Abstract: A snowmobile including a frame; at least one ski; an engine supported by the frame, the engine having an engine air inlet and an exhaust outlet; a turbocharger fluidly connected to the exhaust outlet of the engine, the turbocharger including an exhaust turbine, and an air compressor; a first airbox fluidly connected to the turbocharger, the first airbox receiving air from atmosphere surrounding the snowmobile; and a second airbox having at least a first airbox inlet and a second airbox inlet, the second airbox being fluidly connected to the engine air inlet for providing intake air to the engine, the first airbox inlet receiving air from the air compressor.

Abstract: A snowmobile including a frame; at least one ski; an engine with an engine air inlet and an exhaust outlet; a turbocharger including an exhaust turbine, and a compressor. An air intake system includes a first flow path connecting the compressor to the atmosphere; a second flow path connecting the compressor to the engine air inlet; an intake bypass flow path connecting atmosphere to the engine air inlet for bypassing the compressor; and an intake bypass valve for controlling the flow through the intake bypass flow path. An exhaust system includes a third flow path connecting the exhaust outlet to the exhaust turbine; a fourth flow path connecting the exhaust turbine to the atmosphere; an exhaust bypass flow path connecting the exhaust outlet to the atmosphere for at least partially bypassing the exhaust turbine; and an exhaust bypass valve for controlling the flow through the exhaust bypass flow path.

Abstract: A snowmobile including: a frame; an engine supported by the frame; an exhaust pipe connected to the engine; and a turbocharger connected to the exhaust pipe. The turbocharger includes a bypass conduit fluidly communicating with the turbocharger housing and including an exhaust inlet fluidly connected to the exhaust pipe; a valve in the bypass conduit for controlling the flow of exhaust gas, and an exhaust collector. The valve is movable between first and second positions, a first flow path passing through the exhaust inlet, through the bypass conduit, and into the exhaust collector, a second flow path passing through the exhaust inlet, through the bypass conduit, through the exhaust turbine, and into the exhaust collector, in the first position, a majority of the exhaust gas flowing along the first flow path and in the second position, a majority of the exhaust gas flowing along the second flow path.

Abstract: A method for changing a gear driving configuration of a discrete gear transmission (DGT) in a powertrain including an engine operatively connected to a continuously variable transmission (CVT). The DGT has a DGT input shaft operatively connected to a CVT driven pulley, a plurality of gears having a plurality of gear driving configurations and a DGT output shaft selectively operatively connected to the DGT input shaft based on the gear driving configuration. Responsive to a gear shift request, a target driven pulley speed is determined for synchronizing the DGT input shaft with the DGT output shaft for the desired gear driving configuration. The engine is controlled to change an engine speed to the target engine speed corresponding to the determined target driven pulley speed. Responsive to the DGT input shaft being synchronized with the DGT output shaft, the current gear driving configuration is changed to the desired gear driving configuration.

Abstract: A method of shutting down an off-road vehicle is provided. The vehicle includes two rear wheels, two front wheels, a motor selectively operatively connected to the wheels, a front driveshaft selectively connected to the motor to selectively drive the two front wheels, and a rear driveshaft connected to the motor to drive the two rear wheels. The method includes: interrupting operation of the motor; and automatically operatively connecting the front driveshaft to the motor once the operation of the motor has been interrupted.

Abstract: A method of shutting down an off-road vehicle is provided. The vehicle includes two rear wheels, two front wheels, a motor selectively operatively connected to the wheels, a front driveshaft selectively connected to the motor to selectively drive the two front wheels, and a rear driveshaft connected to the motor to drive the two rear wheels. The method includes: interrupting operation of the motor; and automatically operatively connecting the front driveshaft to the motor once the operation of the motor has been interrupted.

Abstract: A method of limiting belt slip in a continuously variable transmission (CVT) of a vehicle. The CVT is operatively connected to an engine. The method includes determining a slip speed of a belt of the CVT, determining the accumulated energy based on the slip speed of the belt and an engine torque produced by the engine, and controlling the engine torque in an intervention mode when the accumulated energy is greater than a threshold energy. Controlling the engine torque in the intervention mode comprises controlling at least one of cycling the engine torque, and limiting the engine torque. Systems and vehicles for performing the method are also disclosed.

Abstract: A CVT pulley includes a shaft having disposed thereon, a first and second sheave, and a spider. A spring biases the sheaves away from one another. The axially moveable second sheave is disposed axially between the axially fixed spider and the first sheave. A plurality of centrifugal weights, connected to either the spider or the second sheave, have a portion that moves radially outward with rotation of the shaft. The axial distance between the spider and the second sheave depends at least in part on the radial position of the portion which depends on the rotational speed. At least one cylinder is adapted to receive fluid. At least one piston, rotatable with the shaft, is adapted to move in the at least one cylinder in response to fluid being received therein, thereby selectively exerting force on one of the sheaves towards the other. CVTs and vehicles are also disclosed.

Abstract: A watercraft propulsion system has a driveshaft, an impeller or a propeller, an overrunning clutch, an electric motor and an internal combustion engine. The overrunning clutch has a first race and a second race. The first race is one of an inner race and an outer race. The second race is an other one of the inner race and the outer race. The first race is connected to the driveshaft for driving the driveshaft. The electric motor has a motor output shaft operatively connected to the first race. The internal combustion engine has an engine output shaft operatively connected to the second race. The overrunning clutch is connected to the motor output shaft and the engine output shaft such that the electric motor is able to selectively rotate the first race at a higher speed than the second race. A watercraft having the propulsion system is also disclosed.

Abstract: A method of limiting belt slip in a continuously variable transmission (CVT) of a vehicle. The CVT is operatively connected to an engine. The method includes determining a slip speed of a belt of the CVT, determining the accumulated energy based on the slip speed of the belt and an engine torque produced by the engine, and controlling the engine torque in an intervention mode when the accumulated energy is greater than a threshold energy. Controlling the engine torque in the intervention mode comprises controlling at least one of cycling the engine torque, and limiting the engine torque. Systems and vehicles for performing the method are also disclosed.

Abstract: A CVT pulley includes a shaft having disposed thereon, a first and second sheave, and a spider. A spring biases the sheaves away from one another. The axially moveable second sheave is disposed axially between the axially fixed spider and the first sheave. A plurality of centrifugal weights, connected to either the spider or the second sheave, have a portion that moves radially outward with rotation of the shaft. The axial distance between the spider and the second sheave depends at least in part on the radial position of the portion which depends on the rotational speed. At least one cylinder is adapted to receive fluid. At least one piston, rotatable with the shaft, is adapted to move in the at least one cylinder in response to fluid being received therein, thereby selectively exerting force on one of the sheaves towards the other. CVTs and vehicles are also disclosed.

Abstract: A driving pulley for a CVT has a shaft, a fixed sheave mounted on the shaft, a first sleeve disposed around the shaft and being operatively connected to the shaft, a movable sheave mounted on the first sleeve, a second sleeve disposed around the first sleeve and being connected to the shaft, a spring biasing the movable sheave away from the fixed sheave, and a CVT chamber having an annular cross-section. The fixed and movable sheaves are adapted to receive a belt therebetween. The CVT chamber has at least one opening adapted for fluidly communicating the CVT chamber with a hydraulic fluid reservoir. Hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave. The CVT chamber has an inner wall formed by the first sleeve, an outer wall formed by the second sleeve, an outer end, and an inner end formed by the movable sheave.

Abstract: A vehicle powertrain has an engine, a driving shaft having a passage defined therein, a driven shaft, a pump, a hydraulic fluid reservoir, and a CVT. A driving pulley of the CVT includes a fixed sheave and a movable sheave disposed on the driving shaft for rotation therewith, a spring biasing a movable sheave away from the fixed sheave, and a CVT chamber fluidly communicating with the passage of the driving shaft. The pump supplies hydraulic fluid from the reservoir to the passage in the driving shaft. The hydraulic fluid flows from the passage to the CVT chamber to create a hydraulic pressure in the CVT chamber. The hydraulic pressure in the CVT chamber biases the movable sheave toward the fixed sheave.

Abstract: A watercraft propulsion system has a driveshaft, one of an impeller and a propeller, an overrunning clutch having outer and inner races, a driveshaft connector connecting the driveshaft to the outer race, an electric motor having a motor output shaft operatively connected to the outer race, and an internal combustion engine. The engine has a crankcase and a crankshaft operatively connected to the inner race. A lubricant pump supplies lubricant to the overrunning clutch via lubricant passages in the crankshaft. A watercraft having the propulsion system and a hybrid propulsion conversion system for a watercraft are also disclosed.

Abstract: A method of controlling a hydraulic CVT of a vehicle comprises: determining a speed of rotation of a driving shaft; determining a speed of rotation of a driven shaft; determining a ratio of the speed of rotation of the driving shaft versus the speed of rotation of the driven shaft; determining an engine torque; determining a base clamping force to be applied by the driving pulley onto the belt based on the ratio and the engine torque; determining a desired speed of rotation of the driving shaft; determining a corrective clamping force by comparing the speed of rotation of the driving shaft to the desired speed of rotation of the driving shaft; and controlling a hydraulic pressure applied to a movable sheave to apply a sum of the base and corrective clamping forces onto the belt. A vehicle having a CVT controlled by the method is also disclosed.

Abstract: A vehicle has an engine having a crankshaft, a hydraulically controlled multi-plate clutch operatively connected to the crankshaft, and an output shaft operatively connected to the clutch. The clutch selectively transmits power from the crankshaft to the output shaft. A propulsion element is operatively connected to the output shaft. A hydraulic fluid supply system is fluidly connected to the clutch for supplying pressurized hydraulic fluid to the clutch. A controller is connected to the hydraulic fluid supply system. The controller receives a torque signal indicative of engine torque and controls the hydraulic fluid supply system based at least in part on the torque signal. A clutch control method and system are also disclosed.

Abstract: A method of controlling a hydraulic CVT of a vehicle includes: determining a speed of rotation of a driving shaft; determining a speed of rotation of a driven shaft; determining a ratio of the speed of rotation of the driving shaft versus the speed of rotation of the driven shaft; determining an engine torque; determining a base clamping force to be applied by the driving pulley onto the belt based on the ratio and the engine torque; determining a desired speed of rotation of the driving shaft; determining a corrective clamping force by comparing the speed of rotation of the driving shaft to the desired speed of rotation of the driving shaft; and controlling a hydraulic pressure applied to a movable sheave to apply a sum of the base and corrective clamping forces onto the belt. A vehicle having a CVT controlled by the method is also disclosed.

Abstract: A jet propulsion unit has a water inlet, a pump body, an impeller, and a valve assembly fluidly. The valve assembly has a valve housing having an inlet fluidly connected to the pump body, a first outlet and a second outlet. A valve body is disposed in the valve housing and is movable between first and second positions. In the first position, water from a body of water flows consecutively through the water inlet, the pump body, the inlet of the valve housing, the valve housing and the first outlet of the valve housing. In the second position, water from the body of water flows consecutively through the water inlet, the pump body, the inlet of the valve housing, the valve housing, and the second outlet of the valve housing. A watercraft having the jet propulsion unit is also disclosed.

Abstract: A vehicle has an engine having a crankshaft, a hydraulically controlled multi-plate clutch operatively connected to the crankshaft, and an output shaft operatively connected to the clutch. The clutch selectively transmits power from the crankshaft to the output shaft. A propulsion element is operatively connected to the output shaft. A hydraulic fluid supply system is fluidly connected to the clutch for supplying pressurized hydraulic fluid to the clutch. A controller is connected to the hydraulic fluid supply system. The controller receives a torque signal indicative of engine torque and controls the hydraulic fluid supply system based at least in part on the torque signal. A clutch control method and system are also disclosed.

Abstract: A watercraft has first and second jet propulsion units. The first jet propulsion unit includes a first inlet, a first outlet, a second outlet, and a first valve. The second jet propulsion unit includes a second inlet, a third outlet, a fourth outlet, and a second valve. The watercraft also includes first and second discharge ports disposed on opposite sides of a longitudinal centerline, a first pipe fluidly communicating the first discharge port with the second outlet, a second pipe fluidly communicating the second discharge port with the second outlet, third and a fourth discharge ports disposed on opposite sides of the longitudinal centerline, a third pipe fluidly communicating the third discharge port with the fourth outlet, and a fourth pipe fluidly communicating the fourth discharge port with the fourth outlet.