Disclosed herein are active hydraulic cylinders for use in active vehicle suspension systems, and methods for assembling active hydraulic cylinders for use in an active vehicle suspension system. In particular, in certain embodiments a manifold may encircle a portion of an outer tube of a twin tube assembly. The manifold may mechanically and fluidly couple a pump assembly to the twin tube assembly. In certain embodiments, the manifold may be welded onto the outer tube.

A fluid system for a vehicle includes a pump for delivering a fluid, wherein the pump has a first and a second fluid connections, a first and a second actuators to be connected to the first fluid connection via a first and a second actuator valves, respectively, wherein the pump is designed to deliver fluid in a first delivery direction and in a second delivery direction, so that the first actuator and the second actuator are fluidically pressurized by the pump via the first fluid connection when the pump delivers in the first delivery direction, and a control valve for controlling the first and the second actuator valves. The control valve is fluidically separated from the second fluid connection when the pump delivers in the first delivery direction, and the control valve is connected to the second fluid connection when the pump delivers in the second delivery direction.

A fluid system for a vehicle, preferably for a vehicle chassis, includes: a pump for delivering a fluid, wherein the pump has a first fluid connection and a second fluid connection, an actuator which can be connected to the first fluid connection in a fluid-communicating manner via an actuator valve, wherein the pump is designed to deliver the fluid to be delivered in a first delivery direction and in a second delivery direction opposite the first delivery direction, so that the actuator is fluidically pressurized by the pump via the first fluid connection when the pump delivers in the first delivery direction, and the actuator is fluidically separated from the first fluid connection depending on the position of the actuator valve or the actuator is fluidically relieved by the pump via the first fluid connection when the pump delivers in the second delivery direction.

A control valve device for a regulation of damping characteristics, in particular of shock absorbers, includes a valve slide and a hydraulic fail-safe unit which is configured, in a de-energized operation state, to provide a fail-safe damping characteristic of the valve slide, the damping hardness of which in a rebound direction lies between a minimally possible rebound damping hardness and a maximally possible rebound damping hardness, and the damping hardness of which in a compression direction lies between a minimally possible compression damping hardness and a maximally possible compression damping hardness.

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.