This program allows the user to create the Cartesian geometry data for all non-direct-acting cam follower mechanisms in a user-friendly manner. The mechanism can be viewed from any side and the valve may be inclined at any angle.
The viewer selects the view appropriate to his available data set, such as a CAD drawing, and inputs the x-y coordinates and orientation angles of the mechanism according to an on-screen sketch, together with the direction of rotation of the camshaft in the selected view.
The
program then computes the precision geometry data necessary for the execution
of those programs which require it, namely:
Cam
Manufacture
Valve Train Analysis
Cam to Valve Lift
The ensuing 'canonical' data can be saved and exported to these programs, where it can be imported directly and accurately with the elimination of any possibility of typographical errors. Further, the units of input data insertion can be selected to be in imperial (inch) or metric (mm) units while being exported in the necessary metric uinits for program application.
The information screens which you can index below give an example of the data preparation process for a finger follower, but the procedure is similarly available for other non-direct-acting cam follower mechanisms such as rockers and pushrods.
Information data screens for the Cam Follower Geometry Program
There are also two sub-programs that permit the design of a valve follower pad for either finger or rocker followers where the contact point of the valve follower pad can be maintained almost precisely on the valve stem centre-line. If the valve follower pad contacts the valve stem centrally then the valve is not pushed sideways against the valve guide which thereby reduces the friction force to lift the valve, decreases valve guide wear, increases the friction force to return the valve follower and cam, and lowers the power required to turn the camshaft. The design process yields a valve follower pad profile which is not a radius but a scroll and the output data from the computation provides the manufacturing data for the profile of this scroll.
Design and computation strategy for valve follower pads with zero/low eccentricity
©Prof Blair & Associates