A high-speed spindle fault model equipped with the angular contact ball bearing (ACBB) was proposed in this investigation, and some factors such as contact angle, preload, oil film, fit clearance, and speed were considered. Firstly, according to Jones–Harris bearing analytical method, the force–displacement bearing model considering oil film thickness was established, which included the ball centrifugal force and gyro torque. Secondly, based on the change of internal and external contact angles, the bearing rings were divided into two elements to survey the nonlinear dynamic characteristics more accurately. Simultaneously, the bearing support force was converted into an internal force and expressed in the form of stiffness–damping in the system. Based on this, the lubricant stiffness and contact deformation resulting from preload were discussed, and the lubricant stiffness and Hertz stiffness were integrated to form a comprehensive stiffness and added to the system model. Next, the whole spindle fault finite element (FE) model combined with the bearing fit clearance, rub-impact characteristics, and coupling misalignment effect were presented and calculated. Lastly, the influences of the contact angle, speed, clearance, rub-impact eccentricity, and other related variables on the system dynamic performance, such as axis trajectory, spectral response, and maximum amplitude, were analyzed, indicating that the proposed model and related parameters have a significant impact on the dynamic behavior.

Accurately predicting the thermal behavior of motorized spindles is a critical task in manufacturing industry. In this study, a thermo-mechanical-solid coupling-behavior on the motorized spindle in working condition was investigated and analyzed. Firstly, the bearing mechanical analysis of the motorized spindle under assembly constraints was discussed and a new coupling model was founded. Concurrently, the impacts of oil film thickness and the spacing rings on the displacement were considered into this model. Secondly, for the deformation of bearing, combined with Jones-Harris's quasi-static force-deformation bearing model, a mathematical model about a tandem of ball-bearings was built. And in this model, a new analytical method was proposed to decouple the deformation generated by thermal and centrifugal forces from the Hertz contact deformation, making the deformation analysis clear and orderly. Thirdly, from the perspective of heat generation mechanism and principle, based on the above bearing model, the elastohydrodynamic lubrication analysis on the bearing was executed, the thermal network model of bearing with multiple heat sources was set up, and the bearing node's scheme was optimized. Eventually, the effects of parameters such as speed, cooling water flow, and air flow on temperature rise and bearing parameters were calculated and analyzed, and the theoretical results were examined by tests, which provides some reference and guidance for the structural design of precision spindle.

During the operation of the high-speed motorized spindle, the heating of motorized spindle components can cause thermal deformations, which worsens the work performance and shortens the life expectancy of the motorized spindle. In response to the above behaviors, the thermal network model for the motorized spindle in this investigation was built in which the lubricating oil properties and contact characteristics were considered. Next, according to Kirchhoff’s energy balance principle, the theoretical equations of steady-state temperature were established, and the temperature rise of the motorized spindle was obtained by Newton–Raphson method. Lastly, the influences of speed, cooling water flow rate, airflow rate, and other variables on the temperature were analyzed and verified by the experiment. The results show that the thermal network model including lubricating oil and contact factors can predict the temperature rise of motorized spindle accurately, which provides some references and suggestions in motorized spindle design.

The motorized spindle will produce a lot of heat at high speed, thereby making the physical structures deformed and changing the bearing performances. However, the interaction between thermal and mechanical characteristics has not been deeply studied. This paper aimed to consider the coupling of interference fit, centrifugal effect, and thermal effect in these components to build a comprehensive and optimized spindle model. Firstly, the displacements related to contact angles under the thermo-mechanical coupling effect were analyzed, and the oil film factor was added to the bearing static model to be studied together with centrifugal force and gyroscopic moment of the ball. Next, based on thermal network method, a quasi-3D model of cooling water pipe was established by considering its structural characteristics. Meanwhile, for the discussion of the number of balls and their thermal resistances, the heat transfer between the bearing ring and the ball was investigated and improved. Lastly, the influences of thermal characteristics on bearings parameters and spindle temperature rise were investigated under different speed, cooling water, and oil-air variables, which provide a reference for regulating and controlling motorized spindle.

The nonlinear dynamic characteristics of the motorized spindle have a great influence on the precision of processed products in manufacturing. Aiming at the above issue, a new comprehensive motorized spindle dynamic model considering multiple factors was proposed in this paper to investigate its dynamic performance more seriously. First, the angular contact ball bearing was mainly analyzed, in which the oil film thickness and stiffness were considered, and then a bearing mechanical analysis model was established based on the quasi–static analysis method. Simultaneously, the effect of the centrifugal force and gyroscopic moment of the ball on the contact angle was included in the bearing model. Second, the preload of the bearing was investigated, and the Hertz contact load on the rings was identified and classified. Next, the fit clearance between the outer ring and the bearing housing, the static eccentricity between the stator and rotor, and the static eccentricity angle were added in the spindle model, to study the dynamic performance of the rotor more truly and effectively. In addition, the contact characteristics of the cutter head and the rotor were presented in the model. The change of bearing contact angle has an important influence on the dynamic characteristics of the spindle as the contact angle becomes lager. Simultaneously, the clearance value of the bearing affects the unbalanced magnetic force. In addition, static eccentricity has a great effect on the dynamic behavior of the rotor. Under the same length error and length range, the impact of static eccentricity on the rotor dynamic performance is greater than that of fit clearance. Various structural and dynamic parameters are coupled with each other in spindle dynamics. Therefore, it is necessary to systematically consider and analyze various factors to establish a comprehensive and effective dynamic model.

With the rapid development of manufacturing industry, the application of motorized spindle is more and more widely, which puts forward higher requirements for the accuracy and failure rate of motorized spindle. However, a large amount of heat will be generated in the working process, which makes the performance of motorized spindle difficult to meet the requirements, so the thermal properties of motorized spindle need to be further studied to make the dynamic behavior better. In this research, first, the characteristics of inner/outer ring curvature radius and oil film thickness were considered in the mechanical analysis of bearing. Second, a new bearing force equilibrium model including the factors of centrifugal force, gyro moment, and ring expansion was established, in which the deformation caused by centrifugal and thermal effect was separated from the deformation caused by Hertz contact, and then the force-displacement analysis was performed. Third, the heat generation and heat transfer of motorized spindle were fully analyzed and detailed based on the thermal network method, and an optimized convective heat dissipation model for bearings was proposed. In addition, the influence of the oil film thickness on the bearing displacement model was discussed. Next, Newton-Raphson method was employed to calculate the motorized spindle network model and the temperature distribution was obtained. Finally, the temperature rise test of motorized spindle was implemented with variable parameters. And the test data were analyzed and compared with the theoretical results, which indicates that thermal network model established in this investigation has a good validity and reliability.

为实现高精度机床主轴回转误差的在线测试与评价,针对主轴回转误差包含多种误差分量的特点,采用双向正交测量法检测了不同转速下的主轴回转误差.以集合经验模态分解(EEMD)和快速傅里叶变换(FFT)为误差分离的理论基础,以EEMD分离得到的固有模态分量(IMF)的波数为指标,分离并除去偏心误差和主轴变形误差;重构剩余IMF分量后求解总回转误差,利用FFT频域分析方法,采用梳状滤波分离并求解主轴的同步误差和异步误差.基于主轴回转误差测试平台,在多工况下对电主轴进行了回转误差检测与评定,实验结果良好的重复性验证了文章所提方法的可靠性;多工况下的实验结果表明,主轴回转误差主要以同步回转误差为主,特定转速下由于共振,主轴回转误差会异常增大.

分析了铣削加工中振动信号在线检测技术的不足,提出将无线传感器系统集成在刀柄上实现加工振动检测的方案;提出了用于解决刀柄系统刚度、动平衡问题的刀柄结构设计方案;针对测振刀柄离线供电方式续航能力差的问题,通过综合运用多种休眠方式,实现了嵌入式测振刀柄系统采集传输程序的低功耗设计.设计铣削加工振动检测方式对比实验,验证了刀柄系统振动检测的性能.

介绍一种空间在轨末端执行机构设计,由电动机驱动实现压紧头套拧取和压紧杆拧取.空间在轨任务复杂,通过设计维修工具喇叭口式定位机构,实现扳手与螺钉对准,保证了机械臂在定位精度不高的情况下实现精确定位,扳手进行松紧作业.

The stiffness of the rolling bearing has a great influence on the dynamic characteristics of motorized spindle. In order to obtain the stiffness of angular contact ball bearing under oil-jet lubrication, the theoretical calculation model and experiment method are proposed in this paper. Based on hertz contact theory and elastohydrodynamic lubrication theory, the quasi-static analysis model of angular contact ball bearing is established. The factors including ball centrifugal force, gyro moment, preload and oil film thickness are taken into consideration and theoretically analyzed. The test platform on comprehensive stiffness is designed and the stiffness is experimentally verified under different factors. The results show that the comprehensive stiffness increases with the increase of axial, radial load and preload but decreases with the increase of rotational speed. Therefore, the adjustment of the working condition of angular ball bearing can make it work in a better mechanical state and thus improve the bearing life.

文章以高速电主轴为研究对象,从动态回转精度的定义、测试方法出发,对动态回转精度进行了深入分析.分析决定采用适合课题要求的双向测量法测量高速电主轴的动态回转精度,对测试过程中使用的数理统计误差分离技术进行了详细的公式推导,得到了动态回转精度在线测试的完整流程.在实验室现有电主轴的基础上,按需选择了必要的传感器、数据采集卡等组成了测试系统的硬件部分,基于Qt开发出测试软件,搭建出了一套稳定、可靠、高精度的电主轴动态回转精度测试系统,并进行了测试实验进行验证,得到的结果符合实际情况.该论文搭建的测试系统为电主轴性能分析提供了理论依据以及技术支撑.

大型齿圈成形磨削时不同的磨削余量会影响磨削力及磨削热的大小,从而引起不同的磨削变形,合理的余量分配对于保证齿圈加工质量意义重大.基于磨削接触区域模型、磨削力模型和磨削移动热源理论,分析了齿圈成形磨削在热力耦合作用下的变形预测仿真流程,建立了磨齿余量分配模型.以某大型齿圈为研究对象,以变形控制为目标,对不同磨齿余量进行了磨削变形仿真,得到了较优的余量分配值.研究方法对提高齿圈成形磨削加工精度具有一定的借鉴意义.