82results about How to "Prevent resonance effects" patented technology

The invention discloses an anchor of a warp knitting machine, which comprises an upper bearing plate and a lower bearing plate. The upper bearing plate is provided with a first shaft part extending downwards along the lower end face of the upper bearing plate. The lower bearing plate is provided with a second shaft part extending upwards along the upper end face of the lower bearing plate. The first shaft part and the second shaft part are connected in a sliding mode and are matched in an air-tight mode. Springs and a closed air cavity are arranged between the upper bearing plate and the first shaft part thereof and the lower bearing plate and the second shaft part thereof. Both the cross sections of the upper and lower bearing plates are of a round shape. The first shaft part is of a cylinder shape. The second shaft part is provided with a cylindrical blind hole. The closed air cavity is formed by a first air cavity, a second air cavity and a third air cavity, wherein the first air cavity is formed between the first shaft part and the cylindrical blind hole; the second air cavity is communicated with the first air cavity and is formed by an axial hole arranged along the axial direction of the first shaft part; and the third air cavity is communicated with the second air cavity and is formed by a radial hole arranged along the radial direction of the upper bearing plate. The anchor of the warp knitting machine has excellent vibration reduction performance, can bear a larger load, can be used for preventing a machine bed from being turned over and can be popularized and applied in equipment such as the warp knitting machine and the like.

The present invention relates to a microphone with dual effects for enhancing the physical acoustic volume and for acquiring uni-directional acoustic source. The microphone applies the viewfinder theory of the telescope. The sound source at a designated direction is past from the front end of a hollow tube through the tube such that the sound generates resonance and focusing effects when passing through the tube. The microphone provided at the end of the tube is allowed to increase the volume acquired without using a passive amplifying circuit. A high ratio of sound at the designated direction can also be acquired.

The invention discloses a novel multi-ribbed composite wall structure system with three anti-vibration defense lines, which includes a first anti-vibration defense line point contact type X-shaped filling building block, a second anti-vibration defense line reinforced concrete multi-ribbed frame grid unit, a third anti-vibration defense line reinforced concrete invisible outer frame and acast-in-situ reinforced concrete floor, wherein the point contact type X-shaped filling building block and the concrete frame grid are contacted at four corner parts, flexible material is filled between the point contact type X-shaped filling building block and the concrete frame grid, 10-50mm slit is arranged between the side surface of the multi-ribbed frame grid unit and an outer frame column, and the multi-ribbed frame grid unit and top surface and bottom surface of an outer frame beam are anchored in the frame beam through rib column longitudinal steel bars to realize rigid connection. The structure system has three specific anti-vibration energy-dissipating defense lines, each defense line sequentially performs dominant defense effect under earthquake with different grades, thereby reaching the purpose of dissipating earthquake energy and reducing earthquake reaction by stages; and load transmission path is clear, mechanical model is simple and visual, thereby being convenient for realizing elaborate design of the multi-ribbed composite wall structure.

The invention provides a metal vacuum insulated panel which comprises a shell, core materials and vacuum chambers. The metal vacuum insulated panel is characterized in that the shell is a metal panel or a metal composite panel. The core materials are located in the vacuum chambers formed by welding the shell in a sealing mode and provide additional strength for the shell, so that smoothness of the shell under atmospheric pressure is guaranteed. The vacuum chambers are massively automatically welded and sealed in a vacuum furnace under high vacuum and high temperature. A preparation method of the metal vacuum insulated panel is simple in process, the prepared metal vacuum insulated panel can overcome the defects of an existing heat preserving panel and an existing vacuum insulated panel, therefore, air tightness of the vacuum chambers of the metal vacuum insulated panel can be effectively guaranteed, the service life of the metal vacuum insulated panel is prolonged, strength can be increased, and the heat insulation, sound insulation and fireproof performance and the decorative function can be increased.

A method to regulate the electric motor of a handheld power tool, the method encompassing the following steps: prescribing a target speed for the electric motor, varying the prescribed target speed—each time after a certain period of time has lapsed—by a value within a certain variation range in order to supply a varied target speed, and regulating an actual speed of the electric motor to the supplied varied target speed.

One elevator system includes an elevator car, counterweight, traction sheave, support wrapped around the traction sheave and suspending the car and the counterweight, a compensation sheave, a compensation member wrapped around the compensation sheave and being affixed at a first end to the elevator car and at a second end to the counterweight, and a tensioner. The support is driven by rotation of the traction sheave to raise and lower the car, and the tensioner is in communication with the traction sheave for linearly displacing a rotational centerpoint of the traction sheave. Another elevator system has an elevator car, counterweight, compensation sheave, compensation rope wrapped around the compensation sheave and being affixed to the car and the counterweight, a traction sheave driving a support suspending the car and the counterweight, and a tensioner in communication with the traction sheave for inducing a variation in tension of the compensation rope.

The invention aims to provide a heartbeat protocol method and a device based on lease. The method comprises the following steps: sending a heartbeat request to a server in the lease period, and receiving a heartbeat request response from the server; and if the heartbeat request response is abnormal, determining the retry sending interval based on an inverse exponential back-off algorithm, and sending a retry heartbeat request to the server after the retry sending interval until the lease expires or the corresponding heartbeat request response is normal. In the early stage of retry heartbeat requests, two adjacent retry heartbeat requests can be sent at a large sending interval, which reduces the impact pressure of heartbeat requests on network nodes and the server. In the late stage of retry heartbeat requests, the sending interval of retry heartbeat requests is shortened, which enables retry heartbeat requests to be sent at higher frequency. Therefore, the success probability of recovery from network failure is increased, the stability of the network is guaranteed, and the network pressure is reduced.

The invention discloses a metal vacuum insulation plate with a getter. The metal vacuum insulation plate comprises a shell, a core material and a vacuum cavity, and is characterized in that the shell is a metal plate or a metal composite plate, wherein the core material is positioned in the vacuum cavity for providing additional strength to the shell and guaranteeing the flatness of the shell under atmospheric pressure; the vacuum cavity is a closed cavity formed by performing the welding edge sealing under normal pressure and the high-temperature opening sealing under vacuum for the shell; the opening sealing is a step that a prefabricated extraction opening in the shell is automatically sealed in a vacuum furnace by using a low-temperature solder according to a liquid sealing principle; and the getter is arranged in the vacuum cavity. A preparation method of the metal vacuum insulation plate is simple; and the prepared metal vacuum insulation plate with the getter can overcome the defects of a traditional insulation plate and a traditional vacuum insulation plate, and can improve the strength, and the heat insulation, sound insulation, fire prevention and decoration functions.

The invention discloses a propeller design method based on a genetic algorithm. The method comprises the following steps: firstly, presetting initial speed V0; determining value range of initial parameters of a propeller; constructing a genome population; carrying out cavitation checking on the genome population to eliminate/reform genomes not according with requirements; calculating propeller efficiency of genomes; carrying out evolution and elimination on the genome population until a preset evolution times are reached; outputting and selecting highest efficient propeller design parameters,and calculating corresponding speed; and finally, judging, according to the speed, whether optimization is continued. According to the method, an optimization design of the genetic algorithm is employed, limitation that in the prior art, mutual influences in changes among all parameters need to be considered and thus adjustment is continuously carried out for obtaining optimum propeller efficiencyis overcome, and design efficiency of the propeller is improved; and compared with a set of optimal parameters only obtained by using a graph design manner, a set of multi-solution optimization parameter schemes finally obtained by the method more facilitate selection and determination of an optimal propeller design scheme.

A double-vacuum-layer ceramic composite vacuum plate with getters comprises face plates, connecting layers and a vacuum chamber and is characterized in that the face plates are made of ceramic plates or ceramic tiles; the face plates and/or the connecting layers provide additional strength for the vacuum chamber, so that smoothness of the vacuum chamber under atmosphere is guaranteed; the vacuum chamber is a sealed cavity which is formed in the mode that the edges of metal plates are sealed in a welding mode under normal pressure and the openings of the metal plates are sealed by high temperature under vacuum; the opening sealing operation is conducted as follows: an extraction opening preformed in the vacuum chamber is automatically sealed in a vacuum furnace by low-temperature welding fluxes on the basis of the liquid sealing principle; a partition plate is arranged in the vacuum chamber and divides the vacuum chamber into double vacuum layers; upholders are arranged in the vacuum layers. A method for manufacturing the double-vacuum-layer ceramic composite vacuum plate with the getters is simple in process, the prepared double-vacuum-layer ceramic composite vacuum plate with the getters can overcome the defects of an existing heat preservation plate and an existing vacuum heat insulation plate, and strength, heat and sound insulation performance and fireproof performance of the double-vacuum-layer ceramic composite vacuum plate with the getters can be improved.

The invention relates to the technical field of embroidery machines, and particularly discloses an ultrahigh-speed embroidery machine head. The ultrahigh-speed embroidery machine head is characterized in that a case is provided with a left chamber and a right chamber, a dynamic balance cam, a presser foot cam and a take-up-lever cam are positioned in regions on the outer sides of the left chamber, the right chamber and a right cover plate, a spindle between the dynamic balance cam and the presser foot cam is rotationally movably connected with a partition plate, and the presser foot cam and the take-up-lever cam are rotationally movably connected with the right cover plate. The ultrahigh-speed embroidery machine head has the advantages that the dynamic balance cam, the presser foot cam and the take-up-lever cam are isolated in the three regions by the partition plate and the right cover plate, every two adjacent regions are connected with each other by the spindle and the case in a supported manner, and accordingly resonance effects due to centrifugal force generated by various components can be prevented; the dynamic balance cam is integrally formed by a balance block and an eccentric column, the eccentric column can drive needle bars to move via a needle bar driving connecting rod assembly, centrifugal force generated by the balance block is used for offsetting the centrifugal force generated by the other components, accordingly, vibration can be eliminated, and the spindle can rotate at the high speeds.

A hard disk drive frame is provided. The distances from its hard disk drive fixing parts to the substrate center are not the same. During the process of vibrational energy transfer, three-dimensional reactions are induced correspondingly to cancel the kinetic energy transfer. The reactions generated at the static balance point in the three dimensions interfere one another to destroy vibrational frequencies in specific directions. Therefore, the disclosed hard disk drive is resistant to vibrations and suffers less from the resonance effect.

The invention discloses a silicon-based graphene photoelectric detector. The silicon-based graphene photoelectric detector comprises a silicon waveguide, an oxide substrate layer, an oxide cladding layer and graphene, and further comprises sub-wavelength metal electrodes composed of a first metal electrode and a second metal electrode, which are symmetrically arranged, wherein the sub-wavelength metal electrodes are crossly arrayed above the silicon waveguide by adopting two different types of metal. According to the silicon-based graphene photoelectric detector disclosed by the invention, twodifferent types of the metal are in contact with graphene to generate doping of different concentrations or types, so that electric potential difference is introduced between the sub-wavelength metalelectrodes and is used for driving a photon-generated carrier to flow toward the two electrodes. According to the silicon-based graphene photoelectric detector disclosed by the invention, the contactarea between the electrodes and the graphene is enlarged through a crossed arrangement structure of the electrodes, and the absorption efficiency of the carrier is improved; the graphene is laminatedon upper surfaces of the sub-wavelength metal electrodes and the sub-wavelength metal electrodes are used for carrying out optical field regulation and control on a transverse magnetic (TM) model transmitted in the silicon waveguide to increase an electric field component in a direction parallel to the graphene, so that the interaction effect between an optical field and the graphene is enhancedand the responsiveness of the detector is improved.

The invention discloses a double-vacuum layer metal composite vacuum insulation plate. The double-vacuum layer metal composite vacuum insulation plate comprises a panel, a connecting layer and a vacuum cavity, and is characterized in that the panel is a metal plate or a metal composite plate; the panel and/or the connecting layer provide the additional strength to the vacuum cavity, and guarantee the flatness of the vacuum cavity under atmospheric pressure; the vacuum cavity is a closed cavity formed by performing the welding edge sealing under normal pressure and the high-temperature opening sealing under vacuum for the metal plate; the opening sealing is a step that an extraction opening prefabricated in the vacuum cavity is automatically sealed in a vacuum furnace by using a low-temperature solder according to a liquid sealing principle; the low-temperature solder comprises a low-temperature metal and an alloy solder; a spacing plate is arranged in the vacuum cavity for dividing the inside of the vacuum cavity into double vacuum layers; and support objects are arranged in the vacuum layers. A preparation method of the double-vacuum layer metal composite vacuum insulation plate is simple in process; and the prepared double-vacuum layer metal composite vacuum insulation plate can overcome the defects of a traditional insulation plate and a traditional vacuum insulation plate, and can be improved in strength, heat insulation, sound insulation and fire prevention performance.

The invention provides a carbon nano-tube film transducer array, and belongs to the field of ultrasonic medical treatment. The transducer array comprises a transducer array frame and sound producing elements; each sound producing element includes a carbon nano-tube film, metal electrodes and leads; all the sound producing elements are located in the same plane or curved surface; and the arrangement rule and the sizes of the sound producing elements and the distance between the centers of every two adjacent sound producing elements can be adjusted according to function requirements. When each sound producing element is connected with an audio signal, a corresponding temperature variation is generated by the corresponding carbon nano-tube film, so that a surrounding medium swells and shrinksand a sound wave is produced by stimulation; and sound waves produced by all the sound producing elements are superposed and interfere mutually in the space, and thereby, the sound wave with highly concentrated energy is produced. The transducer array has the advantages that a vibrating component is absent, arrangement is flexible, the shape can be arbitrarily changed, the production cost is low,and the like, is capable of producing the sound wave high in frequency, directivity and sensitivity, and is applied to the field of ultrasonic medical treatment, advanced radar and the like.

The invention provides an efficient noise reduction damping dry-type transformer which comprises clamps and a base. Iron cores are fixed on the clampers and fixedly limited by the clampers, high-voltage winding coils and a low-voltage winding coils are wound on the iron cores, the iron cores are arranged on the base, and a plurality of fans are detachably mounted on the base and positioned on twosides of the iron cores. The transformer is characterized in that the clamps comprise one group of elongated steel plates and fixed screws, fixed holes are formed in two ends of each elongated steel plate, the fixed screws penetrate the fixed holes to fix the clamps by the aid of a combined mode of screws and nuts, one group of elongated steel plates include two elongated steel plates with same shapes, an interlayer is arranged on one side surface of each elongated steel plate and can be elastically compressed or elastically expanded, and the thickness of each interlayer without being compressed or expanded is 4-5cm.

The invention provides a high-abrasion-resistant noise reduction dry-type transformer which comprises clamps and a base. Iron cores are fixed on the clampers and fixedly limited by the clampers, high-voltage winding coils and a low-voltage winding coils are wound on the iron cores, the iron cores are arranged on the base, and a plurality of fans are detachably mounted on the base and positioned ontwo sides of the iron cores. The transformer is characterized in that the clamps comprise one group of elongated steel plates and fixed screws, fixed holes are formed in two ends of each elongated steel plate, the fixed screws penetrate the fixed holes to fix the clamps by the aid of a combined mode of screws and nuts, one group of elongated steel plates include two elongated steel plates with same shapes, an interlayer is arranged on one side surface of each elongated steel plate and can be elastically compressed or elastically expanded, and the thickness of each interlayer without being compressed or expanded is 4-5cm.

A metal vacuum insulation board with an extraction opening comprises a housing, core materials and a vacuum cavity, and is characterized in that the housing is a metal plate or a metal composite plate; the core materials are positioned in the vacuum cavity, provide additional strength for the housing, and ensure the smoothness of the housing under the atmospheric pressure; the vacuum cavity is closed and formed in such a way that the housing is subjected to welding and edge sealing under the normal pressure and sealing at a high temperature in vacuum; the sealing is achieved through automatically sealing the extraction opening, prefabricated in the housing, in a vacuum furnace by low-temperature solder according to a liquid sealing principle; and the low-temperature solder comprises low-temperature metal and alloy solder. The metal vacuum insulation board with the extraction opening has the advantages that the preparation method is simple in process, the prepared metal vacuum insulation board with the extraction opening can overcome defects in a conventional insulation board and a conventional vacuum insulation board, and the strength, the heat insulation performance, the sound insulation performance, the fire resistance and the decoration performance can be enhanced.