Sensored rollers for bearings with integrated energy harvesting

Abstract

A sensored roller (18) for a bearing (10) comprises: a roller bore (18b) extending through the roller (18) about an axis (X1-X1); a measuring unit for measuring at least one physical state of the roller bore (18b); a processor for receiving a signal from the measuring unit (28) and configured to transmit the signal to an external receiver; and an energy harvesting device configured to generate electricity and power the measuring unit, wherein the measuring unit, the processor and the energy harvesting device are mounted in an insert (20) mounted in the roller bore (18b).

Description

Technical Field

[0001] The present invention relates to the field of condition monitoring devices and in particular to condition monitoring sensors for monitoring the condition of a system, such as a sensorized roller for example. Background Art

[0002] Condition monitoring devices allow the condition of a system to be monitored without the need for manual inspection.These devices may be particularly advantageous in remote locations or locations that are difficult to access and / or dangerous to approach, such as shafts and / or bearings of railway systems.

[0003] Typically, electrical sensors are used to collect vibration or other measurements, which can then be analyzed to determine the condition of the machine and detect any machine defects.

[0004] In many cases, it may be convenient to power a condition monitoring device from an integrated generation source. In practice, it may be necessary to provide electrical energy to a device located in a remote location, for example where no power supply infrastructure exists or where, if infrastructure exists, power is unavailable at the particular location where the device is installed.

[0005] It is known to power condition monitoring devices using a battery pack or a limited capacity power source such as an energy harvester.

[0006] However, the use of batteries significantly limits the number of measurements that can be performed on the bearing.

[0007] Document US10491076-B2 (SKF) discloses a bearing device comprising a rotating portion, a non-rotating portion, and an energy generation system. The bearing device includes microgenerator modules, each having an eccentric mass at an eccentric shaft along a radial rotational axis. Each eccentric shaft is connected to a generator having a radial axis. When the eccentric mass rotates by rotating the rotating portion of the bearing, energy is generated. The stator of the generator does not rotate along the radial axis of the microgenerator.

[0008] It is also known to provide an energy harvesting system inside the cage of a bearing, as explained in documents WO2015032449-A1 (SKF), WO2015032445-A1 (SKF).However, not all bearings comprise a cage. Summary of the Invention

[0009] It is an object of the present invention to provide an integrated generation source for powering a condition monitoring device mounted on any type of roller bearing.

[0010] A specific object of the present invention is to provide a sensorized roller for a bearing, the sensorized roller comprising: a roller hole extending through the roller; a measuring unit for measuring at least one physical state of the roller hole; a processor for receiving a signal from the measuring unit and configured to transmit the signal to an external receiver; and an energy harvesting device configured to generate power and power the measuring unit.

[0011] The measuring unit, processor and energy harvesting device are mounted in an insert that fits inside the roller.

[0012] Therefore, energy harvesting can be set up for sensored rollers without using a cage.

[0013] For example, the measuring unit, processor and energy harvesting device are mounted in an insert that fits within the roller bore.

[0014] Advantageously, the energy harvesting device comprises a generator having an axis along the axis of the bore of the sensing roller and configured to generate energy using rotation of the sensing roller.

[0015] The generator may include an eccentric mass rigidly fixed to a main shaft of the generator, the main shaft extending along the axis of the roller bore; a rotor fixed to the shaft; and stator coils mounted in a stator rigidly fixed inside an insert and configured to rotate by sensing rotation of the rollers.

[0016] In other words, the eccentric mass or weight is driven by gravity and centrifugal force to maintain the main shaft of the generator during the rotation of the sensing roller. The rotation of the sensing roller drives the rotation of the stator, which in turn drives the stator coils of the generator.

[0017] According to one embodiment, the rotor is fixed directly to the main shaft. In other words, the generator is a direct drive generator.

[0018] According to another embodiment, the rotor is fixed to the main shaft by means of at least two gear wheels.

[0019] Advantageously, the energy harvesting arrangement comprises energy harvesting electronics connected to the stator coils.

[0020] The energy harvesting arrangement may comprise at least one battery or capacitor configured to provide power to the measuring unit and charged by the energy harvesting electronics.

[0021] According to one embodiment, the insert does not extend axially beyond the lateral walls of the roller.

[0022] The insert may be made of a plastic material or an elastomeric material.

[0023] For example, the insert may be suspended, tightly fitted, screwed or otherwise secured within the roller bore using any suitable securing means.

[0024] According to a second aspect, the present invention relates to a bearing having an axis of rotation and comprising an inner ring, an outer ring, and an array of rollers radially mounted between a raceway provided on the inner ring and a raceway provided on the outer ring. At least one of the rollers is a sensorized roller as described above. The roller bore of the roller extends through the roller about an axis.

[0025] The axis may be parallel to the axis of rotation of the bearing or inclined at an angle comprised between 10° and 45° to the axis of rotation of the bearing, for example when tapered rollers are used. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention and its advantages will be better understood by studying the detailed description of specific embodiments given by way of non-limiting examples and illustrated by the accompanying drawings, in which:

[0027] Figure 1 is a schematic diagram of a roller bearing with sensorized rollers according to an embodiment of the present invention;

[0028] Figure 2 Is set in Figure 1 A detailed view of the insert inside the bore of the sensorized roller; and

[0029] Figure 3 and Figure 4 is installed in accordance with two embodiments Figure 2 Detailed view of the generator in the insert. DETAILED DESCRIPTION

[0030] The expressions “external” and “inner” refer to the axis of rotation XX of the bearing, the inner part being closer to said axis of rotation than the outer part.

[0031] Reference Figure 1 , Figure 1 An embodiment of a roller bearing 10 is shown, for example, designed to support the main shaft of a wind turbine (not shown). Roller bearing 10 includes an outer ring 12, an inner ring 14, and an array of rolling elements 16 (such as rollers) disposed between inner ring 12 and outer ring 14. As shown, roller bearing 10 does not include a cage for maintaining circumferential spacing of the rolling elements. Alternatively, the roller bearing may include such a cage.

[0032] The outer ring 12 and the inner ring 14 of the bearing 10 are in the form of concentric rings rotatable about the axis of rotation XX of the bearing 10 , the outer ring 12 radially surrounding the inner ring 14 .

[0033] As shown, the outer ring 12 is radially delimited by a cylindrical outer surface 12a and a cylindrical inner surface 12b having a raceway for the rollers 16. The outer ring 12 also includes two opposite radial frontal surfaces (not numbered) axially delimiting the cylindrical inner surface 12b and the cylindrical outer surface 12a.

[0034] As shown, the inner ring 14 is radially bounded by a cylindrical outer surface 14a having a raceway for rollers 16 and a cylindrical inner surface 14b in radial contact with a shaft (not shown). The inner ring 14 also includes two opposing radial front surfaces (not labeled) that axially bound the cylindrical inner surface 14b and the cylindrical outer surface 14a of the inner ring 14.

[0035] As shown, the array of rollers 16 includes one sensorized roller 18. Alternatively, the array of rollers may include a different number of sensorized rollers, for example, two or more sensorized rollers.

[0036] The sensing roller 18 is delimited radially by a cylindrical outer surface 18a and a hole 18b, and axially by two opposing side surfaces ( / lateral surfaces) 18c. The hole 18b of the roller 18 is delimited axially by the two opposing side surfaces 18c.

[0037] The sensing roller 18 rotates along a first rotation axis X1-X1, which is parallel to the rotation axis XX of the roller bearing 10. The rotation axis X1-X1 can also be at an angle to the rotation axis XX of the bearing, for example, when the rollers are tapered rollers. In this case, the contact angle of the tapered roller bearing is non-zero.

[0038] As a non-limiting example, in the embodiment shown the rollers are cylindrical rollers, but may be any other type of rollers, such as tapered rollers.

[0039] Advantageously, the hole 18 b of the sensing roller 18 is a through-hole. Alternatively, the axial length of the hole 18 b may be smaller than the axial length of the roller 18 .

[0040] The bearing 10 further comprises a cylindrical insert 20 which fits in the hollow bore 18 b of the roller 18 .

[0041] Reference Figure 2 The cylindrical insert 20 is explained in detail.

[0042] As shown, the cylindrical insert 20 includes a shell 20a, inside which are mounted an energy harvesting device 21, a measuring unit 28, and a processor 30, wherein the measuring unit 28 is used to measure at least one physical state of the roller hole 18b, and the processor 30 is used to receive a signal from the measuring unit 28 and is configured to transmit the signal to an external receiver (not shown) via, for example, a wireless transmission device.

[0043] As shown, the housing 20a of the insert 20 does not extend axially beyond the sidewall 18c of the sensing roller 18. The housing 20a of the insert matches the shape of the roller bore 18b.

[0044] For example, the insert 20 is made of an elastic material.

[0045] The outer diameter of the insert 20 is substantially equal to the inner diameter of the bore 18b of the sensing roller 18, so that the insert is press-fit inside said bore.

[0046] Alternatively, the insert 20 may be screwed or fixed within the roller bore 18b using any suitable fixing means as long as the insert 20 maintains an elastic interface with the roller bore.

[0047] For example, the insert 20 may be made of plastic or another rigid material so that the aperture 18b is coaxially separated from the insert 20 by at least 50 microns.

[0048] The preferred embodiment uses a plastic insert 20 that is suspended inside the hole 18b using an O-ring (not shown) which also serves the purpose of hermitically sealing the electronics from the outside of the roller 18 where the lubricant resides.

[0049] Such an embodiment is described in document US 10371206-A1 (SKF).

[0050] The measuring unit 28 comprises one or more condition monitoring devices, such as sensors for measuring, for example, the deformation of the roller bore 18b.

[0051] The energy harvesting device 21 is configured to generate electricity and power the measuring unit 28 .

[0052] The energy harvesting device 21 comprises a generator 22 having an axis along the axis X1 - X1 of the sensing roller 18 and configured to generate energy using the rotation of said sensing roller 18 .

[0053] The energy harvesting device 21 further comprises energy harvesting electronics 24 connected to the generator 22 and a battery 26 configured to provide power to the measuring unit 28 and to be charged by the energy harvesting electronics 24 .

[0054] like Figure 3 and Figure 4 As shown in detail in FIG, the generator 22 includes: a stator 22a rigidly fixed to the housing 20a of the insert 20; an eccentric mass or weight 22b rigidly fixed to a main shaft 22c having an axis along a first axis X1-X1; a rotor 22d fixed to the shaft 22c; and a stator coil 22e mounted in the stator 22a and configured to rotate by the rotation of the sensing roller 18.

[0055] In other words, the eccentric mass 22b is driven by gravity G and centrifugal force to maintain the main shaft 22c of the generator 22 while the sensing roller 18 rotates along the first axis of rotation X1-X1. The rotation of the sensing roller drives the stator 22a to rotate, thereby driving the stator coils 22e of the generator 22. The stator coils 22e are connected to the energy collection electronics 24.

[0056] exist Figure 3 In the example shown, the generator 22 is a direct drive generator ( / DG).

[0057] exist Figure 4 In the example shown, the generator 22 comprises two gears 22f, 22g located between a main shaft 22c supporting an eccentric mass 22b and an auxiliary shaft 22h supporting a rotor 22d. The auxiliary shaft 22h extends along a second axis X2-X2 parallel to the first axis X1-X1.

[0058] In any case, the stator 22a of the generator 22 and therefore the stator coils 22e rotate along a first axis X1-X1 coaxial with the axis of the sensing roller and parallel to the axis of rotation XX of the roller bearing 10 .

[0059] Thanks to the invention, the measuring unit positioned inside the roller can be powered by the energy harvesting device, regardless of whether the bearing comprises a cage or not.

Claims

1. A sensorized roller (18) for a bearing (10), comprising: a roller hole (18b) extending through the roller (18); a measuring unit (28) for measuring at least one physical condition of the roller hole (18b); a processor (30) for receiving a signal from the measurement unit (28) and configured to transmit the signal to an external receiver; an energy harvesting device (21) configured to generate electricity and power the measuring unit, wherein the measuring unit (28), the processor (30) and the energy harvesting device (21) are mounted in an insert (20) mounted in the roller (18), The energy harvesting device (21) comprises a generator (22), the generator (22) comprising: an eccentric mass (22b) rigidly fixed to a main shaft (22c) of the generator, the main shaft (22c) extending along the axis (X1-X1) of the roller hole (18b) of the sensing roller; a rotor (22d) fixed to the main shaft (22c); and a stator coil (22e) mounted in a stator (22a) rigidly fixed inside the insert (20) and configured to rotate by the rotation of the sensing roller (18).

2. The sensor roller (18) according to claim 1, characterized in that The generator (22) has an axis along the axis (X1-X1) of the roller hole (18b) of the sensing roller and is configured to generate energy using the rotation of the sensing roller.

3. The sensing roller (18) according to claim 2, characterized in that The rotor (22d) is directly fixed to the main shaft (22c).

4. The sensing roller (18) according to claim 2, characterized in that The rotor (22d) is fixed to the main shaft (22c) via at least two gears (22f, 22g).

5. The sensorized roller (18) according to any one of claims 1 to 4, characterized in that The energy harvesting device (21) comprises energy harvesting electronics (24) connected to the stator coils (22e).

6. The sensing roller (18) according to claim 5, characterized in that The energy harvesting device (21) comprises at least one battery (26) and / or capacitor configured to provide power to the measuring unit (28) and to be charged by the energy harvesting electronics (24).

7. The sensorized roller (18) according to any one of claims 1 to 4, characterized in that The insert (20) does not extend axially beyond the side wall of the roller (18).

8. The sensorized roller (18) according to any one of claims 1 to 4, characterized in that The insert (20) is made of plastic material.

9. A bearing (10) having an axis of rotation (XX) and comprising: Inner ring (14), outer ring (12), and A row of rollers (16) mounted radially between a raceway provided on the inner ring (14) and a raceway provided on the outer ring (12), wherein at least one of the rollers is a sensorized roller (18) according to any of the preceding claims, the roller bore (18b) of the roller extending through the roller (18) around the axis (X1-X1).

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