Page 513 - MiSUMi 2025

Economy series Product Overview Selection Procedure & Technical Calculation Economy series
Oil Free Bushings Oil Free Bushings

QComplete specifications, stock item can be shipped out in the same day QSelection Procedure for Oil Free Bushings
at the earliest. Unit: mm
Determine operating conditions Confirm the operating environment: General use, heat resistance,
chemical resistance, load, usage frequency, and lubrication requirements.
Straight Type Shouldered Type Thrust Type
Type I.D. Length
Provisionally select specifications · Select the shape, such as straight or flanged.
· Provisionally determine the size and dimensions based on design conditions.
Straight Type* 5~100 6~100
Shouldered Type* 5~100 8~100 NG · Maximum Allowable Surface Pressure
Confirm basic safety Ensure that the applied load is within the maximum allowable surface pressure limit.
Standard Flanged Type Center Flanged Type Pilot Flanged Type Thrust Type 6~50 10~60
Standard Flanged Type 6~50 10~100 · Maximum Allowable Speed
Center Flanged Type 8~40 20~80 Ensure that the travel speed is within the maximum allowable speed limit.
Pilot Flanged Type 10~40 25~60 · Service Life (Wear Calculation)
Selection completed Estimate the expected wear amount and confirm that the required service life can be ensured.
*Including standard and thin wall types
QSpecification comparison (Using the straight type as an example) QCalculation of service life
· The tolerance class of I.D. and O.D. is the same as that of MISUMI Standard products, and the quality The service life of Oil Free Bushing is determined by the amount of wear. The wear amount varies significantly
is guaranteed by factory inspection. depending on factors such as surface pressure, sliding speed, type of motion, lubrication conditions, and the
4 · R chamfer makes installation easier. surface roughness of the mating shaft. From the perspective that wear is proportional to load and sliding distance, 4
the following formula is generally used to calculate wear. Please consider this as a reference when selecting a
· The standard load and operating speed of the catalog are ensured, so it can be used with reliance.
Linear Guides / Linear Shafts / Linear Bushing / Ball Splines / Oil Free Bushings Tolerance class of Tolerance class of Chamfer shape Maximum Allowable Regular lubrication Unlubricated Assumed wear amount (mm)W=K ×P×V×T mm/(N/mm · m/s · hr) Oil Free Bushings Linear Bushing / Ball Splines / Linear Guides / Linear Shafts /
bushing.

Maximum Allowable Velocity
*1
Surface Pressure
O.D.
I.D.
*1 K General Spcific wear rate depending on lubrication conditions
Specific wear rate K ：:mm/(N/mm · m/s · hr)
Lubrication conditions
2
2
0.0006~0.003
-4
MISUMI
Sliding velocity V ：:m/s
6×10 ~3×10
Periodic lubrication
0.00006~0.0003
-5
-4
Standard products R angle 29N/mm 2 1m/s 0.5m/s Design pressure P ：:N/mm 2 Dry (Unlubricated) 6×10 ~3×10 -3 0.000006~0.00003
Sliding hours T
：:hr
Oil lubrication
6×10 ~3×10
-6
-5
Linear Guides Class 7 Class 6 The specific wear amount refers to a bearing wear amount obtained in a bench test divided by a test load, Guides Linear
MISUMI
Economy series Easy to install 20.3N/mm 2 0.7m/s 0.35m/s test velocity and test time. It is specific to each bushings. Surface pressure “P”
Value “P”
Value “PV”
Movement
P.04-011 Reciprocation P= Lo Load Lo : N 2cS Value “V” PV= 2LocS MAX load by projected area. P.04-011
which is obtained by driving
Reciprocation
Cross Roller Guides Generic Products Rough C angle - Lo <Ex> Bushing: I.D20 / Length25 Load: 3000 / Reciprocation cycle speed: 2 / Stroke distance: 40 Lo Guides Cross Roller
I.Dφd
: mm V=
cycle speed c: s -1
φd×L
3
10 ×φd×L
3
10
Length L: mm
Stroke distance s: mm
on the market*
3000
V=
1000×20×25
1000
P.04-039 * Generic Products on the market are similar products randomly purchased by MISUMI from online or offline markets Radial Journal P= P= 20×25 → P=6.0 : mm V= 2×2×40 → V=0.16 PV= 2×3000×2×40 → PV=0.96 φd P.04-039
Load Lo : N
Lo
Linear Shafts / Bushings * The test data are obtained through testing by MISUMI, which are for reference only one way rotation <Ex> Bushing: l.D20 / Length25 Load: 3000 / Rotating speed: 2 10 ×φd×L is a key performance indicator used in Bushings Linear Shafts /
πφdLon
πφdn
Rotating speed n: s -1
PV=
I.Dφd
φd×L
3
I.Dφd: mm
10
L
3
Length L: mm
Lo
QCategories of Use
“PV” (Pressure × Velocity) Value
tribology.
3000
MISUMI Standard products
MISUMI Economy series
1000
1000×20×25
P.04-043 Easily applicable in mechanisms of linear or rotary motion Displays excellent performance in mechanisms of linear motion Oscillation P= 20×25 → P=6.0 V= π×20×2 → V=0.126 PV= π×20×3000×2 → PV=0.754 To prevent abnormal wear, it is P.04-043
necessary to design within the
Oscillating cycle
Ball Splines Standard products Economy series Lo <Ex>Bushing: I.D20 / Length25 Load: 3000 / 0scillating cycle speed: 0.5 / 0scillating angle θ 0.785 (45°) P max allowable limits. Ball Splines
Load Lo : N
Loφdcθ
Lo
φdcθ
Speed c
: s -1
P=
PV=
: mm V=
I.Dφd
3
φd×L
10
10 ×φd×L
Oscillating angle θ: rad
3
MISUMI
Length L: mm
: mm
I.Dφd
MISUMI
P.04-107 P= 20×25 → P=6.0 V= 20×0.5×0.785 → V=0.00785 PV= 3000×20×0.5×0.785 → PV=0.05 P Allowable Max“PV” P.04-107
3000
1000×20×25
1000
Oil Free Bushings In case of bearings with inner diameter of 20mm and length of 10mm, load of 1000N when Allowable Bushings Oil Free
Calculation Example
area
P
K
P.04-126 unlubricated, rotational speed 2r/min and friction time of 100 hours × Use time V V max P.04-126
W=
T
V
×
×
×
Shaft Supports / Collars = wear rate × inner diameter×length × 1000×60 × 100 Collars Shaft Supports /
Load
π×inner diameter×rotational speed
Specific
×
=
×
1000
1000
π×20×2
3
1000
20×10
P.04-144 = 0.00314 (mm) P.04-144
04-127 *Example calculations are shown without units. 04-128