Abstract: A vacuum cleaner having a discharge flow path, which reduces noise generated due to resistance of the flow path, and by a motor. The vacuum cleaner includes a body, a blower fan unit including a blower fan and a motor to generate suction force in the body, an inner case surrounding the blower fan unit and having an inner flow path formed therein, an outer case surrounding the inner case, and a discharge flow path formed between the inner case and the outer case to communicate with the inner flow path. The discharge flow path including a circulation flow path branched from the inner flow path to guide air discharged from the blower fan unit, and a bent flow path branched from the inner flow path to guide the air discharged from the blower fan unit, the air is thereby bent a number of times in the bent flow path.

Abstract: A vacuum cleaner has a discharge flow path and a discharged-air filter optimally positioned to reduce noise. The vacuum cleaner includes a body, a dust collection unit positioned in the body to filter foreign matter, a blower fan unit including a blower fan and a motor to generate suction force, an air vent through which air drawn into the body is discharged, and a discharge flow path to guide the air discharged through a discharge port of the blower fan unit to the air vent. The discharge flow path comprises a space defined between the dust collection unit and the blower fan unit.

Abstract: A cyclonic cleaner which includes a cyclone unit enabling a reduction of noise generated from the cyclone unit, and reduction in pressure loss by forming a smooth air flow. The cyclone unit includes a body having an air inlet and an air outlet, a primary cyclone to primarily separate foreign matter from air drawn through the air inlet, a plurality of secondary cyclones to secondarily separate foreign matter from air discharged from the primary cyclone and to discharge the air having the foreign matter removed therefrom through discharge holes of the secondary cyclones, and a noise reduction member positioned in the discharge hole of each secondary cyclone to reduce noise. The cyclone unit also includes a guide plate to allow the air discharged through the discharge holes of the secondary cyclones to be smoothly discharged through the air outlet.

Abstract: A package tray of a vehicle includes a first reinforcing member installed to a woofer mount of a center panel and supported by a rear member and a second reinforcing member installed to the rear member to correspond to the woofer mount of the center panel in the front-to-rear direction. Thus, stiffness is increased so that noise, caused by vibration and/or tremble generated when a woofer outputs sound waves, can be minimized.

Abstract: An oil separator for an air conditioner includes a cylindrical housing; a refrigerant discharge pipe communicating with the housing for discharging refrigerant gas; an oil discharge pipe for circulating oil collected in the lower portion of the housing; and a refrigerant inflow pipe having one end facing the inner surface of a side wall of the housing in the tangential direction for supplying a refrigerant-oil mixture to the inside of the housing. An insertion hole, into which the refrigerant inflow pipe is inserted, is easily formed, the efficiency of the oil separator is increased, and noise and vibration generated from the oil separator is reduced.

Abstract: A vacuum cleaner for reducing noise from being transmitted to the exterior. The vacuum cleaner includes a main body forming an outer appearance of the vacuum cleaner and including a blower unit for generating suction force and blowing force and a discharge hole through which purified air from which foreign matter has been filtered is discharged, a discharge passage for guiding air discharged from the blower unit to the discharge hole, and a spiral shaped intercepting passage for forming a part of the discharge passage and for preventing noise of the blower unit from being transmitted to the exterior. A guide member forming the intercepting passage is disposed at the outside of the blower unit and serves as an acoustic absorber so that noise transmission to the exterior is reduced.

Abstract: A blower designed to reduce noise generated between impeller blades and diffuser blades positioned around the impeller blades upon rotation of an impeller, and a cleaner including the same are disclosed. The diffuser blades are non-uniformly spaced from each other in a circumferential direction such that interaction between the plurality of impeller blades and the plurality of diffuser blades become irregular upon rotation of the impeller. Distances between the impeller blades and the diffuser blades are non-uniform. With this construction, the blower and the cleaner are reduced in BPF noise, thereby enhancing performance thereof.

Abstract: A cyclone vacuum cleaner including a plurality of cyclone chambers arranged in a group. The cyclone chambers are configured such that frequency characteristics of noises generated from respective cyclone chambers are different from each other.

Abstract: The present invention relates to a high-frequency power amplifier having differential inputs, and more specifically to a high-frequency power amplifier having differential inputs, in which a structure of an output port of a communication system for 2.4 GHz ISM frequency band can be simplified by designing and producing the high-frequency power amplifier having differential inputs for 2.4 GHz ISM frequency band using a silicon germanium (SiGe) microwave monolithic integrated circuit (MMIC), thereby decreasing the number of components of a transmission unit and reducing a price of the communication system.