Use Of Jointed Rails - THK LM Guide Instruction Manual

3.
Marking on the Master Rail and Combined Use
3-3
Serial Number Marking and Combined Use of an LM Rail
and LM Blocks
An LM rail and LM blocks used in combination must have the same serial number. When
removing an LM block from the LM rail and reinstalling the LM block, make sure that they have
the same serial number and the numbers are oriented in the same direction. (Figure 3-3)
Figure 3-3 Combined Use of an LM Rail and LM Blocks (For Example, Model HSR-A)
3-4

Use of Jointed Rails

When a long LM rail is ordered, two or more rails will be connected to one another to reach the
desired length. When connecting rails together, make sure that the joint matching marks shown
in Figure 3-4 are correctly positioned.
When two LM Guides with connected LM rails are to be arranged in parallel to each other, the
two LM Guides will be manufactured so that the two LM Guides are axisymmetrically aligned.
If a large load is applied near the LM rail joint, the LM rail may deflect and cause misalignment.
Therefore, we recommend securely fastening the LM rail by pressing the joint section against the
reference surface using a set screw or the like and keeping the L dimension as short as possible.
(Figure 3-4)
Contact THK for details.
Joint match mark
Subsidiary-rail axis
Reference surface
Master rail axis
Joint match mark
LM block set screw
LM rail set screw
Figure 3-4 Use of Jointed Rails
Joint match mark
B1
Reference surface
A1
Joint match mark
Joint match mark display
Rail reference surface
L
3-2
3. Marking and
Combined Use
Joint match mark
B2
A2
Joint match mark
B
B
Method for Securing
the LM Rails at the Joint
LM Guide