CN113494609A

CN113494609A - Sealing ring

Info

Publication number: CN113494609A
Application number: CN202010199409.6A
Authority: CN
Inventors: 刘鑫; 李定; 寇育豪
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2021-10-12

Abstract

The invention relates to a sealing ring, which has a sealing lip (1) made of an elastomer on the radial inner side of the sealing ring, the sealing lip (1) is intended to slidably abut against a rotating component, so that a dynamic seal is formed between an air side and a fluid side, wherein the sealing lip (1) comprises a first sealing bevel (5) facing the air side and a second sealing bevel (6) facing the fluid side, wherein the included angle of the first sealing inclined surface (5) relative to the rotating component is smaller than the included angle of the second sealing inclined surface (6) relative to the rotating component, wherein, a first rib (7) close to the fluid side and a second rib (8) close to the air side are arranged on the first sealing inclined surface (5), the first ribs (7) are designed as ribs which extend in the circumferential direction and are substantially inclined to the axial direction, and the second ribs (8) are designed as ribs which extend in the circumferential direction.

Description

Sealing ring

Technical Field

The invention relates to a sealing technology. The invention relates in particular to a sealing ring, in particular a dynamic sealing ring.

Background

Lip type sealing rings for rotating shafts have been widely used for sealing rotating parts of various kinds of mechanical equipment. In order to improve the sealing performance of the sealing ring, besides adopting proper materials and accurate dimensions, an oil return structure according to fluid dynamics can be arranged on the sealing part. For example, various structures of rib-like oil return lines can be formed on the sealing portion, particularly on the air side of the lip, by various groove structures provided on the mold. These return lines enhance the "pumping effect" which is advantageous for the fluid leaking from the fluid side to the air side of the sealing area to return to the fluid side, especially at high rotation speeds, to ensure a sealing action. Such lip seals are also suitable for rotating shafts with a two-way rotation regime, the design of the corresponding bead-shaped return line being known from prior art solutions.

For example, in U.S. Pat. No. 3,501,155, a seal for a bidirectionally rotating rotary shaft is disclosed, which is arranged between a housing and a component rotating relative to the housing, is mounted on the housing and has a radially inwardly projecting sealing lip which contacts the rotary shaft in its circumferential direction and which establishes a seal between an oil side and an air side for preventing oil leakage, wherein a row of circumferentially arranged ribs is provided on a slope of the sealing lip facing the oil side and a row of circumferentially arranged ribs is also provided on a slope facing the air side, the two rows of ribs contacting the rotary shaft and being respectively inclined transversely in different directions relative to the axis of rotation of the rotary shaft. When the rotary shaft rotates in one of the two rotational directions, one of the two rows of ribs generates a pumping force toward the seal lip, respectively, to pump oil leaking to the air side back to the oil side.

Another seal for a bidirectionally rotating rotary shaft is disclosed, for example, in US 6,729,624B1, which has on the inclined surface of its sealing lip facing the oil side circumferentially spaced-apart bidirectional ribs, each comprising two ribs which are angled between them and inclined transversely in different directions with respect to the axis of rotation of the rotary shaft.

However, in the above-described design, the ribs arranged in both directions always act in opposition, i.e. when the rotary shaft is rotated in one direction, one part of the ribs is used to provide the pumping force from the air side towards the oil side to reduce leakage, while the other part of the ribs provides the pumping force with a completely different direction. Another part of the ribs will in this case lead to oil leakage.

Disclosure of Invention

Therefore, the present invention is to overcome the above drawbacks, and to provide a seal ring with good sealing performance, which is particularly suitable for dynamically sealing a rotating shaft with bidirectional rotation.

The above object is achieved by a sealing ring having on its radially inner side a sealing lip made of an elastomer for sliding against a rotating component in order to form a dynamic seal between an air side and a fluid side, wherein the sealing lip comprises a first sealing ramp facing the air side and a second sealing ramp facing the fluid side, wherein the first sealing ramp has a smaller angle relative to the rotating component than the second sealing ramp, wherein a first rib is provided on the first sealing ramp close to the fluid side and a second rib is provided on the first sealing ramp close to the air side, wherein the first rib is configured as a circumferentially extending rib extending substantially obliquely to the axial direction and the second rib is configured as a circumferentially extending rib.

Within the scope of the present description, the sealing ring may be used in particular for dynamically sealing a rotating component. The center axis of the sealing ring coincides with the axis of rotation of the rotating part. Herein, unless otherwise stated, the terms "axial", "circumferential" and "radial" are based on the central axis of the seal ring, i.e. the axis of rotation of the rotating component. The sealing ring is arranged in particular between a component, for example a housing, and a rotating part which can rotate relative to the component. The sealing ring is preferably fixed directly or indirectly to the above-mentioned component, for example the housing, so that when the rotating part rotates, the sealing ring rotates relative to the rotating part together with the component. The rotating part can be a shaft or a shaft-like section of a component. Alternatively, the rotating part can also be a further component, for example a flinger or the like, which is fixed to the shaft or the shaft-like section of the part.

Within the scope of the present description, the sealing lip of the sealing ring, in particular the sealing lip serving as the main lip, can bear slidingly against the rotating component, so that a fluid chamber, which can contain a fluid, for example oil, and a space, which is free of fluid or has only a small amount of leakage fluid, are dynamically separated. The fluid side is here the side facing the fluid chamber containing the fluid, for example oil, and the air side is the side facing the space with no fluid or only a small amount of fluid leaking out. Advantageously, a seal formed by the seal lip, in particular the seal lip serving as the main lip, and the rotating member may be formed on the outer circumferential surface of the rotating member, where the seal lip substantially radially abuts against the rotating member. Alternatively, a seal formed by the seal lip, in particular the seal lip serving as the main lip, and the rotating component may be formed on an axial end face of the rotating component, wherein the seal lip at least partially axially abuts against the rotating component.

Within the scope of the present description, the number of sealing lips of the sealing ring is not limited. In other words, the sealing ring according to the invention can have at least one further sealing lip in addition to the sealing lip serving as the main lip. The additional sealing lip can be arranged here on the air side or on the fluid side relative to the main lip. The further sealing lips may establish a non-contacting seal and/or a contacting seal with the rotating component.

The sealing lip, in particular the main lip, has a first sealing bevel facing the air side and a second sealing bevel facing the fluid side, wherein the first sealing bevel has a smaller angle relative to the rotating component than the second sealing bevel. In other words, the first sealing ramp is relatively gentle and the second sealing ramp is relatively steep. It is thereby possible to cause fluid, in particular oil, which has leaked from the fluid side to the air side in a dynamic process, to be pumped back to the fluid side, according to the basic mechanism of the pumping effect. By means of the solution according to the invention, the pumping effect can be correspondingly enhanced, in particular by means of the first ribs, when the rotational shaft rotates in one direction or in both directions, so that the leaked fluid can advantageously be pumped back to the fluid side, and at the same time the fluid is blocked from flowing from the fluid side to the air side, in particular in the region of high risk of leakage, in order to reduce the fluid leakage when the rotational shaft rotates in either direction, in particular by means of the second ribs.

According to a preferred embodiment, the first ribs are designed as ribs arranged in a splayed manner two by two. In other words, each of the ribs constituting the first rib includes first and second ribs alternately arranged in a circumferential direction, wherein the first ribs are inclined laterally in the same direction with respect to the axial direction at an angle, and the second ribs are inclined laterally in the same direction with respect to the axial direction at another angle. An included angle is formed between every two adjacent convex ridges. The pumping back of the fluid may be enhanced by one of the first and second ribs when the rotating shaft is rotated in one direction; the pumping back of the fluid may be enhanced by the other of the first and second ribs when the rotating shaft is rotated in the other direction. With the sealing ring thus designed, in particular the first rib, the sealing ring can be particularly suitable for dynamically sealing a rotating shaft having a bidirectional rotation behavior.

In this case, the second rib is advantageously designed as a rib which extends continuously in the circumferential direction. In other words, the second ribs are configured as ribs which are completely closed in the circumferential direction, so that the risk of fluid leakage can be reduced.

In this case, the second ribs are alternatively designed as ribs which extend intermittently in the circumferential direction, wherein the break points of the second ribs are arranged in the region of the first ribs in which the distance between adjacent ribs increases toward the air side. When the assembly of the sealing ring is completed and the rib of the second rib abuts on the rotating member, the exhaust passage on the second rib may be formed by a discontinuity. In particular in the case of a sealing ring provided with a further sealing lip, for example a dust lip, which is arranged on the air side relative to the sealing lip, in particular the main lip, air can be easily discharged from the air side to the fluid side or from the fluid side to the air side by means of the exhaust channel, as a result of which a negative pressure between the sealing lip, in particular the main lip, and the further sealing lip, for example the dust lip, for example as a result of a temperature increase or a pressure increase, can be avoided, and the sealing lip is protected and the service life of the sealing ring is extended. Further, in the case where the first ribs are configured as ribs arranged in a splayed manner, a region where the pitch of the adjacent first ribs and second ribs decreases in the direction toward the air side forms a high risk region of fluid leakage. The circumferential position of the break points or exhaust ducts provided according to the present embodiment can thus advantageously avoid the above-mentioned high risk areas of fluid leakage, thereby reducing fluid leakage.

According to a further preferred embodiment, the first rib is configured as a rib arranged obliquely to the axial direction in one direction. In this case, a large number of ribs arranged in the circumferential direction are inclined transversely to the axial direction in the same direction. This is particularly applicable to conditions where the rotating shaft is rotated for a longer period of time in one direction and for a shorter period of time in the other direction. In particular, when the rotary shaft is rotated in one direction for a longer time, the pumping back of the leaked fluid towards the fluid side can be intensified mainly by means of the first ribs which are designed in a correspondingly oblique direction; when the rotary shaft rotates in the other direction for a short time, the leakage of the fluid from the fluid side to the air side can be blocked mainly by the second rib.

In this case, the second rib is advantageously designed as a rib which extends continuously in the circumferential direction. That is, the second rib is configured as a rib that is completely closed in the circumferential direction, so that the risk of fluid leakage can be reduced.

Here, the second rib is configured as a rib that extends intermittently in the circumferential direction. When the assembly of the sealing ring is completed and the rib of the second rib abuts on the rotating member, the exhaust passage on the second rib may be formed by a discontinuity. In particular in the case of a sealing ring provided with a further sealing lip, for example a dust lip, which is arranged on the air side relative to the sealing lip, in particular the main lip, air can be easily discharged from the air side to the fluid side or from the fluid side to the air side by means of the exhaust channel, as a result of which a negative pressure between the sealing lip, in particular the main lip, and the further sealing lip, for example the dust lip, for example as a result of a temperature increase or a pressure increase, can be avoided, and the sealing lip is protected and the service life of the sealing ring is extended.

Within the scope of the present description, the shape of each rib of the first rib is not limited. The ribs can be designed here according to known structures. Particularly advantageously, the ribs forming the first rib are each rectilinear or arcuate.

In an advantageous embodiment, the sealing ring comprises a skeleton for supporting the sealing ring. Thereby facilitating the fixing of the sealing ring and its dynamic sealing against the rotating part.

In an advantageous embodiment, the sealing ring comprises a spring ring for pressing the sealing lip against the rotating component. For this purpose, an annular groove for receiving the spring ring can be provided on the respective sealing lip. Thereby, the seal lip can be pressed tightly against the rotating member, achieving a reliable fluid seal.

In summary, a sealing ring particularly suitable for dynamically sealing a bidirectionally rotatable rotary shaft can be provided by means of the above-described solution. The sealing ring can in particular by means of the first rib correspondingly enhance the pumping effect when the rotary shaft is rotating in one direction or in both directions, so that leaking fluid can advantageously be pumped back to the fluid side, and at the same time in particular by means of the second rib blocking the fluid flow from the fluid side to the air side, in particular in the region of high risk of leakage, so that fluid leakage when the rotary shaft is rotating in either direction is reduced. Furthermore, in the case of a sealing ring provided with a further sealing lip, for example a dust lip, which is arranged on the air side relative to the sealing lip, in particular the main lip, air can easily be discharged from the air side to the fluid side or from the fluid side to the air side by means of the exhaust channel formed by the discontinuity of the second rib, as a result of which it is possible to avoid the generation of a negative pressure between the sealing lip, in particular the main lip, and the further sealing lip, for example the dust lip, for example as a result of a temperature increase, a pressure increase, and thus to protect the sealing lip and to prolong the service life of the sealing ring.

Drawings

Preferred embodiments of the present invention are schematically illustrated in the following with reference to the accompanying drawings. The attached drawings are as follows:

figure 1 is a partial perspective view of a seal ring according to a first preferred embodiment,

FIG. 2 is a partial perspective view of a seal ring according to a second preferred embodiment, an

Fig. 3 is a partial perspective view of a seal ring according to a third preferred embodiment.

Wherein identical or functionally identical components or structures are provided with the same reference signs.

Detailed Description

Fig. 1 is a partial perspective view of a seal ring according to a first preferred embodiment. The sealing ring can be used for dynamically sealing a rotating shaft with bidirectional rotating working conditions. As shown in particular in the cross section of the sealing ring in fig. 1, the sealing ring comprises an elastic sealing body made of an elastomer, in particular rubber, a carcass 3 and a spring ring 4, wherein the elastic sealing body at least partially covers the carcass 3 for supporting the sealing ring.

The seal ring according to the first embodiment forms two seal lips, i.e., a main lip 1 disposed on the fluid side and a dust lip 2 disposed on the air side, by its elastic seal portion. The main lip 1 may abut against a rotating member (not shown) substantially in the radial direction in the present embodiment, and a seal portion formed by the main lip 1 and the rotating member may be formed on an outer peripheral surface of the rotating member. In this case, an annular groove for receiving the spring ring 4 is formed on the outer circumferential surface of the main lip 1. The main lip 1 can be pressed tightly against a rotating part (not shown) by means of a spring ring 4.

The main lip 1 has a first sealing bevel 5 towards the air side and a second sealing bevel 6 towards the fluid side, wherein the first sealing bevel 5 is relatively gentle and the second sealing bevel 6 is relatively steep. A first rib 7 on the fluid side and a second rib 8 on the air side are provided on the first seal slope 5.

According to the first embodiment, the first ribs 7 are configured as ribs distributed in a splayed shape divided into first ribs and second ribs alternately arranged in the circumferential direction, wherein the first ribs are inclined laterally in the same direction at an angle with respect to the axial direction, and the second ribs are inclined laterally in the same direction at another angle with respect to the axial direction. The second ribs 8 are designed as ribs which extend intermittently in the circumferential direction, wherein the discontinuities of the second ribs are arranged in the region of the first ribs 8 in which the distance between adjacent ribs increases toward the air side. Here, the ribs of the second ribs 8 correspond one-to-one to regions in which the pitch is reduced toward the air side by the first ribs and the second ribs of the first ribs 7.

Thus, when the rotating member is rotated in one direction, the pumping back of the fluid may be enhanced by one of the first and second ribs of the first rib 7, and when the rotating shaft is rotated in the other direction, the pumping back of the fluid may be enhanced by the other of the first and second ribs of the first rib 7. Further, the areas of adjacent first and second ribs that decrease in spacing in a direction toward the air side form high risk areas of fluid leakage. The second ribs 8 block the flow of fluid from the fluid side to the air side, particularly in the high risk of leakage area, thereby reducing fluid leakage when the rotary shaft is rotated in either direction. The sealing ring according to the first preferred embodiment can thus be particularly suitable for dynamically sealing a rotating shaft having a bidirectional rotation regime.

In addition, the discontinuity of the second rib 8 may form an exhaust passage. Air can be easily discharged from the air side to the fluid side or from the fluid side to the air side by means of the air discharge channel, so that a negative pressure between the main lip and the dust lip, for example, due to a temperature increase or a pressure increase, can be avoided, the sealing lip can be protected and the service life of the sealing ring can be prolonged

Fig. 2 is a partial perspective view of a seal ring according to a second preferred embodiment. The sealing ring according to the second embodiment is designed similarly to the sealing ring according to the first embodiment, with the main difference being the design of the ribs on the first sealing bevel 5.

According to a second embodiment, as shown in fig. 2, the first ribs 7 are configured as ribs that are arranged obliquely to the axial direction in one direction. Here, the plurality of ribs arranged in the circumferential direction are inclined laterally in the same direction with respect to the axial direction. The second rib 8 is configured as a rib intermittently extending in the circumferential direction. This is particularly applicable to conditions where the rotating shaft is rotated for a longer period of time in one direction and for a shorter period of time in the other direction. When the rotary shaft is rotated in one direction for a longer time, the pumping back of the fluid, which has leaked to the air side, towards the fluid side can be assisted mainly by means of the first ribs 7 designed in a correspondingly oblique direction; when the rotary shaft rotates in the other direction for a short time, the leakage of the fluid from the fluid side to the air side can be blocked mainly by the second rib 8.

Fig. 3 is a partial perspective view of a seal ring according to a third preferred embodiment. The seal ring according to the third embodiment is designed similarly to the seal ring according to the first embodiment, with the main difference being, on the one hand, the design of the ribs on the first sealing ramp 5, and, on the other hand, the seal ring according to the third embodiment is provided with only the main lip 1, without the dust lip.

According to a third embodiment, as shown in fig. 3, the first ribs 7 are configured as ribs distributed in a splayed shape, which are divided into first ribs and second ribs alternately arranged in the circumferential direction, wherein the first ribs are inclined laterally in the same direction at an angle with respect to the axial direction, and the second ribs are inclined laterally in the same direction at another angle with respect to the axial direction. The second rib 8 is configured as a rib that extends continuously in the circumferential direction, i.e., a rib that is completely closed in the circumferential direction. Thereby, the first ribs and the second ribs of the first ribs 7 may enhance the pumping back of the fluid in the respective rotational directions, while the second ribs 8 may advantageously block the fluid from flowing from the fluid side to the air side, thereby reducing the fluid leakage when the rotational shaft is rotated in either direction.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

1, sealing lips; main lip

2 dust lip

3 skeleton

4 spring ring

5 first sealing bevel

6 second sealing bevel

7 first rib

8 second rib

Claims

1. A seal ring having on its radially inner side a seal lip (1) made of an elastomer, the seal lip (1) being intended to slidably abut against a rotating component, thereby forming a dynamic seal between an air side and a fluid side, wherein the seal lip (1) comprises a first seal bevel (5) towards the air side and a second seal bevel (6) towards the fluid side, wherein the angle of the first seal bevel (5) relative to the rotating component is smaller than the angle of the second seal bevel (6) relative to the rotating component, characterized in that,

a first rib (7) close to the fluid side and a second rib (8) close to the air side are arranged on the first sealing inclined surface (5),

wherein the first ribs (7) are designed as ribs which extend in a circumferential direction and are substantially inclined relative to the axial direction, and the second ribs (8) are designed as ribs which extend in a circumferential direction.

2. A seal ring according to claim 1, characterized in that the first ribs (7) are configured as ribs arranged in a splayed manner two by two.

3. A seal ring according to claim 2, characterized in that the second rib (8) is configured as a circumferentially continuously extending rib.

4. A sealing ring according to claim 2, characterized in that the second rib (8) is configured as a circumferentially intermittently extending rib, wherein the discontinuity of the second rib (8) is provided in the region of the first rib (7) where the distance between adjacent ribs increases towards the air side.

5. A sealing ring according to claim 1, characterized in that the first rib (7) is configured as a rib arranged obliquely to the axial direction in one direction.

6. A seal ring according to claim 5, characterized in that the second rib (8) is configured as a circumferentially continuously extending rib.

7. A seal ring according to claim 5, characterized in that the second rib (8) is configured as a circumferentially intermittently extending bead.

8. A ring according to claim 1, characterized in that the ridges configuring the first ribs (7) are rectilinear or arcuate.

9. A seal ring according to claim 1, characterized in that the seal ring comprises a skeleton (3) for supporting the seal ring.

10. A seal ring according to claim 1, characterized in that it comprises a spring ring (4) for pressing the sealing lip (1) to the rotating component.