An agitator for vibrating a drill string includes an agitator housing, a rotor and an agitation mass. The drill string has a central axis. The rotor is coupled to the agitator housing and being rotatable about an agitator axis. The agitation mass is coupled to the rotor and is rotatable about the agitator axis. During rotation, a center of mass of the agitation mass is spaced apart from the agitator axis to cause deflection of the agitator axis relative to the central axis to produce vibration in the drill string.

A hydraulic vibration generation device is provided. The device includes a manifold member having an inner volume, a fluid inlet orifice and a fluid outlet orifice. The device further includes a vibration generating member having a channel grooved drive and an off-center weight and bearing retaining plates. The inner volume receives the vibration generating member within the inner volume. The bearing retaining plate that retain bearings operate to retain the vibration generating member within the inner volume in response to coupling the bearing retaining plate to the manifold member wherein two bearings on opposing ends of the vibration generating member are retained within recesses of the bearing retaining plates. The vibration generating member rotates and generates vibration in response to hydraulic fluid flowing into the manifold member through the inlet orifice and out of the manifold member through the outlet orifice.

The invention relates to a machine for stabilising a track, having a machine frame supported on rail-based running gears and at least one height-adjustable stabilising unit which can be rolled on rails of the track by means of work unit rollers, comprising a vibration exciter with rotating unbalanced masses for generating an impact force acting dynamically in a track plane normal to a longitudinal direction of the track as well as a linear drive for generating a load acting on the track. It is provided that a main unbalanced mass and a secondary unbalanced mass produce different centrifugal forces at the same rotational speed depending on the direction of rotation, the two unbalanced masses being coupled in such a way that, during rotation in one direction of rotation, the unbalanced masses have a first phase shift in relation to one another and that, during rotation in the opposite direction of rotation, the unbalanced masses have a second phase shift relative to one another which differs from the first phase shift. Depending on the arrangement of the unbalanced masses, a changed phase shift changes both the direction and the strength of the impact force.

A roller tube concrete finishing machine includes retractable vibration gangs that can be selectively immersed within wet concrete and then retracted with parallelogram linkage. Spaced-apart, drive parallel rollers are journaled between frame ends for supporting and propelling the machine upon and between parallel form rails. A front roller provide a strike-off function. The vibration gangs are deployed by a retractable, parallelogram linkage that moves them forwardly and downwardly for operation, or which retracts the vibrators inwardly and upwardly relative to the frame. When the vibrators are retracted, the are withdrawn upwardly from the concrete and retracted rearwardly towards the machine front to reduce machine dimensions. Substantial retraction of the vibrators prevents subsequent interference with the rebar below. Vibrator retraction reduces overall machine dimensions for clearance and shipping purposes, with gang vibration arrays nested upwardly and inwardly proximate the front of the machine.

A vibratory compactor is provided. The vibratory compactor may include a compactor plate, a frame coupled to the compactor plate, wherein the frame may include an inner space and a housing. The frame may include a plurality of mounting brackets coupled between a first side member and a second side member of the frame. The vibratory compactor may include a vibration generation device coupled to the compactor plate within the inner space of the frame. The vibratory compactor may include a plurality of isolators, each isolator coupled to one mounting bracket of the plurality of mounting brackets. The housing may be coupled to the plurality of isolators, wherein the housing may include couplers removably coupled to a top surface of the housing. The couplers may be configured for coupling the vibratory compactor to an excavator type vehicle.

A tamping unit includes tamping tines and a squeezing drive for squeezing the tamping tines. A vibration exciter has an outer cylinder and an inner cylinder. The inner cylinder is disposed coaxially to a cylinder axis and is mounted for displacement in an axial direction along sliding or gliding surfaces in the outer cylinder. A ring-shaped recess is provided between the two sliding or gliding surfaces which are spaced from one another in the axial direction. A spacer ring, which subdivides the ring-shaped recess into two fluid channels, is connected selectively to the inner or outer cylinder. The fluid channels are spaced from one another relative to the axial direction. The two fluid channels can be hydraulically actuated alternatingly by feed lines for vibration excitation.

A tamping unit includes tamping tines and a squeezing drive for squeezing the tamping tines. A vibration exciter has an outer cylinder and an inner cylinder. The inner cylinder is disposed coaxially to a cylinder axis and is mounted for displacement in an axial direction along sliding or gliding surfaces in the outer cylinder. A ring-shaped recess is provided between the two sliding or gliding surfaces which are spaced from one another in the axial direction. A spacer ring, which subdivides the ring-shaped recess into two fluid channels, is connected selectively to the inner or outer cylinder. The fluid channels are spaced from one another relative to the axial direction. The two fluid channels can be hydraulically actuated alternatingly by feed lines for vibration excitation.

A vibratory drive of a vibrating roller includes an unbalanced-mass vibration generator configured to be used in at least one drum of the vibrating roller. The vibrating roller is operated by an external drive device or advancing device such that the unbalanced-mass vibration generator can be rotated relative to the drum in at least one direction. The unbalanced-mass vibration generator is mechanically coupled to a hydraulic motor, which is configured to be supplied with a pressure medium by a hydraulic pump to rotate the unbalanced-mass vibration generator. At least one high-pressure accumulator is provided to accommodate pressure medium pumped by the hydraulic motor in a pushing operation. The high-pressure accumulator feeds stored pressure medium to the hydraulic motor in a driving operation of the hydraulic motor.

In a tamping unit for tamping sleepers of a track, both squeezing drives of a tamping tine pair are articulatedly connected to a common connecting carrier. A vibration exciter fastened to the tine carrier is connected to the connecting carrier, likewise fastened to the tine carrier, for transmission of tamping tine vibrations from the connecting carrier to the squeezing drives and the tamping tines.

In a tamping unit for tamping sleepers of a track, both squeezing drives of a tamping tine pair are articulatedly connected to a common connecting carrier. A vibration exciter fastened to the tine carrier is connected to the connecting carrier, likewise fastened to the tine carrier, for transmission of tamping tine vibrations from the connecting carrier to the squeezing drives and the tamping tines.