A vibration generator has a first rotationally drivable imbalance shaft, on which a first imbalance is arranged, at least one second rotationally drivable imbalance shaft, on which a second imbalance is arranged, a joint drive for rotationally driving the two imbalance shafts and a transmission arrangement which is arranged between the drive and the imbalance shafts for transmitting a torque of the drive to the imbalance shafts. The transmission arrangement distributes an input torque of the drive to a first output element for the first imbalance and a second output element for the second imbalance. For the torque transmission a first deflection element is arranged between the transmission arrangement and the first imbalance shaft and for the torque transmission a second deflection shaft is arranged between the transmission arrangement and the second imbalance shaft.

Disclosed are a control method for a road roller machine, and a road roller machine. The control method includes: turning up, in response to a request of starting vibration, a revolving speed of an engine until the revolving speed exceeds a preset revolving speed range and turning down a displacement of a driving pump; starting a vibration pump; judging whether a vibration assembly has completed a vibration start; turning down, after the vibration start is completed, the revolving speed of the engine to be within the preset revolving speed range, turning up the displacement of the driving pump, and turning up a displacement of the vibration pump. The road roller machine includes a main body, an engine, a driving assembly, a driving pump, a vibration pump, a vibration assembly and a controller.

An adjustable mass eccentric for a multi-amplitude vibratory mechanism can comprise a body and an internal cavity defined by the body such that the body surrounds the internal cavity. The internal cavity can include a first section, a second section, and a third section between the first section and the second section. The third section can define a volume and/or an area less than respective volumes and/or areas of the first section and the second section of the internal cavity. Filler material may be provided in the internal cavity and can migrate to and from the first, second, and third sections based on rotational movement of the body and internal cavity.

A compactor vibration system, apparatus, and method that selectively provide access to vibration control settings. The control can include receiving a setting for a first set of selectable amplitudes of vibration force at which to operate a vibratory system for a first predetermined amount of time, operating the vibratory system during the first predetermined amount of time by inducing the vibration force at amplitudes by the vibratory system, wherein the amplitudes of the vibration force are selected from among the first set of selectable amplitudes, and after the first predetermined amount of time, changing the setting to a second set of selectable amplitudes of the vibration force that is different from the first set of selectable amplitudes.

A compaction machine may include a chassis, first and second drums rotatably mounted to the chassis, first and second vibration mechanisms, and a vibration controller. The first vibration mechanism may be configured to generate vibrations that are transmitted as impacts by the first drum to a work surface, and the second vibration mechanism may be configured to generate vibrations that are transmitted as impacts by the second drum to the work surface. The vibration controller may be configured to control at least one of the first and second vibration mechanisms so that a first pattern of impacts transmitted to the work surface by the first drum and a second pattern of impacts transmitted to the work surface by the second drum are coordinated as the compaction machine moves over the work surface. Related controllers and methods are also discussed.

A method for providing information related to the compaction state of a soil when performing a compaction operation with a soil compactor comprises the operations: a) detecting a vertical acceleration and a horizontal acceleration of a vibratory roller when moving a soil compactor over a soil to be compacted, b) determining a measurement relationship between a ground contact force (F.sub.b) and a deflection (s.sub.w) of the vibratory roller for one vibration cycle using the vertical acceleration and horizontal acceleration detected in operation a), c) determining a simulation relationship (Z.sub.S) between the ground contact force (F.sub.b) and the deflection (s.sub.w) for one vibration cycle using a ground model taking into account at least one simulation parameter, d) comparing the simulation relationship (Z.sub.S) to the measurement relationship, e) determining that a default value of the at least one simulation parameter taken into account in the ground model substantially represents a corresponding soil parameter of the soil to be compacted when the simulation relationship (Z.sub.S) substantially corresponds to the measurement relationship.

A surface compactor machine includes a compacting surface for compacting a substrate, a first motor, a second motor, a support assembly, and a controller. The first motor rotates a first eccentric shaft. The second motor rotates a second eccentric shaft. The support assembly is connected to the first and second eccentric shafts to transfer vibration forces to the compacting surface. The controller controls speed of at least one of the first and second motors so that a rotational speed of the second eccentric shaft is an integer, greater than 1, times faster than a rotational speed of the first eccentric shaft to generate a composite displacement waveform that vibrates the compacting surface upwards and downwards, wherein the composite displacement waveform includes a zero amplitude coordinate, a wave section located above the zero amplitude coordinate, and a wave section located below the zero amplitude coordinate that is asymmetric relative to the wave section located above the zero amplitude coordinate.

A vibration assembly for a surface compactor machine includes a support subassembly connected to the compacting surface of the surface compactor machine. A primary eccentric shaft is disposed around a secondary eccentric shaft, with the primary and secondary eccentric shafts both rotatable about a common axis of rotation. One or more of primary bearing subassemblies is disposed between the primary eccentric shaft and the support subassembly for supporting the primary eccentric shaft during rotation of the primary eccentric shaft. One or more secondary bearing subassemblies is disposed between the secondary eccentric shaft and the primary eccentric shaft for supporting the secondary eccentric shaft during rotation of the primary eccentric shaft.

An earth working machine (10), in particular a road milling machine, a stabilizer, or the like, having a milling drum (30) that is mounted rotatably on a machine frame (11) and is populated or populatable on its outer circumference with working tools (31); the working tools (31) to come into contact, during working operation, with the ground that is to be worked to remove it; a drive unit (20) drives the milling drum (30) by means of a drive motor (21); an input drive shaft (33) couplable to the drive motor (21) is attached to the milling drum (30); and a ballast element, constituting a kinetic mass (57), increases the kinetic energy of the milling drum (30). The kinetic mass (57) is couplable to or decouplable from the rotatable milling drum (30), or a rotational member indirectly or directly coupled to the milling drum (30), via a shiftable coupling (55).

A compactor includes a compactor structure and at least one roller unit rotatably supported on the compactor structure about a roller axis of rotation. A roller heater is deployed in assignment with at least one roller unit. The roller heater is a liquid fuel-operated heating device with a burner region, a fuel pump for supplying liquid fuel from a fuel tank to the burner region and a combustion air blower for supplying combustion air to the burner region.