RADIAL PISTON PUMP, IN PARTICULAR RADIAL PISTON COMPRESSOR

Abstract

A radial piston pump, in particular radial piston compressor, including a drive shaft with an eccentric, and at least one piston/working chamber combination, wherein the piston/working chamber combination includes a working chamber and a piston, wherein the radial piston pump includes at least two piston/working chamber combinations extending radially from the drive shaft, wherein each working chamber is closed with a cover, wherein the radial piston pump is equipped with a housing component with an integrated retaining ring for fixing all of the covers of the radial piston pump.

Claims

1-14. (canceled)

15. A radial piston pump, in particular radial piston compressor, comprising: a drive shaft having at least one piston/working chamber combination, wherein the piston/working chamber combination includes a working chamber and a piston, wherein the radial piston pump includes at least two piston/working chamber combinations extending radially from the drive shaft, wherein each working chamber is closed with a cover, and wherein the radial piston pump is equipped with a housing component with an integrated retaining ring for fixing all of the covers of the radial piston pump.

16. The radial piston pump of claim 1, wherein the radial piston pump includes at least three piston/working chamber combinations which are arranged in a star shape around the drive shaft.

17. The radial piston pump of claim 1, wherein the radial piston pump has at least one further housing component, in particular a high-pressure housing, a cylinder housing, in particular for receiving the piston/working chamber combinations, and/or a stator housing, in particular for receiving a rotor of an electric motor, wherein the housing component with an integrated retaining ring and the further housing component or components form the housing of the radial piston pump.

18. The radial piston pump of claim 1, wherein the housing component with an integrated retaining ring has plane-parallel axial sealing faces.

19. The radial piston pump of claim 1, wherein the surfaces of the sealing faces of the housing component with an integrated retaining ring are provided with concentric grooves, in particular with a ripple in the radial direction.

20. The radial piston pump of claim 1, wherein the contact faces are provided on the housing component with an integrated retaining ring and on the cover, wherein the contact faces are configured to allow the housing component with an integrated retaining ring can fix the cover on the cylinder housing.

21. The radial piston pump of claim 1, wherein the contact face with respect to and/or of the respective cover is flat or concave/convex, wherein the curvature of the cover or of the housing component with an integrated retaining ring are axially aligned with respect to the drive shaft of the radial piston pump and/or transversely with respect thereto.

22. The radial piston pump of claim 1, wherein the cover and/or the housing component with an integrated retaining ring has an overlap in the joint diameter, in particular in the region of the cover on the cylinder housing, such that an interference fit is produced between the cover and the housing component with an integrated retaining ring.

23. The radial piston pump of claim 1, wherein at least one screw is provided for the connection of all of the housing parts.

24. The radial piston pump of claim 1, wherein the housing component with an integrated retaining ring consists of steel or a steel alloy at least in sections.

25. The radial piston pump of claim 1, wherein surface contact is provided between the cover and the housing component with an integrated retaining ring.

26. The radial piston pump of claim 1, wherein the housing component with an integrated retaining ring and the cover at least partially have mutually corresponding shapes.

27. The radial piston pump of claim 1, wherein the housing component with an integrated retaining ring has at least one passage for the housing screw connection, wherein the passage for the housing screw connection is interrupted inwardly or is designed as a fully enclosed passage for the screw connection.

28. The radial piston pump of claim 1, wherein the at least one positioning means is provided in the housing component with an integrated retaining ring.

Description

[0025] Further features and advantages of the present invention will become apparent from the following description of preferred exemplary embodiments with reference to the accompanying drawings, in which:

[0026] FIG. 1 shows a radial piston pump with a separate retaining ring in a sectional view;

[0027] FIG. 2 shows a radial piston pump according to the invention in a sectional view;

[0028] FIG. 3 shows a radial piston pump with a separate retaining ring in a view from the front;

[0029] FIG. 4 shows a radial piston pump according to the invention in a view from the front;

[0030] FIG. 5 shows a radial piston pump according to the invention in a longitudinal sectional view;

[0031] FIG. 6 shows a radial piston pump according to the invention in a cross-sectional view;

[0032] FIG. 7 shows a housing component of a radial piston pump according to the invention;

[0033] FIG. 8 shows a housing component of a radial piston pump according to the invention;

[0034] FIG. 9 shows a housing component of a radial piston pump according to the invention;

[0035] FIG. 10 shows an enlarged illustration of a region of a housing component according to FIG. 8;

[0036] FIG. 11 shows a schematic illustration of the fluid flow of a radial piston pump according to the invention;

[0037] FIG. 12 shows a schematic illustration of the fluid flow of a radial piston pump according to the invention;

[0038] FIG. 13 shows a schematic illustration of the fluid flow of a radial piston pump according to the invention;

[0039] FIG. 14 shows a radial piston pump according to the invention in a sectional view.

[0040] The following reference signs are used in the figures: [0041] L longitudinal axis [0042] F fluid [0043] D region [0044] Da_Geh1 external diameter of a radial piston pump with a separate retaining ring [0045] Da_Geh2 external diameter of the radial piston pump according to the invention [0046] Di_Geh1 internal diameter of a radial piston pump with a separate retaining ring [0047] Di_Geh2 internal diameter of the radial piston pump according to the invention [0048] 1 drive shaft [0049] 2 (a-g) piston/working chamber combination [0050] 3 high pressure housing [0051] 4 cylinder housing [0052] 5 housing component with an integrated retaining ring [0053] 6 stator housing [0054] 11 eccentric [0055] 21 working chamber [0056] 22 piston [0057] 23 (a-g) cover [0058] 24 inlet valve [0059] 25 outlet valve [0060] 26 seal [0061] 27 screw [0062] 51 retaining ring [0063] 52 sealing face [0064] 53 contact face (on the housing component) [0065] 54 positioning means, in particular positioning bore [0066] 55 passage (for the housing screw connection) [0067] 231 contact face (on the cover) [0068] 241 fluid inlet [0069] 251 fluid outlet [0070] 252 high-pressure fluid channel [0071] 521 groove

[0072] Here, it goes without saying that features and details which are described in conjunction with a method also apply in conjunction with the apparatus according to the invention, and vice versa, with the result that reference is always made or can always be made mutually to the individual aspects of the invention with regard to the disclosure. Moreover, a possibly described method according to the invention can be carried out by way of the apparatus according to the invention.

[0073] The terminology used herein serves only for the purpose of description of particular embodiments, and is not intended to restrict the disclosure. As used herein, the singular forms a/an and the are also intended to include the plural forms unless the context clearly indicates otherwise. In addition, it will become clear that the terms has and/or having, when used in this description, specify the presence of the stated features, integers, steps, operations, elements and/or components, but do not rule out the presence or the addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof. As used herein, the term and/or includes any desired element and all combinations of one or more of the associated, listed elements.

[0074] First, reference is made to FIGS. 2 and 4.

[0075] A radial piston pump substantially comprises a drive shaft 1 with an eccentric 11, and at least one piston/working chamber combination 2, which is incorporated in a cylinder housing 4. To define the axial direction, a longitudinal axis L of the drive shaft 1 is shown in FIG. 5. The piston/working chamber combination 2 substantially comprises a working chamber 21 and a piston 22. The working chamber 21 is closed on the head side or piston head side by a cover 23.

[0076] As a rule, the radial piston pump comprises at least two piston/working chamber combinations 2, 2a, 2b, . . . which extend radially from the drive shaft 1. Preferably, the radial piston pump comprises at least three, preferably six, piston/working chamber combinations 2, 2a, 2b, . . . which extend correspondingly in a star shape from the drive shaft 1. Accordingly, each piston/working chamber combination 2, 2a, 2b, . . . is provided with a cover 23, 23a, . . . . The piston/working chamber combinations 2, 2a, 2b, . . . are preferably all incorporated in the cylinder housing 4.

[0077] Furthermore, a fluid inlet 241 is provided in the cover 23 or on the head side of the working chamber 21. Also, a fluid outlet 251 is provided in the working chamber 21, preferably in the wall of the working chamber 21. The fluid inlet 241 is equipped with an inlet valve 24, which can optionally close or release the fluid inlet 241. The fluid outlet 251 is equipped with an outlet valve 25, which can optionally close or release the fluid outlet 251. Alternatively, it can also be provided that the fluid inlet 241 or the inlet valve 24 is provided in the piston 22, in particular in the piston head. Here, for example, reference can be made to FIG. 10.

[0078] The fluid F to be compressed flows via the fluid inlet 241 or the inlet valve 24 into the working chamber 21, is compressed there by the stroke movement of the piston 22 and leaves the working chamber 21 through the outlet valve 25 or the fluid outlet 251. Here, for example, reference can be made to FIGS. 11 and 12 for the schematic indication of the flow path. The configuration of the valves, for example as a spring plate valve, is sufficiently known to a person skilled in the art and requires no further explanation here.

[0079] According to the invention, it is provided that the radial piston pump is equipped with a retaining ring 51 integrated in a housing component 5 for all of the covers 23, 23a, . . . of the piston/working chamber combinations 2, 2a, 2b, . . . .

[0080] To illustrate the difference over a separate retaining ring, reference should be made to FIGS. 1 and 3, which show a separate retaining ring for all of the covers of the piston/working chamber combinations. By comparing the above-mentioned illustrations, FIGS. 1 and 3, on the one hand, and FIGS. 2 and 4, on the other hand, the effect on the external diameter of the overall assembly is shown. It becomes clear that, in the case of the refinement according to the invention with a housing-integrated retaining ring, see in particular FIGS. 2 and 4, the external diameter Da_Geh2 is smaller than in the variant with a separate retaining ring and its external diameter Da_Geh1, see in particular FIGS. 1 and 3.

[0081] There are also advantages with regard to the internal diameter of the radial piston pump according to the invention. Accordingly, FIGS. 3 and 4 show the internal diameters of the housings of both variants, on which a low pressure p_ND (see in particular FIG. 5) acts. It can be seen that, in addition to the external housing diameter, the internal housing diameter of the housing-integrated retaining ring variant Di_Geh 2 is smaller than the diameter Di_Geh 1 of the separate retaining ring variant.

[0082] The larger internal diameter of the separate retaining ring variant in turn causes the axial force to be greater (with the same pressure). A higher axial force means a greater load on the housing screw connection, in particular a higher operating force for the screws. As a measure for maintaining the sealing effect, in particular axially between the housing parts, the preloading force of the screws would have to be increased, a screw material with higher strength would have to be used and/or the number of screws would have to be increased. All of these measures would lead to an increase in costs. Here, the solution according to the invention of the housing component with an integrated retaining ring affords advantages, since here smaller internal surfaces should be expected or be possible and correspondingly lower forces should be expected.

[0083] In particular, FIG. 5 shows the housing components of the radial piston pump. It is preferably provided that the radial piston pump has at least one further housing component, wherein the housing component 5 with an integrated retaining ring 51 and the further housing component or components form the housing of the radial piston pump. The radial piston pump shown here by way of example preferably consists on the housing side of a total of four housing components, which are in particular axially screwed together. A radial piston pump according to the invention comprises, for example, a high-pressure housing 3, the cylinder housing 4, in particular for receiving the piston/working chamber combinations (2, 2a, 2b, . . . ), the housing component 5 with an integrated retaining ring 51 and a stator housing 6, in particular for receiving a rotor (not shown) of an electric motor. The axial screw connection, preferably a screw connection in the axial direction, which connects all of the housing parts to one another, is preferably designed to ensure the sealing effect with respect to the environment between the housing components, see in particular FIG. 5 in this regard.

[0084] Preferably, the housing component 5 with an integrated retaining ring has plane-parallel axial sealing faces 52 in order to be able to ensure the tightness requirements with respect to the adjacent housing parts. Preferably, the surfaces of the sealing faces 52, at least in the region D, are equipped with concentric grooves 521, in particular with a ripple in the radial direction. Preferably, the grooves 521 are configured in the micrometer range, in particular in the sealing region to the outside. Here, in particular, reference can be made to FIG. 10.

[0085] In a further advantageous refinement of the invention, it can be provided that the housing components 3, 4, 5, 6 for forming the pump housing are screwed together. Preferably, the housing components are jointly screwed together by means of a screw 27. For this purpose, it can be provided that the cylinder housing 4 has a flange 28 or the like, which serves for the screw connection to the further housing components. The cylinder housing may also have a sealing face 52.

[0086] Preferably, fluid channels of the radial piston pump, or at least partial regions of fluid channels, can be formed by means of the housing parts which are screwed together. Such an assembled channel is, for example, the high-pressure channel 252.

[0087] The housing components 3 to 6 can delimit or seal various pressure regions within the radial piston pump or toward the outside. In a further advantageous refinement of the invention, it can be provided that the housing component has plane-parallel axial sealing faces. By means of sealing faces configured in such a way, a tight connection to the adjacent housing component, such as to the high-pressure housing 7 or to the stator housing 8, can be provided.

[0088] Furthermore, it can be provided that seals are arranged in addition to or solely between the sealing faces 52.

[0089] In a further advantageous refinement of the invention, it can be provided that the surfaces of the sealing faces 52 have one or more geometric shapes that deviate from a flat or approximately flat face. Thus, it can be provided that, for the targeted formation of contact faces or linear contacts, at least one of the sealing faces 52 has a concave or convex shape. Thus, for example, a flat sealing face 52 of a housing component can be brought into contact with the convex surface or sealing face 52 of another housing component and therefore provide a seal. By means of contact between a flat and a convex surface, a defined linear contact between the two surfaces is advantageously formed. Such a linear contact can preferably entirely or at least partially represent the function of a seal between corresponding components. Advantageously, one of the surfaces can have elastic behavior, and therefore fluctuations in the distance between the components can be compensated by the elasticity.

[0090] Preferably, contact faces 53 are provided on the housing component 5 with an integrated retaining ring 51 and contact faces 231 on the cover 23, the contact faces preferably being designed in such a way that the housing component 5 with an integrated retaining ring 51 can fix the cover 23 on the cylinder housing 4, in particular axially and/or radially, thus accordingly against pressure from the working chamber 21.

[0091] Further preferably, the cover 23 and the housing component 5 with an integrated retaining ring 51 have an overlap in the joint diameter, in particular in the region of the cover 23 on the cylinder housing 4, such that an interference fit is produced between the cover 23 and the housing-integrated retaining ring 51.

[0092] Preferably, a screw is provided for the connection of all of the housing parts; in other words, the housing parts are connected with a single screw, as shown in FIG. 14 as a detail of a longitudinal section of a radial piston pump according to the invention. When all of the housing components are screwed together by means of one screw, rapid assembly is possible since intermediate screw fittings are omitted.

[0093] It can be advantageous, for example, for the cylinder housing 4 and the housing-integrated retaining ring 5 to form a pre-assembled assembly or a module for assembly. The housing part 5 with the housing-integrated retaining ring 51 fixes all of the covers 23 directly on the cylinder housing 4. The housing parts or the pre-assembled modules can be aligned with one another and then screwed together with at least one screw 27. A further advantage which results from the use of the housing component 5 as a separate component is the ability to pre-assemble (without screws) an assembly comprising the housing component 5 and the cylinder housing 4 (preferably with the cover 23 and the valves 24, 25, piston and optionally seals). This assembly can then be easily screwed to the other housing components and the radial piston pump can be fully assembled. Another advantage is the resulting modularity. The housing components or the housing of the radial piston pump can be produced, for example, by injection molding or diecasting. If a radial piston pump with a different cylinder layout is wanted, e.g. a different cylinder volume or a different arrangement/number of cylinders, the installation space required in the axial direction of the radial piston pump usually also changes. By means of the individually adapted housing component 5, it is possible, for example, to react to a changing axial installation space requirement of a cylinder housing 4 modified in such a way. As long as the contact faces or sealing faces are unchanged, the other housing components can be used without modification. Thus, by means of the housing component 5 with an integrated retaining ring 51, a radial piston pump which is modular and/or scalable in its axial construction length (or performance capability) can be formed. The housing component 5 can also be understood as meaning a housing ring or spacer. Details in this respect are shown in particular in FIG. 14.

[0094] Preferably, the housing component 5 with an integrated retaining ring 51 should be joined to the cylinder housing 4 with respect to the angular position in an angle-oriented manner so that the passages for the housing screw connection(s) are aligned with one another and the screws can be inserted through or the contact faces 231 or 53 of the cover 23 correspond to the retaining ring 51. For this purpose, it can be provided, for example, that the housing component 5 is 25 equipped with an integrated retaining ring 51 and at least one positioning means, in particular positioning bore. The cylinder housing 4 accordingly has a corresponding positioning means, for example in the form of a pin. The positioning means 54 of the housing component 5 is used in particular for the angular orientation of the integrated retaining ring 51 with respect to the joining device. The cylinder housing should be fixed in the mounting nest in an angle-oriented manner, for example on the clamping slugs or a differently configured geometry. The automated assembly can then join the two housing parts in the correct angular position. The angular orientation is recommended because of the assignment of the contact faces between the cover 23 and integrated retaining ring 51.

[0095] By this means, it can be ensured, for example, that, during the assembly, the housing component 5 with an integrated retaining ring 51 can be joined in the correct angular position, for example, for picking up in the gripper of the tool. It can also be advantageously provided that the housing component 5 with an integrated retaining ring 51 is equipped with a second positioning means, in particular second positioning bore 54. A second positioning bore, in particular with an angular offset not equal to 180? with respect to the first positioning bore, is particularly advantageous if, for example, a chamfer or rounding is present on the inner ring edge on one side of the retaining ring 51, which facilitates the joining of the retaining ring 51.

[0096] The second positioning bore arranged offset ensures that the housing component 5 with an integrated retaining ring 51 is always installed at the correct angle.

[0097] The second positioning bore can be on a different hole circle from the first bore, with the advantage of secure angular alignment, and with the advantage that the housing component 5 then also cannot be installed the wrong way round (rotated 180? about the vertical axis) if a chamfer is provided on one side of it for the joining.

[0098] In a further configuration, 3 bores are provided, with one being arranged on a different radius or hole circle. The advantage is, as mentioned above, the clearly angle-oriented and correct side assignment for the housing component.

[0099] It can also be preferably provided that the cover 23 has the inlet valve or valves 24.

[0100] Preferably, the housing component 5 with an integrated retaining ring 51 should be made of steel or a steel alloy at least in sections, but at least the retaining ring 51 as such, so that it advantageously meets the high strength requirements of its function as a retaining ring (surface pressure with respect to the cover).

[0101] The material and/or production method of the housing component 5 with an integrated retaining ring 51 includes all of the materials or production methods known from the prior art, such as casting, turning or milling (coarse and fine).

[0102] It may also be preferably provided that the contact face of the cover and/or the associated contact face of the housing component with an integrated retaining ring is flat or concave/convex, wherein the curvature of the cover or the housing component with an integrated retaining ring can run axially with respect to the shaft of the compressor and/or transversely with respect thereto.

[0103] It can also be preferably provided that surface contact is provided between the cover and the housing component with an integrated retaining ring.

[0104] It can also be preferably provided that compensation of tolerances is provided between the cover and the housing component with an integrated retaining ring.

[0105] It can also be preferably provided that the housing component with an integrated retaining ring and the cover at least partially have mutually corresponding shapes.

[0106] Possible configurations of the housing component with an integrated retaining ring, in particular the passages thereof for the housing screw connection, are illustrated in particular in FIGS. 7 to 9.

[0107] FIG. 7 shows, for example, a variant in which the passage 55 for the housing screw connection is interrupted inwardly. The position of the passages is arranged within the ring next to the region of the cover system. The housing component 5 with an integrated retaining ring 55 preferably has two plane-parallel axial contact faces, which constitute the sealing face with respect to the adjacent housing parts. The arrows show by way of example the contact points for contact on the cover. Eight contact points are provided here, so that the housing component, shown here, with an integrated retaining ring can accordingly be used to fix eight covers. The variant outlined here is distinguished in particular by requiring less installation space, in particular because of a lack of enclosing of the screw passages/bores.

[0108] FIG. 8 shows a housing component with an integrated retaining ring with a stress-optimized interruption for the passages for the screw connection. For illustrative purposes, arrows here show by way of example possible contact points for contact on the cover. The variant outlined here is distinguished in particular by requiring less installation space, in particular because of a lack of enclosing of the passages.

[0109] FIG. 9 shows a housing component 5 with an integrated retaining ring 51 with fully enclosed passages for the screw connection. For illustrative purposes, arrows here show by way of example possible contact points for contact on the cover 23. The variant outlined here is distinguished in particular by the fact that no pressure spreads between the screw and the screw bore. This means that the screw bore is therefore already sealed by the refrigerant inside the compressor. An additional seal, e.g. under the screw head, is not in principle required.

[0110] In particular, FIG. 14 shows the simultaneous screw connection of all of the housing components 3-6. FIG. 14 is a part of a longitudinal section through the radial piston pump; the section is laid out separately (profile indicated in FIG. 6) such that the screw connection/screw is shown. This does not show the cover 23 and the required inlet valve. It is clear that the screw must not cover the inlet opening. As can be seen from the figures, the screw connection is preferably provided next to the contact faces between housing component 5 and cover 23 in order to reduce the radial installation space. In principle, it is conceivable that the geometries of the integrated retaining ring are formed in the stator housing and that the stator housing has integrated the function of the housing component 5. The housing component 5 can be considered to be a type of housing washer. The contact faces can be machined over the entire length of the housing washer. If the functions of housing component 5 and thus the contact faces 53 with respect to the cover 23 are formed on the stator housing 6, the machining is more complex and therefore expensive.