DE1223988B - Rotary piston machine - Google Patents

Description

Rotary piston machine The invention relates to a rotary piston machine with a fixed shaft, which has an eccentric, fixed, cylindrical, carries a stator core deviating from the circle in cross-section, and one centered around the shaft rotatable, consisting of a circular cylindrical, hollow drum and two lateral bearing covers existing housing, with at least two diametrically opposed to each other in slots of the drum opposite working slide, hereinafter also referred to as "shovels" are radially movable, the crescent-shaped working space between the drum and subdivide the stator core into displacement cells that change during rotation, which the conveying or working medium through a longitudinal bore in the shaft and corresponding radial channels in the stator core is supplied and discharged, two each other Opposing working slides always have a constant distance from one another.

In a known machine of this type, two are diametrically opposed to each other Opposed working slide arranged radially movable in slots of the drum, the constant distance between the two slides from each other by a relative wide ring is guaranteed, which is arranged at a radial distance around the drum is and on the radially outer narrow sides of the working slide or on extensions same rests. Because this ring is not very stiff, but rather as resilient is to be seen, it could be possible that under the action of centrifugal force the working slide, the ring is slightly deformed and thus the working slide no longer fit sufficiently sealingly against the circumferential surface of the stator core. Of the The cross-section of the Stator core deviating from the circular shape, roughly corresponding to a cardioid, also called "Conchoid of Limaion", which is so determined that it is more rigid Connection of the working slide with each other, their contact surfaces with the stator core always have the same distance from each other. But this is only possible if only two working slides are provided. In one surrounding the rotating drum outer housing must be provided and a special cavity for this ring this outer housing must be specially designed so that the ring is used at all can be, which results in a complex construction.

In another known machine of a similar type, but in which ten working slides are arranged in the rotating drum so that they can move radially, are two relatively stiff stator concentric to the circular cross-section Rings are provided in special recesses of the drum body, which on the radial on the outer narrow sides of the working slide. The support point of each ring on a working slide shifts by a small amount during the Drum circulation, and the distance between two opposing working slides fluctuates in a certain small area. If the rings are supposed to be stiff, they will relatively difficult. If the machine still has an external fixed housing has, there is a particularly unfavorable ratio of the largest outer diameter of the machine to the outer diameter of the effective work area.

Also known is a rotary piston machine of the type specified above Art with a sickle-shaped working space and radially displaceable in the circumferential housing Working slides, which counter the centrifugal force acting on them by with Swing weights provided, in the surrounding housing mounted levers on the fixed Stator core are pressed. The individual working slides or pistons are included completely independent of each other, and each individual piston depends on its Plant against the drum of several, through joints to each other connected parts, on their storage when rotating the housing considerable forces be exercised. Since the displacement of these pistons is contrary to the occurring and Frictional forces that cannot be safely controlled are a flawless one The pistons are in contact with the drum and the rotary piston machine can therefore work properly very questionable.

In another known rotary piston machine, two are diametrically opposed opposite working slide radially movable in slots of a fixed one Cylinder wall arranged. The inner edges of the working slide touch the Outer circumferential surface of a cylindrical rotary piston, which is like an eccentric rotates in the cylinder cavity. Constructively complex rods with one ring piece each to bypass the rotor shaft are arranged on both sides of the delivery chamber and to larger part stored in the end walls of the cylinder or guided to the two To connect working slide with each other without coming into contact with the conveying chamber come. Unwounds that protrude far beyond the outer circumference of the cylinder At the ends of the rods there are stamps attached, which the working slide on their radial Connect the outer edges with the rods. In terms of design effort and size is not saved.

In a known machine with a drum-shaped cylindrical Rotor, which, eccentrically arranged therein, in a fixed cylindrical housing rotates, two pairs of diametrically opposed plate-shaped Working slides, which with their outer edges the inner circumferential wall of the conveying chamber touch, guided radially movable in slots of the rotor. The two working slides each pair are rigidly connected to a side, a corresponding recess for the Connection piece containing shaft to a unit which is C-shaped in side view connected to each other and are moved as a whole together with the blades.

In order to avoid the disadvantages of the known constructions mentioned and a structurally simple connection between two opposite ones To create work slides, which ensures a constant distance and at the same time contributes to the low-friction guidance of the slide, according to the invention proposed that in a rotary piston machine of the type mentioned the one another opposite working slide of a pair to form a C-shaped body a rigid connecting piece are connected, - the two each from a working slide inwardly protruding prismatic slides corresponding in their strength to the working slides Arms and a ring or half-ring connecting these arms in the area of the shaft consists, and that the prismatic arms in corresponding radial grooves of a bearing cover of the rotating housing are sealingly guided. The non-rotating, rigid Blade pairs connected to one another in a C-shape are therefore always secure and sealing against the drum surface, and the bearing cover also serves to further Guide and preferably also for sealing the blades or the associated Rotary piston working areas.

To improve the seal, the stator core facing Ends of the working slide can be provided with recesses, in which semi-cylindrical Sealing shoes are used which have sealing surfaces adapted to the stator core. The sealing shoes can swivel and move in the recesses so the curvature of the surface of the stator core also in the positions of the working slide adapt where the working slide or blades themselves do not provide a sufficient seal would give. It is advantageous that the sealing surfaces slide on the stator core to shape the sealing shoes so that practically a surface seal, at least but a multiple line seal emerges. In the latter case, the sealing surfaces contain the sealing shoes have recesses that are suitable for holding lubricating fluid are.

Very favorable geometrical relationships in the cross-section through the machine arise when the eccentricity, i.e. H. the ratio of the distance between the centers from housing and stator core to half the distance between the opposing working slide is equal to or less than 0.2. With this choice of eccentricity are the differences due to the shape of the stator core deviating from the circular shape in cross-section conditional curvatures of its surface are relatively small, and the sealing surfaces the sealing shoes can be better adapted to them.

The subclaims contain further details of the invention marked.

The invention is described below with reference to the drawing explained in more detail on the basis of exemplary embodiments. It shows F i g. 1 to 3 an embodiment of a rotary piston machine according to the invention, wherein F i g. 1 shows a section along the line I-I in FIG. 2, fig. 2 a section after the line II-II of FIG. 1 and FIG. 3 individual parts in perspective Illustration shows F i g. 4 shows a working slide with a pivotable sealing shoe in a larger representation, -F i g. 5 shows a simplified excerpt from FIG. 1 with a further detail, FIG. 6 shows a simplified longitudinal section through a Variant of a rotary piston machine according to FIGS. 1 to 3, FIG. 7 to 11 five different embodiments of the sealing surfaces of the pivotable sealing shoes in a larger representation.

In the F i g. 1 to 4, 1 denotes a fixed cylindrical outer housing, to which a foot 2 belongs and which is provided on the right-hand side with a closure cover 3 which has an inwardly directed hub 4. With 5 screws (only one visible in FIG. 1) for fastening the cover 3 on the housing part 1 are designated. The housing part 1 is provided with an inwardly directed hub 101 . Two shaft parts 8, 9 are rigidly connected to the eccentrically mounted stator core 10, also called “piston”. The left shaft part 8 is fastened in the hub 101 by means of the wedge 6, the thread 7 and the nut 102, and the piston 10 is thus also held in place. In the shaft part 8 there is a channel 11 which opens out at 111 on the circumference of the piston 10. The shaft part 9 contains a channel 12 which opens out at 13, that is to say on the side of the piston 10 opposite the opening 111 , on the circumference of the latter. For the most part, the channels 11 and 12 are formed by longitudinal bores in the shaft pieces 8 and 9. A cylindrical inner housing 14 is arranged around the piston 10, the axis of rotation of which coincides with that of the shaft parts 8 and 9 and which is rotatably mounted on the shaft 8, 9 with its closure or bearing caps 15 and 16 and its hubs 17 and 18, wherein the hub 18 of the right bearing cover 16 is also supported in the hub 4 of the cover 3 of the outer housing 1. The wedge 19 on the hub 18 is used to wedge a (not shown) belt pulley. The hub 18 can also be coupled directly to a drive motor, a stuffing box not being absolutely necessary.

The cylindrical housing 14 has four grooves 20, 21, 22, 23 evenly offset from one another by 90 °, which are all at the same distance from the axis of the housing. Four working slides or blades 24, 25, 26, 27 are arranged in these grooves so as to be radially movable. In the ends of the blades facing the stator core or piston 10, there are recesses into which sealing shoes 28, 29, 30, 31, e.g. B. made of metal or plastic, which can make pivoting movements into the recesses about an imaginary axis parallel to the housing axis. As shown in FIGS. 1 to 3, the opposing blades 24, 26 and 25, 27 are each rigidly connected to one another with a ring 32 or 33, prismatic arms 32 a (or 33 a, not shown) as connecting pieces of the working slide or Shovels with rings 32 and 33 are used. The central planes through the blades pass through the axis of rotation of the housing 14 in every position. The ring 32 has an elongated hole 32 'through which the shaft part 9 passes. The ring 33 is designed in the same way. An annular groove is designated by 34, which connects the air spaces located behind the blades 24, 25, 26, 27 in a communicating manner with one another for pressure equalization. Different channels are used for the supply of the lubricant. This is fed at 35 a (Fig. 1), passed through the channels 35 b to the bearing points of the two shaft parts 8, 9 and also to the sliding surfaces between the piston 10 and the housing cover 15, whereby part of the lubricant in the Annular channel 35c (FIG . 1, 3) arrives and from there through the channels 35d of the cover 15 to the bores 35 (FIG. 1, 2, 4) of the pivotable sealing shoes. As a result of the centrifugal effect, the lubricant finally reaches the outer peripheral sides of the channels and from there through the opening 35 e in the cover 15 to the annular channel 35 f (FIGS. 1, 3) of the hub 17, where it leaves the machine at 35 g. The oil path described is shown in FIG. 1 indicated by arrows. To facilitate the production of channels, e.g. B. the groove 34 in the rotating housing, this can be composed of an outer jacket 14 a and an insertable inner part, as shown in FIG. 3 is shown. The inner part consists of four ring sectors 14 b, between the radial surfaces of which the grooves 20, 21, 22 and 23 are formed. In the example shown, the space between the rotating housing 14 and the stationary piston 10 is divided into four mutually sealed chambers 36, 37, 38, 39 by the blades 24, 25, 26, 27 and their sealing shoes 28, 29, 30, 31. Instead of four blades 24, 25, 26, 27, only two or more than four blades can also be present.

In Fig. 4 shows a working slide (shovel) with the pivotable sealing shoe in a larger representation. The blade 27 slides in the groove 23 arranged in the housing 14. B. oil, the channels 45 serve to the sealing surfaces 41 of the insert 31. The sealing shoe 31 itself is pivotable in the recess 42 of the blade 27.

In the case of the in FIG. The embodiment of the sealing shoes 31 shown in FIG. 4, the sealing surfaces of these sealing shoes or inserts 41 (FIG. 4) are continuously curved, for example shaped like a circular cylinder. Since the insert 31 (FIG. 4) can be pivoted in the recess 42 of the blade 27, it adapts itself as far as possible to the curvature of the surface of the piston 10 by pivoting, so that between the piston surface and the sealing surface of the insert practically at least a partial surface seal, i.e. at least a multiple line seal, comes about. The blade 27 has channels 45 for lubricating the sealing or sliding surface 41. These channels 45 are connected to the lubrication channel 35 , which also has an opening in the sealing surface 41 of the insert 31, so that the supply of the lubricant to the sliding surface 41 is secured.

The sealing surfaces of the sealing shoes or inserts can also Have depressions. Such embodiments are shown, for example, in FIGS G. 7 to 11 shown. In the embodiment according to FIG. 7 is the sealing surface 51 of the insert 50 is formed in a wave-like manner. The wave crests form an envelope surface, which is adapted to the piston surface, so that in each case at least some of the wave crests slide on the piston surface so that a multiple line seal is ensured and a similarly good seal as in the case of a surface seal according to FIGS. 4 and 5 is achieved. Show other shapes of sealing surfaces with indentations the F i g. 8 to 11. In Fig. 8 there is a triangular recess 51. When using 50 of the embodiment according to FIG. 9 are the recesses as grooves 51 formed. In the embodiment according to FIG. 10, the sealing surface has a domed shape, with the domed peaks sliding on the piston surface delimit an envelope surface, so that at least some dome mountains each at the same time slide on the piston surface and thus ensure a multiple line seal. The F i g. 11 shows an embodiment in which triangular depressions in zigzag arrangement are present. The sliding on the piston surface Here, too, edges are arranged in such a way that several such edges at the same time slide on the piston surface and result in the multiple line seal. The rest Structure of the blades in FIGS. 7 to 11 corresponds to FIG. 3. In the F i G. 8 to 11 is, for the sake of simplicity, only that in FIG. 7 framed in dash-dotted lines Part shown.

The advantage of the embodiments according to FIGS. 7 to 11 is that the lubricant is held particularly well between the piston surface and the sealing surfaces of the inserts and is only thrown away in small quantities by pressure differences between each two chambers. It can also be advantageous in terms of production technology to give the stator core or piston 10 a small amount of play in the axial direction. The seal between the end face of the piston and the bearing cap 15 can then be achieved by means of a conical, ie frustoconical piston ring which is slotted at one point, preferably on the suction side. Such an embodiment is shown schematically in FIG. 5 shown. The piston 10 has a conical recess 61 on the side facing the bearing cover 15. The piston ring 62 is kept somewhat larger, slotted at 62 'and inserted into the conical recess 61, so that the piston ring 62 provides a sufficient seal thanks to its spring force. An additional advantage is that the piston ring 62 automatically adjusts and readjusts during operation.

For more stable guidance of the blades, the grooves 20, 21, 22, 23 provided in the housing 14 are continued in the side bearing cover 16 and the axial length of the blades is selected so that they protrude into the grooves of the closure cover 16 in a sealing manner. The prismatic arms of the working slide or blades 24, 25, 26, 27 are, as seen in a cross section through the machine, as wide or thick as the working slide itself and fill the grooves in the bearing cover 16 in a sealing manner over a certain length. In Fi g. 6 shows an embodiment in which the blades are designed in two parts in the direction of the axis of rotation of the housing, the right and left blade parts 24a, 24b, 26a, 26b butting against one another flush. The blade parts 24b and 26b -forming -with their prismatic arms 32 b and the ring 32 d as a C-shaped body as the blade parts, not shown, 25 b and 27 b with their arms and the ring d 33rd The same applies to the right blade parts 24 a, 26 a etc. according to FIG. 6. Parts 8, 9 and 10 in FIG. 6 correspond to the same parts in FIGS. 1 and 2. The cylindrical housing 14 has two bearing caps 16 a and 16 b . 7e two diametrically opposed blades 24 a, 26 a, 25 a, 27 a, 24 b, 26 b, 25 b, 27 b are therefore 32 a by their prismatic arms; 32 b and connected by the four rings 32 c, 33 c, 32 d and 33 d as rigidly as the blades 24, 26, 25, 27 with the arms 32 a and the rings 32, 33 in the embodiment according to FIG . 3.

Because of the eccentricity between piston 10 and housing 14 on the one hand and the rigid connection between two diametrically opposed blades provided with sealing shoes or inserts on the other hand, the cross-section of the stator core or piston 10 deviates somewhat from the circular shape in a known manner must, if in every position of the housing between the inserts and the piston surface a perfect seal, in particular practically a surface seal or a multiple line seal, is to exist. In the embodiment according to FIG. 2 is e.g. B. the horizontal piston diameter Db slightly larger than the vertical piston diameter Da. The difference between these two quantities Da and Db is so small that it is not reflected in the drawing.

The particularly useful shape of the piston cross-section results in connection with the eccentricity between piston and housing and the choice of Shape for the sealing surfaces of the inserts. Through this mutual adjustment becomes achieved that in every blade position practically a perfect seal between the chambers is reached. Since the curvature of the piston surface is not constant, thus results from given curvature ratios of the sealing surfaces of the inserts between these sealing surfaces and the piston surface as the housing rotates 14 an alternating game. About the already mentioned surface seal that is as inexpensive as possible or multiple line seals in every position of the blades or inserts To ensure, it is advantageous to reduce the curvature of the sealing surfaces of the sealing shoes or inserts corresponding to the smallest curvature of the circumferential surface of the stator core or piston 10 to be selected. The inserts 28, 29, 30, 31, 50 must be over the radial the inner edges of the working slide protrude somewhat, as is the case in particular from the F i g. 3 and 4, so that only the sealing surfaces of the inserts with the piston surface come into contact and not parts of the working slide or shovels.

The operation of the in the F i g. 1 and 2 shown and described above is the following: The rotatable cylindrical housing 14 can be driven by the belt pulley seated on the hollow shaft 18 or directly. But it can also be coupled directly to the drive motor, not shown. From Fig. 2 it can be seen that the space between the piston 10 and the housing 14 is divided into four chambers by the four blades 24, 25, 26, 27 or their inserts 28, 29, 30, 31, the volume of which changes when the housing is rotated zoom in and out periodically. Through the channel 11 z. B. sucked in air. This is compressed in the chambers and expelled through the channel 12. The most complete possible sealing of the chambers from one another is ensured by the inventive design of the blades or their inserts. The machine can be used as a circulation or pressure pump, compressor, fan, gearbox, but also as a vacuum pump, as a motor and the like.

The main advantage of the rotary piston machine described results from the rigid connection of two diametrically opposed working slides or blades, as this reduces the centrifugal forces with respect to the piston surface of Pick up two diametrically opposed blades. This is a guarantee ensure that the blades or the sealing surfaces of their inserts always on the Rest on or slide on the piston surface. Doing so is kind of rigid Easy connection between two diametrically opposed ° working slides and avoids any unnecessary construction effort. The width of the blades resp. the use depends on the purpose of the machine. With machines for larger ones Pressures, e.g. B. compressors, the width of the blades or the inserts in general must be chosen larger than with machines for smaller pressures, z. B. blower, Circulation pumps, etc. Experiments have shown that in compressors and the like Machines shovels or inserts have proven to be particularly favorable, their width is at least equal to the stroke:

Claims (11)

Claims: 1. Rotary piston machine with a stationary shaft, which carries an eccentric, stationary, cylindrical stator core deviating from the circle in cross-section, and a housing which is rotatable around the shaft and consists of a circular cylindrical hollow drum and two lateral bearing caps, wherein in Slots of the drum at least two diametrically opposed working slides are radially movable, which subdivide the sickle-shaped working space between the drum and the stator core in displacement cells that change during the rotation and to which the conveying or working medium is fed through a longitudinal bore in the shaft and corresponding radial channels in the Stator core is fed and discharged, with two mutually opposite working slides always having a constant distance from one another, characterized in that the mutually opposite working slides (24 and 26; 25 and 27) of a pair form a C-shaped body through h a rigid connecting piece are connected, which consists of two each of a working slide (24, 26; 25, 27) inwardly projecting prismatic arms (32 a) corresponding in their strength to the working slide and a ring (32, 33) or half-ring connecting these arms in the area of the shaft, and that the prismatic arms (32 a) are in corresponding radial grooves of a bearing cover (16) of the rotating housing (14) are sealingly guided. 2. Machine according to claim 1, characterized. characterized in that the drum of the rotatable housing consists of an outer jacket (14a) and ring sector pieces (14b) inserted therein, between which the radial slots (20, 21, 22, 23) for the working slide (24, 26; 25, 27) are spaced ) remain. 3rd machine according to claim 1 or 2, characterized in that two pairs (24, 26; 25, 27) are provided by rigidly interconnected working slides. 4. Machine according to claim 3, characterized in that the prismatic arms (32a) and the connecting rings (32, 33) of both working slide pairs (24, 26; 25, 27) on the one side of the stator core (10) are located. 5. Machine according to one of claims 1 to 4, characterized in that the working slide ends facing the stator core (10) are provided with recesses into which semi-cylindrical sealing shoes (28 to 31, 50) are inserted, the sealing surfaces adapted to the stator core (10) exhibit. 6. Machine according to claim 5, characterized in that that the surfaces of the sealing shoes (28 to 31) sliding on the stator core (10) 50) are adapted to the smallest curvature of the surface of the stator core. 7. Machine according to claim 5 or 6, characterized in that the sealing surfaces of the sealing shoes (28 to 31, 50) have recesses (51). B. Machine according to one of the claims 1 to 7, characterized in that for sealing between the end face of the Stator core (10) and the face of the not with grooves for receiving the prismatic Arms (32a) of the working slide provided bearing cover (15) into a corresponding one Recess engaging, possibly slotted and conical piston ring (62) is provided. 9. Machine according to one of claims 1 to 7, characterized in that on one side or by half of a common stator core (10) two pairs of rigidly interconnected working slides (24 a, 26 a; 25 a, 27 a) and on the other side or around the other half of the stator core (10) also two pairs of rigidly interconnected working slides ( 24b, 26b; 25b, 27b) are arranged, which like the working slides (24a, 26a; 25a, 27a) one side are connected by prismatic arms (32 a) and rings (32 c, 33 c; 32 d, 33 d) to form rigid C-shaped bodies, with one working slide of one group (24a to 27a). abuts against a working slide of the other group (24b to 27b) and in alignment therewith in the axial direction, so that both abutting working slide (z. B. 24 a and 24b) are complementary to a longer working slide. 10. Machine after one of claims 1 to 9, characterized in that between the outer jacket (14a) and the annular sector pieces (14b) of the rotatable housing (14) have at least one annular groove (34) is provided. 11. Machine according to one of the preceding claims, characterized in that the eccentricity, ie the ratio of the distance between the axes of rotation of the housing (14, 15) and stator core (10) to half the distance between the opposing working slide (24, 26; 25, 27; 24a to 27a; 24 b to 27 b) is equal to or less than 0.2. Considered publications: German Patent Specifications Nos. 197175, 292 771, 415 856, 554 827, 578 661, 591076; Austrian patent specifications No. 79 069, 103125; Swiss Patent No. 137 829; French Patent Nos. 594 915, 673 278, 675 645; British Patent No. 435,990; U.S. Patent Nos. 1409,986, 1461998, 1952 834, 2,015,307, 2149,337, 2,232,951, 2,280,272, 2,293,119, 2,359,903, 2,491,670.