2results about How to "Reduce prestress" patented technology

The application provides a MEMS hydrophone and method, and relates to the technical field of MEMS hydrophones.The MEMS hydrophone comprises a base, a sound-permeable shell and an acoustic sensing assembly.The sound-permeable shell and the base form a first cavity filled with hydraulic oil;the acoustic sensing assembly is located in the first cavity and comprises a shielding cover, a printed circuit board, a flexible membrane, a transition carrier plate and a MEMS chip.The shielding cover, the printed circuit board and the flexible membrane surround to form a second cavity, and the shielding cover is provided with a communication hole communicating the first cavity and the second cavity.The MEMS chip, the transition carrier plate and the flexible membrane surround to form a third cavity filled with gas.The application realizes front hydraulic pressure transmission through the hydraulic oil in the first cavity, realizes back gas pressure compensation through compression of the third cavity by the flexible membrane, forms a cooperative pressure balance mechanism, significantly reduces the net pressure difference and the prestress borne by the MEMS chip, effectively inhibits the problems of sensitivity attenuation, linearity deterioration and frequency response drift under a deep-water high hydrostatic pressure environment, and simultaneously improves the structural safety and long-term reliability.

The utility model relates to stress cable technology field, concretely is a kind of adjustable prestressed cable device, including mounting bracket, connecting frame, adjusting screw rod and anti-loosening mechanism;One end of mounting bracket is connected with connecting lug;Connecting frame is set in the end of mounting bracket and is used to fix the end of cable, and connecting frame penetrates mounting bracket and is slidably connected with mounting bracket;Adjusting screw rod is set in mounting bracket, and one end of adjusting screw rod is rotatably connected with mounting bracket, and the other end of adjusting screw rod is threadedly connected with threaded sleeve, and the end, away from adjusting screw rod, of threaded sleeve is fixedly connected with connecting frame;Anti-loosening mechanism is set on mounting bracket, and one end of anti-loosening mechanism is connected with mounting bracket.The utility model is provided with anti-loosening mechanism, check pawl is attached to spring elastic force under the action of check ratchet wheel and attaches to the check tooth of check ratchet wheel, and adjusting screw rod is positioned, to prevent loosening between adjusting screw rod and threaded sleeve, and then avoid the prestress of cable to be small.