Device capable of improving axial rigidity of main shaft of precision machine tool with adjustable bearing pre-tightening force

Abstract

The invention discloses a device capable of improving axial rigidity of a main shaft of a precision machine tool with an adjustable bearing pre-tightening force. The device comprises a main shaft, a locking nut, a gasket, a box seat, an end cover, a clamp ring, a pre-pressing spring assembly and an improved bearing pre-tightening device, wherein the improved bearing pre-tightening device adopts an annular oil chamber structure formed by transformation of a single-sided thin-walled end surface. The main shaft penetrates through the end cover, the clamp ring, a B bearing, a shaft sleeve, an A bearing, the gasket and the locking nut from one end to the other end sequentially; and the pre-pressing spring assembly and the improved bearing pre-tightening device are mounted between the main shaft and the box seat.According to the device, on one hand, the pre-pressing spring assembly is added on one side of the A bearing to improve the axial rigidity produced when the main shaft moves toward the B direction rightward; and on the other hand, a conventional bearing pre-tightening device mounted between the A bearing and the B bearing is improved, so that on one hand, the improved bearing pre-tightening device can be taken as a support of a D annular oil chamber and an oil way for providing oil, and on the other hand, the improved bearing pre-tightening device can be taken as a support of the B bearing and can achieve radial positioning of the B bearing and axial positioning of the main shaft.

Description

technical field [0001] The invention relates to a preloading device suitable for bearings, more particularly, a device capable of improving the axial rigidity of the spindle of a precision machine tool with adjustable bearing preloading force. Background technique [0002] In order to improve the accuracy and dynamic characteristics of precision machine tool spindles, it is usually necessary to preload the bearings. Such as figure 1 The bearing preloading device with double-sided thin-walled end face structure shown will reduce the axial stiffness of the spindle due to the deformation of the double-sided thin-walled oil chamber. The main shaft 1 passes through the end cover 7, the compression ring 9, the B bearing 8, the bushing 5, the A bearing 4, the gasket 2A and the lock nut 2 in order from one end to the other; between the main shaft 1 and the box seat 3 A bearing preloading device is installed, and the bearing preloading device includes an A ring oil chamber 11, a B ...

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Problems solved by technology

[0009] In order to improve the defect that the axial stiffness of the main shaft will be weakened due to the deformation of the thin-walled oil cavity when the main shaft is subjected to axial forces in the A and B directions, the present invention designs a bearing preload with improved adjustable bearing force. Device for Axial Rigidity of Precision Machine Tool Spindle

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