A semiactive damper of the present invention includes a cylinder, a rod movably inserted into the cylinder, a piston slidably inserted into the cylinder and comparting the interior of the cylinder into a rod-side chamber and a piston-side chamber, a tank, a suction passage permitting only flow of a hydraulic fluid from the tank to the piston-side chamber, a damping passage communicating the rod-side chamber with the tank or the rod-side chamber with the piston-side chamber, and a variable damping valve provided on the damping passage, and a detecting portion for detecting an expansion and contraction direction according to pressure in the piston-side chamber.

A bogie, including a frame (1) and a bolster (2), the frame (1) including two parallel side beams (11), and a cross beam (12) coupled to the middle of the side beams (11), wherein a primary suspension is arranged between an end of the side beam (11) and an axle box (31), a secondary suspension is arranged between the below of the bolster (2) and the cross beam (12), and a tertiary suspension coupled to a vehicle body is arranged above the bolster (2). By including a bolster and an extra suspension on the basis of the conventional two suspensions, the disclosed bogie can achieve separation of the functions, so that the tertiary suspension only handles the transverse displacement, and the secondary suspension only handles the rotation, thereby further increasing the relative displacement and rotation angle between the vehicle body and the bogie when the vehicle negotiates a curve.

Disclosed is a bolster of a bogie, wherein a secondary suspension connected with a transverse beam of the bogie is arranged below the bolster, and a third suspension connected with a vehicle body is arranged above the bolster. The bolster of the bogie of the present invention realize a functional separation by adding a suspension between the bottome of the bolster and the transverse beam to make the frame and the vehicle body be connected through a two-stage suspension, so that the third suspension above the bolster is only used to undertake a transverse displacement function, and the secondary suspension under the bolster is only used to undertake a rotation function, thereby further increasing displacement and relative rotation angle between the vehicle body and the bogie when the vehicle passes through a curve, and improving curve passing capability of the vehicle.

A railway vehicle vibration damping device includes: an actuator including a cylinder body configured to expand and contract when supplied with hydraulic fluid, a pump configured to supply the hydraulic fluid to the cylinder body, and a motor configured to drive the pump, and installed on a railway vehicle; and a control unit configured to control the motor. The control unit stops the motor when a current value to be provided to the motor becomes equal to or larger than a current threshold for outputting a restriction torque set to a value exceeding a rated torque of the motor.

A railway vehicle vibration damping device includes: an actuator including a cylinder body configured to expand and contract when supplied with hydraulic fluid, a pump configured to supply the hydraulic fluid to the cylinder body, and a motor configured to drive the pump, and installed on a railway vehicle; and a control unit configured to control the motor. The control unit stops the motor when a current value to be provided to the motor becomes equal to or larger than a current threshold for outputting a restriction torque set to a value exceeding a rated torque of the motor.

The vehicle including an active suspension system (22) parameterized by a set of adjustment parameters. The railway track is cut into segments. For each segment (T), the method includes campaigns for optimization of the set of parameters, such that: during the first campaign, to each passage of the suspension system (22) on the segment (T), a first set of parameters, specific to this passage, is predefined and applied to the suspension system (22), and a comfort quality index is calculated, and then a metaheuristic algorithm is applied for determining second sets of parameters, and during each following optimization campaign, at each passage of the suspension system over the segment, one of the determined sets of parameters by the previous optimization campaign is applied to the suspension system, and the comfort quality index is calculated, and then the metaheuristic algorithm is applied in order to determine new sets of parameters.

A hydraulic device of the present invention includes: a cylinder body (S) including a cylinder (1) and a rod (2) that moves retractably inside the cylinder (1); and a pump unit (30) that is formed with an oil passage (31) and discharges, at an intermediate position in the oil passage (31), liquid into the cylinder (1) through driving of a motor (M). The cylinder body (S) is connected to the pump unit (30) via an extension (40) having an oil passage (41) that provides communication between the oil passage (31) of the pump unit (30) and an interior of the cylinder (1).

A method includes detecting an out of phase condition and an in-phase condition between a vehicle platform and two or more propulsion units attached to the platform. A first speed from a first propulsion unit is compared to a second speed and a torque of one or more propulsion units is controlled to reduce the out of phase condition and/or the in-phase condition when a difference between the first speed and the second speed is greater than a threshold value. A vehicle includes a platform, two or more propulsion units attached to the platform, and a processor. The processor compares a first speed from a first propulsion unit to a second speed, detects from the comparison an out of phase condition between the platform and the two or more propulsion units, and detects from the comparison an in-phase condition between the platform and the two or more propulsion units.

A railway vehicle vibration damping device includes an actuator and a control unit controlling a pump and controls a rotation speed of the pump based on a vehicle speed of a railway vehicle.

A railway vehicle vibration damping device includes an actuator and a control unit controlling a pump and controls a rotation speed of the pump based on a vehicle speed of a railway vehicle.