Crimson Racing Wiki

Rear Upright Assembly

Subteam: SuspensionSubsystem: Wheel HubsAssembly: Rear Upright AssemblyCars: CR21, CR22, CR25, CR26I, CR26E

Purpose

Assembly line covering the rear corner structure.

Function

Groups the rear upright, top mount, camber shims and bearing spacer. Design Philosophies and Processes: Inherited from the Wheel Hubs subsystem design process: 1. Take wheel loads from the cornering, braking and combined load cases. 2. Size the spindle shaft for fatigue at the worst case, then size up to an appropriate bearing and remove as much inner material as possible. 3. Select bearings on required bore, spacing and its effect on moment reaction, static load rating against worst-case load, dynamic load rating against average load and expected life, and then the lightest and smallest option that fits. 4. Design the upright to connect the geometry points, sizing every hole and tab. 5. Analyse. Wheel load applied as a remote load from the contact patch to the bearing faces; lower ball joint and tie rod mount bolt faces react lateral and longitudinal motion; upper ball joint reacts all translation; brake caliper bolt faces take a moment reaction for braking. Global element size 0.045 in, second-order wedge elements. 6. Cross-check with the full-corner model, then state the resulting compliance. CR26I effective angular deformation of the corner in cornering is 0.32 degrees of camber change, including spindle, bearings, upright, tie rod mount and top mount.

Reoccuring issues

None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.

Properties

Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. CR26I_RearUpright_Assembly (mm): 144.70, 14.47, 42.77, 4.28, 19.45, 194.50, 8.40, 84.00, 90.009.00 Source: Cost report drawings: CR26i/Suspension/Competition/Cost Report Drawings/Suspension and Shocks/Rear Upright Assembly/CR26I_RearUpright_Assembly.pdf

Still to document

Nothing in CrimsonStorage covers these yet.