WO2021083788A1

WO2021083788A1 - Bevel gear differential transmission

Info

Publication number: WO2021083788A1
Application number: PCT/EP2020/079775
Authority: WO
Inventors: Martin Bloder
Original assignee: Technische Universität Graz
Priority date: 2019-10-29
Filing date: 2020-10-22
Publication date: 2021-05-06
Also published as: DE102019007513A1

Abstract

The invention relates to a bevel gear differential transmission (1) comprising a differential cage (2), in the interior of which two bevel gears (3) are arranged opposite one another, and each of the bevel gears (3) is mounted rotatably about an output shaft (5), the bevel gear differential transmission (1) further comprising at least one compensating bevel gear (4) which is mounted in the differential cage (2) so as to be rotatable about a compensating bevel gear shaft (7). According to the invention the at least one compensating bevel gear (4) is movable along its compensating bevel gear shaft (7) and/or at least one of the bevel gears (3) is movable along its output shaft (5) between an engaged position (9) and a disengaged position (10), such that in the engaged position (9), but not in the disengaged position (10), the at least one compensating bevel gear (4) is engaged with both bevel gears (3) and connects them to one another.

Description

BEVEL GEAR DIFFERENTIAL GEAR

FIELD OF THE INVENTION

The present invention relates to a bevel gear differential gear comprising a differential cage, inside of which two bevel gears are arranged opposite one another, the bevel gears each being rotatably mounted about an output axis, the bevel gear differential gear further comprising at least one differential bevel gear which is rotatably mounted in the differential cage about a differential bevel gear axis is.

STATE OF THE ART

Differential gears are well known from vehicle construction to drive two wheels on an axle so that they can turn at different speeds when cornering. In particular, bevel gear differentials have been established for this purpose. The latter have bevel gears inside a differential cage, which are non-rotatably connected to side shafts that are to be driven and are located at least in sections outside the differential cage. The differential carrier is driven by an external wheel. The bevel gears are connected in the differential cage via at least one bevel gear which is rotatable about a bevel gear axis and which only then revolves around its

Pinion pinion axle rotates when the wheels turn and so the side shafts rotate at different speeds, especially when cornering.

In all-wheel drive vehicles, which are enjoying increasing popularity in the passenger car sector but of course also play a role in the truck sector, differential gears are provided for each axle. Many all-wheel-drive vehicles nowadays have a switchable all-wheel drive. In this case, additional switching elements, in particular in the form of claw clutches, are mostly used to shut down part of the drive train.

For example, from US 6027422 A and DE 19716386 A1 differential gears with an integrated decoupling function are known in which the establishment or removal of the frictional connection with the side shafts takes place via a dog clutch within the differential cage of the respective differential gear.

The gears of the switching elements are disadvantageous in these known solutions because of their high costs; in the case of said claw clutches, these are in particular the teeth of the two claw coupling halves.

In order to keep the switching elements as small and inexpensive as possible, only one of the side shafts is often switched. However, this means that the bevel gears must continue to rotate inside the differential cage and the potential for drag torque reduction can only be used incompletely, which is also disadvantageous.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a bevel differential gear available that the allows the drive of the side shafts to be switched on and off, thereby avoiding the disadvantages mentioned above.

DISCLOSURE OF THE INVENTION

The essence of the present invention consists in using the at least one differential bevel gear and / or at least one of the bevel gears instead of costly additional shifting elements in order to selectively cancel or establish the frictional connection to the side shafts (from the drive force transmitted to the differential carrier). Correspondingly, in a bevel gear differential gear it comprises a differential cage, inside of which two bevel gears are arranged opposite one another, the bevel gears each being rotatably mounted about an output axis, the bevel gear differential gear further comprising at least one differential bevel gear which is rotatably mounted in the differential cage about a differential bevel gear axis is, according to the invention, that the at least one bevel gear is displaceable along its bevel gear axis and / or at least one of the bevel gears along its output axis between an engagement position and a release position, wherein in the engagement position, but not in the release position, the at least one bevel gear is in engagement with the two bevel gears and connects them to each other.

This means that the bevel gears and the at least one differential bevel gear are arranged in the differential cage.

Regardless of whether only the at least one differential bevel gear along its differential bevel gear axis or only at least one of the bevel gears along its output axis or both the at least one differential bevel gear along its differential bevel gear axis and at least one of the Bevel gears are arranged displaceably along its output axis, in the engagement position the bevel gears and the at least one differential bevel gear are in engagement with one another, so that the known differential function described at the beginning is fulfilled. In particular, the at least one differential bevel gear can compensate for unequal speeds of the bevel gears.

The rotational connection of the bevel gears via the at least one differential bevel gear ultimately creates the frictional connection between the side shafts connected to the bevel gears in a rotationally fixed manner and the differential carrier, so that the side shafts are driven when the differential carrier is driven. The differential cage can be driven in a manner known per se via an outer wheel which is non-rotatably connected to the differential cage or is part of it.

There is no engagement of the at least one differential bevel gear with the two bevel gears if the at least one differential bevel gear and / or at least one of the bevel gears are not in the engagement position but in the respective release position. That is, if the at least one differential bevel gear and / or at least one of the bevel gears are not in the engagement position but in the respective release position, the two bevel gears are not rotationally connected to one another. More precisely, if there are several differential bevel gears, all differential bevel gears must be in the release position in order to exclude a rotational connection of the two bevel gears if none of the bevel gears can be brought into a release position. Correspondingly, in this case, ie when the bevel gears are not connected, the side shafts are not driven either when the differential carrier is driven. The bevel gear differential gear according to the invention can thus be used in a vehicle for optionally switching the drive of an axle on and off. When the bevel gears or the at least one differential bevel gear are in the meshing position, the drive of the axle is switched on. If, on the other hand, the at least one differential bevel gear and / or at least one of the bevel gears are in the respective release position, the drive of the axle is switched off.

The displaceable arrangement of the at least one differential bevel gear along its differential bevel gear axis means that it can be moved parallel to the

Differential bevel gear axis and thus radial mobility in relation to the differential carrier. This mobility can be achieved, for example, by mounting the differential bevel gear on a bearing pin so that it can be rotated as well as be displaceable along the longitudinal axis of the bearing pin.

The displaceable arrangement of at least one of the bevel gears means a mobility parallel to the output axis of the respective displaceable bevel gear and thus a radial mobility in relation to the differential carrier. Such mobility can be achieved, for example, in that the respective bevel gear is mounted on a section of the associated side shaft by means of sliding teeth, so that the bevel gear can be displaced along the longitudinal axis of this section.

Overall, the bevel gear differential gear according to the invention thus results in a weight and cost reduction due to the omission of additional shift elements in comparison with known systems. In particular, no additional force-transmitting shifting elements, such as dog clutches or the like, are necessary in the vicinity of the differential. There is also a reduction in the remaining Drag torque is achieved in comparison to systems that only release or switch one side shaft.

In a preferred embodiment of the bevel gear differential according to the invention it is provided that at least two differential bevel gears are provided. This enables the transmission of particularly high torques to the bevel gears or the side shafts.

In particular, symmetrical arrangements of the differential bevel gears can be provided here. For example, with two or four differential bevel gears, the arrangement can be such that two differential bevel gears are located symmetrically opposite one another in the differential carrier.

As already stated, when there are several sliding bevel gears it is necessary that all bevel gears are in the release position in order to exclude a rotational connection of the two bevel gears if none of the bevel gears can be brought into a release position.

In a preferred embodiment of the bevel gear differential gear according to the invention, it is provided that exactly two differential bevel gears are provided, which are arranged opposite one another. Such a, preferably symmetrical, arrangement is favorable in terms of production technology and has become well established in vehicle construction.

In this case, only one bearing pin can be provided for the two differential bevel gears, which proves to be particularly advantageous in terms of production technology. In other words, the two differential bevel gears are rotatably and displaceably mounted on the same bearing pin in this case.

As already stated, it is also necessary with exactly two displaceable differential bevel gears that all Differential bevel gears are in the release position in order to exclude a rotational connection of the two bevel gears if neither of the bevel gears can be brought into a release position.

In order to be able to switch the at least one differential bevel gear or at least one of the bevel gears conveniently from the outside, a preferred embodiment of the bevel gear differential gear according to the invention provides that at least one actuating element is provided for the at least one differential bevel gear and / or at least one of the bevel gears, whereby the at least one actuating element is movably mounted and wherein the at least one actuating element has an inner section which is operatively connected to the differential bevel gear and / or the bevel gear, and an outer section which protrudes outward through the differential carrier in such a way that the outer portion can be contacted from outside the differential carrier is in order to be able to move the actuating element from the outside at least from a first position into a second position or vice versa.

The at least one actuating element can be constructed in several parts. The actuating element is preferably designed in one piece.

The operative connection between the actuating element or the inner section of the actuating element and the differential bevel gear and / or the bevel gear can be implemented in a manner known per se, for example by form fit, force fit or a combination of form fit and force fit. For example, the operative connection can be established by means of a spring element. Another example would be a magnetic coupling between the inner section and the differential bevel gear and / or the bevel gear.

The outer section does not have to protrude outwards from the differential carrier, but can also be flush with the Lock the differential carrier to the outside. The outer section can in any case be contacted from the outside in order to be able to move the actuating element from the outside at least from the first position into the second position. "At least" is to be understood to mean that, on the one hand, other movements, in particular from the second position to the first position, can also be possible the second position can be achieved by the action from the outside on the outer section.

The movement of the actuating element between the first and second positions does not have to be a linear movement, but can also be a rotary movement or a combination of linear and rotary movement.

The first position of the at least one actuating element can, for example, with the release position of the one

Differential bevel gear or the plurality, in particular the two, be associated differential bevel gears. Analogously, the first position of the at least one actuating element can be associated, for example, with the release position of at least one of the bevel gears. In these cases, the second position of the at least one actuating element is typically associated with the engagement position.

Due to the above-mentioned operative connection, the actuating element moves the at least one differential bevel gear and / or at least one of the bevel gears from the release position to the engagement position during the transition from the first to the second position or during the transition from the second to the first position.

For the return movement of the at least one differential bevel gear and / or of the at least one of the Bevel gears can optionally be provided with a further mechanism, for example a spring mechanism known per se.

Or the actuating element can also be provided for the return movement. For example, the operative connection between the inner section of the actuating element and the differential bevel gear and / or the bevel gear can be both positive and magnetic, the positive connection being used for movement in one direction and the magnetic connection for movement in the other direction.

One or more actuating elements can be provided per displaceable differential bevel gear or per displaceable bevel gear.

Furthermore, a separate actuating element can be provided for each displaceable differential bevel gear or for each displaceable bevel gear, or several differential bevel gears and / or both bevel gears can be operated / switched via a common actuation element.

According to what has been said above, it is provided in a particularly preferred embodiment of the bevel gear differential according to the invention that the operative connection between the inner section of the at least one actuating element and the at least one

The differential bevel gear and / or the at least one of the bevel gears is designed such that the differential bevel gear and / or the bevel gear is in the release position when the actuating element is in the first position and in the engagement position when the actuating element is in the second position , or the other way around.

In a particularly preferred embodiment of the bevel gear differential according to the invention, it is provided that the at least one actuating element, is preferably parallel to the differential bevel gear axis of the at least one differential bevel gear and / or transversely to the output axis of the at least one of the bevel gears, displaceable. This allows a structurally simple and inexpensive implementation.

Here, the at least one actuating element can in particular be displaceable normal to the output shaft.

The displaceability of the at least one actuating element allows in particular a linear movement of the actuating element between its first and second position and vice versa.

As already mentioned, a form fit, for example, can be used as an operative connection between the inner section and the differential bevel gear or bevel gear. Accordingly, it is provided in a particularly preferred embodiment of the bevel gear differential gear according to the invention that the at least one actuating element rests with its inner section on at least one differential bevel gear and / or the at least one of the bevel gears at least in sections in order to move from the first position to the second Position and / or from the second position to the first position to press against the differential bevel gear and / or the bevel gear and to move it. This means that the respective inner section contacts the respective differential bevel gear and / or bevel gear and can thus press against the latter.

In particular, if the movement of the actuating element is only effected in one direction by pressing, the return movement of the at least one

Differential bevel gear or the at least one of the bevel gears, a further mechanism, for example a spring mechanism, can be provided. In a particularly preferred embodiment of the bevel gear differential according to the invention, it is provided that a movable, in particular displaceable, shift sleeve is provided, which is arranged outside the differential cage and can be brought into engagement with the outer section of the at least one actuating element in order to move the actuating element at least from the first position to move to the second position.

It would be conceivable that the shift sleeve can alternatively or additionally be rotated so that its movement is a rotary movement or a combined linear and rotary movement.

By moving the shift sleeve, the shift sleeve can be brought into engagement with the outer section of the at least one actuating element and move the at least one actuating element. By moving the shift sleeve in the opposite direction, the engagement of the shift sleeve with the outer section of the at least one actuating element can be released again.

The at least one actuating element can then either be moved back by the shift sleeve during its return movement. Or the return movement of the respective actuating element can take place by an additional mechanism which is mediated, for example, by the at least one differential bevel gear or the at least one of the bevel gears. The additional mechanism can, for example, be a spring mechanism known per se, which can be provided for the return movement of the at least one differential bevel gear and / or the at least one of the bevel gears, with an operative connection between the at least one differential bevel gear and / or the at least one of the bevel gears also at least one Actuating element is movable by the additional mechanism.

When the shift sleeve engages with the outer section of the at least one actuating element, an operative connection is generally established between the shift sleeve and the respective outer section. For example, a form fit between the involved elements or a force fit or a combination thereof can be implemented here. However, other operative connections known per se, e.g. a magnetic operative connection, are alternatively or additionally conceivable.

In a particularly preferred embodiment of the bevel gear differential gear according to the invention, it is provided that the shift sleeve is displaceably mounted on the differential carrier, preferably parallel to one of the output axes. This allows a very compact design that is inexpensive in terms of production technology and costs.

In a particularly preferred embodiment of the bevel gear differential according to the invention, it is provided that the outer section of the at least one actuating element has a contact surface which preferably runs obliquely to one of the output axes. The contact surface can promote the production of the engagement of the shift sleeve with the outer section.

The contact surface is particularly advantageous when the direction of movement of the shift sleeve has no or only a small component parallel to the direction of movement of the outer section or of the at least one actuating element. In this case, the production of the engagement of the shift sleeve with the respective outer section is favorable if the contact surface runs obliquely to the direction of movement of the shift sleeve in order to convert the direction of movement of the shift sleeve into the direction of movement of the actuating element. A Such a situation is given in particular when the direction of movement of the shift sleeve is parallel to one of the output axes and the direction of movement of the at least one actuating element is parallel to the differential bevel gear axis.

In order to alternatively or additionally facilitate the production of the engagement of the shift sleeve with the respective outer section, the shift sleeve can have a counterpart section which is designed as a counterpart to the contact surface with a corresponding bevel and is provided for contacting the contact surface.

In this context, "oblique to one of the output axes" does not mean normal and not parallel to the output axis or the contact surface forms an acute angle with the output axis.

The run-on surface is preferably designed to be flat, but a curved run-on surface is also conceivable.

According to the above, it is provided in a particularly preferred embodiment of the bevel gear differential gear according to the invention that the shift sleeve has a contact surface in order to facilitate the production of the engagement of the shift sleeve with the outer section of the at least one actuating element. For this purpose, the contact surface preferably runs obliquely to the direction of movement of the shift sleeve, in particular to the output shafts. It also applies to the contact surface of the shift sleeve that the contact surface is preferably designed to be flat, but a curved contact surface is also conceivable.

Likewise, according to what has been said above, in a particularly preferred embodiment of the bevel gear differential gear according to the invention, the contact surface of the shift sleeve as a counterpart to the contact surface of the Outer portion of the at least one actuating element is formed.

In a particularly preferred embodiment of the bevel gear differential according to the invention it is provided that a switching ring is provided as the actuating element, that the switching ring has at least one ramp with eccentric geometry, the at least one ramp forming the inner section of the actuating element, so that the switching ring has at least one switching ring bracket , wherein the at least one switching ring bracket forms the outer section of the actuating element, and that the switching ring can be moved from the first position to the second position and vice versa by rotating through a switching angle relative to the differential carrier.

The switching ring rotates accordingly in principle with the differential carrier.

Typically the first position is with the

Associated engagement position and the second position with the release position. That is, by bringing the shift sleeve into engagement with the shift ring bracket, the shift ring can be moved from the first to the second position, with the bevel gears or the at least one differential bevel gear being transferred from the engagement position to the release position.

In particular, the switching ring can be provided for switching the at least one differential bevel gear, with one plane of the switching ring being normal to the output axis (s).

For the operative connection between the at least one ramp and the at least one differential bevel gear or the at least one of the bevel gears, at least one intermediate piece is typically provided on which the ramp slides. The at least one intermediate piece presses according to the Ramp contour against the at least one differential bevel gear or the at least one of the bevel gears in order to move it axially.

Of course, two ramps can be provided which press against the two bevel gears or two differential bevel gears via two intermediate pieces.

The at least one ramp is typically designed eccentrically, it also being possible for a plurality of sections with different radii to be provided. For example, it would be conceivable to provide two eccentric sections which are curved in the same direction, the two sections having different radii of curvature and being connected via a connecting section with opposite curvature. In principle, however, almost any combination of straight lines, circular arcs, elliptical arcs and / or the like is possible for the respective geometry of the at least one ramp.

The provision of the shift ring allows a dramatic shortening of the path that the shift sleeve has to be moved in one direction of actuation towards the shift ring, while at the same time the force required for this movement of the shift sleeve can be limited to an acceptable level, since the ramp geometry and the switching angle a correspondingly further path can be associated with the operative connection. The switching angle is typically in the range from 45 ° to 180 °, preferably in the range from 60 ° to 120 °, for example 90 °.

Specifically, the path of the shift sleeve can be seen in

Typically shorten the actuation direction from a few tens to a few millimeters, for example to 4 mm instead of 24 mm. On the one hand, this enables a much more compact design. On the other hand, fast switching times, more precisely fast times for the actuation of the shift sleeve or for the movement of the shift sleeve in the direction of actuation, can be realized, with great flexibility in the choice of one Actuator for moving the shift sleeve in the actuation direction. For example, the shift sleeve can be moved in the actuating direction by means of an electromagnet.

In order to be able to realize the engagement of the shift sleeve with the at least one shift ring plate particularly easily, it is provided in a particularly preferred embodiment of the bevel gear differential gear according to the invention that the shift sleeve has at least one friction cone, that the at least one shift ring plate has a friction surface that the shift sleeve can be moved in an actuating direction towards the switching ring and that by moving the switching sleeve in the actuating direction, the at least one friction cone can be brought into engagement with the friction surface of the at least one switching ring bracket when the switching ring is in the first position around which the differential cage is located brake the rotating switching ring and move it relative to the differential cage by the switching angle into the second position.

In particular, the ramp geometry can be designed so that the switching ring then no longer presses against the at least one differential bevel gear or against the at least one of the bevel gears via the intermediate pieces in such a way that it is fixed in the engagement position. The at least one differential bevel gear or the at least one of the bevel gears can then be pressed into the release position via at least one suitable spring element, in particular via at least one axially arranged compression spring.

In a particularly preferred embodiment of the bevel gear differential according to the invention, it is provided that at least one spring, in particular at least one torsion spring, is provided, which by the movement of the switching ring from the first position into the second position is tensioned in order to be able to move the switching ring back into the first position by releasing the spring.

The spring allows rapid switching or moving of the switching ring back from the second position to the first position.

In particular, according to the ramp geometry, the switching ring can push or press the at least one differential bevel gear or the at least one of the bevel gears into the engagement position via the at least one intermediate piece.

In a particularly preferred embodiment of the bevel gear differential according to the invention, it is provided that at least one, in particular spring-loaded, locking element is provided, that the at least one switching ring tab has a locking contour and that the locking element with the locking contour by moving the switching ring from the first position into the second position can be locked to hold the switching ring in the second position.

The at least one spring-loaded locking element can be, for example, at least one locking spring.

When the respective locking element is locked with the respective locking contour, the switching ring is prevented from moving back or rotating back into the first position, in particular due to the spring force of the spring or torsion spring.

Accordingly, after actuation, the shift sleeve can initially be moved back into a starting position or non-engagement position in which the shift sleeve is not in engagement with the shift ring or the at least one shift ring tab, i.e. against the direction of actuation, for example by means of a spring provided for this purpose. In other words, the actuator is not necessary (and also no actuator of its own) to move the selector sleeve back.

In addition, this opens up the possibility of releasing the lock again by actuating the selector sleeve again, i.e. by moving the selector sleeve again in the direction of actuation and thus triggering the movement of the switching ring back into the first position (by the spring or torsion spring). The same actuator can of course be used for the renewed movement of the shift sleeve in the actuation direction as for the previous movement in the actuation direction. Since only one actuator is required, which is also only required for moving the shift sleeve in one direction, the actuator can be designed to work very easily and very quickly, for example as an electromagnet.

In a particularly preferred embodiment of the bevel gear differential gear according to the invention, it is provided that the locking contour of the at least one switching ring tab has a contact section in order to be able to slide the locking element on the contact section when the switching ring is moved from the first position to the second position, and that behind a latching section of the locking contour is provided for the contact section in order to be able to lock the locking element with the latching section when the switching ring has been moved from the first position to the second position.

The contact section ensures problem-free movement of the switching ring from the first to the second position. The locking section in turn ensures reliable locking of the locking element with the locking contour after or immediately after the Switching ring (from the first position) has been moved to the second position. Correspondingly, viewed in a direction of rotation that corresponds to the movement from the first position into the second position, the latching section is arranged behind the run-on section.

As already described, the shift sleeve can be set up to release the lock by moving it again in the actuation direction after the shift sleeve has been moved into the disengaged position, for example (by means of a spring) after the previous movement in the actuation direction, in order to prevent the movement of the Switching rings back into the first position by means of the at least one spring or torsion spring - with a very short switching time and relatively low actuation force. The at least one differential bevel gear or the at least one of the bevel gears is brought back into the engagement position by means of the at least one spring element or the at least one compression spring. Accordingly, it is provided in a particularly preferred embodiment of the bevel gear differential according to the invention that the shift sleeve has at least one unlocking section, the unlocking section - in particular by moving the shift sleeve in an actuation direction towards the shift ring when the shift sleeve is not initially in engagement with the at least a switching ring strap - can be brought into engagement with the at least one locking element in order to release the locking of the locking element with the locking contour. As can already be seen from the above, "initially" is to be understood in particular as "before the movement in the actuating direction" when the shift sleeve is in the non-engagement position after the shift sleeve has previously been brought into engagement with the at least one shift tab (in particular by means of the Actuator) to move the switching ring into the second position, and then moved back into the disengaged position (in particular by means of the spring).

In order to enable the locking solution to be implemented as structurally as simple as possible, it is provided in a particularly preferred embodiment of the bevel gear differential gear according to the invention that the at least one unlocking section is designed as an unlocking cone, that the at least one locking element is designed as at least one locking spring, to slide with a free end on the unlocking cone and so to be able to release the locking of the locking spring with the locking contour by moving the shift sleeve in one actuation direction on the shift ring when the shift sleeve is not initially in engagement with the at least one shift ring bracket.

By sliding on the unlocking cone, the respective locking spring is lifted over or out of the locking section and the locking is thus released.

Clearly, the unlocking cone is arranged or designed in such a way that it comes into engagement with the at least one locking spring before the friction cone can come into engagement with the friction surface of the at least one switching ring. The unlocking cone and the at least one locking spring are appropriately matched to one another.

As can already be seen from the above, "initially" is to be understood in particular as "before the movement in the actuating direction" when the shift sleeve is in the non-engagement position after the shift sleeve has previously been brought into engagement with the at least one shift tab (in particular by means of the actuator) to move the switching ring into the second position, and then has been moved back to the disengaged position (in particular by means of the spring).

Conversely, in order to ensure that the at least one locking spring does not interfere with the movement of the shift sleeve in the actuation direction when the shift ring is to be moved from the first position to the second position by means of the shift sleeve, it is provided in a particularly preferred embodiment of the bevel gear differential according to the invention, that the shift sleeve has at least one recess for receiving the free end of the at least one locking spring, the free end in the recess by moving the shift sleeve in the actuation direction when the shift sleeve is not initially in engagement with the at least one switching ring bracket and the switching ring in the first position is, can be arranged. As can already be seen from the above, "initially" is to be understood in particular as "before the movement in the actuating direction" when the shift sleeve is in the non-engagement position before the shift sleeve (in particular by means of the actuator) engages the at least one shift tab is brought to move the switching ring from the first to the second position.

As a result, the switching ring can and can be moved from the first position to the second position by repeatedly moving the shifting sleeve in the actuation direction (in particular by means of the actuator), followed in each case by moving the shift sleeve back into a starting position or non-engagement position (in particular by means of the spring) the return movement of the switching ring from the second position to the first position can be effected in order to transfer or switch the at least one of the bevel gears or the at least one differential bevel gear from the engagement position to the release position and back. In a preferred embodiment of the bevel gear differential gear according to the invention, it is provided that the output axes are congruent. The result is a particularly simple structure that is particularly relevant for use in vehicles.

In a preferred embodiment of the bevel gear differential gear according to the invention it is provided that the bevel gears and the at least one differential bevel gear are designed as gears, the gears having teeth with a tooth width that is greater than a tooth height of the teeth.

The design as gearwheels creates a particularly relevant embodiment for vehicle construction in particular.

The outer wheel is also preferably designed as a gear wheel, in particular as a crown wheel (which can be driven, for example, via a cardan shaft) or spur gear (which can be driven, for example, via a spur gear).

In general, it should be noted that the bevel gear differential gear according to the invention can also fulfill its function if the bevel gears and the at least one differential bevel gear are not designed as gear wheels but, for example, as friction wheels. It is also conceivable that the outer wheel is not designed as a gear but, for example, as a friction wheel.

Gear wheels usually have teeth with a tooth height that is greater than a tooth width, the tooth width being measured as usual along a reference line on the mean pitch cone diameter. Regardless of the usually relatively slow relative rotation of the bevel gears and differential bevel gears to one another - no relative rotation when driving straight ahead; tight corners are usually taken rather slowly, and fast corners are usually rather far, so that the relative rotation typically takes place at rather low speeds even when cornering - good switchability of the bevel gears is desirable. With a view to improved switchability between the release position and the engagement position and vice versa, provision is made for the tooth width to be larger than the tooth height. This promotes rapid meshing of the gears when shifting.

Alternatively or additionally, in a preferred embodiment of the bevel gear differential gear according to the invention, it is provided for better switchability that the bevel gears and the at least one differential bevel gear are designed as gear wheels, the gear wheels having teeth that each have a Contour have what contour

- Has an elliptical geometry or

- Has a geometry with two different radii or

- Has a flat bevel with a bevel angle between 5 ° and 15 °. In contrast to known types of tooth tip machining, such as breaking the edges of the tooth tip or providing the edges with a single radius, a significant shift improvement can be achieved with each of the three geometries mentioned.

The elliptical geometry means that the contour of the respective tooth in the transition area at least in sections, preferably completely, forms an elliptical arc.

The geometries mentioned encourage the gears to slide on one another when the gears mesh with one another during their shifting, which leads to improved shifting behavior. Analogous to the above, a motor vehicle is provided according to the invention, comprising at least one bevel gear differential gear according to the invention for the optional activation and deactivation of the drive of side shafts connected to the bevel gears in a rotationally fixed manner.

That is, the bevel gear differential gear according to the invention can be used as an axle differential gear in the motor vehicle in order to selectively switch the drive of the axle equipped with the bevel gear differential gear according to the invention on and off. The outer wheel of the bevel gear differential gear is always driven or can always be driven.

In particular, a motor vehicle with switchable all-wheel drive can be implemented in this way.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be explained in more detail on the basis of exemplary embodiments. The drawings are exemplary and are intended to explain the idea of the invention, but in no way restrict it or reproduce it conclusively.

It shows:

1 shows a schematic axonometric view of a first exemplary embodiment of a bevel gear differential gear according to the invention, a differential cage being shown cut open in sections and an outer wheel connected in a rotationally fixed manner to the differential cage not being shown

FIG. 2 shows a plan view of the bevel gear differential gear of FIG. 1 along an output axis 3 shows a sectional view according to section line BB from FIG. 2, with bevel gears with bevel gears of the bevel gear differential gear being in an engagement position

4 is a sectional view like FIG. 3, but the differential bevel gears are in a release position

5 is a schematic axonometric view of a second embodiment of the bevel gear differential gear according to the invention, the differential cage being shown cut open in sections and the outer gear not being shown

6 shows a plan view of the bevel gear differential gear of FIG. 5 along one of the output axes

7 shows a sectional view according to section line C-C from FIG. 6, the bevel gears with the differential bevel gears being in the meshing position

8 is a sectional view like FIG. 7, but with one of the bevel gears in the release position

9 is a side view of a third embodiment of the bevel gear differential gear according to the invention with a switching ring as the actuating element, the differential bevel gears being in the engagement position

10 is a sectional view according to the section line X-X in FIG. 9, the arrows indicating the viewing direction

11 shows a side view analogous to FIG. 9, the differential bevel gears being in the release position

12 shows a sectional view along the section line XII-XII in FIG. 11, the arrows indicating the viewing direction 13 shows a detailed view of a switch tab of the switch ring

14a shows a detail side view, before a movement of the

Shift ring from a first position to a second position by means of a shift sleeve

FIG. 14b shows a detailed side view analogous to FIG. 14a after the switching ring has been moved from the first to the second position by moving the switching sleeve in an actuation direction

14c shows a detailed view analogous to FIG. 14b, the shift sleeve having been moved back into a non-engagement position against the actuation direction

14d shows a detailed view analogous to FIG. 14c, the shift sleeve having been moved again in the actuating direction in order to release a locking of a locking spring with a locking contour of the shift tab

15 shows a schematic representation of a developed

Reference profile of gears, which form the bevel gears and the differential bevel gears, wherein a tooth width of teeth of the gears is greater than a tooth height of the teeth

16 shows a schematic representation of the developed reference profile, the teeth each having a contour optimized for switching in a transition area between a tooth tip and a tooth flank

17a shows an enlarged view of detail XVII in FIG. 16, the contour having an elliptical geometry

FIG. 17b shows a view analogous to FIG. 17a, the contour having a geometry with two different radii FIG. 17c shows a view analogous to FIG. 17a, the contour having a flat bevel

WAYS OF CARRYING OUT THE INVENTION

Fig. 1 shows a schematic representation of a first embodiment of a bevel gear differential 1 according to the invention in an axonometric view, wherein a differential cage 2 of the bevel gear

Differential gear 1 is shown in sections for the sake of clarity. If the differential cage 2 is made in one piece, for reasons of assembly a, preferably closable, opening is actually provided, typically in the cut-open area, whereby at least one further opening can also be provided, which is for example arranged symmetrically opposite the opening. If the differential cage 2 is constructed in several parts, it would be conceivable not to provide any openings, although in this case too, of course, at least one, preferably closable, opening can be provided to facilitate assembly or, if necessary, to enable maintenance. Furthermore, for reasons of clarity, an outer wheel 8 which is connected to the differential cage 2 in a rotationally fixed manner (see, for example, FIG. 2) and via which the differential cage 2 can be driven, is not shown in FIG. 1.

It should be noted that what has been said above also applies analogously to the representation of a second embodiment of the bevel gear differential 1 according to the invention in FIG. 5, which is why the differential cage 2 is also shown cut open in FIG. 5 for reasons of clarity and the outer wheel 8 is not shown.

In the interior of the differential carrier 2, two bevel gears 3 are arranged opposite one another. The bevel gears 3 are each around an output shaft 5 rotatably mounted, the output shafts 5 of the two bevel gears 3 being congruent in the illustrated embodiments or, in other words, only one output shaft 5 being provided for both bevel gears 3.

The bevel gears 3 are non-rotatably connected to a respective side shaft 6, the output shafts 5 being the axes of rotation of the side shafts 6.

When the differential carrier 2 is driven via the outer wheel 8, the differential carrier 2 also rotates about the output shafts 5.

The bevel gear differential 1 further comprises at least one differential bevel gear 4, which is mounted rotatably about a differential bevel gear axis 7. In the illustrated embodiments, exactly two differential bevel gears 4 are provided, which are arranged opposite one another in the differential cage 2 so that the differential bevel gear axles 7 are congruent or, in other words, there is only one differential bevel gear axle 7 for both differential bevel gears 4. Accordingly, a single, continuous bearing pin 13 is sufficient for the rotatable mounting of the two differential bevel gears 14, the

Differential bevel gear axis 7 is congruent with the longitudinal axis of the bearing pin 13.

According to the invention it is provided that the at least one differential bevel gear 4 can be displaced along its differential bevel gear axis 7 and / or at least one of the bevel gears 3 along its output axis 5 between an engagement position 9 and a release position 10, wherein in the engagement position 9, but not in the release position 10, the at least one differential bevel gear 4 meshes with the two bevel gears 3 and connects them to one another. That is, in the engagement position 9, the bevel gears 3 and the at least one differential bevel gear 4 are in engagement with one another. When the differential cage 2 is driven (via the outer wheel 8), the side shafts 6 are correspondingly driven, the bevel gear differential gear 1 being the usual one

Fulfills differential function and allows different speeds of the bevel gears 3 or side shafts 6, such as occur e.g. when cornering. Here, the at least one differential bevel gear 4 compensates for the unequal speeds of the bevel gears 3.

If, on the other hand, all of the bevel gears 4 and / or one of the bevel gears 3 are in its release position 10, there is no longer any rotational connection between the bevel gears 3. Correspondingly, the side shafts 6 are not driven when the differential cage 2 is driven (via the outer gear 8).

In the first exemplary embodiment in FIGS. 1, 2, 3 and 4, only the two differential bevel gears 4 can be displaced, but not the bevel gears 3. In contrast, FIGS. 5, 6, 7 and 8 illustrate the second embodiment, in which only one of the two bevel gears 3 is displaceable. The other bevel gear 3 and the two differential bevel gears 4 cannot be displaced in the second exemplary embodiment. In principle, however, embodiment variants are also conceivable in which both the at least one differential bevel gear 4 and at least one of the bevel gears 3 can be displaced.

In general, it should also be noted that in the exemplary embodiments shown, the bevel gears 3, the differential bevel gears 4 and the outer gear 8 are designed as gear wheels.

The details of the first exemplary embodiment become clear in FIGS. 3 and 4, which are a schematic sectional view according to the section line BB from FIG. 2, the arrows in FIG. 2 indicating the viewing direction. The two differential bevel gears 4 are not only rotatably mounted on the bearing pin 13, but also displaceably parallel to the differential bevel gear axis 7 so that they can be moved back and forth between the release position 10 and the engagement position 9.

3 shows the engagement position 9, in which the two differential bevel gears 4 are each in engagement with two bevel gears 3 and connect the latter to one another in a rotational manner. The two arrows pointing towards one another in FIG. 3 indicate the direction of movement of the two

Differential bevel gears 4 from their respective release position 10 into the engagement position 9.

In contrast, FIG. 4 shows the two differential bevel gears 4 in their release position 10, in which there is no engagement of the differential bevel gears 4 with the bevel gears 3 and the bevel gears 3 are therefore not rotationally connected to one another. The two arrows pointing away from one another in FIG. 4 indicate the direction of movement of the two differential bevel gears 4 from the engagement position 9 into the respective release position 10.

In order to be able to bring about the movement of the differential bevel gears 4 from outside the differential cage 2, an actuating element 11 is provided for each differential bevel gear 4. The actuating elements 11 are also mounted displaceably on the mounting bolt 13 parallel to the differential bevel gear axis 7, whereby they can be moved back and forth between a first position 17 and a second position 18.

The actuating elements 11 comprise facing inner sections 14, between which the two

Differential bevel gears 4 are arranged. Contact specifically the inner sections 14 the differential bevel gears 4 or the inner sections 14 rest at least in sections on the differential bevel gears 4, whereby a form-fitting operative connection between the differential bevel gears 4 and the inner sections 14 is provided.

It would theoretically also be conceivable that the inner sections 14 are connected to the differential bevel gears 4 in a fixed or at least rotationally fixed manner (e.g. by claws) to establish the operative connection, the actuating elements 11 then also having to be rotatably mounted on the bearing pin 13 around the differential bevel gear axis 7.

The actuating elements 11 furthermore each have an outer section 15 which protrudes outward through the differential cage 2, corresponding recesses being provided in the differential cage 2 for the outer sections 15. By contacting and pressing the respective outer section 15 from the outside, the respective actuating element 11 can be moved from the first position 17 into the second position 18 or held in the second position 18.

Due to the positive fit or the contact between the inner sections 14 and the differential bevel gears 4, the differential bevel gears 4 are pressed from their release position 10 into the engagement position 9 when the actuating elements 11 are moved from the first position 17 to the second position 18. For example, the differential bevel gears 4 are held in the engagement position 9 when the actuating elements 11 are held in the second position 18. Correspondingly, the actuating elements 11 are shown in the second position 18 in FIG. 3 and in the first position 17 in FIG. 4.

If the respective outer section 15 is not pressed from the outside, the respective actuating element 11 can be moved from the second position 18 into the first position 17 become. For this purpose, at least one spring element (not shown for reasons of clarity) is provided in the first exemplary embodiment, which presses the differential bevel gears 4 and thus also the actuating elements 11 outwards parallel to the differential bevel gear axis 7. Correspondingly, due to the spring force, the differential bevel gears 4 move from the engagement position 9 into their release positions 10 and the actuating elements 11 move from the second positions 18 into their first positions 17.

To move the actuating elements 11, a shift sleeve 12 is provided in the first exemplary embodiment, which is mounted outside of the differential cage 2 on the differential cage 2 so as to be displaceable parallel to the output shafts 5. By shifting the shift sleeve 12, it can be brought into engagement with the respective outer section 15 of the actuating elements 11 in order to move the actuating elements 11 from the first position 17 into the second position 18 or to hold them in the second position 18. Here, the shift sleeve 12 contacts the outer sections 15 and presses against them.

In Fig. 3, the dotted arrow indicates the movement of the shift sleeve 12 parallel to the output axles 5 and towards the pinion pinion axis 7 in order to establish engagement with the outer sections 15 and the actuating elements 11 and thus also the pinion pinion gears 4 inwards parallel to the pinion pinion axis 7 or to move towards one another, whereby the actuating elements 11 are brought into the second position 18 and the differential bevel gears 4 are brought into the engagement position 9 or are held in this. Similarly, the dotted arrow in Fig. 4 indicates the movement of the shift sleeve 12 parallel to the output axles 5 and away from the pinion pinion axis 7 in order to cancel the engagement with the outer sections 15 so that the actuating elements 11 and the pinion pinion gears 4 are in the Interaction with the above-mentioned at least one spring element parallel to the differential bevel gear axis 7 outward or away from each other, whereby the actuating elements 11 move into the first position 17 and the differential bevel gears 4 into the release position 10.

Since the direction of movement of the shift sleeve 12, on the one hand, and the direction of movement of the actuating elements 11, on the other hand, are essentially normal to each other, the outer sections 15 have flat contact surfaces 16 which run obliquely to the direction of movement of the shift sleeve 12 or obliquely to the output shafts 5 and one with the output shafts 5 Include acute angles. The shift sleeve 12 has a corresponding counterpart section 21, which forms a contact surface of the shift sleeve 12 and is designed as a counterpart to the contact surfaces 16 in order to facilitate the production of the engagement of the shift sleeve 12 with the outer sections 15. The contact surfaces 16 and the counterpart section 21 slide off one another, so that the actuating elements 11 are moved transversely or essentially normal to the direction of movement of the shift sleeve 12.

The details of the second exemplary embodiment are particularly clear in FIGS. 7 and 8, which show a schematic sectional view along the section line C-C from FIG. 6, the arrows in FIG. 6 indicating the viewing direction.

The two differential bevel gears 4 are only rotatably mounted on the bearing pin 13. One of the bevel gears 3 (shown on the left in FIGS. 7 and 8) is on the associated side shaft 6 by means of a sliding toothing 20 parallel to the output axis

5 slidably mounted. The other bevel gear 3 (shown on the right in Fig. 7 and Fig. 8) is with the associated side shaft

6 also connected via a sliding toothing, which is, however, dimensioned such that the bevel gear 3 cannot move parallel to the output shaft 5. 7 shows the engagement position 9 in which the displaceable bevel gear 3 is also in engagement with the two differential bevel gears 4. Correspondingly, the two bevel gears 3 are rotationally connected to one another via the differential bevel gears 4. The arrow drawn in full in FIG. 7 indicates the direction of movement of the displaceable bevel gear 3 from its release position 10 into the engagement position 9.

In contrast, FIG. 8 shows the displaceable bevel gear 3 in its release position 10, in which the displaceable bevel gear 3 is not in engagement with the differential bevel gears 4. The bevel gears 3 are therefore not rotationally connected to one another. The arrow drawn in full in FIG. 8 indicates the direction of movement of the displaceable bevel gear 3 from the engagement position 9 into the release position 10.

In order to be able to bring about the movement of the displaceable bevel gear 3 from outside the differential cage 2, two actuating elements 11 'are provided for the displaceable bevel gear 3. The actuating elements 11 ′ are arranged opposite one another and are mounted so as to be displaceable normal to the output shaft 5, the actuating elements 11 ′ being able to be moved back and forth between the first position 17 and the second position 18. When moving from the first position 17 to the second position 18, the two actuating elements 11 ′ move towards one another or towards the output shaft 5. When moving from the second position 18 to the first position 17, the two actuating elements 11 ′ move correspondingly from one another or away from the output shaft 5.

The actuating elements 11 ′ are in this case along the output shaft 5 and, viewed in the direction of the bearing pin 13, at least in sections in front of the displaceable bevel gear 3 arranged when the displaceable bevel gear 3 is in the engagement position 9.

The actuating elements 11 'comprise mutually facing inner sections 14, which contact a contact section 19 of the displaceable bevel gear 3 or bear at least sections of the contact section 19, whereby an operative connection is provided between the contact section 19 or the displaceable bevel gear 3 and the inner sections 14.

The contact section 19 can be designed in one piece with the rest of the displaceable bevel gear 3 or can be designed as a separate element which is connected to the rest of the displaceable bevel gear 3.

The actuating elements 11 ′ furthermore each have an outer section 15 which protrudes outward through the differential cage 2, corresponding recesses being provided in the differential cage 2 for the outer sections 15. By contacting and pressing the respective outer section 15 from the outside, the respective actuating element 11 ′ can be moved from the first position 17 into the second position 18 or held in the second position 18.

Due to the contact between the inner sections 14 and the contact section 19, the displaceable bevel gear 3 is pressed from its release position 10 parallel to the output shaft 5 and towards the differential bevel gear axis 7 into the engagement position 9 when the actuating elements 11 'move from the first position 17 into the second position 18 can be moved. For example, the displaceable bevel gear 3 is held in the engagement position 9 when the actuating elements 11 ′ are held in the second position 18. Correspondingly, the actuating elements 11 ′ are shown in the second position 18 in FIG. 7 and in the first position 17 in FIG. 8. Since the direction of movement of the actuating elements 11 'on the one hand and the direction of movement of the displaceable bevel gear 3 on the other hand are essentially normal to one another, the contact section 19 has a contact surface 22 which runs obliquely to the direction of movement of the actuating elements 11' or obliquely to the pinion pinion axis 7 and with the pinion pinion axis 7 includes an acute angle. The actuating elements 11 ′ each have a corresponding counterpart section 23, which is designed as a counterpart to the contact surface 22. As a result, the counterpart sections 23 and the contact surface 22 can slide on one another, so that the contact section 19 or the displaceable bevel gear 3 is moved transversely or essentially normal to the direction of movement of the actuating elements 11 '.

If the respective outer section 15 is not pressed from the outside, the respective actuating element 11 ′ can be moved from the second position 18 into the first position 17. For this purpose, several spring elements (not shown for reasons of clarity) are provided in the second embodiment

Actuating elements 11 'outwards or in the first position

17 move and on the other hand the displaceable bevel gear 3 along the output shaft 5 from the engagement position 9 into the release position 10. To move the actuating elements 11 ', the shift sleeve 12 is also provided in the second embodiment, which outside of the differential cage 2 on the differential cage 2 parallel to the output axes 5 is slidably mounted. By shifting the shift sleeve 12, it can be brought into engagement with the respective outer section 15 of the actuating elements 11 'in order to move the actuating elements 11' from the first position 17 into the second position 18 or in the second position

18 to hold. Here, the shift sleeve 12 contacts the outer sections 15 and presses against them. In Fig. 7, the dotted arrow indicates the movement of the shift sleeve 12 parallel to the output axes 5 and towards the pinion pinion axis 7 in order to establish engagement with the outer sections 15 and to move the actuating elements 11 'inwards or towards one another. As a result, the actuating elements 11 'are brought into the second position 18, the displaceable bevel gear 3 being brought into the engagement position 9 or held in this position by being displaced parallel to the output shaft 5 and towards the differential bevel gear shaft 7. Similarly, the dotted arrow in Fig. 8 indicates the movement of the shift sleeve 12 parallel to the output shafts 5 and away from the differential bevel gear axis 7 in order to cancel the engagement with the outer sections 15 so that the actuating elements 11 'can move outward or away from each other . As a result, in interaction with the above-mentioned spring elements, the actuating elements 11 'are brought into the first position 17, the displaceable bevel gear 3 moving parallel to the output axis 5 and away from the differential bevel gear axis 7 into the release position 10.

In addition, it should be noted that an embodiment with only a single spring element (not shown) would also be conceivable, e.g. so that the actuating elements 11 'are moved outward by centrifugal force when released by the shift sleeve 12, whereby the only spring element is the displaceable bevel gear 3 in can bring the release position 10 and the actuating elements 11 ′ are subsequently held in the first position 17 via the contact section 19 of the displaceable bevel gear 3.

Since the direction of movement of the shift sleeve 12, on the one hand, and the direction of movement of the actuating elements 11 ', on the other hand, are essentially normal to one another, the outer sections 15 have flat contact surfaces 16 which are inclined to The direction of movement of the shift sleeve 12 or at an angle to the output shafts 5 and enclose an acute angle with the output shafts 5. The shift sleeve 12 has a corresponding counterpart section 21 which is designed as a counterpart to the contact surfaces 16 in order to facilitate the production of the engagement of the shift collar 12 with the outer sections 15. The counterpart section 21 and the contact surfaces 16 slide on one another, so that the

Actuating elements 11 'are moved transversely or essentially normal to the direction of movement of the shift sleeve 12.

In the side view of Fig. 9, a third embodiment of a bevel gear differential 1 according to the invention is shown, which has a switching ring 28, see. Fig. 10, as an actuating element for the two differential bevel gears 4, resulting in an extremely compact design. The differential bevel gears 4 are shown in FIGS. 9 and 10 in the engagement position 9. The differential bevel gears 4 are mounted on the bearing pin 13, a compression spring 40 being arranged on the bearing pin 13 between the differential bevel gears 4, which is compressed in the engagement position 9 by the differential bevel gears, see first position 17.

The switching ring 28 has two ramps 29 with eccentric geometry, which form the inner section of the actuating element and press against the differential bevel gears 4 via intermediate pieces 41 or are in operative connection with them.

Furthermore, the switching ring 28 has two switching ring tabs 30 which form the outer section of the actuating element and can be contacted by the switching sleeve 12 in order to move the switching ring 28 from the first position 17 to the second position 18 move, the second position 18 being associated with the release position 10 of the differential bevel gears 4.

To move the switching ring 28 from the first position 17 to the second position 18 and vice versa, the switching ring 28 can be rotated relative to the differential cage 2 around the output shaft 5 by a switching angle g, the switching angle g being approx. 90 ° in the exemplary embodiment shown, cf. 12. Due to the eccentric geometry of the ramps 29, the differential bevel gears 4 located in the release position 10 are pressed into the engagement position 9 or moved along the bearing pin 13 against the force of the compression spring 40 into the engagement position 9 (radially inward) when the switching ring 28 is rotated by the switching angle g from the second position 18 to the first position 17, see. Relative rotation 42 'in Fig. 12. Conversely, the differential bevel gears 4 located in the engagement position 9 are pressed or moved into the release position 10 by the compression spring 40 . Moved along the bearing pin 13 (radially outward) when the switching ring 28 by the switching angle g from the first Position 17 is rotated into the second position 18, see relative rotation 42 in FIG. 10.

In principle, the switching ring 28 moves or rotates with the differential carrier 2 about the output shaft 5. In order to bring about the above-mentioned relative rotation 42 of the shift ring 28, the shift sleeve 12 is moved from a non-engagement position 43 in an actuation direction 37 parallel to the output shaft 5 towards the shift ring 28. To move the shift sleeve 12 in the actuation direction 37, an actuator, for example an electromagnet (not shown), is provided.

As a result of this movement of the shift sleeve 12 towards the shift ring 28, a friction cone 31 of the shift sleeve 12 is brought into contact with a respective friction surface 32 that is located on the shift ring tabs 30 when the shift ring 28 is in the first position 17. Due to the Friction between the friction cone 31 and the friction surfaces 32, the switching ring 28 rotating with the differential cage 2 is braked and thus moved or rotated relative to the differential cage 2 by the switching angle g into the second position 18. According to the eccentric geometry of the ramps 29, the compression spring 40 presses the differential bevel gears 4 into the release position 10, see FIGS. 11 and 12.

As a result of the described movement of the switching ring 28 from the first position 17 into the second position 18, two torsion springs 44 are tensioned in the exemplary embodiment shown. The spring force of the torsion springs 44 can subsequently be used to move the switching ring 28 back into the first position 17.

So that the switching ring 28 does not move back into the first position 17 in an uncontrolled manner after reaching the second position 18, two locking springs 33 are provided in the illustrated embodiment, which each lock with a locking contour 34 of the switching ring tabs 30 to keep the switching ring 28 in the second position 18 to hold. Fig.

13 shows the locking contour 34 in detail. The locking contour 34 has a stop section 35 on which the respective locking spring 33, more precisely a region of the respective locking spring 33 having a free end, can slide at the beginning of the relative rotation 42 of the switching ring 28. When the switching ring 28 has finally been moved from the first position 17 to the second position 18, the locking spring 33 locks with a locking section 36 of the locking contour 34 corresponds to the second position 18, arranged behind the run-on section 35.

Since the switching ring 28 is held by locking in the second position 18, the shift sleeve 12 can against the Actuating direction 37 back into the

Non-engagement position 43 can be transferred, whereby no actuator is necessary for this, but for example a simple spring (not shown) can be provided.

To release the lock, the shift sleeve 12 has an unlocking cone 38. When the shift sleeve 12 is moved again (by means of the actuator) in the actuation direction 37, the free ends of the locking springs 33 slide on the unlocking cone 38 in order to release the locking by lifting the locking springs 33 over the respective locking section 36. The tensioned torsion springs 44 then move the switching ring 28 from the second position 18 back into the first position 17, the differential bevel gears 4 being pushed back into the engagement position 9 via the ramps 29.

The sequence described above is illustrated in FIGS. 14a, 14b, 14c and 14d. In FIG. 14 a, the shift ring 28 is in the first position 17 and the shift sleeve 12 is in the disengaged position 43.

By moving the shift sleeve 12 in the actuation direction 37, the free end of the locking springs 33 is first arranged in a locking spring receptacle 39 designed as a groove. The friction cone 31 then comes into contact with the friction surfaces 32, as a result of which the switching ring 28 is moved into the second position 18. In addition, the respective locking contour 34 is brought into engagement with the respective locking spring 33, the latter being locked in the locking section 36 when the switching ring 28 has arrived in the second position 18. 14b shows this state.

In FIG. 14c, the shift sleeve 12 has been moved again (by means of the spring) into the disengaged position 43, so that the free end of the locking springs 33 has slid out of the locking spring receptacle 39 again. Due to the locking ring 28 is still held in the second position 18.

14d illustrates the release of the lock by moving the shift sleeve 12 again in the actuation direction 37, the free end of the locking springs 33 sliding on the unlocking cone 38 so that the locking springs 33 are lifted out of the latching section 36. Here, the friction cone 31 does not touch the friction surfaces 32. The switching ring 28, which is still shown in the second position 18 in FIG. 14d, is then rotated back into the first position 17 by means of the torsion springs 44.

The shift sleeve 12 can be moved back into the disengaged position 43 by means of the spring (not shown).

By moving the shift sleeve 12 again in the actuating direction 37, the shift ring 28 can subsequently be moved back into the second position 18 and so on.

To achieve an optimal switching behavior of the differential bevel gears 4 with the bevel gears 3, it can be provided that the respective gear wheel has teeth 24 with a tooth width b that is greater than a tooth height h of the teeth 24, see shows developed reference profile of such a gear. The tooth width b is measured as usual along a reference line 27 on the mean pitch cone diameter.

As an alternative or in addition, to improve switchability, the teeth 24 each have a contour optimized for switching in a transition area between a tooth tip 25 and a tooth flank 26, see FIG. 16, which is a schematic representation of a developed reference profile of such a gear shows. The enlarged detailed view in FIG. 17a illustrates the case that the contour has an elliptical geometry, ie that the contour of the respective tooth 24 in the transition area at least partially, preferably completely, forms an elliptical arc.

The enlarged detailed view in FIG. 17b again illustrates the case in which the contour has a geometry with two different radii R, r. The radius R is larger than the radius r, the radius R being used first, and then the radius r, as seen at the transition from the head region 25 to the flank 26.

The enlarged detailed view in FIG. 17c finally illustrates the case in which the contour has a flat bevel. A substantially flat transition area between the tooth tip 25 and the tooth flank 26 here, with the substantially flat tooth tip 25, encloses a bevel angle a which is only between 5 ° and 15 °.

REFERENCE LIST

1 bevel gear differential

2 differential cages

3 bevel gear

4 differential bevel gear

5 output axis

6 side shaft

7 Pinion pinion axle

8 outer wheel

9 engagement position

10 release position

11, 11 'actuator

12 shift sleeve

13 bearing pins

14 inner section of the actuating element

15 outer section of the actuating element

16 Contact surface of the outer section

17 First position of the actuating element

18 Second position of the actuating element

19 Contact section of the bevel gear

20 sliding teeth

21 Counterpart section of the shift sleeve 22 Contact surface of the contact section

23 Counterpart section of the inner section

24 tooth

25 tooth tip

26 tooth flank

27 reference line

28 shift ring

29 ramp

30 switch ring bracket

31 Friction cone of the shift sleeve

32 Friction surface of the shift ring plate

33 locking spring

34 Locking contour of the switch ring bracket

35 Approach section of the locking contour

36 Latching section of the locking contour

37 Direction of actuation

38 Release cone

39 Locking spring mount

40 compression spring

41 intermediate piece

42, 42 'relative rotation 43 disengaged position 44 Torsion spring h tooth height b tooth width

R, r radius a chamfer angle g switching angle

Claims

EXPECTATIONS

1. bevel gear differential gear (1) comprising a differential cage (2), in the interior of which two bevel gears (3) are arranged opposite one another, the bevel gears

(3) are each mounted rotatably about an output axis (5), the bevel gear differential gear (1) further comprising at least one differential bevel gear (4) which is rotatably mounted in the differential cage (2) about a differential bevel gear axis (7), characterized in that the at least one differential bevel gear (4) can be displaced along its differential bevel gear axis (7) and / or at least one of the bevel gears (3) along its output axis (5) between an engagement position (9) and a release position (10), wherein in the engagement position (9 ), but not in the release position (10), the at least one differential bevel gear (4) is in engagement with the two bevel gears (3) and connects them to one another.

2. bevel gear differential (1) according to claim 1, characterized in that at least two differential bevel gears

(4) are provided.

3. Bevel gear differential (1) according to one of the claims

1 to 2, characterized in that exactly two differential bevel gears (4) are provided, which are arranged opposite one another.

4. bevel gear differential gear (1) according to one of claims 1 to 3, characterized in that at least one actuating element (11, 11 ') is provided for the at least one differential bevel gear (4) and / or at least one of the bevel gears (3), wherein the at least one actuating element (11, 11 ') is movably mounted and wherein the at least one actuating element (11, 11') has an inner section (14) which is connected to the differential bevel gear (4) and / or the bevel gear (3) is operatively connected, and an outer section (15) which protrudes through the differential cage (2) to the outside in such a way that the outer section (15) can be contacted from outside the differential cage (2) to the actuating element (11, 11 ') from the outside at least to be able to move from a first position (17) to a second position (18) or vice versa.

5. bevel gear differential gear (1) according to claim 4, characterized in that the operative connection between the inner section (14) of the at least one actuating element (11, 11 ') and the at least one differential bevel gear (4) and / or the at least one of the bevel gears (3) is designed in such a way that the differential bevel gear (4) and / or the bevel gear (3) is in the release position (10) when the

Actuating element (11, 11 ') is in the first position (17), and in the engagement position (9) when the actuating element (11) is in the second position (18), or vice versa.

6. bevel gear differential (1) according to one of claims 4 to 5, characterized in that the at least one actuating element (11, 11 '), preferably parallel to the differential bevel gear axis (7) of the at least one differential bevel gear (4) and / or transversely to Output axis

(5) of at least one of the bevel gears (3) is displaceable.

7. bevel gear differential gear (1) according to one of claims 4 to 6, characterized in that the at least one actuating element (11, 11 ') with its inner section (14) on the at least one differential bevel gear (4) and / or the at least one of the Bevel gears (3) at least in sections, in order to move from the first position (17) to the second position (18) and / or from the second position (18) to the first position (17) to press against the differential bevel gear (4) and / or the bevel gear (3) and to move it.

8. bevel differential gear (1) according to any one of claims 4 to 7, characterized in that a movable, in particular displaceable, shift sleeve (12) is provided, which is arranged outside of the differential cage (2) and with the outer portion (15) of the at least an actuating element (11, 11 ') can be brought into engagement in order to be able to move the actuating element (11, 11') at least from the first position (17) into the second position (18).

9. bevel gear differential gear (1) according to claim 8, characterized in that the shift sleeve (12) is slidably mounted on the differential carrier (2), preferably parallel to one of the output axles (5).

10. bevel gear differential (1) according to one of claims 4 to 9, characterized in that the

The outer section (15) of the at least one actuating element (10, 11 ') has a contact surface (16) which preferably runs at an angle to one of the output shafts (5).

11. Bevel differential gear (1) according to one of claims 8 to 10 and claim 8, characterized in that the shift sleeve (12) has a contact surface (21) in order to establish the engagement of the shift sleeve (12) with the outer section (15) ) to facilitate the at least one actuating element (11, 11 ').

12. bevel gear differential (1) according to claim 11 and claim 10, characterized in that the

Contact surface (21) of the shift sleeve (12) as a counterpart to Contact surface (16) of the outer section (15) of the at least one actuating element (10, 11 ') is formed.

13. Bevel gear differential (1) according to one of claims 8 to 9, characterized in that as

Actuating element a switching ring (28) is provided that the switching ring (28) has at least one ramp (29) with eccentric geometry, the at least one ramp (29) forming the inner section of the actuating element so that the switching ring (28) has at least one switching ring bracket ( 30), wherein the at least one switching ring bracket (30) forms the outer section of the actuating element, and that the switching ring (28) is rotated by a switching angle (g) relative to the differential cage (2) from the first position (17) to the second position (18) and vice versa is movable.

14. Bevel gear differential (1) according to claim 13, characterized in that the shift sleeve (12) has at least one friction cone (31), that the at least one shift ring plate (30) has a friction surface (32), that the shift sleeve (12) can be moved in an actuation direction (37) towards the shift ring (28) and that by moving the shift sleeve (12) in the actuation direction (37) the at least one friction cone (31) engages the friction surface (32) of the at least one shift ring bracket ( 30) can be brought when the switching ring (28) is in the first position (17) in order to brake the switching ring (28) rotating with the differential cage (2) and thus by the switching angle (g) relative to the differential cage (2) to move to the second position (18).

15. Bevel gear differential (1) according to one of the

Claims 13 to 14, characterized in that at least one spring, in particular at least one Torsion spring (44) is provided, which is tensioned by the movement of the switching ring (28) from the first position (17) to the second position (18) in order to bring the switching ring (28) back into the first position (17) to move back.

16. Bevel differential gear (1) according to one of claims 13 to 15, characterized in that at least one, in particular spring-loaded, locking element (33) is provided that the at least one switching ring plate (30) has a locking contour (34) and that the The locking element (33) can be locked to the locking contour (34) by moving the switching ring (28) from the first position (17) to the second position (18) in order to hold the switching ring (28) in the second position (18) .

17. Bevel differential gear (1) according to claim 16, characterized in that the locking contour (34) of the at least one switching ring bracket (30) has a run-up section (35) to move the switching ring (28) from the first position (17 ) to be able to slide the locking element (33) on the run-up section (35) into the second position (18), and that a latching section (36) of the arresting contour (34) is provided behind the run-up section (35) in order to lock the locking element ( 33) to be able to latch with the latching section (36) when the switching ring (28) has been moved from the first position (17) to the second position (18).

18. Bevel differential gear (1) according to one of claims 16 to 17, characterized in that the

Shift sleeve (12) has at least one unlocking section (38), the unlocking section (38) - in particular by moving the shift sleeve (12) in an actuating direction (37) towards the shift ring (28) when the shift sleeve (12) is not initially in engagement with the at least one shift ring bracket (30) - in engagement with the at least one locking element ( 33) can be brought to release the latching of the locking element (33) with the locking contour (34).

19. Bevel gear differential (1) according to claim 18, characterized in that the at least one unlocking section is designed as an unlocking cone (38) that the at least one

The locking element is designed as at least one locking spring (33) so that one free end can slide on the unlocking cone (38) and thus the locking of the locking spring (33) with the locking contour (34) by moving the shift sleeve (12) in an actuating direction ( 37) to be able to solve on the switching ring (28) when the switching sleeve (12) is initially not in engagement with the at least one switching ring bracket (30).

20. Bevel gear differential (1) according to claim 19, characterized in that the shift sleeve (12) has at least one recess (39) for receiving the free end of the at least one locking spring (33), the free end in the recess (39 ) by moving the shift sleeve (12) in the actuation direction (37) when the shift sleeve (12) is not initially in engagement with the at least one shift ring bracket (30) and the shift ring (28) is in the first position (17) is.

21. Bevel gear differential (1) according to one of the

Claims 1 to 20, characterized in that the

Output axes (5) are congruent.

22. Bevel gear differential (1) according to one of claims 1 to 21, characterized in that the

Bevel gears (3) and the at least one differential bevel gear (4) are designed as gear wheels, the gear wheels having teeth (24) with a tooth width (b) that is greater than a tooth height (h) of the teeth (24).

23. Bevel gear differential (1) according to one of claims 1 to 22, characterized in that the

Bevel gears (3) and the at least one differential bevel gear (4) are designed as gears, the gears

Have teeth (24) each having a contour in a transition area between a tooth head (25) and a tooth flank (26), which contour

- has an elliptical geometry or - has a geometry with two different radii (R, r) or

- has a flat bevel with a bevel angle (a) between 5 ° and 15 °.

24. Motor vehicle comprising at least one bevel gear differential (1) according to one of claims 1 to 23 for the optional activation and deactivation of the drive of side shafts (6) connected in a rotationally fixed manner to the bevel gears (3).