JP2585420B2 - Turbo vacuum pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a turbo vacuum pump.

[Conventional technology]

As a turbo vacuum pump, for example, JP-A-63-55396
A turbo vacuum pump disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11-27983 has been proposed.

In this turbo vacuum pump, a first bell-shaped rotor and a second rotor arranged inside the first bell-shaped rotor are coaxially provided in a casing, and an outer peripheral portion of the first rotor is provided on the outer periphery of the first rotor. A first exhaust element comprising an axial wing or mixed saliva;
A second exhaust element using a mixed-flow blade or a thread groove molecular pump is arranged in two stages, upper and lower, and a third exhaust element of a swirl vane is arranged on the outer periphery of the second rotor arranged inside a bell-shaped rotor. And a third exhaust element is disposed inside the first and second exhaust elements.

In such a turbo vacuum pump, the axial length of the rotor can be significantly reduced. In addition, since the peripheral speed at the tip of the vortex blade is reduced, the disc friction loss generated in the vortex blade is significantly reduced, so that the rotation of the rotor can be further accelerated and the performance of each exhaust element can be sufficiently improved. Can be demonstrated. Therefore, there is an effect that the gas can be exhausted from the atmospheric pressure to the high vacuum region by one pump.

[Problems to be solved by the invention]

However, in the above-mentioned turbo signal pump, since the first rotor and the second rotor are separate bodies, the number of parts constituting the turbo vacuum pump is increased, which not only takes time to assemble, but also causes mutual trouble between parts. In order to ensure positional accuracy, a high degree of individual processing accuracy required for each component is also required, and individual component processing takes time and is expensive.

In view of the above circumstances, an object of the present invention is to provide a turbo vacuum pump that can be manufactured at a low cost with a simple configuration.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, there is provided a cylindrical casing having a suction port formed at one end thereof, a hollow vortex pump stator having an exhaust passage and an exhaust port formed and fixed to the other end of the casing. A rotor formed in a bell shape and disposed between the casing and the vortex pump stator; a shaft rotatably supported on a shaft portion of the vortex pump stator and having the rotor fixed to one end thereof; A motor is provided between the stator and the shaft to rotate the shaft, and between the inner peripheral surface of the casing and the outer periphery of the rotor, a plurality of stages of axial flow pumps and a plurality of groups of thread grooves from the suction port direction are provided. Form a molecular pump,
A multistage vortex pump was formed between the circumferential surface of the rotor and the outer circumferential surface of the vortex pump stator.

[Action]

With such a configuration, the configuration can be simplified and inexpensively manufactured without lowering the function and performance of the turbo vacuum pump.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of a turbo vacuum pump according to the present invention, in which 32 is a lower casing, in which a cooling water port 28 is formed. A cylindrical projection 32 'is formed at the center of the lower casing. 16 is an oil tank fixed to the lower casing 32,
Lubricating oil 17 is stored.

Reference numeral 6 denotes a vortex pump stator, which is mounted on the lower casing 32 such that one end of a stepped through hole formed in a shaft core portion is fitted to the projection 32 '. On the outer periphery of the vortex pump stator 6, a stepwise ventilation path 7 for constituting the vortex pump is formed. The vortex pump stator 6 has an exhaust passage 11 for exhausting exhaust gas and an exhaust port.
11 ', a purge gas passage 6 for discharging a purge gas containing oil mist, a purge gas port 26', and a cooling water jacket 27 communicating with the cooling water port 28 are formed.

A shaft 4 is rotatably supported by a bearing 15 provided on the projection 32 'of the lower casing 32 and a bearing 13 provided on the vortex pump stator 6. One end of the shaft 4 protrudes into the oil tank 16 and lubricating oil
17 dipped. Further, a hole for sucking up the lubricating oil 17 is formed in the axis of the shaft 4. In addition,
29 is a bearing retainer.

Reference numeral 19 denotes a motor stator, which is fixed inside a through hole of the vortex pump stator 6. 20 is a motor rotor,
It is fixed to the shaft 4 so as to face the motor stator 19 with a predetermined gap.

Reference numeral 1 denotes a bell-shaped rotor, which is mounted on the vortex pump stator 6 so as to cover the vortex pump stator 6 and is fixed to the other end of the shaft 4. The interior of the rotor 1 is formed stepwise so as to oppose the outer periphery of the vortex pump stator 6 with a predetermined gap, and each stage has, as shown in FIG. 5
Are fixed at predetermined intervals. In addition, between each stage, the second
As shown in the figure, a suction port 9 and a discharge port 10 formed before and after the partition portion 8 are connected. Sealing means such as a labyrinth seal is provided between each stage. On the outer peripheral portion of the rotor 1, from the upstream side to the downstream side,
Multi-stage axial flow rotor 21 and multi-stage screw groove molecular pump 22
Are formed.

Reference numeral 25 denotes a spacer, which is a thread groove molecular pump 22 of the rotor 1.
Are mounted so as to face each other at a predetermined interval, and are positioned by the vortex pump stator 6. Reference numeral 24 denotes a spacer which supports, at a predetermined interval, axial flow stators 23 alternately arranged with the axial flow rotor 21 in the axial direction of the rotor 1 (
Positioned by the spacer 25.

Reference numeral 3 denotes a cylindrical casing having an inlet 2 formed at one end. The casing 3 is mounted so as to cover the spacers 24 and 25, and is integrally fixed to the lower casing 32 and the vortex pump stator 6.

With such a configuration, the suction port 2 is connected to a vacuum container (not shown).
When the shaft 4 is rotated by energizing the motor stator 19 and the motor rotor 20, the rotor 1 rotates, and an axial flow pump composed of an axial flow blade rotor 21 and an axial flow blade stator 23 is provided. The inside of the vacuum vessel can be evacuated by the pump 22 and the vortex pump composed of the ventilation path 7 and the blades 5 to make a high vacuum.

When the shaft 4 rotates, the lubricating oil in the oil tank 16
The bearings 13 and 15 can be lubricated by pumping 17 and sprinkling the lubricating oil on the bearings 13 and 15. The oil mist generated at this time is discharged together with the purge gas through the purge gas passage 26 and the purge gas port 26 ', so that the oil mist does not enter the vacuum vessel and does not contaminate the vacuum vessel.

As described above, by using the inner peripheral surface and the outer peripheral surface of the single rotor 1 as a pump, the number of parts constituting the turbo vacuum pump can be reduced and simplified, and the assembling work can be facilitated. In addition, since the processing accuracy of each component can be remarkably reduced as compared with the related art, it is easy to manufacture individual components.

〔The invention's effect〕

As described above, according to the present invention, the configuration of the turbo vacuum pump can be simplified, and the assembling work thereof can be facilitated. In addition, since the processing accuracy of individual parts can be greatly eased compared to the past, it is easy to manufacture individual parts, and it is manufactured at low cost without lowering the function and performance as a turbo vacuum pump. can do.

[Brief description of the drawings]

FIG. 1 is a sectional view of a turbo vacuum pump according to the present invention. FIG. 2 is a sectional view of the vortex pump in FIG. FIG. 3 is a sectional view taken along the line BB of FIG. 1 ... rotor, 2 ... suction port, 3 ... casing, 5 ...
... wing, 6 ... vortex pump stator, 7 ... ventilation path, 4 ...
... shaft, 11 ... exhaust passage, 11 '... exhaust port, 19 ...
Motor stator, 20: Motor rotor, 21: Axial blade rotor, 22: Screw groove molecular pump, 23: Axial blade stator.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takashi Nagaoka 603, Kandamachi, Tsuchiura-shi, Ibaraki Pref. Hitachi, Ltd. Tsuchiura Plant (56) References JP-A-50-133506 (JP, A) JP-A-55- 75587 (JP, A) JP-A-52-142313 (JP, A) JP-A-63-280893 (JP, A) JP-A-63-55396 (JP, A)

Claims (1)

(57) [Claims] 1. A cylindrical casing having a suction port formed at one end, a hollow vortex pump stator having an exhaust passage and an exhaust port formed and fixed to the other end of the casing, and a casing formed into a bell shape. And a rotor disposed between the vortex pump stator, a shaft rotatably supported on the shaft core of the vortex pump stator, and having the rotor fixed to one end thereof, and disposed between the vortex pump stator and the shaft. A motor for rotating a shaft, a plurality of stages of axial flow pumps and a plurality of stages of thread groove molecular pumps are formed between the inner peripheral surface of the casing and the outer periphery of the rotor from the suction port direction. A multi-stage vortex pump formed between the circumferential surface of the vortex pump and the outer peripheral surface of the vortex pump stator.