EP2530260B1 - Coupling shaft, actuator, cam shaft adjustment drive and cam shaft adjuster - Google Patents

Description

The invention relates to a coupling shaft for a camshaft actuator.

Moreover, the invention relates to an actuator for setting a camshaft variable speed gear.

Furthermore, the invention relates to a camshaft adjusting, which is also referred to below as 'variable speed'.

Moreover, the invention relates to a camshaft adjuster for an internal combustion engine.

Out DE10 2004 041 751 A1 . DE 10 2007 049 072 A1 . DE 10 2004 061 711 A1 and DE 102 48 351 A1 are diverse

Couplings for compensating an eccentricity (axial offset) between an axis of a control shaft of an actuator and an axis of a variable speed known. These couplings exercise with appropriate radial axial offset of the corresponding waves inertial forces on these waves and their bearings. In Oldham couplings and the large axial space requirement is disadvantageous.

It is an object of the invention to provide a clutch shaft for a camshaft actuator, with the mass forces can be reduced to these waves and their bearings. In addition, it is an object of the invention to provide an actuator, a camshaft variable speed and a phaser with this advantage.

This object is achieved with a coupling shaft comprising the features of claim 1. Advantageous developments of the inventive concept are the subject of the dependent claims.

According to the invention, the coupling shaft for a camshaft actuator is further developed in that the coupling shaft has at each of its two ends a respective coupling component for each one achschwinkelausgleichende rotary coupling. The fact that the coupling shaft according to the invention has a coupling component at each of its two ends, it is possible to compensate for an axial offset, without causing by this measure a cause or enlargement of an axis angle between the actuator and the adjustment must be accepted. By dividing the axial offset adjustment to two clutches, the developer receives an additional degree of freedom, which he can use to reduce the axial angle for the introduction of force into the actuator or into the adjusting mechanism. By reducing the axial angle for the introduction of force into the actuator or into the adjusting mechanism, a rotational symmetry of the power transmission is improved and a strength of the disadvantageous inertial forces is reduced. The clutch shaft may, but need not, be integral.

An (entire) axial length of the coupling shaft may be greater than w% of a maximum diameter of the larger coupling component, where w% is at least 130%, in particular at least 150%.

The coupling shaft may be tapered between its two ends over more than w% of its (total) axial length, w% being at least 30%, in particular at least 60%.

The coupling shaft may comprise on at least one of its two end faces a cylindrically symmetrical, convex formation which is arranged concentrically to the main longitudinal axis of the coupling shaft.

The coupling shaft may include a flange for a bearing.

The first axis-compensating rotary joint may include a safety pin or a component of a toothed clutch, a dog clutch, a plug-in clutch, a dog clutch, a spur gear, a Tellerzahnradkupplung, a flexible disc, a Belgkupplung, an elastomeric coupling, a helical clutch, a spring clutch, a spring disc clutch, a ridge clutch, a Compensating clutch, a Kardangetriebes or a constant velocity joint comprises. Independently of this, the second angle-compensating rotary joint may comprise a safety bolt or a component of a toothed clutch, a dog clutch, a plug-in clutch, a driving clutch, a spur gear clutch, a Tellerzahnradkupplung, a flexible disc, a Belgkupplung, an elastomeric coupling, a helical clutch, a spring clutch, a spring disc clutch, a bridge coupling , a compensating coupling, a Kardangetriebes or a constant velocity joint. The toothed coupling component may comprise a curved tooth coupling. The toothed coupling component may have a spherical or ball-shaped basic shape on which the teeth of the toothed coupling component are arranged.

According to the invention, the actuator is further developed in that a coupling shaft for providing the Nockenwellenverstellgetriebes is coupled to the actuator by means of a first achswinkelausgleichenden rotary coupling in a region of the actuator, which faces away from the adjusting mechanism. In this way, with an unchanged distance between the actuator and Nockwellenverstellgetriebe the distance between the location of the bendable connection to the rotor and the camshaft Verstellgetriebe be increased, thereby achieving a reduction of the axis angle for the introduction of force in the variator, a rotational symmetry of the transmission improves and a strength of the adverse mass forces is reduced.

The clutch shaft may extend over more than 50% of a (total) axial length of a rotor of the actuator.

The coupling shaft may be rotatably arranged in the actuator at any circumferential angle in the pitch direction, wherein a pitch angle of the coupling shaft with respect to an axis of the actuator to at least 1 °, in particular to at least 2 °, more preferably to at least 3 °.

The coupling shaft may be arranged axially displaceable in the rotor.

The actuator may include a thrust bearing component for biasing the clutch shaft in the direction of the main longitudinal axis of the clutch shaft.

The first axle-compensating rotary coupling for coupling to the rotor may include a safety pin or a component of a toothed clutch, a dog clutch, a plug-in clutch, a dog clutch, a spur gear, a Tellerzahnradkupplung, a flexible disc, a Belgkupplung, an elastomer coupling, a helical clutch, a spring clutch, a spring disc clutch , a bridge coupling, a compensating coupling, a Kardangetriebes or a constant velocity joint.

The actuator may comprise a coupling shaft according to the invention.

According to the invention, the camshaft adjusting mechanism is further developed in that an inner or outer toothing of a gear drive gear of the camshaft adjusting gear for the engagement of the toothed coupling component of a coupling shaft according to the invention is formed or suitable or that the camshaft adjusting a clutch shaft according to the invention comprises.

The gear coupling component of the clutch shaft may form a flying gear drive gear of the camshaft variable speed gear.

According to the invention, the camshaft adjuster is further developed in that it comprises an actuator according to the invention and / or an inventive camshaft transmission.

Fig. 1

schematisch eine teilweise angeschnittene Seitenansicht einer ersten Ausführungsform eines erfindungsgemäßen Nockenwellenstellers;

Fig. 2

schematisch einen perspektivischen Seitenquerschnitt der ersten Ausführungsform des erfindungsgemäßen Nockenwellenstellers;

Fig. 3

schematisch in Seitenansicht ein Grundkonzept des erfindungsgemäßen Achsversatzausgleichs der ersten Ausführungsform;

Fig. 4

schematisch in Seitenansicht ein Grundkonzept eines Achsversatzausgleichs einer Ausführungsform, welche kein Bestandteil der Erfindung ist;

Fig. 5

schematisch eine teilweise angeschnittenen Seitenansicht eines Nockenwellenstellers mit einer zweiten Ausführungsform der erfindungsgemäßen Kupplungswelle;

Fig. 6

schematisch eine Detailansicht eines Seitenquerschnitts der zweiten Ausführungsform des erfindungsgemäßen Nockenwellenstellers; und

Fig. 7

schematisch eine perspektivische Ansicht eines geöffneten Nockenwellenverstellgetriebes mit einem fliegenden Getriebeantriebszahnrad.

The invention will be explained in more detail with reference to an embodiment shown in the schematic drawings. Show it:

Fig. 1

schematically a partially sectioned side view of a first embodiment of a camshaft actuator according to the invention;

Fig. 2

schematically a perspective side cross-section of the first embodiment of the camshaft actuator according to the invention;

Fig. 3

schematically a side view of a basic concept of the invention Achsversatzausgleichs the first embodiment;

Fig. 4

schematically in side view a basic concept of an axial offset compensation of an embodiment which is not part of the invention;

Fig. 5

schematically a partially sectioned side view of a camshaft adjuster with a second embodiment of the coupling shaft according to the invention;

Fig. 6

schematically a detailed view of a side cross section of the second embodiment of the camshaft actuator according to the invention; and

Fig. 7

schematically a perspective view of an open Nockenwellenverstellgetriebes with a flying Getriebeantriebszahnrad.

In the figures, the same reference numerals are used for respective components. Reference numerals related explanations therefore also apply across figures, unless otherwise stated in the context.

The in Fig. 1 and 2 shown camshaft actuator 10 includes a servomotor 12 and an adjusting 32. The servomotor 12 may be for example an electric machine (electric motor), a hydraulic drive or a pneumatic drive. The servomotor 12 comprises a rotor 14, which is mounted in two rotor bearings 16. The rotor 14 includes a hollow shaft 18. The hollow shaft 18 is surrounded by a radial shaft seal 20, which helps to seal the oil-filled camshaft space 22 against parts of the servomotor 12. Cam shaft-side parts 26, 32 of the camshaft actuator 10 are typically located under engine oil 24. A clutch shaft 26 is passed through the hollow shaft 18 and fixed on that side of the rotor 14 to the rotor 14, which faces away from the adjusting 32. The coupling shaft 26 may extend over more than 50% of a (total) axial length of a rotor 14.

At this actuating motor end 30, the coupling shaft 26 is articulated to the rotor 14 for torque transmission to the adjusting mechanism 32 by means of a securing bolt 34. The clutch shaft 26 has at its Stellmotorseitigen end 30 a passage 25 for a safety pin 34. The securing bolt 34 is mounted in opposite holes 36 in the wall of the hollow shaft 18. In the region of the passage 25 for the securing bolt 34, the coupling shaft 26 may have a spindle-shaped or spherical thickening 38 whose outer diameter is only slightly smaller than the inner diameter 40 of the hollow shaft 18. This ensures that the coupling shaft 26 (regardless of its tumbling motion) is fixed in the hollow shaft 18 so that at the location of the securing bolt 34, a main longitudinal axis 27 of the coupling shaft 26 has a common point of intersection 42 with the main longitudinal axis 19 of the hollow shaft 18.

The securing bolt 34 is rotatably mounted in the hollow shaft 18 about its main longitudinal axis 35. Such a rotation is a rolling motion 44 of the securing bolt 34 (see Fig. 2 ). In addition, the securing bolt 34 is mounted in the hollow shaft 18 with so much play that it can be tilted with respect to an axis 37 of the holes 36. Such a tilting 48 is a pitching movement of the securing bolt 34. The fact that the securing bolt 34 in the hollow shaft 18 can perform both a rolling movement 44 and a pitching motion 48, the coupling shaft 26 (based on the intersection 42 of the main longitudinal axes 19, 27) in every radial direction can be tilted, so tumble. In order to support the coupling shaft 26 in the axial direction or to bias it against the adjusting mechanism 32, the coupling shaft 26 on at least one of its two end faces 30, 31 comprises a cylindrically symmetrical, convex formation 28 which is arranged concentrically to the main longitudinal axis 27 of the coupling shaft 26.

As Fig. 3 shows, a (plate-shaped) securing flange 50 may be clamped between elastomeric disks 52, which are arranged concentrically on the rotor side 54. As a result, the coupling shaft 26 can execute a uniform wobbling motion during rotation of the rotor 14. Instead of a securing flange 50, it is also possible for a plurality of extensions to be fastened or integrally formed on the coupling shaft 26, which have circumferential directions, for example in 3, 4 or 5. On the other side 31 of the coupling shaft 26 engages a bevel gear 60 of the clutch shaft 26 in a bevel gear 72 of the adjusting 32 a. Due to the mutual self-centering of the bevel gears 60, 72 and the pressure of the spring-supported ball bearing 62, the teeth of the two bevel gears 60, 72 remain despite the Achswinkels 64 between the clutch shaft 26 and adjusting 32 in loose engagement. The dashed lines indicate ridges of the meshing teeth of the bevel gears 60, 72. The sketch also shows that sufficient clearance 66 can be provided between the coupling shaft 26 and the hollow shaft 18, so that the coupling shaft 26 remains sufficient space for the required wobbling motion. For this purpose, the coupling shaft 26 between its two ends 30, 31 is tapered over more than w% of its axial length 39, wherein w% is at least 30%, in particular at least 60%. With a corresponding axial offset 79, the illustrated angle arrangement can not only result in a side view, but also from the viewpoint of every other circumferential angle of the main longitudinal axis of the rotor 14.

The coupling device of FIG. 4 is not part of the invention. As Fig. 4 shows, the coupling shaft 26 may also be rigidly secured to the rotor 14, if it has a sufficient bending ability while maintaining sufficient torsional strength. With a circular or annular cross-section of the coupling shaft 26, an increase in the bending ability is typically accompanied equally by an increase in the torsional capability. Depending on the application, it may also be that (for example, due to a reduction), a twist of the flexible coupling shaft 26 does not interfere. Or, by choosing a material with a suitable poisson's ratio, by choosing an anisotropic material, or by anisotropic design of the coupling shaft, it is possible to adapt the ratio of flexural rigidity to torsional rigidity to specific application requirements. With a corresponding axial offset 79, the illustrated angle arrangement can not only result in a side view, but also from the viewpoint of every other circumferential angle of the main longitudinal axis of the rotor 14.

In the Fig. 5 and 6 shown clutch shaft 26 has a servo-motor side a gear coupling component 58. The curved toothing allows an angle of the coupling shaft 26 relative to a main longitudinal axis 15 of the rotor 14 and the hollow shaft 18. Independent of which allows the internal teeth 59 of the hollow shaft 18 is an axial positional adjustment of the coupling shaft 26 along the main longitudinal axis 19 of the hollow shaft 18. The clutch shaft 26 of Fig. 5 and 6 Also includes on the side of the adjusting gear 32, a gear coupling component 60 which engages in an internal gear of a gear drive gear 72 of the adjusting gear 32. The gear coupling component 60 here has a larger diameter 69, because the gear drive gear 72 is located at a location at which a mounting screw for the adjusting gear 32 with the sprocket 74 is to be passed to the camshaft 76 during assembly.

As already too FIG. 3 explained, also in the second embodiment, the clutch shaft 26 can be pressed by means of spring force in the direction of adjusting 32. The end 31 of the clutch shaft 26 facing the camshaft 76 may be supported by a self-aligning bearing in the variator 32 (for example on an intermediate gear) or alternatively against the camshaft 76. The end 31 of the coupling shaft 26 may be mounted on a ball bearing 78, which has a convex outer ring 80 so that it can be slightly angled at axial offset 79 relative to the main axis 33 of the adjusting mechanism 32. The coupling shaft 26 may have a flange 81 on which the ball bearing 78 is mounted. The ball bearing 78 may be within a sprocket 72. It can be supported on a journal of the camshaft 76.

The Fig. 7 shows a perspective view of an open Verstellgetriebes 32 with the gear drive gear 72. The gear drive gear 72 is designed here as a flying gear and has an internal toothing and an external toothing. The gear drive gear 72 serves to drive via an (not shown in the figure) reduction gear with intermediate gears 84 an adjusting of the adjusting 32. Flanges 82 on the gear drive gear 72 and on the idler gears 84 hold the gear drive gear 72 at the axis position between the idler gears 84. Regarding the direction perpendicular to the axle connection of the idler gear 84, the gear drive gear 72 is held by guide wheels 86. Regardless, the gear drive gear 72 should also be sufficiently fixed or supported in the axial direction. This can be achieved for example by sliding bearing surfaces or by a (not shown in the figure) ball bearings.

In summary, the invention provides a clutch shaft 26, an actuator 12, a camshaft variator 32 and a camshaft actuator 10 with which radial forces between the clutch and the transmission input shaft can be reduced or avoided. This is especially true in combination with a cantilevered transmission input shaft (Gear drive gear 72). Regardless, the space-saving design allows a reduction in the axial space requirement for the camshaft adjuster 10. Space that can be saved for the clutch of servo motor 12 with adjusting 32, allows the use of a cheaper Verstellgetriebes 32 or a more cost-effective servomotor 12th

Reference numerals:

10

camshaft actuator

12

servomotor

14

rotor

15

Main longitudinal axis of the rotor 14

16

rotor bearing

18

hollow shaft

19

Main longitudinal axis of the hollow shaft 18th

20

Radial shaft seal

22

camshaft chamber

23

Axial length of the rotor 14

24

Engine oil

25

Bushing for safety bolts

26

clutch shaft

27

Main longitudinal axis of the coupling shaft 26

28

convex shape of the coupling shaft 26

30

Stellmotorseitiges end of the clutch shaft 26th

31

Verstellgetriebeseitiges end of the coupling shaft 26th

32

variator

33

Main axis of the adjusting 32th

34

safety bolt

35

Main longitudinal axis of the securing bolt 34

36

Holes in the wall of the hollow shaft 18th

37

Axis of the holes 36

38

Spindle or spherical thickening of the coupling shaft 26th

39

Axial length of the coupling shaft 26

40

Inner diameter of the hollow shaft 18th

42

Intersection of the main longitudinal axes 19 and 27

44

Rolling movement of the securing bolt 34

48

Nick movement of the locking bolt 34th

50

securing flange

52

elastomer discs

54

rotor side

56

securing flange

58

Engine-side gear coupling component of the clutch shaft 26th

59

Internal toothing of the hollow shaft 18th

60

Verstellgetriebeseitige gear coupling component of the coupling shaft 26th

62

spring-supported ball bearing

64

Axis angle

66

Clearance between coupling shaft 26 and wall of the hollow shaft 18th

69

Diameter of the gear coupling component 60

72

Gear drive gear of the variable speed gear 32

74

Sprocket

76

camshaft

78

ball-bearing

79

axial offset

80

Outer ring of the ball bearing 78

81

Flange of the coupling shaft 26

82

Flanges on the gear drive gear 72nd

84

intermediate gear

86

guide wheels

Claims (14)

1. Coupling shaft (26) for a camshaft adjuster (10) which comprises an actuating motor (12), with a hollow shaft (18) which is contained in its rotor (14), and an adjusting mechanism (32), the said coupling shaft (26) being rigid, and the said coupling shaft (26) which is guided through the hollow shaft (18) having in each case one coupling component (58, 60) at each of its two ends (30, 31) and performing a uniform tumbling movement in the hollow shaft (14), characterized in that each coupling component (58, 60) is configured as a rotary coupling (18, 58, 60, 72) for axis angle compensation with respect to both the rotor (14) and the adjuster (32).
2. Coupling shaft (26) according to the preceding claim, characterized in that an axial length (39) of the coupling shaft (26) is greater than w % of a maximum diameter (69) of the larger coupling component (58, 60), w % being at least 130%, in particular at least 150%.
3. Coupling shaft (26) according to either of the preceding claims, characterized in that the coupling shaft (26) is tapered between its two ends (30, 31) over more than w % of its axial length (39), w % being at least 30%, in particular at least 60%.
4. Coupling shaft (26) according to one of the preceding claims, characterized in that the coupling shaft (26) comprises, on at least one of its two end sides, a cylindrically symmetrical, convex shaped-out formation (28) which is arranged concentrically with respect to the main longitudinal axis (27) of the coupling shaft (26).
5. Coupling shaft (26) according to one of the preceding claims, characterized in that the coupling shaft (26) comprises a flange for a bearing (78).
6. Coupling shaft (26) according to Claim 1, characterized in that the first axis angle-compensating rotary coupling (18, 58) is an embodiment from the following list: a securing pin (34) or a component of a tooth coupling, a claw coupling, a plug-in coupling, a driver coupling, a spur gear coupling, a ring gearwheel coupling, a flexible disc, a bellow coupling, an elastomer coupling, a helical coupling, a spring coupling, a disc spring coupling, a web coupling, a compensating coupling, a cardan mechanism or a constant velocity joint, and/or in that the second axis angle-compensating rotary coupling is an embodiment from the following list: a securing pin or a component of a tooth coupling, a claw coupling, a plug-in coupling, a driver coupling, a spur gear coupling, a ring gearwheel coupling, a flexible disc, a bellow coupling, an elastomer coupling, a helical coupling, a spring coupling, a disc spring coupling, a web coupling, a compensating coupling, a cardan mechanism or a constant velocity joint.
7. Actuator (12) for actuating an adjusting mechanism (32) of a camshaft adjuster with a coupling shaft (26) according to Claims 1 to 6, characterized in that a coupling shaft (26) for actuating the camshaft adjusting mechanism (32) is coupled to the actuator (12) by means of a first axis angle-compensating rotary coupling (18, 58) in a region of the actuator (12) which is remote from the adjusting mechanism (32).
8. Actuator (12) according to Claim 7, characterized in that the coupling shaft (26) extends over more than 50% of an axial length (23) of a rotor (14) of the actuator (12).
9. Actuator (12) according to either of Claims 7 and 8, characterized in that the coupling shaft (26) is arranged in the actuator (12) such that it can be rotated in the tilting direction at every circumferential angle, it being possible for a tilting angle (44) of the coupling shaft (26) with respect to an axis (19) of the actuator (12) to be up to 1°, in particular up to at least 2°, in particular preferably up to at least 3°.
10. Actuator (12) according to one of Claims 7 to 9, characterized in that the coupling shaft (26) is arranged axially displaceably in the rotor (14).
11. Actuator (12) according to one of Claims 7 to 10, characterized in that the actuator (12) comprises an axial bearing component (62) for prestressing the coupling shaft (26) in the direction of a main longitudinal axis (27) of the coupling shaft (26).
12. Actuator (12) according to one of Claims 7 to 11, characterized in that, for coupling to the rotor (14), the first axis angle-compensating rotary coupling (18, 58) comprises a securing pin (26) or a component (58) of a tooth coupling (58, 18), a claw coupling, a plug-in coupling, a driver coupling, a spur gear coupling, a ring gearwheel coupling, a flexible disc, a bellow coupling, an elastomer coupling, a helical coupling, a spring coupling, a disc spring coupling, a web coupling, a compensating coupling, a cardan mechanism or a constant velocity joint.
13. Adjusting mechanism (32) for a camshaft adjuster with a coupling shaft (26) according to Claims 1 to 6, characterized in that an internal or external toothing system of a mechanism drive gearwheel (72) of the adjusting mechanism (32) is configured or suitable for the engagement of the tooth coupling component (60) of a coupling shaft (26).
14. Adjusting mechanism (32) according to Claim 13, characterized in that the tooth coupling component (60) of the coupling shaft (26) forms a floating mechanism drive gearwheel (72) of the adjusting mechanism (32).

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