Hydraulic systems and methods for reducing the propagation of flow and/or pressure pulsations within a hydraulic system are described. In one embodiment, a hydraulic system may include a hydraulic device and a differential buffer fluidly connected to the hydraulic device. The differential buffer may include a piston that is exposed to pressure pulsations that propagate along separate flow paths and that are at least partially out of phase with one another. Corresponding displacement of the piston due to the out of phase pulsations may at least partially mitigate propagation of the pulsations within the hydraulic system downstream from the differential buffer.

A linear energy harvesting device that includes a housing and a piston that moves at least partially through the housing when it is compressed or extended from a rest position. When the piston moves, hydraulic fluid is pressurized and drives a hydraulic motor. The hydraulic motor drives an electric generator that produces electricity. Both the motor and generator are central to the device housing. Exemplary configurations are disclosed such as monotube, twin-tube, tri-tube and rotary based designs that each incorporates an integrated energy harvesting apparatus. By varying the electrical characteristics on an internal generator, the kinematic characteristics of the energy harvesting apparatus can be dynamically altered. In another mode, the apparatus can be used as an actuator to create linear movement. Applications include vehicle suspension systems (to act as the primary damper component), railcar bogie dampers, or industrial applications such as machinery dampers and wave energy harvesters, and electro-hydraulic actuators.

A linear energy harvesting device that includes a housing and a piston that moves at least partially through the housing when it is compressed or extended from a rest position. When the piston moves, hydraulic fluid is pressurized and drives a hydraulic motor. The hydraulic motor drives an electric generator that produces electricity. Both the motor and generator are central to the device housing. Exemplary configurations are disclosed such as monotube, twin-tube, tri-tube and rotary based designs that each incorporates an integrated energy harvesting apparatus. By varying the electrical characteristics on an internal generator, the kinematic characteristics of the energy harvesting apparatus can be dynamically altered. In another mode, the apparatus can be used as an actuator to create linear movement. Applications include vehicle suspension systems (to act as the primary damper component), railcar bogie dampers, or industrial applications such as machinery dampers and wave energy harvesters, and electro-hydraulic actuators.

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.

The suspension device for vehicles includes: an electric damper which operates by electricity; a fluid pressure damper which operates by hydraulic pressure; a road-surface state detector which detects a road-surface state ahead of a tire of a vehicle; and a controller which causes at least one to operate among the electric damper and the fluid pressure damper, based on a detection result of the road-surface state detector.

A machine includes a first cylinder coupled to a first wheel and a second cylinder coupled to a second wheel. A first proportional dampening valve fluidly connects to the first cylinder and a second proportional dampening valve fluidly connects to the second cylinder. First accumulators are fluidly connected to the first cylinder and the first proportional dampening valve, and second accumulator(s) are fluidly connected to the second cylinder and the second proportional dampening valve. Additionally, a first proportional flow control valve fluidly connects to the first cylinder and a second proportional flow control valve fluidly connected to the second cylinder. An electronic control module (ECM) communicatively couples to the first proportional flow control valve and the second proportional flow control valve to adjust a ride height of the first wheel via the first cylinder and a ride height of the second wheel via the second cylinder.

A machine includes a first cylinder coupled to a first wheel and a second cylinder coupled to a second wheel. A first proportional dampening valve fluidly connects to the first cylinder and a second proportional dampening valve fluidly connects to the second cylinder. First accumulators are fluidly connected to the first cylinder and the first proportional dampening valve, and second accumulator(s) are fluidly connected to the second cylinder and the second proportional dampening valve. Additionally, a first proportional flow control valve fluidly connects to the first cylinder and a second proportional flow control valve fluidly connected to the second cylinder. An electronic control module (ECM) communicatively couples to the first proportional flow control valve and the second proportional flow control valve to adjust a ride height of the first wheel via the first cylinder and a ride height of the second wheel via the second cylinder.

A suspension system for a vehicle is provided. A linear regenerative suspension system that converts mechanical energy into storable electrical energy is also provided. The system utilizes pistons, one on each side of the vehicle, engaged with a vehicle body at a distal end and having a fluid chamber at the proximal end. The system further has a central chamber having a rod freely laterally moving therein. A fluid communicates between the central chamber and each piston fluid chamber. Upon nonlinear forces applied to the vehicle, the rod is urged in one direction or another. This urging applies force to the fluid in the central chamber, and in turn, to the piston in the corresponding side of the vehicle, urging the piston up and in turn urging the vehicle body up.

A suspension system for a vehicle is provided. A linear regenerative suspension system that converts mechanical energy into storable electrical energy is also provided. The system utilizes pistons, one on each side of the vehicle, engaged with a vehicle body at a distal end and having a fluid chamber at the proximal end. The system further has a central chamber having a rod freely laterally moving therein. A fluid communicates between the central chamber and each piston fluid chamber. Upon nonlinear forces applied to the vehicle, the rod is urged in one direction or another. This urging applies force to the fluid in the central chamber, and in turn, to the piston in the corresponding side of the vehicle, urging the piston up and in turn urging the vehicle body up.

A system includes: a state module configured to selectively set a present state to a first state; a valve control module configured to determine first target open and closed states for valves of a suspension system based on the present state and to open and close the valves of the suspension system according to the first target open and closed states, respectively; a pump control module configured to, when the valves are in the first target open and closed states, respectively, selectively operate an electric pump of the suspension system in a first direction and increase a pressure of hydraulic fluid in a first portion of the suspension system including an accumulator, where the valve control module is configured to decrease the pressure in the first portion after the increase; and a diagnosis module configured to selectively diagnose a fault in the accumulator based on a pressure during the decrease.