A linear guideway is simply a rail that can carry an item through a defined linear path from one place to another. Linear guideways or rails are generally used with carriages and must be durable to withstand the wear and tear of repeated travel. Our linear guideways come in steel, stainless steel, and anodised aluminium (reinforced with hardened stainless steel raceways) and offer accurate and reliable linear motion.
Linear guideways are widely used throughout industry for heavy-duty and precise applications.
The use of steel balls and the design of the carriages and guideways mean that the rails can accept very heavy loads and signifi cant moment loads. Our rails have circular as opposed to friction coefficient, lower driving resistance, lower wear and lower energy consumption.
We can cross reference other manufacturers’ part numbers including THK, INA, Bosch, IKO etc.
Rigid and precise
• High load rating.
• High moment load capacity.
7 rail profiles ready for same day despatch. Lengths up to 4 metres.
• A number of load figures are stated for load capacity:
Dynamic Load – this is the main fi gure considered for linear guideways. It is the moving load that the system can bear. It takes account of the total moving load as well as considerations such as impact, vibration and fatigue.
Static Load – this is a load that is constant for an extended time (i.e. the dead load the system can bear before any movement). It can be in tension or compression.
For these linear guideways the radial and axial load capacities are the same.
Moment loads are twisting loads generated by off set loads in either X, Y or Z planes. Moment loads can be reduced by adding further carriages or rails to reduce any twisting of the carriage due to the load off set.
Our new and improved linear guideway systems include the latest “ball chain” technology with the following benefits:
The rotating balls in conventional profile rail guides have point contact between each other. The rotation speed at the contact point is double the speed of the balls. The contact area (A) is so small that the surface pressure (P) tends towards infinity. This leads to heating and wear of the balls and the linear guide system.
The chain system in our new linear guides have a relatively large contact area (A), this significantly reduces the surface area pressure (P). The rotation speeds at the contact surfaces of ball and chain are the same. The ball chain is used to transport the lubricant and to create a lubrication film on the balls. The design of the carriage allows effective supply of lubricant from the lubricant connection to the circulation areas of the ball chains.
This design of the of the ball chain ends in connection with the spacer ball closes the circulation and makes the movement of the carriage smooth and quiet.
It is not possible to keep the distance of the balls (C1, C2) constant in conventional linear guides. These irregular distances between the balls lead to uneven running behaviour.
The new ball chain system also allows the balls to be continuously supplied with lubricant, which reduces wear of the metal. This significantly extends the service life of the system and reduces lubricant and the maintenance intervals.
We can coat our rail with a type of corrosion protective finish:
- Raydent coating; this is an electro-chemical process that applies a black oxide-ceramic layer (approx. 1 micron thick) that penetrates into the metal. As coating takes place at OC the parts are not deformed. Good resistance against acids, bases and solvents.
Where there may be a high level of dust, dirt, weld splatters etc. we can provide bellows covers to protect the rails.
|Part no.||Type||Length||dyn. Crad|
|Part no.||Type||Length||dyn. Crad|
|Part no.||Type||Length||dyn. Crad|
Radial clearance describes the value for the radial movement of the carriage at a constant vertical load, while the carriage moves in longitudinal direction.
Preload is defined as an effective load on the rolling element in the interior of the carriage in order to remove an existing clearance or to increase the rigidity.
The linear guideways are available in the two different preload classes K0 or K1, see table below.
The preload influences the rigidity, precision and torque resistance and also affects the service life and displacement force.
The radial clearance for the respective preload classes are listed below.
|Degree of preload||Preload class||Preload|
|Small preload||K1||0,02 x C*|
Impact free and easy movement
Small moments, one rail
application, low vibrations
|15||-3 to +3||-8 to -4|
|20||-3 to +3||-8 to -4|
|25||-4 to +4||-10 to -5|
|30||-4 to +4||-11 to -5|
|35||-5 to +5||-12 to -6|
|45||-6 to +6||-15 to -7|
|55||-7 to +7||-19 to -8|
Precision means the guide accuracy or the maximum deviation of the carriage based on the side and support surfaces during the movement along the rails.
|Height tolerance h1||±0,1|
|Width tolerance w4||±0,1|
|Guide accuracy of raceway C based on surface A||δ C see graph below|
|Guide accuracy of raceway D based on surface B||δ D see graph below|
Linear guideway rails must generally be lubricated before commissioning. They can be lubricated with oil or grease. The correct lubricant selection has a large influence on the service life and the function of the rail, insufficient lubrication and tribocorrosion can ultimately lead to total failure.
As well as reducing friction and wear, lubricants also serve as sealant, noise reducer and corrosion protection for the linear guide. Diff erent lubricants for special applications are available upon request (e.g. lubricant with FDA approval for use in the food industry).
Our linear guideways are coated with an anti-corrosion resistant oil at the factory. This coating needs to be removed prior to installation, then lubricated as follows:
We recommend the use of a lithium emulsified lubricant NLGI Class 2 for lubrication.
We recommend a synthetic oil for operating temperatures between 0°C and +70°C.
Operating speed, stroke length and ambient conditions infl uence the selection of time between lubrication intervals. Establishing a safe lubrication interval is based solely on the applications and conditions. However, a lubrication interval should not be longer than one year.
The following lubrication nipples are supplied.
Other lubrication nipples, such as lubrication adapters with hose inlet or with quick-coupling, are available on request.
There are numerous application-specific surface treatments available for profi le rails of the linear guideway product family, for example, black oxide coating (X), hard chrome plating (XC) or nickel plating (NIC) and an FDA-approval type for use in the food industry. For more information please contact us on 0845 850 99 40.
Linear guideways have a low friction characteristic and thus low displacement resistance. The low start-up friction (breakaway force) is almost identical to the moving friction (running resistance).
The displacement resistance (Fm) is dependent upon several factors:
|Type||Max. seal resistance N|
The following formula is used for approximate calculation of the displacement resistance. Please note that the level of preload or the viscosity of the lubricant used can also influence the displacement resistance.
Fm = μ • F + n.f
Fm = Displacement resistance (N)
μ = Coefficient of friction
F = Load (N)
f = Resistance of the seals (N)
n = Number of sliders
Linear guideways have a coefficient of friction of approx. μ = 0.002 - 0.003
The given static load capacity (C0) for each carriage represents the maximum permissible load value, which if exceeded causes permanent deformations of the raceways and adversely affects the operating performance.
Checking the load must be done as follows:
Fx, Fy = radial and axial resultants of external forces (N)
M1, M2, M3 = external moments (Nm)
C0 = static load capacity (N)
Mx, My, Mz = maximum permissible moments in the different loading directions (Nm)
fc = contact factor (see next page)
S0 = safety factor
The safety factor S0 can lie on the lower given limit if the forces can be determined with sufficient precision. If impacts and vibrations aff ect the system, overloads might occur, then the higher value should be selected.
Reduced safety results from simultaneously occurring forces and moments.
For more information please contact our technical department.
|Normal operation||1,0 ~ 1,5|
|Loading with vibration or shock effect||1,5 ~ 2,0|
|Loading with strong vibration or impacts||2,0 ≥ 3,5|
The dynamic load capacity C is a conventional variable used for calculating the service life. This load corresponds to a nominal service life of 50 Km. The relationship between calculated service life LKm (in Km), dynamic load capacity C (in N) and equivalent load P (in N) is given in the formula below.
fc = Contact factor
fi = Application coefficient
ft = Temperature factor
C = Dynamic load (N)
P = See below (N)
The equivalent load P corresponds in its effects to the sum of the forces and moments working simultaneously on a slider. If these different load components are known, P results from the formula below.
The contact factor fc refers to applications in which several carriages pass the same rail section. If two or more carriages are moved over the same point on a rail, the static and dynamic loading values must be multiplied with the numbers from the table below.
|Number of carriages||1||2||3||4||5|
The application coefficient fi can be understood as the dynamic safety factor. Refer to the table below for the values.
|Neither external impacts nor vibrations||Low speed V ≤ 15 m/min.||1 - 1,5|
|Light impacts or vibrations||Average speed < V ≤ 60 m/min.||1,5 - 2|
|Average and high external impacts or vibration||High speed V > 60 m/min.||2 - 3,5|
If the temperature affecting the system exceeds 100°C, the temperature factor ft must be included in the service life calculation.
Note 1: For temperatures above 80°C, the seals and end caps must be designed for higher thermal resistance.
Note 2: Special processing to ensure the movement of the guides is required for temperatures above 120°C.
The following drawings illustrate some assembly examples for rail/carriage combinations corresponding to the structure of various machine frames.
The given radii and shoulder heights in the table must be observed when assembling rails and carriages on the stop edges to ensure perfect seating of carriages or guideways.
|15||0,6||3,1||5||M4 x 16|
|20||0,9||4,3||6||M5 x 20|
|25||1,1||5,6||7||M6 x 25|
|30||1,4||6,8||8||M8 x 30|
|35||1,4||7,3||9||M8 x 30|
|45||1,6||8,7||11||M12 x 40|
|55||1,6||11,8||12||M14 x 45|
Values in mm. HR* is the maximum height when using side seal on carriage.
The maximum permissible deviations of the rail surfaces for assembly are given in the following drawing and the table below.
|Size||Permissible tolerance for parallelism P1 μ|
|P2 = L1 x (calculation factor)Calculator factor (x) P2 μ|
The bolt sizes to be used and optimum tightening torques for rail assembly are listed in the table below.
|Bolt||Tightening torque Mt Nm|
|Tightening torque Mt Nm|
Fixing guide rails 1
Whet the assembly surface with a whetstone and also remove burrs, unevenness and dirt. Note: All linear guides are preserved with anti-corrosion oil at the factory. This protection must be removed before installation. In doing so, please ensure that the surfaces are coated with low-viscosity oil for the purpose of further protection against corrosion.
Fixing guide rails 2
Carefully lay the guide rail on the assembly surface and slightly tighten the fixing screws so that the guide rail lightly touches the assembly surface (align the guide rail along the shoulder edge of the assembly surface). Note: The fixing screws of the linear guide must be clean. Check if the fixing holes are located in the correct place when you insert the bolts. A forced tightening of a fixing screw in an off set hole can negatively aff ect accuracy.
Fixing guide rails 2 continued
Fixing guide rails 3
Tighten the thrust bolts on the guide rail until there is close contact on the side stop surface.
Fixing guide rails 4
Tighten the fixing screws with a torque wrench to the prescribed torque. Note: For a high degree of accuracy, the
fixing screws of the guide rail must be tightened in sequence outward from the centre.
Fixing guide rails 5
Assemble the other rails in the same manner to complete the installation of the guide rails.
Table assembly 1
Set the table carefully on the carriage and tighten the fixing screws only lightly.
Table assembly 2
Press the carriage on the main guide side with the thrust bolts against the shoulder edge of the table and position the table.
Table assembly 3
Tighten the fixing screws on the main side and the lateral side completely tight to finish the installation. Note: To attach the table uniformly, tighten the fixing screws diagonally (1, 2, 3, 4). This method saves time when straightening the guide rail and makes the manufacture of positioning pins unnecessary, which considerably reduces assembly time.
Guide rails longer than the one part maximum length are put together from two or more rails. When putting guide rails together, ensure the register marks are positioned correctly.
Manual rail clamps
The manual rail clamps are used alongside the standard flanged or unflanged rail carriages. When selecting ensure:
a) the rail clamp suits the rail that you are using.
b) that the total assembly height of the rail clamp is the same as that of the rail carriage L1016.U or L1016.F.