The Project HIGHPSLEEVE aimed to find out a way to produce a fixation component for an electrical motor, which turns at 50.000 RPM and works in -50 to 250ºC, of an aircraft by using composites materials with high Tg, such as BMI or Cyanate ester, reinforced with carbon fibres. Production method need to be researched but Filament Winding seems to be the right candidate process. In particular the design and manufacturing of sleeve component was targeted. The project looked for a cost-effective way of producing these fixation components in these composites material while ensuring to withstand with requirements. The aim was to get a cost effective way of manufacturing.
The objective of the project HIGHPSLEEVE was to develop an innovative rotating composite sleeve to be assembled in an electrical motor by Topic Manager.
Reducing specific fuel consumption is a real challenge for future aircrafts. This can be achieved by means of increasing the performance of different systems, such as electrical motors and the associated weight reduction.
The performance improvement means to increase the rotational speed of electrical motors to diminish the dimensions for a given power but has a drawback which is the limitation in using metal sleeve to keep the permanent magnets in place.
The need for a composite sleeve also could help in the second goal which is weight reduction, but this will depend on other constraints such as working speed and assembly needs.
The aim of the project was to study and manufacture a specific sleeve of an electrical machine with some of the following characteristics:
- To meet a specific air gap condition;
- To meet tolerances expected for the fixation’s thickness;
- Uses of metal parts on the sleeve must be reduced, but this will depend on the specific electrical machine on which the sleeve will be assembled (in example: permanent magnet or salient poles rotor);
- Tithing to the rotor has to be done by the fixation itself in case of permanent magnet or with an assembly system in case of salient poles rotor;
- Pressure of fixation on magnet, for rotating speeds of 50.000 rpm, has to be in range of beyond 100 MPa, for -50 to 250 ºC;
- Also similar values of pressure and temperature range but speed of 30.000 rpm will be looked for salient pole rotors.
Also, the attachment of the sleeve to the electrical engine was studied. Finally, some prototypes were manufactured and tested.
To achieve these goals, the HIGHPSLEEVE project addressed through the different work packages in which the project is divided, the following main activities:
- Review of requirement received from Topic Manager = WP1
- Manufacturing process selection = WP1
- Material selection = WP1
- Definition of a text matrix to obtain material properties for design = WP1
- Testing of material = WP1
- Detailed design of the sleeve = WP1
- Detailed design of assembly system = WP1
- Manufacturing of prototypes sleeve in a first run manufacturing trials = WP2
- Testing of sleeve of first run = WP2
- Manufacturing of sleeves in a second run = WP2
- Testing on speed test bench = WP2
- Conclusions of the feasibility = WP2
In the provision of the requirement document the Topic Manager needed to better focus sleeve feasibility in four different cases, two dedicated to a salient poles rotor and two dedicated to a Excitatrice rotor, rather than the one proposed at the call which was one case of permanent magnet rotor.
This new interest made the project address different manufacturing processes than initially foreseen for a permanent magnet sleeve.
Also the need to design four different cases in parallel vs one foreseen for the initial interest has made the design phase longer than expected, also due to this new development needed a more complex assembly solution which will include an assembly fixture to achieve the sleeve onto the rotor.