Example of a Finger follower design with a compound (2 radii) pad (back)
This
is the in-software information picture which accompanies the input data
fields for the geometry of the "type 2" finger follower. Note that the
cam follower pad has two radii where the confluence point of the two radii
can be offset by an angle Ocf. For the sequence of pictures below, all
input data is common except for the numerical value of Ocf.
(back)
This
shows two snapshots from the on-screen movie of the cam profile design
and the lifting of the valve when Ocf is -5 degrees.
(back)
This
shows two snapshots from the on-screen movie of the cam profile design
and the lifting of the valve when Ocf is +5 degrees
(back)
This
shows the cam profile designs when Ocf is -5, 0, and +5 degrees. The movie
snapshot is taken before the commencement of valve lift and where the
tappet is set clear due to the input data valve lash. It is now obvious
that the cam profile design is a function of this offset angle Ocf with
consequential shifts in Hertz stress, oil film
thickness, radius of curvature, etc., all of which are computed by the
4stHEAD
software (back)
©Prof Blair & Associates