CN100473838C

CN100473838C - Cooling of pump rotors

Info

Publication number: CN100473838C
Application number: CNB2005800295740A
Authority: CN
Inventors: M·H·诺尔思
Original assignee: BOC Group Ltd
Current assignee: BOC Group Ltd
Priority date: 2004-09-02
Filing date: 2005-08-17
Publication date: 2009-04-01
Anticipated expiration: 2025-08-17
Also published as: GB0419514D0; CN101010516A

Abstract

A rotor for a screw vacuum pump has a threaded body in which a central cavity is formed. A coolant is supplied to the cavity from a supply line provided in a shaft attached to the body. A coolant flow guide, which may be either separate from or at least partially integral with the shaft, is located within the cavity. The flow guide has an outer surface adjacent, preferably in contact with, the body to enable heat to the transferred from the rotor to the guide. The guide also has an inner surface defining a bore, and defines at least in part a plurality of axially extending slots radially spaced from and in fluid communication with the bore. In use, coolant flows into the cavity through the bore of the guide, and out from the cavity through the axially extending slots, extracting heat from the guide as it flows both into and out form the cavity. The discharged coolant is conveyed form the slots into a discharge line located within the shaft.

Description

The cooling of pump rotor

Technical field

The present invention relates to the cooling of pump rotor, relate to the cooling of screw pump rotor particularly.

Background technique

Screw pump is widely used in industrial treatment, and the manufacturing of thinking product provides the environment of cleaning and/or low-pressure.The application comprises pharmacy and semiconductor manufacturing industry.Typical screw pump mechanism comprises that each all carries two parallel spaced axles of outside thread rotor, and this is installed in and makes the screw thread of rotor intermesh in the pump housing.Close tolerance between the internal surface (it is as stator) of the rotor screw thread of the position of intermeshing and the pump housing makes the gas that enters in the ingress enter between the screw thread and internal surface of rotor, and is driven to delivery side of pump along with the rotor rotation.

In use, owing to the compression of gas being produced heat with the rotor of the mode effect that is bonded to each other.Thus, the temperature of rotor raises rapidly.By contrast, the volume of stator is bigger, and its heating is slower.This has produced the inconsistent of temperature between stator and rotor, if allow not weaken structure, then along with the reducing of gap between them, may cause rotor to be stuck in the stator.Therefore, need provide a kind of system that is used for cooled rotor.

A kind of known structure that the outlet of the both-end rotor of the schematically illustrated cooling screw pump of Fig. 1 is used, as shown in the international patent application No.WO 2004/036049 before us, its content is included in here by reference.In this structure, central chamber 10 is formed in each end of threaded body 12 of rotor (only showing an end among Fig. 1), and chamber 10 is coaxial with main body 12, and the longitudinal axis of main body 12 is represented with 14.Axle 16 is mounted to main body 12 by bolt 18, makes axle 16 extend in the chamber 10, and in use with main body 12 rotations of rotor.Be formed with first central hole 20 in the axle 16.First hole 20 holds freezing mixture supply tube 22, and it is coaxial that freezing mixture supply tube 22 is used for that the freezing mixture from the coolant source pumping is fed to axle 16 second central hole, 24, the second holes 24 and first hole 20.Freezing mixture flow into the chamber 10 from second hole 24, wherein freezing mixture flows radially outward between the end wall 28 in the end 26 of axle 16 and chamber 10, flow away from end wall 28 in narrow annular space 30 then, wherein narrow annular space 30 is between the cylindrical wall 34 in the cylindrical wall 32 of axle 16 and chamber 10.The radial hole 36 that forms in the axle 16 allows freezing mixtures to flow in first hole 20 of axle 16, and flows back to the end 38 of axle 16, and freezing mixture is discharged into the liquid-storage container (not shown) from end 28, and liquid-storage container has and is used to make freezing mixture to return the pumping mechanism of supply tube 22.

Summary of the invention

At least one purpose of the preferred embodiment of the present invention provides a kind of improvement structure that is used for the cooling screw pump rotor.

The invention provides a kind of rotor that is used for vacuum pump, described rotor comprises: threaded body; Extend axially the chamber in the described main body; Be used for the feeding mechanism of supply coolant to described chamber; Be used for from the tapping equipment of described chamber discharging freezing mixture; And in described chamber, be used for the guiding device that conduct coolant flows between described feeding mechanism and described tapping equipment, wherein, described guiding device has the internal surface of limiting hole and locatees so that heat can be passed to the outer surface of guiding device from described main body near described main body, and described guiding device defines a plurality of slits that extend along described guiding device at least, and described slit and described aperture are to spaced apart and be communicated with described orifice flow body.

The present invention also provides a kind of rotor that is used for vacuum pump, and described rotor comprises threaded body, and described threaded body has the chamber in the threaded body of extending at each place, end of threaded body; Be used for the feeding mechanism of supply coolant to each chamber; With the tapping equipment that is used for discharging freezing mixture from each chamber, in each chamber, be used for the guiding device that conduct coolant flows between described feeding mechanism and described tapping equipment, wherein, described guiding device has the internal surface of limiting hole and locatees so that heat can be passed to the outer surface of guiding device from described main body near described main body, and described guiding device defines a plurality of slits that extend along described guiding device at least, and described slit and described aperture are to spaced apart and be communicated with described orifice flow body.

In first aspect, the invention provides a kind of rotor that is used for vacuum pump, described rotor comprises threaded body, extend axially the chamber in the described main body, be used for the device of supply coolant to described chamber, be used for from the device of described chamber discharging freezing mixture, and in described chamber, be used for the device that conduct coolant flows between described feeding mechanism and described tapping equipment, wherein, described guiding device has the internal surface of limiting hole and locatees so that heat can be passed to its outer surface from described main body near described main body, and described guiding device defines a plurality of slits that extend along described guiding device at least, and described slit and described aperture are to spaced apart and be communicated with described orifice flow body.

In the prior art, being exposed of rotor is used for being limited to by the generating surface that freezing mixture cools off the surface area of the cylindrical wall 34 in chamber 10.In order to increase the surface area that is exposed and is used to cool off, the present invention has saved the annular space 30 of prior art, replace being provided with the guide of flow device with main body closely adjacent (preferably contact), and this guide of flow device in the chamber, define the hole and along the fluid guiding device extension and with the aperture to isolated a plurality of slits.Because fluid guiding device is to closely adjacent (usually less than the 0.1mm) of rotor subject, heat can be passed to fluid guiding device from rotor subject.Fluid guiding device can be positioned near the rotor subject, makes in use, and the thermal expansion of fluid guiding device causes fluid guiding device contact main body.Expose now the surface area sum that the generating surface that is used to cool off comprises the wall of the surface area of internal surface (it defines the hole) of guiding device and slit, make along with freezing mixture flows into and flows out rotor, can be by freezing mixture from the rotor draw heat.Compare with the prior art constructions that the chamber of similar size is formed in the rotor subject, this can increase the surface area that is used to cool off significantly.

Guiding device is preferably formed by the material that is different from rotor subject.In order to make the cooling maximization of rotor, at least a portion of guiding device is preferably formed by the material that thermal conductivity is equal to or higher than the material that forms described threaded body.For example, when rotor subject was formed by iron, guiding device was preferably formed by any other suitable material that aluminium or its alloy, copper or its alloy or thermal conductivity are equal to or higher than iron.

In second aspect, the invention provides a kind of rotor that is used for vacuum pump, described rotor comprises threaded body, and described threaded body has the chamber that extends to wherein at each place, end; Be used for the device of supply coolant to each chamber; With the device that is used for discharging freezing mixture from each chamber, each chamber has the device that conduct coolant flows that is used for wherein between described feeding mechanism and described tapping equipment, wherein, described guiding device has the internal surface of limiting hole and locatees so that heat can be passed to its outer surface from described main body near described main body, and described guiding device defines a plurality of slits that extend along described guiding device at least, and described slit and described aperture are to spaced apart and be communicated with described orifice flow body.

In one aspect of the method, the invention provides a kind of rotor that is used for vacuum pump, this rotor comprises threaded body, and threaded body has a plurality of axial cavities that part extended to wherein and centered on the longitudinal axis location of rotor; Be used for the device of supply coolant to each chamber; Be used for the device that conduct coolant flows in each chamber; With the device that is used for discharging freezing mixture from each chamber.The central chamber 10 that has saved prior art in this respect of the present invention replaces being provided with a plurality of chambeies, and preferably, a plurality of chambeies are to be provided with by a plurality of holes in the threaded body that partly is formed on rotor, and these a plurality of chambeies are around the longitudinal axis location of rotor.According to such structure, compare with the prior art constructions of using single central chamber, can increase the surface area that freezing mixture contacts with rotor subject significantly in any given time.Therefore, further in, the invention provides the rotor that is used for vacuum pump, this rotor comprises threaded body, the place, each end of described threaded body has and extends axially wherein and around the chamber of the longitudinal axis location of rotor; Be used for the device of supply coolant to each chamber; With the device that is used for discharging from each chamber freezing mixture, each chamber has the device that conduct coolant flowed into and flowed out described chamber that is used for that is positioned at wherein.

Guiding device preferably is limited to the coolant flowpaths of extending between feeding mechanism and the tapping equipment in the chamber.Coolant flowpaths preferably has first portion and second portion, and freezing mixture flows on first direction along first portion, and freezing mixture flows on the second direction opposite with first direction along second portion.Guiding device preferably comprises in each chamber and is used to limit the first portion of flow path and the pipeline of second portion.The first portion of flow path can extend between the outer wall of main body and pipeline, and the second portion of flow path can extend in the hole of pipeline.Each pipeline preferably comprises the one or more radial holes that are used for the first portion of flow path is connected to the second portion of flow path.The feeding mechanism preferred arrangements is the first portion of supply coolant to flow path, and the tapping equipment preferred arrangements is the second portion reception freezing mixture from flow path.

Description of drawings

Referring now to accompanying drawing preferred feature of the present invention is described, wherein:

Fig. 1 is the sectional view of a part of the known rotor of screw pump;

Fig. 2 (a) is first embodiment's of screw pump rotor the sectional view of a part, and Fig. 2 (b) is the sectional view along the line A-A of Fig. 2 (a);

Fig. 3 (a) is second embodiment's of screw pump rotor the sectional view of a part;

Fig. 4 (a) is the 3rd embodiment's of screw pump rotor the sectional view of a part; Fig. 4 (b) is the sectional view along the line A-A among Fig. 4 (a);

Fig. 5 is the sectional view of the part of another rotor;

Fig. 6 is with amplification view regional shown in the B among Fig. 5; And

Fig. 7 is with amplification view regional shown in the A among Fig. 5.

Embodiment

Fig. 2 illustrates first embodiment's of screw pump rotor 100 a part.Rotor 100 comprises the threaded body 102 with longitudinal axis 104.Chamber 106 is formed in the main body 102, and it is also coaxial with main body 102 basically to make that chamber 106 partly extends in the main body 102.

Pipeline 108 is positioned at chamber 106 and coaxial with main body 102, makes the outer surface 110 of pipeline 108 and the cylindrical wall 112 in chamber 106 form interference fit.Pipeline 108 can use any technology easily (utilize liquid nitrogen to make pipeline 108 initial contraction and be inserted into shrink-fit in the pipeline 108 such as use) to be inserted in the chamber 106, makes thermal expansion subsequently cause that pipeline 108 is positioned in the chamber 106 securely.

Pipeline 108 (its part at least) preferably forms by having the material that equates heat conductivity at least with the material that forms main body 102.In a preferred embodiment, main body 102 is formed by iron, and pipeline 108 is formed by aluminum alloy.

Shown in Fig. 2 (b), interior, the barrel surface 114 of pipeline 108 defines and extends in the chamber 106 and the hole 116 roughly coaxial with main body 102.A plurality of groove 118 machinings or otherwise be formed on the outer surface 110 of pipeline 108, each groove 118 extends along the length of pipeline 108.In a preferred embodiment, the longitudinal axis 104 that each groove 118 is arranged essentially parallel to main body extends, but the part of each groove 118 also can be crooked or be formed other shape as required.The wall 112 in groove 118 usefulness chambeies defines a plurality of axially extended slits 119, and these a plurality of slits 119 are around the hole 116 of pipeline 108.Shown in Fig. 2 (a), pipeline 108 is not inserted in the chamber 106 fully, makes slit 119 be communicated with hole 116 fluids.

Axle 120 parts extend in the hole 116 of pipeline 108, and are installed to main body 102 by bolt 122 etc.Shown in Fig. 2 (a), axle 120 is coaxial with main body 102.Axle 120 is machined as and makes the cylindrical outer surface that extends to the end 126 in the hole 116 124 of axle 120 and the internal surface 114 of pipeline 108 mesh.

Axle 120 comprises length process and the vertical hole 128 coaxial with it along axle 120.On the major part of axle 120, vertically hole 128 has constant diameter, and 126 diameters reduce towards the end of axle 120, divide 130 with the reduced diameter portion that limits vertical hole 128.Freezing mixture supply tube 132 is positioned at vertical hole 128.The external diameter of freezing mixture supply tube 132 is slightly less than the reduced diameter portion in vertical hole 128 and divides 130 external diameter.Freezing mixture supply tube 132 extends through vertical hole 128, makes the end 134 of winning be positioned at hole 116, and its second end (not shown) extends from the other end (not shown) of axle 120.Second end of freezing mixture supply tube can be supported by any device easily.In order to suppress freezing mixture supply tube 132 rotation in vertical hole 128 along with the rotation of rotor 100, the reduced diameter portion that sliding bearing is arranged on vertical hole 128 divide 130 and freezing mixture supply tube 132 between.

Axle 120 also comprises a plurality of second holes 136, each second hole vertical hole 128 and be formed in the axle 102 and and the annular notch of slit 119 radially aligneds or groove 138 between extend.The longitudinal axis 140 in each second hole 136 acutangulates with the longitudinal axis 104 of rotor 100.In this example, this acute angle is approximately 30 °, but also can be to any value easily of this angle Selection.

In use, freezing mixture stream (for example cold oil) is supplied to second end of freezing mixture supply tube 132 from coolant source.Coolant source can be provided with easily by the outside oil cup of stator (rotor is contained in wherein) that is positioned at pump.Freezing mixture flows through the hole 142 of freezing mixture supply tube 132 and flow in the hole 116 of pipeline 108.Freezing mixture 116 is advanced along the hole, and be at the end wall 146 in chamber 106 between the end wall 146 in the end 144 of pipeline 108 and chamber 106 and flow radially outward, and enter the slit 119 that is limited between pipeline 108 and the main body 102, freezing mixture refluxes towards axle 120 in slit 119, and promptly freezing mixture flows in the opposite direction in the side of flowing through hole 116 with freezing mixture.Freezing mixture enters annular notch 138 from slit 119, and freezing mixture is transported to second hole 136 from annular notch 138, second hole 136 with coolant feed in the hole 128 of axle 120.Freezing mixture is advanced in hole 128 along the outside of freezing mixture supply tube 132, and total reflux is in oil cup, and through suitable heat exchange mechanism, freezing mixture can be pumped back to second end of axle 120 from oil cup.Arrow among Fig. 2 (a) represents that freezing mixture flows through the direction of the diagram part of rotor 100.

Being inserted into pipeline 108 in the chamber 106 provides thus be used for the guiding element that conduct coolant flows in the chamber, and it contacts with main body 102, unlike spools 16 of prior art.Because contacting between pipeline 108 and the rotor subject 102, heat can be delivered to the pipeline 108 from rotor subject 102.Therefore the generating surface that is exposed to freezing mixture comprises the surface area of wall of the internal surface 114 of pipeline 108 and slit 119 and both, makes freezing mixture that heat can be by inflow and outflow rotor 100 from rotor 100 discharges.This has strengthened the cooling of rotor 100, and can reduce the cold radial clearance between stator and the rotor thus, and the raising to pumping efficiency is provided thus.

Fig. 3 illustrates second embodiment's the part of the rotor 200 of screw pump, and those wherein identical with feature among first embodiment shown in Figure 2 features are endowed identical reference number.In a second embodiment, first embodiment's pipeline 108 is replaced by pipeline 208, and pipeline 208 is by forming with pipeline 108 materials similar and the cylindrical wall 112 in itself and chamber 106 forms interference fit similarly.Pipeline 208 also has internal surface 214, and internal surface 214 defines and extends in the chamber 106 and the hole 216 coaxial basically with main body 102.Pipeline 208 is positioned at pipeline 208 with different being of pipeline 108 all over along the slit 219 that the length of pipeline 208 is extended, promptly between the internal surface 214 and outer surface 210 of pipeline 208.At pipeline 208 is under the situation of single workpiece, can form these grooves 219 by machining or by any other technology in the process of extruding pipeline 208.Replacedly, pipeline 208 can form two parts, i.e. inner part and outside parts, axially extended slit 219 are limited between the internal surface of the outer surface of inner part and outside parts.For example, can be on the outer surface of inner part machining groove (being similar to first embodiment), wherein the outside parts of sleeve pipe form are positioned at the inner part top with enclosed slot and form slit 219.

Compare with first embodiment, second embodiment provides improved cooling, because the outer surface of pipeline 208 210 contacts with the wall 112 in chamber 106 fully; In first embodiment, the part of the outer surface 110 of pipeline 108, is made directly to contact with less from the surface area of main body 102 conduction heats with main body 102 to form groove 118 by machining.

Fig. 4 illustrates the 3rd embodiment's the part of the rotor 300 of screw pump, and once more, those identical with first embodiment's shown in Figure 2 feature will be endowed identical reference number.In the 3rd embodiment, to compare with first embodiment, axle 120 end 126 is extended, and makes when axle 120 is mounted to main body 102, and narrow radial clearance 348 is limited between the end wall 146 in spools 120 end 126 and chamber 106.Compare with first embodiment, vertically extend similarly in hole 128, makes vertical hole 128 divide 130 to extend to an end 126 of spools 120 from reduced diameter portion.

The 3rd embodiment's pipeline 308 is positioned at cylindrical wall 124 tops of axle 120 end 126, and forms interference fit once more with the cylindrical wall 112 in chamber 106.In this embodiment, for example use internal surface 314 that line cutting comes process pipeline 308 forming groove 318, when pipeline 308 was assemblied on the end 126 of axle 120, the wall 124 of groove 318 usefulness spools 120 limited axially extended slit 319.Replacedly, can use extruding technology to form slit 319.

In the 3rd embodiment, both define pipeline 308 and axle 120 and are used for the mobile guiding element of conduct coolant chamber 106 in.In use, receive by the hole 142 of freezing mixture supply tube 132 and the freezing mixture stream that flows through this hole enters vertical hole 128 from the end 134 of freezing mixture supply tube 132.Freezing mixture flows through axle 120 hole 128, and flows radially outward between the end wall 146 in the end 126 of axle 120 and chamber 106, enters the slit 319 that is limited between pipeline 308 and the axle 120 then.Freezing mixture flows through slit 319 in the side of flowing through hole 128 with freezing mixture in the opposite direction, and enters annular notch 138.Then, has identical path from the passage from the freezing mixture of annular notch 138 among the passage of the freezing mixture of annular notch 138 and first embodiment.

Because the outer surface 310 of pipeline 308 contacts fully with the wall 112 in chamber 106, thus the 3rd embodiment can provide with second embodiment similarly to the improvement of the cooling of rotor 300.

Any one rotor 100,200,300 can form the part of double-end type screw pump among first to the 3rd embodiment, and as described in the international patent application No.WO 2004/036049 before us, its content is included in here by reference.In such pump, gas enters pump in the ingress of central locating, and forms two a fluid streams carrying by pump in the opposite direction towards each outlet that is arranged on the rotor tip place.In this case, the cooling structure shown in any among Fig. 2 to 4 can be arranged on each place, end of rotor.

In first to the 3rd embodiment, when pipeline contacts with the main body of rotor, have been found that existing between the main body of the outer surface of pipeline and rotor under the situation of narrow gap (usually less than 0.1mm) and axle and the hole formation interference fit of pipeline, confers similar advantages can be provided.Have been found that closely close not exceedingly caloric restriction the transmission from main body to pipeline of pipeline, and can simplify the structure of pump to main body.According to the size in gap, in the use of pump, the thermal expansion of pipeline possibility makes the outer wall of pipeline contact the main body of rotor.

Fig. 5 illustrates the part of the rotor 400 of screw pump.Rotor 400 comprises the threaded body 402 with longitudinal axis 404.First chamber 406 is formed in the main body 402, and first chamber 406 is coaxial basically with main body 402.For example by machined holes array in main body, the array in second chamber 408 also is formed in the main body 402, and second chamber 408 is communicated with first chamber, 406 fluids.Each of second chamber 408 axially extends in the main body 402 and is roughly parallel to the longitudinal axis 404 of main body, and each second chamber 408 partly extends in the main body 402.The longitudinal axis 410 of each of second chamber is spaced apart with the longitudinal axis 404 of main body 402.In a preferred embodiment, rotor 400 comprises ten second chambeies 408, and the longitudinal axis 404 of each second chamber 408 and main body 402 is equally spaced from opening, and with closely adjacent second chamber 408 equally spaced from opening.The quantity in second chamber 408 and they are not limited thereto specific structure around the layout of the longitudinal axis 404 of main body 402, can provide the structure in second chamber 408 of any amount and second chamber 408 to satisfy the cooling needs of rotor 400.

Pipeline 414 is positioned at each second chamber 408.With reference to figure 6 and 7, in this embodiment, first end 416 of each pipeline 414 meshes with the end 418 in its second chamber 408 separately, and second end 420 of pipeline 414 is outstanding from second chamber 408.First end 416 near each pipeline 414 forms a plurality of radial holes 422 (as shown in Figure 7, second end 420 near pipeline 414 also forms similar radial hole 424, be inserted in second chamber 408 with first end 418 or second end 420 that allows pipeline 414 easily, although in use, these additional radial holes 424 are unnecessary and therefore do not need to be provided with).The external diameter of each pipeline 414 is less than the hole in its second chamber 408 separately, to limit narrow passage 426 between the cylindrical outer surface 430 of the cylindrical wall 428 in second chamber 408 and pipeline 414.

Axle 432 is positioned at first recess 406 and is mounted to main body 402 by bolt 434 etc.As shown in Figure 5, axle 432 is coaxial with main body 402.Axle 432 has second hole 408 that forms in a plurality of first holes, 436, the first axis holes 436 of end 438 formation that are arranged in first chamber 406 and main body 402 coaxial, so that the end 420 of first axis hole, 436 receiving pipelines 414.

Axle 432 also comprises and passes axle 432 whole length and the second vertical hole 440 coaxial with it.Vertically hole 440 has constant diameter along the major part of

axle

432, and 438 diameters reduce to divide 442 with the reduced diameter portion that limits vertical hole 440 towards the end of axle.Freezing mixture supply tube 444 is positioned at vertical hole 440.The external diameter of freezing mixture supply tube 444 is slightly less than the reduced diameter portion in vertical hole 440 and divides 442 external diameter.Freezing mixture supply tube 444 extends through vertical hole 440, makes its first end 446 extend in first chamber 406, and its second end 448 extends from the end 450 of axle 432.Second end 448 of freezing mixture supply tube 444 can keep by any device easily.For rotation along with rotor 400, the rotation of freezing mixture supply tube 444 is limited in vertical hole 440, the reduced diameter portion that sliding bearing 452 is arranged on vertical hole 440 divide 442 and freezing mixture supply tube 444 between.

Axle 432 also comprises a plurality of the 3rd holes 454, and each is vertically extending between hole 440 and first axis hole 436 separately.The longitudinal axis 456 of each Triaxial hole 454 acutangulates θ with the longitudinal axis 404 of rotor 400.In this example, θ=30 °, but also can select any suitable value for θ.

In use, freezing mixture stream (for example cold oil) is supplied to second end 448 of freezing mixture supply tube 444 from coolant source.Coolant source can be provided with easily by the outside oil cup of stator (rotor is contained in wherein) that is positioned at pump.Freezing mixture flows through the hole 458 of freezing mixture supply tube 444 and flow in first chamber 406, freezing mixture flows radially outward between the end wall 460 in the end 438 of axle 432 and first chamber 406 from first chamber 406, and enters the passage 426 between second hole 408 that is limited to pipeline 414 and rotor.The width of passage 426 makes that preferably the flow velocity of freezing mixture in passage 426 is high as far as possible, strengthens the refrigerating function of freezing mixture thus.Freezing mixture flows along the length of each passage 426, inwardly passes radial hole 422, and flows back to axle 432 by the hole 464 of pipeline 414, and promptly freezing mixture is flowing in the opposite direction with the side of flowing through passage 426.Freezing mixture enters first axis hole 436 from second end 420 of pipeline 414, and freezing mixture is transported to the hole 440 of axle 432 via Triaxial hole 454 from first axis hole 436.Freezing mixture flows in hole 440 along the outside of freezing mixture supply tube 444, and from the end 450 discharging oil return storages of axle, freezing mixture can be pumped back to the end 448 of axle 432 via suitable heat exchange mechanism from oil cup.

By provide the array that wherein is provided with passage 426 with carry therein freezing mixture and with main body 402 contacting structure of rotor 400, compare with the structure that wherein is provided with single this passage as shown in Figure 1, the contact surface between freezing mixture and the main body 402 is long-pending significantly to be increased.This has strengthened the cooling of rotor 400 and the feasible thus cold radial clearance that has reduced between rotor and the stator, and the improvement to pumping efficiency is provided thus.

Rotor 400 can form the part of both-end screw pump, and described in our early international patent application No.WO 2004/036049, its content is included in here by reference.

Claims

1. rotor that is used for vacuum pump, described rotor comprises:

Threaded body;

Extend axially the chamber in the described main body;

Be used for the feeding mechanism of supply coolant to described chamber;

Be used for from the tapping equipment of described chamber discharging freezing mixture; With

In described chamber, be used for the guiding device that conduct coolant flows between described feeding mechanism and described tapping equipment, wherein, described guiding device has the internal surface of limiting hole and locatees so that heat can be passed to the outer surface of guiding device from described main body near described main body, and described guiding device defines a plurality of slits that extend along described guiding device at least, and described slit and described aperture are to spaced apart and be communicated with described orifice flow body.

2. rotor according to claim 1, wherein, described guiding device is formed by different materials with described threaded body.

3. rotor according to claim 1 and 2, wherein, at least a portion of described guiding device is formed by the material that thermal conductivity is equal to or higher than the material that forms described threaded body.

4. according to the described rotor of aforementioned claim 1, wherein, described at least a portion of described guiding device is formed by metallic material.

5. according to the described rotor of aforementioned claim 1, wherein, described at least a portion of described guiding device is formed by any alloy of aluminium, copper, iron or aluminium, copper or iron.

6. according to the described rotor of aforementioned claim 1, wherein, described guiding device comprises the pipeline that is positioned at described chamber.

7. rotor according to claim 6, wherein, described pipeline has circular cross section.

8. rotor according to claim 6, wherein, described guiding device comprises axle, and described pipeline is around described axle location.

9. rotor according to claim 8, wherein, described slit is between described axle and described pipeline.

10. rotor according to claim 1, wherein, the outer surface profile of described guiding device forms with described main body and limits described slit.

11. rotor according to claim 1, wherein, described slit is between the internal surface and outer surface of described guiding device.

12. according to the described rotor of aforementioned claim 1, wherein, described feeding mechanism comprises and is used for supply coolant to the supply tube of described guiding device.

13. rotor according to claim 12, wherein, described supply tube is arranged to the described hole of supply coolant to described guiding device.

14. rotor according to claim 13, wherein, described supply tube is coaxial with described main body basically.

15. rotor according to claim 12, wherein, described supply tube is positioned at the axle that is mounted to described main body.

16. rotor according to claim 15, wherein, bearing between described supply tube and described axle to suppress of the rotation of described supply tube with described axle.

17. rotor according to claim 15, wherein, described tapping equipment comprises the discharge pipe line that is positioned at described axle.

18. rotor according to claim 17, wherein, described discharge pipe line extends also coaxial with described supply tube basically around described supply tube.

19. rotor according to claim 17, wherein, described tapping equipment comprises and is used for carrying the feedway of freezing mixture to described discharge pipe line from described slit.

20. rotor according to claim 19, wherein, described feedway comprises a plurality of second discharge pipe lines, and described a plurality of second discharge pipe lines are positioned at described axle and each and extend to the discharge pipe line of mentioning the first time from the annular pass that is used to receive from the freezing mixture of described slit.

21. according to the described rotor of aforementioned claim 1, wherein, described guiding device is positioned near the described main body, thus, in use described guiding device contacts described main body.

22. according to the described rotor of aforementioned claim 1, wherein, the spaced apart distance of the outer surface of described guiding device and described main body less than 0.1mm.

23. rotor according to claim 1, wherein, the outer surface of described guiding device contacts with described main body.

24. a rotor that is used for vacuum pump, described rotor comprises threaded body, and described threaded body has the chamber in the threaded body of extending at each place, end of threaded body; Be used for the feeding mechanism of supply coolant to each chamber; With the tapping equipment that is used for discharging freezing mixture from each chamber, in each chamber, be used for the guiding device that conduct coolant flows between described feeding mechanism and described tapping equipment, wherein, described guiding device has the internal surface of limiting hole and locatees so that heat can be passed to the outer surface of guiding device from described main body near described main body, and described guiding device defines a plurality of slits that extend along described guiding device at least, and described slit and described aperture are to spaced apart and be communicated with described orifice flow body.