Working Principle of Linear Guide Way

Working principle of linear guide way is like a element riding,is by the steel ball in the slider with infinite rolling cycle between the guide rail, so that the load platform along the guide rail easy high-precision linear movement, and the friction coefficient is reduced to the usual traditional sliding guide fifty times, can easily achieve high positioning accuracy.The terminal unit design between block and guide rail enables linear guide rail to bear loads in all directions at the same time,The reverse-flow system and streamlined structural design allow for smoother and quieter movement of the linear guide rail

Block - Changes motion from a curve to a straight line.The new guide rail system enables the machine tool to obtain fast feed speed. In the case of the same spindle speed, fast feed speed is the feature of linear guide way. Linear guide way is the same as plane guide way, there are two basic units; One serves as a guide for the fixed element, and the other is a moving element.As linear guide rail is a standard component, all that the machine tool manufacturer needs to do is to process a plane to install the guide rail and adjust the parallelism of the guide rail.Certainly, in order to ensure the accuracy of the machine tool, a small amount of scraping and grinding of the bed or column is essential, in most cases, the installation is relatively simple.The guide rail is hardened steel and placed on the installation plane after fine grinding. Compared with the plane guide, the geometric shape of the cross section of the linear guide is more complex than the plane guide. The complex reason is that the guide needs to be processed into grooves to facilitate the movement of the sliding components. The shape and number of grooves depend on the function of the machine tool to be completed.For example, a guide system that withstands both linear forces and overturning moments is compared to one that withstands only linear forces. There's a big difference showing in design.

The fixed element (guide rail) of the linear guide system has the basic function as a bearing ring, a bracket for installing steel balls, and the shape is "V" . The bracket wraps the top and sides of the guide rail. In order to support the working parts of the machine tool, a linear guide has at least four supports. For supporting large working parts, the number of brackets can be more than four.

When the working parts of the machine tool move, the steel ball circulates in the groove of the support, and the wear of the support is apportioned to each steel ball, thus extending the service life of the linear guide. In order to eliminate the gap between the bracket and the guide rail, pre-loading can improve the stability of the guide system, Acquisition of pre-loading. It is to install super-sized steel balls between the guide rail and the bracket. The diameter tolerance of the steel balls is ±20 microns, and the steel balls are screened and classified in increments of 0.5 microns, The steel balls are screened and classified, and respectively installed on the guide rail. The size of the pre-loading depends on the force acting on the steel balls.If the acting force on the steel ball is too large, the pre-loading time is too long, leading to the increase of the movement resistance of the support, there will be a balance effect problem; In order to improve the sensitivity of the system and reduce the motion resistance, pre-loading should be reduced correspondingly. In order to improve the motion accuracy and the retention of precision, sufficient negative preloading is required, which are two contradictory aspects.

When the working time is too long, the steel ball begins to wear and tear, and the pre-loaded load on the steel ball begins to weaken, leading to the decrease of the movement accuracy of the working parts of the machine tool. If the initial accuracy is to be maintained, the guide rail bracket must be replaced or even replaced. If the guide rail system has been pre-loaded. System accuracy has been lost by replacing the rolling element.

The design of the guide rail system, strive to have a large contact area between the fixed element and the moving element, which can not only improve the bearing capacity of the system, and the system can withstand the impact of intermittent cutting or gravity cutting, the force is widely diffused, expand the bearing area. In order to achieve this, there are a variety of groove shapes of the guide system. There are two representative ones. One is called Gothic (pointed arch), and the shape is the extension of a semicircle with the contact point as the vertex. The other is a circular arc, which can also play the same role. No matter what kind of structure of clamping device, the purpose is only one, and strive for more rolling steel ball radius contact with the guide rail (fixed components). The key factor that determines the performance characteristics of the system is how the rolling element contacts with the guide rail.