EP3824532A1

EP3824532A1 - Electric motor and ventilator with corresponding electric motor

Info

Publication number: EP3824532A1
Application number: EP19734683.6A
Authority: EP
Inventors: Joachim Schmezer
Original assignee: Ziehl Abegg SE
Current assignee: Ziehl Abegg SE
Priority date: 2018-07-17
Filing date: 2019-05-29
Publication date: 2021-05-26
Also published as: BR112021000756A2; JP2021530954A; US20210265897A1; US11955847B2; CN112425048A; DE102018211843A1; JP7356492B2; CN112425048B; WO2020015793A1

Abstract

The invention relates to an electric motor with a stator (2) and a rotor which is mounted in a rotatable manner about a motor axis (3) relative to the stator (2). The electric motor (1) comprises an inclination measuring unit with at least one sensor and an electronic sensor unit, wherein the at least one sensor is arranged in a fixed position and orientation relative to the stator (2), and the electronic sensor unit actuates the at least one sensor. The at least one sensor is designed to generate measurement values which allow conclusions to be drawn regarding the spatial orientation of the sensor and thus conclusions regarding the spatial orientation of the electric motor. The electric motor can be part of a ventilator according to the invention. Additionally, a corresponding electronic motor unit is provided which is designed to actuate such an electric motor.

Description

ELECTRIC MOTOR AND FAN WITH CORRESPONDING

ELECTRIC MOTOR

The invention relates to an electric motor with a stator and a rotor which is rotatably mounted about a motor axis relative to the stator. The invention further relates to a fan with a corresponding electric motor. Furthermore, the invention relates to motor electronics for controlling an electric motor, the motor electronics being designed to control windings of a stator and / or windings of a rotor of the electric motor.

Electric motors have a stator and a rotor which can be rotated relative to the stator. Very often, especially in the case of medium and high power motors, the rotor is rotatably supported by means of one or more bearings. When installing such electric motors, the spatial orientation in which the electric motor is later operated can in many cases be chosen relatively freely. This applies in particular to fans with an external rotor design. For example, the shaft of the electric motor can be oriented horizontally, vertically upwards, vertically downwards or in any other angular position.

However, the installation position of the electric motor during its operation has an impact on some properties of the electric motor. The bearing load is very different due to weight forces and the bearing position in different installation positions. This results in a different bearing life from different installation positions. The nominal bearing service life L10h is defined in the ISO 281 standard and indicates the service life that is achieved by 90% of the bearings tested under the same operating conditions. This means that the nominal service life L10h stands for a 10 percent failure probability. Due to the higher load depending on the installation position, a motor with a vertically downwardly directed motor shaft will generally have a shorter service life L10h than a motor in which the shaft is aligned horizontally. The installation position also has an effect with regard to a possible loss of lubricant. This means that bearing grease can escape from the bearing more easily in a vertical installation position, so that - depending on the installation position - different grease usage times can occur.

Another problem area that results from different installation positions relates to heat dissipation. The electric motor and any motor electronics integrated in it generate waste heat that must be dissipated appropriately. This waste heat is usually released into the ambient air via cooling surfaces or cooling fins by means of convection. Depending on the installation position, the cooling surfaces or cooling fins may not work optimally and heat may build up. This can damage temperature-sensitive components and / or lead to a loss of power in the electric motor.

Furthermore, in different installation positions, moisture, for example due to precipitation, can penetrate more or less well into the motor or the motor electronics. If, for example, cable ducts are directed upwards, there is a greater risk of moisture penetration than if the cable ducts are directed downwards. In the latter case, moisture can also drain off the connection cable and drip at a safe point.

The latter two problem areas can also occur if the motor electronics are designed as a separate assembly. In this case too, the installation position can be decisive for how well heat can be dissipated or how high the risk of moisture entering the motor electronics is.

In most cases, a manufacturer of an electric motor does not know in which installation position an electric motor is installed and operated by a customer. This means that there are many unknown parameters that have an impact on the service life and operation of the electric motor. It would be possible to only permit certain installation positions of an electric motor, for example a horizontally aligned motor shaft. However, this is difficult to achieve, in particular in the case of the electric motor of a fan, since the Installation position of the electric motor is not freely selectable, but is determined by the installation situation. Another possibility of being prepared for a wide variety of installation positions would be to design the electric motor in such a way that the specified parameters are met regardless of the installation position. However, this would result in an electric motor that is expensive and oversized for many installation positions.

The present invention is therefore based on the object of designing and developing an electric motor, a fan and motor electronics of the type mentioned at the outset in such a way that operation which is as safe as possible is ensured in different installation positions of the electric motor or the motor electronics.

According to the invention, the above object is achieved by the features of claim 1. According to this, the electric motor in question is characterized by an inclination measuring unit with at least one sensor and sensor electronics, the at least one sensor being arranged in an unchangeable position and orientation relative to the stator, the sensor electronics controlling the at least one sensor and wherein the at least one sensor is designed to generate measured values that allow conclusions to be drawn about the spatial orientation of the sensor and thus conclusions about the spatial orientation of the electric motor.

With regard to a fan, the above object is achieved by the features of claim 18. Thereafter, the fan according to the invention comprises an electric motor according to the invention and an impeller.

With regard to motor electronics, the above object is achieved by the features of claim 19. According to this, the motor electronics in question is characterized by an inclination measuring unit with at least one sensor and one sensor electronics, the at least one sensor being arranged in an unchangeable position and orientation relative to the motor electronics, the sensor electronics actuating the at least one sensor and the at least one Sensor for generating measured values is formed Allow conclusions to be drawn about the spatial orientation of the sensor and thus conclusions about the spatial orientation of the motor electronics

In the manner according to the invention, it was first recognized that a restriction of the installation position or an “oversizing” of the electric motor or the motor electronics is not necessary for all conceivable installation positions if information about the spatial orientation of the electric motor is available and thus a suitable reaction to the installation position can. According to the invention, this can be achieved in that the electric motor has an inclination measuring unit that can be used to determine the spatial orientation of the electric motor. For this purpose, the inclination measuring unit has at least one sensor and sensor electronics, the sensor electronics controlling the sensor (s). The at least one sensor is installed in the electric motor or attached to the electric motor in such a way that its position and orientation relative to the stator does not change, or at most only insignificantly. If several sensors are used, these should also have a fixed spatial relationship to one another. In this way, there is a defined relationship between the orientation of the at least one sensor and the orientation of the entire electric motor. The at least one sensor generates measured values that allow conclusions to be drawn about the spatial orientation of the sensor (s). The spatial orientation of the sensor (s) and the spatial orientation of the motor can be concluded from these measured values.

The same can be achieved if motor electronics are equipped with an inclination measuring unit and are operated in accordance with the inclination measuring unit of the electric motor. With this configuration, the installation position of the motor electronics can be determined, so that it is possible to react to unfavorable heat dissipation or possible moisture ingress. If this motor electronics is attached to an electric motor that is not designed to measure the installation position, the installation position of the entire electric motor can also be determined, as a result of which this functionality can be retrofitted by exchanging the motor electronics. Most of the following explanations therefore apply accordingly to the motor electronics according to the invention, which is why to avoid them of repetitions below only dealt with the design of the electric motor. A person skilled in the art will readily recognize which aspects can be correspondingly transferred to the engine electronics.

The term "installation position" is generally understood in which spatial orientation the electric motor is installed in the surrounding system. The installation position is defined in particular by the direction in which the shaft of the electric motor is oriented. In many cases, this means that the installation position of the electric motor can already be defined with sufficient accuracy. This information can be used, for example, to infer the load on the bearings and the possibility of a loss of lubricant. This information then allows a prediction of the bearing life, a prediction of the grease service life, a calculation of actually acting forces or an adjustment of maintenance intervals. In addition, the installation position can be defined by an angle through which the motor is rotated around the motor axis, the motor axis being the axis around which the rotor rotates. This further dimension of the installation position can be relevant, for example, in order to calculate the penetration probability of moisture into the motor or possibly unfavorable heat dissipation. A third dimension of the installation position could be the angle through which the electric motor is rotated about an axis perpendicular to the motor axis or about an axis parallel to the gravitational vector of the earth. However, since this direction is not important for most of the operating parameters of the electric motor, this third dimension of the installation position can be dispensed with in most applications. Overall, the spatial orientation in which the electric motor is installed is defined by a one-dimensional, a two-dimensional or a three-dimensional size.

The sensor electronics can also be constructed in various ways. In the simplest case, the sensor electronics can be formed by a current limitation using a series resistor. In the case of capacitively measuring systems, the sensor electronics could also include an oscillating circuit with which the sensor is supplied with an alternating voltage. What the sensor electronics look like will depend on the sensor used. If the sensor has multiple sub-sensors or multiple sensors are used, the Activate sensor electronics jointly all sub-sensors or all sensors. However, individual parts of the sensor electronics can also be used individually for one of the part sensors. Corresponding sensor electronics are known from the prior art.

In addition to controlling the sensor, the sensor electronics can also process the sensor signals. This processing could consist of digitizing an analog signal. Depending on the sensor used, it is also conceivable that a spatial orientation of the sensor cannot be read directly in the sensor signals. In such a case, the sensor electronics could evaluate the sensor signals in such a way that values for the spatial orientation of the sensor can be output. This short, exemplary list shows how flexible and differently the sensor electronics can be designed.

The defined spatial relationship between the sensor and the stator can also be formed in various ways. The sensor can thus be arranged on a circuit board, while the circuit board is screwed to a stator socket (for example in an electronics housing formed there). Since the stator is invariably connected to the stator socket, this creates a defined and unchangeable spatial relationship between the sensor and the stator, even if, in principle, the circuit board could be slightly deformed by vibrations. A defined spatial relationship would also be understood when the sensor is embedded in a potting compound that is slightly deformable. In this case too, the position and spatial orientation of the sensor relative to the stator remains largely unchanged, since the sensor is usually only deflected in a defined manner and will return to its starting position. However, the sensor can also be part of a sensor arrangement which is arranged, for example, in a bearing tube. Here, too, there is a defined spatial relationship between the sensor and the stator. Corresponding explanations also apply if the sensor is integrated in motor electronics that are flanged to a motor housing. Since the motor housing is in a defined and unchangeable spatial relationship to the stator and the motor electronics are fixed to the motor housing is fixed, there is a defined spatial relationship between the sensor and stator.

Likewise, the at least one sensor can be designed in various ways. It is important that the sensor signals generated by the at least one sensor can be used to provide conclusions about the spatial orientation of the sensor and thus conclusions about the spatial orientation of the electric motor. However, this requirement can be met by a wide variety of sensors.

In a preferred embodiment of the at least one sensor, it is formed by an inclination sensor that uses the effects of the earth's gravitational field. Such an inclination sensor acts like a digital spirit level and is often constructed as a MEMS (Micro Electro Mechanical System). Depending on the number of measurable axes, an inclination sensor delivers one or two measured values, each of which specifies an angle relative to a vector of the gravitational field, the directions to which the angles relate each being perpendicular to one another. Since the measuring range for 2-axis inclination sensors is often restricted compared to 1-axis inclination sensors, two 1-axis inclination sensors can be used instead of a 2-axis inclination sensor, the two 1-axis inclination sensors then being arranged in this way should be that measurements are made in two directions oriented perpendicular to each other. Regardless of the configuration, the angle values obtained relative to the gravitational field can be used to determine the spatial orientation of the sensor, since the vector of the gravitational field always points to the center of the earth.

In another preferred exemplary embodiment of the at least one sensor, it comprises a 3-axis vibration sensor. It has been recognized that an electric motor oscillates characteristically depending on the installation position. This is due in particular to the fact that the bearings and other parts of the electric motor are loaded differently by the weight depending on the installation position and therefore vibrate differently. If those If vibrations are measured in three vertical directions, the installation position of the electric motor can be determined. To do this, the sensor signals of the individual axes must be analyzed accordingly and compared with reference values. These reference values can be determined by calibration measurements during the commissioning of the electric motor. For this purpose, the electric motor would be operated in different but known spatial orientations and the vibrations measured in each case. A speed dependency can also be recorded. Alternatively, the reference values can also come from measurements of another electric motor of the same type. In any case, the measured values of the 3-axis vibration sensor allow the orientation of the 3-axis vibration sensor to be determined relative to a reference vector. In practice, this reference vector should mostly be the vector of the gravitational field.

To simplify the relationship between the orientation of the electric motor and the orientation of the at least one sensor, it is advisable to connect the sensor to the electric motor in such a way that a measuring axis of the inclination measuring unit is arranged parallel to the motor axis. If the at least one sensor comprises a 2-axis inclination sensor, for example, one of the measuring axes of the sensor could be parallel to the motor axis.

Additionally or alternatively, a further measuring axis of the inclination measuring unit can be arranged essentially parallel or perpendicular to a reference plane of the electric motor, wherein the reference plane can be formed by different planes and preferably runs parallel to the motor axis. It is essential for the reference plane that it has a defined position relative to the electric motor. This enables the position and spatial orientation of other elements of the electric motor, such as cable bushings or the position of cooling surfaces or cooling fins, to be determined. A preferred reference level is formed by a connection level of the electric motor, the connection level being the area of the electric motor to which the supply cable (s) for the electric motor is / are connected. In many cases there are cable bushings with these connections Axes are parallel to each other. The connection level would then be the level that is perpendicular to the axes of the cable entries.

Electric motors often have motor electronics that generate supply voltages for the windings of the stator and / or the rotor. This motor electronics can contain, for example, the power section of the inverter and / or the control electronics. The motor electronics are arranged in an electronics housing of the electric motor or a separate housing is attached to the electric motor. In both cases, the motor electronics have a defined position and spatial orientation relative to the electric motor. In one embodiment, this fact is used for the inclination measuring unit to be integrated in the motor electronics. This can mean that the inclination measuring unit is arranged on the circuit board of the motor electronics. This embodiment offers the advantage that an energy supply for the inclination measuring unit is already available. Parts of the engine electronics can also be used. For example, a microprocessor of the engine electronics can be used to carry out calculations or a memory of the engine electronics can be used to store measured values.

In another embodiment, the inclination measuring unit is arranged in a bearing tube, the bearing tube enclosing at least parts of the shaft of the electric motor and being formed on the at least one bearing receiving area for bearings of the shaft. Such an embodiment is described in more detail in DE 10 2018 211 833 A1, to which express reference is hereby made.

In one development, the inclination measuring unit comprises an evaluation unit, which is designed to determine information about the spatial orientation of the at least one sensor and / or the electric motor from measured values of the at least one sensor. The evaluation unit can be designed in various ways. It is conceivable that the evaluation unit uses a look-up table in which relationships between measured values and a spatial orientation are established. This look-up table can have been generated during a calibration measurement of the electric motor. In many cases However, the installation position does not have to be determined with an accuracy of a few degrees or below, so that any installation tolerances of the inclination measuring unit relative to the stator are mostly of minor importance. In these cases, a look-up table of an identical electric motor can be made available to the evaluation unit. However, the evaluation unit can also carry out calculations based on the measured values. In the simplest case, this can include an interpolation or a calculation of an approximation polynomial. However, complex calculations can also be carried out. If, for example, the inclination measuring unit comprises one or more vibration sensors, the evaluation unit can carry out a frequency analysis in the form of an FFT (Fast Fourier Transform).

The information about the spatial orientation of the at least one sensor and / or of the electric motor determined by the evaluation unit preferably includes a data record that indicates angles with respect to a reference direction. In the simplest case, the reference direction is formed by a vector of the gravitational force. With this, for example, the inclination of the motor axis relative to the gravitational field and the rotation of the electric motor around the motor axis relative to a reference plane can be determined. If further information on the spatial orientation of the electric motor is to be obtained, a second reference direction may be necessary, which is formed, for example, by the earth's magnetic field. The data set indicates how the electric motor deviates from this reference direction (or from the reference directions). Depending on how exactly the orientation of the electric motor is to be specified, the data set can be one-dimensional, two-dimensional or three-dimensional.

In some cases, it may be sufficient to provide qualitative statements about the spatial orientation of the electric motor. Therefore, the information about the spatial orientation of the at least one sensor and / or the electric motor can additionally or alternatively include an evaluation number. This rating number can indicate how favorable or unfavorable the currently determined spatial orientation is. In the simplest case, the rating number can assume a 0 and a 1, for example a 0 indicating that the Electric motor is in an installation position that does not allow safe operation. The rating number can also be a natural number, for example between 1 and 10, with 1 being particularly unfavorable and 10 being particularly favorable. This information can also be used to draw the user's attention to the unfavorable or even impermissible installation position. For example, an LED (light emitting diode) could indicate that safe operation is not possible. In this way, it can be seen, for example, when the electric motor is started up for the first time that, if it is not installed properly, there is a risk of water entering through a condensate drain or a cable entry into the electric motor. An unfavorable installation position can also exist if heat removal due to the installation position can no longer be ensured to a sufficient extent.

Since electric motors are generally installed in a fixed orientation, the inclination measuring unit can measure the spatial orientation when the electric motor is started up for the first time. This measured value can be stored in a memory and used for future operation. However, it is also possible for the spatial orientation to be recorded repeatedly. This repeated recording can take place through special events or at periodic intervals. A special event can include, for example, switching the electric motor on again. If the spatial orientation is recorded periodically, the period length may depend on external factors. A daily survey would be conceivable, for example, if no significant spatial changes in orientation are to be expected. If the electric motor is installed in a moving system, for example in a wind power plant, a detection with a significantly shorter period length can be appropriate. Here, several acquisitions per second can even be useful.

The inclination measuring unit can have a memory which is designed to store measured values of the at least one sensor and / or to store processed measured values of the at least one sensor. The memory can be designed in various ways. In order to avoid data loss when the power supply fails, however, the memory is preferably in the form of non-volatile memory. Such a non-volatile memory can be, for example, a flash memory, an EEPROM (Electronically Erasable Programmable Read-Only Memory), an NVRAM (Non-volatile Random Access Memory) or another semiconductor memory.

In one development, the inclination measuring unit can additionally have a communication interface via which a current measured value, measured values stored in a memory of the inclined measuring unit and / or information derived from the measured values can be transmitted. The communication interface can be constructed in many different ways. Wireless transmission methods, for example radio-based or optical methods, can be used as well as wired methods. The transmission can be analog or digital, serial or parallel, packetized or in direct connections. The transmission technology used in each case will depend on the respective application scenario. As an example, but not limited to this, reference is made to Bluetooth, Bluetooth LE (Low Energy), NFC (Near Field Communication), Ethernet, RS485, Modbus, Profibus, CAN-Bus or USB (Universal Serial Bus).

The communication interface can be designed in such a way that the communication is read out, for example in the case of service, in order to be able to better understand the cause of the failure.

However, the communication interface can also be communicatively connected to engine electronics. In this case, the motor electronics can be designed to adapt the windings of the stator and / or the rotor to be adjusted based on measured values and / or derived information received via the communication interface. For example, a measured value can indicate that the installation position is very unfavorable, which leads to damage to the motor during long-term operation. This can be due, for example, to the fact that adequate heat dissipation from temperature-sensitive components cannot be adequately ensured due to the installation position. In this case, the engine electronics can control the engine with less power or adjust the control objectives, for example for a particularly quiet run. Additionally or alternatively, the communication interface can be communicatively connected to a network that enables communication with the inclination measuring unit. The network (or parts thereof) is then preferably a wide area network that is based on cables or radio. This network can, for example, network an "Industry 4.0" environment or a loT environment (Internet of Things). Measured values can be transmitted to a monitoring unit directly, via a data aggregator or via a gateway. The data obtained can then be further evaluated in the monitoring unit. It would be conceivable that the maintenance intervals for the electric motor are adapted to the current installation position, so that any damage that occurs is prevented. In this way it can be prevented that an increased risk of bearing grease loss due to the installation position leads to destruction of the bearing.

The electric motor can additionally have an estimation unit which is designed to estimate a service life. As already stated, the installation position affects the service life of individual components of the electric motor. These lifetimes can be calculated in advance by the estimation unit. Such a predictable service life can be the service life of a bearing of the electric motor, a temperature-sensitive component of the electric motor and / or of bearing lubricants. Depending on the installation position, there are different loads on the bearing (s). It is relatively well known how bearings behave under a certain load and how the L10h value changes as a result, so that the life of the bearing (s) can be estimated well and maintenance can be initiated, for example, when the end of life is approaching. With regard to the service life of temperature-sensitive components, this has an effect in particular if an unfavorable installation position hinders heat dissipation and the cooling of the components can no longer be adequately ensured as a result. Semiconductor switches that are used in the generation of the alternating voltages for the windings of the stator / rotor are particularly worth mentioning here. Higher component temperatures reduce their service life, which can also be estimated. The service life of the bearing lubricant relates to the risk with which the lubricant escapes from the bearing depending on the installation position. Here you can Grease service life can be calculated in advance and used to adjust maintenance intervals.

The electric motor can be constructed in various ways. However, the teaching according to the invention is preferably used in connection with electric motors in the medium and large power range (ie from about 100 W to 15 kW). In a preferred embodiment, the electric motor is an EC motor (electronically commutated motor) which has no commutator and in which a variable rotating field is fed into the stator and / or rotor windings. In a very particularly preferred embodiment, the electric motor is constructed in an external rotor construction, i.e. the rotor is arranged around the stator.

The electric motor according to the invention is preferably part of a fan according to the invention. The shaft of the electric motor is connected to an impeller and drives it.

There are now various possibilities for advantageously designing and developing the teaching of the present invention. For this purpose, reference is made on the one hand to the claims subordinate to claim 1 and on the other hand to the following explanation of preferred exemplary embodiments of the invention with reference to the drawing. In connection with the explanation of the preferred exemplary embodiments of the invention with reference to the drawing, preferred configurations and developments of the teaching are also explained in general. Show in the drawing

1 shows a section through a stator of an electric motor according to the invention, which is constructed in external rotor construction,

2 shows a schematic drawing of the motor electronics of an electric motor according to the invention, the axis of the inclination sensor being arranged parallel to the connection plane, 3 shows a schematic drawing similar to FIG. 2, the axis of the inclination sensor being arranged approximately parallel to the connection plane of the power semiconductors,

Fig. 1 shows a section through an electric motor 1 according to the invention, the clarity of the rotor of the electric motor is not shown for clarity. The electric motor is constructed in the form of an external rotor. This means that the stator 2 with a motor axis 3 and the rotor (not shown in FIG. 1) is arranged around the stator 2. In the motor axis 3, a bearing tube 4 is formed, on the longitudinal ends of which a bearing receiving area 5 is formed, the bearing tube 4 and bearing receiving areas 5 being formed in a stator bushing. Bearings are accommodated in the bearing receiving areas 5, via which a shaft of the electric motor, which is also not shown, is rotatably mounted. The stator bushing 6 is formed by an aluminum component, at one end of which the bearing tube 4 and at the other end an electronics housing 18 for receiving the motor electronics is formed. Since the electric motor 1 is an EC motor, motor electronics are required which generate and output a feed signal for the stator and / or rotor windings. In the exemplary embodiment shown in FIG. 1, this motor electronics is arranged in the electronics housing 18. A circuit board 7 of the motor electronics is shown in FIG. 1, which carries components of the motor electronics. An elastic potting compound 8 is arranged above and below the circuit board 7, so that the motor electronics are damped in relation to the electronics housing 18. At the same time, the position and orientation of the circuit board 7 and of the components arranged thereon are unchangeable relative to the stator 2. An inclination sensor 9, which is part of an inclination measuring unit, is arranged on the circuit board 7. A measuring axis 10 of the inclination sensor is arranged parallel to the motor axis 3.

FIG. 2 shows a view into the electronics housing 18 of the electric motor 1. The flange edge 11, which is arranged around the electronics housing 18, can be clearly seen. The circuit board 7, which carries the inclination sensor 9, is arranged in the electronics housing 18. The inclination sensor 9 is another Measuring axis 12 drawn in, which forms a second measuring axis of the inclination sensor 9. In this exemplary embodiment, this measuring axis 12 is arranged parallel to a connection plane 13 of the electric motor, which forms a reference plane in this exemplary embodiment. The connection level 13 is formed by the surface of the stator socket to which the cable bushings 14 are attached. The cable bushings 14 enable a connection via connection cable 15 to the motor electronics on the circuit board 7.

FIG. 3 shows a very similar exemplary embodiment to FIG. 2, the reference plane for the alignment of the further measuring axis 12 ′ being formed in this exemplary embodiment by a connection plane 16 for power semiconductors 17 of the electric motor. In the motor electronics of the exemplary embodiment according to FIG. 3, the connection level 16 is rotated by approximately 8 ° with respect to the connection level 13. The connection plane 16 can also form a reference plane, parallel to which a measurement axis 12 'of the inclination sensor 9 can be arranged.

In the following, some functions and preferred further developments of the electric motor according to the invention are summarized briefly:

1. Determination of the lifespan of critical components on the electronics by detecting the spatial position of heat sources and heat sinks / heat sinks and thus the convection / heat dissipation of the components, which, for example, enables position-dependent performance adjustment and extends the lifespan of temperature-critical components.

2. Predicting the bearing life by recording the installation position, resulting in different bearing loads / bearing seat loads.

3. Advance calculation of the grease service life by recording the installation position, whereby a vertical factor results in a different factor in the grease service life calculation. This also determines and outputs maintenance intervals. 4. Detection of an improper installation position of the electric motor. By recognizing the spatial position of the cable entry and the condensate water openings, a warning message can be generated during commissioning. If a failure occurs, water can penetrate into the motor or the electronics and a simpler damage diagnosis is possible.

5. Detection of the installation position and from this determination of the forces actually acting on components of fans for damage diagnosis in the event of component failure or detection of changes in position of motors and fans that rotate in systems, for example in wind turbines.

With regard to further advantageous refinements of the electric motor according to the invention, reference is made to the general part of the description and to the appended claims in order to avoid repetition.

Finally, it should be expressly pointed out that the above-described exemplary embodiments of the electric motor according to the invention only serve to explain the claimed teaching, but do not restrict them to the exemplary embodiments.

LIST OF REFERENCE NUMBERS

1 electric motor (rotor not

shown)

2 stator

3 motor axis

4 bearing tube

5 storage area

6 stator socket

7 board

8 potting compound

9 inclination sensor

10 measuring axis of the inclination sensor

11 flange edge

, 12 'further measuring axis

13 connection level

14 cable entries

15 connection cables

16 connection level

17 power semiconductors

18 electronics housing

Claims

Expectations

1. Electric motor with a stator (2) and a rotor that is rotatable relative to the stator (2) about a motor axis (3),

characterized by an inclination measuring unit with at least one sensor and sensor electronics, the at least one sensor being arranged in an unchangeable position and orientation relative to the stator (2), the sensor electronics controlling the at least one sensor and the at least one sensor for generating measured values is designed to allow conclusions about the spatial orientation of the sensor and thus conclusions about the spatial orientation of the electric motor.

2. Electric motor according to claim 1, characterized in that the at least one sensor comprises an inclination sensor (9) which, based on the gravitational field of the earth, determines the orientation of the inclination sensor (9) relative to a vector of the gravitational field.

3. Electric motor according to claim 1 or 2, characterized in that the at least one sensor comprises a 3-axis vibration sensor which measures vibrations of the electric motor in three directions, the measurement values obtained in this way drawing conclusions about the orientation of the 3-axis vibration sensor relative to allow a reference vector.

4. Electric motor according to one of claims 1 to 3, characterized in that a measuring axis (10) of the inclination measuring unit is arranged parallel to the motor axis (3).

5. Electric motor according to one of claims 1 to 4, characterized in that a further measuring axis (12) of the inclination measuring unit is arranged substantially parallel or perpendicular to a reference plane of the electric motor, the reference plane preferably through a connecting plane (13) of the Electric motor (1) or by a connection level (16) for power semiconductors (17) is formed.

6. Electric motor according to one of claims 1 to 5, characterized in that the inclination measuring unit is integrated in a motor electronics, the motor electronics being designed to control windings of the stator and / or the rotor and is preferably arranged in an electronics housing.

7. Electric motor according to one of claims 1 to 5, characterized in that the inclination measuring unit is arranged in a bearing tube (4) which encloses at least parts of a shaft of the electric motor and on which at least one bearing receiving area (5) is formed for bearings of the shaft is.

8. Electric motor according to one of claims 1 to 7, characterized in that the inclination measuring unit has an evaluation unit, the evaluation unit being designed to obtain information about the spatial orientation of the at least one sensor and / or the electric motor from measured values of the at least one sensor to determine.

9. Electric motor according to claim 8, characterized in that the information comprises a data record which indicates the angle with respect to a reference direction.

10. Electric motor according to claim 8 or 9, characterized in that the information comprises an evaluation number which indicates how favorable or unfavorable a currently determined spatial orientation is.

11. Electric motor according to one of claims 1 to 10, characterized in that the inclination measuring unit is designed to determine the spatial orientation of the electric motor when the electric motor is started up, each time the electric motor is switched on and / or periodically.

12. Electric motor according to one of claims 1 to 11, characterized in that the inclination measuring unit has a memory which is designed for storing measured values of the at least one sensor and / or for storing processed measured values of the at least one sensor.

13. Electric motor according to one of claims 1 to 12, characterized in that the inclination measurement unit additionally has a communication interface via which a current measurement value, measurement values stored in a memory of the inclination measurement unit and / or information derived from the measurement values can be transmitted ,

14. Electric motor according to claim 13, characterized in that the communication interface is communicatively connected to a motor electronics, the motor electronics being designed to adapt a control of the windings of the. Based on measured values and / or derived information received via the communication interface Stator and / or the rotor.

15. Electric motor according to claim 13 or 14, characterized in that the communication interface is communicatively connected to a network, preferably a wide area network.

16. Electric motor according to one of claims 1 to 15, characterized by an estimation unit which is designed to estimate a service life, preferably the life of a bearing of the electric motor, a temperature-sensitive component of the electric motor and / or of bearing lubricant.

17. Electric motor according to one of claims 1 to 16, characterized in that the electric motor is formed by an EC motor - electronically commutated motor - and / or is constructed in an external rotor design.

18. Fan with an electric motor according to one of claims 1 to 17 and an impeller connected to the motor shaft.

19. Motor electronics for driving an electric motor, in particular an electric motor according to one of claims 1 to 17, wherein the motor electronics for

Driving windings of a stator and / or windings of a rotor of the electric motor is formed,

characterized by an inclination measuring unit with at least one sensor and sensor electronics, the at least one sensor being arranged in an unchangeable position and orientation relative to the motor electronics, the sensor electronics controlling the at least one sensor and the at least one sensor being designed to generate measured values, allow conclusions to be drawn about the spatial orientation of the sensor and thus conclusions about the spatial orientation of the motor electronics.