Abstract: The invention relates to a planet gear having a planet carrier rotatable around an axis of rotation, comprising at least one planet wheel arranged on the planet carrier, a sun wheel and a ring gear, wherein the planet wheel is arranged in a movable manner at least radially with respect to the axis of rotation of the planet carrier. To minimize the backlash of a planet gear of this type, it is further provided that the ring gear is formed in two pieces on a plane perpendicular to the axis of rotation of the planet carrier, wherein the two halves of the ring gears can be rotated against each other and thereby effect a radial shift of the planet wheel in the direction towards the sun wheel in order to reduce backlash.

Abstract: A multistage spur-type gearing for small and miniature electric motors having a gearing housing and at least two gear shafts or axles held in the gearing housing, with spur gears of different diameters arranged on the gear shafts or axles. To achieve an extremely small construction at maximum reduction ratios in comparison with conventional spur-type gearings, at least two spur gears are fixedly connected to one another and combined to form a dual gear set, with the dual gear set rotatably supported on a gear axle made from a hard material, such as ceramics. At least one of the gear shafts should fixedly be held as a gear axle in the housing. An input shaft opening through which a motor shaft projects into the gearings is arranged to be substantially coaxial to the center axis of the gearing housing with which the gear shafts also extend in parallel and at some distance. Such a gearing makes it possible to arrange several reduction stages on one gear axle. Preferably, only two gear shafts or axles are used.

Abstract: Methods for fabricating a friction bearing, in particular for ceramic shafts, made of metallic hardenable sintered material having an open pore volume of at least 15%, wherein the sintered material is brought into a predetermined shape and is subsequently sintered. For improving the known friction bearings in that a local wear and tear of shaft and bearing is avoided or at least considerably reduced in the region of mixed friction with high lateral forces, it is provided to harden the friction bearing after the sintering.

Abstract: A friction bearing, for ceramic shafts, made of metallic hardenable sintered material having an open pore volume of at least 15%, wherein the sintered material is brought into a predetermined shape and is subsequently sintered. A local wear and tear of shaft and bearing is avoided or at least considerably reduced in the region of mixed friction with high lateral forces, it is provided to harden the friction bearing after the sintering.

Abstract: A method of producing a composite material, in particular for sintered slide bearings and slide bearings.Composite materials for sintered slide bearings consist of at least one ceramic sintered material and at least one metallic sintered material and have a short service life during operation at low speeds of the shaft and in the case of a simultaneously high radial load because the lubricant stored in the bearing cracks. The novel sintered bearing is to have a long service life under such operating conditions.In the novel bearing use is made of ceramic sintered materials which have a high thermal conductivity, e.g. boron nitride.The novel composite material and the novel slide bearing are particularly suited for electric miniature motors comprising a ceramic shaft.

Abstract: The present invention refers to a planetary gearing comprising a planet carrier which is adapted to be rotated about an axis of rotation, a sun gear, at least one planetary gear, and a ring gear, at least one axle end projecting beyond one end face of said planet carrier and said planetary gear being rotatably supported on said axle end by means of its axle-reception opening. Especially in small-size planetary gearings making use of sintered components, the service life is to be improved. For this purpose, it is suggested that the planetary gear should be constructed such that it is at least radially displaceable with regard to the axis of rotation of the said planet carrier.