CN1171020C - Drive positioning mechanism with backlash adjustment for variable pipe diffuser - Google Patents

Abstract

A drive positioning mechanism with backlash adjustment for use in a variable pipe diffuser for a centrifugal compressor. A rotational drive means is fixedly attached to the housing of a centrifugal compressor with a pinion gear mounted thereto. A rack gear is mounted to the inner ring and adapted to engage in meshing arrangement with the pinion gear. The rotational drive means is operable to position the inner ring between a fully open position and a partially closed position. A travel limiter is provided to positively limited the travel of the inner ring at the fully open and the partially closed positions. The backlash adjustment mechanism is comprised of a housing having a cylindrical body positioned concentrically about a first centerline and having a bore disposed axially though the body positioned about a second centerline. The drive shaft is rotatably disposed concentric with the second centerline within the bore. The inner ring is positioned such that it meshes with the pinion gear. The housing is disposed within the casing and is rotatably operable to effect an adjustment of the backlash between the pinion gear and the rack gear.

Description

A kind of centrifugal compressor

The present invention relates generally to centrifugal compressor, relates in particular to a kind of driving positioning mechanical device and backlash (backlash) that is used for changable type (avariable) pipe diffuser (diffuser) of centrifugal compressor and adjusts mechanical device.

Being used for one of subject matter that compressor loads occurs in an application that changes in a big way at centrifugal vapour compression machine is the discharge stability that flows through compressor.The size of compressor inlet opening, impeller and diffuser channel must can provide required maximum volume flow.When lower volume flow flow through this compressor, it is unstable that flow can become.When volume flow when stability range descends, will enter unsettled slightly range of flow.Be in this scope, local reverse flow can be in diffuser channel occurs, produce noise and reduce the efficient of compressor.Be lower than this scope, compressor enters a kind of known surge (surge) state, occurs periodic reverse flow fully in diffuser channel, thus the efficient of having destroyed machine, and the integrity of machine element constituted threat.Owing in numerous compressor application, need volume flow in a big way, therefore proposed multiple in order to improve the modification of the discharge stability on low volume flow.

The multiple scheme that is used for keeping in a bigger range of operation high gear efficiency has been proposed.The 4th, 070, in No. 123 U. S. Patents, change whole blade wheel structure, so that make the load of machine performance and variation require to be complementary according to load change.The 3rd, 362, a kind of adjustable diffuser restrictor has also been described in No. 625 U. S. Patents, it is used for regulating flow in diffuser, so that improve the stability on low volume flow.

Be used at a centrifugal machine, keeping the current techique of high operational efficiency in a bigger range of flow is the variable-width formula diffuser that is inconjunction with fixing diffuser guide blades by use.

By common bailee deliver the 2nd, 996,996 and 4,378, variable-width formula vane diffuser has been described in No. 194 U. S. Patents, wherein diffuser vane is firmly fixing by being fixed by bolts on one of them diffuser wall.Blade is suitable for passing the opening that is formed in another wall, thereby makes the geometrical shape of diffuser to change according to the variation of load-up condition.

Diffuser vane is fixedly installed on one of them diffuser wall produced many problems, especially at aspects such as manufacturing, maintenance and machine runs.The space that is used for fixing blade in assembling is very little.Blade any do not line up state will make bending blade or when it restores the relative wall of friction.Similarly, if the one or more blades in the series have to replace in assembly, then have to whole machine apart in order to replace.

Can improve compressor efficiency greatly by the geometrical shape that changes the diffuser delivery outlet.In common No. 08/658801 U.S. Patent application of transferring the possession of, disclosed a kind of variable geometry formula pipe diffuser.That application is here cited for referencial use.Variable geometry formula pipe diffuser (being also referred to as branch endless tube road diffuser) is divided into the ring and second outer shroud in first with diffuser.Ring and outer shroud have the mobile trench portions of complementation input that is formed on wherein in being somebody's turn to do.That is, the mobile trench portions of the input of each interior ring has the mobile trench portions of complementation input that is formed in the outer shroud.Interior ring and outer shroud can rotate mutually.Rotate these annulus in order to improve the efficient that changes force value between full open position and the local operating position.When local operating position, not lining up of diffuser output pipeline can increase noise.These annulus are turned over the optimum design point can cause the excessive noise and the decline of efficient.

Geometric tolerances in the centrifugal compressor are less.Meanwhile, the load in the compressor is bigger, and is (dynamic) of power in essence.In minute endless tube road diffuser, facing to dynamic loading, the problem of maintenance tolerance becomes and quite bothers.Ring on exist two kinds of load and need handle, be i.e. axially (thrust) load and circumference load.The diffuser annulus must be able to relatively rotate, and meanwhile, maximum (ultimate) efficient in order to ensure suitable alignment of flow channel and compressor must remain on the strict control on their relative positions.In minute ring diffuser, keep the cost of necessary tolerance very high usually.

Divide another problem of ring diffuser to be that parts wear and tear prematurely.In the gas flow area of centrifugal compressor, do not make with lubricator usually, to prevent gaseous contamination.Be applied to dynamic loading on the branch ring diffuser and caused wearing and tearing in the diffuser element of accelerating owing to the shortage of lubricant oil owing to gas stream goes out impeller.

Except other aspect, it must be rigidly connected being used for the pinpoint relatively drive system of these annulus, so that avoid any element fretting.Because be present in the cause of the circumference load on the annulus, interior ring can be with respect to outer ring vibration, this can cause the instability and the component wear of compressor, and is unfavorable for efficient.This has caused the problem that several needs overcome.The drive system that relatively moves between ring and the outer shroud in need a kind ofly preventing.Also need a kind ofly to be convenient to two annulus and to relatively rotate, and can be in the tight geometric tolerances that keep between the annulus supporting (bearing) principle of opposing circumference and thrust load.Equally also need to provide a kind of and have (positive) reliably minimum and maximum retainer (stop) to avoid unnecessary noise and decrease in efficiency and to carry out the navigation system of on-the-spot renovation (retrofit) simply.In addition, also need this driving and supporting system to have long service life, and be easy to suitably install and adjust.

According to its main aspect and general introduction, the present invention relates to a kind of variable geometry formula pipe diffuser that is used for centrifugal compressor.Relate in particular to a kind of use and adjust mechanical device at the driving positioning mechanical device and the backlash of the variable geometry formula pipe diffuser that is used for centrifugal compressor.

One tooth bar is connected to the interior ring of variable pipe diffuser of the present invention.One small gear is connected to a device of rotation driving, and this device is mounted to the shell of centrifugal compressor and meshes with tooth bar.Handle this device of rotation driving, so that ring rotates between the position of position that the diffuser pipeline is opened entirely and the local closure of diffuser pipeline with respect to outer shroud in making.In addition, drive unit the pipeline of diffuser can be adjusted between open entirely and local operating position between a plurality of positions on.One catch arrangement also is provided, so as reliably in the restriction ring open entirely with local operating position on move.Backlash is adjusted mechanical device and is had a housing and the shell core around second center line around first center line.Small gear is mounted to a driving rotating shaft of passing shell core.Housing is rotatably mounted to shell.Housing of the present invention can rotate around second center line and handle, so that adjust the backlash between tooth bar and small gear.

In the drawings, same numeral is in order to represent the same section in all views;

Fig. 1 is the cross-sectional side elevational view with compressor of the present invention of a variable pipe diffuser of the present invention;

Fig. 2 is the stereogram of variable pipe diffuser of the present invention;

The sectional elevation view of the variable pipe diffuser during local operating position that Fig. 3 and Fig. 4 are respectively that the present invention is in first respectively--full open position and second--;

Fig. 5 is the plan view with compressor of changable type diffuser of the present invention;

Fig. 6 is the sectional view of the annular brace mechanical device of the present invention that roughly dissects along the line 6-6 among Fig. 5;

Fig. 7 is the sectional view of the annular brace mechanical device of the present invention that roughly dissects along the line 7-7 among Fig. 6;

Fig. 8 is the sectional view of roller of the present invention (roller) assembly;

Fig. 9 is the sectional view of wheel shaft of the present invention (axle);

Figure 10 is the sectional view that the present invention of the detail section 10 among Fig. 1 locatees drive mechanism;

Figure 11 is the plan view that the present invention locatees drive mechanism;

Figure 12 is the stereogram of tooth bar of the present invention;

Figure 13 is the performance map of variable pipe diffuser of the present invention;

Figure 14 is the performance map that only has the compressor of input guide blades;

Figure 15 is the performance map with compressor of the present invention of variable pipe diffuser and input guide blades; And

Figure 16 has the sectional view that the present invention axially suppresses the compressor of mechanical device.

See also Fig. 1 now, as shown in the figure, the present invention is installed in the centrifugal compressor 10, as the part of HVAC (heating ventilate and air-conditioning) system's (not shown), have one be used for refrigerant steam accelerate to impeller (impeller) 12, at a high speed be used for this refrigerant be decelerated to low speed, simultaneously kinetic energy is converted into pressure can diffuser 14 and be the form of trap 16, in order to collect the delivery pressure ventilated cavity (plenum) of the output steam that and then flow to condenser.Impeller 12 is driven by a motor (not shown), and this motor gas tight seal ground is positioned at the other end of compressor, and is used for rotating a high speed rotating shaft 19.

Please refer to the type of flow that occurs in the refrigerant in the compressor 10 now, refrigerant flows into the inlet opening 29 of suction chamber 31, flow through blade (blade) ring-shaped component 32 and guide blades 33, flow into compression suction area 23 then, this compression suction area leads to the compressing area that is constituted on the side and be made of on outside it shell 34 by impeller 12 within it.After the compression, refrigerant flows in diffuser 14, trap 16 and the output tube (not shown).

Variable geometry formula pipe diffuser 14 of the present invention comprises ring 40 and 1 second outer shroud 42 in one first, an annular brace mechanical device 35 and a location drive mechanism 121.See also Fig. 3 and Fig. 4, interior ring and outer shroud have the complementary flow channel 44 and 46 that is formed at wherein.The flow channel 44 of ring 40 has a complementary trench portions 46 that is formed in the outer shroud 42 in each.Interior ring 40 and outer shroud 42 can relatively rotate with respect to each other.In a preferred embodiment, interior ring 40 circumference rotate in an outer shroud 42 of fixing.

When an annulus rotated with respect to another annulus, the arrangement between every pair of complementary input flow channel of interior ring and outer shroud changed as shown in Fig. 3 and Fig. 4. Annulus 40 and 42 can be adjusted between the first full open position and the second local operating position, and as shown in Figure 3, when the first full open position, complementary trench portions is alignd, and have the fluid of maximum flow flow through in ring 40 and outer shroud 42; As shown in Figure 4, when the second local operating position, complementary groove does not line up, and has limited the flow of flow through this trench portions 44 and 46.

Figure 5 illustrates the annular brace mechanical device 35 of one embodiment of the invention.This embodiment has adopted three such mechanical devices as shown in the figure, and these three mechanical devices are around the equidistant circle spacing of diffuser.See also Fig. 6-7 now, annular brace mechanical device of the present invention comprises that otch 43, a roll wheel assembly 54, roller shaft assemblies 36 and that an internal support groove 41 and is arranged in the interior ring 40 are arranged on the interior external support groove 45 of outer shroud.As shown in Figure 8, this roll wheel assembly comprises that one has the roller 55 and a pair of thrust bearing face 57 of an outer bearing surface 56.Shown in Fig. 6-7, axle assembly comprises a wheel shaft 37 and an axle bolt 39.As shown in Figure 9, wheel shaft 37 comprises that a hexagonal head 38 and takes turns axis body 47, and take turns axis body center line 48, a wheel shaft core 49 and a wheel shaft core center line 50.Wheel shaft 37 comprises a pair of shoulder 73,74 in addition, and this shoulder is coaxial with wheel shaft core center line 50.

Divide another problem of ring diffuser to be that parts wear and tear prematurely.In the gas flow area of centrifugal compressor, do not make with lubricator usually, to prevent gaseous contamination.Be applied to dynamic loading on the branch ring diffuser and caused wearing and tearing in the diffuser element of accelerating owing to the shortage of lubricant oil owing to gas stream goes out impeller.Because the non-usability of lubricant oil in most of compressors, therefore must take measures so that rub and fretting minimizes.In addition, reach among some embodiment that hereinafter will describe in the present invention, the interface of element applies with hard material, and parts are made by the super high molecular weight plastic material, ring-shaped component is by preload (preload), and backlash is eliminated from the gear of location drive system.

The assembling and the move mode thereof of ring in please refer to now.Outer shroud 42 is fixed with respect to suction chamber, by among the support slot 45 that roll wheel assembly 54 is arranged on outer shroud, wheel shaft is passed mounting hole 58 and roll wheel assembly, axle bolt 39 passed wheel shaft is installed then and axle bolt 39 loosely is screwed in the screw 59 in the outer shroud, thereby three groups of annular brace mechanical devices 35 are installed in the outer shroud.In ring 40 inside that is installed to outer shroud, otch 43 and the support slot 45 and roll wheel assembly 54 circumferential alignment of interior ring clockwise rotate interior ring then as shown in Figure 7, so that roll wheel assembly is positioned among the support slot 41.Under the situation among interior ring is installed to outer shroud, use annular brace mechanical device, the spanner that is placed on the hexagonal head 38 by use comes rotating axle, thus interior ring also is somebody's turn to do in the location in the loop mapping center in suitably making.The wheel axis body center line 48 that has roller 55 to be installed on it departs from and 50 0.021 inches of the coaxial wheel shaft core center lines of shoulder 73,74.The rotation of hexagonal head 38 makes roll wheel assembly rotate round the shoulder in the outer shroud, and makes roll wheel assembly move radially with respect to outer shroud.In case interior ring centre of location suitably in outer shroud is then further rotated hexagonal head, so that the outer bearing surface 56 of roll wheel assembly is pushed down interior ring in advance.Then, tighten axle bolt 39.This preloading condition is preferable, because the cause of tangential and circumference load, thereby prevented moving of interior ring.In one embodiment of this invention, roller 55 and in ring 40 are aluminums, and outer bearing surface 56 and internal support groove 41 quenched (harden), to prevent wearing and tearing.Because by thrust bearing face 57 being positioned at the thrust load that is produced in the internal support groove 41 that quenched and the relative softer external support groove 45, it is mobile on axial direction that roll wheel assembly has suppressed annulus.The rotation of ring and outer shroud in the thrust bearing face 57 of roll wheel assembly must be convenient to, and resist the thrust load that produces by compressor simultaneously.In a preferred embodiment, thrust bearing face 57 is made by the super high molecular weight plastics with 64 hardness of (Shore D scale) on 0.16 the low coefficient of friction and Shore D scale.Plastics thrust bearing face prevents to contact between the roller that quenched and the softer external support groove, and be used to bear the thrust load of compressor and adjust in the axial tolerance of ring.Another characteristics of this annular brace mechanical device are to have under the situation of aforesaid ring-shaped component, can encircle and outer shroud in the assembled in advance, and they are moved to compressor to be used for the finished product general assembly.

Figure 16 shows that and be used for restriction and prevent that interior ring is with respect to the axially movable another embodiment of the present invention of outer shroud.As shown be an axial inhibition system 90, this system comprises a threaded shaft 91, a threaded mounting hole 92, a bearing pad 93, a locking nut 94, a hexagonal head 95 and a depression 96.When assembling during diffuser, this axially suppresses system 90 and is installed into bearing pad 93 and is positioned in the depression 96.This bearing pad is positioned at the space that can be in the depression in that bearing pad and interior ring unexpectedly are used for housing 34 is mounted to outer shroud 42 under the situation of outer contacting to create conditions.In case housing 34 is mounted, then rotate threaded shaft 91, so that bearing pad contacts with interior ring.Suitably locating under the situation of this bearing pad, releasably fix this mechanical device by tightening locking nut 94.In a preferred embodiment, bearing pad is made by a kind of super high molecular weight plastic material.One embodiment of the invention comprise six so axial inhibition mechanical devices, and these mechanical devices are around the equidistant circle spacing of interior ring.

Figure 10 shows that a kind of location drive mechanism 121 that is used for ring 40 in outer shroud 42 circumference rotate.Outer shroud 42 is fixedly linked with tooth bar 123, and this tooth bar extends radially outwardly from outer shroud 42.In gear drive, relevant with tooth bar 123 is small gear (pinion gear) 124, and this small gear is driven by pinion shaft 126 by actuator 128.Select and control actuator 128, so that ring 40 moves between the first full open position and the second local operating position and any amount of neutral position therebetween with respect to outer shroud 42 in making.Pinion shaft 126 is contained in one to be held in the shell 130, and this housing seals this pinion shaft airtightly from compressor inner chamber 132, and prevents that fluid from leaking into the outside of compressor 10 by housing case 130.Owing to refrigerant flowing in diffuser be applied to tangential and circumference load on the annulus make in ring have the tendency of in outer shroud, vibrating back and forth.Excessively moving or vibrating of interior ring will make tooth bar 123 and small gear 124 wear and tear, and cause the wearing and tearing of other parts.Come to encircle in the precompressed to prevent simply moving of interior ring and the vibration under normal operating condition with aforesaid roll wheel assembly.Under the situation of non-normal condition, when for example in surge, moving, then need the secondary mechanical device to prevent moving of interior ring.The invention provides a kind of drive installation system, so that prevent oppositely moving to reach and vibrating of ring in backlash between tooth sector and small gear suppresses relative to the central position by what utilize that axle holds that shell 130 adjusts small gear and tooth bar.Axle housing outer surface 125 is coaxial around housing center line 127, and shell core 129 is coaxial around shell core center line 131.In one embodiment of this invention, housing center line 127 departs from 0.060 inch with shell core center line 129.See also Figure 11, spanner flat 135 and adjustment groove 134 for locating drive mechanism shown in the figure.Locating after drive mechanism is installed in the suction chamber 31, rotate this driving positioning mechanical device by a spanner (not shown) is placed across spanner flat 135, thereby eliminated the backlash between tooth bar 123 and the small gear 124.In case backlash minimizes, then will to locate drive mechanism fixing on the throne by tightening tap bolt 133.In case backlash is eliminated, then directly export the tendency that ring moves in (discharge) by actuator by gear train.

The fluid flow that flows through diffuser 14 in the second local operating position with respect to full open position flow is determined by the smallest cross-section area of the diffuser flow channel that the is in local operating position ratio with the smallest cross-section area of the flow channel (being made of complementary trench portions 44 and 46) that is in full open position.This minimal flow groove area that is referred to as " throat area " generally will be by when diffuser 14 be in full open position, the minimum diameter of the flow channel 52 of interior circular groove groove 44 determines, and will control at the width at the interface 53 between interior ring 40 and outer shroud 42 by when diffuser 14 is in the second local operating position.For example, if a diffuser groove has 1/8 square inch minimum area (throat area) when being in the second local operating position, and the minimum area (throat area) that has 1/4 square inch when being in full open position, the flow that then flows through the fluid of the diffuser that is in local operating position are approximately 50% of the flow that flows through when diffuser is in full open position.The flow that when diffuser 14 is in the second local operating position, flows through compressor 10 be generally the flow that when diffuser is in the first full open position, flows through compressor 10 about 10% to 100% between.

When the second local operating position (as shown in Figure 4), have at least about 10% be in full open position the time flow flow through diffuser 14, to prevent the noise that heat power is overheated, excessive and the decline of compressor efficiency.For reaching this purpose, the relative rotation between two annulus parts will be limited to one for forming the necessary amounts of rotation of the second local operating position.In other words, the fluid that annulus can't be adjusted between two annulus of total blockage flows.The degree of rotation that is allowed between two annulus be when being in full-application position between the annulus the flow quantity of trench portions 44,46 and volume of required flow and the input that is arranged in annulus part 40 and 42 determined with respect to the volume of annulus part 40 and 42.

Please continue to consult Fig. 4, R ₂The radius of definition impeller end (tip), R ₃The outer radius of ring 40 in the definition, R ₄The outer radius of definition outer shroud.By feasible parameter T=R by interior ring 40 ₃-R ₂Defined thickness is not more than and is used for choked flow to cross the requirement part (for example 50% flow) of outer shroud groove 46 necessary, and then control flows is crossed the flow of diffuser 14 effectively.Before any diffusion takes place, interior ring will reduce diffuser throat area with respect to the rotation of outer shroud, thereby preventing to flow after diffusion quickens.In addition, interior ring thickness T is more little, and mobile turnover (turning) angle of then flowing through the diffuser that is in local operating position is more little.Above-mentioned two kinds of effects will improve the compressor efficiency under the partial load running state.

See also Fig. 5 and Figure 12 now, as shown be one embodiment of the invention, this embodiment has a kind of mechanical device, so that reliably decide-the interior ring in position corresponding to the first full open position and the second local operating position.A cavity 137 that is used for holding tooth bar 123 in machine cut in outer shroud 42.Ring 40 in tooth bar 123 accurately is mounted in a kind of tongue and groove mode, its middle rack have one be suitable for holding in the circumferential groove 143 of tongue 139 of ring 40.In order to determine full open position, in outer shroud, and annulus is relatively rotated interior loop mapping, up to flow channel 52 and outer mobile groove 46 complete matchings.Annulus be in this position and by the situation of adjusting the annular brace mechanical device as mentioned above under, tooth bar is mounted to interior ring, simultaneously gear surface 145 contacts with the full open retainer 140 of cavity 137.Then, the bolt (not shown) is installed by gear mounting hole 142, and in the screw 138 in encircling in being screwed to firmly.The size of tooth bar and cavity is fixed on the predetermined closing capacity of pipe diffuser.For example, in one embodiment of this invention, its difference that is of a size of between tooth bar angular width and the cavity provides 10% open position.In this example, it is 10 degree that required tooth bar moves (travel), and the tooth bar angular width is 35 degree, and corresponding cavity angular width is 45 degree.Under the situation of like this this tooth bar of location, between tooth bar and cavity, form a reliable retainer so that accurately and can repeatedly annulus be positioned at open position and the corresponding point of local operating position entirely on.This reliable retainer also is convenient under the situation of ring and outer ring position in need not to adjust actuator 128 be done on-the-spot the renovation.

Can understand operation of the present invention and use by consulting Figure 13, Figure 13 shows that a kind of performance map with compressor of complete installation variable pipe diffuser of the present invention wherein.Performance map shown in Figure 13 comprises a plurality of performance curves 60,62,64,66 and 68, and each performance curve is corresponding to the location of a kind of the carefully thinking out (discreet) between interior ring 40 and the outer shroud 42.Each performance curve has its character representation, and for example 60 represent with pumping point, are maximum effective pressure point as 70.Move compressor with the flow that is in or be lower than pumping point and will cause surging condition, as described in the background technique part of the present invention.

In order to illustrate the present invention, curve 60 can be corresponding with for example first full open position, curve 62 can be corresponding with the local operating position of middle 2 degree, and curve 64 can be corresponding with the local operating position of middle 4 degree, and curve 68 can be corresponding with the local operating position of maximum 8 degree.

Visiblely be annulus part 40 and 42 to be had towards the operating position adjustment in performance curve, adjust pumping point and for example 70,72 be used for towards effect than the compressor of low discharge.Therefore, by annulus 40 and 42 can be avoided surging condition towards the operating position adjustment during low discharge requires.

Figure 14 shows that and the corresponding a kind of performance map of compressor that only has adjustable input guide blades that it helps to compare with performance map shown in Figure 13 and understands the present invention with compressor of changable type diffuser.In Figure 14, curve 80,82,84,86 and 88 considerate location corresponding to the guide blades in the operating position that is in increase by 33.Visible is that closed guide blades 33 has the effect that reduces the pumping point flow as closed diffuser annulus part 40 and 42.Therefore, can avoid surging condition by importing guide blades 33 usually towards the operating position adjustment.

Yet, from performance map shown in Figure 14, can see guide blades 33 also being had the effect of the head pressure (head pressure) that reduction obtained from the compressor 10 that is in pumping point towards the operating position adjustment.Therefore, only adjust can not the satisfy the demand low discharge running state of relative elevated pressures of guide blades 33.

By contrast, from performance map shown in Figure 13, can see, when with diffuser annulus 40 and 42 when operating position is adjusted, the pumping point pressure kept stable that is obtained from compressor 10.Therefore, by with diffuser annulus 40 and 42 towards can the satisfy the demand running state of low discharge and high compressor pressure of operating position adjustment.

Under the temperature difference between ambient temperature and the room temperature big (for example about's 50 or more) situation but sometimes light running situation in the building that is being cooled normally need be with respect to the low discharge of full load operation pressure ratio (for example fully loaded 90%) and the running state of high-pressure ratio.In this case, need relative higher compressor pressure than (for example greater than about 2.5) with corresponding refrigerant saturation pressure of condenser and evaporating temperature, but remove the flow that the heat that is created in the building only need reduce, for example fully loaded 25%.

Figure 15 shows that and have the performance map that has the compressor that to adjust guide blades and variable pipe diffuser among the present invention concurrently.Visiblely be, combine with the adjustment of diffuser annulus 40 and 42, can make the efficiency optimizationization of compressor usually by adjustment with guide blades 33.See also Figure 15, dashed curve 111,112,113,114,115 and 116 expressions one have the various performance curve of the compressor of the changable type diffuser that is in full open position for input guide blades 33, and block curve 101,102,103,104 and 105 expressions simultaneously have the performance map of the compressor of the diffuser annulus that is in local closed (nearly 40% former flow on operating position here) on the various guide blades location.As skilled person institute in the art was well-known, when operating in " knee " (for example 81 among Figure 14) of the performance curve of representing compressor performance, compressor operating was on optimum efficiency.See also Figure 15, by making compressor move the running state of the peak rate of flow of will satisfy the demand most effectively for example about 0.7 pressure maximum and about 0.3, realize this running state most effectively by diffuser annulus 40 and 42 being adjusted to operating position and guide blades 33 being adjusted to 10 degree positions according to curve 104.

Being described the while of the present invention, should be appreciated that spirit of the present invention and scope are limited by accessory claim in conjunction with several specific embodiments.

Claims (9)

1. centrifugal compressor, it has a shell and and is installed in rotatable impeller in this shell (12), be used for working fluid is delivered to the inlet of the branch ring diffuser (14) that radially is provided with of an annular from an inlet opening (29), this diffuser comprises ring (40) and an outer shroud (42) in; Should be formed with many first water conservancy diversion grooves (44) on the interior ring, be formed with many second water conservancy diversion grooves (46) on this outer shroud, each the second water conservancy diversion groove (46) and first water conservancy diversion groove (44) complementation; This compressor comprises a location drive mechanism (121), is used to make this interior ring (40) to rotate between inherent one first fully open position of this outer shroud (42) and second portion closed position; At first fully open position, the first and second water conservancy diversion grooves (44,46) of described complementation are aimed at mutually, allow the peak rate of flow of fluid to flow through complementary water conservancy diversion groove (44,46), in the second portion closed position, first and second water conservancy diversion groove (44, the 46) misalignment of described complementation, flow through this complementary water conservancy diversion groove (44 with limit fluid, 46), it is characterized in that this location drive mechanism (121) comprising:

One is fixedly mounted in the rotating driving device on this shell, and it has a drive end and and is installed in small gear (124) on this drive end;

One is fixedly mounted in the tooth bar (123) on the ring (40) in this, and this tooth bar ring (40) in this extends radially outwardly and is suitable for meshing with this small gear (124); And

One catch arrangement, ring (40) mobile is limited between the second place of primary importance and corresponding to the part closed position corresponding to fully open position in being used for being somebody's turn to do, described catch arrangement comprises a pair of backstop (140 that is arranged on this outer shroud (42), 141), so that in primary importance and this tooth bar (123) positive engagement corresponding to fully open position, and in the second place and this tooth bar (123) positive engagement corresponding to the part closed position.

2. centrifugal compressor as claimed in claim 1 is characterized in that, this rotating driving device is a motor.

3. centrifugal compressor as claimed in claim 1 is characterized in that, this rotating driving device is an actuating device (128).

4. as claim 1,2 or 3 described centrifugal compressors, it is characterized in that ring (40) can be along circumferentially regulating rotationally for a plurality of positions between fully open position and part closed position in this.

5. the described centrifugal compressor of one of claim as described above, it is characterized in that, this catch arrangement also comprises a cavity (137), and this cavity is set in this outer shroud (42) and is suitable for holding this tooth bar (123), and this cavity (137) comprises one first end and one second end; This first end forms first backstop (140) on this outer shroud (42), and this second end forms second backstop (141) on this outer shroud (42).

6. the described centrifugal compressor of one of claim as described above, it is characterized in that, the lower surface of this tooth bar (123) comprises a circumferential groove (143), should in ring (40) comprise one with should in the tongue (138) of the concentric annular projection of ring (40), be suitable for engaging and this tooth bar (123) is positioned to and should interiorly encircles (40) and become the circumferencial direction aligning with the circumferential groove (143) of tooth bar (123).

7. the described centrifugal compressor of one of claim as described above is characterized in that described small gear (124) is fixed on an end of live axle (126) and comprises a backlash regulating mechanism, and this backlash regulating mechanism comprises

Described shell with a mounting hole;

One holds shell (130), and it has a cylindrical body and that centers on one first center line (127) with one heart and axially passes the hole (129) of this cylindrical body around one second center line (131);

This live axle (126), it rotatably is arranged in this hole that holds shell (130) (129) with one heart with this second center line (131);

This holds shell (130) and is installed in the interior also rotatable operation of this mounting hole to regulate the gap between small gear (124) and the tooth bar (123).

8. centrifugal compressor as claimed in claim 7 is characterized in that, this holds shell (130) and comprises that one is suitable for engaging the zone (135) of a wrench.

9. as claim 7 or 8 described centrifugal compressors, it is characterized in that this holds shell (130) and comprises a fixing device, be used for releasedly this being held shell and be fixed on a selected adjusted position.

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