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.

The invention relates to a display system for a timepiece, said system comprising a mobile arranged to be driven by a drive source by means of first teeth provided on the mobile. According to the invention, the mobile comprises at least second teeth including a teeth module of less than 0.05 mm, said second teeth being arranged so as to drive a display member either directly or indirectly.

The invention relates to a display system for a timepiece, said system comprising a mobile arranged to be driven by a drive source by means of first teeth provided on the mobile. According to the invention, the mobile comprises at least second teeth including a teeth module of less than 0.05 mm, said second teeth being arranged so as to drive a display member either directly or indirectly.

An engine system is provided with a crankshaft gear coupled to a crankshaft of an engine for rotation therewith, and a balance gear coupled to a balance shaft for rotation therewith. The balance gear and crankshaft gear are in meshed engagement. The balance gear is formed by a series of sectors connected by a series of resilient blocks, with each sector defining first and second recesses along opposite radial edges sized to receive adjacent blocks, respectively. Each elastomeric block is configured to deform both normally and in shear thereby providing damping for the gear. A gear such as the balance gear, and a method of forming the gear are also provided.

An engine system is provided with a crankshaft gear coupled to a crankshaft of an engine for rotation therewith, and a balance gear coupled to a balance shaft for rotation therewith. The balance gear and crankshaft gear are in meshed engagement. The balance gear is formed by a series of sectors connected by a series of resilient blocks, with each sector defining first and second recesses along opposite radial edges sized to receive adjacent blocks, respectively. Each elastomeric block is configured to deform both normally and in shear thereby providing damping for the gear. A gear such as the balance gear, and a method of forming the gear are also provided.

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 rack bar includes a shaft portion and a rack toothed portion provided on the shaft portion. The rack toothed portion includes a plurality of rack teeth provided side by side in an axial direction of the shaft portion to mesh with a pinion gear. Each of the rack teeth includes a tooth tip portion, a contact face arranged obliquely relative to the axial direction and configured to contact the pinion gear, and a rounded corner portion between the tooth tip portion and the contact face. A first radius defining a central area of the rounded corner portion with respect to a tooth width direction is larger than a second radius defining another area of the rounded corner portion other than the central area.

A rack bar includes a shaft portion and a rack toothed portion provided on the shaft portion. The rack toothed portion includes a plurality of rack teeth provided side by side in an axial direction of the shaft portion to mesh with a pinion gear. Each of the rack teeth includes a tooth tip portion, a contact face arranged obliquely relative to the axial direction and configured to contact the pinion gear, and a rounded corner portion between the tooth tip portion and the contact face. A first radius defining a central area of the rounded corner portion with respect to a tooth width direction is larger than a second radius defining another area of the rounded corner portion other than the central area.

The present disclosure provides an improved cogwheel permitting enhanced meshing of cogwheels when operating perpendicularly. Exemplary embodiments introduce a multi-cogwheel design with specific dimensions and tooth profiles to permit perpendicular engagement of cogwheels whilst permitting translation of such cogwheels.