DE102008061220B4 - System for fastening at least one further component to a crankshaft of an internal combustion engine - Google Patents

Abstract

A system for securing at least one further component to a crankshaft of an internal combustion engine, comprising a crankshaft flange (14) provided on the crankshaft (10) and having a number of threaded holes (16); one provided on one of the at least one further component (12; 60) Bearing surface (27; 66) for screw heads (26) which has a number of bores (22) arranged on a pitch circle (28); a number of screws (24) passing through the bores (22) of the bearing surface (27; 66 ) for screw heads in the threaded holes (16) in the crankshaft flange (14) are screwed; anda thrust piece (38) for placement over a screw head (26) of a screw (24) threaded through one of the bearing surface bores (22) into one of the threaded holes (16) of the crankshaft flange (14) to hydraulically tighten the screw, wherein the pressure piece (38) has a support surface (44) on its side facing the support surface (27; 66), the support surface (44) of the pressure piece (38) placed above a screw head (26) being in the radial direction in contrast to a rotationally symmetrical design Direction of the diameter of the crankshaft (10) has a larger dimension, as in the circumferential direction of the crankshaft (10).

Description

The present invention relates to a system for fastening at least one further component to a crankshaft of an internal combustion engine.

With a crankshaft of an internal combustion engine, for example, a vibration damper, a gear wheel and / or a flywheel, each of which may form a component in the sense of the present invention, are connected via a flange connection. For transmitting the torques such as motor torque and torsional vibration torque between the interconnected components, various solutions are known in the art.

The first known approach is to manually tighten a number of hex-head screws via frictional engagement. This assembly process is cumbersome and time-consuming and is therefore no longer practicable with larger motor types, for example with holes over 400 mm. The spread of the torque is very large, which is why a very large number of screws is used, which in turn leads to correspondingly large pitch diameters. However, large pitch diameters have a negative effect on the design of the vibration diameter with regard to the required installation space and the costs of the vibration dampers. On the other hand, very expensive special tools are necessary to reduce the scattering in the tightening torque.

In the second known approach, the screws are tightened by means of a pressure piece with a circular support surface hydraulically via frictional engagement. This type of suit is more comfortable and practicable compared to the first approach and is particularly preferred for larger engine types. However, only a smaller number of screws can be accommodated on a given pitch circle diameter, since a sufficient contact surface for the pressure piece has to be kept in each case around the holes.

Another option is provided by fitting screws fitted via friction and frictional engagement. The additional positive locking, which allows an increase in the transmitted torque, however, entails the disadvantage that the assembly of the vibration damper or flywheel by the manufacturing step of rubbing significantly more expensive and expensive. Further, the engine-connected components, i. Crankshaft / vibration damper or crankshaft / flywheel, rubbed in a screwed together before final assembly in the assembly hall or on the test stand in order to prevent problems when joining the fitting screws due to positional deviations of the mating surfaces. This procedure must be repeated in a time-consuming manner with the newly installed vibration dampers, if vibration dampers are replaced according to the maintenance interval.

The invention has for its object to provide a system for attaching at least one further component to a crankshaft of an internal combustion engine, which simultaneously allows a compact design and a reliable and time-saving installation.

According to a first aspect of the invention, this object is achieved by a system for fastening at least one further component to a crankshaft of an internal combustion engine having the features of claim 1.

The system for securing at least one further component to a crankshaft of an internal combustion engine includes a crankshaft flange provided on the crankshaft and having a number of threaded holes; a support surface for screw heads provided on one of the at least one further component, which has arranged a number of bores on a pitch circle, the positioning and the number of bores preferably corresponding to those of the threaded holes in the crankshaft flange; a number of screws which are screwed through the bores of the support surface for screw heads in the threaded holes in the crankshaft flange; and a pressure piece for placement over a screw head of a screw threaded through one of the bore holes of the support surface into one of the threaded holes of the crankshaft flange to hydraulically tighten the screw, the pressure piece having a support surface on its side facing the support surface.

According to the invention, the pressure piece is designed such that the support surface of the pressure piece in the radial direction of the crankshaft has a larger dimension than in the circumferential direction when the pressure piece is placed over a screw head. This not in contrast to known pressure pieces with circular support surface non-rotationally symmetrical support surface advantageously makes it possible on the one hand to attach the pressure piece between circumferentially closer together arranged screw heads and on the other hand provides a sufficiently large support surface for the hydraulic suit. Because the fact that the dimension of the support surface of the pressure piece is formed smaller in the circumferential direction, it can be applied between closely adjacent screw heads whose distance in Circumferential direction is low. This makes it possible to tighten the screw heads on the same pitch circle and thus increase the security of the connection and / or provide a smaller pitch circle diameter. Characterized in that the dimension of the support surface of the pressure piece in the radial direction is greater, while a sufficiently large contact surface is still provided.

According to a preferred embodiment of the present invention, the support surface is formed such that the distance between two adjacent holes in the circumferential direction is dimensioned slightly larger than the diameter of a screw head and that in the radial direction inside and outside of the bores in each case a surface is provided, the radial dimension at least equal to the dimension of a surface between two adjacent holes in the circumferential direction. In addition, the support surface of the pressure piece can be formed from two partial surfaces, which lie opposite each other in the radial direction of the arrangement.

This system offers all the advantages of conventional hydraulic tightening of the screws by means of a thrust piece (above second approach) and also allows the arrangement of a larger number of screws on a given pitch circle diameter due to the special design of the thrust piece required for this purpose.

This system is advantageously applicable to the flange connection between crankshaft and vibration damper. In this case, the vibration damper preferably has a vibration damper cover, on which the support surface is designed for the screw heads. In addition, a gear can still be provided, which is arranged on the side facing away from the crankshaft of the vibration damper and is bolted to the vibration damper cover.

The system is also advantageously applicable to the flange connection between crankshaft and flywheel. In this case, the flywheel preferably has the special bearing surface for the screw heads. In addition, a vibration damper can be set between the crankshaft and the flywheel.

According to a second aspect of the invention, the above object is achieved by a pressure piece with the features of claim 9.

The pressure piece for the hydraulic tightening of a screw connection between a crankshaft of an internal combustion engine and at least one further component has a support surface on its side facing a support surface for screw heads on a component side. According to the invention the support surface of the pressure piece is formed such that it has a larger dimension in the radial direction than in the circumferential direction when the pressure piece is placed over a screw head.

According to a third aspect of the invention, the above-mentioned object is achieved by a vibration damper having the features of claim 10.

The vibration damper for a crankshaft of an internal combustion engine has a vibration damper cover, which has a support surface for screw heads, which has arranged a number of holes on a pitch circle. According to the invention, this support surface is formed such that the distance between two adjacent holes in the circumferential direction is dimensioned slightly larger than the diameter of a screw head and that in each case a surface is provided in the radial direction inside and outside of the holes whose radial dimension at least the measure of Area between two adjacent holes in the circumferential direction corresponds.

In one embodiment of the invention, the vibration damper cover has arranged on a further pitch circle a number of threaded holes, with which a further component such as a gear can be screwed to the vibration damper.

According to a fourth aspect of the invention, the above object is achieved by a flywheel having the features of claim 12.

The flywheel for a crankshaft of an internal combustion engine has a support surface for screw heads, which has arranged a number of holes on a pitch circle. According to the present invention, this support surface is formed such that the distance between two adjacent holes in the circumferential direction is dimensioned slightly larger than the diameter of a screw head and that in the radial direction inside and outside of the bores in each case a surface is provided whose radial dimension at least the Measure corresponds to an area between two adjacent holes in the circumferential direction.

Advantageous embodiments and further developments of the invention are the subject of further subclaims.

• 1 eine Schnittansicht einer erfindungsgemäßen Verbindung zwischen einer Kurbelwelle und einem Schwingungsdämpfer;
• 2 eine Perspektivansicht eines Schwingungsdämpferdeckels des Schwingungsdämpfers von 1 aus Sicht der der Kurbelwelle abgewandten Seite;
• 3 eine Perspektivansicht eines bei der Montage der in 1 dargestellten Baugruppe verwendeten Druckstücks gemäß der Erfindung;
• 4 eine Schnittansicht einer erfindungsgemäßen Verbindung zwischen einer Kurbelwelle und einem Schwingungsdämpfer und zwischen dem Schwingungsdämpfer und einem Zahnrad; und
• 5 eine Schnittansicht einer erfindungsgemäßen Verbindung zwischen einer Kurbelwelle und einem Schwungrad.

The above and other features and advantages of the invention will become apparent from the following description of preferred, non-limiting embodiments with reference to the better understood in the accompanying drawings. Show:

• 1 a sectional view of a compound according to the invention between a crankshaft and a vibration damper;
• 2 a perspective view of a vibration damper cover of the vibration damper of 1 from the viewpoint of the side facing away from the crankshaft;
• 3 a perspective view of a during assembly of the in 1 illustrated assembly used pressure piece according to the invention;
• 4 a sectional view of a compound according to the invention between a crankshaft and a vibration damper and between the vibration damper and a gear; and
• 5 a sectional view of a compound according to the invention between a crankshaft and a flywheel.

Referring to 1 to 3 Now, a first embodiment of the invention will be described in more detail.

A crankshaft 10 an internal combustion engine has a Kurbelwellenflansch in the usual way 14 in which a number of threaded holes 16 is trained. About this crankshaft flange 14 is a vibration damper 12 on the crankshaft 10 attached. For this purpose is in the vibration damper 12 a number of holes 18 provided in number and positioning those of the threaded holes 16 in the crankshaft flange 14 correspond. In addition, the vibration damper has 12 a vibration damper cover 20 on, coaxial with the crankshaft flange 14 is arranged.

As in 1 and 2 to recognize, has the vibration damper cover 20 on a first circle 28 a number of holes 22 arranged, their positioning and number of those of the threaded holes 16 in the crankshaft flange 14 and those of the holes 18 in the vibration damper 12 correspond. Through these holes 22 and the holes 18 in the vibration damper 12 be screws 24 in the threaded holes 16 in the crankshaft flange 14 screwed, with the screw heads 26 the screws 24 on a corresponding support surface 27 the vibration damper cover 20 rest, as is the case with conventional arrangements.

It should be noted as a precaution that, although in the described embodiments in each case screws 24 with screw heads 26 for securing a component to the crankshaft 10 The present invention is not limited to this embodiment, but instead, for example, nuts and bolts may be used instead.

It is planned, the screws 24 with the help of a pressure piece 38 , a corresponding press 40 and a corresponding screwing tool to tighten hydraulically. Since this method is already known in principle, as stated in the introduction, this will not be discussed in detail.

But at the same time a secure tightening of the screws 24 and to allow a compact design of the entire arrangement, various measures are provided in the first embodiment. So is the support surface 27 the vibration damper cover 20 for the screw heads 26 designed such that the distance 30 between two adjacent holes 22 in the circumferential direction is dimensioned slightly larger than the diameter of a screw head 26 , That is, in the circumferential direction is between two adjacent screw heads 26 basically no large support surface for a corresponding support surface 44 of the pressure piece 38 available. On the other hand, the bearing surface 27 the vibration damper cover 20 but designed so that in the radial direction inside and outside of the holes 22 one area each 34 . 36 is provided, the radial dimension at least the measure of the area 32 between two adjacent holes 22 in the circumferential direction corresponds. That is, in the radial direction is on both sides of the screw head 26 an enlarged bearing surface for a corresponding support surface 44 of the pressure piece 38 intended.

The pressure piece 38 is to the bearing surface described above 27 the vibration damper cover 20 adapted trained. That is, the pressure piece 38 consists essentially of a hollow profile body with a recess 42 for receiving a screw head 26 at its the vibration damper cover 20 facing side. As in 3 illustrates, there is the support surface 44 of the pressure piece 38 of two partial surfaces, which lie opposite each other in the radial direction of the arrangement and which are each formed on their inner side circular segment.

The support surface 44 of the pressure piece 38 points in the circumferential direction (from top left to bottom right in FIG 3 ) has a smaller dimension than in the radial direction (from bottom left to top right in FIG 3 ), with the circumferential and radial directions at over the screw head 26 placed pressure piece 38 show how this is done in 1 is shown, and are related to the crankshaft.

Unlike conventional pressure pads with a circular support surface needed the pressure piece according to the invention 38 from 3 in the circumferential direction along the pitch circle 28 Due to the lack of support surfaces in this area significantly less space, so that the holes 22 and according to the screws 24 can be set closer to a given pitch circle diameter or a smaller pitch circle diameter can be used. This in turn brings advantages of a more compact design and a material saving both on the vibration damper cover 20 as well as on the crankshaft flange 14 and thus with the entire arrangement with it. The necessary bearing surface on the vibration damper cover 20 and support surface 44 of the pressure piece 38 be through the enlarged support areas 34 and 36 radially inside and outside the holes 22 and the two enlarged partial surfaces of the support surface 44 on the pressure piece 38 achieved.

To the press 40 necessary contact surface on the screw heads 26 opposite side of the pressure piece 38 To create, this extends in the circumferential direction from an axial height, which is greater than the height of the screw heads 26 is. Thus, the narrower in the circumferential direction portion of the pressure piece extends from the screw heads 26 facing support surface 44 vertically upwards and merges in a region in which it no longer collides with screw heads in an annular support on the opposite side. The pressure piece 38 can thus be thought of as resulting from a pipe, on which the bearing surface 44 forming two circular segments were removed to represent the circumferentially smaller dimension.

In the radial direction is the support surface 44 touched, as in 3 to recognize the attachment of the pressure piece to a screw head 26 to facilitate.

With reference to 4 Now, a second embodiment of the invention will be described in more detail. The same components are identified by the same reference numerals as in the above first embodiment and a further description is omitted.

The second embodiment differs from the first embodiment described above in that besides the vibration damper 12 also a gear 50 on the crankshaft 10 is attached. The attachment of the vibration damper 12 on the crankshaft 10 is analogous to the first embodiment of the special vibration damper cover 20 from 2 in cooperation with the special pressure piece 38 from 3 ,

For additional attachment of the gear 50 has the vibration damper cover 20 on his the crankshaft 10 opposite side on a second circle 46 with a smaller pitch circle diameter than the first pitch circle 28 a number of threaded holes 48 arranged as in 2 shown. The gear 50 has a number of holes 56 in positioning and number of those of threaded holes 48 in the vibration damper cover 20 correspond. Through these holes 56 in the gear 50 be screws 58 in the threaded holes 48 the vibration damper cover 20 screwed to the gear 50 on the vibration damper 12 and thus on the crankshaft 10 to fix.

To a desired distance between the vibration damper 12 and the gear 50 to set up, is between the vibration damper cover 20 and the gear 50 an intermediate piece 52 set. This intermediate piece 52 is also with a number of holes 54 trained in the positioning and number of those of the holes 56 in the gear 50 or those of the threaded holes 48 in the vibration damper cover 20 correspond.

With the in 4 illustrated system will have the same advantages as in the above with reference to 1 to 3 achieved explained first embodiment.

A third embodiment of the invention will now be described with reference to 5 described in more detail. The same components are identified by the same reference numerals as in the above first embodiment and a further description is omitted.

In the in 5 illustrated embodiment of 5 are both a vibration damper 12 as well as a flywheel 60 on a crankshaft 10 attached to an internal combustion engine, wherein between the vibration damper 12 and the flywheel 60 an intermediate piece 62 is provided to a desired distance between these two components 12 . 60 to accomplish. The intermediate piece 62 at the same time replaces the vibration damper cover 20 of the first and the second embodiment, which in this third embodiment of 5 is omitted.

For fastening the vibration damper 12 and the flywheel 60 on the crankshaft 10 are in a crankshaft flange 14 a number of threaded holes 16 arranged in the vibration damper 12 a number of holes 18 arranged, in the intermediate piece 62 a number of holes 64 arranged, the flywheel 60 with a support surface 66 for screw heads 26 provided, the bearing surface 66 the flywheel 60 with a number of holes 68 provided and a number of screws 24 through the holes 68 . 64 . 18 in the threaded holes 16 in the crankshaft flange 14 screwed. The positioning and the number of holes 18 . 64 . 68 and the threaded holes 16 Of course, each correspond to each other.

To achieve a compact design and at the same time the screws 24 safely hydraulically via a pressure piece 38 to be able to attract, are the bearing surface 66 and the holes 68 the flywheel 60 analogous to the support surface 27 and the holes 22 the vibration damper cover 20 formed and arranged in the first and second embodiments, so that the same pressure piece 38 from 3 as can be used in the first and second embodiments. On a repetition of the description will be omitted, it is instead again on 2 and 3 with the accompanying explanations.

With the in 5 Thus, the same effects and advantages as those of the above-described first and second embodiments can be obtained.

In addition, it should be noted that in the third embodiment of 5 on the flywheel 60 in addition a gear 70 is mounted, for example, via screws 72 can be attached to the flywheel body.

LIST OF REFERENCE NUMBERS

10

crankshaft

12

vibration

14

crankshaft

16

threaded holes

18

drilling

20

vibration cover

22

drilling

24

Screws or threaded rods

26

Screw heads or nuts

27

Bearing surface of 20

28

first circle

30

Distance between adjacent holes 22

32

first edition

34

second edition

36

third edition

38

Pressure piece

40

Press

42

recess

44

Support surface of 38

46

second circle

48

threaded holes

50

gear

52

connecting piece

54

drilling

56

drilling

58

screw

60

flywheel

62

connecting piece

64

drilling

66

bearing surface

68

drilling

70

gear

72

screw

Claims (12)

System for fastening at least one further component to a crankshaft of an internal combustion engine, with a crankshaft flange (14) provided on the crankshaft (10) and having a number of threaded holes (16); a contact surface (27; 66) for screw heads (26) provided on one of the at least one further component (12; 60) and arranged on a pitch circle (28) a number of bores (22); a plurality of screws (24) threaded through the bores (22) of the screw head support surface (27; 66) into the threaded holes (16) in the crankshaft flange (14); and a thrust piece (38) for placement over a screw head (26) of a screw (24) threaded through one of the bearing surface bores (22) in one of the threaded holes (16) of the crankshaft flange (14) to hydraulically tighten the screw; wherein the pressure piece (38) has a support surface (44) on its side facing the support surface (27; 66), wherein the support surface (44) of the over a screw head (26) placed pressure member (38), in contrast to a rotationally symmetrical formation in the radial direction of the diameter of the crankshaft (10) has a larger dimension, as in the circumferential direction of the crankshaft (10). System after Claim 1 , characterized in that the support surface (44) pressure piece (38) is formed from two partial surfaces, which lie opposite each other in the radial direction of the arrangement. System according to one of the preceding claims, characterized in that the bearing surface (27; 66) is designed such that the distance (30) between two adjacent holes (22) in the circumferential direction is dimensioned somewhat larger than the diameter of a screw head (26). and that in each case a surface (34, 36) is provided in the radial direction inside and outside of the bores (22) whose radial dimension is at least the measure of a surface (32) between two adjacent holes in the circumferential direction. System according to one of the preceding claims, characterized in that the at least one further component includes a vibration damper (12) having a vibration damper cover (20) on which the bearing surface (27) is formed for the screw heads. System after Claim 4 , characterized in that the at least one further component includes a gear (50) which is arranged on the side facing away from the crankshaft of the vibration damper (12) and is screwed to the vibration damper cover (20). System according to one of the preceding claims, characterized in that the at least one further component includes a flywheel (60) on which the bearing surface (66) is formed for the screw heads. System after Claim 6 , characterized in that between the crankshaft (10) and the flywheel (60) a vibration damper (12) is interposed. System according to one of the preceding Claims 2 to 7 , characterized in that the two partial surfaces of the support surface (44) of the pressure piece (38) on their the screw head (26) facing the inside are each formed a circular segment. A pressure piece (38) for hydraulically tightening a screw connection between a crankshaft (10), an internal combustion engine and at least one further component (12, 60), with a support surface (44) on its side facing a support surface (27, 66) for screw heads, wherein the support surface (44) of the over a screw head (26) placed pressure element (38) in contrast to a rotationally symmetrical formation in the radial direction of the diameter of the crankshaft (10) has a larger dimension than in the circumferential direction of the crankshaft (10). A vibration damper (12) for a crankshaft of an internal combustion engine, comprising a vibration damper cover (20) having a support surface (27) for screw heads (26) arranged on a pitch circle (28) a number of holes (22), wherein the support surface (27) is formed such that the distance (30) between two adjacent holes (22) in the circumferential direction is dimensioned somewhat larger than the diameter of a screw head (26) and that in the radial direction inside and outside of the bores in each case a surface (34 , 36) whose radial dimension corresponds at least to the dimension of a surface (32) between two adjacent holes in the circumferential direction. Vibration damper after Claim 10 , characterized in that the vibration damper cover (20) on a further pitch circle (46) has a number of threaded holes (48) arranged, with which a further component such as a gear (50) with the vibration damper (12) can be screwed. Flywheel (60) for a crankshaft of an internal combustion engine, having a bearing surface (66) for screw heads (26) which has a number of bores (68) arranged on a partial circle, wherein the bearing surface (66) is designed such that the distance ( 30) between two adjacent bores (68) in the circumferential direction is dimensioned somewhat larger than the diameter of a screw head (26) and that in each case a surface is provided in the radial direction inside and outside the bores whose radial dimension at least the measure of a surface between two adjacent Drilling in the circumferential direction corresponds.

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