WO2006012955A1

WO2006012955A1 - Traction mechanism drive

Info

Publication number: WO2006012955A1
Application number: PCT/EP2005/006912
Authority: WO
Inventors: Rainer Pflug; Rainer BAUMÜLLER; Thomas Bertelshofer; Peter Kelm; Tino HÄNSEL; Martin Assel
Original assignee: Schaeffler Kg
Priority date: 2004-07-31
Filing date: 2005-06-28
Publication date: 2006-02-09
Also published as: DE102004037262A1

Abstract

The inventive traction mechanism drive (1), in particular for an internal combustion engine comprises at least one drive wheel (3), at least one driven wheel (5, 6), a belt element (4) and at least one traction mechanism drive element (2) connected or connectable to a wheel, wherein at least one traction mechanism drive element (2) is purposefully controllable or adjustable in order to impress a variability into said traction mechanism drive.

Description

Name of the invention

traction drive

Field of the invention

The invention relates to a traction mechanism drive, in particular for a Verbren¬ tion motor, with at least one driving wheel, at least one ange¬ exaggerated wheel, a belt and at least one Zugmittel¬ drive component, which is connected to one of the wheels or connectable.

Background of the invention

Control drives of internal combustion engines usually have a crankshaft drive wheel, one, two or more camshaft driven wheels and a preferably designed as a chain or belt entangling means. In addition, other driven via wheels traction drive components may be present. Such traction drives are subject to vibration excitations due to torque fluctuations or Winkelgeschwindigkeits¬ changes, which can lead to audible noise in resonance ranges. This is associated with increased frictional forces, which can affect the life of the belt drive and its efficiency.

In DE 195 20 508 A1 it has already been proposed to provide a means which imprints the non-uniformity of the belt drive. This non-uniformity can be generated by a non-circular trained and / or eccentrically mounted wheel. These artificially generated irregularities are intended to counteract the oscillatory changes that result from combustion processes and valve movements. From WO 2003/046413 A1 and DE 202 20 367 U1 a Synchronan¬ is driving device known in which a wheel is used with a non-circular profile with at least two protruding sections and recessed sections. During the rotation of the drive device, a periodically fluctuating load torque is generated, furthermore the protruding and recessed portions of the wheel are selected so that an opposing set corrective torque is produced and the two torques cancel each other out substantially. The disadvantage, however, is that a configuration once set can not be changed, although the dy¬ namic behavior of the traction mechanism drive depending on the speed and other factors can be subject in part to strong fluctuations.

Summary of the invention

The invention is therefore based on the problem of specifying a traction mechanism drive, in particular for an internal combustion engine, whose dynamic behavior can be better influenced.

To solve this problem, it is provided according to the invention in a traction mechanism drive of the type mentioned at the outset that the at least one traction mechanism component can be selectively controlled in order to impart a non-uniformity or load to the traction mechanism drive.

In contrast to the traction mechanism drives known in the prior art, it is possible in the traction mechanism drive according to the invention to influence the dynamic behavior in a targeted manner. The non-uniformity generating means is variable, resulting in significantly expanded possibilities for influencing the dynamic behavior of the traction mechanism drive. In particular, the traction mechanism drive according to the invention makes it possible to make changes during ongoing operation so that it can be counteracted immediately when vibrations occur. In the traction mechanism drive according to the invention, provision may be made for the traction mechanism drive component or the traction mechanism components to be selectively switched on or off via a control device. The switching on or off of a traction drive component influences the dynamic behavior of the traction mechanism drive, since it generates a pulse capable of counteracting existing vibrations.

According to one embodiment of the invention, it may be provided that the traction drive component is continuously switched on or off. Depending on the type of traction drive component, the power consumption or output of the traction drive component can also be steplessly controlled or regulated. Stepless control or regulation makes it possible to counteract particularly delicate and precisely occurring irregularities or vibrations. Furthermore, there is the possibility of intermittently switching traction-mechanism components on or off or of steplessly influencing the power consumption of a traction-drive component by driving the traction-drive component, for example, sinusoidally.

In the case of the traction mechanism drive according to the invention, all traction mechanism drive components which can impart uniformity to the traction mechanism drive can be used for controlling or regulating. This may be e.g. To a genera¬ gate, a pump, a compressor or a camshaft adjuster han¬. In addition, other Zugmitteltriebkomponenten in question, which are used in traction drives in internal combustion engines. It is also within the scope of the invention that a plurality of traction mechanism components are simultaneously controlled or regulated in a targeted manner in order to impart a non-uniformity to the traction mechanism drive. These may, for example, be two camshaft adjusters which are actuated simultaneously in order to produce uniformity.

According to one embodiment of the invention, it may be provided that the traction mechanism component has a switchable or controllable damping element. In such damping elements, the damping can eg over In addition, the dynamic behavior of the traction mechanism drive according to the invention can be influenced by switching the controllable damping element on and off.

It is also possible to use a further damping element in addition to the switchable or controllable damping element. With such an arrangement, the further damping element can permanently counteract the formation of vibrations or irregularities in the traction mechanism drive. In addition, the second damping element can be selectively switched on or off and controlled, for example, when the traction drive is in a speed range with particularly strong oscillations.

According to an alternative embodiment of the invention, it may be provided that the traction mechanism drive component has a flywheel mass which can be switched on and off. The flywheel mass can be coupled or decoupled via a coupling with the traction drive component. Preferably, the flywheel mass can be coupled to a crankshaft or a camshaft or to a drive shaft of a traction drive component. The flywheel mass can be used to influence the dynamic behavior of the traction mechanism drive since the mass of the flywheel and its moment of inertia influence the dynamic system. It is also possible to provide an additional wheel which can be coupled to the flywheel.

According to a further alternative embodiment of the invention, it can be provided that the traction mechanism component has a friction pair which can be switched on and off. By the friction pairing, a frictional force or moment can be exerted on the traction drive to convert kinetic energy into heat. The friction pairing can thus be used to reduce irregularities and unwanted vibrations. An advantageous development of the invention provides that the frictional force generated by the Reibpaa¬ tion or the friction torque is controllable, vor¬ preferably, the friction can be steplessly controlled. A further advantageous embodiment of the invention provides that the friction pairing generates a periodically variable frictional force or a frictional torque that can be adapted particularly sensitively to oscillations in the traction mechanism drive.

The invention also includes all expedient combinations of the described means in order to impart nonuniformity to the traction mechanism drive.

Short descriptions of the drawings

Further advantages and details of the invention will become apparent from the fol lowing description of training examples and with reference to the figures. The figures are schematic drawings and show:

1 shows a first Auslührυngsbeispiei of the invention with a ge targeted controllable traction mechanism drive component.

2 shows a second embodiment of the invention with a switchable damper.

Fig. 3 shows a third embodiment of the invention with a

Damper and a switchable additional damper;

4 shows a fourth exemplary embodiment of the invention with a flywheel attached to a drive shaft;

5 shows a fifth exemplary embodiment of the invention with a flywheel attached to an output shaft;

6 shows a sixth embodiment of the invention with a flywheel attached to an additional shaft; Fig. 7 shows a seventh embodiment of the invention with a

Camshaft adjuster;

8 shows an eighth embodiment of the invention with two camshaft adjusters;

FIG. 9 shows a ninth embodiment of the invention with a traction mechanism component having a friction pairing; FIG.

FIG. 10 shows a tenth embodiment of the invention with a friction pair arranged on an additional shaft; FIG. and

Fig. 11a, 11 b, an eleventh embodiment of the invention with a periodically varying friction torque generating

Friction pairing.

Fig. 1 shows a traction mechanism drive 1 with a selectively controllable Zugmitteltrieb¬ component 2. The traction mechanism drive 1 consists of a crankshaft 3, which is coupled to a crankshaft, not shown, of an internal combustion engine. The rotational movement of the crankshaft sprocket 3 is transmitted to a pair of camshaft sprockets 5, 6 from overhead camshafts via a belt-shaped belt 4.

Another wheel 7 is connected via a switchable coupling 8 with the Zugmitteltrieb¬ component 2. In the traction drive component 2 is in the illustrated embodiment is a generator. In other embodiments, however, the traction drive component may be a pump, a compressor or similar device. The traction mechanism component 2 is associated with a control device 9, are controlled by the power consumption and the engagement and disengagement. In certain speed ranges 1 dynamic effects can occur in the traction drive. These include torque fluctuations, speed fluctuations, but also non-uniformities of the angular speeds of the wheels 3, 5, 6 or 7. In order to compensate for these unwanted vibrations, the traction drive component 2 can be switched on and off in a targeted manner. This process is controlled by the control device 9, which causes the engagement and disengagement of the wheel 7 by means of the clutch 8. As a result of these coupling processes, a pulse generated by the wheel 7 is impressed on the traction mechanism drive 1 via the toothed belt 4, which leads to the reduction of vibrations. In addition to the switching on and off the Zugmitteltriebkomponen¬ te 2 can also be controlled so that their power consumption varies. The control device 9 can drive the traction mechanism drive component 2 in such a way that the power consumption has a sinusoidal profile. Accordingly, sinusoidal impulses are generated via the wheel coupled with the traction mechanism drive component 2 7, which influence the toothed belt 4 and the other components of the traction mechanism drive 1. The frequency and the amplitude of these sinusoidal excitations are thereby adapted to the occurring vibration irregularities in the traction mechanism drive 1.

Fig. 2 shows a second embodiment of the invention with a schaltba¬ ren damper. For the same components of the traction drive the same reference numerals as in Fig. 1 are used. The traction mechanism shown in Fig. 2 has a switchable damper 10 which is connected to a wheel 11 which is driven by the toothed belt 4. The switchable damper 10 makes it possible to damp unwanted vibrations of the toothed belt 4. The damper 10 is constructed like a conventional shock absorber whose structure and function is known.

The switchable damper 10 is connected to a control device 12 which can selectively switch the damper 10 on and off. This makes it possible to actuate the damper 10 as a function of other parameters, for example when the engine is in a certain speed range. The damper 10 can be targeted when vibrations occur. are switched, if the vibrations occurring below a limit un¬, the damper 10 remains switched off. In this way, the traction mechanism drive can be relieved in certain positions or specific operating points. In addition, the switchable damper 10 has the option of specifically controlling the damping behavior by the control device 12. This creates a further possibility for selectively influencing the dynamics of the traction mechanism drive.

FIG. 3 shows a third exemplary embodiment of the invention which, in addition to the switchable damper shown in FIG. 2, has a non-switchable damper. The structure of the traction mechanism shown in Fig. 3 corresponds to that of the traction mechanism of FIG. 2, in addition, a damper 13 is provided, which permanently acts on the toothed belt 4 via the wheel 11 connected to it. The damper 13 acts continuously on the traction mechanism, so that unwanted vibrations are reduced. The switchable damper 10 can be switched on by the control device 12, for example if, at certain operating points, a particularly high damping is advantageous. The switchable damper 10 can also be controlled intermittently, as well as a sinusoidal control is conceivable, the generated damping follows a sine function.

Fig. 4 shows a fourth embodiment of the invention with a mounted on a drive shaft flywheel. In the traction mechanism shown in Fig. 4, a flywheel 14 is provided, which is coupled via a coupling 15 with the crankshaft 3. The clutch 15 is controllable via a control device 16. When the flywheel 14 is engaged, the flywheel 14 is moved synchronously with the crankshaft wheel 3 and the crankshaft of the internal combustion engine. The engagement or disengagement leads to pulses which are transmitted to the toothed belt 4 via the crankshaft wheel 3 and can favorably influence the dynamic behavior of the traction mechanism drive. The clutch 15 is provided with a freewheel, so that the damping torque can be transmitted only in one direction. The control device 16 can control the clutch 15 in such a way that the input and output Disengagement occurs gradually, so that these transition areas can be used in vor¬ advantageous manner to compensate for non-uniformities of the traction mechanism.

Fig. 5 shows a fifth embodiment of the invention with a arranged on an output shaft flywheel. The flywheel 14 is attached via the clutch 15 to the camshaft 6, so that dynamic effects in the range of the camshaft gears can be selectively influenced. The basic structure of the flywheel 14 and the clutch 15 and the associated control device 16 corresponds to that shown in Fig. 4. Depending on the available installation space, the position of the flywheel 14 can be selected, as shown in Figures 4 and 5. For certain applications it is expedient to provide a corresponding controllable flywheel mass on the other camshaft wheel 5 as well.

Fig. 6 shows a sixth embodiment of the invention with a Schwung¬ mass, which can be connected via an additional shaft with an additional wheel. The flywheel 14 is connected via the switchable clutch 15 and a shaft with the auxiliary wheel 17 of the traction drive. The control of the clutch 15 is carried out as in the previous embodiments via a control device 16. The auxiliary wheel 17 is provided specifically for imprinting non-uniformities, it can therefore be used independently of another traction drive component.

The additional wheel 17 can be selectively influenced via the control device 16 by the engagement and disengagement of the flywheel 14, whereupon the generated pulses are transmitted from the auxiliary wheel 17 to the toothed belt 4 and the components connected thereto.

Fig. 7 shows a seventh embodiment of the invention with a cam recliner. The camshaft sprocket 6 of the traction mechanism shown in FIG. 7 can be controlled by the camshaft adjuster 18 such that the phase position between the crankshaft and that camshaft, the the camshaft 6 is assigned, can be adjusted. The camshaft adjuster 18 is hydraulically controlled, the dynamic effects occurring during the adjustment can be used selectively in order to influence the traction mechanism drive and to calm vibrations. For this purpose, the camshaft counter 18 is connected to a control device 19, via which the control takes place.

8 shows an eighth embodiment of the invention with two camshaft adjusters. In addition to the exemplary embodiment of FIG. 7, a second camshaft adjuster 20 is provided, which is assigned to the camshaft wheel 5. The control device 19 controls both camshaft adjusters 18, 20. The use of two camshaft adjusters 18, 20, which are each assigned to a camshaft, improves the possibilities of influencing the dynamic behavior.

9 shows a ninth exemplary embodiment of the invention, in which the traction drive component has a controllable friction pairing. The traction mechanism shown in Fig. 9 comprises a friction pair 21, which is connected via a switchable clutch 22 with the cam wel I enrad 6. The control of the clutch 22 via a control device 23, so that the Reibpaa¬ tion 21 can be switched on and off. In this way, increased friction is introduced into the system. However, the increased friction also has an impact on the efficiency, which is thereby worsened. For this reason, the friction pair 21 is turned on only when needed. In addition, the friction of the friction pairing 21 can be adjusted stu¬ fenlos via the control device 23. This adjustment allows a particularly good adaptation to the vibrations occurring during operation of the Zugmit¬ teltriebs.

Fig. 10 shows a tenth embodiment of the invention, in which a switchable friction pair is arranged on an additional shaft. The traction mechanism shown in Fig. 10 is constructed substantially like the traction mechanism in Fig. 9, in contrast to the friction pairing 21 via an additional shaft can be coupled with an additional wheel 24. Otherwise, the control takes place, as in the exemplary embodiment described in FIG. 9, via the control device 23, which actuates the clutch 22. Depending on the friction set on the friction pad 21, pulses are imparted to the additional wheel 24, which act favorably on the vibration behavior of the traction mechanism drive.

Figures 11a and 11b show an eleventh embodiment of the invention with a friction pairing which generates a periodically varying friction torque.

The friction pair consists of a rotatable friction element 25, which cooperates with a fixed friction element 26. As can be seen in FIG. 11, the contour of the friction element 25 is formed by two opposite circular arc segments 27, 28, which are connected to one another by straight line sections 29, 30. The rotatable wheel member 25 is connected to a wheel 31 via a shaft.

In the case of a rotating toothed belt 4, the wheel 31 and the friction element 25 coupled thereto are set in rotation so that the friction element 25 alternately comes in contact with the friction element 26 with its circular arc sections 27, 28. As a result, a periodically variable wheel torque is generated, which can for example be adjusted so that it counteracts the second-order vibrations of the engine. The exemplary embodiment shown in FIGS. 11a and 11b does not require a control device, so it can be realized with little effort. In other embodiments, the friction element can also be coupled to a drive or output shaft of the engine. reference numerals

1 traction drive

2 traction drive component

3 crankshafts rad

4 toothed belts

5 camshaft sprocket

6 camshaft sprocket

7 more wheel

8 clutch

9 control device

10 dampers

11 wheel

12 control device

13 dampers

14 flywheel

15 clutch

16 control device

17 additional wheel

18 camshaft adjuster

19 control device

20 camshaft adjuster

21 friction pairing

22 clutch

23 control device

24 additional wheel

25 friction element

26 friction element

27 circular arc section

28 circular arc section

29 straight line section

30 straight line section

31 wheel

Claims

claims

1. traction drive, in particular for an internal combustion engine, with wenigs¬ least one driving wheel, at least one driven wheel, a belt and at least one Zugmitteltriebkompo¬ nente connected to one of the wheels or connectable, characterized in that the at least one traction drive component ( 2) can be selectively controlled or regulated in order to impart uniformity to the traction mechanism drive (1).

2. Traction drive according to claim 1, characterized in that the traction drive component or the traction mechanism components (2) via a control device (12, 16) is selectively switched on or off or are.

3. traction drive according to claim 1 or 2, characterized in that the traction drive component (2) is continuously switched on or off.

4. traction drive according to one of the preceding claims, characterized ge indicates that the traction drive component (2) via a Kupp¬ ment (8, 15) coupled to the wheel and decoupled.

5. Traction drive according to one of the preceding claims, characterized ge indicates that the power consumption or -abgäbe the Zugmittel¬ drive component (2) is controlled or regulated.

6. traction mechanism according to one of the preceding claims, character- ized in that the Zugmitteltriebkomponente (2) comprises a generator, a pump, a compressor or a camshaft adjuster (18, 20).

7. traction drive according to one of the preceding claims, characterized ge indicates that the traction drive component (2) has a switchable or controllable damping element (10).

8. traction mechanism according to claim 7, characterized in that the traction mechanism component comprises a further damping element (13) auf¬.

9. traction mechanism according to one of the preceding claims, character- ized in that it has an on and off switchable flywheel (14).

10. traction mechanism according to claim 9, characterized in that the flywheel (14) with a crankshaft or a camshaft or an output shaft of a traction drive component (2) can be coupled.

11. traction drive according to claim 9 or 10, characterized in that the flywheel (14) with an additional wheel (17) can be coupled.

12. traction mechanism according to one of the preceding claims, characterized ge indicates that the traction mechanism drive component has an on and ab¬ switchable friction pair (21).

13. traction mechanism according to claim 12, characterized in that the friction force and / or the friction torque of the friction pair (21) is preferably steplessly controlled.

14. Traction drive according to one of the preceding claims, characterized ge indicates that the traction mechanism drive component has a friction pair generating a periodically varying friction torque.

15. Traction drive according to claim 14, characterized in that the friction pairing comprises a fixed friction element (25) and a rotatable, with a wheel (31) coupled friction element (26).