JPS6229796A - Vacuum pump - Google Patents

Abstract

PURPOSE:To perform sealing function and improve cooling effect by providing a vessel made of deformable soft material in a space between a housing and stator, and passing cooling medium through the vessel. CONSTITUTION:A vessel 11 made of heat resisting soft material is provided in a space between a vortex flow type stator 8b and a housing 1. Cooling medium 14 is poured into the soft vessel 11, and the stator 8b and housing 1 are simultaneously cooled. Since being elastic, the soft vessel 14 can adhere closely to both the stator 8b and the housing 1 to perform sealing function. Therefore leakage between the stator and the housing can be prevented.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a vacuum pump in which a vortex-type vacuum pump section having a half-split stator is disposed within a housing having an intake port and an exhaust port. In particular, it relates to a suitable cooling structure and a sealing structure between stators.

[Background of the invention]

Conventionally, a cooling method for a fluid machine such as a vacuum pump that operates in a viscous flow region has been disclosed in "Blowers and Compressors, pp. 361-380, Published by Kyokusho Shoten, Takeshi Ikui Documents." However, the casing of this type of compressor had a structure that was split into upper and lower halves, and was mainly made of cast products. Therefore, the water cooling jacket portion can form a sealed flow path.

However, this method has the problem that, as a cooling method in which half-split stators are sequentially assembled, it is difficult to seal the mating surfaces, resulting in insufficient sealing performance.

[Purpose of the invention]

The present invention was invented in view of the above, and provides a vacuum pump that maintains the seal of the half-split stator and is capable of reliably removing heat generated by the compression action of the impeller via a cooling medium. The purpose is then.

[Summary of the invention]

In order to achieve the above object, the present invention forms a space between a housing and a stator, provides a container made of a soft material that can be deformed according to the shape of the space in this space, and allows a cooling medium to flow through the container. It has the feature of closely contacting the stator to maintain a seal between the stators and cooling the stator and housing.

[Embodiments of the invention]

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

The first figure shows a longitudinal cross-sectional view of the whole, and the housing 1 is formed of a cylindrical body 1a and end plates 1b and lc, and an upper end plate 1b.
An intake port 2 is formed at the cylindrical body 1a, and an exhaust port 3 is formed at the lower end of the cylindrical body 1a. A motor housing 4 is formed below the lower end plate 1c. This motor housing 4 has a cylindrical body 4'
a1 bearing plate 4b.

Bottomed cylindrical bodies 4c are arranged in series. A motor 6 is disposed inside the cylindrical body 4a. The drive shaft 6b, which is integral with the motor shaft 6a supported by bearings 5a+5b, is connected to the housing 1.
It is protruded inward. A centrifugal compression pump section 7 and a vortex compression pump section 8 are successively arranged in the housing 1 . The centrifugal compression pump section 7 includes a centrifugal impeller 7a and a half-split centrifugal stator 7 having a return flow path with rectifying blades.
The vortex compression pump section 8 includes a vortex impeller 8a having a plurality of blades radially provided on the outer circumferential surface, and second and third impellers.
As shown in the figure, it is composed of a half-split whirlpool stator 8b having a horseshoe shape and a U-shaped groove. The centrifugal stator 7b and the whirlpool stator 8b are connected to both the impellers 7a and 8.
In order to maintain a small distance from a, they are combined with a metal touch and fixed to the housing 1. A whirlpool impeller 8a is fixed to the drive shaft 6b, and a centrifugal impeller 7a is fixed to a connecting shaft 8c provided on the impeller 8a. The car 7a rotates in conjunction. Gas to be exhausted is sucked through the intake port 2, compressed by the centrifugal compression pump section 7, and then compressed by the vortex compression pump section 8.
to go into. Here, it is further compressed and exhausted to the atmosphere through the exhaust port 3. The gas in the vortex compression pump section 8 becomes a viscous flow due to the compression effect up to the previous stage. In the viscous flow region, a large amount of heat is generated due to disk friction of the impeller 8a. Therefore, a space is provided between the swirl stator 8b and the housing 1, and a container 11 made of a heat-resistant soft material such as silicone rubber or soft plastic that can be freely deformed according to the shape of the space is used. Place it in the space. This soft container 11 is equipped with a water intake port 12 and a drain port 13.
13 projects through the cylindrical body 1a of the casing 1. A cooling medium 14 (for example, water, liquid helium, etc.) is put into this soft container 11, and the swirling stator 8b is heated.
and the housing l are simultaneously cooled.

According to this structure, since the soft container 11 is expandable and retractable, if the soft container 11 is filled with the cooling medium 14, it can be brought into close contact with the whirlpool stator 8b and the housing 1. The heat is transferred to the cooling medium 14.
The soft container 11 serves as a seal for the swirl stator 8b.

〔Effect of the invention〕

As explained above, according to the present invention, the impeller, particularly the whirlpool type impeller and the housing are cooled, and the heat generated by the disc friction of the whirlpool type impeller is removed, and the soft container is attached to the half-split stator. It serves as a seal between the stators that are successively connected, and also has the effect of eliminating leakage between the stators.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a vacuum pump showing an embodiment of the present invention;
FIG. 2 is a side view of one half-split spiral stator, and FIG. 3 is a bottom view of a pair of half-split spiral stators. DESCRIPTION OF SYMBOLS 1... Housing, 1a... Cylindrical wall, 2... Intake port, 3... Exhaust port, 7... Centrifugal compression pump part, 8...
...Vortex compression pump section, 8a...Vortex type impeller, 8b
...Half-split stator, 11...Soft material container, 1
2... Water intake port, 13... Drain port, 14... Cooling medium.

Claims (1)

[Claims] 1. A housing having an intake port and an exhaust port, a half-split stator disposed within the housing with a space between the housing, and a rotor supported within the stator. In the formed vacuum pump, a container made of a soft material that can be deformed according to the shape of the space is provided in the space between the housing and the stator, and an entrance and exit port of the container protrudes through the housing, and a cooling medium is supplied to the container. A vacuum pump characterized by circulation. 2. The vacuum pump according to claim 1, wherein the vacuum pump is a vortex centrifugal pump. 3. The vacuum pump according to claim 1, wherein a space is formed between the cylindrical wall of the housing and the outer periphery of the stator. 4. The vacuum pump according to claim 1, wherein the soft material is silicone rubber or soft plastic. 5. The vacuum pump according to claim 1, wherein the cooling medium is water or liquid helium.