PreLoad

Preload of a spool using ElastoGap models

Diagram

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

When designing hydraulic valves it is often necessary to hold the spool in a certain position as long as an external force is below a threshold value. If this force exceeds the threshold value a linear relation between force and position is desired. There are designs that need only one spring to accomplish this task. Using the ElastoGap elements this design can be modelled easily. Drawing of spool.

Preload 1
Preload 3
Preload 4

Simulate for 100 s and plot the spool position spool.s as a function of working force force.f. For positive force, the spool moves in positive direction - in figure below the start value spool.s.start influences the offset.

Preload 2

Components (17)

innerContactA

Type: ElastoGap

innerContactB

Type: ElastoGap

spool

Type: Mass

fixedLe

Type: Fixed

springPlateA

Type: Mass

springPlateB

Type: Mass

spring

Type: Spring

outerContactA

Type: ElastoGap

outerContactB

Type: ElastoGap

rod1

Type: Rod

friction

Type: Damper

force

Type: Force

housing

Type: Rod

rod3

Type: Rod

rod4

Type: Rod

rod2

Type: Rod

sineForce

Type: Sine