Electric machine, in particular for a motor vehicle

Abstract

The invention relates to an electric machine having a winding (12) by means of which a magnetic field can be generated, and having a sensor device (22) by means of which the magnetic field can be detected, the sensor device (22) having at least one circuit board (24) having a plurality of circuit board regions (26) that are at least partially mutually spaced in the circumferential direction of the electric machine and between which respective length portions (L) of the winding (12) are arranged. Magnetic field sensors (28) that are held on the circuit board (26) and by means of which the magnetic field can be detected are provided. The respective magnetic field sensor (28) is designed to generate a respective, analogue and electrical measurement signal that characterises the magnetic field detected by means of the respective magnetic field sensor (28). The respective magnetic field sensor (28) has a respective analogue-to-digital converter, by means of which the respective analogue measurement signal generated by the respective magnetic field sensor (28) can be converted into a respective electrical and digital signal (54) that can be provided by the respective magnetic field sensor (28).

Description

[0001] Mercedes-Benz Group AG Dr. Scheidle

[0002] December 16, 2025

[0003] Electric machine, especially for a motor vehicle

[0004] The invention relates to an electric machine, in particular for a motor vehicle, according to the preamble of claim 1.

[0005] DE 102023 000252 A1 discloses an electrical machine as known. Furthermore, WO 2014 / 545079 A1 discloses a measuring device for measuring an angle of rotation.

[0006] The object of the present invention is to create an electric machine, in particular for a motor vehicle, such that a magnetic field of the electric machine can be detected in a particularly advantageous way.

[0007] This problem is solved by an electric machine with the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0008] The invention relates to an electric machine, particularly for a motor vehicle. This means that the motor vehicle, also referred to simply as a vehicle and designed, for example, as a motor car, particularly a passenger car, in its fully manufactured state comprises the electric machine and can be driven electrically by means of the electric machine, in particular purely electrically. The electric machine has at least one winding by means of which a magnetic field can be generated, in particular for driving a rotor of the electric machine. This means, for example, that the electric machine in its fully manufactured state has said rotor, which can be driven by means of the magnetic field. For example, the electric machine in its fully manufactured state has a stator, wherein the rotor is rotatable about a machine axis of rotation of the electric machine relative to the stator.In particular, the rotor can be driven by means of the stator and thereby rotated around the machine's axis of rotation relative to the stator. It is conceivable that the aforementioned winding is a winding of the stator and is therefore also referred to as a stator winding. For example, the electric machine can provide drive torques via its rotor to propel the motor vehicle. The electric machine also has a sensor device by which the magnetic field can be detected. This means that the magnetic field can be detected, i.e., measured, by means of the sensor device. Detecting, i.e., measuring, the magnetic field means, in particular, that a measurand characterizing, i.e., describing or specifying, the magnetic field can be detected or is detected by means of the sensor device.In particular, the detection, or rather measurement, of the magnetic field means that the sensor device detects or measures the magnetic flux of the magnetic field, also simply referred to as flux. Thus, the measured quantity is, for example, the magnetic flux of the magnetic field. Put another way, the sensor device can detect, or measure, the magnetic flux of the magnetic field, which is also referred to as magnetic flux. For example, the magnetic flux in question is a magnetic leakage flux from the electric machine, which is also simply referred to as leakage flux. Since the magnetic flux can be used, or is used, to drive the rotor, the magnetic flux is also referred to as the rotor magnetic field.In particular, the sensor device can be used to measure the magnetic field, so that the detection or measurement of the magnetic field is also referred to as magnetic field measurement or rotor magnetic field measurement.

[0009] To enable particularly advantageous detection, i.e., measurement, of the magnetic field, the sensor device includes a circuit board, also known as a printed circuit board or PCB. The circuit board comprises several sections spaced at least partially, and in particular completely, apart from one another in the circumferential direction of the electrical machine, between which respective length sections of the winding are arranged. The circumferential direction of the electrical machine, whose axial direction coincides with the machine's axis of rotation, runs around the machine's axis of rotation and, in particular, in a plane perpendicular to the axial direction of the electrical machine, whose radial direction is perpendicular to the axial direction of the electrical machine.Since the circuit board sections are at least partially spaced apart, through-openings, particularly of the circuit board itself, are arranged between the circuit board sections in the circumferential direction of the electrical machine. These through-openings are continuous, particularly in the axial direction of the electrical machine, especially when considering only the circuit board. The through-openings are penetrated by the winding sections, particularly in the axial direction of the electrical machine. Specifically, the circuit board sections are arranged between the winding sections in the circumferential direction of the electrical machine such that, viewed in the circumferential direction of the electrical machine, the winding sections are arranged alternately.When the axial direction is mentioned before and below, unless otherwise specified, this refers to the axial direction of the electrical machine, whose axial direction coincides with the machine's axis of rotation. When the radial direction is mentioned before and below, unless otherwise specified, this refers to the radial direction of the electrical machine, whose radial direction is perpendicular to the axial direction and thus perpendicular to the machine's axis of rotation.

[0010] The sensor device also includes magnetic field sensors held on the circuit board, in particular directly, by means of which the magnetic field, in particular the measured quantity and / or the magnetic flux, can be detected.

[0011] In order to detect the magnetic field particularly advantageously and subsequently to realize a particularly advantageous operation of the electric machine, especially one dependent on the detected magnetic field or on the detection of the magnetic field, the invention provides that the respective magnetic field sensor is configured to generate a corresponding analog electrical measurement signal that characterizes, i.e., describes or indicates, the magnetic field detected by the respective magnetic field sensor, in particular the magnetic flux and / or the measured quantity. 2024P02095WG

[0012] 4

[0013] Furthermore, according to the invention, each magnetic field sensor has a corresponding, in particular internal, analog-to-digital converter, also referred to as an A / D converter. By means of the analog-to-digital converter of the respective magnetic field sensor, the analog measurement signal generated by the respective magnetic field sensor can be converted into a corresponding electrical and digital signal, also referred to as a provision signal, which can be provided by the respective magnetic field sensor. In particular, the respective analog-to-digital converter of the respective magnetic field sensor is integrated into the respective magnetic field sensor.

[0014] According to the invention, an evaluation unit is provided, in particular in addition to the magnetic field sensors and thus in addition to the analog-to-digital converters and in particular in addition to the circuit board. This evaluation unit is arranged, in particular entirely, with respect to the magnetic field sensors and, in particular, entirely outside the analog-to-digital converters. It is specifically provided that the magnetic field sensors and the analog-to-digital converters are arranged, in particular entirely, outside the evaluation unit. The evaluation unit comprises, in particular, at least or exactly, a microprocessor. The evaluation unit is configured to receive the electrical and digital signals provided by the magnetic field sensors and to evaluate them, in particular by means of the microprocessor.Alternatively or additionally, the evaluation unit is designed to receive a composite electrical and digital signal resulting from the electrical and digital signals, which, for example, characterizes the electrical and digital signals, also referred to as individual signals. In principle, it would be conceivable for the sensor device to have a signal processing unit, located particularly outside the magnetic field sensors and especially outside the analog-to-digital converters, and, in particular, directly attached to the circuit board, by means of which, for example, the individual electrical and digital signals can be converted into the composite electrical and digital signal, in particular exactly one. It is conceivable that the composite signal can be provided by the signal processing unit. For this purpose, the signal processing unit has, for example, an output at which it can provide the composite signal.In particular, the signal processing unit, especially entirely, is arranged outside the evaluation unit. Furthermore, it is conceivable that the respective magnetic field sensor has a respective output, via which the respective 2024P02095WG.

[0015] 5

[0016] The magnetic field sensor can provide the respective individual electrical and digital signals. For example, the evaluation unit has at least one input through which it can receive the overall signal. Furthermore, it is conceivable that each individual signal is assigned a corresponding input to the evaluation unit, which can receive the individual signals via its inputs.

[0017] The respective magnetic field sensor is a chip, or is also referred to as a chip, or comprises at least or exactly one chip. The respective chip is also referred to as a sensor chip, by means of which, for example, the magnetic field, in particular the measured quantity and / or the magnetic flux, can be detected or recorded. According to the invention, it is provided that the respective measurement signal is digitized directly on or by means of the respective sensor chip and thus converted into the respective digital and electrical individual signals. The individual signals or the total signal can then be transmitted, for example, through electrical and / or magnetic interference fields to the evaluation unit, which receives the individual signals or the total signal. The evaluation unit can evaluate the individual signals or the total signal.The invention enables a significant improvement in the evaluation of individual signals or the overall signal compared to conventional solutions. The evaluation of individual signals or the overall signal can be understood as follows: By evaluating the individual signals or the overall signal, at least one parameter can be determined, for example, that characterizes the magnetic field and / or the electric machine and / or a, in particular, current state of the electric machine. It is particularly conceivable that the magnetic field sensors can be used to measure the magnetic field during a method for operating the electric machine, that is, during operation of the electric machine. For example, in this method, the rotor rotates around the machine's axis of rotation relative to the stator.For example, during the process, the rotor is driven, in particular by means of the magnetic field, causing the rotor to rotate around the machine's axis of rotation relative to the stator. It is conceivable that, in this process, the rotor provides a torque, also known as rotor torque, which, for example, can be used to power or drive a motor vehicle. It is conceivable that the aforementioned parameter characterizes the operation of the electric machine. 2024P02095WG.

[0018] 6

[0019] For example, the parameter is, encompasses, or characterizes the specified torque that can be provided or is provided by the rotor. In other words, by evaluating the individual signals or the total signal, the torque, or at least one value of the torque, can be determined, so that, for example, the torque or its value can be determined as a function of the measured magnetic field. Alternatively or additionally, the parameter is, encompasses, or characterizes a rotational position of the rotor, particularly relative to the stator. Alternatively or additionally, the parameter is a rotational speed at which the rotor, particularly its current speed, rotates around the machine's axis of rotation relative to the stator. Alternatively or additionally, the parameter is a current temperature of the rotor and / or the stator.Alternatively or additionally, the parameter includes or characterizes demagnetization, in particular of magnets of the electric machine, and / or an eccentricity of the rotor, and thus damage to a bearing, also referred to as bearing damage, by means of which, for example, the rotor is rotatably mounted around the machine's axis of rotation relative to the stator. In particular, the magnets mentioned are permanent magnets of the electric machine.

[0020] The invention is based in particular on the following findings and considerations. Since the winding sections extend through the through-holes and thus between the circuit board sections, the sensor device is located directly within the electric machine, also known as an electric motor or capable of being operated as an electric motor. Consequently, the sensor device is exposed to strong interference fields that are technically unavoidable. In particular, a transmission line, via which, for example, the individual signals and / or the overall signal from the magnetic field sensors or from the signal processing unit can be transmitted to the evaluation unit and thus received by the evaluation unit, can be exposed to such interference fields. Despite these interference fields, the overall signal or the individual signals can now be advantageously received and evaluated by means of the evaluation unit.The magnetic field sensor itself measures the aforementioned flux, for example, with so-called harmonics, such as those resulting from saturation of the electrical machine. These harmonics typically generate angular errors in angle calculations, for example, for calculating rotational position. Ideally, these harmonics should be filtered or eliminated without introducing a phase shift. The invention is patented under 2024P02095WG.

[0021] 7. The invention now presents a direct discretization, in particular including filtering of the measurement signals, by converting the measurement signals into individual digital signals using the A / D converters. In particular, the invention enables the elimination of distortions through specifically arranged polyphase multipath acquisition, since preferably the number of magnetic field sensors is three or greater. In particular, the magnetic field sensors can be specifically arranged to selectively compensate for harmonics. The invention makes it possible to provide the respective individual signal or the total signal as a clean, interference-free, or low-interference digital signal and thus transmit it to the evaluation unit, thereby achieving a particularly advantageously precise measurement result. Furthermore, the effort required for magnetic shielding and electromagnetic compatibility (EMC) can be advantageously minimized.Furthermore, excessive, unwanted filtering can be avoided, for example.

[0022] Since each magnetic field sensor incorporates an integrated analog-to-digital converter (ADC), it is designed to convert its measurement signal into a digital signal. Thus, the output of each magnetic field sensor is a digital output, through which it can provide the electrical and digital signal and transmit it to the evaluation unit.

[0023] In order to detect the magnetic field particularly advantageously and consequently to determine the parameter advantageously and precisely, it is further provided in the invention that the magnetic field sensors and thus preferably the circuit board areas are arranged evenly distributed in the circumferential direction of the electric machine.

[0024] It has proven particularly advantageous to have six magnetic field sensors, especially exactly six. Specifically, each magnetic field sensor has exactly one circuit board area, so that preferably the number of circuit board areas is exactly six. Compared to conventional solutions, this allows for a significant improvement in the evaluation of the individual signals or the overall signal, since the harmonics mentioned can be determined using the six measurement signals as six reference points. 2024P02095WQ

[0025] 8 are very well determined and the individual signals are not disturbed by the operation of the electrical machine and its magnetic field on the way to the evaluation unit.

[0026] It has also proven particularly advantageous if the magnetic field sensors, and thus, for example, the circuit board areas, are uniformly distributed around the circumference of the electric machine and spaced 30 degrees apart when viewed in pairs. This allows the magnetic field measurement around the circumference of the electric machine to be efficiently performed over an angular range of 180 degrees, as the magnetic field is measured every 30 degrees across this 180-degree range. This provides, for example, advantageous reference points for the individual signals, enabling the determination of the harmonic(s). While a 360-degree measurement of the magnetic field is not necessary for symmetry reasons, it is fundamentally possible, allowing for particularly high-quality data analysis and thus, for example, parameter determination.

[0027] For example, each individual digital signal comprises individual measured values ​​that characterize the magnetic field. Generating the respective measurement signal involves, for example, direct sampling, particularly in the form of oversampling with averaging and / or filtering and / or sigma-delta processing. Converting the measurement signals into individual digital signals enables a digital and interference-resistant transmission of the measured values ​​to the evaluation unit. Furthermore, a targeted, optimized multiphase transformation is provided or feasible. The direct conversion of the respective analog measurement signal into the respective individual digital signal on the chip includes, for example, oversampling and / or delta A / D conversion, particularly with a larger time domain. In particular, setting a filter time is possible. Furthermore, the use of the so-called SENT protocol, for example, enables high interference immunity.In particular, a signal structure based on pulse-width modulation can be provided, in which information is encoded in a length of pulses. Robust timing measurement is made possible, in particular, by SENT measuring the time between signal edges, which is less susceptible to interference compared to voltage levels. 2024P02095WG.

[0028] 9

[0029] In an advantageous embodiment of the invention, communication between the magnetic field sensors and the connected evaluation unit takes place in the form of digital signals and via a digital communication protocol in the form of pulse width modulation (PWM).

[0030] Furthermore, pulse width modulation (PWM) as a communication method has the advantage of a frequency between 1 kHz and 10 kHz, in order to be able to transmit the signals at the necessary speed.

[0031] In an advantageous embodiment of the invention, communication between the magnetic field sensors and the connected evaluation unit is bidirectional, so that signals are sent both from the magnetic field sensors to the connected evaluation unit and from the connected evaluation unit to the magnetic field sensors. This can be done using the same communication protocol or via separate lines from specific transmitter modules to corresponding specific receiver modules of the magnetic field sensors and the evaluation unit, so that different communication protocols can be used depending on the selected transmitter and receiver modules.However, it is advantageous if both directions of communication use the same communication protocol, so that identical or at least analogous transmitter and receiver modules are used in the magnetic field sensors and the evaluation unit.

[0032] A particular advantage has proven to be that bidirectional communication between the magnetic field sensors and the connected evaluation unit can take place via a single data line, meaning that the magnetic field sensor essentially only needs three connections. One connection is for the data line, and two connections are for the power supply of the magnetic field sensors. Corresponding to this single data line, both a transmitter module and a receiver module are connected to it in the magnetic field sensors and in the evaluation unit, using the data line for communication. Each magnetic field sensor has its own dedicated data line.

[0033] In a further advantageous embodiment, bidirectional communication between the magnetic field sensors and the connected evaluation unit is possible via the respective 2024P02095WG.

[0034] 10. Time-synchronized data transmission occurs by sending a trigger signal from the connected evaluation unit to the respective magnetic field sensor via the respective single data line, in order to transmit a data signal from the respective magnetic field sensor to the connected evaluation unit via the respective single data line in response.

[0035] Of course, according to an alternative embodiment of the invention, the magnetic field sensor can send a data signal to the evaluation unit not only depending on a trigger signal, but also continuously or at fixed or adjustable time intervals. However, this can lead to unintended measurements, increased energy consumption, higher data flow, or, most importantly, unsynchronized measurements. If the magnetic field is measured depending on a trigger signal and the expected measured value is specifically transmitted from the magnetic field sensors to the evaluation unit, a control method can be implemented much more efficiently, effectively, and with less energy consumption.

[0036] In an advantageous embodiment of the invention, it has also been shown that the evaluation unit can always evaluate at least two magnetic field sensors simultaneously, with the two magnetic field sensors being spaced apart from each other by 90 degrees in the circumferential direction of the electric machine. The advantage here is that even with these two measured values ​​from the magnetic field sensors spaced 90 degrees apart, the evaluation unit can essentially make a rough statement about the magnetic field and the control, even if this value may be somewhat inaccurate. It is better to include further measured values ​​from other magnetic field sensors to improve the values ​​and thus determine more precise parameters in the evaluation unit.The remaining magnetic field sensors can then share a data line, so that they can be individually controlled and read out using a common data line and a specific trigger signal from the evaluation unit, but only one magnetic field sensor and one measured value can be used simultaneously with the other two measured values ​​of the individually connected magnetic field sensors, so that only three values ​​can be used for parameter determination.

[0037] For example, if six magnetic field sensors are arranged on the circuit board and these are spaced apart in pairs by 90 electrical degrees, then magnetic field sensors 1 and 4 can be connected to the evaluation unit 2024P02095WG via their own data line.

[0038] The 11th sensor is equipped with a single data line, while the remaining magnetic field sensors 2, 3, 5, and 6 share a common data line. This means that only one additional value can be added to the two readings from magnetic field sensors 1 and 4. This reduces the number of data lines on the circuit board to three, and only three data lines need to be routed to the evaluation unit. The communication module there also requires only three inputs and outputs for bidirectional communication, simplifying the hardware. Furthermore, the bandwidth of the data processing can be reduced by sequentially reading the magnetic field sensors 2, 3, 5, and 6.

[0039] Depending on the layout and design of the circuit board with the magnetic field sensors, the traces on the board must be arranged so that no intersections occur when all traces lie on the same plane. If multiple planes are available for the traces, they can cross if they are arranged on different planes or if the intersection points are on different planes. It should be emphasized again that each magnetic field sensor has two power supply connections, which are then connected via wires to the power supply on the circuit board, specifically to a common power supply line. The power supply is usually a DC voltage, with one wire often serving as ground and the other supplying the DC voltage, for example, 5 volts.The data line, which transmits the digital signals, is also routed across the circuit board as the third connection between the magnetic field sensors and the evaluation unit. It must not come into contact with the power supply's common lines or experience a voltage breakdown. Therefore, fewer data lines on the circuit board can be advantageous, especially when connecting multiple magnetic field sensors.

[0040] Alternatively, additional data lines can be provided, so that with four data lines, magnetic field sensors 1 and 4 can always be read, and then magnetic field sensors 2 and 5 in pairs, or alternatively or alternately, magnetic field sensors 3 and 6. In this way, good measured values ​​for determining the parameters can be obtained with only four data lines and connections in the evaluation unit. 2024P02095WG

[0041] 12

[0042] Of course, additional data lines can be provided to read more magnetic field sensors simultaneously. It is always advantageous to be able to read the magnetic field sensors synchronously in pairs, specifically for pairs of sensors that are separated by 90 degrees electrically.

[0043] In another alternative configuration, all magnetic field sensors can be evaluated simultaneously using the connected evaluation unit. These sensors cover a range of 180 degrees around the circumference of the electric machine. In this configuration, a separate data line is required from each magnetic field sensor to the evaluation unit. This line can also be accessed via a dedicated connection on the evaluation unit and used for communication with the respective magnetic field sensor. While this provides the best measurement results, as all sensors can determine and transmit their readings simultaneously and thus synchronously, the hardware and the circuit board with the necessary data lines must be appropriately equipped to enable this. Naturally, this also results in increased energy consumption and data throughput.

[0044] In another alternative embodiment, at least five magnetic field sensors can be spaced apart as individual measuring points on the circuit board, covering the 180-degree range of the electric machine and, in particular, arranged uniformly across this range. This is based on the understanding that the sums of the products of the sine and cosine terms must be zero in order to remove at least the 5th and 7th harmonics from the measurement.

[0045] Thus, with the conditions for n as the number of magnetic field sensors, the following results: and an n of at least 5 to meet these conditions.

[0046] The best results can be achieved using measurements from at least 5 magnetic field sensors that evenly cover the 180-degree range of the electric machine. 2024P02095WG

[0047] 13

[0048] As a further spatial condition to the number of magnetic field sensors that must cover the range of 180 electrical degrees of the electric machine in an even distribution, the arrangement on the stator on a bridge between the slots is added, so that the distribution of the magnetic field sensors over the electrical angle must also fit with a spatial angle in the mechanics of the slots of the stator.

[0049] For a possible spatial arrangement of the magnetic field sensors, provided that at least five magnetic field sensors are evenly distributed over the range of 180 electrical degrees of the electric machine, the slot spacing and its slot spacing angle must also be taken into account.

[0050] Advantageously, a number of magnetic field sensors greater than or equal to five corresponds to a spatial constraint in the design of the number of pole pairs of the electric machine via the mechanical angle of the slots in the stator. This results in a mechanical angle for the arrangement that corresponds to an integer multiple of the electrical angle between two magnetic field sensors, so that the number of magnetic field sensors is evenly distributed to cover the range of 180 electrical degrees and can always be arranged precisely on a web between the slots of the stator. The webs have the same angles as the slots, so that, as is usual with electric machines, it is simpler to refer to the number of slots, i.e., the number of slots in the stator, and thus to 360°.

[0051] In other words, the electric angle between the n magnetic field sensors, which uniformly cover the range of 180 electric degrees of the electric machine, must be equal to

[0052] 71 6 = - n

[0053] The number of pole pairs can be linearly converted into a mechanical angle, which then corresponds to the integer multiple of the slot spacing angle.

[0054] This means that the magnetic field sensors cover a range of 180 electrical degrees evenly distributed around the circumference of the electric machine and are always positioned precisely on a bridge between two slots of the stator of the electric machine. Thus, the angular distance between the magnetic field sensors corresponds to 2024P02095WG.

[0055] 14 an integer multiple of the slot spacing angle and all magnetic field sensors can thus be arranged on the web between the slots.

[0056] The simple solutions that result here are advantageous: the magnetic field sensors are arranged in the circumferential direction of the electric machine in the range of 180 electrical degrees exactly with the slot spacing angle, and are arranged on each web between two slots, and exactly one slot is arranged between two magnetic field sensors.

[0057] Alternatively, but also advantageously, the magnetic field sensors are arranged circumferentially around the electric machine at intervals of 180 degrees, precisely at twice the slot spacing angle. Between adjacent magnetic field sensors on each bridge, there is always another bridge free of a magnetic field sensor, and exactly two slots are arranged between two magnetic field sensors.

[0058] For example, the conditions for an electric machine with 48 slots and 4 poles (12 slots per pole) dictate that 6 sensors must be arranged. Furthermore, the arrangement requires that the angle of the magnetic field sensors be twice the slot spacing angle, meaning that there are always two slots between each pair of magnetic field sensors. The same applies to electric machines with 72 slots and 6 poles or with 96 slots and 8 poles, all of which have a slot-to-pole ratio of 12.

[0059] Another example is electrical machines with 48 slots and 8 poles, i.e., 6 slots per pole. Here too, 6 sensors must be arranged, but this time the angular spacing of the magnetic field sensors corresponds directly to the slot spacing angle, so that there is only one slot between each magnetic field sensor, and the sensors are arranged adjacent to each other on each rib. The same applies to electrical machines with 36 slots and 6 poles, or with 54 slots and 9 poles, all of which have a slot-to-pole ratio of 6.

[0060] Alternatively, an electric machine with 30 slots and 6 poles or with 40

[0061] With slots and 8 poles (5 slots per pole), only five magnetic field sensors are needed to evenly cover the range of 180 electrical degrees. This results in a distance of 36 electrical degrees between the magnetic field sensors, yet all conditions would still be met.

[0062] Advantageously, the evaluation unit can alternatively be arranged completely outside the circuit board, or completely outside the magnetic field sensors, or completely outside the analog-to-digital converters, or completely spaced away from the circuit board, or completely spaced away from the magnetic field sensors, or completely spaced away from the analog-to-digital converters. Therefore, the arrangement and spatial location of the evaluation unit are not particularly significant for the invention, since the core of the invention is precisely to eliminate the spatial proximity of the magnetic field sensors and the evaluation unit through digital signals and digital communication, and to ensure that the communication is undisturbed by the communication path and distance.Therefore, another embodiment is characterized in that the evaluation unit is arranged completely outside the circuit board, completely outside the magnetic field sensors, and completely outside the analog-to-digital converters. Furthermore, it is preferably provided that the evaluation unit is completely spaced away from the circuit board, completely spaced away from the magnetic field sensors, and completely spaced away from the analog-to-digital converters. This allows the parameter to be determined particularly advantageously, so that, for example, the electric machine can subsequently be operated particularly advantageously depending on the parameter and thus depending on the measured magnetic field.

[0063] In order to be able to measure, i.e. detect, the magnetic field in a particular way, it is provided in a further embodiment of the invention that exactly one of the magnetic field sensors is held on the respective circuit board area.

[0064] In a further, particularly advantageous embodiment of the invention, the circuit board areas are designed as teeth, which are also referred to as tabs or prongs. The teeth project inwards in the radial direction of the electrical machine from a common base area of ​​the circuit board. The teeth are held to the base area and held together by the base area, in particular such that the teeth and the base area are formed as a single unit, i.e., from a single piece. This means, in particular, that the teeth and the base area are not composed of separately formed and connected parts, but preferably the teeth and the base area are formed from a single piece, i.e., as a monoblock or formed by a monoblock.In other words, it is preferably intended that the teeth and the base area are formed from an integral body, that is, manufactured in one piece, and thus formed from a single piece. Each tooth terminates radially inwards at a free end opposite the base area, which is designed, for example, as a ring. Thus, the circuit board is comb-shaped, with the teeth forming the teeth. This allows for a cost-effective, space-saving, and lightweight design of the circuit board and therefore of the sensor device as a whole, while also enabling quick and cost-effective assembly of the circuit board.

[0065] Another embodiment is characterized in that the base area is circular, arc-shaped, or segment-shaped on its side facing outwards in the radial direction of the electric machine. This allows for a particularly space-saving design of the circuit board and thus of the sensor device as a whole, enabling particularly advantageous installation of the circuit board and thus the sensor device, and allowing for particularly advantageous detection of the magnetic field.

[0066] Finally, it has proven particularly advantageous to insert the circuit board radially from the outside inwards between the winding sections of the electric machine. This allows the circuit board, and thus the sensor device, to be arranged in a particularly time- and cost-effective manner, enabling optimal measurement of the magnetic field.

[0067] As an advantageous embodiment of the invention, a vehicle designed as a motor vehicle, preferably as a motor car, and in particular as a passenger car, can also have at least or exactly one electric machine according to the invention and be electrically driven by means of the electric machine, in particular purely electrically. Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0068] The drawing shows in:

[0069] Fig. 1 shows a schematic perspective view of a stator of an electric machine, in particular for a motor vehicle;

[0070] Fig. 2 shows a partial schematic perspective view of a circuit board of a sensor device of the electric machine;

[0071] Fig. 3 shows a schematic representation of part of the electric machine;

[0072] Fig. 4 shows another schematic representation of part of the electric machine;

[0073] Fig. 5 shows another schematic representation of part of an alternative electrical

[0074] machine; and

[0075] Fig. 6 shows another partial schematic perspective view of a circuit board of a sensor device of the electric machine.

[0076] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0077] Fig. 1 shows a schematic perspective view of a stator 10 of an electric machine, in particular of a motor vehicle. This means that the motor vehicle, also simply referred to as a vehicle and designed, for example, as a motor car, in particular as a passenger car, in its fully manufactured state has the electric machine and can be driven electrically by means of the electric machine, in particular purely electrically. Preferably the electric machine is 2024P02095WG

[0078] 18. A high-voltage component whose electrical voltage, in particular its operating and / or rated voltage, is preferably greater than 50 volts, particularly greater than 60 volts, and most preferably several hundred volts. In its fully assembled state, the electric machine comprises the stator 10 and a rotor (not shown in the figures), which is rotatable about a machine axis of rotation of the electric machine, the axial direction of which coincides with the machine axis of rotation, relative to the stator 10. In particular, the electric machine, whose radial direction is perpendicular to the axial direction of the electric machine and thus perpendicular to the machine axis of rotation, can provide drive torques for propelling the motor vehicle via its rotor. Where the radial direction is mentioned before and below, unless otherwise specified, this refers to the radial direction of the electric machine.When the axial direction is mentioned before and in the following, unless otherwise specified, this refers to the axial direction of the electrical machine, whose circumferential direction runs around the axial direction and thus around the machine's axis of rotation, and therefore extends in a plane of consideration that is perpendicular to the axial direction.

[0079] The electric machine, in particular the stator 10, has at least one winding 12 by means of which a magnetic field, in particular a magnetic flux also simply referred to as flux or magnetic flux, can be generated. Most preferably, the magnetic flux is a leakage flux, which is also simply referred to as leakage flux. Most preferably, the winding 12 is designed according to the hairpin technology, also known as hairpin technology, and is therefore also referred to as a hairpin winding. Since the winding 12 is a winding of the stator 10, the winding 12 is also referred to as the stator winding. The stator 10, and thus the electric machine, has a laminated core 14 to which the winding 12 is held. Thus, the winding 12 is supported by the laminated core 14. The axial direction of the electric machine, and thus of the stator 10, is illustrated in Fig. 1 by a double arrow 16.For example, the laminated core 14 is formed, in particular composed, of several separately formed and interconnected laminated core segments. As can be seen from Fig. 1, respective length ranges L of the winding 12 project axially from the laminated core 14, in particular from the axial end face AS1, on a first axial end face AS1, whereby the length ranges L form at least one winding head 18 of the winding 12 arranged on the axial end face AS1. The laminated core 14 also has, for example, a second axial end face AS2 facing away from the axial end face AS1 in the axial direction.It is conceivable, for example, that on the axial end face AS2 second length regions L2 of the winding 12 protrude in the axial direction from the laminated core 14, in particular from the axial end face AS2, whereby, for example, the length regions L2 on the second axial end face AS2 form at least one second winding head 20 of the winding 12.

[0080] The electric machine also includes a sensor device 22 by means of which the magnetic field, in particular the magnetic flux, can be detected. In order to be able to detect, i.e., measure, the magnetic field particularly advantageously, the sensor device 22 includes at least one circuit board 24 (Fig. 2), wherein the circuit board 24 is preferably formed separately from the laminated core 14 and is connected, for example, at least indirectly, and in particular directly, to the laminated core 14.

[0081] Fig. 2 shows a partial schematic perspective view of the sensor device 22. Particularly evident in Fig. 2 is the circuit board 24, which, in the circumferential direction of the electric machine around its axis of rotation, has circuit board sections 26 spaced apart from one another, at least partially, in this case completely, between which the length sections L are arranged. Conversely, the circuit board sections 26 are arranged between the length sections L in the circumferential direction of the electric machine. The sensor device 22 also includes magnetic field sensors 28, in particular such that exactly one magnetic field sensor 28 is provided for each circuit board section 26. The magnetic field sensors 28 are held on the circuit board 24 and thus supported by the circuit board 24, in particular such that the magnetic field sensors 28 are each at least partially embedded in the circuit board 24. Thus, the circuit board 24 is equipped with the magnetic field sensors 28.The magnetic field can be detected by means of the magnetic field sensors 28. Thus, for example, in a method for operating the electric machine, the magnetic field is detected by means of the magnetic field sensors 28. Figure 2 also shows that exactly one of the magnetic field sensors 28 is held on each circuit board section 26. Thus, for example, the magnetic field sensors 28 are arranged between the length sections L. In the embodiment shown in the figures, the circuit board sections 26 are designed as teeth or prongs, which project radially inwards from a base section 30 of the circuit board 24 common to all the teeth and terminate radially inwards at a free end E of each tooth, which is radially opposite the base section 30.Thus, the circuit board 24 is comb-shaped, specifically in the form of a comb bent around the machine's axis of rotation. This allows for particularly time- and cost-effective assembly of the circuit board 24, such that, in a method for manufacturing the electric machine, the circuit board 24 is inserted radially from the outside inwards between the length sections L. The radial direction is perpendicular to the axial direction and is illustrated in Figures 1 and 2 by a double arrow 32. The axial direction is illustrated in Figure 1 by a dashed line 34, which runs around the axial direction in the circumferential direction of the electric machine and thus of the stator 10 and is illustrated by a double arrow 36.

[0082] Fig. 2 clearly shows that the base region 30 is circular or arc-shaped on its side 35, which faces away from the teeth (plate regions 26) and points radially outwards. Fig. 1 shows that, in the circumferential direction of the electric machine and thus of the stator 10, one of the sheet metal segments from which the laminated core 14 is formed adjoins the plate 24 on both sides, wherein a first of the sheet metal segments adjoining the plate 24 in the circumferential direction of the electric machine, in particular directly, is designated 38 and a second of the sheet metal segments adjoining the plate 24 in the circumferential direction of the electric machine, in particular directly, is designated 40.The respective sheet metal segments 38, 40 and the circuit board 24 are arranged at least partially, and in particular completely, at the same height when viewed in the axial direction of the electrical machine, such that the respective sheet metal segments 38, 40 and the circuit board 24 are arranged flush with each other on the axial end face AS1. The circuit board 24 is at least partially, and in particular at least predominantly and thus at least more than halfway or completely, covered by the laminated core 14 in a first direction illustrated by an arrow 42, wherein the first direction illustrated by arrow 42 runs parallel to or coincides with the axial direction. A second direction, illustrated by arrow 44, opposite to the first direction, is also shown.

[0083] In section 21, the circuit board 24 is arranged completely without overlap with the laminated core 14 and is therefore not overlapped by the laminated core 14, wherein the second direction is parallel to the axial direction or coincides with the axial direction and is opposite to the first direction. Thus, the circuit board 24 is arranged axially between the winding head 18 and at least a length of the laminated core 14, which allows the magnetic field to be detected particularly advantageously. Furthermore, the magnetic field sensors 28 are arranged axially between the winding head 18 and at least a length of the laminated core 14. In order to detect the magnetic field with particular precision, it is preferably provided that each magnetic field sensor 28 is designed as an AM sensor, i.e., as an anisotropic magneto-resistive sensor.

[0084] It has proven particularly advantageous if the sensor device 22 is configured to determine, i.e., as a function of the detected magnetic field, at least one rotational position, and in particular several rotational positions, of the rotor, especially with respect to the stator 10, and / or an amplitude of the magnetic field and / or a temperature of the electric machine. The respective rotational position is also referred to as the rotor position and can be used, for example, to operate the electric machine as a function of the determined rotational position, and in particular to control it. The greater the number of magnetic field sensors 28, the higher the accuracy with which the magnetic field can be detected and thus, for example, the rotational position of the rotor can be determined. This ensures particularly precise control of the electric machine.

[0085] Preferably, at least one of the sheet metal segments of the lamination stack 14 and the circuit board 24 itself, i.e., considered on its own, are structurally identical, particularly with regard to their respective outer contours, i.e., their outer circumferential shapes. Preferably, the number of magnetic field sensors 28, and thus the number of circuit board areas 26 corresponding to the number of magnetic field sensors 28, is six. Most preferably, the circuit board 24 is manufactured by an injection molding process and / or by a laser direct structuring process, i.e., by laser direct structuring (LDS).By preferably forming the circuit board 24 in the form of a sheet metal segment of the laminated core 14, the circuit board 24 can be inserted into the manufactured winding 12, for example designed as a hairpin winding, in a time- and cost-effective manner, in particular by inserting the comb-shaped circuit board 24 in a radial direction from the outside to the inside between the length ranges L of the winding 12.

[0086] The temperature, for example as the rotor temperature, can be calculated as a function of the amplitude, particularly from the amplitude itself, for instance, by considering that the amplitude changes proportionally with the temperature. By measuring the magnetic field or magnetic flux, bearing damage can be detected, and a position signal can be acquired redundantly. Furthermore, changes in the electric machine due to aging, temperature, or other damage can be compensated for. Moving parts or couplings are no longer required compared to conventional solutions and can therefore be avoided, resulting in exceptionally high robustness.

[0087] In particular, it is conceivable that the at least one rotational position, in particular the several rotational positions, of the rotor, especially with respect to the stator 10, and / or the amplitude and / or the temperature of the electrical machine is determined or can be determined not only by means of the sensor device 22, but also, in particular, by means of an evaluation unit of the electrical machine, which will be explained in more detail below.

[0088] In order to operate and, in particular, control the electric machine advantageously, especially depending on the measured magnetic field, the respective magnetic field sensor 28 is designed to generate an analog and electrical measurement signal that characterizes the magnetic field detected by the respective magnetic field sensor 28. Furthermore, the respective magnetic field sensor 28 is provided with an analog-to-digital converter, preferably an internal one, by means of which the analog measurement signal generated by the respective magnetic field sensor 28 can be converted into an electrical and digital signal, also referred to as a single signal. The respective single signal is provided by the respective magnetic field sensor.

[0089] Furthermore, the evaluation unit is provided, which is located, in particular completely, outside the magnetic field sensors 28 and, in particular completely, outside the analog-digital 2024P02095WG

[0090] 23

[0091] The transducer of the magnetic field sensors 28 is arranged. The evaluation unit comprises, in particular, at least or exactly, a microprocessor. The evaluation unit is configured to receive the individual electrical and digital signals and / or a composite electrical and digital signal resulting from the individual electrical and digital signals and, in particular, to evaluate them by means of the microprocessor. In particular, for example, by evaluating the individual digital signals and / or the composite digital signal, the at least one rotational position, in particular the multiple rotational positions, and / or the amplitude and / or the temperature can be determined.

[0092] Figures 3 and 4 show schematic representations of individual parts of the electrical machine. Figure 3, for example, shows, in a particularly schematic way, the physically present conductors 46, where, for example, each magnetic field sensor 28 is assigned, and in particular, one of the conductors 46 is assigned to each individual magnetic field sensor 28. The individual signal provided or available from the respective analog-to-digital converter of the respective magnetic field sensor 28 can be transmitted via the respective conductor 46 to the evaluation unit 48, which is shown schematically in Figure 3. For example, the individual electrical and digital signals are transmitted via the conductors 46 to a digital interface 50, which receives the individual digital and electrical signals via the conductor 46.In particular, the digital interface 50 can provide the individual digital and electrical signals via lines 46, such that the evaluation unit 48, whose microprocessor is designated 52, can receive the individual digital and electrical signals via lines 46. One of the individual electrical and digital signals is shown schematically in Fig. 3 and is designated 54. For example, the respective individual digital and electrical signal is designed as a pulse-width modulation signal, which is also referred to as a PWM signal, so that, for example, pulse-width modulation, also referred to as PWM, can be carried out using the individual signals.

[0093] As can be clearly seen in Figures 3 and 4, the number of magnetic field sensors 28, and thus the number of circuit board areas 26, is exactly six, meaning that exactly six circuit board areas 26 and exactly six magnetic field sensors 28 are provided. The magnetic field sensors 28 and the circuit board areas 26 are distributed uniformly around the circumference of the electric machine over the area of ​​180°. 2024P02095WG

[0094] 24 electrical degrees distributed, in the present case such that the magnetic field sensors 28 and the circuit board areas 26 are spaced apart by 30 degrees in the circumferential direction of the electrical machine and considered in pairs.

[0095] It can also be seen in Fig. 4 that the magnetic field sensors 28 are arranged at a distance of twice the slot spacing angle, and that a bridge 58 and two slots 56 are always arranged between two magnetic field sensors 28. This ensures that, in this type of electrical machine, at least five magnetic field sensors 28 cover the range of 180 electrical degrees in a uniform manner, and yet the magnetic field sensors 28 can still be arranged on a bridge, since their angular spacing corresponds to an integer multiple of the slot spacing angle.

[0096] Fig. 5 shows another schematic representation of part of an alternative electric machine, in which the conditions also result in six magnetic field sensors 28, but these are arranged directly with the slot spacing angle. Thus, only one slot 56 is always arranged between two magnetic field sensors 28, and no web 58 remains unused. Nevertheless, the six magnetic field sensors 28 cover the range of 180 electrical degrees uniformly and are arranged directly on a web 58.

[0097] Figure 6 shows another partial schematic perspective view of a circuit board of a sensor device for the electric machine, similar to Figure 2. Figure 5 shows both the power supply 60, 62 of the magnetic field sensors 28 and the digital data line 64, 66, 68 in the circuit board 24 and in the circuit board areas 26 up to the magnetic field sensors 28. It can be seen that each magnetic field sensor 28 essentially has only three connections and is accordingly connected to the circuit board 24 and, via the circuit board, to an evaluation unit 48 by only three lines. The two power lines 60, 62 provide the power supply for the magnetic field sensors 28 and are connected in parallel to all magnetic field sensors 28 as a common line in the circuit board 24.The digital data lines 64, 66, 68, on the other hand, connect as the first digital data line 64 to a first magnetic field sensor 28, as the second digital data line 66 to a second magnetic field sensor 28, and as the third digital data line 68 to a third magnetic field sensor 28. This could, for example, be an embodiment in which each magnetic field sensor 28 has its own digital data line 64, 66, 68. All intersection points, especially between the voltage lines 60, 62 and between the digital data lines 64, 66, 68 and the voltage line 62, can thus be resolved by routing the voltage line 62 in its own layer on the circuit board 24. Advantageously, the voltage line 60 can also be routed in its own layer on the circuit board 24, or at least in a separate layer in the supply line area from the common line to the magnetic field sensor 28.With clever routing of the digital data lines 64, 66, 68, crossing points can be avoided so that they can all be arranged in one plane of the circuit board 24.

Claims

2024P02095WG 26 Mercedes-Benz Group AG Dr. Scheidle 16.12.20255 Patent claims 1. Electric machine, with at least one winding (12) by means of which a magnetic field can be generated, and with a sensor device (22) by means of which the magnetic field can be detected, wherein the sensor device (22) comprises: - at least one circuit board (24) which has several circuit board sections (26) spaced at least partially apart from each other in the circumferential direction of the electrical machine, between which respective length sections (L) of the winding (12) are arranged; and - magnetic field sensors (28) held on the circuit board (26), by means of which the magnetic field can be detected; characterized in that: - the respective magnetic field sensor (28) is designed to generate a respective analog and electrical measurement signal which characterizes the magnetic field detected by means of the respective magnetic field sensor (28); - the respective magnetic field sensor (28) has a respective analog-to-digital converter by means of which the respective analog measurement signal generated by the respective magnetic field sensor (28) can be converted into a respective electrical and digital signal (54) which can be provided by the respective magnetic field sensor (28); and - an evaluation unit (50) comprising a microprocessor (52) is provided, arranged outside the magnetic field sensors (28) and outside the analog-to-digital converters, which is configured to receive and evaluate the electrical and digital signals (54) and / or an overall electrical and digital signal resulting from the electrical and digital signals (54).

2. Electric machine according to claim 1, characterized in that the digital signals (54) between the magnetic field sensors (28) and the connected evaluation unit (50) are transmitted via a digital communication protocol in the form of pulse width modulation (PWM).

3. Electrical machine according to claim 2, characterized in that the pulse width modulation (PWM) communication has a frequency between 1 kHz and 10 kHz.

4. Electrical machine according to claim 2 or 3, characterized in that the communication between the magnetic field sensors (28) and the connected evaluation unit (50) is bidirectional, so that signals are sent both from the magnetic field sensors (28) to the connected evaluation unit (50) and from the connected evaluation unit (50) to the magnetic field sensors (28).

5. Electrical machine according to claim 4, characterized in that the bidirectional communication between the magnetic field sensors (28) and the connected evaluation unit (50) takes place via a single data line, so that the magnetic field sensor (28) only needs to have three connections, one connection for the data line and two connections for the power supply.

6. Electric machine according to claim 5, characterized in that the bidirectional communication between the magnetic field sensors (28) and the connected evaluation unit (50) is time-synchronized via the respective single data line by sending a trigger signal from the connected evaluation unit (50) to the respective magnetic field sensor (28) in order to transmit a data signal from the respective magnetic field sensor (28) to the connected evaluation unit (50) in response. 2024P02095WG 28 7. Electric machine according to one of claims 2 to 6, characterized in that at least two magnetic field sensors (28) can always be evaluated simultaneously with the connected evaluation unit (50), wherein the two magnetic field sensors (28) are spaced apart from each other in pairs by 90 electrical degrees in the circumferential direction of the electric machine.

8. Electric machine according to claim 7, characterized in that all magnetic field sensors (28) can be evaluated simultaneously with the connected evaluation unit (50), wherein the magnetic field sensors (28) cover the range of 180 electrical degrees in the circumferential direction of the electric machine.

9. Electric machine according to one of the preceding claims, characterized in that: at least five magnetic field sensors (28) are spaced apart as individual measuring points on the circuit board, which cover the area of ​​180 electrical degrees of the electric machine and are in particular arranged evenly distributed over the area.

10. Electric machine according to claim 9, characterized in that a number of the magnetic field sensors (28) greater than or equal to five results from a spatial condition of the design of the pole pair number of the electric machine via the mechanical angle of slots in the stator, wherein the mechanical angle represents an integer multiple of the electric angle between two magnetic field sensors (28), wherein the number of magnetic field sensors (28) are uniformly distributed to cover the range of 180 electric degrees.

11. Electric machine according to claim 10, characterized in that the magnetic field sensors (28) are uniformly distributed in the circumferential direction of the electric machine, covering a range of 180 electrical degrees and always being located precisely on a web between two slots of the stator of the electric machine. 2024P02095WG 29 are arranged and are arranged with an integer multiple of the slot spacing angle.

12. Electric machine according to claim 11, characterized in that the magnetic field sensors (28) are arranged in the circumferential direction of the electric machine in the region of 180 electrical degrees exactly with the slot spacing angle and are arranged on each rib between two slots and exactly one slot is arranged between two magnetic field sensors (28), or the magnetic field sensors (28) are arranged in the circumferential direction of the electric machine in the region of 180 electrical degrees exactly with twice the slot spacing angle and there is always a further rib free of a magnetic field sensor (28) between adjacent magnetic field sensors (28) on a respective rib, so that exactly two slots are arranged between two magnetic field sensors (28).

13. Electrical machine according to one of the preceding claims, characterized in that the evaluation unit (50): - is located entirely outside the circuit board (24); and - is located completely outside the magnetic field sensors (28); and - is located entirely outside the analog-to-digital converters; and - is completely spaced away from the circuit board (24); and - is completely spaced away from the magnetic field sensors (28); and - is completely separated from the analog-to-digital converters.

14. Electric machine according to one of the preceding claims, characterized in that exactly one of the magnetic field sensors (28) is held on the respective circuit board area (26) and the circuit board areas (26) are designed as teeth which project inwards in the radial direction of the electric machine from a base area (30) of the circuit board (24) common to the teeth and terminate inwards in the radial direction of the electric machine at a respective free end (E) of the respective tooth opposite the base area (30).

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