Patent Application
20230167851
This application claims priority to German patent application no. 10 2021 213 567.6 filed on Nov. 30, 2021, the contents of which are fully incorporated herein by reference.
The present disclosure is directed to a bearing assembly configured to indicate whether the bearing assembly has been exposed to temperatures above a predetermined level.
Bearing assemblies, in particular for vehicles, can be subjected to high loads. In order to withstand these loads, all parts and components of the bearing assembly should be in perfect condition. However, the perfect condition of the parts and components can be compromised when the bearing assembly is subjected to extreme operating conditions, such as, for example, excessive temperatures. In particular, the permitted maximum temperature may be exceeded for too long a time during bearing operation, whereby a thermal overloading of the bearing assembly can occur.
In a bearing assembly that has been significantly thermally overloaded, the probability is high that it will not achieve its planned service life. It is thus important to recognize early whether a bearing assembly has been thermally overloaded so that suitable countermeasures can be taken, such as, for example, exchanging the bearing assembly earlier than planned, in order to avoid greater damage or unplanned downtime. However, the integrating of temperature sensors that record and control the temperature profile in a bearing assembly during operation is a relatively complex and cost-intensive process.
It is therefore an aspect of the present disclosure to provide a bearing assembly that can indicate whether the bearing assembly has been thermally overloaded.
In the following a bearing assembly is described that includes at least one first bearing ring and at least one second bearing ring that are movable with respect to each other. For example, the first and the second bearing ring can be part of a bearing unit. The bearing unit can be configured as a plain bearing. Alternatively, rolling elements can be disposed between the first and second bearing rings, and the bearing unit can be configured as a rolling-element bearing. Furthermore, the bearing assembly can be used in a vehicle, such as, for example, a motor vehicle.
In order to recognize in a simple manner whether the bearing assembly has been thermally overloaded, at least one of the bearing rings is at least partially provided with a first thermochromatic coating. The first thermochromatic coating can in particular be sprayed, precipitated, evaporated, and/or applied as paint onto the at least one bearing ring. Furthermore, the first thermochromatic coating can be applied as a planar coating, a strip-shaped coating and/or a punctiform coating. Suitable thermochromatic coatings are available from Indestructible Paint Ltd. of Birmingham, United Kingdom under the trade name Colour-Therm.
The first thermochromatic coating preferably has a first color in a first temperature range and a second color at least in a second temperature range. In a third or further temperature range, the first thermochromatic coating can preferably have a third or further color. For example, the first temperature range of the first thermochromatic coating can fall between 50° C. and 100° C., the second temperature range of the first thermochromatic coating can fall between 100° C. and 150° C., and the third temperature range of the first thermochromatic coating can fall between 150° C. and 200° C.
The first thermochromatic coating is preferably applied at least in one region of the at least one bearing ring that is visible and/or easily accessible in an installed state of the bearing assembly. For example, the first thermochromatic coating can be applied on an outer side of the bearing ring, an end side of the bearing ring, and/or a flange of the bearing ring. Alternatively or additionally, the first thermochromatic coating can be applied in the region of an exchangeable seal of the bearing unit so that when the seal is removed, for example, during a maintenance process of the bearing assembly, the color displayed by the coating can be examined directly. This has the advantage that the color shown by the coating can be assessed without disassembling the entire bearing assembly, but the coating is protected from external influences during operation of the bearing assembly.
According to a further embodiment, at least one second region of the bearing assembly is at least partially provided with at least one second thermochromatic coating different from the first thermochromatic coating. Furthermore, the second thermochromatic coating can be applied as a planar coating, a strip-shaped and/or a punctiform coating.
The second thermochromatic coating preferably has a first color in a first temperature range and a second color at least in a second temperature range, wherein in a third or further temperature range, the second thermochromatic coating preferably has a third or further color. For example, the first temperature ranges, in which the first thermochromatic coating and the second thermochromatic coating have their respective first color, can be identical. The second temperature ranges, in which the first thermochromatic coating and the second thermochromatic coating have their respective second color, can advantageously differ from each other. In particular, the second temperature range of the second thermochromatic coating can fall at lower temperatures than the second temperature range of the first thermochromatic coating. For example, the first temperature range of the second thermochromatic coating can fall between 50° C. and 100° C., and the second temperature range of the second thermochromatic coating can fall between 100° C. and 120° C.
Furthermore, the color in the first temperature range can be identical for the first and the second thermochromatic coating, while the colors of the first and second thermochromatic coatings differ from each other in at least one further temperature range. This means that in a state in which the bearing assembly was not subjected to an impermissible temperature, it is not recognizable on the bearing assembly where the first thermochromatic coating is applied and where the second thermochromatic coating is applied. Due to the different colors in the second temperature range, in particular when the second temperature ranges differ, it can be recognized how highly the bearing assembly has been thermally loaded.
According to a further preferred embodiment, the first and the second thermochromatic coatings are applied in different regions from each other. In particular, the first and the second coating can be applied adjacent to each other, in particular directly adjacent to each other. For example, when the first and the second thermochromatic coatings are applied in the form of points and/or strips, the points and/or strips of the first thermochromatic coating and the points and/or strips of the second thermochromatic coating can be applied alternately with respect to each other. In addition, the first thermochromatic coating and the second thermochromatic coating can be applied on mutually differing regions of the bearing assembly and/or on different bearing components. For example, the second coating can be applied in the interior of the bearing assembly and/or onto the sensitive components of the bearing assembly.
The color change of the first and/or of the second thermochromatic coating is preferably irreversible. That is, as soon as the thermochromatic coating has changed its color due to a temperature being reached, it retains this color even when the bearing assembly has cooled again. It can thereby be ensured that during maintenance it is recognizable whether the bearing assembly has been subjected to an impermissibly high temperature.
Furthermore, the bearing assembly can be a wheel bearing assembly, and the first and the second bearing ring can be part of a rolling-element bearing that includes a plurality of rolling elements in which the first and the second bearing rings define between them an interior in which the plurality of rolling elements are disposed, wherein the first bearing ring is preferably connectable to a wheel, and the second bearing is preferably connectable to an axle element. Preferably the first thermochromatic coating is applied on at least one outer side of a bearing ring, and the second thermochromatic coating is applied at least in the interior. In particular, the second thermochromatic coating can be applied in a region of the interior that has no sliding, frictional and/or rolling contact with another element. For example, the second thermochromatic coating can be applied on an end surface of a rolling element, in particular in a recessed region, such as, for example, in a dimple, or a part of the end surface that has no contact with a retaining and/or guide flange, a cage, and/or an inner surface of the bearing rings.
Further advantages and advantageous embodiments are specified in the description, the drawings, and the claims. Here in particular the combinations of features specified in the description and in the drawings are purely exemplary so that the features can also be present individually or combined in other ways.
In the following the invention is described in more detail using the exemplary embodiments depicted in the drawings. Here the exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the pending claims.
In the following, identical or functionally equivalent elements are designated by the same reference numbers.
A plurality of rolling elements 14 are disposed between the first bearing ring 4 and the second bearing ring 6. Alternatively the bearing unit 2 can also be a plain bearing having no rolling elements 14. In the example of
In order to recognize in a simple manner whether the bearing assembly 1 has been thermally overloaded, in
Furthermore, the color change of the first thermochromatic coating 5 is irreversible. That is, as soon as the thermochromatic coating 5 has changed its color due to a temperature being reached, it retains this color even when the bearing assembly 1 has cooled again.
The first thermochromatic coating 5 is configured to display a first color in a first temperature range and a second color in a second temperature range. Here the first temperature range of the first thermochromatic coating falls between 50° C. and 100° C., and the second temperature range of the first thermochromatic coating 5 falls between 100° C. and 150° C. Furthermore, the first thermochromatic coating 5 can display a third color in a third temperature range, wherein for example, the third temperature range of the first thermochromatic coating 5 can fall between 150° C. and 200° C.
In
Furthermore, in
Here the second thermochromatic coating 7 has a first color in a first temperature range and a second color in a second temperature range. Furthermore, the second thermochromatic coating 7 can also be configured to have a third color in a third temperature range. Like the first thermochromatic coating 5, the color change of the second thermochromatic coating is also irreversible.
In the bearing assembly shown in
In the bearing assembly 1 of
In summary, the application of a thermochromatic coating 5, 7 onto at least one bearing component 4, 6, 14 of the bearing assembly 1 makes it possible to recognize whether the bearing assembly 1 has been subjected to an impermissibly high temperature by the thermochromatic coating 5, 7 undergoing a color change. It can thereby be recognized whether the bearing assembly 1 should be serviced and/or exchanged so that by a timely changing of the bearing unit unplanned repair times and/or greater damage can be avoided, whereby costs can also be reduced, since no unplanned downtimes arise, and the extent of damage can be understood with higher probability. In particular, when the bearing assembly 1 is used in a motor vehicle, the risk of accident can be reduced, and safety on the road can be increased.
Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved bearing assemblies.
Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.
All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021213567.6 | Nov 2021 | DE | national |
