DE102019100366A1 - Helical gear differential - Google Patents

Abstract

The invention relates to a differential gear, with a gear housing, a circulating housing which is arranged in the gear housing rotatably about a gear axis, a planet carrier arranged coaxially rotatably in the circulating housing with the gear axis, a first sun gear which is accommodated in the planet carrier, a second Sun gear, which is also accommodated in the planet carrier, a coupling planetary arrangement for counter-rotating coupling of the sun gears in the planet carrier, a coupling device with a coupling plate pack for generating a coupling torque coupling the planet carrier with the rotating housing, and an actuating mechanism for generating an axial force acting on the coupling plate pack, whereby the actuating mechanism 5 has a ramp ring RK1, rolling bodies ZR running thereon and a pressure reduction ring VR, the ramp ring RK1 forms axially positioned ramp surfaces RF and the ramp ring RK1 or the pressure drop ahmering VR are frictionally coupled to the planet carrier for common circulation with it. The coupling torque is coordinated in such a way that the actuation mechanism 5 is at least initially activated.

Description

Field of the Invention

The invention relates to a spur gear differential gear with a gear housing, a rotating housing which is rotatably mounted in the gear housing about a gear axis, and a planet carrier which is seated in the rotating housing, the spur gear differential branching the drive power applied to the rotating housing and the planet carrier and the circulation housing can be selectively coupled in a frictionally locking manner via a coupling device.

Background of the Invention

Differential gears are generally designed as epicyclic gears and are mainly used to branch or distribute an input power supplied via a power input to two drive shafts. Differential gears are most commonly used as so-called axle differential gears in automotive engineering. Here, the drive power provided by a drive motor is distributed to wheel drive shafts of driven vehicle wheels via the differential gear. The two wheel drive shafts leading to the vehicle wheels are each with the same torque i.e. balanced driven. When driving straight ahead, both vehicle wheels turn at the same speed. When cornering, the speeds of the vehicle wheels differ from one another. The axle differential gear enables this speed difference. The speeds can be set freely, but the average of the two speeds remains the same.

In certain applications, in particular in all-wheel drive vehicles, differential gears are used which, if no all-wheel drive is required, enable a switchable interruption of the drive train in order to drive the vehicle via only one axle and thereby reduce the frictional losses of the drive system that is not currently required and is otherwise carried along. A corresponding differential gear is, for example, from DE 10 2008 037 885 A1 or DE 10 2013 206 749 A1 known.

Object of the invention

The invention has for its object to provide a differential gear that enables a switchable cancellation of the drive connection between the power input and the two power outputs and is characterized by an advantageous mechanical operating behavior.

Solution according to the invention

• - einem Getriebegehäuse,
• - einem Umlaufgehäuse, das in dem Getriebegehäuse um eine Getriebeachse drehbar angeordnet ist,
• - einem in dem Umlaufgehäuse zur Getriebeachse gleichachsig drehbar angeordneten Planetenträger,
• - einem ersten Sonnenrad, das in dem Planetenträger aufgenommen ist,
• - einem zweiten Sonnenrad, das ebenfalls in dem Planetenträger aufgenommen ist,
• - einer Koppelplanetenanordnung zur gegensinnig drehbaren Kopplung der beiden Sonnenräder in dem Planetenträger,
• - einer ersten Kopplungseinrichtung mit einer ersten Koppellamellenpackung zur Generierung eines den Planetenträger mit dem Umlaufgehäuse koppelnden Kopplungsmomentes nach Maßgabe einer an der ersten Koppellamellenpackung angreifenden Axialkraft, und
• - einer Betätigungsmechanik zur Generierung der an der ersten Koppellamellenpackung angreifenden Axialkraft, wobei
• - die Betätigungsmechanik einen Rampenring, daran anlaufende Rollkörper und einen Druckabnahmering umfasst,
• - der Rampenring axial angestellte Rampenflächen bildet und
• - der Rampenring oder der Druckabnahmering mit dem Planetenträger zum gemeinsamen Umlauf mit diesem reibschlüssig drehbar gekoppelt sind und das Koppelmoment derart abgestimmt ist, dass damit zumindest ein initiales Aktivwerden der Betätigungsmechanik ermöglicht ist.

The above-mentioned object is achieved according to the invention by a differential gear with:

• - a gearbox,
• a circulation housing which is arranged in the transmission housing so as to be rotatable about a transmission axis,
• a planet carrier which is arranged in the revolving housing with respect to the gear axis and can be rotated coaxially
• a first sun gear which is received in the planet carrier,
• a second sun gear, which is also received in the planet carrier,
• a coupling planetary arrangement for coupling the two sun gears in the planet carrier rotatable in opposite directions,
• a first coupling device with a first coupling plate pack for generating a coupling torque coupling the planet carrier with the revolving housing in accordance with an axial force acting on the first coupling plate pack, and
• - An actuating mechanism for generating the axial force acting on the first coupling plate pack, wherein
• the actuating mechanism comprises a ramp ring, rolling bodies running thereon and a pressure reduction ring,
• - The ramp ring forms axially adjusted ramp surfaces and
• - The ramp ring or the pressure reduction ring are rotatably coupled to the planet carrier for common rotation with the latter and the coupling torque is coordinated in such a way that at least initial activation of the actuation mechanism is thereby made possible.

This advantageously makes it possible to create a differential gear in which the coupling device provided for transmitting the torque applied to the rotating housing to the planet carrier can be actuated by means of a ramp mechanism integrated into the rotating housing, with the pressure reduction ring or the ramp ring in a passive state the actuating mechanism is coupled to the planet carrier only to the extent of the frictional torque.

According to a particularly preferred embodiment of the invention, the frictional coupling is accomplished via a roller bearing. This roller bearing can in particular be designed as a needle bearing. The frictional torque of this roller bearing can then be brought about by constructive design thereof, in particular by designing the cage device, a sealing device and / or the lubricant filling. Furthermore, it is possible to bring about the frictional coupling by means of a slide bearing device or friction surface system which may be provided in addition to the roller bearing.

The actuating mechanism according to the invention is preferably designed in such a way that the pressure reduction ring is frictionally coupled to the planet carrier. The ramp ring can then, as will be deepened in the following, be fixed via a second coupling device, either on the circulating housing or also on the transmission housing.

In the actuation mechanism according to the invention, the pressure reduction ring is preferably guided so as to be axially displaceable relative to the planet carrier and thereby actuates the first coupling device with the force applied to it.

According to a particular aspect of the present invention, the coupling system provided for the frictional coupling of the pressure reduction ring or the ramp ring to the planet carrier can be designed such that, in the course of an axial load on the pressure reduction ring or the ramp ring, the coupling torque with which the pressure reduction ring or the ramp ring with the increases Planet carrier is coupled. For this purpose, for example, the friction surface system provided for the frictional coupling of the pressure reduction ring to the planet carrier can be designed in such a way that its frictional force transmission capacity increases with the displacement or loading of the pressure reduction ring.

The pressure reduction ring is also designed in accordance with a special aspect of the present invention in such a way that it forms a contact track which does not alternate axially in its course around the transmission axis and on which the rolling bodies run,

According to a particularly preferred embodiment of the invention, the contact track is designed as a flat annular disk surface. The rolling elements are then preferably designed as cylindrical rollers. The rolling elements can then contact both the ring disk surface and the ramp surfaces in each case by way of line contact.

As an alternative to the embodiment described above, it is also possible. The rolling elements are designed as balls, as tapered rollers or as barrel rollers. In the case of the rolling bodies being designed as balls, the contact track of the pressure reduction ring is preferably designed as a channel which faces the ramp ring with its open side. In the case of the rolling bodies being designed as tapered rollers, the contact track of the pressure reduction ring is preferably designed as a conical outer ring surface. In the case of the rolling elements being designed as barrels, the contact track is designed as a groove which is concavely curved in cross section.

The pressure ring and the ramp ring are preferably designed such that they form continuous shoulders in the circumferential direction, by means of which the rolling elements are held captively in the space defined between the ramp ring and the pressure ring. In addition, the rolling elements are preferably guided in a cage and are thus coupled to one another in such a way that all rolling elements move together in the circumferential direction on their ramps of the ramp ring. A reset function is preferably also implemented via the cage. For this purpose, the cage can be spring-supported in the circumferential direction, so that if no torque is transmitted via the rolling elements between the pressure ring and the ramp ring, the rolling elements are moved through the cage into a passive position on the ramp ring, i.e. pushed back or swung back into the ramp valleys.

The pressure reduction ring is frictionally coupled to the planet carrier as already explained above. This frictional coupling can be accomplished via friction contact surfaces which e.g. be pushed against corresponding counter surfaces with a spring mechanism. The frictional contact surfaces can in this case be connected to the planet carrier and circulate with it, or can also be coupled to a hub section of the pressure reduction ring and then move accordingly with this ring relative to the planet carrier.

The ramp ring is preferably designed in such a way that it has a hub section and can be coupled to the circulation housing or the gear housing via a second coupling device. The second coupling device preferably comprises a coupling plate pack with a set of coupling plates which are coupled in a rotationally fixed manner to the circulation housing or the transmission housing. This makes it possible to fix the ramp ring to the circulation housing via the second coupling device and to use the relative rotation between the planet carrier and the circulation housing for further activation of the ramp mechanism.

The second coupling plate pack preferably comprises first and second coupling plates, the first coupling plates being axially displaceable and non-rotatably coupled to the circulation housing and the second coupling plates to the Ramp ring are axially displaceably coupled in a rotationally fixed kinematic manner. The second coupling plates of the second coupling plate pack can also be guided axially displaceably on a bushing element, in which case the ramp ring preferably comprises a hub section which is axially immersed in the bushing element.

The first coupling plates of the second coupling plate pack are preferably also axially displaceably guided in a ring element, this ring element then preferably being anchored in a cover element of the circulating housing.

The second coupling plate pack is preferably actuated electromagnetically by a coil. By means of the magnetic field generated by means of this coil, the coupling plates of the coupling plate pack can be axially pressed together, so that a frictional torque is transmitted between subsequent first and second coupling plates. A pressure ring can also be pressed against the plate pack via the magnetic field.

The circulation housing is preferably mounted in the gear housing via a first and a second bearing device, the coil then being arranged in an area surrounded by the second bearing device according to a particularly preferred embodiment of the invention.

The circulating housing is preferably manufactured as a built structure and is composed of a first cover element, a pot housing and a second cover element, the second coupling plate pack then preferably being arranged in an area encompassed by the second cover element.

The second bearing device can advantageously be designed as a roller bearing, in particular as an angular contact ball bearing, in which case its outer bearing ring can then be accommodated in a bearing seat which is formed by the second cover element.

The second coupling plate pack is preferably accommodated in the second cover element, offset axially in the direction of the coupling planet, with respect to the second bearing device. The coil can then plunge axially into the second cover element and in this case into the area surrounded by the second bearing device.

The first coupling plate pack is preferably guided axially loadable between a hub-side inner plate seat and a housing-side outer plate seat. The planet carrier can be designed in such a way that at least a portion of the inner plate seat of the first coupling plate pack still captures the housing section of the planet carrier housing, which surrounds the coupling planet.

The differential gear according to the invention is preferably constructed in such a way that the housing section encompassing the coupling planet arrangement forms a cylinder wall that continues axially above the end face level of the coupling planet and the inner lamella seat of the first coupling clutch pack continues on this cylinder wall.

The first coupling plate pack can advantageously be constructed in such a way that it comprises inner coupling plates, outer coupling plates and a contact ring, the inner coupling plates on the inner plate seat being axially displaceable and in this case non-rotatably guided, the outer coupling plates on the outer plate seat being axially displaceable and are in turn and rotatably guided and the coupling lamella pack is supported on the ring on a ring step in the circulation housing.

The inner lamella seat can be formed directly by the planet carrier, or can also be formed by a bush-like component, for example axially internally and externally toothed, which is connected in a rotationally fixed manner to the planet carrier by means of teeth. The outer lamella seat is preferably formed by the circulation housing or likewise by a pot-like or bush-like component which is connected to the circulation housing in a rotationally fixed manner. If the lamella seats are provided by separate components, it becomes possible to design the geometries provided for guiding the lamellae within the framework of a manufacturing process that is decoupled from the manufacture of the planet carrier housing or the rotating housing. The ring-like, pot-like or bush-like parts can then be produced in particular as deep-drawn parts, and the corresponding geometries, in particular axial profiles, can then be produced in particular by means of forming technology.

According to a further aspect of the present invention, the differential gear is preferably constructed such that the outer plate seat of the first coupling plate pack still detects the axial level of the teeth of at least one of the two sun gears, ie the axial position of at least one plate still overlaps this axial level. The first coupling plate pack can then be plugged onto the largest area of the planet carrier housing in terms of its diameter and then sits at least partially on the outside cylindrical portion of the Planet carrier housing, which surrounds the coupling planet. The external toothing of the first coupling plate pack runs at a radial level which is even greater than the radial level of the cylindrical outer wall of the planet carrier housing, that is to say that section which surrounds the coupling planet. As soon as the first coupling plate pack is pushed onto the planet carrier housing, this coupling plate packing appears as a plate ring or stack of plates, which sits on the housing section of the planet carrier housing, which surrounds the coupling planet.

According to a further special aspect of the present invention, the coupling planets are preferably mounted radially in the planet carrier housing via their tip circular surfaces. The coupling planets are preferably supported axially in the planet carrier housing via their end faces. The coupling planets sit with slight axial play in the planet carrier housing and make no contribution to the transmission of any axial forces acting on the planet carrier housing.

The planetary arrangement is preferably designed in such a way that it comprises a plurality of coupling planets which, as such, are rotatable about planetary axes which are aligned parallel to the transmission axis. The first coupling plate pack is designed such that at least some of the coupling plates are at the axial level of the coupling planet.

According to a special aspect of the present invention, the circulating housing, which is rotatably mounted in the gear housing around the gear axis, is preferably designed as a multi-part, axially assembled pot housing. The planet carrier is rotatably mounted in the pot housing.

The differential gear according to the invention is furthermore advantageously designed such that the first coupling plate pack is composed of a plurality of coupling plates which are axially successively joined together as ring plates. These coupling plates can be designed as flat sheet steel washers, which may be coated with a friction material lining. The coupling plate pack can be constructed in such a way that it comprises inner coupling plates which are coupled kinematically to the planet carrier housing in a rotationally fixed but axially displaceable manner via an inner peripheral contour. Furthermore, the coupling plate pack then also comprises outer coupling plates, which are coupled kinematically to the rotating housing via an outer circumferential contour, but are axially displaceable.

The circulation housing provided for accommodating the planet carrier housing, already mentioned above, is preferably designed as a multi-part pot housing which is composed of a first cover element, a pot element and a second cover element which is axially attached to the pot element. The pot element forms an inner ring end face on which the coupling plate pack is axially supported.

The first coupling plate pack is preferably seated in the pot element and can be axially loaded via a mechanism accommodated in the circulating housing, in particular the second cover element, for axially pressing the coupling plate pack together. This mechanism comprises a rolling ramp mechanism in which rolling elements are supported between an adjusted ramp surface of the ramp ring and a non-axially alternating, ie continuous, axial structure of the pressure reduction ring.

An annular drive wheel is preferably attached to the circulating housing. The power is introduced into the circulating housing via this drive wheel. In conjunction with this drive wheel, an angular gear can also be implemented. This design is particularly suitable for use as a rear axle differential that can be temporarily deactivated. To connect the drive wheel, a flange structure is preferably used, which also serves for the connection, in particular the axial coupling of the first cover element to the cup element of the circulating housing.

Figure list

• 1 eine Axial-Halbschnittdarstellung, zur Veranschaulichung des Aufbaus eines erfindungsgemäßen Differentialgetriebes, bei welchem die Ankoppelung des Planetenträgers an ein diesen aufnehmendes Umlaufgehäuse über eine erste Koppellamellenpackung bewerkstelligt wird, die zwischen einem nabenseitigen inneren Lamellensitz und einem gehäuseseitigen äußeren Lamellensitz axial belastbar geführt ist, wobei die Aktuierung dieser Koppellamellenpackung durch eine Betätigungsmechanik erfolgt, die einen Druckabnahmering aufweist, der mit dem Planetenträger reibschlüssig gekoppelt ist, wobei das Koppelmoment so abgestimmt ist, dass dieses zumindest für eine initiale Aktivierung der Betätigungsmechanik ausreicht;
• 2 eine Detaildarstellung zur weiteren Veranschaulichung des Aufbaus der erfindungsgemäßen Betätigungsmechanik;
• 3 eine Detaildarstellung zur Veranschaulichung des Aufbaus des Rampenringes und des Druckabnahmeringes.

Further details and features of the invention will become apparent from the following description in conjunction with the drawing. It shows:

• 1 an axial half-sectional view to illustrate the structure of a differential gear according to the invention, in which the coupling of the planet carrier to a rotating housing receiving this is accomplished via a first coupling plate pack, which is axially resiliently guided between a hub-side inner plate seat and a housing-side outer plate seat, the actuation this coupling plate pack is carried out by an actuating mechanism which has a pressure reduction ring which is frictionally coupled to the planet carrier, the coupling torque being coordinated such that this is sufficient at least for an initial activation of the actuating mechanism;
• 2nd a detailed view to further illustrate the structure of the actuating mechanism according to the invention;
• 3rd a detailed view to illustrate the structure of the ramp ring and the pressure decrease ring.

Detailed description of the figures

The representation after 1 shows a differential gear according to the invention. This includes a gear housing, which is only indicated here G and a circulation housing U that in the gearbox G around a gear axis X is rotatably mounted. In the circulation housing U is a planet carrier 3rd recorded and rotatably mounted, which in turn to the gear axis X is arranged coaxially.

The differential gear further comprises a first output sun gear 1 , a second driven sun gear 2nd and one in the planet carrier 3rd recorded planetary arrangement P , for coupling the two driven sun gears in opposite directions 1 , 2nd . A first coupling device is located in the differential gear K1 as the first coupling lamella pack BLP1 is executed to generate a planet carrier 3rd with the circulation housing U selectively coupling coupling torque in accordance with a on the first coupling plate pack BLP1 attacking axial force.

This includes the planet carrier 3rd , the planetary arrangement P and the output sun gears 1 , 2nd Differential gear is formed as a spur gear differential with two output sun gears 1 , 2nd executed. The planetary arrangement P comprises several coupling planets P1 , P2 that have their tip circles in the planet carrier housing PG are stored.

The first coupling lamella pack BLP1 is integrated into the differential gear in such a way that the planet carrier is subjected to a corresponding axial load 3rd with the circulation housing U frictionally couples. This approach makes it possible to relieve the first coupling lamella pack BLP1 the drive connection between the planet carrier 3rd and the circulation housing U cancel, or by axially loading the first coupling plate pack BLP1 the planet carrier 3rd with the circulation housing U to couple frictionally. The first coupling lamella pack BLP1 is between a hub-side inner disk seat LS1 and a housing-side outer slat seat LS2 guided axially resilient.

The actuation of this first coupling lamella pack BLP1 takes place via the actuation mechanism 5 , which if necessary, on the first coupling lamella pack BLP1 attacking axial force generated. The actuation mechanism 5 has a second coupling lamella pack BLP2 on what second coupling louvers KL2a includes which with the circulation housing U are rotatably coupled.

The actuation mechanism 5 includes a ramp ring RK1 , rolling bodies running against it ZR and a pressure decrease ring VR . The ramp ring RK1 forms axially aligned ramp surfaces. The pressure decrease ring VR on the other hand forms a continuously non-axially alternating contact path on which the rolling elements ZR on their the ramp ring RK1 run away from the opposite side.

The through the pressure decrease ring VR The contact path formed here is designed as a flat annular disk surface and the rolling elements ZR are designed as cylindrical rollers. The cylindrical rollers ZR are arranged so that their central axes are the gear axis X cut and stand vertically on this.

In the embodiment shown here, the pressure decrease ring VR with the planet carrier 3rd for joint circulation with this frictionally coupled, the coupling torque being coordinated in such a way that an at least initial activation of the actuating mechanism is made possible. The frictional coupling is done here via a roller bearing N2 accomplished. The roller bearing N2 is designed as a needle bearing and the internal structure of this needle bearing is adjusted so that it generates a relatively high frictional torque. This is achieved through a narrow design of the cage and the sealing device. The pressure decrease ring VR is still opposite the planet carrier 3rd also guided axially displaceable.

This for the frictional coupling of the pressure reduction ring VR coupling system provided with the planet carrier - here the bearing N2 - Is designed in such a way that in the course of an axial load on the pressure reduction ring or the ramp ring, the coupling torque with which the pressure reduction ring increases VR or the ramp ring RK with the planet carrier 3rd is coupled.

Although not shown here, the rolling elements are ZR guided in a cage or guide structure and thus between the ramp ring RK1 and the pressure decrease ring VR kept captive. This cage also has a reset function for the rolling elements ZR realized.

The pressure decrease ring VR is in this embodiment with the planet carrier 3rd Coupled frictionally and guided axially displaceably on a hub portion of the planet carrier.

The ramp ring RK1 is designed such that it has a hub section and via the second coupling device seated on this hub section K2 with the circulation housing 3rd is selectively connectable.

In the actuating device according to the invention, the ramp contour is located on the “right” ramp disk, ie the ramp disk that is on the rotating housing 3rd via the second coupling device K2 is selectable. The right ramp disc is with the clutch open K2 freely rotatable. The left thrust washer, that is to say the pressure reduction ring which is at least initially only frictionally coupled to the planet carrier VR does not form a ramp contour and is so far plan. The pressure decrease ring VR is on the planet carrier 3rd guided axially displaceable. There is no ramp contour on the pressure reduction ring on the pressure disc on the main clutch side. This creates the cylindrical roller ZR on the thrust washer VR no more tangential force, just a rolling friction force in the circumferential direction. Thus, the positive connection between the thrust washer VR and differential housing 3rd are made significantly more filigree, which saves space, weight and costs. In addition, this version enables the interface between the differential housing to be loaded to a minimum 3rd and thrust washer VR Concepts that would not work or could not be integrated for larger loads due to installation space and dimensioning reasons.

The ramp ring RK1 is as stated above over the second coupling lamella pack BLP2 frictionally with the circulation housing U Can be coupled kinematically. The second coupling lamella pack BLP2 includes first and second coupling slats KL2a , KL2b , the first coupling lamellae KL2a axially displaceable and non-rotatable with the circulation housing U are coupled and the second coupling lamellae KL2b with the ramp ring RK1 axially displaceably coupled rotatably.

The second coupling slats KL2a the second coupling lamella pack BLP2 are on a socket element BE axially displaceable and the ramp ring RK1 includes a hub portion which fits into the sleeve member BE axially immersed.

The first coupling slats KL2a the second coupling lamella pack BLP2 are in a ring element RE guided axially displaceable. This ring element RE is in a cover element U2 of the circulation housing U anchored.

The second coupling lamella pack BLP2 is actuated electromagnetically by a coil HK. The circulation housing is as already mentioned above U via a first and a second storage device L1 , L2 in the gearbox G stored with the coil HK in one of the second storage facilities L2 bordered area is arranged.

The circulation housing U consists of a first cover element U1 , a pot housing U3 and a second cover element U3 together. The second coupling lamella pack BLP2 is in one of the second cover element U2 encompassed area arranged. Furthermore, the second storage facility L2 received in a bearing seat by the second cover element U2 is formed.

The second coupling lamella pack BLP2 is opposite the second storage facility L2 axially towards the coupling planet P offset in the second cover element U2 added. The sink HK is preferably arranged so that it axially into the second cover element U2 immersed.

The planet carrier 3rd is constructed in such a way that it is a planet carrier housing PG comprises one the coupling planetary arrangement P at the axial level of the two sun gears 1 , 2nd encompassing housing section PG1 and an axially adjoining hub section PGN includes. The inner slat seat LS1 axially covers both sections PG1 , PGN of the planet carrier housing PG . In the differential gear according to the invention, the first coupling plate pack is supported BLP1 via an investment ring AR axially on one shoulder US of the circulation housing U from.

The first coupling lamella pack BLP1 includes inner coupling plates LI , outer coupling plates LA and an attachment ring AR , with the inner coupling plates LI on the inner slat seat LS1 are axially guided, the outer coupling plates LA are guided axially on the outer plate seat and the first coupling plate pack BLP1 over the bearing ring AR on the shoulder US of the circulation housing U is present.

The inner slat seat LS1 is either directly through the planet carrier 3rd formed or as shown here by a bush-like component that with this planet carrier 3rd is rotatably connected. The outer slat seat LS2 is through the circulation housing U formed or also formed by a socket-like component that with the circulation housing U is connected in a rotationally fixed manner, for example via an axial toothing.

The axial position of the first coupling plate pack BLP1 is adjusted here so that the outer slat seat LS2 extends at an axial level, which with the axial region of the coupling planetary arrangement P at least partially overlapped.

The coupling planet P are radial in the planet carrier housing via their tip circular surfaces PG stored and over their end faces in the planet carrier housing PG axially supported.

The differential gear according to the invention is designed as a spur gear differential gear with coupled planetary coupling planets. The coupling planet P1 , P2 are over their tip circular surfaces in the planet carrier housing PG guided and do not need planet bolts. The coupling planet P1 , P2 have slight axial play in the area of their end faces and, apart from tooth reaction forces, are axially unloaded. The inside diameter of the main clutch BLP1 corresponds to the outer diameter of the differential case 3rd in the area around the coupling planet P1 , P2 . The flow of force of the axial contact pressure passes through the circulating housing when closed U , especially using the radial shoulder US as an axially supporting contact surface.

The storage of the circulation housing U in the gearbox G is a first and a second storage facility L1 , L2 accomplished. The first storage facility L1 comprises a first angular contact ball bearing, the second bearing device L2 includes a second angular contact ball bearing.

The planetary arrangement P comprises several coupling planets P1 , P2 that as such about planetary axes XP1 , XP2 are rotatable, parallel to the gear axis X are aligned. The coupling device K is designed such that the first coupling lamella pack BLP1 still partially at the axial level of the coupling planet P1 , P2 located.

In the differential gear according to the invention are the first coupling plate pack BLP1 and the planet carrier 3rd designed in such a way that the first coupling plate pack BLP1 on the section of the planet carrier 3rd with the largest outside diameter and also records the axial level of at least one of the sun gears - here S2. The one on the first coupling lamella pack BLP1 attacking axial force is bypassing the planet carrier housing PG from the circulation housing 3rd added.

The first coupling lamella pack BLP1 has a set of first ring-like coupling plates LI on that over an inner edge contour with the planet carrier 3rd axially displaceable, but non-rotatably engaged. The first coupling lamella pack BLP1 has a set of second coupling plates LA on that over an outer edge contour with the circulation housing U axially displaceable, but non-rotatably engaged. These coupling plates LI , LA are designed as flat sheet steel washers and are preferably coated with a friction material lining.

The axial support of the first coupling plate pack BLP1 on the circulation housing PG takes place with the inclusion of an investment ring AR that is on the ring end wall US of the circulation housing U supports. The planet carrier 3rd and the first coupling lamella pack BLP1 are tuned overall so that the inside diameter of a coupling plate LI , LA is larger than the diameter of the orbit area through which the coupling planets pass P1 , P2 move through when the planet carrier rotates.

That to take the planet carrier 3rd provided circulation housing U is designed as a multi-part pot housing and consists of a first cover element U1 , a second cover element U2 and a pot element U3 together, the pot element U3 the inner shoulder extending radially inward US forms on which the coupling lamella pack BLP axially supported. That shoulder US is at an axial level on which the teeth of the second sun gear are S2 extends.

The aforementioned first and second coupling planets P1 , P2 are in direct engagement with each other and are thus geared together so that they rotate in opposite directions. In this embodiment there are a total of three coupling planets P1 provided with the first driven sun gear 1 are engaged. This with the first output sun gear 1 engaged coupling planets P1 form a first coupling planetary set. Furthermore, in this exemplary embodiment there are a total of three coupling planets P2 provided with the second driven sun gear 2nd are engaged. This with the second output sun gear 2nd engaged coupling planets P2 form a second coupling planetary set. One coupling planet each P1 the first sentence stands with a coupling planet P2 of the second sentence. The intervention of the coupling planet P1 of the first sentence in the coupling planet P2 of the second sentence takes place in the same toothing plane as the engagement of the coupling planet P1 of the first set in the first driven sun gear 1 .

The first driven sun gear 1 and the second driven sun gear 2nd are coordinated with one another with regard to the toothing geometry such that the tip circle of the spur gear toothing 1a of the first driven sun gear 1 is smaller than the root circle of the output sun gear teeth 2a of the second driven sun gear 2nd . The coupling planet P1 of the first set engage in the area of the toothing plane of the first output sun gear 1 into the coupling planet P2 of the second sentence. The two output sun gears 1 , 2nd are therefore in the immediate vicinity.

The two output sun gears 1 , 2nd are designed such that the output sun gear teeth 1a of the first driven sun gear 1 and the output sun gear teeth 2a of the second driven sun gear 2nd have the same number of teeth. Also the coupling planet P1 of the first sentence and the coupling planet P2 of the second set preferably have the same number of teeth.

The drive power is introduced into the differential gear via the drive wheel 7 in the circulation housing U . About the first coupling lamella pack BLP1 the torque on the planet carrier housing PG transfer. About that in the planet carrier housing PG recorded coupling planet P1 , P2 there is a symmetrical torque distribution and power split on the output sun gears 1 , 2nd . The output sun gears 1 , 2nd have collar sections. The output sun gears 1 , 2nd are with internal teeth 1c , 2c Mistake. In this internal toothing 1c , 2c correspondingly complementary toothed end sections of wheel drive shafts or other power transfer components of the respective wheel drive train can be inserted. Instead of the internal toothing shown here, other connection geometries for torque transmission and centering of corresponding components are also possible.

The storage of the planet carrier 3rd in the circulation housing U takes place via a first needle bearing N1 . The storage of the circulation housing U in the gearbox G takes place via the angular contact ball bearings L1 , L2 . These angular contact ball bearings L1 , L2 also direct those on the drive wheel 7 attacking, radially and axially directed gear reaction force components in the gear housing G from. The warehouse N1 does not have to derive any axial forces. Main purpose of this camp N1 is the centering and bearing of the planet carrier 3rd in the circulation housing U .

The operation of the differential gear according to the invention is as follows: The drive wheel is via a gear wheel, not shown 7 driven. The drive wheel 7 is designed as a spur gear ring and rotatably on the circulation housing U fixed. Accordingly, the drive wheel 7 the circulation housing U spun. This circulation housing U is concentric to a gear axis X arranged and over the camp L1 , L2 rotatable in the gearbox G stored.

Together with the circulation housing U are also the coupling plate rings that are coupled in a rotationally fixed manner LA the first coupling lamella pack BLP1 spun. The coupling lamella pack BLP1 arrives when the actuating mechanism is activated 5 in a coupling state. The actuating mechanism 5 loads the first coupling plate pack in this embodiment BLP1 through the pressure ring DR and the ring plate AR in accordance with the by ramp mechanics RK generated axial force. The first coupling lamella pack BLP1 is thus brought into a coupling state in which the circulation housing U and the planet carrier 3rd are frictionally coupled. Inside the planet carrier 3rd there is a power split across the planets P1 , P2 on the output sun gears 1 , 2nd .

This here in the circulation housing U Reciprocating gearboxes, as already stated, form a spur gear differential. The first driven sun gear 1 has a toothing with a small tip circle. The second driven sun gear 2nd has a toothing with a large tip circle. The tip circle diameter of the first driven sun gear 1 and the theoretical foot circle of the second driven sun wheel 2nd correspond approximately to the identical pitch circle diameter. Both gears 1 , 2nd have the same number of teeth. The first driven sun gear 1 stands with the short coupling planet P1 engaged, the second output sun gear 2nd stands with the long coupling planet P2 engaged. The short coupling planet P1 have a large tip diameter. The long coupling planet P2 have a small tip diameter. The coupling planet P1 , P2 are engaged in pairs. The intervention takes place in the plane of engagement of the first coupling planet P1 in the first output sun gear 1 . The first coupling planet P1 have an axial length which is essentially the axial length of the toothing 1a of the first driven sun gear 1 corresponds. The second coupling planet P2 have an axial length which is essentially the sum of the axial lengths of the gears 1a , 2a both output sun gears 1 , 2nd corresponds.

The one to activate the ramp mechanics RK intended actuation mechanism 5 comprises a second lamella pack in this embodiment BLP2 which can either be brought into a coupling state actively, or from a defined relative rotation between the planet carrier housing PG and the circulation housing U becomes active and then a frictional torque on the ramp support RK1 the ramp mechanics RK transmits.

Activation of the ramp mechanics RK is done by increasing the transmission torque of the second coupling plate pack BLP2 . This is done here by controlling the coil device HK . When controlling the coil device HK is about the second coupling lamella pack BLP2 a torque on the hub portion of the axially profiled ramp ring RK1 transfer. The ramp ring RK1 is supported axially via a thrust bearing AX1 on one in the circulation housing U axially fixed ring AXR from.

The ramp ring RK1 forms an axially profiled ramp face. Support rollers are supported on this ZR axially. The support rollers ZR run on a flat ring surface of the axially displaceable pressure reduction ring VR . This pressure decrease ring VR is on the planet carrier 3rd guided axially displaceable, the guide is adjusted so that the pressure reduction ring VR in the circumferential direction with the planet carrier 3rd is coupled with a structurally coordinated friction torque that activates the ramp mechanism RK is sufficient. The pressure decrease ring VR is supported by a second thrust bearing AX2 on the pressure ring DR from. The ramp mechanics RK is designed in such a way that the torque required to activate it is smaller than that between the pressure reduction ring VR and the planet carrier 3rd frictionally transferable torque.

Activation of the second coupling plate pack BLP2 can be caused by external actuators, by electromagnetic means, or by friction phenomena within the coupling plate pack BLP2 take place, for example, at a design relative speed between the plates of the second coupling plate pack BLP2 occur and generate a corresponding torque.

In the exemplary embodiment shown here, the actuation of the second coupling lamella pack takes place via a coil device. This includes a coil HK . According to one over the coil HK the second coupling lamella pack BLP2 active and transmits a torque to the ramp ring RK1 .

In the exemplary embodiment shown here, the first and the second coupling plate pack are seated BLP1 , BLP2 axially sequential in the circulation housing U . The actuation mechanism 5 and the coil device HK are received axially in succession in a hollow cylinder space whose inner diameter is the root diameter of the second sun gear S2 and the outer diameter of the coupling plate pack BLP1 at the axial height of the second sun gear S2 corresponds. The ramp mechanics RK is located axially between the first and the second coupling plate pack BLP1 , BLP2 .

The initiation of through the ramp mechanics RK generated axial force in the pressure ring DR takes place at a circumferential level that is smaller than the inner diameter of the fins of the first coupling lamella pack BLP1 . The pressure ring DR is designed in such a way that an end stop function is provided by it, which defines the maximum axial compression degree of the first coupling lamella pack BLP1 limited. The pressure ring DR is in the circulation housing U axially displaceable, but non-rotatably guided. For guiding the pressure ring DR becomes the guide for the first brake disk pack BLP1 internal toothing of the circulating housing U used.

The initiation of the actuation of the first coupling plate pack BLP1 required thrust is carried out via the thrust bearing AX2 . The ramp mechanism is thus located axially between the first axial bearing AX1 and the second thrust bearing AX2 . The pressure decrease ring VR is on the planet carrier 3rd centered. The pressure decrease ring VR is with the planet carrier 3rd coupled in such a way that a torque can be transmitted via this connection, which is necessary for the ramp mechanics to take effect RK when determining the ramp support RK1 is sufficient. This coupling of the pressure decrease ring VR with the planet carrier 3rd is accomplished in a frictional way. The whole for actuating the first coupling plate pack BLP1 required flow of power goes through the circulation housing U and here on the planet carrier 3rd past. The axial position of the first brake disk pack BLP1 is on the axial position of the second coupling planet P2 Voted. The axial position is coordinated in such a way that there is an axial overlap and thus at least a partial section of the inner lamella seat LS1 the coupling plate pack BLP the housing section PG1 at the axial level of the second coupling planet P2 and at a radial level outside of that of the second coupling planet P2 when rotating around the gear axis X passes through the railway area. The main clutch BLP1 is located radially on a larger diameter than the outer tip diameter of the differential. The main clutch BLP1 is arranged so that at least one lamella axially overlaps the differential. The force flow of the axial contact force goes through the main coupling BLP on the outer case U . The torque of the main clutch BLP attacks the outer differential case diameter.

The outer case U serves here as a turning point introduction for both the main clutch BLP1 (Connection between outer housing U and planet carriers 3rd ) as well as for the actuation clutch BLP2 (Connection between outer housing U and the axial adjustment unit RK ). In addition, both overlap the storage L2 as well as the electromagnet HK axially with the outer casing U . The sun gear 1 , 2nd axially further distant second bearing L2 and the electromagnet HK are arranged here in such a way that they do not just axially fit the outer housing U overlap, but completely within the outer casing U or the second cover element U2 this housing U lie.

The representation after 2nd illustrates the structure of the actuation mechanism again in the form of a detailed representation 5 . This includes the ramp rings RK1 and the pressure decrease ring VR . Both rings are supported axially over the rolling elements ZR to each other and move axially away from each other in the case of a relative rotation or axially approach each other again in the case of a return rotary movement. The ramp ring RK1 is about the second coupling lamella pack BLP2 with the circulation housing U can be frictionally coupled. The coupling torque is determined by the axial contact pressure of the plates LI2 , LA2 the second coupling lamella pack BLP2 set. This contact pressure can be achieved, for example, by metering a coil HK (see. 1 ) can be set. The pressure decrease ring VR is on the planet carrier 3rd guided axially displaceable. The pressure decrease ring VR is supported axially via the second thrust bearing AX2 on the pressure ring DR the first coupling plate pack BLP from.

As long as the second coupling plate pack BLP2 is not activated, the first ramp ring RK1 over the rolling elements ZR from the pressure decrease ring VR taken along and rotates smoothly together with the inner slats LI2 in the pack BLP2 . Will this pack BLP2 Eg activated electromagnetically, so that their slats LI2 , LA2 the inner lamellas transmit to each other LI2 a torque on the first ramp ring RK1 and brake it on the circulation housing U firmly. As a result of the pressure reduction ring VR The two rings become frictionally applied RK1 , VR twisted against each other and the rolling elements RK push the ramp ring RK1 and the pressure decrease ring VR axially apart. The first ramp ring RK1 is supported by the first thrust bearing AX1 on the ring AXR from the axially on the circulation housing U is set. The pressure decrease ring VR transmits via the second thrust bearing AX2 the actuating force generated by the ramp mechanism on the pressure ring DR . The ramp mechanism is thus parallel to the gear axis in both X aligned directions of movement between the axial bearings designed as roller bearings AX1 , AX2 supported. The pressure decrease ring VR is with the planet carrier 3rd coupled in such a way that the torque required for the ramp mechanics to take effect is transmitted in a frictional manner.

The representation after 3rd illustrates the structure of the ramp mechanics in the form of a side view RK the component of the actuation mechanism 5 forms. The ramp mechanics RK includes the ramp ring RK1 , the rolling bodies that run against it ZR and the pressure decrease ring VR . The ramp ring RK1 forms axially aligned ramp surfaces RF . In contrast to this, the pressure decrease ring forms VR one in its course around the gear axis X axially non-alternating contact path throughout RB on which the rolling elements ZR start up. Both the ramp ring RK1 also the pressure reduction ring VR are axial via axial bearings AX1 , AX2 supported, which are designed here as roller bearings, especially cylindrical roller bearings. In the exemplary embodiment shown here, the ramp mechanism comprises RK several, for example four support systems which follow in the same division in the circumferential direction, each with a rolling element ZR and a pair of axially set ramp surfaces RF at the ramp ring RK1 . The system status shown here corresponds to the passive status of the actuation mechanism 5 in which the actuation mechanism 5 no actuation force generated. In this condition, the pressure decrease ring VR with a certain slip on the rolling elements ZR walk past or over the roller reaction forces the ramp ring RK1 take along essentially load-free. The second coupling lamella pack (cf. 1 and 2nd ) is axially unloaded, ie in a freewheeling state.

QUOTES INCLUDE IN THE DESCRIPTION

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Patent literature cited

• DE 102008037885 A1 [0003]
• DE 102013206749 A1 [0003]

Claims (10)

Differential gear, with: - a gearbox (G), a circulating housing (U) which is arranged in the transmission housing (G) so as to be rotatable about a transmission axis (X), a planet carrier (3) which is arranged in the revolving housing (U) with the gear axis (X) and can be rotated coaxially, - a first sun gear (S1), which is received in the planet carrier (3), - a second sun gear (S2), which is also received in the planet carrier (3), - A coupling planet arrangement (P) with first and second coupling planets (P1, P2) for coupling the sun gears (S1, S2) in the planet carrier (3), which can rotate in opposite directions, - A coupling device (K) with a first coupling plate pack (BLP1) for generating a coupling torque coupling the planet carrier (3) to the revolving housing (U), and - An actuating mechanism (5) for generating an axial force acting on the first coupling plate pack (BLP1), wherein - The actuating mechanism (5) has a ramp ring (RK1), rolling bodies (ZR) running on it and a pressure reduction ring (VR), - The ramp ring (RK1) forms axially adjusted ramp surfaces (RF) and - The ramp ring (RK1) or the pressure reduction ring (VR) are frictionally coupled to the planet carrier (3). Differential gear after Claim 1 , characterized in that the frictional coupling is accomplished via a roller bearing (N2). Differential gear after Claim 2 , characterized in that the rolling bearing (N2) is designed as a needle bearing. Differential gear after Claim 2 or 3rd , characterized in that the friction torque of the rolling bearing (N2) is brought about by a cage device, a sealing device and / or lubricant filling. Differential gear according to at least one of the Claims 1 to 4th , characterized in that the frictional coupling is brought about by a plain bearing device. Differential gear according to at least one of the Claims 1 to 5 , characterized in that the pressure reduction ring (VR) is frictionally coupled to the planet carrier (3). Differential gear according to at least one of the Claims 1 to 6 , characterized in that the pressure decrease ring (VR) is axially displaceable relative to the planet carrier (3). Differential gear according to at least one of the Claims 1 to 7 , characterized in that the coupling system provided for the frictional coupling of the pressure decrease ring (VR) or the ramp ring (RK1) to the planet carrier is designed such that the coupling torque increases in the course of an axial load on the pressure decrease ring (VR) or the ramp ring (RK1), with which the pressure decrease ring (VR) or the ramp ring (RK1) is coupled to the planet carrier (3). Differential gear according to at least one of the Claims 1 to 8th , characterized in that the pressure reduction ring (VR) forms a continuously non-alternating contact path (RB) in its course around the gear axis (X), against which the rolling elements (ZR) start. Differential gear after Claim 9 , characterized in that the contact track (RB) is designed as a flat annular disk surface and that the rolling elements (ZR) are designed as cylindrical rollers.

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