hydraulic actuator-mechanical synchronization 2

[lax0o7]

I am currently doing one project on hydraulic actuator synchronization using mechanical coupling( rigid coupling) as part of my internship. it is cost effective, don't have any complicated controls. just pump the fluid. since it is rigid and the mass is centralized the volume and pressure should be equal to both actuators.

This is the basic structure -->

when I was doing my research, I came across so many models which using other techniques like servo valves, but I hardly saw anything about the mechanical coupling., What are the disadvantages of this system?

PS- the connection is rigid, the weight is centralized, might have slight leakage (assuming, since it is for practical use).

 

[HPost]

2 or more cylinders or motors that have a mechanically rigid connection will not need a flow divider or flow sharing capability. With a common flow supply, the principle of fluid dynamics dictates that the cylinders / motor will move at the same speed as the load is evenly distributed.

Where the cylinders / motors move independent loads - or see different pressures, then a method of synchronizing is required.

Depending on the level of synchronicity required, this can be achieved by a flow divider or closed loop control. If the level of speed and position control needs to be highly accurate and highly dynamic, then servo valves are employed with a very high level of PID control.

 

[3DDave]

The reason it doesn't happen often is that making the structure sufficiently rigid is usually more difficult than adding synchronizers.

The time I recall seeing it done, the cylinders were very close together to minimize load differences and were only paired due to space limitations that precluded a larger diameter single cylinder, which would have been the primary choice - capacity goes up as the square of the diameter, so a 40% larger size = 2 cylinders, with less plumbing, less chance for leaks, et al.