Encountered at EMO, Daniel Dünner, Director of Walter Dünner SA Moutier (Switzerland) showed us a new system designed to replace a complete hydraulic group. This innovation is launched jointly with a new hydraulic actuating cylinder and an automatic clamping system for jaws. These novelties present true benefits both in terms of precision and of environmental respect.
How does it work?
The pressure multiplier is a simple device that uses pneumatic to generate hydraulic power. This small device replaces a “large” hydraulic group and compared to this last, request a very reduced floor space. Air pressure is applied on a closed circuit of oil and once the level of pressure needed is reached, the valve is closed and oil remains under pressure. This avoids having a large amount of oil still maintained under pressure and drastically reduces the risk of heating.
The multiplier benefits
Not having to feed a circuit of oil “permanently running”, the quantity of oil is very small as well as energy consumption. These benefits are added to an investment very different than the price of a complete hydraulic group. In the case of the mere replacing of a pump on a standard hydraulic group (for example), to consider a multiplier is already relevant. For a price slightly higher than a pump we can use a system with significant benefits.
Even if it is not common, in the case of an accident, the quantity of oil that can spread is very limited (a few liters) compared to the case of the same even occurring to a group who can reach 20 or more liters.
And what is the actuating cylinder
The actuating cylinder is complementary to the multiplier. Working in closed circuit, there is no loss of oil. In the case of sensitive production like in the medical field, this is a great advantage. The heat produced by a classical solution induces consequences on accuracy of the means of production. This problem simply doesn’t exist with the “multiplier-actuating cylinder” combination.
Many machines have a clamping that uses jaws, the presented solution is likely to automate and ensure the strength of the clamping. Contrarily to pneumatic clamping systems always facing clamping loss due to centrifugal force, the closed-circuit hydraulic system uses the incompressibility of oil to ensure a constant tightening. Dünner offers two solutions, either the installation on a lathe already equipped with hydraulic, or the completely new set up on manual clamping systems.
To see ahead…
Specializing in “small and precise”, Dünner expands its traditional product range with these devices rather dedicated to larger diameters. M. Dünner tells us: “With our LongStar collets, we already have a certain experience for larger diameters systems. The Pneumadraulic® solution presented today is an ideal complement to our portofolio”. He adds: “Users are looking for ways to maintain the quality of their productions while minimizing space and energy used for clamping. This can be seen in the use of the three positions guide bush in small diameters. In the large diameters, there was no real alternative until today. We have filled this gap”!
A few characteristics
- Maximum pressure: 45 bars
- Max speed: 9’500 min-1 (diam. 37 mm) to 4’000 min-1 (diam. 127 mm)
- Max clamping force: 30 KN (diam. 37 mm) at 141 KN (diam. 127 mm)
Do you need more information? You can download the brochure here.