7results about How to "Guaranteed quiet effect" patented technology

A design method for a large-skew contra-rotating propeller propulsion system of a high-speed underwater vehicle comprehensively considers the wake flow distribution characteristics of the tail of the underwater vehicle, and comprises the steps of selecting circular rector distribution matched with the wake flow distribution form, optimizing disc surface ratio and chord length distribution, designing reasonable skew and trim distribution, selecting proper profile thickness and camber distribution and the like. The invention aims to improve the propulsive efficiency, reduce the yawing moment and meet the design requirements on the premise of avoiding cavitation. Particularly, in the design process, the design scheme is iteratively optimized by combining CFD calculation and a potential flow theory method, it is ensured that the final scheme is optimal in the aspects of propulsive efficiency and cavitation performance, and the requirements of the high-speed aircraft are met.

The application discloses a mute door lock assembly and belongs to the technical field of locks. The mute door lock assembly comprises a lock body, a slanting lock tongue and a main lock column which are arranged on the lock body in an extendable mode, and a lock cylinder hole is formed in the lock body. The lock body comprises a lock body and a lock cover, the lock body and the lock cover are fixedly connected through screws, mounting holes are formed in the lock body and the lock cover, a mounting column is arranged between the lock body and the lock cover, screw holes are formed in the mounting column, the mounting column is opposite to the mounting holes, the screws are connected with the screw holes through the mounting holes, and the mounting of the lock body and the lock cover is realized. A mute structure is further arranged in the lock body. The mute door lock assembly has the beneficial effects that the first magnet and the second magnet are arranged, the second magnet generates a certain repulsive force on the first magnet when the first magnet moves to the limit position, the push plate is prevented from impacting the limiting structure, i.e., the lock body, and the impact sound is reduced.

The utility model relates to the technical field of building heat preservation, in particular to an adjustable heat preservation and insulation mute window which comprises a window frame, a window body is arranged at the front end of the window frame, a handle is fixed to the front end of the left side of the window body, a window body positioning frame is fixed to the rear side of the window body, and a pull rope controller is arranged on the outer side of the window body and the outer side of a sealing strip. A glass plate is arranged in the middle of the interior of the window body and the window body positioning frame, pulleys are arranged in the window body and the window body positioning frame, the right sides of the pulleys are connected with cloth body positioning rods through pull ropes, heat preservation cloth is fixed to the right side of the cloth body positioning rod at the front end, and sunshade cloth is fixed to the right side of the cloth body positioning rod at the rear end. Cloth body rotating shafts are fixed in the heat preservation cloth and the sunshade cloth; the window body can rotate through the cooperation of the auxiliary rotating shaft heads and the main rotating shafts, the window body and the window frame can be sealed through the sealing strips, and meanwhile due to the effect of the multiple layers of glass plates, the heat preservation and mute effects of the device can be guaranteed.

The utility model relates to guide rail technical field discloses a kind of mute guide rail device, including guide rail, the guide rail surface is provided with mute component, the mute component inside is provided with lubricating component.The utility model can significantly reduce the noise in the process of movement by the damping mute wheel, this is realized by using the material with sound-absorbing effect such as rubber, PU etc or using specific structure design, when damping mute wheel drives limit shaft to rotate with auxiliary nut as center, damping mute wheel is under the long-time friction of guide rail surface, easy to cause damping mute wheel breakage, when needing to replace damping mute wheel, by fixing fixed bolt and auxiliary nut simultaneously, then rotating auxiliary nut, make auxiliary nut separate from fixed bolt bottom surface, make auxiliary nut drive limit shaft, limit shaft drives damping mute wheel to separate downward, so as to separate damping mute wheel from guide rail to facilitate its replacement, to ensure its mute effect.

The utility model discloses a high-strength wear-resistant silent hanging wheel, and relates to the technical field of silent hanging wheels, according to the high-strength wear-resistant silent hanging wheel, a limiting nut is matched with a limiting block and a limiting sleeve, so that the stability of a first bearing wheel body and a second bearing wheel body during working is conveniently maintained, and the silent hanging wheel is of a double-wheel structure; according to the mute hanging wheel, the whole mute hanging wheel can better balance and share stress, the movement smoothness of the mute hanging wheel can be better improved, the use experience impression is optimized, the anti-rust coating is sprayed on the surface of the wear-resisting ring, the mute ring is made of silicon rubber, the wear-resisting ring and the mute ring are both made of materials with good wear-resisting performance, protection on the first bearing wheel body and the second bearing wheel body is conveniently formed, and the service life of the mute hanging wheel is prolonged. The diameter of the outer ring at the left end of the mute ring is slightly larger than that of the wear-resistant ring, so that the silicon rubber material can be stressed firstly during rolling, vibration is reduced, generated noise is eliminated, the service life of the mute hanging wheel is prolonged, and the mute effect of rolling is guaranteed for a long time.

A construction machine includes: a lower traveling body; an upper rotating body rotatably mounted on the lower traveling body; an external sound pickup unit for picking up ambient external sounds; an in-vehicle playback unit for outputting the external sounds picked up by the external sound pickup unit to the interior of the upper rotating body; and a control unit for switching whether the in-vehicle playback unit outputs the external sounds picked up by the external sound pickup unit according to predetermined conditions.

The utility model discloses a silent multi-sealing drainage lower rail for doors and windows. The silent multi-sealing drainage lower rail comprises a lower rail profile and a first sealing piece. The lower rail profile is provided with a drainage port and a drainage surface; a first rail is arranged above the drainage surface; the first sealing piece is arranged on the first side, close to the water outlet, of the first rail. The first sealing piece is provided with a first shaft body, and the first side portion is provided with a first shaft hole matched with the first shaft body. The first sealing piece is further provided with a limiting structure used for limiting the angle. The detachable first sealing piece is arranged at the water outlet of the lower rail profile, a split structure is formed, and therefore machining and manufacturing are convenient.