Twenty-two-year-old hydraulic power unit replaced to enhance efficiency and reliability

04 July, 2024

The original hydraulic panel with the oil reservoir sunken into a pit in the floor under the unit in the right of the photo.

Due to the nature of the product the factory manufactures, he decided that to protect the new HPU as much as possible, an enclosed cabinet would be required and that if the cabinet was positively pressurised then it would help keep the product dust getting in the system and another major concern was the amount of product literally everywhere in the plant so he decided that to get the clean air the cabinet needed both for pressurisation and for the general HPU function that outside ducting would also be required.

The design started to develop and after many hours of research, reading old datasheets scoured from all over the internet and the back of a lever arch file and then cross referencing the functionality between old parts and possible new alternatives, a new hydraulic circuit was drawn up using Pressure Hydraulic & Controls’ HyDraw CAD software along with a parts list that would meet the customers’ requirements including the various fan controls and sensors to keep the cabinet pressurised @ 15pa (which is around the same level as a hospital operating theatre). Now that the company had a circuit to work from, the CAD work could start using its full Solidworks Premium design package. Some of the challenges of the design included making everything fit inside the restricted size of the cabinet and still be accessible for servicing and having any sensors visible without having to open the cabinet door to stop the product residue getting in. Pressure Hydraulic & Controls’ designer took the approach very similar to an industrial freezer utilising a door seal and handles commonly used in that sector to keep the unit pressurised and even added bonded seals and acorn nuts to every external fixing through the outside of the cabinet to ensure it stays sealed and the only way for air to get in or out is through the fans.

Once a complete set of drawings were produced along with various 3D renders of what the unit would look like they were presented to the customer for their approval along with the new hydraulic circuit. Once the drawings were approved, manufacturing and parts ordering began and despite various delays on parts and a sensor screen damaged in transit from the USA, the new HPU was built in the company’s Liverpool facility and successfully completed factory acceptance testing mid-May 2024 and is currently being prepared to ship to site for installation

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