Abstract: Occlusion devices, earpiece devices and methods of forming occlusion devices are provided. An occlusion device is configured to occlude an ear canal, but other biological and non-biological conduits or chambers can be occluded using the devices and methods herein. The occlusion device includes an insertion element and at least one occluding member or element (which can be expandable) disposed on the insertion element. The occluding member is configured to receive a medium via the insertion element and is configured to expand, responsive to the medium, to contact the ear canal. Alternatively, the occluding member is made of a non-Newtonian fluid and can be enclosed by a balloon or not. Physical parameters of the occlusion device are selected to produce a predetermined sound attenuation characteristic over a frequency band. Use of a non-Newtonian fluid provides additional options or variables in customizing or designing a predetermined sound attenuation characteristic.

Abstract: An electric machine includes a cylindrical stator core and a cylindrical housing having an inner diameter. The core has an outer surface and a plurality of projections extending therefrom. An outer diameter of the core measured between tips of diametrically opposing projections is greater than the inner diameter. The core is disposed in the housing with the tips engaging the inner diameter to create an interference fit between the core and housing to reduce housing resonance.

Abstract: A noise muffler for an air moving device can include a housing with a housing inlet, a housing outlet, and at least a first foam component and a second foam component. The first foam component and the second foam component are placed within a cavity of the housing and define an air passageway. The first foam component and the second foam component redirect air flow through the cavity in three dimensions in order to muffle noise generated by the air moving device.

Abstract: In a rotary electric machine, each of coils includes coil terminals led out from a coil main body. The coil terminals are connected to bus bars. When a diameter of each of the bus bars is defined as D, a diameter of a cross section of a coil wire is defined as “d”, a Young's modulus of the coil wire is defined as E, a linear expansion coefficient of a material of the bus bars is defined as ?1, a linear expansion coefficient of a material of a stator core is defined as ?2, and an estimated temperature difference between a room temperature and a use environment temperature is defined as ?T, a length L of at least one of the coil terminals from an end on the coil main body side to a connecting portion to the bus bar satisfies the following expression: L?((3?dED(?1??2)?T/10)1/2/10.

Abstract: Provided are conduits for air flow that are capable of reducing noise and related methods. The provided conduits include a first section that is tubular and substantially non-perforated and a second section with at least a portion having a multiplicity of microperforations that provide an average flow resistance of from 50 MKS Rayls to 8000 MKS Rayls therethrough. The second section is either (a) tubular and connected in series with the first section, with an outer surface of the second section being in fluid communication with an outer surface of the conduit, or (b) disposed within the first section.

Abstract: A vehicle wheel includes a pair of vertical walls that extend vertically up from an outer circumferential surface of a well portion and extend in a wheel circumferential direction and a Helmholtz resonator that is disposed between the pair of vertical walls and bonded to side surfaces of the pair of vertical walls with an adhesive, in which the Helmholtz resonator is not bonded to the outer circumferential surface of the well portion.

Abstract: An axial-flow machine has a dimensionally stable assembly, a machine shaft, a rotor fastened on the machine shaft and provided with a rotor hub, permanent magnets disposed circularly around the machine shaft, an adhesive and a brace, which is disposed on the outer circumference of the rotor and encircles it in closed manner and which urges the permanent magnets with a radially inwardly directed tension force, and stators disposed on both sides of the rotor. The permanent magnets are seated on the rotor hub via first adhesive joints equipped with adhesive and adjoin one another via second adhesive joints equipped with adhesive, wherein the permanent magnets, the rotor hub, the brace and the adhesive form the dimensionally stable assembly, the radial and axial dimensional stability of which is determined substantially by the radial tension force of the brace on the permanent magnets.

Abstract: A muffler for use with an engine is provided. The muffler includes a first tube defining a first inlet and a first outlet spaced apart from the first inlet. The first tube is configured to receive exhaust at the first inlet. The muffler includes a second tube spaced apart from the first tube. The second tube defines a second inlet and a second outlet spaced apart from the second inlet. The second tube is configured to receive exhaust at the second inlet. The muffler includes a third tube disposed at least partly around the second tube. The third tube defines a third outlet spaced apart from each of the second inlet and the second outlet. The third outlet is in fluid communication with the second outlet of the second tube. The muffler also includes at least one outlet tube in fluid communication with the first outlet and the third outlet.

Abstract: A noise-cancelling earplug assembly is provided, having an ear piece for insertion into the ear canal and a housing removably attached to the ear piece. A hollow core is defined in the housing to receive a sound-selective sound barrier that contains at least one sound filtering element to attenuate sounds reaching the ear drum. An end cap is provided and is attachable to the housing to enclose the sound-selective sound barrier inside the housing. The sound selective sound barrier can be removed from the housing of the earplug and replaced with a different sound selective sound barrier with different sound attenuation characteristics.

Abstract: This application provides a speaker and a sound diffuser thereof. The sound diffuser includes a first diffusion surface and a second diffusion surface. The first diffusion surface faces toward a first driver, and has a first central area that is a circular protrusion, a first outer ring region, and a first concave ring region located between the first central area and the first outer ring region. The second diffusion surface faces toward a second driver, and is a circular dish surface protuberant from center outwards. The sound diffuser is coaxially located between the first driver and the second driver, and the first driver and the second driver respectively generate different sound production frequencies.

Abstract: An internal combustion engine system includes a combustion engine configured to produce exhaust gases as a product of a combustion reaction. An exhaust discharge pipe coupled to the internal combustion engine, and an adaptive valve assembly. The adaptive valve assembly is coupled to the exhaust discharge pipe and configured to receive the exhaust gases prior to the exhaust gases reaching the atmosphere. The adaptive valve assembly includes a valve flapper arranged in the passageway and configured to pivot about a flapper pivot axis from a normally-closed position to an opened position.

Abstract: An internal combustion engine includes an engine block including a cylinder and a muffler assembly configured to receive exhaust gases from the cylinder. The muffler assembly includes a housing defining an interior volume and including an exhaust inlet and an exhaust outlet, and a baffle assembly positioned within the interior volume. The baffle assembly includes a plurality of chambers in fluid communication with each other. The plurality of chambers are in fluid communication with the exhaust inlet and the exhaust outlet so that the plurality of chambers are configured to cause exhaust gases to be directed through the muffler assembly from the exhaust inlet to the exhaust outlet through four passes in the baffle assembly before exiting through the exhaust outlet.

Abstract: An earmuff hearing-protection device (1) including a non-porous, sound-attenuating body (50) disposed within an interior space (31) defined by a shell (30) of an earmuff of the device, the non-porous, sound-attenuating body including sound-attenuating members (100) arranged and spaced to define a set of high aspect ratio air gaps (e.g. 300) between major side surfaces of neighboring members.

Abstract: An engine muffler apparatus for reducing noise and pollution from small gas engines such as those on landscaping tools includes an outer housing having a central neck extension with a principal aperture extending through to an outer housing cavity. The neck extension is selectively engageable with an exhaust of a small gas engine. The outer housing cavity has a plurality of vent apertures. An intake extension tube and a medial tube are coupled to the outer housing cavity. The medial tube has a medial cavity. A first filtering medium is coupled within the medial cavity and filters pollutants passing therethrough. A second filtering medium is coupled within the outer housing cavity outside of the medial tube and dampens sound waves passing through the apparatus from the exhaust.

Abstract: 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.

Abstract: An electric machine rotor including a first stamped rotor lamination and a first stamped sheet of a material different than the first stamped rotor lamination is provided. The first stamped rotor lamination may define a pair of magnet pockets. The first stamped sheet may be coplanar with and scarf jointed to the first stamped rotor lamination to define a center bridge between the magnet pockets that has a magnetic permeability less than, and a mechanical strength greater than, the first stamped rotor lamination. The rotor may further include a second stamped sheet of a material different than the first stamped rotor lamination coplanar with and scarf jointed to the first stamped rotor lamination to define a top bridge adjacent to one of the magnet pockets at a perimeter of the rotor that has a magnetic permeability less than, and a mechanical strength greater than, the first stamped rotor lamination.

Abstract: A muffler unit includes: an inner cylinder connected with a first exhaust pipe; a first outlet pipe that is connected with a downstream end of the inner cylinder and through which exhaust gas is discharged; an outer cylinder that houses thereinside the inner cylinder and defines, between the outer cylinder and an outer surface of the inner cylinder, an expansion chamber communicating with the second exhaust pipe; and a second outlet pipe that houses thereinside the first outlet pipe and defines, between the second outlet pipe and an outer surface of the first outlet pipe, a path connected with the expansion chamber to thereby be used for discharging the exhaust gas. Accordingly, there is provided the muffler unit having a size reduced compared with a configuration including two mufflers disposed in parallel with each other.

Abstract: The sound absorbing board includes a body and multiple sound absorbing elements. The body has a first side surface and a second side surface. The multiple sound absorbing elements are formed on the body at spaced intervals, and each one of the multiple sound absorbing elements has a protrusion, a groove, and two sound absorbing openings. The protrusion is formed on the first side surface of the body. The groove is formed on the second side surface of the body and has multiple concave portions and at least one convex portion. The multiple concave portions are formed on a bottom surface of the groove. The at least one convex portion is formed on the bottom surface of the groove, and is formed between two adjacent ones of the multiple concave portions. The two sound absorbing openings are formed on the two opposite side surfaces of the protrusion, respectively.

Abstract: A rectification structural body includes an inlet port into which air from an air cleaner flows, an outlet port from which air flows out toward an airflow sensor, and a chamber provided between the inlet port and the outlet port. The inlet port and the outlet port are provided in such directions and at such positions that an air flow is bent in the chamber. The chamber includes two cases of a first case and a second case, the chamber being divided into the two cases.

Abstract: Methods and systems are provided for an exhaust system of a vehicle. In one example, the exhaust system includes an exhaust tail pipe with an asymmetric outlet. The asymmetric outlet of the tail pipe may flare outwards, away from a central axis of the tail pipe, circumferentially surrounded by a housing with a geometry matching a geometry of the asymmetric outlet.