Need help with hydraulic pre rotator

[Brent Drake]

I'm having trouble coming up with a switch to turn on and off the hydraulics to a hydraulic engine starter. It needs to switch on with enough power to push up the Bendix without fast rotation of the starter. Then over 30 second period of time, graduate to max RPM.

 

[RayPierce]

hydraulic "potentiometer"?

hydraulic "potentiometer"?

I'm having trouble coming up with a switch to turn on and off the hydraulics to a hydraulic engine starter. It needs to switch on with enough power to push up the Bendix without fast rotation of the starter. Then over 30 second period of time, graduate to max RPM.

Perhaps a hand operated (or remotely) variable relief valve that bypasses the motor? A hydraulic "potentiometer" if you will. MOOG used to make 4-20ma valves to control speeds of hydraulic motors.

https://www.moog.com/products/servovalves-servo-proportional-valves.html

 

[Barry M14]

Hi Brent
I might be able to help but not on line Give me a call at 413 244-5946 and we can talk about it . it will take me all day if I had to type it out. Barry