Radial piston compressor and method for assembling radial piston compressor

Abstract

The invention relates to a radial piston compressor comprising a compressor unit (V) and a drive device (M) for driving the compressor unit (V), the compressor unit (V) comprising at least two piston-cylinder bore assemblies (1, 2), preferably a plurality of piston-cylinder bore assemblies (1, 2), which are arranged radially around an eccentric shaft (4), which is driven by the drive device (M), each piston-cylinder bore assembly comprises a piston (1), and the radial piston compressor, in particular the compressor unit (V), comprises a piston guide ring (13), with which the piston (1) is in contact, in particular in a form-fitting manner, and which is at least partially elastically, preferably fully elastically, in particular in the radial direction. The invention also relates to an advantageous method for assembling the radial piston compressor according to the invention.

Description

Field of the Invention

[0001] The present invention relates to a radial piston compressor as described in the preamble of claim 1 and a method for assembling a radial piston compressor as described in the preamble of claim 18 or 19.

[0002] A radial piston compressor mainly includes a compressor unit and a drive device for driving the compressor unit, preferably an electric motor. The compressor unit mainly includes a plurality of piston-cylinder bore assemblies, which are arranged radially around an eccentric shaft. The eccentric shaft is correspondingly driven by the drive device.

[0003] In addition, the radial piston compressor may include a piston guide ring, which is operatively connected to the piston of the piston-cylinder bore assembly, so as to be able to apply a return stroke movement to the piston, that is, the movement of the piston from the top dead center of its piston movement to the bottom dead center. Background Art

[0004] A radial piston compressor with a piston guide ring is known, for example, from DE102020211680A1. In this way, the piston guide ring usually has a point contact (without losing contact) with the corresponding piston, and the piston abuts against the eccentric. Therefore, additional contact changes between the piston guide ring and the piston and between the piston and the eccentric should be avoided, which has dynamic advantages in terms of the kinematics of the movement process and advantages in terms of wear technology. This also achieves acoustic advantages, because no clicking or other interfering noises are generated. The piston guide ring keeps the piston and the transmission element in sliding contact with the eccentric or the outer ring of the rolling bearing arranged on the eccentric.

[0005] In addition, a reciprocating piston machine is known from DE10356373A1, which has radially directed piston-cylinder units arranged side by side in a ring shape and an eccentric shaft that extends centrally through the housing body of the machine housing. The eccentric of the eccentric shaft controls the outward stroke of the piston, wherein the inward stroke of the piston is controlled by a control ring that surrounds the eccentric shaft and its eccentric with a clearance and engages into the piston, such that the outward stroke control of one piston completely controls the inward stroke of the completely opposite piston.

[0006] A piston guide ring, which is known from the prior art and is configured as a ring, has little flexibility. This flexibility is so small that it is almost non-existent. When the radial distances of the contact points on the piston are different due to component manufacturing tolerances, a contact gap is formed between the piston guide ring and the piston. Due to the small flexibility, the guide ring cannot compensate for these tolerances or fluctuations in the radius or diameter to ensure that the piston continuously bears against the eccentric. Thus, for example, in the reversal point of the piston in the direction from the top dead center position towards the lower position, the contact gap closes. This contact closure, for example, causes an impact on the piston guide ring, which in turn leads to a negative acoustic effect, i.e., noise. A relatively large radial distance of the contact points on the piston may also cause the piston or the pivot section to bear tightly against the eccentric due to the substantially inflexible ring. Here, the result is, for example, increased friction and / or wear. Summary of the Invention

[0007] The present invention starts here, and the task is to provide an improved radial piston compressor, in particular a radial piston compressor that can overcome or at least reduce the above-mentioned disadvantages. In particular, a task of the present invention is to provide a radial piston compressor with a piston guide ring, and the piston guide ring of this radial piston compressor is configured to always establish / maintain contact between the piston and the piston guide ring, that is, to avoid contact gaps, so as to compensate for tolerances and / or fluctuations in the diameter through three contact points of the piston, in particular to ensure that the piston continuously bears against the eccentric.

[0008] According to the present invention, this task is solved by a radial piston compressor having the features of the characterizing part of claim 1. Since the piston guide ring is configured at least partially elastically, preferably completely elastically, especially elastically in the radial direction, the above-mentioned disadvantages can be overcome or at least reduced.

[0009] The guide ring that elastically acts in the radial direction especially allows ovality or desired deformability in its diameter or its effective diameter, so that the guide ring contacts and maintains contact with all contact points of the piston, and these contact points do not lie on a circular locus due to tolerances. Therefore, all pistons are always in contact with the eccentric. In the area of the piston-guide ring connection, elasticity of the guide ring is especially obtained in the radial direction. Continuous contact of the piston or continuous contact of the piston with the eccentric is obtained. This results in little or even no noise, which may be generated, for example, due to the change between contact and loss of contact between the piston and the eccentric. Tolerances or deviations in the effective diameter of the piston guide ring can be compensated, and at this time, a "larger" jump, that is, ovality or deviation from the circular shape, between adjacent pistons is also possible.

[0010] Other advantageous embodiments of the proposed invention especially result from the features of the dependent claims. In principle, the subject matters or features of the various claims can be combined with each other in any way.

[0011] In an advantageous embodiment of the present invention, it can be provided that the elasticity of the piston guide ring is set by the geometry of the piston guide ring and / or the elastic modulus of the piston guide ring.

[0012] In another advantageous embodiment of the present invention, it can be provided that the piston guide ring has a radial stiffness between 100 N / mm and 1000 N / mm.

[0013] In another advantageous embodiment of the present invention, it can be provided that high-strength steel and steels towards high-strength steel are considered as materials for the piston guide ring.

[0014] In another advantageous embodiment of the present invention, it can be provided that the piston guide ring includes an inner side surface. This inner side surface is mainly used for contacting the piston, in particular for contacting the working surface of the corresponding piston. The inner side surface preferably faces the eccentric wheel.

[0015] In another advantageous embodiment of the present invention, it can be provided that each piston respectively includes a working surface for engaging the piston guide ring. This working surface mainly serves as a contact surface with the piston guide ring.

[0016] In another advantageous embodiment of the present invention, it can be provided that the piston guide ring includes a guide ring and a spring elastic element. Here, it can be provided that the guide ring itself is inelastic, and only the spring elastic element is elastic.

[0017] In another advantageous embodiment of the present invention, it can be provided that the spring elastic element extends radially from the inner side of the guide ring. This corresponds to the preferred direction of action, so that the spring elastic element can be used purposefully.

[0018] In another advantageous embodiment of the present invention, it can be provided that the width of the piston guide ring is greater than the height. This embodiment enables a piston guide ring that is already elastic based on its geometry. Such a piston guide ring can be manufactured cost-effectively accordingly.

[0019] In another advantageous embodiment of the present invention, it can be provided that the extension dimension of the piston guide ring in the axial direction in the assembled state is greater than the extension dimension in the radial direction. By using this embodiment, a guide ring with spring elasticity based on its geometry can be obtained. Such a piston guide ring can be manufactured cost-effectively accordingly.

[0020] In another advantageous embodiment of the present invention, it can be provided that the piston guide ring has basically two turns, wherein the ends of each turn are spaced apart from each other at a distance in different planes, and wherein the piston guide ring itself has an inner diameter. Such a guide ring is spring elastic. The profile can be widened for elasticity.

[0021] In another advantageous embodiment of the invention, it can be provided that the piston guide ring is equipped with means for fastening to one of the pistons. Thereby, circumferential movement can be prevented.

[0022] In another advantageous embodiment of the invention, it can be provided that the piston guide ring is made of a wound material or comprises a wound material.

[0023] In another advantageous embodiment of the invention, it can be provided that the piston guide ring is surrounded or at least partially surrounded by a material, in particular a plastic. Thereby, for example, other desired properties of the piston guide ring can be set.

[0024] In another advantageous embodiment of the invention, it can be provided that the piston guide ring has a V-shaped cross-section. Accordingly, a special geometry can be used.

[0025] In another advantageous embodiment of the invention, it can be provided that the piston guide ring is configured as an open ring, wherein the piston guide ring has a gap in which the butt ends of the open ring are opposed to each other, and wherein the piston guide ring has an inner diameter and the butt ends have a distance. The piston guide ring configured in this way can be advantageously assembled. During assembly, the gap can widen and the inner diameter can increase. After assembly, the piston guide ring can assume a state with a corresponding pre-tensioning force.

[0026] In another advantageous embodiment of the invention, it can be provided that the piston guide ring is configured as a closed ring. Conversely, it can also be provided that the piston guide ring is configured as an open ring.

[0027] Another object of the invention is to provide an advantageous method for assembling a piston guide ring in a radial piston compressor according to the invention.

[0028] According to the invention, this object is solved by the following method steps for an open piston guide ring:

[0029] The piston guide ring is in a relaxed state, the piston guide ring having a first inner diameter and a first distance of the butt ends;

[0030] The piston guide ring is transitioned into an assembled state, the inner diameter increasing to a second inner diameter and the distance of the butt ends increasing to a second distance;

[0031] The piston guide ring is mounted, in particular with its inner side, on the piston, in particular on the second working surface of the piston;

[0032] The piston guide ring is transitioned into an assembled state, the inner diameter decreasing to a third inner diameter and the distance of the butt ends decreasing to a third distance;

[0033] The piston guide ring, in particular its inner side, engages, in particular form-fittingly, with the piston, in particular with the contact surface of the piston.

[0034] According to the present invention, this task is also solved by the following method steps for closing the piston guide ring:

[0035] The piston guide ring is in a relaxed state and has a first inner diameter;

[0036] The piston guide ring is transformed into an assembled state, and the inner diameter increases to a second inner diameter;

[0037] The piston guide ring is mounted on the piston, especially on the piston contact surface, especially with its inner side;

[0038] The piston guide ring is transformed into an assembled state, and the inner diameter decreases to a third inner diameter;

[0039] The piston guide ring, especially its inner side, engages with the piston, especially with the contact surface of the piston, especially in a form - fit manner. Description of the Drawings

[0040] The further features and advantages of the present invention will become clear from the following description of the preferred embodiments with reference to the accompanying drawings. Among them:

[0041] Figures 1 to 4 The piston for a piston - cylinder bore assembly, the piston - cylinder bore assembly for a radial piston compressor, and the details of a radial piston compressor are shown in different views according to the prior art;

[0042] Figure 5 The piston - cylinder bore assembly for a radial piston compressor according to the present invention with an elastic piston guide ring in a first embodiment and a second embodiment is shown;

[0043] Figure 5a The elastic piston guide ring for a piston - cylinder bore assembly is shown in a perspective view;

[0044] Figure 5b Parts of the elastic piston guide ring for a radial piston compressor according to the present invention are shown in a cross - sectional view, parts a, b, c;

[0045] Figure 5d The elastic piston guide ring for a radial piston compressor according to the present invention is shown in a cross - sectional view, parts d, e;

[0046] Figure 6 The piston - cylinder bore assembly for a radial piston compressor according to the present invention with an elastic piston guide ring in a third embodiment and a fourth embodiment is shown;

[0047] Figure 6a The elastic piston guide ring for a radial piston compressor according to the present invention is shown in a cross - sectional view;

[0048] Figure 6b The elastic piston guide ring for a radial piston compressor according to the invention is shown in a cross-sectional view;

[0049] Figure 6c -f The elastic piston guide ring for a radial piston compressor according to the invention is shown in a cross-sectional view;

[0050] Figure 7a The elastic piston guide ring for a radial piston compressor according to the invention is shown in a perspective view;

[0051] Figure 7b The elastic piston guide ring for a radial piston compressor according to the invention is shown in a side view;

[0052] Figure 7c The elastic piston guide ring for a radial piston compressor according to the invention is shown in a side view;

[0053] Figure 7d The elastic piston guide ring for a radial piston compressor according to the invention is shown in a side view;

[0054] Figure 8 The elastic piston guide ring for a radial piston compressor according to the invention is shown in a top view;

[0055] Figure 9 The pistons of a compressor unit with an elastic piston guide ring in another embodiment according to the invention are shown;

[0056] Figure 9a The elastic piston guide ring for a radial piston compressor according to the invention is shown in a top view;

[0057] Figure 9b The elastic piston guide ring for a radial piston compressor according to the invention is shown in a top view;

[0058] Figure 9c The elastic piston guide ring for a radial piston compressor according to the invention is shown in a top view;

[0059] Figure 10 The elastic piston guide ring for a radial piston compressor according to the invention is shown in a perspective view;

[0060] Figure 11 The piston-cylinder bore assembly of a radial piston compressor with an elastic piston guide ring in another embodiment according to the invention is shown;

[0061] Figure 11a -d A part of an elastic piston guide ring in another embodiment is shown.

[0062] The following reference signs are used in the drawings:

[0063] 1 Piston

[0064] 2 Cylinder Bore

[0065] 3 Center Line of Cylinder Bore

[0066] 4 Drive Shaft / Eccentric Shaft

[0067] 5 Axis of Rotation of Drive Shaft

[0068] 6 Eccentric Wheel

[0069] 7 Center Point of Eccentric Wheel

[0070] 8 Transmission Element

[0071] 9 First Support Surface of Transmission Element

[0072] 10 Cylindrical Surface

[0073] 11 Working Surface of Piston

[0074] 12 Second Support Surface of Transmission Element

[0075] 13 Piston Guide Ring

[0076] 14 Inner Side Surface of Piston Guide Ring

[0077] 15 Contact Surface of Piston

[0078] 16 Radius of First Support Surface

[0079] 17 Radius of Cylindrical Surface

[0080] 19 Radius of Second Support Surface

[0081] 20 Radius of Second Working Surface

[0082] 21 Center Point

[0083] 22 Radius of First Working Surface

[0084] 23 Radius of Inner Side Surface of Piston Guide Ring

[0085] 24 Outer Side Surface

[0086] 25 Outer Ring

[0087] 26 Rolling Bearing

[0088] 27 Cylinder Housing

[0089] 131 Guide Ring

[0090] 132 Spring Elastic Element

[0091] Device for fastening to one of the pistons

[0092] V Compressor unit

[0093] M Driving device

[0094] A(′,″) Clearance or distance of the docking end

[0095] D(′,″) Inner diameter

[0096] B Width

[0097] H Height

[0098] K Plastic housing Detailed implementation

[0099] Term explanation

[0100] The terms used herein are only for describing specific implementations and should not limit the present disclosure. As used herein, the singular forms "a" and "the" should also include the plural forms, unless the context clearly indicates otherwise. In addition, it is clear that when the expression "having" is used in this specification, it indicates the presence of the mentioned features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations. As used herein, the expression "and / or" includes any and all combinations of one or more of the associated, listed elements.

[0101] First refer to Figures 1 to 4 .

[0102] Here, the pistons for the piston-cylinder bore assembly according to the prior art and the details of the piston-cylinder bore assembly for a radial piston compressor are described in different views in order to explain the basic principle.

[0103] The radial piston compressor mainly includes a compressor unit V and a driving device M for driving the compressor unit V. The compressor unit V mainly includes a plurality of piston-cylinder bore assemblies 1, 2, which are arranged radially around an eccentric shaft 4. The eccentric shaft 4 is accordingly driven by the driving device M.

[0104] The piston-cylinder bore assembly mainly includes a cylinder or cylinder bore 2 and includes a piston 1 movably received in the cylinder bore 2.

[0105] The radial piston compressor preferably further includes a cylinder housing 27 in which the piston-cylinder bore assembly is received. The radial piston compressor also includes a drive shaft 4 with an eccentric wheel 6. The drive shaft 4 is rotated by a drive mechanism 31, preferably an electric motor.

[0106] Unlike an axial piston compressor, the piston 1 or the cylinder 2 or the piston-cylinder bore assembly 1, 2 extends radially from the drive shaft 4 or the eccentric 6. The piston 1 or the cylinder or the piston-cylinder bore assembly is preferably arranged in a star shape around the drive shaft 4 or the eccentric 6. A radial piston compressor can also be referred to as a compressor based on the radial piston principle.

[0107] Figure 1 The piston 1 of the piston-cylinder bore assembly is shown in a radial half-section view. In Figure 1 only the axis of rotation 5 of the drive shaft 4 is marked. The piston 1 is arranged circumferentially around the drive shaft 4. In Figure 1 for the sake of clarity, the intersection of the center line 3 of the cylinder bore 2 with the axis of rotation 5 of the drive shaft 4 is not shown. The cylindrical eccentric 6 is configured as an integral part of the drive shaft 4 or as a member that is non-rotatably connected to the drive shaft 4. The center point 7 of the eccentric 6 is arranged at a distance from the axis of rotation 5 of the drive shaft 4 to produce an eccentricity. The eccentric 6 has a cylindrical surface 10 with a radius 17 on the side.

[0108] The piston-cylinder bore assembly according to the invention preferably further comprises a cylindrical piston guide ring 13, which preferably has an inner side 14.

[0109] A transmission element 8 is preferably arranged between the eccentric 6 and the piston 1 of the piston-cylinder bore assembly. The stroke of the eccentric 6 is transmitted to the piston 1 by means of the transmission element 8, so that the piston performs a compression movement towards the top dead center OT. In Figure 1 the illustrated embodiment, the transmission element 8 is directly supported on the cylindrical surface 10 of the eccentric 6 by a first support surface 9. In Figure 1 the illustrated embodiment, the first support surface 9 is configured as a cylindrically curved concave partial surface with a first support surface radius 16. The first support surface radius 16 corresponds to the radius 17 of the cylindrical surface 10 here. Therefore, the first support surface 9 and the cylindrical surface 10 are configured complementary to each other. In principle, the first support surface 9 can also have a concave shape deviating from a circular ring shape.

[0110] The transmission element 8 has a convexly formed second support surface 12. In Figure 1In the illustrated embodiment, the second support surface 12 is configured as a cylindrical lateral surface partial surface having a second support surface radius 19. In principle, the second support surface 12 can also have a convex shape different from the cylindrical shape instead of the cylindrical lateral surface partial shape. The piston 1 is supported on the second support surface 12 of the transmission element 8 by means of an acting surface 11 configured on the piston 1. The acting surface 11 of the piston 1 is shaped concavely. In the illustrated embodiment, the acting surface 11 of the piston 1 is configured as a concave cylindrical lateral surface partial surface having an acting surface radius 22, which corresponds to the second support surface radius 19. Thus, the acting surface 11 of the piston 1 and the second support surface 12 of the transmission element 8 are configured complementary to each other. In principle, the acting surface 11 of the piston 1 can also have a concave shape deviating from the cylindrical shape.

[0111] On the piston 1, a convexly shaped contact surface 15 is configured. In the illustrated embodiment, the contact surface 15 of the piston 1 is configured as a cylindrical lateral surface partial surface having a contact surface radius 20. The piston 1 engages with the piston guide ring 13, in particular in a form-fitting manner. In particular, the piston engages with the piston guide ring 13, in particular with the inner lateral surface 14 of the piston guide ring 13, in a form-fitting manner via the contact surface 15. This engagement, in particular the form-fitting engagement, acts in the direction of the center line 3 of the cylinder bore 2. The return movement is transmitted to the piston 1, in particular to the contact surface 15 of the piston 1, via the piston guide ring 13, i.e., the movement of the piston 1 from the top dead center OT of the piston movement to the bottom dead center UT.

[0112] In Figure 1 In the illustrated embodiment, the second support surface radius 19 of the transmission element 8 and the second acting surface radius 22 of the piston 1 have the same center point 21. The center point 21 corresponds here to the intersection of the center line 3 of the cylinder bore 2 and the cylindrical surface 10 of the eccentric wheel 6. By means of this design measure, it is preferably achieved that the sum of the radius 17 of the cylindrical surface 10 and the second acting surface radius 22 of the piston 1 is equal to the radius 23 of the inner lateral surface 14 of the piston guide ring 13. Thereby, it is achieved that the inner lateral surface 14 of the piston guide ring 13 generally does not lose contact with the contact surface 15 of the piston 1, i.e., not at any angular position of the eccentric wheel 6 or the drive shaft 4. In this way, the piston guide ring 13 is always in contact with the respective piston 1 (without losing contact), for example. Thus, additional contact changes between the piston guide ring 13 and the piston 1 or between the piston 1 and the eccentric wheel 6 or the eccentric bearing 25 are avoided, which has dynamic advantages in terms of the kinematics of the movement process and advantages in terms of wear technology. Thereby, acoustic advantages are also achieved, since no clicking or other interfering noises are generated.

[0113] As can be seen in Figure 3 the eccentric wheel 6 can also be equipped with a rolling bearing 26. The rolling bearing 26 generally includes an outer bearing ring 25, which forms the surface of the eccentric wheel 6 facing the piston 1 instead of the eccentric disk.

[0114] The piston guide ring 13 guides the piston 1 on the eccentric wheel 6 (or on the outer ring 25 of the bearing) and prevents the piston 1 from "breaking away" from the cylindrical surface 10 (or the outer side 24 of the outer ring 25 of the rolling bearing) during the downward movement / return movement of the piston 1. The piston guide ring 13 slides on the second acting surface 15 constructed on the piston 1. The piston guide ring 13 keeps the piston 1 and the transmission element 8 in sliding contact with the eccentric wheel 6 (or with the outer ring 25 of the rolling bearing 26 arranged on the eccentric wheel).

[0115] Figure 2 The piston 1 of the piston-cylinder bore assembly is shown in an exploded view. The transmission element 8 is supported on the outer ring 25 of the rolling bearing 26. The eccentric wheel 6 is not shown in Figure 2 The contact surface 15 of the piston 1 is also constructed such that it interacts with the inner side 14 of the piston guide ring 13.

[0116] Figure 3 A radial piston compressor with a piston-cylinder bore assembly according to the invention is schematically shown. In the illustrated embodiment, the piston-cylinder bore assembly is constructed such that the transmission element 8 has a cylindrical-sectioned, concave first support surface 9 and the second support surface 12 of the transmission element 8 is cylindrically sectioned and interacts with the cylindrically sectioned first acting surface 11 of the piston 1.

[0117] The cylinder bore 2 is arranged in the cylinder housing 27. Each piston 1 is driven by a single drive shaft 4 with an eccentric wheel 6. For clarity, not all details of a complete radial piston compressor are shown in Figure 3 All valve arrangements and the inlet and outlet channels for the refrigerant are omitted, for example. Based on the piston-cylinder bore assembly, the radial piston compressor according to Figure 3 is constructed small in the radial direction and also in the axial direction, i.e., this radial piston compressor requires little installation space in these two mentioned directions.

[0118] Further correlations and modes of action are sufficiently known to a person skilled in the art. For more details, reference can be made in particular to DE102020211680A1.

[0119] According to the invention, it is provided that the piston guide ring is constructed at least partially elastically, preferably completely elastically, especially elastically in the radial direction.

[0120] The elasticity of the piston guide ring can be set by its geometry and / or its modulus of elasticity. Preferably, it is provided that the piston guide ring has a radial stiffness between 100 N / mm and 1000 N / mm. As materials for the piston guide ring, high-strength steel and ultra-high-strength steel are considered, for example.

[0121] The piston guide ring 13 is elastic in the radial direction, preferably such that the piston guide ring contacts all contact points that are not on a circular path due to tolerances, i.e., the desired deformability of the piston guide ring 13 is sought, with the aim of having no contact gaps.

[0122] To achieve or provide an elastic piston guide ring 13, various different embodiments can be envisaged, which will be described below. The embodiments of the elastic piston guide ring presented here are not exhaustive. Other embodiments not shown here can be envisaged.

[0123] The following refers to Figures 5 to 11d .

[0124] In Figure 5 is shown a piston - cylinder bore assembly of a radial piston compressor with an elastic piston guide ring according to the invention in two different embodiments. The piston guide ring 13 shown on the right is shown in Figure 5a in a perspective view. The piston guide ring 13 mainly comprises a guide ring 131 and a spring - elastic element 132. The guide ring 131 itself has little elasticity in the radial direction. In Figure 5 it can also be seen that the spring - elastic element 132 extends radially from the inner side of the guide ring 131.

[0125] In Figures 5b to 5e are shown other examples for constructing the piston guide ring 13, in particular the spring - elastic element 132. The orientation of the spring - elastic element 132 can be radial, axial or a mixed form of radial and axial orientation, in particular an inclined orientation. For example, in Figure 5c is shown the inclined orientation of the spring - elastic element 132. In Figure 5b is shown the substantially axial orientation of the spring - elastic element 132.

[0126] In Figure 5a , 5d and 5e the diameter D is marked. It is preferably stipulated that the spring - elastic element 132 constitutes the diameter D effective for the piston 1 of the piston guide ring 13.

[0127] In Figure 5b and Figure 5c the guide ring according to Figure 5 is shown in a partial cross - section. The reference mark B denotes the width, H denotes the height, and D denotes the diameter effective at the piston contact site. The marked rotational axis 5 of the drive shaft clarifies the relative position in the assembled state. However, in principle, it is also possible that the guide ring 131 and the spring - elastic element 132 are arranged as in Figure 5d , 5eAs shown in , it extends over the entire circumference of the piston guide ring 13. This piston guide ring 13 can be assembled more easily because it is not necessary to accurately assign each spring elastic element 132 to the piston contact point.

[0128] exist Figure 6 2 shows a piston-cylinder bore assembly for a radial piston compressor according to the invention with two different embodiments of an elastic piston guide ring 13. The piston guide ring 13 shown on the right is Figure 6a The piston guide ring 13 shown on the left is partially shown in a cross-sectional view. Figure 6b 1 is partially shown in cross section. The piston guide ring 13 shown here is spring-elastic due to its geometry, in particular due to its cross-sectional shape, which is wider than it is high. In other words, the piston guide ring 13 in the assembled state has a greater extension in the axial direction than in the radial direction. The width of the piston guide ring 13 is denoted by the reference symbol B, while the height is denoted by the reference symbol H.

[0129] exist Figure 6c and d are shown according to Figure 6 The piston guide ring 13 is in a relaxed state. The piston guide ring 13 has an inner diameter D. Figure 6c and Figure 6d The guide ring 13 is shown in cross section, wherein the position of the axis of rotation 5 of the drive shaft 4 during assembly is also to be clarified here.

[0130] exist Figure 6e The example shows that Figure 6c The piston guide ring 13 is in the state during assembly. The piston guide ring 13 has a second inner diameter D′. It can be seen that the second inner diameter D′ in the state during assembly is larger than the inner diameter (D, Figure 6c ). In the above-mentioned state, the piston guide ring 13 is particularly threaded onto the piston contact surface 15. This is particularly related to the state in which the piston guide ring 13 should be elastically prestressed to the greatest extent.

[0131] exist Figure 6f 1 shows the piston guide ring 13 in a state in which it has been assembled on the piston. The piston guide ring 13 has a third inner diameter D". It can be seen that the third inner diameter D" in the assembled state is smaller than the inner diameter (D', Figure 9b On the other hand, the third inner diameter D″ in the assembled state is larger than the inner diameter (D, Figure 9a ). Thus, in the assembled state, the piston guide ring 13 is elastically prestressed so that it contacts all contact points that do not lie on a circular path due to tolerances, so that no contact gaps are formed at the contact points of the piston 1. The diameter D of the piston guide ring 13 is preferably always smaller than the smallest diameter through the three contact points of the piston.

[0132] However, the pre-tightening force should be as small as possible, because a large pre-tightening force increases friction, which is not desirable. The design of the pre-tightening force should also not exceed the material limits of the piston guide ring 13 and the piston contact surface 15 under long-term loads (especially with regard to Hertzian contact stress and alternating bending fatigue strength).

[0133] Here, the piston guide ring 13 with a rectangular cross-section ( Figure 6a 、 6c ) is taken as an example to describe and illustrate the assembly and the diameters D, D′, D″ set here. These descriptions also apply to the embodiments of the piston guide ring 13 shown in Figure 6b 、d and Figure 5 、 5a 、5b - 5e.

[0134] In Figures 7a to 7d , only the elastic piston guide ring 13 is shown in different states and views. The piston guide ring 13 shown here has two or substantially two turns. The turns are arranged one above the other. The butt ends of the turns are spaced apart from each other by a distance A in different planes. The piston guide ring 13 itself has an inner diameter D. The material width of the piston guide ring 13 is denoted by the reference mark B. In Figure 7a and 7b , the piston guide ring 13 in the relaxed state is shown. Accordingly, the above reference marks D, A, B relate to the corresponding parameters in the relaxed state. For better distinction, these should be referred to here as the first inner diameter D and the first distance A.

[0135] In Figure 7c , the piston guide ring 13 in the maximum elastic pre-tightening state is shown. The reference marks used here correspond to D′ and A′. For better distinction, these should be referred to here as the second inner diameter D′ and the second distance A′. It can be seen that the second distance A′ and the second inner diameter D′ between the butt ends in the state during assembly are greater than the distance and inner diameter in the relaxed state (A, D, Figure 7a 、 7b ).

[0136] In Figure 7d , the piston guide ring 13 in the elastic pre-tightening state during operation is shown. The reference marks used here correspond to D″ and A″. For clearer distinction, these should be referred to here as the third inner diameter D″ and the third distance A″ for distinction. It can be seen that the third distance A″ and the third inner diameter D″ between the butt ends in the assembled state are less than the distance and inner diameter in the state during assembly (A′, D′, Figure 7c ). On the other hand, the third distance A″ and the third inner diameter D″ in the assembled state are greater than the distance and inner diameter in the relaxed state (A, D, Figure 7a 、 7b ).

[0137] In Figure 8 a top view shows an embodiment of the elastic piston guide ring 13. It is hereby stipulated or conceivable that the piston guide ring 13 is configured as a closed ring. In contrast, some of the following-described embodiments of the piston guide ring 13 are configured as non-closed rings, i.e., having interruptions or gaps.

[0138] The piston guide ring 13 is equipped with means 133 for fastening to one of the pistons. Accordingly, due to the fastening of the piston guide ring to the piston, circumferential movement is not possible.

[0139] In Figure 9 a radial piston compressor according to the invention with a plurality of pistons 1 having an elastic piston guide ring 13 in another embodiment is shown. In Figures 9a to 9c the piston guide ring 13 in Figure 9 is shown in different states, which will be discussed below.

[0140] The piston guide ring 13 is a non-closed ring. In other words, the piston guide ring 13 is non-closed, but there is a gap at which the two butting ends of the piston guide ring are opposed to each other. The butting ends have a distance A and the piston guide ring has an inner diameter D or, as will be elaborated later, inner diameters D′, D″ and distances A′, A″. For better distinction, here it should be referred to as the first inner diameter D, the second inner diameter D′, the third inner diameter D″ and the first distance A, the second distance A′, the third distance A″.

[0141] In Figure 9a the piston guide ring 13 in a relaxed state is shown. The distance between the butting ends is denoted by the reference mark A. The piston guide ring has an inner diameter D.

[0142] In Figure 9b the piston guide ring 13 in a state during assembly is shown. The distance between the butting ends is denoted by the reference mark A′. The piston guide ring has a second inner diameter D′. It can be seen that in the state during assembly, the second distance A′ between the butting ends and the second inner diameter D′ are greater than the distance and inner diameter (A, D, Figure 9a ) in the relaxed state. In the above state, the piston guide ring 13 is especially strung onto the piston contact surface 15. Here especially refers to the state in which the piston guide ring 13 should be elastically pre-tensioned to the maximum extent.

[0143] In Figure 9cThe piston guide ring 13 is shown in a state of being assembled onto the piston. The distance between the butting ends is denoted by the reference mark A″. The piston guide ring 13 has a third inner diameter D″. It can be seen that in the assembled state, the third distance A″ between the butting ends and the third inner diameter D″ are smaller than the distance and inner diameter (A′, D′, Figure 9b ) during the assembly state. On the other hand, the third distance A″ and the third inner diameter D″ in the assembled state are larger than the distance and inner diameter (A, D, Figure 9a ) in the relaxed state. In the assembled state, the piston guide ring is elastically preloaded.

[0144] In summary, two methods for assembling a piston guide ring in a radial piston compressor are described herein. For the non-closed piston guide ring 13, it is characterized by the following method steps:

[0145] The piston guide ring 13 is in a relaxed state, and the piston guide ring 13 has a first inner diameter D and a first distance A between the butting ends;

[0146] The piston guide ring 13 is transformed into an assembly state, the inner diameter increases to a second inner diameter D′, and the distance between the butting ends increases to a second distance A′;

[0147] The piston guide ring 13 is installed, in particular with its inner side 14, onto the piston 1, in particular onto the piston contact surface 15;

[0148] The piston guide ring 13 is transformed into an already assembled state, the inner diameter decreases to a third inner diameter D″, and the distance between the butting ends decreases to a third distance A″;

[0149] The piston guide ring 13, in particular its inner side 14, engages, in particular in a form-fitting manner, with the piston 1, in particular with the contact surface 15 of the piston 1.

[0150] In addition, for the closed piston guide ring 13:

[0151] The piston guide ring 13 is in a relaxed state, and the piston guide ring 13 has a first inner diameter D;

[0152] The piston guide ring 13 is transformed into an assembly state, and the inner diameter increases to a second inner diameter D′;

[0153] The piston guide ring 13 is installed, in particular with its inner side 14, onto the piston 1, in particular onto the piston contact surface 15;

[0154] The piston guide ring 13 is transformed into an assembled state, and the inner diameter decreases to a third inner diameter D″;

[0155] The piston guide ring 13, in particular its inner side 14, engages, in particular in a form-fitting manner, with the piston 1, in particular with the contact surface 15 of the piston 1.

[0156] In Figure 10 a three-dimensional view shows another embodiment of the elastic piston guide ring 13 for a radial piston compressor according to the present invention. A closed piston guide ring is involved here. The piston guide ring 13 shown here is made of a wound material, such as a continuous spring, or includes a wound material, such as a continuous spring.

[0157] In Figure 11 a piston-cylinder bore assembly of a radial piston compressor with an elastic piston guide ring 13 in another embodiment according to the present invention is shown. The piston guide ring 13 schematically shown here is in particular a piston guide ring that is surrounded or at least partially surrounded by a material, in particular plastic. The piston guide ring itself can be configured as a closed ring or an open ring.

[0158] In Figures 11a to 11d a detailed view of the piston guide ring 13 is correspondingly shown. Figure 11a And 11b the piston guide ring 13 in is an elastic piston guide ring made of a wound material that is at least partially surrounded by a material, in particular plastic K.

[0159] Figure 11c And 11d the piston guide ring 13 in is an elastic piston guide ring made of a material with a V-shaped cross-section that is at least partially surrounded by a material, in particular plastic K.

[0160] It can be seen from the above exemplary embodiments that the diameter D (i.e., the effective diameter) of the piston guide ring should always be smaller than the minimum outer diameter passing through, for example, three contact points of the piston, that is, the ring is installed with a pre-tightening force. However, the magnitude of the pre-tightening force should be as small as possible because a large pre-tightening force increases friction, which is not desirable. The design of the pre-tightening force for the piston guide ring should also not exceed the material limits of the piston guide ring and the piston in contact (especially with regard to Hertzian contact stress and alternating bending fatigue strength) under long-term loading.

[0161] In summary, the following provisions are preferably considered. The piston guide ring should have the required stiffness so that each piston contacts the eccentric wheel with its piston bottom and thus the stroke curve of the piston follows the stroke curve of the eccentric wheel. Thereby, thermodynamic advantages are especially achieved. The piston guide ring should have the required flexibility, in particular the ability to deform, in order to be able to ensure tolerance compensation in the radial direction of adjacent pistons at the contact points. The diameter of the piston guide ring should have the required interference with respect to the diameter of the contact points. In addition, the required component strength should be achieved with respect to contact stress and alternating bending fatigue strength.

Claims

1. A radial piston compressor, comprising a compressor unit (V) and a drive device (M) for driving the compressor unit (V), the compressor unit (V) including at least two piston - cylinder bore assemblies (1, 2), preferably a plurality of piston - cylinder bore assemblies (1, 2), which are arranged radially around an eccentric shaft (4), the eccentric shaft (4) being driven by the drive device (M), each piston - cylinder bore assembly including a piston (1), the radial piston compressor, in particular the compressor unit (V), including a piston guide ring (13), the piston (1) being in contact with, in particular form - fittingly engaging with, the piston guide ring (13), characterized in that, The piston guide ring (13) is constructed at least partially elastically, preferably completely elastically, and in particular elastically in the radial direction.

2. The radial piston compressor according to claim 1, characterized in that The elasticity of the piston guide ring is set by the geometry of the piston guide ring and / or the elastic modulus of the piston guide ring.

3. The radial piston compressor according to at least one of the preceding claims, characterized in that, The piston guide ring has a radial stiffness between 100 N / mm and 1000 N / mm.

4. The radial piston compressor according to at least one of the preceding claims, characterized in that, High-strength steel and ultra-high-strength steel are used as materials for the piston guide ring.

5. The radial piston compressor according to at least one of the preceding claims, characterized in that The piston guide ring (13) includes an inner side (14).

6. The radial piston compressor according to at least one of the preceding claims, characterized in that Each piston (1) respectively includes a piston contact surface (15) for engaging the piston guide ring (13).

7. A radial piston compressor according to at least one of the preceding claims, characterized in that The piston guide ring (13) includes a guide ring (131) and a spring elastic element (132).

8. The radial piston compressor according to at least one of the preceding claims, characterized in that, The spring elastic element (132) extends radially, axially, and / or obliquely from the inner side of the guide ring (131).

9. The radial piston compressor according to at least one of the preceding claims, characterized in that, The width (B) of the piston guide ring (13) is greater than the height (H).

10. The radial piston compressor according to at least one of the preceding claims, characterized in that, In the assembled state, the piston guide ring (13) has a greater extension dimension in the axial direction than in the radial direction.

11. The radial piston compressor according to at least one of the preceding claims, characterized in that, The piston guide ring (13) has two or substantially two turns, wherein the ends of each turn are opposed to each other at a distance (A, A′, A″) in different planes, and the piston guide ring itself has an inner diameter (D, D′, D″).

12. A radial piston compressor according to at least one of the preceding claims, characterized in that, The piston guide ring (13) is equipped with a device (133) for fastening to one of the pistons (1).

13. The radial piston compressor according to at least one of the preceding claims, characterized in that, The piston guide ring (13) is made of a wound material or includes a wound material.

14. The radial piston compressor according to at least one of the preceding claims, characterized in that, The piston guide ring (13) is surrounded or at least partially surrounded by a material, in particular a plastic (K).

15. The radial piston compressor according to at least one of the preceding claims, characterized in that, The piston guide ring (13) has a V-shaped cross-section.

16. The radial piston compressor according to at least one of claims 1 to 15, characterized in that, The piston guide ring (13) is constructed as an open ring. The piston guide ring has a gap, and the butt ends are opposed to each other in the gap. The piston guide ring has an inner diameter (D, D′, D″) and the butt ends have a distance (A, A′, A″).

17. The radial piston compressor according to at least one of claims 1 to 15, characterized in that, The piston guide ring (13) is constructed as a closed ring.

18. A method for assembling a piston guide ring in a radial piston compressor according to claim 16, characterized in that The following method steps: The piston guide ring (13) is in a relaxed state, and the piston guide ring (13) has a first inner diameter (D) and a first distance (A) between the butt ends; The piston guide ring (13) is transformed into an assembled state, the inner diameter increases to a second inner diameter (D′), and the distance between the butt ends increases to a second distance (A′); The piston guide ring (13) is installed on the piston (1), in particular on the piston contact surface (15), especially with its inner side (14); The piston guide ring (13) is transformed into an assembled state, the inner diameter decreases to a third inner diameter (D″), and the distance between the butt ends decreases to a third distance (A``); The piston guide ring (13), in particular the inner side (14), engages with the piston (1), in particular with the contact surface (15) of the piston (1), especially in a form-fitting manner.

19. A method for assembling a piston guide ring in a radial piston compressor according to claim 17, characterized in that The following method steps: The piston guide ring (13) is in a relaxed state, and the piston guide ring (13) has a first inner diameter (D); The piston guide ring (13) is transformed into an assembled state, and the inner diameter increases to a second inner diameter (D′); The piston guide ring (13) is installed on the piston (1), in particular on the piston contact surface (15), especially with its inner side (14); The piston guide ring (13) is transferred into the assembled state, and the inner diameter is reduced to a third inner diameter (D″); The piston guide ring (13), in particular the inner side (14), engages, in particular in a form-fitting manner, with the piston (1), in particular with the contact surface (15) of the piston (1).

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