Toothed wheel for a transmission and method for producing a toothed wheel

Abstract

The invention relates to a toothed wheel for a transmission, comprising an approximately circular cylindrical basic body (10), which has a left end face (21) and an opposite right end face (22), wherein a through-bore (12) is incorporated in the basic body (10) and extends in an axial direction (X), and wherein a left chamfer region (31) is formed at a transition between the bore (12) and the left end face (21), and wherein a right chamfer region (32) is formed at a transition between the bore (12) and the right end face (22). The left chamfer region (31) comprises at least one main portion (41), which has a convex cross section. The invention relates to a method for producing a toothed wheel according to the invention.

Description

[0001] Gear for a transmission and method for producing a gear

[0002] Description:

[0003] The invention relates to a gear for a transmission comprising an approximately circular-cylindrical base body having a left end face and an opposite right end face. A through bore extending in an axial direction is formed in the base body, and a left chamfer region is formed at a transition between the bore and the left end face, and a right chamfer region is formed at a transition between the bore and the right end face. The invention also relates to a method for producing a gear according to the invention.

[0004] Drives for machines consist of an electric motor and a mechanical gearbox. The electric motor drives the machine via the gearbox. The gearbox comprises several meshing gears arranged in a housing. The housing comprises several housing parts that are connected to each other and surround a cavity in which the gears are arranged. The gears are mounted on rotating shafts.

[0005] Document DE 10 2011 109 104 A1 discloses a gear of this type and a method for manufacturing a gear. The gear comprises a base body in which a through-bore is formed. A chamfered area is formed at each transition between the bore and the end faces.

[0006] US Pat. No. 5,503,494 A discloses a gear for a transmission having an approximately circular cylindrical base body. A through bore is provided in the base body.

[0007] Document DE 10 2019 123 142 A1 discloses a drive gear comprising an inner gear and an outer gear. An elastomer track fills a radial annular gap between the inner gear and the outer gear. Document DE 10 2020 124447 A1 discloses a gear comprising an annular gear body with an inner surface and an outer surface.

[0008] The invention is based on the object of improving a gear for a transmission and a method for producing a gear.

[0009] The object is achieved by a gear for a transmission having the features specified in claim 1. Advantageous embodiments and further developments are the subject of the subclaims. The object is also achieved by a method for producing a gear having the features specified in claim 10. Advantageous embodiments and further developments are the subject of the subclaims.

[0010] A gearwheel for a transmission according to the invention comprises an approximately circular-cylindrical base body having a left end face and a right end face opposite the left end face. A through bore extending in an axial direction is formed in the base body. A left chamfer region is formed at a transition between the bore and the left end face, and a right chamfer region is formed at a transition between the bore and the right end face. The left chamfer region comprises at least one main section having a convex cross-section.

[0011] The inventive design advantageously simplifies the mounting of the gear onto a shaft. The convex cross-section of the main section of the left chamfer area allows for smooth and precise positioning of the gear on the shaft. This prevents damage to the shaft, particularly scratches caused by sharp edges on the gear bore.

[0012] According to an advantageous embodiment of the invention, the main section of the left chamfer region has a cross-section in the form of a circular sector.

[0013] According to an advantageous embodiment of the invention, the main section of the left-hand chamfer region has a cross-section in the shape of an elliptical sector. According to an advantageous further development of the invention, the right-hand chamfer region comprises at least three sections, each of which is designed differently from one another.

[0014] According to an advantageous development of the invention, the right-hand chamfer region comprises at least one section having a cross-section in the shape of a circular sector or an elliptical sector. Said section thus has a convex cross-section.

[0015] According to an advantageous development of the invention, the right-hand chamfer region comprises at least two sections that have different angles of inclination relative to the axial direction. These two sections thus each have a rectilinear cross-section.

[0016] According to an advantageous development of the invention, the right-hand chamfer region comprises an outer section having an outer angle of inclination between 40° and 50°, preferably 45°, to the axial direction, a central section having a cross-section in the shape of a circular sector or in the shape of an elliptical sector, and an inner section having an inner angle of inclination between 25° and 35°, preferably 30°, to the axial direction. The outer section and the inner section thus each have a rectilinear cross-section. The central section thus has a convex cross-section.

[0017] According to an advantageous development of the invention, the right-hand chamfer region comprises a right-hand receiving section having a concave cross-section. The inner section is arranged between the right-hand receiving section and the right-hand end face. The right-hand receiving section extends radially outward from the bore and defines a cavity, which serves in particular to accommodate an anti-corrosion agent.

[0018] According to an advantageous development of the invention, the left chamfer region comprises a left receiving section having a concave cross-section. The main section is arranged between the left receiving section and the left end face. The left receiving section extends radially outward from the bore and defines a cavity, which serves in particular to accommodate an anti-corrosion agent. According to a preferred embodiment of the invention, the left chamfer region and the right chamfer region are designed differently from one another.

[0019] A method for producing a gear according to the invention is also proposed, wherein a through bore with a first diameter is formed in an approximately circular-cylindrical base body having a left end face and an opposite right end face. A left chamfer region is formed at a transition between the bore and the left end face, and a right chamfer region is formed at a transition between the bore and the right end face. The left chamfer region comprises at least one main section having a convex cross-section.

[0020] The inventive design advantageously simplifies the mounting of the gear onto a shaft. The convex cross-section of the main section of the left chamfer area allows for smooth and precise positioning of the gear on the shaft. This prevents damage to the shaft, particularly scratches caused by sharp edges on the gear bore.

[0021] According to a preferred embodiment of the invention, a left auxiliary section is created in the left chamfer region, and a right auxiliary section is created in the right chamfer region, wherein the auxiliary sections extend in the radial direction up to a second diameter. Subsequently, the through bore is enlarged to the second diameter.

[0022] After the auxiliary sections have been created, the bore has a central area with a first diameter that is smaller than the second diameter. To further manufacture the gear, a mandrel is inserted into the bore to hold the base body. An external toothing is then milled and ground. Further processing steps may be performed if necessary. The mandrel is then removed from the bore of the base body. The through bore is then enlarged to the second diameter.

[0023] According to an advantageous development of the invention, the through bore is enlarged to the second diameter by grinding. Subsequently, a groove running in the axial direction is milled at the edge of the bore. According to an advantageous embodiment of the invention, the auxiliary sections each have an inclination angle of between 10° and 20°, preferably 15°, to the axial direction. The two auxiliary sections thus each have a rectilinear cross-section. This configuration of the inclination angles allows for smooth and precise positioning of the base body on the mandrel.

[0024] According to an advantageous development of the invention, after the through bore has been widened to the second diameter, a right receiving section is produced in the right chamfer area, which has a concave cross-section.

[0025] Preferably, the right-hand receiving portion is filled with an anti-corrosion agent before the gear is mounted on a shaft. During and after assembly, the anti-corrosion agent spreads from the right-hand receiving portion onto the shaft and into the bore, thus protecting their surfaces.

[0026] According to an advantageous development of the invention, after the through bore has been widened to the second diameter, a left receiving section is created in the left chamfer area, which has a concave cross-section.

[0027] Preferably, the left-hand receiving portion is filled with an anti-corrosion agent before the gear is mounted on a shaft. During and after assembly, the anti-corrosion agent is distributed from the left-hand receiving portion onto the shaft and into the bore, thus protecting their surfaces.

[0028] The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the task and / or the problem posed by comparison with the prior art. The invention will now be explained in more detail with reference to figures. The invention is not limited to the exemplary embodiments shown in the figures. The figures represent the subject matter of the invention only schematically. They show:

[0029] Figure 1 : a perspective view of a gear,

[0030] Figure 2: a sectional view of a gear during production,

[0031] Figure 3: an enlarged view of a left chamfer area from Figure 2 and

[0032] Figure 4: an enlarged view of a right chamfer area from Figure 2.

[0033] Figure 1 shows a perspective view of a gear. The gear comprises an approximately circular-cylindrical base body 10. The base body 10 has a left end face 21 and a right end face 22 opposite the left end face 21. A through bore 12 is formed in the base body 10. The gear has external teeth milled into the base body 10. The teeth allow the gear to mesh with another gear in a transmission.

[0034] The bore 12 formed in the base body 10 extends in an axial direction X. A groove 14 is formed at one edge of the bore 12, which also extends in the axial direction X. In the transmission, the gear is positioned on a rotatable shaft. The shaft extends through the bore 12. A driver engages in the groove 14.

[0035] The end faces 21, 22 run parallel to each other. The bore 12 runs perpendicular to the end faces 21, 22. A left chamfer area 31 is formed at a transition between the bore 12 and the left end face 21. A right chamfer area 32 is formed at a transition between the bore 12 and the right end face 22, which is hidden in the illustration shown here.

[0036] Figure 2 shows a sectional view of a gear during production. The bore 12 in the base body 10 runs concentrically to a central axis M. The central axis M runs in the axial direction X. A direction perpendicular to the axial direction X is referred to as the radial direction R. First, a through bore 12 is drilled in the axial direction X with a first diameter D1 into the base body 10. Subsequently, the left chamfer region 31 is formed at the transition between the bore 12 and the left end face 21, and the right chamfer region 32 is formed at the transition between the bore 12 and the right end face 22.

[0037] A left auxiliary section 45 is created in the left chamfer area 31. The left auxiliary section 45 extends in the radial direction R up to a second diameter D2. The left auxiliary section 45 has an auxiliary inclination angle AH of 15° to the axial direction X. The second diameter D2 is larger than the first diameter D1. A main section 41 is also created in the left chamfer area 31.

[0038] A right auxiliary section 55 is created in the right chamfer region 32. The right auxiliary section 55 also extends in the radial direction R up to the second diameter D2. The right auxiliary section 55 also has an auxiliary inclination angle AH of 15° to the axial direction X.

[0039] In a later manufacturing step, the through bore 12 is enlarged by grinding from the first diameter D1 to the second diameter D2. In this process, the left auxiliary section 45 of the left chamfer area 31 and the right auxiliary section 55 of the right chamfer area 32 are removed. However, the main section 41 of the left chamfer area 31 remains intact.

[0040] Figure 3 shows an enlarged view of the left chamfer area 31 from Figure 2. The left chamfer area 31 comprises the main section 41. The main section 41 directly borders the left end face 21. The main section 41 of the left chamfer area 31 has a cross-section in the shape of a circular sector with a constant radius. The main section 41 thus has a convex cross-section.

[0041] Temporarily, during production, the left chamfer area 31 additionally comprises the left auxiliary section 45. The left auxiliary section 45 is located between the main section 41 and the bore 12. The left auxiliary section 45 has a straight cross-section. After production, when the left auxiliary section 45 has been removed, the main section 41 borders directly on the bore 12. Figure 4 shows an enlarged view of the right chamfer area from Figure 2. The right chamfer area 31 comprises an outer section 51, a middle section 52 and an inner section 53. The outer section 51 borders directly on the right end face 22. The middle section 52 borders directly on the outer section 51. The inner section 53 borders directly on the middle section 52.

[0042] The outer section 51 has an outer inclination angle A1 of 45° to the axial direction X. The outer section 51 thus has a rectilinear cross-section. The middle section 52 has a cross-section in the shape of a circular sector with a constant radius. The middle section 52 thus has a convex cross-section. The inner section

[0043] 53 has an inner inclination angle A3 of 30° to the axial direction X. The inner section 53 thus has a rectilinear cross-section.

[0044] Temporarily, during manufacturing, the right chamfer area 32 additionally includes the right auxiliary section 55. The right auxiliary section 55 is located between the inner section 53 and the bore 12. The right auxiliary section 55 has a straight cross-section. After manufacturing, when the right auxiliary section 55 is removed, the inner section 53 directly borders the bore 12.

[0045] List of reference symbols

[0046] 10 basic bodies

[0047] 12 holes

[0048] 14 grooves

[0049] 21 left front side

[0050] 22 right front side

[0051] 31 left chamfer area

[0052] 32 right chamfer area

[0053] 41 Main section

[0054] 45 left auxiliary section

[0055] 51 outer section

[0056] 52 middle section

[0057] 53 inner section

[0058] 55 right auxiliary section

[0059] A1 external inclination angle

[0060] A3 internal inclination angle

[0061] AH auxiliary inclination angle

[0062] D1 first diameter

[0063] D2 second diameter

[0064] M central axis

[0065] X axial direction

[0066] R Radial direction

Claims

Patent claims:

1. A gear for a transmission, comprising an approximately circular-cylindrical base body (10) which has a left-hand end face (21) and an opposite right-hand end face (22), wherein a through-bore (12) which extends in an axial direction (X) is introduced into the base body (10), and wherein a left-hand chamfer region (31) is formed at a transition between the bore (12) and the left-hand end face (21), and wherein a right-hand chamfer region (32) is formed at a transition between the bore (12) and the right-hand end face (22), characterized in that the left-hand chamfer region (31) comprises at least one main section (41) which has a convex cross-section.

2. Gear according to claim 1, characterized in that the main section (41) of the left chamfer region (31) has a cross-section in the form of a circular sector or in the form of an elliptical sector.

3. Gear according to one of the preceding claims, characterized in that the right-hand chamfer region (32) comprises at least three sections (51, 52, 53), each of which is designed differently from one another.

4. Gear according to one of the preceding claims, characterized in that the right-hand chamfer region (32) comprises at least one section (52) which has a cross-section in the form of a circular sector or in the form of an elliptical sector.

5. Gear according to one of the preceding claims, characterized in that the right-hand chamfer region (32) comprises at least two sections (51, 53) which have different angles of inclination (A1, A3) to the axial direction (X).

6. Gear according to one of the preceding claims, characterized in that the right-hand chamfer region (32) comprises an outer section (51) which has an outer inclination angle (A1) between 40° and 50°, preferably 45°, to the axial direction (X), a middle section (52) which has a cross-section in the form of a circular sector or in the form of an elliptical sector, and an inner section (53) which has an inner inclination angle (A3) between 25° and 35°, preferably 30°, to the axial direction (X).

7. Gear according to claim 6, characterized in that the right chamfer region (32) comprises a right receiving portion which has a concave cross-section, and that the inner portion (53) is arranged between the right receiving portion and the right end face (22).

8. Gear according to one of the preceding claims, characterized in that the left chamfer region (31) comprises a left receiving portion which has a concave cross-section, and that the main portion (41) is arranged between the left receiving portion and the left end face (21).

9. Gear according to one of the preceding claims, characterized in that the left chamfer region (31) and the right chamfer region (32) are designed differently from one another.

10. A method for producing a gear according to one of the preceding claims, wherein a through bore (12) with a first diameter (D1) is introduced into an approximately circular-cylindrical base body (10) which has a left end face (21) and an opposite right end face (22) in an axial direction (X); a left chamfer region (31) is formed at a transition between the bore (12) and the left end face (21); a right chamfer region (32) is formed at a transition between the bore (12) and the right end face (22); characterized in that the left chamfer region (31) comprises at least one main section (41) which has a convex cross-section.

11. The method according to claim 10, characterized in that a left auxiliary section (45) is produced in the left chamfer region (31); a right auxiliary section (55) is produced in the right chamfer region (32); wherein the auxiliary sections (45, 55) extend in the radial direction (R) up to a second diameter (D2); and that the through bore (12) is subsequently widened to the second diameter (D2).

12. The method according to one of claims 10 to 11, characterized in that the through bore (12) is widened to the second diameter (D2) by grinding.

13. The method according to one of claims 10 to 12, characterized in that the auxiliary sections (45, 55) each have an auxiliary inclination angle (AH) between 10° and 20°, preferably 15°, to the axial direction (X).

14. Method according to one of claims 10 to 13, characterized in that after the through bore (12) has been widened to the second diameter (D2), a right receiving section is produced in the right chamfer region (32) which has a concave cross-section.

15. Method according to one of claims 10 to 14, characterized in that after the through bore (12) has been widened to the second diameter (D2), a left receiving section is produced in the left chamfer region (31), which has a concave cross-section.

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