Abstract: A pressure sensor (17) is provided for detecting the discharge pressure of a hydraulic pump (11). An abnormality detection section (23) of a controller (21) detects a dry operation of the hydraulic pump (11) when the discharge pressure detected by the pressure sensor (17) becomes equal to or lower than a judgment reference pressure determined in advance according to the driving rotation speed of the hydraulic pump (11).

Abstract: An exemplary embodiment of the jet motor includes a control sleeve, and power shaft having at least one opening thereon. The power shaft is rotatable in relation to the control sleeve. The power shaft has a central longitudinal shaft axis and upper and lower ends. The at least one opening in the power shaft generates rotational torque when acting in cooperation with the control sleeve. The jet motor connects to a member that is in fluid communication with the source of drilling or cleaning fluid. Drilling or cleaning fluid pressure is directed to the at least one opening in the power shaft. The power shaft having at least one opening having an opening axis and an interior opening. The at least one opening may be acutely oriented with respect to a plane extending along the power shaft's central longitudinal axis wherein the plane intersects the opening axis at the interior opening. The at least one opening may be oriented toward the upper end of the power shaft to provide downward force.

Abstract: A wobble plate motor comprises a rotatable shaft having a bent end rigid with the shaft and an inclined plate journalled on the bent end. When only one side of the inclined plate is directly subjected to high pressure, the plate rolls on a base in the manner of a spinning coin as it decays, i.e. as its spin rate falls to a value where the coin is inclined to the axis of rotation. As the plate rotates, torque is generated on the rotatable shaft so the shaft may drive a work consumer such as a generator, pump or compressor.

Abstract: A device which converts mechanical deformation in electrical current, these mechanical deformations are generated as a result of liquid pressure over a part of the device. This device is integrated within an implantable lead and inserted into the cardiovascular system of a patient. The purpose of the device is to charge a battery which stores energy for various uses of other implantable devices.

Abstract: When water is pumped manually to the overhead tank, the weight of the water is felt on the opposite end of the lever. Thus, an equal or heavier weights to counter that weight is thought of. This idea works on the output process but not on the input process. However, unlike conventional water pumps, C-M1 works on both processes using techniques (the invention) that employ the underlying principle of equilibrium or perfect balance. These techniques have resulted to the discovery of C-M1, a very powerful perpetual motion machine capable of using equal or heavier weights to counter the weights on the other end of the lever on both the input and output operations. Therefore, since it is perfectly balance, pumping out 1 cubic meter of 10 water per stroke through a 1.6-meter diameter 500-meter high pipe, with a total water weight of 1,000 tons, is simple and easy job for C-M1.

Abstract: Hydraulic machine consisting of two identical rotors comprises two identical rotors R1 ed R2, to which the identical tubular circuits (C1, C2) and (C3, C4) are respectively attached, which with appropriate connections form two series Sc1=(C1, C3) and Sc2=(C2, C4), the equal and opposite oscillating movement generating alternatively in the liquid of each series an identical pulse of forces adapted to the operation of a pump or a turbine; an ama crankshaft imposing on R1 ed R2 an equal and opposite oscillating movement by means of the rod pistons b1.2 and the cranks ma1,2; in R1 in ? (0°, 90°) of ama it is developed the right-handed force of C1 and in ? (180°, 270°) the left-handed force of C2; while in R2 it is developed the force of C3 e C4 respectively in ? (180°,270°) and in ? (0°, 90°).

Abstract: The invention relates to a fluid control device comprising at least one fluid actuator, such as pistons, membranes, disks, base bodies comprising combinations thereof or similar and at least one cover element. Control/supply channels, which are fluidcally connected to fluid channels which are arranged in the base body, are arranged in the base body and/or in the cover element. The control/supply channels are defined between the base body and the at least one cover element by means of welding joints which are produced by laser welding.

Abstract: A hydraulic driver of a magnetic resonance elastography (MRE) system is provided. The hydraulic driver is adapted to be connected to at least a passive actuator for contacting with a subject. The hydraulic driver includes a pump, a hydraulic piston-cylinder unit operatively coupled to the pump, and a tube assembly. The tube assembly includes a proximal end in fluid communication with the hydraulic piston-cylinder unit and a distal end in fluid communication with the passive actuator. The passive actuator oscillates in response to hydraulic energy generated in a fluid in the hydraulic driver as the pump drives the piston forward and backward in the cylinder of the hydraulic piston-cylinder unit.

Abstract: A valve assembly is disclosed. The valve assembly may include a housing having an interior chamber, inlet port, outlet port, and control port. The valve assembly may further include a valve member configured to move within the interior chamber to permit flow between the inlet port and the control port and between the outlet port and the control port. The valve assembly may further include and an actuator configured to move the valve member to form a first opening and second opening to create flow forces tending to close the first and second opening. The valve member may also include a passageway in the valve member configured to direct fluid flow from the inlet port to the control port and from the control port to the outlet port, and counteract the flow forces at the first and second opening.

Abstract: A Hydraulic Gravity Harvester is disclosed; having a plural of slip buckets, each slip bucket has a piston that works with a valve that is connected to the lower end of each piston; each slip bucket reciprocates vertically within a cylinder. When the valve is in the closed position and the slip bucket is on the down stroke, it creates a positive pressure in the cylinder pushing fluid up to a reservoir positioned high above the slip buckets. Each slip bucket on the down stroke is connected so that the opposite valve is in the open position and on the up stroke, so the weight of the fluid that has pushed this slip bucket down now rest on the bottom of the cylinder. This allows the slip bucket that is on the down stroke to turn a shaft creating a rotational torque.

Abstract: A ground engaging vehicle including a movable member, a hydraulically driven actuator, a hydraulic pump, a plurality of valves and at least one hydraulic conduit. The hydraulically driven actuator is coupled to the movable member and the actuator has a first chamber and a second chamber. The plurality of non-proportional valves include a first valve, a second valve, a third valve and a fourth valve. The at least one hydraulic conduit couples the pump with the first valve and the second valve. The first valve is in direct fluid communication with the first chamber. The second valve is in direct fluid communication with the second chamber. The third valve is in direct fluid communication with the first chamber and the fourth valve is in direct fluid communication with the second chamber. The first valve and the second valve each include an open position and a closed position.

Abstract: A method is disclosed for operating a hydropneumatic device (1) for pressure multiplication, with a working piston and a multiplier piston (9) for pressure multiplication on to the working piston and with an accumulator piston (3) for an urgent movement of the working piston by forcing hydraulic fluid out of an accumulator chamber (12), wherein a ventilation opening (13) is provided in the accumulator chamber (12), through which air drawn into the accumulator chamber (12) can be discharged during a maintenance process. According to the invention for an operating mode in which power strokes are executed, the hydraulic fluid volume in the accumulator chamber (12) is discharged below the ventilation opening (13) in the accumulator chamber. The hydraulic fluid pump is additionally disclosed.

Abstract: An actuator comprising an enclosure having a wall impermeable to a first solute and permeable to a solvent and containing, at least temporarily, a catalyst capable of promoting the transformation of at least one second solute into the first solute to vary the osmotic pressure in the enclosure; and a deformable chamber connected to the enclosure, said chambre being capable of increasing in volume under the action of the solvent moving from the enclosure into the chamber by osmosis or said enclosure being designed to be arranged in contact with the solvent, said chamber being capable of increasing in volume under the action of the solvent penetrating into the enclosure by osmosis.

Abstract: A rotary engine is disclosed, which may include a housing having at least one inlet valve and at least one outlet valve. The rotary engine may also include at least one chamber coupled to the housing and to the at least one inlet valve, a generally cylindrical driveshaft extending through the housing, and a rotor that is rotationally mounted in the housing on the driveshaft. The rotor may include a plurality of recessed portions situated radially along the peripheral surface of the rotor. The plurality of recessed portions may be used for receiving a plurality of spheres, for example. The plurality of spheres may be rotationally engaged between an inner surface of the housing and the peripheral surface of the rotor. Each of the plurality of spheres may remain in a corresponding one of the plurality of recessed portions while the rotor rotates within the housing.

Abstract: A fluid transmission that employs a fluid to transmit a force, comprising a conduit for the fluid made from heat shrink polymer tubing, wherein at least a portion of the heat shrink polymer tubing is shrunken, whereby the force can be transmitted by the fluid from a first or proximal end of the conduit to a second or distal end of the conduit. Also, an actuator and methods for manufacturing the transmission and actuator.

Abstract: A fluid system for use with a machine that employs an actuator, that provides for rapid shaking of an implement. The fluid system includes a source for providing fluid flow to the actuator and an operator input device for enabling an operator to control the movement of the implement by inputting a plurality of commands that specify movement of the implement. A controller is provided for monitoring the commands received from the operator input device and entering a mode for controlling the displacement of the source when the controller detects a pattern of commands that indicates an operator-request for rapid movement of the implement.

Abstract: An isolating manifold fluidly connected between a hydraulic valve and a hydraulic manifold operates to automatically isolate the valve from the hydraulic manifold as the valve is removed from the manifold, without requiring any particular blocking and bleeding procedures to be implemented on the valve or the manifold prior to the removal process. The isolating manifold includes an adaptor removably mounted onto a base with various pressure, control and tank fluid channels disposed in alignment through the adaptor and base portions to allow fluid to flow through each of the channels between the hydraulic manifold and the valve. During operation, the valve is mounted onto the adaptor while the base is mounted onto the hydraulic manifold.

Abstract: In one aspect of the present invention, a system for performing work has a hydraulic circuit adapted to store energy within a hose. The hose has an elastic inner layer pre-tensioned by a radial tensioning component disposed within the hose and at least one reinforcing layer of elastic thread disposed around and compressing the inner layer. A hydraulic fluid is in the circuit and in communication with the hose, the radial tensioning component and with a hydraulic actuator for doing the work. The circuit has a mechanism for pressurizing the hydraulic circuit in order to perform the work.

Abstract: In one aspect of the present invention, an energy storage system has an elastic hydraulic fluid vessel with an internal variable volume and being coupled to a hydraulic rotary mechanism. The elastic hydraulic fluid vessel has an elastic material adapted to store a potential energy within its fibers when the internal volume is increased by a hydraulic fluid. The hydraulic rotary mechanism is adapted to be accelerated by the release of the potential energy of the fibers of the elastic vessel by ejecting the hydraulic fluid from the internal variable volume into the rotary mechanism.

Abstract: A drive wheel with an integral fan mountable as a unit to a shaft of a hydraulic power unit for rotation therewith. Fan blades extending from the drive wheel circulate air when the drive wheel is rotated. One or more passageways extending through the drive wheel can be provided to allow air to flow axially therethrough to be circulated around the hydraulic unit. A fan assembly for a hydraulic power unit is also provided including a fan element and a rotatable shroud attached thereto.

Abstract: A hydraulic vehicle power take off system is implemented using modular components and utilizing a vehicle controller area network for integration with vehicle systems. The modular components are preferably in turn adapted from standard industry components.

Abstract: A tractor has a log splitter installed on two loader arms pivoted at a front end of the tractor. The log splitter includes a frame for attachment to the loader arms. The frame includes a surface, to which a ram and a wedge are coupled. An actuator mounted to the frame moves the ram and/or the wedge to split a log received between the ram and the wedge. The wedge includes a main blade and a cross blade perpendicular to the main blade. An edge of the cross blade is offset from an edge of the main blade so as to reduce the force required to achieve a four-way split of the log. The wedge and the frame are designed to enable inverting the log splitter to grasp a log, then raising the inverted log splitter to split the log directly into a truck bed. The uniquely designed hydraulic tank—ballast box combination provides an owner an external high volume hydraulic system without impeding the capability of the tractor hydraulic system.

Abstract: To ensure that liquid and/or vapours do not escape from a tank space during cleaning by means of cleaning equipment, a housing (2) is provided with magnetic coupling equipment according to the invention, comprising two cooperating pole elements (8,9) which extend hermetically isolated from each other with pole parts extending in the turbine housing (3) on the tank space side and the gear housing (1) itself outside the tank space, respectively. This provides a considerable degree of security against liquid and gas leakage, while making it possible to achieve a compact structure with easy access for service and maintenance.

Abstract: An engine suitable for a motor vehicle, preferably a motorcycle, and a related transmission is provided. The transmission is provided with a hydrostatic device and a planetary transmission leading to a driven shaft. In order to optimize the engine with regard to construction and function the hydrostatic device of the transmission cooperating with the internal combustion engine is in an effective connection to the planetary transmission.

Abstract: A priority flow rate control valve (4) increases a distribution ratio of pressurized oil to a power steering device (1) of a fork-lift track via a power steering oil passage (9) as a differential pressure between a power steering pressure (PS) in the power steering oil passage (9) and a pilot pressure (LS) decreases. A load signal port (24) which outputs a pressure indicative of a load exerted on the power steering device (1) and the power steering oil passage (9) are connected via two orifices (26A, 26B), and the pilot pressure (LS) pressure is extracted from a point between the two orifices (26A, 26B). By providing a bypass passage (31, 35) which bypasses one of the two orifices (26A, 26B) and a bypass valve (30) which opens and closes the bypass passage (26A, 26B), a response of the priority flow rate control valve (4) can be increased temporarily.

Abstract: The invention concerns a hydraulic steering arrangement with a steering motor, a supply path between a pressure source and the steering motor, in which supply path a throttling device and a measuring motor are located, a return path between the steering motor and a pressure sink, in which return path a return throttle is located, and a bypass path, which connects the supply path and the return path on the pressure source end or the pressure sink end, respectively, and which has a bypass throttle. It is endeavoured to make such steering arrangements suitable for fast motorboats. For this purpose it is ensured that with a load on the steering motor the pressure drop over the bypass throttle is larger than the sum of the pressure drops between a point before the first throttle and a point after the last throttle of the throttling device.

Abstract: An electrical power generation system comprises a variable capacitor and a power source. The electrical power generation system is configured to generate electric power via movements of the rail. The power source is used in the form of a generator to prime the variable capacitor that effectively multiplies the priming energy of the power source by extracting energy from the passing vehicle. By alternately priming the variable capacitor using charge from the power source and discharging it at a later time in a cyclic manner to change the capacitance, a significantly large amount of electrical energy is produced due to change in capacitance than from the power source itself.

Abstract: The present invention divulges a particularly compact electro-hydraulic generating set and its application in combination with a compact actuator to pilot the traverse movement of a close cupola head assembly or of one or several offset cupola head assemblies. The compactness of the electro-hydraulic generating set and the possibility of the close or offset mounting of one or several cupola head assemblies make various architectures possible.

Abstract: An engine with an integral actuator for a vehicle having an implement needing control. The engine includes a crank shaft, and a pump in a housing and an actuator that extends from the housing. The pump is operably connected to the crank shaft to produce a flow of fluid, such as oil, from the pump to the actuator. A valve is operably connected to the pump or the actuator to selectively move the actuator.

Abstract: A power conversion system converts the horizontal momentum and downward forces of wheeled vehicles into a circular motion capable of driving a shaft, which can be used for generating electricity. The power conversion system includes a torque limiting device that minimizes the amount of reaction vehicle wheels experience when encountering an actuation member, minimizes the pressure required to depress the actuation member, introduces the rapid movement of passing wheeled vehicles gradually into the system, and prevents excessive loading at the drive shaft.

Abstract: An actuating device (1) for carrying out mechanical work by means of a slave piston rod (5) in a hydraulically-operated slave cylinder (2), where the actuating device (1) is made up of a hydraulic pump (3) integrated with a slave cylinder (2) and where the hydraulic pump (3) is driven by a linear electric motor, which consists of a pump piston (7) which is used as rotor in the linear motor at the same time as the pump piston (7) functions as a pumping piston in the hydraulic pump (3) to build up a hydraulic pressure in the slave cylinder (2).

Abstract: What is disclosed is a hydraulic unit for a plastics processing machine, in particular a hydraulically actuated injection molding machine. In accordance with the invention, the drive mechanism of a pump of a hydraulic circuit is provided inside the tank to ensure optimum acoustic and vibration attenuation.

Abstract: A pendulum member swings right and left relative to an air compressor remaining still in a fixed position. As a result, the air compressor slides relative to and from end to end of a piston chamber of the pendulum member. The air compressor compresses air in a portion of the piston chamber forward with respect to a sliding direction of the air compressor, and decompresses air in a portion of the piston chamber rearward with respect to the sliding direction. This action is repeated continuously whereby compressed air in the forward portion of the piston chamber flows through a wind turbine chamber to the rearward portion of the piston chamber. The series of air flows forcibly and continuously rotates a wind turbine, which in turn rotates a generator to obtain electricity.

Abstract: The invention relates to a new type of hydraulic module for actuating at least one hydraulic control element with a hydraulic pump in a housing, with an electric motor fastened to a first housing side for driving the pump, with a tank located on a second housing side opposite the first side for a hydraulic fluid, e.g. hydraulic oil, with flow channels produced in the housing produced preferably by bore holes for the hydraulic fluid to supply this fluid from the tank to a pump chamber, for transmitting the hydraulic fluid conveyed by the pump to a pressure connection located on the housing, for connection of the at least one actuating element and for returning the hydraulic fluid from the pressure connection into the tank.

Abstract: An apparatus comprises first (3) and second (5) force-activated actuators, each having a fluid displacer (7, 9) and force control lever (19, 21) coupled to the fluid displacer, a conduit (15) for transporting fluid between the fluid displacers to couple motion of the fluid displacers, and a force controller (17) responsive to the pressure of the fluid for controlling a force opposing displacement of a fluid displacer.

Abstract: A serial, multi-unit hydraulic system which utilizing a single hydraulic fluid circuit each for extending and retracting all constituent hydraulic units. The fluid circuit for retraction of a remote hydraulic unit extends through intervening, primary hydraulic unit(s), and, after retraction of the remote hydraulic unit, provides retraction oil flow to primary hydraulic unit(s). Control valves effect a prescribed sequence of extension and retraction of the constituent hydraulic units, without involving separate, external control apparatuses.

Abstract: A fluid pressure driven generator which includes a generator housing and a rotor positioned within the generator housing. The rotor will have an internal offset gear which is engaged by a spur gear on a power shaft. A high fluid pressure inlet will be formed in the housing and connected to a source of high pressure fluid. The housing will also have low pressure outlet which will feed a source of low pressure fluid.

Abstract: A system and method for storing energy during an off-peak period and distributing energy during a peak period in a wholesale energy market. The system has a first energy directing device for directing energy produced in the wholesale energy market during the off-peak period into an energy storage device, and a second energy directing device for directing the energy from said energy storage device into the wholesale energy market during the peak period. Also, a method for creating profit in a wholesale energy market.

Abstract: Two motors are arranged on opposing sides of a common shaft, drive plates of the pump/motors being rigidly coupled to each other, for example by being in hard contact with opposing sides of the shaft. By providing hard contact between the pump/motor drive plates and a common shaft, the drive plates and shaft act as a substantially solid element under compression, thereby substantially canceling axial loads generated by the pump/motors directly through the shaft. Residual axial loads are handled via bearings positioned on the shaft adjacent the drive plates in such a manner that the drive plates are in light contact only with the bearings. As a result, friction experienced by the bearings is substantially reduced as compared to conventional systems, thereby improving the efficiency of the system.

Abstract: A fluid, for example, air, is subjected to a high pressure while in a high pressure inducing vessel (101). The high pressure is due to a large mass, such as the ocean. The fluid is then cooled and directed into a depressurized vessel (107), such as a pressure hull, which is at a relatively lower pressure. With this change in pressure, the fluid expands. This expansion is used to generate work/energy using a work producing machine (108), for example, a turbine. Energy from the work producing machine is converted to electricity using a generator (111). The fluid is collected from the work producing machine and again subjected to the high pressure and low pressure to generate additional electricity.

Abstract: My concept of using pressurized water to generate electric power is more efficient and is environmentally friendly than other methods in use today. Thrust from water flow would produce torque by rotating the turbine which is connected to an electric generator. I believe this method to be more efficient than steam, internal combustion, or coal burning methods.

Abstract: A cam mechanism through which torque applied to an input shaft is converted into the bi-directional rotation and reciprocating axial movement of an output shaft. Two cam elements are utilized, one consisting of a roller gear cam attached to the input shaft, and the other of a recessed channel type cam formed on one side of the roller gear cam. Two power transfer mechanisms are also utilized, one consisting of a turret installed adjacently to the roller gear cam as means of imparting a rotational movement to the output shaft, and the other consisting of a reciprocating swing arm of which one end is driven by the channel type cam. The turret is connected to the output shaft through a sliding spline that allows the output shaft to move axially within the turret, by means of a movable connection with the reciprocating swing arm, while being rotationally driven by the splined connection.

Abstract: A hydraulic motor comprising a housing having inlet and outlet ports and an access port for connecting a pressure fluid to an accessory of the motor, such as a brake. A shuttle valve integrally contained within the housing selectively communicates the pressure at one of the inlet port or the outlet port to the access port. In addition, the housing has at least two axial sections that are sealed at a parting line therebetween, and the shuttle valve is inserted through an opening in one section so that when the sections are joined, the opening is sealed at the parting line. A ring of bolts holds the sections together, and the shuttle valve is contained at least partially within the envelope formed by the ring.

Abstract: Automatic transmission, comprising at least one primary hydraulic pump (1) arranged to be powered by a motor, said primary pump (1) being arranged to power a number of at least two secondary hydraulic pumps (21-2n) which are mechanically connected to an outgoing propeller shaft (6), the secondary hydraulic pumps being arranged for active powering of said outgoing propeller shaft when the hydraulic pressure caused by the primary pump in a closed room (A) between the primary pump and the secondary pumps, reaches predetermined levels which are different for the various secondary pumps (21, 22 and . . . 2n respectively).

Abstract: The present invention relates to a system for generating electrical power using hydraulic supports on which a building structure is mounted. A pump injects fluid into the supports to raise the building structure and thereby store energy in the elevated structure. A valve can be opened to deliver fluid under pressure to a turbine to generate electricity.

Abstract: A fluid pressure driven generator which includes a generator housing and a rotor positioned within the generator housing. The rotor will have an internal offset gear which is engaged by a spur gear on a power shaft. A high fluid pressure inlet will be formed in the housing and connected to a source of high pressure fluid. The housing will also have low pressure outlet which will feed a source of low pressure fluid.

Abstract: A pair of flexible actuators (4) according to the present invention is supported by a fixture (2) made of a hard rubber at base ends of the flexible actuators (4). Each flexible actuator (4) includes a movable unit (6) capable of bending, a pump unit (8) integrally connected to the movable unit (6) at an end thereof, for controlling transfer of work fluid sealed in the movable unit, and a pump driver (10) for controlling driving of the pump unit (8). The movable unit (6) includes two long and narrow tubes (12) and (14) each having an accordion wall, a core (16) maintaining the tubes in parallel to each other, and a thin-film-bag-like cover (18) covering the tubes (12) and (14). The tube (12), which comes into contact with a subject (B), is made of a soft material. The movable unit (6) provided with the tube (12) softly comes into contact with the subject at a plurality of plane-contact portions of action of the movable unit (6), thereby holding the subject without scratching the same.

Abstract: To permit forcedly stopping combining flows of pressure fluid from two hydraulic pumps when a load pressure on a combined-flow-driven actuator in which the flows of pressure fluid are combined together exceeds a predetermined pressure and hence to permit driving the combined-flow-driven actuator with the pressure fluid from only one of the hydraulic pumps, a hydraulic drive system is provided with a flow-combining valve 2 connected to a directional control valve 1 in a first group of directional control valves via a center bypass passage 3, a flow-combining circuit 5 communicating the flow-combining valve 2 and a supply port of a flow-combining directional control valve 4 with each other, and a combined-flow-driven actuator 20 controlled by the flow-combining directional control valve 4, and performs overall power control such that a total value of input torques to the two hydraulic pumps 15,18 does not exceed an output torque from an engine 30.

Abstract: A regenerative adaptive fluid motor control system integrating a load adaptive fluid motor control system and a load adaptive energy regenerating system having an energy accumulator. The fluid motor control system includes a primary variable displacement pump (90) being implemented for powering and controlling a fluid motor (1) accumulating a load related energy. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator (122). This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The energy-regenerating adaptive fluid motor control can be used, for example, for constructing the high energy-efficient load adaptive motor vehicles.

Abstract: There is a speed control apparatus and method of a working vehicle which can reduce a working speed of a working machine and a traveling speed of the vehicle to a desired speed range in correspondence to a change of working contents and working conditions at a time of a crane operation on the basis of a preset crane mode, thereby improving a working efficiency. A controller sets an optional pump absorbing curve which can be obtained by connecting an upper limit value of a pump discharge amount in a pump absorbing torque at an intersecting point of an engine speed torque curve at a maximum engine speed required at a time of being in the crane mode with a proper pump absorbing torque curve to a lower limit value of a pump discharge amount at a pump absorbing torque in correspondence to a minimum engine speed required for a working vehicle, when an operator selects the crane mode.