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12/23/2005 | Newly patented: Telescopic screw drive with direct drive for installation in confined spaces

WOOD DALE, IL - The Danaher Motion Group has developed an innovative solution for installation in confined spaces where a relatively long stroke is required: the Direct Drive Telescope – or DDT for short. The DDT, which has just recently been patented, combines the full hydraulic cylinder operation with the advantages of an electrical direct drive. In addition to shallow installation with maximum stroke length and torque, it also offers a high dynamic response and easy installation. An extended rotor – part of the patent – picks up the linear movement of the drive spindle smoothly and without play, thus increasing the efficiency and precision of the solution.

At the heart of the patented system are two spindles with diametrically opposed pitch nested in each other, which move in and out telescopically. As a result and thanks to the electrical direct drive, which provides maximum torque in a minimum amount of space, the depth of the Danaher Motion product is only half that of a conventional solution with the same stroke length. In addition, the DDT is very easy to install. As there are no rotating parts to connect to the customer assembly – unlike in conventional solutions – the customer does not need to provide complex bearing assemblies. Installation is also simplified by the integrated multi-turn shaft encoder. This component, which is responsible for positioning the system and feedback for the motor controller, eliminates the need for additional modules to connect the DDT to the control unit. The multi-turn shaft encoder also eliminates the need for homing when starting the machine.

In addition, the Danaher Motion solution also offers a very high dynamic response. As only the outer spindle is rotated, but not the inner spindle, the mass moved is considerably lower when compared to basic spindles with the same stroke length. In this way higher rates of acceleration can be achieved than with conventional solutions. As the mechanical components are also used as internal motor parts, e.g. the rotating part of the telescopic spindle also acts as the motor shaft, this reduces the number of bearing assemblies required to a minimum, increases the level of efficiency and makes the system cost-effective.

The Danaher Motion telescopic screw drive is available with a stroke length of 140 mm and a maximum force of 35 kN. A speed of 0.6 m/s can be achieved, the net service life is around 20,000 hours. Further sizes are planned and under development for customer-specific solutions.

About Danaher Motion
Danaher Motion is a leading global manufacturer of motion control products that improve the efficiency and productivity of complex manufacturing operations. Danaher Motion's product innovations have been revolutionising the motion control industry through trusted brand names including Kollmorgen, Thomson, Dover, Portescap and Pacific Scientific.  Danaher Motion's co-ordinated precision technology is used within a wide range of industrial contexts, including in semiconductors and robotics, aeronautics and medical engineering as well as in the automotive, plastics and packaging industries.
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©    Danaher Motion/Industrie-Contact 2005.
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