Flow Divider
A flow divider is the element that splits the flow of a single pump among two or more actuators at a defined ratio. In spool type dividers the sharing accuracy is typically 5-10%, and in gear motor type it is higher. It keeps motions advancing together even when the loads are not equal.
Without a divider, of two actuators connected in parallel the lighter one takes all the flow and the heavier one does not move at all. The divider breaks this natural tendency.
- Spool type: two orifices and a spool sliding between them; it preserves the ratio by balancing the pressure differential. It is cheap and compact.
- Gear motor type: two mechanically coupled hydraulic motors; the sharing ratio comes from the geometry and depends very little on load.
- Combining direction: most dividers also work as combiners in the reverse direction.
In practice the place it is most often encountered is platform and outrigger systems lifted by two cylinders; they need to stay synchronized. Small sharing errors are cumulative, so in some systems the cylinders are driven to a stop at the end of each stroke to renew synchronization.
In electronic lever control, knowing this behavior sets the expectation correctly: if a single lever drives two cylinders, the small speed difference between them does not come from the remote control but from the hydraulic sharing tolerance.
Where this term is used: The Importance of Hydraulic Control: Why Should It Be Commanded by an Electronic Signal?