Using piezoelectric actuators to drive cantilever beam structures under low frequency is promising for solving high-precision control of high-end equipment. This paper presents an innovative piezoelectric actuator based on a d33 mode piezoelectric stack. It consists of the piezoelectric stack as the output force element and the sleeve as the protecting element to cater to the characteristic of piezoceramics: considerable ultimate stress, but significantly cannot withstand shearing force. The connectors effectively utilize higher piezoelectric coefficients ( d33 mode piezoceramics) to provide a bending moment that causes the cantilever beam to vibrate. The maximum amplitude is 11.35 mm while the driving voltage is 150 V and the waveform is consistent with the excitation signal. The piezoelectric actuator proposed in this paper is capable of achieving high-precision, low-frequency driving cantilever beam structures for high-end equipment.

Accurate measurement of geometric errors and mass properties is essential to aero-engine manufacturing. The measurement results can provide a reference for assembly. To address the problem of poor parallelism and unbalance prediction accuracy of hyperbolic paraboloid rotors, this paper designs a classifier. It achieves precise differentiation of the rotor surface by combining the Principal Component Analysis (PCA) and Support Vector Machine (SVM). The results show that the surface classifier accuracy is 99%. Then this paper combines the Genetic Algorithm (GA) and Back Propagation Neural Network (BPNN) to predict the parallelism and unbalance of the hyperbolic parabolic rotors. Compared with the traditional prediction model, the GA-BP neural network is more accurate in predicting the parallelism and unbalance of the multi-stage assembled rotors. The trend of the predicted results is more consistent with the experimental data. The prediction error of parallelism is reduced by 7.5 μm, and the maximum deviation of unbalance is reduced by 250.6 g·mm through the GA-BP neural network. The surface classifier and intelligent algorithm designed in this paper can provide a reference for rotor manufacturing and assembly.

To suppress the vibration of rotary parts, this paper established an unbalanced vibration response control model of rotary parts based on rotating axis coordinate system. This model considered the stacking transformation of geometric parameter errors and mass parameter errors of single stage rotor. First of all, the centroid transfer model based on the actual rotation axis was established, and the unbalanced excitation force vector of each stage of the rotor was studied. Secondly, the unbalanced excitation force vector of each stage of the rotor is substituted into the model of assembly vibration control based on the double constraints optimization strategy. Finally, the simulation analysis and the vibration experiment of three-stage rotor stacking assembly is carried out. The results show that the vibration of the engine rotor can be effectively suppressed by adjusting the assembly phase of the rotors, and the vibration amplitude of the combined rotor assembled by the double constraint optimization assembly strategy is 22.5% less than the vibration amplitude assembled by the direct assembly strategy. Besides, the coaxiality and the unbalance are reduced by 44.1% and 78.4%, which fully shows the advantages of the double constraint optimization assembly strategy.

Perpendicularity is an orientation tolerance, and the perpendicularity of end face can be used to assess the axial assembly precision of multistage rotor. The aim of this article is to detect the perpendicularity and parallelism of rotor using turntable-rotating approach. The misalignment between the datum system of the rotor and the measurement datum of the turntable will introduce the datum error, which is difficult to be thoroughly eliminated by the mechanical device of centering and leveling. To ensure that each measurement is carried out in the same datum system of rotor, the residual error of tilt and eccentricity between two datum systems is studied and compensated. The direction of assessment datum axis of rotor perpendicularity is determined by the rotor axis rather than extrinsic measurement datum, e.g., turntable axis. The experiment of rotor is performed to verify the effectiveness of the presented detection approach. The difference and relationship between rotor perpendicularity and parallelism are investigated and discussed. It is recommended that parallelism and perpendicularity should be considered together to fully reflect the axial geometric tolerance of rotor. The presented approach is general, which can also be conveniently used to detect axial geometric tolerances of other rotating components, for example, compressor rotor, motor rotor, and gas turbine rotor.

The ultra-precise measurement of aero-engine rotor geometry error is the basis of its assembly, and adjusting the rotor coaxially with the measurement rotation axis is the key to ensure the measurement accuracy. As a typical adjustment device for rotor alignment, the traditional method of applying a four-degree-of-freedom centering and tilting table for adjustment does not take into account the coupling effect caused by the position of each adjustment motor not being perfectly perpendicular to each other, this paper gives the calibration method of the angle between each adjustment motor and the starting position of the angle grating, analyzes the principle of eccentricity and tilt adjustment and deduces the coupling solution method. Subsequently, the size of the coupling between the two adjustments is analyzed and an efficient adjustment method is given for its mechanical structure characteristics. The experimental results show that the platform can effectively decouple and quickly converge to the setting values of 0.3 µm and 0.5′′ for different initial eccentric distance and tilt angle. With the same adjustment accuracy, the number of adjustments is reduced by more than 50% and more than 37.5%, respectively, compared with the non-decoupled method.

The high-precision metrological measurement of circular profile is crucial for various rotational parts, essential in precision machining, manufacturing, and assembly. The existing roundness error separation methods often suffer from harmonic suppression issues, limiting the range of separable harmonics and reducing accuracy. This article proposes a roundness error separation method based on time-frequency-domain transformation (TFDT) for parameter optimization to overcome these challenges. By establishing the relationship between separation accuracy and rotation angle error and optimizing parameters accordingly, the method balances error separation accuracy with the separable harmonic range. Theoretical simulations and experimental validations confirm the method’s effectiveness. By comparing the separation results under different harmonic separation range requirements with those of the methods currently widely used in the field of roundness metrology, we have validated the effectiveness of this method in balancing separation range and accuracy. When the rotation angle is set to 1.406°, the harmonic suppression-free range expands from [0, 204] undulations per revolution (upr) to [0, 255] upr, representing an increase of approximately 25% compared to single-step rotation error separation technique (SEST). Compared to the SEST method, the deviation of this method from the multistep method is reduced by over 68%, and its standard deviation (STD) is only about 65% of that of the other two methods. This innovative approach provides comprehensive and accurate circular profile data, enabling high-precision roundness error separation across a broad harmonic range. It establishes a robust theoretical basis for advanced measurements in national metrology institutes and key laboratories.