Gear train mechanism of timepiece
AssigneeCitizen Watch Co., Ltd.
InventorsTadahiro Fukuda, Shinpei Fukaya
Life of this patent
Estimating the term…
Abstract
A gear train mechanism of a timepiece is formed by a gear having an involute tooth profile, which is easily manufactured, and a pinion that meshes with the gear. In order to reduce a fluctuation in torque to be transmitted, a gear train mechanism of a timepiece includes a gear including a tooth having a tooth profile of an involute curve and a pinion including a tooth meshing with the tooth of the gear to transmit and receive a torque, wherein the torque to be transmitted from the gear to the pinion is substantially constant at least in a part of a first half of a meshing period of the gear and the pinion.
Claims9
A gear train mechanism of a timepiece, comprising:
- a gear including a tooth having a tooth profile of an involute curve;
- and
- a pinion including a tooth meshing with the tooth of the gear to transmit and receive a torque, wherein:
- the torque to be transmitted from one of the gear and the pinion to the other of the gear and the pinion is substantially constant at least in a part of a first half of a meshing period of the gear and the pinion, and
- a tooth profile of the pinion is set to a constant torque curve having a substantial constant torque to be transmitted from a virtual gear different from the gear, the virtual gear including an involute profile having a pressure angle larger than a pressure angle of the involute curve of the gear to the pinion when the tooth of the pinion meshes with a tooth of the virtual gear.
A gear train mechanism of a timepiece, comprising:
- a gear including a tooth having a tooth profile of an involute curve;
- and
- a pinion including a tooth meshing with the tooth of the gear to transmit and receive a torque, wherein:
- the torque to be transmitted from one of the gear and the pinion to the other of the gear and the pinion is substantially constant at least in a part of a first half of a meshing period of the gear and the pinion, and
- wherein a tooth profile of the pinion is set to a constant torque curve having a substantial constant torque to be transmitted from a virtual gear different from the gear, the virtual gear including an involute profile having a pressure angle smaller than a pressure angle of the involute curve of the gear to the pinion when the tooth of the pinion meshes with a tooth of the virtual gear including an involute profile having a pressure angle smaller than a pressure angle of the involute curve of the gear.
A gear train mechanism of a timepiece, comprising:
- a gear including a tooth having a tooth profile of an involute curve;
- and
- a pinion including a tooth meshing with the tooth of the gear to transmit and receive a torque, wherein:
- the torque to be transmitted from one of the gear and the pinion to the other of the gear and the pinion is substantially constant at least in a part of a first half of a meshing period of the gear and the pinion,
- the torque to be transmitted from the pinion to the gear is substantially constant at least in a part of a second half of the meshing period, and
- a tooth profile of the pinion is set to a constant torque curve having a substantial constant torque to be transmitted from the pinion to a virtual gear different from the gear, the virtual gear including an involute profile having a pressure angle smaller than a pressure angle of the involute curve of the gear when the tooth of the pinion meshes with a tooth of the virtual gear.
Dependencies are inferred from the claim text.