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
|
|
|
|
|
||||||||||||||||||||||||||
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 | |
| me | [kg] | Effective mass | J | [kg.m2] | Moment of interia | |
| v | [m.s-1] | Impact speed | ω | [s-1] | Angular velocity | |
| 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 | |
| F | [N] | Propelling force | t | [s] | Deceleration time | |
| FP | [N] | Pneumatic drive force | FG | [N] | Counterforce |
The calculation procedure is available for download.