An engine system is provided, which includes a supercharger driven by a crankshaft of an engine, an electromagnetic clutch disconnectably connecting the crankshaft to the supercharger, and a controller configured to output a control signal to the electromagnetic clutch. The controller includes a processor configured to execute an uphill-angle detecting module to detect an uphill angle during traveling of a vehicle, an uphill determining module to determine whether the detected uphill angle is above a given first uphill angle, and a boost controlling module to, when the detected uphill angle is above the first uphill angle, control the electromagnetic clutch to connect the crankshaft to the supercharger even when a target torque of the engine is within a not-boosting range.

An engine assembly for a vehicle includes an internal combustion engine operating on a two-stroke engine cycle. A compressor is in fluid communication with an intake port of at least one cylinder of the engine to pump air into the engine. An exhaust pipe is in fluid communication with an exhaust port of the at least one cylinder. The exhaust pipe has an inlet and an outlet defining a length of the exhaust pipe therebetween. A diameter of the exhaust pipe increases along a portion of the length of the exhaust pipe in a flow direction of the exhaust pipe. The diameter of the exhaust pipe does not decrease along the length of the exhaust pipe in the flow direction of the exhaust pipe.

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a central hub, and a plurality of coupler pins. The first hub can be mounted with the input shaft. The second hub can be mounted with the rotor shaft. The central hub can be disposed in between the first and second hubs. The central hub can have an elastomeric body that defines a series of passages therein. The passages can taper inwardly throughout and provide incremental dampening against the first and second plurality of pins. The plurality of coupler pins can be received in the central hub bores. The first and second plurality of pins can be received by the passages in the elastomeric body.

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a central hub, and a plurality of coupler pins. The first hub can be mounted with the input shaft. The second hub can be mounted with the rotor shaft. The central hub can be disposed in between the first and second hubs. The central hub can have an elastomeric body that defines a series of passages therein. The passages can taper inwardly throughout and provide incremental dampening against the first and second plurality of pins. The plurality of coupler pins can be received in the central hub bores. The first and second plurality of pins can be received by the passages in the elastomeric body.

A supercharger assembly comprises a housing, a rotor bore with an outer wall, an outlet in an outlet plane, an inlet in an inlet plane perpendicular to the outlet plane, and an outlet divider wall. The supercharger assembly comprises a first recess, a first perforated material covering the first recess, and an outlet resonator. The first recess is separated from the outlet by the outlet divider wall. The first recess is located between the outer wall and the first perforated material.

A supercharger assembly comprises a housing, a rotor bore with an outer wall, an outlet in an outlet plane, an inlet in an inlet plane perpendicular to the outlet plane, and an outlet divider wall. The supercharger assembly comprises a first recess, a first perforated material covering the first recess, and an outlet resonator. The first recess is separated from the outlet by the outlet divider wall. The first recess is located between the outer wall and the first perforated material.

An engine assembly for a vehicle includes an internal combustion engine operating on a two-stroke engine cycle. A compressor is in fluid communication with an intake port of at least one cylinder of the engine to pump air into the engine. An exhaust pipe is in fluid communication with an exhaust port of the at least one cylinder. The exhaust pipe has an inlet and an outlet defining a length of the exhaust pipe therebetween. A diameter of the exhaust pipe increases along a portion of the length of the exhaust pipe in a flow direction of the exhaust pipe. The diameter of the exhaust pipe does not decrease along the length of the exhaust pipe in the flow direction of the exhaust pipe.

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.

Rotors formed by an additive manufacturing process are presented. In one example, a method of making a rotor is presented including defining a printing order for the application of a first material, and creating a plurality of lobes arranged helically about a central opening or a shaft by adding a first material in the printing order, wherein each of the plurality of lobes defines an outer surface.

Rotors formed by an additive manufacturing process are presented. In one example, a method of making a rotor is presented including defining a printing order for the application of a first material, and creating a plurality of lobes arranged helically about a central opening or a shaft by adding a first material in the printing order, wherein each of the plurality of lobes defines an outer surface.