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Scroll profile plays a key role in determining the performance of a scroll compressor. In this study geometric and dynamic characteristics of the scroll profile are analyzed to investigate the influence of its geometric continuity on property of a scroll compressor. Firstly, scroll profiles are created to redesign the geometry of scroll wrap by using the equidistant-curve approach on the basis of a generation line consisting of involute of circle and circular arc. Subsequently, the geometric and dynamic models of the scroll compressor are established. These models are related to parameters of the generation line of scroll profile and rotation angle of a moving scroll. Lastly, some simulation examples of second-order continuity (SOC) scroll profile are compared with first-order continuity (FOC) scroll profiles and some important conclusions are obtained. Results show that SOC scroll profile is superior to FOC profile in terms of volume ratio, stability of gas force, and possible leakage loss in a scroll compressor.

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According to the elastic theory the calculating formulas of inner ring centrifugal displacement are inferred, in consideration of inner ring centrifugal displacement the basic equations of angular contact ball bearing are set up, effect of inner ring centrifugal displacement on the dynamic characteristics of high-speed angular contact ball bearings are studied. The results from taking 7012C bearing as an example show that, in high-speed condition inner ring centrifugal displacement decreases ball centrifugal force and increases ball gyroscopic moment, reduces the difference between inner and outer contact angles, increases contact deformation and contact stress, decrease spin-roll ratio between ball and inner raceway. Furthermore, the inner ring centrifugal displacement not only compensates angular contact ball bearing axial and angular stiffness softening due to centrifugal force but also greatly increases its radial, axial and angular stiffness. Therefore, in order to make the dynamics analysis of angular contact ball bearing more accurate and closer to the factual condition, the effect of inner ring centrifugal displacement should be considered.

In this paper, based on the actual design of gear during the production process as well as the gradual formation of gear meshing gear principle and the principle of the establishment of a non-circle gear tooth profile curve of the mathematical model parameters. And then combined with MATLAB and Pro / E to achieve the whole parameters design of the gear, First of all in the MATLAB programming environment compile the program of the curve and to generate consistent with the Pro / E format. IBL document further into Pro / E which achieves gear threedimensional parametric modeling. In order to achieve the design of gear is shorter and more precise.