A clamping module a compact power pack type for machining centers

At first, it was just an idea

Carlo Fortis –

At first, it was just an idea: to create a tailor-made hydraulic solution for any application requirement. The material? Steel.

Munich, 1949. Karl Heilmeier, an engineer, and Wilhelm Weinlein, a merchant, founded the company “Heilmeier und Weinlein, Fabrik für Oelhydraulik GmbH & Co. KG”. Their idea: to create a tailor-made hydraulic solution for any application requirement. The material? Steel.

The little factory has become one of the leading manufacturers in the hydraulics industry, better known under the brand name “Hawe Hydraulik”. The company currently has about 2,100 employees working in Germany and at sales locations throughout the world. Our network now consists of five sales offices in Germany and 14 subsidiaries in Europe, America and the Asia-Pacific region.

Now the Germany company presents two new solutions in the field:

the new NSMD clamping module;

the compact power pack type KA for machining centers.

Clamping module type NSMD: the clamping pressure can be reduced down to 3 bar.

Secure clamping for any workpiece, from delicate to massive

The type NSMD clamping module from Hawe Hydraulik, maintains and monitors workpiece clamping pressure. The minimum possible clamping pressure has now been brought down to 3 bar, so thin-walled tubes in delicate workpieces can be machined just as safely as massive workpieces that need clamping pressures as high as 50 bar. That eliminates the effort and expense of providing a differential clamping pressure with a second clamping module on the opposite side of the clamping cylinder when working at low clamping pressures.

Pressure is adjusted with a proportional valve, using a preset signal from the control. There is no need to control clamping pressure by having the machine’s control system perform complicated analyses of analog signals. Instead, the adjustment of the pressure reducing valve is tracked and output as a digital signal. The clamping module also controls the volume flow, thus preventing the workpiece from being released from machining prematurely. As a protective device in the event of power failures, Hawe Hydraulik includes a mechanical lock for the pressure reducer setting. It ensures that the set pressure is maintained even without a power supply.

Hydraulic start-stop automatism for machining centers

The compact power pack type KA from Hawe Hydraulik supplies the hydraulic consumers in machining centers with pressurized oil. It takes up little installation space and is notable for its low power consumption.

The compact power pack type KA; the fluid level gauge (at the front) enables the oil level to be checked in operation.

Its compact form is the result of its oil-submerged construction. Pump and motor are situated submerged in oil in the casing which doubles as the tank. In its smallest version the power pack is just about the size of a shoebox. This means that it can be easily integrated in any machine housing, helped by the fact that it can be installed vertically or horizontally. The minimum filling volume is 1.5 liters, with tank extensions available up to 9 liters.

Depending on the requirement, a radial piston pump for an operating pressure up to max. 700 bar or a gear pump for max. 200 bar is used. A dual-stage system with a combination of both types of pump improves energy efficiency since it considerably reduces the power rating of the unit. In this case the pumps enable a large volume flow at low pressure and operate at high pressure with a reduced volume flow. The maximum volume flow is 22 l/min.

Since the hydraulic fluid dissipates heat more effectively than air, a motor can be used with lower nominal power and smaller dimensions than usual. Consequently a nominal motor power of as little as 1.4 kW is adequate even for the largest version of the power pack. The power pack was developed for short-time and intermittent service. It is particularly power-efficient when used in intermittent service in combination with zero-leakage seated valves from HAWE Hydraulik and a hydraulic accumulator. In this operating mode the power pack charges the accumulator up to a set pressure and then switches off. The consumers are supplied via the stored volume. The power pack does not start up again until the pressure has dropped below a lower value and recharges the accumulator. While the power pack is at a standstill, which can make up as much as 90% of the operating time of a machining center, it does not consume any energy whatsoever.

With connection blocks and valve banks from the modular system, the power pack can be transformed simply into a complete system control.