Torque limiter for valve actuators
AssigneeWatts Regulator Co.
InventorMarkus Kröll
Life of this patent
Estimating the term…
Abstract
A torque limiting coupling assembly shields a valve actuator from abnormally high levels of torque. In normal operation, an actuator coupling transfers a driving torque from an actuator coupling to a valve shaft coupling and the valve shaft coupling engenders a shaft torque on a shaft of a valve. In torque actuated operation, when a counter torque applied to the shaft coupling exceeds a threshold value, the actuator coupling freely rotates relative to the valve shaft coupling and the driving torque is transferred to a biasing element of the torque limiting coupling assembly rather than to the valve shaft coupling, thereby shielding the valve or the actuator from high levels of torque.
Claims15
A torque limiting coupling assembly for a valve assembly having a valve element and an actuator for moving the valve element, the torque limiting coupling assembly comprising:
- a valve shaft coupling for connecting to the valve element, the valve shaft coupling forming opposing helical grooves, each helical groove having a distal closed end;
- an actuator coupling for connecting to the actuator and secured to the valve shaft coupling along an axis for free rotation about the axis, the actuator coupling:
- having a collar;
- and forming opposing linear axial grooves;
- a sleeve slidably mounted on the valve shaft coupling and the actuator coupling, the sleeve forming two or more radially inward facing distal bosses captured to slide in the respective helical groove and two or more radially inward facing proximal bosses captured to slide in the respective linear axial groove;
- and
- a bias element extending between the collar and sleeve to bias the sleeve distally so that the two radially inward facing distal bosses are normally in the distal closed end of the respective helical groove,
- wherein:
- in normal operation when the actuator rotates the actuator coupling in a first direction, the sleeve rotates with the actuator coupling by virtue of the radially inward facing proximal bosses in the linear axis grooves and the valve shaft coupling rotates with the sleeve by virtue of the radially inward facing distal bosses pressed into the distal closed end of the linear axis grooves by the spring and, thereby, the valve element turns with the valve shaft coupling;
- and
- in torque actuated operation during movement or attempted movement in the first direction when the valve element requires large force, torque is limited by the actuator coupling turning freely with respect to the valve shaft coupling so that the radially inward facing distal bosses are driven proximally in the helical grooves by the valve shaft coupling to compress the bias element while the actuator coupling rotates with respect to the valve shaft coupling rather than forcing the valve shaft coupling to turn.
A torque limiting coupling assembly for a valve assembly comprising:
- an actuator coupling configured to be coupled to a rotational actuator and to receive a driving torque from the rotational actuator;
- a valve shaft coupling configured to be coupled to a valve shaft and to apply a shaft torque to the valve shaft;
- and
- a sleeve configured to connect the actuator coupling and the value shaft coupling;
- a bias element;
- wherein the torque limiting coupling assembly is configured to:
- in a first operating configuration, transfer the driving torque received from the rotational actuator to the valve coupling, thereby generating the shaft torque;
- in a second operating configuration, transfer the driving torque received from the rotational actuator to the bias element;
- and
- in a third operating configuration translate a linear force applied to the sleeve by the bias element into a rotational torque and to transfer the rotational torque to the valve coupling, thereby generating the shaft torque.
A torque limiting coupling assembly for a valve assembly having a valve element and an actuator for moving the valve element, the torque limiting coupling assembly comprising:
- a valve shaft coupling for connecting to the valve element, the valve shaft coupling forming at least one helical groove;
- an actuator coupling for connecting to the actuator and secured to the valve shaft coupling for free rotation, the actuator coupling forming at least one linear axial groove;
- a sleeve slidably mounted on the valve shaft coupling and the actuator coupling, the sleeve forming at least one distal boss captured to slide in the respective helical groove and at least one proximal boss captured to slide in the respective linear axial groove;
- and
- a bias element extending between the actuator coupling and sleeve to bias the sleeve distally,
- wherein in torque actuated operation during movement in a first direction when the valve element requires large force, torque is limited by the actuator coupling turning freely with respect to the valve shaft coupling so that the radially inward facing distal boss is driven proximally in the helical groove by the valve shaft coupling to compress the bias element while the actuator coupling rotates with respect to the valve shaft coupling.
Dependencies are inferred from the claim text.