FluidPower.Pro

Tag Archive: Rexroth

Rexroth A4VG clones

Just in case if you need replacement for Rexroth A4VG, it seems to me these guys are brothers:

Rexroth A4VG Parker C-series Dana Brevini S6CV
Rexroth A4VG Parker C-series Dana Brevini S6CV
Available Displacements:
28cc, 40cc, 56cc, 71cc, 90cc, 125cc 55cc, 81cc, 136cc 75cc, 128cc
Nominal pressure:
400 bar (5800 psi) 420 bar (6090 psi) 400 bar (5800 psi)
Input Speed, Continuous:
400 bar (5800 psi) 420 bar (6090 psi) 400 bar (5800 psi)
Available control systems:
HD” Proportional control, hydraulic C” Hydraulic proportional control with internal feedback HIR” Hydraulic proportional with feed-back
EP” Proportional control, electric F” Electric proportional with internal feedback HER” Electric proportional with feed-back
ET” Electric control, direct operated, two pressure reducing valves G” Electric proportional without internal feedback HEN” Electric proportional without feed-back
EZ” Two-point control, electric E” Electric non proportional HE2” Electric on-off
DG” Hydraulic control, direct operated D” Hydraulic proportional control without internal feedback HIN” Hydraulic proportional without feed-back
– – – A” Manual lever HLR” Manual lever with feed-back

Semi-closed hydraulic circuits

Have you ever heard about the semi-closed hydraulic circuit?

The idea is to use open loop pumps in closed loop circuit. In the latest eighties, Mannesmann Rexroth (yes, that time Mannesmann yet!) even offered pumps A4VSH, especially designed for semi-closed circuits.

Bosch Rexroth A4VSH pump

Bosch Rexroth A4VSH pump, from catalog RE92110/01.89

The main difference between closed loop pumps and semi-closed loop pumps was in addition block mounted to the ports A and B with check valves which let to supply suction flow from the tank, while mainstream comes from the motor to pump’s suction port:

Since that time Rexroth still builds A4VSH, but there are a limited number of sizes and options available and its no longer a mainstream published option.

But to make a semi-closed loop you do not need some special pump, it’s really easy to turn most standard open loop pump into a semi-closed loop circuit. Of course, you have to have some knowledge about the application and actuators before trying to apply it. If the pump does not have an integrated boost pump and check valves these are commonly added via an external gear pump and external check valves.

Here is the simplest example of the semi-closed circuit schematic where a regular open loop pump with LS control is involved to run two motors with independent proportional control of their speeds:

Scheme Editor 6.2

The new version 6.2 of Bosch Rexroth Scheme Editor has been released! And now it contains the Hydraulic library, like they promised couple months ago (see my article)!

Download the software you can by this link: http://www.boschrexroth.com/dnc-scheme-editor (78 Mb.)

Free registration is required for downloading. After launching of installing wizard the automatic updating of the previous version will be made. So you do not need to uninstall previous one. And, don’t forget to restart your computer!

After computer restarting it is necessary to import new libraries. So, finally you get 3 libraries:

Scheme Editor 6.2 Libraries

Scheme Editor 6.2 Libraries

Pneumatics library has been updated to ver. 1.2 and new Hydraulics and Electrical libraries have been added to the Symbol Library list.

I quickly checked new hydraulics symbols and found the library a little bit poor.

Hydraulic symbols example

Hydraulics symbols example

For example, I did not find symbols for hydraulic valves pneumatically operated for one of my applications. But a generic schematic can be done with the existing hydraulic library and for other, more complicated systems, you can use wonderful “Symbol Modeling Tool”.

Resume: Bosch Rexroth is moving forward in the right direction and hopefully this software will continue to develop and libraries will be updated with a new symbols, at least with components what BR has in their assortment.