THK Linear Guide Rail And Carriage
The function of the linear guide motion is to support and guide the moving parts to make a reciprocating linear motion in a given direction.
Depending on the nature of the friction, linear motion guides can be classified into sliding friction
guides, rolling friction guides, elastic friction guides, and fluid friction guides. Linear bearings are mainly
used in automation machinery, such as machine tools imported from Germany, bending machines, laser
welding machines, etc. Of course, linear bearings and linear shafts are used together. Linear guides are
mainly used on mechanical structures with high precision requirements. There is no intermediate medium
between the moving parts and fixed elements of the linear guides, and rolling steel balls are used.
Although the form of the rail system is varied, the nature of the work is the same, and the machine
tool's working parts move on the designated rail system, just as the train travels along the rail in the
specified direction. Whether it is the machine guide rail or the railroad track on the railway, it has the
following three basic functions (function):
(1) Provide a smooth moving surface for the carrier
(2) Orientation for the movement of the carrier
(3) Transfer the force generated by the movement of the train or the cutting of the machine tool to
the foundation or the bed to reduce the impact of the resulting impact on the passengers and passively
Type of rail:
1.the nature of work
Main motion guide: The main movement of the moving rail seat, the relative speed between the guide
rail pairs is high.
Feeding motion guide rail: The moving rail is used for feed motion, and the relative movement speed
between the guide rail pairs is low.
Displacement rail: only used to adjust the relative position between the parts, there is no relative
movement during processing, such as the guide rail for the tailstock of the lathe.
2. friction properties
Sliding guide rail: The characteristic of the sliding guide rail is that the frictional property between the
auxiliary working faces of the guide rail is sliding friction.
Sliding rails: hybrid friction rails, boundary friction rails, hydrodynamic rails, hydrostatic rails.
Rolling friction: There are rolling bodies between the auxiliary working faces of the guide rails, so that
there is rolling friction between the two rail faces.
Rolling guides: ball guides, roller guides, needle guides.
3. Stress situation
The open rail relies on the external load and the component's own weight, so that the two rail faces
remain attached to the guide rail over the entire length.
The pressure guide plate for the closed guide rail serves as an auxiliary guide rail surface to ensure the
guide rail of the main guide surface.
4.the motion track
Circular motion guide: The relative movement path of the guide rail pair is a circle, such as the
faceplate and the base rail of the vertical lathe.
Linear motion guide: The relative motion of the guide rail pair is a straight line. Such as the slide of
the ordinary lathe and the bed rail.
1. Linear motion is achieved by rolling the roller bearing with V-groove on the V-shaped guide
surface; under the condition of lubrication, the maximum linear speed can exceed 10m/s. V-shaped guide
rail adopts precision machining process: V-shaped guide rail surface adopts surface hardening process,
surface hardness is HRC58-62; precision grinding, surface roughness up to N5. As a high-speed linear
guide, it has been widely used to achieve accurate positioning.
2. The rolling element in the roller bearing - the steel ball or the tapered roller and the V-shaped
guide surface are not in contact, the pollutants on the guide rail and the rolling element have no direct
contact opportunity; at the same time, the bearing has good sealing performance and prevents the entry
of pollutants. The inside of the roller bearing contacts the roller body and contaminated grease.
3. The contact between the V-shaped roller and the V-shaped guide rail is two wires at a 90-degree V-
shaped angle. The two wires are obliquely intersected with the central axis of the roller and rotate around
it at a high speed; the two wires and the V-shaped guide rail The contact of the surface belongs to the
instantaneous contact, the high-speed approaching the surface of the guide rail, the instantaneous
contact, and then leaving at high speed; in this case, the "line" of the V-shaped roller is continuously
"scratched" on the surface of the guide rail, which can ensure the surface of the guide rail well. The
cleaning, so the V-rail has a self-cleaning function.