Abstract
Primarily in use at present is the nozzle flapper type servo valve providing with a torque motor.
It is not in all cases appropriate for construction machines requiring large flow, owing to small control flow of the nozzle flapper.
To deal with this situation, the linear motor servo valve using a magnet for a proportional solenoid has been developed.
By driving metering spool directly by a linear motor, neutral leak is kept small and control flow increases.
This valve operates independently of supply pressure fluctuation, i.e, pressure compensating characteristics.
For large stroke of the linear motor, the orifice diameter is large, thus greatly lessening the possibility of contamination failure of the valve.
Frequency response of the main spool is as much as 70Hz.
This valve is thus shown suitable for construction machines.
