SPUR GEAR

Abstract

A spur gear includes a radially outer, spur-cut gear rim, a radially inner hub, and a rotationally symmetrical radial connecting structure which integrally connects the gear rim to the hub. The radial connecting structure has mutually spaced struts, which extend between the hub and the gear rim, and axial perforations or holes, which are situated between the struts. The radial connecting structure has a disk-shaped base body, through which the axial holes pass and which has an axial front side and an axial rear side, with the struts being situated on the front side.

Claims

1-10. (canceled)

11. A spur gear, comprising: a radially-outwardly-disposed spur-cut gear rim; a radially-inwardly-disposed hub; and a rotationally symmetrical radial connecting structure integrally connecting said gear rim to said hub; said radial connecting structure having mutually spaced-apart struts extending between said hub and said gear rim and forming axial perforations between said struts; said radial connecting structure having a disk-shaped base body penetrated by said axial perforations, said base body having an axial front side and an axial rear side, and said struts being disposed on said front side of said base body.

12. The spur gear according to claim 11, wherein said struts include a set of struts of a first type and a set of struts of a second type, said struts of said first type having a profile being higher than it is wide and said struts of said second type having a profile being wider than it is high.

13. The spur gear according to claim 12, wherein: said struts have a starting point; said struts are tilted about an axial direction so that they extend in a straight line and relative to a radial line intersecting said starting point; and said struts of said first type are tilted in a direction opposite to said struts of said second type.

14. The spur gear according to claim 13, wherein said struts of said first type are tilted by a larger angular amount than said struts of said second type.

15. The spur gear according to claim 13, wherein: said starting points of said struts include radially outer starting points on said gear rim and radially inner starting points on said hub; and said struts include pairs of two adjacent struts of different types contacting each other either at said radially outer starting points or at said radially inner starting points.

16. The spur gear according to claim 11, which further comprises a reinforcing body disposed on said rear side of said base body, said reinforcing body merging radially inward into said hub and being stretched radially outward in a star shape.

17. The spur gear according to claim 16, wherein said star-shaped reinforcing body has star tips with radial extensions, and said axial perforations are disposed in said radial extensions.

18. The spur gear according to claim 11, wherein said axial perforations have a circular shape.

19. The spur gear according to claim 11, wherein said axial perforations have a rounded, isosceles, flat triangular shape with a radially inwardly facing vertex.

20. The spur gear according to claim 11, wherein said base body is disposed axially off-center.

Description

[0026] In the drawings:

[0027] FIG. 1 shows two simplified views of a first embodiment of a spur gear according to the invention,

[0028] FIG. 2 shows two simplified views of a second embodiment of a spur gear according to the invention,

[0029] FIG. 3 shows a plan view of the front side of a spur gear according to FIG. 2,

[0030] FIG. 4 shows a plan view of the rear side of the spur gear from FIG. 2,

[0031] FIG. 5 shows a view in section along the line of section V-V in FIG. 3,

[0032] FIG. 6 shows a view in section along the line of section VI-VI in FIG. 3, and

[0033] FIG. 7 shows a view in section along the line of section VII-VII in FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] The same reference numerals in the drawings designate the same or similar elements.

[0035] FIG. 1 shows in a simplified view the front side (on the right in FIG. 1) and the rear side (on the left in FIG. 1) of a first embodiment of a spur gear 10 according to the invention. The spur gear 10 comprises a hub 20 radially on the inside and a gear rim 30 radially on the outside, the spur-cut teeth of which have not, ii however, been illustrated in FIG. 1. A radial connecting structure 40, the specific construction of which is within the focus of the present invention, extends between the hub 20 and the gear rim 30.

[0036] The radial connecting structure 40 comprises a disk-shaped base body 42 which can be clearly seen in particular in the rear view of the spur gear 10 (on the left in FIG. 1). Struts of the first type 44 and struts of the second type 46 rise from the disk-shaped base body 42 on the front side, illustrated on the right in FIG. 1, of the radial connecting structure. The struts of the first type 44 are designed so that they are narrow and high, i.e. in particular that they are higher than they are wide. The struts of the first type 46 are designed so that they are flat and wide, i.e. in particular that they are wider than they are high. The struts 44, 46 extend essentially in a straight line but do not run radially. Instead, they are tilted relative to the radial line intersecting them in each case at their starting point (on the hub 20 or on the gear rim 30). The struts of the first type 44, on the one hand, and the struts of the second type 46, on the other hand, are here tilted in opposite directions. In the embodiment illustrated, the struts of the first type 44 are tilted to the left at their starting point with respect to the hub 20, relative to the radial line there. The struts of the second type 46 are tilted to the right at their starting point on the hub 20, relative to the radial line there. The angle by which the struts of the first type 44 are tilted is here greater than the angle by which the struts of the second type 46 are tilted.

[0037] In the embodiment shown, the struts 44, 46 are arranged such that they do not cross over one another. Specifically, the struts of the second type 46 extend from the hub starting point of a strut of the first type 44 as far as the gear rim starting point of the adjacent strut of the first type 44. The same applies for struts of the first type. Each strut of the first type 44 extends from the hub starting point of a strut of the second type 46 as far as the gear rim starting point of the adjacent strut of the second type 46.

[0038] Those regions of the base body 40 which are not strengthened by struts 44, 46 are configured as axial perforations. In the embodiment in FIG. 1, the axial perforations 48 have the form of rounded, flat, isosceles triangles with a radially inwardly facing vertex.

[0039] On the rear side of the base body 42, the radial region adjoining the hub 20 of the latter is strengthened with a star-shaped reinforcing body 49. The latter rises from the surface of the disk and merges into the hub 20. Its star tips each lie on the same radial line as the center of an axial perforation 48.

[0040] FIG. 2 shows an alternative embodiment of a spur gear 10 according to the invention which differs from the embodiment in FIG. 1 only in the form of the axial perforations 48 which are here designed with a circular form.

[0041] FIG. 3 shows a detailed plan view of the front side of the spur gear 10 from FIG. 2. In the view in FIG. 3, the teeth of the gear rim 30 can also be clearly seen. The hub 20 is provided with splines on its inner circumference. FIG. 4 shows the rear side of the same spur gear 10.

[0042] FIGS. 5 to 7 show cross-sections through the spur gear 10 in FIGS. 3 and 4 along the lines of section V-V, VI-VI, and VII-VII in FIG. 3. By studying FIGS. 3 to 7 collectively, a person skilled in the art should obtain a vivid picture of the design according to the invention of the radial connecting structure 40.

[0043] In addition, the views in section in FIGS. 5 to 7 show the preferred embodiment of the invention, according to which the base body 42 is not arranged axially centrally and instead is offset (to the left in the drawings). An offset in the opposite direction and bigger or smaller offsets would also be conceivable.

[0044] The embodiments discussed in the specific description and shown in the drawings of course only represent illustrative exemplary embodiments of the present invention. A broad spectrum of possible variants are available to a person skilled in the art in the light of the disclosure in this document. In particular, the form according to the invention is suited for production of the spur gear according to the invention from a metal material, in particular steel, wherein production can take place by means of forming processes, in particular forging, in a manner which is also preferably provided for creating spur gears for use in drive units of motor vehicles, in particular in gearboxes.

LIST OF REFERENCE NUMERALS

[0045] 10 spur gear

[0046] 20 hub

[0047] 30 gear rim

[0048] 40 radial connecting structure

[0049] 42 base body

[0050] 44 strut of the first type

[0051] 46 strut of the second type

[0052] 48 axial perforation

[0053] 49 reinforcing body