Gears are known to have a whine that can be unpleasant to operators or occupants of vehicles. A gear set is disclosed in which the pressure angle of the teeth varies along the periphery of the gear. A mating gear also has teeth with varying pressure angle. The teeth that mate have an identical pressure angle so that present disclosure is applicable only to 1:1 or integer ratio gears: 2:1, 3:1, etc. Because the teeth meet differently as a function of the pressure angle, the fundamental vibration frequency is not reinforced as would be the case with all teeth having the same pressure angle.

Gears are known to have a whine that can be unpleasant to operators or occupants of vehicles. A gear set is disclosed in which the pressure angle of the teeth varies along the periphery of the gear. A mating gear also has teeth with varying pressure angle. The teeth that mate have an identical pressure angle so that present disclosure is applicable only to 1:1 or integer ratio gears: 2:1, 3:1, etc. Because the teeth meet differently as a function of the pressure angle, the fundamental vibration frequency is not reinforced as would be the case with all teeth having the same pressure angle.

An assembly for acoustically influencing toothed wheels, including at least one first toothed wheel having teeth and one second toothed wheel having teeth, wherein the teeth have flanks, wherein at least one flank of a tooth of the first toothed wheel can be engaged with a flank of a tooth of the second toothed wheel, wherein at least one flank of a tooth of the first toothed wheel forms a contact zone or, in the ideal case, a contact line with an engaging flank of a tooth of a second toothed wheel, wherein the contact zone or the contact line is formed at an angle α.sub.Aq, in particular between 5° and 85° or between 95° and 175°, in relation to an axis of an undulation, a microangle distribution, and/or a microangle periodicity of the engaging flank of the tooth of the second toothed wheel.

An assembly for acoustically influencing toothed wheels, including at least one first toothed wheel having teeth and one second toothed wheel having teeth, wherein the teeth have flanks, wherein at least one flank of a tooth of the first toothed wheel can be engaged with a flank of a tooth of the second toothed wheel, wherein at least one flank of a tooth of the first toothed wheel forms a contact zone or, in the ideal case, a contact line with an engaging flank of a tooth of a second toothed wheel, wherein the contact zone or the contact line is formed at an angle α.sub.Aq, in particular between 5° and 85° or between 95° and 175°, in relation to an axis of an undulation, a microangle distribution, and/or a microangle periodicity of the engaging flank of the tooth of the second toothed wheel.

A display system for a timepiece is disclosed. The system includes a mobile arranged to be driven by a drive source by first teeth provided on the mobile. The mobile includes second teeth including a teeth module of less than 0.05 mm, the second teeth being arranged so as to drive a display member either directly or indirectly.

A display system for a timepiece is disclosed. The system includes a mobile arranged to be driven by a drive source by first teeth provided on the mobile. The mobile includes second teeth including a teeth module of less than 0.05 mm, the second teeth being arranged so as to drive a display member either directly or indirectly.

A toothed transmission element includes a partial region formed with a first material, teeth defining an edge region which is formed additively with a second material having a hardness which is greater than a hardness of the first material, and a third material located between the first material and the second material, wherein a hardness decreases stepwise along a section leading from the edge region to the partial region.

A gear mechanism includes a gear including external teeth, the external teeth including a plurality of tooth parts defined by a cycloid curve, a plurality of contacting members disposed on an outer side and in a circumferential direction of the external teeth, the external teeth being brought into pressure contact with the plurality of contacting members, and a mechanism configured to eccentrically move the gear. A plurality of through holes penetrating the gear in a thickness direction of the gear are formed in the gear in the circumferential direction of the gear, the cycloid curve extends outward from an ideal cycloid curve without the external teeth interfering with the plurality of contacting members, the plurality of contacting members being in contact with the ideal cycloid curve.

A gear mechanism includes a gear including external teeth, the external teeth including a plurality of tooth parts defined by a cycloid curve, a plurality of contacting members disposed on an outer side and in a circumferential direction of the external teeth, the external teeth being brought into pressure contact with the plurality of contacting members, and a mechanism configured to eccentrically move the gear. A plurality of through holes penetrating the gear in a thickness direction of the gear are formed in the gear in the circumferential direction of the gear, the cycloid curve extends outward from an ideal cycloid curve without the external teeth interfering with the plurality of contacting members, the plurality of contacting members being in contact with the ideal cycloid curve.

A method for manufacturing a gear which effectively prevent a crack from occurring inside a tooth part when rolling processing is performed on a teeth part of a gear raw material is achieved. A method according to one embodiment for manufacturing a gear by performing rolling processing on a tooth part of a sintered gear raw material. The method includes, when the rolling processing is performed on the tooth part of the gear raw material, pressing the gear raw material toward a center of rotation of the gear raw material by a rolling machine and, when at least the rolling processing is performed on the tooth part of the gear raw material toward a center of a thickness thereof by a pressing machine, pressing a region where an internal density of the tooth part of the gear raw material decreases.