Abstract:
The present invention relates to a drive comprising a hydro machine whose injection volume is changeable, comprising an adjustment device for the changing of the injection volume of the hydro machine, comprising a first control valve which is in communication with the adjustment device and which is connected such that it effects a position of the adjustment device causing a low injection volume in a first position and effects a position of the adjustment device causingnullcompared with thisnulla large injection volume in a second position. A change in the brake torque of the hydro machine is possible in accordance with the invention in that a control device, preferably a second control valve, is provided on which an inlet pressure acts at the inlet side and which is in communication with a first control connection of the first control valve on the outlet side, with a pressure loading of the first control connection exerting a force directed in the second position of the first control valve, and with the second control valve connecting the inlet side to the first control connection of the first control valve in a region of low performance requirements.
Abstract:
An integrated three function valve (ITFV) that combines the functions of a bypass valve (e.g. 183a, 185a, 161a) into a single assembly is disclosed. The ITFV allows continued operation after any two failures. With the integrated three function valve, no combination of electrical or hydraulic component failures, regardless of expected failure rate, will prevent an actuator from continued safe operation
Abstract:
A swing speed compensation device is provided for use with a flow sharing hydraulic system. The present invention is mounted within the metering spool of a flow sharing valve and includes a poppet that is attached to a spring retainer. The spring retainer encases a compression spring which pushes against a plug and has a drain hole that, depending upon the position of the spring retainer and poppet combination, can vent excess pressure within the present invention to a hydraulic pump tank. When a flow sharing hydraulic system starts or stops, there is a rush in the fluid flow that can cause a spike in the system pressure. The present invention absorbs this pressure spike, allowing for the fluid flow to gradually increase or decrease as the system starts or stops.
Abstract:
A hydraulic spool valve is provided in which two inlet bores and an outlet bore lead into a housing. A spool-valve piston which is under the influence of compression springs on both sides can be displaced longitudinally in the housing. When a difference in pressure of the hydraulic fluid in the inlet bores occurs, the inlet bore which conducts the lower pressure in each case is connected to the outlet bore. The two compression springs are pre-stressed and have an additional expansion path. During the displacement of the spool-valve piston from a neutral central position into an extended intermediate position, the two compression springs therefore remain in operative connection with the spool-valve piston, in which case the spring forces counterbalance each other until the intermediate position is reached.
Abstract:
A bearing system for a turbocharger shaft includes an elongated bearing carrier with two anti-friction ball bearings mounted in its ends and with a radially extending flange at one end that cooperates with stationary housing portions and carries thrust loads of the rotor in both directions. The elongated bearing carrier is supported within the housing by axially spaced elastic supports which permit the rotating assembly to rotate about its mass center and provide a shock and vibration cushion. The elongated bearing carrier and housing cooperate to provide a coolant cavity which communicates with the outside periphery of the elongated bearing carrier between the axially spaced elastic supports, which also act as coolant seals between the elongated bearing cavity and the bearing housing. The coolant cavity protects the bearing system and anti-friction ball bearings from heat conducted from the exhaust gas-driven turbine and also cools the housing. In addition, an externally mounted motor-generator may be carried by the turbocharger and its rotor may be connected to the turbocharger rotor by a coupling that stays connected throughout the entire operating speed range of the turbocharger, and the motor-generator electronic control is mounted on the motor housing, which is cooled by air being drawn into the turbocharger compressor.
Abstract:
A magneto-electrohydraulic power steering system for a vehicle includes a magneto-electrohydraulic power steering pump interconnecting a power steering gear of the vehicle and a drive shaft of an engine of the vehicle. The magneto-electrohydraulic power steering system also includes a controller operatively connected to the magneto-electrohydraulic power steering pump to generate a current signal to vary a speed of the magneto-electrohydraulic power steering pump.
Abstract:
A hydraulic transfer valve system has a main valve selectively placing one of a primary and secondary hydraulic system in communication with a hydraulic load. A pilot valve provides a toggling action between the primary and secondary systems with respect to pressure changes in such systems.
Abstract:
A tandem electrohydrostatic actuator (70) broadly includes a first piston (22) operatively arranged in a first cylinder (23), and a second piston (24) operatively arranged in a second cylinder (25). The pistons are coupled to move together. The first piston has a small extend area (35) and a large retract area (36). The second piston has a large extend area (38) and a small retract area (39). The large areas (36, 38) of the pistons are equal to one another and the small areas (35, 39) of the pistons are equal to one another. A reversible fixed-displacement first pump (45) has equal inlet and outlet flows supplied to the small areas of the first and second pistons, respectively. A reversible fixed-displacement second pump (40) has equal inlet and outlet flows supplied to the large areas of the first and second pistons, respectively. The total volume of the fluid in the actuator remains constant at all positions of the pistons. In the preferred embodiment, a connecting rod (26) joins the pistons, an output rod (29) is connected to the first piston and penetrates an end wall (30) of the first cylinder, and a stationary LVDT coil or body (31) has one end attached to an end wall (32) of the second cylinder and has its movable core connected to the connecting rod.
Abstract:
The speed control apparatus for a hydraulic actuator includes a hydraulic source, an actuator connected with the hydraulic source and driven based on a supply of an operation oil, a direction switching valve which is switchably installed in a flow path between the hydraulic source and the actuator, an inclination piston which is installed between a parallel flow path in parallel connected with a flow path in a supply side of the actuator and the actuator for thereby controlling an inclination angle of an inclination plate of the actuator, a multi-step adjusting inclination piston which is driven when an operation oil is supplied, and adjusts an inclination angle of an inclination plate of the actuator based on multiple steps, and a multi-step adjusting control valve which is switchably installed in a flow path between the parallel flow path and the multi-step adjusting inclination piston, controls an operation oil supplied to the multi-step adjusting inclination piston, and adjusts a speed of the actuator. The multi-step adjusting control valve is formed of a first zone in which the actuator is rotated at a high speed, a second zone in which the actuator is rotated at an intermediate speed, and a third zone in which the actuator is rotated at a low speed.
Abstract:
One preferred embodiment of the present invention, provides an auxiliary hydraulic drive system having a total hydraulic flow. The system includes a primary hydraulic pump operable to provide hydraulic flow for an implement, and a flow control valve in communication with the hydraulic flow. The flow control valve operates to allow an optimum flow rate and diverts the excess flow amount when the total hydraulic flow exceeds the optimum flow rate. A secondary hydraulic pump is selectively operable to provide additional hydraulic flow. A control system is operable to engage the secondary pump when the total hydraulic flow drops below a minimum flow level; and the control system operates to disengage the secondary pump when the total hydraulic flow exceeds a maximum flow level. In a further embodiment, the invention provides a control unit for a hydraulic system. The control unit includes a sensor to measure total hydraulic fluid flow in a system; and a controller coupled to the sensor. The controller is operable to initiate additional fluid flow in the system if the total fluid flow drops below a minimum; and, is operable to reduce the fluid flow in the system if the total fluid flow exceeds a maximum.