Method for producing a differential assembly

Abstract

The invention relates to a method for producing a differential assembly (1, 1') having a toothed rim (2) and a two-part differential cage (3, 4, 5), wherein: the two parts (4, 5) of the differential cage (3) define, in a finished state of the differential assembly (1, 1'), a chamber (6) for receiving differential gearwheels; the toothed rim (2) is designed to be mounted on an outer circumference of the differential cage (3); and the method comprises first pressing together one part (4, 5) of the differential cage (3) and the toothed rim (2) and then fixedly connecting same to form an intermediate assembly, subsequently finishing a toothing of the toothed rim (2), and finally pressing together the other part (4, 5) of the differential cage (3) and the intermediate assembly and then fixedly connecting same.

Description

[0001] Method for manufacturing a differential assembly

[0002] Field of the invention

[0003] The present invention relates to methods for producing a differential assembly having a ring gear and a two-part differential carrier, wherein the two parts of the differential carrier define a chamber for receiving differential gears in a finished state of the differential assembly, and wherein the ring gear is designed for mounting on an outer circumference of the differential carrier.

[0004] State of the art

[0005] The design and function of differential assemblies are well known from the state of the art: when cornering, the outer wheels of a motor vehicle must travel a greater distance and thus rotate faster than the inner wheels. Likewise, road surface irregularities cause different rolling paths and, consequently, different rotational speeds of the wheels on a vehicle axle. To enable different rotational speeds of the wheels with minimal slippage and distortion, the wheels of a drive axle are typically connected to a drive element and to each other via an axle differential assembly.

[0006] The drive connection between the drive element and the differential assembly is established on the differential assembly side via a gear ring with corresponding teeth. Typically, the gear ring is manufactured by first forming the teeth of the gearing, which are then subjected to at least fine and / or final machining. However, during the assembly of the individual components of a differential assembly, radial runout deviations arise in the previously machined gear ring.

[0007] Summary of the invention

[0008] It is an object of the invention to provide an improved method for producing a differential assembly, which is characterized in particular by a low toothing deviation due to radial runout deviations in the gear ring.

[0009] This need can be met by the subject matter of the present invention according to independent claim 1. Advantageous embodiments of the present invention are described in the dependent claims.

[0010] A differential assembly manufactured by the method according to the invention comprises a ring gear and a two-part differential carrier.

[0011] In the finished state of the differential assembly, the two parts of the differential carrier define a chamber for accommodating differential gears.

[0012] The ring gear of the differential assembly is designed for mounting on an outer circumference of the differential carrier.

[0013] The method according to the invention for producing the differential assembly comprises at least the following steps, which essentially take place one after the other:

[0014] Pressing a part of the differential carrier onto the gear ring, Firmly connecting the part of the differential carrier pressed onto the gear ring to the gear ring to form an intermediate assembly, Finishing a toothing of the gear ring,

[0015] Pressing the further part of the differential carrier with the intermediate assembly,

[0016] Firmly connecting the further part of the differential carrier, which is pressed into the intermediate assembly, to the intermediate assembly.

[0017] It is understood that the inventive method for manufacturing the differential assembly, depending on the design of the differential assembly, also includes at least one cleaning step and an assembly step for inserting differential gears into the chamber defined by the differential cage. These steps can be integrated into the chronological sequence of the inventive method at any point, taking the design of the differential assembly into account.

[0018] The respective permanent connection can be achieved by welding or screwing. Other connection types that result in a respective permanent connection are also conceivable.

[0019] Preferably, the respective fixed connection is carried out by welding, namely by welding using a laser welding process.

[0020] Furthermore, the welding preferably creates an annular weld seam that is concentric with a central longitudinal axis of the differential assembly. The formation of a segmented weld seam, i.e., a weld seam that is not continuous all the way around, is also conceivable. Furthermore, the welding can be performed at any angle consistent with the process.

[0021] By means of the method according to the invention for producing a differential assembly, a process-stable concentricity in the toothing of the gear ring can be realized.

[0022] Brief description of the drawings

[0023] The invention is described below by way of example with reference to the drawings.

[0024] Fig. 1 shows a schematic sectional view of a first embodiment of a differential assembly.

[0025] Fig. 2 shows a schematic sectional view of a second embodiment of a differential assembly.

[0026] Detailed description of the invention

[0027] Fig. 1 and Fig. 2 each show an exemplary embodiment of a differential assembly 1, 1' in a sectional view.

[0028] Fig. 1 schematically shows a first embodiment of a differential assembly 1 in a sectional view. Fig. 2 schematically shows a second embodiment of a differential assembly 1' in a sectional view.

[0029] The two design variants of the differential assembly 1, 1' are essentially identical - they differ only in the respective design of a gear ring 2. The respective differential assembly 1, 1' comprises the gear ring 2 and a two-part differential carrier 3 - the differential carrier 3 has a housing 4 that is open on one side axially and a housing cover 5.

[0030] The direction indication “axial” essentially describes a direction along or parallel to a central longitudinal axis 9 of the respective differential assembly 1, 1'.

[0031] In the present embodiment, the housing 4 and the housing cover 5 represent the two parts of the differential carrier 3 and, in a finished state of the respective differential assembly 1, T, define a chamber 6 for receiving differential gears.

[0032] The ring gear 2 of the respective differential assembly 1, 1' is designed for mounting on an outer circumference of the differential carrier 3.

[0033] In the first embodiment of the differential assembly 1, the gear ring 2 is designed such that it completely axially covers a bolt opening 10 in the housing 4 of the differential carrier 3.

[0034] In the second embodiment of the differential assembly 1 ', the gear ring 2 is designed such that the bolt opening 10 in the housing 4 of the differential carrier 3 is not axially covered.

[0035] The method for producing the respective differential assembly 1, 1' comprises at least the following steps, which essentially take place one after the other:

[0036] Pressing the housing cover 5 with the gear ring 2, welding the housing cover 5 with the gear ring 2 to form an intermediate assembly “housing cover 5 / gear ring 2”, finishing a toothing of the gear ring 2,

[0037] Pressing the housing 4 with the intermediate assembly “housing cover 5 / gear ring 2”,

[0038] Welding the housing 4 with the intermediate assembly “housing cover 5 / gear ring 2”.

[0039] A weld seam is formed by welding, namely a first weld seam 7 when welding the housing cover 5 to the gear ring 2 and a second weld seam 8 when welding the housing 4 to the intermediate assembly “housing cover 5 / gear ring 2”.

[0040] The first weld seam 7 and the second weld seam 8 are each annular and concentric to the central longitudinal axis 9 of the differential assembly 1.

[0041] In the second embodiment of the differential assembly 1 ', its design also allows a "reverse" process, namely a process with the following steps, which essentially take place one after the other:

[0042] Pressing the housing 4 with the gear ring 2,

[0043] Welding the housing 4 with the gear ring 2 to form an intermediate assembly “housing 4 / gear ring 2”, finishing a toothing of the gear ring 2,

[0044] Pressing the housing cover 5 with the intermediate assembly “Housing 4 / Gear ring 2”,

[0045] Welding the housing cover to the intermediate assembly "Housing 4 / Gear Ring 2". List of reference symbols, 1' Differential assembly

[0046] sprocket

[0047] differential cage

[0048] Housing

[0049] Housing cover

[0050] chamber

[0051] First weld

[0052] Second weld

[0053] Central longitudinal axis 0 bolt opening

Claims

Patent claims 1. A method for producing a differential assembly (1, T) with a gear ring (2) and a two-part differential carrier (3, 4, 5), wherein the two parts (4, 5) of the differential carrier (3) define a chamber (6) for receiving differential gears in a finished state of the differential assembly (1, T), and wherein the gear ring (2) is designed for mounting on an outer circumference of the differential carrier (3), wherein the method first comprises pressing and then firmly connecting a part (4, 5) of the differential carrier (3) to the gear ring (2) to form an intermediate assembly, then finishing a toothing of the gear ring (2) and finally pressing and then firmly connecting the further part (4, 5) of the differential carrier (3) to the intermediate assembly.

2. Method according to claim 1, characterized in that the respective fixed connection is carried out by welding or screwing.

3. Method according to claim 2, characterized in that the welding is carried out by means of a laser welding process.

4. Method according to claim 2 or 3, characterized in that an annular weld seam (7, 8) is formed via the welding, which is concentric to a central longitudinal axis (9) of the differential assembly (1, 1').

5. Method according to claim 2, 3 or 4, characterized in that the welding takes place at any angle.

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