EP2844836A1

EP2844836A1 - Method for connecting a shaft to a rotary component and turbocharger shaft produced by said method

Info

Publication number: EP2844836A1
Application number: EP13714627.0A
Authority: EP
Inventors: Johannes Schmid; Bernd Reinsch; Ugur Kisa; Andreas Burghardt; Jochen Rager; Bernd Lutz
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2012-05-02
Filing date: 2013-04-03
Publication date: 2015-03-11
Also published as: US20150125306A1; WO2013164147A1; DE102012207271A1

Abstract

The invention relates to a method for producing a connection of at least one rotary component (30) to a shaft (10), wherein the at least one rotary component has a central opening (20) and the shaft has a first section (50) along the shaft and a second section (60) on an end face (65) of the shaft, wherein the method comprises the following steps: fixing the shaft at the first section thereof in the central opening of the at least one rotary component by means of an eccentric arrangement (71), such that the shaft is fixed in the radial direction relative to the at least one rotary component; and fixing the shaft at the second section thereof by press-fitting a ball (40), so that the shaft is secured in the axial direction relative to the at least one rotary component; wherein each fixing step is carried out by means of positive engagement.

Description

Description title

A method of connecting a shaft to a rotating member and a turbocharger shaft made by this method

The present invention relates to a method for connecting a shaft to a rotary component, in particular a turbine and / or compressor, and a turbocharger shaft produced by this method.

State of the art

From the prior art methods for connecting a shaft with a

Turbine or a compressor wheel known, these methods are used for example in the manufacture of exhaust gas turbochargers for the automotive industry.

Here, in particular, the exhaust gas connection of the shaft with the turbine wheel of interest, since the turbine of an exhaust gas turbocharger is exposed to much higher temperatures than the fresh air blown around the compressor. This compound is therefore of increased interest, since the usually different materials of shaft and turbine or their respective

Thermal expansion coefficients at the relatively high temperatures to which these components are exposed, can give rise to problems with the type of connection. From DE 10 2010 010 136 A1 discloses a turbocharger shaft with an attached impeller is known, wherein shaft and wheel by means of a knurling a

Form positive connection, which defines the shaft in the radial direction relative to the impeller. In the axial direction, the shaft is fixed by means of a shaft nut opposite the impeller, i. by means of a frictional connection.

Disclosure of the invention

The invention proposes in a first aspect according to claim 1, a method for producing a connection of at least one rotary member with a shaft, wherein the at least one rotary member a central recess and the shaft at least a first portion along the shaft and a second portion at a Front end of the shaft, the method comprising the following steps:

Fixing the shaft at its first portion in the central recess of the at least one rotary member so that the shaft is fixed in the radial direction relative to the at least one rotary member; and fixing the shaft to its second portion such that the shaft is axially relative to the at least one

Rotational component is set; wherein the steps of fixing are each performed in a form-fitting manner.

In a second aspect according to claim 12, the invention proposes a

Turbocharger shaft, which is connected to at least one rotary member, wherein the connection between the shaft and the rotary member according to the method of the first aspect is carried out.

Advantages of the invention

The advantage of the method or of the turbocharger shaft produced according to the method according to one embodiment results from the fact that the shaft only in each case by a positive connection in both the radial and in the axial direction relative to the rotary member, i. the turbine wheel and / or the compressor wheel is fixed. That is, the connection between the shaft and / or compressor wheel can be produced in a particularly simple manner, which also materials can be used, which otherwise due to their properties, such as mechanical workability and thermal expansion behavior, only with relatively large cost and time-intensive Work out effort.

Advantageously, the step of fixing the shaft at its first portion in the central recess of the at least one rotary component comprises an eccentric configuration arranged on the first portion, namely eccentrically in FIG

Circumferential direction of the shaft, wherein the central recess of the at least one rotational component corresponding to the eccentric configuration is formed such that by rotating the shaft relative to the central recess, the shaft is fixed in a form-fitting manner in the radial direction. Due to the eccentric design of the compound, the manufacturing tolerances can be relatively larger than conventional, which means lower costs. In addition, the transmission power is relatively high in terms of torque due to the positive connection.

The connection between shaft and wheel is also due to the positive engagement of the eccentric configuration also self-locking, but again solvable because of

Positive locking acts only in one direction.

Moreover, the operation of the turbocharger enhances the effect of the positive connection by itself.

Incidentally, the connection between shaft and wheel is also self-centering.

It is further preferred that the step of fixing the shaft at its second portion by means of caulking a ball in a corresponding recess on the one end side of the shaft takes place, so that the shaft is positively fixed relative to the at least one rotational component in the axial direction. Such a connection is relatively easy to manufacture and inexpensive, especially in mass production. The step of fixing the shaft at its first section in the central recess of the at least one rotary component preferably takes place by means of a knurling arranged on the first section, which has axially parallel grooves along the shaft, wherein the central recess of the at least one rotary component has a corresponding knurling with corresponding grooves has, so that the shaft relative to the central recess of the at least one rotary member is fixed in a form-fitting manner in the radial direction. This type of connection is of relatively high connection strength.

It is also preferred that after caulking the ball in the

Recess at the one end face of the shaft, a closure lid member is arranged on the front side, wherein the closure lid member comprises a machinable material, so that a balancing of the at least one rotary component can be carried out by a corresponding processing or cutting of the closure lid member, which has the advantage that the Rotary component for balancing does not need to be machined. Advantageously, the shaft is fixed relative to the at least one rotary component both with the first portion of the shaft and with the second portion of the shaft together in the central recess, wherein the first portion of the shaft and the second portion of the shaft substantially in the region of the end face the shaft are arranged. Thus, the rotary member does not have to be laboriously machined in such a way that the shaft extends completely through the rotary member.

The eccentric configuration preferably has at least two, preferably three wedge-shaped regions in the circumferential direction of the shaft. In this case, the wedge-shaped regions preferably each have a pitch ratio, as seen in the circumferential direction of the shaft, between 1: 25 to 1: 200, which produces a relatively high and secure connection strength when rotating the shaft relative to the rotary component, and is also detachable.

Preferably, the shaft is fixed at its first portion in the central recess of the at least one rotary member by means of a first and a second clamping sleeve, which are slotted in each case in the longitudinal direction, wherein the first clamping sleeve has an inner diameter which substantially the

Outer diameter of the shaft corresponds, and the first clamping sleeve has on its outer side at least two wedge-shaped regions in the circumferential direction of the clamping sleeve, and the second clamping sleeve has an inner diameter corresponding to the

Outside diameter of the first clamping sleeve, wherein for fixing the shaft relative to the rotary member, the first clamping sleeve is arranged on the shaft, and then the second clamping sleeve is pushed over the first clamping sleeve, and then the first clamping sleeve relative to the second clamping sleeve, by means of suitable

Formations respectively on the clamping sleeves, forming a positive connection is rotated, while the first and second clamping sleeve together in the central

Recess of the rotary member are arranged so that the first clamping sleeve is positively fixed with the shaft and the second clamping sleeve is positively fixed with the central recess of the rotary member. This type of connection has a relatively high and secure strength, and is also solvable again.

It is further preferred that the at least one rotary component is a turbine wheel and / or compressor wheel of a turbocharger, wherein the turbine or compressor wheel may preferably be made of titanium aluminide, which has a particularly high strength at the same time relatively low weight.

Brief description of the drawings

The invention will be explained below with reference to embodiments in conjunction with the figures, in which:

Figure 1 shows a shaft and a turbine wheel according to a first embodiment of the

Invention shows;

Figure 2 shows a shaft and a turbine wheel according to a second embodiment of the invention; 3 shows a shaft and a turbine wheel according to a third embodiment of the

Invention shows;

4 shows a shaft and a turbine wheel according to a fourth embodiment of the

Invention shows;

Figures 5a and 5b show a shaft and a turbine wheel according to a fifth embodiment of the invention; and

Figures 6a and 6b, a shaft and a turbine wheel according to a sixth

Embodiment of the invention show.

Embodiments of the invention

With reference to Figure 1, a first embodiment of the invention will now be explained.

In Figure 1, a shaft 10 is shown in a rather schematic and explosive manner, which - in an initially unconnected manner - through a central recess 20 of a rotary member 30 extends therethrough, which in the example shown a turbine wheel of a turbocharger not shown in its entirety

Internal combustion engine is. In addition, a ball 40 is shown in Figure 1, the function will be explained in detail below. The arrangement of the components shown in Figure 1 is chosen for the purpose of explaining the method steps so that the components, as already mentioned above, are not yet connected to each other.

The shaft 10 has a first portion 50 and a second portion 60, wherein the second portion 60 forms an end of the shaft 10, while the second end of the shaft 10 is not shown, since the shaft 10 for clarity in the illustration in Figure 1 is interrupted. In the illustration shown in Figure 1, the shaft 10 would continue to extend (in the drawing in Figure 1 down), so that at its other end, for example, a compressor could be attached. In principle, however, it does not matter for the method described whether it is a turbine wheel or a compressor wheel. The first portion 50 of the shaft 10 has an eccentric configuration 70, i. a protrusion 71 in the form of an eccentric with respect to the longitudinal axis 1 1 of the shaft 10, and a collar-like stopper 72 adjacent to the protrusion 71 and having a larger diameter than the protrusion 71. The central recess 20 corresponds in terms of its inner diameter and shape with the eccentric projection 71, i. The shaft 10 can be axially inserted into the recess 20 in the manner of a clearance fit, until the stop 72 rests against the recess 20, and fix by radial rotation of the shaft 10 relative to the recess 20 such that the shaft 10 in the radial direction is fixed relative to the turbine wheel 30.

In the axial direction relative to the turbine wheel 30, the shaft 10 is pressed by pressing the ball 40 into a recess (not shown in FIG. 1) located on the second portion 60 of the shaft 10, i. on an end face 65 of the shaft 10, fixed or fixed. By pressing or caulking the ball 40 into the recess on the second region of the shaft 10, a Verstemmwulst, which allows the fixing of the shaft 10 in the axial direction relative to the turbine wheel 30.

Thus, the shaft 10 is fixed relative to the turbine wheel 30 both in the radial direction and in the axial direction only in each case in a form-fitting manner. Figure 2 illustrates a second embodiment of the invention.

Again, the components, i. the shaft 10, the turbine wheel 30 and the ball 40, exploded in an unconnected state.

In contrast to FIG. 1, however, this time the first section 50 comprises a projection 71 formed with longitudinal grooves 73 instead of the eccentrically formed projection. A collar-shaped stop 72 in FIG. 2 substantially corresponds to FIG

Stop 72 from FIG. 1.

According to the projection 71 formed with longitudinal grooves 73, a recess 20 corresponds in terms of its diameter and the formation with corresponding grooves 74 with the projection 71, wherein the grooves 74 complementary to the on

Projection 71 trained longitudinal grooves 73 are.

A fixation of the shaft 10 relative to the turbine wheel 30 is again by the first portion 50 is inserted into the recess 20 until the stop 72 abuts the recess 20, and that the grooves 73 engage in the grooves 74 a form-fitting manner. Thus, the shaft 10 is fixed relative to the turbine wheel 30 in the radial direction.

Analogous to what has been said above for FIG. 1, the shaft 10 is then arranged in the axial direction by means of the ball 40 in a second section 60 (not here)

shown) recess caulked. Figure 3 illustrates a third embodiment of the invention, wherein, in contrast to the embodiments shown in Figures 1 and 2, the first portion 50 and the second portion 60 of the shaft 10, based on the longitudinal axis 1 1 of the shaft 10, so to speak coincide. 3 already shows the result of the method, ie the connected state of shaft 10 with turbine wheel 30. The particular difference in this embodiment compared to the previous embodiments is that the shaft 10 does not extend completely through the turbine wheel 30, but only to the depth of the central recess 20. A complete piercing of the turbine wheel 30 is therefore not necessary. Otherwise, the manner of fixing the shaft 10 relative to the turbine wheel 30 in both the radial and in the axial direction is analogous to those with reference to Figures 1 and 2 explained embodiments. The type of radial fixation of the shaft 10 through its first portion 50 in the recess 20 of the turbine wheel 30, for example, via an eccentric or knurling, ie with grooves. The type of axial fixing of the shaft 10 by its second portion 60 relative to the turbine wheel 30 is again effected by means of a ball 40, which is caulked in a, shown in Figure 3 in cross-section, recess 41.

FIG. 4 illustrates a fourth embodiment of the invention, this embodiment essentially corresponding to the embodiments explained with reference to FIGS. 1 and 2, with the difference that on the end face 65 of the shaft 10

Closure cover 80 is attached.

This closure lid member 80 is made of a relatively easy to machine material so as to easily balance the assembly of shaft 10 with turbine wheel 30 attached thereto, otherwise it might be relatively more difficult to achieve balancing by machining the turbine wheel 30. because of the relatively hard material of the turbine wheel 30, such as Titanium aluminide.

Otherwise, the attachment of the shaft 10 takes place on the turbine wheel 30 as already explained above.

Figures 5a and 5b illustrate a fifth embodiment of the invention, this embodiment most closely corresponding to the embodiment explained with reference to Figure 1.

With reference to Figure 5b, which shows a cross-sectional view of the first portion 50 of the shaft 10 in Figure 5a, the essential difference to the explained with reference to Figure 1 embodiment will be explained. As can be seen with reference to Figure 5b, the eccentric projection 71 three wedge-shaped portions 71 a, 71 b, 71 c, which essentially the function of

Replace eccentric of the embodiment with reference to Figure 1. The slope ratio of these wedge-shaped regions 71a, 71b, 71c, ie the ratio of the region length L to the region height H, which in the example illustrated in FIG. 5b are plotted for the wedge-shaped region 71a, is preferably in the range from 1:25 to 1: 200, so that a relatively safe self-locking connection between shaft 10 and turbine wheel 30 results when the shaft 10 is rotated with its portion 50 in the central recess 20 relative to the turbine wheel 30 and the recess 20 is correspondingly complementary to the wedge-shaped portions 71 a, 71 b, 71 c formed (in Figure 5a, however, not shown) ,

However, it is also conceivable that only two wedge-shaped regions or more than three wedge-shaped regions, as shown in Figure 5b, are present.

Figures 6a and 6b illustrate a sixth embodiment of the invention, this embodiment being understood as a modification of the embodiment explained with reference to Figures 5a and 5b.

With reference to Figure 6b, which is composed of three detailed views I, II, III of the first portion 50 of the shaft 10 in Figure 6a, the essential difference to the explained with reference to Figures 5a and 5b embodiment will be explained.

As shown in Figure 6b I, the first portion 50 of the shaft 10 comprises two nested clamping sleeves 91, 92, which are arranged together on the shaft 10. In the example shown in Figure 6b I, the two clamping sleeves 91, 92 are shown as being located in the central recess 20 of the turbine wheel 30, wherein only a part of the turbine wheel 30 is shown.

FIG. 6b II again shows the two clamping sleeves 91, 92 taken individually, but from a different perspective. It can be seen in particular that the clamping sleeve 92 is disposed within the clamping sleeve 91, wherein the outer diameter of the

The inner diameter of the clamping sleeve 92 is slightly larger than the outer diameter of the shaft 10. In addition, Figure 6b II shows that the clamping sleeves 91, 92 each have a collar-shaped stop 72a, 72b in the shape of a hexagon, which together form the stop 72. The stops 72a, 72b serve to the clamping sleeves 91, 92 using for example an open-end wrench

to turn against each other.

Finally, FIG. 6b III shows a cross-sectional view of the two clamping sleeves 91, 92. It can be seen on the one hand that the clamping sleeves 91, 92 each have a slot 93 or 94, the function of which will be explained. On the other hand, it can be seen that the clamping sleeve 92 has along its outer circumference three wedge-shaped portions 92a, 92b, 92c, in analogy to the wedge-shaped portions 71 a, 71 b, 71 c in Figure 5b. Accordingly, the clamping sleeve 91 along its inner circumference complementary to the wedge-shaped portions 92a, 92b, 92c of the clamping sleeve 92 formed wedge-shaped portions 91 a, 91 b, 91 c, in analogy to wedge-shaped areas within the central recess 20 in Figure 5a (Fig. but not shown there).

If now the clamping sleeves 91, 92 rotated against each other, shown in Figure 6b III by arrows P1, P2, while the clamping sleeves 91, 92 are arranged on the shaft 10 and in the central recess 20 of the turbine wheel 30, then gives the interaction The wedge-shaped portions 91 a, 91 b, 91 c with the wedge-shaped portions 92 a, 92 b, 92 c the following: The inner diameter of the clamping sleeve 92 is reduced because the wedge-shaped portions 91 a, 91 b, 91 c press on rotation on the clamping sleeve 92 and the slot 94 permits a reduction in the inner diameter of the clamping sleeve 92. At the same time, the outer diameter of the clamping sleeve 91 increases due to the interaction of the wedge-shaped areas and due to the presence of the slot 93, so that the outer circumference of the clamping sleeve 91 presses against the inner circumference of the recess 20, and thus a - fixed in the radial direction - positive, and detachable connection between shaft 10 and turbine wheel 30 is made. The collar-shaped stopper 72a bears against the recess 20.

A fixation in the axial direction is as above with respect to the other

Embodiments already explained.

Claims

claims

1 . Method for producing a connection of at least one rotary component (30) with a shaft (10), wherein the at least one rotary component (30) has a central recess (20) and the shaft (10) has at least one first portion (50) along the shaft (10 ) and a second portion (60) on an end face (65) of the shaft (10), the method comprising the following steps:

Fixing the shaft (10) at its first portion (50) in the central

Recess (20) of the at least one rotary component (30), so that the shaft (10) in the radial direction relative to the at least one

Rotational component (30) is set; and

Fixing the shaft (10) at its second portion (60) so that the shaft (10) is fixed in the axial direction relative to the at least one rotary member (30); wherein the steps of fixing are each performed in a form-fitting manner.

2. The method of claim 1, wherein the step of fixing the shaft (10) at its first portion (50) in the central recess (20) of the at least one rotary member (30) by means of an eccentric configuration arranged on the first portion (50). 71) takes place eccentrically in the circumferential direction of the shaft (10), wherein the central recess (20) of the at least one

Rotary member (30) corresponding to the eccentric configuration (71) is formed, so that by rotating the shaft (10) relative to the central

Recess (20) the shaft (10) is fixed positively in the radial direction.

3. The method of claim 1 or 2, wherein the step of fixing the shaft (10) at its second portion (60) by caulking a ball (40) in a corresponding recess on one end face (65) of the shaft (10). takes place, so that the shaft (10) relative to the at least one rotary member (30) is fixed positively in the axial direction.

4. The method of claim 1 or 3, wherein the step of fixing the shaft (10) at its first portion (50) in the central recess (20) of the at least one rotary member (30) by means arranged on the first portion (50) knurling (71) which has axially parallel grooves (73) along the shaft (10), wherein the central recess (20) of the at least one

Rotary member (30) has a corresponding knurling with grooves (74), so that the shaft (10) relative to the central recess (20) of the at least one rotary member (30) is fixed positively in the radial direction.

5. The method of claim 3 or 4, wherein after caulking the ball (40) in the recess on the one end face (65) of the shaft (10)

Closure cover element (80) on the end face (65) is arranged, wherein the closure lid member (80) comprises a machinable material, so that a balancing of the at least one rotary component (30) by a corresponding processing, preferably machining the closure lid member (80) can take place.

6. The method according to any one of claims 1 to 4, wherein fixing the shaft (10) relative to the at least one rotary member (30) with the first portion (50) of the shaft (10) and with the second portion (60) of the shaft ( 10) together in the central recess (20), wherein the first portion (50) of the shaft (10) and the second portion (60) of the shaft (10) substantially in the region of the end face (65) of the shaft (10). are arranged.

7. The method according to claim 1 or 2, wherein the eccentric configuration (71) in the circumferential direction of the shaft (10) has three wedge-shaped regions (71 a, 71 b, 71 c).

8. The method of claim 7, wherein the wedge-shaped regions (71 a, 71 b, 71 c) each have a slope ratio, in the circumferential direction of the shaft, between 1: 25 to 1: 200.

9. The method of claim 1, wherein fixing the shaft (10) at its first portion (50) in the central recess (20) of the at least one

Rotary component (30) by means of a first clamping sleeve (92) and a second clamping sleeve (91) takes place, which in each case in their longitudinal direction slots (93, 94), wherein the first clamping sleeve (92) has an inner diameter, which substantially corresponds to the outer diameter of the shaft (10), and wherein the first clamping sleeve (92) on its outer side has three wedge-shaped portions (92a, 92b, 92c) extending in its circumferential direction, and the second clamping sleeve (91) corresponding to an inner diameter to that

Outside diameter of the first clamping sleeve (92), wherein for fixing the shaft (10) relative to the rotary member (30) the first clamping sleeve (92) on the shaft (10) is arranged, the second clamping sleeve (91) via the first clamping sleeve (92 ), and the first clamping sleeve (92) relative to the second clamping sleeve (91) by means of suitable formations (72a, 72b) respectively on the clamping sleeves (92, 91) forming a positive connection is rotated, wherein the first and second clamping sleeve ( 92, 91) are arranged together in the central recess (20) of the rotary component (30), so that the first clamping sleeve (92) is fixed in a form-fitting manner with the shaft (10) and the second clamping sleeve (91) is positively secured to the central recess (30). 20) of the rotary member (30) is fixed.

10. The method according to any one of claims 1 to 9, wherein the at least one

Rotary component (30) is a turbine wheel and / or compressor wheel of a turbocharger.

1 1. The method of claim 10, wherein the at least one rotary member (30) is made of titanium aluminide.

12. turbocharger shaft, which is connected to at least one rotary member (30), wherein the connection between the shaft (10) and the rotary member (30) according to the method of any one of claims 1 to 1 1 is executed.