Recently, we received a request from a wind turbine equipment manufacturer. To expedite the tightening and installation of the connecting bolts on the main shaft planetary carrier, the client plans to use multiple tensioning heads for simultaneous tensioning—initially planning for six heads. We are now seeking a reasonable design solution from WREN.

Taking into account various factors such as bolt specifications, workspace constraints, ease of operation, and safety, WREN technicians designed this 6-bolt synchronous automatic tensioning system. The system operates as follows: the tensioners first apply tension synchronously, followed by the wrenches tightening the bolts in unison. This process is controlled by an intelligent pump station to ensure uniform tensioning and synchronized tightening.

When performing tensioning operations with the HTE series hydraulic bolt tensioners: Due to the narrow bolt spacing, models with a smaller outer diameter are used; to ensure portability, the tensioner should not be too heavy; to prevent the tensioner from flying out, anti-ejection nuts are installed on both sides, which engage with the studs on either side of the tensioner during operation; this tensioner features over-travel protection and an automatic reset function.

In addition, to achieve synchronized tightening, the gearbox section of the tensioner—which was previously tightened manually—has been redesigned as a hollow wrench. This design meets higher torque requirements while minimizing loss due to tension rebound. High-strength support components on both sides of the hollow wrench prevent damage to the mating surfaces. A sensor inside the wrench automatically stops the tightening process once the desired torque is reached.

Matching Smart Hydraulic Power Unit: Equipped with two pumps to power the stretcher and wrench; a distributor for the wrench is located at the top of the power unit, while the stretchers are connected in series. This smart power unit features data monitoring, visualization, and storage capabilities, enabling real-time monitoring and visualization of data such as pressure and tensile force during operation. After each operation, the data from every stretch is automatically stored and can be retrieved or exported for traceability and analysis. Other basic functions: Automatic pressure compensation, pressure curves, and fault alerts are all included.

WREN engineers offer a full range of customized services. We carry a comprehensive selection of hydraulic bolt tightening equipment—including hydraulic wrenches, hydraulic pumps, and tensioners—ranging from standard to specialized models. If you have any needs, please feel free to contact us!