WO2019214883A1

WO2019214883A1 - Bearing device with a structured shaft

Info

Publication number: WO2019214883A1
Application number: PCT/EP2019/058619
Authority: WO
Inventors: Thomas Lang
Original assignee: Robert Bosch Gmbh
Priority date: 2018-05-08
Filing date: 2019-04-05
Publication date: 2019-11-14
Also published as: DE102018207114A1

Abstract

The present invention relates to a bearing device (10) with a housing (12); at least one foil bearing (14) and/or tilting-pad bearing arranged in the housing in order to bear a rotating shaft (16); and the shaft, which is mounted in a bearing region (20) of the at least one foil bearing and/or tilting-pad bearing, wherein the shaft in the bearing region has a defined structuring (24) for defined passage of a working fluid through the bearing region during rotation of the shaft.

Description

description

Bearing device with a structured shaft

State of the art

The invention relates to a bearing device with a structured shaft and a turbomachine, in particular a flow compressor with a

Fast-rotating rotors (for example in turbomachines, such as turbocompressors or turbines) are stored, inter alia, with gas bearings (usually working medium air, ie air bearings). There are classic so-called "externally pressurized bearings", i. Bearings which are pressurized), "herringbone grooved bearings", i. Radial bearing with very fine grooves in the lO-lOOpm range in the form of an arrow on the shaft or "spiral grooved bearings", i. Thrust bearing with spiral grooves. Furthermore, there are still "tilted pad bearings", i.

Tilting pad bearings and the most common "foil bearings", i.

Film bearings.

At extreme peripheral speed, an extremely low power loss due to friction occurs on both the rotating and the stationary side over a comparatively small area. Here is mainly the

Heat development is a problem because the lubricating films are very small (pm range) and the thermal deformations have a comparable magnitude.

DE 10 2014 201 563 A1 discloses an aerodynamic air bearing with a cover film for supporting a shaft, wherein the cover film has a partial

Having coating with a structuring. Disclosure of the invention

The subject of the present invention is a bearing device with a housing; at least one disposed in the housing foil bearing and / or Kippsegmentlager for supporting a rotating shaft; and the shaft, which in a storage area of the at least one foil bearing and / or

Kippsegmentlagers is mounted, wherein the shaft has a defined structuring in the storage area for the defined or targeted management of a working fluid through the bearing area upon rotation of the shaft.

The present invention furthermore relates to a turbomachine, in particular a flow compressor with a bearing device described above.

The foil bearing and / or the tilting pad bearing can be designed as a radial bearing or thrust bearing.

The working medium is preferably air. In this case, the tilting pad bearing can be an air-lubricated tilting pad bearing.

In the context of this invention, a "defined line" is to be understood as meaning a defined fluid flow. The defined line or current is determined upon rotation of the shaft, i. in the operation of the device, for example. The

Turbomachine generated.

Here, the defined structuring is preferably designed such that upon rotation of the shaft, i. in operation, the working fluid is passed from a first area to a second area defined.

It should be noted here that, of course, each surface in the broadest sense has a kind of "structuring". For the purposes of this application, however, the structured region means a region which has a defined structure which differs from the surrounding region in order to generate a defined conduction of a working fluid through the bearing region upon rotation of the shaft. The defined line of the working fluid can in this case by a part of the storage area or through the entire Storage area done. The defined structuring preferably has defined grooves or grooves. Here, the grooves or grooves preferably extend at least partially or completely relative to a rotation axis of the shaft in an angular range of greater than 0 ° to less than 90 ° and / or less than -0 ° to greater than -90 ° and / or arrow-shaped and / or V -shaped and / or helical.

With the storage device according to the invention, it is now possible to cool very easily and inexpensively a rotor bearing system with a foil bearing and / or Kippsegmentlager targeted in the lubrication gap. By means of a corresponding structuring on the shaft in the bearing area of the foil bearing and / or tilting pad bearing, a defined mass flow or cooling flow through the bearing gap can be generated, which dissipates the frictional heat of the foil bearing and / or tilting pad bearing directly from the bearing gap. As a result, in turn, smaller bearings can be realized, resulting in smaller

Power loss or allows more compact designs.

It is advantageous if, in the axial direction, the first region and the second region are arranged relative to the foil bearing and / or tilting-segment bearing opposite outside of the bearing region. The axial direction corresponds to the axis of rotation or longitudinal axis of the shaft. The first region and / or the second region may be adjacent to the foil bearing and / or

Tilting pad storage be arranged. That is, in other words, that

Foil bearing and / or tilting pad bearing is flowed through axially by the working fluid. This allows an efficient cooling flow in the axial direction, i. through the storage area or bearing gap from one side to the other side of the

Foil bearing and / or Kippsegmentlagers are generated.

It is also advantageous if in the axial direction of the first area within, in particular substantially centrally within the storage area, and the second area are arranged outside the storage area. This allows an efficient cooling flow from the storage area or storage gap to the outside, i. be generated in a cooler area outside the film bearing and / or Kippsegmentlagers.

Furthermore, it is advantageous if the defined structuring in the axial direction of the first area outside the storage area and the second Area within, in particular substantially centered within the

Storage area are arranged. In this case, it is particularly advantageous if the film bearing and / or tilting pad bearing in the storage area has at least one vent opening for discharging the working fluid from the storage area. In this case, the first region can have two first partial regions which are arranged opposite one another relative to the film bearing and / or tilting pad bearing. In this way, an efficient cooling flow can be generated from a cooler region outside the foil bearing and / or tilting pad bearing into or through the bearing region or bearing gap, which is derived from the bearing region or bearing gap by means of the ventilation opening.

It is also advantageous if the housing is designed in such a way and the foil bearing and / or tilting pad bearing is arranged in the housing in such a way that in the axial direction a defined pressure gradient at the foil bearing and / or tilting pad bearing and / or a defined dynamic pressure outside the foil bearing and / or or tilting pad bearing. Here, the foil bearing and / or tilting pad bearing is preferably designed as a radial bearing and the grooves of the structuring preferably extend helically. By this measure, a dynamic pressure at a defined location, for example. At the edge of the foil bearing and / or Kippsegmentlagers be generated, whereby an additional sealing function can be realized.

It is also advantageous if the defined structuring is designed such that a bearing property, in particular the damping and / or the rigidity of the foil bearing and / or tilting pad bearing in dependence on a

To change the speed of the shaft defined, in particular to increase and / or lower. This measure is particularly advantageous in foil bearings, wherein both the bearings and the shaft can be optimally designed for the operating speed range.

Embodiments of the approach presented here are shown in the drawings and explained in more detail in the following description. It shows:

1 shows a schematic cross section of a bearing device according to an embodiment of the invention; and Fig. 2 is a schematic cross section of a bearing device according to another embodiment of the invention.

In Fig. 1, a bearing device according to the invention is provided in its entirety by the reference numeral 10.

The bearing device 10 has housing 12, two foil bearings 14 and a shaft 16. The film bearing 14 is accommodated in a bearing receptacle 18 of the housing 12.

The shaft 16 is rotatably mounted about a rotation axis 22 by means of the foil bearings 14 in bearing areas 20 of the foil bearings 14. In this case, the shaft 16 has a defined structuring 24 in the storage areas 20. The defined

Structuring 24 has defined grooves 26, which extend in an arrow shape and have an angle of + -45 ° to the axis of rotation 22 of the shaft 16. The defined structuring 24 is designed in such a way that, with a corresponding rotation of the shaft 16, a working fluid, which in this case is air, is guided from a first region 28 to a second region 30. In this case, in the axial direction 32, the first area 28 outside the storage area 20 and the second area 30 inside, in particular substantially centrally within the storage area 20 are arranged. In order to derive the working fluid from the storage area 20, the foil bearings 14 each have a bearing area 20

Vent 34 on. Accordingly, by means of the defined structuring 24 on the shaft 16, a defined line of a working fluid or air (and thus a cooling flow) in the direction of arrow 36 with corresponding rotation of the shaft 16, i. generated during operation.

2 shows a further embodiment of the bearing device 10, wherein the grooves 26 of the shaft 16 are substantially parallel and at an angle of + 45 ° to the axis of rotation 22 of the shaft 16. In this case, the working fluid or the air is guided with a corresponding rotation of the shaft 16 in the direction of arrow 36 from the first region 28 to the relative to the film bearing 14 opposite arranged second region 30 defined. This results in that the film bearings 14 are traversed by the air in the axial direction 32, so that an efficient cooling flow is generated by the storage areas 20.

Claims

claims

1st storage device (10) with

a housing (12);

- At least one in the housing (12) arranged film bearing (14) and / or Kippsegmentlager for supporting a rotating shaft (16); and

- The shaft (16) which is mounted in a storage area (20) of the at least one foil bearing (14) and / or Kippsegmentlagers, wherein the shaft in the storage area (20) a defined structuring (24) for the defined conduction of a working fluid through the storage area (20) upon rotation of the shaft (16).

Second bearing device (10) according to claim 1, characterized in that the defined structuring (24) is designed such that upon rotation of the shaft (16), the working fluid from a first region (28) to a second region (30) defined becomes.

3. bearing device (10) according to claim 2, characterized in that in the axial direction (32) of the first region (28) and the second region (30) relative to the film bearing (14) and / or tilting pad opposite lying outside of the storage area (20 ) are arranged.

4. bearing device (10) according to claim 2, characterized in that in the axial direction (32) of the first region (28) within, in particular substantially centrally within the storage area (20), and the second area (30) outside the storage area ( 20) are arranged.

5. bearing device (10) according to claim 2, characterized in that the defined structuring (24) in the axial direction (32) of the first region (28) outside the storage area (20) and the second area (30) are arranged within, in particular substantially centrally within the storage area (20).

6. bearing device (10) according to claim 5, characterized in that the film bearing (14) and / or tilting pad bearing in the storage area (20) at least one vent opening (34) for discharging the

Working fluid from the storage area (20).

7. bearing device (10) according to any one of the preceding claims, characterized by the housing (12) formed in such a way and the film bearing (14) and / or Kippsegmentlager such in the housing (12) is arranged in the axial direction (32) a defined

Pressure gradient on the film bearing (14) and / or Kippsegmentlager and / or a defined dynamic pressure outside of the film bearing (14) and / or Kippsegmentlagers sets.

8. bearing device (10) according to any one of the preceding claims, characterized in that the defined structuring (24) is designed to a bearing property, in particular the damping and / or stiffness of the film bearing (14) and / or

Kippsegmentlagers defined as a function of a speed of the shaft (16) defined to change, in particular to increase and / or reduce.

9. bearing device (10) according to any one of the preceding claims, characterized in that the defined structuring (24) defined grooves (26).

10. bearing device (10) according to claim 9, characterized in that the grooves (26) at least partially relative to a rotation axis (22) of the shaft in an angular range of greater than 0 ° to less than 90 ° and / or less than -0 ° to larger -90 ° and / or arrow-shaped and / or V-shaped and / or helical.

11. Storage device (10) according to one of the preceding claims, characterized in that the working medium is air and in particular the tilting pad bearing an air-lubricated

Tilting pad bearing is.

12. Turbomachine, in particular flow compressor with a bearing device (10) according to one of the preceding claims.