There are many stresses and strains exerted on a piston during its use all causing some form of distortion. Piston designers attempt to predict this distortion by manufacturing the piston to allow for these effects. Because of the shape of the piston normal geometrical analysis such as cylindricity, roundness and straightness are not enough on their own to define the shape of the piston. Taylor Hobson's long association with Piston manufacturers have enabled measurement solutions.
Radial and axial form of pistons, high precision cylindricity of gudgeon/wrist pins or even thickness variation and form of piston grooves can be assessed utilising Taylor Hobson's range of roundness measuring instruments as detailed in the Talyrond links below.
When looking at wear or friction qualities of piston rings and pins or sealing faces of ring grooves Taylor Hobson surface finish range of instruments can provide the answer as detailed in the Form Talysurf information below.
Piston Software
All of Taylor Hobson roundness instruments capable of straightness measurement can provide measurement of the geometrical form of a piston.Piston software can then provide analysis of the radial and axial shape of the piston and compare this to the design data. Results output provides both tolerancing and feedback to the machining process. Alignment of the gudgeon/wrist pin bore to the piston major and minor axis is also possible via a dumbbell or optical trigger device.