DE102016220944A1 - Wave gear for a shaft adjustment device and shaft adjustment device with the wave gear - Google Patents

Abstract

Camshaft adjusters are used to change the phase position between a crankshaft and a camshaft in an internal combustion engine so as to change the valve opening and / or closing times. A wave gear mechanism 2 for a shaft adjustment device 1 is proposed, comprising a wave generator 3, wherein the wave generator 3 has an oval output, with a ring gear 8, wherein the ring gear 8 has internal teeth 9, with a flexible Stirnradeinrichtung 6, wherein the Stirnradeinrichtung 6 has an external toothing 7, wherein the wave generator 3 with the output of the flexible Stirnradeinrichtung 6 so deforms that the Stirnradeinrichtung 6 is in engagement with the internal teeth 9 in two tooth engagement areas with the external toothing 7, and with a damping ring 10, wherein the damping ring 10 between the Stirnradeinrichtung 6 and the ring gear 8 is arranged.

Description

The invention relates to a wave gear for a Wellenverstellvorrichtung with the features of the preamble of claim 1. The invention further relates to the Wellenverstellvorrichtung with the wave gear.

Camshaft phasers are used to change the phasing between a crankshaft and a camshaft in an internal combustion engine so as to change the valve opening and / or closing timings. In a conventional design, the camshaft phaser on a rotor and a stator, wherein the rotor is connected to a camshaft and the stator via a timing drive with a crankshaft. The stator and the rotor are rotatable relative to one another, so that in particular the angle of rotation of the camshaft changes. The relative rotation of stator and rotor is implemented, for example, hydraulically or electrically. In electric camshaft adjusters, it is known to use wave gear, which can realize very high gear ratios. Such wave gear usually have a wave generator, an elastic sleeve and a ring gear, wherein the elastic sleeve is deformed by the wave generator on the one hand, that it is engaged with the ring gear in only two tooth engagement areas and on the other hand, that the tooth engagement areas about the major axis of the wave gear to be rotated. By a different number of teeth of the elastic sleeve and the ring gear relative rotation between the elastic sleeve and the ring gear is implemented.

The components of such a wave gear are often made exclusively of metal. In contrast, in the document WO 2015/1511 46 A1 , which probably forms the closest prior art, a wave generator and a hollow body proposed, wherein the hollow body is constructed multi-layered and wherein at least one layer consists of a carbon fiber reinforced plastic material. The hollow body is used as an elastic sleeve in the wave generator in order to increase the stiffness of the hollow body in order to prevent the skipping of the toothing.

It is an object of the present invention to propose a cost-effective design of a damped wave gear. This object is achieved by a corrugated transmission with the features of claim 1 and by a Wellenverstellvorrichtung with the features of claim 10. Preferred or advantageous embodiment of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

The subject of the invention is a wave gear, which is suitable and / or designed for a shaft adjustment device. The wave gear can also be referred to as harmonic drive. The shaft adjustment device is in particular designed to adjust the phase position of a camshaft relative to the phase position of a crankshaft of an internal combustion engine. Preferably, the internal combustion engine is designed for a vehicle, in particular a passenger car, truck or the like. Alternatively, the wave gear and / or the Wellenverstellvorrichtung is adapted to change a compression ratio in a reciprocating engine as an internal combustion engine and / or forms a Variable Compression Ratio (VCR) device.

The wave gear has a wave generator, wherein the wave generator has an oval, in particular elliptical output and / or an oval output surface. In particular, the output and / or the output surface is designed as a main geometry of the corrugated transmission and / or the Wellenverstellvorrichtung circumferential front geometry and / or end face.

Furthermore, the wave gear has a ring gear portion, wherein the ring gear portion has an internal toothing. The internal toothing is designed in particular as an axial toothing, ie, a toothing whose teeth extend in the axial direction to the main axis.

Furthermore, the wave gear has a flexible Stirnradeinrichtung, the Stirnradeinrichtung having an outer toothing. The flexible Stirnradeinrichtung is also referred to as flex spline. In particular, the flexible Stirnradeinrichtung may be formed as a flex collar or as a flex sleeve.

The wave generator, the ring gear and the Stirnradeinrichtung are arranged so that the wave generator, in particular with the output and / or the driven surface deformed the flexible Stirnradeinrichtung in such a way that the Stirnradeinrichtung is in engagement with the internal teeth in two tooth engagement areas with the outer toothing of Hohlradabschnitts , During a rotation of the wave generator about the main axis, the two tooth engagement regions wander in the circumferential direction about the main axis, whereby a relative number of teeth between the internal toothing and the external toothing relative rotation between the ring gear and the flexible ring gear is achieved. Preferably, the flexible Stirnradeinrichtung forms an input in the wave gear and the ring gear portion an output from the wave gear.

In the context of the invention it is proposed that the wave gear has at least or exactly one damping ring, wherein the damping ring between the Stirnradeinrichtung and the ring gear section is arranged. Preferably, the damping ring with the Stirnradeinrichtung on the one hand and with the ring gear on the other hand directly in contact.

The damping ring is designed in particular like an O-ring. For example, this is designed as an elastic plastic ring, in particular made of rubber. In particular, the damping ring is closed in the direction of rotation. A longitudinal section profile of the damping ring can be oval, circular or even rectangular, in particular square.

It is a consideration of the invention that in principle a damping for the flexible Stirnradeinrichtung is advantageous. However, the solution of the prior art has the concomitant that the ring gear in the radial direction has a compliance that could lead to skipping the teeth of the flexible spur gear. In contrast, the invention proposes a solution for damping, which is independent of the torque path via the internal teeth and the external teeth. Rather, the damping is parallel to the engagement between the internal teeth and the external teeth. As a result, the risk of skipping the teeth is almost impossible. Preferably, the damping ring is radially biased in particular slightly and / or dimensioned in that it presses in the radial direction against both the Stirnradeinrichtung and against the ring gear and / or dimensioned in the adial direction with oversize, so that the changing load torque peaks in the backlash damped in the tangential direction and hard stops of the tooth flanks are avoided in the tooth connection. This also reduces noise. Due to the radial bias and the friction torque between the flexible Stirnradeinrichtung and the output surface of the wave generator is increased, so that by a higher friction and damping effects can be generated in addition to the output surface.

Preferably, in the ring gear portion a receiving groove for receiving the damping ring is at least partially or fully recirculating introduced. Thus, the damping ring is located with its radially inner side on the flexible Stirnradeinrichtung with its radial outside on or in the receiving groove. A friction torque can be implemented either by the groove walls or by the groove bottom depending on the design of the receiving groove.

In a preferred embodiment of the invention, the receiving groove is introduced into the internal toothing. In particular, the axial position of the receiving groove is selected so that an internal toothing region remains on both axial sides of the receiving groove. In this way, the damping effect is arranged symmetrically in the region of the internal toothing.

In a preferred development of the invention, the damping ring has a ring toothing, which is directed radially inward, wherein the ring gear engages in the outer toothing of the Stirnradeinrichtung and / or meshes with this.

Through this development it is achieved that the damping ring can not be moved relative to the flexible Stirnradeinrichtung in the direction of rotation.

In a further development of the invention, the wave gear has an outer rotor and an inner rotor. The outer rotor is rotatably coupled to the Stirnradeinrichtung. It can be provided that the outer rotor is rigidly connected to the Stirnradeinrichtung. Alternatively, the outer rotor is geared to the spur gear mechanism in a rotationally fixed manner. The inner rotor has the ring gear section. Alternatively, the outer rotor has the ring gear section or a further ring gear section.

Between the inner rotor and the outer rotor, an axial sliding surface is formed in a radial plane to the main axis. The receiving groove is bounded on the one hand by the outer rotor and on the other hand by the inner rotor. The receiving groove is also cut by the radial plane of the Axialgleitfläche. In a Realtivbewegung between outer rotor and inner rotor thus takes place a different movement between the damping ring on the one hand and the receiving groove portion of the inner rotor and the receiving groove portion of the outer rotor. Preferably, in this embodiment, the receiving groove is formed with a triangular cross-sectional area.

It is also possible that the damping ring between the ring gear portion of the outer rotor and the Stirnradeinrichtung is arranged.

In a possible development of the invention, the wave gear has a second damping ring, wherein the second damping ring between the Stirnradeinrichtung and the outer rotor is arranged. The second damping ring may be constructed identical to the first damping ring.

In one possible development of the invention, the outer rotor has a second internal toothing as a ring gear section or further ring gear section, wherein the second internal toothing meshes with the external toothing and wherein the second receiving groove is introduced into the second internal toothing. In particular, the second receiving groove may be placed in the internal toothing such that an internal toothing region is formed axially on both sides.

Another object of the invention relates to a Wellenverstellvorrichtung for adjusting the phase angle between a crankshaft and an internal combustion engine and a camshaft of the internal combustion engine, wherein the Wellenverstellvorrichtung is formed by a wave gear according to one of the preceding claims or as previously described.

• 1a, b, c, ein Wellgetriebe in einer schematischen Längsschnittdarstellung, Detaildarstellung und axialen Draufsicht als ein erstes Ausführungsbeispiel der Erfindung;
• 2a, b, c in gleicher Darstellung wie in den vorhergehenden Figuren ein zweites Ausführungsbeispiel der Erfindung;
• 3a, b, c in gleicher Darstellung wie die vorhergehenden Figuren ein drittes Ausführungsbeispiel der Figuren;
• 4 die flexible Stirnradeinrichtung in einer dreidimensionalen Darstellung;
• 5a, b, c, d, verschiedene Ausführungsformen des Dämpfungsrings für das Wellgetriebe der vorhergehenden Figuren.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention and the accompanying figures. These show:

• 1a, b , c, a wave gear in a schematic longitudinal sectional view, detail and axial plan view as a first embodiment of the invention;
• 2a, b , c in the same representation as in the preceding figures, a second embodiment of the invention;
• 3a, b , c in the same representation as the preceding figures, a third embodiment of the figures;
• 4 the flexible Stirnradeinrichtung in a three-dimensional representation;
• 5a, b , c, d, various embodiments of the damper ring for the wave gear of the preceding figures.

The 1a shows a schematic longitudinal sectional view along a main axis H a shaft adjustment device 1 with a wave gear 2 as an embodiment of the invention. The 1b shows a detail section according to circle X the 1c shows an axial plan view of the Wellenverstellvorrichtung 1 , wherein the sectional plane AA is drawn.

The wave gear 2 has a wave generator 3 on, which via a motor, not shown, about the main axis H is rotatably arranged. The wave generator 3 carries a ball bearing device 4 with a plurality of balls. The balls roll on the one hand on an inner ring 5 and on the other hand on an outer ring. The outer ring is in contact with a flexible Stirnradeinrichtung 6 , The flexible Stirnradeinrichtung 6 is in a three-dimensional representation in the 4 shown in an undeformed state. It can be seen that the flexible Stirnradeinrichtung 6 assumes a circular shape and on the radial outer side an external toothing 7 wearing. In operation, the flexible Stirnradeinrichtung 6 through the wave generator 3 oval, in particular elliptically deformed.

The wave gear 2 further includes a ring gear portion 8th as part of a Abtriebshohlrads, which on the radially inner side of an internal toothing 9 wearing. The internal toothing 9 is engaged with the external toothing 7 the flexible Stirnradeinrichtung 6 , With a rotation of the wave generator 3 wander the meshing areas of the flexible Stirnradeinrichtung 6 in the ring gear section 8th in the direction of rotation about the main axis H , wherein by a different number of teeth of the internal toothing 9 and the external teeth 7 a relative rotation between the ring gear section 8th and the flexible Stirnradeinrichtung 6 is produced.

In the 1b It can be seen that between the flexible Stirnradeinrichtung 6 and the ring gear portion 8th a damping ring 10 is arranged, which in this embodiment has a circular area in the longitudinal section. In the 5a, b , c, d, are four different embodiments of the damping ring 10 shown. The embodiment in the 5a has a circular sectional area, the embodiment in the 5b a rectangular sectional area, the embodiment in the 5c a triangular cut surface. While the embodiments of the damping ring 10 in 5a, b , c, each have a circumferential radially inwardly directed ring teeth 11 have, which in the internal toothing 9 engages is in the embodiment according to the 5b no ring teeth 11 intended.

The damping ring 10 is in particular radially biased on the flexible Stirnradeinrichtung 6 fitted and optionally engages with the ring teeth 11 in the external teeth 7 one. In the ring gear section 8th is a recording groove 12 introduced, which has a rectangular sectional area with groove side walls and a groove bottom. In the recording groove 12 is the damping ring 10 inserted. The receiving groove 12 is so in the internal teeth 9 introduced that on both sides to the receiving groove 12 an internal gear portion remains. The damping ring 10 has the task the ring gear section 8th relative to the Stirnradeinrichtung 6 to dampen. The damping ring 10 is used in excess, so that this in a radial direction against the groove bottom and / or the ring gear section 8th and the Stirnradeinrichtung 6 suppressed.

Like from the 1a can be seen, the wave gear has an outer rotor 13 on which a sprocket section 14 for gearbox coupling of a crankshaft. For example, the movement of the crankshaft via a timing chain on the sprocket section 14 and thus on the outer rotor 13 transfer. The outer rotor 13 is designed in several parts and has a body 15 as a sprocket and an axial body 16 on which one over a screw 17 connected to each other. The axial body 16 as a driving ring gear has on its radially inner side a second internal toothing 18 as a ring gear portion, which also with the external teeth 7 the flexible Stirnradeinrichtung meshes. It can be provided that in the outer rotor 13 , in particular in the axial body 16 , in particular in the Hohlradabschnitt another receiving groove 19 for another damping ring 20 is arranged, wherein the further damping ring 20 analogous to the first damping ring 10 can be trained. Thus, reference is made to the preceding description. The further recording groove 19 can be designed as well as the receiving groove 12 , In particular, the further receiving groove 19 in the second internal toothing 18 be arranged so that each axially an inner toothing section remains on both sides.

In the 2a, b , c is a second embodiment of the Wellenverstellvorrichtung 1 or the corrugated transmission 2 shown below, with only the differences below. In contrast to the first embodiment, the second embodiment has only one damping ring 10 on. The ring gear section 8th forms part of an inner rotor 21 which through the wave gear 2 relative to the outer rotor 13 with the axial body 16 is pivoted. Between the inner rotor 21 and the outer rotor 13 more precisely, between the ring gear portion 8th and the axial body 16 an axial sliding surface forms 22 out. In the plane of the axial sliding surface 22 is the recording groove 12 arranged, which, however, has a triangular sectional area. A groove wall is through the axial body 16 formed, the other groove wall is through the Hohlradabschnitt 8th educated. In operation, outer rotor slide 13 and inner rotor 21 along the axial sliding surface 22 against each other. Through the damping ring 10 is also the movement of inner rotor 21 and outer rotor 13 muted to each other. In the embodiment in the 2a , b, c, is the damper ring 10 placed on a part of the external toothing.

In the embodiment according to the 3a, b , c is the damping ring set to the same position, however, has the flexible Stirnradeinrichtung 6 a groove 23 for the damping ring 10 on.

LIST OF REFERENCE NUMBERS

1

Phasing device

2

The wave gear

3

wave generator

4

Ball bearing assembly

5

inner ring

6

Stirnradeinrichtung

7

external teeth

8th

ring gear portion

9

internal gearing

10

damping ring

11

ring gear

12

receiving groove

13

outer rotor

14

Kettenradabschnitt

15

body

16

axial body

17

screw

18

internal gearing

19

receiving groove

20

second damping ring

21

inner rotor

22

Axialgleitfläche

23

groove

H

main axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/151146 A1 [0003]

Claims (10)

Wave gear (2) for a shaft adjustment device (1), with a wave generator (3), wherein the wave generator (3) has an oval output, with a ring gear (8), wherein the ring gear (8) has an internal toothing (9) with a flexible Stirnradeinrichtung (6), wherein the Stirnradeinrichtung (6) has an outer toothing (7), wherein the wave generator (3) with the output of the flexible Stirnradeinrichtung (6) deformed so that the Stirnradeinrichtung (6) with the internal toothing (9) in two tooth engagement portions with the external toothing (7) is engaged, characterized by a damping ring (10), wherein the damping ring (10) between the Stirnradeinrichtung (6) and the ring gear portion (8) is arranged. Wave gear (2) after Claim 1 , characterized by a receiving groove (12) for receiving the damping ring (10), wherein the receiving groove (12) in the ring gear section (8) is introduced. Wave gear (2) after Claim 1 or 2 , characterized in that the receiving groove (12) in the internal toothing (9) is introduced. Corrugated transmission (2) according to one of the preceding claims, characterized in that the damping ring (10) has a ring toothing (11), wherein the ring toothing (11) engages in the internal toothing (9) of the Stirnradeinrichtung (6). Wave gear (2) according to one of the preceding claims, characterized by an outer rotor (13) and an inner rotor (21), wherein the outer rotor (13) with the Stirnradeinrichtung (6) is rotatably coupled and the inner rotor (21) and / or the outer rotor the ring gear (8) carries. Wave gear (2) after Claim 5 , characterized in that between the inner rotor (21) and the outer rotor (13) a Axialgleitfläche (22) is formed in a radial plane, wherein the receiving groove (12) on the one hand by the outer rotor (13) and on the other hand by the inner rotor (21) limited is and is intersected by the radial plane. Wave gear (2) after Claim 5 characterized by a second damping ring (20), wherein the damping ring (10) between the Stirnradeinrichtung (6) and the inner rotor (21) and the second damping ring (20) between the Stirnradeinrichtung (6) and the outer rotor (13) is arranged. Wave gear (2) after Claim 6 or 7 , characterized in that in the outer rotor (13) has a second receiving groove (19) for receiving the second damping ring (20) is arranged. Wave gear (2) after Claim 7 or 8th , characterized in that the outer rotor (13) has a second internal toothing (18), wherein the second internal toothing (18) meshes with the external toothing (7) and wherein the second receiving groove (19) in the second internal toothing (18) is introduced. Shaft adjusting device (1) for adjusting the phase position between a crankshaft of an internal combustion engine and a camshaft of the internal combustion engine, characterized by a corrugated transmission (2) according to one of the preceding claims.

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