Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/12—Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
  • F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
  • F01C21/02—Arrangements of bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
  • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
  • F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
  • F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/0092—Removing solid or liquid contaminants from the gas under pumping, e.g. by filtering or deposition; Purging; Scrubbing; Cleaning
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/04—Heating; Cooling; Heat insulation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/06—Silencing
  • F04C29/065—Noise dampening volumes, e.g. muffler chambers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
  • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
  • F04C29/06—Silencing
  • F04C29/068—Silencing the silencing means being arranged inside the pump housing

Definitions

• the invention relates to a screw compressor of the type mentioned in the preamble of claim 1.
• the invention is preferably, but not exclusively, applicable to a screw compressor for generating a compressed air flow for the pneumatic transport of bulk materials, and in particular for a device designed for attachment to a silo vehicle Screw processor.
• Screw compressors are air compressors that work according to the displacement principle and, compared to other types of compressors, have advantageous properties that make them particularly suitable for the pneumatic transport of bulk materials. This applies in particular to so-called dry-running screw compressors, in which the screw rotors synchronized by a synchronous gear have no contact with one another and with the surrounding housing parts. Lubrication is therefore not required in the compression chamber, so that it can be kept oil-free and any contamination of the compressed air with oil is avoided.
• the contact-free running of the rotors means that there is no wear in this area, which reduces the service life, and there is no abrasion that can contaminate the air conveyed.
• screw compressors are particularly suitable for realizing high pressure ratios and are insensitive to short-term increases in pressure that could be caused by clogging of the pipeline loaded with compressed air. After all, they are lighter in weight and smaller in size, which makes them especially for mobile use B. makes suitable for silo vehicles.
• the drive gear for the rotors is arranged at one end and the synchronizing gear at the other end of the rotors. Oil lubrication is therefore necessary on both the pressure-side and the suction-side end of the rotors.
• the air is sucked in via a filter and / or a silencer, which are designed as separate units from the compressor housing and are connected to the compressor housing via a suction line, which bypasses the synchronizing gear near the suction end of the rotor housing.
• the presence of oil lubrication on the suction side of the rotor housing is undesirable because it increases the risk of air being contaminated with oil.
• the design of the intake filter and / or muffler separately from the actual compressor housing runs counter to the requirement for a compact, robust and weight-saving design.
• the invention has for its object to enable a simplified and improved air intake and a compact design of the compressor by an improved construction of the screw compressor in the area of the suction end of the compressor housing.
• any oil lubrication can be dispensed with at the suction end of the rotor housing.
• the area of the suction-side housing cover surrounding the suction-side shaft journals of the rotors and their bearing arrangement can be used directly for the inflow of air into the compressor space. There is no risk of contamination of the intake air with oil in this area.
• a suction housing containing the suction filter and / or the suction silencer can be attached directly to the suction-side end of the compressor housing, which results in a compact, space-saving construction which is particularly robust for mobile use.
• Figure 1 is a perspective view of the compressor with suction filter, seen from the side.
• Fig. 2 is a vertical section through the compressor of Fig. 1;
• FIG. 4 shows a further perspective view of the compressor from below, seen from the suction end, with the suction housing and oil container removed;
• FIG. 5 shows a detail of the perspective view according to FIG. 1, with a modified embodiment of the suction housing;
• Fig. 6 is an enlarged detail of the sectional view of Fig. 2 in the area of the suction-side rotor bearing.
• FIG. 7 shows an enlarged detail of the sectional illustration of FIG. 3 in the area of the rotor bearing on the pressure side.
• a gear housing 1 a gear housing 1
• a rotor housing 3 an inflow housing 4
• an intake housing 5 an oil tank 7.
• the rotor housing 3 there are two rotors, namely a main rotor 9 (profile teeth) and a secondary rotor 11 (profile gaps) are rotatably mounted, which mesh with one another with their helical teeth and tooth gaps and thereby form sealed chambers which move and contract in the axial direction when the rotor rotates and thereby compress the sucked-in air.
• the rotors are driven so that their right end in FIGS. 1-3 is the suction side.
• air is sucked in through inflow openings 13 provided on the end face of the rotor housing 3.
• the air is conveyed to the left by the intermeshing teeth and tooth gaps of the rotor pair and exits as compressed air at the pressure-side end of the rotors at an upward pressure outlet 15.
• the principle of operation of a screw compressor is known and is not explained in detail here.
• the gear housing 1 has the shape of a disk-like stand. In it, the drive shaft 17 of the compressor is mounted in bearings 16, 18, the shaft journal 17a of which protrudes from the housing cover 49 is connected to a rotary drive (not shown).
• the gear housing 1 also contains a drive gear, consisting of a gear 19 fastened on the drive shaft 17 and a gear 21 fastened on the shaft journal 23 of the secondary rotor 11, through which the rotation of the drive shaft 17 is transmitted to the secondary rotor 11 with a suitable transmission ratio. Furthermore, in the gear housing 1, ie also on the pressure side of the rotors 9, 11, the synchronizing gear which ensures the synchronous running of these rotors is accommodated, consisting of the intermeshing gearwheels 25, 27 which are on the shaft journal 23 of the secondary rotor or on the shaft journal 29 of the Main rotor 9 are attached. The synchronizing gear ensures that the rotors 9, 11 interlock with one another with very little play, but without contact.
• the overall stand or disk-shaped gear housing 1 has on its lower base on both sides projecting mounting feet 31 with holes 33 for mounting screws with which the entire compressor on a suitable base, for. B. a vehicle can be attached.
• lubricating oil is injected into the area of the meshing engagement of both gears, which is constantly circulated by an oil pump 45.
• a required supply of oil is kept in stock in the oil container 7, which communicates with the interior of the transmission housing 1.
• Sealing arrangements 35 interact with the shaft journals 23, 29 of the rotors 9, 11 and prevent oil from entering the rotors 9, 11 and thus to the compression chamber of the compressor. These sealing arrangements will be explained in more detail.
• the rotor housing 3 is fastened to the transmission housing 1 by means of a flange connection 37 in such a way that it projects freely from the transmission housing 1.
• the oil container 7, which has a flat box shape, is fastened to the gear housing 1 in such a way that it projects freely therefrom, approximately parallel to the rotor housing 3 and below it.
• the side walls of the oil container 7 are provided with cooling fins 39.
• An oil pump 45 which surrounds and is driven by the drive shaft 17, serves for the circulation of the oil in the interior of the transmission housing 1, or for generating an oil mist.
• the housing of the oil pump 45 has an outwardly projecting flange 47 which serves to center the housing cover 49 fastened to the gear housing 1.
• the oil pump 45 is fastened to the gear housing 1 with 4 screws 51 (FIG. 3) and associated threaded holes.
• the tool engagement consists of two flats 63 for the attachment of a spanner.
• the tool engagement can also have the shape of a square, hexagon, hexagon socket or the like.
• the shaft journals 55, 57 provided with the tool engagement are easily accessible by removing a housing cover 65 fastened with screws on the inflow housing 4.
• a filter 6 made of a suitable porous or air-permeable filter material.
• the filter lies in an air flow path between an outer suction slot 69 and a passage slot 73 arranged in an inner partition wall 71, suction slot 69 and passage slot being offset from one another in such a way that the longest possible flow path for the air between the slots 69, 73 through the filter 6 is formed.
• a modified embodiment of the suction housing 5 in which the air sucked in through the suction slot 69 and deflected by the deflection wall 71 with a passage slot 73 contains e.g. flows through muffler 75 formed from suitable perforated sheets before it reaches the space surrounding the housing cover 69 and flows through the inflow openings 13 into the interior of the rotor housing 3. It is also possible to design the suction housing 5 so that it contains both a filter and a silencer.
• An advantage of the direct attachment of the suction housing 5 containing a filter and / or a muffler to the rotor housing 3 such that it surrounds the inflow housing 4 at a distance is that a separate arrangement of a filter and / or muffler, and a connecting line between this and the suction side of the compressor can be omitted. A particularly simple, compact and robust arrangement is thereby achieved.
• Another advantage is that the air sucked into the suction housing 5 flows around and cools the outside of the inflow housing 4 containing the shaft journal bearings before it flows through the inflow openings 13 into the interior of the rotor housing 3 entry. As a result, effective cooling of the suction-side rotor bearings is achieved.
• FIG. 6 shows an enlarged sectional view of the mounting and sealing of the shaft journal 55 of the rotor 9 in the inflow housing 4.
• the shaft journal 57 of the other rotor 11 is mounted and sealed in an analogous manner.
• the shaft pin 57 provided with the tool engagement (flats 63) is mounted in the middle part of the inflow housing 4, which is designed in the manner of a hub, by means of a roller bearing 53 which is arranged between a shoulder of the shaft pin 57 and a retaining ring 83 engaging in an annular groove of the shaft pin.
• the roller bearing 53 is preferably designed as an encapsulated bearing with a lifetime grease filling, so that it does not require any subsequent lubrication.
• a race 85 is fastened, preferably shrunk, on the shaft journal 57.
• the race 85 which can be a commercially available race for a rolling bearing, for example, is made of steel with a specially hardened peripheral surface. With this two sealing lips of a lip seal ring 87 cooperate, which seals the interior of the rotor housing 3 against the roller bearings 53.
• a protective ring 89 is arranged between the latter and an inner shoulder 4a of the inflow housing 4, the inner circumference of which is opposite the outer surface of the raceway 85 with a very small gap, but without contact.
• the protective ring 89 and the lip sealing ring 87 are fixed to one another and abutting the inner shoulder 4a of the inflow housing 4 in the bore of the housing, preferably glued.
• the function of the protective ring 89 is as follows: When in operation, the compressor generates a stream of compressed air by sucking in air on the suction side and blowing out compressed air at the pressure port 15, which can be used, for example, for the pneumatic transport of dusty material.
• the protective ring 89 protects the lip sealing ring 87 from dust particles getting under the sealing lips of the lip sealing ring 87 and impairing the sealing effect.
• the suction-side bearing arrangement shown in FIG. 6 and described above has the further advantage that it can be pulled off the shaft journal 57 without the rotor 9 or 11 having to be removed or the precise setting of the rotors relative to one another having to be changed.
• the bearing and sealing arrangement can be removed from the shaft journal in the following way:
• the housing cover 65 of the inflow housing 4 is removed, so that the shaft journal 57 with its locking ring 83 is accessible.
• the snap ring 83 is removed.
• the screws connecting the inflow housing 4 to the rotor housing 3 are loosened.
• the entire inflow housing 4 together with the roller bearings 53, lip sealing rings 87 and protective rings 89 contained therein can be removed. This allows the suction-side roller bearings 53, the ones Parts that are most likely to be replaced due to the limited service life of their grease filling can be easily replaced without the rotors 9, 11 having to be adjusted or even removed in relation to one another and to the housing.
• FIG. 7 shows in a sectional view corresponding to FIG. 3, but on a larger scale, the mounting and sealing of the pressure-side shaft journals 29, 23 of the rotors 9, 11 at the pressure-side end of the rotor housing 3.
• the bearing and sealing arrangement for the shaft journal 29 will be described below of the rotor 9 described.
• the one for the shaft journal 23 of the rotor 11 is completely analog.
• the shaft journal 29 is supported in the pressure-side end wall of the rotor housing 3 by two roller bearings 91, 93 arranged next to one another, which are designed as so-called angular contact ball bearings.
• Angular contact ball bearings which are commercially available, are ball bearings whose balls are gripped by the outer and inner race only on one or the other side of the radial center plane.
• the two angular contact ball bearings 91, 93 are arranged side by side in mirror symmetry. Such an arrangement of angular contact ball bearings has the property that it is completely free of play in the axial direction.
• An arranged on the shaft journal 29 shaft nut 95 sets the angular contact ball bearings 91, 93 in the axial direction on the shaft journal 29.
• the outer race of the angular contact ball bearing 93 bears against an inner shoulder 97 of the rotor housing 3.
• This race 101 is made of steel with a specially hardened peripheral surface.
• the sealing lips of a lip sealing ring 103 which seals the compression space of the rotor housing 3 against the oil-loaded transmission and bearing area, lie on the surface of the race 101.
• the hardened and extremely precisely machined, for example polished, outer surface of the race 25 results in a particularly wear-reducing contact surface for the sealing lips of the lip sealing ring 103.
• labyrinth sealing ring 105 which has a plurality of adjacent ring ribs on its inner circumference, which face the outer surface of the race 101 with a very small gap but without contact and form a labyrinth gap with it.
• the race 101 does not normally have any contact with the labyrinth seal 105, it is nevertheless advantageous that the race 101 also extends over the region of the labyrinth seal 105.
• the labyrinth gap seal is normally a non-contact seal, but under extreme operating conditions it can under certain circumstances come into contact between the ring ribs of the labyrinth seal ring 105 and the race 101.
• FIG. 4 shows a perspective view from below of the compressor with the oil container 7 removed, so that the screw holes 44 for fastening the oil container 7 and the large connecting opening 43, through which the oil container communicates with the transmission housing, are visible in the end wall of the transmission housing 1 .
• the suction housing 5 is removed from the suction-side end of the rotor housing 3, so that the view of the inflow housing 4 with its support ribs 14 and the inflow openings 13 leading to the interior of the rotor housing 3 is clear.
• FIG. 4 also shows the mouth of the lantern (ventilation duct) 109 on the underside of the rotor housing 3. As can be seen from Fig.
• projections 111 are provided on the underside of the rotor housing 3, which the mouth of the lantern 109 against linear access from the Shield side.
• These projections 111 can be formed by oil drain channels. The mouth of the lantern 109 is thus at a protected location, to which a straight-line access path is neither possible from below (because of the oil container 7) nor from the side (because of the projections 111).
• the race 101 attached to the shaft journal 29 additionally serves as a spacing element, which is used to maintain a very precisely dimensioned gap between the pressure-side end face of the rotor 9 or 11 and the end face 113 of the rotor housing 3 facing it serves.
• this gap is precisely adjusted and maintained in such a way that, when machining the rotor housing 3, the distance a between the end face 113 facing the rotor 9 and the contact shoulder 97 for the roller bearing 93 is manufactured with very narrow tolerances to a predetermined value .
• the length b of the race 101 which is used as a spacing element between the roller bearing 97 and the end face of the rotor 9, is also ground with correspondingly precise tolerances to a value which has an oversize compared to the distance a, which is exactly the width of the between the Corresponds to rotor 9 and the rotor housing 3 gap to be set.
• This adjustment of the gap due to the length difference of the distances a and b is possible in that angular contact ball bearings 91, 93 are used according to the invention in a symmetrical arrangement, which, as mentioned, result in a bearing arrangement that is completely free of axial play.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Supercharger (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=8070665

Family Applications (1)

Country Status (5)

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• 1999
  • 1999-03-10 DE DE29904410U patent/DE29904410U1/de not_active Expired - Lifetime
• 2000
  • 2000-03-10 WO PCT/EP2000/002152 patent/WO2000053930A1/fr active IP Right Grant
  • 2000-03-10 AT AT00916927T patent/ATE267343T1/de not_active IP Right Cessation
  • 2000-03-10 DE DE50006495T patent/DE50006495D1/de not_active Expired - Lifetime
  • 2000-03-10 EP EP00916927A patent/EP1163451B1/fr not_active Expired - Lifetime
• 2001
  • 2001-09-10 US US09/950,323 patent/US6488488B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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