WO2013143884A1

WO2013143884A1 - Shaft for transmitting a torque

Info

Publication number: WO2013143884A1
Application number: PCT/EP2013/055400
Authority: WO
Inventors: Stephan NEUENDORF; Reinhold PUPKES; Ekkehard Pott; Dirk Warnecke
Original assignee: Volkswagen Aktiengesellschaft
Priority date: 2012-03-29
Filing date: 2013-03-15
Publication date: 2013-10-03
Also published as: IN2014MN02085A; CN104204428A; DE102012006466A1; DE102012006466B4; CN104204428B

Abstract

The invention relates to a shaft (10) for transmitting a torque, which shaft has at least one first axial section (14) in an inner spatial region (16) and one second axial section (18) in an outer spatial region (20). The two spatial regions (16, 20) are separated by a wall (22) having at least one opening (24), and the shaft (10) extends through the opening (24) of the wall (22). A rolling-element bearing (26) that does not support the shaft (10) is accommodated on the shaft (10) in such a way that the opening (24) of the wall (22) is closed off by means of the rolling-element bearing (26) such that the opening of the wall is protected against solid foreign bodies from the outer spatial region (20).

Description

description

Shaft for transmitting torque

The invention relates to a shaft for transmitting a torque having at least a first axial portion in an inner space area and a second axial portion in an outer space area, wherein the two space areas are separated by a wall having at least one opening and the shaft through the opening the wall passes.

In internal combustion engines, waves, in particular crankshafts, often extend through a plurality of spatial regions that are separated from one another by a wall. Among other things, the wall often serves, inter alia, to separate an inner space area from an outer space area in order to arrange certain components, for example a control drive, in particular with a toothed belt for power transmission, protected against influences from the outer space area. Typically, the shaft passage is for

Minimization of friction contactless, for example by means of a labyrinth seal, or medium dry-running sealing rings against foreign bodies, especially dust, sealed. In practice, however, in areas that are particularly polluted, it has been found that these measures are not always adequate and yet an unacceptable amount

Foreign bodies, especially at the implementation of the wave, can penetrate.

From the document DE 40 04 767 A1 discloses a separate bearing sleeve for a crankshaft, in particular for internal combustion engines of chainsaws, known, the bearing sleeve consists of an annular part and a disc-shaped part, wherein the annular part surrounds the roller bearing in the bearing seat of the end wall of the crankcase while the disc-shaped part comprises a sealing ring with lips for tightly enclosing the crankshaft. In this arrangement, the sealing ring with lips, not already the roller bearing alone has a sealing effect.

Object of the present invention is to provide a through an opening in a wall extending shaft whose implementation for use in a with Foreign bodies, especially dust in the ambient air polluted area is sufficiently well sealed.

This object is achieved by a shaft for transmitting torque with the features of claim 1. Advantageous developments of the invention are characterized in the dependent claims.

A shaft for transmitting torque according to the invention has at least a first axial section in an inner space area and a second axial section in an outer space area. The two space areas are separated by a wall having at least one opening, and the shaft passes through the opening of the wall. On the shaft, a non-supporting the shaft bearing is accommodated such that the opening of the wall is closed by means of the rolling bearing protected against solid foreign bodies from the second outer space area.

In particular, the opening of the wall by means of the rolling bearing protected against solid foreign bodies smaller than 12.5 mm, preferably less than 2.5 mm or even less than 1, 0 mm, particularly preferably against dust or dust-tight. In addition, the opening of the wall, especially with regard to automotive applications, also protected against spray, preferably jet water, especially strong and pressurized jet water against immersion, particularly preferably protected against water in high-pressure and / or steam jet cleaning.

In other words, according to the invention, a rolling bearing is used as a shaft seal without the sealing rolling bearing being used for supporting or supporting the shaft. Since substantially, preferably no forces are transmitted, advantageously, a rolling bearing can be used with a low load rating. In this way, a cost-effective solution can be realized.

The fact that the rolling bearing does not support or support the shaft means in particular that the rolling bearing is supported or supported at least to a negligible part, preferably no force and / or torque of the shaft. In other words, the forces and / or torques emanating from the shaft, in particular their weight, are at least up to a negligible small part not according to the invention

used, sealed the opening closing bearing. The shaft can in particular be supported or accommodated by one or more bearings, in particular in an internal combustion engine, wherein the bearings can absorb in particular the weight of the shaft. The second axial section may in particular be a stub shaft or a shaft end. The rolling bearing can be filled with grease.

In a practical embodiment of the shaft according to the invention for transmitting a torque, a toothed belt wheel is received on the first axial section in the inner space region. The toothed belt wheel can be particularly suitable for or part of a

Steuerviebs an internal combustion engine, for example, for the variable valve train, be. In this embodiment, the wall forms part of a timing belt housing, which is typically made of plastic.

According to the invention, it is possible for the shaft to pass through the wall in a caseless and / or sealless manner. A concrete construction can be carried out particularly easily on this basis. In an advantageous consequence wear on a sleeve and / or a seal is avoided. It is particularly advantageous for preventing the ingress of

Solid bodies and in particular dust, when the rolling bearing is executed encapsulated. Advantageously, a readily available, in particular inexpensive standard part can be used.

Preferred embodiments of the rolling bearing of the shaft according to the invention are

Deep groove ball bearings, (preferred) self-aligning bearings or needle roller bearings. In particular self-aligning ball bearings can advantageously compensate for a slight wobbling of the shaft, in particular of the stub shaft. The deep groove ball bearing and / or the self-aligning bearing can be single-row.

An advantageous development of the shaft according to the invention additionally comprises

Tolerance compensation element: The rolling bearing is taken in such developments indirectly via a tolerance compensation element in the wall. Specifically, that can

Tolerance compensation element of the shaft according to the invention have at least one torsionally rigid elastomer contour. In particular, the (preferably gap-free and / or seamless) elastomer contour can completely surround the rolling bearing along its radial circumference.

The tolerance element allows a tolerance compensation of the shaft relative to the wall, such as a timing belt housing, since on the one hand the relative position of the wall to the shaft may have deviations from a desired position within a tolerance interval and / or on the other a Wellenaxialspiel can be present.

In a plurality of embodiments of the shaft according to the invention for transmitting a torque, a vibration damper can be accommodated on the second section in the second spatial area. The vibration damper can be designed in particular for compensation and / or dissipation of undesired vibrations of the shaft.

Particularly significant is the application of the procedure according to the invention for crankshafts. In other words, the shaft according to the invention is preferably a crankshaft of an internal combustion engine.

In the context of the inventive concept is also an internal combustion engine, in particular a spark-ignited or (preferably) a self-igniting internal combustion engine. An internal combustion engine according to the invention comprises at least one shaft for transmitting a torque with individual features or feature combinations according to this representation. A large group of internal combustion engines according to the invention consists of internal combustion engines, which have a timing drive with a toothed belt drive, wherein the toothed belt is encapsulated in a housing and wraps around the shaft. If the

Embodiment of the internal combustion engine according to the invention comprises a tolerance compensation element, this is preferably carried out such that a tolerance compensation can be carried out both in the direction of the vertical axis and in the direction of the transverse axis of the internal combustion engine.

Concrete embodiments of the internal combustion engine according to the invention can in

Vehicles, preferably trackless land vehicles, are used. In particular, the charging vehicles may be passenger cars, commercial vehicles, for example construction machines or special vehicles.

Further advantages and advantageous embodiments and developments of the invention will be described with reference to the following description with reference to the figures. It shows in detail:

Figure 1 shows an embodiment of a shaft according to the invention, here a crankshaft, and

2 shows a view of an embodiment of a tolerance compensation element for the embodiment of the shaft according to the invention shown in FIG. 1 shows schematically an embodiment of a shaft according to the invention. This shaft 10 is a crankshaft of an internal combustion engine 12. The internal combustion engine 12 has a timing drive for a variable valve train. This tax drive includes one

Timing belt drive, which taps off a torque from the shaft 10: A toothed belt wheel 28 is received on the shaft 10 in a first axial section 14 in an inner space region 16. This is in operative connection with a toothed belt (not shown here in FIG. 1) which wraps around the shaft 10. The toothed belt drive, in particular the toothed belt wheel 28, is surrounded by a housing which is fastened to the internal combustion engine 12, in particular in order to prevent external influences on the toothed belt drive.

The shaft 10 has a second axial portion 18 in an outer space portion 20 and penetrates, inter alia, a wall 22, in this embodiment, an outer wall of the housing of the toothed belt drive through an opening 24. According to the invention, the opening 24 is closed by the fact that Shaft 10 a roller bearing 26 at the

Penetration point of the wall 22 is received. The rolling bearing 26 is advantageously fitted in this embodiment indirectly via a tolerance compensation element 30 in the opening 24 of the wall 22. In this way, the opening 24 and the shaft bushing is sealed dust-tight, so that no foreign matter and no dust from the outside

Room area 20 can get into the inner space area 16.

Since the shaft 10 is accommodated in the internal combustion engine 12 by means of bearings not shown in FIG. 1, the roller bearing 26 used according to the invention is used

structurally not substantially powered by the shaft 10. In practice, vibrations or deviations from the desired position can lead to a small, a priori undesirable force effect.

In the outer space region 20, a vibration damper 36 for damping vibrations of the shaft 10 is received on the second axial portion 18, a free shaft end of the shaft 10.

FIG. 2 illustrates an embodiment of the tolerance compensation element 30 of the embodiment shown in FIG. 1. The torsionally rigid tolerance compensation element 30 surrounds the roller bearing 26 and is fitted directly into the opening 24 of the wall 22 (see FIG. 1). It comprises two elastomer contours 32, which are separated from each other by two gaps 34. The courses of the two gaps 34 are respectively oriented along the extension of the outer contour of the long side of the roller bearing 26. As also shown in the figure 1, the perpendicular to the wall 22 extending cross-sections of the elastomer contours 32 have the shape of two equal side, symmetrical trapezoids, their short parallel sides

contiguous. The shaft 10 is therefore accommodated in the sequence for tolerance compensation movable in two orthogonal directions perpendicular to its axis, but a rotation of the shaft 10 and the tolerance compensation element 30 is prevented.

Instead of an elastic suspension or fitting of the rolling bearing, as in the

Embodiment of Figures 1 and 2, may alternatively be provided that the timing belt housing is centered during assembly over the seat of the rolling bearing and only then fixed, so that no elastic suspension is necessary.

Furthermore, in order to create sufficient axial space for the rolling bearing used according to the invention, the vibration damper can be made potted.

LIST OF REFERENCE NUMBERS

wave

Internal combustion engine

first axial section

inner space area

second axial section

outer space area

wall

opening

roller bearing

toothed belt

Tolerance compensation element

elastomer contour

gap

vibration absorber

Claims

claims

A torque transmitting shaft (10) having at least a first axial portion (14) in an inner space portion (16) and a second axial portion (18) in an outer space portion (20), the two space portions (16 , 20) are separated by a wall (22) having at least one opening (24) and the shaft (10) passes through the opening (24) of the wall (22),

characterized,

in that a roller bearing (26) not supporting the shaft (10) is received on the shaft (10) in such a way that the opening (24) of the wall (22) is protected against solid foreign bodies from the outer space region (20) by means of the rolling bearing (26) ) is closed.

Second shaft (10) for transmitting a torque according to claim 1,

characterized,

that on the first axial portion (14) in the inner space region (16) a

Pulley (28) is received.

3. shaft (10) for transmitting torque according to claim 1 or 2,

characterized,

the shaft (10) runs through the wall (22) without sleeves and / or without seals and / or the rolling bearing (26) is encapsulated.

4. shaft (10) for transmitting a torque according to one of the preceding

Claims,

characterized,

the rolling bearing (26) is a deep groove ball bearing, a self-aligning bearing or a needle bearing.

5. shaft (10) for transmitting a torque according to one of the preceding

Claims,

characterized,

in that the roller bearing (26) is received indirectly in the wall via a tolerance compensation element (30).

6. shaft (10) for transmitting torque according to claim 5,

characterized,

the tolerance compensation element (30) has at least one torsional stiffness

Elastomer contour (32) includes.

7. shaft (10) for transmitting a torque according to one of the preceding

Claims,

characterized,

in that a vibration damper (36) is accommodated on the second section (18) in the outer space region (20).

8. shaft (10) for transmitting a torque according to one of the preceding

Claims,

characterized,

the shaft (10) is a crankshaft of an internal combustion engine (12).

9. Internal combustion engine (12),

marked by

a shaft (10) for transmitting a torque according to one of the preceding claims.

10. Internal combustion engine (12) according to claim 9,

characterized,

in that the internal combustion engine (12) has a timing drive with a toothed belt drive, wherein the toothed belt is encapsulated in a housing and wraps around the shaft.