JPH09177684A - Scroll type vacuum pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the differential pressure of internal and external gases of a scroll mechanism where a dynamic seal of a driving shaft rotating in a fuming scroll is made as a border not to be increased. SOLUTION: A scroll type vacuum pump, comprising a combination of a stationary scroll and a fuming scroll, is constituted so that opening holes 4i, 4h, 5i, and 5h are provided at the center of an end plate of the stationary scroll, and a driving shaft 11a of the tuning scroll 3 is rotatably fitted into the opening holes through dynamic seal members 16, 16. Thereby, because the dynamic seals are disposed in such a place where the differential pressure between the external atmosphere and the internal compression gas is not large prior to the stage, the compression gas is discharged outward, very little external atmosphere infiltrate into the inside of the scroll mechanism resulting in the abrasion of the dynamic seal, so that the efficiency of the scroll mechanism can be prevented from being lowered and its durability can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type vacuum pump that compresses gas by a fixed scroll and an orbiting scroll and discharges the gas to the outside.

[0002]

2. Description of the Related Art Conventionally, the wraps of fixed scrolls and orbiting scrolls are formed by the wraps by sucking gas from the container to be evacuated and taking in the gas from the outer peripheral end of the wrap. A technique is well known in which the volume of the closed space is sequentially reduced and compressed, and the compressed gas is discharged from the discharge hole provided on the center side.

This technique is shown in FIGS. 5 (a) and 5 (b).
It will be explained by. In FIG. 5 (a), a wrap 50Ab having a tip seal 54 slidably mounted on the upper end surface of the end plate 50Aa of the fixed scroll 50A and the mirror surface of the opposite end plate is planted, and the wrap 50Ab is illustrated on the outer peripheral side thereof. Not suction hole 50Ac connected to the container used for vacuum, end plate 5
A discharge hole 50Ad for discharging compressed gas is provided on the center side of 0Aa.
Has been established.

An end plate 51Aa of the orbiting scroll 51A has a tip seal 54 whose upper end surface is in sliding contact with the mirror surface of the opposite end plate.
Wrap 51Ab provided with the
On the upper end surface of the wrap 51Ae that is planted on the outside of the, a swivel seal 53 that is in sliding contact with the mirror surface of the end plate 50Aa is provided.
The center side of the end plate 51Aa is connected to an eccentric shaft 51Ac that is connected to a rotating shaft 51Ad that is connected to a motor (not shown),
The wrap 51Ab is meshed with the wrap 50Ab of the fixed scroll 50A, the orbiting scroll 51A is configured to be revolvable to the fixed scroll 50A, and the gas sucked from the suction hole 50Ac is transferred to the wraps 50Ab and 51A.
It is sequentially compressed by the closed space formed by Ab and is discharged from the discharge hole 50Ad.

Further, in FIG. 5 (b), the end plate 50Ba of the fixed scroll 50B is provided with a tip seal 54 on its upper end surface which is in sliding contact with the mirror surface of the opposite end plate.
In the outer peripheral side of the end plate 50Ba, a suction hole 50Bc connected to a container used for vacuum (not shown) and a discharge hole 50B for discharging compressed gas in the center side of the end plate 50Ba.
d has been opened.

The end plate 51Ba of the orbiting scroll 51B has a tip seal 54 whose upper end surface is in sliding contact with the mirror surface of the opposite end plate.
A wrap 51Bb provided with a rotary shaft 51Bd connected to a motor (not shown) is attached to the center of the end plate 51Ba.
Is connected to an eccentric shaft 51Bc connected to the fixed scroll 50B, the wrap 51Bb meshes with the wrap 50Bb of the fixed scroll 50B, and the orbiting scroll 51B can revolve around the fixed scroll 50B.

Further, there is provided a housing 52 which forms an internal space 55 for accommodating the orbiting scroll 51B by connecting the periphery to the end plate 50Ba of the fixed scroll 50B, and an opening 52a is formed at the center thereof. A drive shaft 51Bd of the orbiting scroll is rotatably disposed in the opening 52a via a rotary seal 57, and the suction hole 50B is provided.
The gas sucked from c is sequentially compressed by the closed space formed by the wraps 50Bb and 51Bb, and is discharged from the discharge hole 50Bd.

[0008]

The above-mentioned technique is generally applied to a scroll compressor, and the gas taken in from the outside has the same pressure as the external atmosphere 58 at that time. The pressure of the internal gas in the outer atmosphere 58 is equal to the pressure of the internal gas in the wrap outer peripheral portion 59 of the fixed scroll with the orbiting seal 53 of 5 (a) as a boundary. Similarly, FIG. 5 (b)
The outer atmosphere 58 and the pressure of the internal gas in the wrap outer peripheral portion 56 of the fixed scroll are equal to each other with the rotary seal 57 as a boundary.

During the driving of the scroll compressor, since it is sufficient to always inhale the gas having the same pressure, the pressure difference between the inside and the outside of the orbiting seal 53 or the rotary seal 55 is small, and the gas leakage problem occurs. Does not occur. However, in the case of a vacuum pump, the suction hole 50Ac
The gas in the container to be evacuated, which is connected to (a) or 50Bc (b), is sucked from the container as the suction of the gas proceeds, even if the gas is initially at the same pressure as the external atmosphere 58. At the time when the pressure of the gas decreases, a pressure difference occurs between the wrap outer peripheral portion 56 or 59 of the scroll and the external atmosphere 58 with the orbiting seal 53 or the rotating seal 57 as a boundary, and the vacuum suction operation of the container is completed. Maximum pressure difference.

Therefore, according to the above-mentioned technique, the above-mentioned orbital seal is orbitally driven by the rotation of the orbiting scroll, and the above-mentioned rotary seal is rotationally driven by the rotation of the drive shaft of the orbiting scroll, and the ends thereof are respectively worn by abrasion. When the seal crimping force between the seals that are in sliding contact with the mirror surface of the plate and between the seals that are in sliding contact with the rotating shaft is reduced, the pressure of the external atmosphere pushes up the seals to create a gap, and the external atmosphere enters the inside of the scroll mechanism. As a result, the pump efficiency of the vacuum pump is reduced.

In view of the above-mentioned circumstances, an object of the present invention is to provide a scroll type vacuum pump in which the pressure difference between the gas inside and outside the scroll mechanism does not increase with the dynamic seal of the rotating drive portion as a boundary. To aim. Another object of the present invention is to provide a scroll type vacuum pump having good durability.

[0012]

A feature of the present invention is that in a scroll type vacuum pump comprising a combination of a fixed scroll and an orbiting scroll, an opening hole is opened in the center of an end plate of the fixed scroll, and The drive shaft is rotatably fitted in the opening through a dynamic seal member.

Further, the opening hole through which the drive shaft for the orbiting scroll penetrates and spirally planted from the vicinity of the opening hole toward the outer peripheral portion around the opening hole, and meshes with the wrap for the orbiting scroll. A wrap for the fixed scroll and a gas suction hole for sucking gas in the outer peripheral portion of the wrap are provided, and a discharge hole for compressing and discharging the gas taken in from the outer peripheral end of the wrap is provided in the vicinity of the opening hole. To form a housing, the orbiting scroll is revolvably driven with respect to the fixed scroll in an internal space formed by the housing, and the orbiting scroll drive is provided in the opening hole through a dynamic seal member. It is preferable that the shaft is rotatably supported.

As shown in FIG. 1, an opening 4i is formed in the center of an end plate 4g of a housing 4 forming a fixed scroll.
An opening 4h having a diameter larger than that, and an opening 5h having a diameter larger than 5h are formed at the center of the end plate 5g of the housing 5, and the drive shaft 11a of the orbiting scroll is attached to the dynamic seal member 1.
It is configured to be rotatably fitted into the opening holes 4h and 5i through 6.

Therefore, the housings 4 and 5 and the drive shaft 1
The dynamic seal member 16 interposed between the drive shaft 11a and the drive shaft 11a
Wear due to rotation of the drive shaft 11a and the dynamic seal member 1
When a gap is generated between the scroll 6 and the inner space 6, the outer atmosphere 58 is higher than the inside of the scroll, so that the gas intrudes from the outer atmosphere 58 into the scroll as shown by arrows 20A and 20B as shown in FIG. However, the central spaces 21A, 21B, 2 in which the discharge holes 5c inside the scroll mechanism are opened.
2A and 22B are much higher than the outer peripheral portion of the scroll mechanism during operation because the compressed gas is discharged through the discharge hole 5c when compressed to a pressure higher than the external atmospheric pressure. near.

Therefore, even if the external atmosphere enters the inside of the scroll mechanism through the gap of the dynamic seal member 16,
The amount is small, and the invading gas invades into the adjacent space from between the wraps of the scroll or between the tip seal and the mirror surface of the other side, invades into the adjacent space one after another and flows toward the outer peripheral part of the scroll mechanism. Even if it does, many wraps exist up to the outer peripheral part, and they obstruct the inflow movement of the invading gas and play the role of the labyrinth effect.

Therefore, even if the external gas flows in through the gap of the dynamic seal member 16, the amount of the external gas is small, and the inflowing gas that has entered the central portion of the scroll mechanism is compressed by the closed space in the preceding stage in the central portion. The compressed gas is compressed together with the compressed gas in the preceding stage and discharged to the outside through the discharge hole 5c. Therefore, before the compressed gas is discharged to the outside, the dynamic seal is placed at a position where the pressure difference between the external atmosphere and the internal compressed gas does not become large. It is possible to prevent the efficiency of the scroll mechanism from decreasing due to invasion, and improve the durability of the scroll mechanism.

It is preferable that the housing is divided into a plurality of parts, and the housings are connected to each other via a static seal member outside the sliding area of the outermost peripheral surface of the orbiting scroll.

By thus dividing the housing into a plurality of parts, the drive shaft 11a of the orbiting scroll is inserted into the opening hole at the center of one of the housings 4 (FIG. 1), and the opening hole at the center of the orbiting scroll is inserted. It is placed in the one housing 4 through the drive shaft 11a, the other housing 5 is covered on the housing 4, and both housings are attached with bolts, nuts, etc. at positions not shown.

By dividing the housing in this way, it is possible to assemble them in order, and if necessary, a spacer between the two housings can adjust the distance between the housings in the housing inner space in the axial direction of the drive shaft. . Therefore,
By preliminarily measuring the shape dimensions of the housing and the orbiting scroll and dividing them into appropriate ranges together with the spacer, assembly becomes easy.

The static seal member 1 is provided outside the sliding area of the outermost peripheral surface 3e of the orbiting scroll.
5, the static seal member 15 is used even if the pressure of the gas sucked from the suction port 8 decreases as the degree of vacuum in the container to be evacuated decreases. Does not slide, so there is no gap created by abrasion.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not merely intended to limit the scope of the present invention, but are merely illustrative examples unless otherwise specified. Absent.

FIG. 1 is an assembly structure diagram of a scroll type vacuum pump according to an embodiment of the present invention, FIG. 2 is an enlarged view of an A portion of FIG. 1, FIG. 3 is an enlarged view of a B portion of FIG. 1, and FIG. 5A and 5B are diagrams for explaining the operation when entering the outside air, and FIGS. In FIG. 1, the rotary shaft 11 of the pump body 1 is connected at its right end to a drive shaft of a motor (not shown) and is rotatably provided by the rotational force of the motor. This rotating shaft 11
Has a eccentric portion 11a whose outer periphery is slightly swollen from the center axis of rotation, and both ends of the eccentric portion 11a are supported by the bearings of the housings 4 and 5 and the dynamic seal member 16. It is rotatably installed. Incidentally, the dynamic seal 16 is preferably one having excellent wear resistance for the purpose of preventing the mixing of particles from the outside and the leakage of the gas inside and outside. Since it is arranged in a place where the pressure difference between the inside and the outside is small, an ordinary mechanical seal is sufficient for the sealing property.

The housings 4 and 5 constituting the fixed scroll are each in the shape of a circular lid, and the peripheral walls thereof functioning as a casing are brought into contact with each other via the spacer 10 and the O-ring 15 which is a static seal member, and the housing is placed inside thereof. It forms a closed space. The housing 4 is provided with a lap sliding surface (mirror surface) 4b which is perpendicular to the axial direction, and the sliding surface 4b is provided at the central portion thereof with the eccentric portion 11a of the rotary shaft 11 described above.
An opening 4i into which a non-eccentric part is rotatably fitted and an opening 4h into which the dynamic sealing member 16 having a larger diameter is fitted are provided, and the vicinity of the opening is a spiral end. Wrap 7 is provided, and a tip seal groove is provided at the upper end of the wrap 7, and the groove has a self-lubricating property such as a fluorine-based resin that comes into contact with the mating sliding surface to complete a sealed state. The chip seal 14 it has is fitted.

Further, the peripheral wall portion of the housing 4 has 12
Three pairs of revolution mechanisms 17 are provided at three positions in the circumferential direction at intervals of 0 °. The orbiting mechanism 17 is connected to the orbiting scroll described later. Further, a suction port portion 8 is provided on the outer peripheral portion 4a of the housing 4, and the suction port portion 8 is connected to a container (not shown) to be evacuated and the container is opened through the opening 8a. The gas inside is sucked.

On the other hand, the housing 5 has a lap sliding surface 5
b is provided vertically in the axial direction, and the sliding surface 5b has an opening 5h in which a non-eccentric portion, which is out of the eccentric portion 11a of the rotary shaft 11, is rotatably fitted in the central portion thereof. Further, an opening 5i having a diameter larger than that of the dynamic seal member 16 is provided therein, and a spiral wrap 6 is planted in the vicinity of the opening, and a tip seal groove is provided at the upper end of the wrap 6. A chip seal 14 is provided in the chip seal groove, which is in contact with the mating sliding surface to complete the sealed state.

A discharge hole 5c having an opening is formed in the sliding surface 5b near the tip of the wrap 6, and a check valve 18 is arranged in the discharge hole 5c.
It is composed of an inner wall of c, a head portion 18a for sealing and pressure bonding, and a base portion 18b for urging the head portion 18a with a predetermined pressing force (FIG. 3).
When the compressed gas pressure compressed by the closed space formed by both the fixed scroll and the orbiting scroll wraps becomes higher than the gas pressure in the discharge passage 9d, the head portion 18a descends like an imaginary line 18a ', and the gap created thereby The compressed gas is discharged to the discharge hole 5c through the discharge opening 5d, and the compressed gas is discharged through the discharge passage 9d to the housing 4
It is configured to be discharged to the outside from a discharge port 9a provided on the outer peripheral surface of the.

The orbiting scroll 3 is revolvably fitted into the internal space formed by the housings 4 and 5. The orbiting scroll 3 is a sliding surface 3 of a plate formed in a disc shape.
Wraps 26 and 27 that can be fitted to the wraps provided on the fixed scroll are planted in d and 3e. An opening 3a into which the eccentric portion 11a of the rotary shaft 11 described above is rotatably fitted is formed in the central portion of the orbiting scroll 3, and the eccentric portion 11a of the rotary shaft 11 is surrounded by the opening 3a. It is configured to be surrounded by the wraps 26a and 27a over the entire length thereof.

Fans 12 and 13 for cooling the vacuum pump are attached to the outer side of the housing 5 and the rotary shaft 11 on the outer side of the housing 4. As described above, one end of the orbiting scroll is supported by the housing 4 and the other ends of the three pairs of revolution mechanisms 17 are supported at three 120 ° circumferential positions. The fixed scroll has an eccentric center of rotation, and the outermost peripheral surface 3e of the end plate of the orbiting scroll 3 slides in the internal space of the housing so that the orbiting scroll revolves around the fixed scroll. .

In the pump body 1 thus constructed, the eccentric portion 11a is rotated by the rotation of the rotary shaft 11, and the orbiting scroll 3 is revolved. The gas sucked from the opening 8a of the suction port 8 by the drive of the orbiting scroll 3 is taken in by the wraps 26 and 27 of the orbiting scroll, and is hermetically sealed by these wraps and the wraps 6 and 7 of the fixed scroll. It is sequentially compressed by the space and sent to the central portion, and is discharged from the discharge port 5a through the discharge hole 5c and the discharge passage 9d.

As described above, in this embodiment, in the scroll type vacuum pump composed of a combination of a fixed scroll and an orbiting scroll, an opening hole is opened in the center of the end plate of the fixed scroll, and the drive shaft of the orbiting scroll. Is rotatably fitted in the opening through a dynamic seal member. And, preferably, the opening hole through which the drive shaft for the orbiting scroll penetrates, and it is planted in a spiral shape from the vicinity of the opening hole toward the outer peripheral portion around the opening hole, and meshes with the wrap for the orbiting scroll. A wrap for the fixed scroll and a gas suction hole for sucking gas in the outer peripheral portion of the wrap are provided, and a discharge hole for compressing and discharging the gas taken in from the outer peripheral end of the wrap is provided in the vicinity of the opening hole. To form a housing, the orbiting scroll is revolvably driven with respect to the fixed scroll in an internal space formed by the housing, and the orbiting scroll drive is provided in the opening hole through a dynamic seal member. The shaft is rotatably supported.

Therefore, the housings 4 and 5 and the drive shaft 1
The dynamic seal member 16 interposed between the drive shaft 11a and the drive shaft 11a
Wear due to rotation of the drive shaft 11a and the dynamic seal member 1
When a gap is generated between the scroll 6 and the inner space 6, the outer atmosphere 58 is higher than the inside of the scroll, so that the gas intrudes from the outer atmosphere 58 into the scroll as shown by arrows 20A and 20B as shown in FIG. However, the central spaces 21A, 21B, 2 in which the discharge holes 5c inside the scroll mechanism are opened.
2A and 22B are much higher than the outer peripheral portion of the scroll mechanism during operation because the compressed gas is discharged through the discharge hole 5c when compressed to a pressure higher than the external atmospheric pressure. near.

Therefore, even if the external atmosphere enters the inside of the scroll mechanism through the gap of the dynamic seal member 16,
The amount is small, and the invading gas invades into the adjacent space from between the wraps of the scroll or between the tip seal and the mirror surface of the other side, invades into the adjacent space one after another and flows toward the outer peripheral part of the scroll mechanism. Even if it does, many wraps exist up to the outer peripheral part, and they obstruct the inflow movement of the invading gas and play the role of the labyrinth effect.

Therefore, even if the external gas flows in from the gap of the dynamic seal member 16, the amount thereof is small, and the inflowing gas that has entered the central portion of the scroll mechanism is compressed by the closed space in the preceding stage in the central portion. The compressed gas is compressed together with the compressed gas in the preceding stage and discharged to the outside through the discharge hole 5c. Therefore, before the compressed gas is discharged to the outside, the dynamic seal is placed at a position where the pressure difference between the external atmosphere and the internal compressed gas does not become large. It is possible to prevent the efficiency of the scroll mechanism from decreasing due to invasion, and improve the durability of the scroll mechanism.

In this embodiment, the housing is divided into a plurality of parts, and the housings are connected to each other via a static seal member outside the sliding area of the outermost peripheral surface of the orbiting scroll. I am configuring. With this configuration, by dividing the housing into a plurality of parts, the drive shaft 11a of the orbiting scroll is inserted into the opening hole at the center of one housing 4 (FIG. 1), and the opening at the center of the orbiting scroll is opened. The drive shaft 11a is passed through the hole to be placed in the one housing 4, the other housing 5 is further covered on the housing 4, and both housings are attached by bolts, nuts, etc. at positions not shown.

Further, in the present embodiment, the fixed scroll and the orbiting scroll wrap can adjust the distance between the mirror surfaces 5b and 4b by appropriately selecting the thickness of the spacer 10 as shown in FIG. . That is, the orbiting scroll 3 is pushed through the tip seal 14 by the mirror surface 4b which is the inner surface of the housing 4, and the tip seal 14 fitted in the tip seal groove at the upper end of the wraps 27 and 26 of the orbiting scroll 3 is elastically deformed. The mirror surface 5b, 4b of the other party
It is possible to change the distance between the lap sliding surface (mirror surface) 4b of the housing 4 and the mirror surface 5b of the housing 5 while airtightly slidingly contacting the housing 4. Therefore, the distance between the mirror surface 3e of the orbiting scroll 3 and the mirror surface 4b of the housing 4 can be changed depending on the thickness of the spacer 10.

Therefore, as described above, the cross-sectional narrow width (T1> T2, S from the scroll mirror surface to the upper end).
1> S2) and fixed scrolls and orbiting scrolls, in which chip seals having elastic force for sliding contact with the mirror surface of the counterpart scroll are fitted in the chip seal grooves provided at the upper end of the wrap, respectively. A housing having an internal space for accommodating an orbiting scroll is prepared, and the wrap of the orbiting scroll is meshed with the wrap of the fixed scroll while being displaced by a predetermined angle,
In the internal space, the orbiting scroll is arranged by being pressed in the mirror surface direction of the fixed scroll by the inner surface of the housing, and the housing is attached to the fixed scroll via a spacer, whereby by the inner surface of the housing,
The orbiting scroll is pressed in the direction of the mirror surface of the fixed scroll, and the tip seal fitted in the tip seal groove provided at the top of the scroll elastically compresses and makes a hermetically sliding contact with the mating mirror surface. The scroll position can be adjusted by adjusting the spacing between the wraps.

The dimension between the upper ends of the left and right wraps of the orbiting scroll, the wraps 6 planted in the housings 4 and 5,
Each dimension such as the height from the mirror surface 5b, 4b of 7 to the upper end is
Due to wear of cutting tools in the manufacturing process, variations in initial setting values from lot to lot, etc., the dimensions of finished products are not constant, but vary within a certain product error range. Therefore, if a product with a plus error greater than the specified size is fitted to a product with a minus error, the clearance between the two becomes smaller and sliding becomes impossible, or a product with a plus error than the specified size has a minus error. When they are fitted together, the play between them becomes large.

This is because as the number of members to be combined increases, the accumulated error has a larger variation, and the number of cases in which the members are replaced and the test is repeated and adjusted is increased. However, in this embodiment, the housing is divided into a plurality of parts, and the housings are connected to each other via a static seal member outside the sliding area of the outermost peripheral surface of the orbiting scroll. Since the housing is divided into a plurality of parts, the drive shaft 11a of the orbiting scroll is inserted into the opening hole at the center of one of the housings 4 (FIG. 1), and the drive shaft 1 is inserted into the opening hole at the center of the orbiting scroll.
1a is placed in the one housing 4, and the other housing 5 is covered on the housing 4,
Attach both housings with bolts, nuts, etc. at a position not shown and assemble.

Therefore, the deviation amount from the design value of the manufactured member is measured, and it is classified into a minus deviation amount, a small deviation amount, and a plus deviation amount. The scroll mechanism can be assembled by using the members described above. Therefore, the fixed scroll,
If the orbiting scroll and the housing are prepared by dividing the dimensions into a predetermined range and assembled with members within the same predetermined range, the rotation torque of the device body and the fluid discharge amount within a unit time can be measured during assembly. Therefore, the device can be assembled while maintaining the required proper performance range.

By dividing the housing in this way, it is possible to assemble them in order, and if necessary, a spacer between the two housings can be used to adjust the space in the housing inner space in the axial direction of the drive shaft. . Therefore,
By preliminarily measuring the shape dimensions of the housing and the orbiting scroll and dividing them into appropriate ranges together with the spacer, assembly becomes easy.

Further, in this embodiment, since the housings are connected to each other outside the sliding area of the outermost peripheral surface 3e of the orbiting scroll via the static seal member 15, the suction is made from the suction port portion 8. Even if the pressure of the generated gas decreases as the degree of vacuum in the container to be evacuated decreases, the static seal member 15 does not slide, so that no gap is created by abrasion.

In the above embodiment, the combination of the double wrap orbiting scroll in which the orbiting wraps are planted on both surfaces of the end plate and the fixed scroll are explained, but the present invention is not limited to this and the end is not limited. It is also applied to the case of a combination of a single wrap revolving scroll in which a revolving wrap is planted on one surface of a plate and a fixed scroll.

[0044]

As described above, according to the present invention, an opening hole is formed in the center of the end plate of the fixed scroll, and the drive shaft of the orbiting scroll can be rotated in the opening hole through the dynamic seal member. Since it is configured to fit, the pressure difference between the gas inside and outside the scroll mechanism does not increase at the boundary of the dynamic seal of the drive shaft that rotates the orbiting scroll, and the external gas that invades even if the dynamic seal wears out. It is extremely small, and it is possible to prevent the efficiency of the scroll mechanism from decreasing and improve the durability of the scroll mechanism.

[Brief description of the drawings]

FIG. 1 is an assembly structure diagram of a scroll type vacuum pump according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view of a portion B in FIG. 1;

FIG. 4 is an explanatory diagram of an operation when entering the outside atmosphere.

FIG. 5A is a diagram illustrating a conventional example.

FIG. 5B is a conventional example diagram.

[Explanation of symbols]

 1 Pump Main Body 3 Orbiting Scroll 4, 5 Housing 6, 7, 26, 27 Wrap 8 Suction Port 9 Discharge 10 Spacer 11 Rotating Shaft 12, 13 Fan 14 Chip Seal 15 Static Seal Member (O-Ring) 16 Dynamic Seal member 17 Revolution mechanism 18 Check valve 20 Bearing (20A, 20B)

Claims (3)

[Claims] 1. A scroll-type vacuum pump comprising a combination of a fixed scroll and an orbiting scroll, wherein an opening hole is formed in a central portion of an end plate of the fixed scroll,
A scroll-type vacuum pump, wherein a drive shaft of the orbiting scroll is rotatably fitted in the opening hole via a dynamic seal member. 2. An opening hole through which a drive shaft for an orbiting scroll penetrates, and a spirally planted from the vicinity of the opening hole toward the outer peripheral portion around the opening hole, and meshes with the wrap for the orbiting scroll. Wrap for fixed scroll,
A gas suction hole for sucking gas is provided in the outer peripheral portion of the wrap, and a discharge hole for compressing and discharging the gas taken in from the outer peripheral end of the wrap is provided near the opening hole to form a housing, The orbiting scroll is revolvably driven with respect to the fixed scroll in an internal space formed by a housing, and a drive shaft for the orbiting scroll is rotatably supported in the opening hole through a dynamic seal member. The scroll-type vacuum pump according to claim 1, characterized in that. 3. The housing is divided into a plurality of parts, and the housings are joined together via a static seal member outside the sliding area of the outermost peripheral surface of the orbiting scroll. Item 2. A scroll type vacuum pump according to item 2.