DE102016221802A1 - Well gear and vehicle with the wave gear - Google Patents

Abstract

Wellgetriebeseinrichtungen are reduction gear and have three main components. An adjusting torque is introduced via a wave generator unit, which is rotated about an axis of rotation. The wave generator unit has an oval, in particular elliptical output surface. Coaxially to the wave generator unit, a corrugated box unit is arranged, which is elastically deformable. To this end, a wave gear 1, with a ring gear 4, wherein the ring gear 4 has an internal gear portion 11, wherein the ring gear 4 defines an axis of rotation R, with a Stirnradeinrichtung 5, wherein the Stirnradeinrichtung 5 has an outer toothed portion 10, wherein the internal gear portion 11 is partially engaged with the external gear portion 10, with a wave generator 6, wherein the wave generator 6, the Stirnradeinrichtung 5 deformed so that the regional engagement is formed with a sliding bearing 7, wherein the wave generator 6 via the sliding bearing 7 with the Stirnradeinrichtung 5 cooperates, wherein the wave generator 6 on an outer circumferential surface a first sliding bearing surface 8a and the Stirnradeinrichtung 5 on an inner circumferential surface has a second sliding bearing surface 8b proposed, wherein the first and / or the second sliding bearing surface 8a, b lubricant pockets 16 to S having a lubricant lubricant.

Description

The invention relates to a wave gear with the features of the preamble of claim 1. Furthermore, the invention relates to a vehicle with the wave gear with the feature of claim 10.

Corrugated gearboxes are gearboxes or transmissions made up of three subassemblies. A wave generator device often forms an input or an output in the wave gear and has an oval or elliptical shaped and rotating in the radial outer surface. This engages in a component, usually referred to as a flexspline, as a second subassembly, which is designed to be elastic such that it can be deformed in the radial direction by the wave generator device. On the radial outside of the Flexsplines an external toothing is arranged. As a third subassembly, the wave gear has a ring gear, which carries an internal toothing. The external toothing of the flexspline usually engages at two opposite positions in the internal toothing of the ring gear. By a rotational movement of the wave generator device, the engagement positions between external teeth and internal teeth are moved in the direction of rotation. By a different number of teeth between the external teeth and the internal teeth results in a relative movement between the wave generator and the Flexspline.

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 of a plurality of layers and wherein at least one layer consists of a plastic material. The hollow body is used as an elastic sleeve in the wave generator.

The invention relates to a wave gear, which for a vehicle, preferably a motor vehicle, suitable and / or trained. The harmonic drive is referred to in particular as a harmonic drive transmission. For example, the wave gear transmission is technically connected to a camshaft and / or crankshaft. In particular, the wave gear comprises an inner rotor and an outer rotor, e.g. a sprocket, wherein the inner rotor and the outer rotor are rotatable relative to each other.

The wave gear has a ring gear, wherein the ring gear has an internal gear portion. In particular, the ring gear is formed as a rigid, internally toothed transmission element. The ring gear forms the inner rotor and is coupled for example with a stop disc and / or a camshaft or integrally connected thereto.

The corrugated gear has a Stirnradeinrichtung - often referred to as Flexspline - on, wherein the Stirnradeinrichtung has an outer toothed portion, wherein the inner toothed portion is partially engaged with the outer toothed portion. In particular, the inner toothed portion engages the outer toothed portion only and / or only in regions. Preferably, the internal gear portion and the external gear portion are engaged with each other in exactly two engaging portions and are separated from each other and / or are disengaged in intermediate portions therebetween. Particularly preferably, the two engagement regions are arranged diametrically opposite one another.

The wave gear has a wave generator, wherein the wave generator deforms the Stirnradeinrichtung such that the regional engagement is formed. The function of the wave generator is to contact, drive and / or deform the spur gear. The wave generator preferably forms a drive and has an oval, in particular elliptical basic body. The main body is rotatable about a rotation axis of the corrugated transmission. The Stirnradeinrichtung is deformable formed such that it can be deformed by the wave generator in particular in an oval and / or elliptical shape in particular as intended.

Optionally in addition to the wave generator comprises a radial bearing device with an outer ring, an inner raceway and a plurality of rolling elements, which are arranged abrolling between the outer ring and the inner race. Preferably, the outer ring is flexible. With respect to the radial bearing device, the rolling elements form a first contact partner, the inner raceway a second contact partner.

The wave gear has a sliding bearing, wherein the wave generator cooperates via the sliding bearing with the Stirnradeinrichtung, wherein the wave generator on an outer circumferential surface a first sliding bearing surface and the Stirnradeinrichtung on an inner circumferential surface has a second sliding bearing surface. Preferably, the outer circumferential surface or the first sliding bearing surface is formed by a radial outer side of the main body or of the outer ring. Preferably, the inner circumferential surface or the second sliding bearing surface is formed by a radial inner side, in particular an inner circumference, of the Stirnradeinrichtung.

The outer lateral surface and / or the inner lateral surface is preferably curved in axial plan view. In particular, the sliding bearing surface is at least partially on the outer circumferential surface of the wave generator. Preferably, the first sliding bearing surface extends in the axial direction over the entire outer circumferential surface of the wave generator. Particularly preferably, the second sliding bearing surface extends in the axial direction in the region of the outer toothing section and / or in the region of the first sliding bearing surface. In particular, the first sliding bearing surface extends completely in the circumferential direction over the outer circumferential surface and / or the second sliding bearing surface completely in the circumferential direction over the entire inner circumferential surface.

In the context of the invention, the first and / or the second sliding bearing surface on lubricant pockets for storing a lubricant. The lubricant pockets in particular have the function of storing the lubricant in such a way that displacement of the lubricant, in the axial direction and / or in the direction of rotation and / or in the radial direction with respect to the axis of rotation, is preferably prevented in the two engagement regions. For example, the lubricant is a liquid lubricant, preferably a lubricating oil, or a grease. Furthermore, the lubricant pockets and the associated storage of the lubricant serve to dampen load peaks and / or to dampen a force flow in the two engagement areas. Particularly preferably, a hydraulic damping between the wave generator and the Stirnradeinrichtung is generated by the lubricant stored in the lubricant pockets. In an arrangement of the lubricant pockets on the first and the second sliding bearing surface in particular the damping effect of the hydraulic damping is increased.

In particular, the lubricant pockets are recesses in the first and / or the second sliding bearing surface. In particular, the lubricant pockets are introduced into the first and / or the second slide bearing surface by forming and / or separating. In particular, the first and / or the second sliding bearing surface has more than 100, preferably more than 500, in particular more than 1000 lubricant pockets. For example, the wave generator and the Stirnradeinrichtung are formed of different materials. Optionally, in addition, the first or the second sliding bearing surface may additionally comprise a wear-reducing and / or friction-reducing coating, e.g. Have ceramic. However, particularly preferably, at least one of the two sliding bearing surfaces on the lubricant pockets.

The advantage of the invention is that the lubricant is stored by the lubricant pockets in particular in the engagement areas, so that thereby the friction of the sliding bearing and / or the wear of the sliding bearing is reduced. Furthermore, it is ensured in particular by the storage of the lubricant in the engagement regions, that the lubricant is not displaced in the engagement regions and thus a hydraulic damping can be generated. In addition, due to the hydraulic damping, the spur gear and / or the wave generator, in particular in the radial direction, are made unyielding. Due to the unyielding design of the spur gear and / or the wave generator in particular skipping the teeth is prevented in the engagement areas. By introducing the lubricant pockets thus also the performance of the wave gear is generally improved.

In a first concrete realization, the lubricant pockets are formed by laser honing. In particular, the laser honing reduces the friction and wear of the sliding bearing. In particular, laser honing is understood to mean a combination of honing and laser structuring. In a first production step, the first and / or the second sliding bearing surface are first processed by honing, preferably by pre-honing and intermediate honing, so that a desired output surface for the laser structuring is produced. In a further production step, the lubricant pockets are introduced into the first and / or the second slide bearing surface by means of a laser beam. In a final manufacturing step, the first and / or the second plain bearing surface are processed by deburring and finishing honing, wherein the melt thrown at the laser machining removed and at the same time the average roughness is reduced. Alternatively, the first and / or the second sliding bearing surface can also be structured by electron beam machining or spark erosion.

In an alternative or optional complementary concrete realization, the lubricant pockets are formed by a rolling process. In particular, the surface quality is positively influenced by the rolling process, so that preferably the friction and the wear of the sliding bearing are reduced. In particular, the lubricant pockets are introduced by forming, preferably by cold forming, particularly preferably by edge rims in the first and / or the second sliding bearing surface. In particular, a roll on the outside of the roll shell on a uniform profiling. Preferably, the profiling is formed by elevations, which form the lubricant pockets into the surface during the processing of the first and / or the second sliding bearing surface.

In an alternative or optionally supplementary concrete realization, the lubricant pockets are formed by etching. In particular, the first and / or the second sliding bearing surface is pretreated by honing, so that a corresponding surface quality is produced. In particular, the lubricant pockets are introduced by a deep etching in the first and / or the second sliding bearing surface.

Alternatively, the lubricant pockets are introduced by an area etching in the first and / or the second sliding bearing surface. In particular, the first and / or the second sliding bearing surface are partially provided with an acid-resistant photochemical cover layer and / or with an acid-resistant cover, wherein for the introduction of the lubricant pockets, the first and / or the second sliding bearing surface has recesses, which not with the cover layer and / or the Abdecklack are provided. Subsequently, the first and / or the second sliding bearing surface is exposed to an etching liquid, wherein the lubricant pockets are introduced by the action of the acid.

In a preferred implementation, the sliding bearing is lubricated by a lubricating oil, the lubricating oil is viscous. In particular, the lubricating oil has the function to reduce the friction and / or dissipate heat and / or to generate a hydraulic damping. The lubricating oil is preferably arranged in the sliding bearing between the two sliding bearing surfaces, so that a sliding film is formed. Particularly preferably, however, the lubricating oil is received and / or stored in the lubricant pockets. In particular, the lubricating oil has a kinematic viscosity at a temperature of 100 ° C, preferably after DIN 51550 and DIN 51562 , of more than 3 mm ² / s, preferably more than 10 mm ² / s, in particular more than 20 mm ² / s.

In a preferred constructive implementation, the lubricant pockets are designed as micro-pressure chambers, so that the lubricating oil is stored in the lubricant pockets. Micro-pressure chambers are chambers that can absorb and store the lubricant, in particular the lubricating oil. Preferably, the micro-pressure chambers build up a hydrodynamic pressure. In order to ensure reliable lubrication by the hydrodynamic pressure, the lubricant pockets on an unbroken peripheral edge and preferably form a closed micro-pressure chamber. The micro-pressure chambers thus remain filled even during operation of the wave gear and thus reduce the friction between the two sliding surfaces and / or beneficiaries the hydraulic damping in the two contact areas.

In a specific development, the lubricant pockets have a round and / or a point-like shape and a depth of less than 30 micrometers. In particular, the lubricant pockets have a circular or an elliptical and / or an elongated shape. Preferably, the maximum extension is less than 0.5 mm, preferably less than 0.1 mm. In particular, the micro-pockets extend inwardly, in the first and / or the second sliding surface approximately conical or cylindrical. The maximum depth is in particular less than 20 micrometers, preferably less than 10 micrometers. However, the maximum depth is particularly preferably a multiple of the roughness depth of the adjacent surface areas. In particular, the first and / or the second sliding bearing surface have an average roughness depth of less than 3 micrometers, preferably less than 2 micrometers, in particular less than 1 micrometer.

In a further preferred embodiment, the lubricant pockets are arranged in the axial direction and / or in the circumferential direction with respect to the axis of rotation regularly spaced from each other on the first and / or the second sliding bearing surface. In particular, the lubricant pockets in the circumferential direction and / or in the axial direction are arranged one above the other and / or lying next to each other or lying on a spiral, so that the first and / or the second sliding bearing surface is preferably provided evenly with the lubricant pockets.

In a preferred embodiment, the wave gear is designed as a camshaft adjuster or as a compression plate. In particular, the camshaft adjuster serves to adjust the phase position of the camshaft, preferably an intake and / or an exhaust camshaft, relative to the phase angle of the crankshaft of the vehicle. In particular, the camshaft adjuster is an electric or an electromechanical camshaft adjuster. Preferably, the camshaft adjuster has an actuator for adjusting the phase position, wherein particularly preferably the corrugated transmission is designed as the actuator. In particular, the phaser is a VCT system.

In particular, the compression actuator is used to change a compression ratio of a reciprocating engine. In particular, the compression plate is an electric or an electromechanical compression plate. Preferably, the compression plate has an actuator for changing the compression ratio, wherein the wave gear is particularly preferably designed as the actuator. In particular, the compression plate is a VCR system.

Another object of the invention relates to a vehicle with a wave gear, as previously described or according to one of the preceding claims.

• 1 zeigt ein Wellgetriebe in einer schematischen Schnittdarstellung als ein Ausführungsbeispiel der Erfindung;
• 2 zeigt Getriebeelemente des Wellgetriebes in einer Schnittdarstellung;
• 3 zeigt ein vergrößertes, schematisiertes Detail der Anordnung der Getriebeelemente nach 3;
• 4a zeigt in einer dreidimensionalen Darstellung einen Wellgenerator des Wellgetriebes;
• 4b zeigt in einer dreidimensionalen Darstellung eine Stirnradeinrichtung des Wellgetriebes.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention. Showing:

• 1 shows a harmonic drive in a schematic sectional view as an embodiment of the invention;
• 2 shows gear elements of the wave gear in a sectional view;
• 3 shows an enlarged, schematic detail of the arrangement of the transmission elements 3 ;
• 4a shows in a three-dimensional representation of a wave generator of the wave gear;
• 4b shows in a three-dimensional representation of a Stirnradeinrichtung the wave gear.

Corresponding or identical parts are each provided with the same reference numerals in the figures.

The 1 shows roughly schematically a total with the reference numeral 1 marked wave gear. The wave gear 1 is or can be in a housing 2 be installed, which is not part of the corrugated transmission 1 is. In case of using the wave gear 1 as a control gear of an electric camshaft adjuster is in the housing 2 about a rotatable, by a traction means, in particular a chain, drivable housing of the camshaft adjuster. Normally, in the case of the camshaft adjuster, the housing is counted as a drive shaft to the wave gear. A designated 3 shaft, which is an output element of the wave gear 1 represents is identical or firmly connected to a camshaft. When using the corrugated transmission 1 Within a device for varying the compression ratio of a reciprocating engine is the housing 2 firmly connected to an engine block or an integral part of the engine block, that is, in any case not rotatable. At the wave 3 In this case, it is an eccentric shaft which interacts with the crank mechanism of the internal combustion engine via a secondary connecting rod.

Regardless of use and installation situation of the corrugated transmission 1 assign this one with the wave 3 connected rigid gear member formed as a ring gear 4 on. The axis of rotation of the ring gear 4 is denoted by R and with the symmetry axis of the wave gear 1 identical. The ring gear 4 is internally toothed and acts directly with a flexible, that is yielding, transmission element, designed as a Stirnradeinrichtung 5 For example, a corrugated box, together. The Stirnradeinrichtung 5 is also called a flex ring.

When operating the corrugated transmission 1 becomes the Stirnradeinrichtung 5 permanently by a wave generator 6 deformed. For example, the wave generator 6 designed as Gleitwellgenerator as a rolling bearing generator. In the cut after 1 is the wave generator 6 recognizable, which has a T-shaped cross-section. The wave generator 6 has on a outer circumferential surface a first sliding bearing surface 8a and the Stirnradeinrichtung 5 has a second sliding bearing surface on an inner circumferential surface 8b on. The first sliding bearing surface 8a lies on the second sliding bearing surface 8b on, so that thereby the sliding contact of the sliding bearing 7 is formed.

About the sliding contact of the sliding bearing 7 be radial forces - related to the axis of rotation R - Transfer, wherein in a toothing region designated 9, an outer toothing section 10 the Stirnradeinrichtung 5 with an internal toothing section 11 of the ring gear 4 , meshes, allowing torque between the transmission elements 4 . 5 is transferable.

Like from the 2 and 3 shows, there is the outer toothing section 10 in exactly two diametrically opposite circumferential sections in engagement with the internal gear section 11 , The outer surface of the wave generator 6 acts as the first sliding bearing surface 8a on which the Stirnradeinrichtung 5 as another sliding bearing element with the second sliding bearing surface 8b rests.

The wave generator 6 has an oval or elliptical contour, which ensures that at two exactly on the circumference of the wave generator 6 opposite points, in the arrangement according to 2 at the top and at the lowest point, the gearing sections 10 . 11 the transmission elements 4 . 5 mesh to the maximum extent possible. With increasing distance from these two points on the circumference of the transmission elements 4 . 5 on the other hand, the outer toothing section 10 increasingly from the internal gear section 11 lifted off, in particular from 3 evident.

A slightly different number of teeth between the toothed sections 10 . 11 the transmission elements 4 . 5 ensures that when you walk a gearing areas 12 , which by rotation of the wave generator 6 relative to Stirnradeinrichtung 5 is effected, the transmission elements 4 . 5 relatively slowly turn against each other. The wave generator 6 is directly driven by an electric motor, not shown.

4a shows in a three-dimensional representation of the wave generator 6 as the rolling bearing generator. The wave generator 6 carries a rolling bearing device 13 with a plurality of rolling elements, such as balls or rollers. The rolling elements roll on the one hand on an inner ring 14 For example, on an inner race, and on the other hand on a radial inner side of an outer ring 15 off, with the outer ring 15 is formed deformable. The outer ring 15 forms the outer circumferential surface of the wave generator 6 , in particular forms the outer circumferential surface of the outer ring 15 the first sliding bearing surface 8a ,

The first sliding bearing surface 8a has a variety, eg more than 200, of lubricant pockets 16 on. The lubricant pockets 16 are designed as locally closed recesses, which store as micro-pressure chambers, a lubricant, such as lubricating oil, grease, etc. and build up a hydrodynamic pressure. By the lubricant is, especially in the region of the sliding contact of the sliding bearing 7 , a hydraulic damping for damping of load peaks between the Stirnradeinrichtung 5 and the outer ring 15 generated. So that the lubricant is not in the axial and / or radial direction and / or in the direction of rotation with respect to the axis of rotation R , in particular in the region of the sliding contact, is displaced, the lubricant is stored in the lubricant pockets.

The Stirnradeinrichtung 5 is in a three-dimensional representation in the 4b shown in an undeformed state. It can be seen that the Stirnradeinrichtung 5 takes a circular shape and on the radial outer side of the outer toothing section 10 wearing. In operation, the Stirnradeinrichtung 5 through the wave generator 6 oval, in particular elliptically deformed.

Alternatively or optionally in addition to the in 4a shown embodiment, know the Stirnradeinrichtung 5 the lubricant pockets 16 on. The lubricant pockets 16 For example, by bordering, laser honing, photographic etching, etc. in the first and / or the second sliding bearing surface 8a , b introduced. The lubricant pockets 16 have a round point-like shape and, for example, have a diameter of less than 90 microns, preferably less than 50 microns. For example, the first and / or the second sliding bearing surface 8a , b a surface finish with an average roughness of about 1 to 2 microns. The lubricant pockets 16 For example, have a depth of about 5 to 25 microns.

The lubricant pockets 16 are on the first and the second sliding bearing surface 8a , b arranged in an axial direction in a row, wherein the first and the second sliding bearing surface 8a , b in the direction of rotation with respect to the axis of rotation R has a plurality of mutually parallel rows. The rows are in the direction of rotation and the lubricant pockets 16 in the axial direction with respect to the axes of rotation R regularly spaced from each other. For example, a number has about ten lubricant pockets 16 on.

LIST OF REFERENCE NUMBERS

1

The wave gear

2

casing

3

wave

4

ring gear

5

Stirnradeinrichtung

6

wave generator

7

bearings

8a

first sliding bearing surface

8b

second sliding bearing surface

9

toothed area

10

External tooth section

11

Internal gear section

12

toothed area

13

roller bearing device

14

inner ring

15

outer ring

16

lubricant pockets

R

axis of rotation

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]

Cited non-patent literature

• DIN 51550 [0018]
• DIN 51562 [0018]

Claims (10)

Corrugated gear (1) with a ring gear (4), wherein the ring gear (4) has an internal gear portion (11), wherein the ring gear (4) defines an axis of rotation (R) with a Stirnradeinrichtung (5), wherein the Stirnradeinrichtung (5 ) has an external gear portion (10), wherein the internal gear portion (11) in regions with the external gear portion (10) engages with a wave generator (6), wherein the wave generator (6) the Stirnradeinrichtung (5) deformed so that the regionally Engaging is formed, with a sliding bearing (7), wherein the wave generator (6) via the sliding bearing (7) with the Stirnradeinrichtung (5) cooperates, wherein the wave generator (6) on an outer circumferential surface a first sliding bearing surface (8a) and the Stirnradeinrichtung ( 5) on an inner lateral surface has a second sliding bearing surface (8b), characterized in that the first and / or the second sliding bearing surface (8a, b) lubricant pockets (16) for storing e ines lubricant. Wave gear (1) after Claim 1 , characterized in that the lubricant pockets (16) are formed by laser honing. Wave gear (1) after Claim 1 or 2 , characterized in that the lubricant pockets (16) are formed by a rolling process. Wave gear (1) after Claim 1 , characterized in that the lubricant pockets (16) are formed by etching. Wave gear (1) according to any one of the preceding claims, characterized in that the sliding bearing (7) is lubricated by a lubricating oil, wherein the lubricating oil is viscous. Wave gear (1) according to one of the preceding claims, characterized in that the lubricant pockets (16) are designed as micro-pressure chambers, so that the lubricating oil is stored in the wells. The wave gear device (1) according to one of the preceding claims, characterized in that the lubricant pockets (16) round and / or have a point-like shape and a depth of less than 30 microns. Corrugated transmission (1) according to one of the preceding claims, characterized in that the lubricant pockets (16) in the axial direction and / or in the circumferential direction with respect to the rotation axis (R) regularly spaced from each other on the first and / or the second sliding bearing surface (8a, b) are arranged. Wave gear (1) according to one of the preceding claims, characterized in that the wave gear (1) is designed as a camshaft adjuster or a compression plate. Vehicle with the wave gear (1) according to one of the preceding claims.

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