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61.
62.
针对现有双头螺杆泵转子线型存在的问题以及加工方法的局限性,通过研究非摆线螺杆泵转子线型形成原理,设计了非摆线型采油螺杆泵转子复合加工机床,利用立铣刀对做行星运动的工件进行包络,加工出非摆线型螺杆泵转子。根据机床的机械结构以及转子加工表面的形成运动,对转子加工机床进行了运动分析,确定了机床各轴之间的运动关系。并分析立铣刀在加工转子时所产生的截面轮廓误差,确定了误差随工件自转转速变化的关系,对非摆线型螺杆泵转子的加工提供了参考。 相似文献
63.
根据卡头零件的结构特点及实际生产的技术要求,进行多工位级进模排样设计,由于卡头零件结构为对称结构,故其排样设计采用对称单排结构设计,导正孔设计采用零件本身处于对称轴处的工艺孔,以保证板料冲裁、折弯时的强度,以及确保送料精度,同时采用导正销确定步距。该卡头零件多工位级进模采用顺装结构,使得工件与废料自然分离,有利于减少人工成本。同时,由于该零件折弯次数较多,为保证板料成形精度,故合理地进行了空工位的设计,避免成形零件发生回弹等影响零件精度。生产结果表明,卡头零件多工位级进模能满足产品生产要求,该模具的材料利用率高达75.62%,极大地节省了材料。 相似文献
64.
Andrea Ballo Alfio Dario Grasso Gaetano Palumbo 《International Journal of Circuit Theory and Applications》2020,48(2):157-161
This paper introduces a simple design strategy to increase the power efficiency of linear charge pumps. The technique exploits a voltage amplitude of the clock signal lower than the supply voltage to reduce the power conversion losses. The nominal output voltage is maintained unaltered by increasing the number of stages. 相似文献
65.
66.
为实现超高速模具量产,对经典的U型冲裁结构进行了优化,将原始的分离式U型冲裁和下废料双工位优化为单工位一步式冲裁和下废料工艺,新结构将产品切除和废料切除工位融合到一起,提高了U型凸模的强度、缩短了模具长度、减小了跳废料率,保证了产品质量;新结构在同一工位上同时获得产品且切除废料,无需采用连料方式传送废料,从而缩短了原材料的宽度,降低了材料成本,减少了误送。同时,模具速度从原有的800次·min-1提高到2000次·min-1,实现了超高速的目的,并且该新结构被成功地推广到其他相类似的结构中,实现了技术的互通性。 相似文献
67.
This paper presents and analyzes a novel fossil-fuel–free trans-critical energy storage system that uses CO2 as the working fluid in a closed loop shuttled between two saline aquifers or caverns at different depths: one a low-pressure reservoir and the other a high-pressure reservoir. Thermal energy storage and a heat pump are adopted to eliminate the need for external natural gas for heating the CO2 entering the energy recovery turbines. We carefully analyze the energy storage and recovery processes to reveal the actual efficiency of the system. We also highlight thermodynamic and sensitivity analyses of the performance of this fossil-fuel–free trans-critical energy storage system based on a steady-state mathematical method. It is found that the fossil-fuel–free trans-critical CO2 energy storage system has good comprehensive thermodynamic performance. The exergy efficiency, round-trip efficiency, and energy storage efficiency are 67.89%, 66%, and 58.41%, and the energy generated of per unit storage volume is 2.12 kW·h/m3, and the main contribution to exergy destruction is the turbine reheater, from which we can quantify how performance can be improved. Moreover, with a higher energy storage and recovery pressure and lower pressure in the low-pressure reservoir, this novel system shows promising performance. 相似文献
68.
The generation of dispersions with defined droplet size distributions is important for liquid-liquid extraction. In this respect, the capability of a centrifugal pump to generate dispersions was investigated for different operating points. For the analysis of the mixing process, a centrifugal pump was designed translucent. High-speed images reveal the mechanism of particle breakup. Optical measurement technology and image processing with neural networks were used to determine droplet size distributions. The influence of flow rate, rotational frequency and holdup are discussed for a paraffin oil-water system. 相似文献
69.
An optimized solar dish collector (OPSDC) system was proposed in our previous work, which can achieve excellent the optical efficiency and flux uniformity under ideal optics. On this basis, the impacts of the non-ideal optical factors on the optical performance of OPSDC system with a cylindrical and conical receiver are studied in detail and compared with the conventional solar dish collector (COSDC) system in this paper. Where the non-ideal optical factors considered are relatively comprehensive, including the mirror slope error, tracking error, installation error of the mirror and receiver, and receiver's absorptivity degeneration. An optical model with the non-ideal optical factors is built in detail by the ray tracing method, and the corresponding ray tracing codes are developed and verified by literatures and optical software OptisWorks 2012. The results show that the OPSDC system not only has a significantly smaller peak local concentration ratio (LCR) and non-uniformity factor than the COSDC system under the same non-ideal optical factor, but also has excellent optical performance. This means that OPSDC system can effectively avoid the heat absorber generating high-temperature hot spots, thus significantly improving its working reliability and service lifetime. In addition, the tracking error, installation error of the receiver and mirror all lead to the increase of the peak LCR and non-uniform factor, while the mirror slope error and absorber's absorptivity degeneration are conducive to reducing the peak LCR and non-uniform factor. This work can provide a reference for error control of COSDC system and OPSDC system in manufacturing, installation and operation. 相似文献
70.
本文分析了燃气热水器行业针对无回水管水路系统实现零冷水功能的现有技术方案,指出现有技术方案存在的一些缺陷,并结合试验研究,对无回水管水路系统提出了一套全新的实现零冷水功能的技术解决方案。 相似文献