Mechanical override for a valve actuator

A mechanical override for a valve, comprising:

• a valve actuator;
• an outer housing coupled to the valve actuator, the outer housing having a longitudinal bore therethrough;
• an internally threaded drive ring;
• a rotational locking assembly that prevents rotation of the drive ring while permitting axial movement of the drive ring within the longitudinal bore;
• a rotatable drive shaft extending through the longitudinal bore, wherein a thread is located on an external portion of the shaft, the shaft configured to be manually rotated through the drive ring that is prevented from rotation to impart axial movement to the drive shaft capable of moving a valve between a first position and a second position;
• and
• a bearing mechanism with a rolling element that isolates rotational movement of the drive shaft from a portion of the valve actuator that receives the axial movement.

A mechanical override for a valve, comprising:

• a valve actuator;
• an outer housing coupled to the valve actuator, the outer housing having a longitudinal bore therethrough;
• a drive shaft extending through the longitudinal bore, wherein a thread is located on an external portion of the drive shaft for rotation of the drive shaft through the bore to impart axial movement to the drive shaft capable of moving a valve between a first position and a second position;
• and
• a coupling assembly coupling the drive shaft to a member of the valve actuator, the coupling assembly comprising a bearing mechanism that isolates rotational movement of the drive shaft from the member, wherein the bearing mechanism comprises:
• an intermediate shaft coupled to an operator member of the valve actuator;
• ball bearings positioned between a bottom load surface of the drive shaft and a top surface of the intermediate shaft;
• and
• a coupler connecting the intermediate shaft to the drive shaft, wherein the coupler is capable of rotation about the intermediate shaft.

A mechanical override for a valve, comprising:

• a valve actuator;
• an outer housing coupled to the valve actuator, the outer housing having a longitudinal bore therethrough;
• a drive shaft extending through the longitudinal bore, wherein a thread is located on an external portion of the drive shaft for rotation of the drive shaft through the bore to impart axial movement to the drive shaft, the drive shaft capable of moving a valve between a first position and a second position;
• and
• a coupling assembly coupling the drive shaft to a member of the valve actuator, the coupling assembly comprising a bearing mechanism that isolates rotational movement of the drive shaft from the member, wherein the coupling assembly prevents longitudinal separation between the drive shaft and the member.