A spatial 6R linkage derived from subtractive Goldberg 5R linkages

In this paper, a subtractive Goldberg 5R linkage is defined as a variation of Goldberg 5R linkage. A spatial 6R linkage is constructed by combining two subtractive Goldberg 5R linkages through a common Bennett linkage. This 6R linkage, namely double subtractive Goldberg 6R linkage, appears to be distinct from other existing spatial 6R overconstrained linkages reported before. Both the overconstrained geometric conditions and the closure equations of the proposed linkage are derived. Physical models are also made to validate the linkage.

Research Highlights
► A subtractive Goldberg 5R linkage is proposed as a variation of Goldberg 5R linkage.
► A spatial 6R linkage is constructed from two subtractive Goldberg 5R linkages.
► The resultant double subtractive Goldberg 6R linkage is distinct from other linkages.
► The geometric conditions and closure equations of the proposed linkage are derived.