Abstract: Boom operating valves, a stick operating valve, etc. for respectively controlling hydraulic fluid fed from hydraulic pumps to boom cylinders, a stick cylinder, and other actuators are provided with center by-pass lines Cb. A stick-in meter-out load pressure compensating valve is provided on a rod-side return line, which extends from a rod side of the stick cylinder to a tank. A pressure sensor is provided at the rod side of the stick cylinder so as to detect pressure of hydraulic fluid fed to the rod side. The center by-pass line Cb associated with the stick operating valve is provided with an electromagnetic relief valve for controlling the pressure in the portion of the center bypass line downstream from the stick operating valve so as to increase the pressure in accordance with.

Abstract: Provided is a catalyst for reducing and decomposing oxygen in gas, highly efficiently and stably in from a low temperature region to a relatively high temperature region, in the presence of a reducing substance, containing at least one kind of a metal oxide selected from the group consisting of Ti, Si, W, Mo, Zr and Fe, as a catalyst component A; and at least one kind of a metal selected from the group consisting of Pt, Pd, Rh, Ir, Ru, Ni and Co, and/or a metal oxide thereof, as a catalyst component B; in removing oxygen, presence of a reducing substance in gas is effective.

Abstract: A vibration control mount apparatus capable of absorbing an initial pushing-up load based on a shock and capable of promptly damping a residual vibration generated after the shock. The vibration control mount apparatus includes a case body mounted on a turning frame, a mount rubber is mounted on the case body. A magnetic viscous fluid of which viscosity is changed by a magnetic filed is sealed in a sealing chamber in the case body. A movable body supported by the mount rubber has a damper plate which moves while receiving resistance from the magnetic viscous fluid in the sealing chamber. Viscosity variable controlling device forms the magnetic field in accordance with vibration acceleration detected by the acceleration detecting device to change the viscosity of the magnetic viscous fluid.

Abstract: First and second displacement variable regenerating hydraulic motors are provided in third and fourth flow rate control lines which function as discharge flow paths for oil discharged, respectively, from first and second oil supply and discharge ports of a hydraulic motor, where controlling the displacement of the regenerating hydraulic motors allows the flow rate of discharge oil as well as the pressure of the third and fourth flow rate control lines to be controlled. First and second generators which generate electric power due to the rotation of the first and second regenerating hydraulic motors are further provided.

Abstract: A first fluid channel for operating an actuator and a second fluid channel for operating an actuator are connected to a boom cylinder, including a boom rod side line, a boom head side line. A first and second supply line and a first and second discharge line of each of the first and second fluid channels, respectively, are connected to first and second meter-in control valve and first and second meter-out control valves, respectively. When the boom operating lever is returned an operating position to a neutral position, a pressure vibration generated in each fluid channel for operating the actuators is detected, and respective meter-in control valves and meter-out control valves are controlled to dampen the pressure vibration in each fluid channel.

Abstract: A first fluid channel for operating an actuator and a second fluid channel for operating an actuator are connected to a boom cylinder, including a boom rod side line, a boom head side line. A first and second supply line and a first and second discharge line of each of the first and second fluid channels, respectively, are connected to first and second meter-in control valve and first and second meter-out control valves, respectively. When the boom operating lever is returned an operating position to a neutral position, a pressure vibration generated in each fluid channel for operating the actuators is detected, and respective meter-in control valves and meter-out control valves are controlled to dampen the pressure vibration in each fluid channel.

Abstract: An oil cooler for cooling hydraulic oil that has increased in temperature due to energy loss in a hydraulic circuit a radiator for cooling engine cooling water that has increased in temperature as a result of cooling an engine and an ATAAC for cooling engine intake air that has increased in temperature as a result of being compressed by a turbocharger, are provided with heat pipes for vaporizing low-boiling medium by absorbing heat from the oil cooler the radiator and the ATAAC. A power recovery turbine is rotated by energy provided by vaporized low-boiling medium is provided for the engine. A low-boiling medium circuit is provided so as to drive the turbine by feeding the low-boiling medium that has been vaporized by waste heat energy. The low-boiling medium circuit includes the heat pipes of the oil cooler the radiator, and the ATAAC, as well as the turbine.

Abstract: Engineers are constantly seeking methods to reduce undesirable emissions, noise, and vibrations created by power systems. In the present invention, a power system includes at least one hydraulic cylinder that defines a first fluid volume and a second fluid volume separated from one another via a moveable plunger. Hydraulic power created within the hydraulic cylinder is converted to mechanical energy by a variable displacement hydraulic motor that is fluidly connected to at least the first fluid volume. A generator is attached to the variable displacement hydraulic motor, and produces electrical power that is stored in a power storage system. The stored power can be supplied to an electric motor that is operable to power a hydraulic pump. The hydraulic pump supplies hydraulic fluid to the hydraulic cylinder. The power system of the present invention is a relatively efficient alternative to a power system including a diesel engine that can be a source of undesirable emissions, noise and vibrations.

Abstract: A hydraulic system for a work machine is disclosed. The hydraulic system includes a tank adapted to store a supply of fluid and a source of pressurized fluid in fluid communication with the tank. A first hydraulic actuator and a second hydraulic actuator are in fluid communication with the source of pressurized fluid. A first fluid return line is adapted to direct a return flow of fluid from the first hydraulic actuator to the tank and a second fluid return line is adapted to direct a return flow of fluid from the second hydraulic actuator to the tank. A pressure control device is disposed in the second fluid return line and is operable to selectively adjust a magnitude of fluid pressure in the second fluid return line.

Abstract: First and second displacement variable regenerating hydraulic motors are provided in third and fourth flow rate control lines which function as discharge flow paths for oil discharged, respectively, from first and second oil supply and discharge ports of a hydraulic motor, where controlling the displacement of the regenerating hydraulic motors allows the flow rate of discharge oil as well as the pressure of the third and fourth flow rate control lines to be controlled. First and second generators which generate electric power due to the rotation of the first and second regenerating hydraulic motors are further provided.

Abstract: A method and apparatus to improve regeneration efficiency when regenerating the energy of discharge fluid from a fluid pressure actuator as electrical energy. In a flow rate control line 15, which finctions as a discharge flow path for oil discharged from a head side oil chamber 1c of a hydraulic cylinder 1, is provided a displacement variable regenerating hydraulic motor 20, where controlling the displacement of the regenerating hydraulic motor 20 allows the flow rate of discharge oil from the hydraulic cylinder head side oil chamber 1c to be controlled. A generator 21, which generates electric power due to the rotation of the regenerating hydraulic motor 20, is further provided.

Abstract: In the present invention, a power system includes at least one hydraulic cylinder that defines a first fluid volume and a second fluid volume separated from one another via a moveable plunger. Hydraulic power created within the hydraulic cylinder is converted to mechanical power by a fluid driven rotating device that is fluidly connected to at least the first fluid volume. A generator is attached to the fluid-driven rotating device, and produces electrical power that is stored in a power storage system including at least one of a battery and a capacitor. The stored electrical power can be supplied to an electric motor that is operable to power a hydraulic pump. The hydraulic pump supplies hydraulic fluid to the hydraulic cylinder. The power system of the present invention is a relatively inexpensive and efficient alternative to a power system including a diesel engine that can be a source of undesirable emissions, noise and vibrations.

Abstract: Engineers are constantly seeking methods to reduce undesirable emissions, noise, and vibrations created by power systems. In the present invention, a power system includes at least one hydraulic cylinder that defines a first fluid volume and a second fluid volume separated from one another via a moveable plunger. Hydraulic power created within the hydraulic cylinder is converted to mechanical energy by a variable displacement hydraulic motor that is fluidly connected to at least the first fluid volume. A generator is attached to the variable displacement hydraulic motor, and produces electrical power that is stored in a power storage system. The stored power can be supplied to an electric motor that is operable to power a hydraulic pump. The hydraulic pump supplies hydraulic fluid to the hydraulic cylinder. The power system of the present invention is a relatively efficient alternative to a power system including a diesel engine that can be a source of undesirable emissions, noise and vibrations.

Abstract: In the present invention, a power system includes at least one hydraulic cylinder that defines a first fluid volume and a second fluid volume separated from one another via a moveable plunger. Hydraulic power created within the hydraulic cylinder is converted to mechanical power by a fluid driven rotating device that is fluidly connected to at least the first fluid volume. A generator is attached to the fluid-driven rotating device, and produces electrical power that is stored in a power storage system including at least one of a battery and a capacitor. The stored electrical power can be supplied to an electric motor that is operable to power a hydraulic pump. The hydraulic pump supplies hydraulic fluid to the hydraulic cylinder. The power system of the present invention is a relatively inexpensive and efficient alternative to a power system including a diesel engine that can be a source of undesirable emissions, noise and vibrations.

Abstract: A hydraulic system for a work machine is disclosed. The hydraulic system includes a tank adapted to store a supply of fluid and a source of pressurized fluid in fluid communication with the tank. A first hydraulic actuator and a second hydraulic actuator are in fluid communication with the source of pressurized fluid. A first fluid return line is adapted to direct a return flow of fluid from the first hydraulic actuator to the tank and a second fluid return line is adapted to direct a return flow of fluid from the second hydraulic actuator to the tank. A pressure control device is disposed in the second fluid return line and is operable to selectively adjust a magnitude of fluid pressure in the second fluid return line.

Abstract: The invention relates to a hydraulic control apparatus for a construction machine. The hydraulic control apparatus includes a target velocity table (4) which stores target actuation velocities of a hydraulic actuator (30) corresponding to operation amounts of the operation member (2) to be operated by the operator, a target acceleration table (5) which stores target actuation accelerations of the hydraulic actuator (30) corresponding to operation amounts of the operation member (2), and one of the target velocity table (4) and the target acceleration table (5) can be selected by operation of a selection switch (3) by the operator. Further, by the control means, the target value corresponding to the operation amount of the operation member (2) using the table selected by the selection switch (3), and a control valve (17) for controlling the pressure oil supplying amount from a hydraulic pump (16) to the hydraulic actuator (30) is controlled based on the set target value.

Abstract: The invention relates to a hydraulic control apparatus for a construction machine. The hydraulic control apparatus includes a target velocity table (4) which stores target actuation velocities of a hydraulic actuator (30) corresponding to operation amounts of the operation member (2) to be operated by the operator, a target acceleration table (5) which stores target actuation accelerations of the hydraulic actuator (30) corresponding to operation amounts of the operation member (2), and one of the target velocity table (4) and the target acceleration table (5) can be selected by operation of a selection switch (3) by the operator. Further, by the control means, the target value corresponding to the operation amount of the operation member (2) using the table selected by the selection switch (3), and a control valve (17) for controlling the pressure oil supplying amount from a hydraulic pump (16) to the hydraulic actuator (30) is controlled based on the set target value.

Abstract: A fluid control system includes a pump, a tank, and an actuating cylinder having a rod end chamber and a head end chamber. The fluid control system also includes an independent metering valve arrangement and a pressure sensor configured to sense a pressure of fluid at the head end chamber. A controller communicates with the valve assembly and the pressure sensor. The controller selectively actuates at least one valve of the independent metering valve arrangement based on the sensed pressure at the head end chamber and a mode of operation of the control system.

Abstract: A control valve in fluid communication with an actuator may include a pressurized pilot supply and a fluid reservoir fluidly connected to a passageway defined by a valve body. A pilot operator is selectively moveable within the passageway, and a flow metering operator is moveably disposed within the passageway. A fluid make-up operator, disposed in the passageway and in fluid communication with the fluid reservoir and the actuator, directs pressurized pilot supply fluid in response to a decrease in actuator pressure coinciding with a cavitation condition within the actuator. A control chamber within the valve body contains pressurized fluid from the pilot supply and is in fluid communication with the flow metering operator. The flow metering operator fluidly connects the actuator with the fluid reservoir under the influence of the pressurized fluid within the control chamber through activation by either the pilot operator or the fluid make-up operator.

Abstract: A fluid control system includes at least one double-acting cylinder and at least one fluid-driven motor. A pressurized fluid source supplies pressurized fluid flow to the at least one double-acting cylinder and the at least one fluid-driven motor, and a tank receives return fluid flow from the at least one double-acting cylinder and the at least one fluid-driven motor. A back pressure element is disposed between the tank and the motor and may influence a fluid backpressure condition of fluid discharged from the motor. A dedicated flow line may provide make-up fluid to the motor at a location between the motor and the back pressure element.