NEWS

.: 12/11/2009
Multi-start screw at the Oper theater in Valencia

The renovation of the Oper theater in Valencia involved the construction of four new movable secondary stages. In their construction, they employed screw jacks produced by Servomech.

The movement of theater stages involves some basic requirements such as utmost safety and reliability while in motion, smooth jerk-free motion and very low-noise signature. How to achieve this?
First and foremost is the material selection. The processing and inspection during the various phases of production and the functional test performed at assembly are conducted entirely in-house. This not only allows to achieve a product of high quality content but also a product that is guaranteed to function at installation. The overall quality of the product is reflected in the product performance, its low noise and its high degree of reliability. The results are achieved through the use of multi-start high lead trapezoidal screws. The entire system operates at low input speed, guaranteeing the low overall noise signature of the application.
Servomech engineering examined the installation requirements and proposed a solution, subsequently approved by the customer upon verification of the noise signature of the jacks in operation.

The selection of a 4-starts screw allows the unit to operate at a low input speed and still achieve the desired linear speed. The manufacturing of the 4-start screw as well as the 4-start nut is possible with the manufacturing equipment of Servomech. German made process equipment allows machining of both screw and nut even in multi-start version. This occurs while maintaining the restricted tolerances and surface textures required by the components. The jacks used in this application are provided with complete bellow covers, protection tubes, safety nuts and flanges to connect the screw end to the structure to be moved.

.: 01/12/2009
Trapezoidal screw 12m long in the rocket Ariane 5 assembly

Ariane 5 is a rocket capable of lifting a payload of 6,200 kg in a geo-stationary orbit (GTO). It is 59 m high, has a body diameter of 5.9 m and weighs 777,000 kg (777 Tons). The machining operations of the various rocket stages require the creation of 3 platforms that allow both the lifting and the machining of the stage within the platform itself. Each platform is capable of lifting 50,000 kg (50 Tons), inclusive of its own weight, at a linear speed of 0.5m/min and a stroke of 11 m.

For this application Servomech has supplied MA350 jack type A with 3:32 reduction ratio, acme screw lead pitch 100x16 (Tr 100x16) 12 m long. The screw jacks are fixed on the platforms using a trunnion-mount to allow a single degree of freedom. The screw used is connected to the top mounting structure through a clevis with the axis parallel to the trunnions. The system is suspended with the jacks connected to the moving platform and the screw stationary. A further redundancy is accomplished using a safety nut. Each jack has an actuator feedback to allow synchronous motion using the electric shaft principle. The platform configuration does not allow mechanical connections amongst the jacks thus each jack is individually motorized with a vector drive motor of 7.5 kW.

The 12 m long screws are machined from ground bar by metal removal using a whirling process. This process is performed at Servomech plant using 6-axis CNC equipment produced by a German company.