HAWE Hydraulics is exhibiting at IMTS in Chicago, IL Sept. 8th-13th – booth 4930.
The company will display a wide range of products, some of which are exceptionally well suited for CNC lathes. In this particular application, the unit’s constant delivery pump is powered by a three-phase motor and frequency converter. Radial piston pumps or gear type pumps are available for constant delivery use and provide maximum volume flows of 20 l/min. The main advantage of a constant delivery pump is the availability to adapt a variety of different work piece options and hydraulic units – all while maintaining a constant supply of clamping pressure.
The frequency converter (commonly known as a VFD, variable frequency drive) has its own advantages, like enabling energy-efficient operations by pairing a HK compact, hydraulic power pack with a NSMD clamping module. This ensures a constant volume flow, which compensates for leakage losses at the rotary transfer joint of the chuck. In addition to energy savings, the frequency converter matches the speed of the motor to the volume flow requirements of the hydraulic unit. A pressure sensor measures the system’s pressure and the signal is processed in the frequency converter. The rapid reaction time of the control loop prevents pressure drops and peaks when the volume flow requirement changes.
The NSMD clamping module sets and monitors the clamping pressure through an integrated switch; it transmits proportional signals from the machine’s control system to the valve’s proportional solenoid. It not only measures whether the clamping pressure is correct but also evaluates whether the clamping process is complete. This means the release signal can be used directly for starting the machine; eliminating the need for a pause to ensure the clamping motion is completed.
Although the NSMD clamping module is preferable due to its ability to increase efficiencies, the lathe can operate without the clamping module if the work piece clamping device is the only hydraulic unit being supplied by the power pack. The clamping pressure can then be set directly via the motor speed. Pressure and volume flows are optimally adapted to consumption requirements, guaranteeing the right amount of pressure is supplied at the right time.