Sensor system for a rotating gear wheel

Abstract

A sensor system (10) configured for application to a rotating gear wheel (1) and comprising: at least one sensor device (20) configured for sensing the rotating gear wheel (1) and for providing at least one first signal (4); a cable interface unit (40) configured for receiving the at least one first signal (4) from the at least one sensor device (20); a first control unit (50a) configured for receiving the at least one first signal (4) from the cable interface unit (40), wherein the first control unit (50a) further comprises a trigger module (52) configured for managing a plurality of data sets in the at least one first signal (4) and for generating at least one second signal (5); a second control unit (50b) comprising a wireless transmission module (51) configured for wirelessly transmitting the at least one second signal (5) to an external operating unit (2); at least one battery unit (60) configured for supplying power to at least the first control unit (50a) and to the second control unit (50b).

Description

[0001] Title: Sensor system for a rotating gear wheel

[0002] DESCRIPTION

[0003] Technical field

[0004] The present invention relates to a sensor system for a rotating gear wheel, in particular comprising a wireless transmission module of a measurement signal to an external operating unit.

[0005] In particular, the present invention is applied in the field of the direct deformation or indirect force measurements, suitably adapted to systems and gears for specific aims.

[0006] Prior art

[0007] There are systems for measuring the deformation of gear teeth roots, which typically use strain gauge sensors.

[0008] The monitoring of strain gauge signals coming from the tooth of the gear wheel is fundamental for the application of monitoring and inspecting strategies for gears during the service life thereof.

[0009] Deformation signals measured in steady state conditions, acceleration state, deceleration state and in case of vibrations, are used as essential reference parameters for the early identification, accurate diagnosis and the monitoring of the correct gears functioning.

[0010] These systems for measuring the deformation of gear tooth feet or roots require the measurement during the rotational movement (spinning) of the gears.

[0011] There is the document “Experimental study of dynamic strain for gear tooth using fiber Bragg gratings and piezoelectric strain sensors” https: / / doi.org / 10.1177 / 0954406217744000.

[0012] There is also the document “Some Experimental and Simulation Results on the Dynamic Behaviour of Spur and Helical Geared Transmissions with Journal Bearings” https: / / doi.org / 10. 1155 / 2012 / 163575.

[0013] In the two above-mentioned measuring systems, the signal collection is made by sliding contacts (rotary joints) .

[0014] There is the document “Internal Gear Strains and Load Sharing in Planetary Transmissions: Model and Experiments” https: / / doi.org / 10. 1115 / 1.2890110, which uses a strain gauge on a stationary gear wheel, hence there are no rotation problems.

[0015] Document US2004251895A1 relates to an inductive system for determining the inclination of a shaft equipped with a gear wheel comprising a plurality of gear teeth; the inductive measuring device comprises a transmitting coil and at least two receiving coils.

[0016] Document WO2013104900A1 relates to a method for monitoring the local defects in a gear which uses one or more eddy current sensors arranged to interact with the motor component as it is rotating during service. A device is arranged to measure an output signal from the eddy current sensors and the output signal is processed to detect a change which is indicative of a local defect.

[0017] Document WO2012126485A1 relates to a gear equipped with a vibration sensor, consisting of an accelerometer coupled to a data transmitter.

[0018] Summary of the invention

[0019] The object of the present invention is to remedy some drawbacks and to overcome some limitations of the prior art.

[0020] A further particular object of the present invention is to provide a compact solution for the acquisition of data concerning the deformation of gear teeth.

[0021] A further particular object of the present invention is to provide a solution which allows a rapid and high-resolution evaluation of the deformation using an integrated sensor.

[0022] A further particular object of the present invention is to provide a solution which allows an effective monitoring of the conditions of a gear, allowing an accurate diagnosis and the monitoring of degradation.

[0023] A further particular object of the present invention is to provide a solution which allows an effective wireless signal transfer.

[0024] A further particular object of the present invention is to provide a solution which is more effectively integrated in a single system.

[0025] These and other purposes are achieved by a sensor system for a rotating gear wheel according to the features of the attached claims, which form an integral part of the present description.

[0026] An idea underlying the present invention is to provide a sensor system configured for application to a rotating gear wheel.

[0027] The sensor system comprises at least one sensor device configured for sensing the rotating gear wheel and for providing at least a first signal.

[0028] The sensor system comprises a cable interface unit configured for receiving the at least one first signal from the at least one sensor device.

[0029] The sensor system comprises a first control unit configured for receiving the at least one first signal from the cable interface unit, wherein the first control unit further comprises a trigger module configured for managing a plurality of data sets in the at least one first signal and for generating at least one second signal.

[0030] The sensor system comprises a second control unit comprising a wireless transmission module configured for wirelessly transmitting the at least a second signal to an external operating unit.

[0031] The sensor system comprises at least one battery unit configured for supplying power to at least the first control unit and to the second control unit.

[0032] Preferably, the second control unit further comprises a subunit configured for receiving a trigger signal generated by the trigger module.

[0033] Preferably, the first control unit further comprises a feedback module which advantageously allows to receive a transmission confirmation of the at least a second signal by the wireless transmission module.

[0034] Advantageously, the first control unit and the second control unit are integrated on respective Printed Circuit Boards (PCBs).

[0035] Preferably, the sensor system comprises a container housing that includes at least the cable interface unit, the first control unit, the second control unit and the at least one battery unit. Advantageously, the sensor device remains outside the container housing, for an easier positioning onto the rotating gear wheel.

[0036] Advantageously, the whole sensor system, for example consisting of the sensor device and the container housing, is configured for complete mounting onto a body jointly rotating with the rotating gear wheel. It is thus possible to form a light, compact and effective sensor system.

[0037] Advantageously, the sensor system is applicable to gears, i.e. gear toothed wheels, both with straight teeth and with helical teeth, or to bevel gears, or in general to gears of any type.

[0038] Preferably, the sensor device comprises at least one deformation or strain sensor, in particular at least one strain gauge. In combination or as an alternative, the sensor device preferably comprises at least one vibration sensor, preferably a piezoelectric sensor. In general, for an advantageous compactness the sensor device can comprise a MEMS device integrating one or more sensor elements.

[0039] Further features and advantages will be more apparent from the following detailed description of preferred non-limiting embodiments of the present invention, and from the dependent claims which outline preferred and particularly advantageous embodiments of the invention.

[0040] Brief description of the drawings

[0041] The invention is illustrated with reference to the following figures, given by way of non-limiting examples, in which:

[0042] Figure 1 illustrates the application of a sensor system according to the present invention applied to a rotating gear wheel.

[0043] Figure 2 illustrates a particular embodiment of a cable interface unit, a first control unit, a second control unit and at least one battery unit in a sensor system according to the present invention.

[0044] Figure 3 schematizes the embodiment of Figure 2.

[0045] Figure 4 illustrates the operation of a sensor system according to the present invention.

[0046] In the different figures, similar elements will be identified by similar reference numbers.

[0047] Detailed description

[0048] Figure 1 illustrates in a merely schematic and illustrative manner a sensor system 10 according to the present invention applied to a rotating gear wheel 1 of a gear arrangement.

[0049] The sensor system 10 forms an assembly of miniaturized devices for measuring local quantities (deformation, vibrations) in gears 1 which are rotating components, which are usually found in environments characterized by the presence of lubricants or dirt. The sensor system 10 does not require the presence of sliding electrical contacts thus enabling a better signal acquisition.

[0050] As it will be further described, the sensor system 10 is configured for complete mounting onto a body jointly rotating with the rotating gear wheel 1. For example, this body to which the sensor system 10 is applied can be the body itself of the rotating gear wheel 1 , as exemplified in Figure 1. On the other hand, in another example, said body to which the sensor system 10 is applied may be the shaft on which the rotating gear wheel 1 is mounted. The position of the sensor system 10 in Figure 1 is merely illustrative and not limiting.

[0051] The sensor system 10 comprises at least one sensor device 20, which is configured for sensing the rotating gear wheel 1. The position of the sensor device 20 in Figure 1 is merely illustrative and not limiting.

[0052] As it will be further described, the at least one sensor device 20 is configured for providing at least one first signal corresponding to the detection on the rotating gear wheel.

[0053] The at least one sensor device 20 is schematically represented as a single component, but it can comprise multiple components even of a different type, to perform a plurality of sensing operations. Thus, in embodiments, the sensor device 20 could be distributed at multiple points on the rotating gear wheel 1.

[0054] The sensor device 20 preferably comprises at least one deformation sensor, such as at least one strain gauge, i.e. one or more strain gauge bridges. Preferably, the deformation sensor 20 is configured for measuring the deformation due to the bending of a tooth of the rotating gear wheel 1.

[0055] In particular, the deformation sensor 20 may comprise one or more local deformation sensors, for example strain gauges positioned on the gear tooth side, and / or strain gauges positioned on a gear tooth root.

[0056] The sensor device 20 may comprise, in addition or as an alternative, at least one vibration sensor, preferably a piezoelectric sensor or an accelerometric sensor. Preferably, the sensor device 20 comprises a MEMS device, which may integrate one or more sensing functionalities, such as temperature and / or acceleration.

[0057] The sensor device 20 may comprise, in addition or as an alternative, a housing for receiving the acquisition from an encoder element, being thus adapted to sense a rotational position of the rotating gear wheel 1. This solution is particularly advantageous since it allows to achieve measurements of quantities of the rotating gear wheel 1 synchronously with a rotational position of the gear wheel 1 itself.

[0058] Preferably, the sensor system 10 comprises a container housing 30, which includes further functional elements of the sensor system 10 which will be further described. In particular, preferably, inside the container housing 30 there is a transmitter device capable of wirelessly transmitting a signal corresponding to the sensing performed by the sensor device 20 to an external operating unit 2. The position of the container housing 30 in Figure 1 is merely illustrative and non-limiting.

[0059] Figure 2 illustrates a particular embodiment of elements of the sensor system 10 according to the present invention, while Figure 3 schematizes the embodiment of Figure 2.

[0060] Preferably, the elements of the sensor system 10 described below are included in the already-described container housing 30.

[0061] The sensor system 10 comprises a cable interface unit 40 configured for receiving at least one first signal 4 coming from the at least one already- described sensor device 20. The connection between the at least one sensor device 20 and the cable interface 40 comprises one or more cables appropriate for the type of transmitted signal.

[0062] Preferably, the cable interface unit 40 further comprises an amplifier 41 configured for signal amplification of the at least one first signal 4.

[0063] The sensor system 10 comprises a first control unit 50a, configured for receiving the at least one first signal 4 from the cable interface unit 40. The first control unit 50a comprises a trigger module 52 configured for managing a plurality of data sets in the at least one first signal 4 and for generating at least one second signal 5.

[0064] The sensor system 10 comprises a second control unit 50b comprising a wireless transmission module 51 configured for wirelessly transmitting the at least one second signal 5 to the external operating unit 2, for further signal processing and analysis.

[0065] The second control unit 50b further comprises a subunit configured for receiving a trigger signal generated by the trigger module 52.

[0066] The first control unit 50a further comprises a feedback module 53 configured for receiving a transmission confirmation of the at least one second signal 4 from the wireless transmission module 51.

[0067] The control unit 50b further comprises an Analog to Digital converter module 54 configured for converting the at least one first signal 4 into the at least one second signal 5.

[0068] Preferably, the first control unit 50a and the second control unit 50b are integrated on respective Printed Circuit Boards (PCBs), in particular respectively integrating:

[0069] - For the first control unit 50a, integrating the trigger module 52 and the feedback module 53.

[0070] - For the second control unit 50b, integrating the wireless transmission module 51 and the Analog to Digital converter module 54.

[0071] Preferably, the second control unit 50b further comprises a Real Time Clock module (not shown in the Figures).

[0072] In general, the control units 50a and 50b form a wireless-triggered hardware. Preferably, the first control unit 50a also enables a bidirectional real-time wireless transmission. The sensor system 10 comprises at least one battery unit 60 configured for supplying power to at least the control units 50a and 50b. Preferably, the at least one battery unit 60 is further configured for supplying power to the cable interface unit 40, in particular for powering the amplifier 41.

[0073] Preferably, the sensor system 10 further comprises a data storage module 70, for example including a TF card module.

[0074] The sensor system 10 is therefore capable to perform the online transmission of wireless signals with multiple signal channels and it has a compact layout inside the container housing 30.

[0075] Moreover, the performances of the second control unit 50b are high, for example with a 64k-SPS sampling rate with a 24-bit resolution.

[0076] The integration of one or more elements of the control unit 50a or of the second control unit 50b on a respective PCB board (possibly a single PCB board) allows to realize a highly compact solution which meets the specific application requirements, minimizing the overall dimensions and volume of the sensor system 10.

[0077] Figure 4 illustrates the operation of the sensor system 10, which, as already described, includes a first control unit 50a and a second control unit 50b, which are at least functionally separated according to the specific functions, and preferably physically separated.

[0078] The first control unit 50a acts as an experimental data collection subsystem, while the second control unit 50b is dedicated to wireless data transmission and time synchronisation.

[0079] The trigger module 52 on the first control unit 50a serves as a central control unit, supervising wireless data transmission and coordinating multiple subunits.

[0080] This configuration allows the simultaneous collection of dynamic samples from sensors 20 on different gears positioned at different positions. As a result, the collected data are bundled and transmitted to the host device 2 by the trigger module 52 on the first control unit 50a, facilitating the complete wireless data collection from various locations.

[0081] The advantage of this configuration is that the user can send commands to the trigger module 52 via the same host device 2; the trigger module 52 manages the distribution of the commands to different subunits, improving the independence of each system and enabling the wireless mesh data transmission.

[0082] This block diagram of Figure 1 illustrates the process of this measuring system. The host device is labelled with 2, which wirelessly sends instructions to the sensor system 10. After receiving the command from the host device 2, the first control unit 50a transmits the measurement requirements to the second control unit 50b using wired means. Once data have been measured by the sensors 20 and sent to the second control unit 50b, the measurement data are aggregated again and provided to the first control unit 50a. The data set is then wirelessly sent to the host device 2.

[0083] The host device 2 or external operating unit 2 can be a PC or a mobile device.

[0084] Industrial applicability

[0085] The sensor system according to the present invention enables the real time monitoring of gears.

[0086] The sensor system according to the present invention also allows it to operate even in aggressive environments, for example due to the presence of oils typically used in gear transmissions.

[0087] The sensor system according to the present invention enables the study of the rotational dynamics behaviour of moving / rotating gears.

[0088] The sensor system according to the present invention enables low-cost and high-precision sensing operations.

[0089] The sensor system according to the present invention is compact, with a very small size.

[0090] The sensor system according to the present invention has no need for sliding contacts for signal transmission.

[0091] The sensor system according to the present invention allows to work in dirty / oily environments.

[0092] In summary, the sensor system according to the present invention provides a low-cost micro-device which can be applied to the gear wheel for providing a direct online measurement of the deformation of a portion of the gear wheel. The solution of the present invention ensures a high measurement resolution and sampling frequency. The design of the point-to-point layout of the sensor system ensures that requirements are perfectly met, no waste function and that the system achieves a compact size and low costs.

[0093] Clearly, if there are no technical incompatibilities which are apparent to the person skilled in the art, the configurations of specific elements described with reference to certain embodiments might be used in other here-described embodiments.

[0094] Considering the here-quoted description, the person skilled in the art will be allowed to devise further modifications and alternatives, in order to meet contingent and specific requirements.

[0095] For example, the conformation and size of the container housing 30 are in particular merely exemplary, and different shapes and sizes can be adopted.

[0096] The here-described embodiments are therefore to be considered as illustrative and non-limiting examples of the invention.

Claims

CLAIMS1. Sensor system (10) configured for application to a rotating gear wheel (1) and comprising: at least one sensor device (20) configured for a detection on said rotating gear wheel (1) and for providing at least a first signal (4); a cable interface unit (40) configured for receiving said at least one first signal (4) from said at least a sensor device (20); a first control unit (50a) configured for receiving said at least one first signal (4) from said cable interface unit (40), wherein said first control unit (50a) further comprises a trigger module (52) configured for managing a plurality of data sets in said at least a first signal (4) and for generating at least a second signal (5); a second control unit (50b) comprising a wireless transmission module (51) configured for wirelessly transmitting said at least a second signal (5) to an external operating unit (2); at least one battery unit (60) configured for supplying power at least to said first control unit (50a) and to said second control unit (50b).

2. The sensor system according to claim 1, wherein said second control unit (50b) further comprises a subunit configured for receiving a trigger signal generated by said trigger module (52).

3. The sensor system according to claim 1 or 2, wherein said first control unit (50a) further comprises a feedback module (53) configured for receiving a transmission acknowledgement of said at least a second signal (5) from said second control unit (50b).

4. The sensor system according to any one of claims 1 to 3, wherein said first control unit (50a) and said second control unit (50b) are integrated on Printed Circuit Boards (PCB), respectively.

5. The sensor system according to any one of claims 1 to 4, further comprising a container housing (30) including at least said cable interface unit (40), said first control unit (50a), said second control unit (50b) and said at least one battery unit (60) .

6. The sensor system according to any one of claims 1 to 5, wherein said second control unit (50b) further comprises an Analog to Digital converter module (54).

7. The sensor system according to any one of claims 1 to 6, wherein said second control unit (50b) further comprises a Real Time Clock module.

8. The sensor system according to any one of claims 1 to 7, wherein said cable interface unit (40) further comprises an amplifier (41) configured for signal amplification of said at least one first signal (4), said at least one battery unit (60) being further configured for supplying power to said cable interface unit (40).

9. The sensor system according to any one of claims 1 to 8, wherein said sensor device (20) comprises at least one deformation sensor, preferably at least one strain gauge.

10. The sensor system according to claim 9, wherein said deformation sensor is configured for measuring a bending deformation of a tooth of said rotating gear wheel (1).

11. The sensor system according to any one of claims 1 to 10, wherein said sensor device (20) further comprises at least one vibration sensor, preferably a piezoelectric sensor.

12. The sensor system according to any one of claims 1 to 11, wherein said sensor device (20) comprises a MEMS device.

13. The sensor system according to any one of claims 1 to 12, wherein said sensor device (20) comprises an encoder element.

14. The sensor system according to any one of claims 1 to 13, further comprising a data storage module (70), preferably a TF card module.

15. The sensor system according to any one of claims 1 to 14, wherein said sensor system (10) is configured for complete mounting onto a body jointly rotating with said rotating gear wheel (1).

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