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
  • F04C27/00—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids
  • F04C27/008—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids for other than working fluid, i.e. the sealing arrangements are not between working chambers of the machine
  • F04C27/009—Shaft sealings specially adapted for pumps
• • 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
  • F04C23/00—Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps specially adapted for elastic fluids
  • F04C23/008—Hermetic pumps
• • 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
  • F04C2240/00—Components
  • F04C2240/50—Bearings
  • F04C2240/51—Bearings for cantilever assemblies

Definitions

• the invention relates to a screw compressor comprising a compressor screw housing, two screw rotors with interlocking screw bodies arranged in the compressor screw housing and with shaft sections arranged on both sides of the screw body, through which the screw rotors are mounted in bearing housings arranged on both sides of the compressor screw housing.
• Screw compressors of this type are known from the prior art. The problem with these is to provide the tightest possible seal on the pressure side between the screw bodies and the compressor screw housing in order to prevent pressure losses.
• the advantage of the solution according to the invention is that the seal between the intermediate piece and the inner surface of the opening means that the gap existing between them cannot be penetrated by a parasitic flow of working medium to be compressed - which changes from the volume region with compressed working medium to one would lead to the volume area opposite the outlet near the outlet-side end wall of the compressor housing - and thus would not open a bypass, which would result in a loss of the compressed working medium which is to escape from the outlet.
• a particularly expedient solution provides that a radial movement of the intermediate piece relative to the inner surface is arranged between the intermediate piece and the inner surface.
• This solution has the advantage that, in contrast to a seal with oil, which requires a substantially uniform gap, which should also be as small as possible, the seal allows the intermediate piece to move radially relative to the inner surface and still ensures sufficient tightness, so that the solution according to the invention can be used in conventional screw compressor solutions in which a radial movement of the intermediate piece relative to the inner surface is permitted, which occurs because the screw bodies are exposed to forces acting on one side.
• the seal could be provided in the direction of the axis of rotation in each section of the intermediate piece and the inner surface.
• a particularly favorable solution provides for the seal to be substantially close to an edge of the opening facing the respective screw body, preferably in an edge facing the screw body Edge area of the opening is arranged. The volume existing in the gap between the intermediate piece and the inner surface up to the seal is thus kept as small as possible from the outset.
• the seal preferably lies in a third of the opening, which adjoins the edge of the opening facing the respective screw body.
• a particularly advantageous solution provides for the seal to comprise a sealing ring which in a simple manner opens up the possibility of sealing between the intermediate piece and the inner surface.
• Such a sealing ring could be made of elastic material, for example, so that radial movements of the intermediate piece relative to the inner surface would lead to different pressures of the sealing ring.
• the seal comprises a sealing ring which is seated in a groove and is radially movable with respect thereto. There is thus the possibility of realizing the radial movements of the intermediate piece relative to the inner surface by a relative displacement of the sealing ring with respect to the groove.
• the groove is arranged in the intermediate piece.
• a particularly favorable solution provides that the groove is arranged near the pressure-side end of the respective screw body in the intermediate piece.
• the distance of the groove from an end face of the respective screw body is a maximum of five times, more preferably a maximum of three times, a width of the groove in the direction of the respective axis of rotation.
• Another expedient solution is designed in such a way that the intermediate piece, following the pressure-side end of the respective screw body, has a recess opposite the edge of the opening.
• Such a recess has the advantage that contact between the intermediate piece and the edge of the opening can be avoided when the intermediate piece moves radially with respect to the inner surface of the opening.
• the groove is arranged essentially following the recess in the egg.
• the groove there is preferably a distance between the groove and an end face of the respective screw body, which corresponds to a maximum of three times the extent of the depression in the direction of the axis of rotation, the depression preferably having an extent in the direction of the axis of rotation, which corresponds approximately to a width of the groove.
• the distance of the groove from the end face is of the order of twice the extent of the recess in the direction of the respective axis of rotation.
• an annular bead is preferably provided between the recess and the groove.
• This annular bead expediently has a maximum extension in the direction of the axis of rotation, which corresponds approximately to an extension of the recess in the direction of the axis of rotation.
• a particularly preferred embodiment provides for successively arranging a plurality of sealing rings in the direction of the axis of rotation.
• FIG. 1 shows a longitudinal section through a first embodiment of a screw compressor according to the invention along line 1-1 in Fig. 2.
• FIG. 2 shows a section along line 2-2 in FIG. 1;
• Fig. 3 is a section along line 3-3 in Fig. 1;
• Fig. 4 is an enlarged view of area A in Fig. 3;
• Fig. 5> a front view of a sealing ring and 6 shows a section along line 6-6 in FIG. 5.
• FIG. 1 An exemplary embodiment of a screw compressor according to the invention, shown in FIG. 1, comprises an outer housing designated as a whole by 10, which consists of a central section 12, an engine-side end section 14 and a pressure-side end section 16 arranged on the side of the central section 12 opposite the motor-side end section 14 is constructed.
• the central section 12 and the motor-side end section are preferably connected to one another by two flanges 18 and 20, and the central section 12 to the pressure-side end section 16 by flanges 22 and 24, respectively.
• a drive motor designated as a whole by 30, which is designed, for example, as an electric motor and comprises a stator 32 and a rotor 34.
• the stator 32 is preferably fixed in the outer housing 10, in particular in a motor region 36 of the central section 12 facing the motor-side end section.
• a compressor screw housing designated as a whole by 40, which, as shown in FIG. 2, has two rotor bores 42 and 44 which merge into one another and a slide bore 46, for example for a drawing in FIG. 1 undetectable control slide.
• the rotor bores 42 and 44 serve to receive two screw rotors 48 and 50 which are customary for a screw compressor, the screw rotors 48 and 50 being only indicated by dashed lines in FIG. 2.
• the two screw rotors 48 and 50 rotate about their respective axes of rotation 52 and 54 and are rotatably supported on both sides of their respective screw bodies 56 about their axes of rotation 52 and 54.
• the compressor screw housing 40 is adjoined on a side facing the drive motor 30 by a bearing housing 60 which has first bearing receptacles 62 for first rotary bearings 64 of the two screw rotors 48, 50, the screw rotors 48, 50 having shaft sections extending from suction-side ends 65 of the screw body 56 66, on which the pivot bearings 64 are seated.
• One of these shaft sections 66 is arranged coaxially with a drive shaft 38 of the drive motor 30 and connected to it.
• screw rotors 48, 50 are rotatably mounted on their side opposite the bearing housing 60 in a second bearing housing 70 with second bearing receptacles 72, likewise by means of second rotary bearings 74, the screw rotors also having shaft sections 76 protruding from the pressure-side ends 75 of the screw body 56.
• the compressor screw housing 40 extends between the first bearing housing 60 and the second bearing housing 70 over the entire length of the screw body 56 in the direction of their rotor axes 52 and 54 and encloses the screw rotor 48 and 50 in the region of their screw body 56, so that a sealing gap S remains between the screw body 56 and the rotor bores 42 and 44, which is designed to be as small as possible for sealing.
• a pressure-side sealing of the volume area with compressed working medium from volume areas lying at a lower pressure takes place in particular by a small gap 95 between end faces 92 of the screw body 56 and a surface 94 of an end wall 96 of the compressor screw housing 40.
• the end wall 96 is provided with openings 98 which penetrate the shaft sections 76, which are finally supported with bearing sections 100 in the second rotary bearings 74, the shaft sections 76 respectively with the bearing section 100 penetrating the second rotary bearing 74 and between the bearing section 100 and
• An intermediate piece 102 of the respective shaft section 76 extends from the pressure-side end 75 of the respective screw body 56, which is required in order to be able to store the second rotary bearing in the second bearing housing 70 in a sufficiently stable manner at a sufficiently large distance from the end wall 96.
• the intermediate piece 102 essentially has a cylindrical lateral surface 104 which runs at a short distance from an inner surface 106 of the respective opening 98 in the end wall 96. According to the invention, a gap 110 between the inner surface 106 and the outer surface 104 is now sealed in the region of the intermediate piece 102 and the opening 98 receiving the latter, in order to prevent a parasitic flow of compressed working medium from occurring in this gap 110 at lower pressure standing volume areas, in particular volume areas opposite the outlet 90 and close to the end wall 96.
• a seal designated as a whole with 120 is provided in the solution according to the invention, which is intended to prevent the medium to be compressed from penetrating into the gap 110 and in particular preventing the medium from penetrating in the direction of the second rotary bearing 74.
• the intermediate piece 102 is provided near the end face 92 with a circumferential groove 122 which has a groove base 124 and groove walls 126 and 128 rising therefrom and into which a sealing ring 130 with play in the radial direction to the axis of rotation 54 is used, the sealing ring 130 abuts with an outer peripheral surface 132 on the inner surface 106 of the opening 98, and also extends with its two opposite end faces 134 and 136 into the groove 122 between groove walls 126 and 128 of the groove 122 and thereby through the pressure in the area of the outlet 90 with the end face 136 is applied to the groove wall 128, but has an inner surface 138 with a diameter which is larger than a diameter of the groove base 124, so that the sealing ring 130 in the radial direction to the axis of rotation 54 opposite the Groove 122 is movable.
• the sealing ring 130 is preferably designed as a ring with a rectangular cross section, which forms the outer circumferential surface 132 on its outside and the end faces 134 and 136 as surfaces which are parallel to one another but offset in the direction of its axis 142, the groove walls 126 and 128 preferably lie in planes running perpendicular to the axis 142 and also to the axis of rotation 54.
• sealing ring 130 is provided with a slot 144, which permits radial expansion of the sealing ring 130 with respect to the axis 142.
• the sealing ring 130 is preferably made of cast iron or Teflon filled with a strength-increasing, in particular pressure-increasing substance.
• the edge 146 of the opening 98 is preferably included provided with an inclined surface 148 which runs in the form of a conical surface with respect to the respective axis of rotation 54.
• the intermediate piece 102 is provided in direct connection to the end face 92 with an annular recess 150, the base 152 of which has a smaller diameter than the cylinder jacket surface 104.
• the groove 122 is so close to the recess 150 that an annular bead 154 remains between the recess 150 and the groove 122, the outer surface 156 of which has a diameter which is approximately that of the cylindrical Shell surface 104 of the intermediate piece 102 corresponds, preferably is identical to this.
• the annular bead 154 has an extent in the direction of the axis of rotation 54 which corresponds at most to the extent of the recess 150 in the direction of the axis of rotation 54 and likewise a maximum of a width of the groove 122 in the direction of the axis of rotation 54.
• the groove 122 is preferably arranged at a distance from the end face 92 of the screw body 56 which corresponds to a maximum of five times the width of the groove 122 in the direction of the axis of rotation 54.

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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)
• Rotary Pumps (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7652616

Family Applications (1)

Country Status (10)

Families Citing this family (13)

Family Cites Families (10)

• 2000
  • 2000-08-16 DE DE10040020A patent/DE10040020A1/de not_active Ceased
• 2001
  • 2001-07-25 DE DE50103903T patent/DE50103903D1/de not_active Expired - Lifetime
  • 2001-07-25 TR TR2004/02812T patent/TR200402812T4/xx unknown
  • 2001-07-25 CN CNB018024408A patent/CN1181262C/zh not_active Expired - Lifetime
  • 2001-07-25 EP EP01960553A patent/EP1309799B1/fr not_active Expired - Lifetime
  • 2001-07-25 PT PT01960553T patent/PT1309799E/pt unknown
  • 2001-07-25 DK DK01960553T patent/DK1309799T3/da active
  • 2001-07-25 AT AT01960553T patent/ATE278109T1/de not_active IP Right Cessation
  • 2001-07-25 ES ES01960553T patent/ES2228928T3/es not_active Expired - Lifetime
  • 2001-07-25 WO PCT/EP2001/008597 patent/WO2002014694A1/fr active IP Right Grant
• 2002
  • 2002-04-12 US US10/122,130 patent/US6572354B2/en not_active Expired - Lifetime

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