VDI Guidelines - Support material Version March 2020


VDI (= Verein Deutscher Ingenieure) is the Association of German Engineers. It publishes many guidelines, written by honorary expert groups, to promote technology development in science and engineering businesses. Originally just in German language, nowadays also in English.

Printed versions of the Guidelines can be bought from the publisher or, for the academic community, can be viewed in licensed university libraries.

Here is an example of such a guideline in the field of Mechanisms: The design of a planar four-bar linkage with the best possible transfer quality (Guideline VDI 2123).

For those who are familiar with the type of design problem, the support material that the expert group has made may be beneficial: Excel sheets that contain the calculations as described in the (intended) new version of the guideline VDI 2123. These Excel sheets are free for a download.

Scope of the guideline VDI 2123:

The two pictures above describe the two main solution types of the design problem: a four-bar mechanism in which the driving link a and the output link c move either in equal direction (left picture) or in contrary direction (right picture). The links a and c will move between a start position and an end position regarding their angles with the frame. This motion must be contiguous: intermediate return of the output link is not allowed.

The guideline assumes that the rotation angle jH of the driving link and the rotation angle yH of the output link are given. In addition a so-called dead point, in one or both end-positions of the driving link, may be required. The problem to solve is: determine the link dimensions for maximum quality of motion transfer. This quality is indicated by the transmission angle μ: its smallest value in the figures this is angle μ3 - should be as high as possible. For all cases the highest achievable transfer quality can be viewed in diagrams and, switching to the right sheet, the link dimensions can be determined easily. In some cases it is required to read off design parameters from a diagram.

Follow the appropriate link below to obtain the Excel sheets supporting VDI 2123:

Download the English version, filename: VDI-Guideline2123(E).zip (1.8 kB)

Download the German version, filename: VDI-Guideline2123(D).zip (1.8 kB)


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