Misalignment faults in gear systems lead to violent vibration and noise, shortening the life of equipment. The aim of this work is the demonstration of vibration suppression of parallel-misaligned gear shafts using an...Misalignment faults in gear systems lead to violent vibration and noise, shortening the life of equipment. The aim of this work is the demonstration of vibration suppression of parallel-misaligned gear shafts using an integral squeeze film damper(ISFD). Using a first grade spur gear in engineering for reference, an open first-grade spur gear system is built and the vibration characteristics of the gear system with rigid supports and ISFD elastic damping supports are studied under different degrees of misalignment. The experimental results show that ISFD supports have excellent damping and vibration attenuation characteristics, which have improved control of the gear system vibration in horizontal, vertical and axial directions under different degrees of misalignment. This work shows that an ISFD structure can effectively suppress vibration of characteristic frequency components and resonance modulation frequency components. The test results provide evidence for the application of ISFD in vibration control of gear shaft misalignment faults in engineering.展开更多
背景:神经内镜经鼻蝶手术因其微创、显露充分、术后恢复快等特点,已成为前颅底中线及侧颅底占位最常用的手术方式。随着手术范围及适应证也的不断扩展,颅底磨除范围相应增加,这也使术后脑脊液漏发生率也相应增高。严重的脑脊液漏可导致...背景:神经内镜经鼻蝶手术因其微创、显露充分、术后恢复快等特点,已成为前颅底中线及侧颅底占位最常用的手术方式。随着手术范围及适应证也的不断扩展,颅底磨除范围相应增加,这也使术后脑脊液漏发生率也相应增高。严重的脑脊液漏可导致患者致命性的颅内感染及极差的预后。因此在神经内镜手术后,可靠的颅底重建是手术成功的基本条件,文章以此对颅底重建原则、方法、颅底重建应用的不同材料的生物学特性等展开综述。目的:阐述颅底重建的原则方法,总结不同重建材料的研究进展及不同生物学特性在颅底重建中的作用。方法:计算机检索万方及PubMed数据库2012年1月至2022年1月收录的文献,中文检索词为“颅底重建、神经内镜、颅底骨缺损、经鼻蝶手术入路、多重修补、带蒂黏膜瓣、聚醚醚酮、羟基磷灰石”,英文检索词为“Skull base reconstruction,Neuroendoscopy,Skull base bone defect,Transnasal-sphenoidal operative approach,Multiple repair,Pedicled mucosal flap,Polyether-ether-ketone(PEEK),Hydroxylapatite”,最终纳入60篇文献进行综述。结果与结论:(1)神经内镜经鼻蝶术后,即使颅底缺损越来越大,颅底重建的目地依旧是预防脑脊液漏避免严重并发症,目前多层修补是一致认可的修复原则。(2)骨性支撑的类骨材料诸如聚醚醚酮、羟基磷灰石因为价格昂贵且术前准备繁琐,临床应用较少;临床医生多靠类硬膜结构的生物材料及带蒂黏膜瓣完成修补,但受限于修补支撑力弱及黏膜瓣血运情况,少数病患仍有一定概率存在脑脊液漏的风险。(3)因此,术中类硬膜、类骨结构人工生物材料以及带蒂黏膜瓣修补颅底缺损符合恢复颅底的解剖修复,有助于硬膜、骨质结构的再生,这样也使疏水组织-类硬膜结构-类骨结构-黏膜的一体化生物材料研发具有广阔的应用前景。展开更多
基金Supported by the National Basic Research Program of China(No.2012CB026000)2015 Beijing Scientific Research and Graduate Training Project(No.0318-21510028008)Key Laboratory Fund for Ship Vibration and Noise(No.614220406020717)
文摘Misalignment faults in gear systems lead to violent vibration and noise, shortening the life of equipment. The aim of this work is the demonstration of vibration suppression of parallel-misaligned gear shafts using an integral squeeze film damper(ISFD). Using a first grade spur gear in engineering for reference, an open first-grade spur gear system is built and the vibration characteristics of the gear system with rigid supports and ISFD elastic damping supports are studied under different degrees of misalignment. The experimental results show that ISFD supports have excellent damping and vibration attenuation characteristics, which have improved control of the gear system vibration in horizontal, vertical and axial directions under different degrees of misalignment. This work shows that an ISFD structure can effectively suppress vibration of characteristic frequency components and resonance modulation frequency components. The test results provide evidence for the application of ISFD in vibration control of gear shaft misalignment faults in engineering.
文摘背景:神经内镜经鼻蝶手术因其微创、显露充分、术后恢复快等特点,已成为前颅底中线及侧颅底占位最常用的手术方式。随着手术范围及适应证也的不断扩展,颅底磨除范围相应增加,这也使术后脑脊液漏发生率也相应增高。严重的脑脊液漏可导致患者致命性的颅内感染及极差的预后。因此在神经内镜手术后,可靠的颅底重建是手术成功的基本条件,文章以此对颅底重建原则、方法、颅底重建应用的不同材料的生物学特性等展开综述。目的:阐述颅底重建的原则方法,总结不同重建材料的研究进展及不同生物学特性在颅底重建中的作用。方法:计算机检索万方及PubMed数据库2012年1月至2022年1月收录的文献,中文检索词为“颅底重建、神经内镜、颅底骨缺损、经鼻蝶手术入路、多重修补、带蒂黏膜瓣、聚醚醚酮、羟基磷灰石”,英文检索词为“Skull base reconstruction,Neuroendoscopy,Skull base bone defect,Transnasal-sphenoidal operative approach,Multiple repair,Pedicled mucosal flap,Polyether-ether-ketone(PEEK),Hydroxylapatite”,最终纳入60篇文献进行综述。结果与结论:(1)神经内镜经鼻蝶术后,即使颅底缺损越来越大,颅底重建的目地依旧是预防脑脊液漏避免严重并发症,目前多层修补是一致认可的修复原则。(2)骨性支撑的类骨材料诸如聚醚醚酮、羟基磷灰石因为价格昂贵且术前准备繁琐,临床应用较少;临床医生多靠类硬膜结构的生物材料及带蒂黏膜瓣完成修补,但受限于修补支撑力弱及黏膜瓣血运情况,少数病患仍有一定概率存在脑脊液漏的风险。(3)因此,术中类硬膜、类骨结构人工生物材料以及带蒂黏膜瓣修补颅底缺损符合恢复颅底的解剖修复,有助于硬膜、骨质结构的再生,这样也使疏水组织-类硬膜结构-类骨结构-黏膜的一体化生物材料研发具有广阔的应用前景。
