ɪt wʌz ɚɹˈɪdʒɪnəli ɪnvˈɛntᵻd tə ɹᵻplˈeɪs ɐ kɹˈæŋkʃæft, ænd ɪz wˈʌn ʌvðə mˈoʊst pˈɑːpjʊlɚ kˈɑːnsɛpts jˈuːzd ɪn kɹˈæŋkləs ˈɛndʒɪnz.
It was originally invented to replace a crankshaft, and is one of the most popular concepts used in crankless engines.