A transmission for a vehicle includes: an input shaft, a main shaft, and a countershaft, the main shaft being coaxial with the input shaft and the countershaft being parallel therewith, first and second primary gear planes arranged for torque transfer between the input shaft and the countershaft, and at least one secondary gear plane arranged for torque transfer between the countershaft and the main shaft. The transmission further includes a crawler shaft arranged in parallel with the main shaft, wherein the first primary gear plane comprises a first crawler shaft gearwheel arranged on the crawler shaft, and wherein the second primary gear plane comprises a second crawler shaft gearwheel arranged on the crawler shaft, the second crawler shaft gearwheel being selectively rotationally connectable to the first crawler shaft gearwheel so as to engage a crawler gear of the transmission.

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.

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.

A gear train includes a first gear having teeth meshed with teeth of a second gear. Each tooth of the first gear includes a coast side and a drive side opposed to the coast side. The drive side has a pressure angle that is greater than that of the coast side. The gear train can be part of a powertrain system for a rotorcraft, and can replace a traditional gear train in a retrofit or new build. The first gear is a planet gear and the second gear is a ring gear wherein the planet gear and ring gear are in a planetary gear train configuration.

A double helical gear includes a rotating shaft, a first gear, a second gear, a first weld zone, and a second weld zone. The first gear and the second gear are disposed side by side in an axial direction on the rotating shaft, the first gear includes a first teeth part, the second gear includes a second teeth part, and the first gear includes a first annular part to be fitted to the rotating shaft. The first weld zone is located on the first end surface, and has a welded part extending over a fitting portion between the first annular part and the rotating shaft as the first end surface is seen from the axial direction. The second weld zone is located on the second end surface of the first annular part at a gap between the first teeth part and the second teeth part in the axial direction.

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.

A drive transmission mechanism includes a first gearbox including a driving source, a first gear train, a first frame configured to support one ends of a plurality of shafts of the first gear train, and a first gear cover configured to support the other ends of the shafts of the first gear train, wherein the first gear box is configured to transmit a driving force from the driving source; and a second gearbox including a second gear train, a second frame configured to support one ends of a plurality of shafts of the second gear train, and a second gear cover configured to support the other ends of the shafts of the second gear train, wherein the second gearbox is configured to receive the driving force from the driving source through the first gear train and configured to transmit the driving force. The second gearbox is fixed to the first gearbox.

The present invention provides an inner meshing transmission mechanism, which comprises an outer wheel, the outer wheel being provided with a first number of circular arc teeth on its inner edge, and said first number of circular arc teeth being arranged around the inner edge of the outer wheel; an inner wheel, the inner wheel being provided with a second number of teeth on its outer rim, said second number of teeth being arranged around the outer rim of the inner wheel, wherein m>n; an eccentric rotation device configured to enable said inner wheel to be eccentrically placed inside of outer wheel; wherein one of said outer wheel, said inner wheel and said eccentric rotation device is connected to an input power, while another one of them being connected to an output device so that power is transmitted through engagement between said outer wheel and said inner wheel; and wherein the toothed profile of said inner wheel is designed such that at any time when said inner wheel is engaging with said outer wheel for transmission, only a portion of said second number of teeth engage with said first number of circular arc teeth, while the rest of said second number of teeth are separate from said first number of arc teeth.

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.

A low-cost railway vehicle gear device of parallel cardan drive system is provided in which the vibrations and noises can be reduced only by means of 2-D tooth surface modifications. In a railway vehicle gear device of parallel cardan drive system having a helical pinion (1) and a helical gear wheel (2), a pinion and a gear wheel respectively having gear specifications of module of 4 to 8, pressure angle of 20 to 30?, and helix angle of 15 to 30?, crowning is performed on a gear surface in the flank line direction of the pinion. The tooth surface (11) has a shape of a sinusoidal curve with an apex (11a) being positioned in a central area of the face width direction of the pinion, the sinusoidal curve being expressed by a single sinusoidal function and extending over an entire width in the face width direction of the helical pinion.