Patent ID: 8259969
Filing Date: 2012-09-04
Classification: H04R

Abstract:
1. A high-frequency pneumatic loudspeaker for sound broadcasting, comprising: a housing formed by an upper housing body and a lower housing body, wherein an upper end of the upper housing body is opened, a side of the upper housing body is provided with silencer exhaust holes; a central portion of a lower end of the lower housing body has an air inlet port, a supporting plate arranged between the upper and lower housing bodies, wherein said supporting plate divides an internal space of the housing into an upper portion and a lower portion communicating with each other by an air channel, a throat canal, a central cone, an annular nozzle, an obstructing ring, a voice coil, and a lead of the voice coil provided in said upper housing body, wherein a lower end of said throat canal forms an annular flow-splitter, an inner side of the flow-splitter and an outer wall of the central cone form a throat channel, a lower plate and an upper plate for holding the obstructing ring and the voice coil in position, a magnet mounted in the lower housing body, and an inner magnetic pole and an outer magnetic pole mounted in the lower housing body and connected with the magnet, wherein the voice coil is arranged in a magnetic gap between the inner and the outer magnetic poles, a high-pressure air chamber is formed within a space between the outer magnetic pole and the lower housing body, and a high-pressure airstream is allowed to enter the high-pressure air chamber from said air inlet port and to enter the annular nozzle through said air channel, and wherein a gap is provided between the obstructing ring and an end of the annular nozzle, for avoiding friction between the obstructing ring moving upward and downward and the end of the annular nozzle, and a cooling system comprising: whereby a first stream of air going through said central orifice from said high-pressure air chamber is led to go through the gap between an inner side of said voice coil and the inner magnetic pole toward a free edge of the voice coil, where said first stream of air meets with a second stream of air going through said at least one side orifice and turns to go through the gap between an outer side of said voice coil and the outer magnetic pole, to exit said high-frequency pneumatic loudspeaker as low-pressure airstream through said silencer exhaust holes, wherein said first stream of air drops its temperature while it expands after it passes said central orifice, and said second stream of air drops its temperature while it expands after it passes said side orifice.