ROTARY BLADE MACHINE

Abstract: A rotary blade machine, for example, a blades pump mainly comprising a rotor (1) having outwardly opening, axial slots (3), a blade (7) slidably arranged in each slot and a stator surrounding the rotor with the blades and having inlet and outlet ports, wherein in an axial sense the blades project at both ends beyond the rotor into a chamber formed by a re-entrant side wall part (10) of the stator, said chamber accomodating a shut-off body (12) associated with each blade, in order to prevent leakage along the blades, particularly along their side edges.

Description: - / - Rotary blade machine. The invention relates to a rotary blade machine, for example, a blades pump mainly comprising a rotor having outwardly opening axial slots and blades each slidably arranged in each slot and a stator surrounding the rotor with the blades and having inlet and outlet ports. The invention has for its object to improve the seal across the moving blades in a rotary blade machine of the kind set forth in the preamble. In the successive com¬ partments between two blades different pressures will pre- vail so that leakage will occur along the blades, in parti¬ cular along the sides thereof. The rotary blade machine embodying the inven¬ tion is distinguished in that in an axial sense the blades project at both ends beyond the rotor into a chamber formed by a re-entrant sidewall part of the stator, said chamber accomodating a shut-off body associated with each blade. By this shut-off body any leakage along the side and top edges of the blades is avoided since this shut-off body closes the. gap between each blade and the stator. In one embodiment the shut-off body is construc¬ ted in the form of a filling body comprising eight wear- resistant blocks interconnected by a flexible intermediate layer. The flexible intermediate layer serves as a spring element to urge the blocks against the slot. One of the additional advantages of the filling bodies in this embodiment is that the blades furthest slipped out of the rotor remain in the desired position, that is to. say, they will not tilt. This is furthered by urging the inwardly slipped blades against one side of the unavoidably larger slot in the rotor, which can be performed in accordance with the invention by providing relief grooves at each blade at least on the low-pressure side. According to a further embodiment the shut-off. body grips around the side edge of the blade, whilst the bodies are resiliently interconnected so that a single ring is obtained, which simplifies mounting and manufacture. According to a further aspect the shut-off body is connected with a strip extending at the side of the blade. In order to facilitate mounting of the rotor with the blades in the stator, the wall of the chamber in the stator facing the rotational centre as well as the edge . of the projecting blade end have a locating rim so that in addition the leakage gap is reduced. In order to minimize drop of pressure across the blades a great number of blades are distributed in known manner along the circumference of the rotor. This means that a large number of grooves have to be made in the rotor, which involves problems in the manufacture of solid rotor bodies. In order to eliminate this drawback the inven¬ tion proposes to build up the rotor body by means of plates, each plate being punched in the desired shape with slots in a star-shaped array from a basic plate. By providing slots of relatively different widths in the plates the relief grooves can be formed in the rotor. In order to ensure small tolerancesof the stator dimensions the stator embodying the invention is formed by an outer ring having inlet and outlet ports and two bearing plates comprising the chamber. Moreover the materials of the various component parts can now be appropriately chosen. These stator parts are enclosed in a housing. Such a construction is particularly suitable for establishing a communication between two diametrically opposite inlet and outlet channels respectively in the stator ring by means of two distribution channels arranged in the housing so that a uniform load on the rotary shaft of the machine is ensured. This implies that the filling bodies between the blades have a long lifetime owing to the minor deformations. The invention will be described more fully with reference to an embodiment. The drawing shows in Fig. 1 an axial longitudinal sectional view of the machine embodying " the invention, Fig. 2 a sectional view taken on the line II-II in Fig. 1 , Fig. 3 a perspective view of part of the rotor in which blades are arranged and of part of the stator. Fig. 4 a cross-sectional view of a blade arran- ged in a slot of the rotor. Fig. 5 a perspective view of the stator ring. Fig. 6 an elevational view like Fig. 3 of a second embodiment. Fig. 7 a cross-sectional view of a blade arran- ged in a slot in the embodiment shown in Fig. 6, Fig. 8 a perspective view like Fig. 3 of a third embodiment. Figs. 9a and 9b a side elevation and a plan view respectively of a shut-off strip used in said third embo- di ent. The rotary blade machine shown in the Figures comprises a rotor 1 formed by a plurality of annular plates 2 (see Fig. 2) each having a crown of slots 3 at the outer circumference. Along the inner circumference a toothing 4 is arranged to co-operate with a spline shaft part 4 of the rotary shaft 6. The slots 3 in the plates 2 constitute in the mounted state of the rotor axially extending slots, each of which receives a radially slidable blade 7. Around the rotor with the blades 7 is arranged a stator comprising a ring 8 having two head plates 9, which form at the same time a bearing ring for the shaft 6. The inwardly directed sidewalls of the plates 9 are inwardly bent over at 10 and the blades 7 are provided at both ends with protruding parts 11. The outer edge of the protruding part 11 is complementary to the cross-^^ctional shape of the sidewall of part 9. In the space between two blades 7, the outer plates of the rotor 1 , the re-entrant sidewalls of the head plates 9 and the inner wall of the ring 8 a filling body 12 is arranged as a shut-off member, (see Fig. 3) . This filling body 12 comprises eight wear-resistant blocks of suitable shape, between which a layer of flexible material is sand¬ wiched. This intermediate layer 13 ensures a constant pres¬ sure of the blocks on the slots between the relatively moving parts. Moreover deformation of the filling body 12 is possible during the inward and outward movements of the blades with respect to the rotor, during which movements the dis¬ tance between the blades increases and decreases respec¬ tively. The rotor and the stator are arranged in a housing comprising a central ring 14 and two head plates 15 f stened to one another by bolts 16. The central ring 14 has an inlet port 17 (see Fig. 1) and an outlet port 18 off-set through 90° indicated in Fig. 2 by broken lines. The inlet port 17 and the outlet port 18 commu¬ nicate with the inlet port 1 in the stator * ring 8 and the outlet ports 20 thereof respectively (see Fig. 5) . In the stator ring 8 the outlet and inlet ports are respectively located diametrically opposite one another and they communicate with one another by an annular communi¬ cation channel 21 in each head plate 15. This channel is milled in annular form in the head plate and subsequently closed by a sealing plate 22 (see Fig. 1). Through registering openings 23, which are also provided in the side plates of the stator, the channels 21 communicate with the ports in the stator ring 8. A sealing ring 24, which bounds sector-shaped regions around the inlet and outlet ports is arranged between each plate 9 and the neighbouring head plate 15. Each sector communicate with a port through the passage 23 or the channel O PI 25. The purpose is to transfer the pressure at the outlet port to the outer side of the plate 9 so that owing to the larger outer surface said pressure has an inwardly directed pressure resultant so that ' the gap between the plate 9 and the rotor with blades is automatically minimized. The size of the intermediate sectors between the port sectors of the seal 24 depends on the desired value of the pressure resul¬ tant. These sectors can communicate through a bore 25 in the plate 9 with a zero line (not shown) . The sectors between the seal are filled out by filling plates 26, which prevent deformation of the seal. The edge of the protruding end of each blade 7 as well as the re-entrant wall of the chamber in the side plate are bevelled or rounded off (see Fig. 1 or 3, respectively), which provides a pilot edge to facili- tate mounting. In order to minimize the fluid to be expelled from the space in the rotor below the blade 7, the blades are constructed as thin as possible. Tilting of the blades in the relatively wide slots of the rotor 1 is avoided by providing relief grooves 27 on the low-pressure side of the blade 7, which is further described with reference to Fig. 4. In the case of a pump the blade will move in the direction of the arrow P1 so that a high pressure is created on the front side of the blade 7. The grooves 27 on the rear side ensure uniform evacuation of fluid out of the slot be¬ tween the low-pressure side and the adjacent side wall of the groove in the rotor 1. The blade 7 will therefore smoothly engage the rear wall of the slot in the rotor 1 , whilst the straight position is imparted through the filling bodies 12 to the vanes lying further outwards so that tilting is avoided and hence a quiet run is obtained. Since in this case the machine can be used in the direction of rotation opposite the arrow P1, the blades are also provided with grooves 27' on the opposite side. Figs. 6 and 7 show an alternative, second embodi¬ ment of the shut-off bodies. The same reference numerals designate corresponding parts in the Figures described above. The difference resides in the shut-off bodies 12* formed into a ring 60 and having each a radial groove 61 for receiving the head rim of a blade. Between the bodies 12' is arranged a U-shaped spring body 62. The bodies 12' and the spring bodies 62 may be made from the same material and be shaped into the desired form for example by etching. This has the advantage that each body 12' has a great freedom of movement and can thus match any desired position. This results inter alia in the use of conventionally shaped blades 7, which may be slightly tilted in the slot (see Fig. 7) , which promotes a satisfactory seal at the upper rim 64 of the slot as well as a correct hydraulic pressure P on the lower side of the blade. The supply of fluid to the slot space below the blade is ensured through the grooves 27" in the rotor body. The grooves 27" are formed in this case by a locally broader incision in a rotor plate than in the adjacent plates. It should be noted that the pilot rim 63 is straight. Referring to Figs. 8 and 9 the shut-off body 12" is connected on the underside with a strip 70 extending along the blade 7. In the embodiment shown the second blade 7 r is disposed on the other side of the strip. The strip is provided with ridges 71 so that channels are formed between the strip and the blade to enable fluid transport during the inward and outward slide of the blade system into and out of the slot respectively. Also in this embodiment the blades are provided with the relief grooves 27. The invention is not limited to the embodiments described above; in particular the filling pieces 12 may have a different shape. In specific structures a filling piece of flexible, wear-resistant material, for example, a synthetic resin may be conceived as a single cast or spray-cast unit. The ends of the blades 7 may have any desired form, whilst the blades may occupy another position than the radial one in the rotor. They may be in draggin or protruding positions. The machine shown here as a pump may as well ^ -be— a motor.

Claims: C A I M S 1. A rotary blade machine, for example, a blades pump mainly comprising a rotor having outwardly opening, axial slots, a blade slidably arranged in each slot and a stator surrounding the rotor with the blades and having inlet and outlet ports characterized in that in an axial sense the blades project at both ends beyond the rotor into a chamber formed by a re-entrant side wall part of the stator, said chamber accomodating a shut-off body associated with each blade. 2. A rotary blade machine as claimed in claim 1 characterized in that the shut-off body is constructed in the form of a filling body consisting of eight wear-resistant blocks interconnected by a flexible intermediate layer. 3. A rotary blade machine as claimed in claim 1 characterized in that the shut-off body grips around the end rim of the blade, the bodies being joined to one another to form a ring. 4. A rotary blade machine as claimed in claim 3 characterized in that a U-shaped spring body is integrally connected with every two neighbouring shut-off bodies. 5. A rotary blade machine as claimed in claim 1 characterized in that the shut-off body is connected with a strip extending along a blade. 6. A rotary blade machine as claim in claim 5 characterized in that the shut-off body and the strip are made from elastic material. 7. A rotary blade machine as claimed in claim 5 or 6 characterized in that the strip is provided with channels for fluid transport. 8. A rotary blade machine as claimed in claims 1 to 7 characterized in that the wall of the chamber facing the centre of rotation and the edge of the protruding blade end constitute a pilot edge. 9. A rotary blade machine as claimed in claims 1 to 8 characterized in that each blade has grooves on one side or on both. 10. A rotary blade machine as claimed in any¬ one of the preceding claims characterized in that the rotor body is formed by plates. 11. A rotary blade machine as claimed in claim 10 characterized in that the relief grooves in the rotor are formed by providing incisions of relatively different widths in the rotor plates. 12. A rotary blade machine as claimed in any¬ one of the preceding claims characterized in that the stator comprises an outer ring having inlet and outlet ports and two bearing plates enclosing the stator and arranged in a housing. 13. A rotary blade machine as claimed in claim 12 characterized in that the outer ring has diametrically opposite inlet and outlet ports respectively and the housing has an inlet opening and an outlet opening respectively, each of them communicating through a distribution channel with the inlet and outlet ports respectively of the stator ring. 14. A rotary blade machine as claimed in claims 12 and 13 characterized in that a sector-shaped seal is arranged between the bearing plate and the housing around the ports,the sector communicating with the port channel. OM?I

Inventors: BAGHUIS LUDOVICUS HENDRIKUS, BAGHUIS, LUDOVICUS, HENDRIKUS
Applicants: MULLEKOM INNOVATION B V VAN, VAN MULLEKOM INNOVATION B.V.
Application year: 1984
Main classification: F01C21
IPC codes: F01C1, F01C19, F01C21, F03C2, F04C2