JPS6336680U

JPS6336680U -

Info

Publication number: JPS6336680U
Application number: JP12945886U
Authority: JP
Priority date: 1986-08-27
Filing date: 1986-08-27
Publication date: 1988-03-09

Description

[Brief explanation of the drawing]

第１図は本考案の軸封装置へのシールガス導入
経路を示す系統図、第２図は本考案の軸封装置を
適用する概略断面図、第３図と第４図は第１図の
要部拡大断面図、第５図は軸封部の圧力状態を説
明する圧力分布図である。７ａ，７ｂ……玉軸受、１０ａ……吸気側軸封
部、１０ｂ……排気側軸封部、１７ａ，１７ｂ…
…自給シールガス導入管路、１８……他給シール
ガス導入管路、２２……回転ロータの軸、２３…
…軸周上の溝、２４……シールケース、２５，２
６……シールリング、２５ｂ，２６ｂ……永久磁
石、２７……シールスリーブ、３０……シールガ
ス導入室、３１……ねじシール、３２……環状の
突起、３４……スプリング、Ａ……すきまシール
部、Ｂ，Ｃ……端面密着シール部。 Figure 1 is a system diagram showing the sealing gas introduction route to the shaft sealing device of the present invention, Figure 2 is a schematic sectional view to which the shaft sealing device of the present invention is applied, and Figures 3 and 4 are the same as those shown in Figure 1. FIG. 5, which is an enlarged sectional view of the main part, is a pressure distribution diagram illustrating the pressure state of the shaft seal portion. 7a, 7b...Ball bearing, 10a...Intake side shaft seal part, 10b...Exhaust side shaft seal part, 17a, 17b...
...Self-supplied seal gas introduction pipe, 18...Other supplied seal gas introduction pipe, 22...Rotor shaft, 23...
...Groove on shaft circumference, 24...Seal case, 25,2
6...Seal ring, 25b, 26b...Permanent magnet, 27...Seal sleeve, 30...Seal gas introduction chamber, 31...Screw seal, 32...Annular protrusion, 34...Spring, A...Gap Seal part, B, C... End face close seal part.

Claims

[Scope of utility model registration request]

In a vacuum pump in which a rotating rotor is supported by an oil-lubricated bearing, a circumferential groove is provided on the shaft of the rotating rotor on the vacuum chamber side of the oil-lubricated bearing, and an annular protrusion facing the groove and an annular protrusion behind the groove are provided. A seal sleeve having a threaded groove and an introduction chamber for self-supplied seal gas and externally supplied seal gas on the inner circumferential surface is attached to the seal case, and a radial oil drain hole communicating to the outside is bored through the seal case. a very small gap is formed in the radial direction with the axis of the rotating rotor behind the seal sleeve on the vacuum chamber side of the first sealing means, and the axial end surface is connected to the seal case or the seal. a second sealing means constituted by a floating ring that is capable of floating with respect to the seal case and the rotating rotor shaft while always being in close contact with the sleeve or both end faces; and the seal of the first sealing means. During pump operation, gas is extracted from the compression chamber of the pump or from the exhaust side and introduced as self-sufficient seal gas into the seal gas introduction chamber of the sleeve, and when the pump is stopped, externally supplied seal gas is introduced from the outside. A shaft sealing device for a vacuum pump, characterized in that a seal gas introduction system consisting of a seal gas introduction pipe and a valve is connected.