Technical Data 　Linear actuator 　Linispeed Jack 　Allowable Buckling Load

Allowable buckling load table

  • ・Use this graph to select the correct frame number based on a specific buckling load, for compression loads. This buckling load selection graph includes a buckling safety factor of SF = 4.
    • (1)For the installation conditions shown below, please select an appropriate distance L. (Please contact Tsubaki other than installation below. )
    • (2)The graphs allow you to select the correct frame number based on a specific load W (vertical axis) and stroke distance LA (horizontal axis).
  • ・Ensure that no lateral loads are applied. The buckling selection graph on the right assumes that there is no lateral load.
  • ・In the installed condition, it is economical because there is no buckling if the equipment is designed so that the threaded shaft is subjected to tensile load.
Fixed base - Guided shaft end
Fixed base - Guided shaft end
Fixed base - Fixed shaft end
Fixed base - Fixed shaft end
Allowable Buckling Load
  • Note)
  • 1.The dotted line in the graph represent an example when the load W is 20 kN and the distance L is 900 mm when using above installation conditions and with an assumed buckling safety factor (sf = 4). In this case, SJ030H model can be selected.
  • 2.If detailed examinations are required, please refer to the calculation formulas below.

Distance between points of load ：L(Distance from installation surface to load mounting surface )

SJ015H SJ030H SJ050H
Table type end fitting (M) 25mm 33mm 33mm
I-shaped end fitting (I) 50mm 75mm 80mm
X dimension (MIN) 187mm 202mm 236mm

When using table-type or I-type end fittings, be sure to add the actual length of each end fitting to the actual stroke.

Example) SJ030H　When using an I-type end fitting that has a stroke of 500 mm.
500 + 277 = 777mm

Note)
If you wish to use your own custom end fitting, please add the X dimension (MIN) and the length of the end fitting itself to the actual stroke. Please note that the X dimension does not include the 32 mm screw length on the end of the screw shaft for attaching the end fitting.

Table type end fitting

Allowable buckling load calculation formula

The allowable buckling load of the screw shaft can be calculated as follows.

PCR = m× d2 L 2

Make sure that PCR > W x Sf.

PCR：Allowable Buckling Load N

d：Screw Root Dia. mm

m：Support coefficient (20×104)

L：Distance between points of load Note) mm

W：Load / jack N

Sf：Buckling safety rate (Assume 4 )

Fixed base - Guided shaft end
Fixed base - Guided shaft end
Fixed base - Fixed shaft end
Fixed base - Fixed shaft end
Allowable buckling load calculation example

The following procedure can be used to calculate PCR when the equipment is in use with SJ030H-TUT8M model (fixed base - fixed shaft end with table-type end fitting) when the load (W) is 24,500 N.

PCR = 20×104×(30.72/1035)2
= 165,845 N
W×Sf = 24500×4(assuming sf = 4 )
= 98,000 N Comparing these values
PCR > W×sf
165845 > 98000 ...OK

*L = 1002 + 33 = 1035mm

X dimension at 800mm stroke ：1002mm

Table-type end fitting ：33mm

From the product page

Lateral loads

The Linispeed Jack cannot hold lateral load.

If lateral load is to be applied, please install guides as shown in the image to and make sure that lateral load do not directly apply on the jack.

Guide
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