초록 ▼

A valve assembly (10) comprising a valve member (14) having surfaces (70, 72, 74, 76, 78) radially sized and axially situated to provide an axial sealing force to insure leakfree operation. When the valve member (14) is in a supply position, the sum of fluid forces imposed on the radial surfaces is

A valve assembly (10) comprising a valve member (14) having surfaces (70, 72, 74, 76, 78) radially sized and axially situated to provide an axial sealing force to insure leakfree operation. When the valve member (14) is in a supply position, the sum of fluid forces imposed on the radial surfaces is positive towards supply position, and, when the valve member (14) is a nonsupply position, the sum of fluid forces imposed on the radial surfaces is positive towards the nonsupply position. The valve assembly (10) is compatible with a piezo-type actuator (18) that provides lift-shift forces early in its stroke. Once movement of the valve member (14) has been initiated by the actuator (18), the fluid forces can be relied upon to complete the shift and seal the valve member (14) against the corresponding seat (40/42).

대표청구항 ▼

The invention claimed is: 1. A valve assembly comprising a valve body and a valve member; the valve body comprising a supply port, a delivery port, and a supply chamber communicating with the supply port; the valve member being at least partially positioned within the supply chamber and being movab

The invention claimed is: 1. A valve assembly comprising a valve body and a valve member; the valve body comprising a supply port, a delivery port, and a supply chamber communicating with the supply port; the valve member being at least partially positioned within the supply chamber and being movable in an axial direction between a supply position, whereat the supply chamber communicates with the delivery port, and, a nonsupply position, whereat the supply chamber is sealed from the delivery port; and the valve member comprising radial surfaces; wherein the radial surfaces are radially sized and axially situated so that 1) when the valve member is in the supply position, the sum of fluid forces imposed on the radial surfaces, including the anti-interface force imposed on the seated radial surface(s), is positive towards the supply position, and 2) when the valve member is in the nonsupply position, the sum of fluid forces imposed on the radial surfaces, including the anti-interface force imposed on the seated radial surface(s), is positive towards the nonsupply position. 2. A valve assembly as set forth in claim 1, wherein when the valve member is the selected position, the surface-area sum of the selected-supply radial surface(s) is greater than the sum of the surface-area sum of the nonselected-supply radial surface(s) and the surface-area sum of the seated radial surface(s). 3. A valve assembly as set forth in claim 2, wherein the radial surfaces are concentric, are radially offset from each other, and define different surface areas. 4. A valve assembly comprising a valve body and a valve member; the valve body comprising a supply port, a delivery port, and a supply chamber communicating with the supply port; the valve member being at least partially positioned within the supply chamber and being movable in an axial direction between a supply position, whereat the supply chamber communicates with the delivery port, and, a nonsupply position, whereat the supply chamber is sealed from the delivery port; and the valve member comprising radial surfaces radially sized and axially situated so that, when the valve member is in a selected position that is one of the supply position or the nonsupply position, the sum of fluid forces imposed on the radial surfaces, including the anti-interface force imposed on the seated radial surface(s), is positive towards the selected position; wherein the radial surfaces are concentric, are radially offset from each other, and define different surface areas projected axially into a plane perpendicular to the axial direction. 5. A valve assembly as set forth in claim 4, wherein the valve body comprises a seating surface within the supply chamber, and wherein the first sealing surface is seated against the seating surface when the valve member is in one of the supply position or the nonsupply position, and is unseated from the seating surface when the valve member is in the other of the supply position or the nonsupply position. 6. A valve assembly as set forth in claim 4, wherein the seating surface within the supply chamber is an elastomeric seating surface. 7. A valve assembly as set forth in claim 4, wherein the seating surface within the supply chamber is a nonelastomeric seating surface. 8. A valve assembly as set forth in claim 4, characterized by the absence of pressure-force compensating components apart from the valve member. 9. A valve assembly comprising a valve body and a valve member; the valve body comprising a supply port, a delivery port, and a supply chamber communicating with the supply port; the valve member being at least partially positioned within the supply chamber and being movable in an axial direction between a supply position, whereat the supply chamber communicates with the delivery port, and, a nonsupply position, whereat the supply chamber is sealed from the delivery port; and the valve member comprising radial surfaces radially sized and axially situated so that, when the valve member is in a selected position that is one of the supply position or the nonsupply position, the sum of fluid forces imposed on the radial surfaces, including the anti-interface force imposed on the seated radial surface(s), is positive towards the selected position; wherein the valve body further comprises an exhaust chamber in which the valve member is also positioned, and an exhaust port communicating with the exhaust chamber; wherein the delivery port communicates with the exhaust chamber when the valve member is in its nonsupply position; and wherein both when the selected position is the supply position and when the selected position is the nonsupply position: the surface-area sum of the selected-supply radial surface(s) is greater than the sum of the surface-area sum of the nonselected-supply radial surface(s) and the surface-area sum of the seated radial surface(s), by a net surface-area greatness; and the net surface-area greatness is greater or equal to the difference between the surface-area sum of the nonselected-exhaust radial surface(s) and the selected-exhaust radial surface(s). 10. A valve assembly as set forth in claim 9, wherein the radial surfaces are concentric, are radially offset from each other, and define different surface areas. 11. A valve assembly as set forth in claim 1, wherein the radial surfaces are concentric, are radially offset from each other, and define different surface areas projected axially into a plane perpendicular to the axial direction. 12. A valve assembly as set forth in claim 9, wherein the valve member has a central passageway and wherein fluid flows from the exhaust port through this central passageway when the valve member is in its nonsupply position. 13. A valve assembly as set forth in claim 12, wherein the valve body comprises a groove between the supply chamber and the exhaust chamber in which a seal external to the valve member is positioned. 14. A valve assembly as set forth in claim 13, wherein a portion of the groove member contacts the external seal; and wherein the radial surfaces which seat against the valve body when the valve member is in the supply position and in the nonsupply position are radially offset from this external-seal-contacting portion of the groove member. 15. A valve assembly as set forth in claim 9 further comprising an actuator for moving the valve member from the supply position to the nonsupply position and/or for moving the valve member from the nonsupply position to the supply position. 16. A valve assembly as set forth in claim 15, wherein the actuator comprises a displacement device wherein drive force is inversely proportional to displacement. 17. A valve assembly as set forth in claim 15, wherein the displacement device comprises a piezo-electric device.