Explanation of Linear Guides

The Basic Structure of the Linear Motion Guide

(1) Basic structure and performance

Basic structure of linear guide includes (1) a linear guide rail, (2) a linear motion block, and (3) balls as a roller bearing element. In order to meet wide range of requirements different elements can be combined with basic structure. Like adding seal plates to linear block as contamination-protection accessories makes this product suitable for clean room environments, and adding ball retainers improves sliding performance (see [Fig.2]). Depending on the accuracy and load requirements single linear guide or two parallel linear guide configurations can be used.

(2) The structure and motion of the rolling bearing

Basic structure of linear guide includes (1) a linear guide rail, (2) a linear motion block, and (3) balls as a roller bearing element. In order to meet wide range of requirements different elements can be combined with basic structure. Like adding seal plates to linear block as contamination-protection accessories makes this product suitable for clean room environments, and adding ball retainers improves sliding performance (see [Fig.2]). Depending on the accuracy and load requirements single linear guide or two parallel linear guide configurations can be used.

a) The structure of the rolling bearing

Performance of a linear motion guides is mostly determined by the structure of the roller bearing used. To explain the structure of the roller bearing in this text we refer to guide groove cuts in the rail as ÒracewaysÓ, and to ball contact points with raceways as Òpoint contactsÓ. Each ball contacts raceway at two or four-point contacts as shown in [Fig.2]. This design allows linear guides to achieve and maintain high accuracy under moment load during sudden acceleration or deceleration or in long, continuous motion.

Number of the point contacts also varies in a "preload state".

b) Low Noise, Smooth Motion

With small friction resistance between re-circulating balls and raceway achieved motion is very smooth [Fig.4]. Linear block equipped with ball retainers is also available. It enables the circulating balls to attain longer lifetimes without frictional noise usually generated when they contact one another.

(3) Other types of linear motion guides

Low-cost precision ball slides are available when application does not require high rigidity, compact and light weight product. Low-cost precision ball slides are made of stainless steel plate precision-formed into a U-shape and possess an integrated raceway and mounting face.