Fichtel & Sachs Ag

Sachs Systemtechnik Gmbh

Mannesmann Sachs Ag

Gerd Brunken

Werner Gob

Dieter Neugebauer

Hans Fliege

Volker Eibl

Rupert Stangl

Oswald Reis

Peter Rossmanek

A viscous coupling is designed with a coupling housing and at least one drivable rotor, which is provided for the transmission of torque via shearing areas in a working chamber filled with viscous fluid. This working chamber is partitioned from a supply chamber for viscous fluid by a dividing wall. The viscous fluid can be delivered from the working chamber via a pumping into the supply chamber or from the supply chamber via a feed line. A volumetric-flow setting device having an electromagnetic adjusting device operably complete with the feed line back into the working chamber. The feed line, at least along part of its extension length, is directed through a region in which a magnetic field can be produced by the electromagnet. The viscous fluid is enriched with magnetizable particles, in, order to realize a magnetorheological behavior. As a result the flow velocity of the viscous fluid in tie feed line, when flowing through the magnetic field, can be varied as a function of the intensity of the applied magnetic field, this enables the volumetric flow between supply chamber and working chamber to be selectively, dynamically set.

Viscous coupling with a volumetric-flow setting means

The torsional oscillation damper intended in particular for the driving train of a motor vehicle comprises a disc part 11 which is rotatable round an axis of rotation and a housing part 17 which is equiaxially rotatable relative to the disc part 11, at least partially surrounds the disc part 11 and, together with the disc part 11, limits at least one damper chamber which is sealed from the exterior for receiving a viscous damper fluid. A displacement member 31 arranged on the disc part 11 or on the housing part 17 in each damper chamber divides the damper chamber into two displacement compartments which are connected to one another by a throttle channel 41. The disc part 11 and the housing part 17 are resiliently coupled together by a plurality of springs 23. On the side of the damper chamber located toward the axis of rotation 1 there are adjoined shearing gaps 47, 49 which are open toward the displacement compartments thereof and into which at least a proportion of the damper fluid from the damper chambers can escape during the relative rotation of disc part 11 and housing part 17. The quantity of damper fluid filling is calculated such that it is centrifuged substantially completely into the damper chamber in the absence of rotary oscillations and, as the oscillation amplitude increases, is displaced from the damper chamber into the shearing gaps 47, 49 to produce a frictional moment.

Torsional oscillation damper

The fluid friction clutch, suitable especially for the cooling fan of an internal combustion engine, has an aluminum housing mounted rotatably by means of a rolling bearing on a drive shaft. The outer race ring of the bearing is seated directly in a tubular bearing extension piece of the aluminum housing. A ring part, held on the bearing extension piece, of a material with lower coefficient of thermal expansion than aluminum, is secured on the bearing extension piece and prevents its widening with rising working temperature.

Fluid friction clutch

A fluid friction clutch, suitable especially for a cooling fan of an internal combustion engine, has a shear gap of substantially serpentine form seen in axial longitudinal section, which is formed by concentric annular ribs. The ribs of the two parts which form the shear gap engage in each case in concentric annular grooves between radially adjacent ribs of the other part. The ribs have conical ring flanks with a flank angle preferably of 30.degree. and terminate in a flat end face perpendicular to the rotation axis. The groove bottom opposite to this end face has a rounded cross section and is spaced from the end face by a distance about equal to 1.2 to 1.4 times the width of the shear gap between opposed rib flanks. Because of this geometry, the fluid friction clutch has a very great torque transmission capacity with small dimensions and reacts very rapidly to variations of state. The configuration of the ribs and channels guarantees an optimum conductance of heat and affords only a relatively slight flow resistance to the shear fluid.

The temperature-dependently controllable fluid friction clutch comprises a temperature-control device for the shear fluid circulation, with a bimetallic element (35) held on an end wall of the housing (7) and coupled, through a pin (39) freely displaceably guided in a bore (37), with a valve (25, 27) of the temperature-control device. To seal the pin (39) in relation to the housing (7) on the part of the pin (39) issuing from the housing (7) there is set a sealing element (41) which rests under axial stress through a sealing flange (43) of substantially annular disc form on a sealing surface (45) extending transversely of the axis (1) of rotation. The sealing flange (43) has substantially the form of a relatively shallow or flat frusto-conical shell widening towards the sealing surface (45) and is stressed substantially only to flex elastically. In this way friction forces between the pin (39) and the bore (37) can be reduced, which improves the accuracy of the temperature control.

Temperature-dependently controllable fluid friction clutch

The fluid friction clutch comprises a clutch input part drivable about a rotation axis and a clutch output part rotatable coaxially in relation to the clutch input part. The clutch output part together with the clutch input part defines at least one shear gap. A cover which forms a cavity enclosing at least the region of the shear gap is filled partially with viscous fluid and otherwise with gas. The gas-filled volume of the cavity contains less than 18 percent of oxygen by volume, preferably not more than 5 percent of oxygen by volume, in order to preclude a chemical reaction of the viscous fluid with the oxygen under thermal overloading which limits the utility of the viscous fluid. To reduce the proportion of oxygen either the cavity is evacuated or it is filled with a substantially oxygen-free protective or noble gas.

The fluid friction coupling, which is suitable especially for a fan of an internal combustion engine, comprises a buffer chamber (39) which receives a part of the entire quantity of shear fluid contained in the coupling, through an inlet opening (43) placed beneath the shear fluid level (47), when the coupling is not in rotation. The received partial quantity lowers the liquid level in the shear gaps (23). In cold starting therefore the coupling transmits a reduced torque, which by reason of the consequently increased slip increases the pump effect of a pump device (37) and reduces the fan noise. The quantity of shear fluid contained in the buffer chamber (39) is delivered again to the shear fluid cycle of the coupling with time retardation through a constricted opening (45) when the coupling is in operation.

Fluid friction coupling

The invention relates to a fluid-friction coupling for the cooling fan of an internal combustion engine. The torque transmission of the coupling is controlled in dependence upon the working temperature of the internal combustion engine. In order to suppress undesiredly high temperatures within the coupling at excessively high drive-input rotation speed, the torque transmission and thus the power loss are reduced when the working temperature of the coupling rises.

Fluid-friction coupling for a cooling fan of an internal combustion

A key assembly for operating a coded security system is structured with a plurality of information carrier members mounted on a longitudinal member of the key assembly and angularly arranged thereon to define a code for a security system operated by the key. Alteration of the code is effected by changing the relative orientation of the information carrier members by threadedly loosening the longitudinal member upon which the carrier members are held, readjusting the position of the carrier members and tightening the longitudinal member to hold the information carrier members fixed in a desired relative position defining the code.

Key assembly for coded security system

An operating mechanism for a lock and the like is operated by means of a key on which permanent magnets may be secured in available magnet positions of a fixed pattern of such positions, selected positions being occupied by magnets. A reading device includes a reader body and a guide for guiding the key into a predetermined position in which respective sensors are contiguously adjacent each available magnet position and respond to the presence of a magnet in the adjacent position by generating an electrical signal. The several signals are compared with a reference signal, and an operating signal is generated by a comparator connected to the sensors and to the source of the reference signal when the sensor signals agree with the reference signal.

Key-controlled electromagnetic operating mechanism for a lock and the

A magnetic security system is controlled by a magnetic key having magnetic devices defining an operating code which may be operatively interposed relative to a sensing device which will read the code defined on the key and will activate an electrical control system for delivering an electrical signal depending upon the code sensed upon the interposed key. The sensor device includes a code storage element and when the magnetic key is interposed relative to the sensor device, a comparison is drawn between the code on the key and the code programmed into the storage element. The storage element includes means for changing the code which is stored therein and lock means are provided to enable and disable changing of the code stored in the storage element.

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Dittelbrunn, Germany

Gerd Brunken