CN114667393A

CN114667393A - Scroll pump

Info

Publication number: CN114667393A
Application number: CN202080080157.3A
Authority: CN
Inventors: P·C·兰布; M·A·加尔特里
Original assignee: Edwards Ltd
Current assignee: Edwards Ltd
Priority date: 2019-11-19
Filing date: 2020-11-03
Publication date: 2022-06-24
Also published as: EP4062068A1; GB2589104A; GB201916841D0; WO2021099759A1

Abstract

A scroll pump (100,200) comprising a first scroll (130) having a cooling conduit (170) extending through the first scroll, and a fan (160) configured to blow cooling gas towards the first scroll (130), wherein the cooling conduit (170) is configured to receive the cooling gas blown by the fan (160) and convey the received cooling gas through the first scroll (130).

Description

Scroll pump

Technical Field

The present invention relates to scroll pumps.

Background

A scroll pump is a known type of pump used in a variety of different industries, for example, in research and development laboratories. Scroll pumps operate by using the relative motion of two cooperating "scrolls" to pump fluid.

In scroll pumps, a significant amount of heat is generated during operation. Accordingly, it is desirable to provide a method of cooling a scroll pump.

Disclosure of Invention

According to a first aspect, there is provided a scroll pump comprising a first scroll having a cooling duct extending therethrough and a fan configured to blow cooling gas towards the first scroll, wherein the cooling duct is configured to receive cooling gas blown by the fan and to convey the received cooling gas through the first scroll.

The scroll pump may further include a second scroll interfitting with the first scroll, wherein the second scroll is located further from the fan than the first scroll.

One of the first and second scrolls is a fixed scroll, and the other of the first and second scrolls is an orbiting scroll.

The scroll pump may further include a drive shaft coupled to at least one of the first and second scrolls and the fan, wherein the shaft is configured to rotate to drive blowing by the fan and orbiting of the orbiting scroll.

The scroll pump may further include a shroud extending around the first and second scrolls, the shroud configured to direct the cooling gas exiting the cooling conduit around the first and second scrolls.

The shroud may be attached to the fixed scroll.

The cover may include one or more surface features selected from the following group of surface features: one or more ridges, one or more grooves, one or more grid structures, one or more fins, one or more corrugations.

The cooling conduit may be defined by a surface and the surface comprises one or more surface features selected from the group of surface features consisting of: one or more ridges, one or more grooves, one or more grid structures, one or more fins, one or more corrugations.

The surface defining the cooling conduit may be a surface of an insert disposed within the first scroll.

The first scroll may be formed from a single piece of material.

The first scroll may be formed from two pieces of material attached to each other.

One of the two pieces may include the spiral wall of the first scroll and the other of the two pieces may include the inlet passage of the cooling conduit and the outlet passage of the cooling conduit.

The cooling conduit may extend from an axially facing surface of the first scroll to a circumferential surface of the first scroll.

The scroll pump may include a plurality of cooling ducts, each of the plurality of cooling ducts being configured to receive cooling gas blown by the fan and convey the received cooling gas through the first scroll.

Each of the plurality of cooling conduits may extend from an axially facing surface of the first scroll to a circumferential surface of the first scroll.

According to a second aspect, there is provided a vacuum pumping system comprising a scroll pump according to the first aspect.

Drawings

FIG. 1 is a schematic illustration (not to scale) showing a cross-sectional view of a scroll pump;

FIG. 2 is a schematic illustration (not to scale) showing a cross-sectional view of another scroll pump;

FIG. 3 is a schematic illustration (not to scale) showing a cross-sectional view of a two-piece construction of a scroll for a scroll pump;

FIGS. 4 and 5 are schematic illustrations (not to scale) showing perspective views of structures that may be formed on the inner surface of a two-piece structure;

fig. 6A to 6D are schematic illustrations (not to scale) showing perspective views of an example of an insert that may be inserted into a fixed scroll of a scroll pump.

Detailed Description

FIG. 1 is a schematic illustration (not to scale) showing a scroll pump 100 according to an embodiment of the invention.

Scroll pump 100 includes a housing 110, an orbiting scroll 120, a fixed scroll 130, a drive shaft 140, a motor 150, and a fan 160. It should be understood that the scroll pump 100 also includes various other components, but these components will not be described for the sake of brevity. The scroll pump 100 may be used as part of a vacuum pumping system, for example in a research and development laboratory.

In this embodiment, the housing 110 and the fixed scroll 130 together define the entire outer casing of the scroll pump 100 within which the other components of the scroll pump 100 are located.

An orbiting scroll 120 is located within the entire housing of the scroll pump 100 and cooperates with a fixed scroll 130. Orbiting scroll 120 is configured to orbit relative to fixed scroll 130 to pump fluid from an inlet (not shown) of scroll pump 100 to an outlet (not shown) of scroll pump 100. Orbiting scroll 120 includes a first base 122 and a first spiral wall 124 extending from base 122. The fixed scroll 130 includes a second base 132 and a second spiral wall 134 extending from the second base 132. The first and second

spiral walls

124, 134 cooperate with one another to define a space therebetween that is used by the scroll pump 100 to pump fluid during operation. The details of the physical mechanism by which fluid is pumped by the orbiting scroll 120 relative to the orbiting of the fixed scroll 130 are well known and, for the sake of brevity, will not be described herein.

In this embodiment, orbiting scroll 120 and fixed scroll 130 are each formed as a single piece structure.

The drive shaft 140, motor 150 and fan 160 are located within the entire housing of the scroll pump 100. Drive shaft 140 is coupled to both orbiting scroll 120 and fan 160. More specifically, drive shaft 140 is coupled to orbiting scroll 120 at a first end thereof and to fan 160 at a second, opposite end thereof. The motor 150 is configured to actuate the drive shaft 140 to cause rotation of the drive shaft 140. Rotation of drive shaft 140 drives both the orbiting of orbiting scroll 120 and the rotation of fan 160. Rotation of the fan 160 blows gas (e.g., air) through (and/or across) the scroll pump 100 toward the fixed scroll 130 and the orbiting scroll 120 to cool the fixed scroll 130 and the orbiting scroll 120 (as indicated by arrows 162).

The fixed scroll 130 includes a plurality of cooling conduits or passages 170 extending through the fixed scroll 130. Each cooling duct 170 is configured to receive cooling gas blown by the fan 160, convey the received cooling gas through the fixed scroll 130 (as indicated by arrow 164), and output the cooling gas out of the fixed scroll 130. In more detail, each cooling conduit 170 includes an inlet 172 at which cooling gas is received into the cooling conduit 170 and an outlet 174 at which the cooling gas is output out of the fixed scroll 130.

In this embodiment, each cooling conduit 170 extends from an axially facing surface of the fixed scroll 130 to a circumferential surface of the fixed scroll 120. The axially facing surface faces away from orbiting scroll 120.

Advantageously, directing the gas through the fixed scroll 130 in the manner described above tends to bring the cooling gas closer to the orbiting scroll 120, and thus tends to provide improved cooling of the orbiting scroll 120 as compared to when the cooling conduit 170 is not present. For example, if the cooling conduits 170 were not present, all of the cooling gas would simply impinge on the axially facing surface of the fixed scroll 120 and be directed away from the scroll pump 100 in a direction parallel to the axially facing surface (i.e., the radial direction), and thus would not flow close to the orbiting scroll 120. Furthermore, directing the cooling gas in the manner described above tends to improve cooling of the fixed scroll 130 because the cooling gas is in contact with a relatively large surface area and the cooling is more evenly dispersed through the fixed scroll 130.

FIG. 2 is a schematic illustration (not to scale) showing a cross-sectional view of a scroll pump 200 according to another embodiment.

The scroll pump 200 includes a housing 210, an orbiting scroll 220, a fixed scroll 230, a drive shaft 240, a motor 250, and a fan 260. It should be understood that the scroll pump 200 also includes various other components, but these components will not be described for the sake of brevity. The scroll pump 200 may be used as part of a vacuum pumping system, for example in a research and development laboratory.

In this embodiment, the housing 210 and the fixed scroll 230 together define the entire outer casing of the scroll pump 200 within which the other components of the scroll pump 200 are located.

Orbiting scroll 220 is located within the entire housing of scroll pump 200 and interfits with fixed scroll 230. Orbiting scroll 220 is configured to orbit relative to fixed scroll 230 to pump fluid from an inlet (not shown) of scroll pump 200 to an outlet (not shown) of scroll pump 200. Orbiting scroll 220 includes a first base 222 and a first spiral wall 224 extending from base 222. The fixed scroll 230 includes a second base 232 and a second spiral wall 234 extending from the second base 232. The first and second

spiral walls

224, 234 cooperate with one another to define a space therebetween that is used by the scroll pump 200 to pump fluid during operation. The details of the physical mechanism by which fluid is pumped by the orbiting scroll 220 relative to the orbiting of the fixed scroll 230 are well known and, for the sake of brevity, will not be described herein.

In this embodiment, the orbiting scroll 220 and the fixed scroll 230 are each formed as a single-piece structure.

The drive shaft 240, motor 250 and fan 260 are located within the entire housing of the scroll pump 200. Drive shaft 240 is coupled to both orbiting scroll 220 and fan 260. More specifically, drive shaft 240 is coupled at a first end thereof to orbiting scroll 220 and at a second, opposite end thereof to fan 260. The motor 250 is configured to actuate the drive shaft 240 to cause rotation of the drive shaft 240. Rotation of the drive shaft 240 drives both the orbiting of the orbiting scroll 220 and the rotation of the fan 260. Rotation of the fan 260 blows gas through (and/or across) the scroll pump 200 toward the fixed scroll 230 and the orbiting scroll 220 to cool the fixed scroll 230 and the orbiting scroll 220 (as indicated by arrows 262).

The fixed scroll 230 includes a plurality of cooling conduits or passages 270 that extend through the fixed scroll 230. Each cooling duct 270 is configured to receive cooling gas blown by fan 260, convey the received cooling gas through fixed scroll 230 (as indicated by arrow 264), and output the cooling gas out of fixed scroll 230. In more detail, each cooling conduit 270 includes an inlet 272 at which the cooling gas is received into the cooling conduit 270 and an outlet 274 at which the cooling gas is output out of the fixed scroll 230 at the outlet 174.

In this embodiment, each cooling conduit 270 extends from an axially facing surface of the fixed scroll 230 to a circumferential surface of the fixed scroll 220. The axially facing surface faces away from orbiting scroll 220.

In this embodiment, the scroll pump 200 also includes a shroud 280 that extends around the fixed scroll 230 and the orbiting scroll 220. The shroud 280 is configured to direct cooling gas that has been output from the cooling conduit 270 along the exterior of the entire housing of the scroll pump 100, through the orbiting scroll 220, and out of an outlet aperture located in line with the drive shaft 240 (as indicated by arrow 266). The shroud 280 is annular and extends around the circumference of the fixed scroll 230 and the orbiting scroll 220. Although not shown in FIG. 2, the shroud 280 is attached to the fixed scroll 230.

The shroud 280 includes one or more surface features (e.g., molded surface features) on a surface of the shroud 280 facing the fixed scroll 230 and/or the orbiting scroll 220. In general, the one or more surface features may be any surface feature that is used to direct gas flow, alter gas velocity, induce turbulence, or attenuate noise from gas flow. For example, the one or more surface features may include one or more of: one or more ridges, one or more grooves, one or more grid structures, one or more fins, one or more corrugations.

Advantageously, directing the gas through the fixed scroll 230 in the manner described above tends to bring the cooling gas closer to the orbiting scroll 220, and thus tends to provide improved cooling in a manner similar to that described above with respect to the embodiment of FIG. 1. In addition, the presence of the shroud 280 brings the cooling gas flow even closer to the orbiting scroll 220 and thus tends to provide further improved cooling of the orbiting scroll 220.

FIG. 3 is a schematic illustration (not to scale) showing a cross-sectional view of a two-piece construction of the fixed scroll 130,230 that may be used with the embodiments of FIGS. 1 and 2.

For this two-piece construction, the fixed scroll 130,230 includes a first piece 310 and a second piece 320. The first piece 310 includes the second spiral wall 134,234 and the first portion of the second base 132,232, while the second piece 320 includes the second portion of the second base 132,232, one or more inlet channels 330a of the cooling

conduits

170, 270 and one or more outlet channels 330b of the cooling

conduits

170, 270. The one or more inlet passages 330a are configured to receive cooling gas blown by the fan into the fixed scroll 130,230, and the one or more outlet passages 330b are configured to output the received cooling gas out of the fixed

scroll

130, 230. The first piece 310 and the second piece 320 are each separately manufactured and subsequently attached to each other to form the fixed

scrolls

130, 230. The first piece 310 and the second piece 320 may be secured together by any suitable method (e.g., by bolting). When attached, the two pieces define an internal cavity 340 therebetween that is fluidly connected to the inlet and

outlet passages

330a, 330 b. More specifically, when attached, the interior cavity 340 is defined by an interior surface of the first piece 310 and an interior surface of the second piece 320. The inlet channel 330a, the outlet channel 330b, and the internal cavity 340 together form the cooling

conduits

170, 270 when the first and

second pieces

310, 320 are attached together.

One or more surface structures for directing the gas flow may be provided on the inner surface of the first and/or second piece 310 to form a pathway for directing the gas flow from the inlet channel 330a to the outlet channel 330 b. These surface structures also increase the amount of surface area to improve cooling of gases passing through them. For example, the one or more surface features may include one or more of: one or more ridges, one or more grooves, one or more grid structures, one or more fins, one or more corrugations.

Fig. 4 and 5 are schematic illustrations (not to scale) showing perspective views of examples of structures that may be formed on the inner surface of the first and/or

second members

310, 320 described above with reference to fig. 3. Fig. 4 shows a finned structure 410. The fins of the finned structure 410 may extend between the inner surfaces of the first and

second pieces

310, 320. Fig. 5 shows a honeycomb grid structure 510.

Fig. 6A-6D are schematic illustrations (not to scale) showing perspective views of examples of

inserts

600A,600B,600C,600D that may be inserted into one or more of the cooling

conduits

170, 270.

Each of the

inserts

600A,600B,600C,600D includes an

insert body

610A,610B,610C and an

insert conduit

620A,620B,620C,620D extending through the

insert body

610A,610B, 610C. The

insert conduits

620A,620B,620C,620D are defined by the inner surfaces of the

insert bodies

610A,610B, 610C. In the illustrated example, the

insert bodies

610A,610B,610C are elongate, and the

insert conduits

620A,620B,620C,620D extend longitudinally through the

elongate insert bodies

610A,610B, 610C. When inserted, the

inserts

600A,600B,600C,600D may be secured in place by a friction fit between the

insert bodies

610A,610B,610C and the inner surfaces of the fixed

scrolls

130, 230.

When the

inserts

600A,600B,600C,600D are inserted into the cooling

ducts

170, 270, the cooling gas blown by the fans 160,260 flows through the

insert ducts

620A,620B,620C, 620D. In this way, the

insert conduits

620A,620B,620C,620D function as cooling conduits for the blown gas flowing through the fixed

vortices

130, 230. The inner surface of the

insert body

610A,610B,610C includes one or more surface features for increasing the surface area for cooling. For example, the one or more surface features may include one or more of: one or more ridges, one or more grooves, one or more grid structures, one or more fins, one or more corrugations. It should be appreciated that the inner surface of the insert may generally be of any form that will increase the surface area for heat transfer (relative to a smooth surface).

Fig. 6A shows an example of an insert 610A having an inner surface of an insert body 610A with a plurality of helically extending ridges/grooves. Fig. 6B shows an example of an insert 610B having an inner surface of an insert body 610B with a plurality of ridges/grooves defining a star shape. Fig. 6C shows an example of an insert 610C having a plurality of pleats on an inner surface of an insert body 610C. Fig. 6D shows an example of an insert 610D having an inner surface of an insert body 610D with a plurality of radially extending fins.

The use of inserts to provide this additional surface area is often advantageous because it is often easier to fabricate complex surface features in the insert rather than directly in the fixed scroll cooling conduit.

Description of the reference numerals

A scroll pump: 100,200

A housing: 110,210

And (3) orbiting vortex: 120,220

Fixing vortex: 130,230

Drive shaft: 140,240

A motor: 150,250

A fan: 160,260

A first base portion: 122,222

A first helical wall: 124,224

A second base portion: 132,232

A second spiral wall: 134,234

An inlet: 172,272

And (4) outlet: 174,274

Covering: 280

A first item: 310

A second part: 320

An inlet channel: 330a

An outlet channel: 330b

Internal cavity: 340

The structure with fins is as follows: 410

Grid structure: 510

An insert: 600A,600B,600C,600D

An insert body: 610A,610B,610C,610D

An insert conduit: 620A,620B,620C,620D

Claims

1. A scroll pump comprising:

a first scroll having a cooling conduit extending therethrough; and

a fan configured to blow cooling gas toward the first scroll,

wherein the cooling duct is configured to receive cooling gas blown by the fan and convey the received cooling gas through the first vortex.

2. A scroll pump as claimed in claim 1, further comprising a second scroll interfitting with the first scroll, wherein the second scroll is located further from the fan than the first scroll.

3. A scroll pump as claimed in claim 2, wherein one of the first and second scrolls is a fixed scroll and the other of the first and second scrolls is an orbiting scroll.

4. A scroll pump as claimed in claim 3, further comprising a drive shaft coupled to the fan and at least one of the first scroll and the second scroll, wherein the shaft is configured to rotate to drive blowing by the fan and orbiting of the orbiting scroll.

5. A scroll pump as claimed in any one of claims 2 to 4, further comprising a shroud extending around the first and second scrolls, the shroud being configured to direct cooling gas exiting the cooling conduit around the first and second scrolls.

6. A scroll pump as claimed in claim 5, wherein the shroud is attached to the fixed scroll.

7. A scroll pump as claimed in claim 5 or 6, wherein the shroud comprises one or more surface features selected from the following group of surface features:

one or more ridges, one or more grooves, one or more grid structures, one or more fins, one or more corrugations.

8. A scroll pump as claimed in any one of the preceding claims, wherein the cooling conduit is defined by a surface and the surface includes one or more surface features selected from the following group of surface features:

9. A scroll pump as claimed in claim 6, wherein the surface defining the cooling conduit comprises a surface of an insert disposed within the first scroll.

10. A scroll pump as claimed in any one of the preceding claims, wherein the first scroll is formed from a single piece of material.

11. A scroll pump as claimed in any one of claims 1 to 9, wherein the first scroll is formed from two pieces of material attached to one another, wherein one of the two pieces comprises a spiral wall of the first scroll and the other of the two pieces comprises an inlet passage of the cooling conduit and an outlet passage of the cooling conduit.

12. A scroll pump as claimed in any one of the preceding claims, wherein the cooling conduit extends from an axially facing surface of the first scroll to a circumferential surface of the first scroll.

13. A scroll pump as claimed in any one of the preceding claims, wherein the scroll pump comprises a plurality of cooling ducts, each of the plurality of cooling ducts being configured to receive cooling gas blown by the fan and convey the received cooling gas through the first scroll.

14. A scroll pump as claimed in claim 13, wherein each of the plurality of cooling conduits extends from an axially facing surface of the first scroll to a circumferential surface of the first scroll.

15. A vacuum pumping system comprising a scroll pump as claimed in any one of claims 1 to 14.