WO2016102049A1

WO2016102049A1 - Bearing device for an exhaust gas turbocharger, and exhaust gas turbocharger

Info

Publication number: WO2016102049A1
Application number: PCT/EP2015/002479
Authority: WO
Inventors: Hermann Burmester; Joachim Delitz; Paul Widenmaier
Original assignee: Ihi Charging Systems International Gmbh
Priority date: 2014-12-22
Filing date: 2015-12-08
Publication date: 2016-06-30
Also published as: DE102014119319A1

Abstract

The invention relates to a bearing segment for an exhaust gas turbocharger (1), comprising a bearing device (11) having a bearing bush (12), wherein a shaft (5) can be rotatably accommodated in an interior (21) of the bearing bush (12), and wherein a fastening element (22) for fastening the bearing bush (12) is formed in the bearing segment (4). According to the invention, the fastening element (22) is designed to establish a snapping connection between the fastening element (22) and the bearing bush (12).

Description

Bearing device for an exhaust gas turbocharger and turbocharger

The invention relates to a bearing device for an exhaust gas turbocharger in the

The preamble of claim 1 specified type and an exhaust gas turbocharger according to claim 5.

During operation of high-speed machines, in particular in exhaust gas turbochargers, vibrations occur at high speeds. Exhaust gas turbochargers, which are operated at very high speeds, rotational speeds of about 270000 rev / min, are particularly affected. Floating plain bearings, which are referred to as so-called full-floating bearings, have the advantage that occurring during operation

Vibrations can be damped because between the bearing portion and the bearing bush, a fluid, generally a lubricating oil, is present. With the help of this fluid, the vibrations are damped, so that a relatively smooth and smooth running of the shaft can be secured.

In addition to these full-floating plain bearings, which are characterized by the fact that the ~ relative movement between the shaft and bearing bush is possible, there are so-called semi-floating plain bearings, with their help also the vibration damping can be brought about, but here is no or one Minimal relative movement between the bearing bush and bearing portion possible, since the bearing bush is secured by means of a fixing element against rotation and axial displacement in the bearing section. A minimal axial movement of the bearing bush is to be provided, so that a

Tolerance compensation and adequate lubrication of the bearing are secured. JP 2006-029148 A discloses an exhaust-gas turbocharger which has an air-guiding section, an exhaust-gas guide section and a shaft, wherein the shaft acts as a rotationally fixed connection between a first impeller positioned in a first receiving space of the air-guiding section and a second accommodating space of the exhaust-gas guide section positioned second impeller is formed.

The shaft is rotatably mounted in a bearing portion, wherein the bearing portion between the air guide portion and the exhaust gas guide portion is arranged. The bearing section has a bearing device with at least one bearing bush. The shaft is rotatably mounted within the bearing bush. The bearing bush is fixed by means of a fixing element in the bearing section, so that a relative movement, d. H. a rotational movement and an excessive longitudinal movement, between the bearing bush and the bearing portion is avoided.

The object of the present invention is a bearing section for a

Exhaust gas turbocharger, as well as to provide an exhaust gas turbocharger, which is cheaper to manufacture compared to the prior art.

This object is achieved by a bearing section with the features of claim 1 and an exhaust gas turbocharger with the features of claim 5. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the respective subclaims, wherein advantageous embodiments of the bearing section are to be regarded as advantageous embodiments of the exhaust gas turbocharger - as far as applicable - and vice versa.

According to the invention, the bearing section has a bearing device with a

Bearing bush, wherein a shaft is rotatably received in an interior of the bearing bush. For fixing the bearing bush in the bearing portion, a fixing element is formed, wherein the fixing element is designed for producing a snap connection between the fixing element and the bearing bush. It is thus designed as a snap connection element. This is a quick and easy and thus cost-effective installation. While in the hitherto conventional fixing a screw connection is formed, wherein the usual fixing element is to be mounted with a tool, the fixing element of the invention

Storage device quickly and inexpensively mounted without tools.

In one embodiment of the invention is between the fixing and the

Bearing portion formed a positive connection. This has the advantage that the fixing element can be supported on the bearing portion and thus a secure fixation of the bearing bush is formed relative to the bearing portion.

In a further embodiment of the invention, the fixing element has a multipart element mandrel extending in the direction of an element longitudinal axis of the fixing element, which element has a variable second circumference. This has the advantage that the element mandrel for mounting in a cross section along a

Longitudinal axis of the fixing is variable. In other words, the

Element mandrel compressed for mounting so that it has a relation to a relaxed state smaller circumferential cross-section, and are easily inserted into an opening. By releasing the element mandrel, eg by releasing it as soon as it has reached its mounting position, the element mandrel presses against the opening surface and thus achieves a radial tensioning of the fixing element in the opening. The radial strain is just so great that the minimum axial

Movement of the bearing bush is maintained, so that the tolerance compensation and the adequate lubrication of the bearing are secured.

In a further embodiment of the invention, the fixing element is made of a

Plastic formed. Due to the production of the fixing element made of a plastic, this can be inexpensively manufactured in, for example, an injection molding process, so that a further cost reduction is possible.

The second aspect of the invention relates to an exhaust gas turbocharger, comprising a bearing portion for supporting a rotatable shaft, wherein the bearing portion is formed according to one of claims 1 to 4. Thus, a functionally reliable and cost-effective exhaust gas turbocharger is to be provided. Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features mentioned above in the description and

Feature combinations as well as subsequently mentioned in the figure description and / or alone in the single figure features and feature combinations can be used not only in the combination, but also in other combinations or alone, without departing from the scope of the invention. Show it:

Fig. 1 in a longitudinal section an exhaust gas turbocharger according to the invention with

a storage device according to the invention,

Fig. 2 is a perspective view of a fixing of the

Inventive storage device, and

3 is a perspective view of a detail of a bearing bush of the

Storage device acc. Fig.1

An exhaust gas turbocharger 1 according to the invention is designed according to FIG. Of the

Exhaust gas turbocharger 1 comprises a flow-through air guide section 2, a flow-through ble exhaust duct section 3 and a between the

Air guide section 2 and the exhaust gas guide section 3 positioned

Bearing section 4. In the bearing section 4, a shaft 5 is rotatably mounted, which rotatably connects a positioned in a first receiving space 6 of the air guide section 2 first impeller 7 with a second receiving space 8 of the exhaust gas guide section 3 second impeller 9. For example, an operation of the exhaust gas turbocharger 1 by means of an internal combustion engine, not shown. In this case, exhaust gas emitted from the internal combustion engine is guided through exhaust pipes, not shown in detail, wherein the exhaust pipes an outlet region of the internal combustion engine not shown in detail with a not closer arranged inlet region of the exhaust gas guide section 3 are arranged connecting.

The exhaust gas is passed over the inlet region, the second impeller 9 flowing on, causing an expansion of the exhaust gas in the exhaust gas guide section 3, so that the second impeller 9 is set in a rotational movement. With the help of the shaft 5, the first impeller 7 is also placed in a rotational movement, so that air is sucked in and compressed in the air guide section 2. The compressed air can then be supplied to the internal combustion engine via fresh air lines (not shown in more detail), which are arranged so as to connect an outlet region (not shown) of the air guide section 2 to an inlet region of the internal combustion engine, not shown.

The bearing portion 4 according to the invention shown in Fig. 1 has a

Storage device 11, which comprises a sleeve-like bushing 12. The bushing 12 is simultaneously formed in this embodiment as a radial bearing, wherein the ends 13, 14 of the bearing bush 12 are designed in the form of a radial bearing. Likewise, the bearing bush 12 could also be arranged between two radial bearings for securing an axial position of the radial bearings.

Furthermore, the bearing device 11 comprises a thrust bearing 15, which is arranged in the bearing section 4 in the region of the side of the bearing bush 12 facing the first wheel 7.

A lubricant supply to the storage device 11 takes place with the aid of a first

Oil supply channel 16 and a second oil supply channel 17, which of a in the

Bearing portion 4 positioned oil supply channel 18 are arranged branching.

The shaft 5 is rotatably mounted within the bearing bush 12. To prevent a solid friction between an inner wall of the bearing bush 12 and an outer wall of the shaft 5, the bearing bush 12 has at least one radially arranged flow-through inflow opening 19 and a non-illustrated Outflow opening on. It could also have other inflows and / or

Have drainage holes.

Via the inflow opening 19, an inner space 21 of the bearing bush 12 and the radial bearings 13, 14 formed at the ends of the bearing bush 12 can be supplied with lubricating oil. A removal of the lubricating oil via the drain opening.

For fixing the bearing bush 12, a fixing element 22 is formed. With the aid of the fixing element 22, both a rotational movement and a movement of the bearing bush 12 oriented in the direction of a longitudinal axis 23 of the shaft 5 and in the radial direction of the shaft 5 are prevented.

The fixing element 22 is formed a snap connection with the bearing bush 12 producible. For this purpose, the bearing bush 12 has a receiving opening 24 which, starting from the inner space 21, has a so-called counterbore. This counterbore does not necessarily have to be produced with a corresponding cutting tool, but can also be produced in a casting process. The receiving opening 24 has the shape of a counterbore.

In the bearing section 4, a through-channel 25 is formed, which receives the fixing element 22.

So that a secure fixation is realized, the fixing element 22 has a

Element head 26, whose first diameter D1 is greater than a second

Diameter D2 of an element mandrel 27 of the fixing element 22, s. Fig. 2. The

Element mandrel 27 is formed integrally with the element head 26.

The fixing element 22 is received in the bearing section 4 in the through-channel 25, that the element mandrel 27 of the shaft 5 is arranged facing, wherein the

Element head 26 is positioned away from the shaft 5. To realize a snap connection, the element mandrel 27 has three mandrel arms 28 which extend along an element longitudinal axis 29 of the fixing element 22

are arranged extending. Between the mandrel arms 28 in each case a cavity 30 is formed in the longitudinal direction, so that the mandrel arms 28 are movable relative to each other. Likewise, a different number of mandrel arms 28 could be formed.

Furthermore, the mandrel arms 28 are designed barb-like at their arm ends 32 facing away from the element head 26, so that in the installed state these arm ends 32 are supported on an inner surface 31 of the bearing bush 12

be positioned. For this purpose, the arm ends 32 have a first shoulder 20 with which they are positionally supportable against the inner surface 31. to

Ensuring a minimum axial movement of the element mandrel 27 is spaced at its arm ends 32 of the bearing bush 12, so that the minimum axial movement in an order of the spacing is possible.

The push-through channel 25 is configured adapted to hold the fixing element 22 of a longitudinal contour 33 of the fixing element 22. In the region of the element head 26, the push-through channel 25 has a first circumference U1 of the element head 26

adapted first cross-sectional area Q1 while maintaining a game 34 on. The game 34 is to be provided for simplified assembly.

In the region of the element mandrel 27, the push-through channel 25 has a second cross-sectional area Q 2 adapted to the second circumference U 2 of the element mandrel 27.

Since the first cross-sectional area Q1 is greater than the second cross-sectional area Q2, a second shoulder 35 is formed, which serves to support the element head 26 on the bearing section 4.

The fixing element 22 is advantageously formed from a plastic.

Claims

claims

Bearing portion for an exhaust gas turbocharger (1), comprising a bearing device (11) comprising a bearing bush (12), wherein a shaft (5) in an interior space (21) of the bearing bush (12) is rotatably receivable, and wherein a fixing element (22) for Fixing the bearing bush (12) in the bearing section (4) is formed,

characterized in that

the fixing element (22) is designed to produce a snap connection between the fixing element (22) and the bearing bush (12).

Bearing portion according to claim 1,

characterized in that

between the fixing element (22) and the bearing portion (4) is formed a positive connection.

Bearing section according to claim 1 or 2,

characterized in that

the fixing element (22) has a multipart element mandrel (27) extending in the direction of an element longitudinal axis (29) of the fixing element (22), which element has a variable second circumference (U2).

Bearing section according to one of the preceding claims,

characterized in that

the fixing element (22) is formed from a plastic.

Exhaust gas turbocharger comprising a bearing section (4) for supporting a rotatable shaft (5), characterized in that

the bearing portion (4) according to one of claims 1 to 4 is formed.