Automotion Components Aluminium Linear Guideways
What are aluminium linear guideways?
Aluminium linear guideways or rails are systems that support load transfer in a linear path. Our aluminium linear rails are made from aluminium with hardened stainless steel raceways and roller balls - this means they are extremely resistant to corrosion and wear, and they offer up to a 60% weight saving as compared to the standard stainless steel or steel versions.
Features
Product overview
Automotion's aluminium profile rails and ball bearing runner blocks are designed especially for applications requiring a precise. lightweight linear guide system with a very high degree of corrosion resistance. The rails consist of profiled aluminium with two pressed-in hardened stainless steel raceways for the stainless steel balls of the runner blocks to run along. This increases the service lifetime of the lightweight linear rails.
Fixing holes in the attachment surfaces enable machine parts to be directly mounted onto the runner blocks. With this combination it is possible for us to offer a guide system which achieves a good price/performance ratio.
Product range
- There are two versions of our carriages: flanged and unflanged.
- There are two accuracies for our carriages: Standard precision (0) and a high precision called “P” (available on request).
- The standard carriage is not pre-loaded.
- The dynamic load rating (C in the data tables) is based on a service life of 100 km.
Advantages
- Compact, light-weight design with a weight saving of 60% compared to steel versions.
- Same fixing hole dimensions as steel ball linear guideway systems.
- Much greater parallelism and height off sets of mounting bases possible, providing a degree of misalignment.
- Performs well in aggressive environments (dust, shavings etc.).
- Significantly better corrosion resistance compared to steel versions.
- Carriages initially greased in-factory, therefore provided with long-term lubrication.
- Due to ball retainers in the carriages, carriages can be removed from the rail without any loss of balls.
- Complete interchangeability between other manufacturers steel rail systems.
- Both sides of rail are reference edges. The carriages has one reference edge, which can be verified by turning it on the rail.
Application range:
Speed - vmax = 2 m/s
Acceleration - amax = 30 m/s2
Temperature - T = 0o - 60oC
Applications
Our rails can be used in a broad range of applications. Especially in light machinery, handling technology, jigs and fixtures, assembly technology, manual displacement systems, machine enclosures, door – and window technology, display systems, aerospace, medical, food and many more.
Our aluminium rail guides cannot be used in the following applications:
- Main axis of a CNC or tooling machine.
- Aggressive and dusty enviroments.
- Oscillating conveyor systems.
- Danger of life or physical systems (for example unsecured overhead installation).
Technical Specs
Determination of the carriage size
1. Pre-select the carriages
2. Determine Fcomb (see below)
3. Calculate the ratio of the dynamic load capacity “C”
of the selected carriages relative to Fcomb (Fcomb divided by “C”)
If Fcomb /C > 0.4: carriages is sized too small. Select the next largest size and repeat the calculation (step 2 and 3).
The ratio must always be Fcomb / C≤ 0.4, otherwise Fmax will be exceeded.
Note:
The load ratio Fcomb / C is the quotient of the equivalent dynamic load on the bearing divided by the dynamic load capacity “C”.
Calculation of load on bearing for a carriage:
Fcomb = combined equivalent load (N)
FY, FZ = Dynamic load (N)
MX = torque of the X-axis 1) (Nm)
MY = torque of the Y-axis 2) (Nm)
MZ = Moment um die Z-Achse 2) (Nm)
Mt = dynamic torsional moment load capacity (Nm) - For values, see carriage data tables
ML = dynamic longitudinal moment load capacity (Nm) - For values, see carriage data tables
C = dynamic load capacity (N) - For values, see carriage data tables
b = operating factor, (see below)
For values, see table “Recommended values for operating factors “b”.
- Torque MX will only be fully effective in an application with a single guide rail.
- Torque MY or MX will only be fully effective when only a single carriage is mounted on one guide rail.
Recommended operating factors b
Values for operating factors b
| 1,0 | Clean environment, low technical demands, manual operation |
| 1,5 | In a linear motion axis with ball screw drive |
| 2,0 | Linear motion axis with toothed belt drive |
| 6,0 | Linear motion axis with pneumatic drive |
| 9,0 | In very dirty environments |
Static load rating
A static load rating can not be easily determined because of the composite material (aluminium/ stainless steel combination). Instead of this you can find the values Fmax and Mmax.
Parallelism
Please note the parallelism required in the structure for correct installation. Parallelism of the installed rails is measured at the guide rails and the carriages. Any parallelism off set causes a slight increase in preload on one side of the assembly. As long as values specified in the table are met, the effect of parallelism off sets on the service life can generally be neglected.
| Size | Permissible deviation in parallelism PmaxStandard | Permissible deviation in parallelism PmaxPreload |
| 15 | 0,027 | 0,018 |
| 20 | 0,031 | 0,021 |
| 25 | 0,034 | 0,022 |
Height deviation
Permissible height deviation in lateral direction “hw”
Allowable height deviation in longitudinal direction
Allowable height deviation in longitudinal direction “hl”
Height tolerance "H"
The height tolerance of several carriages on a rail is maximum ±30μ. In a combination of several carriages and rails the maximum is ±120μ.
Side tolerance "D"
The maximum side tolerance of several carriages on a rail is ±30 μ. In a combination of several carriages and rails, the maximum is ±70 μ.
Deviation of parallelism
We aim to achieve a lifetime lubrication, which we define as at least 30,000Km. The following conditions apply:
- Initial greasing with Dynalub 510
- Mounted seal unit
- No exposure to metal-working fl uids
- Ambient temperature T = 20° to 30°C
First, the ratio Fcomb / C is calculated with Fcomb according to the formula on the previous page and the dynamic load rating C from the data tables. With this value you go then in to the diagram below.
If Fcomb / C ≤ 0,15, it lies in the zone A of the diagram bellow. This means it will have lifetime lubrication.
With 0,15 < Fcomb/C ≤ 0,4 it lies in the zone B of the diagram below.
For this you must distinguish two cases:
For example Fcomb / C = 0,25 goes up to 6400km.
a) If the running distance required < 6400 km, then there is a lifetime lubrication here.
b) If the running distance required > 6400 km, then instead of the sealed unit you should use the lubrication unit option.
If value Fcomb/C > 0,4 then Fmax is exceeded.
Notes:
- Take account of the general service life of lubricants.
- If other lubricants are used, this may lead to a reduction in the re-lubrication intervals, the achievable travel in short-stroke applications and the load capacities. Possible chemical interactions between the plastic materials, lubricants and preservative oils must also be taken into account.
- Do not use greases with solid particles such as graphite or MoS2.
- If your application involves more demanding environmental requirements such as clean room, vacuum, food industry, increased exposure to fluids or aggressive media, extreme temperatures, please consult us. These situations must be investigated on a case by case basis and may require the use of a special lubricant.
