Multi-stage active suspension actuator

A suspension actuator comprising:

• a first mount configured for connection to a sprung mass of a vehicle;
• a second mount configured for connection to an unsprung mass of the vehicle;
• a first ball screw actuator for selectively applying a first output force between the first mount and the second mount;
• and
• a second ball screw actuator for selectively applying a second output force between the first mount and the second mount in parallel to the first ball screw actuator, wherein the second ball screw actuator is configured to produce the second output force with less power than the first ball screw actuator to produce the first output force.

A suspension actuator comprising:

• an upper mount connectable to a sprung mass of a vehicle;
• a lower mount connectable to an unsprung mass of the vehicle;
• a first ball screw actuator forming a first load path between the upper mount and the lower mount;
• a second ball screw actuator forming a second load path in parallel with the first load path between the upper mount and the lower mount;
• a spring, wherein the second ball screw actuator acts in series with the spring between the upper mount and the lower mount;
• a spring seat that presses against the spring, wherein the second ball screw actuator is configured to move the spring seat axially to apply force via the spring between the upper mount and the lower mount;
• and
• an annular body connected to the upper mount to move therewith and a shaft connected to the lower mount to move therewith,
• wherein the first ball screw actuator is connected between the annular body and the shaft and configured to axially move the shaft relative to the annular body, and
• wherein the first ball screw actuator and the second ball screw actuator are coaxial.