Drive motor for suction devices or machine tools

Abstract

The present invention relates to a drive motor (10) for absorbing instruments or tools, wherein the drive motor (10) has a stator (20) with a stator winding assembly (26) and a rotor (30) with a motor shaft (33), the rotor being rotatably supported at the stator about a rotation axis (D), wherein the rotor (30) has a magnet assembly (37) with permanent magnets (38) arranged annularly about the rotation axis, wherein a sensor assembly (60) is fixedly arranged about the stator position for detecting the corresponding rotational angular position of the rotor (30) with respect to the stator, the sensor assembly having at least two sensors (67A, 67b, 67C), the sensors being designed to generate, in particular, digital switching signals (SA, SB, SC) for a current-carrying mechanism for supplying current to the stator winding assembly (26), thereby enabling the rotor (30) to be rotatably driven about the rotation axis by the current carried by the stator winding assembly. The at least two sensors are configured to detect two phase-shifted waves of the magnetic rotating field (FB) of the rotor (30) at a rotational angle, wherein the sensors depend on whether the corresponding wave of the magnetic rotating field (FB) passing through the sensor exceeds or falls below the switching threshold (SH, SL) of the sensors (67A, 67b, 67C) and the permanent magnets of the magnet assembly (37) having an angular spacing relative to each other about the axis of rotation to generate the switching signal, thereby causing the wave of the magnetic rotating field (FB) to be detected by the corresponding sensor (67A, 67b, 67C). At positions 67A, 67b, 67C, there are continuous, particularly approximately sinusoidal, half-waves (HO, HU), which have vertex regions between consecutive rising and falling edges (AF, DF). The waves have transition sections (UG) between correspondingly successive half-waves (HO, HU) of different polarities. The waves have at least one stepped portion (ST), protrusion, or discontinuity in the transition sections (UG), and the switching threshold of the sensor is arranged in the region of the consecutive rising or falling edges of the half-waves.

Description

Technical Field

[0001] This invention relates to a drive motor for a tool machine of the type of handheld or semi-fixed tool machine, for picking up instruments, wherein the drive motor has a stator with a stator winding assembly and a rotor with a motor shaft, the motor shaft being rotatably supported about a rotation axis at or about the stator by means of a support assembly, wherein the rotor has a magnet assembly with permanent magnets arranged annularly about the rotation axis, wherein a sensor assembly having at least two sensors is fixedly arranged about the stator position to detect the corresponding rotational angular position of the rotor about the stator, the sensors being designed to generate, in particular, digitally switched signals for a current-carrying mechanism for supplying current to the stator winding assembly, thereby driving the rotor to rotate about the rotation axis by the current flowing through the stator winding assembly. Background Technology

[0002] Such drive motors are, for example, so-called electronically commutated motors or EC motors. A current-carrying mechanism is provided to supply current to the stator winding assembly of the motor. To achieve precise current supply to the stator winding assembly, that is, to supply current to the stator winding assembly particularly at matched switching times, the current-carrying mechanism requires information about the corresponding rotational angular position of the rotor, for which a sensor assembly is provided. However, during the operation of such drive motors, interference effects occur, for example, due to the superposition of the magnetic field of the permanent magnet and the magnetic field generated through the stator winding assembly, thus the switching signal typically provided by the sensor assembly is not optimal. Summary of the Invention

[0003] Therefore, the objective of this invention is to provide an improved drive motor, and more particularly an improved electronically commutated drive motor.

[0004] To solve the aforementioned task, in a drive motor of the type mentioned at the beginning, at least two sensors are configured to detect two phase waves of the rotor's magnetic rotating field that are displaced by a rotational angle. The sensors generate switching signals depending on whether the corresponding magnetic wave of the rotating field passing through the sensor exceeds or falls below a switching threshold of the sensor, and the permanent magnets of the magnet assembly have an angular distance from each other about the axis of rotation. Thus, the magnetic wave of the rotating field has continuous, particularly approximately sinusoidal, half-waves at the respective sensor locations, the half-waves having vertex regions between consecutive rising and falling edges. The waves have transition sections between correspondingly successive half-waves of different polarities, the waves having at least one stepped portion, protrusion, or discontinuity in the transition sections, and the switching thresholds of the sensors are arranged in the region of the consecutive rising or falling edges of the half-waves.

[0005] Furthermore, the present invention provides a machine tool, particularly a handheld or semi-fixed machine tool, having a drive motor according to the invention. The machine tool is, for example, a sawing machine, a drilling machine, a turning machine, or the like. For example, a mobile machine, transportable to the application site, such as a construction site, particularly a table saw or the like, is understood to be a semi-fixed machine tool.

[0006] Here, the basic concept is that the sensor assembly is not located in the transition zone region where steps, protrusions, or other similar discontinuities can be observed, but rather the switching threshold is outside the transition zone.

[0007] The drive motor according to the present invention is, for example, a brushless DC motor or a brushless DC motor, also simply referred to as a BLDC motor or BL motor (BL = Brushless, DC = Direct Current / Gleichstrom). The drive motor can also be a BLAC motor (BL = Brushless, AC = Alternating Current / Wechselstrom). The drive motor can also be an electronically commutated (EC) motor, a permanent magnet synchronous motor (PMSM), or the like.

[0008] The corresponding hysteresis of the sensor is preferably adjusted in the sense of the present invention such that the switching threshold of the sensor is in the region of the continuous rising or falling edge of the half-wave.

[0009] Advantageously, the sensor assembly has a magnetic sensor or magnetic field sensor designed to output a digitally switched signal, such as a Hall sensor, a magnetoresistive sensor (MR sensor), especially anisotropic MR sensor or AMR sensor, GMR sensor, magneto-optical sensor or the like.

[0010] It is feasible, for example, for an evaluation agency of the sensor assembly to generate a digital switching signal from the analog measurement signal of the sensor, wherein the evaluation agency compares the analog measurement signal with a corresponding switching threshold. However, preferably, the sensor already outputs a digital switching signal. Accordingly, it is advantageous that the switching threshold is set and / or adjusted in or at the sensor. The switching threshold in or at the sensor can also be, for example, pre-adjusted and / or preset by production accuracy or production conditions.

[0011] While it would be feasible in principle to have magnets at the rotor that are designed to switch magnets or sensor magnets, without being configured to interact with the stator winding assembly in the sense of rotating the rotor, it is preferred that the rotor only have magnets configured to rotate the rotor or to manipulate it. That is, the permanent magnets of the magnet assembly are preferably designed and configured to interact with the stator winding assembly to rotate the rotor. In other words, the permanent magnets necessary for the rotational drive of the rotor and thus the motor are ultimately used for other purposes, namely, for manipulating the sensors of the sensor assembly.

[0012] However, it should be mentioned in this regard that, without a problem, in addition to the permanent magnet configured for rotating the drive rotor, at least one additional magnet or magnetic transmitter or magnetic switching transmitter may be provided, the magnetic field of which is scanned by at least one sensor of the sensor assembly.

[0013] However, it is preferable that no magnetic transmitter or magnet is arranged at the rotor, which is only configured to manipulate the sensor assembly and not to drive the rotor in rotation. At the rotor, preferably only permanent magnets configured to drive the rotor in rotation are arranged as permanent magnetic structural components or permanent magnets.

[0014] Between the permanent magnets of the magnet assembly, particularly between the opposing sides of adjacent permanent magnets, there is preferably an angular spacing and / or gap and / or intermediate space with respect to the axis of rotation. The angular spacing with respect to the axis of rotation is, for example, at least 5°, preferably at least 10°, and especially at least 15°. Thus, the existence of gaps between the permanent magnets negatively impacts the quality of the rotating field acting on the sensor assembly. Due to the switching threshold of the sensor, it is feasible, however, to eliminate or conceal the discontinuities, steps, or protrusions caused by this in the magnetic rotating field.

[0015] The permanent magnet is preferably designed as a plate, plate-shaped, or disk-type.

[0016] Advantageously, the permanent magnet and / or rotor, as a whole, protrude from the stator or the end of the stator in the direction toward the sensor assembly. This allows the magnetic field of the permanent magnet to be detected more effectively by the sensor.

[0017] A minimum spacing is advantageous between the magnet assembly and the sensor assembly, that is, between the mutually facing sides of the rotor permanent magnet and the sensor, for example, a minimum spacing of at least 0.4 mm, preferably at least 0.8 mm, and especially at least 1 mm. The nominal minimum spacing between the magnet assembly and the sensor assembly is, for example, 1 mm, wherein a spacing between 0.4 mm and 1.6 mm is feasible due to tolerances.

[0018] While it is feasible for the sensors of the sensor assembly to be arranged or positioned individually or separately on or about the stator, it is preferred that the sensors of the sensor assembly be arranged on a sensor carrier, for example, on a circuit board. Preferably, the sensor carrier has a form-fit profile, such as a form-fit protrusion, a form-fit receptacle, or the like, for form-fit fixation to the stator and / or for force-fit fixation to the stator, for example, by means of a clamping mechanism.

[0019] Particularly advantageous is that the sensor carrier is designed for mounting at the motor housing or between the motor housing and the stator laminations of the stator. The motor housing is, for example, a so-called motor guard. A receiving portion, particularly a deepened portion, for the sensor carrier can be provided at the motor housing. The motor housing has a swivel support for the motor shaft, for example a support assembly, or a swivel support with a support receiving portion for the support assembly. The motor housing can also form a sensor carrier, that is, a sensor or sensor assembly is arranged at the motor housing.

[0020] Furthermore, it is advantageously configured that the sensor carrier has at least one shape-fitting profile for assembly at or about the stator, such that the sensor carrier at or about the stator about the rotational axis of the drive motor can be assembled only in a single angular position, or only in such an angular position, in which a predetermined angular distance is provided between each sensor of the sensor assembly and the stator winding assembly arranged next to the sensor. That is, multiple angular positions can be provided in any way, in which the sensor carrier or sensor assembly can be arranged at the stator about the rotational axis. However, these angular positions are advantageously predetermined angular positions, in which a predetermined angular distance is provided between the sensor of the sensor assembly and the stator winding about the rotational axis. Advantageously, the angular distance is zero.

[0021] The mating shape-fitting profiles for engaging the sensor carrier can be arranged at the stator and / or the motor housing. The motor housing is preferably fixed to the stator in a single rotational angular position or in a predetermined rotational angular position, so that the sensor carrier, held at the motor housing in the predetermined angular position, can be assembled in a predetermined angular position relative to the stator. Preferably, there are multiple shape-fitting profiles and mating shape-fitting profiles that have angular spacing, particularly equidistant angular spacing, relative to each other about the rotational axis of the drive motor.

[0022] Advantageously, at least one sensor of the sensor assembly, preferably each sensor, is arranged centrally about the stator winding, with its associated sensor. However, it is also advantageous to arrange at least one sensor of the sensor assembly, preferably each sensor, in a zigzag pattern and / or centrally between adjacent stator windings.

[0023] The switching threshold can be set directly in the corresponding sensor, so that the sensor changes the digital value of its sensor signal or switching signal accordingly when the value exceeds and / or falls below the switching threshold. However, it is also possible for the evaluation agency to change the value digitally when the sensor signal or switching signal value exceeds and / or falls below the threshold.

[0024] In practice, the optimal configuration settings include the following types of switching thresholds:

[0025] The corresponding half-wave of the magnetic rotating field passes through a phase angle range of 180°, and correspondingly, the full wave of the magnetic rotating field passes through a phase angle range of 360°. The full wave comprises two successive half-waves, namely positive and negative half-waves, or half-waves with opposite polarities, such as first and second polarities. The zero-crossing can be considered between the negative and positive half-waves or half-waves with different polarities.

[0026] In a rotor with one pole pair, that is, two magnetic poles, the full wave of the magnetic rotational field appears at the corresponding sensor during the mechanical rotation of the rotor; in a rotor with two pole pairs, it appears twice, for example. Whenever the wave of the magnetic rotational field is subsequently described, it is described in electrical angles.

[0027] The switching threshold of the sensor, or for the sensor, is advantageously selected such that the switching signal of the corresponding sensor changes after the wave of the magnetic rotating field transitions from a positive half-wave to a negative half-wave or from a negative half-wave to a positive half-wave, with an electrical phase angle of approximately 30° or precisely 30°. In other words, it can also be configured such that the switching signal of the sensor, or for the sensor, changes after the wave of the magnetic rotating field transitions from a half-wave with a first polarity to a half-wave with a second polarity, with a phase angle of approximately 30°.

[0028] Here, the switching signal changes, for example, from a logical "0" to a logical "1" or vice versa. A certain tolerance of 30° is feasible. However, it is preferable to precisely adjust the switching threshold so that, with a phase angle of 30°, the switching signal change is obtained as precisely as possible after the wave of the magnetic rotating field transitions from the first polarity to the second polarity.

[0029] By using the switching thresholds mentioned above, the drive motors can operate in opposite directions of rotation without any problems.

[0030] Furthermore, since the switching threshold is selected precisely or approximately 30°, it is feasible to operate without mechanical or electrical modifications, even when the sensor assembly has the same mechanical structure as the drive motor, but the stator winding assembly is switched on differently in a delta or star circuit. Moreover, selecting the switching threshold precisely or approximately 30° also allows for different coil assemblies and / or different interconnections in the stator winding assembly.

[0031] Advantageously, the hysteresis effect of a corresponding sensor, such as a Hall sensor, is used to adjust the phase angle and / or the switching threshold. Preferably, the phase angle and / or the switching threshold are adjusted by means of the hysteresis effect of the corresponding sensor by means of the hysteresis effect.

[0032] The current-carrying mechanism is preferably an integral part of the drive motor. The drive motor and the current-carrying mechanism can also form a system. The types of machine tools mentioned at the beginning, such as handheld or semi-stationary machine tools, particularly have a drive motor and a current-carrying mechanism.

[0033] The stator winding assembly can be connected, for example, in a delta or star circuit and / or connected to a current-carrying mechanism.

[0034] The current-carrying mechanism is preferably designed to conduct block current through a given sub-winding assembly. Preferably, the current-carrying mechanism has a bridging circuit for conducting current through a given sub-winding assembly.

[0035] Preferably, the current-carrying mechanism has a commutation table for a delta circuit of the stator winding assembly and a commutation table for a star circuit of the stator winding assembly. The commutation tables can be stored, for example, in the memory of the current-carrying mechanism. The program module of the current-carrying mechanism can be parameterized to access the commutation table appropriate for either the star or delta circuit.

[0036] Preferably, the delta circuit supplies current to the drive motor via a movable energy storage device, such as a battery pack or accumulator. That is, it is particularly preferred to have a machine tool with a drive motor according to the invention, the stator winding assembly of which has a delta circuit and is connected to a current-carrying mechanism that supplies current via an energy storage device. In other words, the machine tool has, for example, a supply coupling for detachably arranging the energy storage device. The energy storage device is provided, for example, with a DC voltage of 10.8V, 12V, 14V, 18V, 36V, or the like as the supply voltage for the current-carrying mechanism and thus for the drive motor. Therefore, the energy storage device advantageously provides high current with relatively low supply voltage. The machine tool is advantageously a turning machine or turning instrument.

[0037] A star-connected circuit is preferred when supplying current to a drive motor via an AC voltage grid having, for example, 120V, 230V, or the like. The AC voltage grid provides a proportionally higher supply voltage, thus the current-carrying mechanism receives a smaller current from the AC voltage grid. A drive motor having a stator winding assembly connected in a star-connected circuit and linked to the current-carrying mechanism is advantageously part of a machine tool having a supply connection for the AC voltage grid. For example, the machine tool has a connection cable for connecting to the AC voltage grid and / or a plug-in connection for connecting the connection cable to the AC voltage grid.

[0038] Based on the switching signal of the sensor assembly, the current-carrying mechanism can control the stator winding assembly in the sense of neutral commutation (in principle but also in the sense of pre-commutation or subsequent commutation).

[0039] The neutral commutation is configured such that the voltage of the stator winding is adjusted so that the magnetic rotational field generated by the stator winding is synchronized or coordinated with the rotor position or rotation angle position of the rotor.

[0040] The pre-commutation setting is configured such that the voltage of the stator winding is adjusted so that the magnetic rotational field generated by the stator winding precedes or precedes the rotor position or rotation angle position.

[0041] The commutation is then configured accordingly, such that the voltage of the stator winding is adjusted so that the magnetic rotational field generated by the stator winding follows the rotor position or rotation angle position of the rotor.

[0042] A preferred design involves the sensor assembly generating a switching signal in the sense of neutral commutation in the case of a delta circuit in the stator winding assembly. Advantageously, the sensor assembly is arranged with respect to the stator such that the sensor generates a switching signal in the sense of neutral commutation in the case of a delta circuit in the stator winding assembly. This design is particularly advantageous when supplying current to the drive motor or machine tool via an energy storage device, preferably providing a DC voltage in the range of 12 to 48 V. This design is particularly advantageous when the drive motor is used in a machine tool, where high starting torque is desired, for example, in designs where the machine tool is used as a turning machine.

[0043] Neutral commutation is facilitated by setting the switching threshold of the sensor such that the sensor outputs a switching signal before and after the zero-crossing of the wave in the magnetic rotating field at a phase angle of approximately 30°.

[0044] Furthermore, it is feasible for the sensor assembly to generate a switching signal in the sense of pre-commutation in the case of a star circuit in the stator winding assembly. Advantageously, the sensor assembly is arranged with respect to the stator such that the sensor generates a switching signal in the sense of pre-commutation in the case of a star circuit in the stator winding assembly. This design is particularly advantageous in machine tools configured for current supply via an AC voltage grid and having a supply connection suitable for this purpose. For example, this machine tool relates to a sawing machine, where a low starting torque of the drive motor is acceptable because the working tool, such as a saw blade, is first brought to a predetermined speed before being engaged with or cut into the workpiece. Pre-commutation preferably corresponds electrically to approximately 30°.

[0045] However, it is also feasible to arrange the sensor assembly with respect to the stator such that the sensor generates a switching signal in the sense of neutral commutation in the case of a star circuit of the stator winding assembly, and generates a switching signal in the sense of subsequent commutation or pre-commutation in the case of a delta circuit.

[0046] It is feasible for the wave measured by the sensor to be simply a wave generated by a permanent magnet. However, in practice, due to the magnetic rotational field generated by the stator winding assembly, there is a superposition effect. The magnetic rotational field measured by the sensor or acting on the sensor may include, for example, a magnetic subfield generated by the stator winding assembly and a magnetic subfield generated by the permanent magnet, wherein the subfields are superimposed on each other.

[0047] The rotor and / or stator preferably have laminations. The laminations of the rotor and / or stator are preferably made of laminated electronic laminations or transformer laminations.

[0048] The motor shaft passes through, for example, the shaft through-opening of the lamination assembly, which is held at the motor shaft.

[0049] Embodiments of the invention will then be explained with reference to the accompanying drawings. Even though this embodiment presents a bipolar rotor, this does not imply a limitation on the application of the invention. Undoubtedly, the principles can also be implemented with rotors having additional poles, such as four-pole or six-pole rotors, or rotors with different magnet assemblies. Modifications to the stator winding assembly are also possible. The stator winding assembly of the subsequent embodiments can also be connected or switched differently than in a delta or star circuit, for example, in a combination of star and delta circuits, a series circuit, a parallel circuit, or similar configurations. Attached Figure Description

[0050] in:

[0051] Figure 1 An exploded view of the drive motor is shown, which is in

[0052] Figure 2 The middle is shown from one side.

[0053] Figure 3 The diagram shows a longitudinal sectional view of the drive motor as shown in the preceding figure.

[0054] Figure 4 This illustrates a handheld tool machine of the type of electric motor with a drive motor according to the preceding diagram.

[0055] Figure 5 It is shown to be used with the aid of a portable energy storage device and according to Figure 1-3 A type of handheld tool machine that uses a drive motor to operate.

[0056] Figure 6 An exploded view of the drive motor rotor and sensor assembly, based on the preceding figures, is shown.

[0057] Figure 7 The rotor and the permanent magnet at the rotor are shown in detail, approximately corresponding to the... Figure 6 Local D1 in

[0058] Figure 8 The circuit diagram shows the drive motor and its current-carrying mechanism.

[0059] Figure 9 A schematic front view showing the drive motor and sensor assembly is provided.

[0060] Figure 10 It shows that it can be achieved by... Figure 9 The direction of the magnetic field measured by the sensor components driving the motor.

[0061] Figure 11 This is a schematic diagram showing the switching signals of the sensor assembly of the drive motor according to the previous figure.

[0062] Figure 12 A commutation table is shown for a stator winding assembly used in a drive motor according to the preceding figures, the stator winding assembly being connected to a current-carrying mechanism in a star configuration.

[0063] Figure 13 A commutation table is shown for a stator winding assembly used in a drive motor according to the preceding figures, the stator winding assembly being connected to a current-carrying mechanism via a delta circuit.

[0064] Figure 14 The branch voltage of the stator winding assembly in a star circuit is shown, which corresponds to the reaction EMK (EMK = electromotive force).

[0065] Figure 15 This illustrates the current-carrying mechanism of the drive motor corresponding to the stator winding assembly in a star-connected circuit. Figure 14 The adjusted block voltage trend is parallel to the ideal voltage trend, and

[0066] Figure 16 The diagram illustrates the direction of the reaction EMK of the stator winding assembly in a delta circuit and individual exemplary block voltage directions. Detailed Implementation

[0067] The drive motor 10 has a stator 20, on which a rotor 30 is rotatably supported about a rotation axis D. The stator 20 has a stator lamination assembly 21 with laminations 22. The lamination assembly 21 has a receiving portion 23 in which the rotor 30 is received. Motor covers 50 and 40 are arranged at opposite end sides 24 and 25, which enclose the receiving portion 23.

[0068] In addition, the stator 20 carries a stator winding assembly 26 having stator windings 27A, 27B and 27C.

[0069] The rotor 30 has a rotor lamination assembly 31, which is housed in a receiving portion 23. The lamination assembly 31 has laminations 32, which are laminated on top of each other. The lamination assembly 31 is passed through by a motor shaft 33, which is rotatably supported about the rotation axis D of the stator 20 by means of a support assembly 47A. The end sides 34 and 35 of the rotor 30 are opposite to the motor covers 50 and 40.

[0070] A magnet receiving portion 36 for a permanent magnet 38 of a magnet assembly 37 is provided at the rotor lamination group 31. The permanent magnet 38 is inserted into the magnet receiving portion 36, for example, by means of a plug-in assembly in the force direction SR.

[0071] The permanent magnets 38 are designed in a plate-like shape and have, for example, flat sides 38F, with narrow sides 38S extending therebetween. The permanent magnets 38 are arranged side by side with their narrow sides 38S, thus forming a ring configuration.

[0072] However, there is an angular gap W between the permanent magnets 38. There are no permanent magnets within the angular gap W.

[0073] The flat side 38F is, for example, orthogonal to the radius line, which extends away from the axis of rotation D.

[0074] Motor housings 40 and 50 have support receiving portions 43 and 53, in which rotating supports 47 and 57 of support assembly 47A are received and rotatably support motor shaft 33. Rotating supports 47 and 57 are, for example, rolling supports, particularly ball supports. Motor shaft 33 protrudes, for example, from the stator 30 or motor housings 40 and 50 at one or both sides, and in this embodiment even at both sides, i.e., at the end sides or front sides 45 and 54 of motor housings 40 and 50. End sides 44 and 55 of motor housings 40 and 50 face the stator 20 and close it at the end sides.

[0075] The stator winding assembly 26 is connected to the current-carrying mechanism 85 via connecting parts 28A, 28B, and 28C, which are connected to the stator windings 27A, 27B, and 27C.

[0076] The current-carrying mechanism 85 carries current through the stator winding 27 as follows, thereby generating a rotating field that drives the rotor 30 to rotate about the rotation axis D in a manner that interacts with the magnet assembly 37.

[0077] The current-carrying mechanism 85 has, for example, a control unit 80, by means of which the bridging circuit 86 can be operated. The bridging circuit 86 includes upper switching elements SA1, SB1, SC1 and lower switching elements SA2, SB2, SC2, wherein the upper switching elements SA1, SB1, SC1 are connected to the supply potential V1 and the lower switching elements SA2, SB2, SC2 are connected to the potential V0, for example, a ground wire. Corresponding connection lines LA, LB, and LC are connected between the corresponding upper and lower switching elements SA1, SA2 or SB1, SB2, or SC1 and SC2, and these connection lines are connected to connection units 28A-28C.

[0078] To optimally control the stator winding 27, the control unit 80 requires information regarding the rotor 30 and the corresponding rotational position of the stator 20 relative to the rotation axis D. For this purpose, a sensor assembly 60 is provided. The sensor assembly 60 includes a sensor carrier 61, such as a circuit board 62, which is fixed in position relative to the stator 20. For example, the sensor carrier 61 is held in a sandwich configuration between the motor housing 40 and the stator 20.

[0079] The sensor carrier 61 is housed in the receiving portion 41 of the motor housing 40. The sensor carrier has a form-fitting receiving portion 42 at its radial outer periphery; that is, a mating form-fitting profile 42A is fitted into the form-fitting receiving portion. A form-fitting protrusion 63 of the sensor carrier 61, that is, a form-fitting profile 63A, engages with the form-fitting receiving portion. The form-fitting protrusion is designed, for example, in a star shape, so that it fits form-fittingly into the complementary form-fitting receiving portion 42. Thus, the sensor carrier 61 is torsionally held in the receiving portion 41 about the rotation axis D.

[0080] Another shape-fitting profile, such as a shape-fitting receptacle 66 of the type of plug-in receptacle, provides additional anti-torsional fixation. A shape-fitting protrusion 46, extending from the motor housing 40 in the direction toward the receptacle 41, that is, a mating shape-fitting profile, engages with the shape-fitting receptacle. The shape-fitting protrusion 63 and the shape-fitting receptacle 66 are angularly spaced about the axis of rotation D. Similarly, the complementary shape-fitting receptacle 42 and the shape-fitting protrusion 46 of the motor housing 40, which hold the shape-fitting parts together, are also angularly spaced.

[0081] The end side 35 of the rotor 30 protrudes ahead of the end side 25 of the stator 20 by a predetermined size 39, so that the magnetic field and the magnetic field of the permanent magnet 38 therefrom can pass well through the sensors 67A, 67B and 67C of the sensor assembly 60.

[0082] Sensors 67A, 67B, and 67C are advantageously arranged on the end side 64 of the sensor carrier 61 facing the rotor 30. Other electrical components, such as resistors and the like, can also be arranged there. Sensor 67 is, for example, a Hall sensor with a pre-adjusted or adjustable switching threshold. However, it is also possible for sensor 67 to be a sensor that generates an analog measurement signal corresponding to a magnetic field acting upon it, which is then evaluated by an evaluation mechanism 70 of the sensor assembly 60, such as a threshold circuit.

[0083] The sensor assembly 60 has a coupling mechanism 68 for connection to a control unit 80. The coupling mechanism 68 includes, for example, a connector 69, which connects via a line 69L to the sensor carrier 61 and electrical components disposed thereon, such as the sensor 67. Accordingly, the line 69L transmits the switching signals SA, SB, and SC from the sensors 67A, 67B, 67C or the evaluation mechanism 70. As mentioned, it is feasible for the sensors 67A, 67B, 67C to already generate digital switching signals. However, it is also feasible for the evaluation mechanism 70 to generate digital switching signals SA, SB, and SC based on the analog measurement signals or sensor signals from the sensors 67A, 67B, 67C. Essentially, it is also conceivable that the sensors 67A, 67B, 67C transmit analog measurement signals to the control unit 80, from which the control unit generates the digital switching signals 67A, 67B, 67C. The control unit 80 can thus be said to form an evaluation mechanism for the sensor assembly 60 or a component of the sensor assembly 60.

[0084] The control unit 80 includes a processor 81 that communicates with a memory 82, in which a control program 83 is stored for operating the current-carrying mechanism 85. The current-carrying mechanism 85, particularly the bridging circuit 86, is a power electronics device that can be controlled by the control unit 80 via an interface 84. Switching elements SA1-SC2 involve, for example, power transistors. This is known in itself.

[0085] The stator winding assembly 26 can be connected to the current-carrying mechanism 85, for example, in a delta circuit. The stator windings 27 are then labeled 27Ad, 27Bd, and 27Cd. In contrast, in a star circuit illustrated with dashed lines, the stator windings 27 are labeled 27As, 27Bs, and 27Cs.

[0086] A delta circuit is advantageous, for example, for a handheld tool machine 80, which can be supplied with electrical supply voltage P2 via an energy storage device 206, such as a battery pack.

[0087] Conversely, a star circuit, for example, is suitable for a machine tool 300, such as a circular saw, which can be supplied with voltage P1 by an energy supply grid EV.

[0088] Handheld tool machines 200 and 300 have housings 203 and 303, in which drive motors 10 are arranged to drive tool receptacles 201 and 301. Tool receptacles 201 and 301 are used to detachably hold working tools 202 and 302, such as drilling tools, turning tools 202, or sawing tools 302.

[0089] With the aid of switch 204 or 304, the current-carrying mechanism 85 of the handheld tool machine 200 and 300 can be activated to turn the drive motor 10 on or off and / or change its speed and / or its power.

[0090] The handheld tool machine 200, such as a screwdriver or a drilling instrument, has a supply connection 205 for the energy storage 206, such as having a plug-in contact, a plug-in interface or the like.

[0091] In contrast, the handheld tool machine 300 has a supply connection 305, such as an electrical grid cable with an electrical grid connector, for insertion into a connection mechanism connected to the electrical grid EV.

[0092] exist Figure 9 The drive motor 10 is schematically shown. It is evident that sensors 27A, 27B, and 27C are respectively centrally located on the given sub-windings 27A, 27B, and 27C.

[0093] The stator winding assembly 26 is connected to a multi-phase ground, such as a three-phase ground.

[0094] The rotor 30 is, for example, a bipolar rotor, wherein the opposing permanent magnets 38 have the same polarity radially outward about the axis of rotation D (that is, along the direction toward the gap between the rotor 30 and the stator 20), while permanent magnets 38 offset at a 90-degree angle about the axis of rotation D have the opposite polarity, as indicated by reference numerals 38S (e.g., magnetic south pole) and 38N (e.g., magnetic north pole). Figure 9 The permanent magnet in the middle is indicated at 38 locations.

[0095] exist Figure 10 The magnetic field direction, i.e., the ideal field direction FBI, is shown, which is sinusoidally oriented starting from zero (phase angle y=0). From said zero, the temporal direction of the wave of the right-hand RL and left-hand LL, or magnetic rotation field, driving motor 10, is shown. The rotation field is shown with respect to a fixed observer at stator 20 (in this case, the corresponding sensor 67) after rotation y=X° and with respect to the number of pole pairs of rotor 30.

[0096] The ideal field orientation FBI is given in what can be described as an ideal rotor 30, in which the permanent magnets 38 are arranged directly side by side, that is, without angular spacing and / or without the influence of the rotating field emanating from the stator winding assembly 26. In the case of an ideal wave in the magnetic rotating field, for example, of the type of wave FBI, sensors 67A, 67B, and 67C correspondingly switch the ideal switching signals SAI, SBI, and SCI at the zero-crossing of the ideal wave in the magnetic rotating field, that is, according to Figure 10In the case of the switching threshold N or the zero-crossing part N.

[0097] However, magnetic sensors, such as Hall sensors, exhibit a so-called hysteresis effect. This hysteresis effect, as will become clearer later, is optimally adjusted and utilized by adjusting the upper switching threshold SH and the lower switching threshold SL in sensor 67 or evaluation mechanism 70. The upper and lower switching thresholds SH and SL are symmetrical.

[0098] Conversely, by measuring the angular spacing between the permanent magnets 38, the true direction of the magnetic rotation field wave detected by the sensor 67 can be obtained, such as the true direction of the rotation fields FA, FB and FC detected or acted upon by the sensors 67A, 67B and 67C.

[0099] However, in addition to the influence of the current flowing through the stator windings 27A-27C or the field generated therefrom, the waves of the magnetic rotating field detected by sensors 67A, 67B, and 67C can also have maximum or minimum trajectories. For example, the maximum and minimum trajectories FBO and FBU of the magnetic rotating field acting on sensor 67B are possible.

[0100] Between the continuously rising half-waves HO and HU above and below the rotating fields FA, FB, and FC along the AF or continuously falling half-waves DF, there is a transition section UG with a stepped portion ST, where the wave of the magnetic rotating field FB is not continuous. This region or transition section UG, which can be considered indifferent, is essentially hidden by the upper and lower switching thresholds SH and SL of sensors 67A, 67B, and 67C. Accordingly, the upper switching threshold SH and the lower switching threshold SL are selected and / or planned.

[0101] In the example of sensor 67B, this should then become clearer:

[0102] In the case of right-hand rotation RL of rotor 30 starting from phase angle γ=0°, the magnetic rotational field acting on sensor 67B and / or detected by said sensor initially has a positive or upper half-wave HO and changes its polarity at the switching threshold N or zero crossing N to the lower half-wave HU. At time point T1R, the lower half-wave HU passes the lower switching threshold SL, which causes sensor 67B to switch, that is, causes the switching signal SW1 to change, for example, causing a logical "1" to change to a logical "0".

[0103] After the rotating field FB has passed its maximum value at phase angle γ=180°, the lower half-wave HU transitions to the upper half-wave HO at phase angle γ=270° and exceeds the upper switching threshold SH at time point T2R. Thus, sensor 67B can be said to switch again and generate a switching signal to change SW2, for example, from logical "0" to logical "1".

[0104] The same mode works when the rotor 30 is rotating left LL: starting from the positive or upper half-wave HO, at phase angle γ=0°, the rotating field FB transitions to the negative half-wave HU and is below the lower switching threshold SL at time point T1L, so that sensor 67B changes the level of switching signal SB from logical "1" to logical "0", that is, performs switching signal change SW2.

[0105] In the case of the other left-handed LL of rotor 30, the rotating field FB first passes through the minimum value and then rises and passes through the switching threshold N or the zero-crossing part N, and then passes through the upper switching threshold SH at the phase angle γ=-300°, which causes the switching signal SW1 to change at time point T2L.

[0106] exist Figure 12 An exemplary commutation table KS is shown for supplying current to the stator winding assembly 26 of a star circuit. Figure 13 An exemplary commutation table KD for conducting current in a delta circuit is shown. Commutation tables KS and KD are stored, for example, in the memory 82 of the control unit 80 and can be selectively used by program 83 to manipulate the bridge circuit 86, wherein program 83 uses commutation table KS for the stator winding assembly 26 in a star circuit and commutation table KD for the stator winding assembly 26 in a delta circuit.

[0107] In the two commutation tables KS and KD, segment S is described by values ​​1 to 6, which are obtained by binary addition of the signal levels of switching signals SA, SB and SC. The switching signal SA with a binary value of "1", the switching signal SB with a binary value of "2" and the switching signal SC with a binary value of "4" enter the corresponding values ​​1 to 6 of segment S.

[0108] In the corresponding left-hand columns of commutation tables KS and KD, the potentials are further marked as LA, LB, and LC, which are provided by the current-carrying mechanism 26 at the connection lines LA, LB, and LC for the stator winding assembly 26. In commutation tables KS and KD, "+" indicates that the corresponding connection lines LA, LB, and LC are connected to the supply potential V1, and "-" indicates that the corresponding connection lines LA, LB, and LC are connected to potential V0, such as ground. When the corresponding connection lines LA, LB, and LC are not connected to either potential V1 or V0, "0" is indicated accordingly in commutation tables KS or KD.

[0109] exist Figure 14 The back electromotive force (EMK) present at the stator windings 27As, 27Bs, and 27Cs connected in a star circuit is described in the form of voltages USA, USB, and USC (EMK = electromotive force) or in English as BEMF (=back electromotive force), which occurs when the rotor 30 rotates. Ideally, the voltages USAS, USBs, and USCs corresponding to the voltages USA, USB, and USC are, for example, in... Figure 15 As shown, the voltages can be adjusted via the current-carrying mechanism 85. Ideally, the voltages USAs, USBs, and USCs present at the stator windings 27As, 27Bs, and 27Cs should be sinusoidally adjusted via the current-carrying mechanism 85. However, in practice, the current-carrying mechanism 85 advantageously performs block current carrying, that is, the voltages at the stator windings 27As, 27Bs, and 27Cs are adjusted as block voltages USAb, USBb, and USCb, so that the voltages USAs, USBs, and USCs can be approximated. The switching mode for generating the block branch voltages USAb, USBb, and USCb is preset via the commutation table KS. The segments S with values ​​1 to 6 are shown side by side. Here, it is identified that pre-commutation is performed in the case of a star circuit.

[0110] exist Figure 16 The diagram shows the reaction EMK voltages UDA, UDB, and UDC present at the stator windings 27Ad, 27Bd, and 27Cd connected in a delta circuit, which occur when the rotor 30 rotates. These voltages UDA, UDB, and UDC can be said to ideally correspond to voltages that the current-carrying mechanism 85 ideally adjusts to a predetermined voltage direction; that is, the voltage UDAs adjusted by the current-carrying mechanism 85 at the stator winding 27Ad corresponds to voltage UDA. This is as shown by the combination of a star circuit and... Figure 14 and 15As explained, however, the current-carrying mechanism 85 adjusts the block voltage according to the commutation table KD, thus adjusting, for example, the block voltage UDAb. The additional block delta voltages adjusted by the current-carrying mechanism 85 in the stator windings 27Bd and 27Cd according to the commutation table are for simplification purposes. Figure 16 The values ​​are not shown, but segments S with values ​​from 1 to 6 are displayed. It can be seen that, in the case of a delta circuit, commutation can be described as ideal or neutral. At the corresponding switching or commutation points, the maximum voltage exists at stator windings 27Ad, 27Bd, and 27Cd, resulting in high torque on the drive motor and thus high power output. This is particularly beneficial in turning instruments that should operate from a standstill with high starting torque, thus enabling ideal or neutral commutation.

Claims

1. A drive motor for picking up instruments or handheld or semi-fixed tool machines, wherein... The drive motor (10) has a stator (20) with a stator winding assembly (26) and a rotor (30) with a motor shaft (33), the motor shaft being rotatably supported about a rotation axis (D) at or about the stator by means of a support assembly (47), wherein the rotor (30) has a magnet assembly (37) with permanent magnets (38) arranged annularly about the rotation axis (D), wherein the position of the rotor (30) about the stator (20) is fixedly arranged in order to detect the corresponding rotational angular position of the rotor (30) about the stator (20). A sensor assembly (60) is provided, the sensor assembly having at least two sensors designed to generate switching signals (SA, SB, SC) for a current-carrying mechanism (85) to conduct current through the stator winding assembly (26), thereby enabling the rotor (30) to be rotated about the rotation axis (D) by the current through the stator winding assembly (26). The rotor (30) is characterized in that the at least two sensors (67A, 67b, 67C) are designed to detect two rotationally oriented magnetic rotational fields (FB) of the rotor (30). A phase-shifted wave, wherein the sensors (67A, 67b, 67C) depend on whether the corresponding wave of the magnetic rotation field (FB) passing through the sensors (67A, 67b, 67C) exceeds or falls below the switching thresholds (SH, SL) of the sensors (67A, 67b, 67C) and the permanent magnets (38) of the magnet assembly (37) having an angular spacing relative to each other about the rotation axis (D) to generate the switching signals (SA, SB, SC), thereby causing the wave of the magnetic rotation field (FB) to shift at the corresponding sensors (67A, 67b, 67C). The device has continuous half-waves (HO, HU) with vertex regions between continuous rising and falling edges (AF, DF), wherein the waves have transition sections (UG) between correspondingly successive half-waves (HO, HU) of different polarities, wherein the waves have at least one stepped portion (ST), protrusion, or discontinuity in the transition section (UG), and the switching thresholds (SH, SL) of the sensors (67A, 67b, 67C) are arranged in the region of the continuous rising or falling edges (AF, DF) of the half-waves (HO, HU).

2. The drive motor according to claim 1, characterized in that, The permanent magnet (38) of the magnet assembly (37) is configured and designed to work in conjunction with the stator winding assembly (26) to rotate and drive the rotor (30).

3. The drive motor according to claim 1 or 2, characterized in that, There is no magnetic transmitter arranged at the rotor (30) that is only configured to manipulate the sensor assembly (60) or a permanent magnet (38) that is only arranged at the magnet assembly (37) as a permanent magnet structural component, the permanent magnet (38) being configured to drive the rotor (30) to rotate.

4. The drive motor according to claim 1 or 2, characterized in that, There is an angular spacing about the axis of rotation between the opposing sides of the adjacent permanent magnets (38) of the magnet assembly (37).

5. The drive motor according to claim 1 or 2, characterized in that, The magnet assembly (37) protrudes in the direction toward the sensor assembly (60) before the stator (20).

6. The drive motor according to claim 1 or 2, characterized in that, A gap of at least 0.4 mm is provided between the magnet assembly (37) and the sensor assembly (60).

7. The drive motor according to claim 1 or 2, characterized in that, The sensor assembly (60) has a sensor carrier (61) on which the sensors (67A, 67b, 67C) are arranged.

8. The drive motor according to claim 7, characterized in that, The sensor carrier (61) is designed to be mounted at the motor housing (50) or between the motor housing (50) and the stator lamination group (21) of the stator (20) or the motor housing (50) forms the sensor carrier (61).

9. The drive motor according to claim 7, characterized in that, The sensor carrier (61) has at least one shape-fitting profile (63A) for mounting at or about the stator (20) such that the sensor carrier (61) can be mounted about the stator (20) and about the axis of rotation (D) of the drive motor (10) in a single angular position or only in such an angular position, in which a predetermined angular distance is provided between each sensor (67A, 67b, 67C) of the sensor assembly (60) and the windings (26A, 26B, 26C) of the stator windings arranged next to the sensors (67A, 67b, 67C).

10. The drive motor according to claim 1 or 2, characterized in that, At least one sensor (67A, 67b, 67C) or each sensor (67A, 67b, 67C) of the sensor assembly (60) is respectively arranged centrally between adjacent stator windings (27A, 27B, 27C) or centrally about the stator windings (27A, 27B, 27C), the stator windings being associated with the sensor (67A, 67b, 67C).

11. The drive motor according to claim 1 or 2, characterized in that, The full wave of the magnetic rotating field (FB) comprises half waves (HO, HU) of different polarities, each half wave passing through a phase angle of 180°, and the switching thresholds (SH, SL) are set such that the switching signals (SA, SB, SC) of the corresponding sensors (67A, 67b, 67C) have a switching signal change (SW1, SW2) after the wave of the magnetic rotating field (FB) transitions from one half wave (HO, HU) of one polarity to another half wave (HO, HU) of the other polarity at a phase angle of 30°.

12. The drive motor according to claim 1 or 2, characterized in that, The phase angle of 30° and / or the switching threshold (SH, SL) are adjusted by means of the magnetic hysteresis of the corresponding sensors (67A, 67b, 67C).

13. The drive motor (10) according to claim 1 or 2, characterized in that, The sensor assembly (60) is arranged with respect to the stator (20) such that the sensors (67A, 67b, 67C) generate the switching signals (SA, SB, SC) in the sense of neutral commutation in the case of a delta circuit of the stator winding assembly (26).

14. The drive motor according to claim 13, characterized in that, The neutral commutation is facilitated by setting the switching thresholds of the sensors (67A, 67b, 67C) such that the sensors (67A, 67b, 67C) change the output switching signal (SW1, SW2) before and / or after the zero-crossing of the wave of the magnetic rotating field (FB) at a phase angle of 30°.

15. The drive motor according to claim 1 or 2, characterized in that, The sensor assembly (60) is arranged with respect to the stator (20) such that the sensors (67A, 67b, 67C) generate the switching signals (SA, SB, SC) in the sense of pre-commutation in the case of a star circuit of the stator winding assembly (26).

16. The drive motor according to claim 15, characterized in that, The pre-commutation corresponds precisely to 30° in electrical terms.

17. The drive motor according to claim 1 or 2, characterized in that, The current-carrying mechanism (85) has a commutation table for a stator winding assembly (26) in a delta circuit and / or a commutation table for a stator winding assembly (26) in a star circuit, or can be parameterized with commutation tables for delta and star circuits.

18. The drive motor according to claim 1 or 2, characterized in that, The magnetic rotation field (FB) acting on the sensors (67A, 67b, 67C) comprises a magnetic subfield generated by the stator winding assembly (26) and a magnetic subfield generated by the permanent magnet (38), wherein the subfields are superimposed on each other.

19. The drive motor according to claim 1, characterized in that, The switching signal is a digital switching signal.

20. The drive motor according to claim 1, characterized in that, The half-wave is a sinusoidal half-wave.

21. The drive motor according to claim 4, characterized in that, The angular spacing is at least 5°.

22. The drive motor according to claim 21, characterized in that, The angular spacing is at least 10°.

23. The drive motor according to claim 22, characterized in that, The angular spacing is at least 15°.

24. The drive motor according to claim 5, characterized in that, The rotor (30) as a whole protrudes ahead of the stator (20) in the direction toward the sensor assembly (60).

25. The drive motor according to claim 6, characterized in that, The distance between the magnet assembly (37) and the sensor assembly (60) is at least 0.8 mm.

26. The drive motor according to claim 25, characterized in that, The distance between the magnet assembly (37) and the sensor assembly (60) is at least 1 mm.

27. The drive motor according to claim 7, characterized in that, The sensor carrier (61) is a sensor carrier of the type of circuit board (62).

28. A machine tool having a drive motor (10) according to any one of claims 1 to 27 and a current-passing mechanism (85) for passing current through the drive motor.

29. The machine tool according to claim 28, characterized in that, The stator winding assembly (26) of the drive motor (10) is connected to the current-carrying mechanism (85) in a delta circuit and the machine tool has a supply connection for connecting a DC voltage energy storage device (206), or the stator winding assembly (26) of the drive motor (10) is connected to the current-carrying mechanism (85) in a star circuit and the machine tool has a supply connection (305) for an AC voltage grid.

30. The machine tool according to claim 28, characterized in that, The tool machine is a handheld tool machine (200, 300) or a semi-fixed tool machine.

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