Method and device for testing dynamic stiffness of high-speed main shaft

Abstract

The invention relates to a method for testing dynamic stiffness of a high-speed main shaft, which is high in testing precision and convenient to operate. The method comprises the radial loading step, the shaft center displacement measuring step and the dynamic stiffness value calculating step, when the radial loading step is performed, a readable loading element is used for pushing a rolling part to be in contact with the tested high-speed main shaft and enabling the direction of loading force to point to the shaft center of the tested high-speed main shaft, and the rolling part performs synchronous autorotation under the action of frictional force during the rotation of the tested high-speed main shaft. A device for testing the dynamic stiffness of the high-speed main shaft, which is simple in structure, small in occupied space, low in cost and high in precision, comprises a radial loading device and a shaft center displacement measuring device, wherein the radial loading device comprises the readable loading element, the rolling part and a fixed frame of the loading element, the loading element is fixed on the fixed frame of the loading element, the rolling part capable of performing the autorotation is assembled at the output end of the loading element, the rolling part is further in contact with the circumferential surface of the tested high-speed main shaft and the direction of the loading force of the loading element points to the shaft center of the tested high-speed main shaft.

Description

technical field [0001] The invention relates to a spindle dynamic stiffness testing technology, in particular to a high-speed spindle dynamic stiffness testing method and device. Background technique [0002] The high-speed spindle is the core functional component of modern machine tools. Its function is to drive the tool (grinding wheel) or workpiece to rotate to achieve high-speed precision machining. With the continuous improvement of modern industry's requirements for machining accuracy and machining efficiency of machine tools, machine tools have higher and higher requirements for spindle performance. [0003] Rigidity is one of the important indicators to measure the performance of high-speed spindle. Spindle stiffness includes static stiffness at rest and dynamic stiffness at high speed. The currently feasible and widely used stiffness testing method in engineering is the static stiffness testing method. However, the static stiffness cannot truly reflect the abilit...

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Problems solved by technology

[0005]1. The electromagnetic loading measuring device has the disadvantage that the electromagnetic loading device is complicated and occupies a large space. Spindle detection for special experiments is more effective and difficult to use universally

Its disadvantages are as follows: a. The rigidity of the air bearing is small, and the loading force is limited; b. The air bearing measuring device takes up a lot of space, which is restricted by the space at the extension end of the spindle; c. It is difficult to maintain the air pressure during the loading process. In the floating state, it is easy to cause the bearing and the main shaft to collide due to the bias of the load.

[0007]3. Non-contact liquid suspension loading type measuring device, its loading capacity is higher than that of air flotation loading, but it also has complex structure, limited by space, prone to collision, etc. Disadvantage, only suitable for specific test spindles

The disadvantages of this method are: (1) It can only measure the stiffness in the vertical direction; (2) When the spindle size is large, the bearing size is large and limited by vibration, it is only suitable for use when the spindle speed is low

[0010]The above measurement methods still have common shortcomings, that is, the loaded spindle section and the spindle section of the displacement measurement are not uniform, and it is difficult to accurately convert the loaded size into the displacement detection section. Equivalent load, resulting in inaccurate dynamic stiffness test results

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