The issue of balance between the secondary oil pressure of the slide valve and the spring force of the throttle valve
Thread Content
This post was last edited by yxmqh on 2009-10-10 14:18. When the secondary oil pressure acting on the spool reaches a new balance with the spring force, the spool returns to its middle position. Question: Since the forces are in balance, the spool should remain stationary at that point of force equilibrium. Then what force causes the spool to return to its central position? ； Does the secondary oil pressure change after the spool returns to the middle position? Confused?
There are posters in the speed control system principle station that explain things very well; take a close look! http://bbs.hcbbs.com/viewthread.php?tid=294189 http://bbs.hcbbs.com/viewthread.php?tid=346378 http://bbs.hcbbs.com/viewthread.php?tid=203287 http://bbs.hcbbs.com/redirect.php?fid=147&tid=214657&goto=nextnewset
The spring force changes under the action of the feedback ramp; as the secondary oil pressure increases, the spool moves upward, the hydraulic cylinder changes, and the change in the feedback ramp exerts a force on the spring, causing the spool to settle at the middle position.
When the secondary oil pressure increases, the spring force changes under the action of the feedback ramp; as the spring force rises, the spool returns to the middle position. The secondary oil pressure and spring force reach another new equilibrium point. (Note: it’s another instance) The secondary oil pressure remains unchanged. By how much has it increased?