Valve Actuator Sleeve Mechanism to Prevent Thread Wear and Jamming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing remotely controlled actuators for control valves face issues with high manufacturing complexity and costs, mechanical strain leading to wear and seizure of threaded components, and lack of a suitable independent mechanical actuation system for emergency operations.
Innovation Solution
An actuator design with a limited number of sliding components using pins inside longitudinal flutes, allowing adjustable inclination of helical flutes for uniform contact and torque distribution, and an integrated emergency mechanical device with a bevel gear system for rotational motion transmission, minimizing jamming and enabling efficient mechanical intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If high precision helical threaded shapes are used for motion conversion, then the actuator achieves compact configuration and motion transformation, but manufacturing complexity and costs increase significantly
Solution Approach 1:
The actuator is divided into three separate coaxial cylindrical hollow bodies (first, second, and third bodies) that can be manufactured independently and then assembled together. This segmentation allows each body to be produced using standard machining processes without requiring complex helical thread formation, thereby reducing manufacturing complexity while maintaining the compact actuator configuration.
Solution Approach 2:
The three cylindrical hollow bodies are arranged in a nested configuration where the first body contains the second body, and the second body contains the third body. This nesting approach achieves a compact actuator design without requiring complex threaded motion conversion mechanisms, as the bodies can be connected through simpler means such as flanges or coupling elements.
2Device complexity
If three coaxial cylindrical bodies are coupled through helical threads for motion conversion, then compact configuration is achieved, but mechanical strain causes thread wear and seizure over time
Solution Approach 1:
The problematic helical threaded coupling mechanism is extracted and removed from the design. Instead of using threads to couple the three coaxial cylindrical bodies, the patent employs alternative connection methods such as flanged joints or coupling elements that do not subject the connection points to repeated mechanical strain during operation, thereby eliminating thread wear and seizure issues.
Solution Approach 2:
Instead of using helical threads to convert axial motion to rotary motion, the invention inverts the approach by using the axial displacement of the piston directly to drive the rotation of the stem through a different mechanism, such as a cam-follower system or a rack-and-pinion arrangement, thereby avoiding the mechanical strain problems associated with threaded couplings.
3Reliability
If independent mechanical control system is added for emergency actuation, then operational reliability improves, but device complexity increases
Solution Approach 1:
The emergency mechanical control system is merged with the existing actuator structure by integrating it into the same housing and utilizing shared components such as the piston-cylinder assembly. The mechanical override system uses the same axial displacement mechanism but applies it in reverse or through a different transmission path, allowing emergency operation without requiring a completely separate control system, thereby limiting the increase in device complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The actuator achieves high mechanical efficiency, reduces manufacturing costs, minimizes jamming, and provides a reliable override system for emergency operations, particularly suitable for oil and petrochemical control valves in offshore and underwater installations.
Implementation Method 1
each of said pins (60) acting through a roller (70) on a helical flute (90) formed in said inner sleeve (80) so as to rotate the same inner sleeve (80) around the longitudinal axis of the casing (20)
Implementation Method 2
each of said pins (60) acting through a roller (70) on a helical flute (90) formed in said inner sleeve (80)
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Actuator (10) for a control valve, where a plug of the aforesaid actuator (10) can be operated by fluidic actuation or by an alternatively operating mechanical device (100), where the aforesaid actuator (10) comprises a case (20) having a longitudinal axis, where inside the aforesaid case (20) there is a cylinder (40) which, as a result of the fluidic actuation, can axially slide inside the aforesaid case (20), where said cylinder (40) has at least one support (50) for a pin (60), where each of the aforesaid pins (60) can act on an inner sleeve (80) through corresponding helical flutes (90) formed in the inner sleeve (80) in order to rotate the aforesaid inner sleeve (80) around the longitudinal axis of the aforesaid case (20), while an outer sleeve (82) constrains the aforesaid pins (60) to an axial translation and where the rotation of the aforesaid inner sleeve (80) acts on the plug of the valve. Advantageously, the aforesaid alternatively operating mechanical device (100) can act by rotating the aforesaid outer sleeve (82) in such a way that the aforesaid pins (60) act on the aforesaid longitudinal flutes (90) of the inner sleeve (80) by rotating the aforesaid inner sleeve (80), which acts on the movement of the plug.