Brochure

Selection
Danger
1. Absorbed energy
Select a model so that the aggregated energy of an impacting
material should not exceed the maximum absorbed energy.
Otherwise, it could cause changes in properties or result in
damaging the shock absorber.
2. Equivalent mass
Select a model so that the equivalent mass should not exceed
the allowable range. Otherwise, pulsation could occur in buffer
capacity and deceleration force, thus making it difficult to
absorb shock smoothly.
3. Collision speed
Use the product within the specified collision speed range.
Otherwise, it could cause the changes in buffer characteristics
or result in damaging the shock absorber.
Warning
1. Static load
Design the system so that any other forces than the buffer
capacity or impacts should not be applied to the piston rod
which is stopped at the retracted state.
Caution
1. Maximum operating frequency
Design the system in the conditions under which it is not used
at the frequency exceeding the specified maximum operating
frequency.
2. Stroke
The specified maximum absorbed energy cannot be exerted
unless the full stroke is used.
3. Work surface of an impacting material
The contact surface of an impacting material with which the
piston rod comes into contact must be highly rigid (hardness
of HRC35 or more). A high surface compression load is
applied to the contact surface of the impacting material with
which the piston rod comes into contact.
4. Be aware of the backlash of the impacting material.
When used in a conveyor line, the object may be pushed back by
the built-in spring force after energy is absorbed. For backlash,
refer to the spring force in the specifications. (Pages 5 and 6)
5. Selection of size
As the number of operation proceeds, the maximum absorbed
energy of shock absorbers will be decreased by the reasons
such as deterioration, etc. of the internal working fluid. Taking
this into consideration, selecting a size which is 20 to 40%
affordable against the amount of absorbed energy is recom-
mended.
6. Resisitive force characteristics
In general, the values of resisitive force (resisitive force gener-
ated during the operation) generated by the operating speed
will vary in oil hydraulic shock absorber. The RJ series can
adapt to such this fast/slow speed and can absorb shock
smoothly in a wide range of speed.
But, take note the stroke time could be long, and the motion
would not be smooth, etc., depending on the operating condi-
tions. If this would be a problem, we recommend the stroke
amount should be restricted by using our optional component
“stopper nut”, etc.
Caution
7. Parallel usage
When using multiple shock absorbers in parallel, energy will
not be divided evenly because of differences in product
dimensions and devices. For this reason, select the following
options.
E= Ea/N/0.6
E: Energy used per shock absorber
Ea: All energies
N: The number of shock absorbers used in parallel
Operating Environment
Danger
1. Operation in an environment which requires explosion-
proof
s7HENMOUNTINGINPLACESWHERESTATICELECTRICITYISACCUMU-
lated, implement a distribution of electrical energy by
grounding.
sDo not use materials for the buffer surface which might cause
to spark by collision.
Warning
1. Pressure
Do not use the product in the vacuum state which is substan-
tially different from the atmospheric pressure (above sea
level) and in the atmosphere under being pressurised.
2. Using inside a clean room
Do not use the product in a clean room, as it could contami-
nate the clean room.
Caution
1. Temperature range
Do not use the product, exceeding the specified allowable
temperature range. Seal could be softened or hardened or
worn out, or leading to working fluid leak, deterioration, or
buffer characteristic changes.
2. Deterioration by atmosphere
Do not use the product in the presence of salt damage,
sulfurous acid gas which makes the metal corroded, or
solvent which makes the seal deteriorated.
3. Deterioration by ozone
Do not use the product under the direct sunlight on the beach,
or by the mercury lamp, or the ozone generator, because the
rubber material will be deteriorated by ozone.
4. Cutting oil, water, blown dust
Do not use the product under the condition where the liquid
such as cutting oil, water, solvent, etc. is exposed either
directly or in atomised form to the piston rod, or where blown
dust could be adhered around the piston rod. This could
cause a malfunction.
5. Vibration
When vibrations are applied on an impacting material, imple-
ment a secure guide on the impacting material.
Series RJ
Specific Product Precautions 1
Be sure to read this before handling. Refer to the back cover for Safety Instructions,
“Handling Precautions for SMC Products” (M-E03-3) for Common Precautions.
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