Abstract: A hydraulic apparatus for a hydraulic work vehicle capable of supplying pressure oil to any of a bucket cylinder, an arm cylinder, a boom cylinder, a swing cylinder, a blade cylinder, a turning hydraulic motor, a left traveling hydraulic motor, a right traveling hydraulic motor, and a PTO hydraulic motor by a first hydraulic pump, a second hydraulic pump, or a third hydraulic pump. The pressure oil can be branched off from a discharge oil passage of the third hydraulic pump and supplied through an external pipe to a downstream side of a load check valve disposed on an oil passage communicating with a pump port of a PTO control valve for switching supply of pressure oil from the second hydraulic pump to an external hydraulic work machine.

Abstract: The subject matter of this specification can be embodied in, among other things, a multi-axis rotary actuator that includes a first rotary piston actuator configured to controllably actuate a first pivotal joint between a first linkage to a second linkage about a first axis, and a second rotary piston actuator configured to controllably actuate a second pivotal joint connecting the second linkage to a third linkage about a second axis.

Abstract: An example valve includes: a piston movable between a neutral position and an actuated position, wherein in the neutral position: a second port of the valve is fluidly coupled to a first port, and a third port is fluidly decoupled from the second port; a solenoid actuator sleeve movable between an unactuated state and an actuated state, wherein in the actuated state, the solenoid actuator sleeve allows pilot fluid to apply a fluid force on a piston in a distal direction; a first feedback spring; and a second feedback spring disposed in series with the first feedback spring, wherein the first feedback spring and the second feedback spring cooperate to apply a biasing force in a proximal direction on the piston against the fluid force, wherein the piston is configured to move to the actuated position based on a relationship between the fluid force and the biasing force.

Abstract: A hydrostatic propulsion drive for a vehicle is disclosed including an electronic control unit and a hydrostatic transmission having a hydraulic pump with an adjustable swept volume and a hydraulic motor with an adjustable swept volume, the hydraulic pump being arranged in a closed hydraulic circuit. The swept volumes of the hydraulic pump and the hydraulic motor are changeable in accordance with a correction factor which is stored in a characteristic diagram and is dependent on the rotational speed and the drive torque of the hydraulic motor, the operating pressure at the hydraulic motor being increased if the correction factor is used. Due to the increased operating pressure, flow-induced pressure drops are reduced by way of volumetric flows, and leakage flows via gaps between moving parts of the hydraulic pump and the hydraulic motor are kept large enough to avoid excessive friction and loss of efficiency.

Abstract: A hydraulic system for a work machine includes a tank to store an operation fluid, a hydraulic device to be operated by the operation fluid, a control valve to control the hydraulic device, a first fluid tube connecting the hydraulic device and the control valve, the first fluid tube being to supply the operation fluid from the control valve to the hydraulic device, a second fluid tube branching from the first fluid tube and connected to the tank, a switch valve provided to the second fluid tube, the switch valve being to control a flow rate of the operation fluid, and an oil cooler provided to the second fluid tube between the switch valve and the tank.

Abstract: A hydraulic system of a work machine includes a first hydraulic device to operate in a first operation mode while pressure of hydraulic oil supplied from a hydraulic pump via a first oil passage is equal to or higher than a first pressure threshold. The hydraulic oil in the first oil passage is to be discharged via a second oil passage. A pilot check valve is provided in the second oil passage and has a pilot port to receive a pilot pressure of the hydraulic oil. The pilot check valve is closed to stop discharging the hydraulic oil in the first oil passage through the second oil passage while the pilot pressure is higher than or equal to the second pressure threshold. The pilot check valve is opened while the pilot pressure is less than the second pressure threshold.

Abstract: An example pump includes: (i) a swash block having (a) a first trunnion arm on a first side of the swash block, and (b) a second trunnion arm on a second side of the swash block; and (ii) a housing including (a) a through-hole disposed on a respective first side of the housing, (b) a blind hole disposed on a respective second side of the housing opposite the respective first side thereof, and (c) an internal chamber. The swash block is supported within the internal chamber of the housing by the first trunnion arm being positioned in the through-hole of the housing and the second trunnion arm being positioned in the blind hole of the housing.

Abstract: A gas cylinder actuator with safety device, which comprises: a tubular containment jacket, two opposing heads for closing the tubular jacket, with corresponding sealing elements between the heads and the jacket, a first head provided with a through hole for the passage of a stem-piston, and a second head provided with a gas filling duct, a stem-piston, between the tubular jacket, the heads and the stem-piston there being a chamber for pressurized gas; the second head has a seat for the accommodation of a flow control element of the gas filling duct and corresponding sealing means, the flow control element comprising a tab for controlling a retracting stroke of the stem-piston, the control tab protruding from a body that has a lightened portion for triggering a controlled fracture or deformation in the event the control tab is crushed by the stem-piston.

Abstract: A hydraulic circuit is disclosed. The hydraulic circuit may comprise an actuation valve configured to actuate a flow of hydraulic fluid to and from the hydraulic consumer, a first control valve in fluid communication with the actuation valve through a first pilot line and configured to displace the actuation valve to a first position when actuated, and a second control valve in fluid communication with the actuation valve through a second pilot line and configured to displace the actuation valve to a second position when actuated. The first pilot line and the second line may each have a fixed minimum back pressure sufficient to maintain dissolved air in the hydraulic fluid.

Abstract: An electro hydrostatic actuator comprises a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator. The pump comprises an inlet and an outlet for the hydraulic fluid and an active flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path arranged to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet.

Abstract: An improved vacuum material handler having an onboard drive engine powering a vacuum pump and a hydraulic pump. The vacuum material handler also having a frame with integrated forklift lugs.

Abstract: A hydraulic system for construction machinery includes a boom cylinder, a main control valve including a boom control spool that is configured to selectively supply a hydraulic oil from a hydraulic pump to a boom head chamber and a boom rod chamber of the boom cylinder, a regeneration device connected to the boom head chamber of the boom cylinder through a hydraulic regeneration line, a regeneration valve unit installed in the regeneration line, and a control unit connected to the main control valve and the regeneration valve unit, wherein in a boom down low speed mode the hydraulic oil is drained through the regeneration device to lower the boom at a first speed, and in a boom down high speed mode the hydraulic oil is drained through the regeneration device and the main control valve to lower the boom at a second speed greater than the first speed.

Abstract: A brake booster for a brake master cylinder of a motor vehicle, including a drive motor, which is connected/is connectable via a transmission to a pressure piston for the brake master cylinder, the transmission including a rotatable spindle nut having an inner thread, and a rotatably fixed axially displaceable spindle rod having an outer thread, the threads engaging with one another in order to convert a rotational movement of the drive motor into a translational movement of the spindle rod, and the spindle nut including an outer toothing, which is engaged with a toothing of a drive wheel of the transmission. It is provided that the spindle nut is displaceable axially relative to the drive wheel.

Abstract: In an interior of a cylinder tube of a fluid pressure cylinder, a piston unit is displaced along an axial direction under the supply of a pressure fluid, and the piston unit is connected to one end of a piston rod. Further, a rod cover is disposed on another end of the cylinder tube, and in the center thereof, a cylindrical holder is provided that displaceably supports the piston rod. The holder is fixed integrally by a plurality of first rivets, in a state in which a flange member, which is expanded radially outward, abuts against an inner wall surface of the rod cover.

Abstract: A hydraulic excavator drive system includes: first and second pumps; arm cylinder; arm first control valve connected to the cylinder by an arm crowding supply line and arm pushing supply line; arm second control valve connected to the supply lines by a first and second replenishment line; and arm operation device that outputs an operation signal corresponding to an inclination angle of an operating lever. The arm second control valve is configured so, when performing an arm crowding operation, an opening area at a meter-in side changes in accordance with the operation signal, and an opening area at a meter-out side is: kept to zero when a predetermined condition is not satisfied; and kept to zero until the operation signal becomes a setting value or greater, and when the operation signal has become the setting value or greater, increases to a maximum value when the predetermined condition is satisfied.

Abstract: The present disclosure relates to a hydro-mechanical transmission having two rotating groups that mount on a common shaft. At least one of the rotating groups operates as a variable displacement pump or motor. At least one of the rotating groups interacts with a torque transfer unit rotatable about the shaft axis relative to both the shaft and the rotating group. The torque transfer unit includes a valve plate, a swash plate and a torque output section that all rotate in unison with one another about the shaft axis relative to the shaft and the rotating group. The valve plate includes an inlet passage for inletting hydraulic fluid to the rotating group and an outlet passage for outletting hydraulic fluid from the rotating group.

Abstract: A modular non-linear spring system capable of simulating traditional brake pedal feel when incorporated into a hydraulic and/or electro-hydraulic vehicle braking system. The system can include a first spacer having a top surface and a bottom surface and an optional second spacer having a top surface and a bottom surface. In one arrangement, a first mechanical spring is in abutting engagement with the top surface of said first spacer, a second mechanical spring is in abutting engagement with the bottom surface of said first spacer and the top surface of said second spacer, and an optional third mechanical spring is in abutting engagement with the bottom surface of said second spacer. The springs are arranged to be progressively compressed using a brake pedal of the braking system.

Abstract: A piston for a diesel engine is provided. The piston includes a thermal barrier coating applied to a crown formed of steel. A layer of a metal bond material is first applied to a combustion surface of the crown, followed by a gradient structure including a mixture of the metal bond material and a ceramic material, followed by a layer of the ceramic material. The ceramic material includes at least one of ceria, ceria stabilized zirconia, yttria stabilized zirconia, calcia stabilized zirconia, magnesia stabilized zirconia, and zirconia stabilized by another oxide. The thermal barrier coating is applied by a thermal spray process or HVOF. The thermal barrier coating has a porosity of 2% by vol. to 25% vol., based on the total volume of the thermal barrier coating, a thickness of less than 1 mm, and a thermal conductivity of less than 1.00 W/m·K.

Abstract: This clutch actuator includes a hydraulic pressure generating mechanism (51) configured to operate a clutch (26) to provide a connected state or a disconnected state, a motor (52) configured to generate a rotary driving force for driving the hydraulic pressure generating mechanism (51) to a driving shaft (52a), a transmission mechanism (54) configured to transmit the rotary driving force generated in the driving shaft (52a) of the motor (52) to a driven member (54b) parallel to the driving shaft (52a) in an axial direction and disposed coaxially with a cylinder main body (51a), and a conversion mechanism (55) configured to convert the rotary driving force transmitted to the driven member (54b) into a reciprocal driving force of a piston (51b) in a stroke direction, wherein the hydraulic pressure generating mechanism (51), the motor (52), the transmission mechanism (54) and the conversion mechanism (55) are integrated as a unit.

Abstract: An energy storage and regeneration system that converts irregular, non-constant, and variable input power to regular, constant, and controlled output power using hydraulics whereby the irregular input power is used to pump hydraulic fluid into an accumulator array where it is stored pressurized. Energy is released in a controlled fashion using a hydraulic motor operated by the pressurized hydraulic fluid from the accumulator array, in accordance with the specified power demand. One or more power units may be deployed depending on the amount of energy required at the output. Each power unit includes a hydraulic motor and associated floating accumulator whose internal pressure is controlled to maintain a substantially constant pressure differential across its associated motor. The system can be integrated into various energy system sources including renewable energy such as wind, PV or thermal solar, wave, tidal, etc.