The use and maintenance of ball screw

With the wide application of CNC machine tools and other automatic control equipment, as energy-efficient, precision transmission ball screw use more and more.

Correct use and maintenance it is often encountered. In all kinds of mechanical equipment, the installation of ball screw, must pay attention to the following matters:

1, The ball screw is precision transmission device, must be lubricated. Recommend the use of potassium soap grease and 1 ~ 3 turbine oil lubrication in the nuts.

2, The ball screw like the rolling bearing, mixed with dust and foreign matter, will reduce the service life. Therefore, must use the screw protective cover to protect. At home and abroad all kinds of ball screw most parts have been equipped with a labyrinth seal ring, to prevent dirt from entering the ball screw body. In addition, use in the places of metal filing easily enter screw, should also consider the use of screw protective cover in the screw length protection.

3, Because of the special structure of the ball screw nut, should not bear radial load, in order to avoid screw bending, affect the transmission accuracy and flexibility of movement, reducing service life. Therefore, when installed, with particular attention to the axial lead of the screw and nut seat moving trajectory of the parallel, and the central axis of the screw bearing should be consistent with the central axis of the nut seat.

4, The screw is installed on the device, be careful not to separate the screw and nut, to avoid ball prolapse. Do not knock the ball screw in installation, with particular attention to the protection of the ball catheter, because of its thin wall, collision deformation will make the ball flow restriction.

Source: http://www.machineballscrew.com Ball Screw Use And Maintenance.

Precision high-speed ball screw selection matters need to pay attention

The high speed of linear servo feed system is a system engineering, and each link in the system must meet the requirements of high speed transmission.

Inversely proportional to the moment of inertia of the ball screw feed system and the system's maximum processing speed, in order to improve acceleration, the system should make finite element analysis and CAD optimized design, under the premise of meet the dynamic and static stiffness, reducing the number of parts, optimize parts parameters and make it high-strength, lightweight.

To choose the precision ball screw assembly matched high speed rolling linear guide at the same time. For example, Japanese THK's SHS Quartet and other load series, SNR, SNS high stiffness heavy duty series, SSR ultra high-speed series, the line speeds up to 200m/min or more. German INA's drum-shaped roller linear guide according to user requirements can also configured with "RUDS" damping sliding seat, the amplitude decreased to 1/30 of the original, noise decreased significantly to meet the high-speed, high-precision, heavy cutting requirements.

To attach great importance to the installation accuracy of precision high-speed ball screw assembly on the machine tool, it plays an important role in improve the critical speed Nc, positioning accuracy, improve stability at high speeds, reducing noise and so on. Screw both ends using pre-stretching high stiffness support structure, to ensure strictly screw both ends bearing and ball nut center "three coaxial". Should use ball screw special high rigidity thrust angular contact bearings.

Make full use of ball screw "synchronization" characteristic, high speed machining centers installed in pairs of high-speed precision ball screw assemblies, is the effective measure to improve the stability of the servo feed system at high speed, improved dynamic characteristics. For example, Japanese Makino Milling Machine production the A55E type of horizontal high-speed machining center and Niigata Iron Works of SPN50-H0 type horizontal high speed machining center and Toyoda Machine EV33 vertical high-speed machining center, have adopted the double motor double screw drive mode.

In the servo feed system, to configure the brake device, the flexible buffer, the self-locking in vertical transmission, and so on.

In the purchase and acceptance of precision high-speed ball screws, and to differentiate the general large lead ball screw, and require manufacturers to provide the ordered products operating speed, acceleration, precision, noise, temperature rise and other testing data. If you are using Si3N4 ceramic balls, you should check the Si3N4 ceramic balls accuracy, hardness, surface roughness, pressure-fed load test certificate. If the selection of strong cold hollow screw, should also check the straightness of the deep hole, the test results of the outer circle coaxiality. In order to ensure the reliability of the high-speed operation, and also view the screw shaft, nut, loop back device raw material and heat treatment inspection reports.

Source: http://www.machineballscrew.com Precision High Speed Ball Screw Assemblies.

Notes the use of linear guides

Linear Guides are precision parts, thus requiring the use of quite a cautious attitude, even with a high-performance linear guide, if used improperly, it can not achieve the expected performance results, and easy to make linear guide for damage. Therefore, the use of linear guide should note the following:

Prevent corrosion

Direct with the hands to pick up the linear guide, need to fully wash hands sweat, and coated with high-quality mineral oil for the operation, during the rainy season and summer with particular attention to rust protection.

Keep the environment clean

Keep the linear guide and the surrounding environment clean, even if the tiny invisible dust into the guide rail, will increase wear, vibration and noise of the guide rail.

Installation should carefully

When using and installing the linear guide should be careful, it does not allow a strong punch, not allow the use of a hammer to knock the guide directly, not allow pass the pressure through the rolling.

Installation tools appropriate

Linear guide using appropriate and accurate installation tools, try best to use of special tools, try to avoid using fabric and staple fiber such things.

Source: http://www.machineballscrew.com Ball Screw Linear Guides.

Linear guide rail use six don'ts

With the rapid development of China's industry, the use of linear guide rail is also becoming more common, so, what the do's and don'ts in the use of linear guide, how to solve some of the problems?

1, Linear guides do not run without lubrication. Linear guide before out of factory has filled with the lubricating oil, if you want to clean, first to be dry, then reraise lubricants.

2, Do not arbitrarily disassemble the linear guide parts, so as not to affect the accuracy and flexibility.

3, Please do not hammer with hard or sharp tools when installing linear guide rail.

4, After installation, don't let any object speeding on the impact, if the plastic parts break, the ball will be rolled out, the slider will fall.

5, Do not arbitrarily set the line guide with the ball does not comply with the provisions.

6, Do not remove the slider from the linear guide rail, if necessary, it must first align the auxiliary linear guide rail, and then remove the slider.

Source: http://www.machineballscrew.com Ball Screw Linear Guides.