The present invention discloses a mechanism that transfers an oscillating rotation into a unidirectional rotation. In one embodiment, the present invention discloses a spur gearing mechanism using spur gears. In another embodiment, the present invention discloses a bevel gearing mechanism using bevel gears, which reduces the total number of gears in comparison the spur gearing mechanism.

Described is a device for synchronization of a reverse gear for a vehicle gearbox including: a support shaft fixed in rotation; an idle gear wheel for engagement with a first reverse gear wheel on a gearbox primary shaft and a second reverse gear wheel on a gearbox secondary shaft, said idle gear wheel mounted rotatable and axially slidable on said support shaft and having a hub including a first friction surface; and a synchronizer ring mounted mobile on said support shaft along an axial travel and countered axially by an elastic element along said axial travel, said synchronizer ring having a second friction surface for engagement with said first friction surface. Axial movement of the idle gear wheel towards an engagement position of the reverse gear causes drawing of the synchronizer ring implementing, prior to reverse gear engagement, braking of rotary movement of the idle gear wheel.

Described is a device for synchronization of a reverse gear for a vehicle gearbox including: a support shaft fixed in rotation; an idle gear wheel for engagement with a first reverse gear wheel on a gearbox primary shaft and a second reverse gear wheel on a gearbox secondary shaft, said idle gear wheel mounted rotatable and axially slidable on said support shaft and having a hub including a first friction surface; and a synchronizer ring mounted mobile on said support shaft along an axial travel and countered axially by an elastic element along said axial travel, said synchronizer ring having a second friction surface for engagement with said first friction surface. Axial movement of the idle gear wheel towards an engagement position of the reverse gear causes drawing of the synchronizer ring implementing, prior to reverse gear engagement, braking of rotary movement of the idle gear wheel.

A powershifting multispeed reversing transmission includes a converter lockup clutch (31) arranged in a space (13) provided by arranging the forward-driving clutch (8) between the fixed gear (5) and the loose gear (7) on a forward-driving shaft, and the reverse-driving clutch (12) between the fixed gear (9) and the loose gear (11) a reverse-driving shaft.

A powershifting multispeed reversing transmission includes a converter lockup clutch (31) arranged in a space (13) provided by arranging the forward-driving clutch (8) between the fixed gear (5) and the loose gear (7) on a forward-driving shaft, and the reverse-driving clutch (12) between the fixed gear (9) and the loose gear (11) a reverse-driving shaft.

A reduction reverse gear according to the invention of the present application includes: an input shaft to which rotational driving force from a main engine is input; a front-reverse housing accommodating forward-backward switching mechanisms with which the rotational driving force from the input shaft is switched among forward, neutral, and backward; an output shaft through which the rotational driving force from the forward-backward switching mechanisms is output; and a reduction housing accommodating a reduction mechanism with which the rotational driving force from the output shaft is reduced to be transmitted to a propeller shaft. The housings are detachably coupled to each other on front and rear sides in an axial direction. The input shaft and the output shaft are arranged on the same plane while facing each other.

In accordance with an example embodiment, a transmission reverser may include a forward mode and a reverse mode. In the forward mode, a forward clutch is in the engaged condition causing an output gear to rotate with an output shaft. In the reverse mode, a reverse clutch and a disconnect clutch are in engaged conditions causing a counter shaft to rotate relative to the output shaft based upon the ratios of a first reverse gear to an idler gear and the idler gear to a second reverse gear and further causing the output gear to rotate relative to the counter shaft based upon the ratio of a third reverse gear to the output gear.

A transmission reverser for reversing a direction of an output gear carried by an output shaft includes a reverse shaft, a reverse clutch mounted about the reverse shaft and having engaged and disengaged conditions, and a reverse disconnect synchronizer mounted about the reverse shaft and having engaged and disengaged conditions. When the reverse clutch and the reverse disconnect synchronizer are in the engaged conditions, the reverse shaft rotates the output gear in a reverse direction of rotation opposite a direction of rotation of the output shaft. When the reverse disconnect synchronizer is in the disengaged condition, the reverse clutch is disconnected from the output gear.

A forward/backward switching mechanism having an intermediate gear supported by an intermediate shaft perpendicular to a drive shaft is interposed between first and second input shafts. A clutch body is a dog clutch having upper and lower locking dogs. As the dog clutch moves along an axial direction of the second input shaft and is engaged with upper or lower gears, rotation of the first input shaft is forwardly or reversely transmitted to the second input shaft.

A forward/backward switching mechanism having an intermediate gear supported by an intermediate shaft perpendicular to a drive shaft is interposed between first and second input shafts. A clutch body is a dog clutch having upper and lower locking dogs. As the dog clutch moves along an axial direction of the second input shaft and is engaged with upper or lower gears, rotation of the first input shaft is forwardly or reversely transmitted to the second input shaft.