In this paper,a novel 2-DOF rotational pointing mechanism(RPM)is designed inspired by the guidelines of the graphical approach.The mechanism integrates with a fast steering mirror(FSM)for compensating pointing errors ...In this paper,a novel 2-DOF rotational pointing mechanism(RPM)is designed inspired by the guidelines of the graphical approach.The mechanism integrates with a fast steering mirror(FSM)for compensating pointing errors of a laser beam.The design intends to achieve an angular travel of±10 mrad and steers a 25 mm mirror aperture.A planar flexure with beam flexures accompanied in parallel with an axial flexure build-up mechanism configuration.Compliant mechanismbased RPM ensures high precision and compactness.Compliance characteristics are established based on the stiffness matrix method for four different planar flexure layouts.One layout with best in-plane rotational compliance is then assessed for performance sensitivity to mechanism dimension parameters and parasitic error,thus informing the design space.Rotational stiffness in both the inplane rotational axes and stress is determined based on finite element analysis(FEA).The wire electrical discharge machining(EDM)is employed for developing the proof of concept for the RPM and is then assembled in FSM.Experiments are conducted to determine the rotational stiffness and angular travel about both in-plane rotational axes.Comparison among theoretical,numerical and experiments reveal excellent linearity of rotational stiffness along the rotational travel range.The maximum theoretical error is less than 5.5%compared with FEA while,the experimental error has a mean of 5%and 3%for both rotational axes thus satisfying the intended design requirement.展开更多
Gerotor pumps are a kind of internal gear pump, widely used in applications of lubricating system of on-road or off-road engines. Normally their outer rotors are the circular arc profile while their inner rotor profil...Gerotor pumps are a kind of internal gear pump, widely used in applications of lubricating system of on-road or off-road engines. Normally their outer rotors are the circular arc profile while their inner rotor profile is the conjugate curve of the outer rotor. This research focuses on how to derive the combined trochoidal profile of a gerotor pump. The hypocycloidal and epicycloidal profile of the inner rotor is generated at first. And then the profile of the outer rotor, based on the inner rotor profile, is obtained by analytical approach and computationally graphical approach. The paper provides feasibility to develop the unconventional profile of a gerotor pump.展开更多
基金co-supported by the National Natural Science Foundation of China(No.91748205 and 51675032)the Fundamental Research Funds for the Central Universities(No.YWF-18-BJ-Y-34 and YWF-18-BJ-J-23)of China。
文摘In this paper,a novel 2-DOF rotational pointing mechanism(RPM)is designed inspired by the guidelines of the graphical approach.The mechanism integrates with a fast steering mirror(FSM)for compensating pointing errors of a laser beam.The design intends to achieve an angular travel of±10 mrad and steers a 25 mm mirror aperture.A planar flexure with beam flexures accompanied in parallel with an axial flexure build-up mechanism configuration.Compliant mechanismbased RPM ensures high precision and compactness.Compliance characteristics are established based on the stiffness matrix method for four different planar flexure layouts.One layout with best in-plane rotational compliance is then assessed for performance sensitivity to mechanism dimension parameters and parasitic error,thus informing the design space.Rotational stiffness in both the inplane rotational axes and stress is determined based on finite element analysis(FEA).The wire electrical discharge machining(EDM)is employed for developing the proof of concept for the RPM and is then assembled in FSM.Experiments are conducted to determine the rotational stiffness and angular travel about both in-plane rotational axes.Comparison among theoretical,numerical and experiments reveal excellent linearity of rotational stiffness along the rotational travel range.The maximum theoretical error is less than 5.5%compared with FEA while,the experimental error has a mean of 5%and 3%for both rotational axes thus satisfying the intended design requirement.
文摘Gerotor pumps are a kind of internal gear pump, widely used in applications of lubricating system of on-road or off-road engines. Normally their outer rotors are the circular arc profile while their inner rotor profile is the conjugate curve of the outer rotor. This research focuses on how to derive the combined trochoidal profile of a gerotor pump. The hypocycloidal and epicycloidal profile of the inner rotor is generated at first. And then the profile of the outer rotor, based on the inner rotor profile, is obtained by analytical approach and computationally graphical approach. The paper provides feasibility to develop the unconventional profile of a gerotor pump.
