Cross Roller and Ball Rail Load Calculations

LOAD DEFINITIONS

The load ratings are based on each roller/ball bearing element. When calculating actual rating, the number of rolling elements must be determined.

Roller/Ball Bearing Capacity The max usable load per rolling element.

Basic Dynamic Load Used when calculating life for each rolling element. Based on 50Km of travel.

Basic Static Load Rating Maximum impact load prior to causing permanent deformation for each rolling element.

STROKE AND ROLLER ⁄ BALL QUANTITY CALCULATIONS

When selecting Cross Roller or Ball Rails, several considerations must be made:

  • Stoke Length
  • Quantity of rolling elements (Roller or Ball)
  • Accuracy
  • Load capacity

Calculation of retainer length and roller quantity
The number of rolling elements is dependent on the retainer length. To calculate the number of rolling elements you must first calculate the retainer length. Retainer Length is the length of engagement between both side of the rail when fully extended.

Calculating the retainer length





Calculating the number of rolling elements



CROSS ROLLER / BALL RAIL ASSEMBLY LOAD CALCULATIONS

Calculating Cross Roller / Ball Rail assembly load rating



Selecting the correct travel length

When selecting the appropriate rail assembly, the expected travel should be 80% of catalog Max Travel.



LIFE CALCULATION

Basic dynamic load rating is based on 50km of travel. Use the formulas below to calculate equivalent life in given applications.




APPLICATION EXAMPLE

When using cross roller side by side, which specification should be chosen?


Specification......GRV04
Loading.............P = 4000N
Stroke length.....SW = 120mm




LOAD CAPACITY & LOADING DIRECTION SAFETY FACTOR













Figure 1