CN1615184A

CN1615184A - Method to rough size coated components for easy assembly

Info

Publication number: CN1615184A
Application number: CNA028274644A
Authority: CN
Inventors: B·布什; B·鲁索; M·丹尼斯; R·林; T·瓦纳; D·延纳斯科利
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2002-01-23
Filing date: 2002-01-23
Publication date: 2005-05-11
Also published as: EP1467822A1; BR0215527A; KR20040077712A; AU2002237937B2; KR100625731B1; JP2005515067A; WO2003061852A1

Abstract

A method for coating surfaces of a screw machine includes the steps of providing at least one of a plurality of screw machine components including a rotor housing having at least a pair of parallel, overlapping bores; at least a conjugate pair of intermeshing rotors located in the bores, wherein each of the rotors has helical lobes having radially outward tip portions and intervening radially inward root portions; rough coating a surface of at least one of the plurality of components with a conformable coating, wherein the coating is substantially unevenly applied to the surface and has variable thickness over said surface; and levelling the conformable coating to a substantially uniform thickness prior to final assembly of the plurality of components, the substantially uniform thickness selected to ease assembly of the component, while maintaining coating performance criteria.

Description

Application member is carried out thick smooth so that the method for assembling

Technical field

The present invention is directed to the coating that is used for machine part, more specifically saying so is applied to method on the compressor part at being fit to coating.

Background technology

In a kind of conventional screw machine, male rotor of arranging in the overlapping hole of respective parallel that rotor case limits and female rotor acting in conjunction are so that hold back and the compressed air volume.Though two rotors are the most common structures, the acting in conjunction in couples of three or more rotors.The lobe profile of male rotor and female rotor and the quantity of lobe and teeth groove have difference.For example, female rotor can have six lobes that separated by six teeth groove, and the male rotor that cooperates can have five lobes that separated by five teeth groove.Therefore, lobe and teeth groove coefficient some or all possible combination periodically appear between the rotor.Rotor cooperate between acting in conjunction be can produce the combination that the slip of different rates of depreciation and rolling contact.Except paired acting in conjunction, rotor also with the housing acting in conjunction.Since a plurality of rotors contact combination occur in cooperation between, the sealing/leakage between the various combination may be different with wear form because of manufacturing tolerance.Can be following situation:, still need provide suitable lubricated or other liquid to spray so that sealing even manufacturing tolerance keeps very tightly under the manufacturing cost rising situation following.

Screw rotor cooperates right profile structure in most of section the gap to be set.The demand that the gap is set is the result of a plurality of factors, and these factors comprise: because gas heats rotor thermal expansion in compression process; Cause rotor deflection by the compression process pressure loading; Be tending towards sometimes thereby rotor arrangements is got tolerance and epitrochanterian machining tolerance in the block bearing structure that too closely causes interfering mutually; And also can cause rotor profile self machining tolerance of interfering.Be superimposed upon on these factors is to discharge loop condition pressure and temperature increase down and the pressure and temperature gradient occurs along with proceeding to from suction.

This barometric gradient of duration of work makes fluid pressure tend to force rotor to move towards the suction side usually toward the direction.Each end of rotor is installed in the bearing traditionally so that radial and axial constraint is provided.Rotor is conclusive in the tip-clearance of discharge side for sealing and fluid pressure tends to force this gap to magnify.

There are for example contact zones of some rotor section, keep the zero clearance there between the rotor.The rotor portion that limits contact zones is the zone that required torque is transmitted between rotor.Load between rotor is different for male rotor drive and female rotor drive.In male rotor drive, load may be equivalent to 10% of compressor total torque between rotor, yet under the female rotor drive situation, load may be equivalent to 90% of compressor total torque between rotor.These parts are conventionally positioned near rotor pitch circle place, and this is epitrochanterian rotary speed location of equal, thereby the contact that causes rolling also reduces or eliminates sliding-contact whereby, therefore reduces wear.

In order to prevent to come from the fault that rotor blocks, discharge the place, end at screw compressor and must keep a large amount of ends running clearance.Occur blocking when rotor is discharged end contact compressor end housing during operation, and can be owing to rotor thermal expansion or owing to the Intermittent Contact between rotor and the end housing causes, described Intermittent Contact causes because of the pressure fluctuation in the compression process for example.

Summary of the invention

Thereby the purpose of this invention is to provide a kind of be used for coating is applied on the Screw Compressor Parts reduce improving one's methods of screw compressor internal leakage.

Another object of the present invention provides a kind of as the rough-coated screw compressor building block method that coating is applied to the Screw Compressor Parts first step.

Other purpose of the present invention is that face coat is assembled Screw Compressor Parts easily by obtaining more uniformly, and described acquisition equilibrium surface coverage more is by means of using a kind of layer of initially rough covering to apply method and used planarization step before assembling.

Another purpose of the present invention is to reduce the excessive and uneven gauge of component of coatings so that assembling parts.

It is clearer and more definite that these and other objects can become hereinafter, and they are finished by the present invention.

According to the present invention, provide a kind of being used for that coating is applied to the one or more sections of screw rotor and/or the method on the housing bore area.

Above-mentioned purpose and thing followed advantage realize by the inventive method that is used for applying the screw compressor surface.This method may further comprise the steps: at least one in a plurality of Screw Compressor Parts is provided, and described a plurality of Screw Compressor Parts comprise the rotor case with at least one pair of parallel overlapping hole; Be positioned at the rotor cooperation group that is meshing with each other in this hole, each rotor has the helical form lobe herein, and this lobe has radially outer top and radially inner root placed in the middle; Then with the surface that is fit in the rough-coated a plurality of parts of coating at least one, this coating is applied on this surface haply and is had the variable or excessive thickness that spreads all over this surface; And it is smooth to homogeneous thickness roughly should to be fit to coating before final assembling this a plurality of parts, this roughly homogeneous thickness through selection in case in maintenance coating performance index easy these parts of assembling.

Description of drawings

In order to understand the present invention more fully, describe its various embodiment now in conjunction with the accompanying drawings in detail, wherein:

Fig. 1 is the cross-sectional view by screw compressor;

Fig. 2 is the partial section of Fig. 1 rib machine;

Fig. 3 is the zoomed-in view that Fig. 1 screw compressor is discharged end sections;

Fig. 4 is Fig. 1 amplifier section that has described various coatings of the present invention;

Fig. 5 is the partial section that expresses the DLC coating on rotor tip;

Fig. 6 is the partial section that expresses discharging the DLC coating on the housing;

Fig. 7 is the partial section that expresses DLC coating dish;

Fig. 8 is the zoomed-in view of DLC coating;

Fig. 9 is the perspective view of Fig. 1 rotor to axial section;

Figure 10 is the coating signal image before coating formation process of the present invention, and is used for the calibration devices of smooth this coating;

Figure 11 implements layer levelling method schematic diagram of parts afterwards of rough covering shown in Figure 10; And

Figure 12 is the further embodiment of a method that is used for realizing result shown in Figure 11, and it is specifically applied to rotor, makes no coated rotor be used for the smooth coated rotor that has.

The specific embodiment

Describe a kind of screw compressor 10 of screw compressor that for example is in Fig. 1, it has rotor case or shell 12, is wherein arranging overlapping hole 12-1 and 12-2.Has pitch circle P _F Female rotor 14 be arranged on 12-1 inside, hole.Has pitch circle P _M Male rotor 16 be arranged on 12-2 inside, hole.Vertical with Fig. 1 plane and with paralleling to the axis of representing of an A and B with equaling female rotor 14 pitch circle P _FRadius R _FAnd male rotor 16 pitch circle P _MRadius R _MThe distance of sum separates.The axis of representing with an A is the rotation of female rotor 14 and the center of hole 12-1 normally, and the diameter of hole 12-1 usually and the tip circle T of female rotor 14 _FDiameter conforms to.Equally, be the rotation of male rotor 16 and the center of hole 12-2 normally with the axis represented of some B, and the diameter of hole 12-2 usually and the tip circle T of male rotor 16 _MDiameter conforms to.Usually, rotor and centerline hole thereof depart from minimum value so that compensate for clearance and deflection.Ignoring under the working clearance situation, pass with the hole 12-1 extension branch of hole 12-2 overlap section with 16 round R of male rotor _MRPoint of contact place intersect with line A-B.Equally, pass with the hole 12-2 extension branch of hole 12-1 overlap section with 14 round R of female rotor _FRPoint of contact place intersect with line A-B, and for female rotor 14, this common point is labeled as F ₁, and, be labeled as M for male rotor 16 ₁

Describe among the embodiment in this institute, female rotor 14 has six tooth ridges or the top 14-1 that is separated by six grooves or teeth groove 14-2, and male rotor 16 has five tooth ridges or the top 16-1 that is separated by five grooves or teeth groove 16-2.Therefore, the rotary speed of rotor 16 is 6/5 or 120% of rotors 14.Female rotor 14 or male rotor 16 can be connected to prime mover (not describing) thereby go up as driving rotor.Also can use yin, yang rotor tooth ridge, the groove combination of other quantity.

Referring now to Fig. 2 and 3,, rotor 14 has shaft part 14-3, wherein forms shoulder 14-4 between shaft part 14-3 and the rotor 14.The shaft part 14-3 of rotor 14 is bearing in outlet with one or more bearings 30 or discharges in the housing 13.Equally, rotor 16 has shaft part 16-3, wherein forms shoulder 16-4 between shaft part 16-3 and the rotor 16.The shaft part 16-3 of rotor 16 is bearing in the outlet housing 13 with one or more bearings 31.

Rotor

14 and 16 suction side shaft part 14-5 and 16-5 separately is contained in the rotor case 12 with roller bearing 32 and 33 respectively with supporting.

At work, as refrigerating compressor, suppose male rotor 16 for driving rotor, the rotor 14 of rotor 16 engagement in rotation also makes its rotation.Be arranged in the rotor 16 of hole 12-2 and 12-1 inside separately and 14 acting in conjunction and drive cooling gas and enter the groove of

rotor

16 and 14 via suction inlet 18, these grooves engagements are transported to outlet 19 so that hold back with the Compressed Gas volume and with the Compressed Gas of heat.Thereby the gas that is trapped that acts on

movable rotor

14 and 16 tends to make discharge end 14-4 and 16-4 to leave outlet surface of shell 13-1 formation/increase

leakage path.Rotor

14 and 16 motions away from outlet surface of shell 13-1

cause rotor

14 and 16 towards the motion of the surperficial 12-3 of rotor case 12 or enter and the engaging of the latter by means of shoulder 14-6 and 16-6 respectively.Except the leakage path between rotor shoulder 14-4,16-4 and the outlet surface of shell 13-1, can also pass between

rotor

14 and 16 and at the top of tooth ridge 14-1,16-1 respectively and the contact of the line between hole 12-1, the 12-2 occur leaking.Can pass the leakage that tooth ridge/line contacts by using Seal Oil to reduce, but oil produces viscous loss thereby must remove between motion parts from discharge gas.

As pointing out that above contact zones limit by the zero clearance rather than by the position.The amplifier section of Fig. 4 presentation graphs 1 is so that describe displacement according to the contact zones of one aspect of the invention.Referring to Fig. 1, these contact zones should be arranged on the pitch circle P that is in the female rotor 14 in the 14-1 of the portion scope of female rotor top _FInboard and the male rotor 16 pitch circle P in being in male rotor root 16-2 scope _MThe outside.

For nothing oil or few hydraulic shrinking machine, necessary as close as possible rotor case body opening 12-1 of rotor top and 12-2, thus reduce owing to not using oil-tightening leakage.If come in contact between rotor and housing, will produce undue wear and power loss owing to rub between rotor top and the housing.Even rotor is lubricated, also produce and pass oil-tightening leakage, thereby must from refrigerant, remove oil, so that reduce the phenomenon that oil circulates and makes the heat transference efficiency reduction by refrigerating system, and keep necessary oil, so that in compressor, be lubricated.

Therefore, the wear-resistant coating of low friction is set respectively on the top of

rotor

14 and 16 or tooth ridge 14-1 and 16-1.A kind of suitable low friction, wear resistant coatings is in the U.S. Patent No. 5,672 of authorizing jointly, the coating of low friction diamond shaped carbon (DLC) type disclosed in 054, and it uses on the blade top surface in rotary compressor partly.This DLC coating is used for overcoming and uses the fresh oil lubricated difficulty relevant with refrigerant compositions.This DLC coating is not only lubricated and is anti abrasive, as at U.S. No.5, go through in 672,054 like that, therefore whole disclosures of this patent are incorporated into own forces in this as a reference, this coating by hard material for example the alternating layer of tungsten carbide and agraphitic carbon constitute.

Other low friction, wear resistant coatings example that is suitable for comprises the individual layer nitride coatings of titanium nitride and other independent material and carbide and the ceramic coating that not only has high-wearing feature but also have low-friction coefficient.On the paddy of the top of rotor separately or tooth ridge, low friction, wear resistant coatings is set series of advantages is provided.At first, for rotor, can not have not have oil or few oily operation under excessive wear or the friction situation.The second, owing to can allow with some of rotor hole and contact, machining tolerance can be imprecise.The 3rd, owing to can reduce or eliminate for the oil seal demand between rotor and the rotor hole moving under the less situation in gap between rotor top or tooth ridge 14-1 and 16-1 and respective rotor hole 12-1 and the 12-2.

Because the contact zones on the female rotor 14 are provided with near the top, can cover two important areas on the female rotor with independent DLC coating, this is because narrow and small or overlapping according to the spacing in these two zones of this rotor profile.As the independent DLC coating 40 on the female rotor of Fig. 4 description is best for easy to manufacture.The section 40-1 of coating 40 is corresponding to these contact zones, and section 40-2 is corresponding to top of approaching hole 12-1 most or tooth ridge 14-1.Corresponding DLC coating on male rotor 16 by being arranged in this rotor top coating 60 and the coating 61 that is arranged in corresponding to the root place of these contact zones separate widelyer.

The same with rotor top, thus arrange also that on rotor tip the gap constitutes leakage path.According to another aspect of the present invention, the DLC coating can be applied to the discharge end place of rotor, at the opposed face place that discharges housing 13 or be arranged in rotor and discharging having on the coating pad between the housing 13, thereby reduces running clearance and leakage path.Referring now to Fig. 5,, wherein the DLC coating applies on the discharge end of pressing rotor 14 and 16.More particularly DLC coating 42 is applied on the discharge end of female rotor 14, and DLC coating 62 is applied on the discharge end of male rotor 16.Since

DLC coating

42 and 62 can adapt to export surface of shell 13-1 some contact, thereby can be by the end running clearance minimizing leakage that reduces.Referring now to Fig. 6,, coating 82 is applied to surface of shell 13-1 and goes up rather than be applied to as Fig. 5 embodiment on the end of rotor 14 and 16.And in Fig. 7 embodiment, placing separating member 90 between

rotor

14,16 and the surface of shell 13-1.Because member 90 is consistent with the cross section of hole 12-1 and 12-2 or stop motion with respect to surface of shell 13-1 by another kind mode, it can not rotate, so relative motion will appear between the discharge end of member 90 and rotor 14 and 16.Therefore, member 90 surfaces that only face

rotor

14 and 16 need be provided with DLC coating 92.In Fig. 5-7 embodiment, the DLC coating is arranged between

rotor

14,16 ends and the surperficial 13-1, make its lubricating ability can make rotor and housing avoid wearing and tearing, thereby allow the end running clearance that connects airtight and narrow leakage path at period of contact occasionally.

Referring now to Fig. 8,, very exaggerative coatings cross-section is wherein described out, although it is named as 40, representing

coating

40,42,60,61,62,82 and 92.DLC coating 40 is by hard bilayer 40 ' and lubricated double-deck 40 " constitute.The scope of bilayer thickness is 1 to 20nm, and optimum range is between 5 to 10nm.Except wear-resistant coating, but a kind of may be can wear away or the suitable coating of extrusion molding can be applied to

rotor

14 and 16, rotor shoulder 14-4 and/or 16-4, surface of shell 13-1 goes up and/or hole 12-1 and 12-2 on.When whole rotor and hole can be coated, describe as Fig. 9, the local coating in rotor teeth groove or paddy 14-2 and 16-2 roughly provides all benefits for the common work between rotor respectively.Although contact zones are no clearance area and need Precision Machining that this tolerance can be loose for the acting in conjunction between the rotor lobe profile remainder.In addition, thus the suitable coating of hole 12-1 and 12-2 can adapt to

rotor

14 and 16 that the deflection during real work keeps sealing function.Referring to Fig. 4 and 9, female rotor valleys may be provided with conformable coating 44 and male rotor valley may be provided with conformable coating 64.In addition, hole 12-1 and 12-2 may be provided with conformable coating 84.

The suitable coating of various plasticity be can use, ferric phosphate for example, magnesium phosphate, nickel polymer mercury alloy, nickel zinc alloy, the alusil alloy that has the alusil alloy of polyester and have polymethyl methacrylate (PMMA) comprised.For example comprise that heat spray, physical vapor deposition (PVD), chemical vapour deposition (CVD) or any suitable traditional painting method of moisture deposition all can be used to handle screw compressor of the present invention surface.

As shown in figure 10, shown in apply on the parts the best approach of the present invention that is fit to coating is described will be through rough-coated and finishing or flattening process.

According to this method, plan to comprise the suitable coating of all coatings described here, generally be called and be fit to coating 100, be applied to cursorily on parts 102 surfaces, make its cross section on these parts, represent excessive coating 100.Should be fit to coating 100 and be applied cursorily, and make minimum satisfy the minimum cover performance need of this assembly in fact in arbitrary position.Described herein surperficial 102 can be any parts surface of admitting suitable coating.Shown in Figure 10, the suitable coating that applies usually has Feng Hegu, and in the prior art, they are not removing or causing when smooth the assembling difficulty, and this is because form interference by this surface irregularity between parts.Therefore, for example the existence of the surface irregularity at peak makes cooperation or interactional parts have interference engagement when for example screw rotor is relative at the required part of combining closely.

As an alternative, this coating can be applied with roughly homogeneous thickness, but described thickness can be owing to normal processes changes from parts to the component change.In this case, allow that the scope of thickness can be chosen, cause the minimum normal minimum cover performance need that thickness satisfies this assembly that generates.The parts of typical coated can have excessive thickness in this case, so assemble difficulty because of interference between components causes.

According to embodiments of the invention, before assembling cooperation or interactional parts, at first for example bar or plate or similar device 104 are smooth by calibration devices for coating on the parts, this device remove excessive coating material and according to the performance indications needs of this machine with this surfacing to minimum thickness that suits the requirements and structure.This calibration devices preferably stably is flattened with smooth, as shown in figure 11 until whole surface near this parts surface.For for example being the shape of cylinder or ball, other device that can will have a suitable shape by on this coating so as removal and smooth should the surface.

In for example being applied to another embodiment especially, as shown in figure 12,, for new application member, use actual component in order to finish this formation process for the cooperation of screw type compressor rotor or interaction parts.Therefore, for example the parts 102 of the screw rotor of screw compressor are undertaken rough-coated by being fit to coating.Then its no coating or the cooperation screw rotor 104 of having finished coating by this process being moved to this has the coating screw compressor to cooperate the position of aiming at, and relative motion has the coating screw compressor, wherein this cooperation rotor is used for removing excessive peak and the paddy of flattening, thereby forms the cooperation rotor of smooth coating.If this cooperation, smooth parts are not coated,, it sentences the coating layer thickness that acquisition suits the requirements on another parts just just must being maintained at the optimum distance that limits in advance.This cooperation, smooth parts can be main fixture, that is to say that it can be to be used for finishing any amount rotor 102 so that the permanent instrument that cooperates with their respective rotor 104.

Although the present invention carries out special description and explanation according to twin-rotor screw compressor, it also can be applicable to adopt the screw compressor of three or more rotors.Therefore the present invention only is subjected to the restriction of claims scope.

Claims

1. method that is used for applying the screw compressor surface may further comprise the steps:

At least one parts in a plurality of Screw Compressor Parts are provided, and described a plurality of Screw Compressor Parts comprise the rotor case with at least one pair of parallel overlapping hole; The cooperation that is positioned at described hole is to the rotor that is meshing with each other, and each described rotor has the helical form lobe herein, and described lobe has radially outer top and radially inner root placed in the middle;

With the surface that is fit at least one parts in the rough-coated described a plurality of parts of coating, wherein said coating is applied on the described surface and has the variable thickness that spreads all over described surface, and is applied to equably on the described surface with roughly excessive thickness; And

With the smooth roughly homogeneous thickness that arrives of described suitable coating, described roughly homogeneous thickness process is selected so that assemble described parts easily when keeping the coating performance index before the described a plurality of parts of final assembling.

2. the method for claim 1 is characterized in that, described planarization step also comprises the step of mobile device, and described device is used for the described surface of smooth adjacency.

3. method as claimed in claim 2 is characterized in that, describedly is used for smooth device and comprises finishing bar or fixture.

4. method as claimed in claim 2 is characterized in that, describedly is used for smooth device and comprises the parts that cooperate with described at least one parts of a plurality of parts.

5. method as claimed in claim 4 is characterized in that, at least one parts comprises screw rotor in described a plurality of parts, and described component comprises intermeshing screw rotor.

6. method as claimed in claim 5, it is characterized in that, described intermeshing screw rotor has the surface of being meshing with each other, wherein said planarization step also comprises the location and rotates the described rotor that is meshing with each other, make the described surface that is meshing with each other be positioned in and leave on the described surperficial preset distance that described preset distance is chosen so that allow the described coating of the described surfacing that is meshing with each other.

7. method as claimed in claim 2 is characterized in that, described surface is the surface at the described lobe of described rotor top.

8. method as claimed in claim 2 is characterized in that, described surface is the surface of the described lobe root of described rotor.

9. method as claimed in claim 2 is characterized in that, described surface is the surface in described hole.

10. method as claimed in claim 6 is characterized in that, described surface is the surface at the described lobe of described rotor top.

11. method as claimed in claim 6 is characterized in that, described surface is the surface of the described lobe root of described rotor.

12. method as claimed in claim 6 is characterized in that, described surface is the surface in described hole.

13. a method that is used for applying the screw compressor surface may further comprise the steps:

At least one parts in a plurality of Screw Compressor Parts are provided, and described a plurality of Screw Compressor Parts comprise the rotor case with at least one pair of parallel overlapping hole; The cooperation that is positioned at described hole is to the rotor that is meshing with each other, and each described rotor has helical form lobe and teeth groove placed in the middle; Be arranged on the outlet housing at the place, discharge end of described rotor case; Each described rotor has the discharge end towards described outlet housing;

14. method as claimed in claim 13 is characterized in that, described surface is the surface of the described discharge of described rotor end.

15. method as claimed in claim 13 is characterized in that, described surface is the surface of described outlet housing.

16. method as claimed in claim 13 is characterized in that, is placed on the described discharge end of described rotor and the member in the middle of the described outlet housing, described member has the surface of discharging the end towards described rotor, and described surface is the surface of described member.