Device for the continuous adjustment of unbalance of steerable vibration plates

A device operable to adjust first and second adjustable unbalanced masses mounted on a common shaft on a vibration plate, comprising:

• a storage unit for a hydraulic fluid;
• a delivery pump having an inlet connected to the storage unit;
• a first double acting hydraulic cylinder connected to the first unbalanced mass and a second double acting hydraulic cylinder connected to the second unbalanced mass, each of the first and second double-acting hydraulic cylinders having a first and a second fluid chamber and a piston that separates the first and second fluid chambers from one another,
• wherein the piston of the first hydraulic cylinder is configured to actuate the first unbalanced mass and the second hydraulic cylinder is configured to actuate the second unbalanced mass,
• wherein the position of the piston of the first double acting hydraulic cylinder is adjustable independently of the position of the piston of the second double acting hydraulic cylinder, and vice versa, and
• wherein, in order to displace each piston, one of the first and second fluid chambers is selectively fluidically connected to the outlet of the delivery pump and, at the same time, the other of the first and second fluid chambers is connected to the storage unit.

A method of adjusting first and second unbalanced masses mounted on a common shaft on a vibration plate, the method comprising the steps of:

• providing first and second double acting hydraulic cylinders, each of which has a piston operatively connected to a respective one of the first and second unbalanced masses and first and second chambers disposed on opposite sides of the piston;
• directing pressurized fluid from an outlet of a pump to the first chamber of at least one of the first and second double acting hydraulic cylinders while fluidly connecting the second chamber of the at least one double acting cylinder to an unpressurized storage unit in order to actuate the unbalanced mass associated with the at least one double acting cylinder;
• then
• operating a valve arrangement to isolate the first and second chambers of the at least one double acting hydraulic cylinder from both the outlet of the pump and the unpressurized storage unit in order to fix the piston of the at least one double acting cylinder in position.

A method of adjusting first and second unbalanced masses mounted on a common shaft on a vibration plate, the method comprising the steps of:

• providing first and second double acting hydraulic cylinders, each of which has a piston connected to a respective one of the first and second unbalanced masses and first and second chambers disposed on opposite sides of the piston;
• directing pressurized fluid from an outlet of a pump to the first chamber of at least one of the first and second double acting hydraulic cylinders while fluidly connecting the second chamber of the at least one double acting cylinder to an unpressurized storage unit in order to actuate the unbalanced mass associated with the at least one double acting cylinder;
• and
• operating a valve arrangement to regulate fluid flow to and from the first and second double acting hydraulic cylinders independently of one another, hence actuating the first and second unbalanced masses independently of one another.