Torque transmission device

Abstract

Torque transmission device (1) comprising a vibration damping device (2), a torque converter (3) arranged at least partially within a housing (18) of the torque transmission device (1) with a pump impeller (4), a turbine impeller (5) and a guide wheel (6), a transmission input shaft (7) and a power splitting device (8) arranged between the torque converter (3) and the transmission input shaft (7), wherein the vibration damping device (2) is arranged outside the housing (18) of the torque transmission device (1) and the power splitting device (8) is arranged inside the housing (18) of the torque transmission device (1), wherein the power splitting device (8) is designed as a planetary gear or comprises one, characterized in thatthat the sun gear (13) and / or the vibration damping device (2) is directly connected to the guide gear hub (20) or to a guide gear freewheel inner ring.

Description

[0001] The invention relates to a torque transmission device comprising a vibration damping device, a torque converter arranged at least partially within a housing of the torque transmission device with a pump wheel, a turbine wheel and a stator wheel, a transmission input shaft and a power split device arranged between the torque converter and the transmission input shaft.

[0002] Such torque transmission devices are well known in the art, using, for example, a torsional damper in combination with a power split. For example, US Pat. No. 8,939,860 B2 discloses a torque transmission device that features such a combination of torsional damper and power split. A vibration damping device is arranged within the housing of the torque converter, with power input, for example, via the lock-up clutch being split by means of a planetary gear. Due to the arrangement of the vibration damping device within the torque converter or the housing of the torque converter, the vibration damping device is subject to the boundary conditions that exist within the housing of the torque converter. The vibration damping device therefore experiences an absolute speed and is subject to the influences of centrifugal force.Furthermore, the vibration damping device is operated within the same medium that is present within the housing of the torque converter.

[0003] As further prior art, reference is made to US 2015 / 0 072 822 A1, US 2015 / 0 065 294 A1, DE 10 2013 219 033 A1, DE 11 2015 001 230 T5 and DE 10 2014 218 743 A1.

[0004] The invention is therefore based on the object of providing a torque transmission device which enables operation of the vibration damping device independently of the boundary conditions of the torque converter.

[0005] This object is achieved by a torque transmission device having the features of patent claim 1. In particular, to achieve this object, in a torque transmission device of the type mentioned at the outset, the invention provides that the vibration damping device is arranged outside the housing of the torque transmission device and the power splitting device is arranged inside the housing of the torque transmission device.

[0006] The invention is based on the finding that arranging the vibration damping device within the housing of the torque transmission device or the housing of the torque converter results in the vibration damping device experiencing the absolute speed. Thus, negative influences, such as friction hysteresis, influences on durability, and characteristic curve design, must be taken into account when designing the vibration damping device. In contrast, the invention proposes arranging the vibration damping device outside the housing of the torque transmission device or the torque converter. This allows the vibration damping device, which is designed, for example, as a torsion damper, to be operated independently of the boundary conditions of the remaining torque transmission device or the torque converter.

[0007] It is particularly preferably possible to operate the vibration damping device in a targeted manner, for example encapsulated, with a different lubricant than the fluid within the torque converter.

[0008] According to a further development of the torque transmission device according to the invention, the vibration damping device is arranged on the transmission side. The vibration damping device is thus arranged on the transmission side in the torque transmission device according to the invention and not, as is usual in the prior art, in the housing of the torque converter. The arrangement on the transmission side makes it possible to support the vibration damping device independently of the housing of the torque converter or the torque transmission device, so that it can be operated independently of the described boundary conditions.

[0009] Particularly preferably, the vibration damping device is supported on a transmission housing directly or by means of an actuator. According to the invention, the vibration damping device is supported relative to the transmission housing, so that the vibration damping device does not rotate with the torque converter, but rather one side of the vibration damping device is ultimately stationary together with the transmission housing. Furthermore, it can be provided that, as an alternative to the direct support of the vibration damping device on the transmission housing, an "active" support of the vibration damping device is formed on the transmission housing. An actuator can preferably be used for this purpose, so that the vibration damping device is indirectly supported on the transmission housing and can be influenced via the actuator.

[0010] According to a further development of the above-described embodiment of the torque transmission device according to the invention, it can be provided that a spring rate or a characteristic curve of the vibration damping device can be changed by means of the actuator. Accordingly, the actuator can be specifically controlled or the vibration damping device can be switched via the actuator in such a way that the spring rate or the characteristic curve of the vibration damping device can be changed. Thus, the spring rate or the characteristic curve of the vibration damping device can be adjusted depending on the current operating point of the torque transmission device. Advantageously, this makes it possible to change the vibration damping device in any operating state of the torque transmission device in such a way that the vibrations that occur can be damped as efficiently as possible.

[0011] The above-described development of the torque transmission device according to the invention can further provide that the spring rate or the characteristic curve of the vibration damping device can be adjusted by means of the actuator in such a way that vibrations of one power branch of the power split device destructively interfere with vibrations of the other power branch.

[0012] The power split device splits incoming power or torque between two power branches, with one of the two power branches being dampened by the vibration damping device. The vibrations split between the two power branches are then superimposed at the point where the power branches rejoin. Depending on the operating condition, as previously described, the characteristic curve or spring rate of the vibration damping device can be changed using the actuator, so that the vibrations of the damped power branch can destructively interfere with the vibrations in the undamped power branch. The resulting anti-resonance ensures particularly effective damping or cancellation of the vibrations that occur, so that as few of the original vibrations as possible are transmitted to the transmission input shaft.

[0013] The torque transmission device according to the invention is further developed in that the power split device is designed as a planetary gear or has one. Consequently, it is possible to route one power branch of the power split device through a ring gear of the planetary gear and the other power branch through a sun gear of the planetary gear, so that these can be reconnected by means of the planetary gear, in particular through the two inputs to the planets. One of the two power branches is coupled to the vibration damping device, as described above, so that one power branch can be damped and the other power branch undamped.

[0014] According to a further development of the torque transmission device according to the invention, it can further be provided that a stator connection of the torque converter is connected to a sun gear of the planetary gear, or that the stator connection of the torque converter is connected to the sun gear of the planetary gear and the vibration damping device. One of the two power branches runs through the stator into the sun gear, and the other power branch runs through the turbine wheel and / or the lock-up clutch via the ring gear into the planetary gear. The force supported on the stator or the torque introduced into it is thus transmitted to the sun gear and introduced into the planetary gear. It is particularly preferably provided that the sun gear of the planetary gear, which is connected to the stator connection, is simultaneously connected to the vibration damping device, so that the power branch guided via the stator is the damped power branch.Vibrations introduced into the guide wheel can thus be transmitted to the vibration damping device and dampened by it.

[0015] For this purpose, the sun gear and the stator support or stator are arranged on a common stator shaft. According to this embodiment of the invention, the stator is not rigidly connected to the torque converter housing, but rather is rotatable relative to it. This allows relative movement between the stator and the torque converter housing, so that vibrations in the torque transmission device, which are transmitted to the stator, can be guided via the common stator shaft and damped by the vibration damping device. The stator shaft does not rotate absolutely at the speed of the torque converter, but merely experiences a "vibrational power," which it transmits to the vibration damping device or, in a damped manner, to the sun gear.

[0016] Particularly preferably, the sun gear and / or the vibration damping device can be connected directly to the stator support or to a stator freewheel inner ring. The stator has a freewheel inner ring, which ensures free rotation as long as the lock-up clutch is engaged. This means that, starting at a certain speed, as soon as the lock-up clutch is engaged, it is ensured that the stator can rotate freely with the turbine wheel.

[0017] The torque transmission device according to the invention can be further developed such that the transmission input shaft is connected to a planet carrier of the planetary gear set. The two power branches, which, as described above, are introduced firstly via the stator connection into the sun gear and secondly via the turbine wheel into the ring gear, are combined by the planetary gear set, so that the two superimposed torques of the two power branches are transmitted via the planet carrier to the transmission input shaft. As also described above, the vibrations of the power branches are superimposed, so that in the particularly preferred case of anti-resonance, destructive interference occurs between the vibrations of the two power branches, thus achieving almost complete cancellation of the vibrations.This ensures that the vibrations transmitted via the planetary carrier to the transmission input shaft can be almost completely eliminated.

[0018] Furthermore, the torque transmission device according to the invention can be provided with the ring gear of the planetary gear being connected to an output of a lock-up clutch and the turbine wheel, with the input of the lock-up clutch being connected to the drive. The power is thus split depending on the opening or closing state of the lock-up clutch, either via the lock-up clutch into the ring gear or via the turbine wheel into the ring gear. The second power branch is routed to the sun gear via the stator or via the stator connection, as described above.

[0019] The invention is explained below using an exemplary embodiment with reference to the drawing. The drawing is a schematic representation and shows a torque transmission device according to the invention.

[0020] The single figure shows a torque transmission device 1, comprising a vibration damping device 2 and a torque converter 3 with a pump wheel 4, a turbine wheel 5 and a stator wheel 6. The torque transmission device 1 is also assigned a transmission input shaft 7 and a power split device 8.

[0021] The power split device 8 comprises a ring gear 9, which is coupled or connected to a lock-up clutch 10 and the turbine wheel 5. The power split device 8 further has a plurality of planets 12 carried by a planet carrier 11, which mesh with the ring gear 9 on the one hand and with a sun gear 13 on the other. The planet carrier 11 is connected to the transmission input shaft 7. The sun gear 13 is arranged at one end of a stator shaft 14, wherein the stator shaft 14 is coupled to the vibration damping device 2 at its end opposite the sun gear 13. The vibration damping device 2 is designed, for example, as a torsion damper. As can be seen, the vibration damping device 2 is connected by one side 15 to the stator shaft 14 and by one side 16 to a transmission housing 17. The vibration damping device 2 is thus arranged outside a housing 18 of the torque converter 3.

[0022] A torque introduced into the torque transmission device 1 via a drive 19 is transferred via the impeller 4 to the turbine wheel 5. Due to the power split, the torque in the first power branch is transferred to the ring gear 9 via the turbine wheel 5 coupled to the ring gear 9, and in the other power branch, the torque is transferred via the stator 6 via a stator socket 20 to the stator shaft 14. The two power branches are thus combined in the power split device 8, which is clearly designed as a planetary gear, since the planets 12 mesh with both the ring gear 9 and the sun gear 13. If the lock-up clutch 10 is closed, the torque induced by the drive 19 is introduced into the ring gear 9 via the lock-up clutch 10.

[0023] This results in two power branches, one of which, passing through the stator 6 or the stator nozzle 20, is damped by the vibration damping device 2. The two power branches are combined in the power splitting device 8, so that the vibrations occurring in the individual power branches are superimposed. By appropriately selecting or designing the vibration damping device 2, it is possible, in particular, to ensure that the vibrations occurring in one power branch can be destructively superimposed on the vibrations occurring in the other power branch.For this purpose, the vibration damping device 2 can be modified, particularly by means of an actuator (not shown), such that the spring rate or the characteristic curve can be adjusted so that the vibrations occurring in the damped power branch oscillate anti-resonantly to the vibrations of the undamped power branch and can therefore be destructively superimposed on them. As a result, the vibrations ultimately introduced into the transmission input shaft 7 can be virtually canceled out due to the anti-resonance. List of reference symbols 1 torque transmission device 2 Vibration damping device 3 torque converters 4 pump wheel 5 Turbine wheel 6 Idler 7 Gearbox input shaft 8 Power split device 9 ring gear 10 Lock-up clutch 11 planet carrier 12 planets 13 Sun gear 14 Stator shaft 15 pages 16 pages 17 Gearbox housing 18 housings 19 Drive 20 idler nozzles

Claims

[1] Torque transmission device (1), comprising a vibration damping device (2), a torque converter (3) arranged at least partially within a housing (18) of the torque transmission device (1) with a pump wheel (4), a turbine wheel (5) and a stator wheel (6), a transmission input shaft (7) and a power splitting device (8) arranged between the torque converter (3) and the transmission input shaft (7), wherein the vibration damping device (2) is arranged outside the housing (18) of the torque transmission device (1) and the power splitting device (8) is arranged inside the housing (18) of the torque transmission device (1), wherein the power splitting device (8) is designed as a planetary gear or has such a planetary gear, characterized bythat the sun gear (13) and / or the vibration damping device (2) is connected directly to the stator support (20) or to a stator freewheel inner ring. [2] Torque transmission device according to claim 1, characterized by that the vibration damping device (2) is arranged on the gearbox side. [3] Torque transmission device according to claim 1 or 2 characterized by that the vibration damping device (2) is supported on a transmission housing (17) directly or by means of an actuator. [4] Torque transmission device according to claim 3, characterized by that a spring rate or a characteristic curve of the vibration damping device (2) can be changed by means of the actuator. [5] Torque transmission device according to claim 4, characterized bythat the spring rate or the characteristic curve of the vibration damping device (2) can be adjusted by means of the actuator in such a way that vibrations of one power branch of the power branching device (8) destructively interfere with vibrations of the other power branch. [6] Torque transmission device according to claim 5, characterized by that a stator support (20) of the torque converter (3) is connected to a sun gear (13) of the planetary gear or that the stator support (20) of the torque converter (3) is connected to the sun gear (13) of the planetary gear and the vibration damping device (2). [7] Torque transmission device according to one of the preceding claims, characterized by that the transmission input shaft (7) is connected to a planet carrier (11) of the planetary gear. [8] Torque transmission device according to one of the preceding claims, characterized bythat the ring gear (9) of the planetary gear is connected to an output of a lock-up clutch (10) and the turbine wheel (5), wherein the input of the lock-up clutch (10) is connected to a drive (19).

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