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:
Jun. 04, 2019
Filed:
Sep. 24, 2015
Kobe Steel, Ltd., Hyogo, JP;
Yoshio Yano, Hyogo, JP;
Toshiyuki Miyatake, Hyogo, JP;
Kobe Steel, Ltd., Hyogo, JP;
Abstract
An oil-free screw compressor includes: a casing having a rotor chamber; a bearing supporting rotary shafts of the screw rotors; a shaft seal device including an oil seal portion and an air seal portion; an atmosphere open hole formed in the shaft seal device; at least one communication hole formed in the rotary shaft; and an annular space communicating the atmosphere open hole with the at least one communication hole communicate with each other. The annular space includes an inner peripheral annular space formed on an inner peripheral side of the casing. Assuming an open cross-sectional area of the inner peripheral annular space as Sa total open cross-sectional area of the communication holes as San open cross-sectional area of the i-th communication hole out of the communication holes as Si, and the number of communication holes as n (n being a natural number of 1 or more), a following relationship is satisfied.