Sensor arrangement for detecting the angular position of a rotor shaft of an electric motor

Abstract

Sensor arrangement for detecting the angular position of a rotor shaft (1) of an electric motor, wherein the sensor arrangement has a rotor shaft (1) of the sensor which is rotatably mounted to a housing part (31) of the sensor, where an adapter is arranged between the sensor and the motor wherein the adapter has an adapter shaft (3) which is mounted in a housing part (31) of the adapter by means of at least one bearing (7), wherein the outer ring of the bearing (7) is received in the housing part (31) of the adapter and the inner ring of the bearing (7) receives the adapter shaft (3), wherein the adapter shaft (3) has a damping element and / the housing part (31) of the adapter has a second damping element, wherein the adapter shaft (3) has a metallic adapter shaft part (40) which is radially surrounded by the damping part, wherein the inner ring of the bearing (7) receives, touches and / or radially surrounds the casing (41), such that the damping element acts as a thermal barrier and / or electrical insulating medium between the adapter shaft part (40) and the housing part (31) of the adapter and / or the housing part (31) of the sensor, wherein the adapter shaft (3) is arranged with the rotor shaft (1) of the sensor by means of a claw coupling (4), between the coupling parts of which a further damping part is arranged, wherein the housing part (31) of the adapter has a metallic sleeve (20) radially surrounded by the second damping part, which receives, positions, spaces apart and / or centers the bearing (7) or bearing (7) of the adapter shaft (3), wherein the sleeve (20) has axially spaced bearing seats, each of which is limited at least on one axial side by a step.

Description

[0001] The invention relates to a sensor arrangement for detecting the angular position of a rotor shaft of an electric motor.

[0002] It is generally known that in an electric motor equipped with an electromagnetically actuated brake, a change in the acceleration of the motor's rotor shaft can be caused when the brake is applied. This change in acceleration can be caused by a corresponding axially propagating shock wave through the motor's rotor shaft.

[0003] If a sensor for detecting the angular position of the motor is connected to the motor, mechanical and thermal stresses as well as errors in the measured value acquisition can occur.

[0004] The closest prior art known from DE 199 57 062 A1 is a claw coupling with a plastic star.

[0005] A sound-damped bearing is known from DE 1 966 463 U.

[0006] The invention is therefore based on the object of improving the reliability of the sensor arrangement.

[0007] According to the invention, the object is achieved in the sensor arrangement according to the features specified in claim 1.

[0008] Important features of the invention in the sensor arrangement, in particular for detecting the angular position of a rotor shaft of an electric motor, is that the sensor arrangement has a rotor shaft of the sensor, which is rotatably mounted to a housing part of the sensor, where an adapter is arranged between the sensor and the motor, wherein the adapter has an adapter shaft which is mounted in a housing part of the adapter by means of at least one bearing, wherein the outer ring of the bearing is accommodated in the housing part of the adapter and the inner ring of the bearing accommodates the adapter shaft, wherein the adapter shaft has a damping part and / or the housing part of the adapter has a second damping part,

[0009] in particular wherein the damping part is made of plastic, in particular of PEEK or of an elastomer.

[0010] The advantage here is that waves propagating axially from the motor to the sensor are damped. Especially when an electromagnetically actuated brake is applied, shock waves are generated that propagate in all spatial directions, especially axially, and are damped according to the invention. Furthermore, by means of the By using the respective damping element, an electrical connection can be interrupted and a thermal barrier can be implemented. The motor can be equipped with an electromagnetically actuated brake, the braking torque of which can be applied to the motor's rotor shaft. Furthermore, the motor can be equipped with a fan that can be arranged axially between the brake and the sensor.

[0011] Advantageously, the damping part is made of a thermally high-strength and mechanically damping plastic.

[0012] Another advantage is that circulating currents caused by magnetic circuit asymmetries through the motor bearing cannot damage the motor and attached components because such circulating currents can be prevented by means of the damping part as electrical insulation.

[0013] Compensating currents, which could be transmitted into the motor rotor by fast-switching semiconductors and the associated switching delays caused by charge shifts and could damage motor bearings and attached components such as rotary encoders, can thus be equally prevented by the invention.

[0014] According to the invention, the adapter shaft is arranged with the rotor shaft of the sensor by means of a claw coupling, between whose coupling parts a further damping part, in particular a star-shaped damping part, is arranged. The advantage here is that This provides further improved damping on the rotating part. Furthermore, there is no electrical connection between the motor's rotor shaft and the sensor's rotor shaft. A thermal barrier is also created.

[0015] According to the invention, the adapter shaft has a metallic adapter shaft part which is radially surrounded by the damping part, in particular wherein the damping part is designed as a casing made of damping material, in particular plastic, in particular PEEK or an elastomer,

[0016] in particular wherein the inner ring of the bearing receives, touches and / or radially surrounds the casing, In particular, the damping part acts as a thermal barrier and / or electrical insulation between the adapter shaft part and the housing part of the adapter and / or the housing part of the sensor. The advantage here is that the damping part can be easily manufactured as a composite part, in particular as a plastic overmold.

[0017] According to the invention, the housing part of the adapter has a metallic sleeve, in particular a centering sleeve, radially surrounded by the second damping part, which receives, positions, spaced apart, and / or centers the bearing or bearings of the adapter shaft. The sleeve has axially spaced-apart bearing seats, each of which is delimited by a step on at least one axial side. Advantageously, the spacing and centering of the bearings can be achieved by means of the metallic sleeve, and the damping part can be used to dampen shock waves.

[0018] In an advantageous embodiment, the housing part of the adapter is designed as an intermediate flange, wherein the intermediate flange is connected in a rotationally fixed manner to a housing part of the sensor and to a housing part of the motor, in particular - wherein the second damping part is arranged between the metallic sleeve and the housing part of the motor and - wherein the second damping part is arranged between the metallic sleeve and the housing part of the sensor.

[0019] The advantage here is that a non-rotatable connection of the sensor can be achieved, thus providing torque support for the sensor on the motor housing. When the electric motor is designed as a fan motor, a fan cover is part of the motor housing, on which the sensor can be supported.

[0020] In an advantageous embodiment, a further metallic part, in particular a sleeve, radially surrounds the second damping part of the housing part of the adapter,

[0021] In particular, the metallic part is integrally or press-connected to the second damping part and / or the second damping part is integrally or press-connected to the metallic sleeve, in particular the centering sleeve. The advantage here is that a simple connection technique can be used.

[0022] In an advantageous embodiment, the housing part of the adapter is designed as a composite part. This provides a strong connection between the metal part and the damping part. Furthermore, overmolding is easy to implement and ensures a firmly bonded connection.

[0023] In an advantageous embodiment, the housing part, in particular the second damping part or the further metallic part, in particular sleeve, is connected by means of a sheet metal part to a fan cover of the motor, which is connected to the housing part of the motor

[0024] The advantage here is that an easily manufactured support can be provided. The torque can be supported via a sheet metal part on the fan cover in such a way that the sheet metal part and the fan cover are more torsionally rigid in the circumferential direction than in the axial direction.

[0025] In an advantageous embodiment, the housing part of the adapter has sealing ring seats for shaft seals, with the bearing(s) and their bearing seats arranged axially between the sealing ring seats. This advantageously ensures that lubricant remains in the area of ​​the bearings and does not reach the environment, in particular, the interior of the motor or the sensor.

[0026] In an advantageous embodiment, the housing part of the adapter, the housing part of the sensor, the adapter shaft, the rotor shaft of the sensor, and / or the rotor shaft of the motor are made of metal. This is advantageous because it allows for the transmission of high forces and torques.

[0027] In an advantageous embodiment, the housing part of the adapter has a recess, in particular an actuating opening, through which a clamping connection between the adapter shaft and a coupling part of the claw coupling or between a rotor shaft of the sensor and a coupling part of the claw coupling can be actuated. The advantage here is that the claw coupling parts can be connected easily.

[0028] Further advantages are apparent from the dependent claims. The invention is not limited to the combination of features of the claims. The person skilled in the art will recognize further possible combinations of claims and / or individual

[0029] Claim features and / or features of the description and / or the figures, in particular from the task and / or the problem arising from comparison with the prior art.

[0030] The invention will now be explained in more detail with the aid of illustrations: In the Fig. 1 shows a first sensor arrangement according to the invention in an electric motor, wherein an intermediate flange 2 is provided for shock absorption. In the Fig. 2 shows a second sensor arrangement according to the invention in an electric motor, wherein an overmolded sleeve 20 is provided as an intermediate flange for shock absorption. In the Fig. 3 shows a third sensor arrangement according to the invention in an electric motor, wherein a sleeve 30 arranged between two metallic parts is provided as an intermediate flange for shock absorption. In the Fig. 4 shows a fourth sensor arrangement according to the invention in an electric motor, wherein an overmolded adapter shaft part 40 is provided for shock absorption.

[0031] As in Fig. As shown in Figure 1, an adapter is arranged between a sensor of the sensor assembly and the rest of the electric motor. An adapter shaft 3 is connected via

[0032] Bearing 7 is mounted in an intermediate flange 2. The adapter shaft 3 is connected to the rotor shaft 1 in a rotationally fixed manner, particularly by a screw connection, by means of a screw 8. For this purpose, the screw is inserted through the center of the adapter shaft 3 and screwed into a threaded hole in the rotor shaft 1.

[0033] A first claw coupling part of a claw coupling is connected in a rotationally fixed manner to the adapter shaft 3. For this purpose, a clamping connection between the claw coupling part and the adapter shaft 3 is actuated by means of a screw part. For actuation by means of a

[0034] Tool, such as screwdriver or the like, the intermediate flange has an actuating opening 10 through which the tool can be inserted and the screw part can be rotated so that the clamping connection can be effected or released.

[0035] A star-shaped damping part made of an elastomer is arranged between the claw sections of the first claw coupling part and the claw sections of the second claw coupling part of the claw coupling 4.

[0036] In this way, vibrations acting in the circumferential direction, in particular torsional vibrations, can be damped - at least if they are coupled to the sensor via the rotor shaft 1.

[0037] The second claw coupling part is connected to the rotor shaft of the sensor 6 in a rotationally fixed manner, in particular again by means of a corresponding clamping connection.

[0038] The housing of the sensor 6 is connected, in particular in a rotationally fixed manner, to the intermediate flange 2 by means of a centering flange 5. The intermediate flange 2 is connected to a sheet metal part 9 that is attached to the fan cover of the motor, which is preferably designed as a fan motor.

[0039] The sensor 6 is designed as an angle sensor and is therefore intended to detect the angular position of the rotor shaft 1 of the motor.

[0040] The intermediate flange 2 contains not only the two bearings 7 for the adapter shaft 3 but also two shaft seals, which prevent the lubricant provided in the area of ​​the bearings 7 from entering the environment. Furthermore, the penetration of dirt particles into the area of ​​the bearings 7 is prevented.

[0041] The design of the intermediate flange 2 made of damping material also prevents the flow of current through the bearing 7, whose outer ring is accommodated by the intermediate flange 2, which is made of electrically insulating material. Electrical currents that interfere with the angle detection can be prevented. This also creates a thermal barrier between the motor housing and the housing part of the sensor 6. In this way, the influence of disturbances on the angle detection of the sensor can be suppressed or at least reduced.

[0042] In the example according to Fig. 2 is in contrast to Fig. 1 not the entire intermediate flange is made of material with high damping for mechanical vibrations, but the intermediate flange has a metallic centering sleeve 20, in which the bearings 7 of the adapter shaft 3 are accommodated, and an overmolding with

[0043] Plastic. Thus, the intermediate flange is designed as a composite part. The sleeve 20 is provided for precise alignment and spacing of the bearings, and the overmolding is made of plastic, preferably elastomer, to dampen mechanical vibrations, especially shock waves.

[0044] Instead of an overmolding, a plastic sleeve part can also be used into which the centering sleeve 20 is pressed.

[0045] The design of the overmolding 21 or the plastic sleeve part made of electrically insulating damping material also prevents the flow of current through the bearing 7 when the centering sleeve 20 is accommodated in the damping material and surrounded by it in an electrically insulating manner. This would prevent disruptive electrical currents, benefiting the service life. This also creates a thermal barrier between the motor housing and the housing part of the sensor 6. In this way, the influence of disturbances on the sensor's angle detection can be suppressed or at least reduced.

[0046] In the example according to Fig. 3 is in contrast to Fig. 2, the intermediate flange is constructed in three parts, with a metallic centering sleeve 32 being provided radially inside, in which the bearings 7 of the adapter shaft 3 are accommodated. Radially outside A metallic housing part 30 is arranged so that the sheet metal part 9 can be securely fastened. A damping sleeve 30 is arranged between the housing part 30 and the sleeve 32. This is preferably made of plastic, preferably elastomer, for damping mechanical vibrations, in particular waves or shock waves.

[0047] Preferably, the intermediate flange is again designed as a composite part, but press-fit connections of the sleeves (30, 31, 32) or other connection types are also possible. In this case, the metallic sleeve 32 is used for precise alignment and

[0048] Spacing of the bearings is provided. The metallic design of the radially outer sleeve 31 as a housing part enables a rigid connection of the housing part of the sensor 6 to the centering flange 5.

[0049] A shock transmitted to the sensor via the rotor shaft 1 causes the adapter shaft 3 to move in all three spatial directions in the worst case scenario. Accordingly, the associated jolt is transmitted via the bearings 7, which are corresponding steps of the adapter shaft 3 and the retaining rings arranged on the adapter shaft 3, in particular axially. This means that this movement is limited by the bearing 7 directly and / or via the centering sleeve 32. is transmitted to the damping sleeve 30. However, since this is accommodated in the radially surrounding sleeve 31, the shock wave is dampened and thus dissipated as it passes through the damping sleeve 30.

[0050] The design of the sleeves 31 and 32 of the intermediate flange 2 made of damping material also prevents the flow of current through the bearing 7 when the damping sleeve 30

[0051] Sleeve 32 radially surrounds and an electrically insulating retaining ring is used for axial securing of the bearings 7, which, like the damping sleeve 30, is made of made of electrically insulating material. This prevents electrical currents that interfere with the angle measurement. This also creates a thermal barrier between the motor housing and the housing part of the sensor 6. In this way, the influence of disturbances on the angle detection of the sensor can be suppressed or at least reduced.

[0052] In the example according to Fig. 4 is in contrast to the Fig. 1 to 3 on the rotating part. For this purpose, a metallic adapter shaft part 40 with a damping casing 41, in particular

[0053] Plastic sheathing, which accommodates the inner rings of the bearings 7. Thus, a shock wave transmitted from the motor via the adapter shaft part 40, which is non-rotatably connected to the rotor shaft 1, is dampened when transmitted from the adapter shaft part 40 via the damping sheathing 41 to the bearings 7.

[0054] Since the first claw coupling part of the claw coupling is connected to the damping casing 41 and this is thus arranged between screw 8 and adapter shaft part 40, the rotor shaft 1 is electrically insulated from the rotor shaft of the encoder.

[0055] This prevents electrical currents that interfere with the angle measurement. Furthermore, current flow through bearing 7 is also prevented, as the inner ring is on the

[0056] The damping jacket 41 is electrically insulating. This also creates a thermal barrier between the rotor shaft 1 of the motor and the rotor shaft of the sensor 6.

[0057] In this way, the influence of disturbances on the angle detection of the sensor can be suppressed or at least reduced.

[0058] In the Fig. 1 to 3 show the stator-side, i.e. housing-side, damping measures. Fig. 4 shows a rotor-side damping measure. For further In the embodiments according to the invention, one of the stator-side and the rotor-side measures are implemented simultaneously. List of reference symbols 1 rotor shaft of the motor 2 Intermediate flange, shock-absorbing 3 adapter rotor 4 Claw coupling with damping part arranged between the coupling parts 5 Centering flange 6 Angle sensor 7 camps 8 screw 9 Sheet metal part 10 Operating opening 20 Sleeve, especially metallic centering sleeve 21 Plastics, especially plastic overmolding 30 Damping sleeve, especially made of plastic 31 Housing part, metallic 32 Sleeve, in particular metallic centering sleeve 40 Adapter shaft part, metallic 41 Damping sheathing, especially plastic sheathing

Claims

[1] Sensor arrangement for detecting the angular position of a rotor shaft (1) of an electric motor, wherein the sensor arrangement comprises a rotor shaft (1) of the sensor, which is rotatably mounted to a housing part (31) of the sensor, where an adapter is arranged between the sensor and the motor, wherein the adapter has an adapter shaft (3) which is mounted in a housing part (31) of the adapter by means of at least one bearing (7), wherein the outer ring of the bearing (7) is received in the housing part (31) of the adapter and the inner ring of the bearing (7) receives the adapter shaft (3), wherein the adapter shaft (3) has a damping part and / the housing part (31) of the adapter has a second damping part, wherein the adapter shaft (3) has a metallic adapter shaft part (40) which is radially surrounded by the damping part, wherein the inner ring of the bearing (7) receives, touches and / or radially surrounds the casing (41), such that the damping part acts as a thermal barrier and / or electrical insulation means between the adapter shaft part (40) and the housing part (31) of the adapter and / or the housing part (31) of the sensor, wherein the adapter shaft (3) is arranged with the rotor shaft (1) of the sensor by means of a claw coupling (4), between the coupling parts of which a further damping part is arranged, wherein the housing part (31) of the adapter has a metallic sleeve (20) radially surrounded by the second damping part, which receives, positions, spaced from each other and / or centers the bearing (7) or bearings (7) of the adapter shaft (3), wherein the sleeve (20) has axially spaced-apart bearing seats, each of which is delimited at least on one axial side by means of a step. [2] Sensor arrangement according to claim 1, characterized by , that the housing part (31) of the adapter is designed as an intermediate flange (2), wherein the intermediate flange (2) is connected in a rotationally fixed manner to a housing part (31) of the sensor and to a housing part (31) of the motor. [3] Sensor arrangement according to at least one of the preceding claims, characterized by that a further metallic part radially surrounds the second damping part of the housing part (31) of the adapter. [4] Sensor arrangement according to at least one of the preceding claims, characterized by that the housing part (31) of the adapter is designed as a composite part. [5] Sensor arrangement according to at least one of the preceding claims, characterized by that the housing part (31) is connected by means of a sheet metal part (9) to a fan cover of the motor, which is connected to the housing part (31) of the motor. [6] Sensor arrangement according to at least one of the preceding claims, characterized bythat the housing part (31) of the adapter has sealing ring seats for shaft sealing rings, wherein the bearing(s) (7) and its bearing seats are arranged axially between the sealing ring seats. [7] Sensor arrangement according to at least one of the preceding claims, characterized by that the housing part (31) of the adapter, the housing part (31) of the sensor, the adapter shaft (3), the rotor shaft (1) of the sensor and / or the rotor shaft (1) of the motor is made of metal. [8] Sensor arrangement according to at least one of the preceding claims, characterized by that the housing part (31) of the adapter has a recess through which a clamping connection between the adapter shaft (3) and a coupling part of the claw coupling (4) or between a rotor shaft (1) of the sensor and a coupling part of the claw coupling (4) can be actuated.

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