In a method of operating a tamping unit of a track maintenance machine, the track maintenance machine having the tamping unit is first provided on a track bed. The tamping unit is displaced relative to the track bed. A driving force, acting on the tamping unit and required for the displacement, and acceleration acting on the tamping unit are determined. A ballast force acting between the tamping unit and the track bed is determined by way of the driving force and the acceleration, and is evaluated.

A tamping unit for tamping a track has tamping tines which are designed for immersion into a ballast bed and which can be set in vibrations by a vibration drive. The vibration drive includes a housing in which a shaft including an eccentric is arranged for rotation about a shaft axis. A transmission element for transmitting a vibratory motion is mounted on the eccentric. The eccentric is connected to the shaft in a rotation-locked and radially displaceable manner, wherein the position of the eccentric relative to the shaft is adjustable in radial direction by an adjustment device. Thus, while retaining the advantages of an eccentric drive, it is possible to adjust vibration parameters during operation.

The present disclosure relates to a rail vehicle having a track stabilization unit for use in stabilizing rails into ballast. The rail vehicle comprises a frame and a track stabilization unit coupled to the frame. The track stabilization unit includes a base and a plurality of wheels disposed about the base. The wheels are configured to bias against rails of a railroad track. At least one of the wheels is coupled to a motor through a drive shaft such that rotation of the drive shaft drives rotation of the wheel. Related methods are described.

A method for compaction of a track ballast bed uses a tamping unit including two oppositely positioned tamping tools which are actuated with vibrations and are lowered into the track ballast bed during a tamping operation and moved towards one another with a squeezing motion. A progression of a force acting upon the tamping tool over a path covered by the tamping tool is recorded during a vibration cycle by sensors disposed at the tamping unit for at least one tamping tool. At least one characteristic value is derived therefrom and used to carry out an evaluation of the tamping operation and/or of a quality of the track ballast bed. The tamping unit is thus used as a measuring apparatus during operative use. A device for performing the method is also provided.

The invention relates to a machine for stabilizing a track, including a machine frame supported on on-track undercarriages and a vertically adjustable stabilizing unit designed to roll on rails of the track by means of unit rollers, the stabilizing unit comprising a vibration exciter with rotating imbalance masses for generating an impact force (F.sub.S) acting dynamically in a track plane perpendicularly to a track longitudinal direction and a vertical drive for generating a vertical load acting on the track. In this, it is provided that the vibration exciter comprises at least two imbalance masses which are driven applying a variably adjustable phase shift (.sub.1, .sub.2). The invention further relates to a method for operating such a machine.

A tamping unit for tamping a track has tamping tines which are designed for immersion into a ballast bed and which can be set in vibrations by a vibration drive. The vibration drive includes a housing in which a shaft including an eccentric is arranged for rotation about a shaft axis. A transmission element for transmitting a vibratory motion is mounted on the eccentric. The eccentric is connected to the shaft in a rotation-locked and radially displaceable manner, wherein the position of the eccentric relative to the shaft is adjustable in radial direction by an adjustment device. Thus, while retaining the advantages of an eccentric drive, it is possible to adjust vibration parameters during operation.

A rail maintenance vehicle includes a frame, a workhead, and a vibration unit. The frame includes wheels that travel along rails. The vibration unit includes a rod member having a coil assembly coupled thereto. The vibration unit further includes a core assembly operable to receive the rod member therein. The core assembly includes a plurality of magnet members disposed along the periphery of the core assembly. The coil assembly and magnet members are operable to impart linear motion to the rod member relative to the core assembly.

A tamping assembly for a track tamping machine comprises a carrier guided in a height-adjustable manner with respect to a tamping assembly frame along guides, on which carrier pairs of tamping tools formed as oscillating levers are pivotably mounted, the tamping tools of which can be oppositely driven by an oscillation drive and can be hydraulically adjusted relative to one another, said tamping tools being intended for introduction into a ballast bed. To reduce the number of required drives, several of the tamping tools are combined into tamping units with a compartment between them engaging around a rail and are mechanically connected to each other, and each oscillating lever is associated with a tamping unit and an adjusting drive, wherein the guides, especially the guide rods, act directly on the respective carrier and run in fixed guides of the tamping assembly frame.

A vibratory tamping machine for compacting a ballast bed of a track has a vibration mechanism which is driven by means of an electric drive motor. The vibratory tamping machine has a vibration decoupling device, which defines a decoupling plane and separates a working side from an operating side, for the vibration-decoupling of at least one handle. The handles are arranged on the operating side, whereas the electric drive motor and the vibration mechanism are arranged on the working side.

A vibratory tamping machine for compacting a ballast bed of a track has a vibration mechanism which is driven by means of an electric drive motor. The vibratory tamping machine has a vibration decoupling device, which defines a decoupling plane and separates a working side from an operating side, for the vibration-decoupling of at least one handle. The handles are arranged on the operating side, whereas the electric drive motor and the vibration mechanism are arranged on the working side.