阅读说明：本技术 密封装置 (Sealing device ) 是由 刘鑫 吴丽娟 于 2021-09-17 设计创作，主要内容包括：本发明涉及一种用于动态密封的密封装置。该密封装置包括围绕转动轴线布置的环形的外密封圈和内密封圈,外密封圈安装在内密封圈的径向外侧并且能够相对于内密封圈转动,外密封圈具有位于径向内侧的第一边缘部段并且在第一边缘部段的径向外侧限定环形腔,环形腔朝向被密封的内部侧开放,内密封圈具有位于径向外侧并且与第一边缘部段间隙配合的第二边缘部段。其中,该密封装置还包括固定在第二边缘部段上的至少一个刮片,该至少一个刮片分别在环形腔中的经过转动轴线的平面中延伸,并且具有无接触地沿着第一边缘部段延伸的内边缘。本发明的密封装置具有改进的密封效果。(The invention relates to a sealing device for dynamic sealing. The sealing arrangement comprises an annular outer sealing ring and an inner sealing ring arranged around the axis of rotation, the outer sealing ring being mounted radially outside the inner sealing ring and being rotatable relative to the inner sealing ring, the outer sealing ring having a first rim section located radially inside and defining an annular cavity radially outside the first rim section, the annular cavity being open towards the sealed inner side, the inner sealing ring having a second rim section located radially outside and in clearance fit with the first rim section. Wherein the sealing device further comprises at least one wiper blade fixed on the second edge section, which at least one wiper blade respectively extends in a plane passing through the axis of rotation in the annular chamber and has an inner edge extending along the first edge section without contact. The sealing device of the present invention has an improved sealing effect.)

1. A sealing arrangement for dynamic sealing, comprising an annular outer sealing ring (10) and an inner sealing ring (20) arranged around an axis of rotation, the outer sealing ring (10) being mounted radially outside the inner sealing ring (20) and being rotatable relative to the inner sealing ring (20), the outer sealing ring (10) having a first edge section (13) located radially inside and defining an annular cavity (40) radially outside the first edge section (13), the annular cavity (40) being open towards an interior side (I) to be sealed, the inner sealing ring (20) having a second edge section (22) located radially outside and clearance-fitting with the first edge section (13),

it is characterized in that the preparation method is characterized in that,

the sealing arrangement further comprises at least one wiper fixed to the second edge section (22), which extends in each case in a plane in the annular chamber (40) passing through the axis of rotation and has an inner edge extending without contact along the first edge section (13).

2. The sealing arrangement according to claim 1, characterized in that the at least one wiper blade comprises a plurality of wiper blades spaced apart in the circumferential direction, the plurality of wiper blades comprising a first wiper blade (31), a gap between an inner edge of the first wiper blade (31) and the first edge section (13) being smaller than a gap between other wiper blades of the plurality of wiper blades and the first edge section (13).

3. A sealing arrangement according to claim 2, characterized in that the inner sealing ring (20) is kept stationary in the mounted state, a radial plane of the sealing arrangement perpendicular to the axis of rotation being intended to be arranged non-horizontally in the mounted state, such that the first wiper (31) is located at the highest point of the radial plane.

4. The sealing arrangement according to claim 3, wherein the plurality of wiper blades further comprises a second wiper blade (32) arranged diametrically opposite the first wiper blade (31) along the second edge section (22).

5. The sealing arrangement according to claim 1, characterized in that it further comprises an annular base ring (33) fixed on the second edge section (22), the at least one wiper being fixed on the base ring (33) and extending from the base ring (33), respectively.

6. The sealing arrangement according to claim 5, characterized in that the base ring (33) has outer edges of uniform radius, the outer edges of the at least one wiper extending flush with the outer edges of the base ring (33), respectively.

7. The sealing arrangement, as set forth in claim 6, characterized in that the at least one wiper is formed integrally with the base ring (33), respectively.

8. A sealing arrangement according to any one of claims 1-7, characterized in that the first edge section (13) extends in an axial direction, and that the inner edges of the at least one wiper respectively extend parallel to the first edge section (13).

9. A sealing arrangement according to claim 8, characterized in that the second edge section (22) extends radially and is axially spaced from the free end of the first edge section (13).

10. The sealing device according to claim 9, characterized in that the at least one wiper has a rectangular profile in each case in a cross section through the axis of rotation.

Technical Field

The invention relates to the technical field of sealing. In particular, the present invention relates to a sealing device for dynamic sealing.

Background

In the presence of relatively rotating parts, such as bearings, it is often necessary to install sealing devices to prevent the intrusion of external contaminants and the leakage of internal grease. The existing sealing devices can be classified into a contact type sealing device and a non-contact type sealing device according to different sealing methods. Contact seals typically contact the inner component with an outer seal lip to form a contact seal surface. Such sealing devices generally have a good sealing effect, but are prone to wear and elevated temperatures of the sealing surfaces due to friction in the sealing surfaces contacting each other. In order to avoid wear and temperature increase, non-contact sealing devices are used in some cases.

A typical non-contact seal arrangement is seen, for example, in US 3393324 and EP1382868, which include an outer seal ring fixed to the outer race of a bearing and an inner seal ring fixed to the inner race of the bearing, the two rings extending towards each other without contacting each other, thereby forming a tortuous flow path between them and thus forming a non-contact labyrinth seal arrangement.

Labyrinth seals have a good sealing effect at high relative rotational speeds of the rotating parts, but are prone to leakage at lower rotational speeds. For example, in current bearings of wind turbines, non-contact sealing devices are generally employed in order to avoid temperature increases. Since the bearing of the wind turbine has a very low rotation speed and the grease usually presents a very viscous paste, the outer sealing ring of the sealing device drives the grease to move from the bottom position of the bearing to the upper position of the bearing when rotating, and the grease can leak randomly at any position in the whole circumferential direction. This will result in contamination of the entire outer surface of the bearing.

Disclosure of Invention

The invention is therefore based on the object of providing a sealing arrangement with an improved sealing effect.

The above-mentioned technical problem is solved by a sealing device according to the present invention. The sealing arrangement comprises an annular outer sealing ring and an inner sealing ring arranged around the axis of rotation, the outer sealing ring being mounted radially outside the inner sealing ring and being rotatable relative to the inner sealing ring, the outer sealing ring having a first rim section located radially inside and defining an annular cavity radially outside the first rim section, the annular cavity being open towards the sealed inner side, the inner sealing ring having a second rim section located radially outside and in clearance fit with the first rim section. Wherein the sealing device further comprises at least one wiper blade fixed on the second edge section, which at least one wiper blade respectively extends in a plane passing through the axis of rotation in the annular chamber and has an inner edge extending along the first edge section without contact.

Lubricating greases used inside many bearings generally have high viscosity, low fluidity characteristics, and often exhibit a state similar to a paste. At low bearing speeds, this grease tends to accumulate in the annular chamber outside the first edge section. Due to the clearance fit of the edge sections of the outer and inner sealing rings, grease accumulating in the annular cavity may leak through the clearance to the outside of the bearing or other sealed component. The wiper blades in the annular chamber extend in a plane passing through the axis of rotation, so that grease accumulating in the annular chamber can be scraped off when the outer seal ring and the inner seal ring rotate relative to each other, thereby reducing the possibility of grease leakage.

According to a preferred embodiment of the invention, the at least one blade may comprise a plurality of circumferentially spaced blades, which may comprise a first blade, the gap between the inner edge of the first blade and the first edge section being smaller than the gap between the other blades of the plurality of blades and the first edge section. Thus, the first wiper blade has a minimum clearance with the first edge section and can be used to be placed in a position where leakage is most likely to occur. For example, the inner sealing ring may remain stationary in the mounted state, and a radial plane of the sealing device perpendicular to the axis of rotation may be used for being arranged non-horizontally, in particular may be arranged vertically or close to vertically, in the mounted state, such that the first wiper is located at the highest point of the radial plane. This situation is present, for example, in the rotor bearings of wind turbines. In this mounted state, the gap at the highest point is most likely to leak and the leaked grease is difficult to collect, so arranging the first wiper blade with the smallest gap here can effectively improve the sealing effect.

According to a further preferred embodiment of the invention, the plurality of blades may further comprise a second blade arranged diametrically opposite the first blade along the second edge section. In the case of a vertical placement of the sealing device, the second wiper is thus arranged at the lowest point. The second wiper at the lowest point can effectively prevent the outer sealing ring from carrying grease accumulated at a low position to a high position when rotating.

According to a further preferred embodiment of the invention, the sealing device may further comprise an annular base ring fixed on the second edge section, the at least one wiper blade being respectively fixed on and extending from the base ring. When there are a plurality of blades, these blades may be connected together by a base ring.

According to a further preferred embodiment of the invention, the base ring may have outer edges of uniform radius, and the outer edges of the at least one wiper blade may extend flush with the outer edges of the base ring, respectively. The plurality of blades can thus have the same outer diameter, so that the difficulty of machining can be reduced. Preferably, the at least one wiper blade may be formed integrally with the base ring, respectively.

According to a further preferred embodiment of the invention, the first edge section may extend in the axial direction, and the inner edges of the at least one wiper blade may each extend parallel to the first edge section. Preferably, the second edge section may extend radially and be axially spaced from the free end of the first edge section.

According to a further preferred embodiment of the invention, the at least one wiper blade can have a rectangular contour in each case in a section plane through the axis of rotation. This shape is easy to manufacture and enables efficient sweeping of the grease accumulated in the annular chamber.

Drawings

The invention is further described below with reference to the accompanying drawings. Identical reference numbers in the figures denote functionally identical elements. Wherein:

fig. 1 shows a plan sectional view of a sealing device according to an exemplary embodiment of the present invention; and

fig. 2 shows a perspective cross-sectional view of a sealing device according to an exemplary embodiment of the present invention.

Detailed Description

Hereinafter, a specific embodiment of the sealing device according to the present invention will be described with reference to the accompanying drawings. The following detailed description and drawings are included to illustrate the principles of the invention, which is not to be limited to the preferred embodiments described, but is to be defined by the appended claims.

According to an embodiment of the present invention, a sealing device for dynamic sealing is provided. Such a sealing device is intended to be mounted in an annular space between two relatively rotatable parts. For example, such a sealing device is particularly suitable for being installed between an outer ring and an inner ring of a bearing for preventing grease leakage inside or intrusion of external contaminants.

Fig. 1 and 2 show an exemplary embodiment of a sealing device according to the invention. Fig. 1 shows a sectional view through the axis of rotation of the sealing device. As shown in fig. 1, the sealing device comprises an outer sealing ring 10 and an inner sealing ring 20. Both the outer sealing ring 10 and the inner sealing ring 20 are made of metal or other rigid material. The outer sealing ring 10 and the inner sealing ring 20 are clearance fitted, separating the inner side I and the outer side O in the axial direction. The inner side I is a sealed space inside a rotating member such as a bearing, and the outer side O is an outer space with respect to the inner side I. In the inner side I there may be e.g. grease for lubrication etc. The outer sealing ring 10 and the inner sealing ring 20 are both annular parts arranged around the axis of rotation, wherein the central axis of the rings substantially coincides with the axis of rotation. The outer sealing ring 10 is located radially outside the inner sealing ring 20. The inner seal ring 20 may be secured to a radially inner rotating component (e.g., a shaft or bearing inner race), such as by an interference fit or otherwise. The outer seal ring 10 may be secured to a radially outer rotating component (e.g., a bearing outer ring), such as by an interference fit or otherwise, and may be rotatable about an axis of rotation relative to the inner seal ring 20.

As shown in fig. 1, the outer sealing ring 10 includes a first fixing section 11, a connecting section 12, and a first edge section 13. The first fixing section 11 is an annular section extending substantially in the axial direction. The first fastening portion 11 may be used to fixedly connect with a radially outer rotating component by interference fit or other means, so that the outer sealing ring 10 may rotate together with the radially outer rotating component. The first rim section 13 is an annular section located radially inside the first fixing section 11, which defines the inner circumference of the outer sealing ring 10. The first edge section 13 is connected to the first fixing section 11 by a connecting section 12. The connecting portion 12 extends between the ends of the first fixing portion 11 and the first edge portion 12 facing the outer side O, and may extend substantially in the radial direction, may extend obliquely with respect to the radial direction, or may extend in a step shape as shown in fig. 1. By this construction, the outer sealing ring 10 defines, radially outside the first rim section 12, an annular cavity 40 which is open towards the inner side I.

The inner sealing ring 20 comprises a second fixing section 21 and a second edge section 22. The second fastening portion 21 is also an annular portion extending substantially in the axial direction. The second fastening portion 21 may also be used for fastening with a radially inner rotary part by interference fit or other means. The second edge section 22 is an annular section located radially outside the second fixing section 21, which defines the outer periphery of the inner sealing ring 20. The second edge section 22 can extend directly from the end of the second fixing section 21 facing the interior side I towards the radial inside, in particular can extend substantially in the radial direction. The second edge section 22 is axially closer to the inner side I than the first edge section 13 and is axially spaced from the free end of the first edge section 13. The gap between the first edge section 13 and the second edge section 22 is small, so that a clearance-type sealing fit is formed, which may prevent grease in the interior side I from leaking to the exterior side O to some extent.

The sealing device further comprises at least one wiper blade. The wiper is fixed to the second edge section 22 of the inner sealing ring 20 and extends into the annular chamber 40. As shown in fig. 2, the blade is formed as a sheet-like or plate-like structure extending in a plane passing through the axis of rotation. The blade may have a thickness in a direction perpendicular to the plane, but the thickness is generally less than its dimensions in the axial and radial directions. The inner edge of the wiper blade extends radially outside along the first edge section 13 without contacting the first edge section 13 and without also contacting any other section of the outer sealing ring 10. By extending along the first edge section 13 is meant extending substantially in the same direction, e.g. parallel or at a smaller angle. Thus, a radial gap of smaller size is formed between the inner edge of the wiper blade and the first edge section 13. The wiper blade may have two flat side surfaces facing the circumferential sides, respectively. The wiper blade may have a rectangular profile in a cross section perpendicular to the axis of rotation. The wiper blade may also have a rectangular profile in a section through the axis of rotation. Since the wiper is a plate-like or plate-like structure extending in a plane passing through the axis of rotation, when there is relative rotation between the outer seal ring 10 and the inner seal ring 20, the wiper can scrape off grease or other matter accumulated in the annular cavity 40, causing it to return into the interior side I, thereby reducing the likelihood of leakage.

The wiper blade may be made of different materials, such as plastic, rubber or metal. The wiper blade should be made with good stiffness and strength so as not to deform easily during use. Therefore, if a softer material such as rubber is used for the manufacturing, the blade should have a larger thickness in order to ensure sufficient rigidity.

The sealing means may comprise a plurality of circumferentially spaced wiper blades. A first blade 31 may be included among the plurality of blades. The gap between the inner edge of the first blade 31 and the first edge section 13 may be smaller than the gap between any other blade and the first edge section 13. That is, the first blade 31 is the blade closest to the first edge section 13 of all blades. Therefore, the first blade 31 has the best scraping effect. In some application scenarios, for example in a rotor bearing of a wind turbine, the radial plane (i.e. the plane perpendicular to the axis of rotation) of the sealing device is not arranged horizontally (e.g. vertically), so that different locations in the circumferential direction of the sealing device are located at different height positions. Grease accumulating at the highest point in the annular chamber 40 is more prone to leakage under the influence of gravity. In this case, the inner sealing ring 20 may thus remain stationary in the mounted state, while the outer sealing ring 10 may rotate relative to the inner sealing ring 20, preferably with the first wiper 31 being arranged at the highest point of the radial plane of the sealing device, thereby contributing to a reduction of the risk of leakage at the highest point.

In addition to the first blade 31 at the highest point, a second blade 32 disposed at the lowest point may be included among the blades. The second wiper 32 is thus arranged diametrically opposite the first wiper 31 in the direction of the inner seal ring 20. The second wiper 32 at the lowest point prevents grease accumulated at a low point from being carried up by the rotating outer seal ring 10. As mentioned before, the gap between the inner edge of the second blade 32 and the first edge section 13 is larger than the first blade 31. A certain degree of leakage is allowed at the lowest point. A dedicated collection device may be provided in the outer side O at the lowest point to collect leaked grease. This means that even in the case of gap seals which do not completely avoid leakage, the distribution of the wiper blades can still be used to guide the leakage of grease at a more advantageous location. Furthermore, the sealing device may also comprise further wiper blades. Other blades may be circumferentially spaced between the first blade 31 and the second blade 32. Of course, the sealing device may also comprise only the first blade 31 and the second blade 32, or the sealing device may also comprise only one blade, for example only the first blade 31.

Preferably, the sealing device may further comprise a base ring 33. An annular base ring 33 can be fixed on the free end of the second edge section 22. The base ring 33 may extend substantially along a radial plane. The wiper blades may extend from the base ring 33 into the annular cavity 40. Thus, when there are a plurality of wiper blades, these can be connected together by the base ring 33 and fixed on the second edge section 22 via the base ring 33. In particular, the wiper blade and the base ring 33 may be integrally formed and then integrally fixed to the second edge section 22. For example, both the blade and the base ring 33 may be made of a material such as plastic or rubber, which may be fixed to the second edge section 22 by an overmolding or vulcanization process. In this case, in order to ensure that the blade is not easily deformed, the blade may have a large circumferential thickness.

When a plurality of blades are connected by the base ring 33, the base ring 33 may have outer edges with a uniform radius, and the outer edges of each blade may extend flush with the outer edges of the base ring 33, respectively, thereby reducing the difficulty of machining. In this case, the radial length of the lowermost second wiper blade 32 is smaller than the radial length of the uppermost first wiper blade 31. At the same time, the outer edge of the second wiper 31 may ensure a certain distance from the outer boundary structure of the annular chamber 40, thereby helping to guide the leakage of grease from the predetermined position of lowest point.

The sealing device of the invention can effectively reduce the leakage caused by grease accumulation, thereby improving the sealing effect under the condition of not increasing the friction. Furthermore, although the present invention has been described by taking as an example a sealing device that does not have a contact seal face at all, this solution can also be applied to a contact sealing device. For example, an elastomeric seal body and seal lip may be added to the seal described above.

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

10 outer sealing ring

11 first fixing section

12 connecting section

13 first edge section

20 inner seal ring

21 second fixing section

22 second edge section

31 first wiper blade

32 second wiper blade

33 base ring

40 annular cavity

I interior side

O outer side