Hydraulic shock absorber selection
Five basic criterias are required for sizing the shock absorbers:
a) impacting mass m (kg)
b) impact speed v (m/s)
c) additional external forces acting on the mass e.g. propelling force F (N)
d) number of strokes of the shock absorber per hour X (1/h)
e) number of parallel shock absorbers
Free falling mass |
Mass on driven rollers |
Mass without propelling force |
Mass on incline |
Mass with propelling force, horizontal |
Rotary table with propelling force |
Swinging mass without propelling force |
Swinging mass with propelling force |
Formulae
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Used values and variables
Wk | [Nm] | Kinetic energy |
K1 | [1] | Correction factor for pneumatic drive force K1=0,65 | |
WA | [Nm] | Propelling force energy |
M | [Nm] | Torque | |
Wkg | [Nm] | Total energy |
R, r | [m] | Radius | |
Wkg/h | [Nm] | Total energy per hour |
H | [m] | Height | |
m | [kg] | Mass | g | [m.s-2] | Acceleration due to gravity |
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me | [kg] | Effective mass |
J | [kg.m2] | Moment of interia |
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v | [m.s-1] | Impact speed |
ω | [s-1] | Angular velocity |
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ve | [m.s-1] | Effective speed |
µ | [1] | friction coefficient (steel=0,2) | |
X | [h-1] | Number of strokes per hour |
α | [°] | Angle | |
S | [m] | Stroke | a | [m.s-2] | Acceleration / deceleration |
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F | [N] | Propelling force |
t | [s] | Deceleration time |
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FP | [N] | Pneumatic drive force |
FG | [N] | Counterforce |