Abstract: A rotary electric machine includes a rotor and a stator. The stator has windings and teeth extending radially from a stator core. Each tooth is separated from an adjacent tooth by a stator slot that opens to a radial stator-rotor airgap via a slot opening. The windings are positioned within each slot. Each stator tooth has a tooth tip with a surface profile configured to guide rotor flux away from areas of the windings proximate the respective slot opening. The tip surface profile may be a concave region, e.g., a dent/chamfer, and/or a convex region, e.g., a bump/bulge, and is formed in a distal end surface of the tip proximate the opening. The stator-rotor airgap is smaller at the convex region and larger at the concave region than elsewhere along the distal end surface. An electrical system includes the machine, a battery, and a power inverter module.

Abstract: A stator assembly for a permanent magnet motor is disclosed. The assembly includes a yoke having a plurality of teeth in connection therewith and extending into an opening formed by the yoke. The plurality of teeth includes a first tooth and a second tooth. The first tooth is arranged adjacent to the second tooth about a rotational axis of the motor. The assembly further includes a first coil and a second coil. The assembly is configured to receive three winding phases including a first winding phase, a second winding phase, and a third winding phase. The first tooth and the second tooth form adjacent pairs of the stator teeth including two of the three winding phases, and the adjacent pairs of the stator teeth are distributed around the opening and form an opening configured to receive a rotor.

Abstract: Certain embodiments of the present disclosure provide an acoustic inlet barrel of an engine. The acoustic inlet barrel may include an inner barrel configured to provide a boundary for directing airflow through the engine. The inner barrel may include an inner face sheet separated from an outer face sheet by an acoustic core. The inner barrel may include a plurality of elongated, non-circular perforations formed through the inner face sheet.

Abstract: The invention disclosed herein is an automotive acoustic panel including a porous sound-absorption material made from a polymer and an expanded perlite. One or more silane compounds may be coupled or coated onto the expanded perlite while a coupling agent and a chemical foaming agent may additionally be added to the automotive acoustic panel.

Abstract: A sound suppression assembly is provided for absorbing acoustic energy from an air circulation device. The assembly includes an air circulation device, such as an axial fan, and a plurality of sparsely-arranged two-sided Helmholtz unit cells disposed in a periodic array. Each unit cell includes a lossy resonator and a lossless resonator. The lossy resonator includes a first chamber portion bounded by at least one first boundary wall defining a first chamber volume, and a first neck forming an opening in the first chamber portion. The lossless resonator includes a second chamber portion bounded by at least one second boundary wall defining a second chamber volume, and a second neck forming an opening in the second chamber portion. The unit cells can be positioned in a circular pattern with the first neck of the lossy resonators directed to a source of acoustic energy from the air circulation device.

Abstract: The present invention provides a cooling mechanism between a linear motor rotor and a platform coupled thereto, characterized essentially in that a cooling portion is provided between the rotor and the platform, and further in that heat transfer is blocked between the cooling portion and the platform, thereby preventing heat received by the cooling portion during heat dissipation from being transferred to the platform, so as to ensure the precision of the platform.

Abstract: Embodiments disclosed herein include a sound attenuating enclosure defining an interior space, formed by a plurality of composite panels. In some embodiments the composite panels include a frame having a plurality of elongate frame members coupled to one another. The frame defines an inner side facing toward the interior space and an outer side facing away from the interior space. Additionally, some embodiments may include an outer skin secured to the outer side of the frame, an inner skin secured to the inner side of the frame, and a foam layer disposed between the outer skin and the inner skin and between at least a pair of the frame members.

Abstract: A muffler for a vehicle includes: a case sealed at both ends by first and second side panels; first and second baffle plates installed in the case; a first chamber formed between the first side panel and the first baffle plate; a second chamber formed between the first baffle plate and the second baffle plate; a third chamber formed between the second baffle plate and the second side panel; an intake tube passing through the first side panel, and the first and second baffle plates, and including a first hole formed in a first body section located in the first chamber, and a second hole formed in a second body section located in the second chamber; and a pair of exhaust tubes passing through the first and second baffle plates, and the second side panel, and including a vent hole formed in body section located in the second chamber.

Abstract: A sound isolation window includes a frame and a plurality of sound blocking bars. The frame has an upper frame portion and a lower frame portion. The frame further has a first sidewall and a second sidewall connected to the upper and lower frame portion. The upper frame portion, the lower frame portion, the first sidewall and the second sidewall form a first opening and an opposite second opening. Each sound blocking bar includes a plane perpendicular to the upper frame portion and the lower frame. The sound blocking bars are arranged along the first direction from the first opening to the second opening and spaced apart from each other. Projections along the first direction of the sound blocking bars over the first opening cover the first opening. The width of each sound blocking bar is less than one-half of the width of the first opening.

Abstract: A breakaway stethoscope includes a chest piece, a headset, a tube, and a coupler. The chest piece captures sounds generated inside a person's body when the chest piece is positioned adjacent the person's body. The headset directs the sounds captured by the chest piece toward a person's ear when the headset is positioned on an ear of the person. The tube connects the chest piece to the headset and conveys the sounds captured by the chest piece toward the headset. The tube has a length and includes a first portion connected to the chest piece and a second portion connected to the headset. The coupler releasably connects the tube's first portion to the tube's second portion and releases one of the tube's portions when the tube experiences a force that urges at least one of the tube's portions to move away from the coupler.

Abstract: A broad-band resonance silencer has an at least two-part housing which is designed to receive an exhaust-or gas-conveying pipe, which defines, with a circumferentially surrounding pipe jacket with acoustic openings formed therein, a pipe interior, wherein the pipe, in its installed position, is enclosed by a damping chamber formed by the housing, which chamber is actively connected to the pipe interior via the acoustic openings, and wherein the housing includes two axially split housing half-shells. In order to broaden the scope of use of such a broad-band resonance silencer, it is proposed that the pipe be designed as an insert which includes a central pipe section with two end-side pipe ends, that the insert be designed such that it can be inserted into the housing half-shells of the housing, and that the broad-band resonance silencer includes at least one acoustic channel.

Abstract: A dynamic acoustic ceiling baffle and a dynamic acoustic ceiling baffle system, that includes multiple shaped baffles that can be quickly and easily installed onto construction ceiling hangers without the need for additional tools, to provide an aesthetically pleasing image, such as an undulating image, along with a reduction in unwanted noise or room acoustics.

Abstract: An air inlet (3) for a nacelle (2) for an aircraft (1) includes at least one acoustic panel (5), adapted to lower noise generated by the engine (21) to which the air inlet (3) is connected. At least one lip (6) defines the profile upon which an airflow flowing into the air inlet (3) acts. If necessary, at least one engine ring (4) is adapted to allow the air inlet (3) to be connected to an engine (21) of the nacelle (2). If necessary, at least one outer barrel (7) is adapted to define the outer shape of the air inlet (3) upon which an airflow acts. The air inlet (3) is manufactured as one single piece, made of a composite material.

Abstract: A muffler for receiving exhaust gas from a combustion engine is disclosed. The muffler includes a casing and a pipe. The casing includes a shell coupled to first and second end caps that cooperate to define an internal volume. The pipe is disposed within the internal volume and extends substantially a length of the shell. Each of the first and second end caps includes a circumferentially extending flange engaging an outer surface of the pipe to provide support for the pipe. Each circumferentially extending flange extends at an acute angle relative to a shell axis of the shell. Each circumferentially extending flange is coaxial along a pipe axis of the pipe.

Abstract: Method for forming a collar in a muffler shell including: providing a muffler shell made of a metal sheet and forming a muffler housing, the muffler shell having an exhaust gas opening, providing a collar forming head having a rotational axis and at least two movable expanders, introducing a collar forming head into a muffler housing, moving the expanders of the collar forming head introduced into the muffler shell radially away from the rotational axis of the collar forming head from a retracted position to an expanded position rotating the collar forming head around the of the collar forming head, bringing the rotating expanded collar forming head in contact with the metal sheet forming an outwardly projecting collar around the exhaust gas opening by flaring the edge of the metal sheet.

Abstract: An alternating clockwise and counterclockwise helicoid cell structure for use in acoustic panels. The cell structure geometry may be easily replicated and tiled using additive manufacturing. The cell structure has at least an outer cavity and an inner cavity. The cavities are coaxial, share the same height, same entrance side, and same cell structure floor. The inner cavity includes a number of equal-volume inner chambers rotated uniformly in a first direction around the shared central axis; and the outer cavity includes a second number of equal-volume outer chambers rotated uniformly in an opposite direction to the first direction around the shared central axis. In various embodiments, one or more perforated baffles may extend, internally, across a chamber, perpendicular to direction of sound waves at the location of the perforated baffle. In various embodiments, one or more port openings from the outer cavity to the inner cavity may be present.

Abstract: A dismantlable anechoic chamber for sound attenuation includes a number of interconnected panels. The panels have a groove around their edges. The spaces produced by the corresponding grooves at contacting edges of adjacent panels are occupied by battens. The panels have a sandwich-type structure, in which a layer of sound-attenuating material is positioned between the two main faces of the panel. There is dimensional interference between the battens and the panels. The chamber has, on its internal face, an additional sound-attenuating layer. This sound-attenuating material is a foam-like material. The batten has an intermediate layer of sound-attenuating foam material.

Abstract: A stethoscope includes a headset including a first eartube terminating in a first earpiece and a second eartube terminating in a second earpiece, and a chestpiece having a diaphragm. The stethoscope further includes flexible acoustic tubing having a first tubing segment connected to the headset and a second tubing segment connected to the chestpiece. The first tubing segment is manually disconnectable from the second tubing segment, and the first tubing segment is manually connectable to the second tubing segment to align and seal the first and second tubing segments and form an acoustic passageway extending from the chestpiece through the first and second tubing segments and the first and second eartubes to the first and second earpieces. Optionally, the flexible acoustic tubing with the disconnectable and connectable segments may be provided as a replacement component for a stethoscope.

Abstract: The vehicular exhaust system presents a plurality of flow paths that transport exhaust gases between one or more catalytic converters and a muffler. The span of the length of each of the plurality of flow paths varies such that phase differences in the sound waves carried by the exhaust gas are generated. These phase differences cause the sound waves to cancel thereby reducing combustion engine sounds before the exhaust enters the muffler. The vehicular exhaust system comprises a plurality of pipes, a plurality of connectors, and a plurality of cants. The plurality of connectors form fluidic connections between the plurality of pipes to form a manifold that creates the plurality of flow paths. The plurality of cants are angles formed within the manifold structure that change the span of length of each of the plurality of flow paths.

Abstract: A muffler, for an internal combustion engine exhaust system, includes a muffler housing (12) with a housing jacket (14) elongated in a housing longitudinal axis (A) direction and with an outer panel (16) connected to the housing jacket at both axial end areas thereof to define a muffler interior (18). An inner panel (20) is arranged in and divides the muffler interior. A muffling unit (24) includes an exhaust-gas-carrying inner pipe (26), an outer pipe (28) enclosing the inner pipe and muffling material (32) arranged between the inner pipe and the outer pipe. The inner pipe is accommodated in an opening (48) of an inner panel and in an opening (40) of one of the outer panels or of an additional inner panel. The outer pipe is permanently connected to the inner panel or/and to one of the outer panels or to the additional inner panel.