초록 ▼

An apparatus is provided for controllably positioning a movable element within a hydraulic motor in response to a flow request signal. An electric circuit receives the flow request signal and responsively produces an energization signal. An electromagnetic actuator has a core, and a coil with a plur

An apparatus is provided for controllably positioning a movable element within a hydraulic motor in response to a flow request signal. An electric circuit receives the flow request signal and responsively produces an energization signal. An electromagnetic actuator has a core, and a coil with a plurality of windings wound as a helix around the core. The coil is adapted to receive the energization signal and responsively produce a magnetic force proportional to the magnitude of the energization signal forcing the core to move bidirectionally relative to the coil. A mechanical coupling has one end connected to and movable with the core. A directional valve includes a spool connected to the other end of the mechanical coupling. The directional valve precisely meters pressurized fluid to the motor causing the movable element to move in response to the movement of the core.

대표청구항 ▼

1. An electro-hydraulic apparatus for controllably moving a movable element within a hydraulic motor in response to a flow request signal, comprising: processing means for receiving said flow request signal, and producing a desired position signal in response to the magnitude of said flow request

1. An electro-hydraulic apparatus for controllably moving a movable element within a hydraulic motor in response to a flow request signal, comprising: processing means for receiving said flow request signal, and producing a desired position signal in response to the magnitude of said flow request signal; driver means for transmitting an energization signal in response to said desired position signal; a single high force linear actuator including: a core; a plurality of cylindrical permanent magnets being axially spaced with and contiguous to said core; and a coil with a plurality of helical windings circumjacent said magnets, said coil being adapted to receive said energization signal and responsively energize, said energized coil producing a magnetic flux proportional to the magnitude of said energization signal forcing said core to move bidirectionally relative to said coil; a mechanical coupling having one end connected to and movable with said core; and a directional valve including: a longitudinal valve housing having a plurality of fluid ports; a spool being slidably disposed within said valve housing and being connected to the other end of said mechanical coupling, said spool being moveable within a range of three flow positions to deliver pressurized fluid to said motor causing movement of the element; and a pair of centering springs disposed within said valve housing and being adapted to move said spool to a second flow position stopping the delivery of pressurized fluid to and from said motor; whereby said spool is moved to a first and third flow position by the core in response to said coil being energized, and the second position by the centering springs in response to said coil being deenergized. 2. An apparatus, as set forth in claim 1, wherein said linear actuator includes a cylindrical shell which encloses said coil, said cylindrical shell having a plurality of cooling fins formed at the periphery thereof. 3. An apparatus, as set forth in claim 1, wherein said directional valve is connected between a source of pressurized fluid and said hydraulic motor. 4. An apparatus, as set forth in claim 3, wherein said hydraulic motor is a hydraulic cylinder and said movable element is a piston. 5. An apparatus, as set forth in claim 1, including sensor means for determining the linear position of said core and producing a position signal. 6. An apparatus, as set forth in claim 5, wherein said processing means receives said sensed position signal, and produces an error signal proportional to a difference between the magnitude of said desired position signal and said sensed position signal. 7. An apparatus, as set forth in claim 6, wherein said driver means transmits said energization signal in response to said error signal. 8. An apparatus, as set forth in claim 7, including sensor means for determining the linear position of said core and producing a position signal. 9. An apparatus, as set forth in claim 8, wherein said processing means receives said sensed position signal, and produces an error signal proportional to a difference between the magnitude of said desired position signal and said sensed position signal. 10. An apparatus, as set forth in claim 9, wherein said driver means transmits said energization signal in response to said error signal.