35results about How to "Reduce air noise" patented technology

An air conditioning apparatus for a rear seat of a vehicle includes a centrifugal fan disposed at a downstream air side of an evaporator. The centrifugal fan is a backward curved fan having a plurality of blades each of which is curved backward relative to a rotation direction of the centrifugal fan. In the centrifugal fan, because a main component of velocity vector is in a radial direction of the centrifugal fan, a dynamical-pressure component of air blown from the centrifugal fan can be effectively changed to a hydrostatic-pressure component. Thus, during a cooler mode where air is simultaneously blown from first and second air outlets toward the rear space of the passenger compartment, a pressure of air blown from the first and second air outlets can be increased, and an amount of air blown toward the rear space of the passenger compartment can be sufficiently increased.

An air filtering apparatus includes a housing defining a top opening and having a front portion defining a bottom opening. A filter is positioned within the top opening and sealed to the housing so that air flowing into the housing passes through the filter. An expansion chamber is in fluid communication with the bottom opening. A motorized fan is located within the housing and is configured for drawing air through the filter, into the housing and out through the expansion chamber. The air output of the motorized fan is directed toward a bottom of the housing proximate a rear of the housing with the expansion chamber extending from the air output of the motorized fan to the front portion of the housing.

A method of alleviating the sound masking effects of wind noise on a cyclist wearing a safety helmet comprising the following steps: designing an ear cover shield having a generally smooth exterior side; positioning the cover shield adjacent to but generally spaced from an ear of the cyclist so that wind is generally deflected from the ear so that the noise of air rushing over the ear is substantially reduced, and the cyclist is better able to hear proximate sound especially that sound generated from directions which he cannot readily see; and, positioning and holding the cover shield adjacent to the ear most preferably by adjustably attaching it to a strap on the helmet. When wearing a cover shield, even in a strong wind, a cyclist is able to hear a vehicle approaching from the rear so that he can accordingly move close to the side of a roadway and ensure that his cycle moves in a straight, unswerving path.

A laser scanning unit is provided comprising: a housing; a scanning device; a first pre-scan assembly generating a first light beam and directing the first light beam toward the scanning device; a second pre-scan assembly generating a second light beam and directing the second light beam toward the scanning device; a first post-scan assembly receiving the first light beam reflected from the scanning device and causing a first portion of the first light beam to scan along a first scan path; and a second post-scan assembly receiving the second light beam reflected from the scanning device and causing a first portion of the second light beam to scan along a second scan path. The first post-scan assembly further reflects a second portion of the first light beam in a direction away from the first scan path. A shield is associated with the housing for blocking the second portion of the first light beam reflected by the first post-scan assembly during at least a portion of the scan of the first portion of the first light beam along the first scan path so as to prevent the second portion of the first light beam from entering the second post-scan assembly.

A continuously variable transmission cooling fan includes a moveable sheave cover attached to a drive clutch assembly of a continuously variable transmission, with a plurality of fan blades molded into the moveable sheave cover and arranged around the perimeter of the moveable sheave cover. Each fan blade may have a different length, curvature and angle of position than the adjacent fan blades. The continuously variable transmission cooling fan also may include a plurality of openings in the moveable sheave cover located radially inwardly from the fan blades.

A zone damper having a first portion responsive to the static pressure in a HVAC system to open and bleed an amount of conditioned air past the damper when the static pressure of the system increases above a selected level, a second portion controlled by a actuator to move between an open and a closed position in response to a zone thermostat, and a coupling mechanism coupling the first and second portions to limit the relative movements of the two portions with respect to each other, and a biasing mechanism exerting a torque against the system static pressure differential. The first portion can be a single one-piece undivided blade pivotally mounted with a shell surrounding the zone damper.

The invention relates to a low-noise high-speed floating acoustic test device in a water tank, and belongs to the technical field of underwater aircraft hydrodynamic noise control. The test device comprises a test model, a flexible cable, an underwater acoustic measuring device, two fixed pulleys, an induction type speedometer, a movable pulley unit, a fixed pulley unit, a guide mechanism I, a connector, a weight I, a weight II and a shock absorbing mechanism. When the weight II descends to the shock absorbing mechanism by the aid of the gravity of the weight II, the accelerated speed acquired by the test model under the action of the pulley units is far higher than that of the weight II, and the test model reaches floating speed needed by tests. However, the resistance of a test system is overcome by the gravity of the weight I, the test model keeps the needed speed and floats at constant speed until the weight I descends to contact with the weight II, the test model exactly floats out of a water surface, and near-field noise and free far-field noise characteristics of the test model are acquired by analyzing data recorded by the underwater acoustic measuring device and an internal data acquisition recorder of the test model.

The invention provides a rotor processing method capable of reducing motor vibration and noise. The processing method is characterized by including step one, performing coarse grinding on a bearing retainer of a motor and an external circle of an iron core; step two, performing a first dynamic balance correction; step three, performing a second fine grinding on the rotor; and step four, performing a second dynamic balance correction. Grinding and dynamic balance correction are performed twice for the rotor processing, compared with grinding and dynamic balance correction which are performed once, the motor vibration severity is improved by at least one standard grade, structural noise is reduced by 3-5dB, different motors have different specific circumstances, air noise is reduced due to reduction of the vibration severity and the structural noise, and therefore vibration and noise reduction effects are obvious.

A roller chain of a metallic material, with alternating inner and outer chain links which are respectively joined together via a chain joint, whereby the outer chain links comprise two parallel outer plates, joined together by means of two parallel joint pins, and the inner chain links comprise two parallel inner plates, joined together by means of two parallel joint sleeves, a joint pin of an outer chain link extends in each case through a joint sleeve of an inner chain link to form a chain joint and a rotatable roller is arranged on the outer surface of the joint sleeve, whereby a size ratio of the height of the outer and inner plates to the external diameter of the roller is greater than 1.4, and a size ratio of the mean thickness of the inner plate to the mean thickness of the outer plate is greater than 1.1.

A hand dryer with reduced air-intake noise includes a housing, a flow-guide plate, and an air supply module. The housing includes an accommodating space and a plurality of narrow air inlets. The flow-guide plate is disposed inside the accommodating space, but the flow-guide plate is not contacted with the housing. The flow-guide plate includes a plurality of narrow air guide holes. The air supply module is disposed inside the accommodating space, and includes a blower that extracts air inside the accommodating space to generate a drying air flow after being started and an air-guide piece connected to the blower to receive the drying air flow. An interval between the narrow air inlet and the narrow air guide hole interferes with transmission of a sound wave formed by the air flowing between the narrow air inlet and the narrow air guide hole, so that generated noise can be greatly reduced.

The invention provides a commutator and a motor. The commutator comprises a commutator base body and a plurality of commutator segments, wherein the plurality of commutator segments are arranged around the commutator base body along the circumferential direction, and the adjacent commutator segments are provided with a first gap section and a second gap section therebetween which are adjacent to each other along the circumferential direction; each commutator segment is provided with a winding wiring portion at the second end along the axial direction, and the first end of the commutator segment along the axial direction is away from the winding wiring portion; the width L2 of the second gap section between the second ends of the adjacent commutator segments is greater than the width L1 ofthe first gap section between the first ends; and the width L2 of the second gap section is less than the width L3 of the spacing between the winding wiring portions of the adjacent commutator segments. According to the technical scheme of the invention, the setting of the width-varying gap between the adjacent commutator segments increases the spacing of burr-prone areas during the processing process so as to avoid the risk of short circuits one the one hand; and on the other hand, the working area of the commutator is kept to have a narrow spacing, thereby improving the EMC, reducing the airnoise and vibration, and enabling the motor performance to be more stable.

An air mover is provided. The air mover includes a housing, a spacer, a co-axial motor, a first fan and a second fan. The housing includes a first housing member and a second housing member. A first inlet, a second inlet and an outlet are formed on the housing. The first inlet is formed on the first housing member and the second inlet is formed on the second housing member. The spacer is disposed between the first housing member and the second housing member. The co-axial motor includes a shaft, wherein the co-axial motor is disposed on the spacer. The shaft includes a first free end and a second free end. The first free end extends in a first direction, and the second free end extends in a second direction.

The invention provides an air conditioning system of a low-temperature laboratory. The air conditioning system comprises an air conditioning device, a temperature control unit, a refrigerating device, an electric control box, a temperature and humidity sensor and the like. The temperature and humidity sensor is used for monitoring the temperature and humidity in the low-temperature laboratory in real time, when the real-time temperature and humidity deviate from preset values, the electric control box regulates and controls an electromagnetic valve in the air conditioning device and also regulates and controls an electromagnetic valve in the temperature control unit at the same time, and temperature and humidity regulation and control are more accurate through two times of regulation and control. Meanwhile, under the action of the air supply cavity and the air supply pore plate, air flow is stably supplied into a working area of the low-temperature laboratory, and an air return opening of the air return cavity is formed in the bottom, so that an air flow organization type of top air supply and lower air return is formed, and the constancy of the temperature is ensured. Compared with an existing air cooler cooling mode, the indoor constant-temperature constant-humidity and low-noise design environment is achieved, and high comfort of personnel is guaranteed.

The invention discloses a direct-current brushless mute water pump, which comprises a water pump main body, wherein a rotor, a stator and a pump head are arranged inside the water pump main body, the rotor and the stator are mutually connected with each other, the pump head is fixed on the upper part of the water pump main body, a pump cavity is formed between the rotor and the stator, the center of the rotor is provided with a central shaft, the central position, adjacent to the upper part of the central shaft, of the pump head is provided with a water inlet, a water inlet passage is formed between the central shaft and the rotor, a plurality of groups of balance pores are arranged in the water inlet passage, the pump cavity can be instantaneously fully filled with the water by adopting the design of the balance pores, and the negative pressure is generated in the water inlet, so that the rotor is imbalanced, the rotor and the stator are mutually balanced, the rotor is enabled to work under the freedom state, the friction resistance force between the rotor and a mechanical member in work can be reduced, and no mechanical abrasion noise is realized when the water pump works; since the pump cavity is rapidly filled with the water, the air inside the water passage can be thoroughly emptied in a short time, the air noise generated by the rotation of the air in the pump cavity can be lowered, more than 80 percent of noise pollution can be reduced, and the direct-current brushless mute water pump has broad market prospect.

A resonator (12) for reducing intake air noise is connected to an intake air duct (6) connecting a throttle chamber (5) and an air cleaner case (7). This blow-by gas treatment device is equipped with a fresh air introduction passage comprising a fresh air introduction hose (16), and, a blow-by gas passage comprising a blow-by gas hose (20), with the fresh air introduction hose (16) connecting a cylinder head cover (4) and the resonator (12). A connector part (15) of the resonator (12) to which the fresh air introduction hose (16) is connected is provided with an orifice (21) formed integral with a lower body (13) formed of a synthetic resin, as a part thereof. Pulsation is effectively reduced by the throttling effect of the orifice (21) and the expansion effect of the resonator (12).