Device for monitoring a set of bearings

Abstract

A device monitors the operating temperature of at least one set of bearings in a plurality of sets of bearings. The at least one set of bearings is arranged between a shaft and a carrier. The carrier has at least one temperature sensor that senses the temperature of the at least one set of bearings and generates a signal representative of an operating temperature of the at least one set of bearings. The at least one temperature sensor is operatively electrically connected to at least one controller. The controller processes the signal from the temperature sensor, including determining the operating temperature of the respective at least one set of bearings and whether the operating temperature of the respective at least one set of bearings exceeds at least one threshold temperature. The controller memory holds a unique identifier associated with the at least one bearing set.

Claims

1. A device for monitoring the operating temperature of at least one set of bearings in a plurality of sets of bearings, wherein the at least one set of bearings is arranged between a shaft and a carrier, the carrier having at least one temperature sensor adapted and configured to sense the temperature of the at least one set of bearings and generate a signal representative of an operating temperature of the at least one set of bearings, the at least one temperature sensor being operatively electrically connected to at least one controller, the controller being adapted and configured to process the signal from the temperature sensor, including determining the operating temperature of the respective at least one set of bearings and whether the operating temperature of the respective at least one set of bearings exceeds at least one threshold temperature, the controller storing in a memory of the controller a unique identifier associated with the at least one bearing set, the at least one temperature sensor facing radially towards an outer surface of the at least one set of bearings and being arranged on a bottom of a cylindrical portion of a housing of the device for determining the operating temperature of the respective at least one set of bearings, and wherein a code number indicates on which axle or shaft a respective set of bearings in the plurality of sets of bearing is located.

2. The device according to claim 1, wherein the at least one temperature sensor is arranged in a recess of the carrier.

3. The device according to claim 1, wherein the at least one temperature sensor has at least one cavity facing towards the respective set of bearings, with the cavity being filled with a thermally conductive and/or adhesive compound.

4. The device according to claim 1, wherein the at least one temperature sensor is operatively electrically connected to said controller by means of at least one transmitting element.

5. The device according to claim 1, wherein the device has at least one electrical parameter that varies depending on the sensed operating temperature of the respective at least one set of bearings, the at least one varying electrical parameter being adapted and configured to provide a varying input voltage into the at least one controller.

6. The device according to claim 1, wherein the at least one temperature sensor is positioned adjacent to the set of bearings.

7. The device according to claim 1, wherein a time interval between individual measurements performed by the at least one temperature sensor is varied based upon on the sensed operating temperature of the set of bearings.

8. The device according to claim 1, further comprising at least one of a printed circuit board (PCB), a rectifier, a transceiver circuit, an antenna, a radio-frequency module (RF-module).

9. The device according to claim 1, further comprising at least one of an energy harvesting system, an energy storing device, an energy storing device charger.

10. The device according to claim 1, wherein the device is powered by an electrical harvesting system.

11. The device according to claim 10, wherein the electrical harvesting system comprises a magnet adapted and configured to move in a center of a coil in a direction of corresponding to gravity and in a direction opposite to the direction of gravity, wherein the magnet is supported by a spring.

12. The device according to claim 1, wherein each set of bearings in the plurality of the sets of bearings is assigned a unique identifier.

Description

DESCRIPTION OF THE DRAWINGS

(1) Aspects of the invention as well as further advantages of the invention are shown in the following drawings:

(2) FIG. 1 shows the device for monitoring the set of bearings mounted on a hub of a wheel (carrier).

(3) FIG. 2 shows the device for monitoring the set of bearings with its temperature sensor bordering the set of bearings.

(4) FIG. 3 shows a front side of a hub of a wheel (carrier) arranged on the shaft or axle over a set of bearings.

(5) FIG. 4 features the functional diagram of the energy harvesting system.

(6) FIG. 5 shows the receive—transmit functional diagram of the device for monitoring the set of bearings.

(7) FIG. 6 shows a flow chart representing the communicative connection between the temperature sensor and the controller of the device for monitoring a set of bearings.

DETAILED DESCRIPTION

(8) The FIGS. 1 to 3 show a device for monitoring a set of bearings 1 which is mounted onto a hub of a wheel 2 (carrier).

(9) The device for monitoring the set of bearings comprises a temperature sensor 3 which is positioned neighboring and/or adjacent to set of bearings 5. The set of bearings 5 comprises a casing 4.

(10) In the FIGS. 1 to 3, the set of bearings 5 is designed as a ball bearing, comprising two rolls of balls 6.

(11) The balls 6 of the set of bearings 5 are arranged adjacent to each other within races 7 of the set of bearings 5.

(12) A lubricating grease 8 is arranged inside of the set of bearings 5.

(13) Said lubrication grease 8 avoids at least two separate mechanical components rubbing against each other. Lubricating grease 8 avoids friction between the balls 6 of the set of bearings 5 and the races 7. Said friction between the metal components of the set of bearings 5 leads to an augmentation of the operating temperature in the set of bearings.

(14) A shaft or axle 9 is rotatably mounted within the hub 2 of a wheel over a set of bearings 5.

(15) The device for monitoring the set of bearings 1 comprises a housing 10 which is manufactured of a thermally conductive material.

(16) The housing 10 houses the at least one component of the device for monitoring the set of bearings 1.

(17) Among other things, the component of the device for monitoring the set of bearings 1 can be a printed circled board (PCB) 11.

(18) Within the housing 10 of the device for monitoring the set of bearings 1 there is an energy harvesting system 12. The components can also be an energy storing device 32 and/or a rectifier 34. A further component can be an energy storing device charger 32 (all not shown).

(19) The housing 10 of the device for monitoring the set of bearings 1 also houses a transceiver circuit 35 and/or an antenna 36 or a radio frequency module (RF-Module). Said components of the device for monitoring the set of bearings 1 are not depicted in the FIGS. 1 to 3.

(20) The housing 10 of the device for monitoring the set of bearings 1 comprises a cylindrical portion 13.

(21) The device for monitoring the set of bearings 1 is arranged on the outer circumference 29 of the hub 2 of the wheel (carrier). Whereas the cylindrical portion 13 protrudes into the hub of the wheel 2.

(22) The cylindrical portion 13 has a thin wall. On the bottom 14 of the cylindrical portion 13, facing towards the set of bearings 5 there is a temperature sensor 3 arranged bordering and/or neighboring and/or adjacent to the set of bearings 5.

(23) The set of bearings 5 comprise outer and inner races 7 between which the balls of the set of bearings 5 are arranged.

(24) The temperature sensor 3 has electrical parameters that vary with the operating temperature measured by said set of bearings 5.

(25) Also, the electrical parameters, varying with the sensed operating temperature of the set of bearings 5 lead to a varying output voltage of a controller 15 of the device for monitoring a set of bearings 1.

(26) One parameter, which is critical for all sets of bearings 5 is the maximum operating temperature of the set of bearings 5. Typically, when the operating temperature of the set of bearings 5 has reached and/or exceeded 120° C., the lubricant inside the set of bearings 5 deteriorates. Or, fluid lubricant leaks out through damaged seals 31.

(27) The varying output voltage can be measured along a fully predetermined temperature showing values, typically ranging from −40° C.-120° C.

(28) The cylindrical portion 13 of the device for measuring the set of bearings 1 is fitted inside a recess 16 of the hub 2 of wheel (carrier).

(29) The cylindrical portion 13, comprising the temperature sensor 3, is fitted into the recess 16 of the hub 2 of the wheel, positioned as close as possible to the set of bearings 5, by a tolerance stack-up to the set of bearings 5, having inner and outer races 7.

(30) In the FIGS. 1 to 3 a cavity 17 is arranged between two arms 18, 19 of the temperature sensor 3. Thus, the cavity 17 is arranged between the arms 18, 19 of the temperature sensor 3.

(31) Being arranged between the arms 18, 19 of the temperature sensor 3 the cavity 17 is directed towards the set of bearings 5.

(32) Any cavity 17 between the arms 18, 19 of the temperature sensor 3 and the set of bearings 5, having races 7, is filled with a conductive and/or adhesive compound 20.

(33) Filling the cavity 17 of the temperature sensor 3 with the conductive and/or adhesive compound 20 reduces the negative effect of a deteriorating transfer of the heat from the set of bearings 5 to the temperature sensor 3.

(34) The cavity 17 hampers the transfer of the operating temperature from the set of bearings 5, having races 7, to the temperature sensor 3.

(35) Said conductive and/or adhesive compound 20 is filled into the cavity 17 to improve the transfer of the operating temperature from the set of bearings 5 to the temperature sensor 3.

(36) The temperature sensor 3 is fixed rigidly to the controller 15 of the device for monitoring the set of bearings 1.

(37) Said controller 15 is designed as the PCB 11.

(38) Said arms 18, 19 of the temperature sensor 3 are connected to the controller 15 by means of transmitting elements 21.

(39) The arms 18, 19 of the temperature sensor and/or the transmitting elements 21 are supported by a carrying structure 22.

(40) The controller 15 transfers the signal, received from the temperature sensor 3 to at least one receiver including a display device of the driver (not shown) in the drivers cabin.

(41) The temperature sensor 3 is fixed rigidly to said carrying structure 22. The temperature sensor 3 is connected to the controller 15 (PCB 11) in a direct manner. The temperature sensor 3 may also be connected with the controller 15 by means of the transmitting elements 21 (not shown).

(42) Said transmitting elements 21 (not shown) form an integral part of said carrying structure 22.

(43) In the FIGS. 1 to 3 the controller 15 (PCB 11) is made up of a plurality of components.

(44) Said components are an energy storage device and/or a rechargeable battery 33. The component may also be a super capacitor or the energy harvesting system 12.

(45) The component can also be a rectifier 34 or an energy storage device charger 32 and monitor.

(46) Also it can be a transceiver circuit 35 including an antenna 36.

(47) The energy harvesting system 12 shown in the FIGS. 1 to 3 is arranged within in housing 10 of the device for monitoring a set of bearings 1.

(48) The energy harvesting system 12 comprises a cylindrical magnet 23.

(49) The magnet 23 is suspended on a spring element 24.

(50) The magnet 23 moves vertically inside a coil 25.

(51) Said coil 25 is made of copper wire which is wound on a bobbin 26.

(52) Thus, electrical energy is generated in form of an alternating current (AC).

(53) Said alternating current is rectified and the voltage is regulated.

(54) The current generated by the energy harvesting system 12 is used to charge a super capacitor or a battery 33 (not shown).

(55) To further increase the efficiency of the energy harvesting system 12 describe above, the magnet 23 is arranged with an orientation of the magnet 23 perpendicular to the shaft 9.

(56) When the truck drives on a solid ground (road) the hub of the wheel 2 bounces up and down with the wheel of the truck.

(57) Thus, the magnet 23 moves in a direction of gravity 27 within the coil 25.

(58) It goes without saying that the magnet 23 moves in the direction of gravity 27 and in the opposite direction 28.

(59) FIG. 4 features the functional diagram of the energy harvesting system 12. The energy harvesting system 12 comprises a cylindrical magnet 23. The cylindrical magnet 23 is suspended on a spring element 24. Said spring element 24 moves axially inside a copper wire coil 25. The copper wire coil 25 is wound on a bobbin 26 thus generating electric energy in form of an alternating current (AC).

(60) The alternating current is rectified. Also, the alternating current voltage regulated. A battery charger 32 is arranged to charge a battery 33. Alternatively, the battery 33 can also be designed as a super capacitor.

(61) In order to increase the efficiency of the energy harvesting system 12, the energy harvesting system 12 may comprise with an orientation of the moving magnet 23 in a direction, perpendicular to the solid ground.

(62) In the FIG. 4 the PCB 11 (not shown) comprises the energy storing system 32 (battery 33; super capacitor). The energy storing system 32 also has an energy harvesting system 12 as well as a rectifier 34.

(63) The rectifier 34 changes the alternating current (AC) to direct current (DC).

(64) In the FIG. 4 the battery charger 32 is also described as an energy storage device charger, comprising a monitor.

(65) The FIG. 5 shows the receive-transmit functional diagram of the device for monitoring the set of bearings 1 (not shown).

(66) In the FIG. 5 a temperature sensor 1 is rigidly fixed to a carrying structure 22 (not shown). The temperature sensor 3 is connected to the PCB 11 (also not shown), either directly or through the transmitting element 21.

(67) Both the temperature sensor 1 and the PCB 11 as well as the transmitting elements 21 (not shown) form an integral part of the carrying structure 22.

(68) The controller 15, the transceiver circuit 35 and an antenna 36 are also part of the PCB 11 assembly.

(69) FIG. 6 shows a flow chart representing the communicative connection between the temperature sensor 3 (not shown) and the controller 15 (not shown) of the device for monitoring a set of bearings 1 (not shown).

(70) The FIG. 6 shows a flow chart having various steps, ranging from steps 1 (S1) to step 14 (S14).

(71) In S1 the power of the vehicle is switched on.

(72) All data necessary for running the vehicle are requested from the various systems of the vehicle in the step S2.

(73) The step S3 represents the step, at which the controller 15 wakes up the device for monitoring the set of bearings 1, comprising the temperature sensor 3.

(74) The acquisition of data is performed in step S4. In this step, preferably, but not exclusively, various data such as the operating temperature of the individual set of bearings 5 and/or the state of charge of the battery 33 is acquired and collected. It goes without saying that in the step S4 other data can also be acquired and/or collected.

(75) The various data which are acquired and special collected are listed in the step S5. The conditioning of the data takes place in step S6, wherein a data management takes place and further optimization techniques are applied to said data.

(76) The conditioning of the data also implies an intelligent routing and/or a protection of the data for further data storage.

(77) In this step S7, it is determined, whether the data are within a preset valid range.

(78) In the step S7 the operating temperature of the individual set of bearings 5 is checked, as to whether at least one threshold temperature is reached or exceeded.

(79) The data and/or information gathered in the step S7 is transferred to the controller 15.

(80) Also, in the step S8, each set of bearings 5 is assigned an individual code number. By means of the individual code number the controller 15 of the device for monitoring the set of bearings 1 identifies the individual set of bearings 5 exceeding at least one threshold temperature.

(81) By means of the individual code number the individual set of bearings 5 exceeding at least one threshold temperature can be allocated to the corresponding wheel of the vehicle.

(82) In the step S9 the controller 15 checks, whether the operating temperature of each of the sets of bearings 5 reach and/or exceed at least one threshold temperature.

(83) In the step S10 the controller sends the device for monitoring a set of bearings 1 “to sleep” when the result of the step S9 indicates that the operating temperature of each of the individual sets of bearings 5 are still below the various threshold temperatures.

(84) Depending on whether or not at least one threshold temperature is exceeded by the operating temperature of the individual sets of bearings 5, in the step S11 a time interval is set.

(85) The time interval indicates the time gaps between the moments when the device for monitoring the set of bearings 1 is activated. When the device for monitoring the set of bearings 1 is activated the temperature sensor 3 measures the operating temperature of each individual set of bearings 5.

(86) The measured operating temperature of the individual set of bearings 5 is transferred to the controller by means of the transmitting element 21.

(87) In the step S12 a transaction ID is released and further diagnostics are performed when in step S7 the data are not within the valid range.

(88) When the necessary efforts of step S12 are performed the system is led back to step S9.

(89) In the step S13 and is checked whether in the step S9 the complete set of data has been gathered.

(90) If this is not the case, the driver receives a warning in that at least one of the temperature sensor is issues faulty results (S14).

(91) When the step S13 and S11 has been successfully fulfilled the system is led back to the step S3.

LIST OF REFERENCES

(92) 1 device for monitoring a set of bearings 2 hub of wheel (carrier) 3 temperature sensor 4 casing of the set of bearings 5 set of bearings 6 balls of the set of bearings 7 races of the set of bearings 8 lubricating means 9 shaft/axle 10 housing of the device for monitoring the set of bearings 11 PCB 12 energy harvesting system 13 cylindrical portion 14 bottom of cylindrical portion 15 controller 16 recess 17 cavity 18 arm 19 arm 20 conductive/adhesive component 21 transmitting element 22 carrying structure 23 magnet 24 spring element 25 coil 26 bobbin 27 direction of gravity 28 opposite direction of gravity 29 outer circumference 30 free 31 seal 32 battery charger 33 battery 34 rectifier 35 transceiver circuit 36 antenna