Gear unit of a motor vehicle actuating drive

Abstract

A gear unit for an actuating drive, in particular a window lifter drive, of a motor vehicle is provided that includes a gear housing and a pivot bolt rotatably fixedly connected thereto for rotatably supporting a gear wheel, in particular of a worm gear, the pivot bolt has a second pivot section, which is adjacent to a first pivot section having a first outer diameter, and which has a free end section on the front, the outer diameter of the second pivot section being smaller than the outer diameter of the first pivot section at least over one part of it pivot section length.

Claims

1. A gear unit for an actuating drive of a motor vehicle, the gear unit comprising: a gear housing; a pivot bolt rotatably fixedly connected to the gear housing; and a gear wheel injection molded onto the pivot bolt, the pivot bolt comprising: a first section; and a second section adjacent to the first section; wherein the first section has an outer diameter and has a front free end section; wherein the second section has an outer diameter being smaller than the outside diameter of the first section at least over one part of the second section length; wherein the second section has a first section of constant diameter and is widened conically or frustoconically outwardly from the first section to form a conical or frustoconical free end section; and wherein the conical or frustoconical free end section has a plurality of indented radial notches formed within an axial end surface of the conical or frustoconical free end section in a secant manner.

2. The gear unit according to claim 1, further comprising axial indentations on the second section.

3. The gear unit according to claim 1, wherein a number of axial notches that run at least largely in an axial direction are introduced into the second section on a circumferential side.

4. The gear unit according to claim 1, wherein the second section of the pivot bolt includes a section region which has the outer diameter that is reduced in comparison to the outer diameter of the first section between the first pivot section and the front free end section.

5. The gear unit according to claim 1, wherein an outer diameter of the front free end section is smaller or at maximum equal to the outer diameter of the first section of the pivot bolt.

6. The gear unit according to claim 1, wherein the gear wheel is a worm gear.

7. The gear unit according to claim 1, wherein the outer diameter of the second section is less than the outer diameter of the first section by 20% to 30%.

8. The gear unit according to claim 1, wherein the first section of the pivot bolt has a circumferential groove.

9. The gear unit according to claim 1, wherein the radial notches are V-shaped.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 shows a sectional representation of a gear unit of an actuating drive comprising a pivot bolt provided with a notching, on which a worm wheel is supported;

(3) FIG. 2 shows a perspective representation of the gear unit according to FIG. 1, including a partially cut away gear housing;

(4) FIGS. 3 and 4 show the pivot bolt having the notching in a side view and a front top view, respectively, of the free end section having the notching; and

(5) FIG. 5 shows a perspective view of an electromotive cable window lifter having a gear unit according to FIGS. 1 and 2.

DETAILED DESCRIPTION

(6) FIGS. 1 and 2 show a sectional representation and a perspective representation, respectively, of a gear unit 1 comprising a housing section 2a of a gear housing 2, which accommodates a worm wheel 3 as the gear wheel, which is rotatably supported around a pivot bolt. 4. Gear housing 2, or this housing section 2a, is formed by a housing base 5 and housing side walls 6 extending perpendicularly thereto, pivot bolt 4, which is designed as a steel pin or steel bolt, a solid element or as a hollow cylinder, projects partially out of housing section 2a from housing base 5, extending perpendicularly thereto, and is rotatably fixedly anchored in housing base 5. Pivot bolt 4 is used as a rotation axis for worm wheel 3 and possibly for a cable drum, which is not illustrated herein.

(7) A driving worm 7, which is fixedly connected to the shaft on the shaft end of a motor shaft 8 (FIG. 2) and engages with a helical outer gearing 9 of worm wheel 3, extends over a cylindrical bore hole on the left edge (FIG. 1) and right edge (FIG. 2) of gear housing section 2a. Worm wheel 3 and driving worm 7 form a worm gear, whose reduction ratio is determined by the gearings or worm wheel 3 and driving worm 7.

(8) A sealing ring 11 overlaps an upper housing edge 10 of side wall of housing section 2a in a form-locked and frictionally engaged manner, so that worm wheel 3 is sealed against gear housing 2. Worm wheel 3 has an annular bulge 12 on the base side and is supported thereby on housing base 5 to reduce friction losses. Opposite annular bulge 12, worm wheel 3 has multiple receptacles 13 in the form of recesses, with which corresponding pins or grips of the cable drum engage to connect it to worm wheel 3 in a form-locked manner.

(9) As is comparatively clearly apparent in FIG. 2, housing section 2a illustrated in FIG. 1 is located on the front housing end of gear housing 2, which has a motor housing section 2b for fastening an electric motor 14 or its motor housing illustrated in FIG. 5. Multiple fastening regions 15 are provided on gear housing 2 for fastening the actuating drive formed by motor 14 and gear housing 2, for example to a vehicle door. An electronic system (FIG. 5), which controls electric motor 14, may be pushed into gear housing 2 via a push-in opening 16 of gear housing 2. A particularly compact overall structure of the actuating drive is thus provided.

(10) As is comparatively clearly apparent in connection with FIGS. 3 and 4, pivot bolt 4 has a first pivot section 4a, which has a first outer diameter d1, and an adjoining second pivot section 4b in axial direction Avia a chamfered transitional section 4d in the exemplary embodimentsecond pivot section 4b having a second outer diameter d2 which is smaller than outer diameter d1 of first pivot section 4a. Second pivot section 4b, which has a comparatively small outer diameter d2, is provided with a notching in the form of axial notches 17, on the one hand, which extend in axial direction A, and radial notches 18, on the other hand, which extend in radial direction R.

(11) After radial notches 18, which are designed in the shape of a cross according to FIG. 4, have been introduced, a frustoconical free end section 4c, which widens conically in the direction of front 19, is provided in the direction of front 19 of this notched pivot section 4b. Maximum outer diameter d.sub.3 in the region of end face 19 is preferably also smaller than and otherwise at most the same size as outer diameter d.sub.1 of first pivot section 4a of pivot bolt 4, which is used as the bearing surface for worm wheel 3 and possibly the cable drum.

(12) Pivot bolt 4 is rotatably fixedly anchored by this notched pivot section 4b in housing base 5 of gear housing 2 and, in this location, in its housing section 2a. For this purpose, the plastic material of gear housing 2, which is manufactured by injection molding, is also injection-molded around corresponding (second) pivot section 4b as well as preferably a certain axial region of adjoining (first) pivot section 4a, which is used as the bearing surface for worm wheel 3, to thereby rotatably fixedly anchor pivot bolt 4 easily and reliably in gear housing 2 and thus in gear unit 1.

(13) In manufacturing pivot bolt 4, diameter-reduced pivot section 4b is produced by a cutting process initially or following a grinding process of pivot bolt 4, including introduction of chamfered intermediate or transition section 4d as well as a chamfered bolt end section 4e on the bolt end opposite notched free end section 4c on the front. Diameter d.sub.2 in this case is approximately 20% to 30% smaller than outer diameter d.sub.1 of pivot section 4a ground with the desired or required surface condition. Axial notches 17 are subsequently introduced into this diameter-reduced pivot section 4b. Preferably V-shaped radial notches 18 are then introduced by forming conical or frustoconical free end section 4c on the front for providing desired notching 17, 18.

(14) In the area of (first) pivot section 4a, a circumferential groove 4f, which is indicated only by the dash-dot line in FIG. 3, may be introduced into pivot bolt 4.

(15) A retaining ring (not illustrated) may be introduced into this annular groove 4f to axially secure the cable drum on pivot bolt 4.

(16) FIG. 5 shows a perspective representation of the actuating drive designed as a cable window lifter, comprising gear housing 2 and electric motor 14, whose motor housing is, for example, detachably connected to gear housing 4 via a flange joint 20. Push-in electronic system 21 is inserted into gear housing 21 via push-in opening 16.

(17) The illustrated cable window lifter furthermore comprises a circumferentially guided cable 22, which is deflected in deflection regions 23 with the aid of deflection rollers 24, and whose cable ends are accommodated in cable means receptacles of the cable drum, which is not illustrated, in a manner which is not illustrated in further detail. A base plate, on which gear housing 2 is fixed via its fastening regions 15, is used to fasten the window lifter, which is formed by motor gear unit 2, 14 as the actuating drive, to a guide rail 25 or to a vehicle door module.

(18) The invention is not limited to the exemplary embodiments described above. Instead, other variants of the invention may be derived herefrom by those skilled in the art without going beyond the subject of the invention. Moreover, in particular, all individual features described in connection with the exemplary embodiments may also be otherwise combined with each other without going beyond the subject of the invention.