Circular eccentric 1 rotates about fixed axis A and is connected by a turning pair to sleeve e of link 2. Rigidly attached to sleeve e is concentric sleeve f. Link 2 reciprocates along straight guide slot k of crosshead 3 which is connected by sliding pairs B to fixed housing 4. When eccentric 1 rotates, sleeve f rolls and slides around sleeve 4 which is part of the fixed housing. This pumps the liquid through channels a and d. Collar 5 with shank b separates the suction and discharge chambers.
$3840$LHP,RP$