Abstract: A large hydraulic excavator permits an easy change from a machine mode corresponding to a backhoe excavator to a machine mode corresponding to a loader excavator, and vice versa. A hydraulic circuit is provided with hydraulic pumps and directional control valves, solenoid valves for controlling the hydraulic pumps and the directional control valves, and a controller for controlling the solenoid valves in accordance with operation of control lever devices and control pedal devices. The controller performs its control in a backhoe mode or loader mode selectively instructed by a mode instruction unit. Control of the solenoid valves in the backhoe mode makes the hydraulic circuit function as a backhoe hydraulic drive circuit, while control in the loader mode makes the hydraulic circuit function as a loader hydraulic drive circuit.

Abstract: A method is provided for controlling a hydraulic cylinder in a work machine, which hydraulic cylinder is arranged to move an implement in relation to a part of a vehicle, with the hydraulic cylinder being controlled by a hydraulic machine. The method includes the steps of detecting initiation of a movement of the implement that is such that the piston of the hydraulic cylinder is moved in a first direction, of driving the hydraulic machine in a first rotational direction, prior to the movement of the implement taking place, so that a line from the hydraulic machine is pressurized, which line is arranged to connect the hydraulic machine to the side of the cylinder toward which the piston will be moved during the movement of the implement.

Abstract: The invention relates to a hydraulic unit of a vehicle hydraulic brake system having a hydraulic block, a storage unit, and a holding unit. The storage unit is inserted into the hydraulic block, and the holding unit is adjusted for holding the hydraulic block locally fixed to an associated vehicle. The storage unit is constructed with a holding surface which forms a section of the outer side of the hydraulic unit, and the holding unit engages with the holding surface of the storage unit in order to hold the hydraulic block locally fixed above the storage unit. Furthermore, the invention also relates to a storage unit where one outer surface of the storage unit which forms an outer side of the hydraulic unit is constructed as a holding surface for attaching the hydraulic block in the vehicle.

Abstract: A hydrodynamic coupling has an impeller and a turbine wheel that together form a toroidal working chamber. Viewed as an axial section through the hydrodynamic coupling the working chamber has a circular or essentially circular cross-section with a convexity in the axial direction on the circumference in the radially outer area of said turbine wheel and/or in the radially inner area of said impeller.

Abstract: A sealing mechanism is mounted at an end section of a cylinder tube, which configures a cylinder device, by having a step section in between, and the sealing mechanism is sandwiched between the cylinder tube and a rod cover. The sealing mechanism includes a thin plate formed of a metal material, and a sealing member attached to one side surface of the plate. The plate and the sealing member are integrally arranged.

Abstract: A servobrake for motor vehicles including a control valve which can be actuated by an electromagnet independently of an actuating rod which displaces a valve piston, which electromagnet actuates a third seal seat which makes possible ventilation of a working chamber. The third seal seat is formed on a sleeve which cooperates with the electromagnet, an annular element being provided which is arranged displaceably with respect to the third seal seat and which bears against the sleeve via an interposed elastic or compressible element. The annular element has means for guiding an air flow produced during normal braking in the direction of the working chamber.

Abstract: A hydraulic control system for controlling at least two consumers (2, 4) includes a pump (6) with an adjustable delivery quantity. The consumers are each associated with an adjustable metering orifice (24, 38), having a power beyond connection (72) to which at least one power beyond consumer (74) is connectable. An inlet pressure governor unit (60) is connected downstream of the pump (6) and opens a connection to a tank (T). Its setting occurs as a function of a load pressure of the consumers (2, 4) or of the at least one power beyond consumer (74). The inlet pressure governor (60) is provided in the pressure fluid flow path between the pump (6) and one of the two consumers (2, 4), while the power beyond connection (72) branches off from the pressure fluid path between the pump (6) and the inlet pressure governor (60).

Abstract: An energy conversion system, including a wave chamber, and a turbine wheel coupled to a shaft and fluidly coupled with the wave chamber. The energy conversion system may also include a first radial flow passage fluidly coupled with the wave chamber and the turbine wheel, and first vanes disposed at least partially in the first radial flow passage, each of the first vanes being compliantly mounted and pivotal between first and second positions, the first vanes being configured to allow a motive fluid to flow in a first radial direction through the first radial flow passage when the first vanes are in the first position, and the first vanes being configured to substantially prevent the motive fluid from flowing through the first radial flow passage in a second radial direction when the second vanes are in the second position.

Abstract: A method of braking a hydrostatic drive machine includes steps of reducing a displacement of a pump of a hydrostatic drive system to a non-zero displacement, and increasing a displacement of a motor of the hydrostatic drive system to a displacement that is less than a maximum displacement. The method also includes a step of accelerating an engine of the hydrostatic drive system toward a desired engine speed range.

Abstract: An annular sealing member 95 for establishing sealing between a boosted hydraulic pressure application chamber 22 and an input-side annular chamber 93 formed between a casing and a backup piston 64A and connected to a hydraulic pressure source is disposed between the casing and the backup piston 64A, and communication passage 216 for establishing communication between the input-side annular chamber 93 and the boosted hydraulic pressure application chamber 22 as the backup piston 64A moves forward by a predetermined stroke or more is provided in one of the backup piston 64A and the casing.

Abstract: A hydraulic control device for moving at least one hydraulic consumer comprises at least one supply line, a discharge line or bypass line to which the hydraulic consumer is connected, and at least one pressure source and, optionally, a directional control valve. The line contains a dosing device for measuring a hydraulic medium dose by using a given compressibility of the hydraulic medium. The measured hydraulic medium dose either is supplied from the dosing device into the hydraulic consumer connected downstream or is discharged from the hydraulic consumer connected upstream into the dosing device. The dosing device comprises from upstream to downstream in series first and second blocking members which respectively can be switched into a leakage-free blocking position and into a through flow position, and a dead space between the blocking members. For dosing the hydraulic medium dose the blocking members are switched several times alternatingly.

Abstract: A method and apparatus are provided for hydraulic fluid supply between a hydraulic pump and a hydraulic drive unit, switching hydraulic fluid flow direction to the hydraulic drive unit or stopping hydraulic fluid flow to the hydraulic drive unit when measured hydraulic fluid pressure crosses a predetermined pressure threshold value. The method further comprises calculating an amount of mechanical work done by the hydraulic drive unit and warning an operator or limiting hydraulic fluid flow rate to the hydraulic drive unit when the calculated mechanical work for the drive cycle is less than an expected amount of mechanical work. The apparatus for practicing the method further includes a pressure sensor associated with a hydraulic fluid supply conduit between the pump and the drive unit, and an electronic controller programmed to operate the drive system according to the method.

Abstract: A method is provided for controlling a hydraulic machine in a control system when utilizing the hydraulic machine as a pump, in which an electric machine is connected in a driving manner to the hydraulic machine. The method includes detecting at least one operating parameter, determining, based on the detected operating parameter, whether a pressure supplied by the hydraulic machine is to be limited, and controlling the electric machine correspondingly.

Abstract: A control system for a machine is disclosed. The control system may have a pump, a low pressure reservoir, and at least one actuator connected to receive fluid pressurized by the pump and discharge fluid to the low pressure reservoir. The control system may also have a bypass passage situated to allow fluid to bypass the at least one actuator, and a warmup valve disposed within the bypass passage and being movable between a flow-passing position and a flow-blocking position. The control system may further have a hydraulic temperature sensor configured to generate a signal indicative of a temperature of the fluid, and a controller in communication with the pump, the warmup valve, and the hydraulic temperature sensor. The controller may be configured to move the warmup valve to the flow-passing position, fix a displacement position of the pump, and adjust an input speed of the pump in response to the signal.

Abstract: A method is provided for controlling a hydraulic cylinder, including detecting at least one operating parameter, and variably controlling a communication path between the piston-rod side and piston side of the hydraulic cylinder on the basis of the detected operating parameter.

Abstract: 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.

Abstract: A fast-fill braking system in one embodiment includes a master cylinder, a first chamber within the master cylinder, a second chamber within the master cylinder located forward of the first chamber, a fast-fill piston within the first chamber, a primary piston within the first chamber and movable with respect to the fast-fill piston, and a secondary piston within the second chamber.

Abstract: The invention relates to a motor vehicle master cylinder (1). More specifically, the invention relates to a piston (4, 5) of the master cylinder which has a first indentation (24) and a second indentation (27), which indentations are formed upstream of a port (13, 14) of the piston. The first indentation and the second indentation delimit a space within which hydraulic brake fluid can be stored so that it can be tapped off by an auxiliary braking device of the E.S.P. type.

Abstract: The invention pertains to a piston-cylinder unit for a hinged lid, especially a motor vehicle hinged lid, with a closed first end, a cylinder, a piston installed in the cylinder with freedom to slide back and forth, the piston dividing the cylinder into a working chamber remote from the first end and a second working near the first end; and a piston rod, which is attached to one side of the piston, projects through the first working chamber, and passes out of the cylinder concentrically to the central longitudinal axis of the cylinder through a guide and sealing device at the second end opposite the first end, where a first locking element is provided on the piston rod, and a second locking element is provided on the cylinder to establish a mechanical interlock, and where one of the locking elements comprises a sleeve, which cooperates with the other locking element to establish an interlock.

Abstract: 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.