The Definition And Assessment Of Bearing Part Form Error Based On GPS Standard

The bearings parts'geometrical error is one of the most important specifications which affect rotation accuracy of bearings. The first generation GPS has many problems in definition of geometric error and can't meet the needs of the manufacturing sector any longer. So, a more scientific new generation GPS is imperative to be developed and implemented. This article based on the new generation GPS and takes geometrical tolerances whose tolerance zones take on turning characteristic as major research object, gives the description method of bearing rotary parts'geometrical tolerances. Meanwhile, it puts forward a Fast Geometric Approximation Algorithm based on space straightness and cylindricity geometry features, and offers the process of how to obtain the space straightness error and cylindricity error.This article analyzes the basal definition and a general outline theory of the new generation GPS. Bases on GPS theory, this article describes the definition methods of bearing rotary parts. Comparison and analysis show that the new generation GPS, which based on metrology, actualized unity of standardization throughout the whole production cycle, optimized resources in the whole production process, and provided a clear geometric tolerance definition system. So, it can help improving product quality and reducing production costs.This article studied the error assessment of spatial straightness and cylindricity, and proposed an assessment method naming Fast Geometric Approximation Algorithm. Spatial line is the rotation center of rotary parts and reference elements of measurement and evaluation. Determining the spatial location and error evaluation algorithm are the key issues must to be solved. Cylinder because of its easy processing, processing costs are relatively low, and has good overall performance, has been widely used in antifriction bearings and rings. The contrasts between the algorithmic assess result and the result from CMM proves that this arithmetic can obtain the straightness error of median line and cylindricity error quickly as well as inerrably. And it provides a new practicable arithmetic on how to estimate the space straightness error and cylindricity error. Meanwhile, it offers a new clue on how to estimate other geometrical errors, because it can be used in other geometrical errors. Therefore, we selected spatial straightness and cylindricity for subject investigated.