Title:
POSITIVE DISPLACEMENT PUMP
Document Type and Number:
Japanese Patent JP3644796
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce a noise level along all the frequency zones by arranging a plurality of a positive displacement chambers so as to alternately repeat advance/delay of a timing when a plurality of positive displacement chambers are communicated with a suction port or a discharge port in order, by adjacent positive displacement chambers.
SOLUTION: When a vane pump 20 is operated, noise of a fundamental frequency according to its rotational frequency and a frequency of a higher harmonics are generated. The width (a pitch of each vane 6) of each positive displacement chamber 10 for deciding a timing when each positive displacement chamber 10 is converted from a suction stroke into a discharge stroke, is not set to a constant level, it is set so that its increasing/decreasing is alternately repeated for each adjacent positive displacement chambers 10, and a periodicity shorter than a rotational frequency of a driving shaft 3 is provided for a pump 20. Noise energy of a basic frequency according to the rotational frequency of the driving shaft 3 is dispersed toward noise of a higher harmonics of the basic frequency, the distribution of its noise frequency is uniformized so as to hold a noise oval level in a small level.
Inventors:
Seiichi Nagata
Shinyuki Saito
Shinji Yakabe
Megumi Noguchi
Shinyuki Saito
Shinji Yakabe
Megumi Noguchi
Application Number:
JP15383597A
Publication Date:
May 11, 2005
Filing Date:
June 11, 1997
Export Citation:
Assignee:
Kayaba Industry Co., Ltd.
International Classes:
F04C2/344; F04C15/00; (IPC1-7): F04C2/344; F04C15/00
Domestic Patent References:
| JP603494A | ||||
| JP680871U |
Attorney, Agent or Firm:
Masaki Goto
Yoshio Matsuda
Yoshio Matsuda