Abstract
A rotary piston compressor for compressing gas, in particular carbon dioxide, in which a side wall face of a housing side wall and a respective planar sealing face of a respective housing cover enclose a working chamber and a rotary piston is rotatably mounted in the working chamber on an eccentric. A respective planar-seal receiving channel is formed in the piston bases of the rotary piston and a planar seal is arranged in each of the planar-seal receiving channels. To press the seal surface of the respective planar seal against the respective planar sealing face, lateral-surface openings in the piston lateral surface of the rotary piston have a pressure-transmitting connection to the respective planar-seal receiving channel via pressure leadthrough lines, formed inside the rotary piston and each open into the respective planar-seal receiving channel on a side of the respective planar seal facing away from the seal surface.
Claims
1. A rotary piston compressor for compressing gas, the rotary piston compressor comprising: a working housing; a rotary piston; the working housing has a housing side wall and two housing covers arranged on oppositely situated sides of the housing side wall; a side wall face of the housing side wall and a respective planar sealing face of the respective housing cover enclose a working chamber arranged in the working housing; an eccentric on which the rotary piston is rotatably mounted in the working chamber; a gas inlet for introducing the gas to be compressed into the working chamber; a gas outlet with a pressure-relief outlet valve for discharging the compressed gas from the working chamber; the rotary piston has two piston bases, which face toward a respective one of the planar sealing faces of the housing covers, and a piston lateral surface which faces toward the side wall face of the housing side wall; a respective planar-seal receiving channel is formed in the piston bases; and a planar seal is arranged in each of the planar-seal receiving channels, the planar seals each have a seal surface for contacting one of the planar sealing faces of the housing covers; wherein to press the seal surface of the respective planar seal against the respective planar sealing face, lateral-surface openings are formed in the piston lateral surface of the rotary piston, the lateral-surface openings have a pressure-transmitting connection to the respective planar-seal receiving channel via pressure leadthrough lines, which are formed inside the rotary piston and each open into the respective planar-seal receiving channel on a side of the respective planar seal that faces away from the seal surface.
2. The rotary piston compressor as claimed in claim 1, wherein the pressure leadthrough lines are at least one of: tubular, formed as a bore, or formed as a sequence of bores inside the rotary piston that lead into one another.
3. The rotary piston compressor as claimed in claim 1, wherein the lateral-surface openings are formed in the piston lateral surface at a distance from the piston bases.
4. The rotary piston compressor as claimed in claim 1, wherein the planar seals are each injected in the respective planar seal receiving channel as an injection molded part, or the planar seals are each printed in the respective planar-seal receiving channel as a 3D printed part, or in planar seals are each pressed in the respective planar-seal receiving channel as a molded pressed part.
5. The rotary piston compressor as claimed in claim 1, wherein the planar seals are each prefabricated as an insert part and inserted in the respective planar-seal receiving channel.
6. The rotary piston compressor as claimed in claim 1, wherein the pressure leadthrough lines are each covered by a cap in a region of a opening thereof into the respective planar-seal receiving channel.
7. The rotary piston compressor as claimed in claim 1, wherein the planar seals are intrinsically each formed in one piece in one of the planar-seal receiving channels in one of the piston bases.
8. The rotary piston compressor as claimed in claim 1, wherein the side wall face of the housing side wall has a completely or at least partially trochoidal form when viewed in a sectional plane parallel to the planar sealing faces of the housing covers.
9. The rotary piston compressor as claimed in claim 1, wherein the rotary piston has two or more corner regions.
10. The rotary piston compressor as claimed in claim 9, wherein the piston bases are each delimited by a boundary line in a region between two respective ones of the corner regions of the rotary piston, and the boundary lines are each in a form of an envelope of an array of trochoid curves.
11. The rotary piston compressor as claimed in claim 9, wherein a respective radial seal for sealing the rotary piston with respect to the side wall face of the housing side wall is arranged in the corner regions, and a respective elastic element, pointing toward the rotary piston, for pressing the respective radial seal against the side wall face of the housing side wall is integrally molded in one piece on the radial seals.
12. The rotary piston compressor as claimed in claim 11, wherein the planar seals each have contact faces for pressing the respective radial seal against the side wall face of the housing side wall.
13. The rotary piston compressor as claimed in claim 9, wherein the planar seals are each sealed, with respect to the planar-seal receiving channel that receives them, in the corner regions of the rotary piston on a side thereof facing away from the respective seal surface.
14. The rotary piston compressor as claimed in claim 1, wherein the planar seals are formed of a polymer or a polymer comprising at least one of a dry lubricant or reinforcing fibers.
15. The rotary piston compressor as claimed in claim 1, wherein the housing side wall and the housing cover each have a main body made of an aluminum alloy or a cast iron and a coating, which is applied to the main body to form the side wall face of the housing side wall and the planar sealing faces of the housing covers, and the coating comprises a nickel-phosphorus layer or an aluminum-oxide layer or a dry-film lubricating layer or a combination of at least two of these layers.
16. The rotary piston compressor as claimed in claim 9, wherein a respective radial seal for sealing the rotary piston with respect to the side wall face of the housing side wall is arranged in the corner regions.
17. The rotary piston compressor as claimed in claim 16, wherein the radial seals are formed of a polymer or a polymer comprising at least one of a dry lubricant or reinforcing fibers.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Further features and details of preferred configurations of the invention are explained by way of example in the following description of the figures on the basis of various embodiment variants of the invention. In the figures:
[0028] FIGS. 1 to 21 show illustrations relating to a rotary piston compressor according to the invention with a transmission ratio of 1:2, and modifications thereof;
[0029] FIGS. 22 and 23 show illustrations of a rotary piston compressor according to the invention with a transmission ratio of 2:3; and
[0030] FIGS. 24 to 39 show illustrations relating to a rotary piston compressor according to the invention with a transmission ratio of 7:6.
DETAILED DESCRIPTION
[0031] FIG. 1 shows an exploded illustration of the first exemplary embodiment of a rotary piston compressor 1 according to the invention. It is a rotary piston compressor 1 with a transmission ratio of 1:2. The rotary piston compressor 1 comprises a working housing 2 and a rotary piston 3. The working housing 2 in turn comprises a housing side wall 4 and housing covers 5 and 6 arranged on mutually opposite sides of the housing wall 4. In this exemplary embodiment, these components of the working housing 2 are connected to one another by the screws 37 and the nuts 38. However, this does not necessarily have to be the case, of course; other types of connection are also conceivable.
[0032] The side wall face 7 of the housing side wall 4 and the two planar sealing faces 8 and 9 of the respective housing covers 5 and 6 enclose the working chamber 10 arranged in the working housing 2. The rotary piston 3 is rotatably mounted on the eccentric 11 in the working chamber 10. In this first exemplary embodiment, the eccentric 11 sits on a drive shaft 30 for conjoint rotation. As can be seen in FIG. 2, this drive shaft 30 ends in a connecting journal 31, which protrudes from the rotary piston compressor 1 in the assembled state and to which a motor for rotating the drive shaft 30 and thus also the eccentric about the axis of rotation 60 can be connected. In this exemplary embodiment, the eccentric 11 is thus connected to the drive shaft 30 and also the connecting journal 31 for conjoint rotation, so that rotation of the drive shaft 30 about the axis of rotation 60 also automatically results in a corresponding conjoint rotation of the eccentric 11.
[0033] In this exemplary embodiment, an external toothing 32 is also connected to the drive shaft 30 for conjoint rotation. This external toothing 32 engages in an internal toothing 33, which is connected to the rotary piston 3 for conjoint rotation. This threaded engagement causes the rotary piston 3 to conjointly rotate in the working chamber 10 when there is corresponding rotation of the connecting journal 31 or drive shaft 33. The rotary piston 3 is rotatably mounted on the eccentric 11 in the working chamber 10.
[0034] The drive shaft 30 is rotatably mounted in the working housing 2 via the bearings 34 and the securing ring 36. The bearings 34 may be both ball bearings and plain bearings or the like. In the exemplary embodiment shown, the bearing 34 in the housing cover 5 is a ball bearing and the bearing 34 in the housing cover 6 is a plain bearing. However, this does not have to be the case, of course, and can also be configured differently.
[0035] A balance weight 35, which compensates the unbalance resulting from the eccentricity of the rotary piston 3, is mounted on the drive shaft 30 for conjoint rotation below the housing cover 6 and thus outside the working housing 2 In the exemplary embodiment shown, the working housing 2 is surrounded by an outer shell 39 of the rotary piston compressor 1. However, this also does not necessarily have to be the case, of course.
[0036] In the case of the rotary piston compressor 1 of this first exemplary embodiment, a gas inlet 12 for introducing the gas to be compressed into the working chamber 10 and also a gas outlet 13 with a pressure-relief outlet valve 14 for discharging the compressed gas from the working chamber 10. As explained below, this can be seen particularly clearly in FIGS. 3 to 6.
[0037] The rotary piston 3 has two piston bases 15 and 16 which face one of the planar sealing faces 8 and 9, respectively, of the housing covers 5 and 6 and a piston lateral surface 17 facing toward the side wall face 7 of the housing side wall 4. A respective planar-seal receiving channel 18 is in the piston bases 15 and 16. A planar seal 19 is arranged in each of these planar-seal receiving channels 18, wherein the planar seals 19 each have a seal surface 20 for bearing against one of the planar sealing faces 8 and 9 of the housing covers 5 and 6. This is explained in more detail on the basis of the subsequent figures. According to the invention, what is in any case also provided in the case of the rotary piston compressor 1 of this first exemplary embodiment is that, to press the seal surface 20 of the respective planar seal 19 against the respective planar sealing face 8, 9, in the piston lateral surface 17 of the rotary piston 3 there are formed lateral-surface openings 21, which have a pressure-transmitting connection to the respective planar-seal receiving channel 18 via pressure leadthrough lines 22, which are formed inside the rotary piston 3 and each open into the respective planar-seal receiving channel 18 on a side of the respective planar seal 19 that faces away from the seal surface 20. This is explained below, in particular on the basis of FIGS. 7, 8 and 11-13.
[0038] For the sake of completeness, it should be noted that the internal toothing 33 in the rotary piston 3 of this first embodiment is illustrated in FIGS. 1, 7 and 9, but is not shown in FIGS. 3 to 6, 11, 14 and 18. The fact that the internal toothing 33 is not illustrated in the stated Figures is a simplification purely for the drawing and does not mean that the internal toothing 33 is actually missing.
[0039] FIG. 2 is a side view of the assembled rotary piston compressor 1 of this first exemplary embodiment, with the sectional plane A-A being depicted. FIGS. 3 to 6 each show somewhat simplified sectional drawings relating to this sectional plane A-A, different positions of the rotary piston 3 during one revolution about the drive shaft 30 or its longitudinal axis being illustrated in order to explain the mode of operation of the rotary piston compressor 1. The arrow 42 shows the direction of rotation of the rotary piston 3 in the working chamber 10.
[0040] It can be seen in FIGS. 3 to 6 that, in this exemplary embodiment, the side wall face 7 of the housing side wall 4 has a completely trochoidal form when viewed in a sectional plane parallel to the planar sealing faces 8, 9 of the housing covers 5, 6. The rotary piston 3 has two corner regions 25. In these corner regions 25 there is a respective radial seal 26 for sealing the rotary piston 3 with respect to the side wall face 7 of the housing side wall 4. The piston bases 15 and 16 are each delimited by a boundary line 27, which is an envelope of an array of trochoid curves, in the region between two respective ones of the corner regions 25 of the rotary piston 3. The rotary piston 3 subdivides the working chamber 10 into a low-pressure side 40 and a high-pressure side 41 by means of its corner regions 25 and the radial seals 26 arranged there. On the low-pressure side 40, gas is introduced or sucked into the working chamber 10 through the gas inlet 12 as the rotary piston 3 rotates. On the high-pressure side 41, the volume of which decreases with increasing rotation of the rotary piston 3, the previously sucked-in gas is compressed, with the result that the gas pressure continuously rises on the high-pressure side 41 as the rotary piston 3 rotates. If the desired gas pressure or the desired compression of the gas on the high-pressure side 41 is reached, the pressure-relief outlet valve 14 opens, with the result that the compressed gas can flow out of or be discharged from the working chamber 10 through the gas outlet 13. Correspondingly setting or selecting a corresponding pressure-relief outlet valve makes it possible to set the extent to which the gas is compressed by the rotary piston compressor 1 before it flows away through the gas outlet 13. Briefly, it is thus possible to define or set the degree to which the gas is compressed in the rotary piston compressor 1.
[0041] FIGS. 3 to 6 show by way of example four different positions of the rotary piston 3 during one revolution and thus during the compression process depicted. This mode of operation of rotary piston compressors 1 is known per se and does not need to be explained further. The arrows 43 in FIGS. 3 to 6 depict the gas which flows in or is sucked in through the gas inlet 12 and is yet to be compressed. The arrows 44 depict the already compressed gas that flows out through the gas outlet 13.
[0042] FIG. 7 now shows a vertical section through the rotary piston compressor 1 of this first exemplary embodiment along a sectional plane BB, which is indicated in FIG. 2 and is vertical, or extends along the axis of rotation 60 of the drive shaft 30 and in the case of which the lateral-surface openings 21 and pressure leadthrough lines 22 essential to the invention are sectioned. FIG. 8 shows an enlargement of the region D from FIG. 7. In these two sectional illustrations, it can be clearly seen that a respective planar-seal receiving channel 18 is formed in each of the two piston bases 15 and 16, wherein there is a planar seal 19 in each of the planar-seal receiving channels 18. The planar seals 19 each have a seal surface 20, with which they rest against one of the planar sealing faces 8 and 9 of the housing covers 5 and 6, respectively, for sealing purposes. FIG. 8 illustrates in detail that in the piston lateral surface 17 of the rotary piston 3 there are formed lateral-surface openings 21, which have a pressure-transmitting connection to the planar-seal receiving channel 18 via pressure leadthrough lines 22, which are formed inside the rotary piston 3 and each open into the respective planar-seal receiving channel 18 on a side of the respective planar seal 19 that faces away from the seal surface 20. In preferred embodiments, like the one shown here, the pressure leadthrough lines 22 are tubular. Here, specifically, they are in the form of a sequence of bores inside the rotary piston that open out into one another. The lateral-surface openings 21 are arranged in the piston lateral surface 17 at a distance from the piston bases 15 and 16. The arrow 47 illustrating the direction in which pressure is applied depicts how the correspondingly pressurized gas in the working chamber 10 applies pressure to the planar seal 19 through the lateral-surface opening 21 and the pressure leadthrough line 19 on the side situated opposite the seal surface 20, whereby the seal surface 20 is pressed against the respective planar sealing face 8 and 9, respectively. This has the effect that the gas pressure in the working chamber 10 is used to press the seal surface 20 of the planar seal 19 against the corresponding planar sealing face 8 and 9. This makes it possible to achieve a very good seal even in the event of very high pressures in the working chamber 10. In the exemplary embodiment shown according to FIG. 8, there is a cap 24, which covers the pressure leadthrough line 22, in the region of the opening 23 of the pressure leadthrough line 22 in the planar-seal receiving channel 18. This cap 24 is designed such that it does not obstruct the transfer of pressure. When there is a corresponding buildup of pressure the pressure leadthrough line 22, gas can flow, expediently past the cap 24, into the planar-seal receiving channel 18 on that side of the planar seal 19 that is situated opposite the seal surface 20, in order to correspondingly press the seal surface 20 of the planar seal 19 against the respective planar sealing face 8 and 9.
[0043] As explained in the introduction, the cap 24 can in principle also be omitted. If, however, the planar seal 19 is, as realized here, injected in the planar-seal receiving channel 18 in the form of an injection molded part or printed in the respective planar-seal receiving channel 18 in the form of a 3D printed part, the cap 24 prevents inadvertent closing of the respective opening 23 when the planar seal 19 is being formed or produced.
[0044] FIG. 9 shows a section through the rotary piston compressor 1 of this first exemplary embodiment along the sectional plane C-C, which is depicted in FIG. 3 and extends through the corner regions 25 and the radial seals 26 of the rotary piston 3 that are arranged there. FIG. 10 shows an enlargement of the region E from FIG. 9.
[0045] What can be seen here first of all is how the radial seals 26 bear against the side wall faces 7 of the housing side wall 4 to seal the rotary piston 3. In order to generate the contact pressure necessary for the sealing, here two measures are taken. Firstly, an elastic element 28 facing the rotary piston 3 is integrally molded on the radial seal 26 and presses the radial seal 26 against the side wall face 7 of the housing side wall 4. Secondly, however, the contact faces 57 of the planar seals 19 also press the respective radial seal 26 against the side wall face 7. In FIGS. 10, 14 and 16, the elastic element 28 integrally molded on the radial seal 26 on the radial seal surface 49 is formed in the manner of an exposed leaf spring. FIG. 17 shows a variant of this in which the elastic element 28 is in the form of a corresponding bulge on that side of the radial seal 26 that is situated opposite the radial seal surface 49.
[0046] Returning to FIG. 10, it should be noted that the contact faces 57 of the planar seal 19 for pressing the respective radial seal 26 against the side wall face 7 are expediently in the form of slanted faces 45. As can be clearly seen in FIG. 10, the radial seal 26 expediently has corresponding slanted faces 46, on which the contact faces 57 or inclined faces 45 of the respective planar seal 19 act.
[0047] FIG. 11 shows a perspective view of the rotary piston 3, with the planar seal 19 arranged on the piston base 15 in the planar-seal receiving channel 18. This is likewise correspondingly formed on the oppositely situated piston base 16, which cannot be seen in FIG. 11. Also clearly visible here are the boundary lines 27 of the piston bases 15 and 16, which are each in the form of an envelope of an array of trochoid curves between the corner regions 25 of the rotary piston 3. The lateral-surface openings 21 provided according to the invention are arranged in the piston lateral surface 17. In section F-F, which is illustrated in FIG. 12, the pressure-transmitting connection according to the invention between the lateral-surface openings 21 and the planar-seal receiving channel 18 via one of the pressure leadthrough lines 22 is again illustrated. Apart from the housing cover 5 that is missing here in FIG. 12, the illustration according to FIG. 12 corresponds to the already discussed illustration according to FIG. 8, and therefore reference can substantially be made to what was said above. It should again be noted here at this juncture, however, that in this exemplary embodiment the planar seal 19 is injected in the respective planar-seal receiving channel 18 in the form of an injection molded part in each case. Similarly, the planar seal 19, as already set out, could of course be in the form of a 3D printed part or molded pressed part in the planar-seal receiving channel 18.
[0048] FIG. 13 shows an alternative to this by way of example. Here, the planar seal 19 is prefabricated in the form of an insert part and inserted as such in the respective planar-seal receiving channel 18. The projections 58 of this planar seal 19 ensures corresponding guidance, when gas pressure is applied to the planar seal 19 according to the invention in the pressure application direction 47 through the lateral-surface opening 21, the pressure leadthrough line 22 and the planar-seal receiving channel 18 on the side facing away from the seal surface 20, in order to press the seal surface 20 of the planar seal 19 against the planar sealing faces 8 and 9, not illustrated in FIG. 13, of the housing covers 5 and 6, respectively. In the alternative according to FIG. 13, no caps 24 for covering the openings 23 are provided. It would also be possible, however, of course to also use corresponding caps 24 to cover the openings 23 in this variant according to FIG. 13.
[0049] FIG. 14 shows an exploded illustration of the rotary piston 3, in which the planar seals 19 and the radial seals 26 are illustrated as detached from the rotary piston 3. It can also be clearly seen in FIG. 14 that the planar seals 19, which are arranged in one of the planar-seal receiving channels 18, are preferably intrinsically formed in one piece. In FIG. 14, it is also possible again to see the openings 23 of the pressure leadthrough lines 22 in the planar-seal receiving channel 18.
[0050] FIG. 15 is a side view of one of the planar seals 19 from the direction 59 depicted in FIG. 14. Here, underneath the already discussed slanted face 45 of the sealing projection 48, it is possible to see the planar seal 19, which, as will be explained again later on, serves to seal the planar seal 19 in the respective corner regions 25 of the rotary piston 3 on its side facing away from the respective seal surface 20 with respect to the planar-seal receiving channel 18 that receives it. This type of sealing at this point could of course also be effected differently, for example by an adhesive bond, clipping on or the like. This sealing, however, is particularly preferably effected by arranging the mentioned sealing projection 48 in a sealing-projection receiving groove 50, which is in the respective corner region 25 in the form of a depression in the planar-seal receiving channel 18. In this respect, reference is made to FIGS. 18 to 21. FIG. 18 shows a plan view of one of the piston bases 15 of the rotary piston 3 and the sectional lines or sectional planes GG and HH. The sectional line GG is in the region of the sealing-projection receiving groove 50, as can be seen in FIG. 19. In the sectional plane HH, the rotary piston 3 is sectioned in the region of the radial-seal receiving channel 51, in which the radial seal 26 is inserted. FIG. 21 shows the same section as FIG. 19, although in FIG. 19 a respective planar seal 19 is arranged in the respective planar-seal receiving channel 18. What can also be seen here is how the sealing projection 48 of the respective planar seal 19 is arranged in the respective sealing-projection receiving groove 50, in order to achieve the desired sealing effect.
[0051] As already explained in the introduction, the planar seals 19 and also the radial seals 28 expediently consist of a polymer, preferably comprising a dry lubricant and/or reinforcing fibers. The housing side wall 4 and the housing covers 5 and 6 expediently have a main body made of an aluminum alloy or a cast iron. A coating 29 is expediently formed on the respective main body to form the side wall faces 7 of the housing side wall 4 and of the planar sealing faces 8 and 9 of the housing covers 5 and 6. This is also preferably the case in this first exemplary embodiment. In this respect, reference is made to the explanations already set out in the introduction as regards the details and preferred embodiment variants of such a coating 29.
[0052] FIGS. 22 and 23 show, in turn in an exploded illustration, a second exemplary embodiment according to the invention of a rotary piston compressor 1, which is broadly similar to the first exemplary embodiment, and therefore here only the differences will be explained. The essential difference is that here a transmission ratio of 2:3 was realized. Accordingly, the rotary piston 3 of this exemplary embodiment also has three corner regions 25. The number of gas inlets 12 and gas outlets 13 and of the pressure-relief outlet valves 14 is correspondingly adapted, as is the shape of the side wall face 7 and the shape of the planar seal 19. In all other respects, however, what was said above applies in a form adapted to the necessary extent, and therefore further statements in this respect are omitted. It should be noted only that the internal toothing 33 illustrated in FIG. 22 was also not illustrated in FIG. 23. In this exemplary embodiment, in any case, it is also the case that the boundary lines 27 of the piston bases 15 and 16 that extend between the corner regions 25 also have the form of an envelope of an array of trochoid curves. The side face 7 of the housing wall 4 also has a completely trochoidal form here, as viewed in a sectional plane parallel to the planar sealing faces 8 and 9 of the housing covers 5 and 6. The arrangement according to the invention of the lateral-surface openings 21 and the pressure leadthrough lines 22 in the rotary piston 3 corresponds to the first exemplary embodiment and does not need to be explained again.
[0053] FIGS. 24 to 39 show a third exemplary embodiment of a rotary piston compressor 1 according to the invention. Here, it is a variant with a transmission ratio of 7:6. The rotary piston 3 of this rotary piston compressor 1 therefore has six corner regions 25. The regions of the piston lateral surface 27 that are between the corner regions 25 are in turn configured such that the boundary lines 27 delimiting the piston bases 15 and 16 each have the form of an envelope of an array of trochoid curves. The side wall face 7 of the housing side wall 4 has trochoid arcs, as viewed in a sectional plane 7 parallel to the planar sealing faces 8 and 9 of the housing covers 5 and 6.
[0054] By contrast to the previously explained exemplary embodiments of rotary piston compressors 1 according to the invention, in this exemplary embodiment it is provided that the eccentric 11 on which the rotary piston 3 is rotatably mounted in the working chamber 10 is not rotated like in the first two exemplary embodiments, but rather is arranged rigidly in the outer shell 39 of the rotary piston compressor 1. In this exemplary embodiment, the rotary piston 3 is rotated together with the working housing 2 and thus together with the housing side wall 4 and the two housing covers 5 and 6 about an axis of rotation 60 extending through the eccentric 11, while the eccentric 11 remains stationary. In order to achieve this, the rotary piston compressor 1 of this third exemplary embodiment has a rotor 52, which is connected by means of screws 37 and nuts 38 to the working housing 2 for conjoint rotation and interacts with a stator 54 rigidly connected to the outer shell 39 of the rotary piston compressor 1. The rotor 53 and the stator 54 form a drive motor, which rotates the working housing 2 with the rotary piston 3 mounted on the eccentric 11 in the working chamber 10 of the working housing 2.
[0055] A further difference of the third exemplary embodiment in relation to the two previously explained exemplary embodiments is that the gas inlet 12 and the gas outlet 13 in this third exemplary embodiment pass through the eccentric 11, and not through the housing wall 4 as in the first-explained exemplary embodiments. Correspondingly, flow transfer openings 55 that pass through the piston lateral surface 17 are also provided in the rotary piston 3. The gas can enter the corresponding portions of the working chamber 10 from the gas inlet 12 through these flow transfer openings 55 and from there also be conveyed back out again through the gas outlet 13 in compressed form.
[0056] In this third exemplary embodiment, the gas inlets 12 and gas outlets 13 that pass through the eccentric 11 open out into a valve cover 52, which sits on the outside of the outer shell 39 of the rotary piston compressor 1 and guides both the gas inlet 12 and the gas outlet 13 into or out of the rotary piston compressor.
[0057] Apart from the differences explained up to now and those yet to be explained below, reference can substantially be made to the description of the first exemplary embodiments. This applies in particular to the type of pressure application according to the invention, the planar seals 19 arranged in the planar-seal receiving channels 18 of the piston bases 15 and 16, for pressing their seal surfaces 20 against the planar sealing faces 8 and 9 of the housing covers 5 and 6.
[0058] FIG. 25 shows the rotary piston compressor 1, illustrated in an exploded illustration in FIG. 24, of the third exemplary embodiment in a side view. FIG. 25 depicts the sectional plane II. FIGS. 26 to 32 each show sections in the sectional plane II relating to different current positions during operation of the rotary piston compressor 1 and thus during the rotation of the working housing 2 including the rotary piston 3 about the corresponding axis of rotation 60, which extends through the eccentric 11 and is depicted in FIGS. 24 and 25. In order to be able to better understand the rotary movement of the rotary piston 3 and the working housing 2 in FIGS. 26 to 32, a point 61 is depicted on the rotary piston 3 in FIGS. 26 to 32. This is only an illustrative aid which can be used to better understand the current position of the rotary piston 3 in the various illustrations according to FIGS. 26 to 32.
[0059] FIGS. 26 to 32 thus depict various intermediate stations during one revolution of the working housing 2 and the rotary piston 3 about the axis of rotation 60. The gas inlet 12 and the gas outlet 13 can be clearly seen in the eccentric 11. The arrows 43 each depict the gas which is yet to be compressed and flows into the respective subregions, currently acting as low-pressure side 40, of the working chamber 10 through the gas inlet 12 and the corresponding flow transfer openings 55. The arrows 44 depict the already compressed gas that is forced into each gas outlet 13 from the corresponding high-pressure side 41 of the working chamber 10. Following the position of the rotary piston 3 through FIGS. 26 to 32, it can be seen that the sub-volumes of the working chamber 10 that are denoted the low-pressure side 40 in the respective illustration are connected to the gas inlet 12 via the corresponding flow transfer openings 55 in the rotary piston 3, so that gas can flow in. In the sub-volumes of the working chamber 10 that are denoted the high-pressure side 41 in each case and in which there is no longer a connection to the gas inlet 12, the gas is then compressed by a corresponding relative movement between the rotary piston 3 and the working housing 2, in order then to be able to flow into the gas inlet 13 in compressed form, when the corresponding sub-volumes of the working chamber 10 are connected to the gas outlet 13 via the corresponding flow transfer opening 55 in the rotary piston 3.
[0060] FIG. 33 shows a plan view of the third exemplary embodiment of the rotary piston compressor 1 according to the invention. FIG. 33 also depicts the sectional planes JJ and KK. FIG. 34 shows the section in the sectional plane JJ. What can be clearly seen in this FIG. 34 is how the gas inlet 12 passes through the valve cover 52 and the eccentric 11. What can be similarly clearly seen is how the gas outlet 13 likewise passes through the eccentric 11 and the valve cover 52. The pressure-relief outlet valve 14 provided in the gas outlet 13 in the region of the valve cover 52 is also illustrated. This is a spring-loaded closure which opens when the compressed gas coming from the working chamber 10 or from a high-pressure side 41 is at the desired pressure predefinable by the corresponding design of the pressure-relief outlet valve 14.
[0061] In the section according to FIG. 34, it is also possible to see the planar seals 19, which are arranged in the piston bases 15 and 16 in the corresponding planar-seal receiving channels 18 and correspondingly sealingly bear by way of their seal surfaces 20 against the planar sealing faces 8 and 9, respectively, of the housing covers 5 and 6.
[0062] FIG. 35 shows the section along the sectional plane KK from FIG. 33. This is a sectional plane in which the lateral-surface openings 21 and pressure leadthrough lines 22 according to the invention are arranged. The corresponding detail L from FIG. 35 is illustrated as an enlargement in FIG. 36. Here, it can clearly be seen that it is also the case in this exemplary embodiment that, to press the seal surface 20 of the respective planar seal 19 against the respective planar sealing face 8 and 9, respectively, in the piston lateral surface 17 of the rotary piston 3 there are formed lateral-surface openings 21, which have a pressure-transmitting connection to the planar-seal receiving channel 18 via pressure leadthrough lines 22, which are formed inside the rotary piston 3 and each open into the respective planar- seal receiving channel 18 on a side of the respective planar seal 19 that faces away from the seal surface 20. FIG. 36 in turn uses the arrow 47 to depict the direction in which pressure is applied to the planar seal 19 on its side facing away from the seal surface 20. Like in the two first exemplary embodiments, it is thus also possible in this third exemplary embodiment for the pressurized gas present in the working chamber 10 to act on that side of the planar seal 19 that is opposite the seal surface 20 via the lateral-surface opening 21 and the pressure leadthrough line 22 that passes through the rotary piston 3, in order to press the seal surface 20 of the planar seal 19 against the corresponding planar sealing face 8 and 9 of the corresponding housing cover 5 and 6, respectively.
[0063] FIG. 36 also depicts the cap 24, the function of which was already explained above. This cap 24 can of course also be omitted here.
[0064] FIG. 37 shows a perspective illustration of the rotary piston 3 of this exemplary embodiment of the rotary piston compressor 1. What can be clearly seen in this perspective illustration is how the planar-seal receiving channel 18 is formed in the piston base 15 and the planar seal 19 is arranged therein. Also clearly visible are the flow transfer openings 55 and the lateral-surface openings 21 arranged in the piston lateral surface 17. FIG. 38 shows an exploded illustration of this, in which the planar seal 19 has been removed from the respective planar-seal receiving channel 18 of the respective piston base 15 and 16. Therefore, in FIG. 38 it is also possible to see the openings 23 in the planar-seal receiving channel 18, which are connected to the corresponding lateral-surface openings 21 via the corresponding pressure leadthrough lines 22.
[0065] The inwardly pointing sealing projections 48 that are integrally molded on the planar seals 19 are arranged in the corresponding sealing-projection receiving grooves 50 of the rotary piston 3 in the assembled state. They ensure, as is the case in the other exemplary embodiments, that the planar seals 19 are each sealed, with respect to the planar-seal receiving channel 18 that receives them, in the corner regions 25 of the rotary piston 3 on their side facing away from the respective seal surface 20.
[0066] As can be seen particularly clearly in FIGS. 37, 38 and 39, the planar seals 19 of this exemplary embodiment each have seal corner regions 56 with correspondingly rounded contact faces 57. These rounded contact faces 57 provide sealing with respect to the corresponding rounded corner portions 62 of the side wall face 7 of the housing side wall 4, when the respective corner region 25 of the rotary piston 3 engages in the corresponding corner portion 62 of the housing side wall 4. The corner portions 62 are denoted as such in FIG. 24. When the respective seal corner region 56 rolls in the corner portion 62, the rounded contact face 57 of the seal corner region 56 always bears sealingly against the corresponding corner portion 62 and thus against the side wall face 7 at least at one point between the two end points X and Y illustrated in FIG. 39.
TABLE-US-00001 List of Reference Signs: 1 Rotary piston compressor 2 Working housing 3 Rotary piston 4 Housing side wall 5 Housing cover 6 Housing cover 7 Side wall face 8 Planar sealing face 9 Planar sealing face 10 Working chamber 11 Eccentric 12 Gas inlet 13 Gas outlet 14 Pressure-relief outlet valve 15 Piston base 16 Piston base 17 Piston lateral surface 18 Planar-seal receiving channel 19 Planar seal 20 Seal surface 21 Lateral-surface opening 22 Pressure leadthrough line 23 Opening 24 Cap 25 Corner region 26 Radial seal 27 Boundary line 28 Elastic element 29 Coating 30 Drive shaft 31 Connecting journal 32 External toothing 33 Internal toothing 34 Bearing 35 Balance weight 36 Securing ring 37 Screw 38 Nut 39 Outer shell 40 Low-pressure side 41 High-pressure side 42 Direction of rotation 43 Inflowing gas 44 Outflowing gas 45 Slanted face 46 Slanted face 47 Pressure application direction 48 Sealing projection 49 Radial seal surface 50 Sealing-projection receiving groove 51 Radial-seal receiving channel 52 Valve cover 53 Rotor 54 Stator 55 Flow transfer opening 56 Seal corner region 57 Contact face 58 Projection 59 Direction 60 Axis of rotation 61 Point 62 Corner portion
