Electric motor comprising a first angle sensor

Abstract

The invention relates to an electric motor comprising a first angle sensor. The first angle sensor has a first stationary part, in particular a transducer stator, and a first rotatably mounted part, in particular a transducer rotor, and the rotor shaft of the electric motor is rotationally fixed to the first rotatably mounted part, in particular the transducer rotor, of the first angle sensor. A second angle sensor has a second stationary part, in particular a transducer stator, and a second rotatably mounted part, in particular a transducer rotor, and the rotor shaft of the electric motor is rotationally fixed to the second rotatably mounted part, in particular the transducer rotor, of the second angle sensor via an interposed coupling.

Description

[0001] Electric motor with first angle sensor

[0002] Description:

[0003] The invention relates to an electric motor with a first angle sensor.

[0004] It is known that the angular position of a rotor shaft of an electric motor can be determined using an angle sensor.

[0005] From CN 1 12 448 547 A, an angle sensor arrangement is known as the closest prior art.

[0006] A drive system with planetary gear is known from DE 102023 000 496 A1.

[0007] The invention is therefore based on the object of ensuring that an electric motor can be operated as safely as possible.

[0008] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0009] Important features of the invention are that the electric motor is provided with a first angle sensor, wherein the first angle sensor has a first stationary part, in particular a sensor stator, and a first rotatably mounted part, in particular a sensor rotor, wherein a rotor shaft of the electric motor is connected in a rotationally fixed manner to the first rotatably mounted part, in particular a sensor rotor, of the first angle sensor, wherein a second angle sensor has a second stationary part, in particular a sensor stator, and a second rotatably mounted part, in particular a sensor rotor, wherein the rotor shaft of the electric motor is connected in a rotationally fixed manner to the second rotatably mounted part, in particular a sensor rotor, of the second angle sensor via an intermediate coupling.

[0010] The advantage here is that increased safety can be achieved through redundant angle determination. By comparing the angular positions of the rotor shaft determined by the two angle sensors and monitoring for exceedance of a permissible deviation, a malfunction can be detected.

[0011] In an advantageous embodiment, the first angle sensor is a hollow shaft encoder. Advantageously, the first angle sensor is mounted on the rotor shaft.

[0012] In an advantageous embodiment, the second angle sensor is a solid shaft encoder. This is advantageous in that the weight is supported by the adapter and the solid shaft is connected to the rotor shaft via a coupling.

[0013] In an advantageous embodiment, the first stationary part, in particular the sensor stator, of the first angle sensor is connected, in particular only, by means of a support plate to the first cheek of an adapter, in particular for torque derivation, wherein the second stationary part, in particular the sensor stator, of the second angle sensor is connected to the second cheek of the adapter, in particular is screwed to the second cheek of the adapter by means of screws, in particular for torque derivation, wherein the first cheek is connected to the second cheek by means of webs of the adapter, in particular wherein the webs are all arranged at the same radial distance. It is advantageous in this case that the second angle sensor is carried by the adapter and the torque is thereby derived. However, the first angle sensor is carried by the rotor shaft, since it is plugged onto the rotor shaft as a hollow shaft sensor.Torque is transferred solely via a support plate, which is attached to the adapter on one side and to the first angle sensor on the other. In an advantageous embodiment, the webs are spaced apart from each other in the circumferential direction, particularly evenly spaced. This is advantageous because the adapter achieves high rigidity.

[0014] In an advantageous embodiment, each of the webs extends further in the circumferential direction than in the radial direction and / or the radial wall thickness of the webs is smaller than the extent in the circumferential direction, with the first cheek being spaced axially from the second cheek. This is advantageous in that a high rigidity of the adapter is achieved.

[0015] In an advantageous embodiment, the first angle sensor is spaced apart from the second angle sensor in the axial direction, in particular, the axial direction being aligned parallel to the rotational axis of the rotor shaft of the electric motor, in particular, the circumferential direction and the radial direction each being related to this rotational axis. This is advantageous in that safety is increased by implementing the angle determination redundantly.

[0016] In an advantageous embodiment, the solid shaft of the second angle sensor extends through the second flange. Advantageously, the solid shaft is connected to the coupling.

[0017] In an advantageous embodiment, the area covered by the webs in the axial direction encompasses, in particular completely encompasses, the area covered by the coupling in the axial direction, in particular wherein the coupling is axially spaced from both the first cheek and the second cheek. It is advantageous in this case that the coupling is arranged within the adapter.

[0018] In an advantageous embodiment, the first flange is attached to the bearing plate of the electric motor, wherein the bearing plate accommodates a bearing for the rotatable mounting of the rotor shaft of the electric motor. Advantageously, the adapter is attached to the bearing plate and is thus securely mounted. In an advantageous embodiment, a stator housing is arranged axially between the bearing plate and a bearing flange, which accommodates another bearing of the rotor shaft, wherein the stator housing is connected to the bearing plate and the bearing flange. Advantageously, the rotor shaft is securely mounted.

[0019] In an advantageous embodiment, the support plate is designed with multiple bends, in particular with the bends being formed in the radial direction, but in particular not in the circumferential direction. This is advantageous because it enables simple manufacturing and axial impacts do not significantly influence the angle determination.

[0020] In an advantageous embodiment, the support plate is less stiff in the axial direction than in the circumferential and / or radial directions. This has the advantage that the angular position can be precisely determined even in the case of axial impacts.

[0021] In an advantageous embodiment, the second flange is arranged on the side of the adapter axially facing away from the stator housing and / or the bearing plate. This is advantageous because the second angle sensor is connected directly to the second flange, thus providing a stable and rigid connection. However, the first angle sensor is supported by the rotor shaft and is only connected to the first flange of the adapter by a support plate serving as a torque support, in particular a torque transfer device.

[0022] In an advantageous embodiment, the bearing plate has axially directed edge depressions on its end face facing the coupling, in particular on its radially outer end region, wherein the length of a first edge depression measured in the circumferential direction is different from the length of a second edge depression. The advantage here is that the vibration capability of the bearing plate is reduced and thus fewer vibration modes are introduced into the coupling. In an advantageous embodiment, the first cheek is designed in the shape of a perforated disk and the second cheek is designed in the shape of a perforated disk. The advantage here is that simple production is enabled. In addition, the rotor shaft protrudes through the hole in the first cheek and the solid shaft of the second angle sensor protrudes through the hole in the second cheek.

[0023] In an advantageous embodiment, a strain gauge is attached to a web, particularly for monitoring the adapter's torsion for exceeding a permissible deviation from zero. The advantage here is that if the torsion is too strong, the angular positions determined by the two angle sensors deviate from each other, even though the actual angular positions do not deviate. Thus, greater safety is achieved by monitoring for excessive torsion.

[0024] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0025] The invention will now be explained in more detail using schematic illustrations:

[0026] Figure 1 shows a section of an electric motor according to the invention in a schematic side view.

[0027] Figure 2 shows the area in an oblique view.

[0028] Figure 3 shows a coupling 6 of the electric motor in an oblique view.

[0029] Figure 4 shows a solid shaft encoder 5 of the electric motor in an oblique view.

[0030] Figure 5 shows a hollow shaft encoder 7 of the electric motor in an oblique view.

[0031] Figure 6 shows an adapter of the electric motor in an oblique view.

[0032] Figure 7 shows an oblique view of the bearing plate 1 of the electric motor.

[0033] As shown in the figures, the electric motor has a rotor shaft 8 which is rotatably mounted via a bearing accommodated in a bearing plate 1.

[0034] The bearing shield 1 is connected to a stator housing 9, which is connected to a bearing flange not shown in the figures, which accommodates a further bearing for the rotatable mounting of the rotor shaft 9.

[0035] The stator housing surrounds the stator winding of the electric motor.

[0036] To reliably detect the angular position, the electric motor is equipped with two angle sensors. The first of the two angle sensors is designed as a hollow-shaft encoder 7, and the second of the two angle sensors is designed as a solid-shaft encoder 5.

[0037] Both angle sensors are designed to detect the rotational position of the rotor shaft 8. The angle values ​​of the rotor shaft 8 detected by the angle sensors are fed to a converter, which, depending on the signals, feeds the electric motor in such a way that a setpoint, such as the torque supplied by the rotor shaft 8, the rotational speed of the rotor shaft 8, or the rotational speed of the rotor shaft 8, is reached.

[0038] The hollow shaft encoder 7 is mounted with its hollow shaft on the rotor shaft 8 or on a shaft extension connected in a rotationally fixed manner to the rotor shaft 8, and is connected in a rotationally fixed manner to its rotating part. To support the torque of the stationary part of the hollow shaft encoder 7, this stationary part is connected to an adapter 2, in particular to a first flange of the adapter 2, by means of a support plate 60.

[0039] The first cheek of the adapter 2 is screw-connected to the bearing plate 1 by axially directed screws protruding through the first cheek of the bearing plate and into axially directed threaded holes of the bearing plate 1.

[0040] The first cheek of the adapter 2 is designed in the shape of a perforated disc and is connected to a second cheek 4 via webs 3 extending in the axial direction and spaced apart from one another in the circumferential direction. This second cheek 4 is preferably also designed in the shape of a perforated disc.

[0041] The rotor shaft 8 protrudes through the hole of the first cheek.

[0042] The solid shaft encoder 5 is fixed with its stationary part to the second cheek 4 and protrudes with its solid shaft through the hole of the second cheek 4.

[0043] A coupling 6 connects the solid shaft with the rotor shaft 8.

[0044] The coupling 6 is arranged axially between the hollow shaft encoder 7 and the solid shaft encoder 5.

[0045] The signals from the two sensors are compared and monitored for an unacceptably high degree of deviation between the two signals. This increases safety due to the redundant angle determination. As can be seen in Figure 7, the bearing plate 1 has axially directed edge recesses on the end face facing the coupling 6, particularly on its radially outer end region. The lengths of the edge recesses vary in the circumferential direction.

[0046] Preferably, in the circumferential direction, two first edge recesses, which have a first length in the circumferential direction, are followed by two second edge recesses, which have a second length in the circumferential direction. All edge recesses, in particular all first and second edge recesses, are spaced apart from one another in the circumferential direction.

[0047] These edge recesses, and in particular their longitudinal structure in the circumferential direction, reduce or prevent the formation of structure-borne sound vibration nodes on the bearing plate 1, thus introducing fewer vibration modes into the coupling 6 located on the front face. In this way, essentially undisturbed angle detection is possible.

[0048] The area covered by the coupling 6 in the axial direction is encompassed by the area covered by the webs 3 in the axial direction.

[0049] In further embodiments of the invention, a longitudinal structure of the edge recesses is formed that exhibits no rotational symmetry. This further reduces the vibration capability of the bearing plate 1.

[0050] List of reference symbols

[0051] 1 bearing plate 2 adapter, two-cheek

[0052] 3 bridge

[0053] 4 cheek

[0054] 5 solid shaft encoders

[0055] 6 Coupling 7 Hollow shaft encoder

[0056] 8 Rotor shaft

[0057] 9 Stator housing

[0058] 60 support plate

Claims

Patent claims:

1. Electric motor with a first angle sensor, wherein the first angle sensor has a first stationary part, in particular a sensor stator, and a first rotatably mounted part, in particular a sensor rotor, wherein a rotor shaft of the electric motor is rotationally connected to the first rotatably mounted part, in particular a sensor rotor, of the first angle sensor, characterized in that a second angle sensor has a second stationary part, in particular a sensor stator, and a second rotatably mounted part, in particular a sensor rotor, wherein the rotor shaft of the electric motor is rotationally connected to the second rotatably mounted part, in particular a sensor rotor, of the second angle sensor via an intermediate coupling.

2. Electric motor according to claim 1, characterized in that the first angle sensor is a hollow shaft sensor and / or that the second angle sensor is a solid shaft sensor.

3. Electric motor according to one of the preceding claims, characterized in that the first stationary part, in particular the sensor stator, of the first angle sensor is connected, in particular only, by means of a support plate to the first cheek of an adapter, in particular for torque derivation, wherein the second stationary part, in particular the sensor stator, of the second angle sensor is connected to the second cheek of the adapter, in particular is screwed by means of screws to the second cheek of the adapter, in particular for torque derivation, wherein the first cheek is connected to the second cheek by means of webs of the adapter, in particular wherein the webs are all arranged at the same radial distance.

4. Electric motor according to one of the preceding claims, characterized in that the webs are spaced apart from one another in the circumferential direction, in particular are evenly spaced.

5. Electric motor according to one of the preceding claims, characterized in that each of the webs extends more in the circumferential direction than in the radial direction and / or the radial wall thickness of the webs is in each case smaller than the extension in the circumferential direction, wherein the first cheek is spaced from the second cheek in the axial direction.

6. Electric motor according to one of the preceding claims, characterized in that the first angle sensor is spaced apart from the second angle sensor in the axial direction, in particular wherein the axial direction is aligned parallel to the axis of rotation of the rotor shaft of the electric motor, in particular wherein the circumferential direction and the radial direction are each related to this axis of rotation.

7. Electric motor according to one of the preceding claims, characterized in that the solid shaft of the second angle sensor projects through the second cheek.

8. Electric motor according to one of the preceding claims, characterized in that the area covered by the webs in the axial direction comprises, in particular completely comprises, the area covered by the coupling in the axial direction, in particular wherein the coupling is axially spaced from both the first cheek and the second cheek.

9. Electric motor according to one of the preceding claims, characterized in that the first cheek is fastened to the bearing plate of the electric motor, wherein the bearing plate accommodates a bearing for the rotatable mounting of the rotor shaft of the electric motor.

10. Electric motor according to one of the preceding claims, characterized in that the bearing plate has axially directed edge recesses on its end face facing the coupling, in particular on its radially outer end region, wherein the length of a first edge recess measured in the circumferential direction is different from the length of a second edge recess.

11. Electric motor according to one of the preceding claims, characterized in that a stator housing is arranged axially between the bearing shield and a bearing flange which accommodates a further bearing of the rotor shaft, the stator housing being connected to the bearing shield and to the bearing flange.

12. Electric motor according to one of the preceding claims, characterized in that the support plate is in particular designed to be bent several times, in particular wherein the bends are formed in the radial direction, but in particular not in the circumferential direction.

13. Electric motor according to one of the preceding claims, characterized in that the support plate is less rigid in the axial direction than in the circumferential direction and / or in the radial direction.

14. Electric motor according to one of the preceding claims, characterized in that the second cheek is arranged on the side of the adapter axially facing away from the stator housing and / or the bearing plate, and / or that the first cheek is designed in the shape of a perforated disc and the second cheek is designed in the shape of a perforated disc.

15. Electric motor according to one of the preceding claims, characterized in that a strain gauge is attached to a web, in particular for monitoring the torsion of the adapter for exceeding a permissible degree of deviation from zero.

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