Gkn Automotive Ag

Uni-cardan Aktiengesellschaft

John R Botterill

Eugen Stall

Jorg Bensinger

Robert Rickell

Helmut Mildt

Gerald Kuhn

The invention relates to a gearbox switchable under load, which has an input shaft coupled to at least one further shaft, which extends parallel to the input shaft, via pairs of gearwheels to achieve different gear stages. One gearwheel of each pair of gearwheels is rotatively fixedly connected to one of the two shafts and the other gearwheel of each pair of gearwheels is optionally rotatively fixedly connectable to the other of the two shafts by a respective friction coupling. Also, in the gearbox, the input shaft is rotatively fixedly connected to an engine shaft; mechanism to reverse the direction of rotation is provided in the torque flow from the input shaft to the output pinion; and mechanism for approximately simultaneously loading the friction couplings of the two lowest gear stages is provided and for starting purposes when driving forward and reversing, the torque flow through both friction couplings is maintained, at most, until an identical speed has been reached between the elements of the friction coupling of the lowest gear stage.

Gearbox switchable under load

Device for switching on a drive train

A drive assembly for auxiliary units of an internal combustion engine of a motor vehicle, which may be mounted at an end wall of the internal combustion engine especially coaxially relative to the crankshaft, has two switchable gear stages between its input shaft, driven by the crankshaft and its output shaft, driving the auxiliary units. Gear changing is ejected by actuating a friction coupling. The friction coupling, in the connected condition, engages a direct gear and, in the disconnected condition, drives a reduction gear via a locking freewheeling device. An actuating assembly for the friction coupling includes adjusting discs which are held in a housing of the drive assembly so as to be arranged coaxially relative no the friction coupling and which are rotatable relative to one another. One of the adjusting discs, in the form of a supporting ring, is axially supported in the housing of the drive assembly. The other one, in the form of a pressure ring, is axially movable in the housing and acts on the friction coupling. At least two rolling members are guided in circumferentially directed ball grooves between the end faces of the adjusting discs facing one another. The depth of the ball grooves changes across the circumference in such a way that any rotation of the adjusting discs relative to one another results in a reciprocal axial displacement which is transferred to the friction coupling.

Drive assembly for auxiliary units

A switchable differential drive, preferably for a vehicle driven by an electric motor, has a differential drive housing, a drivable differential carrier rotatably supported in the housing, two axle shaft gears supported therein, which are connected to output shafts extending out of the differential carrier and which are connected to one another via differential gears. A first output shaft is designed directly as an axle shaft and a second output shaft is coaxially supported in the first axle shaft. Two switching couplings are arranged coaxially relative to the latter axle shaft. To obtain a first gear stage, the first switching coupling is engaged, thereby non-rotatingly connecting the output shaft to the axle shaft, while the second switching coupling is open. To obtain a second gear stage with one wheel drive, the second switching coupling is engaged, thereby non-rotatingly connecting the output shaft to the differential drive housing while the other switching coupling is open.

Switchable differential drive

A gearbox switchable under load, has at least two parallel shafts to achieve different transmission stages. The shafts both carry gears which permanently engage each other in pairs. Each one of the gears may be connected to its associated shaft via a friction coupling which is switchable by an axially effective operating assembly. The operating assembly includes at least one first adjusting ring which is rotatable and axially fixed relative to the shaft. Also, the operating assembly has at least one second pressure ring which is non-rotatable and axially movable relative to the shaft. The rings are arranged relative to each other and rotate a limited angular amount. The opposed end faces of the pressure ring and adjusting ring are provided with circumferentially extending groove pairs to accommodate at least three rolling members. The depths of the groove pairs are variable in opposite directions. The pressure ring acts, via an axial pressure bearing, on the friction coupling. The adjusting ring and the pressure ring may be rotated relative to each other, via a rotator assembly, to spread apart relative to each other via the rolling members and the groove pairs. The above-mentioned parts form a spreading mechanism with the friction coupling, at least partially, radially embracing the spreading mechanism. The rotator assembly, via teeth at an outer disc connected to the adjusting ring, engages the adjusting ring with a gear drive and/or chain drive.

Gearbox switchable under load including a coupling spreading assembly

A differential unit comprises a differential carrier (12) supported in a housing (1) for rotation; output elements (16, 17) differentially rotatable relative to the carrier and connected to respective output shafts, differential gears connecting the output elements, and a friction assembly comprising a number of plates (22) rotationally fast with one element of the differential interleaved with a number of plates (24) rotationally fast with another element of the differential, the friction plates being axially loadable into frictional engagement with one another to restrict the differential rotation of the output elements. The friction plates are loadable by an actuating mechanism comprising an abutment ring (54) fixed in the housing and an actuating ring (28) movable angularly and axially relative thereto, with cam surfaces provided by circumferentially extending variable depth grooves (47, 48) in the rings with balls (49) therebetween engaging the grooves. The cam grooves are arranged so that on angular movement of the actuating ring initially the rate of change of axial position thereof is high and then becomes lower with further angular movement.

Differential unit

A differential unit comprises a differential carrier (12) supported in a housing (11) for rotation; output elements (16, 17) differentially rotatable relative to the carrier and connected to respective output shafts; differential gears connecting the output elements; and a friction assembly comprising respective plates (22, 24) rotationally fast with elements of the differential, the friction assembly being axially loadable to restrict the differential rotation of the output elements. An actuating mechanism for loading the friction assembly comprises abutment and actuating rings angularly and axially movable relative to one another, with cam surfaces provided by circumferentially extending variable depth grooves in the rings with balls therebetween engaging the grooves. In order to avoid unintentional restriction of the differential action, the grooves and balls are arranged so that no frictional self-inhibition of relative movement between the abutment and actuating rings can occur.

A gearbox comprising two shafts (20, 27) with their axes parallel to one another and at least two pairs of gear wheels each pair comprising a wheel (38) on one of the shafts permanently in mesh with a wheel (45) on the other shaft, the wheels (45) on one of the shafts being connectable to the shaft by friction clutches, and actuating means disposed between adjacent friction clutches to selectively engage one or other of them; the actuating means comprising two pressure rings (2) and an adjusting ring (1) disposed between them, adjusting rings (5) for causing relative angular movement between the adjusting ring and pressure rings, and opposed pairs of grooves (21, 22) in the facing surfaces of the adjusting ring and pressure rings. Angular movement of the adjusting ring in one direction relative to the pressure rings causes axial movement of one pressure ring to operate on its adjacent friction clutch, while angular movement of the adjusting ring in the other direction causes axial movement of the other pressure ring to operate on the other friction coupling.

Gear box with gears shiftable under load

The present invention relates to an externally controlled lockable differential drive with the load application on its friction assembly being effected via a selectively actuatable rotary drive via a pressure ring. For this purpose, there is provided an actuating ring which is drivable by an electric motor via a pinion and which effects an axial adjustment of the pressure ring. The pressure ring itself cannot be rotatable relative to the housing. End faces of the pressure ring and the actuating ring which face each other are provided with control curves or profiles, which together with interplaced rolling elements, as necessary, displace the pressure ring upon rotation of the actuating ring, and can feature a nonlinear rate of change of the axial component acting on the pressure ring as a function of the angle of rotation of the actuating ring.

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Saarbrucken, Germany

John R Botterill