A vibratory compactor that generates vibrations by rotation of eccentric masses is provided, which includes an inner eccentric rod positioned inside a roller drum of the vibratory compactor and provided with a rack formed on one side of the inner eccentric rod, a pinion engaged with the rack, a variable eccentric weight engaged with the pinion so that a distance between the variable eccentric weight and a rotation axis of the inner eccentric rod is changed as the pinion is rotated, and an outer eccentric tube including a hole formed thereon to guide movement of the rack back and forth and a support fixture formed thereon to fix a shaft of the pinion so that the pinion is rotated in engagement with the rack, wherein when the inner eccentric rod moves back and forth, the pinion that is engaged with the rack is rotated as much as the movement of the rack, and as a position of the variable eccentric weight is changed, an amplitude of vibration of the roller drum is changed.

The present disclosure provides vibratory compactor comprising an active isolation apparatus for reducing a vibration generated during the rotation of an eccentric shaft having an eccentric weight attached thereto. The active isolation apparatus comprises a drum, a propulsion motor configured to rotate the drum, a drive plate disposed between the propulsion motor and the drum in such a way as to be connected to the propulsion motor to transmit a rotating force to the drum, and a drum support configured to rotatably support the drum. The active isolation apparatus further comprises a first active isolation mass disposed between the drum support and the drum, a second active isolation mass disposed between the drive plate and the drum, an eccentric shaft configured to be rotated while penetrating through the first active isolation mass, the drum, and the second active isolation mass, a primary eccentric weight attached to the eccentric shaft inside the drum, an active isolation eccentric weight attached to each of the eccentric shaft inside the first active isolation mass and the second active isolation mass, and a vibration motor configured to rotate the eccentric shaft. In accordance with the active isolation apparatus of the present disclosure, when the eccentric shaft is rotated, a phase of a vibration generated by the active isolation eccentric weights is opposite to that of a vibration generated by the primary eccentric weight, and the vibration generated by the active isolation eccentric weights cancels the vibration generated by the primary eccentric weight.

The present disclosure provides vibratory compactor comprising an active isolation apparatus for reducing a vibration generated during the rotation of an eccentric shaft having an eccentric weight attached thereto. The active isolation apparatus comprises a drum, a propulsion motor configured to rotate the drum, a drive plate disposed between the propulsion motor and the drum in such a way as to be connected to the propulsion motor to transmit a rotating force to the drum, and a drum support configured to rotatably support the drum. The active isolation apparatus further comprises a first active isolation mass disposed between the drum support and the drum, a second active isolation mass disposed between the drive plate and the drum, an eccentric shaft configured to be rotated while penetrating through the first active isolation mass, the drum, and the second active isolation mass, a primary eccentric weight attached to the eccentric shaft inside the drum, an active isolation eccentric weight attached to each of the eccentric shaft inside the first active isolation mass and the second active isolation mass, and a vibration motor configured to rotate the eccentric shaft. In accordance with the active isolation apparatus of the present disclosure, when the eccentric shaft is rotated, a phase of a vibration generated by the active isolation eccentric weights is opposite to that of a vibration generated by the primary eccentric weight, and the vibration generated by the active isolation eccentric weights cancels the vibration generated by the primary eccentric weight.

Method for laying down a pavement consisting of paving material with a road paver screed in which a compaction unit pre-compacts the paving material at cyclical work cycles with a selectable stroke and at a selectable frequency while the pavement is laid down at a selectable paving speed and at least the stroke is automatically adjustable in response to paving parameters.

The invention relates to a vibratory pile-driving apparatus having a carrier implement with a mast, on which, for the purpose of generating vibrations, a vibration generator with a transmission housing is supported, in which at least one pair of rotatably supported unbalanced units is arranged that are driven in a rotating manner by at least one rotary drive. According to the invention provision is made in that the transmission housing is surrounded by a soundproof housing, in which the transmission housing is supported by way of damping elements, and in that from the transmission housing at least one oil supply line and one oil discharge line are led out of the soundproof housing, wherein transmission oil can be cooled outside the soundproof housing.

A vibration motor includes a base portion arranged to extend perpendicularly to a central axis extending in a vertical direction; a cover portion arranged above the base portion, and fixed to an outer edge portion of the base portion; a lower bearing portion fixed to the base portion; an upper bearing portion fixed to the cover portion; a shaft arranged to extend along the central axis, and having a lower end portion and an upper end portion rotatably supported by the lower bearing portion and the upper bearing portion, respectively; a rotor holder attached to the shaft; a magnet portion including a plurality of magnetic poles, and attached to the rotor holder; an eccentric weight attached to the rotor holder; a circuit board arranged above the base portion; and a coil portion attached onto the circuit board, and arranged vertically opposite to the magnet portion with a space therebetween.

A vibration motor includes a base portion arranged to extend perpendicularly to a central axis extending in a vertical direction; a cover portion arranged above the base portion, and fixed to an outer edge portion of the base portion; a lower bearing portion fixed to the base portion; an upper bearing portion fixed to the cover portion; a shaft arranged to extend along the central axis, and having a lower end portion and an upper end portion rotatably supported by the lower bearing portion and the upper bearing portion, respectively; a rotor holder attached to the shaft; a magnet portion including a plurality of magnetic poles, and attached to the rotor holder; an eccentric weight attached to the rotor holder; a circuit board arranged above the base portion; and a coil portion attached onto the circuit board, and arranged vertically opposite to the magnet portion with a space therebetween.

A base portion of a vibration motor includes a first plate including a first plate recessed portion in an upper surface thereof; and a second plate arranged in the first plate recessed portion, and fixed to the first plate. One of the first and second plates is made of a magnetic metal, while another one is made of a nonmagnetic metal. An upper surface of the second plate is arranged at the same level as that of a portion of the upper surface of the first plate which lies adjacent to and along the first plate recessed portion. The second plate includes an annular second plate support portion centered on a central axis; and a plurality of second plate projecting portions arranged to project radially inward or radially outward from the second plate support portion, and arranged in a circumferential direction at a position vertically opposed to a magnet portion.

A base portion of a vibration motor includes a first plate including a first plate recessed portion in an upper surface thereof; and a second plate arranged in the first plate recessed portion, and fixed to the first plate. One of the first and second plates is made of a magnetic metal, while another one is made of a nonmagnetic metal. An upper surface of the second plate is arranged at the same level as that of a portion of the upper surface of the first plate which lies adjacent to and along the first plate recessed portion. The second plate includes an annular second plate support portion centered on a central axis; and a plurality of second plate projecting portions arranged to project radially inward or radially outward from the second plate support portion, and arranged in a circumferential direction at a position vertically opposed to a magnet portion.

A tamper drive includes a wobble shaft rotatable about a central axis. The wobble shaft includes an eccentric hub recess within a movable bearing coupled to a yoke. The movable bearing rotates when the wobble shaft rotates to induce reciprocal movement of the yoke. In another tamper drive, an eccentric portion of a wobble shaft is rotatable within a bearing coupled to or integrated with an offset lobe having a pin slidingly disposed therein. Still another tamper drive includes an arm having a shaft fixedly coupled to one end, and first and second cam followers disposed at the other end. A rotatable cam provides a cam surface for each of the first and second cam followers.