DE102005007726B4 - Compensation and transfer case with active lock - Google Patents

Abstract

Compensating and transfer case for a motor vehicle, with a locking value of the transmission affecting active lock for setting the blocking value, the
A drive basket (1),
• a first output shaft (2) and
A second output shaft (3)
wherein the active lock of at least one actuator (5) and at least one, via the actuator (5) by applying a compressive force switchable clutch (4) is formed and the clutch (4) with the first output shaft (2) and the second Has output shaft (3) rotatably connected clutch plates, on whose compressed active surfaces, the coupling forces are transferable, and wherein the clutch (4) at least one further rotatably connected to the drive cage (1) and slidable in the direction of the clutch plates force introduction lamination (6) and the Actuator (5) capable of applying the pressure force on the force introduction blade (6), characterized in that
the force introduction lamella (6) is designed as an inner lamella or as an outer lamella.

Description

The The invention relates to a balancing and transfer case for a motor vehicle, with an active value influencing a locking value of the transmission Lock for setting the lock value, the transmission has a Drive basket, a first output shaft and a second output shaft having. The active lock is provided by at least one actuator and at least one, over the actuator by applying a compressive force switchable coupling educated. The clutch has with the first output shaft and the second output shaft rotatably connected clutch plates on the compressed active surfaces the coupling forces are transferable, and wherein the coupling at least one further, rotatably with the Drive basket connected and slidable in the direction of the clutch plates force introduction lamella and the actuator has the compressive force on the force introduction lamella can raise.

such Gearboxes are used as balancing or transfer cases in motor vehicle construction as a transverse or longitudinal compensation the different rotational speeds of the individual wheels when cornering used to avoid tension in the drive train. she Furthermore serve the targeted drive force distribution to individual Drive wheels. The Speeds of the drive wheels can independently with the help of these gearboxes the different path lengths set the individual lanes, with the drive torque ideal Symmetrical way and thus free of momentum transmitted to the individual wheels. One over The input power applied to the drive basket is thereby reduced to usually transmitted two output shafts. When driving straight ahead that runs Gearbox in block and the speeds and moments of the two output shafts and the drive basket are identical.

Usual applications therefor For example, differential gear between wheels of the same Axis (transverse compensation). For several driven axles, such as the 4-wheel drive, this type of gearbox are also the different Speeds of the drive wheels balanced between different axes (longitudinal compensation). Furthermore Transfer boxes are becoming increasingly important, especially for several driven axles the driving force in a defined ratio distribute the axes to be driven. Most common executions are bevel gear differentials, spur gear differentials, in particular in planetary construction, or worm wheel differentials.

By the provision of a barrier overcomes the major drawback of this transmission namely without a planned blocking effect at different traction potentials the driven wheels the height of the transferable to the output shafts Torque directed to the drive wheel with the lower traction potential. When spinning a drive wheel is thus on the other Drive wheel transferable Moment extremely low. Through the lock can now be achieved that this compensation movement is hampered and the moment that is on the drive wheel with the higher one Traction potential is transferable is increased. The degree of disability of this compensation movement is the lock value, between 0 and 0% (lossless, non-locking differential gear) and 1 or 100% (rigid drive) can be.

nowadays are a variety of systems with different principles of action and lock values known. In modern transmissions of the aforementioned Type locks are provided, the lock value electronically controlled is and the over Actuators depending on the driving situation very fast and independent of Differential speeds of individual wheels can be optimally adjusted at any time.

Also can the occurrence of disturbances, the through the intervention of modern control systems such as ABS or ESP in the drive train can be caused be prevented. These active locking systems also win in In terms of driving dynamics more and more important, as they are a good possibility offer, the distribution of the driving forces on the individual drive wheels optimally adapt to the driving condition and the traction potential of the individual drive wheels and thus positively influence the driving dynamics and driving safety.

When Locks are couplings common, whose clutch plates are arranged so that they the compensatory movements hinder. In the arrangement of the clutch plates different essentially two types. In the shaft-basket arrangement are the Clutch plates of a clutch side arranged on the drive basket, the the other coupling side on one of the output shafts. At a classic bevel gear differential, for example, with a so-called Slit viscous clutch, forms the differential carrier as drive basket So an outer plate carrier, a the output shafts, however, the inner disk carrier. In the so-called wave-wave arrangement On the other hand, the clutch plates are rotationally fixed to the output shafts connected.

The main difference between the shaft-basket and the shaft-shaft arrangement is that in the shaft-basket arrangement, the differential speed between the clutch input side and clutch output side in amount only half as large as the speed difference between the Ab drive shafts. Further, due to the branching of the torque transmitted in the clutch directly from the drive basket, the torque difference in the shaft-basket assembly applied to the wheels is only half that of the shaft-shaft assembly. Therefore, in the shaft-basket assembly to achieve the same blocking value a much higher clutch identifier is required. Since the control behavior of clutches also deteriorates with lower peripheral speed (transition between static friction and sliding friction), a shaft-shaft arrangement is also desirable from a control engineering point of view.

The Application of a passive, that is not externally externally switched Lock, does not make big Problems, because here is the clutch inside the differential carrier arranged and it must no powers an actuator, for example by serving as a drive basket, rotating differential cage through, are routed to the clutch. With an active lock this is necessary. There must be sealing measures provided between rotating parts and taken precautions which are the differential speeds between different parts of the actuator, which can either be arranged stationary or rotate with the drive basket or the output shafts, compensate.

at The wave-wave arrangement is made more difficult, that not just the ones mentioned above Differential speeds between the stationary and the with must be compensated for the drive basket rotating parts of the actuator, but that in addition still a speed difference between the drive basket and the clutch plates, because the output shafts, and thus also the rotatably arranged clutch plates, rotate at speed compensation between the output shafts not with the Drive cage speed.

Therefore were earlier Compensation and transfer case with active lock often in the frame a shaft-basket assembly provided since the Antriebskorbseitigen Clutch plate by definition with drive basket speed rotate. For shaft-shaft arrangements are due to the structurally difficult situation rare systems been realized with active lock. However, it would be desirable to have an active lock to provide also in the shaft-shaft arrangement in a simple manner, to the advantages of such an arrangement with those of an active lock to connect more efficiently.

From the DE 43 12 145 A1 is a differential with a differential lock according to a shaft-shaft arrangement is known in which by a basket speed rotating force introduction blade in the form of a fixedly connected via webs with the drive basket pressure plate a multi-plate clutch is actuated. The webs thereby support the applied torque against the drive basket. The construction of the actuator with an actuation of the pressure plate on the projecting through the drive basket webs is complicated and requires a large amount of space. The webs as part of the actuator must also be dimensioned so that applied forces and moments can be safely dissipated. The webs must also penetrate the drive basket in such a way that the lubricant-containing space inside the drive basket is securely sealed to the outside.

task The invention is to a balance and transfer case with active lock, which requires less space and opposite leads the known systems to a cost advantage. In addition, it should be possible to the actuating device to be kept free of the occurring clutch torques.

Further should the invention as possible create a transmission that reduces efficiency with improved power density known solutions avoid and save components. The advantages of the shaft-wave solution should be largely under optimization of constructive designs remain.

These The object is achieved according to the invention in that the force introduction lamella as inner lamella or as outer lamella accomplished is.

The inventive arrangement allows a compensation or transfer case of the beginning provided type, which operates on the shaft-wave principle and in which an intervention for the operation a friction clutch through the drive basket is possible, without doing an extra Speed difference between the drive basket and the output shafts arranged to have to dispose of arranged clutch plates of the clutch. hereby can the advantages described are the shaft-shaft arrangement, whereby the ones mentioned above be avoided design structural difficulties.

If a rotationally fixed to the drive basket arranged clutch plate used as a force introduction blade, so used to transmit the actuation forces of the actuator to the clutch, there is no difference in speed between this force introduction plate and the parts of the actuator, which rotate at Anriebskorbdrehzahl. The speed difference now exists exclusively between the side facing away from the actuator of the force introduction plate and the adjacent to one of the output shafts rotationally fixed clutch plate le. Since this is preferably an already provided friction pairing of the coupling, the transmitting friction torque can be used simultaneously as a locking torque.

According to the invention Force introduction blade rotationally fixed and preferably in the direction of the coupling center axis axially displaceable connected to the drive basket. The force introduction blade is usually seen in the axial direction outer clutch plate be, whose actuator side facing the actuator cooperates, while the the actuator facing away from another, with one of the output shafts rotatably connected clutch plate acts.

So is usually a single, the actuator facing and with the drive basket rotatably connected force introduction lamella. Of course can Also several force introduction lamellae be provided with the Drive cage are rotatably connected, between these force introduction fins then one or more clutch plates may be provided can, which are non-rotatably connected to one of the output shafts.

The Lock the balancing or transfer case is inventively by formed an externally switched coupling. This can preferably a lamellae clutch, in particular a lamellar viscocoupling or be a cone clutch or a Konax coupling. It is at the active principle according to the invention in principle a range of couplings conceivable on a wide variety of physical Effects are based. This can In addition to hydraulic or hydrostatic clutches and electromagnetic Couplings, for example magnetic rotary field couplings or induction couplings, be.

at For example, a hydrostatic clutch could the primary or secondary side externally with a friction surface Be provided with the rotatably mounted on the drive basket clutch plate interacts.

A preferred embodiment of the invention provides that with the Drive basket non-rotatably connected force introduction blade of a friction element the coupling is formed. This will make the structure of the aktivern Lock further simplified. Furthermore, such a friction element is constructive of in front for it designed to interact with another friction element of the clutch, so that further constructive measures on this friction element Essentially unnecessary. About that In addition, a dual function of the force introduction blade is achieved, in which this one hand compensates for the speed difference and on the other hand effectively contributes to the locking torque.

Advantageous the invention is characterized in that the actuator with its essential components fixed in a transmission housing is, for example, in a cover of the transmission housing. The stationary arrangement of the actuator has the advantage that leads to the actuator via stationary arranged fasteners are possible, thereby consuming Sealing or contact measures be largely avoided between relatively movable components can. That's just action to compensate for the differential speed rotating drive basket and provide stationary actuator, for which simple mechanical measures are sufficient.

A Further embodiment of the invention provides that the actuator a preferably hydraulically actuated, arranged in the transmission housing Piston, which in turn acts against the clutch Pressure stamp actuated. A hydraulic system will be preferred here, as this is a compact and lightweight design allows and high powers allows. The active medium can also rela tively fed easily to the actuator can be. But there are also conceivable actuators, the electric motor or work electromagnetically, pneumatically or purely mechanically. The preferred embodiment will depend on the individual case of application. So is For example, in trucks it is conceivable that a pneumatic Actuator is preferable because a truck anyway on a pronounced Pneumatic circuit features. For the same reason, for example in an electric vehicle, an electromagnetic or an electromotive Actuator may be preferred.

Between the rotating with the drive basket components of the actuator, in particular the pressure stamps, and the fixedly arranged components of the actuator, in particular the piston is in a preferred embodiment the invention, a thrust bearing to compensate for the relative movement between provided these components.

A advantageous detail solution may for example provide that a bearing ring of the thrust bearing of in the gearbox arranged piston is formed and the other bearing ring on forms the coupling acting plunger. This is not only a compact design possible, in the case of an additional Component can be omitted, but can also be additional fixing measures for the Thrust bearings are dispensed with.

It is also advisable to arrange the force introduction lamella on the likewise non-rotatably arranged on the drive basket pressure punches. So form plunger and the force introduction lamella a compact unit that as a composite has good mechanical properties. As a result, it is unnecessary to take measures to arrange the force introduction blade directly to the drive basket, which may be desirable if necessary. In principle, therefore, the force introduction lamella can not only be arranged directly but also indirectly rotatably relative to the drive basket. Of particular importance is that speed and torque of the drive basket is transmitted to the force introduction blade.

It becomes explicit noted that the term drive basket in the sense of this Non-limiting application to understand. A drive basket in the context of the invention, everyone Be over the body the power required to drive the output shafts in the gear assembly can be brought. As mentioned, for example, is Under drive basket also a differential basket to understand. The same applies mutatis mutandis to the output shafts of the transmission.

alternative The actuator can also be arranged such that a relative movement in the direction of rotation between the actuator and the force introduction lamella does not occur. In this case, the actuator is thus in the direction of rotation moved with the force introduction blade and is via suitable Medium supplied with the adjusting force.

A preferred embodiment, for example, a hydraulic actuator have, from the outside can be acted upon with pressure. This is the pressure of an external Pressure line introduced into the inner disc carrier. The pressure line is then arranged with a on the inner disk carrier, as an actuator connected piston connected. To the rotational movement of the inner disk carrier relative to gearbox to be able to balance For example, in the inner disk carrier and the transmission housing respectively a ring-shaped Be arranged ring area, with the Druckzu- or -ableitungen communicates, with the two ring areas in each rotational position fluidly connected to each other are.

alternative In all embodiments, an electrically actuated actuator be provided, in which case the supply current via conventional means is transmitted to the actuator of the actuator. At relative moved to the gear housing Actuator can do this, for example, via a slip ring contact respectively.

Further Features and advantages of the invention will become apparent from the dependent claims and from the following description of preferred embodiments based on the drawings.

In the drawings shows:

1 an inventive limited slip differential for a transaxle,

2 the active lock with a friction clutch according to the axle after 1 in detail and

3 a further embodiment of a differential gear.

In 1 an inventive active locking differential for a axle drive is shown. The drive basket 1 is formed here by the differential carrier, which forms a non-rotatable unit at play with a conically toothed ring gear over which the drive power is introduced into the transmission. The differential carrier is rotatable about two bearings in a transmission housing 8th stored. This in 1 illustrated locking differential is exemplified here as Stirnraddifferential planetary design. A variant of this, for example as bevel gear differential or worm gear differential, is of course also possible.

Inside the differential carrier are a first output shaft 2 and a second output shaft 3 arranged, on which the power introduced into the transmission is distributed. Similar to a limited slip differential with passive lock acts through the clutch 4 exerted blocking effect between the first output shaft 2 and the second output shaft 3 , being used as a clutch 4 Here, purely by way of example, a multi-plate clutch is shown. Here is an outer disk carrier 13 with the first output shaft 2 and an inner disc carrier 12 with the second output shaft 3 connected. At the two plate carriers 12 . 13 Here are three clutch plates 6 the clutch 4 arranged. The illustrated balancing and transfer case thus operates at least also after the shaft-shaft system described above.

In order to achieve an influence on the blocking value of this multi-plate clutch is in the gearbox 8th a hydraulically powered actuator 5 intended. This one needs to go to the clutch 4 to be able to act forces through the drive basket 1 through to the coupling 4 transfer. Because the drive basket 1 however, relative to the transmission housing 8th rotates, is between the components of the actuator 5 a measure that compensates for this relative movement is necessary. In the embodiment shown is an example of a thrust bearing 10 intended.

The thrust bearing is between a hydraulically actuated piston, the rotationally fixed to the transmission housing 8th arranged and designed in the form of a piston ring and a pressure ring 14 putting in the drive basket 1 recessed plunger 9 acts, arranged. Rotate plunger 9 and pressure ring 14 with the drive basket 1 , The pressure ring is over a wavy ring spring 15 against the thrust bearing 10 employed and keeps the individual components in play-free plant.

Will the in the gearbox 8th located oil pressure chamber 16 pressurized oil, the piston pushes over the thrust bearing 10 against the pressure ring 14 and the printing stamps 9 , To avoid being between plunger 9 and a clutch plate of the lock a further relative movement occurs is, as in particular also from 2 it can be seen in the coupling 4 the the printing stamp 9 facing clutch plate according to the invention as a force introduction lamella 6 educated. The force introduction lamella 6 is not on the outer or inner disk carrier 12 . 13 arranged, but rotatably with the drive basket 1 connected.

Between the force introduction lamella 6 and the printing stamp 9 So there is no difference speed. This is more likely between the pressure stamp 9 facing force introduction lamella 6 and the adjacent non-rotatably to the Innenlammelenträger 12 and the second output shaft 3 arranged balanced clutch plate. Thus, the takes over the pressure stamps 9 facing force introduction lamella 6 According to the invention, a dual function, because it not only takes over the compensation of the differential speed and the transmission of the coupling forces, but transmits simultaneously, as is the case with a shaft-basket arrangement, torque from the drive cage 1 on the clutch 4 and thus on the two output shafts 2 . 3 ,

In the example shown is a force introduction lamella 6 as outer disk rotatably to the drive basket 1 arranged. Depending on the desired blocking characteristic of the barrier or depending on the individual structural conditions to be found, other arrangements can also be selected. So that can be with the drive basket 1 non-rotatably connected power transmission plate 6 Also be designed as an inner plate, or there may be a plurality of power transmission fins 6 be provided, in turn, with a plurality of with one of the output shafts 2 or 3 rotatably connected clutch plates cooperate to reinforce, for example, the shaft-basket characteristics of this transmission according to the invention.

Basically Also, the number of clutch plates following the shaft shaft Principle work, according to the desired Direct the blocking characteristic of the balancing or transfer case.

To that of the actuator 5 on the lock and thus also on the first output shaft 2 or the second output shaft 3 To support applied forces is also support camp 11 provided, this example between the first output shaft 2 and the drive basket 1 is arranged. To the clutch forces bending moment-free on the clutch 4 To be able to transfer, are preferably a variety of printing stamps 9 arranged at a regular distance from each other about the coupling center axis.

In 3 a further embodiment of a transfer case is shown. Here is the relative movement between the as an actuator 5 used hydraulic piston and the force introduction lamella 6 thereby avoiding the actuator 5 fixed to the inner disk carrier 12 is arranged. Such an arrangement is particularly interesting for large transmissions of a vehicle, which already has a standard hydraulics, as is the case with trucks or agricultural machinery.

The actuator 5 is driven via a pressure line which is connected to an annular receiving channel in the inner disk carrier. This receiving channel corresponds to an adjacent, rotatable relative to him discharge channel in the transmission housing in which a pressure can be built up via a hydraulic pressure generator.

1

drive cage

2

First output shaft

3

Second output shaft

4

clutch

5

actuator

6

Force application Slam hurry

7

disk pack

8th

gearbox

9

plunger

10

thrust

11

support bearings

12

Inner disk carrier

13

External disk carrier

14

pressure ring

15

Ringfeder

16

Oil pressure chamber

Claims (12)

Compensating and transfer case for a motor vehicle, having an inhibiting value of the transmission influencing active lock for setting the blocking value, the • a drive basket ( 1 ), • a first output shaft ( 2 ) and • a second output shaft ( 3 ), wherein the active barrier of at least one actuator ( 5 ) and at least one, about the Ak tuator ( 5 ) by applying a compressive force switchable coupling ( 4 ) is formed and the coupling ( 4 ) with the first output shaft ( 2 ) and the second output shaft ( 3 ) rotatably connected clutch plates, on whose compressed active surfaces, the coupling forces are transferable, and wherein the clutch ( 4 ) at least one further, rotationally fixed to the drive basket ( 1 ) and slidable in the direction of the clutch plates force introduction lamella ( 6 ) and the actuator ( 5 ) the pressure force on the force introduction lamella ( 6 ), characterized in that the force introduction lamella ( 6 ) is designed as an inner plate or as an outer plate. Compensation and transfer case according to claim 1, characterized in that the clutch plates to at least one disc pack ( 7 ) and the actuator ( 5 ) next to the disk pack ( 7 ), wherein on the, the actuator ( 5 ) facing the end of the disk pack ( 7 ) at least one force introduction lamella ( 6 ) is arranged. Compensation and transfer case according to one of the two preceding claims, characterized in that the force introduction lamella ( 6 ) of a friction element of the clutch ( 4 ) is formed. Compensation and transfer case according to claim 1, characterized in that the actuator ( 5 ) has a piston / cylinder unit whose pressure force the actuator ( 5 ) on the force introduction lamella ( 6 ) can muster. Compensation and transfer case according to the preceding claim, characterized in that the drive basket ( 1 ) rotatably in a transmission housing ( 8th ) is mounted and the piston / cylinder unit on the transmission housing ( 8th ) is arranged and the actuator ( 5 ) the actuating force of the piston / cylinder unit on one of the drive basket ( 1 ) displaceably arranged in the direction of actuation plunger ( 9 ), wherein between the piston / cylinder unit and the plunger ( 9 ) a balancing warehouse ( 10 ) is arranged. Compensation and transfer case according to the preceding claim, characterized in that the compensating bearing ( 10 ) is a thrust bearing. Compensation and transfer case according to claim 6, characterized in that a first bearing ring of the thrust bearing ( 10 ) of which in the gearbox ( 8th ) arranged pressure piston is formed and a second bearing ring of the thrust bearing ( 10 ) of which on the clutch ( 4 ) acting plunger ( 9 ) is formed. Compensation and transfer case according to one of claims 5, 6 or 7, characterized in that the force introduction lamella ( 6 ) of the disc pack ( 7 ) facing side of the plunger ( 9 ) is formed. Compensation and transfer case according to one of claims 1 to 4, characterized in that the actuator ( 5 ) is arranged such that no relative movement in the direction of rotation between the actuator ( 5 ) and the force introduction blade ( 6 ) occurs. Compensating and transfer case according to claim 9, characterized in that the actuator ( 9 ) via a slip ring or a circumferential pressure channel with an actuating medium, in particular a hydraulic pressure or a supply voltage, can be supplied, from one to the drive basket ( 1 ) stationary Beaufschlagungsmittel with the actuating medium can be acted upon. Compensation and transfer case according to one of the preceding claims, characterized in that the actuator ( 5 ) is driven hydraulically or pneumatically or electromagnetically. Use of a coupling arrangement with a compensation Transfer case according to one of the preceding claims, for Coupling an auxiliary axis to a primary shaft.