Devices, systems, and methods for detecting properties of motion of at least one component of fluid exchange devices, such as, for example, a pressure exchange device or system.

A hydraulic actuator includes two or more cylinder parts that nest inside each other, each cylinder part including a piston and piston rod forming an operating element and a cylindrical component, inside which the operating element is arranged, the piston of the inner cylinder part being inside the piston rod of the outer cylinder part, chambers formed for each cylinder part, a pressure-medium feed arrangement creating work-movement in the operating element by the pressure medium led to the chambers, a pressure-difference-controlled valve controlling operation of the hydraulic actuator between a first ducting and a second ducting, controlling the feed of the pressure medium among the chambers and a pressure-difference-controlled spool valve including a housing, connecting chambers and a spool arranged to move backwards and forwards in the housing to open and close the connections creating a work movement alternately by the operating element of the inner or outer cylinder part.

A shovel includes a lower traveling structure, an upper swing structure swingably mounted on the lower traveling structure, an engine mounted on the upper swing structure, a first hydraulic pump and a second hydraulic pump each configured to be driven by the engine, a first regulator configured to control the first geometric displacement of the first hydraulic pump, a second regulator configured to control the second geometric displacement of the second hydraulic pump, and processing circuitry configured to electrically control the first and second regulators. Each of the first and second hydraulic pumps is an electrically controlled variable displacement hydraulic pump. The processing circuitry is configured to calculate the limit value of the first and second geometric displacements based on the respective discharge pressures of the first and second hydraulic pumps, and to control each of the first and second geometric displacements based on the calculated limit value.

A shovel includes a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an attachment including a boom and an arm, a boom cylinder configured to drive the boom, an arm cylinder configured to drive the arm, a hydraulic pump configured to supply hydraulic oil to the boom cylinder and the arm cylinder, an input device configured to receive an input from a user, and a control device configured to control the hydraulic pump. The boom is attached to the upper turning body, and the arm is attached to a tip of the boom. When a predetermined work mode for performing hoisting work involving use of the attachment is selected in response to the input received by the input device, the control device sets a standby flow rate of the hydraulic pump to be greater than when the predetermined work mode is not selected.

A shovel includes an undercarriage, an upper slewing structure which is rotatably mounted on the undercarriage, a boom attached to the upper slewing structure, an arm attached to a tip end of the boom, an auxiliary attachment attached to a tip end of the arm, a main pump configured to supply a hydraulic oil to the auxiliary attachment and other hydraulic actuators, and a controller. The controller performs a setting related to a flow rate of the main pump at a time of a combined operation in which the auxiliary attachment and the other hydraulic actuators are operated simultaneously.

A shovel includes an undercarriage, an upper slewing structure which is rotatably mounted on the undercarriage, a boom attached to the upper slewing structure, an arm attached to a tip end of the boom, an auxiliary attachment attached to a tip end of the arm, a main pump configured to supply a hydraulic oil to the auxiliary attachment and other hydraulic actuators, and a controller. The controller performs a setting related to a flow rate of the main pump at a time of a combined operation in which the auxiliary attachment and the other hydraulic actuators are operated simultaneously.

A hydraulic cylinder comprising a cylinder, a piston element movably guided in the cylinder in a working direction and comprising an active surface, and a first opening for feeding a fluid into a cylinder chamber by the active surface. A working pressure of the fluid acting on the active surface drives the piston element in the working direction. The active surface includes a first partial surface and at least one second partial surface, the cylinder chamber being divided into a first sub chamber with the first opening by the first active surface and a second partial surface with a second opening by the second partial surface, and the partial surfaces are hydraulically separated from each other at least in a selectable operating mode.

A hydraulic system includes: a travel motor; travel pump connected to the travel motor, the travel pump driven by an engine; a work pump that sucks hydraulic oil from a tank through a suction line, and supplies the oil to a work hydraulic actuator through a delivery line, the work pump driven by the engine; a switching valve connected to the delivery line, and connected to a part of the suction line downstream of the check valve; and an accumulator connected to the switching valve. The switching valve switches between a neutral position in which the switching valve blocks a pressure accumulation line, a pressure release line, and the relay line, the pressure accumulation position in which the switching valve wherein the pressure accumulation line communicates with the relay line, a pressure release position in which the switching valve brings the relay line into communication with the pressure release line.

A slewing-type work machine includes a slewing state determination section which determines whether or not slewing motion of an upper slewing body is in a deceleration state, and a capacity control section which controls a motor capacity. The capacity control section sets the motor capacity to a capacity set for a combined operation during a performance of the combined operation in which an operation for slewing the upper slewing body and an operation for actuating an attachment are performed simultaneously, while setting the motor capacity to a preset default capacity even during the performance of the combined operation when the slewing state determination section determines that the slewing motion of the upper slewing body is in the deceleration state.

A slewing-type work machine includes a slewing state determination section which determines whether or not slewing motion of an upper slewing body is in a deceleration state, and a capacity control section which controls a motor capacity. The capacity control section sets the motor capacity to a capacity set for a combined operation during a performance of the combined operation in which an operation for slewing the upper slewing body and an operation for actuating an attachment are performed simultaneously, while setting the motor capacity to a preset default capacity even during the performance of the combined operation when the slewing state determination section determines that the slewing motion of the upper slewing body is in the deceleration state.