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
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
• • 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
  • F04C2/00—Rotary-piston machines or pumps
  • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
  • F04C2/082—Details specially related to intermeshing engagement type machines or pumps
  • F04C2/084—Toothed wheels
• • 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
  • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
  • F04C15/0042—Systems for the equilibration of forces acting on the machines or pump

Definitions

• the invention relates to measures for balancing a screw, otor set in an axially parallel arrangement with opposing external axis engagement and with wrap angles of at least 720 ° in a single-run design.
• Center of gravity center distance, end face and wrap angle determine the sizes of the static and dynamic unbalance that occur with screws with single-profile.
• this method offers the possibility of using special materials or, on the other hand, leads to reduced balancing cavities, which increases the dimensional stability.
• the use of screw rotors for pumping certain media and the desired reduction in temperature at the screw end on the output side require small, smooth, cavern-free screw surfaces that are dirt-repellent and easy to clean.
• the demands for reduced effort in service, assembly, spare parts inventory and for small, compact pumps make the use of external additional masses an obstacle.
• the invention has for its object to define measures for balancing single-start screws with a cavern-free, smooth surface without the use of external additional masses.
• Design options within the framework of a given screw geometry lie in the choice of the number, shape and material of the individual rotor parts and in the design of the balancing space 3, as characterized in the subclaims.
• Fig. 2 The representation of the spiral front profile center of gravity locus of a right-hand screw from Fig. 1.
• Fig. 3 An embodiment of a rotor of the screw rotor set of Fig. 1 in a two-part design in a first variant with a wing-shaped balancing space in an axial section.
• Fig.4 The rotor of Fig.3 in the end section along the line A-A.
• Fig. 5 The representation of the spiral forehead profile center of gravity locus e as well as dash-dot lines for the locus branches I, II, III, IV, V of the forehead intersection centers of gravity of the wing-shaped balanced balancing area of Fig. 3, 4.
• Fig. 6 The face cut geometry of the first rotor variant with the center of gravity and the maximum permissible internal cavity.
• Fig. 7 Different end cut contours of a balancing room 103, varying with the axial position W.
• Fig. 8 An embodiment of a rotor of the screw rotor set of Fig. 1 in a two-part design in a second variant with a straight balancing space in an axial section.
• Fig.9 The rotor of Fig.4 in the end section along the line B-B.
• Fig. 10 The representation of the spiral front profile center of gravity locus and dash-dot line the center of gravity of the straight balancing space of Fig. 8, 9.
• Fig. 11 An embodiment of a rotor of Fig. 8 in a sub-variant with one-sided rotor axis.
• the screw rotors 101; 201 each formed from two parts, a cylindrical screw body and a coaxial rotor axis.
• the screw body 104; 204 (Fig. 3; 8) is provided with a screw thread of approx. 9/2 loops and with a coaxial central bore.
• Within the screw body 104; 204 is the central bore 106; 206 (Fig. 3; 8) expanded to an eccentric cavity, balancing room 103; 203 (Fig. 3; 8).
• the central bore 106; 206 of the screw body 104; 204 is the rotor axis 105; 205 (Fig. 3; 8) fixed by press fits and thus closes the balancing chamber 103; 203 to the outside.
• a form-fitting area ensures the torque transmission between the rotor axis 105; 205 and screw body 104; 204.
• screw bodies 104; 204 and rotor axis 105; 205 made of different metallic materials.
• One in the rotor axis 105; 205 provided channel 107; 207 (Fig. 3; 8) serves to ventilate or cool the balancing chamber 103; 203 from a point sealed against the pump medium;
• the present version shows a central bore with a transverse bore in the area of the balancing chamber for ventilation.
• ⁇ o Yo " 3 [9 sec 2 / cm 4 ]
• ⁇ 0 specific weight of the screw body [g / cm 3 ]
• the rotor axis has no influence on the unbalance; the balancing chamber is formed inside the solid screw and it alone provides compensation for static and dynamic imbalance; thus the problem is reduced to pure design without the influence of the material data i.e.
• the static and dynamic values of the solid screw and the balancing chamber must be matched in such a way that the following 4 equations are fulfilled:
• the required pitch depth t (FIG. 3) is relatively large, corresponding to a relatively small core diameter c (FIG. 3).
• the effective balancing chamber 103 here consists of three axially aligned, equidistantly arranged, congruent, spiral vanes 108 (FIG. 4), which follow the course of the screw thread at a distance parallel. 5 shows 5 potential wing positions 1-V in dash-dot lines; In the variant described here, only the middle positions II, III, IV were populated (rough coordination).
• the area f 0 and the center of gravity position r 0 , ⁇ s can first be determined from the given screw face cutting contour (FIG. 6) using known methods. You get
• the shape of the balancing room cannot necessarily be derived from conditions (2b), (4b), (1b), (3b); it is rather necessary to first define a geometry, to do this to determine the 4 basic data, then to correct the geometry, to redetermine the 4 basic data, etc., until (2b), (4b), (1b), (3b) with sufficient Accuracy are met.
• the limit for the expansion of the balancing area is given by a stability-related minimum wall thickness.
• w constant
• the balancing chamber is divided into N axially one after the other, staggered disks of the same thickness ⁇ W.
• the face contour of each disc is defined separately by many individual points and is saved in this way.
• An EDP sub-program first calculates the values g n and ⁇ n for each slice and stores them in field data memories.
• the middle area extends over a (initially) variable number of m identical disks, the end areas each have 5 disks of decreasing contours (Fig. 7).
• ⁇ W 0.108 [cm] and variation of m, the values shown in Table 2 are obtained for the 3-wing balancing room.
• the gear ratio t required (FIG. 8) is relatively small, corresponding to a relatively large core diameter c (FIG. 8).
• the effective balancing space 203 (FIG. 8) runs in a straight line, axially parallel with a constant cross section (FIG. 9) eccentrically within the screw core area, axially mediated (FIG. 10).
• a balancing chamber 203 designed in this way has no influence on the dynamic unbalance.
• Some values for different wraps are shown in Tab. 3. From this follows directly (1a) the (profile-dependent) value of the static imbalance of the screw:
• the screw rotor 302 is overhung on the rotor axis which is coaxially attached to the screw body on one side.
• the eccentric balancing chamber 303 is accessible from the axisless end face of the screw rotor via a large coaxial bore and can therefore be manufactured in several ways.
• Screw body and rotor axis preferably form a one-piece unit, the coaxial bore on the rotor end face is optionally closed by a plug 309. Special proportions of the screw body, e.g. due to the one-sided mounting, the proportions e, d, j of the balancing chamber 303 lead to different proportions for the same calculation.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Applications Or Details Of Rotary Compressors (AREA)
• Rotary Pumps (AREA)
• Supercharger (AREA)
• Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
• Cereal-Derived Products (AREA)
• Refuse Collection And Transfer (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

Applications Claiming Priority (5)

Publications (3)

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ID=25689859

Family Applications (1)

Country Status (16)

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• 1997
  • 1997-07-21 AU AU34322/97A patent/AU714936B2/en not_active Expired
  • 1997-07-21 CN CN97197830A patent/CN1093228C/zh not_active Expired - Lifetime
  • 1997-07-21 EP EP97930285A patent/EP0925452B9/fr not_active Expired - Lifetime
  • 1997-07-21 KR KR10-1999-7001867A patent/KR100509640B1/ko not_active IP Right Cessation
  • 1997-07-21 ES ES97930285T patent/ES2180061T3/es not_active Expired - Lifetime
  • 1997-07-21 DE DE59708019T patent/DE59708019D1/de not_active Expired - Lifetime
  • 1997-07-21 AT AT97930285T patent/ATE222641T1/de active
  • 1997-07-21 SK SK289-99A patent/SK28999A3/sk unknown
  • 1997-07-21 WO PCT/CH1997/000279 patent/WO1998011351A1/fr not_active Application Discontinuation
  • 1997-07-21 CZ CZ1999755A patent/CZ292634B6/cs not_active IP Right Cessation
  • 1997-07-21 CA CA002262898A patent/CA2262898C/fr not_active Expired - Lifetime
  • 1997-07-21 US US09/242,228 patent/US6158996A/en not_active Expired - Lifetime
  • 1997-07-21 DK DK97930285T patent/DK0925452T3/da active
  • 1997-07-21 PT PT97930285T patent/PT925452E/pt unknown
  • 1997-07-21 JP JP51309498A patent/JP4307559B2/ja not_active Expired - Lifetime
• 1999
  • 1999-03-11 NO NO991212A patent/NO991212L/no not_active Application Discontinuation

Non-Patent Citations (1)

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