moved ( 105 ) a first page ( 105a ) has, which is the stator ( 20 ) opposite, and a second side ( 105b ) has, which is facing away from the stator, wherein a first diameter of the first side is larger than a second diameter of the second side. [11] Electric disc motor according to claim 10, wherein in the first side ( 105a ) the exception ( 40 ) is arranged in which the permanent magnets ( 130 ) are at least partially arranged, with the permanent magnets ( 130 ) on one of the stator ( 20 ) opposite side with a ring-shaped return element ( 160 are provided. [12] Electric disc motor according to claim 11, where the permanent magnets ( 130 ) at least partially via the first page ( 105a) protrude, or wherein the ring-shaped return element ( 160 ) about the first page ( 105a ) precedes, or where the permanent magnets ( 130 ) a first length over the first side ( 105a ) protrude and the ring-shaped return element ( 160 ) by a second length, which is greater than the first length, over the first side ( 105a ) is in charge. [13] Electric disc motor according to one of claims 10 to 12, where the first page ( 105a ) a lead ( 276 ) has a ring-shaped return element ( 160 ) a groove ( 278 ) exhibits which is trained to take the lead ( 276 to intervene, or where the first page ( 105a ) has a groove and the ring-shaped return element ( 160 ) has the projection, the projection being designed to engage the groove. [14] Electric disc motor according to one of the preceding claims, in which a motor housing ( 110 ) has a cover with which the stator ( 20 ) and the encapsulation material ( 70 ) are connected, or where the lid is made from the encapsulation material in one piece, or wherein the cover is detachably connected to a motor housing part, and wherein a seal is provided at an interface between the cover and the motor housing part ( 120 ) is formed, through which the first area ( 50 ) from the second area ( 60 ) is sealed. [15] Electric disc motor according to one of the preceding claims, wherein the element to be moved ( 105 ) is a radial wheel with blades, wherein the blades are designed to convey gas to a third area at a higher pressure than the first pressure when the radial wheel rotates. [16] Electric disc motor according to claim 15, wherein the encapsulation material ( 70 ) is arranged such that the third area communicates with the first area, and that the first and third areas do not communicate with the second area. [17] Electric disc motor according to one of the preceding claims, which is designed such that the motor gap ( 30 ) is less than 1.5 mm, or where the diameter of the stator ( 20 ) between 3 cm and 7 cm, or where the height of the stator ( 20 ) is smaller than 4 cm, or is designed to run at a speed greater than 50,000 rpm. [18] Electric disc motor according to one of the preceding claims, wherein the rotor ( 10 ) with the element to be moved ( 105 ) is connected, wherein the element to be moved is made of aluminum or plastic, and the rotor ( 10 ) Permanent magnets ( 130) and a magnetic return element ( 160 ) exhibits. [19] Electric disc motor according to any of the preceding claims, which is trained to draw a medium from a source area through the element to be moved ( 90 ) into a target area ( 100 ) to promote, whereby the pressure in the target area ( 100 ) higher than a pressure in the source area ( 90 ) is, the electric disc motor further has the following feature: a pressure reducer ( 140 ) to reduce pressure acting on the rotor due to rotor operation ( 10 ). [20] Electric disc motor according to claim 19, where the pressure reducer ( 140 ) a first finite flux resistance ( 140a ) between the target area ( 100 ) and the engine gap ( 30 ) or a second finite flux resistance ( 140b ) between the engine gap (30 ) and the source area ( 90 ) shows, where the first flux resistance ( 140a ) as a labyrinth seal ( 210a – 210c ) between a motor housing ( 110 ) and the rotor ( 10 ) is formed, or wherein the second flux resistance ( 140b ) as a bore ( 200 ) is formed in the rotor so that gas communication between the source area ( via the borehole is possible ( 90 ) and the engine gap ( 30 ) is made possible. [21] Electric disc motor according to claim 20, wherein the bore ( 200 ) has a diameter between 1 and 4 mm. [22] Electric disc motor according to one of the preceding claims, wherein the element to be moved ( 105 ) is designed as a paddle wheel connected to the rotor, wherein the element to be moved ( 105 ) furthermore within a guide element ( 180) is rotatably arranged, with a clearance ( 190 ) between the guide element ( 180 ) and the paddle wheel ( 105 ) is smaller than 1.5 mm. [23] Heat pump with the following features: an evaporator ( 300 ); a compressor ( 400 ); and a liquefaction ( 500 ), where the compressor ( 400 ) has an electric disc motor according to one of claims 1 to 22. [24] Heat pump according to any one of the preceding claims, where the element to be moved is a paddle wheel, with an intake area of ​​the evaporator ( 300 ) with a guide element ( 180 ) is connected, so that when the electric disc motor is operated, evaporated working fluid is drawn in, where, in operation of the heat pump, a source pressure exists in the intake area of ​​the evaporator ( 300 ) is available, where at one end of the radial wheel is the first area with the first pressure that is higher than the source pressure, where in the liquefier ( 500 ) is a condenser pressure that is greater than the first pressure, and where the second pressure is in the second region ( 60 ) is equal to the condenser pressure or equal to ambient pressure. [25] Method for manufacturing an electric disc motor with a rotor ( 10 ), which is an element to be moved ( 105 ) has a stator ( 10 ), wherein the stator is positioned relative to the rotor ( 20 ) is arranged so that an engine gap ( 30 ) between the rotor and the stator, using the following steps: Performing a recess ( 40 ) in the rotor ( 10 ), in which the stator ( 20 ) is arranged, Arranging the rotor ( 10 ) in a first area ( 50 ) with an initial print; Stator arrangement ( 20 ) in a second area ( 60 ) with a second pressure, wherein the second pressure differs from the first pressure, and Arrangement of encapsulation material ( 70 ) in the engine gap ( 30 ), through which the first area ( 50 ) from the second area ( 60 ) is separated.

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