Patent ID: 7037092

Claim:
A roller pump comprising: a pump housing having a cylindrical inner surface; a reduction gear case having a reduction gear therein; a rotor fixed to a drive shaft placed at the central portion of said pump housing; a driver for driving said drive shaft through said reduction gear; and rollers provided around said rotor, said rollers pressing an elastic tube installed between said rollers and said inner surface of said pump housing, wherein said pump housing and said reduction gear case are formed from a single, one-piece member, and an output shaft of said reduction gear is fixed to said drive shaft of said rotor, wherein a part of said inner surface of said pump housing is composed of a semicircle of which center coincides with the center of said drive shaft, another part of said inner surface is composed of a partial circle of which center is shifted from the center of said drive shaft, and of which the length of radius is equal to that of said semicircle, each of end portions of said semicircle and each of end portions of said partial circle are connected by each of tangential lines extending from each of said end portions of said semicircle toward each of said end portions of said partial circle respectively, said partial circle is made to be a form suitable to be connected to an inlet slot for attaching an inlet portion of said elastic tube, and to an outlet slot for attaching an outlet portion of said elastic tube.