4results about How to "Reduce margin" patented technology

This invention provides a method and system for extracting front-end power from a high-bypass turbofan engine, including a low-pressure rotor front-end power extraction subsystem and a support structure. The support structure includes a coaxial outer casing and an inner casing. The outer casing is connected to a fan casing. The front end of the inner casing is connected to the outer casing via a load-bearing support plate. The rear end of the inner casing overlaps with the low-pressure rotor blade disk, and the generator is assembled in the inner cavity of the front end of the inner casing. The method includes a front-end power extraction method design step and a front-end power extraction system design step. The front-end power extraction method design step includes: the extraction and allocation of high-pressure rotor front-end power and low-pressure rotor front-end power. The method and system designed in this invention extract low-pressure rotor power through a front-end power extraction method, ensuring the power demand of the aero-engine while guaranteeing compressor margin, filling a gap in the industry and having significant guiding significance.

The application provides a method and device for determining equipment parameters of a high-voltage direct-current power transmission system and a storage medium. The method comprises: obtaining a voltage fluctuation limit value used to indicate an AC filter switching state of the high-voltage direct-current power transmission system; calculating a first product between the voltage fluctuation limit value and a first coefficient set in advance to obtain a voltage fluctuation coefficient, wherein the voltage fluctuation coefficient is not greater than the voltage fluctuation limit value; determining a group capacity of a reactive power compensation device in the high-voltage direct-current power transmission system based on the voltage fluctuation coefficient; calculating a second product between the voltage fluctuation limit value and a second coefficient set in advance to obtain a tap distance of a converter transformer in the high-voltage direct-current power transmission system; and determining a trigger angle interval of a converter valve in the high-voltage direct-current power transmission system according to the tap distance and a highest gear position of the converter transformer. The application can reduce the overall margin of the high-voltage direct-current power transmission system to reduce the power transmission cost.

This invention belongs to the field of advanced metallic materials and powder metallurgy technology, specifically relating to a low-cost, multi-scale twinned synergistic deformation superplastic medium-heavy alloy and its preparation method. The preparation method includes melting the medium-heavy alloy using vacuum induction melting technology, then casting the molten medium-heavy alloy into an ingot and machining electrodes; preparing the electrodes into powder of a predetermined particle size; loading the powder into a casing, and after compaction, heating and degassing the casing until the required vacuum level is met, followed by sealing the casing; hot isostatic pressing of the sealed casing, and finally machining to remove the casing, yielding the superplastic medium-heavy alloy material. The superplastic medium-heavy alloy material prepared by this invention possesses multi-scale twins and an FCC matrix, with the FCC matrix accounting for more than 95% of the alloy, both ensuring good plasticity of the medium-heavy alloy material.

The application discloses a tool for machining a rotation-stopping structure on a rotary part, and belongs to the technical field of pin machining in connectors. The tool solves the problems of complicated operation and high cost in machining the rotation-stopping structure on the part in the prior art. The tool comprises an upper die assembly, a lower die assembly, extrusion forming parts and positioning blocks. The lower die assembly is internally movably provided with two extrusion forming parts. The two extrusion forming parts are provided with the positioning blocks therebetween, the positioning blocks are provided with part positioning holes in the centers, and the parts to be machined are fixed in the part positioning holes. The upper die assembly drives the two extrusion forming parts to approach each other, and the two extrusion forming parts machine the limiting portions on the parts. In the application, the two extrusion forming parts are used to extrude the parts on both sides to machine the limiting portions on the parts. Compared with the existing rotation-stopping structure, the tool does not need to add steps on the outer circles of the parts and machine symmetrical flat positions, the machining efficiency and material utilization are improved, the machining cost is reduced, the turning allowance is reduced, and the quality of the parts is ensured.