Slow STICK IN - No Regeneration

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Slow STICK IN - No Regeneration

Depending on the position of the stick, for a slow STICK IN, regeneration may not be required due to the supply oil from the pump being able to fill and pressurize the head end of the stick cylinder to force the stick in.

For a slow STICKINthe pilot signal is reduced and will only partially shift the stick 1 spool. The stick 2 control valve may or may not shift.

Pilot oil shifts the regeneration valve down, which allows return oil to be sensed at the check valve.

The regeneration valve also allows pump supply oil pressure to be sensed at the unloading valve. The unloading valve does not shift due to the supply oil pressure being below the setting of the unloading valve spring.

Areduced NFCsignal is sensed at the idlerpump, and the pump upstrokes to provide flow.

Most of the supply oil from the idlerpump is directed to the stick cylinder head end through the stick 1 control spool.

Return oil from the rod end flows to the drift reduction valve. The lock check valve in the drift reduction valve is unseated and return oil flows back to the tank through the stick 1 control valve.

Even though the return oil is restricted through the stick 1 control spool, the back pressure created is insufficient to cause the return oil pressure to be above the supply pressure. The check valve remains seated.