Method for assembling a differential arrangement with switching and locking function using a single ball ramp

Abstract

Drive arrangement (2) comprising a differential (1) with a rotary axis A, an input and two outputs connected to the input via side shaft gears (28); a controllable engagement clutch for connecting the differential (1) to a drive source; a controllable locking clutch for locking the compensating movement between the two outputs of the differential; wherein the engagement clutch and the locking clutch are arranged coaxially to the rotary axis A, at one of the outputs, characterized in that the engagement clutch and the locking clutch are each constructed as jaw clutches with coaxially nested sleeves.

Description

[0001] The invention relates to a method for assembling a drive arrangement, more precisely a differential arrangement comprising a differential with a rotational axis A, an input and two outputs drivingly connected to the input via sideshaft gears; a controllable engagement clutch for drivingly connecting the differential to a drive source; a controllable locking clutch for locking the compensating movement between the two outputs of the differential; wherein the engagement clutch and the locking clutch are arranged coaxially to the rotational axis A, at one of the outputs. State of the art

[0002] DE 10 2008 063 904 B4 shows a drive arrangement that incorporates two functionalities, namely the engagement of a secondary drive train and the locking of the compensating movement of the differential unit, while having a compact design. Because the engagement clutch and the locking clutch are arranged coaxially to each other or to the differential unit, both clutches can be actuated by means of a single actuator. In this respect, the drive arrangement requires relatively few components, which has a positive effect on the overall volume and manufacturing costs. However, it is also possible for a first actuator to be provided for the engagement clutch and a separate second actuator for the locking clutch. In this case, the engagement clutch is represented by a multi-plate clutch, while the locking clutch can be a dog clutch.

[0003] A further advantage of such a drive arrangement is that the bevel gear, which transfers torque from the longitudinal drive shaft to the differential, remains stationary when the clutch is disengaged. This reduces bearing rotation losses in the ring gear and drive pinion bearings, which are typically subject to high forces. Furthermore, churning losses caused by the ring gear rotating around its axis are avoided, which in turn has a positive effect on the vehicle's fuel consumption.

[0004] DE 11 2017 004 344 T5 proposes an axle deactivation and differential locking system for a vehicle using a sliding sleeve. The sliding sleeve has a plurality of splines extending from an inner surface of the sliding sleeve and further has a plurality of clutch teeth extending axially outward from one end of the sliding sleeve. The sliding sleeve slidably engages an axle half-shaft having a plurality of splines extending from the outer surface of the axle half-shaft and complementary to and interlocking with the plurality of splines on the inner surface of the sliding sleeve. One end of a differential side gear is then rotatably connected to one end of the axle half-shaft. A plurality of splines extend from the outer surface of the end of the differential side gear connected to the axle half-shaft.A differential case having a plurality of clutch teeth extending axially outward from one end of the differential case surrounds the differential axle gear.

[0005] To drive the sliding sleeve to selectively engage the differential housing or the differential side gear and the differential housing, the outer surface of the sliding sleeve is drivingly connected to one end of a shift fork. The shift fork, in turn, is driven by an actuator connected to a shift shaft, which in turn is connected to one end of the shift fork opposite the sliding sleeve.

[0006] EP 1 860 344 A1 discloses a differential gear system with a three-stage control device comprising a left shaft, a right shaft, and a planetary gear carrier arranged between the left and right shafts. A locking device is provided with a central holding section located within the planetary gear carrier between a left gear and a right gear to allow space-saving installation of the locking device. An axial movement of a single element effects the "on," "off," and "lock" functions of the differential gear system.

[0007] According to WO 2016 / 018 203 A1, a vehicle axle drive unit assembly comprises a differential and a torque distribution device. The differential includes a differential housing and a differential gear set housed in the differential housing. The torque distribution device transmits torque between the differential gear set and a sideshaft of the vehicle and may include a clutch and an actuator assembly. The actuator assembly includes an actuator and a clutch driven by the actuator.The clutch is selectively moved by the actuator to a first position in which the sideshaft is disconnected from the differential and not actively driven, to a second position in which the sideshaft is coupled to the differential gear set, to a third position in which the sideshaft is coupled to the differential housing, and to a fourth position in which the clutch actuates the clutch to couple the sideshaft to the differential gear set.

[0008] The object of the invention is to propose a drive arrangement with a differential arrangement which represents a simplified solution and is very easy to assemble. Description of the invention

[0009] The object is achieved by a method for assembling a drive arrangement according to claim 1.

[0010] A further development of the method is the subject of the subclaims.

[0011] The object is also achieved by a method for assembling a drive arrangement with the steps, a) wherein a first assembly unit with the locking sleeve with a toothing is placed on the connecting / separating sleeve and the sleeves are inserted into a housing part which is enclosed by a ball bearing ring, b) a second assembly unit is provided with the outer piston ring and a spring platform and a ball bearing as well as spring assemblies, c) a third assembly unit is constructed with the inner piston ring with ball bearing and snap ring, d) then the first assembly unit is connected to the second assembly unit, e) the package of the two first and second assembly units is welded to the differential housing, f) the third assembly unit as well as a wave spring and the ball ramp unit are mounted, g) and a side shaft is inserted into the connecting / separating sleeve.

[0012] Steps e) and f) in the process can be swapped.

[0013] The drive arrangement comprises a differential with a rotational axis A, an input and two outputs drivingly connected to the input via sideshaft gears; a controllable clutch for drivingly connecting the differential to a drive source; a controllable locking clutch for locking the compensating movement between the two outputs of the differential; wherein the clutch and the locking clutch are arranged coaxially to the rotational axis A, at one of the outputs, wherein the clutch and the locking clutch are each constructed as claw clutches with coaxially inserted sleeves.

[0014] The circuit arrangement for the drive arrangement has a modular design, with a first assembly unit with the sleeves, a second assembly unit for an outer piston ring, and a third assembly unit for an inner engagement sleeve being prefabricated.

[0015] This design offers simpler assembly, as it only takes place from one side, as well as cost and space advantages. The sleeves are each part of the coupling partners.

[0016] The engagement clutch and the locking clutch can be actuated by a single actuator. By using one actuator and a two-stage ball ramp design, for example, both one actuator and two position sensors can be eliminated, since the ball ramp actuation provides a rotation angle and thus position information.

[0017] The locking coupling is constructed with a locking sleeve with teeth and a connecting / disconnecting sleeve with teeth.

[0018] The clutch is constructed with a connecting / disconnecting sleeve with teeth and a sideshaft gear.

[0019] The actuator operates a ball ramp arrangement which is used to engage the engagement clutch and the locking clutch. Description of the characters Fig. 1 shows a section through the drive arrangement, Fig. 2 shows a section through a first assembly unit, Fig. 3 shows a section through a second assembly unit, Fig. 4 shows a section through a third assembly unit, Fig. 5 shows a section of the assembly of the first and second assembly units, Fig. 6 shows in section the assembly of the first, second and third assembly units, Fig. 7 shows in a spatial view the connection of the mounting units with the housing, Fig.8 also shows the section of the attachment of the ball ramp unit, Fig. Figure 9 shows a cross-section of the installation of the sideshaft.

[0020] Fig. 1 shows a drive arrangement 2 according to the invention. The drive arrangement 2 comprises a differential 1, a clutch which can engage the drive axle located behind it in the torque flow as needed, and a locking clutch for locking the compensating movement of the differential 1 as needed. Both the locking clutch and the clutch are actuated by a single actuator (not shown).

[0021] The drive assembly 2 comprises a ring gear 27, via which torque can be introduced into the drive assembly 2 by means of a pinion (not shown here). The ring gear 27 is fixedly connected to a flange and is rotatably mounted about a rotational axis A in a differential housing 3 of the drive assembly 2 via bearing means. The ring gear and other components of the differential represent the input of the differential. The drive energy from any drive source, whether electric motor or internal combustion engine, is divided into two outputs in the differential, with the torque always being equal at both outputs. The sideshaft gears are considered the outputs.

[0022] A further housing part 3a comprises a connecting / separating sleeve 7, which is designed as a hollow shaft and which has a toothing 7a at its end facing the differential unit 1, into which a correspondingly opposite toothing of a side output gear on the differential 1, see Fig. 8, engages to transmit torque when the clutch is engaged.

[0023] In a differential carrier, differential gears are rotatably mounted on pins and rotate together with the differential carrier around the rotation axis A. The differential gears mesh with sideshaft gears 28.

[0024] The connecting / separating sleeve 7 has a bore with a longitudinal toothing 20, into which an associated side shaft 18, of which only the right side shaft 18 is shown here, is inserted for torque transmission.

[0025] The connecting / separating sleeve 7 is encompassed by a locking sleeve 6, which has a toothing 6a arranged on the front side on a flange 6b in the direction of the differential.

[0026] This toothing 6a can engage with a toothing 7b of the connection-separating sleeve 7, which is also applied to a flange 7c.

[0027] When assembling the components to form a first assembly unit SA1, the locking sleeve 6 is pushed onto the connection-separation sleeve 7, which in turn is inserted into the housing part 3a.

[0028] A bearing ring 4 is placed on the stepped outer diameter of the housing part 3a in this embodiment, which bearing ring rests against one end face of a step and is fastened with a snap ring 5.

[0029] Fig. Figure 3 shows the structure of a second assembly unit SA2. An outer engagement sleeve, a piston ring 8, has an annular inner web 8a. An annular ball bearing 9 is inserted into the outer piston ring 8 and brought to a stop against the web 8a.

[0030] A spring platform 10 surrounds the outer piston ring 8 and, via a flange 10a with a reduced-radius opening, holds the ball bearing 9 on the outer piston ring 8. The spring platform 10 has spring retainers 10b, which are designed as cylindrical spring retainers 10b with a central pin 10c. Spring assemblies 11 are inserted into the spring retainers 10.

[0031] Fig. 4 shows the structure of a third assembly unit SA3.

[0032] An annular ball bearing 13 is inserted into an inner piston ring 12 and supported on an edge 12a. The ball bearing 13 is held by a snap ring 14, which is inserted into a groove 12b of the inner piston ring 12.

[0033] Fig. 5 shows the assembly of the assembly units SA1 and SA2.

[0034] The pre-installed SA2 unit is pushed onto the locking sleeve 6. This has a step 6d on its outer circumference. The end face of the step serves as a stop for the ball bearing 9 located in the outer piston ring. The locking sleeve 6 has a circumferential annular groove 6e into which a snap ring 15 is inserted, connecting the two assembly units.

[0035] In the Fig. Figure 7 explains the next assembly step. In this step, the two housing parts, the differential housing 3 and the housing part 3a, are welded together so that the connecting / separating sleeve 7 is aligned with the sideshaft gear 28 of the differential 1.

[0036] Once the components are welded, the wave springs 16 are inserted into the outer piston ring 8 and the ball ramp arrangement 17 is attached.

[0037] The ball ramp arrangement 17 has an axially supported support disc 17a and an axially movable adjusting disc 17b, wherein the adjusting disc 17b is axially displaceable by relative rotation of the two discs relative to one another. The two discs are each provided with ball grooves of variable depth around their circumference, in which balls are received, wherein the two discs are axially supported relative to one another via the balls. The ball grooves of the two discs are designed such that the engagement clutch is actuated by relative rotation in one direction of rotation, and further rotation of the two discs additionally actuates the locking clutch.

[0038] In a final assembly step, as shown in Fig. 9, the side shaft 18 is inserted into the connecting / separating sleeve 7. The side shaft 18 carries an external toothing that meshes with the longitudinal toothing 20 of the connecting / separating sleeve 7.

[0039] Due to the combined coupling approach, it is only possible to perform the functions sequentially, namely: function Path (start: 0 mm) Path (position 1: x mm) Path (position 2: x+y mm) Clutch Open Closed Closed Locking clutch Open Open Closed

[0040] The connecting / disconnecting sleeve 7 is moved toward or separated from the sideshaft gear 28. If the connecting / disconnecting sleeve 7 is connected, the locking sleeve 6 can switch. However, if the connecting / disconnecting sleeve 7 is disconnected, locking via the locking sleeve 6 is not possible. Reference symbol 1 differential 2 Drive arrangement 3 Differential housing 3a Housing part 4 bearing ring 5 clamping ring 6 locking sleeve 6a Gearing 6b Flange 6d level 6th groove 7 Connecting / separating sleeve 7a, 7b Gearing 7c flange 8 outer piston ring 8a footbridge 9 ball bearings 10 spring platform 10a flange 10b Spring holder 10c Central Spine 11 spring package 12 inner piston ring 12a edge 12b groove 13 ball bearings 14 snap ring 15 snap ring 16 Wave spring 17 Ball ramp arrangement 17b Adjusting disc 17a Support disc 18 Wave 20 Longitudinal toothing 27 Ring gear 28 sideshaft gears

Claims

[1] Method for assembling a drive arrangement (2) comprising a differential (1) with a rotational axis (A), an input and two outputs drivingly connected to the input via sideshaft gears (28); a controllable clutch for drivingly connecting the differential (1) to a drive source; a controllable locking clutch for locking the compensating movement between the two outputs of the differential (1); wherein the clutch and the locking clutch are arranged coaxially to the rotational axis (A) at one of the outputs, characterized bythat the engagement clutch and the locking clutch are each constructed as claw clutches with coaxially inserted sleeves, wherein the locking clutch is constructed with a locking sleeve (6) with a toothing (6a) and a connecting / disconnecting sleeve (7) with toothing (7b) and the engagement clutch is constructed with a connecting / disconnecting sleeve (7) with toothing (7b) and a sideshaft gear (28) with corresponding toothing and wherein the circuit arrangement for the drive arrangement (1) is of modular construction and a first assembly unit (SA1) with the sleeves, a second assembly unit (SA2) for an outer piston ring, a third assembly unit (SA3) for an inner piston ring are prefabricated, wherein a) the first assembly unit (SA1) with the locking sleeve (6) with a toothing (6a) is placed on a connecting / separating sleeve (7) and the sleeves are inserted into a housing part (3a) which is enclosed by a ball bearing ring (4), b) a second assembly unit (SA2) is provided with an outer piston ring (8) and a spring platform (10) and a ball bearing (9) as well as spring assemblies (11), c) a third assembly unit (SA2) is constructed with an inner piston ring (12) with ball bearing (13) and snap ring (14), d) then the first assembly unit (SA1) is connected to the second assembly unit (SA2), e) the package of the two first and second assembly units (SA1, SA2) is welded to the housing part (3a) with the differential housing (3), f) the third assembly unit (SA3) as well as a wave spring (16) and a ball ramp unit (17) are mounted, g) and a side shaft (18) is inserted into the connecting / separating sleeve (7). [2] Method for assembling a drive arrangement (2) according to claim 1, characterized by that the engagement clutch and the locking clutch can be operated by a single actuator. [3] Method for assembling a drive arrangement (2) according to one of the preceding claims, characterized by that the actuator actuates the ball ramp arrangement (17) which serves to engage the engagement clutch and the locking clutch. [4] Method for assembling a drive arrangement (2) according to one of claims 1 to 3, wherein steps e) and f) are interchanged in the sequence.

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