Toyota Jidosha Kabushiki Kaisha

Katsuro Harada

Naofumi Masuda

Nobuo Kobayashi

Shigenori Tamaki

Takahiro Iwase

Kichiro Kato

Takuo Sibata

Hiroyuki Mochizuki

Hisao Shirai

Yoshio Kuroiwa

A Roots type pump comprising a pair of mating lobed rotors which are supported by rotor shafts, respectively. Each rotor is fixed to the corresponding rotor shaft by a pin forcibly inserted in a through hole provided through the rotor and rotor shaft. The outer surface of each rotor is surrounded by a coating layer of plastic material, at which the through hole has end openings having cross sectional dimensions greater than that of the substantial part of the through hole.

Roots type pump with pin connection for plastic coated rotor

A Roots pump having a plurality of rotor assemblies each including a light-alloy rotor, a steel shaft press-fitted in a bore of the rotor and a lock pin which is inserted through the rotor and the shaft to prevent removal of the shaft from the rotor. The lock pin is located substantially at an axial center of a press-fitted portion of the shaft accommodated the axial bore. The shaft has a timing gear at one end thereof for meshing with a timing gear of the shaft of the adjacent rotor assembly. The shaft further has a plurality of engagement teeth provided at one of opposite ends of the press-fitted portion on the side of the timing gear. The engagement teeth are at least partially embedded in an inner surface defining the axial bore of the rotor, upon press-fitting of the press-fitted portion in the axis bore, to thereby prevent a rotational movement of the shaft relative to the rotor.

Rotor assembly of roots pump

Growing community of inventors

Tajimi, Japan

Katsuro Harada