WO2020083434A1

WO2020083434A1 - Bearing device for a turbocharger, and turbocharger

Info

Publication number: WO2020083434A1
Application number: PCT/DE2019/100902
Authority: WO
Inventors: Oliver Baumann; Epameinondas CHRISTODOULOPOULOS; Joachim Delitz; Matthias DEUTSCHER; Henryk JOHN
Original assignee: Ihi Charging Systems International Gmbh
Priority date: 2018-10-25
Filing date: 2019-10-16
Publication date: 2020-04-30
Also published as: DE102018126591A1

Abstract

The invention relates to a bearing section for a turbocharger (2), comprising a section housing (3), in which a bearing device (6) comprising a bearing bush (7) is arranged in a receiving cut-out (10) of the section housing, wherein: a shaft (4) is rotatably received in an interior (11) of the bearing bush; a fastening element (15) is designed to fasten the bearing bush in the section housing; and the bearing bush is designed in the form of a semi-floating bearing. According to the invention, the fastening element is used to supply lubricant to an exterior surface (23) of the bearing bush, and the supply of lubricant to the interior of the bearing bush is prevented, the fastening element being removable without destruction. The invention further relates to a turbocharger.

Description

Storage device for an exhaust gas turbocharger and exhaust gas turbocharger

The invention relates to a storage device for an exhaust gas turbocharger

The preamble of claim 1 specified type and an exhaust gas turbocharger according to claim 12.

When operating high-speed machines, especially with exhaust gas turbochargers, vibrations occur at high speeds. Exhaust gas turbochargers, which are operated at very high speeds, speeds of about 270,000 rpm, are particularly affected. Floating plain bearings, which are referred to as so-called full-floating plain bearings, have the advantage that they occur during operation

Vibrations can be damped since a fluid, generally a lubricant, is present between the bearing section and the bearing bush. With the help of this fluid, the vibrations are damped, so that a relatively smooth and even running of the shaft can be ensured.

In addition to these full-floating plain bearings, which are characterized by the fact that the

Relative movement between the shaft and the bearing bush is possible, there are so-called semi-floating plain bearings, with the help of which vibration damping can also be brought about, but here no or a minimal relative movement between the bearing bush and the bearing section is possible, since the bearing bush is countered with the help of a fixing element Rotation and axial displacement in the bearing section is secured. A minimal axial movement of the bearing bush is to be provided, so that a

Tolerance compensation and sufficient lubrication of the bearing are ensured.

From the published patent application JP 2006-029148 A, an exhaust gas turbocharger emerges which has an air duct section, an exhaust duct section and a shaft, the shaft being a non-rotatable connection between one in one first receiving space of the air guide section positioned first impeller and a second impeller positioned in a second receiving space of the exhaust gas guide section.

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

European patent specification EP 2 131 053 B1 discloses a bearing section with a multi-part fixing element for fixing the bearing bush. The fixing element consists of a securing section and a positioning section, whereby after mounting the fixing element and fixing the bearing bush with the help of the securing section, the positioning section is removed by breaking a nose which is formed in one piece with the positioning section and engages in the securing section for positioning the fixing element.

Since the so-called "semi-floating" bearing, also known as a semi-floating bearing, is movable, even if only minimally movable, it is necessary to dampen these minimal movements of the bearing bush. This is done by creating a film of lubricant between the bearing bush and the bearing section.

To avoid a complex lubricant channel system, which the

Supply of the bearing sleeve with lubricant serves both inside and over its circumference, and which leads to high manufacturing costs of the bearing section, it is the object of the present invention to provide a bearing section for an exhaust gas turbocharger, which is designed in a simple manner to provide the bearing sleeve . Another object of the invention is to provide an inexpensive exhaust gas turbocharger. This object is achieved by a bearing section with the features of claim 1 and by an exhaust gas turbocharger with the features of claim 12.

Advantageous configurations with expedient and non-trivial developments of the invention are specified in the respective subclaims, with advantageous configurations of the bearing section being advantageous configurations of the

Exhaust gas turbocharger - if applicable - and vice versa.

A bearing section according to the invention for an exhaust gas turbocharger comprises a

Section housing, in which a bearing device comprising a bearing bush is arranged in a receiving recess of the section housing. In one

Inside the bearing bush, a shaft of a running gear of the exhaust gas turbocharger is rotatably received. A fixing element is used to fix the bearing bush in the

Section housing formed, the bearing bush in the form of a

semi-floating camp is formed. The fixing element is received in a channel of a lubricant channel system of the bearing section. According to the invention, the fixing element serves to supply lubricant to an outer surface of the

Bearing bush, and being a lubricant supply to the interior of the

Bearing bush is prevented, the fixing element being designed to be non-destructively removable.

The fixing element is designed to secure the position of the bearing bush and to transmit axial forces to the section housing. Since the fixing element, in addition to securing the position of the bearing bush, both in the axial direction and in relation to rotation in the housing section, at the same time for transmission or

Absorption of the axial forces and for supplying lubricant to the outer surface of the bearing bush is the advantage of a compact design of the

Given storage section. Furthermore, a major advantage is his

non-destructive disassembly, as it can be reused inexpensively. Thus, a garbage and / or scrap rate, which is increased in the event of destruction-prone dismantling, is reduced while at the same time saving costs, since no new fixing element is required, since the fixing element previously used can continue to be used. At this point it should be mentioned that this invention is deliberately a simultaneous

Avoid supplying the outer surface of the bearing sleeve and an interior of the bearing sleeve with the help of the fixing element, since lubricant which is the first

Outer surface of the bearing sleeve and then its interior,

possibly has particles which lead to damage to the bearing sleeve and / or the shaft received in the interior. Furthermore, with this

Supply path the lubricant pressure resulting in the interior is reduced. If the interior were first supplied with lubricant and then the exterior, the result would be vice versa.

In one embodiment, the fixing element can be removed with the aid of a non-positive connection to the section housing, an outer contour and / or a wall formed in the interior of the fixing element to bring about the

Traction connection is formed. Frictional connections can be formed in the form of frictional connections, the parts involved both when establishing the frictional connection and when releasing the

Do not damage the frictional connection. So with this type of

Connection a non-destructive disassembly of the fixing element can be brought about. The external contour is advantageously designed in the form of an external thread which is complementary to an internal thread formed in the channel.

The fixing element is preferably predominantly cylindrical. This has the advantage that the forces to be absorbed or absorbed in the fixing element can be absorbed evenly distributed over its cross-sectional area.

In a further embodiment, the fixing element has at least one lubricant channel formed on its circumference, which extends along a

Element axis of the fixing element, which is formed in the direction of a longitudinal axis of the channel. The advantage is that the lubricant can continue to flow in the direction of the direction given by the channel. Usually, the channel is formed perpendicular to the bearing bush, which is the shortest

Supply path and thus a rapid supply of lubricant are formed. So that no lubricant can reliably get into the interior of the bearing sleeve, a section of the fixing element which is in engagement with the bearing sleeve has a height which brings about a complete covering of a wall surface of the bearing sleeve which engages with it. The fixing element is usually in engagement with the bearing bush at a right angle. That is, one

Longitudinal axis of the bearing bush to the element axis of the fixing element is arranged at an angle of 90 °. In this case, it would mean that the section has a height of at least one wall thickness of the bearing bush.

It could also be the case that the angle formed between the longitudinal axis of the bearing bush and the element axis of the fixing element is not equal to 90 °. The section of the fixing element which is in engagement with the bearing bush must be larger than the wall thickness so that no lubricant can safely get into the interior of the bearing bush. The section must therefore have at least a height which leads to the complete covering of the wall surface of the bearing bush surrounding it.

For reliable lubricant supply, the lubricant channel extends from its end remote from the bearing bush to the section of the fixing element which is in engagement with the bearing bush. This ensures a secure filling of the lubricant channel.

In a further embodiment of the bearing section, the fixing element has elastic regions in sections along its element axis over its circumference. The advantage is that a full press fit between the fixing element and the section housing over the circumference of the fixing element is not necessary, since a fixing contact between the fixing element and the section housing is brought about by the elastic regions. This fixing contact serves to transmit the forces acting on the bearing bush.

In a further embodiment, the fixing element has at least one notch extending along an element axis. The advantage is the possibility of non-destructive removal of the fixing element, since the notch is only elastic and is not subject to plastic deformation. In the case of several notches, it can still be ensured that the fixation can be reliably established with the aid of the notches.

So that the fixing element can be gripped easily and securely for assembly and disassembly, it has a receiving means that brings about a positive fit. This

Receiving means can be designed, for example, in the form of a polygonal hole, into which a tool can be protruded and can bring about a positive connection with the hole.

In a further embodiment, the fixing element has a support ring which is designed such that it can be abutted against a stop formed in the channel of the section housing. This serves for a secure and reliable positioning of the fixing element, so that it can neither be inserted too deeply into the bearing bush nor that only a slight engagement of the fixing element in the bearing bush is formed.

The fixing element is preferably formed from a metallic material, which gives the advantage of a temperature-resistant element. Alternatively, the fixing element can be formed from a plastic. This has the advantage that it can be manufactured inexpensively. Temperature and lubricant resistant plastics are preferred.

With the help of one or more means which are designed for pre-centering the bearing sleeve, in particular with the aid of a in a passage opening of the bearing sleeve

engaging pin can improve the assembly of the fixing element

The bearing sleeve must be correctly arranged in the bearing section before the fixing element is installed.

The second aspect of the invention relates to an exhaust gas turbocharger, comprising an air guide section, an exhaust gas guide section and a bearing section for supporting a rotatable shaft of a running gear of the exhaust gas turbocharger, the bearing section being designed according to one of claims 1 to 11 is. A functionally reliable and cost-effective exhaust gas turbocharger is thus provided, which is characterized in particular by vibration and vibration damping of the bearing bush. As a result, it also has an increased service life, since wear on the bearing bush is significantly reduced.

Overall, the bearing section according to the invention is significantly reduced in cost, since in particular the number of manufacturing process steps is reduced. Thus, since the fixing element has two functions, the oil supply to the

Bearing bush and its fixation, for example the manufacture of a receiving point for a fixing element, which has only the function of fixing.

Another equally important advantage is the avoidance of a new training device and / or the joining steps of the same, so that it can be used as before and installed as is known.

Further advantages, features and details of the invention result from the following description of a preferred exemplary embodiment and from the drawing. The features mentioned in the description and

Characteristic combinations as well as features and combinations of features mentioned below in the description of the figures and / or shown in the single figure alone can be used not only in the respectively specified combination but also in other combinations or on their own without departing from the scope of the invention. Show it:

1 is a longitudinal section of a bearing section according to the invention in a first embodiment,

Fig. 2 likes a detailed view II of the bearing section. Fig. 1,

Fig. 3 in a longitudinal section like a fixing element of the bearing section. Fig. 1,

Fig. 4 in a perspective view of the fixing element. Fig. 3 5 is a longitudinal section of the bearing section according to the invention in a second embodiment,

Fig. 6 like a detailed view VI of the bearing section. Fig. 5,

Fig. 7 in a longitudinal section like the fixing element of the bearing section. Fig. 5,

Fig. 8 in a perspective view of the fixing element. Fig. 7,

9 is a longitudinal section of the bearing section according to the invention in a third embodiment,

Fig. 10 like a detailed view X of the bearing section. Fig. 9, and

Fig. 1 1 in a perspective view like the fixing element of the bearing section. Fig. 9.

A bearing section 1 according to the invention of an exhaust gas turbocharger 2 according to the invention in a first exemplary embodiment is designed according to FIG. 1. The

Exhaust gas turbocharger 2 includes a flow-through, not shown

Air guide section, a flow through, not shown

Exhaust gas guide section and between the air guide section and the

Exhaust gas guide section positioned bearing section 1, which a

Section housing 3 has. In the section housing 3, a shaft 4 is rotatably mounted, which rotatably connects a first impeller 5 positioned in a first receiving space (not shown) of the exhaust gas guiding section to a second impeller (not shown in detail) in a second receiving space (not shown) of the air guiding section. For example, the exhaust gas turbocharger 2 is operated with the aid of a not shown

Bre nn force. In operation, exhaust gas expelled from the internal combustion engine is led through exhaust gas lines (not shown in more detail), the exhaust gas lines having an outlet area (not shown in more detail) of the internal combustion engine with one not shown

shown entry area of the exhaust duct section are arranged connecting.

The exhaust gas is directed to the first impeller 5 in an inflow manner, causing the exhaust gas to expand in the exhaust gas guide section, so that the first impeller 5 is set into a rotational movement. With the help of the shaft 4, the second impeller is also set in a rotational movement, so that air is sucked in and compressed in the air guide section. The compressed air can then via fresh air lines, not shown, which one not shown

Exit area of the air duct section with a not shown

Inlet region of the internal combustion engine are arranged connecting the

Internal combustion engine are supplied.

The bearing section 1 according to the invention shown in FIG. 1 has one

Bearing device 6 in the section housing 3, which comprises a sleeve-like bearing bush 7. In this embodiment, the bearing bush 7 is simultaneously designed as a radial bearing, the ends 8, 9 of the bearing bush 7 being designed in the form of a radial bearing. Likewise, the bearing bush 7 could also be arranged between two radial bearings to secure an axial position of the radial bearings. The

Bearing device 6 is received in a receiving recess 10 extending axially completely through the section housing 3.

The bearing bush 7 is hollow-cylindrical, the shaft 4 in one

Interior 1 1 of the bearing bush 7 is rotatably received.

A lubricant is supplied to the bearing device 6 with the aid of a

Lubricant channel system 44 of the bearing section 1, comprising at least a first lubricant supply channel 12, a second lubricant supply channel 13 and a lubricant supply channel 14, from which the supply channels 12, 13 are arranged branching in the section housing 3. A fixing element 15 is designed to fix the bearing bush 7. With the aid of the fixing element 15, both a rotational and a movement of the bearing bush 7 oriented in the direction of a longitudinal axis 16 of the shaft 4 and in the radial direction of the shaft 4 is prevented. In other words, the fixing element 15 secures the bearing bush 7 against axial displacement and against rotation in the

Section housing 3. Furthermore, with the aid of the fixing element 15, axial bearing forces and friction moments of the bearing 6, which is designed in the form of a semi-floating bearing, are transmitted to the section housing 3.

The fixing element 15, which is predominantly cylindrical and pin-like, a

Element axis 17 is formed, is in a detailed view II in the installed state in the first lubricant supply channel 12 of the invention

Bearing section 1 in the first embodiment, illustrated in detail in a side view in FIG. 3 and in a perspective view in FIG. 4.

The fixing element 15 of the bearing section 1 in the first exemplary embodiment has an outer contour 19 on its outer circumference 18, which is at least partially

Complementary to an inner contour 20 of a receiving opening 21 formed in the section housing 3, wherein the contours 19, 20 are designed for non-destructive removal and assembly. In the present first two

Exemplary embodiments, the outer contour 19 is designed in the form of a thread, the inner contour 20 being complementary to this.

The first lubricant supply channel 12 is branched from the lubricant supply channel 14 and is supplied with lubricant by it, in other words, that lubricant flows through the first lubricant supply channel 12 for supplying lubricant to the bearing device 6. For simple assembly of the fixing element 15, it is arranged in the first lubricant supply channel 12, which is coaxial with a throughflow axis 36 of the lubricant supply channel 14. It could also be off-axis to the throughflow axis 36

be arranged. In other words, that means that the receiving opening 21 is part of the first lubricant supply channel 12 in the present exemplary embodiment. So that with the help of the fixing element 15 an outer surface 23 of the bearing bush 7 is supplied with lubricant, the fixing element 15 has a realization

Lubricant forwarding on its outer circumference 18 has four lubricant channels 22 which extend in the direction of the element axis 17. The lubricant channels 22 are groove-like. The number of lubricant channels 22 is dependent on a width b and a depth t of the lubricant channel 22, which should be designed overall to bring about a sufficient flow of lubricant on an outer surface 23 of the bearing bush 7.

The fixing element 15 can be divided into three sections, a first section 24, which is used in particular for fixing and non-destructive disassembly and assembly, a second section 25, which serves to position the fixing element 15 in the receiving opening 21, and a third section 26, which is also which serves to hold and fix the bearing bush 7, with a positive connection between an opening 27 of the bearing bush 7 and the fixing element 15. The second section 25 is designed to make contact with the section housing 3, the lubricant channel 22 being designed to extend over it, to ensure a lubricant supply to the bearing bush 7.

The first section 24 has a first diameter D1, which is larger than a second diameter D2 of the second section 25. This is necessary for the secure and operationally stable formation of a non-positive connection between the fixing element 15 and the section housing 3, in particular when the non-positive connection in the form of a thread a sufficient thread depth can be achieved for the realization of a break-proof thread. Of

Furthermore, with the help of the smaller second diameter D2, one is the second

Section 25 formed in the radial direction protruding support ring 39, which serves to limit a depth of penetration of the fixing element 15 during its assembly, starting from the lubricant supply channel 14. The support ring 39 is formed in sections due to the lubricant channels 22 penetrating it. The third section 26 has a third diameter D3, which is larger than the second diameter D2 but smaller than the first diameter D1.

The first section 24, which is arranged facing away from the bearing bush 7 in the bearing section 1, has a receiving means 28 for the form-fitting receiving of a mounting tool. In the present exemplary embodiment, the receiving means 28 is designed as a cavity for bringing about a positive connection with a tool in the form of an external hexagon key or a so-called Allen key.

The receiving opening 21 is designed for the introduction of the fixing element 15, the first section 24 being in a first after the fixing element 15 has been installed

Opening section 29 and the second section 25 is positioned in a second opening section 30. The first section 24 has a stop 40 for striking the support ring 39.

The third section 26 is viewed in the direction of the element axis 17, predominantly received in the opening 27. Here, the third section 26 can at least partially extend in the interior 11 of the bearing bush 7. Likewise, it can be at least partially formed in a recess 10 in the receptacle

Lubricant chamber 31 extend. This depends on its height h and a wall thickness w of the bearing bush 7. The position of the bearing bush 7 is secured with the aid of a clearance fit between the third section 26 and the opening 27.

The first opening section 29 is largely complementary to the first section 24, in an end region of the first opening section 29

Thread free cuts 32 are formed. The second opening section 30 has a diameter D which corresponds to the third diameter D3, so that the third section 26 can be pushed through.

The fixing element 15 of the exhaust gas turbocharger 2 respectively. of the bearing section 1 in a second embodiment differs from the fixing element 15 of the Exhaust gas turbocharger 2 of the first embodiment essentially by receiving an element head 33 facing away from the bearing bush 7

trained end of the first section 24, s. FIG. 5. In FIG. 6, a detailed view VI, the fixing element 15 of this exemplary embodiment is illustrated in detail in the installed state in the first lubricant supply channel 12, in a side view in FIG. 7 and in a perspective illustration in FIG. 8.

The element head 33 serves for an improved assembly, since the element head 33 is securely graspable, both during assembly and during the disassembly of the fixing element 15. Another advantage of the element head 33 is that it is in the form of the support ring 39 as a stop of the Fixing element 15 can strike in the housing section at the stop 40. Thus, the fixing member 15 can not be accidentally mounted too far into the interior 1 1. The lubricant channels 22 extend from the third section 26, in which they are not formed so that the lubricant cannot get into the interior 11 via the fixing element 15, up to and including in the direction of the element axis 17 through the

Element head 33, so that the lubricant can flow from the first lubricant supply channel 12 via the element head 33 into the lubricant channels 22.

In a third embodiment of the bearing section 1, respectively. of the exhaust gas turbocharger 2 according to the invention, the fixing element 15 is designed in the form of a notch pin for simple assembly and for non-destructive disassembly. It has elastic regions 34 in sections along its element axis 17 over its circumference. The term elastic regions is to be understood in such a way that, although these regions are plastic, they have an elastic function when assembled. These elastic regions 34 lie in the region of notches 35, which are configured to extend along the element axis 17. Overall, the fixing element 15 of this exemplary embodiment has three notches 35.

In order to achieve a preferred elasticity, the elastic regions 34 have a tapering in the radial direction in the direction of the element axis 17

Cross section Q on. Thus, non-destructive deformation due to material shift caused mainly in the circumferential direction can be realized.

This fixing element 15 has a single diameter D, which the

Corresponds to diameter D3. It is therefore cheaper to produce than the two previously described fixing elements 15 of the first two exemplary embodiments of the

Exhaust gas turbocharger 2 or the bearing section 1.

The notches 35 are formed in the groove-free areas of the fixing element 15, which are located between the groove-like lubricant channels 22.

The notches 35 have a notch length L which is smaller than an overall length GL of the fixing element 15.

A secure connection between the fixing element 15 and the

Section housing 3 is brought about with the aid of the elastic regions 34, since in these regions 34 the diameter D of the fixing element 15 is due to the

The elasticity of the regions 34 is variable. This means that in these elastic regions 34, in which contact is made with the section housing 3, the forces of the axial forces and the frictional moments are absorbed.

For non-destructive disassembly, the fixing element 15 of this exemplary embodiment is designed to have a central indentation 37 which extends along its element axis 17 and which has a threaded profile on its wall 38. In this thread profile there is a tool

Completely designed outer profile, can be inserted like a screw so that the fixing element 15 can be safely removed by a tensile load.

In these exemplary embodiments, the fixing element 15 is formed from a metallic material. Likewise, it could be made from a lubricant resistant

Be made of plastic.

In FIG. 1, the bearing section 1 according to the invention furthermore has a passage opening 42 in a housing part 41 receiving the bearing bush 7, in which a Pin 43 is arranged, which is in engagement with the bearing bush 7. This pin 43 serves for pre-centering the bearing bush 7.

In the present exemplary embodiments, the openings 27, 42 are designed in the form of a bore. However, they could also be made differently from a hole.

Claims

1. bearing section for an exhaust gas turbocharger (2), comprising a section housing (3), in which a bearing device (6) comprising a bearing bush (7) is arranged in a receiving recess (10) of the section housing (3), a shaft (4) in an interior (1 1) of the bearing bush (7) is rotatably received, and wherein a fixing element (15) for fixing the bearing bush (7) in

Section housing (3), and wherein the bearing bush (7) is designed in the form of a semi-floating bearing, and wherein the fixing element (15) is received in a channel (12; 14) of a lubricant channel system (44) of the bearing section (1),

characterized in that

the fixing element (15) serves to supply lubricant to an outer surface (23) of the bearing bush (7), and a lubricant supply to the interior (11) of the bearing bush (7) is prevented, the fixing element (15)

is designed to be non-destructively removable.

2. bearing section according to claim 1,

characterized in that

the fixing element (15) with the aid of a frictional connection

Section housing (3) can be dismantled, an outer contour (19) and / or a wall (38) formed in the interior of the fixing element (15) for guiding the non-positive connection in place.

3. bearing section according to claim 1 or 2,

characterized in that the fixing element (15) is predominantly cylindrical.

4. Bearing section according to one of the preceding claims,

characterized in that

the fixing element (15) has at least one formed on its circumference

Lubricant channel (22) which extends along an element axis (17) of the fixing element (15), which is formed in the direction of a longitudinal axis of the channel (12; 14).

5. Bearing section according to one of the preceding claims,

characterized in that

a section (26) of the fixing element (15) which is in engagement with the bearing bush (7) has a height (h) which brings about a complete covering of a wall surface of the bearing bush (7) which is in engagement with it.

6. bearing section according to claim 5,

characterized in that

the lubricant channel (22) extends from its end remote from the bearing bush (7) to the section (26).

7. bearing section according to one of the preceding claims,

characterized in that

the fixing element (15) has at least one notch (35) extending along an element axis (17).

8. bearing section according to one of the preceding claims,

characterized in that

the fixing element (15) has a receiving means (28) which brings about a positive fit.

9. bearing section according to one of the preceding claims,

characterized in that

the fixing element (15) has a support ring (39) which is attached to one in a Receiving opening (21) of the section housing (3) designed stop (40) is designed stopable.

10. bearing section according to one of the preceding claims,

characterized in that

the fixing element (15) is made of a metallic material or a plastic that is particularly resistant to lubricants.

1 1. storage section according to one of the preceding claims,

characterized in that

Means (42, 43) for precentering the bearing sleeve (7) are formed.

12. Exhaust gas turbocharger, comprising an air duct section, a

Exhaust gas routing section and a bearing section for supporting a rotatable shaft (4) of a running gear of the exhaust gas turbocharger (2),

characterized in that

the bearing section (1) is designed according to one of claims 1 to 1 1.