Zeus Hydratech were approached by a major Aerospace manufacturer in the Southwest of the UK to design and manufacture a Hydraulic Power Unit (HPU) to replace an existing system that had become unreliable and was suffering with a severe deterioration in performance. Furthermore, due to the age of the existing power unit, components were obsolete making it virtually impossible to effectively service the unit.

With a requirement for precise control, the quenching press had developed issues with pressure loss, jerky movement, and overheating. This press is responsible for mating two precise gear sections on to a rotor shaft, these components are then quenched in a temperature-controlled environment.

Typically, failure to successfully complete the full duty cycle will result in critical components loosing up to 0.1mm from the finished shaft surface. Consistent tolerances for these critical components are vital to meet manufacturing build schedules and to avoid excess wastage.

THE BRIEF

To design and manufacture a Hydraulic Power Unit that will interface with the existing hydraulic press connections (Electrical and hydraulic) It must also be capable of delivering consistently smooth and reliable operational performance, be easy to maintain and provide visual feedback to the machine operator.

The following parameters required consideration within the design:

1: The existing control logic was to be retained, therefore all solenoid valves needed to be carefully specified to allow direct integration and permit a seamless control transition.

2: The operating fluid is a specialist fire safe fluid which meant components needed to be carefully selected to prevent adverse performance. In addition, a stainless steel oil reservoir would be required as there was evidence of paint deteriation on the existing reservoir.

THE APPROACH

The existing hydraulic power unit (certainly when new) provided sufficient performance for the hydraulic press however, after reviewing the hydraulic schematic and components, the Zeus engineers felt we could provide a more elegant solution that would provide smoother operation, reduce potential leak points, and give additional operator feedback.

After running all relevant performance calculations for each of the components, our design team was able to commence with the overall design of the power unit. Utilising Solidworks software (CAD) we started with the fixed points of the existing press connections (namely the 13 hydraulic pipe connections) to insure the finished power pack would seamlessly interface within the available space and existing connections. From this point, the overall power pack model was designed to incorporate all required features. While designing the power pack, we gave high priority to future servicing and accessibility. In additional, we specified high quality filtration systems to safeguard the complete hydraulic press and significantly prolong the power pack operational life.

In addition to the HPU performance, we also wanted to consider site installation, so designed the power unit to accept a forklift and pump truck to permit easy installation on site and accurately position the unit without the need for an overhead crane.

Below: CAD design completed by Zeus Hydratech prior to manufacture

THE RESULTS

Following the initial design process, the manufacturing aspect of the new hydraulic power pack was completed within the quoted 12 weeks from design sign off. The new power pack now features individual, large pressure gauges installed at operator eye level (previously a single gauge with selector switch was utilised which made it difficult for the operator to have a clear handle on the complete system performance)

Utilising a variable displacement, pressure compensating vane pump coupled to a high efficiency electric motor (installed on anti-vibration mounts) means the new power pack will deliver incredibly efficient and low noise performance. The hand built 304 grade stainless steel oil reservoir eliminates any concern over adverse reactions with paint (as per the original), therefore removing the risk of introducing contamination to the system.

The complete hydraulic power unit is now set to give many years of efficient and reliable service within the client’s facility.

Below: Completed power pack following FAT (Factory Acceptance Test) at Hydratech HQ

Rob Waygood | Contract manager, Hidrostal commented.

“Zeus Hydratech have been instrumental in the provision of vital hydraulic engineering goods and services over the past couple of years.

The company provides us with a rapid, comprehensive, and proactive support package. Recently, Zeus have been manufacturing a bespoke hydraulic pack as part of an ongoing plant improvement initiative. The experience has been excellent and pain free with regular detailed updates.

I highly recommend Zeus Hydratech if you’re interested in top quality products/ services and superb customer service"

UK Helicopter Manufacturer - Hydraulic Power Pack project