EP1702163B1 - Worm compressor provided with a sound absorber - Google Patents

Abstract

In order to avoid pulsations in a screw compressor comprising an outer housing, a compressor screw housing which is arranged in the outer housing and in which rotor bores for screw rotors are arranged, a drive arranged in the outer housing on one side of the compressor screw housing and a bearing housing arranged in the outer housing on a side of the compressor screw housing located opposite the drive, it is suggested that an acoustic wave damping device having the compressed working medium flowing through it be arranged within the outer housing.

Description

The invention relates to a screw compressor comprising an outer casing, a compressor screw housing arranged in the outer casing, in which rotor bores for screw rotors are arranged, a drive arranged in the outer casing on one side of the compressor screw casing and a bearing casing arranged in the outer casing on a side of the compressor screw casing opposite the drive ,

Such screw compressors are from the DE 198 45 993.9-15 known.

In these, there is the problem that the compacted by the screw rotors working medium is excited to oscillations with a correlated with the speed of the screw rotor fundamental frequency, which leads to at least a noise pollution, but with random resonances, however, to mechanical problems in the subsequent conduit system for the compressed working fluid and even lead to mechanical damage in the pipe system.

The invention is therefore based on the object largely to avoid such vibrations.

This object is achieved according to the invention in a screw compressor of the type described above, as well as specified in claim 1.

Such a silencer has the great advantage that the formation of pressure oscillations can be suppressed already within the outer housing and thus the screw compressor already emits a lower noise and also in the subsequent lines for the compressed working fluid substantially no unwanted vibrations can occur more.

The muffler can be designed far easier to construct, since this no longer has to be designed as a pressure vessel, as in the interior of the muffler and around this approximately the same pressure is present, in contrast to the case that the muffler is arranged outside of the outer housing, because in In this case, the silencer, since it leads to compressed working fluid to perform as a pressure vessel that withstands the differential pressure between the pressure of the compressed working fluid and the ambient pressure.

With such a damper tube can be advantageously dampen the unwanted pressure oscillations by the phenomenon of reflection of pressure oscillations at the open end of the damper tube.

For reasons of space, however, it is expedient if the muffler is arranged directly following the outlet channel for the compressed working medium and thus the outlet channel can be designed to save space.

With regard to the connection with the outlet channel a variety of ways are conceivable. An expedient solution provides that the muffler is connected to an inlet port to the outlet channel.

With regard to the course of the outlet channel so far no details have been made. For example, it would be conceivable to provide the outlet channel in the compressor screw housing and to guide it out of the compressor screw housing in the region of the compressor screw housing.

A spatially expedient solution provides that the outlet channel for the compressed working fluid extends in the bearing housing, which is arranged on a side opposite the drive side of the compressor screw housing, so that the outlet channel can be easily guided in a suitable manner.

The muffler could be arranged, for example, next to the bearing housing or side of the bearing housing.

A structurally particularly favorable solution provides, however, that the muffler is arranged on a side facing away from the compressor screw housing side of the bearing housing and thus can be arranged in a simple manner within the outer housing.

Spatially particularly useful it is when the muffler is arranged between the bearing housing and end-side termination of the outer housing.

The damper tube can be tuned to different frequencies.

A particularly expedient solution provides that the damper tube has a length which corresponds approximately to a quarter of a wavelength of a pressure oscillation in the working medium to be compressed at a fundamental frequency of the screw compressor. The fundamental frequency results here as a drive speed of the screw rotor correlated frequency.

A particularly favorable damping effect can be achieved if the compressed working fluid in the damper housing is guided meander-like and in particular must run in the damper housing meander similar to emerge from the silencer again.

With regard to the arrangement of the muffler housing, it is particularly advantageous if this is arranged between the bearing housing and the end-side termination of the outer housing.

A particularly good decoupling of the pressure oscillations to the environment can be achieved if the muffler is arranged connection-free to the outer housing and thus no sound can be transmitted to the outer housing via the connection between the muffler and the outer housing.

Preferably, in this case, the muffler is supported on the bearing housing.

This can be done either by the fact that the muffler is fixed via the connection to the outlet channel or by additional holding elements.

In order to preferably make an oil separation, it is provided that the muffler emits the compressed working fluid in a distribution space of the interior, on which the following flows through the compressed working fluid an oil separator.

The oil separator element can be arranged in various ways. An expedient solution provides that the interior space in the outer housing is divided by the oil separator element into a distribution space and an outflow space, wherein the compressed working medium flows from the outflow space to an outlet space.

The oil separator element can be particularly favorable then arranged in conjunction with the muffler within the outer housing when the muffler passes through the oil separator, so that the possibility exists to arrange the oil separator between the bearing housing and the conclusion of the outer housing, wherein the oil separator expediently over the entire Cross section of the Outer housing extends in this area to have the largest possible cross-sectional area, which is reduced by the cross-sectional area, however, with which the muffler passes through the oil separator.

With regard to the best possible damping and with regard to the interception of pressure peaks, a flow cross-sectional constriction is preferably provided in the outlet channel.

Pressure peaks can then be intercepted in a particularly favorable manner if the flow cross-sectional constriction is designed in such a way that the compressed working medium flows through it in meandering fashion.

With regard to the outer housing so far no further details have been made.

The outer housing can in principle be formed in various ways, for example, composed of a plurality of housing sleeves with end caps.

A particularly expedient solution provides that the outer housing comprises a compressor section housing the compressor screw housing and a subsequent to the central portion of the pressure-side end portion.

In this case, the pressure-side end section is preferably designed as a housing capsule extending from the middle section.

Such a housing capsule is preferably carried out pressure-resistant as a whole and connected via a flange with the central portion.

Preferably, the housing capsule is designed so that in this both the bearing housing and the muffler and in particular the oil separator element are arranged.

Further features and advantages of the invention are the subject of the following description and the drawings of an embodiment.

Fig. 1

einen Längsschnitt längs Linie 1-1 in Fig. 4;

Fig. 2

einen Längsschnitt längs Linie 2-2 in Fig. 4;

Fig. 3

einen Längsschnitt längs Linie 3-3 in Fig. 4;

Fig. 4

eine Draufsicht auf den erfindungsgemäßen Verdichter in Richtung des Pfeils A in den Fig. 1 bis 3;

Fig. 5

eine perspektivische Darstellung eines erfindungsgemäßen Schraubenverdichters mit abgenommener druckseitiger Gehäusekapsel des Außengehäuses, so daß ein Lagergehäuse und ein Schalldämpfer erkennbar sind;

Fig. 6

eine Darstellung des Schalldämpfers des erfindungsgemäßen Schraubenverdichters in Seitenansicht und

Fig. 7

einen Längsschnitt durch den in Fig. 6 dargestellten Schall- dämpfer.

In the drawing show:

Fig. 1

a longitudinal section along line 1-1 in Fig. 4 ;

Fig. 2

a longitudinal section along line 2-2 in Fig. 4 ;

Fig. 3

a longitudinal section along line 3-3 in Fig. 4 ;

Fig. 4

a plan view of the compressor according to the invention in the direction of arrow A in the Fig. 1 to 3 ;

Fig. 5

a perspective view of a screw compressor according to the invention with removed pressure-side housing capsule of the outer housing, so that a bearing housing and a muffler can be seen;

Fig. 6

an illustration of the muffler of the screw compressor according to the invention in side view and

Fig. 7

a longitudinal section through the in Fig. 6 shown silencer.

An in Fig. 1 illustrated embodiment of a screw compressor according to the invention, comprises a designated as a whole with 10 outer housing, which is composed of a central portion 12, a motor-side end portion 14 and a pressure-side end portion 16.

For example, the motor-side end portion 14 is formed by an integrally formed on the central portion 12 first housing sleeve 18 which is closed by a first housing cover 20 which is connected via a flange 22 releasably connected to the first housing sleeve 18.

In the motor-side end portion 14 is a designated as a whole with 30 drive motor, which is for example designed as an electric motor, which has a held in the first housing sleeve 18 stator 32 which surrounds a rotor 34, wherein the rotor 34 on a as a whole 36 designated drive shaft is seated.

In the central portion 12 of the outer housing 10 is a designated as a whole by 40 compressor screw housing is provided, which is preferably integrally formed on the central portion 12 and rotor bores 42 and 44 for receiving screw rotors 46 and 48, the order are rotatable to each other parallel axes. For example, the screw rotor 46 is seated on the drive shaft 36 extending from the stator 32 and passing through the screw rotor 46.

The rotatable mounting of the screw rotors 46 and 48 takes place on a side facing the drive motor 30 via first rotary bearings 50 and 52, which are seated in a first bearing housing 54, which is integrally formed on the compressor screw housing 40 on the drive motor 30 side facing.

On a side facing away from the drive motor 30, the bearing of the screw rotors 46 and 48 via second rotary bearing 60 and 62, which are arranged in a second bearing housing 64 releasably connected to the compressor screw housing 40 on its side facing away from the drive motor 30 via a flange 66 at the Compressor screw housing 40 is held, wherein the second bearing housing 64 in turn has a rotor bores 42, 44 on the pressure side final wall 68 which is penetrated only by leading to the second pivot bearings 60 and 62 stub shafts to support the screw rotor 46, 48, wherein in Fig. 1 and 2 only the stub shaft 70, the drive shaft 36 can be seen.

Preferably, the pivot bearings 60 and 62 are seated in the second bearing housing 64 bearing recesses 72 and 74 which on a side facing away from the compressor screw housing 40 openings 76 and 78 which are closed by a cover 80 of the second bearing housing 64, wherein the openings 76th and 78, the pivot bearings 60 and 62 in the bearing recesses 72 and 74 are used.

As in the section according to Fig. 2 can be seen, in the compressor screw housing 40 is still a spool 82 is provided in a slide bore 84 which is displaceable in the direction parallel to the axes of rotation of the screw rotors 46 and 48, namely controllable by a designated as a whole by 90 actuating cylinder in the second bearing housing 64th is arranged and comprises a displaceable in a cylinder chamber 92 of the second bearing housing 64 actuating piston 94, which is connected via a piston rod 96 with the spool 82.

The cylinder chamber 92 is also provided with an opening 98 which is closed by the end cover 80 of the second bearing housing 64.

In the screw compressor according to the invention to be compressed working fluid is supplied via a provided in the first housing cover 20 inlet opening 102 an inlet space 104 which is disposed within the motor-side end portion 14 and in which the electric motor 30 is arranged so that cooling of the electric motor 30 through the the inlet space 104 flowing through the working medium takes place.

From the inlet space 104, the working fluid flows into a provided on a side facing the drive motor 30 side of the compressor housing 40 inlet 106, which supplies the working fluid to the screw rotors 46 and 48 for compression.

The compressed by the screw rotors 46 and 48 working fluid is discharged from the screw rotors 46 and 48 in an outlet 108 in the compressor screw housing 40, which faces away from the drive motor 30 Side of the compressor screw housing 40 is disposed, and passes from the outlet 108 in an outlet passage 110 which is disposed in the second bearing housing 64 and initially formed by a subsequent to the slide bore 84 slide receptacle 112, in which the spool 82 enters slide positions, the correspond to a lower compressor capacity than the maximum power.

The slider receptacle 112 is also penetrated by the guided by the actuating piston 94 to the spool 82 piston rod 96.

From this slide holder 112, the outlet channel 110 leads via an outlet window 114, which is arranged laterally of the slide holder 112 and can be flowed through by the compressed working medium in a direction transverse to a positioning direction 116 of the spool 82, to an outflow 124th

The outlet window 114 is preferably provided with both sides of the same Strömungsumlenkwänden 118 and 120 which prevent direct flow of the compressed working fluid transverse to the direction of adjustment 116 and force the compressed working fluid to flow through the outlet 114 in the form of a meandering flow path 122 before the compressed working fluid in the outflow channel 124 enters the second bearing housing 64 which extends in the direction of the end cover 80, to an outflow opening 126 of the end cover 80th

The Strömungsumlenkwände 118 and 120 in the region of the outlet window 114 serve to dampen the propagation of strong pressure spikes between the slider receptacle and the outflow 124 through the meandering flow course 122.

Connected to the discharge opening 126 is a silencer designated as a whole with 130 with its inlet port 132, wherein the inlet port 132 is part of an inlet pipe 134, which extends from the sealingly engaging into the exhaust port 126 inlet port 132 into a damper housing 136 of the muffler and an orifice 138 located within the damper housing 136, at which the compressed working fluid carried in the inlet tube 134 undergoes a jump in cross-section, for example, more than a factor of 2 when entering an interior 140 of the damper housing 136.

Furthermore, the muffler 130 includes a damper tube 142 which penetrates the damper housing 136 and has an inner mouth opening 144 and an outer mouth opening 146. The compressed working medium which propagates in the interior 140 of the damper housing 136 enters the inner mouth opening 144 of the damper tube 142 with a jump in cross-section of more than a factor of 2 and flows through it in the direction of the outer mouth opening 146 located outside the damper housing 136 ,

The length of the damper tube 142 between the inner mouth opening 144 and the outer mouth opening 146 is approximately one quarter of the wavelength of the forming by the rotary screw rotors 46 and 48 and correlated with their speed fundamental oscillation, so that the are damped by the basic vibration occurring in the pressure-side working fluid pressure fluctuations through the muffler 130 to the damper tube 142, before this working fluid from the outer orifice 146 of the muffler 130 exits.

The muffler 130 is preferably formed so that the inlet pipe 134 and the damper pipe 142 extend approximately parallel to each other and partially overlap with their extent in their longitudinal direction, so that the orifice 138 of the inlet pipe 134 and the inner orifice 144 of the damper tube 142 based on a longitudinal direction 148 of the damper tube 142 are arranged radially and axially offset, and consequently the compressed working fluid in the damper housing 136 meander similar to the mouth opening 138 of the inlet nozzle 132 to the inner mouth opening 144 of the damper tube 142 must flow.

The damping effect of the muffler 130 can be further improved when seen in the longitudinal direction 148, end walls 135 and 137 of the damper housing 136 have a distance from each other, which also corresponds to the order of one quarter of the wavelength of the propagating with the fundamental frequency pressure oscillations , wherein the distance may preferably vary up to 25%, more preferably up to 15% of a quarter of the wavelength.

Since oil can likewise already be deposited in the damper housing 136, in particular because of the meander-like guidance of the compressed working medium, the damper housing 136 is provided on its side lying lowest in the direction of gravity with an opening 149 from which oil which separates out in the damper housing 136 can drain off.

The pressure-side end portion 16 is formed in the illustrated embodiment by a housing capsule 150 which is connected to the central portion 12 with a flange 152 and extending away from the central portion on a side opposite the drive motor 30 therefrom with a capsule sleeve 154 which both the second bearing housing 64 and the silencer 130 surrounds the outside and is closed with a capsule bottom 156 on one of the flange 152 opposite side.

The housing capsule 150 encloses a penetrated by the compressed working medium interior space 158 in which the second bearing housing 64 and the muffler 130 are arranged, the interior 158 by an approximately parallel to the capsule bottom 156 and the end cover 80 extending oil separator 160 in a distribution chamber 162, which between the oil separator 160 and the capsule bottom 156, and a discharge space 164 is divided, which is located between the oil separator 160 and the compressor screw housing 40.

As in Fig. 1 and 5 shown in detail, the oil separator 160 comprises a support member 159 in the form of a perforated plate, which in turn is penetrated by the muffler 130 and supports the muffler 130 in the region of its damper housing 136.

The support member 159 is in turn, for example via studs, rigidly connected to the bearing housing 64, in particular the end cap 80 thereof.

In addition, the oil separator 160 comprises a position held by the support member 159 position of a fabric, mesh or fabric made of metal or plastic, which has the task to unite the entrained in the compressed working fluid oil mist to drip and thus for the separation of oil from the compacted Contributing to the working medium.

Already in the course of the flow through the oil separator 160 thus oil drops are formed, which are either already settle in the oil separator 160 itself in the direction of gravity and collect the gravity direction following or settle from the compressed working fluid after flowing through the oil separator due to the gravitational effect also.

The silencer 130 is arranged in the inventive solution so that it passes through the oil separator 160, wherein the inlet port 132 is located on one side of the Ölabscheiders 160 and surrounded by the discharge chamber 164, while the outer orifice of the damper tube 142 opens into the distribution chamber 162, in which the compressed working medium with a cross-sectional jump of more than a factor of 2 is distributed over a large flow cross-section, which substantially corresponds to an internal cross-section of the capsule sleeve 154 minus the cross-sectional area occupied by the silencer 130 when passing through the oil separator 160, so that the compressed Working medium can flow through the oil separator 160 with a large flow cross-section in the direction of the outflow 164, then from the discharge chamber 164 provided in the region of the central portion 12 and the compressor screw housing 40 at least partially encompassing Auslaßra 166 to be supplied, which leads to an opening provided in the outer housing 10 outlet opening.

The oil separated by the oil separator 160 collects in the form of an oil sump 170 which extends over both a lower region of the distribution space 162, a lower region of the discharge space 164 and a lower region of the discharge space 166.

From the oil sump 170, the oil is absorbed and thereby filtered by an oil filter 172, which is arranged for reasons of space savings in the bearing recess 72 of the second bearing housing 64, preferably via the end cap 80, a supply and removal of oil to the oil filter 172 ,

Claims (19)

1. Screw compressor comprising
   an outer housing (10),
   a compressor screw housing (40) arranged in the outer housing, rotor bores (42, 44) for screw rotors (46, 48) being arranged in said compressor screw housing,
   a drive (30) arranged in the outer housing (10) on one side of the compressor screw housing (40),
   and a bearing housing (64) arranged in the outer housing (10) on a side of the compressor screw housing (40) located opposite the drive (30),
   characterized in that an acoustic wave damping device (130) having the compressed working medium flowing through it is arranged within the outer housing (10), that the acoustic wave damping device (130) is arranged in an interior space (158) of the outer housing (10) accommodating the compressed working medium, that the compressed working medium passes directly into the acoustic wave damping device (130) from an outlet channel (110) for the compressed working medium, that the acoustic wave damping device (130) has an acoustic wave damping device housing (136), a damping device pipe (142) having a jump in cross section in relation to the surroundings on its inlet side and its outlet side being inserted into said housing, said damping device pipe being arranged on the outlet side of the acoustic wave damping device housing (136) and opening into the interior space (158) of the outer housing (10).
2. Screw compressor as defined in claim 1, characterized in that the acoustic wave damping device (130) is arranged so as to follow on directly from the outlet channel (110) for the compressed working medium.
3. Screw compressor as defined in claim 1 or 2, characterized in that the acoustic wave damping device (130) is connected to the outlet channel (110) with an inlet connection piece (132).
4. Screw compressor as defined in any one of the preceding claims, characterized in that the outlet channel (110) for the compressed working medium extends in the bearing housing (64).
5. Screw compressor as defined in any one of the preceding claims, characterized in that the acoustic wave damping device (130) is arranged on a side of the bearing housing (64) facing away from the compressor screw housing (40).
6. Screw compressor as defined in claim 5, characterized in that the acoustic wave damping device (130) is arranged between the bearing housing (64) and an end-side closure (156) of the outer housing (10).
7. Screw compressor as defined in any one of the preceding claims, characterized in that the damping device pipe (142) has a length corresponding approximately to a quarter of a wavelength of a pressure pulsation in the working medium to be compressed at a basic frequency of the screw compressor.
8. Screw compressor as defined in claim 7, characterized in that the basic frequency of the screw compressor is correlated to the driving speed of the screw rotors (46, 48).
9. Screw compressor as defined in any one of the preceding claims, characterized in that the compressed working medium is guided in the damping device housing (136) in a meandering manner.
10. Screw compressor as defined in any one of the preceding claims, characterized in that the acoustic wave damping device housing (136) is arranged between the bearing housing (64) and the end-side closure (156) of the outer housing (110).
11. Screw compressor as defined in any one of the preceding claims, characterized in that the acoustic wave damping device (130) is held free from connection to the outer housing (10).
12. Screw compressor as defined in any one of the preceding claims, characterized in that the acoustic wave damping device (130) discharges the compressed working medium into a distribution chamber (162) in the interior space (158), the compressed working medium flowing through an oil separator element (160) following said distribution chamber.
13. Screw compressor as defined in claim 12, characterized in that the interior space (140) in the outer housing (10) is divided by the oil separator element (160) into the distribution chamber (162) and a flow-off chamber (164).
14. Screw compressor as defined in claim 13, characterized in that the acoustic wave damping device (130) penetrates the oil separator element (160).
15. Screw compressor as defined in any one of the preceding claims, characterized in that the compressed working medium flows through a constriction in the flow cross section (118, 120) in the outlet channel (110).
16. Screw compressor as defined in claim 15, characterized in that the compressed working medium flows through the constriction in the flow cross section (118, 120) in the form of a meander.
17. Screw compressor as defined in any one of the preceding claims, characterized in that the outer housing (10) comprises a central section (12) accommodating the compressor screw housing (40) and an end section (16) on the pressure side adjoining the central section (12).
18. Screw compressor as defined in claim 17, characterized in that the end section (16) on the pressure side is designed as a housing capsule (150) extending from the central section (12).
19. Screw compressor as defined in claim 18, characterized in that the housing capsule (150) is of a compression resistant design and is connected to the central section (12) via a flange connection (152).

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