Papers by Keyword: Manufacturing Error

Abstract: According to problems in manufacturing and measuring process of cycloidal gear used in RV reducer, the profile coordinates of cycloidal gear captured by three coordinates measuring instrument Surveying and mapping do not coincide with the designed tooth profile coordinates in theory, it is difficult to precisely capture the addendum and dedendum of each cycloidal gear teeth, furthermore, the captured addendum and dedendum do not coincide with the actual tooth items. For these problems, this paper introduced a method can accurately calculating the manufacturing error of cycloidal gear.Based on the captured coordinate points of cycloidal gear tooth profile, firstly, find out 39 approximate addendums by calculating and comparing the radial radius of all points, divide the whole scanning points into 39 profile points groups by the 39 approximate addendums, with each group include a whole single tooth profile. Then, in each profile points group, interpolate the spline and precisely calculate the addendums and dedendums by fitting and recalculating radial radius.Set up the coordinate system of surveying and mapping profile by the 39 addendums. calibrate the coordinate system of surveying and mapping profile with the new coordinate system through coordinate transformation, calculate the radial runout error at top and root of tooth profile, pitch error, adjacent pitch error and accumulated pitch error as well as other manufacturing errors of the cycloidial gear at last.Through experiment, this process solve the problem in measuring process of cycloidal gear that the captured point by three coordinates measuring instrument could not be directly used for calculating the errors items.

Abstract: Abstract. A diffraction limited circularly symmetric optical imaging system with “0,π” phase pupil mask was studied, which extended depth of field. The optimal radiuses of the mask in the different amount of defocus are calculated, which in a certain contrast value 0.05 and 0.1, can provide the largest spatial frequency band. On the other hand, the effect of mask manufacturing error is analyzed, and the performance of the simulation imaging system has been verified experimentally that the image system still can obtain the high quality output images even without any post-processing.

Abstract: All the effects of manufacturing errors on transmission spectrum are analyzed for a vertical coupling microring resonator (MRR). Results show that the core refractive index, core thickness and radius errors of ring result in central wavelength shift of the transmission spectrum, and the central deviation and thickness between the ring and channel lead to nonresonant light intensity change. In order to obtain satisfactory spectrum for a fabricated MRR device, some allowed manufacturing errors are discussed, and the accumulation and compensation of manufacturing errors are investigated.

Abstract: In order to solve the problem of load sharing in planetary gear train, the design of planetary gear train was described briefly in this paper. The calculation model of type NGW planetary gear train was established. By analyzing the variety of factors, such as selection of bearing clearance, gear modification, using of flexible structure and the sun gear floating design technology, several ways to improve the load sharing of the planetary gear train techniques were obtained, and they were verified by experiments finally.

Abstract: The effects of gear manufacturing error on the dynamic characteristics of planetary gear transmission system of wind turbine are studied in this paper. Firstly, the static transmission error combined with manufacturing error of the gear is deduced. Then, the nonlinear dynamic model of planetary gear transmission system of wind turbine is set up with the consideration of time-varying mesh stiffness, backlash and manufacturing error. Finally, the statistical characteristics of Vibration displacement response process of each component of planetary gear transmission system are obtained by simulation analysis of the planetary gear system of 1.5MW Semi-direct drive wind turbine with the consideration of the torque fluctuation caused by wind speed. The research results lay a foundation for reliability design and optimizing of gear transmission system of wind turbine.

Abstract: 800MN forging press uses plate laminated parallel structure as the main bearing mode, where the force transfer and the stiffness match play key roles in achieving satisfactory performance of the equipment. Although the traditional design methods can obtain desirable stiffness or strength for bearing structure, they less consider the effect of manufacturing errors on the system performance and thus are ineffective. This is because manufacturing errors can cause local structure variation and heavy stress concentration, which may do great harms to the working performance of the equipment. In this paper, a new design approach is proposed to consider the effect of manufacturing errors to the system performance. First, a three-dimension finite element model of the 800MN forging press is built using Marc, upon which stress distributions and concentrations under different combination modes of manufacturing errors are studied. Then, combination law of manufacturing errors is established and validation is carried out through physic test.

Abstract: The present study investigates the dynamic response of single-cylinder reciprocating engines. In particular, simplified models of the crank-connecting rod mechanism are examined, which take into the flexibility of the crankshaft. Crankshaft, connecting rod and piston are major parts of the crank-connecting rod mechanism, and their size, mass, centroid location parameters are required precisely in manufacturing process. However, manufacturing error cannot be avoided completely in practical manufacturing process, and it would lead to different vibration performance of engine. Therefore, understanding the effect of manufacturing error on the vibration performance of engine is the aim of this paper. In order to obtain dynamic characteristics of engine, both rigid and flexible body dynamics simulation were done by using software ADAMS.

Abstract: In order to improve the drift accuracy of aerostatic bearings, the air supply pressure and manufacturing errors effect on vortex torque of aerostatic bearings were studied by using the finite element method. This paper analyzed the influence of air supply pressure on vortex torque, in view of elliptical error, incline error of throttle slit and radial eccentricity ratio exist. The quadratic regression orthogonal design was adopted to establish function expression of vortex torque among air supply pressure, elliptical error, incline error of throttle slit and radial eccentricity ratio. In research, the simulation vortex torque values of a certain aerostatic bearing are compared with the experimental values. The predicted characteristics are in good agreement with experimental results and then prove that the finite element model, the method used to solve the problem and the function expression obtained are correct. The research has great significance for predicting performance and choosing the air supply pressure of aerostatic bearings.

Abstract: In order to improve the drifting accuracy of aerostatic bearings, the manufacturing errors effects on disturbing torque of aerostatic bearings is studied by using the finite element method. The finite element mathematic model of the major influence factors of disturbing torque is established. Then, the finite element equation in the gas film domain is solved and the disturbing torque in the presence of disturbing factors is calculated. The research focuses on elliptical error and prismatic error of journal and incline error of throttle slit. The setting angle of journal, incline position angle of throttle slit and radial eccentricity ratio which affect the disturbing torque is also studied. The results show that roundness error of journal and incline error of throttle slit affect the disturbing torque significantly, that is the greater roundness error of journal and incline error of throttle slit the greater disturbing torque. Disturbing torque is periodic function of setting angle of journal and incline position angle of throttle slit. Radial eccentricity ratio affects the disturbing torque, and there is specific radial eccentricity ratio makes disturbing torque to be extreme point or zero point. In the research, the theoretical disturbing torque value is compared with the experimental value of a certain aerostatic bearing, find that they are on the whole accordant with each other and then prove that the finite element model and the method use to solve the problem is correct. The research is of great significance for designing, manufacturing and assembling aerostatic bearings and for performance prediction of aerostatic bearings.