DE102014119319A1 - Bearing device for an exhaust gas turbocharger and turbocharger - Google Patents

Abstract

The invention relates to a bearing section for an exhaust-gas turbocharger (1), having a bearing device (11) comprising a bearing bush (12), wherein a while (5) is rotatably receivable in an inner space (21) of the bearing bush (12), and wherein a fixing element (22) for fixing the bearing bush (12) in the bearing section (4) is formed. According to the invention, the fixing element (22) is designed to produce a snap connection between the fixing element (22) and the bearing bush (12).

Description

The invention relates to a bearing device for an exhaust gas turbocharger of the type specified in the preamble of patent claim 1 and to 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 Gleitiager, 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 a minimum Relative movement between the bearing bush and bearing section 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 provided so that a tolerance compensation and adequate lubrication of the bearing are secured.

From the publication JP 2006-029148 A goes out an exhaust gas turbocharger, which has an air guide portion, an exhaust guide portion and a shaft, wherein the shaft is formed as a rotationally fixed connection between a first receiving space of the air guide portion positioned in a first impeller and a second receiving space of the exhaust gas guide portion positioned second impeller.

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 bushing 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 to provide a bearing section for an exhaust gas turbocharger, as well as 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 receivable in an inner space 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 serves a quick and simple 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 of the storage device according to the invention is quick and inexpensive to install without tools. In one embodiment of the invention, a positive connection is formed between the fixing element and the bearing portion. 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 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 element is variable. In other words, the element mandrel may be compressed to be assembled so as to have a smaller circumferential cross section than a relaxed state, and to be inserted shallowly 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 obtained, so that the Tolerance compensation and adequate lubrication of the bearing are secured.

In a further embodiment of the invention, the fixing element is formed from a plastic. Due to the production of the fixing element made of a plastic, this can be produced at low cost 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 and feature combinations mentioned above in the description as well as features and feature combinations mentioned below in the description of the figures and / or in the single figure alone can be used not only in the respectively indicated combination but also in other combinations or in isolation, without the scope of To leave invention. Show it:

1 in a longitudinal section of an exhaust gas turbocharger according to the invention with a bearing device according to the invention,

2 in a perspective view of a fixing element of the storage device according to the invention, and

3 in a perspective view a section of a bearing bush of the bearing device acc. 1

An inventive exhaust gas turbocharger 1 is according to 1 educated. The turbocharger 1 comprises a flow-through air guide section 2 , a flow-through exhaust gas guide section 3 and one between the air guide section 2 and the exhaust gas guide section 3 positioned bearing section 4 , In the warehouse section 4 is a wave 5 rotatably mounted, which one in a first receiving space 6 of the air guide section 2 positioned first impeller 7 with one in a second recording room 8th the exhaust gas guide section 3 positioned second impeller 9 rotatably connects. For example, an operation of the exhaust gas turbocharger takes place 1 with the help of an internal combustion engine, not shown. In this case, exhaust gas emitted from the internal combustion engine is guided through exhaust gas lines, not shown, wherein the exhaust gas lines an outlet region of the internal combustion engine, not shown, with an inlet region of the exhaust gas guide section, not shown 3 are arranged connecting.

The exhaust gas is the second impeller via the inlet region 9 flowing on, causing an expansion of the exhaust gas in the exhaust gas guide section 3 so that the second wheel 9 is put into a rotary motion. With the help of the wave 5 becomes the first wheel 7 also set in a rotary motion, so that sucked air and in the air duct section 2 is compressed. The compressed air can then via fresh air lines, not shown, which a non-illustrated outlet region of the air duct section 2 are arranged connecting with an inlet portion of the internal combustion engine, not shown, to be supplied to the internal combustion engine.

The in 1 illustrated bearing portion according to the invention 4 has a storage device 11 on which a sleeve-like bearing bush 12 includes. The bearing bush 12 is simultaneously formed in this embodiment as a radial bearing, the ends 13 . 14 the bearing bush 12 are designed in the form of a radial bearing. Likewise, the bushing could 12 be arranged between two radial bearings to secure an axial position of the radial bearings.

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

A lubricant supply to the bearing device 11 takes place with the help of a first oil supply channel 16 or a second oil supply channel 17 that of one in the storage section 4 positioned oil supply channel 18 are arranged branching.

The wave 5 is inside the bearing bush 12 rotatably mounted. To prevent a solid friction between an inner wall of the bearing bush 12 and an outer wall of the shaft 5 has the bearing bush 12 at least one radially arranged flow-through inflow opening 19 and a drain port, not shown. It could also have further inflow openings and / or drainage openings.

About the inflow opening 19 is an interior 21 the bearing bush 12 as well as at the ends of the bearing bush 12 trained radial bearings 13 . 14 Lubricating oil can be fed. A removal of the lubricating oil via the drain opening.

For fixing the bearing bush 12 is a fixing element 22 educated. With the help of the fixing element 22 will be both a rotational and a one in the direction of a longitudinal axis 23 the wave 5 and in the radial direction of the shaft 5 oriented movement of the bearing bush 12 prevented.

The fixing element 22 is a snap connection with the bearing bush 12 produced formed. For this purpose, the bearing bush 12 a receiving opening 24 on which starting from the interior 21 having 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 warehouse section 4 is a push-through channel 25 formed, which the fixing element 22 receives.

For a secure fixation is realized, the fixing element 22 an element head 26 on, whose first diameter D1 is greater than a second diameter 02 an element thorn 27 of the fixing element 22 , s. 2 , The element thorn 27 is integral with the element head 26 educated.

The fixing element 22 is so in the warehouse section 4 in the push-through channel 25 recorded that the element thorn 27 the wave 5 is disposed facing, wherein the element head 26 from the wave 5 is positioned away from the other.

To realize a snap connection, the element mandrel 27 three spur arms 28 on, which extends along an element longitudinal axis 29 of the fixing element 22 are arranged extending. Between the spine arms 28 is a cavity in the longitudinal direction 30 formed so that the spine arms 28 are movable relative to each other. Likewise could also have a different number of spines 28 be educated.

Furthermore, the spine arms 28 at their from the element head 26 turned away arm ends 32 designed barb-like, so that when installed these arms ends 32 on an inner surface 31 the bearing bush 12 be positioned supporting. For this the arm ends 32 a first paragraph 20 on, with which they are against the inner surface 31 can be positioned supporting. To ensure a minimum axial movement is the element mandrel 27 at the ends of his arms 32 from the bearing bush 12 spaced, so that the minimum axial movement in an order of the spacing is possible.

The push-through channel 25 is to hold the fixing 22 a longitudinal contour 33 of the fixing element 22 adapted trained. In the area of the element head 26 has the push-through channel 25 a the 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 installation.

In the area of the element thorn 27 has the push-through channel 25 a second circumference U2 of the element mandrel 27 adapted second cross-sectional area Q2. Since the first cross-sectional area Q1 is greater than the second cross-sectional area Q2 is a second paragraph 35 formed, the support of the element head 26 at the storage section 4 serves.

The fixing element 22 is advantageously formed of a plastic.

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

• JP 2006-029148 A [0004]

Claims (5)

Bearing section for an exhaust gas turbocharger ( 1 ), with a storage device ( 11 ) comprising a bearing bush ( 12 ), where a wave ( 5 ) in an interior ( 21 ) of the bearing bush ( 12 ) is rotatably receivable, and wherein a fixing element ( 22 ) for fixing the bearing bush ( 12 ) in the storage section ( 4 ), characterized in that the fixing element ( 22 ) for producing a snap connection between the fixing element ( 22 ) and the bearing bush ( 12 ) is trained. Bearing portion according to claim 1, characterized in that between the fixing ( 22 ) and the storage section ( 4 ) A positive connection is formed. Bearing portion according to claim 1 or 2, characterized in that the fixing element ( 22 ) in the direction of a longitudinal axis of the element ( 29 ) of the fixing element ( 22 ) extending multipart element mandrel ( 27 ), which has a variable second circumference (U2). Bearing section according to one of the preceding claims, characterized in that the fixing element ( 22 ) is formed of a plastic. Exhaust gas turbocharger, comprising a bearing section ( 4 ) for supporting a rotatable shaft ( 5 ), characterized in that the bearing section ( 4 ) is formed according to one of claims 1 to 4.

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