Polar graph for engine balance on common types?

In summary, a trade journal in the late 1980s featured a full-page of polar balance diagrams for major engine types, including V6, V8, inline 6, inline 4, and V12. These diagrams showed 1st, 2nd, and 3rd order balance for 360 degrees of crankshaft rotation, representing inertial forces. The graphs for an inline 6 were almost circular, indicating excellent balance, while those for an inline 4 were oblong. The use of balance shafts was not shown. This type of plot can be found in Theory of Machines textbooks, but not specifically for a particular engine.
  • #1
joema
106
3
In a late 1980s trade journal, I saw a full-page of polar balance diagrams for each major engine type. For each engine type (V6, V8, inline 6, inline 4, V12, etc) a circular polar chart was presented with overlaid color-coded graphs showing 1st, 2nd and 3rd order balance for 360 degrees of crankshaft rotation. By "balance" I think it depicted inertial forces in the crankshaft rotational plane.

E.g, an inline 6 had an almost circular graphs since it has almost perfect first and second order balance. By contrast an inline 4 had oblong graphs. I don't remember if engines assisted by balance shafts were shown.

On that one page, you could easily see the engine smoothness of each type.

Does anyone remember seeing that or have any idea what journal it was? Have you seen any similar graphic?
 
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  • #2
This sort of plot is commonly found in a Theory of Machines textbook, although usually not identified with a particular engine.
 

What is a polar graph for engine balance?

A polar graph for engine balance is a graphical representation of the forces acting on the engine components during operation. It shows the magnitude and direction of the forces on a circular grid, with the center representing the center of rotation for the engine.

Why is a polar graph used for engine balance?

Polar graphs are used for engine balance because they provide a visual representation of the forces acting on the engine components, which helps engineers identify any imbalances and make adjustments to improve the engine's performance and lifespan.

What are the common types of polar graphs used for engine balance?

The most common types of polar graphs used for engine balance are the inertia polar graph and the pressure polar graph. The inertia polar graph shows the forces caused by the rotating and reciprocating parts of the engine, while the pressure polar graph shows the forces caused by the combustion process.

How is a polar graph for engine balance created?

A polar graph for engine balance is created by measuring the forces acting on the engine components during operation using specialized equipment. The data is then plotted on a circular grid to create the polar graph.

What are the benefits of using a polar graph for engine balance?

Using a polar graph for engine balance allows engineers to accurately identify any imbalances in the engine and make adjustments to improve its performance and reduce wear and tear. This can lead to increased efficiency, smoother operation, and longer lifespan for the engine.

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