S23-12414-0 Denison stroker eléctrico 5C

Denison stroker eléctrico 5C S23124140 27006104 EHS 5C B+B 1/2XP/V WDB A/B Electro Hid Stroker 5C

This control is used on pumps. The rotary servo input shaft is actuated by a hydraulic
spool. A jet pipe is directed to two receiver orifices connecting to opposite ends of the
hydraulic spool. The jet pipe is mechanically centered by a null adjust spring opposed
by a feedback spring linked to spool position. A “voice coil” attached to the jet pipe
creates an unbalance force in proportion to electrical current magnitude and direction.
This causes the jet pipe to offset, increasing pressure on the one receiver and lowering pressure on the other receiver. The hydraulic spool responds causing the feedback
spring to oppose the force, until the jet pipe is again centered at a new position of the
servo.
When servo pressure to the jet pipe is blocked, the rotary servo spring centers, and
may be manually positioned.
One version of the cross center control requires a small signal (deadband) prior to
commencing stroke in either direction. This control contains spring centering pistons
and neutral trimmer adjustment for accurate centering. Another version, (no deadband)
provides linear displacement with input command for accurate servo applications.
In the control cover is contained the brake and bypass valve option. A brake spool,
when energized, connects the brake port to servo pressure. When de-energized, a
spring shifts the spool, connecting the brake port to tank. Another port, located on the
end of the brake valve, is closed by the energizing of the brake spool. When de-energized, this port dumps both pump system ports to the replenishing source, thus
bypassing the small flow generated by slight errors on zero position.
The operation is controlled in this manner: A restricted servo flow is applied to shift
the brake spool. This flow is dumped when a slot in the servo plate aligns with a passage connecting to this spool. This occurs when the pump is on zero stroke. Another
restricted flow is applied to a spool adjacent to the brake spool. This flow is also connected to a passage in one centering piston, containing a ball and seat. When the
control is off center, the ball seats, sealing the passage, to apply servo pressure to the
spool. When the control is on center, a pin extending from the other centering piston
pushes the ball off the seat, to dump the flow,
The brake spool is thus de-energized to set the brake when BOTH the pump cam is at
zero stroke and the rotary servo is at zero command. If the pump is on stroke or the
input is on stroke, the brake spool is energized, releasing the brake.