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DE-102024112768-B4 - Sealing ring with integrated adaptation fiber(s) for friction reduction by shrinking when heated; and bearings

DE102024112768B4DE 102024112768 B4DE102024112768 B4DE 102024112768B4DE-102024112768-B4

Abstract

Sealing ring (1) for sealing a gap (4) arranged between two components (2, 3) that are rotatable relative to each other, comprising a base carrier (5) prepared for attachment to a first component (2) and a sealing lip (6) arranged on the base carrier (5), projecting from the base carrier (5) and designed to abut a second component (3), wherein the sealing lip (6) is made of an elastomer, wherein the elastomer is reinforced by means of one or more adaptation fiber(s) (7), which adaptation fiber(s) (7) is/are designed such that it changes dimensionally due to thermal activation when the ambient temperature changes, characterized in that the adaptation fiber(s) (7) is/are twisted at least in sections.

Inventors

  • Marco Krapf
  • Patrick Schmitt

Assignees

  • Schaeffler Technologies AG & Co. KG

Dates

Publication Date
20260513
Application Date
20240507

Claims (9)

  1. Sealing ring (1) for sealing a gap (4) arranged between two components (2, 3) that are rotatable relative to each other, comprising a base carrier (5) prepared for attachment to a first component (2) and a sealing lip (6) arranged on the base carrier (5), projecting from the base carrier (5) and designed to abut a second component (3), wherein the sealing lip (6) is made of an elastomer, wherein the elastomer is reinforced by means of one or more adaptation fiber(s) (7), which adaptation fiber(s) (7) is/are designed such that it changes/changes dimensionally due to thermal activation when the ambient temperature changes, characterized in that the adaptation fiber(s) (7) is/are twisted at least in sections.
  2. Sealing ring (1) according to Claim 1 or the umbrella term of Claim 1 , characterized in that the adaptation fiber(s) (7) in the elastomer are made of two or more materials in a layered structure (sandwich).
  3. Sealing ring (1) according to one of the preceding claims, characterized in that the adaptation fiber(s) (7) has a negative coefficient of thermal expansion in a temperature range.
  4. Sealing ring (1) according to one of the preceding claims, characterized in that the adaptation fiber(s) (7) are designed as short fiber, long fiber, i.e. filler fibers, consisting of single material fibers or sandwich fibers (multi-material fibers) or coated fibers.
  5. Sealing ring (1) according to one of the preceding claims, characterized in that the adaptation fiber(s) (7) is part of a fiber mat, fiber woven or fiber knitted fabric or a fiber bundle.
  6. Sealing ring (1) according to one of the preceding claims, characterized in that the adaptation fiber(s) (7) is a carbon fiber.
  7. Sealing ring (1) according to one of the preceding claims, characterized in that a heating device (8) is provided which is designed such that the adaptation fiber(s) (7) is heated in an activated state and thus shrunk.
  8. Sealing ring (1) according to Claim 7 , characterized in that the heating device (8) has a current supply means which directs a temperature-increasing current directly through the adaptation fiber (7) or through the elastomer material receiving the adaptation fiber (7).
  9. Sealing ring (1) according to one of the preceding claims, characterized in that the elastomer contains one or more additional filler(s) which increases the thermal conductivity in the elastomer.

Description

The invention relates to a sealing ring for sealing a gap arranged between two components that are rotatable relative to each other, preferably for use in a bearing arranged in a motor vehicle, particularly preferably in a wheel bearing, comprising a base carrier prepared for attachment to a first component (preferably a first bearing ring of the bearing or a component non-rotatably connected to this first bearing ring) and a sealing lip arranged on the base carrier, projecting from the base carrier and designed to abut a second component (preferably a second bearing ring or a further component non-rotatably connected to this second bearing ring), wherein the sealing lip is made of an elastomer (preferably a conventional crosslinkable or thermoplastic elastomer). The invention further relates to a bearing, e.g., a wheel bearing, with this sealing ring. Wheel bearings and seals/sealing rings of this type are already well known from the prior art. For example, the DE 10 2021 109 419 A1 A wheel bearing with a sealing element featuring a sealing lip. With known seals, there is a fundamental need to further reduce the friction generated by the seals during operation. These seals are mostly designed for use when the wheel bearing is stationary, as this is when the maximum forces act on the existing sealing lips due to water accumulation in the area of the sealing lips. In particular, larger quantities of water can accumulate locally. At the same time, however, the seal should, during operation, maintain contact with the contact surface with the lowest possible pressure to minimize friction. Other sealing rings are made of DE 103 06 728 A1 , DE 10 2017 123 654 A1 , FR 3 070 740 A1 and DE 10 2021 109 419 A1 previously known. DE 10 2012 216 271 A1 shows a generic sealing ring with a sealing lip made of elastomer, which has fibers. The object of the present invention is therefore to provide a sealing ring which, on the one hand, achieves reduced friction during operation, but on the other hand, provides a reliable seal against accumulating water when the device is at rest. This is achieved according to the invention by the subject matter of claims 1 and 2. The elastomer (of the sealing lip) is reinforced by means of a filler in the form of adaptation fiber(s) (=twisted fibers or fibers in a sandwich structure, i.e., two different fiber materials bonded together or coated fibers for insulation), which adaptation fiber is designed such that it contracts when its temperature increases (and thus the sealing lip preferably shortens/shrinks). By incorporating these adaptation fibers, the sealing lip's overlap is cleverly reduced during operation, when the ambient temperature typically also increases. This reduces friction during operation and significantly improves the bearing's efficiency. Nevertheless, sufficient sealing lip stiffness is maintained outside of operation, when the bearing is at rest, to prevent water from entering the bearing. Further advantageous embodiments are claimed in the dependent claims and are explained in more detail below. In this regard, it has also proven advantageous if the adaptation fiber(s) have a negative coefficient of thermal expansion in a temperature range (preferably already at a temperature increase between 5°C and 20°C). A particularly easy-to-manufacture design has proven to be one in which the adaptation fiber(s) is configured as a short fiber (up to 1 mm) or a long fiber (up to 2.5 mm). Furthermore, it is preferable that the adaptation fiber(s) in both short and long configurations are arranged in a random arrangement, such that the orientations of the individual adaptation fibers differ from one another in their spatial orientation. Furthermore, the adaptation fibers can also be part of a fiber layup, fiber fabric (continuous fibers as a component of woven fabrics), yarn (polymer yarns), knitted fabric, or a fiber bundle. In principle, the adaptation fiber can also be implemented as a single long fiber contained within the sealing lip. This allows for highly variable adjustment of the sealing lip's stiffness. It is also advantageous if the adaptation fiber(s) is/are twisted (normally, sufficient shortening is only achieved through twisting), meaning they have a spiral/helical shape. In this context, it has proven particularly useful if the adaptation fiber(s) are implemented as short or long fibers. This gives the adaptation fiber a geometry that is durable enough for adapting to the sealing lip across various temperature ranges. It is considered advantageous if the adaptation fiber(s) consist of/are made of carbon fiber. The adaptation fibers can also be formed from carbon nanotubes. Preferably, at least one sealing lip incorporates numerous adaptation fibers during the mixing or compounding process. Furthermore, it is advantageous to have several sealing lips, each containing one or more adaptation fibers. This further improves the sealing effect. Furthermore, it is advantage