Differential with differential gears, a drive gear and at least one cover

Abstract

Differential (1) with compensating gears (2, 3), a drive gear (4) and with at least one cover (5, 13), wherein - the drive wheel (4) has a toothing (7) extending circumferentially around an axis of rotation (6) on the outside and is provided with bearing points (8, 9) on the inside, - the compensating gears (2, 3) are mounted at the bearing points (8, 9) in the drive gear (4) and - the differential (1) is closed on one side with the cover (5, 13), wherein the differential gears (2, 3) are held in the drive gear (4) by means of the cover (5, 13), and that the cover (5, 13) and the drive gear (4) are attached to each other without the effect of any further fastening means only by a material bond (11) such that at least the differential (1) formed from the differential gears (2, 3), the drive gear (4) and the cover (5, 13) is a self-supporting unit (25), wherein the material bond (11) is a welded joint between two metallic materials, and the compensating gears (2, 3) are each rotatably mounted with a pin (12, 14) in the drive gear (4), wherein the lids (5, 13) are made as drawn parts from sheet metal and The weld joint is a circumferentially closed weld joint.

Description

Field of invention

[0001] The invention relates to a differential with compensating gears, a drive gear and at least one cover, wherein the drive gear has a toothing extending circumferentially around an axis of rotation on the outside and is provided with bearing points on the inside, the compensating gears are mounted at the bearing points in the drive gear and the differential is closed on one side with the cover. Background of the invention

[0002] Such a differential is described in DE 10 2007 040 479 A1. The differential has two covers, one on the left and one on the right. The covers are attached to the drive gear by means of rivets. The drive gear is provided with a flange that has through-holes for riveting. The covers have a hole pattern that corresponds to that of the flange and are axially opposed to each other on the flange. Each rivet passes through the hole in the flange and its heads are pressed against the cover.

[0003] Another differential of this type is described in US 6,616,565 A. The differential gears are mounted on a common bolt, which is connected to the drive gear flange via a dowel pin connection. The differential covers are also attached to the flange by means of bolted connections, which have through-holes for these bolted connections.

[0004] EP 1 803 972 A1 discloses a differential assembly, particularly for motor vehicles, for transmitting motion from an input shaft to a pair of opposing coaxial output shafts. The assembly comprises a ring gear driven by the input shaft, a gear set for transmitting motion from the ring gear to the output shafts, and a satellite carrier pin with an axis orthogonal to the axis of rotation of the ring gear, which rotates with the ring gear. The ring gear has coupling means for the satellite carrier pin.

[0005] DE 10 2014 000 430 A1 discloses a differential gear, particularly for a motor vehicle, with an annular gear driven by a pinion, which is arranged on a two-part differential housing rotatably mounted on rolling bearings on both sides. Planet gears are mounted on at least one drive pin in this housing, meshing with output gears on output half-shafts. The gear is mounted on the housing circumferentially without a positive locking mechanism and has recesses into which the drive pin engages positively. The cup-shaped section and the cover of the differential housing are held in place by the rolling bearings on both sides without fasteners. The gear is supported by an annular extension directly against one of the rolling bearings, opposite the gear housing. Description of the invention

[0006] The purpose of the invention is to create a differential that can be manufactured and assembled easily and cost-effectively.

[0007] The problem is solved according to the subject matter of claim 1.

[0008] The differential gears are held in the bearing points in the flange and, with the aid of the cover, in the drive gear. The cover is attached to the drive gear by at least one bonded connection without the need for any additional fasteners. The differential, consisting at least of the differential gears, the drive gear, and the cover, is thus a self-supporting unit. The advantage of the invention lies in the fact that no fasteners such as rivets or screws are used, thereby saving the cost of these components. Furthermore, assembly costs are reduced because the threading and screwing or pressing of rivet heads is eliminated. In addition, the accuracy of the assembly is increased, which has a particularly positive effect on the precision of the tooth contact between the differential gears and the driven gears.The drive gear is the differential's summing shaft, through which power from the vehicle's drive system is introduced into the differential and from there distributed to the vehicle's wheels, or where the power transmitted back through the vehicle's wheels is summed. The differential gears, in conjunction with the output gears, compensate for differential rotational speeds at the vehicle's wheels. To achieve this, the differential gears mesh with the output gears and are mounted on the drive gear so they can rotate around their own axis of rotation.

[0009] One embodiment of the invention provides that the drive wheel has a flange. The drive wheel has external teeth, which are either spur gears or, alternatively, bevel gear teeth. The flange extends radially inward from these external teeth and is segmented or disc-shaped, extending radially inward toward the axis of rotation. The flange incorporates bearing points. These bearing points are formed entirely by recesses in the flange and sections of the cover(s). One of the compensating gears is mounted in each bearing point. The advantage of this embodiment of the invention is that no separate components, such as webs or cages, are required for mounting the compensating gears.

[0010] One embodiment of the invention provides that the differential is closed by two covers. One cover connects to the flange on the left side and the other on the right side. This embodiment of the invention is particularly advantageous if the covers are designed as identical parts – i.e., structurally identical. Such covers can preferably be manufactured as drawn sheet metal parts. Due to their identical design, the covers can be produced in larger batches and thus cost-effectively. In general, the differential design allows the use of various materials, especially metals of different alloys and processing conditions. For example, it is conceivable that the drive gear is a forged steel part or a cast part. When using only one cover, it is also conceivable that a "cover" or one half of a differential carrier is integrated into the drive gear as a single, single-material component.According to the invention, the other side is closed with the cover, which is preferably attached to the drive wheel by welding. It is advantageous that the material-bonded connection is preferably a welded joint between metallic materials, preferably ferrous materials and their alloys.

[0011] In a further embodiment of the invention, the compensating gears are each rotatably mounted in the drive gear by means of a pin. The pin can be formed integrally with the respective compensating gear or be embedded within that gear. The pin is rotatably seated in the bearing point or is supported there by a plain bearing or roller bearing in the bearing point of the drive gear. Such a mounting is simple and robust.

[0012] Alternatively, in one embodiment of the invention, the compensating gears are mounted on a common bolt, which is accordingly provided with the pins and which is supported at opposite radial positions in a bearing point of the drive gear. Such an arrangement is simple and can be manufactured cost-effectively.

[0013] In a further embodiment of the invention, the differential has at least one, and preferably two, output gears integrated into the self-retaining unit. Each output gear is connected to an output shaft, which leads, for example, to a driven vehicle wheel. This embodiment of the invention is advantageous because the output gears, which are formed by meshing with the differential gears, can be easily integrated into the assembly. The connection between the output shafts and the output gears is then preferably made via stub axle connections. Description of the drawings

[0014] The invention is explained in more detail below using an exemplary embodiment. Fig. Figure 1 shows a differential 1 in an overall view. The differential 1 comprises a drive gear 4 with a helical tooth profile 7, a cover 5, and the shafts 18 and 19 of two output gears 16. Fragments of an output gear 16 are also visible through holes 20. The drive gear 4, the cover 5, and the output gears 16 are arranged coaxially with respect to a rotational axis 6 of the differential 1. Several metallurgical connections 11, symbolized by crosses, are formed between the cover 5 and a flange 10 of the drive gear 4. Alternatively, the crosses symbolize the course of a welded connection between the cover 5 and the drive gear 4, which extends partially, partially, or completely circumferentially around the rotational axis. Fig. Figure 2 shows a view of the differential 1 without one of the two covers 5 and 13. It should be noted that, according to the invention, the cover(s) 5 and 13 are permanently connected to the drive wheel 4 by means of a material-bonded connection. The cover(s) 5 can therefore only be removed by force through separation. Consequently, Fig. Figure 2 is intended only to illustrate the internal design of the differential 1. The disc-shaped flange 10 is circumferentially surrounded on its outer surface by a base body 21 of the drive gear 4, which has teeth 7, and extends radially inwards from the base body 21. Recesses 22, open radially inwards and in both axial longitudinal directions, are formed in the flange 10. The recesses 22 form bearing positions 8 and 9. Two differential gears 2 and 3 are mounted in the drive gear 4. The differential gears 2 and 3 are mounted on a bolt 15 such that radial pins 12 and 14 of the bolt 15 project beyond it. Each pin 14 and 15 sits in a recess 22 such that the bolt 15 is supported circumferentially around the axis of rotation in the bearing positions 8 and 9. A driven gear 16 is in tooth mesh with both compensating gears 1 and 2. Fig.Figure 3 shows a detailed longitudinal section through the differential 1 in a longitudinal plane in which the axis of rotation 6 of the differential 1 also extends axially. Visible are the base body 21 of the drive gear 4 and a section of the journal 12, as well as flange sections 23 and 24 of the covers 5 and 13. The teeth 7 and the flange 10 project radially outwards from the drive gear 4. The journal 12 sits in a recess 22, which forms the bearing point for the differential gear 2 of the differential gears 2 and 3. The recess 22 is closed axially by one of the flange sections 23 or 24 of the respective cover 5 or 13, so that the journal 12 is held and guided axially in the flange 10. For this purpose, the covers 5 and 13 with the flange sections 23 and 24 lie flat against the flange 10 and are welded-connected to the drive wheel 4 via the material-bonded connections 11.The recesses 22 and the parts of the flange sections 23 and 24 that cover the respective recesses 22 each form one of the bearing points 8 or 9.

[0015] The fully assembled differential 1 is a unit 25 consisting of the drive gear 4, the compensating gears 2 and 3, the covers 5 and 13, the bolt 15 and two output gears 16, which is held together in a self-supporting manner only by the material connection(s) without the aid of other fastening means. Reference symbol list 1 Differential 2 compensating gear 3 Compensating wheel 4 drive wheel 5 lids 6 Rotation axis of the differential 7 Gearing 8 storage location 9 storage location 10 Flange 11. material-bonded connection 12 cones 13 lids 14 cones 15 bolts 16 Output gear 17 Rotation axis of the compensating wheel 18 shaft 19 shaft 20 holes 21 Basic shapes 22 Exclusion 23 Flange section of the cover 5 24 Flange section of a cover 13 25 units

Claims

Differential (1) with differential gears (2, 3), a drive gear (4) and with at least one cover (5, 13), wherein: - the drive gear (4) has a toothed section (7) extending circumferentially around an axis of rotation (6) on the outside and is provided with bearing points (8, 9) on the inside; - the differential gears (2, 3) are mounted in the drive gear (4) at the bearing points (8, 9); and - the differential (1) is closed on one side with the cover (5, 13), wherein the differential gears (2, 3) are held in the drive gear (4) by means of the cover (5, 13); and that the cover (5, 13) and the drive gear (4) are attached to one another without the use of any further fastening means solely by a material-fit connection (11) such that at least the differential (1) formed from the differential gears (2, 3), the drive gear (4) and the cover (5, 13) has a a self-supporting unit (25), wherein the material-bonded connection (11) is a welded joint between two metallic materials,and the compensating gears (2, 3) are each rotatably mounted with a pin (12, 14) in the drive gear (4), wherein the covers (5, 13) are manufactured as drawn parts from sheet metal and the welded joint is a circumferentially closed welded joint. Differential (1) according to claim 1, characterized in that the drive wheel (4) has a flange (10), wherein the flange (10) is provided with the bearing points (8, 9) and that the cover (5, 13) rests against the flange (10). Differential (1) according to claim 1, characterized in that the differential (1) is closed by two of the covers (5, 13). Differential (1) according to claim 3, characterized in that the covers (5, 13) are identical parts. Differential according to claim 1, characterized in that the pins (12, 14) are formed on a bolt (15) common to the compensating gears (2, 3), wherein the bolt (15) is supported in the bearing points (2, 3) by means of the pins (12, 14). Differential (1) according to one of the preceding claims, characterized in that the differential (1) has at least one output gear (16) which engages in tooth mesh with the compensating gears (2, 3), wherein the output gear (16) is part of the self-supporting unit (20). Differential (1) according to one of the preceding claims 1 or 2, characterized in that the differential (1) has at least one output gear (16) which engages with the compensating gears (2, 3) and is mounted in the cover (5).

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