Abstract:
A linear actuator system includes a linear actuator and at least one integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.
Abstract:
A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus, and a piston that separates the piston chamber from the annulus. The hydraulic drive also includes a first hydraulic pump hydraulically connected with the piston chamber, a second hydraulic pump hydraulically connected with the annulus, a third hydraulic pump, and a directional control valve that has a first switching position and a second switching position. The third hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber, and the third hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.
Abstract:
An electropneumatic positioner for a pneumatic actuator to operate a control device of a processing plant can include two modular pneumatic slots and a pneumatic control output. The two modular pneumatic slots can engage with a respective modular pneumatic component. The two pneumatic slots and the pneumatic components can be modularly matched to one another such that their respective pneumatic interfaces merge into one another when a pneumatic slot is engaged. The pneumatic control output can output a pneumatic control pressure signal to the pneumatic actuator. The two modular pneumatic slots and the pneumatic control output can form a pneumatic series connection.
Abstract:
The dunnage airbag inflation circuit of this invention includes a pilot valve that is controlled by a pressure sensing line in communication with the dunnage bag, and an arrangement of other valves to allow the dunnage bag to inflate up to a certain preset pressure. The pressure sensing line controls pilot air to various valves and ultimately to the main pilot valve allowing airflow to the dunnage bag until the dunnage bag reaches a certain preset pressure. The inflation circuit also includes (i) a safety pressure valve to stop airflow to the dunnage bag if for some reason the dunnage bag continues to be inflated past the preset pressure, and (ii) a stop valve that allows an operator to manually override the pressure valve and stop the airflow to the dunnage bag.
Abstract:
Disclosed is a hydraulic circuit for an option device of heavy construction equipment which can facilitate manipulation of the option device such as a breaker and optionally control a flow rate by supplying hydraulic fluid from a hydraulic pump to the option device at a constant flow rate, regardless of the size of load produced on the option device. The hydraulic circuit includes a variable displacement hydraulic pump, an option device connected to the hydraulic pump, a first spool, installed in a flow path between the hydraulic pump and the option device, for being shifted in response to a pilot signal pressure applied from an outside to control a flow rate applied from the hydraulic pump to the option device, a poppet, operatively installed in a flow path between the hydraulic pump and the first spool, for supplying hydraulic fluid to the option device when the first spool is shifted, a piston resiliently urged in a back pressure chamber of the poppet, and a second spool for being shifted by a pressure difference between pressures of the hydraulic fluid before and after the hydraulic fluid passes through the first spool, and controlling the flow rate applied to the back pressure chamber of the poppet via a through-path communicating with the back pressure chamber when the second spool is shifted.
Abstract:
A hydraulic device comprises a variable displacement pump, a plurality of hydraulic actuators, a plurality of directional valves capable of controlling the delivery oil flowing into each of the actuators, a plurality of pressure compensation valves which compensate the pressures of respective directional valves, and a delivery oil flow rate varying means capable of controlling the pump delivery. At least one of the pressure compensation valves decreases its output flow to a particular actuator according to an increase in the loaded pressure of the particular actuator. With this arrangement, if the loaded pressure of the particular actuator suddenly changes, the loaded pressure attenuates to ensure stable operation of the hydraulic device. Further, the stable operation is fee of hunting for both low-load actuators and high load actuators, regardless of an independent operation or a compound operation.
Abstract:
A power sensing regenerator includes a pair of displacers (24 and 26) connected in tandem for dividing a flow of fluid from a pump (12) into predetermined proportions for servicing one or more loads (42). Flow control valves (32 and 34) regulate respective flows from the displacers (24 and 26) to the one or more loads (42). A control system, which includes differential pressure regulators of the flow control valves (32 and 34), responds to a difference between discharge pressures of the displacers (24 and 26) for reducing discharge pressure of the pump (12).
Abstract:
Fluid systems having fluid motors which control aiding type loads many times have problems with cavitation in one end of the fluid type motor during lowering thereof. It is desirable to eliminate all cavitation in the fluid motor during operation. In order to eliminate cavitation during lowering of an aiding type load and to provide a positive pressure therein, the subject arrangement provides an exhaust pressurizing control for use in a fluid system. The exhaust pressurizing control includes an exhaust manifold means having selector means to provide a positive pressure in the exhaust manifold means during lowering of an aiding type load. The selector means includes pressure limiting and unloading means operative to provide a positive pressure in the exhaust manifold means during lowering of the aiding type load and to unload the pressurized fluid in the exhaust manifold means during raising of a resisting type load. The pressurized fluid in the exhaust manifold means is available to the fluid motor through anti-cavitational valve means. This arrangement effectively eliminates cavitation in the fluid motor.
Abstract:
Disclosed herein is a hydraulic modulator valve for a control system of a hydraulically operated mechanism having a casing with a bore therein, a stepped spool axially and slidably engaged within the bore to form an annular fluid throttle passage against the circumference of the bore between a first and a second ports drilled through the casing, and spool actuator for controlling axial displacement of the spool. The stepped spool comprises a large diameter portion to be hermetically engaged within the bore, a small diameter portion and a medium diameter portion in sequence, the throttle passage being formed by the bore and the medium and small portions of the spool.
Abstract:
The invention relates to a control device for a hydraulic drive motor, such as a rotating motor or a screw jack, such that it can function in its two displacement directions, that it can be an engine functioning in rotation or in translation and with a manually adjustable speed, an optimal acceleration or deceleration is automatically obtained during operation or standstill, or simply during the manual control of the change of speeds of the said motor and its load.