Provided is a utility vehicle including a seat, an engine disposed rearward of the seat, and a supercharger disposed between the seat and the engine.

An improved turbocharged internal combustion engine, having an air intake system that avoids compressor surge. A positive displacement blower is installed on the air intake line between the compressor and the engine cylinders. The blower has variable speed control so that its speed may be modulated. A controller controls the speed of the blower, such that the average pressure ratio across the blower is 1.0 across each engine cycle.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A watercraft propulsion system includes a propulsion unit to be driven by an engine. The engine includes a cylinder block, an air intake channel, an exhaust channel, a supercharging device, and a fuel injector. The watercraft propulsion system includes the engine, the propulsion unit to be driven by the engine, a rotation speed sensor to detect a rotation speed of the engine, an air intake pressure sensor to detect an air intake pressure of the engine, and a controller. The controller is configured or programmed to compute a command fuel injection amount so that the engine performs a combustion operation at an air/fuel ratio in a lean-burn range (lean-combustion range) according to the rotation speed detected by the rotation speed sensor and the air intake pressure detected by the air intake pressure sensor, and to drive the fuel injector based on the computed command fuel injection amount.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

A supercharger includes a rotor housing defining a pair of cylindrical chambers. A driving shaft bearing is to support a driving rotor shaft for rotation in the rotor housing. A driven shaft bearing is to support a driven rotor shaft for rotation in the rotor housing. An oil sump housing is to enclose a timing gear end of the rotor housing. A shaft seal is disposed between the rotor housing and each respective rotor shaft. The oil sump housing, the rotor housing and driving and driven shaft seals define a closed container for oil to lubricate the driving shaft bearing, the driven shaft bearing, a driving timing gear and a driven timing gear. The oil pools in the closed container and a top surface of the oil is spaced below the timing gears when the driving rotor shaft is in a vertical orientation.

Provided is a utility vehicle including a seat, an engine disposed rearward of the seat, and a supercharger disposed between the seat and the engine.

A supercharged engine is provided, which includes an engine body having cylinders, an intake passage disposed outside the engine body and connected to the cylinders via intake ports, a supercharger provided in the intake passage and spaced apart from an intake-side side surface of the engine body, the intake-side side surface being connected to the intake passage, and a fuel pump disposed on the intake-side side surface. A portion of the intake passage constitutes an intervening part located between the supercharger and the engine body. The intervening part overlaps with the fuel pump in one of vertical and lateral directions of the engine body.

A supercharged engine is provided, which includes an engine body having cylinders, an intake passage disposed outside the engine body and connected to the cylinders via intake ports, a supercharger provided in the intake passage and spaced apart from an intake-side side surface of the engine body, the intake-side side surface being connected to the intake passage, and a fuel pump disposed on the intake-side side surface. A portion of the intake passage constitutes an intervening part located between the supercharger and the engine body. The intervening part overlaps with the fuel pump in one of vertical and lateral directions of the engine body.