The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 2015
Filed:
Oct. 16, 2012
Sumitomo Electric Sintered Alloy, Ltd., Takahashi, JP;
Masato Uozumi, Itami, JP;
Toshiyuki Kosuge, Itami, JP;
Sumitomo Electric Sintered Alloy Ltd., Okayama, JP;
Abstract
An internal gear pump includes an inner rotor having n teeth and an outer rotor having (n+1) teeth. A tooth profile of the inner rotor is an envelope of a group of locus circles () each having a diameter C and having a center on a trochoidal curve (T), the trochoidal curve being drawn along a locus of a fixation point, which is located distant from a center of a rolling circle () by e, when the rolling circle () rolls along a base circle () without sliding. A tooth profile of the outer rotor is an envelope of a group of tooth-profile curves of a formation inner rotor, the envelope being obtained by first drawing the formation inner rotor in which a diameter of the locus circle () is equal to C' determined from expression (C−t), revolving a center (O) of the formation inner rotor by one lap along a circle (S) having a diameter (2e) and centered on a center (O) of the outer rotor, and rotating the formation inner rotor 1/n times during the revolution.