Initial situation

In mechanical engineering and e-mobility, metallic materials dominate the rotating components of drivetrains. This is due to many years of experience in the design and manufacture of high-precision, rotating metal components.

In principle, FRP, especially CFRP, is suitable for drive shafts and FRP is indispensable for high-speed sleeves in electric drives and pumps, where precision is decisive for the performance and resource efficiency of the units. CFRP in particular is predestined for these applications due to its low density combined with high rigidity and strength as well as adjustable minimal thermal expansion.

A major obstacle to the use of FRP in general is the lack of maturity of manufacturing processes to achieve the required tolerances for high-precision components such as the hollow shank taper interface (concentricity; axial run-out < 0.002 mm). The production of tubular FRP base bodies and semi-finished products using the winding process is the industrial standard. However, these generally do not achieve the required tolerances.

While high-precision grinding processes for post-processing suitable for series production exist for metallic components, there is a lack of established grinding technology for FRP and CFRP in particular.

Objective

The aim of the project is to create the prerequisites for grinding processes suitable for series production of high-precision FRP components in order to enable the broad industrial application of FRP in resource-saving drive components (mechanical engineering, automotive, aviation). The entire production process chain (production simulation, semi-finished product production, grinding processes) and the utilization phase of the manufactured FRP components will be examined using various test benches and scenarios as well as demonstrator applications.

The project aims to achieve the following objectives:

• Production of FRP components with high-precision functional surfaces (shafts, reinforcement sleeves)
• Development of FRP-compatible grinding technology (clamping of long winding tubes and sleeves sleeves of different radial stiffnesses, grinding tool, process parameters) to achieve dimensional/form tolerances and surface roughness in the range of the fiber diameter on inner, outer and flat surfaces
• Grinding process-compatible component design with laminate optimization based on the production parameters
• Testing and measuring technologies and corresponding hardware to ensure the required component properties (wear, speed resistance, etc.)
• Design recommendation for FKV-compatible precision grinding machines (clamping device, filtering or extraction, cooling lubricants, avoidance of electrochemical corrosion)
• Technology demonstration on high-performance components, e.g. CFRP motor spindle, CFRP bandages
• Tribological examination

Procedure

As an application case, the project aims to manufacture components of electric drives and motor spindles made of CFRP, whose tolerance requirements and functional requirements, e.g. for stiffness and strength as well as wear resistance, are particularly high.

In order to investigate the behavior of the components under operating conditions and to validate the influence of manufacturing quality, a test bench for the metrological investigation of CFRP motor spindle components is being developed and put into operation. The behavior of the CFRP components in relation to the bearing forces is of particular importance here.

Funding source

Consortium partners