COAXIAL GEAR MECHANISM

Abstract

Coaxial gear mechanism (1) includes a toothing (5) which is oriented axially with respect to an axis of rotation (3) of the coaxial gear mechanism (1), a tooth carrier (7) which in each case has axially oriented guides (9), and tooth pins (11) which each comprise a body (50), which is mounted so as to be axially displaceable in a guide (9) of the tooth carrier (7), and a head region (51), wherein the head region (51) includes at least one tooth (52) for engagement with the toothing (5), and wherein the tooth carrier (7) wherein the tooth carrier has an irregular angular pitch.

Claims

1. Coaxial gear mechanism (1), comprising: a toothing (5) which is oriented axially with respect to an axis of rotation (3) of the coaxial gear mechanism (1), a tooth carrier (7) which in each case has axially oriented guides (9), and tooth pins (11) which each comprise a body (50), which is mounted so as to be axially displaceable in a guide (9) of the tooth carrier (7), and a head region (51), wherein the head region (51) comprises at least one tooth (52) for engagement with the toothing (5), wherein the tooth carrier has an irregular angular pitch.

2. Coaxial gear mechanism (1) according to claim 1, wherein the irregular angular pitch comprises a group of identical first angles (57) between adjacent guides (9) and at least one second angle (59), which is different from the first angles (57), between adjacent guides (9).

3. Coaxial gear mechanism (1) according to claim 1, wherein the tooth pins (11) each comprise at least two teeth (52) in the head region (51).

4. Coaxial gear mechanism (1) according to claim 1, wherein the tooth pins (11) are uniformly formed.

5. Coaxial gear mechanism (1) according to claim 1, wherein the tooth pins (11) comprise a group of uniform tooth pins (61) and at least one special tooth pin (63) which is different from the uniform tooth pins (61).

6. Coaxial gear mechanism (1) according to claim 5, wherein the at least one special tooth pin (63) has, in the head region (51), a special number of teeth (52) which is different from a number of teeth (52) of a tooth pin of the uniform tooth pins (61).

7. Coaxial gear mechanism (1) according claim 5, further comprising a tooth bearing for mounting the tooth pins (11) on a cam disk (15) of the coaxial gear mechanism (1), wherein the tooth bearing comprises bearing segments (17) for pivotably mounting a tooth pin base of a tooth pin (11), wherein the bearing segments (17) comprise a group of uniform bearing segments (62) and at least one special bearing segment (64) for the at least one special tooth pin (63).

8. Coaxial gear mechanism (1) according to claim 1, wherein the coaxial gear mechanism (1) is produced from a kit for a range of coaxial gear mechanisms having different transmission ratios, and wherein the tooth carrier (7) is selected from a plurality of tooth carriers, wherein the tooth carriers (7) each have different angular pitches of the guides (9) for realizing the different transmission ratios.

9. Coaxial gear mechanism (1) according to claim 8, further comprising an antirotation securing ring (29) for rotationally securing the tooth pins (11), wherein an angular pitch of the antirotation securing ring (29) is equal to the angular pitch of the tooth carrier (7), and wherein the antirotation securing ring (29) is selected from a plurality of antirotation securing rings having different angular pitches.

10. Coaxial gear mechanism (1) according to claim 8, further comprising a cam disk (15) which in the circumferential direction has at least one axial elevation for axially driving the tooth pins (11), wherein the cam disk (15) is selected from a plurality of cam disks having different numbers of axial elevations.

11. Coaxial gear mechanism (1) according to claim 8, wherein the toothing (5) for the coaxial gear mechanisms of the range having different transmission ratios is provided identically.

12. Range of coaxial gear mechanisms having different transmission ratios, in each case according to claim 8.

13. Method for producing a coaxial gear mechanism (1) from a range comprising a plurality of coaxial gear mechanisms having different transmission ratios, wherein the coaxial gear mechanism (1) comprises: a toothing (5) which is oriented axially with respect to an axis of rotation (3) of the coaxial gear mechanism (1), a tooth carrier (7) which in each case has axially oriented guides (9), and tooth pins (11) which each comprise a body (50), which is designed to be axially displaceably mounted in a guide (9) of the tooth carrier (7), and a head region (51), wherein the head region (51) comprises at least one tooth (52) for engagement with the toothing (5), wherein the method comprises: selecting the tooth carrier (7) from a plurality of tooth carriers, wherein the tooth carriers each have different angular pitches of the guides (9) for realizing the different transmission ratios, and mounting the coaxial gear mechanism (1) with the toothing (5), the selected tooth carrier (7) and the tooth pins (11).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The invention will be explained in more detail below on the basis of the appended drawings. In the figures:

[0054] FIG. 1 shows a typical embodiment of the coaxial gear mechanism in a partially schematic sectional view;

[0055] FIGS. 2A-2B show schematic views of bearing segments, tooth pins and of an antirotation securing ring according to one typical embodiment;

[0056] FIGS. 3A-3C show schematic views of bearing segments, tooth pins and of an antirotation securing ring according to a further typical embodiment;

[0057] FIG. 4 shows a schematic view of a tooth carrier according to a further embodiment;

[0058] FIGS. 5A-5B show schematic views of an antirotation securing ring having an angular pitch corresponding to the tooth carrier of FIG. 4; and

[0059] FIG. 6 shows a schematic view of a tooth pin according to typical embodiments.

DETAILED DESCRIPTION

[0060] Typical embodiments of the invention will be described below on the basis of the figures, with the invention not being limited to the exemplary embodiments; rather, the scope of the invention is defined by the claims.

[0061] In the description of the embodiments, in some cases in different figures and for different embodiments, the same reference signs are used for identical or similar parts. For the sake of clarity, features which have already been described in conjunction with other figures will sometimes not be mentioned or described repeatedly. For clarity, sometimes not all the respective features are provided with a reference sign, for example the bearing segments or the tooth pins.

[0062] FIG. 1 illustrates a detail of a typical embodiment of the invention in a schematic sectional view. FIG. 1 shows part of a coaxial gear mechanism 1 having a toothing 5 oriented with respect to an axis of rotation 3 of the coaxial gear mechanism 1. The toothing 5 is configured as a toothing of a crown gear 18 running around the axis of rotation 3. The crown gear 18 is connected to a housing 31 of the coaxial gear mechanism 1 for rotation therewith.

[0063] The coaxial gear mechanism 1 comprises a tooth carrier 7 which is provided on an output shaft 34. The output shaft 34 is mounted on the housing 31 so as to be rotatable about the axis of rotation 3 via a first bearing 33. The tooth carrier 7 has axially oriented guides 9 in which in each case tooth pins 11 are received. The tooth pins 11 are mounted along their respective longitudinal axes 13 in the guides 9 so as to be displaceable axially with respect to the axis of rotation 3.

[0064] The tooth pins 11 each comprise a head region, which is oriented to engage with the toothing 5, and a tooth pin base which projects out of the guide 9 of the respective tooth pin 11 and is mounted on a bearing segment 17. A tooth pin 11 further comprises a body between the tooth pin base and the tooth head, wherein the body is at least partially received in the guide 9 of the tooth pin 11.

[0065] The tooth pin base of the tooth pin 11 is mounted by a recess 21 on a partially spherical cap-shaped elevation 19 of the bearing segment 17. Between the tooth pins 11 and the bearing segments 17 there is arranged an antirotation securing ring 29 for securing the tooth pins 11 against rotation about the respective longitudinal axis 13. The bearing segments 17 are each mounted by a running surface 23 on their side facing away from the tooth pin on a rolling bearing having rolling bodies 27, which rolling bearing is in turn mounted on a profiling 25 of a cam disk 15 of the coaxial gear mechanism 1. What can be seen of the rolling bearing sectioned in FIG. 1 is substantially a web of a cage 26 for the rolling bodies 27 (these being partially concealed). The rolling bodies 27 are configured as needle rollers.

[0066] The cam disk 15 is provided on a drive shaft 36. The drive shaft 36 is mounted on the tooth carrier 7, and thus indirectly also on the housing 31, so as to be rotatable about the axis of rotation 3 via a second bearing 35. The cam disk 15 is mounted with respect to the housing 31 via an axial bearing 37 having needle rollers. The profiling 25 of the cam disk 15 is configured to run around the axis of rotation 3 and has, in FIG. 1, an axial elevation in the direction of the tooth pins 11.

[0067] FIGS. 2A-2B schematically show the bearing segments 17, the antirotation securing ring 29 and the tooth pins 11 without tooth carrier and other components for better clarity. In the embodiment of FIGS. 2A-2B, the tooth carrier (not shown) comprises 24 guides for 24 tooth pins 11. The embodiment has a number of teeth Z.sub.v=120 of the toothing, a calculated number of teeth Z.sub.z=121, a number p=1 of axial elevations of the cam disk and a transmission ratio i=121. The tooth pins 11 are uniformly formed. The tooth pins 11 each comprise a head region having five teeth. The angular pitch of the tooth carrier and of the antirotation securing ring 29 comprises a group of uniform first angles of in each case, rounded, 14.876 degrees (=360 degrees*5/121) and precisely one second angle of, rounded, 17.851 degrees, which corresponds to the sum of a first angle and 360 degrees/121. In particular, the second angle is larger than one of the first angles. In the angular range of the second angle, a gap 55 is formed between the tooth pins 11.

[0068] A range according to embodiments, comprising a coaxial gear mechanism having the toothing parts of FIGS. 2A-2B, comprises, for example, a further coaxial gear mechanism having a toothing with a number of teeth Z.sub.v=120 that is identical to the embodiment of FIGS. 2A-2B. The further coaxial gear mechanism has a calculated number of teeth Z.sub.z=122, a number p=2 of axial elevations of the cam disk and a transmission ratio i=61. The angular pitch comprises first angles of 14.754 degrees and two second angles. The two second angles are arranged spaced apart in the circumferential direction such that two gaps are formed between the tooth pins. The range comprises, for example, yet a further coaxial gear mechanism having a number of teeth of the toothing Z.sub.v=120, a calculated number of teeth Z.sub.z=123, a number p=3 of axial elevations of the cam disk and a transmission ratio i=41. The angular pitch comprises first angles of 14.634 degrees and three second angles which are spaced apart in the circumferential direction such that three gaps are formed between the tooth pins in the circumferential direction.

[0069] FIG. 2B shows a further schematic view of the embodiment illustrated in FIG. 2A, in particular with a view of the running surfaces 23 of the bearing segments 17. The bearing segments 17 are uniformly formed. The bearing segments 17 are nondisplaceable relative to the antirotation securing ring 29, being prevented from rotating by means of inner lugs 28 and outer lugs 30 of the antirotation securing ring 29. In each case one of the inner lugs 28 supports a respective inner edge of a bearing segment 17 against radially inward displacement. The radially outer corners 41 of the bearing segments 17 are each flattened in order to be in engagement with the cross-sectionally triangular outer lugs 30, with the result that a radially outward movement and a rotation are prevented in each case. Here, one of the outer lugs 30 in each case engages with two bearing segments 17.

[0070] In the region of the gap 55 between two tooth pins 11, the antirotation securing ring 29 comprises a web 32 on the side of the antirotation securing means 29 that faces the cam disk. The web 32 extends in the axial direction substantially up to the axial height of the running surface 23 of the bearing segments 17 adjacent to the web. The web 32 prevents rolling bodies from falling out of the cage into the gap between the bearing segments 17. Further embodiments of antirotation securing rings having inner lugs 28, outer lugs 30 or webs 32 are shown, for example, in FIGS. 3C and 5A-5B.

[0071] FIGS. 3A-3C show schematic views of bearing segments 17, an antirotation securing ring 29 and tooth pins 11 of a further embodiment, wherein the tooth carrier and other components of the coaxial gear mechanism are not shown for better clarity. The coaxial gear mechanism has a number of teeth Z.sub.v=118 of the toothing, a calculated number of teeth Z.sub.z=119, a number p=1 of axial elevations of the cam disk and a transmission ratio i=119. The tooth pins comprise a group of uniform tooth pins 61 each having five teeth 52 and a special tooth pin 63 having four teeth. As shown in the view of FIG. 3B of the teeth 52 of the tooth pins, the angular pitch of the tooth carrier and of the antirotation securing means 29 comprises a group of identical first angles 57, of which only two are depicted for the sake of clarity, and two second angles 59 arranged around the guide of the special tooth pin 63. The second angles 59 are each less than one of the first angles 57. FIG. 3C shows a view of the running surfaces 23 of the bearing segments 17. The bearing segments 17 comprise a group of uniform bearing segments 62 and a special bearing segment 64 assigned to the special tooth pin 63. The special bearing segment 64 is designed to be narrower in the circumferential direction than one of the uniform bearing segments 62.

[0072] FIG. 4 shows a tooth carrier 7 for a coaxial gear mechanism according to a further embodiment, in particular from a further range having an identical toothing to that of the coaxial gear mechanism of FIG. 3A-3C. The angular pitch of the guides 9 of the tooth carrier 7 comprises identical, first angles 57 and two second angles 59 which are different from one of the first angles 57, wherein the second angles 59 are each larger than a first angle 57. For the sake of clarity, not all the first angles 57 are indicated in FIG. 3B. The second angles 59 are situated opposite one another in the circumferential direction such that two gaps occur in the circumferential direction between tooth pins inserted into the tooth carrier 7. In particular, uniformly formed tooth pins can be received in the tooth carrier 7. The tooth carrier 7 is designed for a coaxial gear mechanism having a number of teeth Z.sub.v=118 of the toothing, a calculated number of teeth Z.sub.z=122, a number p=4 of axial elevations of the cam disk and a transmission ratio i=30.5.

[0073] The further range comprises, for example, a further coaxial gear mechanism having a number of teeth Z.sub.v=118 of the toothing, a calculated number of teeth Z.sub.z=121, a number p=3 of axial elevations of the cam disk and a transmission ratio i=40.333. A gap is formed between the tooth pins in the circumferential direction. The further range comprises, for example, yet a further coaxial gear mechanism having a number of teeth of the toothing Z.sub.v=118, a calculated number of teeth Z.sub.z=120, a number p=2 of axial elevations of the cam disk and a transmission ratio i=60. The tooth carrier comprises 24 guides configured as bores. The angular pitch of the guides is regular and comprises only identical, first angles. The tooth pins are uniformly formed. Coaxial gear mechanisms according to embodiments have the advantage in particular that coaxial gear mechanisms of a range having different transmission ratios can be produced using the same toothing and identical tooth pins.

[0074] FIGS. 5A-5B show schematic views of an antirotation securing ring 29, in particular views of the side of the antirotation securing ring 29 that faces the cam disk. The antirotation securing ring 29 has inner lugs 28, outer lugs 30 and webs 32 according to embodiments described herein. In addition, the antirotation securing ring 29 has a respective opening 38 for each of the tooth pins 11. On their radial outer side, the openings 38 have a formation 39 which is straight in certain portions and which projects into the otherwise circular ring-shaped cross section of the opening 38. Each of the formations 39 interacts with a respective flattened portion of a tooth pin (see FIG. 6). In embodiments, a noncircular cross section of the tooth pin in the region of the tooth pin base allows an engagement to occur with the correspondingly shaped opening with formation in the antirotation securing ring such that the tooth pin is rotationally secured about its longitudinal axis.

[0075] FIG. 6 schematically shows a tooth pin 11 in an inclined view. The tooth pin 11 comprises a head region 51, a tooth pin base 49 and a body 50 which is arranged between the head region 51 and the tooth pin base 49. The tooth pin 11 has the concave recess 21 on the tooth pin base and a widened head region 51 with a plurality of teeth 52. With the widened head region 51, a plurality of teeth 52 are brought into engagement with the toothing 5 of the crown gear 18 such that a high torque can be transmitted via the teeth. FIG. 6 also shows the flattened portion 53 in the region of the tooth pin base 49 by means of which rotation of the tooth pin 11 is prevented by engagement with the formation in a respective opening of the antirotation securing ring.