Rexroth’s new generation of hydraulic load-holding valves use gravity to help improve energy savings and mobile equipment performance
Rexroth introduces a new concept in load-holding and lowering valves to make mobile equipment more energy efficient and easier to control. Using the force of gravity instead of engine power to help lower a boom, Rexroth’s new “Green Valves” dramatically decrease power requirements, thereby saving fuel and cutting emissions.
Rexroth’s new Green Valves all but eliminate the need for energy consuming high pressure and high oil flow. Engineered to replace traditional counterbalance valves, the patent-pending design allows the use of gravity to help lower the loaded or unloaded boom, while at the same time providing increased stability and control. This results in quicker boom movement and also smoother starting and stopping action. In addition, the Green Valves barely require any oil flow to lower the boom so more oil flow is available for faster execution of other simultaneous movements. This can further shorten machine cycle times for better performance.
By drastically reducing the energy required from the diesel engine to lower the boom, the new load-holding valves can provide significant fuel savings and also help in meeting emission standards. Higher fuel savings result in a more sustainable use of resources, which led to the product name, Green Valves.
The high level of stability and controllability integrated into the valves eliminates the need for damping devices such as orifices, thereby saving costs and also valuable installation space.
Suitable for any type of hydraulic circuit, Rexroth’s Green Valves are compact, easy to install, and interchangeable with current Rexroth counterbalance valves.
I don’t see such a new concept in these valves and honestly I cannot understand how they could have achieved a Patent on it: an equal idea has been patented by Bucher in 2006 (Patent number US 7752842) and if you look at Wessel online catalogue you find an equal solution (for example valve type 427.063.967.9 which you can find here http://www.wessel-hydraulik.de/wessel-hydraulik_englisch/datenblaetter/427.063.967.9.pdf).
Speaking about installation, especially on telehandler machines, they require a completly different system: in fact normally telehandlers are equipped with cross piloted overcenter valves, while this new type of valves needs to be piloted by joysticks pressure and needs an extra connection to tank for drain lines, so basically they need at least 2 extra pipes, and in order to work properly they require a different type of spool in the directional valve: this sound to me a little bit different from ‘easy to install and interchangeable’
I’m a crane operator, The crane I,m operating is a Tadano GR1000XL, I squirt the boom out and in a 2 hr period, it will retract 1 ft, could this be a bad holding valve? How do they work and how do I check them?
Neil Mc