A shock absorber includes: a cylinder; a piston slidably inserted into the cylinder; a piston rod connected to the piston and extending outside the cylinder; a main valve that generates a damping force; a pilot chamber that applies pressure to the main valve; an introduction passage that introduces the fluid into the pilot chamber; a pilot passage that communicates the pilot chamber and a downstream side of the main valve with each other; and a control valve provided in the pilot passage. In an upstream side of the pilot passage from the control valve, the pilot passage is provided with a first orifice, a first passage provided in parallel with the first orifice, a first check valve that is opened at a predetermined differential pressure and allows a flow toward the control valve through the first passage, and a second orifice.

Suspension systems for recreational vehicles are disclosed. The suspension systems may include at least one adjustable member coupling a sway bar to respective suspensions. The suspension systems may include a torque actuator associated with a sway bar.

Methods and apparatus for position sensitive dampening. In one aspect a fluid damper is provided comprising a damper chamber divided by a piston into a primary compression and a primary rebound chamber; a secondary compression chamber in fluid communication with the damper chamber; and an adjustable fluid meter controlling fluid flow out of the secondary compression chamber.

[Problem] The present invention provides a damping force adjustable shock absorber capable of reducing manufacturing cost. [Means for Solving] A shock absorber 1 is configured in such a manner that a main valve 32 is disposed below a piston valve 5, and a sub valve 68 for variably adjusting a set load of the main valve 32 is provided in a piston case 21 above the piston valve 5, with a first valve body 53 of the sub valve 68 slidably sealed to a case member 60 by a metal seal at only one portion. Due to the configuration, the shock absorber 1 can ease precision of components of the sub valve 68, thereby reducing the manufacturing cost.

A suspension including a spring interposed between the body (B) of the vehicle and the wheel (W); a regenerative hydraulic shock-absorbing unit comprising a hydraulic shock-absorber arranged parallel to the spring, a motor and pump unit with a volumetric hydraulic machine and an electric machine coupled to the hydraulic machine), and an electronic control unit arranged to control the torque of the electric machine. A hydraulic actuator is arranged in series with the spring. A reservoir and a hydraulic circuit are connected to each other, the hydraulic shock-absorber, the hydraulic machine the hydraulic actuator and the reservoir. The hydraulic circuit includes a valve assembly for controlling the flow of a working fluid between the hydraulic shock-absorber, the hydraulic machine, the hydraulic actuator and the reservoir.

An actuator system for a vehicle suspension system including: an actuator having a piston and a first fluid chamber separated from a second fluid chamber by the piston; a hydraulic pump having a first port, a first hydraulic circuit operable to connect the first port to the first chamber, the first hydraulic circuit including a first valve, the first valve being a damper valve operable to variably restrict flow of hydraulic fluid out of the first chamber; a first hydraulic accumulator connected to a first gallery of the first hydraulic circuit between the first port and the first valve; a second hydraulic accumulator connected to a second port of the pump via a second gallery; and a second valve, the second valve being a variable pressure relief valve operable to variably restrict flow of hydraulic fluid from the first gallery to the second gallery.

An actuator system for a vehicle suspension system includes: an actuator having a piston and a first fluid chamber separated from a second fluid chamber by the piston; a hydraulic pump having a first port connected by a first hydraulic circuit to the first chamber via a first valve, the first valve being a damper valve operable to variably restrict flow of hydraulic fluid out of the first chamber; a first hydraulic accumulator connected to the first hydraulic circuit between the first port and the first valve; and a second hydraulic accumulator connected to the first port by a second valve, the second valve being a variable pressure relief valve operable to variably restrict flow of hydraulic fluid from the first port to the second hydraulic accumulator.

Hydraulic fluid in a cylinder's lower chamber is introduced into a back pressure chamber through the outer periphery of an extension-side main valve during a compression stroke of a piston rod. This eliminates the necessity of forming paths by arranging a plurality of discs and a check valve, the paths for introducing into the back pressure chamber the hydraulic fluid in the cylinder's lower chamber that becomes an upstream chamber during the compression stroke. This makes it possible to decrease the axial length of a shaft portion of the piston rod and therefore the entire length of a cylinder, and also downsize a shock absorber.

A hydraulic suspension system for a motor vehicle having at least a pair of road engaging wheels. The suspension system includes, a hydraulic cylinder coupled with the each of the pair of road engaging wheels, the hydraulic cylinder defining a cap end volume and a rod end volume separated by a piston. A hydraulic supply circuit for the hydraulic cylinder includes, a high pressure hydraulic source, a low pressure hydraulic drain, a pair of hydraulic sub circuits each coupled to one of the hydraulic cylinder cap and rod end volumes. Each hydraulic sub circuit includes, a proportional supply flow valve coupled with the high pressure hydraulic source and one of the cylinder volumes, a return flow control proportional valve coupled with the low pressure hydraulic drain and the one cylinder volume, and an accumulator coupled to the associated hydraulic cylinder volume through an accumulator fill control proportional valve.

A shock assembly with automatically adjustable ride height is disclosed. The assembly includes a main chamber including a fluid therein. A pump tube within the main chamber, the pump tube having a fluid flow path internal thereto, the pump tube disposed axially along a center of the main chamber. A damping piston coupled to a shaft, the damping piston and a portion of the shaft disposed axially about the pump tube, the damping piston disposed in the main chamber to divide the main chamber into a compression side fluid chamber and a rebound side fluid chamber. An automatic ride height adjustment assembly including a tube-in-shaft pump assembly and a spring preload piston assembly.