A rotation control system may be provided for a material handling machine. The rotation control system may include a boom and a work tool attached to the boom. A swing motor may be capable of swinging the boom and the work tool. A work tool motor may be capable of rotating the work tool relative to the boom. An input device may generate a first signal indicative of a desired swinging of the boom and a second signal indicative of a desired rotation of the work tool. A controller may be in communication with the input device, the swing motor, and the work tool motor. The controller may be capable of actuating the work tool motor based only on the second signal during a first mode of operation and may be capable of actuating the work tool motor based on swinging of the boom during a second mode of operation.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

The crane includes a swing brake device installed between a hydraulic motor and a control valve and having a flow restrictor; a first backpressure detector detecting a motor backpressure between the flow restrictor and one of ports of the hydraulic motor; a second backpressure detector detecting a motor backpressure between the flow restrictor and the other port of the hydraulic motor; and a control device. The control device has an external-force direction estimation unit that estimates a swing direction of an upperstructure under an external force acting on the upperstructure on the basis of a motor backpressure detected by the first backpuressure detector and a motor backpressure detected by the second backpressure during an operating state of the swing brake device. The control device has a notification control unit that causes the notification device to provide notification of the estimated swing direction of the upperstructure.

The crane includes a swing brake device installed between a hydraulic motor and a control valve and having a flow restrictor; a first backpressure detector detecting a motor backpressure between the flow restrictor and one of ports of the hydraulic motor; a second backpressure detector detecting a motor backpressure between the flow restrictor and the other port of the hydraulic motor; and a control device. The control device has an external-force direction estimation unit that estimates a swing direction of an upperstructure under an external force acting on the upperstructure on the basis of a motor backpressure detected by the first backpuressure detector and a motor backpressure detected by the second backpressure during an operating state of the swing brake device. The control device has a notification control unit that causes the notification device to provide notification of the estimated swing direction of the upperstructure.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

A hydraulic circuit for use on a construction machine includes a first valve, a second valve, and at least a third valve. The second and third valve each includes at least one inlet port connected to a first outlet port of the first valve. The first outlet port of each of the second and third valves are configured to reduce a first pressure to a second pressure and/or a third pressure downstream of the second valve and the third valve, respectively. The second valve and the third valve also include at least a second outlet port connected to a reservoir tank. A hydraulic motor is connected to the first outlet port of the second valve, which operates the hydraulic motor in a first direction. The hydraulic motor also is connected to the first outlet port of the third valve, which operates the hydraulic motor in a second direction.

A hydraulic machine includes an undercarriage; a rotating structure rotatably mounted on the undercarriage and configured to rotate with and with respect to the undercarriage; a first controller configured to receive user input and configured; a user interface configured to accept commands from a user and output a command signal to the controller; and a first gyroscope fixed to the rotating structure and electrically connected to the controller and configured to provide a data signal of rotation information of the rotating structure to the controller. An axis of rotation of the gyroscope is parallel to the axis of rotation of the rotating structure. The controller is configured to generate a control signal to control the rotating structure and cause the rotating structure to rotate with respect to the undercarriage based on the command signal from the user interface and the data signal from the first gyroscope.

A hydraulic machine includes an undercarriage; a rotating structure rotatably mounted on the undercarriage and configured to rotate with and with respect to the undercarriage; a first controller configured to receive user input and configured; a user interface configured to accept commands from a user and output a command signal to the controller; and a first gyroscope fixed to the rotating structure and electrically connected to the controller and configured to provide a data signal of rotation information of the rotating structure to the controller. An axis of rotation of the gyroscope is parallel to the axis of rotation of the rotating structure. The controller is configured to generate a control signal to control the rotating structure and cause the rotating structure to rotate with respect to the undercarriage based on the command signal from the user interface and the data signal from the first gyroscope.

The invention relates to an electro-hydraulic device for moving a jib for a tower crane, in which device the motor of the hydraulic unit is switched off when the position of the jib is not altered for a predetermined time period.