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

Abstract

A device for monitoring a shaft coupling coupling a first shaft to a second shaft includes an optical unit comprising a receiving element which is designed to receive an electromagnetic radiation in a form of light, and an error notification element designed for arrangement on and/or within the first shaft and on and/or within the second shaft. The error notification element is designed to notify when the first shaft runs asynchronously with respect to the second shaft.

Claims

1. A device for monitoring a shaft coupling coupling a first shaft to a second shaft, the device comprising: an optical unit comprising a receiving element which is designed to receive an electromagnetic radiation in a form of light; and an error notification element designed for arrangement on and/or within the first shaft and on and/or within the second shaft, said error notification element designed such as to shear off or break off when the first shaft runs asynchronously with respect to the second shaft.

2. The device of claim 1, wherein the error notification element includes a front axial end fastenabie to the first shaft, and a rear axial end fastenable to the second shaft.

3. The device of claim 1, wherein the error notification element is designed such that a first fracture surface of a first part of the error notification element arising as a result of shearing-off and/or breaking-off and a second fracture surface of a second part of the error notification element arising as a result of shearing-off and/or breaking-off rub against one another during operation of the first shaft and second shaft so that the electromagnetic radiation is capable of being emitted in particular by triboluminescence.

4. The device of claim 1, wherein the error notification element includes plastic.

5. The device of claim 1, wherein the error notification element includes polytetrafluorethylene and/or polydimethylsiloxane.

6. The device of claim 1, wherein the error notification element includes a predetermined breaking point.

7. The device of claim 1, wherein the error notification element comprises a reflection element.

8. The device of claim 7, wherein the reflection element is a mirror.

9. The device of claim 1, further comprising an emission element designed to emit the electromagnetic radiation.

10. The device of claim 9, wherein the emission element is a light-emitting diode.

11. The device of claim 1, wherein the receiving element is a photodiode.

12. The device of claim 1, wherein the receiving element is designed to receive emitted electromagnetic radiation or reflected electromagnetic radiation.

13. The device of claim 1, wherein the receiving element is designed to detect a change in reflection properties.

14. A shaft coupling for coupling a first shaft to a second shaft, the shaft coupling comprising a device, said device comprising an optical unit comprising a receiving element which is designed to receive an electromagnetic radiation in the form of light, and an error notification element designed for arrangement on and/or within the first shaft and on and/or within the second shaft, said error notification element designed such as to shear off or break off when the first shaft runs asynchronously with respect to the second shaft.

15. The shaft coupling of claim 14, wherein the error notification element includes a front axial end fastenable to the first shaft, and a rear axial end fastenable to the second shaft.

16. The shaft coupling of claim 14, wherein the error notification element is designed such that a first fracture surface of a first part of the error notification element arising as a result of shearing-off and/or breaking-off and a second fracture surface of a second part of the error notification element arising as a result of shearing-off and/or breaking-off rub against one another during operation of the first shaft and second shaft so that the electromagnetic radiation is capable of being emitted in particular by triboluminescence.

17. A dynamoelectric rotary machine, comprising: a first shaft, a second shaft; a shaft coupling designed to couple the first shaft and the second shaft; and a device for monitoring the shaft coupling, said device comprising an optical unit comprising a receiving element which is designed to receive an electromagnetic radiation in the form of light, and an error notification element designed for arrangement on and/or within the first shaft and on and/or within the second shaft, said error notification element designed to shear off or break off when the first shaft runs asynchronously with respect to the second shaft.

18. The dynamo-electric rotary machine of claim 17, wherein at least one of the first shaft and the second shaft is a hollow shaft.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The invention is described and explained in greater detail below on the basis of the exemplary embodiments represented in the figures. In the drawings:

(2) FIG. 1 shows an exploded view of an exemplary servomotor actuator,

(3) FIG. 2 shows a possible embodiment of the device for monitoring a shaft coupling coupling a first shaft to a second shaft,

(4) FIG. 3 shows a further possible embodiment of the device for monitoring a shaft coupling coupling a first shaft to a second shaft,

(5) FIG. 4 shows a method.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(6) FIG. 1 shows an exploded view of an exemplary servomotor actuator 100. The servomotor actuator has a sensor 1, a brake 2, a shaft 3, a connecting device 4 and an active part 5.

(7) FIG. 1 further shows a rotation direction 6.

(8) The FIG. 1 also shows a device 10 for monitoring a shaft coupling coupling a first shaft and a second shaft. The device 10 is described in more detail in the following figures. The device 10 can be used to monitor a shaft coupling, which couples a sensor shaft to a machine shaft (as shown in the figure). Furthermore, it is conceivable for the device 10 to be arranged for the purpose of monitoring a coupling of the machine shaft with a load. The device 10 is also suitable for other shaft couplings.

(9) FIG. 2 shows a possible embodiment of the device 10 for monitoring a shaft coupling coupling a first shaft to a second shaft.

(10) In FIG. 2. the first shaft is a machine shaft 3. In FIG. 2, the second shaft is a sensor shaft 31. FIG. 2 moreover shows that the machine shaft 3 and the sensor shaft 3 are coupled by means of a coupling 7 (also: shaft coupling).

(11) FIG. 2 additionally shows an axis of rotation A.

(12) The device 10 comprises an optical unit 121 with a receiving element, embodied for receiving an electromagnetic radiation, in particular light. In FIG. 2, this is a photodiode 14. Other receiving elements are also conceivable.

(13) In the embodiment shown in FIG. 2, the optical unit 121 does not comprise any emission element.

(14) In FIG. 2, the optical unit 121 is arranged in or on the sensor 1.

(15) The device 10 comprises a bar 51. In FIG. 2, the bar 51 is fastened within the machine shaft 3 embodied as a hollow shaft by means of a first fastening 50.

(16) The bar 51 is moreover fastened within the sensor shaft 31 embodied as a hollow shaft with a second fastening 52.

(17) It is also possible to fasten the bar 51 at another point, e.g. at an external periphery of the shaft 3 or 31.

(18) FIG. 2 shows a front axial end 511 and a rear axial end 512 of the bar 51.

(19) The bar is advantageously embodied so that it can shear off or break off if the machine shaft 3 runs asynchronously with respect to the sensor shaft 31.

(20) A first fracture surface, in particular a machine shaft-side fracture surface, of a first part of the bar arising as a result of shearing-off and/or breaking-off and a second fracture surface, in particular a sensor shaft-side fracture surface, of a second part of the bar arising as a result of shearing-off and/or breaking-off during operation of the machine shaft 3 and sensor shaft 31 advantageously rub against one another so that radiation, preferably light, can be emitted in particular by means of triboluminescence.

(21) The photodiode 14 detects this and can transmit this information to a control unit of the servomotor actuator (not shown), for instance.

(22) The bar 51 advantageously has plastic, e.g. PTFE.

(23) The bar 51 can be glued into the shaft 3 or 31 embodied as a hollow shaft, for instance, or glued onto the outer periphery of the shaft 3 or 31.

(24) Injection is also conceivable.

(25) The material of the bar 51 is advantageously transparent, in particular transparent plastic.

(26) A transparent material is advantageous, on account of the optical active principle, so that an optical signal can be transmitted optimally through the bar.

(27) If the connection between the sensor shaft 31 and machine shaft 3 established by means of the coupling 7 is lost, the bar 51 shears off or breaks off.

(28) To this end, the bar 51 can have a predetermined breaking point 200.

(29) The breaking of the bar 51 or the friction of the fracture surfaces can be evaluated by means of the photodiode 14 by measuring triboluminescent effects.

(30) A distance of a few centimeters, e.g. 1 cm to 50 cm, is advantageous between the optical unit 121, which is advantageously arranged on the sensor side, and the fastening 50.

(31) In the case of very large machines, it is also possible, however, for a distance to extend over several meters, e.g. 1 to 10 m.

(32) FIG. 3 shows a further possible embodiment of the device 10 for monitoring a shaft coupling coupling a first shaft to a second shaft.

(33) Instead of the triboluminescence described in FIG. 2, changed reflection properties of the broken bar 51 can also be evaluated.

(34) An additional illumination is useful here.

(35) This is achieved by an optical unit 122, which has an emission element in the form of a light-emitting diode 17. Other emission elements are also conceivable. It is moreover also conceivable for lighting conditions prevailing at the place of installation of the device 10 to be adequate as lighting.

(36) FIG. 3 shows the sensor shaft 31 coupled to the machine shaft 3. The shafts 3 and 31 are embodied as a hollow shaft in the figure. The bar 51 is located therein.

(37) There is lighting on the sensor side and advantageously a reflection on a mirror 16, which is arranged on the machine shaft side. The brightness is detected with the photodiode 14 which is arranged on the sensor side.

(38) The described arrangement of the components is preferred. However, it is also possible to arrange the optical unit 121 or 122 at the axial end of the machine shaft 3 and to replace the other components analogously.

(39) A distance of a few centimeters, e.g. 1 cm to 50 cm, is advantageous between the optical unit 122, which is advantageously arranged on the sensor side, and the mirror 16.

(40) In the case of very large machines, it is also possible, however, for a distance to extend over several meters, e.g. 1 to 10 m.

(41) The invention is advantageous in that a damaged coupling can be identified reliably and in a cost-effective manner.

(42) FIG. 4 shows a method.

(43) In an optional method step S1, the emission element emits electromagnetic radiation, in particular light.

(44) In a method step S2, the machine shaft runs asynchronously with respect to the sensor shaft, whereupon the bar breaks or shears off.

(45) In a method step S3, for the embodiment of the device described in FIG. 2, the following occurs: The fracture surfaces rub against one another so that radiation, preferably light, is emitted in particular by means of triboluminescence.

(46) In the method step S3, for the embodiment of the device described in FIG. 3, the following occurs: The reflection properties change as a result of the breaking or shearing-off of the bar and/or as a result of the fracture surfaces rubbing against one another. This is because, in this embodiment, the emitted radiation (see S1) is advantageously reflected by the mirror.

(47) In a method step S4, the emitted radiation or the changed reflection property is identified by the photodiode.