ELECTRIC MOTOR, HEAT PUMP WITH ELECTRIC MOTOR, METHOD FOR MANUFACTURING THE ELECTRIC MOTOR AND METHOD FOR OPERATING THE ELECTRIC MOTOR

Description

[0001] The present invention relates to electric motors and in particular to electric motors that can be operated at very high speeds, such as are necessary, for example, when such electric motors are used as compressor motors in heat pumps that are operated with water as the working fluid.

[0002] Fig. 8A und Fig. 8B These components represent a heat pump as described in European patent EP 2016349 B1. The heat pump initially comprises an evaporator 10 for evaporating water as the working fluid in order to generate steam in a working steam line 12 at the outlet. The evaporator comprises an evaporation chamber (in Fig. 8A (not shown) and is designed to generate an evaporation pressure of less than 20 hPa in the evaporation chamber, so that the water evaporates at temperatures below 15 °C in the evaporation chamber. The water can be, for example, groundwater, brine circulating freely in the ground or in collector pipes (i.e., water with a specific salinity), river water, lake water, or seawater. All types of water can be used, including hard water, soft water, saline water, or salt-free water. This is because all types of water, i.e., all these "hydrogens," possess the favorable property of water, namely that water, also known as "R 718," has a usable enthalpy difference ratio of 6 for the heat pump process, which is more than twice that of the typical usable enthalpy difference ratio of, for example, R134a.

[0003] The steam is fed through the suction line 12 to a compressor / condenser system 14, which includes a turbo compressor such as a radial compressor, for example in the form of a turbo compressor, which is located in Fig. 8A The turbomachine is designated 16. It is designed to compress the working steam to a vapor pressure at least greater than 25 hPa. 25 hPa corresponds to a condensing temperature of approximately 22 °C, which can be a sufficient flow temperature for underfloor heating, at least on relatively warm days. To generate higher flow temperatures, pressures greater than 30 hPa can be produced with turbomachine 16, where a pressure of 30 hPa corresponds to a condensing temperature of 24 °C, a pressure of 60 hPa to a condensing temperature of 36 °C, and a pressure of 100 hPa to a condensing temperature of 45 °C. Underfloor heating systems are designed to provide sufficient heating even on very cold days with a flow temperature of 45 °C.

[0004] The turbomachine is coupled to a condenser 18, which is designed to liquefy the compressed working steam. Through condensation, the energy contained in the working steam is transferred to the condenser 18 and then fed to a heating system via the supply line 20a. The working fluid flows back into the condenser via the return line 20b.

[0005] The energy-rich water vapor can have its heat (energy) extracted directly by the colder heating water, which then absorbs this heat and warms it up. So much energy is extracted from the vapor that it liquefies and also participates in the heating circuit.

[0006] This results in the introduction of material into the condenser or the heating system, which is regulated by a drain 22, such that the condenser in its condensing chamber has a water level that, despite the constant supply of water vapor and thus condensate, always remains below a maximum level.

[0007] As already explained, an open circuit can be used. This means that the water, which serves as the heat source, is evaporated directly without a heat exchanger. Alternatively, the water to be evaporated could first be heated via a heat exchanger from an external heat source. Furthermore, to avoid losses for the second heat exchanger, which is currently necessary on the condenser side, the medium can also be used directly there. If the house has underfloor heating, the water from the evaporator can be circulated directly in the underfloor heating system.

[0008] Alternatively, a heat exchanger can also be arranged on the condenser side, which is supplied with the flow 20a and has the return 20b, whereby this heat exchanger cools the water in the condenser and thus heats a separate underfloor heating fluid, which will typically be water.

[0009] Because water is used as the working medium, and because only the evaporated portion of the groundwater is fed into the turbomachine, the water's purity level is irrelevant. The turbomachine, as well as the condenser and any directly connected underfloor heating system, is always supplied with distilled water, resulting in reduced maintenance compared to current systems. In other words, the system is self-cleaning, as it is always supplied with distilled water, and therefore the water in outlet 22 remains uncontaminated.

[0010] Furthermore, it should be noted that turbomachinery has the characteristic that – similar to an aircraft turbine – it does not bring the compressed medium into contact with problematic substances such as oil. Instead, the water vapor is merely compressed by the turbine or turbo compressor, but is not brought into contact with oil or any other medium that could impair its purity and thus not contaminated.

[0011] The distilled water discharged through the drain can therefore – provided no other regulations prohibit it – be readily returned to the groundwater. Alternatively, it can also be allowed to seep into the ground in the garden or an open area, or, if required by regulations, it can be conveyed to a wastewater treatment plant via the sewer system.

[0012] The combination of water as a working fluid with a usable enthalpy difference ratio that is twice as good as that of R134a, and the resulting reduced requirements for the system's closedness, and the use of a turbomachine that efficiently achieves the necessary compression factors without compromising purity, creates an efficient and environmentally neutral heat pump process.

[0013] Fig. 8B The table shows an illustration of different pressures and the evaporation temperatures associated with these pressures, from which it can be seen that particularly for water as the working medium, quite low pressures should be chosen in the evaporator.

[0014] German patent DE 4431887 A1 discloses a heat pump system with a lightweight, large-volume, high-performance centrifugal compressor. Steam exiting a second-stage compressor has a saturation temperature exceeding the ambient temperature or that of available cooling water, thus enabling heat dissipation. The compressed steam is transferred from the second-stage compressor to the condenser unit, which consists of a packed bed located within a cooling water spray device at the top, supplied by a water circulation pump. The compressed steam rises through the packed bed in the condenser, where it comes into direct countercurrent contact with the downward-flowing cooling water.The steam condenses, and the latent heat of condensation, absorbed by the cooling water, is released to the atmosphere via the condensate and the cooling water, which are removed from the system together. The condenser is continuously purged with non-condensable gases via a vacuum pump through a pipeline.

[0015] WO 2014072239 A1 discloses a condenser with a condensation zone for condensing vapor to be condensed in a working fluid. The condensation zone is designed as a volume zone and has a lateral boundary between its upper and lower ends. Furthermore, the condenser includes a vapor inlet zone extending along the lateral end of the condensation zone and designed to introduce vapor to be condensed laterally over the lateral boundary into the condensation zone. This transforms the actual condensation into volume condensation without increasing the volume of the condenser, because the vapor to be condensed is not only introduced frontally from one side into a condensation volume or zone, but laterally and from all sides.This not only ensures that the available condensation volume is increased compared to direct countercurrent condensation with the same external dimensions, but also that the efficiency of the condenser is improved because the vapor to be liquefied has a flow direction perpendicular to the flow direction of the condensing liquid in the condensation zone.

[0016] A general problem with electric motors, and especially with those operating at high speeds, is the heating in the bearing area. Contact bearings, such as ball bearings or roller bearings, are typically used. These contact bearings generate friction, which leads to power loss. This power loss is problematic in two ways: firstly, it must be dissipated, and secondly, if it is not dissipated, or not sufficiently dissipated, it increases bearing wear and thus reduces the service life of the bearing and the entire electric motor.

[0017] At the same time, the problems with imbalances become increasingly severe as the rotational speeds of the electric motors increase. Furthermore, power loss also increases significantly with higher rotational speeds and greater imbalances.

[0018] High rotational speeds are necessary to operate a heat pump using water as the working fluid within a reasonably manageable volume. Water has the property of producing a large amount of water vapor relative to a given volume of liquid. While this is generally advantageous for the overall efficiency of the heat pump, this large quantity of vapor must be extracted and, in particular, compressed. Therefore, compressor motors are required, which, if they are to remain within reasonable dimensions, must operate at very high speeds, such as those exceeding 50,000 rpm. However, the power loss in the bearings and ultimately the bearing lifespan are problematic with such high-speed motors. The faster the motor operates, the greater the power loss it generates and the shorter its lifespan becomes.All these points are disadvantageous because high power loss means that the efficiency of the electric motor is reduced. Furthermore, a shorter service life leads to higher costs, or conversely, to achieve a sufficient service life despite these drawbacks, extreme demands are placed on the components, requiring the components, and especially the bearings, to withstand the high power losses with minimal wear.

[0019] JP 2006 109592 discloses a motor intended for injecting adhesive that does not require high precision in the dimensional tolerances of components and avoids long cycle times. The motor comprises a stator, a load-side housing, and a counterload-side housing attached to opposite ends of the stator, a bearing inserted into an opening provided in each housing, and a motor shaft rotatably mounted between the two bearings. A bearing cap covering the counterload side bearing is formed from a spring material, and the bearing cap material, or spring material, is attached to the counterload side housing in such a way as to apply a fixed-position preload to the counterload side bearing, with the opening of the counterload side housing partially covered by a portion of the bearing cap or spring material.

[0020] Further prior art is disclosed in US 2009 / 224618 A1, DE 44 45 024 A1 and EP 2 800 251 A1.

[0021] The object of the present invention is to create an improved electric motor and an improved heat pump concept with such an electric motor.

[0022] This problem is solved by an electric motor according to claim 1, a heat pump according to claim 13, a method for manufacturing the electric motor according to claim 14 or a method for operating the electric motor according to claim 15.

[0023] The electric motor according to the present invention comprises a motor housing, a motor shaft with a first end and a second end, and a bearing section for supporting the motor shaft relative to a bearing holder, wherein the bearing section is located closer to the first end than to the second end of the motor shaft. This means that the motor shaft is supported, in effect, only on one side, in the manner of a cantilever bearing. The electric motor further comprises a driven element, which is located at the second end of the motor shaft or closer to the second end of the motor shaft than to the first end of the motor shaft. Furthermore, the drive section of the electric motor, i.e., the section comprising the rotor and the stator, is arranged between the bearing section and the driven element.

[0024] The bearing holder is coupled to the motor housing via a spring arrangement designed to allow a tilting deflection of the bearing holder relative to the motor housing at least about one, preferably about two tilting axes, which are perpendicular to an axis of the motor shaft, while preferably a translational deflection in the direction of the motor shaft is made more difficult or avoided.

[0025] This one-sided mounting of the electric motor, which is essentially eccentrically mounted rather than on both sides of the shaft's center of gravity as is typical, causes the motor to rotate not on an axis defined by the bearings, but rather on its axis of inertia. Ideally, this axis of inertia would coincide with the geometric axis of the motor shaft. In reality, however, the axis of inertia deviates from the geometric axis. Due to the one-sided mounting, with the bearing section positioned closer to the first end of the shaft than the second, the mechanical system is able to rotate on its axis of inertia. This, however, results in a constant tilting or tilting deflection of the bearing section relative to the housing.To avoid high power loss and thus rapid wear of the bearing section, the bearing holder is held to the motor housing by means of a spring assembly, according to the invention. This allows the bearing section to yield to the tilting of the motor shaft, enabling it to rotate on its axis of inertia. This prevents any continuous additional force from being exerted on the bearings, as the entire bearing holder is deflectable. This allows the motor to rotate with minimal or virtually no force. The bearing section defines the axial and radial position of the motor shaft, but does not hold the motor so rigidly that the shaft cannot tilt about axes perpendicular to the axis coinciding with the motor shaft.

[0026] In preferred embodiments, the bearing section is defined using two ball bearings arranged relatively close to each other. Due to the small distance between these two ball bearings in the bearing section, the system has relatively low rigid body resonances, and the motor is driven through these rigid body resonances during startup and is typically operated well above these resonances.

[0027] This is possible because the bearing section is located only on one side of the center of mass, or the center of gravity, of the entire rotating system of the motor, which comprises the motor shaft, the rotor, and the driven element, while on the other side of the center of mass there is no bearing that engages the rotor or the motor shaft during operation. In preferred embodiments, only a temporary bearing is provided, which is designed so that it has no effect during normal operation, meaning that the motor shaft rotates without contact with the temporary bearing. However, the temporary bearing only "engages" when the motor is subjected to a shock during operation, i.e., when, due to an external force, for example, the motor shaft rotating on its axis of inertia is deflected from this axis. This temporary bearing is, for example, simply a bore in a material with sliding properties, such as...The emergency bearing is made of brass, with a bore that has a larger diameter than the motor shaft passing through it. The resulting bearing gap of the emergency bearing defines the maximum deflection of the motor shaft from its geometric axis. For deflections smaller than this defined maximum axis, the emergency bearing does not engage and therefore does not touch the motor shaft.

[0028] Preferably, the bearing holder is coupled to the motor housing not only by a spring assembly but also by an additional damping arrangement. This ensures that undesirable vibrations of the bearing holder relative to the motor housing, such as those that would lead to resonance amplification, are suppressed or that resonances are dampened. The damping system is particularly useful in the event of an impact to the motor, as it allows the motor shaft to return to its axis of inertia relatively quickly. Furthermore, the damping system has proven especially effective during motor startup, when the motor shaft passes through rigid body resonances.

[0029] In preferred embodiments of the present invention, the spring arrangement is implemented by two or more spring struts, preferably distributed evenly around the circumference of a circle. The damping system, in turn, can be implemented by one or more elastic damping elements, such as O-rings, which are continuously "flexed" due to the tilting deflection of the bearing holder relative to the motor housing, so that the bearing holder can, in a sense, dissipate energy through vibration via the work performed on the damping element.

[0030] The spring system allows the rotating system of the electric motor of the present invention to rotate on its axis of inertia. The spring system defines the position. The spring system transmits forces to both the stationary and the rotating components. In the case of resonance, energy is dissipated via the preferably included damping system.

[0031] In exemplary embodiments, a star ring is fixed to the outside of the motor housing and connected via an O-ring, which forms the damping arrangement, to an inner ball bearing holder that is oscillating via the spring arrangement. These oscillations flex the O-ring and thus dissipate energy.

[0032] Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings. These show: Fig. 1 a schematic view of a heat pump with an interlocking evaporator / condenser arrangement; Fig. 2 a schematic representation of a heat pump with convective wave cooling according to one aspect; Fig. 3 a schematic representation of a heat pump with convective wave cooling on the one hand and motor cooling according to another aspect on the other; Fig. 4 a sectional view of a heat pump according to an embodiment with convective wave cooling on the one hand and motor cooling on the other, with special consideration of the convective wave cooling; Fig. 5 an electric motor according to an embodiment in schematic representation; Fig. 6 a detailed representation of the rotating system with bearing holder according to an embodiment of the present invention; Fig. 7A a detailed representation of the rotating system arranged in the motor housing; Fig. 7A a detailed view from Fig. 7A Fig. 8a a schematic representation of a known heat pump for evaporating water; Fig. 8 a table illustrating pressures and evaporation temperatures of water as the working fluid; Fig. 9 a detailed representation of the bearing holder according to an embodiment of the present invention; Fig. 10 a representation of the rotating system including the bearing holder with special reference to a cooling system for bearing cooling; and Fig. 11 a cross-section through a motor shaft with the bearing section and with the drive section according to an embodiment of the present invention.

[0033] Fig. 1 Figure 1 shows a heat pump 100 with an evaporator for evaporating working fluid in an evaporator chamber 102. The heat pump further comprises a condenser for condensing the evaporated working fluid in a condenser chamber 104, which is bounded by a condenser base 106. As shown in Fig. 1 As shown in the figure, which can be viewed as a sectional or side view, the evaporator chamber 102 is at least partially surrounded by the condenser chamber 104. Furthermore, the evaporator chamber 102 is separated from the condenser chamber 104 by the condenser base 106. In addition, the condenser base is connected to an evaporator base 108 to define the evaporator chamber 102. In one implementation, a compressor 110 is provided above the evaporator chamber 102 or elsewhere, which is located in Fig. 1 which is not described in detail, but is in principle designed to compress evaporated working fluid and direct it as compressed vapor 112 into the condenser chamber 104. The condenser chamber is further bounded externally by a condenser wall 114. The condenser wall 114, like the condenser base 106, is attached to the evaporator base 108. In particular, the dimensions of the condenser base 106 in the area that forms the interface with the evaporator base 108 are such that the condenser base, when exposed to the heat generated by the evaporator, is designed to withstand the pressure of the evaporator. Fig. 1 In the illustrated embodiment, the capacitor compartment is completely surrounded by the capacitor space wall 114. This means that the capacitor compartment, as shown in Fig. 1 shown, extends to the evaporator base, and that the evaporator chamber simultaneously extends very far upwards, typically through almost the entire condenser chamber 104.

[0034] This "interlocked" or interlocking arrangement of condenser and evaporator, characterized by the connection between the condenser base and the evaporator base, delivers particularly high heat pump efficiency and therefore allows for a very compact heat pump design. For example, in a cylindrical form, the heat pump is dimensioned such that the condenser wall 114 forms a cylinder with a diameter between 30 and 90 cm and a height between 40 and 100 cm. However, the dimensions can be selected depending on the required performance class of the heat pump, but preferably within the dimensions mentioned.This results in a very compact design that is also easy and inexpensive to manufacture, because the number of interfaces, especially for the almost vacuum-operated evaporator chamber, can be easily reduced if the evaporator base is designed according to preferred embodiments of the present invention in such a way that it includes all liquid inlets and outlets, thus eliminating the need for liquid inlets and outlets from the side or from above.

[0035] Furthermore, it should be noted that the operating direction of the heat pump is as shown in Fig. 1 This is shown. This means that, during operation, the evaporator base defines the lower section of the heat pump, except for connecting lines to other heat pumps or corresponding pump units. This means that, during operation, the vapor generated in the evaporator chamber rises and is redirected by the motor and fed from top to bottom into the condenser chamber. The condenser fluid is guided from bottom to top, then fed into the condenser chamber from above, and then flows from top to bottom within the condenser chamber, for example, as individual droplets or small liquid streams, to react with the preferably transversely supplied compressed vapor for condensation purposes.

[0036] This interlocking arrangement, in which the evaporator is located almost entirely or even completely within the condenser, enables a highly efficient heat pump design with optimal space utilization. Since the condenser chamber extends to the bottom of the evaporator, it occupies the entire height of the heat pump, or at least a significant portion of it. Simultaneously, the evaporator chamber is also as large as possible, as it too extends almost the entire height of the heat pump. This interlocking arrangement, in contrast to a configuration where the evaporator is located below the condenser, ensures optimal use of space.This allows for particularly efficient operation of the heat pump and a particularly space-saving and compact design, because both the evaporator and the condenser extend over the entire height. While this reduces the thickness of the evaporator and condenser chambers, it has been found that the reduction in the thickness of the evaporator chamber, which tapers within the condenser, is not problematic because the main evaporation takes place in the lower section, where the evaporator chamber fills almost the entire available volume. Conversely, the reduction in the thickness of the condenser chamber, especially in the lower section where the evaporator chamber fills almost the entire available space, is not critical because the main condensation occurs at the top, where the evaporator chamber is already relatively thin, thus leaving sufficient space for the condenser chamber.The interlocking arrangement is thus optimal in that each functional space is given the largest volume precisely where it requires it. The evaporator space has the largest volume at the bottom, while the condenser space has the largest volume at the top. Nevertheless, the corresponding smaller volume remaining for each functional space where the other has the largest volume also contributes to increased efficiency compared to a heat pump where the two functional elements are arranged one above the other, as is the case, for example, in WO 2014072239 A1.

[0037] In preferred embodiments, the compressor is arranged at the top of the condenser chamber such that the compressed vapor is both redirected by the compressor and simultaneously fed into a marginal gap of the condenser chamber. This achieves condensation with particularly high efficiency because a cross-flow direction of the vapor towards a downward-flowing condensate liquid is created. This cross-flow condensation is especially effective in the upper region, where the evaporator chamber is large, and in the lower region, where the condenser chamber is smaller to allow for the condensation of vapor particles that have penetrated to this area, a particularly large space is no longer required.

[0038] An evaporator base connected to the condenser base is preferably designed to accommodate both the condenser inlet and outlet and the evaporator inlet and outlet, and may also include specific feedthroughs for sensors into the evaporator and condenser, respectively. This eliminates the need for pipes for the condenser inlet and outlet through the evaporator, which is under near-vacuum. This makes the entire heat pump less prone to failure, as any penetration through the evaporator would represent a potential leak point. To achieve this, the condenser base is provided with a recess at each of the condenser inlet and outlet locations, ensuring that no condenser inlets or outlets run within the evaporator chamber defined by the condenser base.

[0039] The condenser chamber is bounded by a condenser wall, which can also be attached to the evaporator base. The evaporator base thus has an interface for both the condenser wall and the condenser base, and additionally houses all liquid inlets for both the evaporator and the condenser.

[0040] In certain designs, the evaporator base is shaped to include connection ports for the individual inlets, each with a cross-section that differs from the cross-section of the opening on the opposite side of the evaporator base. The shape of each connection port is designed such that its form, or cross-sectional shape, changes along its length, while the pipe diameter, which influences the flow velocity, remains nearly constant within a tolerance of ± 10%. This prevents cavitation of the water flowing through the connection port. The resulting improved flow characteristics, achieved through the design of the connection ports, allow for the shortest possible pipes / lines, contributing to a compact overall heat pump design.

[0041] In a specific evaporator base design, the condenser inlet is divided into two or more sections, almost like a "glasses." This allows the condenser fluid to be fed into the condenser at two or more points simultaneously at its upper section. This results in a strong yet exceptionally uniform condenser flow from top to bottom, enabling highly efficient condensation of the vapor also introduced into the condenser from above.

[0042] Another smaller inlet for condenser water can also be provided in the evaporator base to connect a hose that supplies coolant to the compressor motor of the heat pump, whereby the cooling is not done with the cold liquid supplied to the evaporator, but with the warmer liquid supplied to the condenser, which is still cool enough to cool the motor of the heat pump in typical operating conditions.

[0043] The evaporator base is characterized by its dual functionality. Firstly, it ensures that no condenser supply lines need to pass through the evaporator, which operates at very low pressure. Secondly, it provides an external interface, preferably circular, as this maximizes the available evaporator surface area. All inlet and outlet lines pass through the single evaporator base and from there into either the evaporator chamber or the condenser chamber. Manufacturing the evaporator base from injection-molded plastic is particularly advantageous because the relatively complex shapes of the inlet / outlet connections can be easily and cost-effectively produced using this process.On the other hand, due to the design of the evaporator base as an easily accessible workpiece, it is readily possible to manufacture the evaporator base with sufficient structural stability so that it can easily withstand the low evaporator pressure in particular.

[0044] In the present application, identical reference numerals refer to identical or equivalent elements, and not all reference numerals are repeated in all drawings.

[0045] Fig. 2 The image shows a heat pump according to an exemplary embodiment in conjunction with the first aspect, convective wave cooling. Thus, the heat pump comprises Fig. 2 a condenser with a condenser housing 114, which includes a condenser chamber 104. Furthermore, the compressor motor is attached, which is schematically represented by the stator 308 in Fig. 4 This compressor motor is shown in Fig. 2 The condenser housing 114 is attached in a manner not shown and comprises the stator and a rotor 307, the rotor 307 having a motor shaft 306 to which a radial wheel 304 is attached, extending into an evaporation zone which is in Fig. 2 not shown. Furthermore, the heat pump includes a guide chamber 302, which is designed to receive steam compressed by the radial wheel and direct it into the condenser, as shown schematically in Figure 112.

[0046] Furthermore, the motor comprises a motor housing 300 that surrounds the compressor motor and is preferably designed to maintain a pressure at least equal to the pressure in the condenser. Alternatively, the motor housing is designed to maintain a pressure higher than the average pressure between the evaporator and the condenser, or higher than the pressure in the wider gap 313 between the radial wheel and the guide chamber (302), or greater than or equal to the pressure in the condenser. The motor housing is thus designed such that a pressure drop occurs from the motor housing along the motor shaft towards the guide chamber, drawing working steam through the motor gap and the wider gap along the motor shaft to cool the shaft.

[0047] This area within the engine casing, with the necessary pressure, is in Fig. 2 Figure 312 shows the motor housing 300. A steam supply 310 is also provided to supply steam to a motor gap 311 located between the stator 308 and the shaft 306 within the motor housing 300. Furthermore, the motor includes another gap 313 extending from the motor gap 311 along the radial wheel to the guide chamber 302.

[0048] In the arrangement according to the invention, a relatively high pressure p3 prevails in the condenser. In contrast, a medium pressure p2 prevails in the guideway or guide chamber 302. The lowest pressure, apart from the evaporator, prevails behind the radial wheel, specifically where the radial wheel is attached to the motor shaft, i.e., in the wider gap 313. A pressure p4 exists in the motor housing 300, which is either equal to or greater than the pressure p3. This creates a pressure gradient from the motor housing to the end of the wider gap. This pressure gradient causes a steam flow through the steam supply into the motor gap and the wider gap up to the guideway 302. This steam flow carries working steam from the motor housing past the motor shaft into the condenser. This steam flow provides convective shaft cooling of the motor shaft through the motor gap 311 and the wider gap 313, which adjoins the motor gap 311.The radial wheel draws steam downwards, past the motor shaft. This steam is then drawn into the motor gap via the steam inlet, which is typically implemented as specially designed bores.

[0049] Fig. 3 shows a further schematic embodiment of the convective wave cooling according to the first aspect of the present invention, which is preferably combined there with the motor cooling according to the second aspect of the present invention.

[0050] However, it should be noted at this point that the two aspects, convective shaft cooling on the one hand and motor cooling on the other, can also be used separately. Motor cooling without a separate convective shaft cooling system already leads to significantly increased operational reliability. Furthermore, convective motor shaft cooling without additional motor cooling also leads to increased operational reliability of the heat pump. However, as will be explained below... Fig. 3 As shown, they can be connected particularly favorably in order to implement both convective shaft cooling and motor cooling with a particularly advantageous design of the motor housing and the compressor motor, which in a further preferred embodiment can be supplemented individually or jointly by special ball bearing cooling.

[0051] Fig. 3 shows an embodiment with combined use of convective shaft cooling and motor cooling, wherein in the Fig. 3 In the illustrated embodiment, the evaporator zone is shown at 102. The evaporator zone is separated from the condenser zone, i.e., from the condenser area 104, by the condenser base 106. Working steam, which is schematically shown at 314, is drawn in by the rotating radial wheel 304 (shown schematically and in section) and "forced" into the guideway 302. The guideway 302 is located in the Fig. 3 In the illustrated embodiment, the radial wheel is designed such that its cross-section increases towards the outside. This results in further steam compression. The first stage of steam compression occurs through the rotation of the radial wheel and the drawing in of steam. However, when the radial wheel feeds the steam into the inlet of the guideway—that is, where the radial wheel ends at the top—the already pre-compressed steam encounters a kind of steam buildup. This buildup is caused by the narrowing and curvature of the guideway. This leads to further steam compression, so that finally the compressed and thus heated steam 112 flows into the condenser.

[0052] Fig. 3 further shows the steam supply openings 320, which are shown in a schematically depicted engine wall 309 in Fig. 3 are executed. This engine wall 309 has in the Fig. 3 In the illustrated embodiment, bores for the steam supply openings 320 are located in the upper area. However, these bores can be situated at any point where steam can penetrate into the motor gap 311 and thus also into the further motor gap 313. The resulting steam flow 310 leads to the desired effect of convective shaft cooling.

[0053] The in Fig. 3 The illustrated embodiment further includes, for the implementation of motor cooling, a working fluid inlet 330, which is designed to direct liquid working fluid from the condenser to the motor wall for motor cooling. Furthermore, the motor housing is designed to maintain a maximum liquid level 322 of liquid working fluid during operation of the heat pump. In addition, the motor housing 300 is also designed to form a vapor space 323 above the maximum level. The motor housing also has provisions to direct liquid working fluid above the maximum level into the condenser 104. This embodiment is used in the [reference to be added] Fig. 3 In the illustrated embodiment, the overflow is formed by, for example, a flat, channel-shaped overflow 324, which serves as the vapor outlet and is located somewhere in the upper condenser wall and has a length that defines the maximum level 322. If too much working fluid is introduced into the motor housing, i.e., the fluid area 328, through the condenser fluid supply 330, the liquid working fluid flows through the overflow 324 into the condenser volume. Furthermore, the overflow also provides a buffer zone in the event of... Fig. 3 The passive arrangement shown, which could alternatively be a tube of a corresponding length, creates a pressure equalization between the motor housing, and in particular the vapor space 323 of the motor housing, and the condenser interior 104. Thus, the pressure in the vapor space 323 of the motor housing is always almost equal to, or at most slightly higher than, the pressure in the condenser due to a pressure loss along the overflow. Therefore, the boiling point of the liquid 328 in the motor housing will be similar to the boiling point in the condenser housing. Consequently, heating of the motor wall 309 due to power loss generated in the motor leads to bubble boiling in the liquid volume 328, which will be explained later.

[0054] Fig. 3 The figure also shows various seals in schematic form at reference numeral 326 and at similar locations between the motor housing and the condenser housing on the one hand, and between the motor wall 309 and the condenser housing 114 on the other. These seals are intended to symbolize that a liquid- and pressure-tight connection is to be established here.

[0055] The motor housing defines a separate space, which, however, represents a pressure zone almost identical to that of the condenser. Due to the heating of the motor and the energy thereby transferred to the motor wall 309, this promotes bubble boiling in the liquid volume 328. This, in turn, results in a particularly efficient distribution of the working fluid within volume 328 and thus particularly effective cooling with a small volume of coolant. Furthermore, it is ensured that cooling is performed with the working fluid at its most favorable temperature, namely the warmest temperature in the heat pump. This ensures that all condensation problems, which always occur on cold surfaces, are eliminated for the motor wall, the motor shaft, and the areas in the motor gap 311 and the further gap 313. Furthermore, in the Fig. 3 In the illustrated embodiment, the working fluid vapor 310 used for convective shaft cooling is vapor that is otherwise located in the vapor space 323 of the motor housing. This vapor, like the liquid 328, also has the optimal (warm) temperature. Furthermore, the overflow 324 ensures that the pressure in area 323 cannot rise above the condenser pressure due to the nucleate boiling caused by the motor cooling or the motor wall 309. Additionally, the vapor discharge dissipates the heat energy generated by the motor cooling. This ensures that the convective shaft cooling always operates consistently. If the pressure were to rise too high, excessive working fluid vapor could be forced through the motor gap 311 and the further gap 313.

[0056] Although the electric motor according to the present invention is particularly well suited for use in heat pumps, as described in the Fig. 1 bis 4 As has been shown, the electric motor can also be used for other applications where a small, compact motor is needed that can also be operated at high speeds. However, the motor according to the invention can also offer advantages at lower speeds.

[0057] The following refers to Fig. 5 An electric motor according to an embodiment of the present invention is described, which is advantageously referred to as the electric motor 110, for example, from Fig. 1 can be used, or which can also be used for other applications.

[0058] The electric motor comprises a motor housing 500, which encloses the motor. In contrast, the motor casing 300, which is located in the Fig. 2 , 3 , 4 The engine casing 500 is provided, in addition to the engine housing, to create the specific cooling devices shown. Part of the engine casing 500 is the engine wall 309, which is also shown in the Fig. 2 , 3, 4 is shown.

[0059] The electric motor further comprises a motor shaft 306 with a first end 306a and a second end 306b, as well as a bearing section 343 for supporting the motor shaft 306 with respect to a bearing holder 504. The bearing section 343 is located closer to the first end 306a than to the second end 306b on the motor shaft and, in particular, is positioned on one side with respect to the center of gravity of the rotating system. Fig. 5 Furthermore, the rotating system comprises a driven element 304, which can be, for example, a radial wheel or impeller, but can also be implemented as any other driven element. A drive section 502 is also provided, which is arranged between the bearing section 343 and the driven element and has a rotor 307 and a stator 308.

[0060] In particular, the bearing holder 504 is coupled to the motor housing 500 via a spring assembly 510, the spring assembly 510 being designed to allow a tilting deflection 514 of the bearing holder 504 with respect to the motor housing at least about a tilting axis perpendicular to an axis of the motor shaft 306, and to reduce or prevent a translational deflection in the direction of the motor shaft. Regarding the Fig. 5 The motor shaft 306 extends along the z-axis along the axes shown. In particular, the motor shaft 306 rotates about the z-axis during operation. A tilting deflection 514 is possible either about the y-axis or the x-axis, or preferably about both tilting axes, such that the rotating system formed by the motor shaft 306, the rotor 307, and the driven element 304 can rotate on its axis of inertia. The tilting deflections 514 are necessary to achieve this. In contrast, the spring arrangement 510, which is shown in Fig. 5 for example, leaf springs, designed to be rigid in the z-axis. Preferably, the spring arrangement should also define the radial position of the bearing holder with respect to the motor housing 500, such that a tilting deflection of the bearing holder actually occurs, but no radial displacement of the bearing holder.

[0061] In particular, the following applies to the Fig. 5 The illustrated embodiment shows that the bearing section 343 exclusively supports the motor shaft during operation, so that no further bearing is arranged between the drive section 502 and the driven element 304 for supporting the motor shaft during operation. Only, as can be seen, for example, from Fig. 4 As previously explained, an emergency bearing 344 exists, which, however, does not engage with the shaft during operation but is spaced away from it. Its purpose is to engage the shaft in the event of an emergency, such as an impact, to prevent excessive shaft deflection. Thus, the emergency bearing is arranged between the drive section and the driven element. During operation, it does not engage with the motor shaft or the driven element, but in an emergency, it engages with the motor shaft to prevent deflection beyond an emergency bearing gap.

[0062] In one embodiment, for example, the rotor 307 comprises Fig. 6 As shown, permanent magnets are attached to the motor shaft. Furthermore, a stator, such as that found in 308, comprises Fig. 7A The image shows windings connected to the motor casing 500.

[0063] In preferred embodiments of the present invention, the spring arrangement 510 is configured to have a first spring stiffness in the direction of a translational movement of the axis of the motor shaft and a second spring stiffness in the direction of a first or second tilting movement perpendicular to the axis of rotation, which is lower than the first spring stiffness, so that, as is referred to Fig. 5 As has been explained, a tilting movement is enabled while a translational deflection in the direction of the motor shaft is avoided. In any case, it is sufficient that for certain embodiments the spring stiffnesses are of different magnitudes and that the stiffness with respect to translational movement along the axis of the motor shaft is greater than the spring stiffness with respect to tilting movements.

[0064] In particular, in Fig. 5 shown that the bearing holder 504 has two or more elongated springs, which are e.g. at 600 in Fig. 6 are shown, connected to the motor housing 500, wherein the spring struts each have a spring section that is parallel to the axis of the motor shaft 306, i.e. referring to Fig. 5 extends parallel to the z-axis, as is also shown schematically at 510 in Fig. 5 as indicated.

[0065] Depending on the implementation, the spring struts of a bearing holder 504, which is preferably circular in plan view, are evenly distributed around the circumference. When using three spring struts, the angles between them would be 120°, and when using, for example, four spring struts, the angles would be 90°. However, if the bearing holder is not circular in plan view but polygonal, such as a triangle, square, pentagon, hexagon, etc., it is also preferred that the spring struts be evenly spaced from one another to create an optimal spring arrangement. Deviations from a uniform arrangement are also possible, however, as long as tilting movements about axes perpendicular to the axis of rotation are permitted.

[0066] The electric motor, as schematically depicted in Fig. 5 The assembly shown further comprises a damping arrangement 512, by which the bearing holder 504 is also connected to the motor housing 500. The damping arrangement 512 is designed to dampen a mechanical vibration that is enabled by the spring arrangement 510 of the bearing holder 504 relative to the motor housing 500. The damping strength of the damping arrangement 512 is set so that the damping arrangement prevents resonance of the oscillating bearing holder 504, while at the same time allowing the tilting movement 514 that the rotating system must perform in order to oscillate on its axis of inertia.

[0067] The following refers to Fig. 6 A detailed description is given. The element 304 to be driven is in Fig. 6 designed as a radial wheel or impeller wheel, which has a cross-section in Fig. 6 The figure shows various balancing holes 602, which can typically be fitted with set screws to balance the radial gear or the radial gear together with shaft and rotor. Balancing measures can also be achieved by other means, such as material removal at a specific point, either as an alternative or in addition to the weight input due to the balancing screws that may be used in the balancing holes 602. In the figure shown in Fig. 6 In the illustrated embodiment, the shaft 306 is made of a different material than the wheel 304. However, both components can be made of the same material or can be formed in one piece. In the embodiment shown Fig. 6 In the implementation shown, the radial gear 304 is made of aluminum and the shaft is made of steel. The gear 304 is held on the shaft 306 by a fork-shaped mounting section 395, which is Fig. 6 The rotor 307, in the form of permanent magnets, is arranged on the shaft in the drive section and is held by a stabilizing sleeve 396 and stabilizing bands 397, as also shown in reference to Fig. 11 This will be explained later.

[0068] In storage section 343, the storage holder 504 is shown, referring to Fig. 7B , which shows a detailed representation of the bearing holder, will be discussed in even greater detail. In particular, the bearing holder 504 is connected to the spring arrangement, which is illustrated using a strut 600, with which in Fig. 6 connected to the engine casing (not shown). The spring assembly comprises the 600 spring strut and two further 600 spring struts, which are shown in cross-section in Fig. 6 are not shown, but are in Fig. 9 The struts connect a mounting section 602 to the bearing holder 504. The mounting section 602 is, as shown again in Fig. 9 It is better seen as a ring which is screwed onto the engine casing 500 when the engine is fully assembled.

[0069] The bearing holder further comprises an outer sleeve 604 and an inner sleeve 606. A space is provided between the outer sleeve 604 and the inner sleeve 606, which is sealed at the bottom by a connecting web and at the top by an O-ring 610. Coolant can be supplied to the bearing holder via an inlet 612, which is discharged through a drain in Fig. 10 The flow is shown being led back out of the cooling chamber. The outlet is labelled 614. The cooling chamber 616 is connected to the inner bearing section via the inner sleeve 606, in which, during the Fig. 6 In the illustrated embodiment, two ball bearings are arranged, namely as shown in Fig. 7B As shown in the detailed view, there is a lower ball bearing 701 and an upper ball bearing 702. The lower ball bearing 701 has a rotating bearing section 701a and a fixed bearing section 701b. Furthermore, the upper bearing 702 has a fixed bearing section 702b and a rotating bearing section 702a. In addition, in Fig. 7B The fastening ring 602 of the spring section is shown, which is attached to the motor casing, of which a small section at 500 in Fig. 7B As shown, the two bearings 701 and 702 are connected. An inner spacer sleeve 704 and an outer spacer sleeve 706 are located between the two bearings 701 and 702. The inner spacer sleeve 704 is arranged between the rotating parts 701a, 702a of the bearings, while a spring washer 708 and, if necessary, another spring washer or a washer 710 are installed between the outer sleeve and the fixed parts 701b, 702b.

[0070] To assemble the bearing, an element is first provided, consisting of the outer bearing sleeve 604 and the inner bearing sleeve 606. The outer and inner bearing sleeves are connected and sealed at the bottom by the wall 608 and at the top by the O-ring 610. The bearing assembly then proceeds. First, the lower ball bearing 701 is glued into the inner bearing sleeve. This lower bearing forms the fixed bearing. Then, the sleeves 704, 706, and the spring washer 708, and possibly other elements such as the washer 710, and finally the bearing 702 are inserted into the inner sleeve. Fig. 7B The shaft 306 is inserted in the sequence shown. Then, using a special insertion tool, the first end 306a of the shaft 306 is pulled into the bearing holder, which has already been prepared in this way. A mate fit exists between the shaft and the rotating sections 701a, 702a of the bearings, for which typically no further fastenings, such as adhesives or similar, are required.

[0071] Then, once the shaft is inserted, the bearings are secured by fastening a bearing washer 712 to a thread in the shaft 306 using a screw 714. This presses the two bearings together, with the spring washer providing the necessary spring action. This fixed / floating bearing combination ensures that thermal expansion of the shaft can be easily accommodated, even though the distance between the two ball bearings is so short that two fixed bearings could potentially be used. However, it is preferred to use the fixed / floating bearing combination, as shown, for example, in Fig. 7B as described above, while other fixed / floating bearing implementations with differently shaped sleeves / spring washers etc. could also be used.

[0072] Fig. 7B The damping system is shown in the form of a ring 714, which is also used in Fig. 9 This ring 714 is shown and can be referred to as a star ring. It is coupled to the bearing holder 504 at its inner edge or inner periphery via an O-ring 716. This allows movement between the inner sleeve 606 and the ring 714. It should also be noted that the ring 714 is connected to the motor housing 500 at its outer periphery, as is the case, for example, in... Fig. 7A This is evident. However, because the O-ring is an elastic element that requires a force to deform or "flex" it, the damping function of the damping arrangement 512 is created. The damping arrangement is thus created by the O-ring, which rests on the inner sleeve 606 on one side and on the retaining ring 714 or the star ring 714 on the other.

[0073] The rigid engine casing also includes an engine bulkhead 309, which, as described in Fig. 7A It is shown whether or not it may be equipped with cooling fins. In the area of ​​the cooling fins, which are, for example, in Fig. 7A As can be seen, the drive section is formed, i.e. the stator 308, in which heat generation occurs due to the considerable current flow through the stator windings.

[0074] Furthermore, it shows Fig. 7A Further aspects of the electric motor according to the preferred embodiment of the present invention include a cover element 720, which is fastened to the motor housing 500 by screws 722. However, a gap exists between the cover 720 and the screw 714 of the shaft, such that the cover 720 does not impede the rotation of the shaft. Furthermore, the cover 720, together with a further support 722, holds the fixed sections 701b, 702b of the bearings. The inner bearing area is also sealed by seals 724 to be hermetically sealed against liquids and vapors. This ensures that the bearing lubrication required for the bearings 701, 702 is maintained for as long as possible and is not affected by liquids or working vapors, or generally by the external environment. This ensures that the bearing is well lubricated.On the other hand, the water cooling ensures that bearing cooling extends into the inner bearing area, in order to achieve the longest possible service life.

[0075] Furthermore, in order to have an additional cooling functionality, namely in the form of convective wave cooling, the mounting ring or star ring 714 comprises recesses 900 which are designed to allow gas present around the motor casing 500, in particular working steam, which is located inside the motor housing 300, to escape. Fig. 4 , Fig. 3 , Fig. 2 For example, the current is to flow along the shaft and the motor gap 307 to the radial gear 304. Furthermore, another opening 902 is provided for cables to supply the stator with power or, if present, for sensors. The ring 602 also includes a recess 904 through which the cable, which already runs through the recess 902, can be routed further upwards. The cable arrangements are designed so that they run outside the bearing holder 504 and, in particular, so that no cable runs through the sealed hermetic area of ​​the ball bearings, which is located in Fig. 9 is located at 908, and is then finally sealed when the cover 720, which is in Fig. 7A It is shown, it is mounted.

[0076] As has already been shown, and as in Fig. 10 As explained once again, the damping system is formed by the O-ring, which is positioned between the bearing holder and the motor casing, as is particularly evident from... Fig. 7B and also in Fig. 10 This is evident. This allows a relative movement, which is damped, between the bearing holder and the motor housing, causing the O-ring to deform elastically.

[0077] Furthermore, a preferred embodiment of the present invention, as also described by Fig. 7B As shown, the first bearing 701 and the second bearing 702 are shown. Both bearings are designed as ball bearings in this implementation. However, these bearings can also be designed alternatively, for example as rolling bearings or something similar. These two bearings are very close together, which results in a rigid body resonance of the electric motor below the motor's operating speed. The electric motor is preferably operated such that it has an operating speed higher than the rigid body resonances.

[0078] One of the two bearings is designed as a fixed bearing and the other of the two bearings as a floating bearing, whereby, due to better ease of assembly, it is preferred that the lower bearing 701, which is closer to the radial wheel 304, is designed as a fixed bearing, while the upper bearing 702 is designed as a floating bearing.

[0079] Although the spring arrangement has been depicted as three spring struts 600 extending along the motor shaft axis and thus achieving the necessary spring stiffnesses, it should be noted that other spring arrangements in the form of coil springs, leaf springs, or other springs can also be used, and that arrangements consisting of spring / damping systems can also be used which do not connect the bearing holder to the housing at separate positions, but rather at one and the same position. The essential point is simply that the bearing holder can perform tilting movements with respect to the motor housing. Furthermore, it is preferred that the bearing holder is not only held relatively rigidly axially with respect to the motor shaft by the spring or damping arrangement, but also that its radial position is defined, so that tilting movements occur whose center lies within the bearing section 343.

[0080] Fig. 11 Figure 1 shows a schematic cross-section through a motor shaft 306, as it can be used for preferred embodiments. The motor shaft 306 comprises a hatched core, as shown in Figure 2. Fig. 11 The figure shows a rotor, which in its upper section, representing bearing section 343, is supported by preferably two ball bearings 398 and 399. Further down the shaft 306, the rotor is formed with permanent magnets 307. These permanent magnets are mounted on the motor shaft 306 and are held at the top and bottom by stabilizing bands 397, which are preferably made of carbon. The permanent magnets are further held by a stabilizing sleeve 396, which is also preferably made of carbon. This retaining or stabilizing sleeve ensures that the permanent magnets remain securely on the shaft 306 and cannot detach from the shaft due to the very strong centrifugal forces resulting from the high rotational speed of the shaft.

[0081] Preferably, the shaft is made of aluminum and has a fork-shaped mounting section 395, which serves as a holder for the radial gear 304 when the radial gear 304 and the motor shaft are not formed in one piece, but as two separate elements. If the radial gear 304 and the motor shaft 306 are formed in one piece, the gear mounting section 395 is not present; instead, the radial gear 304 connects directly to the motor shaft. As can be seen from the figure, the area of ​​the gear mounting section 395 also contains a... Fig. 10 As can be seen, the emergency storage unit 344 is preferably also made of metal and in particular aluminium.

Claims

1. An electric motor having the following features: a motor shell (500); a motor shaft (306) with a first end (306a) and a second end (306b); a bearing portion (343) for supporting the motor shaft (306) relative to a bearing mount (504), wherein the bearing portion (343) is attached to the motor shaft (306) closer to the first end (306a) than to the second end (306b); an element (304) to be driven, which is attached to or closer to the second end (306b) than to the first end (306a) of the motor shaft (306); and a drive portion (502), which is disposed between the bearing portion (343) and the element (304) to be driven and has a rotor (307) and a stator (308), characterized in that the bearing mount (504) is coupled to the motor shell (500) via a spring assembly (510), wherein the spring assembly (510) is configured to allow a tilt deflection (514) of the bearing mount (504) relative to the motor shell (500) about at least one tilt axis, which is perpendicular to an axis of the motor shaft (306).

2. The electric motor according to claim 1, in which the bearing portion (343) supports exclusively the motor shaft (306) in operation, so that no further bearing for supporting the motor shaft (306) in operation is disposed between the drive portion (502) and the element (304) to be driven.

3. The electric motor according to claim 1 or 2, in which an emergency bearing (344) with an emergency bearing gap is disposed between the drive portion (502) and the element (304) to be driven and in operation does not enter into engagement with the motor shaft (306) or the element (304) to be driven, but in an emergency situation enters into engagement with the motor shaft (306) in order to prevent a deflection of the motor shaft (306) beyond the emergency bearing gap.

4. The electric motor according to any one of the preceding claims, in which the spring assembly (510) is configured to have a first spring stiffness in the direction of a translatory movement of the axis of the motor shaft (306) and to have a second spring stiffness, which is lower than the first spring stiffness, in the direction of a first or second tilt movement, which is perpendicular to the axis of rotation.

5. The electric motor according to any one of the preceding claims, in which the bearing mount (504) is connected to the motor housing via two or more elongate springs (600), wherein the elongate springs have spring legs, which form a spring portion which extends parallel to the axis of the motor shaft (306).

6. The electric motor according to any one of the preceding claims, which further has a damping assembly (512), by which the bearing mount (504) is coupled to the motor shell (500), wherein the damping assembly (512) is configured to damp a mechanical vibration that is made possible on account of the spring assembly (510).

7. The electric motor according to claim 6, in which the damping assembly (512) has a damping element, which is disposed between the motor shell (500) and the bearing mount (504) in such a way that it is elastically deformed in the event of a relative movement of the bearing mount (504) and the motor shell (500).

8. The electric motor according to claim 7, in which the damping element is an elastic O-ring.

9. The electric motor according to any one of the preceding claims, in which the bearing portion (343) has a first bearing (701) and a spaced-apart second bearing (702).

10. The electric motor according to claim 9, in which the first bearing (701) and the second bearing (702) are spaced apart from one another such that a rigid body resonance of the electric motor is below an operating speed of the electric motor, and in which the electric motor is configured, in operation, to be operated at the operating speed.

11. The electric motor according to any one of the preceding claims, in which the bearing mount (504) has a retaining ring (722), which is secured to the bearing mount (504) in such a way that it exerts a compressive force on a fixed portion (702b, 701b) of at least one bearing in order to hold the fixed portion (702b, 701b) of the at least one bearing on the bearing mount (504).

12. The electric motor according to any one of claims 6 to 8, in which the motor shell (500) has a ring (714), which, at an outer region thereof, is fixedly connected to the motor shell (500) and, at an inner region thereof, engages with a damping element (716), wherein the damping element further engages with the bearing mount (504).

13. A heat pump having the following features: an evaporator; a condenser; and a compressor, which comprises the electric motor according to any one of preceding claims 1 to 12, wherein the element (304) to be driven is an impeller wheel, and wherein the electric motor is disposed such that the impeller wheel during operation of the electric motor sucks in vapour from the evaporator and delivers compressed vapour into the condenser.

14. A method for producing an electric motor having: a motor shell (500); a motor shaft (306) with a first end (306a) and a second end (306b); a bearing portion (343) for supporting the motor shaft (306) relative to a bearing mount (504), wherein the bearing portion (343) is attached to the motor shaft (306) closer to the first end (306a) than to the second end (306b); an element (304) to be driven, which is attached to or closer to the second end (306b) than to the first end (306a) of the motor shaft (306); and a drive portion (502), which is disposed between the bearing portion (343) and the element (304) to be driven and has a rotor (307) and a stator (308), characterized by the following step: coupling the bearing mount (504) to the motor shell (500) via a spring assembly (510), wherein the spring assembly (510) is configured to allow a tilt deflection (514) of the bearing mount (504) relative to the motor shell (500) about at least one tilt axis, which is perpendicular to an axis of the motor shaft (306).

15. A method for operating an electric motor having: a motor shell (500); a motor shaft (306) with a first end (306a) and a second end (306b); a bearing portion (343) for supporting the motor shaft (306) relative to a bearing mount (504), wherein the bearing portion (343) is attached to the motor shaft (306) closer to the first end (306a) than to the second end (306b); an element (304) to be driven, which is attached to or closer to the second end (306b) than to the first end (306a) of the motor shaft (306); and a drive portion (502), which is disposed between the bearing portion (343) and the element (304) to be driven and has a rotor (307) and a stator (308), characterized by the following step: allowing, by a spring assembly (510) by which the bearing mount (504) is coupled to the motor shell (500), a tilt deflection (514) of the bearing mount (504) relative to the motor shell (500) about at least one tilt axis, which is perpendicular to an axis of the motor shaft (306).