Rotary compressor drive line

Abstract

The present invention relates to a drive system, and in particular to a direct coupling between a driving shaft and a driven shaft in a drive system of a rotary compressor, and further to the integration of a lubricating oil circuit in said drive system, including all associated flow paths and components.

Description

[Technical Field]

[0001] The present invention relates to a drive train of an oil-free rotary compressor, in particular to a coupling for directly connecting a drive shaft to a driven shaft for driving a compression element, in particular a tooth or a movable tooth set, movably arranged in an oil-free compression chamber of a rotary tooth compressor. Furthermore, the present invention relates to the direct coupling of a lubricating oil circuit, including all associated flow paths and components, to this drive train. [Background technology]

[0002] Oil-free rotary compressors can be used in the production of a wide range of products, from semiconductors to pharmaceuticals to paper. Oil-free refers to the absence of lubricating oil in the compression chamber. A typical oil-free rotary compressor consists of a compression element, specifically a tooth or a set of movable teeth, located in the oil-free compression chamber, and a motor that drives the movement of the compression element.

[0003] In conventional systems, drive is achieved by an indirect connection between the drive motor and the driven compression element, for example via a series of gears. In the latter case, the drive gear may be attached to a shaft driven by the motor (drive shaft or drive shaft), which acts via a pinion on a shaft that drives the compression element (driven shaft).

[0004] It would be clear that direct coupling of the drive shaft and driven shaft of a rotary compressor offers certain advantages, were it not for the fact that a special drivetrain design is required. To clarify, the direct drive shaft is subject to significant torque loads at high operating speeds, since gear ratios cannot be used to compensate for low engine speeds. This means that a maintenance-free coupling must be very robust to prevent any form of damage or wear. Furthermore, the material properties of all components must be carefully considered, e.g., thermal expansion coefficients, friction coefficients, etc.

[0005] An additional factor that can complicate direct-coupled designs is the high-temperature environment, which is typically contaminated with oil or other contaminants. However, compressors require some form of lubrication to cool, seal, and / or lubricate certain internal components, such as bearings disposed around the drive shaft. Alternative components that do not require lubrication, such as "greased-for-life" or magnetic bearings, are known, but generally are not suitable for applications requiring long life, high loads, and / or high rotational speeds, or introduce additional complexity and / or energy consumption.

[0006] Typically, the required lubrication oil is supplied by an integrated oil circuit, with the lubrication oil being supplied at the required injection pressure by an external, e.g., electrically driven, pump. However, an externally driven pump requires the presence of an additional drive and associated control unit, which increases the complexity of the compressor. This creates the risk that the external pump may accidentally fail, e.g., as a result of a power failure or control error, causing the drive train to continue operating indefinitely without the required lubrication, leading to accelerated wear of the components. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there is a need to develop a solution that overcomes the shortcomings of the prior art. In particular, there is a need for a direct connection that can achieve the high power and / or high speed torque inherent in rotary compressor drivelines between a drive shaft on the one hand and a driven shaft disposed in the rotary compressor driveline on the other hand. [Means for solving the problem]

[0008] To address the above needs and the shortcomings of the prior art, the present inventors have provided a coupling capable of achieving torque having high power and / or high rotational speeds typical of compressor drivelines between one drive shaft and another driven shaft disposed in the driveline of a rotary compressor. The coupling described herein can also significantly improve the life of the driveline, even in very high-temperature environments and / or environments contaminated with oil or contaminants, eliminating or limiting the need for maintenance. Additionally, the coupling described herein can also enable easy and quick installation and / or removal (i.e., shaft decoupling) of the driveline in obscured or difficult-to-access spaces, as well as easy and quick installation and replacement of damaged or worn components. Additionally, the coupling described herein can enable a simple and robust construction and reduce the number of separate compressor and driveline components, which in turn leads to embodiments that are more reliable, more compact, and require less cooling, less lubrication, and / or less maintenance.

[0009] As will become apparent from the present specification, the couplings described herein can further enable the integration of a lubricant pump, such as an oil pump configured to drive a lubricant circuit, into the same drive train. Such integration is difficult due to the high speeds typical of compressor drives, and coupling to the lubricant pump requires a small drive shaft outer diameter to avoid the risk of cavitation (i.e., rotational speed must be limited to reduce dynamic pressure within the pump). As will also become apparent, the dimensions of the coupling can be limited by the clamping force.

[0010] One aspect of the present invention relates to a coupling for a drive train of a rotary compressor, the coupling comprising: a driven shaft configured to drive a compression element, such as a tooth or set of teeth, movably arranged in an oil-free compression chamber; a drive shaft driven by a drive element such as a motor; are configured to directly connect to each other, The coupling is a coupling hub disposed on the driven end of the driven shaft; a coupling disc attached to and / or integral with the drive end of the drive shaft; Equipped with The drive shaft has a hollow passageway running through its entire length, and the coupling has an elongated stud disposed within the hollow passageway of the drive shaft, the stud being connected to a driven end of the driven shaft and configured to clamp the coupling disc to the coupling hub.

[0011] In one embodiment, the coupling further comprises a tensioning element disposed on the stud, the tensioning element configured to contact the non-drive end of the drive shaft and apply tension to the stud to apply a preferably controllable clamping force to the coupling.

[0012] In one embodiment, the stud is secured in contact with the non-drive end of the drive shaft by a tension element disposed on the stud, the tension element exerting a preferably controllable clamping force on the coupling.

[0013] In one embodiment, the stud includes an externally threaded end onto which a complementary female-threaded tension element can be fastened to secure the stud in contact with the non-drive end of the drive shaft, preferably the tension element includes a nut, more preferably a lock nut.

[0014] In one embodiment, the surface of the coupling hub and the abutment surface of the coupling disc include a plurality of mating radial grooves.

[0015] In a preferred embodiment, the mating radial grooves are Hirth type, preferably with a profile angle of 50 to 70 degrees, more preferably about 60 degrees.

[0016] In one embodiment, the coupling includes a friction disc disposed between a surface of the coupling hub and an abutment surface of the coupling disc, the friction disc configured to increase the coefficient of friction between the abutment surfaces.

[0017] In one embodiment, the coupling comprises a conical clamping ring disposed between the driven end of the driven shaft and the coupling hub, the clamping ring being configured to clamp the driven shaft to the coupling hub, preferably a plurality of conical clamping rings arranged in series.

[0018] In one embodiment, the coupling is disposed between the driven end of the driven shaft and the stud, and includes a fastening portion having a larger diameter than the stud and configured to couple the stud to the driven shaft.

[0019] In one embodiment, the stud has an externally threaded end and the fastening portion has a complementary internally threaded opening into which the stud can be threaded, preferably the fastening portion comprises a bolt having a bolt head with an opening.

[0020] In one embodiment, the coupling comprises a fastening element, preferably a plurality of fastening elements, disposed between the drive end of the drive shaft and the coupling disc, configured to clamp the drive shaft to the coupling disc.

[0021] In one embodiment, the fastening element includes a bolt that threads into the drive end of the drive shaft.

[0022] In one embodiment, the non-drive end of the drive shaft is configured to couple to a lubrication pump disposed on the drive shaft, with the stud protruding beyond the lubrication pump.

[0023] In one embodiment, the coupling hub includes a bevel disposed on the side of the coupling hub and configured to direct injected lubricant toward a component of the coupling requiring lubrication, preferably a conical clamp ring disposed adjacent the coupling hub.

[0024] A further aspect of the present invention relates to a drive system for a rotary compressor, the drive system comprising: a driven shaft configured to drive a compression element, such as a tooth or a set of teeth, movably arranged in an oil-free compression chamber; a drive shaft driven by a drive element such as a motor; a coupling as described herein for directly connecting a driven shaft and a drive shaft; Equipped with.

[0025] A further aspect of the present invention relates to a rotary compressor, comprising: a compression element, such as a tooth or a set of teeth, movably arranged in an oil-free compression chamber, and a driven shaft configured to drive the compression element; a drive element, such as a motor, and a drive shaft driven by the drive element; a coupling as described herein for directly connecting a driven shaft and a drive shaft; Equipped with.

[0026] In one embodiment, the rotary compressor includes a lubricant injector having an injection nozzle configured to inject lubricant, such as oil, onto a side of a coupling hub, the coupling hub including a beveled surface disposed on the side of the coupling hub configured to direct the injected lubricant towards components of the coupling requiring lubrication, preferably towards bearings disposed adjacent the coupling hub.

[0027] In one embodiment, the rotary compressor includes a lubricant pump, such as an oil pump, configured to drive a lubricant circuit, the lubricant pump being disposed on a non-drive end of a drive shaft, the drive shaft being coupled to drive operation of the lubricant pump.

[0028] In one embodiment, the lubricant pump is coupled to the drive shaft by a recess disposed on the lubricant pump, the recess configured to mate with a protruding element disposed on the end of the drive shaft, or vice versa, and preferably the drive shaft comprises a keyway and a key disposed within the keyway.

[0029] In one embodiment, the lubricant pump includes an outer rotor and an inner rotor (92) rotatably disposed within the outer rotor, the outer rotor and inner rotor having complementary trochoidal profile shapes.

[0030] It will be apparent that further variations and / or combinations of the embodiments are possible, particularly with regard to various aspects of the invention.

[0031] To better illustrate the features, structures, or characteristics of the present invention, some embodiments of the present invention are illustrated in the accompanying drawings, without limitation. The following description of these accompanying drawings is merely exemplary and is not intended to limit the subject matter, its application, and / or its uses. The reference numerals used in the accompanying drawings serve to more easily identify particular elements without limiting the illustrated elements and / or embodiments of the present invention.

[0032] The following reference numerals are used throughout the drawings, claims, and description: Driveline 10 、 Drivetrain shaft 11 、 Rotary Compressor 100 、 Driven shaft 1 、 Drive shaft 2 、 hollow passage 21 、 Coupling 3 、 Driven part 3´ 、 Coupling Hub 31 、 Coupling disc 32、 Radial groove 33 (e.g., Hirth coupling) 、 Friction disc 34 、 Elongated Studs 4 、 tension element 41 (e.g. 、 nut) 、 Clamp ring 5 (e.g. 、 Conical clamping ring) , pressure ring 51, Fastening part 6 (e.g. 、 bolt) , bolt head 61, Opening 62 、 Fastening element 7 (e.g., bolt) 、 Lubricant Injector 8 , injection nozzle 81, Slope 82 、 Lubricating Oil Pump 9 、 Outer rotor 91 、 Inner rotor 92 、 Keyway 94 、 Key 95 、 Oil pan 97 、 Oil filter 96 、 First compressor element 101, second compressor element 102, timing gear 103, timing gear 104, pinion 105, bearing 106, bearing 107, bearing 108, bearing 109, motor 200, bearing 201, bearing 202, housing 300, transmission gear 302, bearing 303, bearing 304, flexible coupling 305, housing 900, axial clamping force A 、 is the radial clamping force R. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a schematic diagram of an embodiment of a coupling 3 for a rotary compressor drive train 10. FIG. [Figure 2] 1 is a schematic diagram of an alternative embodiment of a coupling 3 for a rotary compressor drive train 10. FIG. [Figure 3] 1 is a schematic diagram of clamping forces that can effect torque transmission in one embodiment of driveline 10. FIG. [Figure 4] 10 is a schematic diagram of clamping forces that can effect torque transfer in an alternative embodiment of the driveline 10. FIG. [Figure 5]Schematic illustration of an embodiment of a coupling 3, in which a friction disc 34 is arranged between a coupling hub 31 and a coupling disc 32. [Figure 6] 1 is a schematic diagram of a preferred embodiment of a coupling 3, in which a plurality of radial grooves 33 are provided between a coupling hub 31 and a coupling disc 32. [Figure 7] 1 is a schematic diagram of an alternative embodiment of a coupling 3, in which a plurality of radial grooves 33 are provided between a coupling hub 31 and a coupling disc 32. FIG. [Figure 8] Schematic view of an embodiment of a coupling 3, in which a driven shaft 1 is clamped by a conical clamping ring 5 and fixed to a stud 4 by a pressure ring 51 and a fastening portion 6. [Figure 9] 1 is a schematic diagram of an embodiment of a coupling 3, in which the driven shaft is further clamped by a plurality of conical clamping rings 5. [Figure 10] Schematic illustration of an embodiment of a coupling 3, in which the drive shaft 2 is further attached to a coupling disc 32 by means of a fastening element 7. [Figure 11] Schematic diagram of a preferred embodiment of a coupling 3, in which the stud 4 is further coupled to a lubricant pump 9. [Figure 12] 1 is a cross-sectional view of an embodiment of the driven part of a coupling 3', where the driven shaft 1 is press-fit into the coupling hub 31. FIG. [Figure 13] FIG. 1 is a cross-sectional view of a preferred embodiment of the driven part of a coupling 3′, in which the driven shaft 1 is clamped in a coupling hub 31 by a conical clamping ring 5. [Figure 14] 1 is a cross-sectional view of a preferred embodiment of the driven part of a coupling 3', in which the driven shaft 1 is clamped within a coupling hub 31 by a plurality of conical clamping rings 5. [Figure 15A] FIG. 1 is a side perspective view of a preferred embodiment of a compressor 100. [Figure 15B] A detailed view of the driven part of the coupling 3' is shown. [Figure 16] 1 is an exploded perspective view of a preferred embodiment of a coupling 3 of a drive train 10 of a rotary compressor 100. FIG. [Figure 17] FIG. 10 is a front perspective view of a preferred embodiment of the drive portion of the coupling 3 ″. [Figure 18] FIG. 10 is a cross-sectional perspective view of a preferred embodiment of the drive part of the coupling 3 ″. [Figure 19] FIG. 10 is a side perspective view of a preferred embodiment of the drive part of the coupling 3 ″. [Figure 20] 1 is a side perspective view of a lubricant injector 8 in an embodiment of a driven part 3' of a compressor 100. FIG. [Figure 21] 1 is a cross-sectional view of a lubricant injector 8 in an embodiment of a driven part 3' of a compressor 100. FIG. [Figure 22A] FIG. 1 is a partial cross-sectional perspective view of a preferred embodiment of a rotary compressor 100. [Figure 22B] A detailed view of the coupling 3 is shown. [Figure 22C] A detailed view of the lubricating oil pump 9 is shown. [Figure 23A] FIG. 1 is a partial cross-sectional perspective view of a preferred embodiment of a rotary compressor 100. [Figure 23B] A detailed view of the coupling 3 is shown. [Figure 23C] A detailed view of the lubricating oil pump 9 is shown. [Figure 24A] FIG. 1 is a side perspective view of a preferred embodiment of a rotary compressor 100. [Figure 24B] A detailed perspective view of the lubricating oil pump 9 is shown. [Figure 24C] A detailed front view of the lubricating oil pump 9 is shown. [Figure 25] 1 is a schematic perspective view of an embodiment of a coupling for a lubricating oil pump 9, in which the drive shaft 2 is provided with a keyway 94. FIG. [Figure 26] 1 is a schematic perspective view of an embodiment of a lubricant pump coupling, in which a lubricant pump 9 is keyed to a drive shaft 2 by a key. [Figure 27]FIG. 1 is a schematic view of an embodiment of an assembly having a coupling 3 similar to that of the preceding figures. [Figure 28] FIG. 28 is a schematic view similar to FIG. 27 of an assembly with a flexible coupling according to the prior art. [Figure 29] FIG. 28 is a schematic view similar to FIG. 27 of an assembly with a prior art gear coupling. DETAILED DESCRIPTION OF THE INVENTION

[0034] Before describing aspects and embodiments of the present invention, it is to be understood that the present invention is not limited to the particular systems, methods, and / or combinations described herein, as such aspects and embodiments may, of course, vary. It is also to be understood that the particular aspects and embodiments described herein are not intended to be limiting, since the scope of the present invention will be limited only by the appended claims. Similarly, reference signs in the specification and appended claims should not be construed as limiting the scope of the present invention.

[0035] Where used, the terms "comprise," "comprising," and "comprises" are synonymous with "including," "include," "including," or "contain," "containing," and "contains," and are inclusive or open-ended and do not exclude additional, unspecified elements, components, and / or method steps. Reference to particular elements, components, and / or method steps in particular embodiments of the invention does not exclude the possible presence of other elements, components, and / or method steps.

[0036] The singular forms "a", "the", and "the" include both the singular and the plural unless expressly indicated otherwise.

[0037] Sequence terms such as "first," "second," "third," and the like, unless otherwise indicated, are used in this specification and the appended claims to distinguish between similar elements and not necessarily to describe a sequential or chronological order. These terms are interchangeable under appropriate circumstances, and it is understood that the embodiments of the invention described herein may operate in sequences other than those described or illustrated in this application.

[0038] The term "approximately" is used in this specification and the appended claims to provide flexibility to numerical ranges by specifying that a given value may be "slightly above" or "slightly below" the stated value or range. For example, when referring to a measurable value such as a parameter, amount, duration, etc., it is intended to encompass a variation of no more than ±10%, preferably no more than ±5%, more preferably no more than ±1%, and even more preferably no more than ±0.1% of the stated value, insofar as such variation is appropriate for functioning in the invention described herein. Values ​​referred to by the term "about" should be understood to be themselves disclosed. Recitation and / or listing of numerical ranges includes all values ​​and fractions included within the relevant ranges, as well as the recited endpoints.

[0039] The terms "substantially," "essentially," or "mostly" refer to the complete or nearly complete extent or degree of an action, property, quality, state, structure, object, and / or result. For example, an object that is "essentially" enclosed means that the object is completely enclosed or nearly completely enclosed. For example, an object that is "substantially" vertical means that the object is completely or nearly completely perpendicular to a reference plane. In some cases, the precise allowable degree of deviation from absolute perfection may depend on the specific context. However, generally, the degree of perfection will be such that the overall result is the same as for absolute and complete completion. The use of "essentially" also applies when used in a negative sense, meaning the complete or almost complete absence of an action, property, quality, state, structure, object, or result. For example, a composition that is "nearly free" of particles is completely free of particles or contains so few particles that the result will be similar to if the composition were completely free of particles. In other words, a composition that is "nearly free" of a component or element may still contain such component or element if there is no measurable effect of it.

[0040] Relative terms such as "left," "right," "front," "rear," "top," and "bottom" are used in this specification and the appended claims for descriptive purposes and do not necessarily represent permanent positions or orientations depending on the context in which they are used. It is understood that the terms used are interchangeable under appropriate circumstances, for example, so that the embodiments described herein can be used in positions or orientations other than those shown or described.

[0041] The terms "adjacent," "adjacent," or "contacting" each other are used in this specification and the appended claims for descriptive purposes and do not necessarily describe permanent locations, depending on the context in which the terms are used. For example, objects described as "adjacent" each other may be in physical contact with each other, in close proximity, or in the same general area or region, depending on the context in which the terms are used.

[0042] In the following sections, various aspects of the present invention are further defined. Any aspect thus defined may be combined with one or more other aspects, unless expressly stated otherwise. In particular, any feature designated as "preferred" or "advantageous" may be combined with other features or attributes designated as "preferred" and / or "advantageous." References herein to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is applicable to at least one embodiment of the present invention. The phrases "in one embodiment" or "an embodiment" appearing in different places herein do not necessarily refer to the same embodiment, although they are not intended to exclude such combinations. Furthermore, the disclosed features, structures, or characteristics may be combined in any suitable manner, as would be apparent to one skilled in the art based on this specification. The embodiments described and claimed in the appended claims may be used in any combination.

[0043] Reference is made in this specification to the accompanying drawings, which form a part hereof and which illustrate specific embodiments of the present invention. The use of bracketed or bolded numbers associated with particular elements indicates the associated elements by way of example, and not by way of limitation. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is not to be construed in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0044] Unless otherwise defined, all terms used in this specification and the appended claims, including technical and scientific terms, have the meanings commonly understood by those skilled in the art. For further guidance, definitions are incorporated herein for further explanation of terms used in the description of the present invention. All documents cited herein are incorporated herein by reference in their entirety.

[0045] To address the above-mentioned needs and shortcomings of the prior art, the present inventors have developed a means for coupling a "drive shaft" or "drive shaft" configured to be driven directly or indirectly by a driving element, such as a motor, with a "driven shaft" configured to drive directly or indirectly a compression element, particularly a rotating tooth or tooth set, movably disposed within a preferably oil-free compression chamber of a rotary compressor.

[0046] In particular, the present invention relates to a direct coupling by which high power and / or high rotational speed torque typical of rotary compressor operation can be achieved between abutting drive shafts and driven shafts in the driveline of the rotary compressor, preferably positioned substantially in line with one another along the driveline axis. The direct coupling described herein can significantly improve the life of the driveline, even in very high temperature and / or lubricant-contaminated environments, with no or limited maintenance. Additionally, the coupling described herein can facilitate installation and / or removal of the driveline (i.e., disconnection of the connecting shafts) in areas that are difficult to see or access.

[0047] A further advantage of the direct coupling described herein is that it is suitable for oil-free rotary compressor drive trains. Oil-free in this context means that there is no lubricating oil in the compression chamber. The purity of the supplied compressed air can be classified according to ISO standards into ISO Classes 0-5. ISO Class 1 means that the oil concentration in the supplied compressed air is a maximum of 0.01 mg / m³ at 1 bar (bar(a)), 14.5 psia, and 20°C. 3 Compressed air solutions that meet ISO Class 1 standards are also called "technically oil-free." On the other hand, ISO Class 0 refers to 100% oil-free compressed air, i.e., compressed air without any trace of oil concentration. Compressed air that meets ISO Class 0 standards is also called "totally oil-free." The same nomenclature will be used further in this specification.

[0048] As will become more apparent from this specification, the direct coupling described herein also allows for the integration of a lubrication pump, such as an oil pump configured to drive an integrated oil circuit, into the same driveline, preferably in line with the directly coupled shaft, i.e., along the same longitudinal axis or "driveline axis" of the driveline. Such integration is typically difficult because the oil pump's drive shaft requires a smaller outer diameter to avoid the risk of cavitation due to the high power and / or high rotational speed typical of rotary compressor drives (i.e., the rotational speed must be limited to reduce dynamic pressure within the pump). As will be explained in more detail, it is clear that in the described direct coupling, which is advantageously achieved by an applied clamping force, the diameter of the positioned stud is advantageously limited in size because it is limited by the maximum outer diameter of the drive shaft at its non-drive end. Clearly, this applied clamping force is determined by the amount of pretension applied to the coupling element by applying tension to the positioned stud connected between the driven end of the driven shaft and the non-drive end of the drive shaft.

[0049] The following provides an initial summary of various aspects of the present invention. This initial summary is intended to help the reader more quickly understand the technical concepts described herein, but is not intended to identify key or essential features thereof, nor is it intended to limit the scope of the present invention, which is limited only by the appended claims.

[0050] Those skilled in the art will understand that, unless otherwise specified, the aspects described below can be combined in a simpler manner. Also, a specific embodiment of a specific aspect can be interpreted as a specific embodiment of another aspect without a separate discussion thereof. For example, an embodiment of a coupling described herein also constitutes an embodiment relating to the manufacture of the coupling, the use of the coupling, etc. The same applies to the advantages of specific embodiments when integrated in a comprehensive aspect, for example, the integration of a coupling described herein in the drive train of a rotary compressor.

[0051] FIG. 1 shows one embodiment of a coupling 3 for directly connecting a driven shaft 1 and a driving shaft 2 in a driveline 10 of a rotary compressor. The longitudinal axis of the driveline 10 (hereinafter referred to as the driveline shaft 11) is represented diagrammatically by a dotted line. The illustrated coupling 3 comprises a coupling hub 31 and a coupling disc 32 arranged adjacent to each other, with the surface of the coupling hub 31 being in contact with or near the abutment surface of the coupling disc 32. As shown, the coupling hub 31 can be driven by the coupling hub 31. Driven shaft 1 The end of ( driven end ) Similarly, the coupling disc 32 is arranged on the end (drive end) of the drive shaft 2 which is able to drive the coupling disc 32.

[0052] The components of the coupling 3 can be connected to one another by a clamping force exerted by a stud 4 and an associated tension element 41 that secures the stud 4 to the drive shaft 2. As shown, the stud 4 has at least two ends: a first end that is directly or indirectly connected to or attached to the driven end of the driven shaft 1, and a second end that is directly or indirectly connected to or attached to the drive shaft 2, preferably at the non-drive end of the drive shaft 2 (i.e., the end of the drive shaft 2 that does not drive the coupling disc 32 and therefore does not drive the driven shaft 1 - this does not exclude that the non-drive end can or will drive other elements).

[0053] 1, the drive shaft 2 includes a hollow passage 21 having an inner diameter suitable for locating this stud 4. In the embodiment shown, the hollow passage 21 extends the entire length of the drive shaft 2, i.e., from the drive end to the non-drive end of the drive shaft 2. The embodiment shown has the advantage that the stud 4 and optionally the associated tension element 41 are easily accessible along the end of the drive shaft 2, allowing for easy installation / removal of the coupling.

[0054] As further shown in FIG. 1 , the stud 4 can be secured in contact with the non-drive end of the drive shaft 2 by a tensioning element 41, which preferably exerts a controllable clamping force on the coupling 3. In other words, the tensioning element 41 fastens the stud 4 to the non-drive end of the drive shaft and applies a clamping force to the coupling 3. In other words, the stud 4, one end of which is connected to the driven shaft 1 as shown, is engaged by this tensioning element 41, which directly or indirectly applies tension to the other end of the stud 4 against the non-drive end of the drive shaft 2. In other words, the stud 4 is subjected to a tensile load along the length of the stud 4 by this tensioning element 41, or in other words, a pretension is introduced into the stud 4 by this tensioning element 41, which is transmitted to the coupling 3 via the connection with the driven shaft 1 on the one hand and via the tensioning element 41 in contact with the drive shaft 2 on the other hand, so that the coupling hub 31 and the coupling disc 32 are forced towards each other along the length of the stud 4. It is clear from this that the clamping force exerted by the stud 4 is axial, and the stud 4 is pulled against the non-drive end of the drive shaft 2 along the axial direction, in other words along the longitudinal direction of the stud 4. In one embodiment, a tension element 41 can be positioned around the body of the stud 4, preferably on the end of the stud 4, and the relative position of the tension element 41 to the end of the stud 4 determines the degree of clamping force. To this end, the tension element 41 can be fastened onto the stud 4 along the driveline shaft 11.

[0055] In one embodiment, the tension element 41 can comprise a nut. To this end, the stud 4 can comprise an end that is at least partially provided with an external thread, onto which the nut 41, provided with a complementary internal thread, can be fastened. Furthermore, a lock washer can be added between the nut 41 and the end of the drive shaft 2 to prevent the nut 41 from loosening due to vibration. In one embodiment, the tension element 41 can comprise a lock nut that already has a locking element, such as a plastic ring, built into it.

[0056] 2 shows an embodiment of a coupling 3 in which a coupling disc 32 is at least partially integrated into the drive shaft 2 to form an "integral coupling disc" 32. Specifically, the drive end of the drive shaft 2, which is located at or near the abutment surface, can provide the function of the coupling disc 32. This embodiment has the advantage of simplifying the complexity of the drive train 10, but requires that the entire drive shaft 2 be replaced when it wears out.

[0057] By fastening the stud 4 to the driven end of the driven shaft 1 on the one hand and the non-drive end of the drive shaft 2 on the other hand, an axial clamping force (i.e. substantially in the direction of the driveline shaft 11) can be generated between the abutment surfaces of the coupling hub 31 and the coupling disc 32. This "axial clamping force" A is represented diagrammatically in Figures 3 and 4 by arrows pointing towards each other and positioned between the abutment surfaces of the coupling hub 31 and the coupling disc 32.

[0058] Returning to FIG. 1 , an axial pressing force can be applied to the drive shaft 2 by tightening a tension element 41, such as a nut, located at the end of the stud 4. The axial pressing force is then transmitted to the coupling disc 32, which is pressed against the coupling hub 31, i.e., clamped between the drive shaft 2 and the coupling hub 31 by an axial clamping force A. In other words, it is clear that the elongated stud 4 is thus configured to clamp the coupling disc 32 to the coupling hub 31. According to the example shown in FIG. 1 , this can be achieved, for example, by clamping the coupling disc 32 against the coupling hub 31; however, as will be explained in more detail, alternative embodiments are also possible, in which one or more suitable elements, such as, for example, friction discs and / or other suitable elements, are present between the coupling disc 32 and the coupling hub 31 when clamping the coupling disc 32 to the coupling hub 31. When driving the drive shaft 2, a load can be transmitted via the coupling disc 32 to the coupling hub 31, which can then drive the driven shaft 1, as will be explained later. It will therefore be appreciated that the axial clamping force A in the illustrated driveline 10 can be achieved by the friction that exists between the abutting surfaces of the coupling hub 31 and the coupling disc 32. However, since the maximum torque that can be achieved will typically be high in rotary compressor drives with high torque pulsations, it may be advantageous to reduce the magnitude of the required axial clamping force A.

[0059] FIG. 5 shows an embodiment of a coupling 3 in which a friction disc 34 is disposed between the surface of the coupling hub 31 and the abutting surface of the coupling disc 32. The friction disc 34 can be configured to increase the coefficient of friction, thereby reducing the required clamping force and enabling high torque transmission. In one embodiment, the friction disc 34 can include granules / crystals bonded to a matrix material, for example, coated with diamond granules. These granules then act on the abutting surfaces of the coupling hub 31 and the coupling disc 32 under the influence of a sufficiently high surface pressure. The friction disc 34 preferably increases the coefficient of friction between the abutting surfaces by a factor of two, preferably three, more preferably four, and even more preferably five or more. Examples of suitable friction discs 34 are "EKAgrip" (registered trademark) (3M) or "DiaNiP-G" (Atela), although other friction discs 34 known in the art are equally suitable.

[0060] FIG. 6 shows a preferred embodiment of the coupling 3, in which the surface of the coupling hub 31 and the abutting surface of the coupling disc 32 are provided with a plurality of mating radial grooves 33. In one embodiment, the mating radial grooves may include crown gears or bevel gears. It is clear that further alternative embodiments are possible, such as ball couplings or other suitable couplings. The provision of such radial grooves 33 has the advantage of reducing the required clamping force and enabling high torque transmission. For example, the radial grooves 33 may be machined into the surface of the coupling hub 31 and / or the coupling disc 32. While providing radial grooves in the surface is more complex than applying the friction discs 34 described above, it has the advantage of not requiring additional alignment structures to limit tolerance buildup in the assembly of the components.

[0061] 7 shows a preferred embodiment of coupling 3 in which a plurality of mating radial grooves 33 are formed in the surface of coupling hub 31 and the abutment surface of drive shaft 2, so that the abutment end of drive shaft 2 acts as a "one-piece" coupling disc 32. While machining radial grooves into the surface of drive shaft 2 is certainly more complicated than milling the surface of a coupling disc, it has the added benefit of reducing tolerance build-up in the assembly of the components.

[0062] In a preferred embodiment, the mating radial grooves 33 may be of the Hirth type as known in the art. Hirth couplings are self-aligning and, in some embodiments described below, have the added advantage of being able to achieve high torque transmission with limited pretension. Figure 16 shows an example of a Hirth coupling provided on the abutting surfaces of the coupling hub 31 and the coupling disc 32. Other examples will be described throughout the following text.

[0063] Hirth couplings typically consist of multiple radial teeth formed by grooves milled into the shaft surface. The characteristics of a Hirth coupling are largely determined by the number of teeth and the tooth profile angle measured relative to the contact surface. Those skilled in the art understand that there is no standardized measurement system for tooth profile angle. Typically, tradeoffs can be made between tooth thickness (tooth strength), tangential contact surface angle, pretension required to transmit torque, and alignment (alignment force). Illustratively, in the extreme case of a profile angle of 0°, everything is transmitted by axial friction, requiring a very large clamping force, while in the other extreme case of 90°, practically no clamping force is required. It is understood that in the embodiments described herein, the appropriate profile angle is selected between these extreme cases.

[0064] In one embodiment, the profile angle of the Hirth coupling is between 45° and 75°, preferably between 50° and 70°, more preferably between 55° and 65°, and even more preferably about 60°, e.g., 59° or 61°. A person skilled in the art can select a suitable embodiment of the Hirth coupling based on the above parameters, with the preferred values ​​being preferred embodiments of the Hirth coupling to achieve greater torque transmission for more limited pretension.

[0065] Further torque transmission between the connecting shafts 1, 2 can be achieved by providing a clamping force between the respective abutment sides of the driven shaft 1 and the coupling hub 31, and between the drive shaft 2 and the coupling disc 32. By disposing the coupling hub 31 around the driven end of the driven shaft 1, a radial (i.e., substantially perpendicular to the driveline shaft 11) clamping force can be achieved between the abutment surfaces of the driven shaft 1 and the coupling hub 31. This "radial clamping force" R is represented diagrammatically in Figures 3 and 4 by arrows pointing towards each other and positioned between the abutment surfaces of the driven shaft 1 and the coupling hub 31.

[0066] In one embodiment, this radial clamping force R can be achieved by press-fitting the driven shaft 1 into the inner diameter of the coupling hub 31, preferably by a press fit or shrink fit. However, those skilled in the art will appreciate that other force-fit or form-fit connections suitably designed to secure the shaft and hub are equally suitable, provided that after press-fitting, the driven shaft 1 can no longer move relative to the coupling hub 31. Figure 13 shows an example of an embodiment of a coupling 3 in which the driven shaft 1 is clamped to the coupling hub 31 by a press fit.

[0067] In one embodiment, this radial clamping force R can be achieved by disposing a conical clamping ring 5 around the driven shaft 1, preferably between the driven end of the driven shaft 1 and the coupling hub 31, the conical clamping ring 5 being configured to clamp the driven shaft 1 to the coupling hub 31 and to drive the driven shaft when driven by the (rotational) movement of the abutting coupling hub 31. It is clear that in this case the clamping ring 5 is disposed radially between the driven end of the driven shaft 1 and the coupling hub 31.

[0068] FIG. 8 shows an embodiment of a coupling 3 in which one conical clamping ring 5 is arranged around the driven shaft 1. The advantage of the conical clamping ring 5 is that a large torque transmission can be achieved between the coupling hub 31 and the driven shaft 1, which is well suited to high torque pulsations such as those typically found in rotary compressors. One example of a suitable conical locking element is known in the prior art and is sold, for example, under the trade name Ringfeder and described, for example, at https: / / www.ringfeder.com / globalassets / downloads / 02-product-paper / product-paper-tech-paper-ringfeder-locking-elements-en-08-2019.pdf. The conical locking element comprises two axially abutting rings that, when axially moved relative to one another, expand in diameter and contract in diameter, thereby providing a friction-based coupling between the shaft and the hub on which the rings of the conical locking element are arranged. FIG. 13 shows another example of an alternative embodiment of a coupling 3 , in which the driven shaft 1 is similarly clamped to the coupling hub 31 by a conical clamping ring 5 .

[0069] FIG. 9 further illustrates an embodiment of a coupling 3 in which multiple conical clamp rings 5 ​​are arranged in series around the driven shaft 1. Specifically, while this illustration shows two consecutive conical clamp rings 5, it is understood that the number of conical clamp rings shown is merely exemplary and that a greater number, e.g., three or four conical clamp rings 5, is equally suitable. The appropriate number depends, inter alia, on the length of the coupling hub 31, the required torque force, and the desired complexity of the drive shaft. Those skilled in the art will appreciate that the number of conical clamp rings 5 ​​is preferably selected to be less intensive to facilitate easier installation and maintenance of the drive shaft. FIG. 14 illustrates another example of an alternative embodiment of a coupling 3 in which the driven shaft 1 is similarly clamped to the coupling hub 31 by multiple conical clamp rings 5.

[0070] As mentioned above, the pretension required to lock the one or more conical clamping rings 5, in other words to generate a clamping force for clamping the coupling hub 31 to the driven shaft 1, may be higher than can be safely applied to the stud 4. For this reason, a pressure ring 51 and a fastening portion 6 can be arranged between the driven shaft 1 and the stud 4, i.e. axially, in other words along the longitudinal direction of the stud 4, preferably between the one or more conical clamping rings 5 ​​and the stud 4. This allows the fastening portion 6 to be arranged as shown in the figure: Pressure Ring 51The fastening portion 6 is configured to apply pretension to the clamp ring 5 via the fastening portion 6; in other words, the pretension for applying the clamping force to the clamp ring 5 is provided by a tensile stress applied to and absorbed by the fastening portion 6. Therefore, the pretension for the clamp ring 5 does not need to be provided by the stud 4, or it no longer needs to be provided entirely by the stud 4; the stud 4 is still subjected to a tensile load to generate a clamping force between the coupling disc 32 and the coupling hub 31. In other words, such an embodiment with the fastening portion 6 allows the pretension for generating the clamping force on the clamp ring 5 to be absorbed by the fastening portion 6 or distributed between the fastening portion 6 and the stud 4. An example of a suitable pressure ring 51 is a circular panel, also called a ring or washer, which has an opening configured to receive the tapped end of the fastening portion 6 and abut against the bolt head 61 of the fastening portion 6, and is configured to transmit the pressure generated from the bolt head 61 toward the clamp ring 5. Preferably, the suitable pressure ring 51 can absorb clearance when pressing the clamp ring 5 and distribute the tension on the surface of the clamp ring 5. Clearly, further alternative embodiments are possible, for example the fastening portion 6 and the stud 4 are formed integrally, in other words the stud 4 preferably has a portion with a larger diameter which serves as the fastening portion 6 adapted to absorb at least part of the tension forces generated when the one or more clamping rings 5 ​​are fastened, the thinner portion of the stud 4 then being used in the same way as above to axially clamp the coupling disc with the coupling hub.

[0071] 8 to 11, a fastening portion 6 having a larger diameter than the stud 4 is disposed between the driven end of the driven shaft 1 and the stud 4 and configured to couple the stud 4 to the driven shaft 1. In one embodiment, the end of the stud 4 on the driven shaft 1 is provided with an external thread, and the fastening portion 6 includes an opening 62 with a complementary internal thread into which the stud 4 can be screwed.

[0072] According to such an embodiment, as shown, the fastening part 6 preferably consists of a bolt, for example, having a bolt head 61 with an opening 62 into which the end of the stud 4 can be screwed, and a tapped end that can be screwed into a corresponding opening in the driven shaft 1, in particular an opening provided in the abutment surface of the driven shaft 1. In this way, the bolt can longitudinally connect the stud 4 to the driven shaft 1. Those skilled in the art will recognize that this variant is equally suitable. Understand For example, the bolt 6 can be threaded onto the stud 4, or the driven end of the driven shaft 1 can be threaded onto the bolt 6. However, threading the stud 4 onto the bolt 6 has the advantage of simplifying installation and removal compared to alternative embodiments.

[0073] Figure 8 shows an embodiment of a coupling 3 in which a stud 4 is connected, in other words fastened, to a driven shaft 1 by a bolt 6. In particular, the stud 4 is located in an opening 62 provided in a bolt head 61. Figure 8 further shows that a pressure washer 51 is located on the bolt 6, in particular between the bolt head 61 and the conical clamping ring 5.

[0074] As mentioned above, the coupling disc 32 can be directly integrated into the drive shaft 2 or can be provided as a separate component that is fixed to the drive shaft 2 by means of tension elements for torque transmission. In the second case, depending on the embodiment of the coupling 3, radial and / or axial clamping forces can be applied between the abutment surfaces of the drive shaft 2 and the coupling disc 32. Some suitable examples are explained in more detail below.

[0075] As shown in Figure 3, the axial surface of the drive end of the drive shaft 2 (i.e., the end face of the drive shaft 2 in the direction of the driveline shaft 11) can be placed in contact with the abutment surface of the coupling disc 32. By fastening the drive end of the drive shaft 2 with the coupling disc 32, an axial clamping force A can be achieved between the abutment surfaces of the driven shaft and the coupling hub 31. This "axial clamping force" A is represented diagrammatically in Figure 3 by arrows pointing towards each other, positioned between the drive shaft and the coupling disc 32.

[0076] In one embodiment of coupling 3, The coupling disc 32 is connected to the drive shaft 2 by a plurality of fastening elements 7. It has been concluded. Two fastening elements 7 It is possible but, Those skilled in the art will appreciate that drivetrain 10 It can be seen that a different number of fastening elements 7, for example 1, 4, 8, etc., is equally suitable, depending on the desired complexity and simplicity of assembly. It is thus clear that a suitable number of fastening elements is preferably large enough to ensure the desired axial clamping force between the coupling 3 and the coupling disc 32, and preferably small enough to keep the contact surface of, for example, a radial groove of the coupling disc 32 as small as possible, for example as a result of the openings provided in this contact surface for the attachment of the fastening elements 7.

[0077] In one embodiment, the fastening element 7 is preferably a bolt having a bolt head and a tapped end, which can be screwed into a corresponding opening in the drive shaft 2, in particular an opening in the abutment surface of the drive shaft 2. In this way, the bolt 7 can longitudinally connect the coupling disc 32 to the drive shaft 2. Those skilled in the art will understand that variants are equally suitable, for example, in which the bolt 7 can be screwed into the coupling disc 32. However, screwing the bolt into the drive shaft 2 has the advantage of simplifying installation and removal compared to alternative embodiments. Figure 18 shows an example of an embodiment in which the coupling disc 32 is fixed to the drive shaft 2 by four bolts 7. Figure 18 further shows how these bolts 7 are arranged at the drive end of the drive shaft 2.

[0078] 4, the radial surface of the drive end of the drive shaft 2 can be placed in contact with the abutment surface of the coupling disc 32; in particular, the drive shaft 2 has an elongated drive end with a small diameter, and the coupling disc 32 is placed around the drive end of the drive shaft 2. In such an embodiment, a "radial clamping force" R can be achieved between the abutment surfaces of the drive shaft 2 and the coupling disc 32, equivalent to the above-described connection between the drive shaft 1 and the coupling hub 31. Those skilled in the art will appreciate that the above-described embodiment for connecting the driven shaft 1 and the coupling hub 31 can be transferred to an equivalent connection between the drive shaft 2 and the coupling disc 32.

[0079] A further aspect of the present invention relates to a drivetrain 10 comprising a coupling 3 as described herein, and / or a rotary compressor 100 comprising a coupling 3 as described herein. In particular, the present invention relates to a rotary compressor 100 including a drivetrain 10, wherein a drive shaft 2 and a driven shaft 1 are preferably directly coupled to each other by a coupling 3 as described herein, and are preferably aligned with each other, i.e., along the drivetrain shaft 11. It will be understood that preferred embodiments of the coupling 3 as described herein also constitute preferred embodiments of the drivetrain 10 and / or rotary compressor 100.

[0080] In one embodiment, rotary compressor 100 can include a drive element, specifically a motor capable of generating torque suitable for driving driveline 10 as described herein, and a drive shaft 2 that can be driven by the drive element. In a preferred embodiment, the drive element can include an electric motor, as these types of motors are typically capable of achieving sufficiently high power and / or rotational speeds necessary to drive rotary compressors. Those skilled in the art will appreciate that coupling 3 as described herein is not limited to any particular embodiment of the drive element.

[0081] In one embodiment, the rotary compressor may comprise a compression chamber, preferably oil-free, and a compression element movably arranged in the compression chamber, in particular a tooth or set of teeth driven by a driven shaft 1. The compression element in this specification forms a driven element, and it is understood that the rotary compressor comprises a driven element that can be directly driven by a drive train by the above-mentioned drive element. Those skilled in the art will understand that the compressor described herein is not limited to a particular embodiment of the compression element, in particular the teeth, and that in principle any type of teeth as known in the art, e.g. with known variations in shape, geometry, size, etc., may be considered suitable.

[0082] In one embodiment, the rotary compressor may include a lubricating oil circuit configured to supply lubricating oil to components of the rotary compressor that may require lubrication, particularly the drive train. The rotary compressor may further include a lubricating oil pump, such as an oil pump known in the art, configured to generate the necessary pressure in the lubricating oil circuit. Those skilled in the art will appreciate that oil or a liquid mixture containing oil is commonly used as a lubricating oil for rotary compressors, although in principle other types of lubricating oil known in the art may be used.

[0083] The lubrication oil circuit, preferably the oil circuit, is understood to include all components necessary to ensure adequate lubrication to driveline components that may require lubrication, including all associated flow paths and components within the rotary compressor. For example, the oil circuit typically includes an oil pan 97 for storing oil and an oil filter 96 for removing contaminants from the oil flowing therethrough. For the sake of brevity, other components will not be described individually, but those skilled in the art will appreciate that the oil circuit also typically includes seals, filters, plugs, drains, etc.

[0084] In one embodiment, the lubricant circuit can comprise a lubricant injector 8, which is configured to supply lubricant to components of the coupling 3 that may require lubrication. For this purpose, the lubricant injector 8 can comprise an injection nozzle 81 that injects lubricant under the required pressure as a liquid jet towards this component of the coupling 3. Advantageously, the injection nozzle 81 is directed towards this component. In another embodiment, the injection nozzle 81 can be directed towards the component of the coupling 3, for example by diffusing and / or bouncing the injected jet, thereby directing the injected lubricant to the component of the coupling 3 that may require lubrication. For this purpose, the coupling 3 can be provided with a beveled side 82 that directs the injected lubricant towards parts of the coupling 3 that require lubrication, preferably to facilitate distribution of the supplied, preferably injected, lubricant.

[0085] Figure 15A shows an embodiment of a lubricant injector 8 positioned along the coupling hub 31. Figure 15B further shows that the lubricant injector 8 includes an injection nozzle 81 oriented at a spray angle of approximately 90 degrees relative to the driveline shaft 11, thereby enabling the injection nozzle 81 to inject lubricant directly onto the side of the coupling hub 31 to lubricate components of the driven portion 3' of the coupling, such as the bearing 106 mounted around the driven shaft 1.

[0086] To further explain the operation of the lubricant injector 8, reference is made to Figure 20, which shows a detailed view of the embodiment of Figure 15A, in which the injected lubricant flow is indicated schematically by dotted lines. Specifically, a liquid flow consisting of or including lubricant can be injected from an injection nozzle 81 toward a sloped surface 82 provided on the side of the coupling hub 31, which reflects the liquid flow at a substantially right angle toward the adjacent conical clamp ring 5.

[0087] Those skilled in the art will appreciate that the bevel angle, defined as the angle of the surface of the bevel end 82 relative to the driveline shaft 11, must be adapted to the location of the lubricant injector 8 relative to the location of components of the coupling 3 that may require lubrication, such as the bearings 106, and in particular the spray angle of the injector nozzle 81. In one embodiment, the bevel 82 has a bevel angle of 80° to 10°, preferably 70° to 20°, more preferably 60° to 30°, even more preferably 55° to 35°, even more preferably 50° to 40°, and even more preferably substantially 45°, e.g., 44° or 46°, relative to the driveline shaft 11. To assist those skilled in the art in selecting an appropriate bevel angle, exemplary embodiments will be described in more detail below.

[0088] As further shown in Figure 21, which shows a cross-sectional view of Figure 20, the lubricant can be supplied by a lubricant circuit driven by a lubricant pump 9. Figure 21 shows that the lubricant is sprayed onto a ramp 82 disposed on the side of the coupling hub 31 at a spray angle of 90° relative to the driveline shaft 11. The ramp 82 has a ramp angle of 45° relative to the driveline shaft 11, which causes the sprayed lubricant to travel towards a bearing 106 disposed along the driveline shaft 11. Rotation of the coupling hub 31 and the bearing 106 disposed around the driveline shaft 11 ensures that substantially all parts of the bearing 106 are lubricated.

[0089] As mentioned above, the drivetrain 10 described herein may further provide the possibility of directly coupling a lubricant pump 9 to the same drive shaft 2 or an extension thereof, and similarly to the coupling 3 described herein, the lubricant circuit driven by this lubricant pump 9 may be driven by the same drive shaft 2. In one embodiment, the lubricant pump 9 may be located along the same drivetrain shaft 11 as the coupled shafts 1, 2, preferably in line with the drive shaft 2 and therefore also in line with the coupling 3 described herein. It will be understood that direct coupling of the lubricant pump 9 to the drivetrain 10 constitutes an "integral lubricant pump", as distinguished from an externally driven oil pump, i.e., an oil pump driven by an external drive device.

[0090] 11 shows a preferred embodiment of the coupling 3 in which the lubricant pump 9 is located adjacent the non-drive end of the drive shaft 2. In the embodiment shown, the drive shaft 2 has an extended end of smaller diameter, and the lubricant pump 9 is located around this extended end of the drive shaft 2. Those skilled in the art will appreciate that the extended end can be a separate component connected or attached to the non-drive end of the drive shaft 2, or can be a component of the lubricant pump 9. However, the embodiment shown has the advantage of allowing for a more robust connection.

[0091] As further shown, the hollow passage 21 extends the entire length of the drive shaft 2, i.e., from the drive end of the drive shaft 2 to the non-drive end on which or against which the lubricant pump 9 is located. The second end of the stud 4, i.e., the end facing the non-drive end of the drive shaft 2, may be secured to the non-drive end of the drive shaft 2 with a nut-like fastener, as in the previous embodiment. tension element 41 Preferably, this only clamps onto the non-drive end of the drive shaft 2 and does not come into direct contact with the lubricant pump 9 so as not to interfere with its operation.

[0092] Figure 22A shows an embodiment of a rotary compressor 100 including the preferred embodiment of Figure 11, in particular a coupling 3 with an integrated oil pump 9. Figure 22B shows this coupling 3 in more detail, and Figure 22C further shows the connection of the oil pump 9 to the studs 4. Figure 22A also shows several components of the oil circuit that can be driven by the oil pump 9, such as an oil pan 97 and an oil filter 96.

[0093] 23A also shows an embodiment of the rotary compressor 100 with the preferred embodiment of FIG. 11, in particular the coupling 3 with an integral oil pump 9. Subsequently, FIG. 23B shows details of the coupling 3, and FIG. 23C further shows the connection of the oil pump 9 to the stud 4.

[0094] In one embodiment, the lubricant pump 9 can include an outer rotor 91 and an inner rotor 92 rotatably disposed within the outer rotor 91, the inner rotor 92 configured to rotate relative to the outer rotor 91 to generate the necessary flow rate to drive the lubricant circuit. In a preferred embodiment, the lubricant pump 9 comprises a gerotor pump as known in the art. An example of a suitable gerotor is a trochoidal pump, where the profile of the inner rotor 92 preferably has a trochoidal profile shape generated as an equidistant portion of an epitrochoidal profile determined by the profile of the outer rotor 91, such that the outer rotor 91 and inner rotor 92 have complementary trochoidal profile shapes. Those skilled in the art will appreciate that the gerotor described herein is not limited to any particular embodiment of the outer rotor 91 and / or inner rotor 92, and that in principle, any type of rotor known in the art, preferably having a trochoidal profile shape, is considered suitable.

[0095] FIG. 24A illustrates the preferred embodiment of FIG. 11 , specifically a rotary compressor 100 including a coupling 3 with an integrated oil pump 9, which is comprised of a gerotor. As shown in more detail in FIG. 24B , the oil pump includes an outer rotor 91 and an inner rotor 92 arranged around the drive shaft 2, with the ends of the studs 4 passing through the center of the oil pump 9. Adjacent to the oil pump 9, a tension element 41 is positioned on the studs 4, which, as described above, exerts a clamping force on the coupling 3. The tension element 41 preferably clamps only the end of the drive shaft 2 and therefore does not directly contact the lubricant pump 9 so as not to interfere with its operation. Subsequently, FIG. 24C illustrates in detail the complementary trochoidal profile shapes of the outer rotor 91 and inner rotor 92.

[0096] In one embodiment, the lubricant pump 9 can be coupled to the drive shaft by a mechanical coupling, for example, the lubricant pump 9 can be provided with a recess, which is adapted to mate with a corresponding protrusion or stopper provided on the drive shaft 2, or vice versa.

[0097] Figure 25 shows an embodiment of a suitable lubricant pump coupling, in which the end of the drive shaft 2 is provided with a keyway 94. Figure 26 then shows how the lubricant pump 9 of the embodiment of Figure 25 can be coupled by means of a key 95 provided in this keyway 94, which is configured to couple with a corresponding recess in the lubricant pump 9. This key 95 can be arranged to directly drive the rotation of the inner rotor 92 upon rotation of the drive shaft 2 through this coupling. Those skilled in the art will understand that the keyway 94 and the key 95 can be replaced in a simple manner by a protrusion or stop protruding from the end of the drive shaft 2, for example a D-shaped protrusion.

[0098] FIG. 27 shows a schematic diagram of one embodiment of an assembly including an oil-free rotary compressor 100 using a coupling 3 similar to that described above to connect the rotary compressor 100 to a motor 200. As shown, the assembly also includes a lubrication pump 9, which is coupled to a drive shaft 2 similar to that described above. Like elements are designated with like reference numerals and function in a similar manner to that described above. As shown, the coupling 3 for the drive train 10 is Driven shaft 1 and drive shaft 2 are coupled in an axially straight line by a rigid coupling, in other words, they operate as an integrated drive shaft in a coupled state. Drive shaft 2 is already journalled, the drive shaft 2 on the motor 200 side can be supported by only one bearing 201. According to the exemplary embodiment shown, Drive shaft 2 is journalled on the side of the rotary compressor 100 by two bearings 106, 108 axially disposed on either side of the compressor element 101. However, it will be understood that alternative embodiments are possible in which a different number or positioning of bearings within the rotary compressor 100 is possible, with at least one bearing 106 being disposed axially opposite the coupling 3 on the driven shaft 1.

[0099] Furthermore, the bearings shown generally herein may be mounted within one or more housings of the assembly. Drive shaft 2 It is clear that the housing of the assembly comprises a number of sub-housings arranged together, in accordance with the illustrated exemplary embodiment. Thus, in accordance with the illustrated exemplary embodiment, along the axial direction of the drive shaft, the housing of the rotary compressor 100 is arranged in the housing 300 of the coupling 3, which is arranged in the housing of the motor 200, which is arranged in the housing 900 of the lubricating oil pump 9.

[0100] In the illustrated embodiment, a rotary compressor 100 similar to those known as oil-free rotary tooth compressors sold by Atlas Copco under the trade names ZT15-22, ZR / ZT30-45, ZT22 VSD, and ZR / ZT37-55 VSD, for example, and described in detail at https: / / www.atlascopco.com / content / dam / atlas-copco / local-countries / belgium / documents / oil-free-air / Olievrije-tandrotor-compressoren-ZT-15-22-en-ZR_ZT-30-45-en-ZT-22-VSD-en-ZR_ZT-37-55-VSD.pdf, is shown. Such a rotor includes two compressor elements 101, 102 configured to rotate closely together to compress gas. As shown, the first compressor element 101 is disposed on a driven shaft 1, which is journaled within the housing of the rotary compressor 100 by two bearings 106, 108 and includes a timing gear 103. The second compressor element 102 is mounted on a shaft parallel to the driven shaft 1 to cooperate with the first compressor element 101, which shaft is similarly journaled by two bearings 107, 109 on either side of the compressor element 102 and includes a timing gear 104. The timing gear 104 on the shaft of the second compressor element 102 is configured to cooperate with the timing gear of the first compressor element 101 to synchronize the rotation of the second compressor element 102 with the rotation of the first compressor element 101. Clearly, alternative embodiments of the rotary compressor 100 are possible, in which the component configurations, as well as the specific implementation of, for example, the compressor elements 101, 102, differ from the embodiments described above. For example, instead of the timing gears 103, 104, other suitable elements for synchronizing the rotation of the compressor elements 101, 102 could be used.

[0101] As can be seen from Figure 27, Drive shaft 2is journalled by three bearings, of which two bearings 106, 108 on the housing of the rotary compressor 100 are arranged to journal the driven shaft, and only one bearing 201 on the housing of the motor 200 is arranged to journal the drive shaft 2. Due to the rigid connection achieved by the coupling 3, Drive shaft 2 However, this embodiment with two bearings on the driven shaft 1 is advantageous as it ensures the alignment of the compressor elements 101, 102 in the rotary compressor 100 as separate modules. However, it is clear that alternative embodiments are also possible in which only one bearing is provided to journal the driven shaft 1 of the rotary compressor 100.

[0102] For comparison, FIG. 28 shows a prior art assembly with a known flexible coupling 305, and FIG. 29 shows a known assembly with a gear coupling and / or gear transmission. Like elements are designated with like reference numerals and function in a similar manner as described above. As shown in FIG. 28 , the embodiment with the flexible coupling 305 clearly includes two bearings 201, 202 for journaling the drive shaft 2 within the housing of the motor 200, since the flexible coupling 305 does not provide a rigid connection between the driven shaft 1 and the drive shaft 2. Furthermore, in the embodiment with a gear transmission, the flexible coupling 305 is used to connect the drive shaft 2 to the gear transmission, and this flexible coupling 305 drives the pinion 105 fixed to the driven shaft 1 of the rotary compressor 100 via a transmission gear 302. Therefore, it is clear that two bearings 201, 202 are also required for journaling the drive shaft 2 within the housing of the motor 200. According to the exemplary embodiment shown in Figure 29, it is clear that additional bearings are required, such as bearings 303, 304, as shown, for journalling the transmission gear 302 within the gear coupling housing 300. Thus, as will become clear with reference to Figure 27, it is clear that in the embodiment of coupling 3 described above, an assembly can be achieved with fewer bearings, resulting in a simpler, more robust and less maintenance-intensive structure, which can be manufactured in a more efficient manner.

Claims

1. A coupling (3) for a drive system (10) of an oil-free rotary compressor (100), said coupling (3) comprising: a driven shaft (1) adapted to drive a compression element movably arranged in an oil-free compression chamber; - a drive shaft (2) driven by a drive element; are configured to directly connect to each other, said coupling (3) is - a coupling hub (31) placed on the driven end of said driven shaft (1); a coupling disc (32) attached to and / or integral with the drive end of said drive shaft (2); Equipped with the drive shaft (2) comprises a hollow passage (21) running along its entire length; the coupling (3) comprises an elongated stud (4) arranged in the hollow passage (21) of the drive shaft (2), the stud being connected to the driven end of the driven shaft (1) and configured to clamp the coupling disc (32) to the coupling hub (31); the coupling (3) further comprises a tensioning element (41) mounted on the stud (4), the tensioning element (41) being configured to hold the stud (4) against the non-drive end of the drive shaft (2) to apply a clamping force to the coupling (3); the surfaces of the coupling hub (31) and the abutment surfaces of the coupling disc (32) comprise a plurality of mating radial grooves (33); and the coupling hub (31) comprises a bevel (82) arranged on a side of the coupling hub (31) and configured to direct injected lubricating oil towards components of the coupling that require lubrication.

2. 2. The coupling (3) of claim 1, wherein the stud (4) comprises an externally threaded end onto which a complementary internally threaded tension element (41) can be fastened to secure the stud (4) to the non-drive end of the drive shaft (2).

3. 2. The coupling (3) according to claim 1, wherein the mating radial grooves (33) are hearth-type with a profile angle between 45° and 75°.

4. 2. The coupling (3) according to claim 1, comprising a conical clamping ring (5) arranged between the driven end of the driven shaft (1) and the coupling hub (31) and configured to clamp the driven shaft (1) to the coupling hub (31).

5. 2. The coupling (3) according to claim 1, comprising a fastening portion (6) arranged between the driven end of the driven shaft (1) and the stud (4), having a diameter larger than that of the stud (4), and configured to connect the stud (4) to the driven shaft (1).

6. 6. The coupling (3) according to claim 5, wherein the stud (4) comprises an externally threaded end and the fastening portion (6) comprises a complementary internally threaded opening (62) into which the stud (4) can be screwed.

7. 2. The coupling (3) according to claim 1, comprising a fastening element (7) arranged between the drive end of the drive shaft (2) and the coupling disc (32) and configured to clamp the drive shaft (2) to the coupling disc (32).

8. 2. The coupling (3) according to claim 1, wherein the non-drive end of the drive shaft (2) is configured to couple to a lubrication oil pump (9) disposed on the drive shaft (2), and the stud (4) protrudes beyond the lubrication oil pump (9).

9. An oil-free rotary compressor (100), a compression element movably arranged in an oil-free compression chamber and a driven shaft (1) adapted to drive said compression element; a drive element and a drive shaft (2) driven by said drive element; - a coupling (3) according to any one of claims 1 to 8 for directly connecting the driven shaft (1) and the drive shaft (2); - a lubricant injector (8) having an injection nozzle (81) configured to inject lubricant onto the side of a coupling hub (31), the coupling hub (31) having a slope (82) arranged on the side of the coupling hub (31) configured to direct the injected lubricant towards components of the coupling (3) requiring lubrication.

10. 10. The rotary compressor (100) of claim 9, further comprising a lubricant pump (9) configured to drive a lubricant circuit, the lubricant pump (9) being disposed on a non-drive end of the drive shaft (2), the drive shaft (2) being coupled to drive operation of the lubricant pump (9).

11. 11. The rotary compressor (100) of claim 10, wherein the lubricating oil pump (9) is coupled to the drive shaft (2) by a recess arranged on the lubricating oil pump (9), the recess being configured to couple with a protruding element arranged on an end of the drive shaft (2), or the lubricating oil pump (9) is coupled to the drive shaft (2) by a protruding element arranged on the lubricating oil pump (9), the protruding element being configured to couple with a recess arranged on the end of the drive shaft (2).

12. 11. The rotary compressor of claim 10, wherein the lubricating oil pump comprises an outer rotor and an inner rotor rotatably disposed within the outer rotor, the outer rotor and the inner rotor having complementary trochoidal profile shapes.

13. Use of a coupling according to any one of claims 1 to 8 for directly connecting a driven shaft (1) and a driving shaft (2) in a drive train (10) of an oil-free rotary compressor (100).

14. 10. Use of a rotary compressor (100) according to claim 9 for producing oil-free compressed air.

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