초록 ▼

A linear actuator for actuating a valve or other control element. The actuator measures the in-line or axial force exerted on a drive sleeve after the valve disk engages the valve seat or back seat In response to detection of an axial force in excess of a predetermined threshold level, the motor is

A linear actuator for actuating a valve or other control element. The actuator measures the in-line or axial force exerted on a drive sleeve after the valve disk engages the valve seat or back seat In response to detection of an axial force in excess of a predetermined threshold level, the motor is de-energized. The linear actuator includes a drive sleeve rotatably supported by bearings; a pack of friction springs for axially supporting the drive sleeve; a drive motor for driving rotation of the drive sleeve by way of gearing; a ball screw nut coupled inside and coaxial with the drive sleeve such that the ball screw nut rotates with the drive sleeve; a ball screw which translates axially in response to rotation of the ball screw nut; an anti-rotation device for preventing rotation of the ball screw during its translation; a switch for controlling the ON-OFF state of the motor; and a mechanical assembly for actuating the switch in response to a predetermined amount of axial deflection of the drive sleeve.

대표청구항 ▼

A linear actuator comprising: a drive sleeve having a centerline and a circumferential shoulder on its outer periphery; a ring attached to said drive sleeve and separated from said shoulder by an annular slot; bearing means for rotatably supporting said drive sleeve such that said drive sleeve is ro

A linear actuator comprising: a drive sleeve having a centerline and a circumferential shoulder on its outer periphery; a ring attached to said drive sleeve and separated from said shoulder by an annular slot; bearing means for rotatably supporting said drive sleeve such that said drive sleeve is rotatable about said centerline spring means for axially supporting said drive sleeve; a stationary support structure which supports said bearing means and said spring means; gearing coupled to said drive sleeve; a drive motor for driving rotation of said drive sleeve by way of said gearing; a ball screw drive mechanism having a nut coupled to the drive sleeve and having a ball screw which translates along the centerline in response to rotation of the ball screw nut; means for preventing rotation of said ball screw during translation thereof; a first switch connected to de-energize said motor when said first switch is actuated; and an actuator assembly for actuating said first switch when axial deflection of said drive sleeve reaches a predetermined amount, wherein said actuator assembly comprises a member interposed in said annular slot, said member fitting into said slot so that said member is not deflected during rotation without axial deflection of said drive sleeve and said member deflects during axial deflection of said drive sleeve.