A hydraulic system including a first cylinder conduit configured to couple to a cylinder, a second cylinder conduit configured to fluidly coupled to the cylinder, and a bypass conduit fluidly coupled both to the first cylinder conduit upstream of the cylinder and to the second cylinder conduit downstream of the cylinder. The bypass conduit is configured to enable intermittent fluid flow of a hydraulic fluid from the first cylinder conduit to the second cylinder conduit while bypassing at least a portion of the cylinder.

In a fluid circuit for an air cylinder connected to a switching valve provided with exhaust ports, a head-side pressure chamber is connected to the switching valve by a first pipe, and a rod-side pressure chamber is connected to the switching valve by a second pipe. A first restrictor is disposed at a connection point between the first pipe and the switching valve or in the vicinity of a first output port of the switching valve, and a second restrictor is disposed at a connection point between the second pipe and the switching valve or in the vicinity of a second output port of the switching valve.

The present patent of invention relates to a hydraulic unit (U) with a pneumatic cylinder (15) that works jointly with a servomotor (M), together with a ball screw (29) to together move a hydraulic piston pump (8), made up of a hydraulic plunger (7), with related sealing elements to prevent oil leaks, noise, metal-on-metal attrition and loss of efficiency, that is moved upwards and downwards using a ball screw (29) and a pneumatic cylinder (15), jointly with a servomotor (M) which, when moved, pushes the pressurized oil outwards while filling the opposite hydraulic chamber with an oil suction movement, the pumped oil entering a hydraulic pressure accumulator (25), where it remains idle to be used when required and being supplied by the up/down movement of the piston, generating continuous pumping, which is automatically stopped when the hydraulic pressure accumulator (25) is full and has reached the predetermined hydraulic pressure. With regard to the field of application, the invention is intended to be used to move hydraulic actuators in a variety of different machines and equipment.

Sod harvesters can have hydraulic systems that are configured to actuate components with precise timing. The hydraulic system of a sod harvester can be configured to maintain the temperature of hydraulic fluid both during harvesting and while harvesting is paused to thereby eliminate or minimize the occurrence of periods of variation in the timing of actuation of the components that the hydraulic fluid drives. As a result, these components can be consistently actuated with precise timing even after harvesting has been paused. Additionally, such configurations can minimize the amount of time required to warm the hydraulic fluid to a steady operational temperature.

A compressor is disclosed. The compressor compressing and discharging a refrigerant sucked inside a cylinder includes a frame configured to support the cylinder, and a discharge cover assembly disposed in front of the frame. A gas layer is formed between the discharge cover assembly and the frame.

Disclosed are seal arrangements in a hydraulic device. The seal arrangement includes a seal channel defining a loop. A seal is seated within the seal channel. A coolant flow passage has a first part intersecting with the seal channel at a first point and a second part intersecting with the seal channel at a second point. The first part of the coolant flow passage is configured to provide hydraulic fluid to the seal channel such that, at the first point, a first portion of the hydraulic fluid flows in a first direction around the loop and a second portion of the hydraulic fluid flows in a second direction opposite to the first direction around the loop. At the second point, the first portion of hydraulic fluid and the second portion of hydraulic fluid are configured to flow into the second part of the coolant flow passage.

A method of performing wireless actuation by inductive heating of magnetic particles. The method provides a bladder having an inner surface and an outer surface, the inner surface forming an interior area, the bladder configured to expand or retract so as to change an area of the interior area, (ii) a plurality of magnetic particles suspended in a fluid medium and disposed within the interior area, and (iii) a sleeve disposed on the outer surface of the bladder. The method excites the plurality of magnetic particles by application of an alternating magnetic field to which the particles reaction. The method causes, by the excited magnetic particles, a phase transition to the fluid medium within the interior area which causes the bladder to expand, such that the sleeve confining the bladder generates actuation from the expansion or retraction of the bladder.

A self-rotation graphene heat-dissipation device for a direct-drive electro-hydrostatic actuator, that includes inner and outer walls of a shell eccentrically arranged relative to each other, the shell sleeves on an outer side of a self-rotation mechanism. The self-rotation mechanism is arranged on an outer side of a shaft; the shaft is coaxial with the inner wall of the shell and connected with outer and inner end covers. The self-rotation mechanism includes a rotor and blades, the rotor sleeves on the shaft and is connected with the outer and inner end covers. The rotor is slidably connected with the blades, and outer walls of the blades are closely attached to the inner wall of the shell. Graphene heat-dissipation layers are coated on outer walls of all of the shell, blades, the rotor, the inner and outer end covers respectively.

In a fluid circuit for an air cylinder connected to a switching valve provided with exhaust ports, a head-side pressure chamber is connected to the switching valve by a first pipe, and a rod-side pressure chamber is connected to the switching valve by a second pipe. A first restrictor is disposed at a connection point between the first pipe and the switching valve or in the vicinity of a first output port of the switching valve, and a second restrictor is disposed at a connection point between the second pipe and the switching valve or in the vicinity of a second output port of the switching valve.

The claimed invention is an end-of-stroke recirculation system for use with a hydraulic cylinder. Generally speaking, the fluid in a hydraulic cylinder remains trapped on one side of the piston and is unable to recirculate. The claimed invention provides a bypass that allows for hydraulic fluid to circulate through a cylinder when the hydraulic cylinder is at either end or both ends of its stroke.