CN101218435A

CN101218435A - Radial compressor

Info

Publication number: CN101218435A
Application number: CNA2006800239232A
Authority: CN
Inventors: 诺贝特·奥斯特; 格哈德·弗赖; 朱尔根·菲舍尔
Original assignee: Gardner Denver Schopfheim GmbH
Current assignee: Gardner Denver Schopfheim GmbH
Priority date: 2005-07-20
Filing date: 2006-07-19
Publication date: 2008-07-09
Also published as: EP1746290A1; US20100158679A1; JP2009501865A; KR20080024486A; CA2614710A1; AU2006271917A1; EP1915536A1; WO2007009766A1

Abstract

The present invention provides a pair of one piece cast impellers having radially extending curved and twisted three dimensional blades and being in a compressor housing which is connected to a drive motor and the impellers being mounted onto a motor drive shaft by jamming or press fitting the impellers on the shaft to provide a two stage radial compressor wherein the drive motor (5), a drive shaft (14) on which there a arranged two impellers (10, 12) there is envisaged that the drive motor (5) is a fast-running asynchronous motor with a speed in excess of 10,000 rpm and a power of around 5 to 10 kW.

Description

Centrifugal compressor

The small-sized centrifugal compressor that the present invention relates to a kind of small-sized centrifugal compressor impeller and comprise this impeller is characterized in that, this impeller has size and is suitable for clamped or presses fit in center hole on the motor drive shaft.

Background technique

As everyone knows, small-sized centrifugal compressor has the driving power of 5-10kw, and it can be used for providing pressurized air to other machine as (for example assembling machine or other production machine).Standard compression machine in this dynamic range is 2 in volume flow rate, 000m ³It is poor to produce about 80 millibars total pressure during/h, and its efficient is relatively low.

And in the small size multistage compressor, known way is to remove some materials with machining, so that center of gravity is positioned on the spin axis.Generally speaking, the impeller of small size multistage compressor is divided into two-part manufacturing at least---have the wheel hub of impeller blade and the impeller chimney of closed impeller blade.First portion is the impeller hub of casting, and it has a plurality of two-dimentional blade that radially extends from impeller hub.Although with regard to manufacture difficulty, two-dimentional blade more has superiority, and this simple Blade Design will make that efficient suffers damage.Second portion is an impeller chimney, and impeller chimney is welded on the impeller hub usually.This two-part impeller makes it more be difficult to balance on motor shaft, and has also increased manufacture cost.In addition, known small size multistage compressor generally has blade in diffuser.

Summary of the invention

The invention provides a kind of two-stage centrifugal compressor with drive motor, the live axle of drive motor is provided with two impellers, and drive motor is that speed exceeds the asynchronous motor that 10,000 rev/mins, the scope of power source are 5 to 10kW fast turn-around.Two stage compressor provides a kind of very high performance compressor with combining of running on critical velocity, and this compressor is 700 to 900m in volume flow rate ³It is poor to produce the integral pressure that surpasses 200 millibars during/h.

In one embodiment, two impellers of the present invention are identical integrated type impellers.Reduced manufacture cost so in theory, made more substantial impeller because allow for the centrifugal compressor of equal number like this.

In another embodiment, integrated type impeller of the present invention all is identical except impeller bore, and impeller bore is different.Each impeller bore is the truncated cone on its length of 75% at least, near second impeller bore of motor greater than first impeller bore away from described motor, this makes impeller relatively easily to take off from motor driving shaft.

Impeller of the present invention has whole impeller blade, and this impeller blade and impeller hub are one, and are the three dimendional blades from the radial and axial extension of described impeller hub.This impeller is spatial warping.The deviation that surpasses center line on major diameter in the deviation of center line on the minor diameter.

Impeller light weight of the present invention, its aluminium alloy castings by monolithic constitutes, with impeller hub, impeller blade and the impeller chimney that one is provided.This allows leaf production to become the shape of three-dimensional bending of the present invention.For this reason, can adopt fusible core method (lost core).The distinctive light weight of aluminium alloy castings that adopts provides lower overall weight.Can carry out machining (promptly by the smear metal processing technology) to the outer surface of impeller, so that level and smooth surface uniformly to be provided.

In another embodiment of the invention, by impeller being clamped (jam) or pressing fit in live axle, make impeller be attached on the motor driving shaft.This makes and can save feather key etc. when the impeller high-speed driving, can produce the element of the problem of aspects such as uneven and intensity.

In another embodiment, by provide tolerance ring between live axle and impeller, the present invention guarantees that impeller keeps accurately limiting, and is preferably located in the central position with respect to live axle.

In another embodiment, compressor has a pair of integrated type impeller all identical except impeller bore.The impeller hub bore of first impeller is the truncated cone, and first end of this truncated cone (from a compressor electric motor end farthest) has the diameter less than its second end.The impeller hub bore of second impeller also is the truncated cone, and first end of this truncated cone (from a compressor electric motor end farthest) has the diameter less than its second end.First end of described second impeller bore has the diameter greater than first impeller bore, second end.The diameter of first end of described second impeller bore also extends to any part that exceeds second impeller greater than motor driving shaft, thereby second impeller can easily take off from motor driving shaft, with maintenance or change.

In another embodiment, have the truncated cone separately on the integrated type impeller drive shaft, each truncated cone is slightly larger than the truncated cone body opening of the first and second corresponding impellers, thereby impeller can press fit on the live axle.

In another embodiment, the invention provides impeller with a plurality of equalizing orifices, can randomly adhere to balancing component (as bolt, screw or disk etc.) in the described equalizing orifice.Because impeller is driven in more than the critical velocity, after the compressor assembling, must carry out very careful balance.This can only carry out after centrifugal compressor assembling, even because the impeller of complete equilibrium before, the imbalance that (for example because live axle off-centre configuration slightly) produces in the impeller process is installed also can produce serious consequence in operation process.First impeller (with motor at a distance of farthest impeller) equalizing orifice be come-at-able in the aspiration end of compressor, therefore, after balance, need not do any work at rotating part.The verified equalizing orifice of first impeller that only utilizes realizes that last balance is fully enough.Second impeller (with motor at a distance of nearest impeller) equalizing orifice be unwanted, after first impeller was installed, the equalizing orifice of second impeller no longer can be approaching.

According to another embodiment of the present invention, described impeller downstream is provided with outlet diffuser.Described outlet diffuser has parallel wall and does not have blade.Described outlet diffuser guarantees to reduce the flow velocity of the media of discharging from impeller, can improve static pressure like this.As everyone knows, although vane diffuser is raised the efficiency, possible flow range is restricted, and produces the high efficiency performance of wide range at diffuser introspection defoliation sheet.

According to another embodiment, described live axle is supported on two roller bearings, and wherein a roller bearing is installed between impeller and the drive motor, and another roller bearing is positioned at the end of drive motor away from described impeller.In other words, two impellers are arranged on the live axle that freely stretches out.This set of bearing (can unexpectedly be subjected to the influence that potential possible impeller vibrates) has such advantage, that is, it is necessary having only contact (i.e. two contacts) seldom between two bearings.Two bearing sleeves are arranged at the end plate inside of drive motor, and each end plate directly is installed on the electric machine casing.Otherwise if the bearing at the impeller two ends is necessary, all parts of compressor housing must be manufactured to has very high precision.Form by a plurality of parts owing to housing, just must prevent the housing tolerance accumulation and cause the axle of two bearings that unallowed errors present is arranged.

In order to improve the bearing setting of described live axle, described roller bearing has bearer ring of being made by iron and steel and the roller of being made by pottery.This hybrid bearing to oiling agent require low, and long service life.

In another embodiment, the end away from described impeller on the drive motor is provided with Balance disc.With regard to the speed (on critical velocity) of drive motor and impeller, proved Balance disc is comprised that with realization the balance of the device of live axle, impeller and motor is favourable as extra balancing component.

Preferably described Balance disc is connected with the roller bearing heat conduction that is adjacent, the frictional heat that is therefore produced and shed and the heat that enters roller bearing all can be released into the external world by Balance disc by motor.

According to preferred embodiment the present invention is described below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 is first stereogram according to centrifugal compressor of the present invention;

Fig. 2 is second stereogram of the centrifugal compressor of Fig. 1;

Fig. 3 is a kind of partial sectional view of embodiment of the centrifugal compressor of Fig. 1;

Fig. 4 is first schematic representation according to the blade of the impeller of centrifugal compressor of the present invention; And

Fig. 5 is second schematic representation of blade.

Fig. 6 is the stereogram of impeller of the present invention.

Fig. 7 is the partial schematic sectional view of another embodiment of centrifugal compressor of the present invention.

Embodiment

Referring to Fig. 1 and 2, two-stage centrifugal compressor of the present invention has drive motor 5, drive motor external refrigeration fan 6, compressor housing 7, compressor housing outlet 22 and compressor housing import 24.

Drive motor 5 is the asynchronous motors that have the fast turn-around of frequency inverter, and it has about 15000 rev/mins actuating speed.

Referring to Fig. 3, it shows embodiment of the present invention.Drive motor 5 has the live axle of being made by single serialgram (being preferably iron and steel) 14.Live axle 14 is supported on two roller bearings 16, and two roller bearings 16 are positioned on the two end plates: a front end that is positioned at drive motor 5, another is positioned at the rear end of drive motor 5.Roller bearing 16 is hybrid bearings, and it has bearer ring of being made by iron and steel and the roller of being made by pottery.Owing to contact between the element that holds roller bearing 16 is less, so roller bearing 16 can relative to each other be aimed at accurately.

What be connected with drive motor 5 is compressor housing 7.Compressor housing is made of a plurality of parts.First compressor impeller 10 of the present invention and second compressor impeller 12 are contained in the compressor housing 7.Double-walled outlet diffuser 18,20 is led to outlet 22 (referring to Fig. 1 and 2).At the end away from drive motor 5, import 24 and live axle 14 are concentric.

In two impellers 10,12 each all is an aluminium alloy castings, and it adopts the sand casting process manufactured.The cylindrical hole 13 that each impeller is impeller hub 17, limited by impeller hub, from the single piece of described impeller hub 17 extended a plurality of basic radial impeller blade 26 integrally castings, and by impeller chimney 19 sealings of one.Runner extends between the blade of impeller.In casting process, but runner and blade 26 are limited by the fusible core method.Each blade 26 is designed to three-dimensional bending.When the center line that adopts live axle 14 during as blade centreline, the angle of blade increases to parallel at the center line of outlet end with live axle from about 45 degree.As mentioned above, the deviation of center line on minor radius surpasses the deviation at bigger radius.Blade self is with the shape distortion of about screw thread.Three-dimensional impeller of the present invention provides higher fluid flow efficiency.

Figure 4 and 5 show the shape of the three-dimensional bending of blade 26.Fig. 5 illustrates the Y view of Fig. 4 with expansion mode.E fingering mouth edge, A points out a mouthful edge, and D refers to profile on the cover board, the profile of N finger wheel hub.

As shown in Figure 3, live axle 14 has a plurality of grooves 27.Each impeller 10,12 and spacer 30 are corresponding at least one groove.Tolerance ring 34 is installed in each axial trough 27.Before impeller and spacer are placed on the axle, earlier tolerance ring 34 is arranged in the zone on its plane, center of gravity place.Tolerance ring is that cross section is that wavy stiffness spring clamps packing ring basically.Tolerance ring has been eliminated the gap between live axle and the impeller, and this is necessary for assembling.Tolerance ring helps transmitting torque between live axle and impeller, and is used as much as possible, so that heart is located in two impellers 10,12, and keeps their position in operating process.The slightly larger in diameter of live axle is in the diameter of impeller bore.

Two impellers the 10, the 12nd, identical integrated type impeller is only by they being clamped to live axle and they are fixed on the live axle 14.Before being placed in impeller 10,12 and spacer 30 on the live axle 14, they are by static equilibrium.After static equilibrium, second impeller 12 and isolating ring 30 are clamped to live axle 14, and first impeller 10 is clamped to live axle 14 then.Only two impellers 10,12 are fixed on the live axle by the drive fit between live axle and the impeller bore 13.In the embodiment of Fig. 3, contact ring 32 is arranged on the axle, with the shaft shoulder 35 adjacency, second impeller 12 and isolating ring 30 are clamped to live axle then, last first impeller 10 is clamped to axle 14.Adopt locking nut 28 by isolating ring 30 lockings two impellers 10,12, and make contact disc 32 be resisted against the shoulder 35 of live axle 14 and finish last fastening.

In addition, laggard action attitude balance is finished in assembling.For this reason, each impeller all has a plurality of equalizing orifices 36, selectively is attached with balancing component in the equalizing orifice 36, as screw, bolt or disk.When needs adopt screw or bolt, has suitable screw thread in the hole.When preferably adopting the Equilibrator of disk or other type, the hole also is suitably configured.Only first impeller 10 is carried out transient equiliblium.On second impeller 12 equalizing orifice may be arranged also, this only is for the reason of making, because impeller 10,12 is made in the same manner.

In addition, drive motor 5 has Balance disc 38 away from an end of impeller 10,12.Owing to adopt Balance disc 38, therefore can further reduce imbalance.Balance disc 38 also can be used for the roller bearing 16 of cooling settings in this end.For this reason, roller bearing 16 has heat conduction with Balance disc 38 and is connected, and Balance disc 38 is arranged in the cooling blast of external fan 6.

Referring to Fig. 6, it is the one piece cast that has a plurality of compensating grooves or hole 36, wheel hub 17, impeller blade 26 and cover 19 of the present invention.

In a further preferred embodiment, as shown in Figure 7, two-stage centrifugal compressor of the present invention has two one

piece cast

41 and 42 and live axle 43.Fig. 7 only shows the partial sectional view of compressor, not shown all features that are installed on the impeller in the compressor housing.Fig. 7 shows the key character and the motor driving axle construction of preferred impeller of the present invention.In Fig. 7, adopt the same section of numeral each parts identical with Fig. 1-3.Except the shape in impeller hub hole, the impeller of Fig. 7 has identical substantially structure with the impeller of Fig. 3.Two impellers the 41, the 42nd, aluminium alloy castings, it adopts the sand casting process manufactured.Each

impeller

41,42 has the three dimendional blade 26 that radially extends of wheel hub 17, a plurality of curvature of space and covers 19.Form runner between the integral blade 26.In casting process, runner and blade 26 are limited by the fusible core method.Shown in Figure 4 and 5, each blade 26 is three-dimensional bendings.

Except

hole

43 and 44,

impeller

41 and 42 is mutually the same.The impeller bore 43 of first impeller 41 is such truncateds cone, and this truncated cone has first end 46 of diameter less than its second end 47.The hole 44 of second impeller 42 is such truncateds cone, and this truncated cone has first end 48 of diameter less than its second end 49.The diameter of first end 48 in the hole 44 of second impeller 42 is greater than second end 47 in the hole 43 of first impeller 42.The diameter of first end 48 in the hole 44 of second impeller 42 also extends to any part that exceeds second impeller 42 greater than live axle 50 to first impeller 41, therefore second impeller 42 can be easy to take off from live axle 50 along the direction of arrow 51, also be easy to be installed onto on the live axle 50, another impeller identical with second impeller 42 can certainly be installed on the live axle 50.

Live axle 50 has truncated cone part 52, and truncated cone part 52 is adjacent to an end that is connected with motor of axle.Truncated cone part 52 expands towards motor.Truncated cone part 52 is slightly larger than the truncated cone body opening 44 of impeller 42, thereby impeller can be by press fit thereon.

Live axle also has another truncated cone part 53, and truncated cone part 53 is adjacent to the axle head opposite with the axle head that is connected with motor.Truncated cone part 53 is slightly larger than the truncated cone body opening 43 of impeller 41, thereby impeller 41 can be pressed fit on the axle 50.

The truncated cone part 52 of axle 50 contacts with the surface greater than 75% of impeller bore 43 and impeller bore 44 respectively with 53 outer surface.For the press fit that realize to need between the truncated cone body opening of live axle and impeller, the diameter of axle is more bigger at the point of contact of itself and impeller bore.

Impeller can be fixed on the live axle impeller in the press fit on the axle, and need not unnecessary extra outer member, and allows impeller to turn round more evenly.

Preferably impeller bore forms in casting process, but if desired, also can be formed by machining after casting.

Only,

impeller

41,42 can be fixed on the live axle 50 by

impeller

41,42 is pressed fit on the live axle truncated cone part 52,53.Before being placed in

impeller

41,42 and spacer 55 on the live axle 50, they are by static equilibrium.In the present embodiment, do not have shoulder on the axle, but compressor housing 7 is formed with groove near the end near motor.Contact ring 54 and back-up ring 56 remain in this groove.After static equilibrium, manually second impeller 42 is pushed on the axle.Then, by rotational lock nut 28 (a), the final press fit that second impeller 42 presses fit on the truncated cone part 53 is finished.Then the isolating ring 55 and first impeller 41 manually are pressed on the live axle, and impeller 41 is cooperated with the axle truncated cone 52.Afterwards,, finish final press fit, make

impeller

41 and 42 against isolating ring 55 with locking nut 28 rotation half-turns.Above-mentioned is to make impeller move " path control " press fit of the distance of qualification.Yet, also can adopt " strength control " press fit that applies predetermined force to impeller.

In addition, discuss in conjunction with the embodiment of Fig. 3, after assembling, carry out transient equiliblium as above-mentioned.For this reason, each impeller has a plurality of equalizing orifices 36, is attached with balancing component in the equalizing orifice 36 alternatively, as screw, bolt or disk.When needs adopted screw or bolt, the hole had suitable screw thread.When preferably adopting the balancing component of disk or other type, the hole also is suitably configured.Only first impeller 41 is carried out transient equiliblium.On second impeller 12 equalizing orifice may be arranged also, this only is that if desired, the equalizing orifice on second impeller 12 also can be eliminated for the reason of making.

Because

impeller

10,12,41,42 has lighter weight relatively, also can keep very high balance quality owing to impeller of the present invention, therefore, although in the impeller field, live axle is to design in the mode of freely stretching out, but impeller of the present invention also can be driven to more than critical velocity and turns round.

Claims

1. light duty compressor impeller, have wheel hub (17) and a plurality of impeller blades (26) that radially extend that are connected with described wheel hub (17) and around the impeller chimney (19) of described impeller blade (26), it is characterized in that described wheel hub (17) has size and is suitable for clamped or presses fit in live axle (14; 50) hole on (13,43).

2. impeller according to claim 1 is characterized in that, described impeller blade (26) is an one with described wheel hub (17).

3. impeller according to claim 1 and 2 is characterized in that, described impeller blade is the impeller blade (26) of curvature of space, three-dimensional.

4. according to any described impeller among the claim 1-3, it is characterized in that described wheel bore (43,44) has truncated cone part, the described truncated cone partly extends at least 75% length of described wheel bore.

5. according to any described impeller among the claim 1-4, it is characterized in that described impeller chimney (19) has a plurality of balances attachment portion (36), moves to running shaft with the center of gravity with described impeller.

6. impeller according to claim 5 is characterized in that, described balance attachment portion is a plurality of tapped holes (36) of wound impeller inlet ambient.

7. according to any described impeller among the claim 1-6, it is characterized in that described impeller is the integrated type impeller.

8. impeller according to claim 7 is characterized in that, described impeller is a cast-in-block aluminum alloy impeller.

9. according to any described impeller among the claim 1-8, it is characterized in that a pair of described impeller (10,12 is arranged in the two-stage centrifugal compressor; 41,42), the two axially is installed on the motor driving shaft.

10. impeller according to claim 9, it is characterized in that, described impeller is installed on the motor driving shaft (14,50), and it is that the motor of about fast turn-around of 5 to 10kW connects that described motor driving shaft (14,50) and speed exceed 10,000 rev/mins, the scope of power source.

11. according to any described impeller among the claim 1-10, it is characterized in that, have in the two-stage centrifugal compressor of drive motor (5), live axle (14,50) a pair of described impeller is arranged, described live axle (14,50) is provided with two impellers (10,12; 41,42).

12., it is characterized in that described impeller (10,12) is identical according to claim 9,10 or 11 described impellers, be provided with tolerance ring (34) between described axle (14) and the described impeller (10,12).

13., it is characterized in that described impeller (10,12 according to any described impeller among the claim 9-12; 41,42) have a plurality of equalizing orifices (36), can randomly adhere to balancing component in the described equalizing orifice (36).

14., it is characterized in that described impeller downstream is provided with outlet diffuser (18,20) according to any described impeller among the claim 9-13.

15. impeller according to claim 14 is characterized in that, described outlet diffuser (18,20) is designed to have parallel wall and does not have blade.

16. according to any described impeller among the claim 9-15, it is characterized in that, described axle (14,50) is supported on two roller bearings (16), wherein a described roller bearing (16) is installed between described impeller (10,12,41,42) and the described drive motor (5), and another described roller bearing (16) is positioned at the end of described drive motor away from described impeller.

17., it is characterized in that for supporting described live axle (14,50), the bearer ring of employed roller bearing (16) is made by iron and steel according to any described impeller among the claim 9-16, the roller of roller bearing (16) is made by pottery.

18., it is characterized in that described Balance disc (38) is arranged at the last end away from described impeller of described drive motor (5) according to any described impeller among the claim 9-17.

19. impeller according to claim 18 is characterized in that, heat conduction is connected described Balance disc (38) with the roller bearing that is adjacent (16).