A progressing cavity pump is sometimes referred to as an eccentric screw pump, because it features a screw that turns abound an axis other than its center. 'Eccentric screw pump' yields many Google hits, while professionals seem to use the term 'PC pump'.
The German term would be Exzenterschneckenpumpe, so to me and to other Germans it may come naturally to translate this verbatim and arrive at eccentric screw pump. But 'eccentric screw' might also sound like a sex act. Does the term 'eccentric screw pump' have sexual connotaions to a native English speaker?