Steer-by-wire road wheel actuator ball screw anti-rotation mechanism

A steering system for a vehicle, comprising:

• a rack moveable in an axial direction;
• an anti-rotation device disposed about an outer surface of the rack, the anti-rotation device comprising;
• a yoke having a bearing journal extending therefrom, the yoke having a through bore bounded by an inner clamp surface and the rack extends through the through bore with the inner clamp surface being brought into clamped, fixed engagement with the rack to prevent relative movement between the yoke and the rack, wherein the yoke includes a split to allow for enough deflection to clamp the yoke on the outer surface of the rack, and wherein the yoke is located on the rack with a pinch bolt providing clamp force;
• a first bearing pressed onto the bearing journal;
• a second bearing pressed onto the bearing journal;
• and
• a running surface in a rack housing, the running surface extending in a longitudinal direction of the rack, the running surface having a first side and a second side opposite the first side, wherein the first side and the second side are generally parallel, wherein the first side and the second side are flat, wherein the distance between the first side and the second side is slightly larger than an outer diameter of an outer ring of the first bearing and an outer diameter of an outer ring of the second bearing, wherein the outer ring of the first bearing has a spherical profile in order to make a point contact on the first side and the outer ring of the second bearing has a spherical profile in order to make a point contact on the second side, wherein the first bearing is positioned to contact and move along the first side of the running surface and the second bearing is positioned to contact and move along the second side of the running surface during operation.

A steering system for a vehicle, comprising:

• a rack moveable in an axial direction;
• an anti-rotation device disposed about an outer surface of the rack, the anti-rotation device comprising;
• a yoke having a bearing journal extending therefrom, the yoke having a through bore bounded by an inner clamp surface and the rack extends through the through bore with the inner clamp surface being brought into clamped, fixed engagement with the rack to prevent relative movement between the yoke and the rack, wherein the yoke includes a split to allow for enough deflection to clamp the yoke on the outer surface of the rack, and wherein the yoke is located on the rack with a pinch bolt providing clamp force;
• a first bearing pressed onto the bearing journal;
• a second bearing pressed onto the bearing journal;
• and
• a pair of running plates comprising a first plate and a second plate at least partially disposed within a rack housing, the running plates extending in a longitudinal direction of the rack, the running plates disposed on opposing sides of the first and second bearing, wherein the first plate has a first inner running plate surface and the second plate has a second inner running plate surface, wherein the first inner running plate surface and the second inner running plate surface are flat, wherein the distance between the first inner running plate surface and the second inner running plate surface is slightly larger than an outer diameter of an outer ring of the first bearing and an outer diameter of an outer ring of the second bearing, wherein the outer ring of the first bearing has a spherical profile in order to make a point contact on the first inner running plate surface and the outer ring of the second bearing has a spherical profile in order to make a point contact on the second inner running plate surface, wherein the first bearing is positioned to contact and move along the first plate and the second bearing is positioned to contact and move along the second plate during operation.