초록 ▼

A valve assembly includes a valve stem which is connected with a valve. A drive member is disposed in engagement with the valve stem. A gear assembly is operable to rotate the drive member to effect axial movement of the valve stem. The gear assembly is driven by an electrical motor. In the event of

A valve assembly includes a valve stem which is connected with a valve. A drive member is disposed in engagement with the valve stem. A gear assembly is operable to rotate the drive member to effect axial movement of the valve stem. The gear assembly is driven by an electrical motor. In the event of a power failure, the valve may be moved to a closed condition by either a return spring or an auxiliary source of electrical energy. To facilitate movement of the valve between the open and closed conditions, the valve is pressure balanced.

대표청구항 ▼

Having described the invention, the following is claimed: 1. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a closed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve

Having described the invention, the following is claimed: 1. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a closed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve is ineffective to block fluid flow through the conduit, a housing, a valve stem connected with said valve and at least partially enclosed by said housing, a drive member disposed in engagement with said valve stem, a gear assembly at least partially disposed in said housing and connected with said drive member, a clutch assembly at least partially disposed in said housing and operable between an engaged condition and a disengaged condition, an electric motor at least partially disposed in said housing and operable to move said drive member relative to said valve stem under the influence force transmitted from said electric motor through said gear assembly and through said clutch assembly to said drive member when said clutch assembly is in the engaged condition, a spring connected with said housing and said drive member, said spring being stressed to store energy upon movement of said drive member relative to said valve stem, said spring being effective to move said drive member relative to said valve stem to move said valve from the open condition to the closed condition, first and second pressure chambers disposed in said housing, said first pressure chamber having a side surface connected with said valve stem, said second pressure chamber having a side surface connected with said valve stem, a first conduit extending through said valve and through a portion of said valve stem to conduct fluid pressure from a first side of said valve to said first pressure chamber, and a second conduit to conduct fluid pressure from a second side of said valve to said second pressure chamber. 2. An assembly as set forth in claim 1 wherein said valve includes a main section which is engagable with a valve seat upon movement of said valve to the closed condition and a projection which extends outward from said main section of said valve in a direction away from said first and second pressure chambers, said first conduit extends through and has an open end portion on said projection. 3. An assembly as set forth in claim 2 further including a guide having an opening into which said projection extends, said guide and projection cooperating to guide movement of said valve between the open and closed conditions. 4. An assembly as set forth in claim 1 wherein said gear assembly includes a harmonic drive unit which is disposed in a coaxial relationship with said valve stem. 5. An assembly as set forth in claim 4 wherein said harmonic drive unit includes a flexspline which extends around a portion of said valve stem, a rigid circular spline which extends around a portion of said valve stem; and a wave generator which effects deflection of at least a portion of said flex spline. 6. An assembly as set forth in claim 1 wherein said valve stem includes an external thread convolution, said drive member includes an internal thread convolution which is disposed in engagement with said external thread convolution, said electric motor being operable to rotate said drive member about a central axis of said valve stem. 7. An assembly as set forth in claim 1 wherein said electric motor includes a stator which is disposed in said housing and extends around said valve stem and a rotor which is disposed in said housing and extends around said valve stem. 8. An assembly as set forth in claim 1 wherein said drive member is rotatable under the influence of force transmitted from said electric motor when said electric motor is energized to increase stress in said spring during movement of said valve member from the closed condition to the open condition, said drive member being rotatable under the influence of force transmitted from said spring to move said valve member from the open condition to the closed condition when said electric motor is in a deenergized condition. 9. An assembly as set forth in claim 8 wherein said spring is disposed in a coaxial relationship with said electric motor and extends at least part way through said electric motor. 10. An assembly as set forth in claim 1 wherein said spring has a central passage in which at least a portion of said valve stem is disposed, said electric motor has a central passage in which at least a portion of said spring and a portion of said valve stem are disposed. 11. An assembly as set forth in claim 10 wherein said clutch assembly has a central passage in which at least a portion of said spring and said valve stem are disposed. 12. An assembly as set forth in claim 11 wherein said drive member has a central passage in which at least a portion of said valve stem is disposed, said spring being disposed between said drive member and said valve. 13. An assembly as set forth in claim 10 wherein said gear assembly has a central passage in which at least a portion of said valve stem and drive member are disposed. 14. An assembly as set forth in claim 1 wherein said gear assembly is connected with a portion of said drive member, said clutch assembly is connected with a portion of said gear assembly, said electric motor is connected with a portion of said clutch assembly, said electric motor being disposed in said housing at a location which is closer to said valve than a location where said gear assembly is disposed in said housing, said clutch assembly being disposed in said housing between said gear assembly and said electric motor. 15. An assembly as set forth in claim 1 wherein said electric motor is normally maintained in an energized condition when said valve is in the open condition to enable said electric motor to oppose said spring, said spring being effective to move said valve from the open condition to the closed condition when said electric motor is in a deenergized condition. 16. An assembly as set forth in claim 1 wherein said electric motor includes a rotor and a stator, said stator being energizable to urge said rotor to rotate against the influence of said spring to move said valve to the open condition and to maintain said valve in the open condition against the influence of said spring, said spring being effective to move said valve from the open condition to the closed condition upon deenergization of said stator. 17. An assembly as set forth in claim 16 wherein said valve stem and said spring extend through said rotor and are coaxial with said rotor. 18. An assembly as set forth in claim 16 wherein said rotor is rotatable about a central axis of said valve stem. 19. An assembly as set forth in claim 16 wherein said stator is connected with a first source of electrical energy, said assembly further includes a second source of electrical energy which is connected with said stator and is effective to energize said stator in the event said first source of electrical energy fails. 20. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a closed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve is ineffective to block fluid flow through the conduit, a housing connectable with the conduit, a valve stem connected with said valve and at least partially enclosed by said housing, a drive member at least partially disposed in said housing and disposed in engagement with said valve stem, said drive member having a central passage in which at least a portion of said valve stem is disposed, a gear assembly at least partially disposed in said housing and connected with said drive member, said gear assembly having a central passage in which at least a portion of said valve stem is disposed, a clutch assembly at least partially disposed in said housing and operable between an engaged condition and a disengaged condition, said clutch assembly having a central passage in which at least a portion of said valve stem is disposed, and an electric motor connected with said clutch assembly and operable to move said drive member under the influence of force transmitted to said gear assembly through said clutch assembly when said clutch assembly is in the engaged condition, said electric motor having a central passage in which at least a portion of said valve stem is disposed. 21. An assembly as set forth in claim 20 further including first and second pressure chambers disposed in said housing, said first pressure chamber having a side surface connected with said valve stem, said second pressure chamber having a side surface connected with said valve stem, a first conduit extending through said valve and through a portion of said valve stem to conduct fluid pressure from a first side of said valve to said first pressure chamber, and a second conduit to conduct fluid pressure from a second side of said valve to said second pressure chamber. 22. An assembly as set forth in claim 20 further including a spring connected with said housing and drive member, said spring having a central passage in which at least a portion of said valve stem is disposed, said spring is effective to move said drive member relative to said valve stem upon operation of said clutch assembly to the disengaged condition to move said valve from the open condition to the closed condition. 23. An assembly as set forth in claim 20 wherein said motor is connected with a first source of electrical energy, said assembly further includes a second source of electrical energy which is connected with said motor and is operable to effect operation of said motor in the event said first source of electrical energy fails. 24. An assembly as set forth in claim 23 further including an electrical actuator which is connected with said clutch assembly and is operable to effect operation of said clutch assembly between the engaged and disengaged conditions, said electrical actuator being connected with said first source of electrical energy, said electrical actuator being connected with said second source of electrical energy which is operable to supply power to said electrical actuator in the event said first source of electrical energy fails. 25. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a closed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve is ineffective to block fluid flow through the conduit, a housing, a valve stem connected with said valve and at least partially enclosed by said housing, said valve stem having a central axis which extends through said valve, a drive member at least partially disposed in said housing, said drive member being disposed in a coaxial relationship with said valve stem, a gear assembly at least partially disposed in said housing and connected with said drive member, said gear assembly being disposed in a coaxial relationship with said valve stem, a clutch assembly at least partially disposed in said housing and operable between an engaged condition and a disengaged condition, said clutch assembly being disposed in a coaxial relationship with said valve stem, an electric motor connected with said clutch assembly and operable to move said drive member under the influence force transmitted through said gear assembly and through said clutch assembly when said clutch assembly is in the engaged condition, said electric motor being disposed in a coaxial relationship with said valve stem, and a spring connected with said housing and said drive member, said spring being stressed to store energy upon movement of said drive member, said spring being effective to move said drive member relative to said housing to move said valve from the open condition to the closed condition, said spring being disposed in a coaxial relationship with said valve stem. 26. An assembly as set forth in claim 25 further including first and second pressure chambers disposed in said housing in a coaxial relationship with said valve stem, said first pressure chamber having a side surface connected with said valve stem, said second pressure chamber having a side surface connected with said valve stem, a first conduit extending through said valve and through a portion of said valve stem to conduct fluid pressure from a first side of said valve to said first pressure chamber, and a second conduit to conduct fluid pressure from a second side of said valve to said second pressure chamber. 27. An assembly as set forth in claim 25 wherein said gear assembly includes a harmonic drive unit. 28. An assembly as set forth in claim 27 wherein said harmonic drive unit includes a flexspline which extends around a portion of said valve stem, a rigid spline which extends around a portion of said valve stem, and a wave generator which effects deflection of at least a portion of said flex spline. 29. An assembly as set forth in claim 25 wherein said valve stem includes an external thread convolution, said drive member includes an internal thread convolution which is disposed in engagement with said external thread convolution, said electric motor being operable to rotate said drive member about the central axis of said valve stem. 30. An assembly as set forth in claim 25 wherein said electric motor includes a stator which is disposed in said housing and extends around said valve stem and a rotor which is disposed in said housing and extends around said valve stem, said valve stem being rotatable relative to said rotor and stator of said electric motor during operation of said electric motor. 31. An assembly as set forth in claim 25 wherein said drive member is rotatable about a central axis of said valve stem under the influence of force transmitted from said motor to increase stress in said spring during movement of said valve member from the closed condition to the open condition, said drive member being rotatable about the central axis of said valve stem under the influence of force transmitted from said spring to move said valve member from the open condition to the dosed condition when said clutch assembly is in the disengaged condition. 32. An assembly as set forth in claim 25 wherein said electric motor is normally maintained in an energized condition when said valve is in the open condition to enable said electric motor to oppose said spring, said spring being effective to move said valve from the open condition to the closed condition when said electric motor is in a deenergized condition. 33. An assembly as set forth in claim 25 wherein said electric motor includes a rotor and a stator, said stator being energizable to urge said rotor to rotate against the influence of said spring to move said valve to the open condition and to maintain said valve in the open condition against the influence of said spring, said spring being effective to move said valve from the open condition to the dosed condition upon deenergization of said stator. 34. An assembly as set forth in claim 33 wherein said stator is connected with a first source of electrical energy, said assembly further includes a second source of electrical energy which is connected with said stator and is effective to energize said stator in the event said first source of electrical energy fails. 35. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a dosed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve is ineffective to block fluid flow through the conduit, a housing connectable with the conduit, a valve stem connected with said valve and at least partially enclosed by said housing, a drive member at least partially disposed in said housing and disposed in engagement with said valve stem, said drive member having a central passage in which at least a portion of said valve stem is disposed, a gear assembly at least partially disposed in said housing and connected with said drive member, said gear assembly having a central passage in which at least a portion of said valve stem is disposed, an electric motor connected with said gear assembly and operable to move said drive member under the influence of force transmitted through said gear assembly to move said valve from the closed condition to the open condition, and a spring connected with said housing and having a central passage in which at least a portion of said valve stem is disposed, said spring being at least partially disposed in a central passage in said motor and being effective to move said drive member relative to said valve stem to move said valve from the open condition to the closed condition. 36. An assembly as set forth in claim 35 further including first and second pressure chambers disposed in said housing, said first pressure chamber having a side surface connected with said valve stem, said second pressure chamber having a side surface connected with said valve stem, a first conduit extending through a portion of said valve stem to conduct fluid pressure from a first side of said valve to said first pressure chamber, and a second conduit to conduct fluid pressure from a second side of said valve to said second pressure chamber. 37. An assembly as set forth in claim 35 wherein said motor is connected with a first source of electrical energy, said assembly further includes a second source of electrical energy which is connected with said motor and is operable to effect operation of said motor in the event said first source of electrical energy fails. 38. An assembly as set forth in claim 37 further including a clutch assembly at least partially disposed in said housing and operable between an engaged condition and a disengaged condition, said clutch assembly being connected with said electric motor and having a central passage in which at least a portion of said valve stem and at least a portion of said spring are disposed. 39. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a closed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve is ineffective to block fluid flow through the conduit, a housing, a valve stem connected with said valve and at least partially enclosed by said housing, a drive member having an internal thread convolution which cooperates with an external thread convolution on said valve stem, a gear assembly at least partially disposed in said housing and connected with said drive member, a clutch assembly at least partially disposed in said housing and operable between an engaged condition and a disengaged condition, an electric motor at least partially disposed in said housing and operable to rotate said drive member relative to said valve stem under the influence force transmitted from said electric motor through said gear assembly and through said clutch assembly when said clutch assembly is in the engaged condition, a spring connected with said housing and said drive member and disposed in a coaxial relationship with and extending at least part way through said electric motor and said clutch assembly, said spring being stressed to store energy upon movement of said drive member relative to said valve stem, said spring being effective to move said drive member relative to said valve stem to move said valve from the open condition to the closed condition, first and second pressure chambers disposed in said housing, a first conduit to conduct fluid pressure from a first side of said valve to said first pressure chamber, and a second conduit to conduct fluid pressure from a second side of said valve to said second pressure chamber. 40. An assembly for use in controlling a flow of fluid through a conduit, said assembly comprising a valve movable between a closed condition at least partially blocking fluid flow through the conduit and an open condition in which said valve is ineffective to block fluid flow through the conduit, a housing, a valve stem connected with said valve and at least partially enclosed by said housing, a drive member disposed in engagement with said valve stem, a gear assembly at least partially disposed in said housing and connected with said drive member, a clutch assembly at least partially disposed in said housing and operable between an engaged condition and a disengaged condition, said clutch assembly being connected with said drive member and with said gear assembly, an electric motor at least partially disposed in said housing and operable to move said drive member relative to said valve stem under the influence force transmitted from said electric motor through said gear assembly and through said clutch assembly to said drive member when said clutch assembly is in the engaged condition, said electric motor being disposed in said housing at a location which is closer to said valve than a location where said gear assembly is disposed in said housing, said electric motor includes a rotor and a stator, said rotor being rotatable relative to said valve stem during operation of said electric motor with said clutch assembly in the engaged condition, and a spring connected with said housing and said drive member, said spring being stressed to store energy upon movement of said drive member relative to said valve stem, said spring being effective to move said drive member relative to said valve stem to move said valve from the open condition to the closed condition, first and second pressure chambers disposed in said housing, said first pressure chamber having a side surface connected with said valve stem, said second pressure chamber having a side surface connected with said valve stem, a first conduit to conduct fluid pressure from a first side of said valve to said first pressure chamber, and a second conduit to conduct fluid pressure from a second side of said valve to said second pressure chamber.