Abstract: A sound attenuation arrangement for an inverter cover of an electric compressor, which is characterised in that in addition to fasteners for the inverter cover on the compressor housing of the electric compressor, a sound attenuation means for reducing noise emission via the inverter cover is provided, where the sound attenuation means is made up of a screw with a screw head and a screw shaft, and in that on the screw head a damping element is arranged, where the screw is in contact via the screw shaft with the compressor body, and via the damping element arranged on the screw head with the inverter cover, in a manner that absorbs vibrations.

Abstract: An absorbing system for disrupting short and long sound energy wavelengths. The absorbing system comprises a two hanging bars, a plurality of hanging straps, a suspended mass assembly. The suspended mass assembly hangs from the two hanging bars with the plurality of hanging straps. The suspended mass assembly comprises a suspended absorbing mass. The suspended absorbing mass comprises a cover and an absorptive portion. The cover encases and holds the absorptive portion. The suspended absorbing mass comprises a plurality of depths between a top point and a bottom point. The plurality of depths comprise a minimum depth and a maximum depth.

Abstract: An acoustic panel for an aircraft propulsion unit, comprises a core and an entry layer in contact with the core, the entry layer comprising lower elements and upper elements, each comprising an inner face, an outer face and at least one through-hole, the inner faces of the lower elements and upper elements being in contact with each other and forming a channel defining a baffle and opening into a cell of the core.

Abstract: Embodiments of the present disclosure provide a diffusion muffling device, a diffusion resonance muffling device, a full-frequency diffusion muffling device, a muffling system for a ventilation channel, and a muffling method using the same, which include a plurality of diffusion muffling units disposed in the ventilation extension direction of the ventilation channel, wherein the plurality of diffusion muffling units are arranged in parallel in a direction with a predetermined angle between the direction and the ventilation extension direction of the ventilation channel, and a muffling passage is formed between each two adjacent diffusion muffling units, wherein each of the diffusion muffling units includes at least one diffuser, and each diffuser includes a plurality of convex portions so that sound waves entering the muffling passage are reflected multiple times in the muffling passage by the plurality of convex portions and then sound is attenuated.

Abstract: A vertiport for an aircraft. The vertiport includes a landing platform that includes a landing surface and a plurality of primary through-openings, wherein the landing platform at least partially defines a primary chamber subjacent to the landing platform, the primary chambering having a primary chamber volume, and wherein the plurality of primary through-openings are in fluid communication with the primary chamber. The disclosed vertiport further includes an air moving unit positioned to withdraw air from the primary chamber.

Abstract: A fairing for a power generation machine, the fairing comprising: a first layer comprising a metallic material; a second layer comprising a composite; and a third layer positioned between the first layer and the second layer, the third layer being configured to attenuate acoustic waves over a predetermined frequency range.

Abstract: Provided is a motor for a drone comprising: a rotary shaft; a stator including a hole in which the rotary shaft is disposed; a rotor disposed outside the stator; and a housing coupled to the stator, wherein the stator comprises a stator core and a coil wound around the stator core, wherein the stator core comprises an annular yoke coupled to the housing, teeth extending radially from the yoke, and a shoe disposed at one end of the teeth, wherein the teeth comprise protrusions projecting from the side surface thereof. As such, the present invention provides an advantageous effect of securing an air flow path for heat radiation to enhance a heat radiating effect while preventing water or foreign matter from flowing into the motor.

Abstract: A quick release structure of a diaphragm assembly of a stethoscope is disclosed, including a stethoscope having two collecting surfaces each being connectable with a diaphragm assembly. The collecting surface has a portion adjacent to an outer periphery thereof and formed with an annular fitting groove that has a height lower than the collecting surface. The collecting surface is formed with a trough. The annular fitting groove has an inclined internal wall. The diaphragm assembly includes an elastic piece combined with a diaphragm assembly. The elastic piece includes a raised rib, a projection portion, and an inclined inside surface. Through pressing the raised rib into the annular fitting groove, the inside surface is set in tight engagement with the internal wall, and this, in combination with the projection portion fit in the trough, forms a secure and stable fitting engagement and allowing easy release performed in an opposite way.

Abstract: A sound isolation assembly comprising: a center ferrule; a top grommet isolator; a bottom grommet isolator; a spring; and a furring channel engagement portion. The sound isolation assembly is configured to engage with a structure and a furring channel, which itself is connected to a ceiling panel, such that the noise passing from one floor to the other is lessened as compared to a control system that does not use the sound isolation assembly. The spring may be steel and the grommet isolators may be rubber or the like, and the combination of the steel spring and grommet isolators reduces noise.

Abstract: A sound attenuator has an inner pipe (12) with expansion sections (121) of enlarged diameter corresponding to the constriction sections (141) of an outer pipe (14). The expansion sections (121) in pairs axially delimit an intermediate inner pipe section (122) containing a wall opening (18) and having a reduced diameter relative to the expansion sections (121). The inner surface of the outer pipe (14) in each of its constriction sections (141) is connected to the outer surface of the inner pipe (12) in its respective corresponding expansion section (121). A method of manufacturing such a sound attenuator (10) also is provided and uses internal high-pressure forming.

Abstract: A housing arrangement has a blower motor including a rotation shaft that traverses through an underside and a topside of the blower motor, the rotation shaft being configured to mount a fan impeller thereupon, a first housing part that receives the blower motor, a second housing part that covers the blower motor received in the first housing part, a first decoupling unit arranged circumferentially between the underside of the blower motor and an inner bottom of the first housing part, and a second decoupling unit arranged circumferentially between the topside of the blower motor and an inner surface of the second housing part. Here, the spring stiffness of the first and the second decoupling units are substantially constant in an axial direction, a radial direction, or a normal direction.

Abstract: A noise damper for a compressed-air system, for a brake system of a utility vehicle, including: a housing having an inlet channel for a compressed-air stream and with a chamber for accommodating sound-damping material, in which the inlet channel and the chamber are separated, perpendicularly with respect to the compressed-air stream, by a separating plate which is closed in a central region and which, in an outer peripheral region of the compressed-air stream, has multiple openings for introducing the compressed air directly into the chamber. Also described are a related pneumatic brake system and method.

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: 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: 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: 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.