【机械工程】旋转活塞传动装置，流体静力学的

rotary haymaker (rotary-drum rake and tedder) haymaking (haying)

rotary-type discharge control vane, rotary-type admission control vane

ducted wheel rotary pump (non-clogging rotary pump)

rotary seal

lobe rotary pump

rotary-bar type opener

sheet metal rotary offset press

trailer type sliding vane rotary air compressor