Static Safety Factor
The basic static load rating C0 refers to the static load with constant direction and magnitude, under which the calculated contact stress in the center of the contact area between the roller and the raceway under the maximum load is 4000 MPa. (If the contact stress exceeds this level, it will affectthe rotation.) This value is indicated as "C0" in the specification tables. When a load is statically or dynamically applied, it is necessary to consider the static safety factor as shown below.
| fS | Static safety factor (see Table3 ) |
|---|---|
| C0 | Basic static load rating (N) |
| P0 | Static equivalent radial load (N) |
Table3 Static Safety Factor (fs)
| Load conditions | Lower limit of fs |
|---|---|
| Normal load | 1 to 2 |
| Impact load | 2 to 3 |
- * Target minimum values for the static safety factor are shown in the table above. For better service life and other aspects of dynamic performance, THK recommends maintaining a figure of 7 or above.
Static Equivalent Radial Load P0
The static equivalent radial load of the Cross-Roller Ring is obtained from the following equation.
| P0 | Dynamic equivalent radial load (N) |
|---|---|
| Fr | Radial load (N) |
| Fa | Axial load (N) |
| M | Moment (N･mm) |
| X0 | Static radial factor (X0=1) |
| Y0 | Static axial factor (Y0=0.44) |
| dp | Roller pitch circle diameter (mm) |
