The Design And Development Of Machine Tool Ball Screws Test-bed

As the transmission part of machine tool, the performances of ball screw directly affect the quality of the products processed by machine tool largely. With the continuous improvement of manufacturing technology, people’s requirements on performances of the ball screw are increasing. There is a big gap between the level of our country and the international advanced level in performance indicators of the ball screw. The reasons of causing these disparities, in addition to materials and processing equipment, the lack of test equipment and tools is one of the main reasons. Therefore, the design of the test-bed, which can detect a number of performances of the ball screws, is very necessary.The main content of this paper includes:Firstly, described the characteristics and classification of ball screw, and compared with their respective advantages and disadvantages, and then lists the overall architecture design of the test-bed.Secondly, according to overall mechanical structure of the general scheme to analyze the external loads suffered by the entire test-bed, list the formula of each component; based on Hertz contact theory, analyze the contact characteristics of the ball screw, which is between the raceway of the nut and ball, the raceway of the screw and ball.Afterward, according to general design scheme, choosing the right parts, design appropriate mechanical structure, and pre-stretch the measured ball screw, proposed installation requirements, draw a three-dimensional assembly renderings。Certain cutting conditions assumed, according to the formula of cutting force, calculated for each cutting force, using ANSYS software to analyze the situation of static stress and strain of the test-bed, compared the size of the maximum stress suffered by test-bed with the yield stress of the material, verify the reasonableness of the mechanical structure design.At last, select the servo motor, and select the drive by the model of servo motor, completed the connection between them, and debugging for the drive. In order to make the running of test-bed more autonomy, the test-bed selected YK2004 movement control card as a controller. We completed the connection between the movement control card and the drive by the selected mode of pulse output, and confirm the drive way. Based on the drive way, use Lab view programming software to write the motion control program by calling subroutine in dynamic link library (DLL).The innovation of this paper:Mounted tool turret and tool on the basis of the original test-bed, calculated reaction force suffered by tool during cutting process, and as an external load throughout the test-bed.The selected test ball screw contains single and double nut, deal them with different preload accord to the actual situation.Selected the motion control card as a control device, use program software custom programming, more autonomy.Currently test-bed has been completed, and completed the installation and commissioning by required, using the control programs to run the test-bed by computer, test-bed runs smoothly.