5457results about "Servomotors" patented technology

Hydraulic fill and drain of a clutch chamber is controlled with a blocking valve and a trim valve. The blocking valve selectively provides pressurized fluid to the trim valve which in turn selectively provides the pressurized fluid to the clutch chamber. Exhausting of the clutch chamber is effected through one of two alternate paths utilizing deactivation of one of the trim and blocking valves. Back up exhausting of the clutch chamber is effected through the other of the alternative paths. Such system allows for determination of valve failures and continued operation until such failures can be rectified.

The invention relates to systems and methods for rapidly and isothermally expanding and compressing gas in energy storage and recovery systems that use open-air hydraulic-pneumatic cylinder assemblies, such as an accumulator and an intensifier in communication with a high-pressure gas storage reservoir on a gas-side of the circuits and a combination fluid motor/pump, coupled to a combination electric generator/motor on the fluid side of the circuits. The systems use heat transfer subsystems in communication with at least one of the cylinder assemblies or reservoir to thermally condition the gas being expanded or compressed.

An energy recovery system for a machine is disclosed. The energy recovery system may have a pump configured to provide a flow of pressurized fluid. The energy recovery system may also have a first fluid actuator with a first chamber and a second chamber and being configured to receive the pressurized fluid, a second fluid actuator with a third chamber and a fourth chamber and being configured to receive the pressurized fluid, and a first valve fluidly connected between the pump and the first and second actuators. The energy recovery system may additionally include an isolation unit with a first selectively restrictable passageway fluidly connecting the first chamber, the third chamber, and a first outlet of the first valve, and a second selectively restrictable passageway fluidly connecting the second chamber, the fourth chamber, and a second outlet of the first valve, as well as an energy recovery unit in fluid communication with the isolation unit. The isolation unit may be configured to direct a flow of pressurized fluid from the second actuator to the energy recovery unit. The energy recovery unit may be configured to convert the flow of pressurized fluid to a first mechanical power output.

The invention relates to systems and methods for rapidly and isothermally expanding gas in a cylinder. The cylinder is used in a staged hydraulic-pneumatic energy conversion system and includes a gas chamber (pneumatic side) and a fluid chamber (hydraulic side) and a piston or other mechanism that separates the gas chamber and fluid chamber while allowing the transfer of force/pressure between each opposing chamber. The gas chamber of the cylinder includes ports that are coupled to a heat transfer subassembly that circulates gas from the pneumatic side and exchanges its heat with a counter flow of ambient temperature fluid from a reservoir or other source.

A hydraulic system has a valve assembly with two workports coupled to chambers of first and second cylinders which are connected mechanically in parallel to a machine component. A separation control valve is connected between first chambers of both cylinders, and a shunt control valve is connected between the workports. A recovery control valve couples an accumulator to the first chamber of the second cylinder. Opening and closing the valves in different combinations routes fluid from one or both cylinders into the accumulator where the fluid is stored under pressure, and thereafter enables stored fluid to be used to power one or both cylinders. The shunt control valve is used to route fluid exhausting from one chamber of each cylinder to the other chambers of those cylinders. Thus the hydraulic system recovers and reuses energy in various manners.

A driving device of a work machine includes a power generator adapted to be driven by an engine, and a power storage device for storing the electric power generated by the power generator. Electric motors and a motor generator, both adapted to be operated by electric power supplied from either one or both of the power generator and the power storage device respectively drive pumps and a pump motor. Supporting circuits for feeding supporting hydraulic oil are provided between a plurality of driving circuits that drive a plurality of hydraulic actuators of a working unit by oil hydraulics generated by the pumps and the pump motor. By enabling the plurality of driving circuits to effectively share excess energy, the invention makes possible a compact construction of a driving device of a work machine.

A hybrid machine with a hydraulic drive device having hydraulic actuators allowed to operate against and by external loads is provided. To this end, the hybrid machine comprises hydraulic cylinders (7), first hydraulic pumps (P1) connected, with closed circuits, to head side pressure receiving chambers (7S) and bottom side pressure receiving chambers (7L) of the hydraulic cylinders (7), and second hydraulic pumps (P2) connected, with open circuits, to the bottom side pressure receiving chambers (7L) and an external oil chamber (10), wherein the first and second hydraulic pumps (P1, P2) are connected to electric motors (M) so as to be driven.

A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

The present invention relates to a method for attenuating the motion of hydraulic cylinders of mobile work machinery, in particular of hydraulic excavators, in which prior to the hydraulic cylinder reaching one of the limits of travel, its motion speed is reduced, and the hydraulic cylinder is moved to the respective limit of travel at reduced speed; wherein for the purpose of reducing the speed, the inflow to, and/or the outflow from, the hydraulic cylinder are/is throttled by a flow control device. According to the invention, the method is characterized by, prior to the respective limit of travel being reached, the motion speed of the hydraulic cylinder is registered, and the point in time when throttling commences is changed depending on the registered motion speed. Furthermore, the present invention relates to a device for attenuating the motion of hydraulic cylinders of mobile work machinery, in particular of hydraulic excavators, a position registering device for registering a preliminary limit position of the hydraulic cylinder, a control device for throttling the inflow and/or outflow of the hydraulic cylinder, and a control device for controlling the flow control device when the preliminary limit position is reached. According the invention, the device has a speed registering device for registering the motion speed of the hydraulic cylinder when the preliminary limit position is reached, and the control device has a delay device for delaying driving the flow control device, depending on the recorded motion speed.

The system includes a hydraulic powered actuator. A pump system having first and second hydraulic lines is coupled to the first and second ports, respectively and is capable of providing hydraulic fluid to either the first and second lines. First and second pressure sensors are coupled to the first and second lines, respectively. A third line is coupled between the first and second lines and includes first and second valves mounted in series therein. Preferably, the first and second valves are capable of latching in the open position. A reservoir is coupled to the third line between the first and second valves. A shut off valve is included for cutting off the flow from the reservoir.

A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

A hydraulic circuit that enables smooth absorption of the energy of a return fluid from a hydraulic actuator by means of an energy recovery motor. A return fluid passage to which the fluid discharged from a boom cylinder is branched is provided at the tank passage side of a solenoid valve of a boom control circuit. The return fluid passage comprises two return passages, which are provided with a flow rate ratio control valve for controlling a ratio of fluid that branches off into the return passages. The flow rate ratio control valve is comprised of a solenoid valve disposed in the return passage, which is provided with an energy recovery motor, and a solenoid valve disposed in the return passage, which branches off the upstream side of the solenoid valve.

A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

A cylinder assembly is disclosed. The cylinder assembly may include a cylinder body having an internal cavity therein and a piston and rod assembly disposed for axial movement within the internal cavity of the cylinder body. The piston and rod assembly may have an axial passage extending therein. The cylinder assembly may further include a tubular element received within the axial passage of the piston and rod assembly. At least a portion of the tubular element may extend out of the axial passage and into the internal cavity of the cylinder body between the axial passage and a wall of the cylinder body.

A cylinder driving system capable of reducing the number of hydraulic devices and the amount of energy loss and an energy regenerating method thereof are provided. To this end, the system includes i) a hydraulic cylinder, ii) a hydraulic pump having three suction/discharge ports of a first port for supplying oil to a bottom chamber of the hydraulic cylinder or draining oil from the bottom chamber, a second port for draining oil from a head chamber of the hydraulic cylinder or supplying oil to the head chamber, and a third port for draining oil from a tank or supplying oil to the tank, the suction rate or the discharge rate in the first port being the sum of the respective discharge rates or suction rates in the second port and the third port, and iii) a driving source for driving the hydraulic pump.

Apparatus and method for controlling a hydraulic actuator in an injection molding machine, where the hydraulic actuator moves in a linear or rotary manner to effect movement of an injection molding device, such as a mold clamp. A microcontroller is locally disposed adjacent to the actuator or the hydraulic fluid distribution manifold to cause the actuator to drive the device. The microcontroller is electrically coupled to the system control processor. This distributed control architecture increases system processing throughput, enhances reliability, and permits easier upgrades/repair. Preferably, the microcontroller is mounted on the manifold and controls all of the actuators supplied from that manifold.

The present invention provides a speed governor (5) suitable for use in a fluid driven down-hole tool (3). The speed governor comprises an actuator (7) operatively coupled to a motive fluid flow control valve (6). The actuator is and arranged so as to be activatable, directly or indirectly, in response to the running speed of the tool (3), for opening of the control valve (6) with increasing rotational speed of the motor (3) above a predetermined speed limit thereby to limit the rotational speed of the downhole tool (3).

A hoisting device can be small-sized and energy can be saved. A hoisting device 10 according to the present invention has a hoist 30 and a control unit 32. The hoist 30 rotates a drum 12 having a wire 14 wound thereon by an oil pressure motor 42 rotatable in normal and reverse directions. To the oil pressure motor 42, operating oil is supplied from an oil pressure pump 44. The oil pressure pump 44 is a two-way discharge fixed capacity type, and rotated by a servomotor 46. An acceleration/displacement transducer 34 in the control unit 32 finds a moving direction and a moving speed of a wire hanging point in the vertical direction from an output signal of an acceleration sensor 24. The control unit 32 outputs a drive control signal of the servomotor 46 according to a paying-out speed or a rolling-up speed of the wire 14 offsetting the vertical motion of the wire hanging point caused by the heaving of a hull based on a speed instruction Vi of the paying-out or rolling-up speed of the wire, a detected signal of the acceleration sensor 24 and a detected signal of a wire speed sensor 26.

According to principles of this invention, an override controller is structured for being placed in pressurized fluid lines between a valve position transducer and a valve position actuator of an automatic position-controlled valve assembly, with the override controller receiving uncontrolled supply pressurized fluid and having an exhaust. The override controller receives pressurized fluid at first and second inlet ports from the valve position transducer and furnishes this pressurized fluid to the valve position actuator through first and second outlet ports for controlling the position of the valve during normal operation. However, valve mechanisms of the override controller can also be placed in positions for stopping flow of pressurized fluid through the first and second inlet ports and providing fluid flow from the uncontrolled pressurized fluid to the first and second outlet ports for controlling the position of an industrial valve during override operation.

First and second hydraulic pumps each adapted to operate plural actuators are activated by separate electric motors respectively. In accordance with signals provided from a controller on the basis of operations of levers, the number of revolutions of the electric motor and that of the electric motor are controlled each independently and simultaneously to control the discharge rates of both hydraulic pumps.

A hydraulic system is disclosed. The hydraulic system includes an actuator including a first, a second, and a third fluid chamber. The hydraulic system also includes a high pressure source of pressurized fluid in selective fluid communication with the first and second fluid chambers. The hydraulic system also includes a low pressure source of pressurized fluid in selective fluid communication with the first and second fluid chambers. The hydraulic system further includes a hydraulic motor in fluid communication with the third fluid chamber.

An electrically powered steering device comprises a ball screw mechanism for transmitting a steering force from a steering wheel to steerable vehicle wheels. The ball screw mechanism includes a rotary nut 11 having a nut body 11a in which a circulating passage 15 is formed so as to extend axially thereof, and end caps 14a and 14b secured respectively to opposite ends of the nut body 11a. Each of the end caps 14a and 14b has defined therein respective guideways 17a and 17b for balls 13 that communicate opposite ends of the circulating tunnel 14 with a ball rolling passage 12. The end caps 14a and 14b and the nut body 11a are made of a sintered alloy. The nut body 11a has an outer periphery of one end thereof that is axially progressively reduced in diameter to define a tapered surface.

In a fluid displacement system having a pressure vessel, an expansion vessel, first and second tubes in fluid communication with the two vessels, and an energy source, fluid contained within the system is transferred from one vessel to the other by activating the energy source, which in turn generates pressure in the pressure vessel. The generated pressure in the pressure vessel, in turn, displaces the fluid in the expansion vessel, and the system advantageously has no moving parts.

A flow rate control device in a hydraulic excavator, comprising a hydraulic pump which is driven rotatively by an engine, a hydraulic actuator which is driven by a hydraulic oil discharged from the hydraulic pump, a control valve which controls the supply of the hydraulic oil to the hydraulic actuator, an operating means which operates the control valve so as to change over the valve from one position to another, a relief valve disposed in a discharge oil path extending from the hydraulic pump to limit the maximum pressure in the discharge oil path, an operational condition detecting means for detecting an operational condition of the hydraulic actuator, a pump pressure detecting means for detecting the discharge pressure of the hydraulic oil discharged from the hydraulic pump, a flow rate adjusting means for adjusting the discharge flow rate of the hydraulic oil discharged from the hydraulic pump, and a control means to which are inputted detection signals from both the operational condition detecting means and the pump pressure detecting means. When a specific operational condition of the hydraulic actuator is detected and when the said discharge pressure is held at a predetermined relief cut-off pressure or higher for a predetermined period of time, the control means makes control so that the discharge flow rate of the hydraulic oil discharged from the hydraulic pump is decreased to a relief cut-off pressure by the flow rate adjusting means. According to this construction, the relief cut-off control can be made only where required for each of various works of different conditions which the hydraulic excavator performs, such as excavating work, crushing work and land readjusting work. That is, even when the discharge pressure is held at a predetermined relief cut-off pressure or higher for a predetermined period of time, the relief cut-off control is made if the hydraulic actuator is in the specific operational condition.

The present invention relates to a hydraulic pressurization system, in particular for application to pressurization devices operating in accordance with the high hydrostatic pressure principle. In particular, the present invention provides a pressurization system for modifying the pressure in a pressurization device. The system comprising a first hydraulic circuit in which one or more primary pressure accumulators are connected to the pressurization device in controlled manner in order to permit a substantially incompressible fluid to be admitted to and removed from the pressurization device at a first pressure, the primary pressure accumulators being precompressed-gas pressure accumulators.

Hydraulic systems and methods for using such systems in a variety of machinery, including but not limited to machines having multiple functions performed by one or more hydraulic circuits. The systems enable valves and actuators within the systems to reconfigure themselves so that flow from assistive loads on one or more actuators can be used to move one or more other actuators subjected to a resistive load.

A hydraulic control apparatus for a working machine in which a flow rate and a direction of pressure oil discharged from a hydraulic pump are controlled by a control valve to supply it to a swing motor, comprising: a bleed-off oil path for bleeding off a part of the pressure oil supplied to the swing motor, a cut valve provided on the bleed-off oil path to adjust a bleed-off amount, a controller for controlling the cut valve through a solenoid proportional valve, and pressure sensors for detecting an operating amount of a remote control valve for swing, characterized in that the controller sets the bleed-off amount according to the operating amount detected by the pressure sensors, controls an opening area of the cut valve on the basis of the bleed-off amount set, and suppresses the shock when sudden swinging operation takes place.

A control system for a hydraulic steering cylinder utilizes a supply valve and a drain valve. The supply valve is configured to supply pressurized hydraulic fluid from a pump to either of two cavities defined by the position of a piston within the hydraulic cylinder. A drain valve is configured to control the flow of hydraulic fluid away from the cavities within the hydraulic cylinder. The supply valve and the drain valve are both proportional valves in a preferred embodiment of the present invention in order to allow accurate and controlled movement of a steering device in response to movement of a steering wheel of a marine vessel.

There is provided an abnormality determination unit that determines whether or not an output measurement unit is abnormal, in order to determine abnormality of the output measurement unit. When the output measurement unit is abnormal, the operation of an elastic actuator is controlled not in accordance with a measurement result of the output measurement unit but in accordance with an internal state model.