An electric suspension apparatus includes electric actuators provided for a plurality of wheels, respectively, an acceleration sensor disposed in each of the electric actuators, the acceleration sensor detecting a first acceleration, and an electric suspension control ECU controlling each of the electric actuators based on the first acceleration, and the electric suspension control ECU decreases a control amount to the electric actuator, in a case where a first speed based on the first acceleration in an up-down direction is equal to or less than a predetermined speed.

A linear actuator comprising a housing with a proximal end and a distal end, and defining a central cavity extending axially; a piston tube at least partially positioned axially within the central cavity; a first elongated rotatable screw positioned axially within the central cavity; a first cylindrical nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second cylindrical nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second cylindrical nut and the distal end of the housing, wherein the spring is configured to bias the second cylindrical nut away from the distal end of the housing.

A linear actuator comprising a housing with a proximal end and a distal end, and defining a central cavity extending axially; a piston tube at least partially positioned axially within the central cavity; a first elongated rotatable screw positioned axially within the central cavity; a first cylindrical nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second cylindrical nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second cylindrical nut and the distal end of the housing, wherein the spring is configured to bias the second cylindrical nut away from the distal end of the housing.

A suspension device includes: a hydraulic damper including a rod provided with a valve for generating a hydraulic pressure when the rod is displaced between a first liquid chamber and a second liquid chamber; an electric damper configured to electrically displace the rod by an actuator; and a communication passage that establishes communication between the first liquid chamber and the second liquid chamber while bypassing the valve during operation of the electric damper.

A suspension device includes: a hydraulic damper including a rod provided with a valve for generating a hydraulic pressure when the rod is displaced between a first liquid chamber and a second liquid chamber; and an electric damper configured to electrically displace the rod by an actuator. The electric damper includes: an outer cylinder; an inner cylinder; a piston provided on the rod and configured to stroke in the inner cylinder; and a communication passage disposed inside the inner cylinder at a central portion where the piston strokes. The communication passage establishes communication between the first liquid chamber at one axial end side of the piston and the second liquid chamber at another axial end side of the piston.

A linear actuator comprising a housing with first and second ends, and defining a central cavity extending axially therethrough; a tube having first and second portions, the first portion arranged to slide within the central cavity of the housing, and the second portion extending outwardly from the second end of the housing; a first elongated rotatable screw positioned axially within the central cavity and coaxial with the rube; a first nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second nut and the second end of the housing.

A linear actuator comprising a housing with first and second ends, and defining a central cavity extending axially therethrough; a tube having first and second portions, the first portion arranged to slide within the central cavity of the housing, and the second portion extending outwardly from the second end of the housing; a first elongated rotatable screw positioned axially within the central cavity and coaxial with the rube; a first nut mounted about the first elongated rotatable screw and configured to move axially as the first elongated rotatable screw rotates; a second elongated rotatable screw positioned axially within the central cavity; a second nut mounted about the second elongated rotatable screw and configured to move axially within the central cavity as the second elongated rotatable screw rotates; and a spring positioned around the second elongated rotatable screw between the second nut and the second end of the housing.

A suspension structure of a utility vehicle includes: a shock absorber; and a trailing arm extending in a longitudinal direction of the utility vehicle. A lower end of the shock absorber is supported by a rear end of the trailing arm within a wheel as viewed in a side view of the utility vehicle.

A suspension structure of a utility vehicle includes: a shock absorber; and a trailing arm extending in a longitudinal direction of the utility vehicle. A lower end of the shock absorber is supported by a rear end of the trailing arm within a wheel as viewed in a side view of the utility vehicle.

In some examples, a vehicle suspension for supporting, at least in part, a sprung mass, includes a damper connected to the sprung mass, the damper including a movable piston. The vehicle suspension further includes an actuator and a controller. The controller may be configured to determine a frequency of motion associated with the sprung mass. When the frequency of motion is below a first frequency threshold, the controller may send a control signal to cause the actuator to apply a deceleration force to the sprung mass. Further, when the frequency of motion associated with the sprung mass exceeds the first frequency threshold, the controller may send a control signal to cause the actuator to apply a compensatory force to the sprung mass. For instance, a magnitude of the compensatory force may be based on a friction force determined for the damper.