预紧力对风力发电机组偏航轴承螺栓的影响

Influence of Pre⁃tightening Force on Yaw Bearing Bolts of Wind Turbine

螺栓连接是风力发电机组中最重要、使用最广泛的连接方式,确保螺栓能够提供足够的强度和预紧力对于风力发电机组的整体安全具有至关重要的现实意义。首先从理论方面阐述预紧力对螺栓和被连接件刚度和强度的影响,然后建立某2.5 MW风力发电机组偏航轴承内外圈螺栓有限元分析模型,对偏航轴承螺栓施加6种占螺栓最大许用轴向载荷不同比例的轴向预紧力,最后对各测试方案中偏航轴承螺栓的极限应力分布规律进行统计和总结。根据螺栓应力统计结果,主机架与偏航轴承连接螺栓的应力最大值高于塔筒与偏航轴承连接螺栓,最大应力值出现在主机架与偏航轴承后半部分45°对角线上的连接螺栓,主机架螺栓尺寸与外载荷呈一定正比关系,得出的螺栓强度特性和设计原则对技术人员设计和分析偏航轴承螺栓具有工程借鉴意义。

Bolt is the most important and widely used connection mode in wind turbine.Ensuring that the bolt can provide suffi⁃cient strength and preload is of great practical significance for the overall safety of wind turbine.Firstly,the influence of pre⁃tightening force on the stiffness and strength of bolts and connected parts was expounded theoretically.Then,the finite element analysis model of the inner and outer ring bolts of the yaw bearing of a 2.5 MW wind turbine was established,and six axial pre⁃tightening forces with different proportions of allowable axial load were applied to the yaw bearing bolts.Finally,the distribu⁃tion law of ultimate stress of yaw bearing bolts in each test scheme was counted and summarized.According to the statistical re⁃sults of bolt stress,the maximum stress of the connecting bolts between the main frame and the yaw bearing is higher than that of the connecting bolts between the tower and the yaw bearing.The maximum stress appears in the connecting bolts on the 45°diago⁃nal of the rear half of the main frame and the yaw bearing.The bolt size of the main frame is in direct proportion to the external load.The bolt strength characteristics and design principles obtained have engineering reference significance for technicians to design and analyze yaw bearing bolts.