Flexible gear and gear mechanism having the same

Abstract

The present invention relates to a gear mechanism with a gear ring, the gear mechanism having a flexible gear arranged in the gear ring and a wave generator that contacts the flexible gear and deforms the flexible gear so that it meshes in sections in the gear ring. The object of the present invention is to improve such a gear mechanism so that interference with gear tooth meshing and gear backlash are reduced, noise performance and power transmission are improved, and service life is extended. To this end, according to the present invention, it is provided that the flexible gear includes at least two flexible gear plates, which are arranged adjacent to each other in the axial direction, and each gear plate includes at least two toothed sections in the circumferential direction connected to each other by means of spring sections.

Description

Technical Field

[0001] The present invention relates to a gear mechanism having a ring gear, which has a flexible gear arranged in the ring gear and a wave generator that contacts the flexible gear and deforms the flexible gear so that it is segmentally (in several sections) meshed in the ring gear. Background Art

[0002] Such gear mechanisms are known and used, for example, in robotics. Use in the automotive sector is also known. For example, WO 2016 / 165684 A2 shows an adjustment mechanism for adjusting two components having a ring gear, a drive wheel, a wave generator and an elastic spur gear. The elastic spur gear comprises a number of tooth elements of identical structure. Each tooth element comprises a head region facing the ring gear and a foot region facing the wave generator. The head region of the tooth element is provided with gear teeth that can contact the ring gear. In addition, each tooth element has an outwardly open recess in its head section, which interrupts the gear teeth and contacts the drive pin of the drive wheel. The tooth elements positioned adjacent to each other are connected to each other by means of an elastic connecting element. The wave generator is substantially elliptical and also makes the elastic spur gear elliptical, so that two oppositely arranged regions of the elastic spur gear mesh in the ring gear.

[0003] In such gear mechanisms, due to bearing problems, the central flexible gear can be tilted towards the ring gear axis, so that not the entire gear width is meshed for transmitting torque, but only certain parts of the entire gear width. In addition, lateral direction errors occur due to manufacturing tolerances, which also lead to the fact that only a part of the entire gear width is also used. Therefore, due to geometric deviations, circular run-out tolerances and other manufacturing tolerances can lead to meshing interferences.

[0004] Starting from this prior art, the above-mentioned gear mechanism or the flexible gear used for the gear mechanism, respectively, is now further improved so that interference with the meshing of the gear teeth and the gear backlash are reduced, thereby improving the noise generation performance and power transmission and extending the service life. Summary of the invention

[0005] To this end, the invention provides that the flexible gear comprises at least two flexible gear plates which are arranged adjacent to each other in the axial direction and each gear plate comprises at least two toothed sections in the circumferential direction which are connected to each other by means of spring sections.

[0006] In this context, the axial direction means the direction along the axis of the ring gear. This corresponds essentially to the direction of the central axis of the gear mechanism. Due to the segmentation of the flexible gear in the axial direction into independent flexible gear discs, the tooth width of the independent flexible gear discs corresponds at most to half of the total gear tooth width. The inclination of the individual gear discs relative to the axis of the ring gear or to the central axis of the gear mechanism can be compensated by other flexible gear discs. This increases the meshing of the flexible gears across the entire gear tooth width and thus significantly reduces the possibility of only partial gear overlap or edge support. The individual radial flexibility of the individual flexible gear discs makes flexible meshing possible. The individual flexible gear discs can therefore be slightly rotated relative to each other in the circumferential direction, thereby reducing the tooth backlash to 0°. Power transmission, noise generation and gear backlash are thereby improved.

[0007] In an advantageous embodiment, provision can be made for the flex gear disks located adjacent to one another in the axial direction to have the same number of teeth and the same tooth geometry. Thus, a wider flex gear is formed by the flex gear disks located adjacent to one another in the axial direction. Since the gear teeth of the flex gear consist of individual regions, namely the gear teeth of the individual flex gear disks, which are movable relative to one another in the axial direction, disturbances in the meshing of the individual flex gear disks can be compensated by the other flex gear disks, so that overall a reduction in disturbances in the meshing of the entire flex gear is achieved, which also leads to a reduction in the gear backlash and thus improves the noise generation and increases the service life.

[0008] It can also be preferably provided that the flexible gear disks located adjacent to each other in the axial direction bear against each other. This also results in the fact that the flexible gear disk forms an integral gear with a greater width and the advantages associated therewith.

[0009] A particularly simple design and a uniform structure of the flexible gear can be achieved if flexible gear disks located adjacent to one another in the axial direction have the same gear tooth width in the axial direction.

[0010] In a further advantageous embodiment, it can be provided that the flexible gear comprises more than two flexible gear discs, preferably four flexible gear discs, which are positioned adjacent to one another in the axial direction. It has been shown that with the number of four flexible gear discs which are positioned adjacent to one another in the axial direction, the probability of only partial gear overlap or edge bearing occurring is very low, which leads to the above-mentioned advantages.

[0011] In a particularly advantageous embodiment, the flexible gear discs are formed as identical components. The flexible gear is thus formed from four identically constructed individual gears, namely flexible gear discs, which are arranged adjacent to one another in the axial direction. Since the flexible gear discs are constructed as identical components, production is simplified and costs are saved.

[0012] In a further embodiment, it can be provided that at least one toothed section of each flexible gear disk comprises a recess, wherein the flexible gear disk is arranged such that the recesses are located one above the other and the pin elements are arranged in the recesses which are located one above the other, and each spring section of the flexible gear has a center plane which contains the center axis of the gear mechanism and divides the respective spring section into two regions of equal length, and each region recess has a center plane which contains the center axis of the gear mechanism and divides the recess into two regions of equal size, and the center plane of each spring section has a different distance from the center plane of the recess located adjacent thereto on each side of the center plane of the spring section. This allows increasing the flexibility of the flexible gear disk and thus of the entire flexible gear, so that sufficient elastic deformation of the flexible gear disk or the flexible gear can still be achieved, in particular in the case of smaller diameters of the gear mechanism. Since the recesses in the individual flexible gear disks are located one above the other and are therefore identical, the pin elements can be easily inserted and extended through all flexible gear disks and thus through the entire flexible gear.

[0013] It can also be provided that at least one toothed section of each flexible gear disk has a waist in the radial direction of the flexible gear and that the spring section engages in the toothed section in the region of the waist. As a result, the spring section can be designed to be longer, thereby further increasing the flexibility of the flexible gear disk, which is particularly advantageous for small diameters.

[0014] The spring segments should be designed such that they are elastic in the radial direction and rigid in the tangential direction. Deformations of the flexible gear disk are then permitted only in the radial direction. In the tangential direction, forces can be transmitted from one toothed segment to an adjacent toothed segment without deforming the flexible gear disk. As a result, the gear backlash between the gear mechanism input and the gear mechanism output is kept as small as possible. This can be achieved in a particularly simple manner in that the spring segments are designed as webs that connect adjacent toothed segments to one another. The spring segments are then advantageously formed integrally with the toothed segments.

[0015] In order to further increase the flexibility of the flexible gear plate and thus also the flexibility of the entire flexible gear, it can be provided that each flexible gear plate comprises at least one first toothed section provided with a recess and at least one second toothed section without a recess. As a result, the spring section extending between the toothed sections can be configured to be longer, and a good combination of flexibility and strength of the toothed sections is obtained. The gear tooth force of the at least one second toothed section, i.e., the gear tooth force of the toothed section without a recess, is transmitted to the at least one first toothed section via the spring section. The toothed section provided with a waist is preferably a second toothed section and does not comprise a recess.

[0016] In a further embodiment, the spring section engages in the at least one first toothed section at the level of the recess in the at least one first toothed section. This enables a good transmission of the gear tooth forces of the at least one second toothed section to the at least one first toothed section. If the spring section comprises a relief notch in its area of ​​contact with the at least one first toothed section, the flexibility of the flexible gear disk and thus of the entire flexible gear can be further increased.

[0017] Furthermore, it can be provided that each flexible gear disk comprises a plurality of toothed segments, in particular at least four toothed segments. Each flexible gear disk then preferably has an even number of toothed segments, wherein half of the toothed segments, the first toothed segments, comprise recesses, and the other half of the toothed segments, the second toothed segments, are designed without recesses. This makes it possible to achieve a good compromise between the flexibility of the flexible gear disk and thus of the flexible gear, and sufficient strength.

[0018] In a particularly advantageous embodiment, it is provided that the recess in the first toothed section is arranged inside the corresponding toothed section and has a closed contour. The pin element arranged in the recess thus rolls along a closed circumferential contour, whereby the contact between the pin element and the recess in the corresponding toothed section is never interrupted. This increases the running smoothness of the gear mechanism. The recess is advantageously configured to be essentially elliptical. Furthermore, the toothed section can have end-to-end gear teeth in the head region facing the toothed ring.

[0019] According to a further embodiment, each toothed segment of the flex spline disc can be supported at two support points on the wave generator. The foot region of the toothed segment facing the wave generator is then formed concave so that it contacts the wave generator only at the two support points. Due to the concave shape of the foot region of the toothed segment, the region formed between the two support points of the toothed segment is bent away from the wave generator so that there is no contact between the toothed segment and the wave generator. The angle between the two support points is preferably about 170°. Thus, the alignment of the toothed segment orthogonal to the outer contour of the wave generator can be improved.

[0020] In a further embodiment, it is provided that the wave generator comprises at least one cam which is in contact with the flexible gear and which is configured so that the toothed segments are deformed in the region in which they mesh in the ring gear so that they form part of an imaginary gear having a constant radius and rotating about an axis at a fixed distance from the central axis of the gear mechanism.

[0021] In a simple embodiment, it can be provided that the pin element is configured as a bolt, which is connected to the output shaft. As a result, the movement of the flexible gear is converted into a uniform rotational movement of the output part via the bolt. Preferably, a sleeve is arranged on each bolt, thereby forming a sliding bearing with the associated advantages. Alternatively, an elastic sleeve or an elastic O-ring can also be arranged on each bolt. In this construction variant, the relevant recess can alternatively be configured to have a circular cross section. In an alternative configuration, the pin element is formed to be fixed and the ring gear is rotatable. The ring gear is driven here by the meshing of the flexible gear and therefore serves as an output element in this variant.

[0022] In another preferred embodiment, the flexible gear disc of the flexible gear is made of metal or metallic glass. In addition, the ring gear meshing in the flexible gear is also preferably made of metal or metallic glass.

[0023] In a preferred embodiment, the flexible gear plate has a thickness of approximately 1.5 mm, such that a flexible gear having, for example, two flexible gear plates positioned adjacent to each other in the axial direction has a thickness of approximately 3 mm, and a flexible gear having, for example, four flexible gear plates positioned adjacent to each other in the axial direction has a thickness of approximately 6 mm.

[0024] In another preferred embodiment, the flexible gear plate has a thickness of approximately 3 mm, such that a flexible gear having, for example, two flexible gear plates positioned adjacent to each other in the axial direction has a thickness of approximately 6 mm, and a flexible gear having, for example, four gear plates positioned adjacent to each other in the axial direction has a thickness of approximately 12 mm.

[0025] Furthermore, the present invention also relates to a flexible gear for the above-mentioned gear mechanism, wherein the flexible gear comprises at least two, preferably four flexible gear plates, which are positioned adjacent to each other in the axial direction, and wherein each gear plate comprises at least two toothed sections connected to each other by means of spring sections in the circumferential direction.

[0026] The flexible gear therefore comprises several individual gears, i.e. flexible gear plates, which are positioned adjacent to one another in the axial direction. Due to the segmentation of the flexible gear in the axial direction into individual flexible gear plates, the tooth width of an individual flexible gear plate corresponds at most to half of the total gear tooth width. The inclination of the individual gear plates and therefore of the gear tooth area of ​​the individual gear plates relative to the ring gear axis or to the central axis of the gear mechanism can be compensated by other flexible gear plates. This increases the meshing of the flexible gear across the entire flexible gear tooth width and thus significantly reduces the probability of only partial gear overlap or edge bearing. The individual radial flexibility of the individual flexible gear plates makes flexible meshing possible. The individual flexible gear plates can therefore be slightly rotated relative to one another in the circumferential direction, whereby the gear backlash can be reduced to 0°. Power transmission, noise generation and backlash are thereby improved.

[0027] In an advantageous embodiment of the flex gear, it can be provided that at least one toothed section of each flex gear disk comprises a recess for receiving a pin element, wherein the flex gear disks are arranged such that the recesses are arranged one above the other, and wherein each spring segment has a center plane which comprises the center axis of the flex gear and which divides the respective spring segment into two areas of equal length, and wherein each recess has a center plane which comprises the center axis of the flex gear and which divides the recess into two areas of equal size, and wherein the center plane of each spring segment has a different distance from the center planes of the recesses which are located adjacent to each side of the center plane of the spring segment. Since the recesses in the individual flex gear disks are located one above the other and are therefore identical, the pin element can be easily inserted and extended through all the flex gear disks and thus through the entire flex gear. This allows the flexibility of the flex gear to be increased so that sufficient elastic deformation of the gear can still be obtained, in particular in the case of small diameters of the gear mechanism.

[0028] In another preferred embodiment of the flex gear, the flex gear plate is made of metal or metallic glass.

[0029] In a preferred embodiment of the flexible gear, the flexible gear plate has a thickness of about 1.5 mm, so that a flexible gear having, for example, two flexible gear plates positioned adjacent to each other in the axial direction has a thickness of about 3 mm, and a flexible gear having, for example, four flexible gear plates positioned adjacent to each other in the axial direction has a thickness of about 6 mm.

[0030] In another preferred embodiment of the flexible gear, the flexible gear plate has a thickness of about 3 mm, so that a flexible gear having, for example, two flexible gear plates positioned adjacent to each other in the axial direction has a thickness of about 6 mm, and a flexible gear having, for example, four gear plates positioned adjacent to each other in the axial direction has a thickness of about 12 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be described in more detail below using the accompanying drawings, in which:

[0032] Figure 1 : shows a gear mechanism according to the present invention,

[0033] Figure 2 : Shows Figure 1 The flexible gear of the gear mechanism,

[0034] Figure 3 : Shows Figure 2 A front view of the flex gear plate of the flex gear,

[0035] Figure 4 : Shows Figure 3 Detail of the flexure gear disc. DETAILED DESCRIPTION

[0036] The same reference numerals apply to the following description, in which identical parts are denoted by identical reference numerals. In the event that a figure contains reference numerals which are not explained in greater detail in the associated figure description, reference is then made to the preceding or subsequent figure description.

[0037] Figure 1 An embodiment of a gear mechanism 1 of the present invention is shown. The gear mechanism 1 comprises a housing 10 in which a wave generator 2, a flexible gear 6 and a fixed ring gear 9 are arranged. The cover of the housing 10 has been removed to provide a view into the interior of the gear mechanism. The gear mechanism 1 is generally disc-shaped with a central axis M. The central axis M corresponds to the axis of the ring gear 9.

[0038] The wave generator 2 includes a base body 3 having an approximately elliptical cross section. Due to the approximately elliptical cross section, two cams 30 are formed on the base body 3 and therefore on the wave generator 2. A rolling element 4 surrounded by a deformable sleeve 5 is arranged on the base body 3. The wave generator 2 is arranged in a flexible gear 6. Therefore, the flexible gear 6 is in contact with the base body 3 via the deformable sleeve 5 and the rolling element 4. The elliptical shape of the base body 3 of the wave generator 2 is transmitted to the flexible gear 6 via the rolling element 4 and the deformable sleeve 5, so that the flexible gear 6 is deformed elliptically, thereby contacting the ring gear 9 in two meshing areas.

[0039] The flexible gear 6 comprises several toothed sections 7.1, 7.2, which are connected to one another by means of flexible spring sections 8. The flexible gear 6 is provided with external gear teeth 14, while the fixed ring gear 9 comprises internal gear teeth 15. Due to the elliptical deformation of the flexible gear 6 caused by the wave generator 3, the external gear teeth 14 of the flexible gear 6 mesh with the internal gear teeth 15 of the ring gear 9 in two oppositely arranged areas, namely the meshing areas.

[0040] In the embodiment shown, the flexible gear 6 comprises twelve toothed sections 7.1, 7.2, which are divided into six first toothed sections 7.1 and six second toothed sections 7.2. The first toothed sections 7.1 each comprise a recess 17, which is configured as an end-to-end opening in the interior of each first toothed section 7.1. A corresponding bolt 12 of the pin element 11 is received in each recess 17. Each bolt 12 is surrounded by a sleeve 13, thereby forming a sliding bearing. The bolt 12 is connected to the output shaft. The recess 17 is somewhat larger than the sleeve 13. As a result, the bolt 12 can roll along the recess 17. In the case shown, the recess 17 has an elliptical cross section. The cross sections of the bolt 12 and the sleeve 13 are circular. The diameter of the recess 17 is slightly larger than the outer diameter of the sleeve 13.

[0041] The wave generator 2 is preferably connected to a drive shaft. The rotation of the drive shaft causes the wave generator 2 to rotate. This rotational movement is transmitted to the flexible gear 6. The outer gear teeth 14 of the flexible gear 6 thus run along the inner gear teeth 15 of the ring gear 9. The spring section 8 arranged between the toothed sections 7.1, 7.2 enables the flexible gear 6 to deform flexibly or elastically. The movement of the flexible gear 6 is converted into a uniform rotational movement of the output part via the bolt 12. However, it can also be provided that the bolt is connected to the housing and is therefore rigid. In this case, the ring gear serves as the output part.

[0042] Figure 2 The stereogram shows Figure 1 The flexible gear 6 in the embodiment. The flexible gear 6 is constructed to form sections in the axial direction, i.e. in the direction of the center axis M. This means that the flexible gear 6 is divided into a number of flexible gear plates, which are arranged adjacent to each other in the axial direction. In the embodiment shown, the flexible gear 6 includes four flexible gear plates 6.1, 6.2, 6.3, 6.4. However, it can also be provided that the flexible gear includes more or fewer flexible gear plates. The flexible gear plates 6.1 to 6.4 are constructed as identical components and are therefore identical to each other. The flexible gear plates are preferably made of metal or metallic glass. The structure of the flexible gear plates will be referred to below. Figure 3 Describe in more detail.

[0043] Figure 3 A front view of a single flexible gear disc 6.1 is shown. The other flexible gear discs 6.2 to 6.4 are formed identically. Therefore, the following description applies to all flexible gear discs 6.1 to 6.4.

[0044] The flexible gear disc 6.1 is formed as a separate gear and comprises a first toothed section 7.1 and a second toothed section 7.2. The first toothed sections 7.1 and the second toothed sections 7.2 are arranged alternately and are each connected to one another by means of a respective spring section 8. In the embodiment shown, the flexible gear disc 6.1 comprises twelve toothed sections 7.1, 7.2. Every other toothed section, i.e. the first toothed section 7.1, comprises a recess 17. In the case shown, the recess 17 is oval. However, the recess may also be circular. The first toothed sections 7.1 are each configured identically to one another. The second toothed sections 7.2 are arranged between the first toothed sections 7.1. The second toothed sections 7.2 do not comprise a recess. Adjacent toothed sections 7.1, 7.2 are connected to one another by means of a spring section 8. The spring section 8 is designed as an arcuate web extending along a circular line, in which the center of the web is arranged on the center axis M of the gear mechanism 1 .

[0045] The shapes of the first toothed section 7.1 and the second toothed section 7.2 will be described in more detail below:

[0046] Each first toothed segment 7.1 comprises a foot region 18 which is in contact with the wave generator 2. Starting from the foot region 18, a trunk region 19 adjoins radially outwards, in which a recess 17 is formed. The recess 17 thus has a closed contour located inside the toothed segment 7.1. The bolt 12 or the sleeve 13 respectively rolls along this contour. As a result, the contact of the bolt 12 or the sleeve 13 with the recess 17 is not interrupted, thereby improving the running smoothness of the gear mechanism 1. The head region 20 adjoins the trunk region 19 in the radial direction. The external gear teeth 14 are formed on the outwardly facing circumferential surface of the head region 20 of each first toothed segment 7.1. Since the recess 17 is arranged inside the first toothed segment 7.1, the external gear teeth 14 extend over the entire outwardly facing circumferential surface of the first toothed segment 7.1. If we now examine the width of the first toothed segment 7.1 in the circumferential direction U of the flexible gear disk 6.1, the first toothed segment 7.1 has a first width in the foot area 18, which tapers in the trunk area and increases again toward the outside, so that the first toothed segment 7.1 has a maximum width at the outer periphery.

[0047] The second toothed section 7.2 also comprises a foot region 21 which is in contact with the wave generator 2. In the case of the second toothed section 7.2, a trunk region 22 which transitions into a head region 23 also adjoins this foot region 21 on the outside in the radial direction. The second toothed section 7.2 does not comprise a recess. Instead, the second toothed section 7.2 tapers strongly in the trunk region 22 and therefore has a waist 24. The external gear teeth 14 are also formed on the outwardly facing circumferential surface of the head region 23 of the second toothed section 7.2.

[0048] Each toothed segment 7.1, 7.2 is connected to the adjacent toothed segment 7.2, 7.1 by means of a spring segment 8. The spring segment 8 is designed as an arcuate web which extends on a circular line in the circumferential direction of the flexible gear disk 6.1. The spring segment 8 engages in the first toothed segment 7.1 approximately at the level of the center of the recess 17. The connection between the spring segment 8 and the second toothed segment 7.2 is at the level of the waist 24. As can be clearly seen in Figure 3 As can be seen in FIG. 6 , the flexible gear plate 6.1 is integrally formed.

[0049] The second toothed section 7.2, which does not include a recess, transfers the gear tooth force to the first toothed section 7.1 with the recess 17 via the spring element 8. This allows the spring section 8 to be constructed larger, thereby increasing the flexibility and still being able to obtain sufficient elasticity with a smaller diameter gear mechanism 1. The shape of the spring elements 8 shown ensures that they are as inelastic as possible in the tangential direction and are only elastic in the radial direction.

[0050] Each spring section 8 has a center plane M FS , the center plane M FS The center plane M contains the center axis M of the gear mechanism 1 and divides the corresponding spring section 8 into two areas of equal length. Since the spring section 8 is formed by a circular arc-shaped web, the length corresponds to the arc length. Each recess 17 also has a center plane M A , the center plane M A The spring section 8 between the toothed sections 7.1, 7.2 is asymmetrically configured so that the center plane M of each spring section 8 is symmetrically disposed between the toothed sections 7.1, 7.2. FS In the two center planes M of the concave portion 17 adjacent thereto A The center plane M of each spring segment 8 is FS and the center plane M of each recess 17 A The spring segments intersect at the central axis M of the gear mechanism 1. Therefore, the central plane M of each spring segment FS and two center planes M respectively arranged adjacent thereto A The distance between them can be expressed by angles of different sizes.

[0051] Figure 3 Details of III are in Figure 4 2. The first toothed segment 7.1 and the second toothed segment 7.2 are shown. As already described, the first toothed segment 7.1 comprises a foot region 18, a trunk region 19 and a head region 20. The recess 17 is located in the trunk region 19 of the first toothed segment 7.1. The outer gear teeth 14 are formed in the head region 20. The second toothed segment 7.2 also comprises a foot region 21, a trunk region 22 with a waist 24 and a head region 23. The outer gear teeth 14 are formed on the outer peripheral surface of the head region 20. The foot region 21 of the second toothed segment 7.2 and the foot region 18 of the first toothed segment 7.1 both comprise concave depressions, so that each toothed segment 7.1, 7.2 is supported on the wave generator 2 via two support points. As a result, the alignment of the toothed segments 7.1, 7.2 orthogonally to the outer contour of the wave generator 2 is improved. The concave depression has an opening angle β of approximately 170°.

[0052] The spring section 8 engages in the first toothed section 7.1 approximately at the level of the recess 17. The spring section 8 has an undercut 25 in the region of the transition from the spring section 8 to the first toothed section 7.1. This undercut 25 can increase the flexibility of the flexible gear 6 in the region of the transition from the spring section 8 to the first toothed section 7.1.

[0053] The spring section 8 engages in the second toothed section 7.2 at the level of the waist 24. Since the second toothed section 7.2 has a very small width in this area, sufficient flexibility is imparted there. The adjacently arranged toothed sections 7.1, 7.2 are arranged at a distance from one another both in the head area and in the foot area.

[0054] If you can Figure 4 As can be seen in FIG. 1 , the first toothed section 7.1 may have a different number of teeth than the second toothed section 7.2. Therefore, the number of teeth of the flexible gear 6 is not an integer multiple of the number of toothed sections 7.1 and 7.2. Therefore, the number of toothed sections 7.1 and 7.2 is not determined by the number of teeth of the entire flexible gear 6. Therefore, the number and / or arrangement of teeth on the toothed sections 7.1 and 7.2 is not necessarily uniform. In order to make each tooth on the toothed sections 7.1 and 7.2 have the same shape, the geometry of the wave generator 2 can be selected, that is, an elliptical cross-sectional shape with two oppositely arranged cams can be selected so that the constant radius extends in the area of ​​the highest point (elevation) within the angle range where the tooth meshing occurs. All toothed sections 7.1 and 7.2 located in this section, that is, within this angle, realize an imaginary gear with a constant radius and rotating around an axis. The axis is at a certain distance from the central axis M of the gear mechanism 1. The length ratio of this distance to the radius of the ring gear is less than 10%. The only limiting condition is that the distance between two external teeth on adjacent gear mechanism elements 7 . 1 , 7 . 2 is an integer multiple of the tooth width in this region. The tooth width is currently defined as twice the distance between two adjacent teeth of the external gear teeth 14 .

[0055] Next, we will refer to Figure 2 The structure of the flexible gear 6 is described in detail again. The flexible gear comprises four flexible gear plates 6.1, 6.2, 6.3, 6.4. As already described with reference Figure 3 and 4 As described, the four flexible gear discs 6.1 to 6.4 are configured as individual gears. The flexible gear discs 6.1 to 6.4 are arranged in the axial direction so that their sides are supported against each other. The flexible gear discs 6.1 to 6.4 are aligned in the circumferential direction so that the second gear sections 7.2 of all flexible gear discs 6.1 to 6.4 are superimposed on each other. Therefore, the first toothed sections 7.1 of all flexible gear discs 6.1 to 6.4 are also superimposed on each other. As a result, the recesses 17 of all flexible gear discs 6.1 to 6.4 are also substantially consistent so that they extend through the entire width B of the flexible gear 6 in the axial direction M. A sleeve 13 is arranged in the recess 17, in which a bolt 12 is received. The flexible gear discs 6.1 to 6.4 are therefore respectively supported first in the ring gear teeth and secondly on the bolt 12 or the pin element 11. This makes torque transmission possible.

[0056] The flexible gear plates 6.1 to 6.4 can each be tilted slightly perpendicularly to the central axis M. As a result, a tilt of one of the flexible gear plates relative to the central axis M or the ring gear axis, for example due to bearing problems, can be compensated by the other flexible gear plates. Lateral orientation errors of the individual flexible gear plates, for example due to manufacturing tolerances, can also be compensated by the other flexible gear plates.

[0057] Since the flexible gear disks 6 . 1 to 6 . 4 can also be slightly offset from one another in the circumferential direction, a flexible meshing of the toothing areas of the individual flexible gear disks in the ring gear teeth is possible, so that the backlash can be reduced to 0°.

[0058] Reference numerals list

[0059] 1 Gear mechanism

[0060] 2 Wave Generator

[0061] 3 Matrix

[0062] 4 Rolling elements

[0063] 5 Deformable sleeve

[0064] 6 Flexible gear

[0065] 6.1 Gear Plate

[0066] 6.2 Gear Plate

[0067] 6.3 Gear Plate

[0068] 6.4 Gear Plate

[0069] 7.1 First toothed section

[0070] 7.2 Second toothed section

[0071] 8 Spring section

[0072] 9 Ring gear

[0073] 10 Housing

[0074] 11 Pin element

[0075] 12 Bolts

[0076] 13 Sleeve

[0077] 14 external gear teeth

[0078] 15 internal gear teeth

[0079] 17 recess

[0080] 18 Foot region of the first toothed section

[0081] 19 Main region of the first toothed section

[0082] 20 Head region of the first toothed section

[0083] 21 Foot region of the second toothed section

[0084] 22 Main region of the second toothed section

[0085] 23 Head region of the second toothed section

[0086] 24 Waist

[0087] 25 Backing notch

[0088] M Center axis of the gear mechanism

[0089] U Circumferential direction

[0090] B Width of the flexible gear

[0091] M FS Center plane of the spring section

[0092] M A center plane of recess

[0093] β Opening angle

Claims

1. A gear mechanism (1), comprising a toothed ring (9), a flexible gear (6) arranged in the toothed ring (9), and a wave generator (2), the wave generator being in contact with the flexible gear (6) and deforming the flexible gear (6) so that it meshes in sections in the toothed ring (9), characterized in that: The flexible gear (6) comprises at least two flexible gear plates (6.1, 6.2, 6.3, 6.4) arranged adjacent to each other in an axial direction, and each flexible gear plate (6.1, 6.2, 6.3, 6.4) comprises at least two toothed sections (7.1, 7.2) connected to each other by means of spring sections (8) in a circumferential direction (U), and wherein, in the axial direction, the gear teeth (14) of the flexible gear (6) consist of separate areas, namely the gear teeth of each flexible gear plate (6.1, 6.2, 6.3, 6.4), which are movable relative to each other.

2. The gear mechanism (1) according to claim 1, characterized in that: The flexible gear plates (6.1, 6.2, 6.3, 6.4) located adjacent to each other in the axial direction comprise the same number of teeth and the same tooth geometry.

3. The gear mechanism (1) according to claim 1, characterized in that: The flexible gear plates (6.1, 6.2, 6.3, 6.4) located adjacent to each other in the axial direction are supported against each other.

4. The gear mechanism (1) according to claim 1, characterized in that: The flexible gear plates (6.1, 6.2, 6.3, 6.4) located adjacent to each other in the axial direction have the same gear tooth width in the axial direction.

5. The gear mechanism (1) according to claim 1, characterized in that: The flexible gear (6) comprises two or more flexible gear plates (6.1, 6.2, 6.3, 6.4) located adjacent to each other in the axial direction.

6. The gear mechanism (1) according to claim 5, characterized in that: The flexible gear (6) comprises four flexible gear plates (6.1, 6.2, 6.3, 6.4) located adjacent to each other in the axial direction.

7. The gear mechanism (1) according to claim 1, characterized in that: The flexible gear plates (6.1, 6.2, 6.3, 6.4) are constructed as identical components.

8. The gear mechanism (1) according to claim 7, characterized in that: At least one of the toothed sections (7.1) of each flexible gear disk (6.1, 6.2, 6.3, 6.4) comprises a recess (17), wherein the flexible gear disks (6.1, 6.2, 6.3, 6.4) are arranged such that the recesses are positioned above each other and the pin elements (11) are arranged in the recesses (17) positioned above each other, each of the spring sections (8) of the flexible gear having a center plane (M FS ), the central plane contains the central axis (M) of the gear mechanism (1) and divides the corresponding spring section (8) into two regions of equal length, and each recess (17) has a central plane (M A ), the central plane contains the central axis (M) of the gear mechanism (1) and divides the recess (17) into two equally large areas, and the central plane (M) of each spring section (8) FS ) has a central plane (M) with respect to the spring section (8) FS ) on each side of the recess (17) located adjacent thereto. A ) different distances.

9. The gear mechanism (1) according to claim 1, characterized in that: At least one of the toothed sections (7.1, 7.2) of each flexible gear disk (6.1, 6.2, 6.3, 6.4) has a waist (24) in the radial direction of the flexible gear (6), and the spring section (8) engages in the toothed section (7.2) in the region of the waist (24).

10. The gear mechanism (1) according to claim 1, characterized in that: The spring sections (8) are configured such that they are elastic in the radial direction and rigid in the tangential direction.

11. The gear mechanism (1) according to claim 10, characterized in that: The spring section (8) is formed as a web which connects adjacent toothed sections (7.1, 7.2) to one another.

12. The gear mechanism (1) according to claim 8, characterized in that: Each flexible gear plate (6.1, 6.2, 6.3, 6.4) comprises at least one first toothed section (7.1) provided with a recess (17) and at least one second toothed section (7.2) without a recess.

13. The gear mechanism (1) according to claim 12, characterized in that: The spring section (8) engages in the at least one first toothed section (7.1) at the level of the recess (17) in the at least one first toothed section (7.1).

14. The gear mechanism (1) according to claim 1, characterized in that: Each flexible gear plate (6.1, 6.2, 6.3, 6.4) comprises a plurality of toothed sections (7.1, 7.2).

15. The gear mechanism (1) according to claim 14, characterized in that Each flexible gear plate (6.1, 6.2, 6.3, 6.4) comprises at least four toothed sections (7.1, 7.2).

16. The gear mechanism (1) according to claim 12, characterized in that: The recess (17) in the first toothed section (7.1) is arranged inside the respective toothed section (7.1) and has a closed contour.

17. A flexible gear (6) for a gear mechanism (1) according to one of claims 1 to 16, the flexible gear comprising at least two flexible gear plates (6.1, 6.2, 6.3, 6.4) located adjacent to each other in an axial direction, and wherein: Each flexible gear plate (6.1, 6.2, 6.3, 6.4) comprises in the circumferential direction at least two toothed sections (7.1, 7.2) which are connected to each other by means of spring sections (8).

18. A flex gear (6) for a gear mechanism (1) according to claim 17, comprising four flex gear discs (6.1, 6.2, 6.3, 6.4) located adjacent to each other in an axial direction.

19. The flexible gear (6) according to claim 17, characterized in that At least one of the toothed sections (7.1) of each flexible gear plate (6.1, 6.2, 6.3, 6.4) comprises a recess (17) for receiving a pin element, wherein the flexible gear plates (6.1, 6.2, 6.3, 6.4) are arranged such that the recesses (17) of the flexible gear plates (6.1, 6.2, 6.3, 6.4) are located above each other and each spring section (8) has a center plane (M FS ), the central plane contains the central axis (M) of the gear mechanism (1) and divides the corresponding spring section (8) into two regions of equal length, and each recess (17) has a central plane (M A ), the central plane contains the central axis (M) of the gear mechanism (1) and divides the recess (17) into two equally large areas, and the central plane (M) of each spring section (8) FS ) has a central plane (M) with respect to the spring section (8) FS ) on each side of the recess (17) located adjacent thereto. A ) different distances.

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