Let the rear spindle rotate in the upright while carrying radial and axial wheel loads.
An SKF 61814-2RZ. The move from the contact-seal 61814-2RS1 to the non-contact 61814-2RZ was a deliberate drag reduction.
No part-specific design process is documented. The Wheel Hubs subsystem design process applies: 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.
70 mm bore, limited by half-shaft tripod geometry rather than by load.
CR22 with the contact-seal 61814-2RS1: pressed drag effort 3.4 lb-ft, calculated power loss at 60 mph 0.8416 hp. CR25 with the non-contact 61814-2RZ: 1.8 lb-ft, 0.4455 hp. Decrease in overall resistance 0.396 hp. CR26I improvements in assembly fitment decreased static friction further, past what the available measuring tools could resolve.
Purchased.
SKF 61814-2RZ, 70 mm bore, non-contact seal.
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.
Weighed mass: 134.0 g (0.295 lb). Source: Subteam weight books: CR25/Suspension/Validation/Component Weight.xlsx Quantity per car, as costed: 4
Nothing in CrimsonStorage covers these yet.