A gearbox housing includes a set of ribs on an inner surface of a wall portion of the housing. During a fire event, heat received at the outside of the gearbox is transferred to the ribs, which transfer the heat away from the wall portion, in turn resisting the fire. The ribs may transfer the heat to oil, which may flow toward an oil drain. In addition or alternatively, the ribs may transfer the heat to a heat sink of the housing to which they are connected. The ribs may allow a thin region surrounding the ribs to a have a minimum thickness that is thinner than required to pass a fire test, thereby allowing for lighter weight gearbox houses that are still fire resistant.

A transmission case houses a plurality of coupling elements and a plurality of gears therein. Each of the plurality of coupling elements may be controllable by at least one of a plurality of actuators and at least one of a plurality of struts. Actuator pads and strut pockets are formed into opposing sides of at least one side wall of the transmission case. The side wall is strong enough to receive the forces created by the strut engaging the coupling elements, while eliminating the need for an extra coupling member that otherwise extends between the transmission housing side wall and the notch plate.

The disclosure relates to a transmission and all-terrain vehicle having the same. The transmission includes a casing body defining an air inlet and an air outlet; a casing cover mounted to the casing body, the casing cover and the casing body cooperatively defining a cavity in communication with the air inlet and the air outlet separately; and a transmission mechanism having at least a part provided in the cavity.

A mechanical system comprising a sump and at least one component to be lubricated or cooled arranged in the sump, the mechanical system comprising a lubricating fluid system provided with a lubricating fluid and a tank arranged in the sump. The tank is a leaking tank and is situated above said at least one component to be lubricated or cooled, the lubricating fluid flowing out of the tank by force of gravity, so as to reach said at least one component to be lubricated or cooled. The lubricating fluid system has at least one lift flow generator connected by at least one filling line to the tank and to at least one suction point present in a bottom of the sump. The lift flow generator fills the tank with the lubricating fluid present in said bottom at least during a starting phase.

An encapsulated gear train gear train for a machine comprising a support frame, which is non-encasing, an input shaft rotatably mounted in the support frame, an output shaft rotatably mounted in the support frame, gears configured to operatively connect the input shaft with the output shaft, and an encasement configured to encapsulate the input shaft, the output shaft, the gears, and at least a portion of the support frame, wherein the support frame is configured to be mounted on a structure of the machine such that the support frame does not apply any loads onto the encasement.

A turbofan engine having one or more heat exchangers tied to an accessory gearbox is provided. The accessory gearbox is mechanically coupled with a spool, and a hydraulic pump is mechanically coupled with the accessory gearbox. The one or more heat exchangers have a heat exchanger capacity defined by a product raised to a half power, the product being determined by multiplying a resultant heat transfer surface area density of the one or more heat exchangers by a heat conductance factor that relates an accessory gearbox heat load, a power of the hydraulic pump, a diameter of a fan, and a bypass ratio of the turbofan engine. The heat exchanger capacity is between 23.9 and 97.7 for a rotational speed of the spool between 7,500 and 35,000 revolutions per minute at one hundred percent capacity and a resultant heat transfer surface area density being between 4,000 m.sup.2/m.sup.3 and 13,000 m.sup.2/m.sup.3.

A gearbox for a vehicle includes: a housing; first and second shafts extending parallel to one another; first transmission gears mounted to the first shaft; and second transmission gears mounted to the second shaft. The transmission gears are helical gears. The first transmission gears are in constant mesh with the second transmission gears to form a plurality of gear pairings engageable to operate the gearbox in different gears. A drive gear is mounted to an input shaft extending into the housing. The input shaft is operatively connected to an engine of the vehicle. A driven gear is mounted to the second shaft and is configured to engage the drive gear. The drive and driven gears are spur gears. A flexible driving member is configured to drivingly connect one of the first shaft and the second shaft to an output shaft. A snowmobile including a gearbox is also contemplated.

An oil management system for a vehicle includes a differential housing, a transmission housing, a lubricant tank, a suction line, a lubricant pump, and an air suction pump. The transmission housing is connected to the differential housing in an air-tight manner, and a lubricant through-passage is defined between the transmission housing and the differential housing. The lubricant tank is provided in the differential housing and has a lubricant suction opening in a lower region. The lubricant pump conveys lubricant from the lubricant tank through the suction line and conducts the lubricant to the lubrication points in the differential housing and the transmission housing. The air suction pump pumps air from the lubricant tank into the transmission housing so that an excess air pressure is maintained in the transmission housing.

A transmission lubrication system for a vehicle providing a continuous return flow of a lubricant. The transmission lubrication system includes a differential housing, a transmission housing, a lubricant tank, a suction line, a lubricant pump, and an air suction pump. The transmission housing is connected to the differential housing in an air-tight manner and a lubricant through-passage is provided between the transmission housing and the differential housing. The lubricant tank is provided in the differential housing and has a lubricant suction opening in a lower region. The lubricant pump conveys lubricant from the lubricant tank through the suction line and conducts the lubricant to the lubrication points in the differential housing and transmission housing. The air suction pump pumps air from the lubricant tank into the transmission housing so that an excess air pressure is maintained in the transmission housing.

A transmission includes a transmission main housing, an intermediate plate secured to the transmission main housing; and a rear housing attached to the intermediate plate. An input shaft is connected to an extension shaft including a plurality of splitter gears selectively couple-able to the extension shaft. A main shaft is rotatably supported on the extension shaft and includes a plurality of main box gears selectively couple-able to the main shaft. A range shaft is drivingly connected to the main shaft and provides input to a planetary gear assembly, the range shaft being supported by a first bearing disposed within the intermediate plate and further including a bore disposed within a forward end. The extension shaft is supported at a first end by a bearing assembly within a partition wall and a second end is supported by a bearing assembly disposed within the bore in the range shaft.