An air blower is provided. The blower includes a flow modulator tube assembly positioned modulate the flow of air into the blower and to modulate the flow of sound out of the blower. The blower also includes a sound damper. The flow modulator tube assembly directs sound to the sound damper, and the sound damper absorbs and/or reflects the sound.

A muffler has a housing enclosing a plurality of chambers. A first flow path extends from an inlet to an outlet passing through a bypass chamber. A flow tube has a plurality of perforations being open to a chamber other than the bypass chamber. A second in flow path passes from the inlet to the outlet without passing through the bypass chamber and passing through the perforations. Exhaust gas is introduced into the muffler via the inlet and discharged therefrom via the outlet. A first portion of the exhaust gas flows from the inlet to the outlet along the first flow path. A second portion of the exhaust gas flows from the inlet to the outlet along the second flow path, the first and second portions mixing at least in the outlet chamber. A semi-closed tube has an open end being open to one of the chambers and a closed end.

A marine drive has a primary exhaust outlet on its lower gearcase that discharges a primary flow of exhaust gas from the engine to seawater in which the marine drive is situated. A secondary exhaust outlet is located on the marine drive above the primary exhaust outlet and discharges a secondary flow of exhaust gas from the engine to atmosphere around the marine drive at least when the engine is operated at an idle speed. A tertiary exhaust outlet is located on the marine drive between the primary and secondary exhaust outlets, and discharges a tertiary flow of exhaust gas from the engine to the seawater or to the atmosphere depending upon a current location of the tertiary exhaust outlet with respect to the seawater. A muffler is configured to reduce noise emanating from the tertiary exhaust outlet.

Methods and systems are provided for a noise mitigating device for a turbocharger compressor. In one example, the noise mitigating device includes a set of perforated rings arranged in a recirculation passage of a compressor casing treatment. The rings of the set of perforated rings may be oriented so that apertures of one ring are offset from apertures of one or more adjacent rings, forcing air to flow through the apertures via a non-linear path while deflecting at least a portion of sounds waves generated in the compressor.

An air blower is provided. The blower includes a flow modulator tube assembly positioned to modulate the flow of air into the blower and to modulate the flow of sound out of the blower. The blower also includes a sound damper. The flow modulator tube assembly directs sound to the sound damper, and the sound damper absorbs and/or reflects the sound.

A valve assembly for an exhaust system of a vehicle. The valve assembly includes a first housing, a second housing, a valve flap and a spring. The first housing defines an inlet, an outlet, and an exhaust gas passageway in fluid communication with the inlet and the outlet. The second housing is attached to the first housing and defines a compartment. The valve flap is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is allowed. The spring is disposed in the compartment and out of the exhaust gas passageway. The spring engages the valve flap to bias the valve flap toward the first position.

A valve assembly for an exhaust system of a vehicle. The valve assembly includes a housing, a valve shaft and a valve plate. The housing defines an inlet, an outlet, and a longitudinally exhaust gas passageway in fluid communication with the inlet and the outlet. The valve shaft is rotatable. The valve plate is coupled to the valve shaft and is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is less restricted. The first housing includes spaced apart ears integral with and laterally extending from the first housing. The ears opposing each other. The shaft includes an axis of rotation being positioned at the ears and outside of the exhaust gas passageway.

A vehicle exhaust system includes a tubular component having an inner surface and an outer surface. The vehicle exhaust system also includes at least one opening defined by the tubular component. The at least one opening extends through each of the inner surface and the outer surface. The vehicle exhaust system further includes a patch adapted to cover the at least one opening. The patch includes a first portion extending parallel to the central axis. The first portion defines a plurality of pores. The first portion covers the at least one opening. The patch also includes a second portion extending away from the first portion. The first portion has a first thickness and the second portion has a second thickness.

An exhaust device for a saddle-type vehicle having a pipe section with respect to a vehicle body and housing a catalyzer therein, and a muffler connected to a rear end of the pipe section includes an upstream oxygen sensor disposed on the pipe section and positioned upstream of the catalyzer and a downstream oxygen sensor disposed on the pipe section and positioned downstream of the catalyzer. The pipe section includes a larger-diameter portion having an increased diameter for housing the catalyzer therein. The downstream oxygen sensor is disposed in the larger-diameter portion. The upstream oxygen sensor and the downstream oxygen sensor are positioned upwardly of a central line of the larger-diameter portion with respect to the vehicle body as viewed in side elevation of the vehicle body.

Power systems and enclosures having improved cooling air flow are disclosed. An example power system includes an enclosure; an air inlet location at a first location on an exterior of the enclosure to permit intake of air from the exterior of the enclosure to an interior of the enclosure; an air exhaust location at a second location on the exterior of the enclosure to exhaust the air taken in through the air inlet location; and an air routing path defined by the enclosure to direct the air from the air inlet location to the air exhaust location, in order: through one or more first compartments in the enclosure, the one or more first compartments containing at least one of a compressor, a generator, or power conversion circuitry; and through one or more second compartments, the one or more second compartments comprising an engine and a muffler.