Abstract: A viscous coupling for a motor vehicle which may be connected or disconnected under load and which, in a reliable and interference-free way and with a short delay time, selectively permits the transmission or interruption of the driving force relative to the wheels of the rear and/or front axle, including a locking ring which is axially movable between two switching positions and may be moved into one of the two switching positions against the returning force of a spring by a force-actuated setting member which includes a firmly connected annular tongue which consists of a low-remanence ferromagnetic material and which may be transferred in an annular gap selectively loaded with a magnetic flow and formed by a soft iron core, with the axial length of the annular gap being greater than or equal to the axial distance covered by the setting member between the two switching positions.

Abstract: The invention relates to a viscous coupling 1 in the case of which one of the two coupling parts, i.e. either the coupling hub 9 or the coupling housing 2, is produced of plastics. To permit non-rotating accommodation of the associated coupling plates 11 or 12, metallic round bars 18 are embedded in the plastic coupling part 2 or 9 so as to be circumferentially distributed. The inner circumference or the outer circumference of the associated coupling plates 11, 12 is provided with an adapted profile. This measure ensures that in spite of the high loads occurring in the course of the transmission of torque it is possible to use plastic parts.

Abstract: A viscous coupling having a flushing pump for a drive assembly, in which the abrasion particles occurring as a result of friction between the plates are flushed out of the coupling housing. This is achieved by connecting the viscous coupling to a storage and a supply channel, and the flushing pump is driven as a result of relative movement of the two sets of plates in the viscous coupling and ensures that the viscous fluid flushes the interior of the viscous coupling.

Abstract: A spur gear differential (1) lockable to a limited extent and used as a differential gear for a motor vehicle. The differential makes use of the friction losses resulting from the oil flow conveyed by the teeth and teeth gaps of the planetary gears (6) and the sun gear (2) or the hollow gear (3). For control purposes, a cover ring (16) is provided which may be moved into a close position, i.e. a sealing position, relative to the end face (17) of the gear teeth or away therefrom to throttle or release the oil flow.

Abstract: A viscous coupling having outer plates which are provided with index recesses which serve to assemble the outer plates in a specific way relative to each other, depending on the respective application. If the outer plates have to be assembled in the housing with the apertures being aligned inphase relative to each other, the torque transmitting capacity of the coupling is lower than in those cases where the slots are circumferentially offset relative to each other in the housing, thereby forming a kind of labyrinth, in which case the viscous coupling achieves a 100% torque transmission because it may be transferred into the hump mode.

Abstract: A driving assembly includes a viscous shear coupling (15), a clutch (17) and a hysteresis or eddy current brake (19). The clutch comprises inner and outer parts (20 and 21) between which are received torque-transmitting balls (18) received in a cage (16) to which is connected a disc (30) forming part of the brake. The outer part (21) can overrun the inner part whether or not the brake is actuated. The inner part (20) can overrun the outer part (21) if the brake (19) is not actuated but drives the outer part (21) if the brake is actuated. The outer part (21) is connected to one part of the viscous shear coupling (15). A drive member (34) is connected to the inner clutch part (20) and a driven member (38) forms the other part of the viscous shear coupling.

Abstract: A clutch (1) including an inner part (3) and an outer part (4) having races (6 and 5) respectively between which are arranged rollers (4). The rollers are arranged in a cage (7) which is in two parts (8 and 9) which are connected by leaf springs (10). One part (8) of the cage may be operated upon by a brake (11) to retard it relative to the other part of the cage thus to cause the rollers to skew and jam between the races and thus transmit torque between the inner and outer member. The clutch may be associated with a viscous shear coupling (18) and the combination may be used in the driveline of a motor vehicle.

Abstract: A viscous shear coupling has housing and hub parts (20 and 22) with interleaved sets of plates (35, 36, 37), the set of plates carried by the housing part being in two sub-sets (35 and 36), the plates (36) of one sub-set being rotationally fast with the housing part and the plates (35) of the other sub-set being capable of limited relative rotation to the housing part and the plates of the other sub-set; plates of the first set carry projections (50, 52) so that upon said relative rotation the spacing of the plates is varied thus to control the torque transmitted by the coupling.

Abstract: A disconnectable transmission assembly comprising a coupling member within which is rotatably mounted in bearings a viscous coupling having a housing member and a hub which respectively carry interleaved plates. The coupling member and the housing member are connectable and disconnectable by means of a deformable sleeve which closes a chamber formed in the housing member and which can be supplied by fluid under pressure from a cylinder by movement of a piston. Deformation of the sleeve, which is connected to the housing member, engages the bore of the coupling member thus connecting the housing member and the coupling member for rotation. When the chamber is de-pressurized there is a running clearance between the sleeve and the coupling member.

Abstract: The invention relates to a coupling assembly which is controllable to vary the amount of torque transmitted by the assembly. The latter comprises a housing (2, 70) and hub carrying sets (12, 26, 97, 98, 99) of interleaved plates, the housing being filled with a viscous liquid. Means (4, 29; 23, 24, 25, 51) externally of the housing is provided rapidly and repeatedly to increase and decrease pressure applied to the liquid in the housing. Application of such pressure causes the plates of the two sets to come into contact and release of the pressure allows the plates to move apart.