500-5E0
Point of Design Linear Bushing
Assembling the Linear Bushing
[Inner Diameter of the Housing]
Table1 shows recommended housing inner-diameter tolerance for the Linear Bushing. When fitting
the Linear Bushing with the housing, loose fit is normally recommended. If the clearance needs to be
smaller, provide transition fit.
Table1 Housing Inner-diameter Tolerance
Type Housing
Model No. Accuracy Loose fit Transition fit
High accuracy
grade H7 J7
LM (no symbol)
Precision
H6 J6
Grade (P)
LME — H7 K6, J6
LMF
LMK
LMH High accuracy
LM-L grade H7 J7
LMF-L (no symbol)
LMK-L
LMH-L
[Clearance between the Nut and the LM Shaft]
When using the Linear Bushing in combination with an LM shaft, use normal clearance in ordinary
use and small gap if the clearance is to be minimized.
Note1) If the clearance after installation is to be negative, it is preferable not to exceed the radial clearance tolerance indicated
in the specification table.
Note2) The shaft tolerance for Linear Bushing models SC, SL SH and SH-L falls under high accuracy grade (no symbol).
Table2 Shaft Outer-diameter Tolerance
Type LM Shaft
Normal
Model No. Accuracy Small gap
clearance
High accuracy
grade f6, g6 h6
LM (no symbol)
Precision
f5, g5 h5
Grade (P)
LME — h7 k6
LMF
LMK
LMH High accuracy
LM-L grade f6, g6 h6
LMF-L (no symbol)
LMK-L
LMH-L
A5-20
500-5E0
Point of Design
Assembling the Linear Bushing
[Mounting the Nut]
Although the Linear Bushing does not require a large amount of strength for securing it in the axial
direction, do not rely only on a press fit to support the nut. For the housing inner-diameter tolerance,
see Table1 on A5-20.
Installing the Standard Type
Fig.1 and Fig.2 show examples of installing the standard type Linear Bushing.
When securing the Linear Bushing, use snap rings or stopper plates.
Linear Bushing
Fig.1 Snap Ring Fig.2 Stopper Plate
A5-21
500-5E0
Snap Ring for Installation
To secure Linear Bushing model LM, snap rings Table3 Types of Snap Rings
indicated in Table3 are available. Snap ring
Note1) For models indicated with parentheses, use C-shape
concentric snap rings. For outer surface For inner surface
Note2) The Table3 commonly applies to models LM, LM-
GA, LM-MG and LM-L. Model No. Needle Needle
C-shape C-shape
snap snap
snap ring snap ring
ring ring
LM 3 — — AR 7 —
LM 4 — — 8 —
LM 5 WR 10 10 10 10
LM 6 12 12 12 12
LM 8 — 15 15 15
LM 8S — 15 15 15
LM 10 19 19 19 19
LM 12 21 21 21 21
LM 13 23 22 23 —
LM 16 28 — 28 28
LM 20 32 — 32 32
LM 25 40 40 40 40
LM 30 45 45 45 45
LM 35 52 52 52 52
LM 38 — 56•58 57 —
LM 40 — 60 60 60
LM 50 — 80 80 80
LM 60 — 90 90 90
LM 80A — 120 120 120
LM 100A — (150) 150 —
LM 120A — (180) 180 —
Set Screws Not Allowed
Securing the nut by pressing the outer surface
with one set screw as shown in Fig.3 will cause
the nut to be deformed. Set screw
Nut Housing
Fig.3
A5-22
500-5E0
Point of Design
Assembling the Linear Bushing
Installing a Flanged Type
With models LMF, LMK and LMH, the nut is integrated with a flange. Therefore, the Linear Bushing
can be mounted only via the flange.
Linear Bushing
Nut mounted via socket and spigot joint Mounted via a flange only
Installing a Clearance-adjustable Type
To adjust the clearance of a clearance-adjust-
able type (-AJ), use a housing that allows
adjustment of the nut outer diameter so as to
facilitate the adjustment of the clearance
between the Linear Bushing and the LM shaft.
Positioning the slit of the Linear Bushing at an
angle of 90° with the housing's slit will provide
uniform deformation in the circumferential direc-
tion. (See Fig.4.)
Fig.4
Mounting an Open Type
For an open type (-OP), also use a housing that
allows adjustment of the nut outer diameter as
Housing
shown in Fig.5.
Open types are normally used with a light pre-
load. Be sure not to give an excessive preload.
Adjustment bolt
Whirl-stop plate Whirl-stop plate
Fig.5
A5-23
500-5E0
[Mounting the Shaft End Support]
Shaft end support model SK can easily be
Tightening bolt
secured to the table using mounting bolts.
Model SK enables the LM shaft to firmly be
secured using tightening bolts.
Mounting bolt
Washer
THK
SK30
Reference surface
[Installing an LM Case Unit]
Attaching Model SC (SL)
Since models SC and SL can be attached from
the top or bottom by simply tightening it using
bolts, the installation time can be shortened.
(See Fig.6.)
Fig.6
Attaching Model SH (SH-L)
Since models SH and SH-L can be attached
Basic installation
from the top or bottom by simply tightening it
using bolts, the installation time can be short-
ened.(See Fig.7.)
Alternative installation
Fig.7
A5-24
500-5E0
Point of Design
Assembling the Linear Bushing
[Incorporating the Nut]
When incorporating the standard Linear Bush-
ing into a housing, use a jig and drive in the nut,
D-0.3 D : Nut outer diameter
or use a flatter plate and gently hit the nut, dr: Bore diameter
instead of directly hitting the side plate or the
seal. (See Fig.8.)
dr-0.3
Fig.8
[Inserting the LM Shaft]
When inserting the LM shaft into the Linear
Linear Bushing
Bushing, align the center of the shaft with that of
the nut and gently insert the shaft straightfor-
ward into the nut. If the shaft is slanted while it is
inserted, balls may fall off or the retainer may be
deformed. (See Fig.9.)
Fig.9
[When Under a Moment Load]
When using the Linear Bushing, make sure the load is evenly distributed on the whole ball raceway.
In particular, if a moment load is applied, use two or more Linear Bushing units on the same LM shaft
and secure an adequately large distance between the units.
If using the Linear Bushing under a moment load, also calculate the equivalent radial load and iden-
tify the correct model number. (See A5-16.)
[Rotational Use Not Allowed]
The Linear Bushing is not suitable for rotational
use for a structural reason. (See Fig.10.)
Forcibly rotating it may cause an unexpected
accident.
Fig.10
A5-25
500-5E0
[Precautions on Installing an Open Three-ball-row Type Linear Bushing]
When installing an open three-ball-row type Lin-
ear Bushing, mount it while taking into account Load
the load distribution as indicated in Fig.11.
LM12
13
Fig.11
[Attaching Felt Seal Model FLM]
The felt seal can be press-fit into a housing fin-
ished to H7, but cannot be used as a stopper for
preventing the Linear Bushing from coming off.
Be sure to use the felt seal by attaching it as
indicated in the Fig.12.
Also make sure to impregnate the felt with suffi-
cient lubricant before attaching it.
Fig.12
A5-26
