Trapezoidal screws for barriers on Hydroelectric Power Plant Sava Brod

For the purpose of lifting and lowering the barriers at the hydroelectric power plant (HPP) Sava Brod, we supplied various stainless steel trapezoidal screws TR 60x9, which are custom-made with specific processing. The trapezoidal screws are made of 1.4404 stainless steel (AISI 316 L). Half of the screws have a right-hand thread and the other half have a left-hand thread. For the purpose of lifting and lowering the barriers and mobile walls in hydroelectric power plants, we can also optionally supply trapezoidal screws of TR 55x9 and TR 70x10 size, which can be optionally made of 1.4301 stainless steel (AISI 304) or classic steel C35 or C45.

Trapezoidal screws and nuts are self-locking, which means that they stay in a certain position and do not unscrew themselves. As a result, they act as a safety feature and do not need additional safety brakes. This feature of trapezoidal screws is especially beneficial in the case of lifting and lowering of the hydroelectric power plant's barriers, as it prevents the uncontrolled lowering of the barriers.

In the case of HPP Sava Brod, trapezoidal screws are longer than standard trapezoidal screws, with the longest spindle being 5250 mm long. Upon request, we can also supply even longer trapezoidal screws. The maximum length of a spindle made of one piece is 7500 mm, but we can supply even longer screws made of several pieces.

The mentioned trapezoidal screws were used together with AUMA reducer GK 16.2. Trapezoidal screws are used to convert the rotational motion of the AUMA reducer into a linear movement of the barriers. In addition to the screws, we also arranged the insertion of a suitable trapezoidal thread into the AUMA bronze nuts, which ensures smooth lowering and lifting of the barriers. For optimal performance of the spindle and nut and minimal wear, these are suitably lubricated.

In the hydroelectric power plant Sava Brod, trapezoidal screws TR 60x9 are used for lifting and lowering the sheet piles in front of the valve, for the intake barrier into the canal, for the intake barrier into the turbine chamber and for the outtake barrier from the canal.