A railroad car truck including a first side frame, a second side frame, a bolster, and a first plurality of warp restraints, each first warp restraint configured to reduce, inhibit, or minimize warping of the bolster relative to the side frame, and in one embodiment including a first inner bearing race at a first end of the bolster, a second opposing outer bearing race at the first side frame, and a roller positioned in a channel formed by and between the first and second opposing bearing races, and a second plurality of warp restraints, each second warp restraint including a first inner bearing race at a second end of the bolster, a second opposing outer bearing race at the second side frame, and a roller positioned in a channel formed by and between the first and second opposing bearing races.

A railroad car articulated split friction wedge assembly including first and second articulated friction wedges, wherein the first friction wedge includes a first body, a first decoupling insert, a first pivot member pivotally moveable with respect to the first body and the first decoupling insert, and a first wear pad removably attached to the first pivot member, and wherein the second friction wedge includes a second body, a second decoupling insert, a second pivot member pivotally moveable with respect to the second body and the second decoupling insert, and independently of the first body and the first pivot member, and a second wear pad removably attached to the second pivot member, which in combination provide required damping, provide high warp restraint, reduce binding, and enable lateral decoupling.

A secondary spring for a rail vehicle springs a wagon body of the rail vehicle on the chassis of the rail vehicle. The secondary spring is divided along a predefined axis into a first and at least one further, second section. The first section is configured to be axially stiff and springy orthogonally to the predefined axis, and the second section is configured to be stiff orthogonally to the predefined axis and axially springy. The secondary spring contains at least one horizontal stop, which is arranged on the secondary spring such that a force which acts on the horizontal stop orthogonally to the predefined axis is introduced into the secondary spring between the first and the second section.

A secondary spring for a rail vehicle springs a wagon body of the rail vehicle on the chassis of the rail vehicle. The secondary spring is divided along a predefined axis into a first and at least one further, second section. The first section is configured to be axially stiff and springy orthogonally to the predefined axis, and the second section is configured to be stiff orthogonally to the predefined axis and axially springy. The secondary spring contains at least one horizontal stop, which is arranged on the secondary spring such that a force which acts on the horizontal stop orthogonally to the predefined axis is introduced into the secondary spring between the first and the second section.

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.

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 rail vehicle with two sideframes and a bolster as the freight car truck has limits on stability. A railway freight car truck having a friction shoe with a constant force device acting directly on the shoe flat surface is provided, such that the friction shoe is forced to remain in contact with the side frame mating vertical surface. The control spring acting on the friction shoe which applies a varying force to the side frame mating surface. The damping of the friction shoe is retained when there is less variable force of friction, which decreases vertical acceleration of the rail vehicle, providing high speed stability for most track conditions.

The performance of a passive-levitation vehicle is improved for moving over a path, wherein the vehicle has a levitation skid slidable on the path and capable of developing a levitation force to support a compartment at a certain distance from the path. For this aim, there is a suspension, connected between the compartment and the skid, comprising a kinematic structure to confer degrees of freedom and relative constraints between the skid and the compartment; a passive elastic element connected between the skid and the compartment; and a controlled-dynamic element able to exert a force having controlled dynamics between the skid and the compartment; wherein the passive elastic element and the controlled-dynamic element being mounted in parallel to each other and connected, e.g. at their ends, respectively to the skid and the compartment. By means of a sensor the distance is detected between the skid and the path, and an electronic circuit, connected to the sensor and to the controlled-dynamics element, carries out a feedback control in order to adjust said distance.

A railway freight car bogie includes a side frame, a bolster and a friction damper. The friction damper includes a wedge, a constant friction damping spring, a variable friction damping spring and an ejector rod. The variable friction damping spring in the middle and below the wedge is deviated at a distance in a direction away from a center of the bolster with respect to damping springs at two sides of the variable friction damping spring. An axis of each of the constant friction damping spring and the ejector rod is coincident with an axis of the variable friction damping spring in the middle and below the wedge. The bogie not only has an ideal relative friction coefficient in both an unloaded condition and a loaded condition, a large diamond resistant rigidity, a better vertical dynamics performance and a better transverse dynamics performance.

A rail vehicle includes a bogie, multiple wheels, a chassis, and a carriage. The wheels are disposed on the bogie. The chassis is disposed on the bogie and connected to the bogie through a first suspension. The carriage is disposed on the chassis and connected to the chassis through a second suspension.