DE102011081414A1 - Elastic bellows used for rotating shaft used in automobile, has static seal that is formed between shaft and bellows main portion - Google Patents

Abstract

The bellows (1) has shaft (4) that is arranged between first and second axial ends. A static seal (6) is formed between the shaft and the bellows main portion. A needle bearing (5) is arranged on the second axial end. The needle bearing is held in the bearing holder.

Description

Field of the invention

The invention relates to a bellows having a first, axial end and a second, axial end, wherein between the two ends of the bellows for radially covering a shaft is provided and the first axial end of a first, static seal between the bellows and to a relative to the Has shaft fixed part.

State of the art

Background of the invention

A bellows is used in automotive technology and also generally in mechanical engineering to protect rotating parts, especially waves, from environmental influences. The same applies to hinges, which are intended to rotate rotating shafts, which occupy an angle to each other for a torque transmission to connect mechanically.

Out US 7,950,669 B2 For example, a rotating shaft bellows is known which is attached to a constant velocity universal joint and to the shaft itself to protect a portion of that shaft to the outside. The bellows is secured at its two axial ends with brackets which simultaneously form a stationary seal between the bellows and the shaft, or the bellows and a component of the rotary joint. Due to the two-sided mounting with rotating parts, the stationary seals are rotating, stationary seals in which both sealing partners do not move relative to each other.

In addition, an elastic bellows, which is made of an elastomer for example, at high speeds (eg 30,000 revolutions) due to its own centrifugal force damages and thus a protective function would not be realized. Thus, such an elastic bellows would only be suitable for slowly rotating shafts and rapidly rotating shafts would inevitably have to be protected with a standing bellows.

At a speed of about 30,000 revolutions per minute, the limit for co-rotating bellows is exceeded. However, the length of a standing bellows is not always adaptable to the length of a fast rotating shaft, that is, it can not be extended over large portions of the shaft because the bellows would become too large.

task

Summary of the invention

The object of the invention is therefore to provide a bellows for fast rotating, long shafts, or fast rotating, long shaft sections.

The object is achieved by a bellows of the type mentioned above in that the second, axial end has a second, sliding seal between bellows and shaft. This makes it possible to limit the length of the bellows to the important areas and uncover unappreciable parts of the shaft.

According to the invention, the bellows has a first, axial end and a second, axial end and, like conventional bellows, can be made of an elastic material. The bellows may further be formed annularly at said ends, the annular end extending either around the shaft or around the shaft fixed part and for example by means of adhesion, such as by a clamp attached thereto.

Between the two ends of the bellows for radial coverage of a shaft is provided. In this case, by the bellows and a joint, for. B. at least partially a constant velocity joint of the shaft are covered, so that the two ends each comprise axially differently aligned shaft parts. In addition, the bellows ideally have annular folds arranged around the shaft, which are formed by alternately arranged Faltenaufwürfen and folding valleys. The pleats can be unilaterally compressed or pulled as needed and structurally support the material strength of the pleat.

The first axial end of the bellows has a first, static seal between the inside of the bellows and a part fixed to the shaft, the second, axial end having a second, sliding seal between the bellows and the shaft. In this way, the bellows can be attached to the first end with a fixed part and therefore remains fixed even during operation of the shaft. It is only a torsional moment to be intercepted by the folds of the bellows, which results from the friction torque of the second, sliding seal.

A static seal is understood to mean that the sealing partners forming the sealing contact are arranged relative to one another in such a way that they either carry out a movement together, or both perform no movement. A static seal can thus quite perform a movement. The arrangement of the two sealing partners to each other does not change.

In contrast, the sliding seal permits a relative movement of the sealing partners, the sliding seal being formed between them, for example a sealing lip resting on a moving sealing surface or, for example, two optionally lubricated running surfaces of a sliding bearing.

In an advantageous embodiment, the sliding seal is a plain bearing or is at least partially formed by the sliding bearing. A lubricant may also contribute to the sealing of the sliding sliding bearing of the bellows. Of course, the sliding bearing can form the abrasive seal as a whole, with additional sealing elements can also be provided.

Preferably, the outer ring of the sliding bearing can be at least partially formed by an elastomer which has a hollow cylindrical shape to encompass the shaft and to form the sliding gap. The same elastomer can axially offset at the same time form the abrasive seal, for example in the form of a radial sealing lip.

Ideally, the sliding bearing is enclosed radially by the elastic bellows and axially at least on one side. In this case, the sliding bearing can be formed from an outer ring and the shaft, wherein only the outer ring is enclosed by the bellows.

Ideally, the bellows are designed to absorb a torsional moment which arises between the first, static seal and the second, abrasive seal, since the abrasive seal absorbs torque and the first, static seal does not. This torsional moment increases with the speed of the shaft.

Advantageously, the second abrasive seal has at least one radial sealing lip. In addition to the radial sealing lip and other radial or axial sealing lips may be provided which are arranged adjacent to the sliding bearing or rolling bearing, so that the respective bearing is arranged in the sealed area of the bellows.

In an advantageous embodiment, the bellows forms a rolling bearing receptacle at the second, axial end. Thus, a bearing, such as a rolling bearing or plain bearing can be accommodated in the bellows and held by it. In this way, inexpensive standard storage can be used. The rolling bearing receptacle can be formed by a hollow cylindrical part, of which at the distance of the bearing width two substantially radially inwardly outgoing boundary pieces are arranged. It is also conceivable such a limiting piece on one side and on the other, the radial sealing lip which holds the bearing axially in position.

Advantageously, a rolling bearing, in particular a needle bearing or a deep groove ball bearing, is arranged in the rolling bearing receptacle. In this case, bearings are mounted with at least one cold-formed bearing ring. In needle bearings, it is advantageous to produce the outer ring by cold forming and to let the rolling elements, in particular cylindrical rollers or needles, roll on the shaft.

Advantageously, the rolling bearing receptacle forms or merges with the radial sealing lip. For example, a cylindrical part of the rolling bearing receiving taper on one side and at the end, optionally spring loaded, rest on the shaft. It is advantageous if the bellows, and the Wälzkörperaufnahme and the radial sealing lip are made of an elastomer.

Advantageously, the bellows has a receptacle for the second, abrasive seal. This also low-cost standard seals can be placed in the bellows to protect the bearing, or the shaft or the joint. For this purpose, cassette sightings or simple sealing rings, which consist of a metallic carrier carrying at least one elastic part, which forms the radial or axial sealing lip are suitable.

Particularly preferably, the second, abrasive seal is formed from a separate sealing ring. Thus, a high degree of sealing can be achieved, and depending on the degree of sealing to be achieved, the respective suitable sealing ring can be attached.

Advantageously, the receptacle for the second, abrasive seal is at least partially formed by a cold-formed, annular part. This part contributes to the better positioning of the sealing ring, so that an optimal bias of the sealing lips can be achieved. In addition, the installation is simplified because the sealing ring can be inserted more easily, especially when it is secured by an elastic retaining element of the bellows.

Advantageously, the cold-formed, annular part forms an outer ring of the rolling bearing. Thus, the number of components can be reduced. Optionally, a fold of the annular member is used to partially form the bearing, For example, to ensure the axial guidance of the rolling elements.

Alternatively, the annular member may also be used to support the radial or axial sealing lip.

Further advantageous embodiments and preferred developments of the invention can be taken from the description of the figures and / or the dependent claims.

In the following the invention will be described and explained in more detail with reference to the exemplary embodiments illustrated in the figures.

Show it:

1 a bellows in longitudinal section along the shaft to be protected,

2 the seal assembly of the bellows 1 , and

3 an alternative seal arrangement with needle bearing for the bellows 1 ,

embodiment

Description of the drawings

1 shows a bellows 1 in longitudinal section along the shaft to be protected 4 , The fixed part 3 may be attached to another fixed part, such as a housing or a stator of an electric motor, in particular a near-the-wheel electric motor.

By means of the clamp 2 is by the against the fixed part 3 clamped bellows 1 formed the first, static seal of the first, axial end. At the second axial end are the needle roller bearings 5 and the sealing ring 6 which are arranged axially to each other and both with the shaft 4 stay in contact.

In the warehouse 15 becomes the needle bearing 5 held. The camp recording 15 goes into the gasket holder 16 over, wherein both receptacles have a correspondingly adapted cylindrical cavity, which receives the needle bearing 5 , or the sealing ring 6 enable.

2 shows the seal assembly 6 the bellows 1 out 1 coming from a carrier 18 and an elastic part 19 consists. The elastic part 19 forms two radial sealing lips, including those with the round spring 9 loaded, radial sealing lip 10 ,

The elastic retaining element 7 Holds both the cold formed part 12 , as well as the sealing ring 6 axially on the bellows 1 , By doing that part 12 both the outer ring 5 and the gasket holder 16 forms, the axial arrangement does not change. Thus, the bellows can contract axially, with the two axial ends migrate toward each other. This is possible because both the radial sealing lips 10 as well as the needle bearing 5 are axially displaceable. The same applies to a deep groove ball bearing or plain bearing.

3 shows an alternative sealing arrangement 8th with needle bearing 5 for the bellows 1 out 1 , This seal arrangement 8th points, as a low-cost variant, one from the bellows 1 formed radial, spring-loaded sealing lip, due to their bearing-side taper, the operation of the recording 15 of the camp is not endangered. The sealing lip 10 forms a sliding sealing contact with the shaft 4 ,

The feather 9 It is also called a worm spring because it consists of a spring spiral whose ends are connected to each other, in other words, it is an endless spring 9 , The feather 9 is arranged in a notch over the adjacent region of the radial lip and makes by their Rejüngungsbestreben the required pressing force.

Alternatively, the needle bearing 5 be replaced by a plain bearing ring so that it forms the plain bearing together with the shaft. Ideally, the sliding bearing ring is a ring of Teflon (polytetrafluoroethylene, PTFE) or a ring which is coated on the inside with Teflon. If the needle bearing 5 and the sliding bearing ring have the same outer dimensions, so is the bellows shown 1 suitable for both the rolling bearing insert and the plain bearing insert.

In summary, the invention relates to a bellows having a first, axial end and a second, axial end, wherein between the two ends of the bellows for radially covering a shaft is provided and the first axial end of a first, static seal between the bellows and to one opposite Has the shaft fixed part. With the aim of offering a solution for high-revving and long shaft parts to be covered, it is proposed to provide the second, axial end with a sliding seal between the bellows and the shaft. Thus, the bellows can be attached to the rotating shaft and still stand firmly, which does not have to bridge the distance to another fixed part. For the configuration of the second end, various embodiments proposed, for example, various bearing-seal combinations.

LIST OF REFERENCE NUMBERS

1

bellow

2

clamp

3

fixed part

4

wave

5

needle roller bearings

6

sealing ring

7

elastic retaining element

8th

abrasive seal

9

feather

10

radial sealing lip

11

outer ring

12

annular part

13

fold

14

needle

15

Rolling admission

16

seal Housing

17

Rolling bearing cage

18

carrier

19

elastic part

R

Rotary axis of the shaft

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 7950669 B2 [0003]

Claims (10)

Bellows having a first, axial end and a second, axial end, wherein between the two ends of the bellows for radial coverage of a shaft ( 4 ) is provided and the first axial end of a first, static seal between the bellows and to a relative to the shaft ( 4 ) fixed part, characterized in that the second, axial end of a second, sliding seal ( 6 ) between bellows and shaft ( 4 ) having. A bellows according to claim 1, wherein the second, abrasive seal is a sliding bearing or at least partially formed by the sliding bearing. A bellows according to claim 1, wherein the second abrasive seal ( 6 ) at least one radial sealing lip ( 10 ) having. A bellows according to claim 3, wherein the bellows at the second, axial end of a rolling bearing receptacle ( 15 ) trains. A bellows according to claim 4, wherein in the rolling bearing receptacle ( 15 ) a rolling bearing ( 5 ), in particular a needle bearing ( 5 ) or a deep groove ball bearing, is arranged. A bellows according to claim 4, wherein the rolling bearing receptacle ( 15 ) the radial sealing lip ( 10 ) or goes into these. Bellows according to one of the preceding claims, the bellows having a receptacle ( 16 ) for the second, abrasive seal ( 6 ) having. A bellows according to claim 7, wherein the second abrasive seal ( 6 ) from a separate sealing ring ( 6 ) is formed. A bellows according to claim 7 or 8, wherein the receptacle ( 16 ) for the second, abrasive seal ( 6 ) at least partially from a cold-formed, annular part ( 12 ) is formed. A bellows according to claim 9, wherein the cold-formed annular member (16) 12 ) an outer ring ( 11 ) of the rolling bearing ( 5 ).

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