Mecos Traxler Ag

Richemont International S.a.

Mecos Ag

Philipp Buhler

Rene Larsonneur

Denis Zimmermann

Stephan Germann

A contactless electromagnetic sensor device for determining displacements of a rotor () is disclosed. Two sensing coils () interact with surfaces of the rotor. A bridge circuit is formed by the sensing coils and by two secondary windings () of an input transformer (). The primary winding of the input transformer receives an excitation signal. An output signal is obtained at an output tap formed by a common node between the sensing coils () and a common node between the secondary windings of the input transformer. In this manner excitation and detection are separated. If cables are used for connecting the bridge circuit to signal processing circuitry, the input and output impedances of the bridge circuit can be matched to the characteristic impedance of the cables. An output transformer can be connected to the output tap. The roles of the input and output transformers can be interchanged.

Contactless sensor for determining rotor displacements

A magnetic bearing device and a method of operation for such a device are provided. The device comprises a group () of electromagnetic actuators (). Each actuator is electrically connected to an amplifier unit (). The actuators of a first subgroup are connected to a first common node (), while the actuators of a second subgroup are connected to a second common node (). The common nodes () are connected either directly or through means like an additional actuator. Preferably the common nodes () have no additional electrical connection to the amplifier unit. According to a special embodiment of the invention, each subgroup of actuators consists of only one single actuator and the common node has an electrical connection to the amplifier. Thus the device comprises two actuators in a series configuration connected to an H bridge. The common node may be connected to either of two different voltages. The invention enables simplified wiring without increased load requirements for the wires.

Magnetic bearing device with simplified wiring

A magnetic bearing device () with an improved vacuum-tight electrical feedthrough through its housing () is disclosed. The feedthrough () comprises a flat connection element () such as a rigid or flexible printed circuit board extending through the wall of the housing (), preferably all the way along an inner circumference of the housing. The connection element is sealed in a gas-tight manner to the housing. The element preferably has a central opening () for receiving the rotor shaft. Connections to the bearing units and sensors may be achieved by flat-ribbon cables () or flexprints. The sensors are preferably also implemented as printed sensors. Thus a very compact and cost-efficient magnetic bearing device can be obtained. An alternative embodiment uses a connection element on a side wall of the housing as a feedthrough to the bearing components.

Magnetic bearing device with an improved vacuum feedthrough

A rotor shaft () for a magnetic bearing device () is disclosed. The shaft comprises an inner portion on whose periphery a plurality of targets () separated by spacers () are mounted. This is achieved exerting an axial pressing force (F, F') to the peripheral parts, rather than applying a radial press fit. In this manner, a simplified construction, a higher stiffness and a higher stability at high rotational speed are achieved. Further disclosed is a rotor having a thrust disk () whose diameter decreases towards the periphery. This allows to use a larger thrust disk at a given rotational speed.

Rotor shaft for a magnetic bearing device

A magnetic bearing device () for rotatably supporting a shaft () for rotation about a rotation axis () is disclosed. The device () comprises a first active radial bearing (), one or more first radial displacement sensors (), and an axial bearing (). At least a part of the axial bearing () is disposed between the first active radial bearing () and the first radial displacement sensors () when viewed in an orthogonal projection onto the rotation axis (). A vacuum pump including the magnetic bearing device () and a multiple-sensing unit () are also disclosed.

Magnetic bearing device and vacuum pump

A lunar phase display mechanism includes an upper disc which is the lunar display disc and a lower disc mounted concentrically to this disc. One of the discs is mounted so that during normal operation of the mechanism that one disc rotates relative to the other disc, and the other disc is mounted in a stationary position during normal operation of the mechanism while this position can be changed by a rotary motion. The gear train driving the rotating disc allows that the direction of rotation of this disc can be reversed so that the different appearance of the lunar phases at the latitudes of the earth and, in particular, in the northern and southern hemisphere can be taken into account in the display.

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Zurich, Switzerland

Philipp Buhler