Dual Airbag Lapping Device for Ball Valve Seat Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Achieving precise lapping of ball and seat surfaces in severe and critical service ball valve applications is challenging due to irregular surfaces, which leads to difficulties in maintaining constant pressure and preventing deformation, especially with cutouts in the ball, resulting in reduced tolerance and increased maintenance costs.
Innovation Solution
A lapping device with a dual airbag system and a linear compensator that restricts the seat to float only horizontally, maintaining constant pressure and adjusting force from zero to maximum, allowing for automatic contour following and precise alignment without deforming the ball.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional lapping methods are used on ball and seat with cutouts, then lapping can be performed, but the ball deforms due to the cutouts reducing manufacturing precision
Solution Approach 1:
The support structure is segmented into multiple independent airbags positioned at different locations around the ball. Each airbag independently supports a portion of the ball's weight and applies controlled pressure, allowing the ball to be supported without deformation even in the presence of cutouts that compromise structural integrity.
Solution Approach 2:
The invention uses pneumatic airbags instead of traditional mechanical support structures. The airbags can be inflated to precise pressure levels to support the ball and apply controlled lapping pressure, avoiding the rigid contact points that would cause deformation in balls with cutouts.
2Productivity
If irregular surfaces are lapped with conventional methods, then lapping process can proceed, but constant pressure cannot be maintained reducing manufacturing precision
Solution Approach 1:
The airbag support system is designed to be dynamically adjustable, allowing the pressure to be modified in real-time during the lapping process. This dynamic capability enables the system to compensate for surface irregularities and maintain constant pressure despite variations in the ball and seat geometry.
Solution Approach 2:
The invention changes the pressure parameter of the airbags during the lapping process to compensate for irregular surfaces. By adjusting the air pressure, the system maintains optimal contact pressure between the lapping tool and the workpiece throughout the entire lapping cycle.
3Productivity
If floating or bouncing of the ball relative to the seat occurs due to irregular surfaces, then lapping can continue, but tolerances are reduced worsening manufacturing precision
Solution Approach 1:
The airbag support system acts as a counterbalancing mechanism that compensates for the floating and bouncing effects caused by irregular surfaces. The airbags provide continuous supportive force that counteracts the destabilizing effects of surface irregularities, keeping the ball stable relative to the seat during lapping.
4Productivity
If force is applied to maintain pressure during lapping, then lapping can proceed, but ball deformation occurs increasing device complexity
Solution Approach 1:
The invention replaces complex mechanical force application mechanisms with a pneumatic airbag system. The airbags can be inflated to the required pressure levels through simple air supply, eliminating the need for complex mechanical linkages, springs, or actuators that would be required to apply and maintain force with traditional systems.
Data Source
AI summary
An apparatus for rotating a seat relative to ball in a valve lapping machine includes a seat spindle assembly, an airbag assembly with a first and a second airbag, and a linear compensator affixed to a frame of the seat spindle assembly and to the seat tooling adapter plate. The airbag assembly is adapted to apply contact force between the seat and the ball. The linear compensator has a top plate, middle plate and a bottom plate. A first set of rails extends in a first direction so as to allow movement between the top plate and the middle plate, while a second set of rails which extends in a second direction perpendicular to the first direction allow movement of the bottom plate relative to the middle plate. A ball valve lapping machine utilizing this apparatus is also provided.