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
  • F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
  • F04C2/107—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member with helical teeth
  • F04C2/1071—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member with helical teeth the inner and outer member having a different number of threads and one of the two being made of elastic materials, e.g. Moineau type
  • F04C2/1073—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member with helical teeth the inner and outer member having a different number of threads and one of the two being made of elastic materials, e.g. Moineau type where one member is stationary while the other member rotates and orbits

Definitions

• the invention relates to an eccentric screw pump, which has a stator and a rotor, between which the material to be conveyed is shifted from a suction-side input area to a pressure-side discharge area when the rotor is rotated in the stator, a pressure-volume area and a suction-volume area being located in the pressure-side discharge area the stator and the rotor are opposite and changing due to rotor rotation.
• Known eccentric screw pumps of this type contain a rotor designed as a screw, which has the shape of a round thread screw with a high pitch and a large thread depth, and a stator, which has a thread-like inner structure and thus has the shape of a screw shell.
• the thread-like inner structure of the stator from the suction side to the pressure side, forms cavities which are formed axially one after the other and in which the rotor rotates. Parts of the inner surface of the stator and parts of the outer surface of the rotor touch during the rotation of the rotor, with conveying chambers and associated sealing areas being present between the inner surface of the stator and the outer surface of the rotor, the material to be conveyed in the conveying chambers when the rotor is rotating in the cavities of the stator is shifted from the suction side to the pressure side along a conveyor line.
• Such an eccentric screw pump is known from document EP 0 713 974, in which continuous rotation of abrasive material to be conveyed is possible by rotating the rotor in the cavities of the stator.
• the stator is made of elastic material and bears against the rotor with a preload, which always creates a seal at the running chamber end.
• the material to be conveyed pressed out of the discharge cavity on the pressure side, due to the material to be conveyed in the downstream pressure pipe, presses on the rearward conveyed material as opposing external pressure.
• the conveying process thus builds up internal pressure, particularly against the sealing areas. The higher the external pressure built up in the pressure pipe, the greater the preload between the rotor and the stator in order to ensure a secure seal.
• the rotor and the stator are subject to wear, particularly during the conveying of the conveyed material. Essentially, the wear occurs at the aisles of the stator designed as seals of the cavities, starting from the side of the discharge-side discharge area in the direction of the inlet-side entry area. The increase in wear causes the decrease in the delivery rate of the eccentric screw pump.
• the elastic stator rests on the rotor with a pre-tension, whereby the material being conveyed can cause high wear between the stator and the rotor, which increases with increasing pressure. The wear progressively moves from the pressure to the suction side and removes the original sealing areas. If the internal pressure can no longer overcome the external pressure, the conveying process is finally stopped.
• the clamping devices can be used to make radial compressions of the stator in detail or, as required, as a whole, and thus to bring the inner surface of the stator closer to the outer surface of the rotor, whereby the approximation should lead to the creation of the original seal in the sealing areas.
• An eccentric screw pump is also known from the document DE 202 15 849.7, in which a check valve device which allows the material to be conveyed is present on the discharge-side discharge area and which includes a closure disk rigidly attached to the end face of the stator.
• the end face of the rotor rotates on the sealing disc, which is intended to seal the changing pressure and suction volume ranges.
• the stator-attached sealing disc has two stationary through openings for the discharge of the conveyed material, each of which is assigned a check valve.
• the two valve-fitted through openings are assigned to the pressure volume area and suction volume area occupied by the discharge area of the rotor and are opened when the internal pressure in the respective volume areas between the stator and the rotor is greater than is the pressure pipe passing on the valve in the conveyed material.
• stator-fastened closure disk with the valves requires additional components.
• the valves must at least be cleaned after the eccentric screw pump has been used.
• the invention is based on the object of specifying an eccentric screw pump which is designed in the area of the discharge in a manner which is simple to install and improves maintenance.
• the wear in the sealing areas of the stator and rotor, in particular in the pressure area of the discharge cavity on the pressure side, is to be substantially slowed down or largely reduced.
• the already short lengths of the stator and the rotor or the conveying path should also be further shortened and the original conveying capacity should be largely retained over a longer period of time.
• a rotor head part which closes off the discharge-side discharge area and is fastened to the end face of the rotor and rotates with the rotor and has at least one recess through the head part which is introduced into the rotor head part in this way in relation to the holding rotor end face that the recess, which rotates in the conveying direction in conformity with the rotor, opens the pressure volume area and that a recess-free rotor head part area keeps the opposite suction volume area sealed in the opening period of the pressure volume area.
• the rotor head part is attached to the rotor end face by screwing, welding or the like. brought about with the back of the rotor head part.
• the rotor head part can be attached to the rotor end face in such a way that the central axis of the rotor head part can coincide with the center of the rotor end face. Then the movement of the center axis represents a centric straight-line elongation; if there is no match, an eccentric cam track can be run.
• the continuous recess is made directly laterally on the end face of the rotor in the rotor head part, the recess cross section being specified in accordance with the dimensions with the pressure build-up within the pressure volume range and the discharge of the conveyed material by the rotating rotor.
• the rotor head part can preferably be a perforated rotor disk with circular surfaces.
• the associated continuous recess can preferably be an elongated hole which is largely bean-shaped in plan cross section.
• the rotor head part is attached to the rotor end face in such a way that the hole, starting from the edge of the holding rotor end face in the radial direction with its effective opening cross section, enters the pressure volume area with the hole beginning area and later with the pressure generation within the pressure volume area with the hole beginning area Hole end area emerges from the pressure volume area again.
• the continuous recess of the rotor head part can optionally also be designed as a radially directed sector-section-shaped through opening or sector-like recess starting from the edge of the holding rotor end face, which, like in the case of the elongated hole design with its respectively effective opening cross section, conforms to the rotor with the generation of pressure within the pressure volume range by the rotor the pressure volume area enters and exits the pressure volume area after the pressure volume area has been crossed.
• the rotor head part has such circumferential dimensions that the rotor head part with its remaining, recess-free rotor head part area keeps the suction volume area in the area of the stator opening that is created during rotation closed.
• the rotor can be designed as a worm in the form of a round-thread screw with a high pitch and large thread depth, the stator representing a worm shell and cavities formed axially one after the other - at least one suction-side entry cavity and one pressure-side discharge cavity - containing a conveying path, with the stator inner surface and the rotor outer surface form conveying chambers by sealing areas adapted between the stator and the rotor, the material to be conveyed in the conveying chambers being displaceable from the suction-side input area to the pressure-side discharge area when the rotor is rotated in the cavities of the stator.
• a pressure pipe can be connected to the stator face, via which the material to be conveyed is passed, the pressure pipe can be locked on the stator in a sealed manner by means of at least one holding element that surrounds the stator and pressure pipe.
• the invention makes it possible for the presence of the rotor head part or the rotor perforated disk on the discharge-side discharge region to separate the original pressure-tube-related pressure space after the pump outlet from the original pump-related discharge-side discharge cavity. After the discharge area on the pressure side has been opened through the opening, which is dependent on the rotor rotation, by means of the continuous recess, a subsequent gentle filling of the conveyed material is obtained from the suction-side entrance area and directed by the rotating rotor.
• FIG. 1 shows a schematic perspective exploded view of an eccentric screw pump according to the invention with a rotor head part detached from the rotor end face and a connectable pressure pipe detached from the stator end face,
• Fig. 2 is a schematic frontal plan view of a
• Volume range at a fixed rotor angle ⁇ equal to 0 ' 3 shows a schematic frontal top view of the perforated rotor disk with the hole in a position with maximum discharge of conveyed material from the pressure volume range when the rotor is rotated through a rotor angle equal to 90 ° according to FIG. 2,
• Fig. 4 is a schematic frontal top view of the perforated rotor disk with the hole in a position after the end of the discharge of conveyed material from the previous pressure volume range or at the beginning of the discharge of
• FIG. 5 shows a longitudinal section through a shortened eccentric screw pump with the rotor perforated disk according to FIG. 3 along the line I-I.
• FIG. 1 shows a schematic exploded view of an eccentric screw pump 1, which has a stator 2 and a rotor 3, between which the material to be conveyed is shifted from a suction-side input area 4 to a pressure-side discharge area 5 when the rotor 3 is rotated in the stator 2, wherein in the discharge area 5, a pressure-volume area 11 and a suction-volume area 12 between the stator 2 and the rotor 3, due to the rotation of the rotor, lie opposite one another in a volume-changing and changing manner.
• a discharge area 5 that closes on the pressure side and is attached to the end face 6 of the rotor 3 rotor head part 7 rotating with the rotor 3 is provided, which has at least one recess 8 which is continuous with the head part and which is introduced into the rotor head part 7 in relation to the holding rotor end face 6 in such a way that the recess 8 which rotates in the conveying direction 10 in conformity with the rotor 3 withstands the pressure Accompanying volume area 11 Opens and that a recess-free rotor head portion 13 keeps the opposite suction volume area 12 sealed during the opening period of the pressure volume area 11.
• the rotor head part 7 is preferably designed as a perforated rotor disk, flat on its rear surface 30 and with its rotor head part rear surface 30 by screwing, welding or the like. attached to the rotor end face 6 of the helical rotor 3, actually the rotor worm end face.
• the rotor head part 7 is thus an integral part of the rotor 3 outside the stator 2.
• the rotor perforated disk 7 can be attached with its disk rear surface 30 to the rotor end face 6 such that the central axis 33 of the rotor perforated disk 7 can preferably coincide with the center 28 of the rotor end surface 6, the central axis 33 only straight elongated.
• the central axis 33 of the rotor head part 7 is displaced away from the center 28 of the rotor end face 6, then no centric straight elongation, but an eccentric cam path is traversed.
• the front surface 9 and the rear surface 30 can also be oval-shaped, pear-shaped or egg-shaped in cross-section or the like. especially designed for material reduction his.
• a material-reduced second rotor head part 27 (dashed) is inserted.
• the recess 8 is designed in such a way that the suction volume area 12, 12 'always remains sealed and rotated during the rotor rotation and the pressure volume area 11, 11' is opened in a rotor-conforming manner.
• the rotor perforated disk 7 in FIG. 1 preferably has, as a continuous recess 8, an elongated hole which is largely bean-shaped in cross section.
• the elongated hole 8 is made directly to the side of the edge and expands in the radial direction on the end face 6 of the rotor 3 in the rotor perforated disk 7, the hole cross section on it being dimensioned in accordance with the pressure build-up in the pressure Volume area 11 and the discharge of the material to be conveyed out of the pressure volume area 11 by the rotating rotor 3 is predetermined.
• the rotor 3 is designed in the form of a round thread screw (cord thread) with a high pitch and large thread depth and acts as a displacement material displacer and as a seal along the conveying path 14 from the suction-side input area 4 to the pressure-side discharge area 5 between the rotor 3 and the stator 2.
• the stator 2 and holds axially one after the other and due to the pitch and the depth of the thread formed cavities 15, 16, 17 - a suction-side entry cavity 15, a central conveying cavity 16, a discharge-side discharge cavity 17 - the between the stator surface 18 and the rotor outer surface 19 Delivery chambers 20,21,22 by between see the stator 2 and the rotor 3 form sealing areas 23, 24, the material to be conveyed in the conveying chambers 20, 21, 22 when the rotor 3 is rotated in the cavities 15, 16, 17 of the stator 2 from the suction-side inlet area 4 to the discharge-side discharge area 5 is transported.
• the rotor 3 moves the material to be conveyed in the axial direction 10 along the conveying path 14 and at the same time in the radial direction with respect to the pump central axis 26 alternately in the discharge cavity 17 via the feeding conveying chambers 20, 21, 22 provided for this purpose, which form and opposing volume regions 11, 12, which are part of the discharge cavity 17 on the pressure side.
• the rotor head part rear surface 30 and the stator end surface 25 are flat and each have an angle of approximately 90 ° to the pump central axis 26.
• the rotor head part front surface 9 can be flat with respect to a disk-shaped configuration, but also spherical cap and / or with at least one wing or other projections having a profile for improving throughput and mixing of the conveyed material.
• the discharge-side discharge area 5 of the eccentric screw pump 1 comprises the last section of the eccentric screw pump 1 that delivers the material to be conveyed, while the suction-side input area 4 represents the first section of the eccentric screw pump 1 that receives the material to be conveyed.
• the invention thus makes it possible for the material to be conveyed out of the eccentric screw pump 1 on the discharge side after the rotor-rotation-related opening of the pressure volume region 5 and the sealing of the suction volume region 12 no longer to flow back through the hole-free disk part 13 and not to the rotor 3 pushed or rotated by the rotor 3. can suck in the conveyed material.
• the hole 8 allows the material to be conveyed to flow through it without substantial resistance, while a backflow of the material to be conveyed in the direction of the suction volume region 12 is blocked through the hole-free disk part 13.
• a pressure tube 34 which faces the rotor head part front surface 9 and via which the conveyed material is conveyed, can be fastened to the stator end face 25.
• the pressure tube 34 can be locked in a sealed manner on the stator 2 by means of at least one holding element (not shown) that preferably surrounds the stator and pressure tube.
• the rotor 3 is in the suction volume area 12 with its circular rotor end face 6 at an angular and rotational position 28, in which the rotor angle ⁇ e.g. is set to 0 °.
• the perforated rotor disk 8 is attached to the rotor end face 6 in such a way that the bean-shaped elongated hole 8 begins with its hole start area 35 to a very small part of its effective opening cross section to cover the pressure volume area 11. Compliant with the pressure generated by the rotating rotor 3 in the pressure volume range
• the cross-sectionally elongated hole size of the opening coverage of the pressure volume region 11 also becomes larger.
• the remaining and hole-free disk part 13 can close off a part of the remaining pressure volume area 11 and the suction volume area
• the rotor 3 has rotated through an angle ⁇ of 90 ° into the center position 28 ', as a result of which the bean-shaped elongated hole 8, including the hole start area 35 and the hole end area 36, has the largest part of the pressure volume area 11 in terms of hole cross section covered and thus opened it and the hole-free disk part 13 still seals the suction volume area 12.
• the hole 8 with its hole end area 36 emerges from the reduced pressure volume area 11.
• the original suction volume area 12 is still sealed off by the hole-free disk part 13, but is opened as a result of the rotor rotation as the pressure volume area 11 ', as in FIG.
• the hole 8 enters with its hole start area 35 into the opposing pressure volume area 11 'which is building up.
• FIG. 4 also shows that the hole 8 can be designed as a continuous recess in a different configuration in the form of a radially directed sector-section-shaped through opening 32 or sector-like recess 31 starting from the holding rotor end face 6, each of which is dashed.
• the rotor perforated disk 7 shown in FIGS. 2, 3, 4 in front view for reducing the pressure at least on the sealing area 24 within the eccentric screw pump 1 has such circumferential dimensions that the stator opening 27 always rotates the suction volume area that arises when the rotor perforated disk 7 rotates 12 keeps sealed.
• the eccentric screw pump 1 is shown schematically as an abbreviated longitudinal section along the line II in FIG. 3.
• the rotor perforated disk 7 is dimensioned in such a way that its range of motion during rotor rotation preferably remains within the stator casing 29, ie does not move beyond the stator casing 29.
• the rotor perforated disk 7 is firmly connected to the rotor end face 6 on its rear disk surface 30.
• the disk rear surface 30 is flat in the hole-free region 13 such that it lies tightly against the stator end face 25, which is also preferably flat, and forms an angle of approximately 90 ° with the pump center axis 26.
• the hole 8 opens the passage of the conveyed material to the downstream pressure pipe 26 to the pressure volume region 11.
• the hole-free disk part 13 keeps the suction volume part 12 of the discharge cavity 17 on the pressure side closed.
• FIG. 5 according to the invention, in a minimally short design of the stator 2, only one sealing area 24 of a worm gear can be formed, wherein the suction-side input area 4 can be followed directly by a discharge-side discharge area 5.
• the position of the rotor 3 in the worm gear is stabilized by the rotor head part 7 resting on the stator face 25.
• the eccentric screw pump 1 works as follows:
• the metallic rotor 3 rotates in the stator 2 (worm shell) consisting of elastic material and seals the delivery chambers 20, 21, 22 on the inner surface of the stator 18.
• the rotation of the rotor 3 moves the material to be conveyed in the conveying chambers 20, 21, 22 from the suction-side input region 4 to the discharge-side discharge region 5. This results in a continuous flow of material to be conveyed in the stator 2, which pulsatingly leaves the hole 8 of the rotor head part 7.
• the material to be conveyed is reduced within the decreasing volume area 11 by the rotor rotation in the pressure Volume area 11 positioned hole 8 pressed through, while the suction volume area 12 remains closed.
• the rotor end face 6 reaches a position 28 ′′ in which the decreasing pressure volume region 11 changes into a pressure volume region 11 ′ that is completely soaked up with the material to be conveyed, which previously was the Suction volume area 12 has been. Due to the rotor rotation beyond a rotor angle ⁇ of 180 °, the pressure is built up in the resulting pressure volume area 11 ′, which presses the material to be conveyed out of the hole 8 in a rotor-conforming manner. The previous pressure volume range 11 merges into the newly created suction volume range 12 'due to the rotor rotation.
• the previously opened pressure volume area 11 is closed by the hole-free disk part 13 and built up to the suction volume area 12 '.
• the sealing areas 24, 23, in particular the last sealing area 24 of the discharge cavity 17 on the pressure side are also not subjected to back pressure.
• the increasing suction volume area 12 ′ exerts a strong suction effect on the following material to be conveyed from the conveying chamber 21.
• the rotor perforated disk 7 results in a change of pumping processes and suction processes of the conveyed material within the discharge cavity 17, whereby the suction of the conveyed material into the in each case disc-closed volume regions 12 or 12 ', a higher degree of filling of conveyed goods is achieved there.
• the invention enables the conveyor path 14 to be shortened and to be able to relate to two “cavity lengths” or to a “single-cavity-cavity-discharge-cavity” arrangement 15-16-17.
• the conveyor section 14 can be shortened to a worm gear of the stator 2.
• the required drive power can be achieved by means of a motor which is also reduced in power, whereby thus energy and material can also be saved.
• An increase in the delivery pressure is fundamentally achieved by an increase in the pretension between the stator 2 and the rotor 3, which in a conventional manner usually has an axial surface e.g. by means of a clamping jacket comprising the stator 2.
• One problem is that this involves a correspondingly increased energy expenditure for pump operation.
• a corresponding increase in preload in the radial direction to the pump center axis 26 is provided with the least possible axial shape.
• a radial cross-sectional taper can optionally be provided in the regions of the stator 2, preferably in integer intervals of a screw casing thread corresponding to one revolution, from the rotor end face 6.
• a radial cross-sectional tapering element (not shown) can be assigned to the stator 2 at a distance from the rotor end face 6 corresponding to a worm shell thread of the stator 2.
• the radial cross-sectional tapering element can be configured and arranged in the manner of a sleeve inside and / or outside of the stator casing 29, which can be changed in the radial direction, either in a controllable manner or via actuators, and with which the radial prestressing of the sealing areas 23, 24 of the stator 2 with respect to that Rotor 3 can be adjusted either step by step or continuously depending on the specified delivery pressure.
• the invention opens up the possibility that, in addition to the time delay in the formation of wear, the manufacturing costs can also be reduced compared to the complicated designs of known re-tensionable and non-re-tensionable eccentric screw pumps and known check valve devices at the stator end area of eccentric screw pumps.
• stator jacket rotor head part rear surface Sector-like recess Sector section-shaped through opening rotor head part center axis pressure pipe hole start area hole end area second rotor head part

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Rotary Pumps (AREA)
• Details And Applications Of Rotary Liquid Pumps (AREA)
• Reciprocating Pumps (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7980896

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (6)

• 2003
  • 2003-03-12 DE DE20304292U patent/DE20304292U1/de not_active Expired - Lifetime
• 2004
  • 2004-03-11 DE DE502004000924T patent/DE502004000924D1/de not_active Expired - Lifetime
  • 2004-03-11 DE DE112004000856T patent/DE112004000856D2/de not_active Expired - Fee Related
  • 2004-03-11 WO PCT/DE2004/000538 patent/WO2004081385A1/fr active IP Right Grant
  • 2004-03-11 CN CNB2004800106462A patent/CN100429402C/zh not_active Expired - Fee Related
  • 2004-03-11 AT AT04719362T patent/ATE332443T1/de not_active IP Right Cessation
  • 2004-03-11 EP EP04719362A patent/EP1601875B1/fr not_active Expired - Lifetime
  • 2004-03-11 ES ES04719362T patent/ES2268641T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events