Device for monitoring a coupling coupling a first shaft to a second shaft

Abstract

The invention relates to a device (10) for monitoring a coupling (7) which couples a first shaft (3) to a second shaft (31), the device having an optical unit (12) with a receiving element (14) which is designed to receive electromagnetic radiation, in particular light, and a changing unit (11) which is designed to change the radiation energy (41) which impinges on the receiving element (14) when the first shaft (3) is operated asynchronously with respect to the second shaft (31). The invention also relates to a coupling (7) and to a rotary electric machine (100).

Description

Device for monitoring the coupling connecting the first shaft and the second shaft. Technical Field

[0001] The present invention relates to a device for monitoring a coupling that connects a first shaft and a second shaft. Background Technology

[0002] CN 111 982 508A provides a coupling slippage monitoring system and method, relating to the field of couplings. The coupling slippage monitoring system includes a coupling, a controller, at least two signal receiving and transmitting devices, and at least two signal feedback devices. The coupling includes a first body and a second body. The first body and the second body are arranged opposite to each other. Each of the first body and the second body has at least one signal feedback device. The controller is electrically connected to at least two signal receiving and transmitting devices. The coupling slippage monitoring system and method provided by this invention have the advantages of simple measurement method and simple slip angle detection.

[0003] Couplings are critical components in transmission systems and can be damaged, for example, under overload conditions.

[0004] For example, a failure in the connection between the sensor and the motor is particularly important for safety because it can result in erroneous reference signals for control, compromising the motor's safe operation. Furthermore, such damage makes it impossible to adhere to precise speed specifications.

[0005] To avoid damaging the coupling, individual or all components of the coupling are often designed to be oversized. However, this is very expensive. Summary of the Invention

[0006] The purpose of this invention is to improve upon this.

[0007] The solution to this objective is achieved by the present invention, namely, a device for monitoring a coupling connecting a first shaft and a second shaft, the device having:

[0008] - An optical unit with a receiving element designed to receive electromagnetic radiation, particularly light.

[0009] - A changing unit designed to alter the radiant energy incident on the receiving element when the first axis operates asynchronously relative to the second axis.

[0010] The alteration unit has a holographic optical component, which can be arranged on and / or within the first axis.

[0011] The changing unit has an aperture, which can be arranged on and / or within the second axis.

[0012] The aperture has slots arranged radially in at least a substantially regular order and filling regions arranged radially.

[0013] The aperture has an opening that is at least substantially located in the center.

[0014] The holographic optical component is capable of being irradiated / illuminated by an emitting element with electromagnetic radiation, particularly coherent radiation. The holographic optical component generates a pattern, in particular, through diffraction and / or refraction and / or reflection and / or interference of the radiation. The pattern has regions with a first radiant energy arranged radially in at least substantially regular order and regions with a second radiant energy arranged radially.

[0015] This invention is applicable to various couplings, such as couplings connecting mechanical shafts and loads, and couplings connecting sensor shafts and mechanical shafts.

[0016] In particular, this invention can be applied to servo motors. Servo motors are designed specifically for tasks requiring high precision. Understanding the integrity of the coupling is especially advantageous in this regard.

[0017] Electromagnetic radiation in the form of light is particularly well-suited for this invention. Light is generally understood to refer to the visible portion of the electromagnetic spectrum in the range of 380 nm to 780 nm. Electromagnetic radiation in the invisible range can also be used in this invention, particularly infrared or ultraviolet light.

[0018] One implementation is advantageous in which the receiving element is designed as a photodiode.

[0019] Photodiodes are advantageous because they are inexpensive and robust.

[0020] However, the receiving element can also be designed as a diode array, a camera, or a common photodetector. Other forms are also possible.

[0021] One implementation is advantageous in which the optical unit has an emitting element designed to emit electromagnetic radiation, particularly light.

[0022] One implementation is advantageous in which the emitting element is designed to emit beams of electromagnetic radiation and / or emit electromagnetic radiation with a constant wavefront.

[0023] One advantageous implementation is that the emitting element is a laser diode.

[0024] Laser diodes are advantageous because they are inexpensive and robust.

[0025] Other types of coherent light sources can also be used.

[0026] The alteration unit has holographic optical components, wherein the holographic optical components can be arranged on and / or within a first axis.

[0027] Holographic optical components are preferably elements of optical devices whose holographic properties are used in the device. It is feasible to replace traditional lenses, mirrors, and prisms with holograms. However, additional holographic properties often have particular advantages.

[0028] Holographic optical components have special properties, such as the selectivity of color and the angle of incidence of light.

[0029] For example, holographic optical components can refract light at a specific angle of incidence but are transparent to other angles. Depending particularly on the axial length, different diffractions of light can be split into spectral colors like a prism. For example, reflection holograms can also be used to construct plane mirrors, concave mirrors, or convex mirrors that reflect light at angles of incidence different from their exit angles.

[0030] Holographic optical components are, for example, embossed films. They are easy to assemble, insensitive to large accelerations, and especially inexpensive for mass production.

[0031] Plastic components with direct structural design can also be used as holographic optical components. Other shapes are also feasible.

[0032] The changing unit has an aperture, wherein the aperture can be arranged on and / or within the second axis.

[0033] The aperture has slots arranged radially in at least a substantially regular order and filled areas arranged radially.

[0034] However, other types of shapes are also possible, such as shapes that produce continuous intensity variations (e.g., cyclic sine curves). Other shapes are also possible.

[0035] The aperture has an opening that is at least substantially located in the center.

[0036] This is for lighting.

[0037] Holographic optical components can be irradiated / illuminated by an emitting element with electromagnetic radiation, particularly coherent radiation, wherein the holographic optical components generate patterns, particularly through diffraction and / or refraction and / or reflection and / or interference of the radiation, wherein the patterns have regions with a first radiative energy arranged radially in at least substantially regular order and regions with a second radiative energy arranged radially.

[0038] For example, this could be a pattern with both light and dark areas.

[0039] One implementation is advantageous in which the region having the first radiant energy can be shielded and / or blocked by the filling region of the aperture.

[0040] One advantageous implementation involves arranging holographic optical components and apertures such that when the first axis operates synchronously with respect to the second axis, the second radiant energy irradiates the receiving element.

[0041] One implementation is advantageous in which the holographic optical components and aperture are arranged such that when the first axis is running asynchronously relative to the second axis, the first radiant energy at least partially irradiates the receiving element.

[0042] Asynchronous operation, especially continuous asynchronous operation not just for short periods, is often an indication of an error. Therefore, it can help identify damage to the coupling.

[0043] The advantage provided by this invention is that it eliminates the need for costly, oversized components, particularly sensor couplings, sensor shafts, and sensor bearings.

[0044] For example, the present invention can identify clutches that are damaged or destroyed due to overload.

[0045] This invention is particularly well-suited for servo motors. Servo motors typically have self-supporting sensors. Here, the sensor shaft is connected to the machine shaft via a clutch. If the sensor bearing fails, it becomes sluggish and the sensor coupling bears a heavier load. This can lead to failure. However, this invention offers the advantage of being able to recognize this.

[0046] The solution to the above objective is also achieved by the present invention, namely, a coupling having such a device.

[0047] The solution to the above objective is further achieved by the present invention, namely, a rotary motor having: a first shaft and a second shaft, wherein the first shaft and the second shaft are connected by means of a coupling; and such a device.

[0048] One implementation is advantageous in which the first shaft and / or the second shaft is designed as a hollow shaft. Attached Figure Description

[0049] The invention will now be described and explained in more detail with reference to the embodiments shown in the accompanying drawings. The drawings show:

[0050] Figure 1 shows an exploded view of an exemplary servo motor.

[0051] Figure 2 illustrates a feasible embodiment of the device 10 for monitoring the coupling connecting the first and second shafts.

[0052] Figure 3 illustrates a feasible implementation scheme for the aperture.

[0053] Figure 4 illustrates one method. Detailed Implementation

[0054] Figure 1 shows an exploded view of an exemplary servo motor 100. The servo motor has a sensor 1, a brake 2, a shaft 3, a connecting device 4, and an active component 5.

[0055] The diagram also shows the rotation direction 6.

[0056] The figure also shows a device 10 for monitoring the coupling connecting the first and second shafts. The device 10 is described in more detail in the following figures. The device 10 is capable of monitoring the coupling (as shown) connecting the sensor shaft and the machine shaft. Furthermore, it is conceivable that the device 10 for monitoring the connection of the machine shaft is loaded. The device 10 is also applicable to other couplings.

[0057] Figure 2 illustrates a feasible embodiment of the device 10 for monitoring the coupling connecting the first and second shafts.

[0058] The first axis in the diagram is machine axis 3. The second axis in the diagram is sensor axis 31. The diagram also shows that machine axis 3 and sensor axis 31 are connected by a clutch 7 (also called a coupling).

[0059] The figure also shows the rotation axis A.

[0060] Device 10 includes an optical unit 12 with a receiving element designed to receive electromagnetic radiation, particularly light. In the figure, this is a photodiode 14. Other receiving elements may also be considered.

[0061] The figure also shows that the optical unit 12 has an emitting element designed to emit electromagnetic radiation, particularly light. The emitting element is advantageously designed to emit beams of electromagnetic radiation and / or to emit electromagnetic radiation with a constant wavefront. The emission of radiation is indicated by arrow 40.

[0062] This is laser diode 13 in the diagram. Other emitting elements can also be considered.

[0063] The optical unit 12 is arranged in or at the sensor 1 shown in the figure.

[0064] The device 10 also includes a changing unit 11, which is designed to change the radiation energy irradiated onto the receiving element when the first axis (machine axis 3 in the figure) is operating asynchronously relative to the second axis (sensor axis 31 in the figure).

[0065] The alteration unit 11 advantageously includes a holographic optical component 111, which can be arranged on and / or within a first axis. In the figure, the holographic optical component is arranged within a machine axis 3. For this purpose, the machine axis 3 is preferably designed as a hollow axis.

[0066] Holographic optical component 111 is, for example, an embossed film.

[0067] In the figure, the changing unit 11 has an aperture 15, which can be arranged on and / or within the second axis. In the figure, the aperture 15 is arranged inside the sensor shaft 31. For this purpose, the sensor shaft 31 is preferably designed as a hollow shaft.

[0068] A feasible implementation of the aperture 15 is shown in Figure 3.

[0069] In the figure, the aperture 15 has slots 20 arranged radially in at least substantially regular order and filling regions 22 arranged radially.

[0070] A centrally located, at least substantially circular, opening 21 is advantageous because it is used for lighting. The aperture 15 may be designed, for example, as a hollow cylinder or as a disc with a central opening.

[0071] Holographic optical components can be illuminated or irradiated by an emitting element (laser diode 13 in the figure) using electromagnetic radiation, particularly coherent radiation. This is indicated by arrow 40.

[0072] The holographic optical component 111 advantageously produces patterns (indicated by arrow 41), particularly through diffraction and / or refraction and / or reflection of radiation.

[0073] The pattern advantageously has regions with a first radiant energy, such as bright regions, arranged radially in at least a substantially regular order, and regions with a second radiant energy, such as dark regions, arranged radially.

[0074] The region with the first radiant energy can be shielded and / or blocked by the filling region of the aperture 15 shown in Figure 3.

[0075] Holographic optical component 111 and aperture 15 are arranged in the figure such that when the machine axis 3 is running synchronously with respect to the sensor axis 31, the second radiant energy is irradiated onto the receiving element (photodiode 14).

[0076] The holographic optical component 111 and the aperture 15 are arranged such that when the machine axis 3 is running asynchronously relative to the sensor axis 31, the first radiant energy at least partially irradiates the photodiode 14.

[0077] The photodiode 14 thus detects changes in radiated energy and can transmit this information to a control unit (not shown), such as a servo motor.

[0078] In other words, the aperture 15 is positioned within a sensor shaft 31, which is designed as a hollow shaft. This aperture includes, for example, a radial slit with a central opening for illumination. A reflective hologram, for example in the form of an embossed film, is mounted on the end of the machine shaft 3. The hologram advantageously incorporates radial light and dark patterns and lenses, such that it projects an image at the location of the aperture 15 within the sensor shaft 31. On the sensor side, in the figure, the hologram on the machine shaft is illuminated through the hollow shaft of the sensor 1, preferably with coherent light. The image is designed such that bright areas are shielded by the aperture within the sensor shaft.

[0079] If axes 3 and 31 move synchronously, a stable image is produced. However, if axes 3 and 31 move relative to each other under incorrect conditions, the brightness of the image will change. This change is detected by a simple photodiode 14.

[0080] The torsion of machine shaft 3 under load, especially in the event of a sudden change in torque, results in a limited change in brightness. If the change exceeds this range, a defect in the connection of sensor 1 or a defect in the connection of sensor shaft 31 is identified.

[0081] This principle can be extended to torque measurement by performing a more detailed brightness assessment of the holographic image, rather than simply monitoring a threshold.

[0082] Here, a finite change in brightness during shaft torsion caused by torque load is quantitatively detected and converted into the corresponding torque value.

[0083] The distance between the optical unit 12, which is advantageously arranged on the sensor side, and the holographic optical component 111 is advantageously a few centimeters, for example, from 1 cm to 50 cm.

[0084] However, in the case of very large machines, the distance can also be extended to several meters, such as 1 to 10 meters.

[0085] Figure 4 illustrates one method.

[0086] In method step S1, the emitting element emits electromagnetic radiation, especially light.

[0087] Holographic optical components are therefore irradiated by electromagnetic radiation, especially by light, from the emitting element.

[0088] In method step S2, a pattern is generated by a holographic optical component, wherein the pattern has regions with first radiant energy arranged radially in at least substantially regular order and regions with second radiant energy arranged radially.

[0089] In method step S3, when the first axis is running synchronously with respect to the second axis, the second radiant energy irradiates the receiving element because the area with the first radiant energy is shielded or blocked by the filling area of ​​the aperture.

[0090] In method step S4, when the first axis is running asynchronously relative to the second axis, the first radiated energy at least partially irradiates the receiving element. Due to the asynchronous operation, shading no longer occurs.

Claims

1. A device (10) for monitoring a coupling (7) connecting a first shaft (3) and a second shaft (31), the device comprising: - an optical unit (12) with a receiving element designed to receive electromagnetic radiation; - a changing unit (11) designed to change the radiation energy (41) incident on the receiving element when the first shaft (3) is operated asynchronously relative to the second shaft (31), wherein, The alteration unit (11) has a holographic optical component (111), wherein the holographic optical component (111) is capable of being arranged on and / or within the first axis (3), wherein the alteration unit (11) has an aperture (15), wherein the aperture (15) is capable of being arranged on and / or within the second axis (31), wherein the aperture (15) has slots (20) arranged radially in at least a substantially regular order and filling regions (22) arranged radially, wherein the aperture (15) has an opening (21) arranged at least substantially centrally, wherein the holographic optical component (111) is capable of being illuminated / irradiated by an emitting element (13) with electromagnetic radiation, wherein the holographic optical component (111) generates a pattern (41), wherein the pattern (41) has regions with a first radiant energy arranged radially in at least a substantially regular order and regions with a second radiant energy arranged radially.

2. The apparatus (10) according to claim 1, wherein, The receiving element is designed to receive light.

3. The apparatus (10) according to claim 1, wherein, The holographic optical component (111) can be illuminated / irradiated by the emitting element (13) with coherent radiation.

4. The apparatus (10) according to claim 1, wherein, The holographic optical component (111) generates patterns through diffraction and / or refraction and / or reflection and / or interference of radiation.

5. The apparatus (10) according to claim 1, wherein, The receiving element (14) is designed as a photodiode.

6. The apparatus (10) according to claim 1, wherein, The optical unit (12) has a emitting element designed to emit one or more electromagnetic radiations.

7. The apparatus (10) according to claim 6, wherein, The emitting element is designed to emit light.

8. The apparatus (10) according to claim 6, wherein, The transmitting element is designed to emit beams of electromagnetic radiation and / or to emit electromagnetic radiation with a constant wavefront.

9. The apparatus (10) according to claim 6 or 8, wherein, The emitting element is a laser diode (13).

10. The apparatus (10) according to claim 1, wherein, The region carrying the first radiant energy can be shielded and / or blocked by the filling region (22) of the aperture (15).

11. The apparatus (10) according to claim 1, wherein, The holographic optical component (111) and the aperture (15) are arranged such that the second radiant energy is irradiated onto the receiving element (14) when the first axis (3) operates synchronously with respect to the second axis (31).

12. The apparatus (10) according to claim 1, wherein, The holographic optical component (111) and the aperture (15) are arranged such that, when the first axis (3) operates asynchronously relative to the second axis (31), the first radiant energy is at least partially irradiated onto the receiving element (14).

13. A coupling (7) having a device (10) according to any one of claims 1 to 12.

14. A rotary electric motor (100) comprising: - a first shaft (3), - a second shaft (31), wherein, The first shaft (3) and the second shaft (31) are connected by means of a coupling (7), - the device (10) according to any one of claims 1 to 12.

15. The rotary electric motor (100) according to claim 14, wherein, The first shaft (3) and / or the second shaft (31) are designed as hollow shafts.

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