The present invention relates to a power transmission device, which includes: a worm shaft; a Janggu (slim waist drum)-shaped worm which is provided on the worm shaft, and has a diameter-reduced part whose outer diameter is increased toward both ends from a center thereof in an axial direction of the worm shaft, wherein the diameter-reduced part has spiral worm teeth formed thereon; a first transmission shaft disposed in parallel to the worm shaft at an interval; and a first transmission gear which is provided on the first transmission shaft, and includes first gear teeth having tooth shapes conjugated with the worm teeth of the Janggu-shaped worm and are continuously formed in a spiral shape on an outer circumferential surface thereof, thus to rotate by threadedly engaging with the worm teeth of the Janggu-shaped worm.

A vehicle drive device uses a parallel shaft gear reducer (30) in which a gear is composed of helical gear, as a speed reducer part (B) that decelerates and outputs a rotation of an electric motor part (A). In the vehicle drive device, of meshing parts of the gears formed in the speed reducer part (B), two gears form a meshing part in which the amount of misalignment that occurs between the tooth surfaces of the two gears meshing with each other is different during driving and during coasting of a vehicle. A first tooth surface (S1) meshing with a mating tooth surface during driving is subjected to tooth surface modification, and a second tooth surface (S2) meshing with a mating tooth surface during coasting is subjected to tooth surface modification of an amount different from an amount of the tooth surface modification to the first tooth surface (S1).

A gear tooth for a gear of a planetary gear device may include a profile modification that alters a profile of the gear tooth to reduce wear and noise. Aspects of the profile modification may include a planar surface that connects a tip surface of the gear tooth with a first or second side of the gear tooth. Other aspects of the profile modification may include a curved surface connecting a tip surface of the gear tooth with a first or second side of the gear tooth. The gear tooth may also include non-constant profile width as measured between the first side and the second side in a gear thickness direction extending between the top and bottom surfaces of the gear. Aspects of gear teeth with either or both the profile modification and non-constant profile width may reduce tooth wear and gear noise during operation of the planetary gear device.

A planetary gearbox includes a sun gear having one tooth, a ring gear, planet gears, and a planet carrier on which the pant gears are rotatably arranged. Each of the sun gear, the planet gears, and the ring gear have evoloid toothing. The planetary gearbox enables high load capacity at high transmission ratios by using three circulating planetary gears in the ring gear, which is frame-fixed. The planet gears do not hit each other at a high transmission ration of i=24:1 because of defined addendum modification coefficients and addendum coefficients of the individual gears of the planetary gearbox.

A deceleration mechanism is provided with first and second gears, a first tooth part arranged in the first gear and extending spirally in an axial direction of the first gear, an engagement projected part arranged on the first tooth part, second tooth parts arranged on the second gear, and an engagement recessed part arranged between the adjacent second tooth parts. The engagement projected part is formed in an arc shape in a direction orthogonal to the axial direction of the first gear and has a curvature center eccentric from a rotation center of the first gear. The second tooth parts are inclined with respect to the axial direction of the first gear and arranged in a circumferential direction of the second gear. The engagement projected part is formed in an arc-shape in a direction orthogonal to the axial direction of the first gear and engaged with the engagement projected part.

An accessory drive gear for use in the integrated drive generator includes a gear body extending between a first end and a second end and having a plurality of gear teeth at a radially outer surface adjacent the first end, and the gear teeth having a gear tooth profile, with roll angles A, B, C, and D, and the roll angle at A being between 17.0 and 18.5, the roll angle at B being between 20.0 and 21.5, the roll angle at C being between 29.5 and 31.0, and the roll angle at D being between 32.5 and 34.0. In addition, an integrated drive generator is disclosed as is a method of replacing an accessory drive gear in an integrated drive generator.

The present invention discloses a line gear mechanism for rotation-movement conversion, comprising a driving line gear (1) and a driven line gear (2). A stagger angle between an axis of the driving line gear and an axis of the driven line gear is any value from 0 to 180. By a point contact meshing between a driving contact curve of a driving line tooth on the driving line gear (1) and a driven contact curve of a driven line tooth on the driven line gear (2), and by utilizing rotation of the driving line gear (1), it achieves that the driven line gear (2) rotates while moving smoothly. The line gear mechanism for rotation-movement conversion is simple in structure, easy to design, can achieve small displacement of movement, and is especially suitable for the conversion of small machinery from rotation to linear motion.

Gear mechanism, in particular coaxial gear mechanism or linear gear mechanism, having a toothing system, a tooth carrier with radially oriented guides, teeth which are received in the guides for engagement with the toothing system, the teeth being mounted in the guides such that they can be displaced radially relative to the tooth carrier in the direction of their longitudinal axis, a cam disk for radially driving the teeth, the tooth carrier comprising a first tooth carrier part and a second tooth carrier part.

The present invention relates to a concave-convex arc line gear mechanism for parallel shaft transmission, which comprises a driving line gear and a driven line gear, axes of the driving line gear and the driven line gear being parallel to each other to form a transmission pair.

A deceleration mechanism is provided with first and second gears, a first tooth part arranged in the first gear and extending spirally in an axial direction of the first gear, an engagement projected part arranged on the first tooth part, second tooth parts arranged on the second gear, and an engagement recessed part arranged between the adjacent second tooth parts. The engagement projected part is formed in an arc shape in a direction orthogonal to the axial direction of the first gear and has a curvature center eccentric from a rotation center of the first gear. The second tooth parts are inclined with respect to the axial direction of the first gear and arranged in a circumferential direction of the second gear. The engagement projected part is formed in an arc-shape in a direction orthogonal to the axial direction of the first gear and engaged with the engagement projected part.