WO2018082801A1

WO2018082801A1 - Reciprocating-piston machine, compressed-air supply system, vehicle having a compressed-air supply system, methods for assembling and for operating a reciprocating-piston machine

Info

Publication number: WO2018082801A1
Application number: PCT/EP2017/001234
Authority: WO
Inventors: Klaus Bredbeck; Uwe Stabenow
Original assignee: Wabco Europe Bvba
Priority date: 2016-11-02
Filing date: 2017-10-20
Publication date: 2018-05-11
Also published as: EP3535494A1; DE102016013454A1; EP3535494B1

Abstract

The invention relates to a reciprocating-piston machine, in particular a single-, two- or multi-stage piston compressor or a single-, two- or multi-cylinder compressing device, comprising: at least one cylinder and at least one piston, each piston being associated with one cylinder, wherein during operation the piston is deflected along a radially oriented cylinder axis in a cylinder displacement space of the cylinder, a crankshaft, which can be driven during operation and which has a crankshaft journal, which is arranged eccentric to a shaft axis of the crankshaft, and which has a drive shaft coupling, which is designed for coupling a drive shaft for driving the crankshaft, at least one connecting rod, which can be moved by means of the crankshaft journal, each connecting rod being designed to deflect one of the at least one piston and extending along a connecting rod axis. According to the invention, the crankshaft journal and/or the drive shaft coupling is oriented along an axially oriented shaft axis, which extends perpendicularly to the radially oriented cylinder axis, and the connecting rod axis of the connecting rod is tilted with respect to the radially oriented cylinder axis such that the bearing play of at least one connecting rod bearing is reduced.

Description

LIFTING PISTON MACHINE, COMPRESSED AIR SUPPLY SYSTEM, VEHICLE WITH A COMPRESSED AIR SUPPLY SYSTEM, METHOD FOR ASSEMBLING AND OPERATING AN ONE

reciprocating engine

Reciprocating piston engine, in particular a two-stage or multistage piston compressor,

Compressed air supply system, compressed air supply system and vehicle, in particular passenger car with a compressed air supply system, method for assembling and operating a reciprocating piston engine, in particular on a compressed air supply system.

The invention relates to a reciprocating piston engine, in particular a one- or more-stage piston compressor or a one- or more-cylindrical compressor, according to the preamble of claim 1. In particular, the invention also relates to devices for providing negative pressure, such as a vacuum pump. Furthermore, the invention relates to a compressed air supply system and a compressed air supply system and a vehicle, in particular a car, with a reciprocating engine, in particular with a reciprocating compressor or compressor. Furthermore, the invention relates to a method for assembling and operating a reciprocating piston engine, in particular a reciprocating compressor or compressor, in particular on a compressed air supply system.

A compressed air supply system is used in vehicles of all kinds, in particular for supplying an air spring system of a passenger car or a commercial vehicle with compressed air. Air suspension systems may also include level control devices, with which the distance between the vehicle axle and vehicle body can be adjusted. An air spring system of a pneumatic compressed air supply system mentioned at the beginning comprises a number of air bellows pneumatically connected to a common line (gallery) which, with increasing filling, can lift the vehicle body and lower it with decreasing filling. Such

System is used for example in an off-road vehicle and a sports utility vehicle (SUV) or a utility or passenger transport vehicle.

To ensure long-term operation of the compressed air supply system, this has an air dryer with which the compressed air is to be dried. This will be the Avoiding accumulation of moisture in the compressed air supply system, which can otherwise lead to valve-damaging ice crystal formation and other undesirable effects in the compressed air supply system and in the pneumatic system at relatively low temperatures. An air dryer has a desiccant, usually a granular bed, which can be flowed through by the compressed air, so that the granular bed can absorb moisture contained in the compressed air at relatively high pressure by adsorption. It has often proven useful to accommodate the dry granules in a dryer cartridge having a dryer bed for guiding a flow of compressed air.

A compressed air supply system for use in a pneumatic compressed air supply system with a pneumatic system, for example with an air spring system described above, is operated with compressed air from a compressed air supply, for example, within a pressure level of 5bar to 20 bar. The compressed air is provided by means of an air compressor (compressor), in the present case with a reciprocating engine, preferably with a one- or multi-stage piston compressor, the compressed air supply available.

In a compressed air supply system for a compressed air supply system in a vehicle, the compressed air supply supplied by the air compressor is pneumatically connected on the one hand to supply the pneumatic system with a compressed air connection and on the other hand pneumatically connected to a vent connection. The compressed air supply system and / or the pneumatic system can be vented to the vent connection by discharging air via a venting valve arrangement which is necessary for this purpose.

The drive of the reciprocating engine in the air compressor (compressor) of the compressed air supply is carried out regularly with a drive motor, the drive power is transmitted via a crankshaft and one or more connecting rods to one or more pistons of the preferred one- or multi-stage reciprocating compressor - a piston runs sealed during operation in a cylinder by being deflected along a cylinder axis oriented radially with respect to a shaft axis of the crankshaft in a cylinder stroke space of the cylinder, namely as indicated in the preamble of claim 1. Here, the arrangement of the piston for the operation of the invention is not relevant. The drive of the reciprocating engine in the air compressor (compressor) of the compressed air supply can also be done for example via a belt drive. In this way, sucked in ambient air is compressed. Alternatively, in the context of a closed operation or a boost operation, an intake air supplied from another compressed air source can be compressed. Basically, so-called TWIN reciprocating compressors have proven themselves; ie two-stage reciprocating compressors whose two pistons are driven via two connecting rods assigned to each of these, which in turn are aligned exactly along a radially oriented cylinder axis which is preferably aligned exactly parallel and center-symmetrical to the cylinder running surfaces in the cylinder stroke space for the piston. are aligned.

Depending on the requested dynamics and pressure load, such or other two-stage or multi-stage compressor can develop increasing operating noise during operation, which, as it turns out, is largely due to a transmission of structure-borne noise by the connecting-rod drive. may be caused in the drive motor of the compressor or its housing. It is desirable to realize an improved acoustics and a nevertheless reliable connecting rod drive in a compressor in the form of said reciprocating piston engine. This should be sufficient in particular for a particularly low noise level in the car area.

EP 1 225 332 A1 discloses a compressor having at least one compressor unit, which has two pistons, two cylinders and a connecting element, wherein longitudinal axes of the pistons and cylinders are aligned with one another and form a longitudinal axis. The pistons of each compressor unit are connected via a connecting rod to the crankshaft and the connecting rod is located in the longitudinal axis.

DE 10 2004 020 104 discloses approximately a TWIN compressor with symmetrically mounted double piston for a compressor, with an elongate piston carrier having a piston at each end, and with a connecting rod extending approximately parallel to the piston carrier, which is supported by a bearing on a bolt the piston carrier is rotatably mounted and is mounted at a distance thereof by means of a connecting rod bearing on an eccentric drive means. The piston carrier contains in a middle region which extends between the two pistons, a space dimensioned for freely movable reception of the connecting rod, in which the connecting rod is received in a freely movable manner.

It turns out, as recognized by the invention, that solutions of this type run the risk of a comparatively high level of sound and mE structure-borne sound transmissions caused by the connecting rod drive in the compressor drive motor and thus also to the outside.

In contrast, EP 1 707 812 B1 of the applicant discloses a motor vehicle small compressor with a single piston which is sealed off in the cylinder and with a connecting rod for the articulated connection of a crankshaft journal of the crankshaft to the piston in a connecting rod bearing. By a Pleuelschrägstellung arises at each pressure, a force vector that pushes the connecting rod always in the direction of crankshaft with pin. This has the advantage that the connecting rod can be stored freely movable. The connecting rod is bent only slightly in the high pressure range. Specifically, this is a reciprocating engine, in particular a reciprocating compressor, provided with a cylinder and with the cylinder sealed in the running piston, with a working on a crankshaft drive motor whose drive shaft is received by a bore of the crankshaft, and a connecting rod for articulated connection of a crankshaft journal the crankshaft with the piston in a connecting rod bearing. The connecting rod is arranged relative to the drive shaft in a drive shaft deflection counteracting skew. The angle of inclination is between 0 ° and 1, 5 °. Specifically, the connecting rod bearing is designed as a needle bearing, wherein the connecting rod bearing is axially movable on the crankshaft journal; The connecting rod is set at an angle but not offset. Because to achieve the inclination of the connecting rod, the crankshaft bore for the drive shaft is formed obliquely or the inclination of the connecting rod is realized by an inclination of the bearing bore in the connecting rod eye for the crankshaft journal. The inclination of the connecting rod can also be realized by a misalignment of the crankshaft journal bore in the crankshaft. The inclination of the connecting rod can also be realized by an inclination of the drive shaft. For this purpose, the inclination of the connecting rod can be realized by an inclined position of the cylindrical housing block bore for the piston.

This last-mentioned solution can still be improved, especially since it does not take account of acoustics of the reciprocating piston engine, in particular of a reciprocating compressor.

At this point, the invention is based, whose task is a reciprocating piston engine, in particular a one-, two- or multi-stage piston compressor, preferably TWIN compressor, or a one, two or more-cylinder compressor, and a compressed air supply system for operating a pneumatic system with indicate a compressed air flow, by means of which an improved acoustics and a reliable connecting rod drive in a reciprocating compressor is to be realized. This should special be suitable for noise level requirements in the car sector. In particular, as part of an acoustic improvement, structure-borne noise emissions of a connecting rod drive into adjacent, radiating components, such as electric motor, crank mechanism or the like components of an air compressor (compressor) are to be reduced. In particular, the compressed air supply system should be relatively compact. The object of the invention is also to provide a corresponding compressed air supply system and a vehicle with the compressed air supply system, in particular for an air spring system. The object of the invention is also to provide a corresponding method for assembling and operating the reciprocating engine, in particular the one-, two- or multi-stage reciprocating compressor.

The object with regard to the reciprocating engine is achieved with a reciprocating engine, in particular with the one-, two- or multi-stage piston compressor, preferably TWIN compressor, or the one-, two- or multi-cylinder compressor of claim 1.

This indicates:

at least one cylinder and at least one respective piston associated with a cylinder, wherein in operation the piston is deflected along a radially oriented cylinder axis in a cylinder stroke space of the cylinder,

an operationally drivable crankshaft with a crankshaft journal arranged eccentrically to a shaft axis of the crankshaft and a drive shaft coupling adapted for coupling a drive shaft, in particular a drive shaft of an engine, for driving the crankshaft,

- At least one each for deflecting the at least one piston formed and extending along a connecting rod connecting rod, which is movable by means of the crankshaft journal.

According to the invention, it is provided that

- The crankshaft journal and / or the drive shaft coupling is aligned along an axially aligned shaft axis which is perpendicular to the radially oriented cylinder axis, and

- The connecting rod axis of the connecting rod is tilted against the radially oriented cylinder axis, so that the bearing clearance of a connecting rod bearing is reduced. The task with regard to the compressed air supply system is achieved with a compressed air supply system of claim 20. A compressed air supply system for operating a pneumatic system, in particular an air spring system of a vehicle, preferably a passenger car, with a compressed air flow, has:

- An air dryer assembly in a pneumatic main line which pneumatically connects a compressed air supply (1) from an air compressor and a compressed air connection (2) to the pneumatic system, and

- A pneumatically connected to the pneumatic main valve assembly for controlling the flow of compressed air and an air dryer in the pneumatic main, wherein

- To the compressed air supply an air compressor with a reciprocating engine, in particular a one-, two- or multi-stage piston compressor, preferably TWIN compressor, in particular of claims 1 to 19 is connected.

The object concerning the compressed air supply system is achieved with a compressed air supply system of claim 21. The invention also leads to a vehicle, in particular a passenger vehicle, of claim 22.

A compressed air supply system with a pneumatic system and with a compressed air supply system is used to operate the pneumatic system with a compressed air flow, in particular an air spring system of a vehicle, preferably a car, the pneumatic main line a compressed air supply from an air compressor with a reciprocating engine, in particular a one- or multi-stage reciprocating compressor, preferably TWIN compressor, or a one-, two- or multi-cylinder compressor pneumatically connecting claims 1 to 19 and a compressed air connection to the pneumatic system.

A vehicle, in particular a car, is provided with a pneumatic system, in particular an air suspension system, and a compressed air supply system according to claim 18 for operating the pneumatic system with a compressed air flow.

The invention also leads to a method of claim 23 for mounting and / or operating the reciprocating piston engine, in particular the piston compressor, in particular the one- or multi-stage piston compressor, preferably TWIN. Compressor, or the one-, two- or multi-cylinder compressor, in particular on a compressed air supply system, in particular for a car vehicle.

For the method, a reciprocating piston engine, in particular according to one of claims 1 to 19, comprises:

an operationally drivable crankshaft having a crankshaft journal arranged eccentrically to a shaft axis of the crankshaft and a drive shaft coupling adapted to couple a drive shaft of a drive motor for driving the crankshaft,

According to the invention for mounting and / or operation of the reciprocating engine provided that

- The crankshaft journal and / or the drive shaft coupling along an axially aligned shaft axis of the crankshaft journal is aligned, which is perpendicular to the radially oriented cylinder axis, and

- The connecting rod axis of the connecting rod tilted against the radially oriented cylinder axis mounted and / operated, so that the bearing clearance of at least one connecting rod bearing is reduced, in particular such that at least one connecting rod bearing is biased.

The radially oriented cylinder axis is aligned substantially symmetrically to cylinder running surfaces for the at least one piston in the cylinder stroke of the at least one cylinder. A radially aligned cylinder axis with a cylinder stroke space aligned therewith is to be understood in particular as meaning that the cylinder running surfaces on the cylinder stroke space of a cylinder for the piston are exactly parallel and symmetrical to the radially aligned cylinder axis. Preferably, the crankshaft journal, in particular also the drive shaft coupling, is aligned along an axially aligned shaft axis aligned perpendicular to the radially aligned cylinder axis; ie that the crankshaft journal and / or a connecting rod bearing surrounding it with a connecting rod bearing axis is perpendicular to the radially aligned cylinder axis.

Conceptually, the radially aligned cylinder axis with aligned Zylinderhubraum or cylinder surfaces and the axially aligned shaft axis with it aligned crankshaft journal and / or the drive shaft coupling are exactly perpendicular to each other. This may also be the case with the concept of the invention, however, in this invention, the conrod bearing is offset along the axially aligned shaft axis with aligned crankshaft journal radially oriented cylinder axis relative thereto; In simple terms, a connecting rod axis and the connecting rod bearing are offset from the radially oriented cylinder axis. This adjusts an angle of the connecting rod or connecting rod axis against the axis of the cylinder surfaces (radially aligned cylinder axis) - they are thus no longer arranged parallel to each other.

The invention is based on the consideration that depending on the requested dynamics and pressure load in an air compressor, a one-, two- or multi-stage compressor or other reciprocating engine during operation increasingly developed operating noise, which -as it turns out - especially by a structure-borne sound transmission through may be caused by the connecting rod drive in the compressor drive motor. It turns out, as recognized by the invention, that the operating noise is partly due to structurally required Pleuellagerspiel. Thus, the emission of operating noise also occurs at idle, in particular, the emission occurs due to the inertia in a load change in which the direction of movement is reversed. The invention has now recognized that by a clever adjustment of the constructionally required conrod bearing games improved acoustics and nonetheless to realize reliable connecting rod drive in a compressor; also with a low noise development which is acceptable in particular for a passenger car sector. In addition, the concept of the present invention is also preferred for a commercial vehicle or passenger transport vehicle, in particular if in this case the compressed air supply system is designed for comparatively high pressure amplitudes.

As recognized by the invention, previous solutions - simplified represent - see an axis of the cylinder bores (radially oriented cylinder axis) and an Ebe ne of a crankshaft bearing and connecting rod bearing before (conrod axis), which are aligned substantially parallel to each other, in particular aligned with each other. Consequently, for example, the connecting rod bearing (such as, for example, a ball bearing on a crankshaft) is usually mounted with a certain mounting dimension X (for example, given here with [X] = 15.00 mm) in alignment with the cylinder running surfaces; ie the mounting dimension X is given, for example, as the distance between a cylinder surface and the flat surface of the connecting rod bearing.

The invention has recognized that now, however, with a - preferably a bias voltage of the connecting rod bearing inducing - reduction of large rod bearing games in a connecting rod bearing, the noise can be significantly reduced; The invention provides for an offset of the axis of the cylinder bores (radially oriented cylinder axis) and a plane of a connecting rod bearing, in particular a connecting rod bearing, which is mounted directly on the crankshaft or indirectly coupled to the crankshaft. In other words, an offset between the axis of the cylinder surfaces and the axis of the connecting rod shaft bearing is provided. The noise can be advantageously significantly reduced.

The bearing bearing of the connecting rod bearing describes a mobility between a first and a second bearing part of the connecting rod bearing. This mobility is limited for the reciprocating piston engine according to the invention by tilting the connecting rod relative to the cylinder axis. The tilting of the connecting rod is in this case synonymous with a deflection, in particular a one-sided deflection, the Pleuelachse. Preferably, the axes of the crankshaft journal and the connecting rod bearing remain parallel, wherein the axes of the two pistons are slightly displaced with respect to the cylinder axis in the axial direction of the crankshaft axis by an amount X mm (for example, X = 15.00mm). This then results in the slight inclination of the first and second connecting rod or piston axis relative to the cylinder axis.

However, the reciprocating piston engine, in particular the reciprocating compressor, described here within the context of a compressed air supply system for use in a pneumatic compressed air supply system can in principle also be used in other fields of application, especially where comparatively high pressure amplitudes are to be achieved flexibly and dynamically in the aforementioned compressed air supply systems. Furthermore, the reciprocating engine described here also for the provision of negative pressure, for example, be used within a vacuum pump.

Advantageous developments of the invention can be found in the dependent claims and specify in particular advantageous ways to realize the above-described concept within the scope of the task and with regard to further advantages.

A connecting rod can be rigid without spherical plain bearings or also articulated, in particular with spherical plain bearings. A piston may be held on the connecting rod, held or integrally formed on the connecting rod.

In an advantageous development of the reciprocating engine according to the invention is characterized in that the connecting rod axis of the connecting rod is tilted against the radially oriented cylinder axis such that the at least one connecting rod bearing is biased. Here, the connecting rod axis of the connecting rod is tilted overall relative to the cylinder axis, wherein this is preferably realized by a deflection, in particular by a one-sided deflection, in particular by a lower deflection of the connecting rod.

Preferably, at least one connecting rod bearing is set with a certain mounting dimension in alignment with the and then changed the set mounting dimensions, (preferably enlarged, if necessary. Also reduced) such that the connecting rod axis of the connecting rod against the radially aligned cylinder axis tilted attached and / / or is operated, in particular such that at least one connecting rod bearing is biased.

For example, in one embodiment, the new solution contemplates the concept of the invention to increase the above mounting dimension X (from, for example, [X] = 15.00mm to [X] = 15.50mm) (in that case in another case, it is basically also possible to reduce the above-mentioned mounting dimension). In both cases, thereby the orientation of the connecting rod axis is tilted against the radially aligned cylinder axis, namely in the present case preferably by a displacement and / or move a connecting rod bearing relative to the radially oriented cylinder axis.

By such a tilting due to a displacement of a connecting rod bearing is preferably both a first connecting rod bearing, preferably a ball bearing directly on the crankshaft, and a second connecting rod bearing, preferably a joint sliding bearing, which is indirectly coupled to the crankshaft, in particular attached directly to the first connecting rod is slightly biased. This bias leads in any case to a reduction the free bearing clearance in the first and second connecting rod bearings, so that they generally less play and thus have a lower noise.

The concept of the invention thus provides the basis for the use of a connecting rod bearing (for example a roller bearing or joint and / or sliding bearing) with reduced clearance and nevertheless avoids the known technical problems (eg at low temperatures) of completely backlash-free bearings. Although an elastic, in particular rubber-elastic decoupling of the individual bearing points of the connecting rod bearings (eg radial and axial bearing points) is additionally possible also in the concept of the invention; However, no longer required in high technical effort. The concept of the invention thus proves to be a simple and feasible with relatively less commercial effort concept.

It shows after performing experiments on noise reduction and under acoustic measurements in the measurement results for a total sound level with different mounting dimensions [X] a strong dependence between noise and mounting dimensions for a connecting rod bearing position on the crankshaft journal of the crankshaft depending on the mounting position [X].

Preferably, the at least one connecting rod against the radially oriented cylinder axis is tilted with a tilt angle such that the connecting rod axis of the at least one connecting rod is tilted in a direction from the piston to the crankshaft journal with an increasing tilting distance against the radially oriented cylinder axis. Such a tilting distance may preferably be up to 0.5 mm, if necessary. Up to 1 mm or 2mm; this may be adjusted as needed for an original mounting dimension. In principle, however, the tilting distance is independent of the original mounting dimension. Conceptually, the tilting distance on the piston is the lowest and the crankshaft journal the largest.

In a particularly preferred embodiment, the at least one connecting rod by means of at least one connecting rod bearing, that is preferably

- with a single connecting rod bearing directly or indirectly, or

- With a first and a second connecting rod bearing, each directly or indirectly

preferably with a first direct and a second conrod bearing indirectly, or

- With a first and a second connecting rod bearing and possibly one or more wide conrod bearings, each directly or indirectly

mounted on the crankshaft journal. Under a direct storage is to be understood that the connecting rod is moved directly over the connecting rod bearing through the crankshaft journal. An indirect storage means that the connecting rod is moved by another component (for example, preferably the first connecting rod), that is indirectly, by the crankshaft journal, but is not stored directly on this.

In the context of a particularly preferred development, a first connecting rod running along a first connecting rod axis can be moved directly by means of the eccentric crankshaft journal, and a second connecting rod running along a second connecting rod axis can be moved indirectly indirectly by means of the crankshaft journal, in particular directly by means of the first connecting rod. Preferably, in this development, the second connecting rod (as Schlepppleuel) from the first connecting rod (as drive connecting rod) movable, wherein the first connecting rod is moved directly from the crankshaft journal. An aforementioned development has proved particularly useful for the realization of a two-stage reciprocating compressor, which can also be referred to as TWIN compressor, namely with two opposite pistons along a radially oriented cylinder axis.

The at least one first or second connecting rod bearing of the at least one first or second connecting rod is preferably mounted offset relative to the radially aligned cylinder axis, characterized in that the first or second connecting rod axis is tilted against the radially oriented cylinder axis. In particular, the first or second connecting rod axis extends outside the radially aligned cylinder axis.

Preferably, the connecting rod axis is tilted against the radially oriented cylinder axis such that the at least one first or second connecting rod bearing is biased. In this respect, in the following a significant, albeit small tilt angle, such a tilt angle understood that is so great that makes a bias in the connecting rod bearing noticeable by reducing the free bearing clearance of the connecting rod bearing. A tilt angle of the tilt is preferably between more than 0 ° and less than 5 °. Particularly preferred embodiments concerning the tilt angles are shown in FIG. 4 and FIG. 5 is shown.

Preferably, the at least one connecting rod bearing, in particular a first connecting rod bearing of a first connecting rod, mounted directly on the crankshaft journal and offset to the radially oriented cylinder axis. Preferably, the aforementioned tilting of the connecting rod axis of the connecting rod is achieved by means of the staggered connecting rod bearing, in particular such that the at least one connecting rod bearing is biased. Preferably, additionally or alternatively, the at least one connecting rod bearing, in particular a second connecting rod bearing of a second connecting rod, is mounted indirectly on the crank pin, preferably on the first connecting rod. The second connecting rod is typically connected via a separate bearing pin with the first connecting rod and has no direct connection to the crankshaft journal. Preferably, the at least one connecting rod bearing, in particular the second connecting rod bearing of the second connecting rod, is offset relative to the radially aligned cylinder axis. By means of this offset, the abovementioned tilting of the connecting rod axis of the connecting rod against the radially aligned cylinder axis is thus preferably achieved, in particular such that the at least one, in particular second, connecting rod bearing is prestressed.

In principle, it has proved to be advantageous that at least one connecting rod bearing of the at least one connecting rod, in particular a first connecting rod bearing of the first connecting rod, which is mounted directly on the crankshaft journal, is offset, such that the connecting rod axis of the connecting rod is tilted against the radially oriented cylinder axis is, in particular such that at least one connecting rod bearing is biased and additionally also a second connecting rod bearing of the second connecting rod, which is preferably mounted indirectly on the crankshaft journal, namely directly on the first connecting rod, tilted against the radially oriented cylinder axis, in particular such that at least one Preload bearing is biased.

A particular advantage of the aforementioned developments is that the orientation of the eccentric crankshaft journal and / or the drive shaft coupling along an axially aligned shaft axis remains unchanged, so far as the crankshaft journal and the shaft axis are co-aligned along the axially aligned shaft axis. A proposed according to the concept of the invention tilting the connecting rod axis of the connecting rod against the radially aligned cylinder axis, preferably under bias of the connecting rod bearing, is particularly preferably achieved according to this development on the displacement of the connecting rod bearing outside of the radially aligned cylinder axis.

In other words, the connecting rod bearing is issued, preferably issued inward, that is offset in the direction of the connection of the crankshaft journal to the crankshaft or in the direction of the drive shaft coupling. An exhibition of the connecting rod bearing inward has, by the typically associated reduction in the distance between the engine bearing and connecting rod bearings, a further improvement in the acoustics result. In principle, however, to achieve the acoustics also parts the connecting rod bearing to the outside, that is, in a direction away from the crankshaft journal, that is, away from the drive shaft coupling.

Particularly preferably, as part of a so-called TWIN compressor, a first connecting rod bearing can be mounted directly on the crankshaft journal and an offset between the radially oriented cylinder axis and a bearing plane, ie a bearing section plane, of the first connecting rod bearing can be set. In this case, a displacement is referred to as offset by which the cylinder axis is deflected relative to the bearing plane of the corresponding connecting rod bearing. Therefore, setting an offset leads to tilting of the cylinder axis relative to the bearing plane. The bearing plane is the plane formed by a movement of the connecting rod bearing around the crankshaft journal without the action of transverse forces. Additionally or alternatively, a second connecting rod bearing can be mounted indirectly on the crankshaft journal, in particular directly on the first connecting rod, and an offset can be set up between the radially aligned cylinder axis and a bearing sectional plane of the second connecting rod bearing.

In the context of a particularly preferred structural realization, an offset may exist between the radially aligned cylinder axis and a ring plane of a ring ball bearing (a preferred realization of the first connecting rod bearing), preferably a groove ball bearing, and / or a center axis of a sliding bearing (a particularly preferred realization of the second connecting rod bearing).

As already mentioned above, the measures of tilting the connecting rod axle or additionally or alternatively displacing the connecting rod bearing serve to pretension the at least one connecting rod bearing and reduce its bearing clearance to an upper limit which lies below the free bearing clearance in the unstressed state of the bearing.

Specifically, it is provided in the context of continuing education that

- The connecting rod axis of the at least one connecting rod is tilted so far against the radially oriented cylinder axis to the shaft axis, that

- The at least one connecting rod bearing is mounted with the connecting rod outside the radially aligned cylinder axis, whereby the at least one connecting rod bearing is biased.

In the aforementioned development, therefore, a minimum tilt is achieved, through which the connecting rod bearing is biased. Such tilting can be in different directions perpendicular to the connecting rod axis. In this case, in particular in, for example, a left and a right direction of tilting, it can happen that a different offset is necessary depending on the component, in order to achieve the minimum tilt, that is, a tilt which is necessary in order to bias the at least one connecting rod bearing.

In a particularly preferred embodiment, the bearing clearance of the connecting rod bearing, in particular the axial and / or radial bearing clearance, the reciprocating engine is reduced to an upper limit, which lies wholly or partially below a free bearing clearance in the unstressed state. The bearing clearance of the connecting rod bearing in this development is at least partially, that is, for example, in the axial or radial direction relative to the connecting rod, reduced compared to the bearing clearance in an unstressed state of the reciprocating engine. The mobility between a first and second bearing part of the connecting rod bearing is consequently reduced in at least one movement axis (that is to say for two opposing directions of movement) in relation to an unstressed state.

Preferably, the connecting rod axis against the radially oriented cylinder axis inwardly to the crankshaft journal, in particular inwardly to the drive shaft coupling, tilted. Here, a tilting inwardly to the crankshaft journal means that the connecting rod axis is tilted in the direction of the connection of the crankshaft journal to the crankshaft, that is, the angle between the connecting rod and crankshaft in this direction of the crankshaft is acute-angled.

Additionally or alternatively, the at least one connecting rod bearing is offset inwardly toward the crankshaft journal, in particular offset inwardly toward the drive shaft coupling and / or towards the drive.

In the context of a further development, it has proved to be advantageous that a first connecting rod is mounted directly on the crankshaft journal by means of a first connecting rod bearing and a first piston is held on the first connecting rod by means of a piston holder. Additionally or alternatively, a second connecting rod by means of a second connecting rod bearing and a coupling element, in particular a bearing pin, be attached to the first connecting rod and be formed on the second connecting rod, a second piston. In this case, the training is preferably a Schleugg connecting rod with a molded piston and a drive connecting rod realized with a piston held thereon. Basically, regardless of this development, a piston formed on the connecting rod may relate to As a piston held on the piston to be realized as needed. For a Schlepppleuel formed with the (low-pressure) compressor stage of a TWIN compressor above all a molded piston has proven. For a below-explained high-pressure compressor stage of a TWIN compressor, above all, a drive connecting rod with a piston held thereon has proven itself.

As part of a preferred structural realization, the first connecting rod bearing can be realized as a ring ball bearing, in particular as a grooved or roller bearing of any kind, which is preferably formed in the form of a grooved ball bearing on the crankshaft journal, that is directly on the crankshaft journal. Additionally or alternatively, the second connecting rod bearing may be formed as a joint bearing, in particular in the form of a sliding bearing or rolling bearing on the first connecting rod.

As already mentioned above, a reciprocating piston engine has proven particularly useful as a reciprocating compressor with a two-stage compressor having first and second compressor stages for providing compressed air to a compressed air supply system. In particular, the two-stage compressor may be formed as a TWIN compressor.

It is specifically intended that

- A first connecting rod of the second, in particular high-pressure, compressor stage is formed, wherein the first connecting rod is mounted directly by means of a first connecting rod bearing on the crankshaft journal.

Additionally or alternatively, it has proved to be advantageous that the second connecting rod of the first, in particular low-pressure, compressor stage is formed, wherein the second connecting rod is mounted directly on the first connecting rod by means of a second connecting rod bearing and a coupling element, insbesondre a bearing pin.

Preferably, the at least one connecting rod bearing, in particular a first connecting rod bearing and / or a second connecting rod bearing, in particular a ring ball bearing, in particular a groove or roller bearing, and / or a spherical plain bearing, provided with a radial bearing clearance detected along the radially oriented cylinder axis. This radial bearing clearance changes due to the concept of the invention in a direction along the axially aligned shaft axis of the crankshaft journal. In other words, the radial bearing play is not evenly distributed over the axial extent of the connecting rod bearing, but asymmetrical with respect to the bearing plane; For example, it prefers outward to. Basically, the rod bearing play can also increase inwards. The outward direction is, for example, the direction to the left in FIG. 2, and the inward direction is the rightward direction. In this development, therefore, the corresponding radial bearing play increases in exactly one axial direction with axial extent of the connecting rod bearing.

Additionally or alternatively, at least one connecting rod bearing, in particular a first and / or second connecting rod bearing, in particular a ring ball bearing and / or a joint bearing, realized along the axially aligned shaft axis of the crankshaft journal bearing in which a thrust bearing clearance is detected. The axial bearing clearance is preferably changed in one direction along the axially aligned shaft axis, that is to say that it has a different value to the left of the connecting rod bearing than to the right of the connecting rod bearing. Such asymmetry of the thrust bearing clearance is typically component related. This asymmetry causes a greater tilt in the appropriate direction along the shaft axis must be made to bias the connecting rod bearing.

Preferably, the thrust bearing play and / or the radial bearing clearance is away from the crankshaft journal, that is, in particular outside, greater than close to the crankshaft journal, in particular thus greater than the inside.

An axial bearing clearance of the connecting rod bearing is preferably in the range of 0.1 to 0.3 mm. Additionally or alternatively, the radial bearing clearance of the connecting rod bearing can be in the range of 0.05 to 0.08 mm.

Embodiments of the invention will now be described below with reference to the drawing. This is not necessarily to scale the embodiments, but the drawing, where appropriate for explanation, executed in a schematized and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. It should be noted that various modifications and changes may be made in the form and detail of an embodiment without departing from the general idea of the invention. The disclosed in the description, in the drawing and in the claims features of the invention may be essential both individually and in any combination for the development of the invention. In addition, all combinations of at least two of the features disclosed in the description, the drawings and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to an article that would be limited in comparison to the subject matter claimed in the claims. For the given design ranges, values within the stated limits should also be disclosed as limit values and arbitrarily usable and claimable. Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing.

In detail, the drawing shows in:

FIG. 1: a pneumatic circuit for an embodiment of a compressed air supply system with connected pneumatic system in the form of an air spring system for a vehicle, wherein a shown in detail D1 two-stage and shown in detail D2 single-stage piston compressor in the context of an air compressor, the air spring system supplied with compressed air via a Air dryer assembly and designed as a lockable check valve valve assembly, which is switchable via a controllable solenoid valve;

FIG. 2: for an air compressor, a reciprocating engine in the form of a two-stage reciprocating compressor with a first connecting rod for a piston of a first (low pressure) stage and a second connecting rod of an air compressor of a second (high pressure) stage with connecting rod bearings, in an unconfined setting before the operating position a temporary installation;

FIG. 3: in each case a schematic diagram of a section of a first connecting rod bearing directly on the crankshaft journal as a ring ball bearing (FIG. 3A - in view A1 no-load, in view A2 under axial load, in view A3 under axial load and radial load) and in a second conrod bearing as a spherical plain bearing in FIG Shape of a sliding bearing between the ring ball bearing and a piston holder (FIG 3B - load-free);

FIG. 4: the two-stage reciprocating compressor, in which for installation the connecting rod axis of the second connecting rod of the second (high pressure) stage is tilted against the radially oriented cylinder axis by a first connecting rod bearing directly on the crankshaft journal and a second connecting rod bearing as a joint bearing with the connecting rod axis as far outside the radially oriented cylinder axis is mounted, that the first and second connecting rod bearing is biased thereby; FIG. 5: the two-stage reciprocating compressor of FIG. 4 with a detail D5 to

Explanation of the second connecting rod bearing as a joint bearing, which is mounted so far outside the radially aligned cylinder axis with the connecting rod, that the second connecting rod bearing is biased thereby.

FIG. 1 shows in detail D1 an air compressor with a reciprocating piston engine in the form of a two-stage reciprocating compressor 400 with a first compressor stage 401 and a second compressor stage 402, which is driven via a motor 500 as a drive motor M.

As an alternative, in detail D2, an air compressor with a reciprocating engine in the form of a single-stage reciprocating compressor 400 'with a single compressor stage 403 is shown driven by a drive motor M.

Such reciprocating compressors 400, 400 'are preferably used for pneumatic air supply systems 1000, such as one shown in FIG. 1 is shown.

FIG. 1 shows a pneumatic circuit diagram of a pneumatic compressed air supply system 1000 with a compressed air supply system 1001 with an air dryer arrangement 100 and a pneumatic system 1002 in the form of an air spring system. The compressed air supply system 1001 is used to operate the pneumatic system 1002. The compressed air supply system 1001 has for this purpose a previously mentioned compressed air supply 1 and a compressed air connection 2 to the pneumatic system 1002.

The compressed air supply 1 is presently formed with an air supply 0, one of the air supply 0 upstream air filter 0.1 and one of the air supply 0 via the air supply line 270 downstream driven via the motor 500 air compressor. The air compressor is here as an example of a reciprocating engine in the form of a double air compressor, namely a two-stage reciprocating compressor 400 having a first compressor stage and a second compressor stage 402 and an unspecified connection of the compressed air supply 1 formed.

At the connection of the compressed air supply 1 is followed in the main pneumatic line 200 to the first part 201 of the main pneumatic line, the connection of the drying container 101 of the air dryer assembly 100 at. The air dryer of the air dryer assembly 100 is further pneumatically connected by means of the second part 202 of the main pneumatic line for guiding a compressed air flow DL to the pneumatic system 1002. In the in FIG. 1 main view is provided that a branch line 230 branches off at the compressed air supply 1 from the main pneumatic line 200 and connects to a vent line 240 for venting 3 to a vent downstream venting filter 3.1; the vent is connected by means of further branch connection 241 and a connection section 242 to the vent line 240 as well as to a further vent line 260 via the branch connection 261.

The pneumatic main line 200 thus pneumatically connects the compressed air supply 1 and the compressed air connection 2, wherein in the pneumatic main line 200, the air dryer assembly 100 and further in the direction of the compressed air connection 2 a entsperrba- res check valve 31 1 and a first throttle 331 is arranged.

In the present case, the pneumatically releasable check valve 311 is a part of the directional control valve arrangement 310 which, in addition to the unlockable check valve 31 1, has a controllable venting valve 312 connected in series with a second restrictor 332 in the venting line 230. The pneumatically releasable check valve 31 1 is presently also arranged in a series connection with the first throttle 331 in the main pneumatic line 200, wherein the main pneumatic line 200 is the only pneumatic line of the first pneumatic connection, which continues to the pneumatic system 1002 with a further pneumatic line 600. The series arrangement of first throttle 331 and pneumatically releasable check valve 31 1 is thus arranged between the air dryer arrangement 100 and the compressed air connection 2 to the pneumatic system 1002 in the main pneumatic line 200.

Next, the compressed air supply system 1001 has a pneumatically connected to the main pneumatic line 200 and the vent port 3 and further filter 0.3 and / or muffler second pneumatic connection; namely, the aforementioned vent line 230. The nominal diameter of the second throttle 332 is present above the nominal diameter of the first throttle 331th

The venting valve 312 arranged in the second pneumatic connection is presently formed in the venting line 230 as a separate 2/2 valve from the pneumatically releasable check valve 311.

The controllable vent valve 312 is thus part of a valve arrangement 300 with a control valve 320 in the form of a 3/2-way solenoid valve as an indirectly switched relay valve. The control valve 320 may be connected to a control unit via an electrical control tion 321 transmissible electrical control signal, in the form of a voltage and / or current signal to the coil 322 of the control valve 320 are electrically controlled. In this electrical control, the control valve 320 from the in FIG. 1, the pneumatic control line 250 interrupting position shown are transferred to a pneumatically open position, in the over the pneumatic control line 250 from the main pneumatic line 200 derived pressure for pneumatic control of the controllable vent valve 312 is relayed as a relay valve.

In the present case, the controllable venting valve 312 is additionally provided with a pressure limitation 313. The pressure limitation 313 accesses via a pneumatic control line in front of the venting valve 312 - concretely between second throttle 332 and venting valve 312- a pressure which, when a threshold pressure exceeds the piston 314 of the venting valve 312 against the force of an adjustable spring 315 from the valve seat lifts - So brings the controllable vent valve 312 without control via the control valve 320 in the open position. In this way it is avoided that an undesirably high pressure in the pneumatic system 1000 is produced.

The control valve 320 separates in the presently closed state, the control line 250 and is pneumatically connected via a further vent line 260 with the vent line 240 to the vent 3. In other words, a lying between the venting valve 312 and control valve 320 line section 251 of the control line 250 in the in FIG. 1 shown closed position of the control valve 320 connected to the other vent line 260 between the control valve 320 and vent 3. The further vent line 260 closes in the further branch connection 261 to the vent line 230 and the further vent line 240. Thus, these are combined in a lying between the other branch connection 261 and the vent 3 section of a vent line 240.

Via the control valve 320, the venting valve 312 can thus be opened when the piston 314 is pressurized when a control pressure derived from the main pneumatic line 200 or from the further pneumatic line 600 via the pneumatic control line 250 from the control connection 252 is reached.

The piston 314 is in the present case designed as a double piston, so that provided with particular advantage, the transfer of the control valve 320 in the above-sense opened state not only to open the venting valve 312, but also to unlock the pilot-operated check valve 311. In other words, the control valve 320 of the solenoid valve assembly 300 is used to control the separately provided by the check valve 31 1 vent valve 312 and the check valve 311. This leads to a two-sided pneumatic opening of the air dryer assembly 100 upon transfer of the control valve 320 in the open position. This further operating position, which can be captured by the compressed air supply system 1001, can be used during operation for venting the pneumatic system 1002 and at the same time for regenerating the air dryer arrangement 100.

The in FIG. 1 operating position of the compressed air supply system 1001 is used in flow direction of the check valve 31 1 in particular for filling the pneumatic system 1002 via the main pneumatic line 200 and the other pneumatic line 600.

The pneumatic system 1002 of FIG. 1 in the form of an air spring system has in this case a number of four so-called bellows 101 1, 1012, 1013, 1014, which are each associated with a wheel of a non-illustrated car vehicle and form an air spring of the vehicle.

Furthermore, the air suspension system has a memory 1015 for storing rapidly available compressed air for the bellows 1011, 1012, 1013, 1014. Those bellows 101 1 to 1014 are respectively in a outgoing from a gallery 610 spring branch line 601, 602, 603, 604 each a solenoid valve 1 1 11, 1112, 1 1 13, 1 1 14 upstream, each as a level control valve to open or close a with a bellows 101 1 to 1014 formed air spring is used. The solenoid valves 1 1 11 to 11 14 in the spring branch lines 601 to 604 are formed as 2/2-way valves in a valve block 1 1 10. A memory 1015 is preceded by a solenoid valve 1 1 15 in the form of a further 2/2-way valve as a storage valve in a memory branch line 605. The solenoid valves 101 1 to 1015 are connected by means of the spring and storage branch lines 601 to 604 and 605, respectively, to a common manifold, namely the aforementioned gallery 610 and then to the further pneumatic line 600. The gallery 610 is pneumatically connected via the pneumatic line 600 to the compressed air connection 2 of the compressed air supply system 1001. In the present case, the solenoid valves 111 1 to 1 1 15 are arranged in a valve block 1010 with the five valves. The solenoid valves are shown in FIG. 1 shown in a de-energized state, while the solenoid valves 1 1 1 1 to 1 1 15 are formed as normally closed solenoid valves. Others, not shown here modified embodiments can realize a different arrangement of the solenoid valves - it can also be used less solenoid valves in the context of the valve block 1010.

For filling the pneumatic system 1002, the bellows 1011 to 1014 upstream solenoid valves 1111-1114 and / or the memory 1015 upstream solenoid valve 11 15 are brought into an open position.

Nevertheless, in the closed position of the solenoid valves 1 11 1 to 1 1 14 or 1 115 in the pneumatic system 1001 - due to the presently not unlocked check valve 311- an operating position of the pneumatic system 1002 decoupled from the compressed air supply system 1001 possible. In other words, switching of bladders 101 1 to 1015 (eg, in off-road operation of a vehicle) may fill the bladders 101 1 to 1015 from the reservoir 1015 or pressure measurement in the pneumatic system 1002 via the gallery 610 be without the compressed air supply system 1001 is pressurized.

In particular, the air dryer arrangement 100 is protected against unnecessary admission of compressed air due to the check valve 31 1 blocked by the compressed-air connection 2 to the compressed air supply 1 and the closed control valve 320. In an advantageous manner, therefore, pressurization of the air dryer arrangement 100 with compressed air is not advantageous in every operating position of the pneumatic system 1002. Rather, it is advantageous for an effective and rapid regeneration of the air dryer system 100, if this is carried out exclusively in the case of a venting of the pneumatic system 1002 from the compressed air connection 2 to the compressed air supply 1 with unlocked check valve 31 1.

For this purpose-as explained above-the control valve 320 is brought into an open switch position, so that both the venting valve 312 opens and the check valve 31 1 is unlocked. Venting of the pneumatic system 1002 can take place via the first throttle 331, the unlocked check valve 31 1 with regeneration of the air dryer assembly 100 and then via the second throttle 332 and the open vent valve 312 for venting 3.

In other words, for the simultaneous unlocking operation of the check valve 31 1 and for the opening actuation of the venting valve 312, a control piston 320 pneumatically controllable control piston 314 is provided as a double relay piston. The dual relay piston illustrates this principle for unlocking the check valve 31 1 and simultaneously actuating the venting valve 312 via the two coupled actuators-namely, via the relay check body 314.2 and the relay vent body 314.1- which can be formed as a one-piece double relay body or in a modification as a separate body. In the context of a particularly preferred modification of a structural realization, the aforementioned actuating elements of the double relay piston can be formed as one-piece regions of a double relay piston.

FIG. 2 to FIG. 5 will now explain the details of the concept of the invention using the example of a reciprocating engine especially in the form of the two-stage reciprocating compressor 400 of FIG. 1.

Referring first to FIG. 2 shows this reciprocating piston engine in the form of a double compressor according to detail D1 of FIG. 1, namely a TWIN compressor designed as a two-stage piston compressor 400 with a first compressor stage 401 and a second compressor stage 402 and with a motor 500 which is coupled as a drive motor M with a drive shaft 501 to a crankshaft 430 of the piston compressor 400.

For this purpose, the crankshaft 430 has a drive shaft coupling 431, which serves as a receptacle for the drive shaft 501 of the drive motor M. The crankshaft 430 is rotatably mounted on the outside of the drive shaft coupling 431 in a bearing 502, which is designed here as a ring ball bearing. The bearing 502, in turn, is held on the motor housing 503 with a corresponding retention mechanism. In this way, the crankshaft 430 drivable in operation by means of the drive motor M is formed via said drive shaft coupling 431 for coupling the drive shaft 501 of the drive motor 500 for driving the crankshaft 430.

The crankshaft 430 also has an eccentric crankshaft journal 432 formed eccentrically to the axis A on the crankshaft 430, which extends along an eccentric axis, which is referred to herein as axially aligned shaft axis E. With the crankshaft 430 rotationally driven, the eccentric crankshaft journal 432 is configured to indirectly drive a first connecting rod P1 directly and a second connecting rod P2. For this purpose, the eccentric crankshaft journal 432 is formed by means of a first connecting rod bearing L1 for direct storage and direct drive of the first connecting rod P1. The second connecting rod P2, in turn, is movably mounted on the first connecting rod P1 functioning as the drive connecting rod P1, ie as a connecting connecting rod, via a further connecting rod bearing L2. The first connecting rod bearing L1 is designed as a ring ball bearing with an inner ring IR and an outer ring AR. The second connecting rod bearing L2 is designed as a joint bearing in the form of a sliding bearing.

The first piston K1 is inserted by means of a piston holder K1 1 as a separate part in the head end of the first connecting rod P1 and held there. The second piston K2 is formed integrally and integrally at the head end K22 of the second connecting rod P2 - that is, along a radially aligned cylinder axis Z distally opposite the first piston K1. The second connecting rod P2 is for this purpose as a one-piece, approximately ring-like component - as shown in FIG. 2 visible- suspended from the second connecting rod bearing L2.

In this construction, while the crankshaft 430 is being driven in rotation, an eccentric rotational movement of the crankshaft journal 432 can be achieved during operation of the compressor 400, so that the first and second pistons K1, K2 with a reciprocating motion for compressing compressed air in the corresponding second and second pistons K1, K2 first compressor stage 402, 401 are respectively moved.

For this purpose, the second piston K2 of the first compressor stage 401 moves in a cylinder stroke space 41 1 of the first cylinder 410 in the first (low-pressure) compressor stage 401. The first piston K1 therefore moves in a cylinder stroke space 421 of a second cylinder 420 of the second (high-pressure) compressor. ) Compressor stage 402. The first and second cylinders 410, 420 are part of a housing 440 of the entire air compressor with reciprocating compressor 400, drive motor M and crankshaft 430. The housing 440 of the air compressor is by other components 441 on the housing of a compressed air supply system 1001, as shown in FIG FIG.1 is shown held.

FIG. 2 shows the TWIN compressor 400, in this case in an operating position according to which the second piston K2 of the (low-pressure) compressor stage 401 is in a stroke position HS, that is, the compression of the air in the displacement 41 1 is imminent. By contrast, the first piston K1 of the second compressor stage is 402 in one Compression position VS, that is to say from the second high-pressure stage 402 compressed air is compressed to be discharged to the compressed air supply system 1001.

Hereinafter, with respect to the mounting of the reciprocating compressor 400, reference will be made to FIG. 2 and FIG. Third

The movement of the first and second pistons K1, K2 during operation of the piston compressor 400 basically takes place along a radially aligned cylinder axis Z. This is centered symmetrically to cylinder running surfaces Z1 or Z2 of the first and second Zylinderhubraums 41 1, 421 for the second and first piston K2, K1 of the first and second cylinders 410, 420. In FIG. 2, the connecting rod length of the first connecting rod P1 with 52.00 mm is given as an example of the magnitude of the high-pressure stage 420 of the piston compressor 400.

The radially oriented cylinder axis Z is radially oriented insofar as it extends along a radius about the axially aligned shaft axis E (eccentric axis E). The axially aligned shaft axis E extends exactly perpendicular to the radially aligned cylinder axis Z. That is, the eccentric crankshaft journal 432 of the crankshaft 430 is also arranged exactly perpendicular to the radially aligned cylinder axis Z in the piston compressor 400. A sufficiently reliable and tight running of the second and first pistons K2, K1 in the first (low-pressure) compressor stage or (high-pressure) compressor stage 401, 402 is thus ensured along the radially oriented cylinder axis Z due to the running direction of the pistons K2, K1 ,

For this purpose, the arrangement of the first connecting rod P1 with piston K1 and the second connecting rod P2 with piston K2 under storage thereof by means of the first connecting rod bearing L1 and the second connecting rod L2 is made exactly along the radially aligned cylinder axis Z; However, this initially provisionally with a mounting dimension of X = 15.00 mm shown here as an example.

In this installation situation, a in FIG. 3A bearing load and bearing clearance of the first connecting rod bearing L1 according to the situation A1. The second connecting rod bearing L2 has a radial bearing clearance L2-RS and a drive shaft side axial bearing clearance L2-RS1 and a thrust bearing L2 -RS2 opposite thereto; in the view of FIG. 3B, ie right and left of the first connecting rod P1, between the first connecting rod P1 and the second connecting rod P2. As further shown in FIG. 3B, the bearing clearances L2-RS and L2-AS of the first and second connecting rods P1, P2 are cushioned against a bearing pin L2-B with a corresponding bearing collar L2-M. This means that the second connecting rod bearing L2 is a true joint sliding bearing - the bearing sleeve L2-M is in this case designed as an annular bearing sleeve double-shelled.

Accordingly, in FIG. 2, or in detail of FIG. 3A a bearing ball L1-K recognizable with bearing sleeve L1-M, which in turn is designed as an annular sleeve for the representation of the ring ball bearing L1. The bearing clearance L1-S of the first connecting rod bearing L1 is shown in FIG. 3A is shown symmetrically on both sides as the distance between the bearing ball L1-K and the bearing sleeve L1-M.

This situation in FIG. 3A (A1) and FIG. However, FIG. 3B consists only after a preliminary assembly as shown in FIG. 2 that is load-free for the connecting rod bearings P1, P2, L1, L2 is present.

FIG. 3A shows, for the situation of a merely axial load in the illustration A2 and for the situation of a radial load in the illustration A3, that the bearing ball L1-K relative to the bearing sleeve L1-M does not have a symmetrical bearing clearance L1-S; Rather, a in the figure A3 of FIG. 3A shown left-side bearing clearance L1-SL as a result of the acting radial and axial forces Frad, Fax much less than the right-side bearing clearance L1-SR. In other words, the resulting operating force F reduces the bearing clearance L1 -SL, L1-SR asymmetric, which has been explained here as the ring ball bearing on the example of the first connecting rod bearing L1.

The same applies analogously to the second connecting rod bearing L2. In the case of a similar load situation of a resulting force F (not shown in FIG. 3B), the bearing clearance L2-RS and L2-AS1, L2-AS2 are changed asymmetrically.

The invention has recognized that such naturally changing bearing clearances lead to body noise at the bearings, connecting rods and finally the crankshaft 430, resulting in significantly increased acoustics of the reciprocating compressor 400 as a result of transmission to the housings 440 and the drive motor M and the further housings 441 leads.

The concept of the invention therefore provides that a connecting rod axis P shown in FIG. 4, along which a first and second connecting rod P1, P2 extends (that is to say the connecting rod P1, P2 moved in operation by means of the eccentric crankshaft journal 432), projects radially against the latter aligned cylinder axis Z is tilted. FIG. 4 indicates a tilt angle that is between a> 0 ° to 5 °. The length of the connecting rod P1 is 52.00 mm in the following example. The tilting of the connecting rod axis of the first connecting rod P1 at an angle of a> 0 ° to 5 ° is evident on the increasing Verkippungsabstand d of the first connecting rod P1 against the radially oriented cylinder axis Z; namely, this increases from the first piston K1 to the crankshaft journal 432. That is, the connecting rod axis P runs with increasing Verkippungsabstand d against the radially aligned cylinder axis Z and that (apart from the vertex of the angle a at the level of the upper pressure point of the first piston K1) outside the radially oriented cylinder axis Z.

The tilting of the connecting rod axis P against the radially aligned cylinder axis Z is so great (preferably in the tilt angle range a> 0 ° to 5 °), that the first connecting rod bearing P1 is biased. In other words, in FIG. 3A in view A1 symmetrical bearing clearance L1-S in the subsequent assembly step (that is, after the pre-assembly as shown in FIG 2) is asymmetrically changed.

The change, or the bias of the first connecting rod bearing L1 is now such that this situation, as shown in view A3 of FIG. 3A, exactly counteracts; that is, the tilting of the connecting rod axis P with respect to the radially aligned cylinder axis Z is performed with a bearing clearance L1-SL, which is greater than the bearing clearance L1-SR. In the present case, this is preferably achieved in that the structure shown in FIG. 2 mounting dimension X shown on a mounting dimension X 'of FIG. 4 is increased; in this example from X = 15.00 mm to X '= 15.50 mm. Put simply, as shown in FIG. 4, the connecting rod axis P is already offset during the assembly of the first connecting rod P1 with connecting rod bearing L1 on the eccentric crankshaft journal 432 by an offset of Δχ = 0.50 mm (in the present example). The offset .DELTA.χ is in this case directed in the direction of the drive motor M out, that is made in the direction of the drive shaft coupling 431. Thereby, the with respect to FIG. 3A, view A3, explained opposite unbalanced change of the bearing clearance L1-SL> L1-SR achieved. This is on the right side of FIG. 4 symbolically represented for the diameter assumed here by way of example of the first connecting rod bearing L1 in the form of a ring ball bearing; with a diameter of about 18 mm and due to the Offset Δχ results in a bearing offset AL due to the roughly same tilt angle a> 0 ° to 5 °.

As a result of the design chosen here of the first connecting rod bearing L1 for direct storage on the eccentric crankshaft journal 432 and the second connecting rod bearing L2 for indirect storage on the crankshaft journal 432-namely rather for direct storage of the second connecting rod P2 on the first connecting rod as Schlepppleuel- arises due to the offset .DELTA.χ according to FIG.5 also shows a tilting of the second connecting rod P2. Ie. In the present case, the connecting rod axis Pa for the first connecting rod P1 and Pb for the second connecting rod P2 is identical and in this respect, both the first and the second connecting rod P1, P2 with respect to the radially aligned Zylinderachs Z by the same Verkip- angle a> 0 ° tilted to 5 °.

The extent of the offset B for the second connecting rod bearing L2 is as shown in FIG. 5 but is lower and is B = 0.30769 compared to the extent A = 0.55. This is due to the fact that the length of the second connecting rod P2 is shorter with respect to the eccentric axis E and in the following example is 32.00 mm.

In detail D5 of FIG. 5, the asymmetrical variation Y of the radial bearing clearance L2-RS and the asymmetrical variation U for the axial bearing clearance L2-AS are shown by way of example for the tilt angle of A = 0.55 °. Put simply, the slide bearing results in an inclination, so that the radial bearing clearance (in the perspective shown here on the left, ie in the point Y remote from the drive motor M) increases in the range between 0.05 to 0.08 mm. On the other hand, the axial bearing clearance u also increases on the left side, that is to say in the case of L2-AS2 by u = 0.14 mm. This also means that the connecting rod axis P of the second connecting rod P2 as a connecting rod from the first connecting rod P1 as a drive connecting rod is tilted by a tilting angle a that results in a pretensioning of the second connecting rod bearing L2 already intended after assembly.

The bias of the first and second connecting rod bearing L1, L2 is thus achieved by an asymmetrical distribution of the bearing clearance, which is achieved in this case by issuing the connecting rod bearings L1, L2; that is, the bearing clearance (radial and axial) L1-RS, L2-RS, L1-AS, L2-AS are increased in a side facing away from the drive coupling 431 side of the crankshaft journal 432, while on the shaft journal 432 and the drive side 431 thereof facing side are reduced. Preferably, the losses achieved by this asymmetry and bias are Components L1-RS, L2-RS, L2-AS1, L1-AS1 on a side facing the drive coupling 431 below the free bearing clearance (FIG. 3A, view A1) in the unclamped state.

This is the result of the connecting rod axis P preferably offset inwards to the crankshaft journal and the drive shaft coupling 432, 431 in comparison to the radially aligned cylinder axis Z.

As a result, a reciprocating engine in the form of a TWIN compressor 400 with a first and second compressor stage 401, 402 is provided, in which a first connecting rod P1 of the second, namely (high-pressure) compressor stage 402 is formed, wherein the first connecting rod P1 by means of a first connecting rod bearing L1 is mounted directly on the crankshaft journal 432 -that is formed as Antriebspleuel- and a second connecting rod P2 of the first, here (low-pressure) compressor stage 401, wherein the second connecting rod P2 by means of a second connecting rod L2 indirectly to the crankshaft journal, the means directly at the first connecting rod P1 -also as a tow bar at Antriebspleuel- is stored.

In both cases results from the offset of a connecting rod P against the radially aligned cylinder axis Z one of the tilt following misalignment, so that both connecting rod bearings L1, L2 are biased in the aforementioned manner. The free bearing clearances are thus asymmetrically changed, so that impact noises in the bearings are reduced and transmission of bearing noise via the connecting rods P1, P2 to the housings 440, 441 is largely reduced.

Basically, this also applies to other types of bearings and especially based on other constructions, which is a direct storage of both the first connecting rod P1 and also within a first connecting rod bearing L1 as a ring ball bearing and a second connecting rod bearing P2 of the second connecting rod P2 provide directly on the spherical shaft journal. In other words, the above-described embodiments with drive connecting rod and Schlepppleuel prove to be particularly advantageous for a TWIN compressor. However, the concept of the invention is not limited thereto. In principle, bearing noises can also be reduced in relation to embodiments in which both connecting rods P1, P2 are mounted directly on the crankshaft journal, or a first and second connecting rod are stored independently, or even for single-stage compressors with a single connecting rod; For example, the description of FIG. 4 applies analogously to the first connecting rod P1. If the reciprocating compressor has only a single connecting rod, or has only a single compressor stage 403, as shown in detail D2 of FIG.1.

List of Reference Numerals (part of the description)

0 air supply, intake

0.1 filter element, air filter

1 compressed air supply

2 compressed air connection

3 exhaust connection

3.1 Vent filter, filter element, silencer

100 air dryer arrangement

101 drying container

200 pneumatic main

201 first part of the main pneumatic line

202 second part of the main pneumatic line 230 branch line, vent line

240 more vent line

241 further branch connection

242 connection section

250 pneumatic control line

251 line section

252 control connection

260 more vent line

261 branch connection

270 air supply line

300 valve arrangement, solenoid valve arrangement

310 directional valve arrangement

311 check valve

312 bleed valve

313 pressure limit

314 pistons

314.1 Relay vent body

314.2 Relay Unlocking Body

315 adjustable spring

320 control valve

321 electrical control line 322 coil

331 first throttle

332 second throttle

400, 400 'air compressor in the form of a reciprocating compressor

401 first (low pressure) compressor stage

402 second (high pressure) compressor stage

403 compressor stage

410 first cylinder

41 1, 422 cylinder stroke

420 second cylinder

430 crankshaft

440 housing

431 Drive shaft coupling

432 crankshaft journals

441 housing

500 engine

M drive motor

502 bearings

600 more pneumatic lines

601, 602, 603, 604 spring branch line

605 memory branch line

610 gallery

1000 compressed air supply system

1001 compressed air supply system

1002 pneumatic system

1011, 1012, 1013, 1014 bellows

11 10 Valve block

1015 memory

11 11 to 1 1 14 Solenoid storage valve

1 1 15 Solenoid valve a Tilt angle

Δ L bearing offset Δ χ offset

A axis

AR outer ring

A1, A3 view

B offset

D1, D2, D5 detail

DL compressed air flow

E eccentric axis, shaft axis

F force

Fax, Frad axial force, radial force

HS lifting position

IR inner ring

K1, K2 pistons

K11 piston holder

K22 headboard

L1, L2 connecting rod bearings, ring ball bearings, joint plain bearings

LS-RS, L1-S, L1-SL, L1-SR radial bearing clearance

L2-AS1, L2-AS2, L2-RS1, L2-RS2 axial bearing play

L2B bearing pin

L1 K bearing ball

L2M bearing collar

M drive motor

P, Pa, Pb connecting rod axis

P1, P2 first, second connecting rod

U Unsymmetrical change

VS compaction position

Z cylinder axis

Z1, Z2 Cylinder surface

Claims

claims

1. Reciprocating piston engine, in particular a one-, two- or multi-stage piston compressor (400, 400 ') or a one-, two- or multi-cylinder compressor, comprising:

- At least one cylinder (410, 420) and at least one respective cylinder (410, 420) associated piston (K1, K2), wherein in operation the piston (K1, K2) along a radially oriented cylinder axis (Z) in a Cylinder stroke (411, 421) of the cylinder (410, 420) is deflected

- An operable crankshaft (430) having a crankshaft journal (432), which is arranged eccentrically to a shaft axis (E) of the crankshaft (430), and a drive shaft coupling (431) for coupling a drive shaft (501 ) is configured to drive the crankshaft (430),

- At least one each for deflecting the at least one piston (K1, K2) formed and along a connecting rod axis (Pa, Pb) extending connecting rod (P1, P2), which is movable by means of the crankshaft journal (432), characterized in that

- The crankshaft journal (432) and / or the drive shaft coupling (431) along an axially aligned shaft axis (E) is aligned, which is perpendicular to the radially oriented cylinder axis (Z), and

- The connecting rod axis (Pa) of the connecting rod (P1) is tilted against the radially oriented cylinder axis (Z), so that the bearing clearance of at least one connecting rod bearing (L1, L2) is reduced.

2. A reciprocating piston engine according to claim 1, characterized in that the at least one connecting rod (P1) against the radially aligned cylinder axis (Z) in such a way with a tilt angle ^(a) tilted so that the connecting rod (Pa) of the at least one connecting rod (P1) in a direction from the piston (K1) to the crankshaft journal (432) is tilted with an increasing tilting distance against the radially oriented cylinder axis (Z).

3. Reciprocating piston engine according to claim 1 or 2, characterized in that

- The at least one connecting rod (P1) by means of at least one connecting rod bearing (L1) directly or indirectly on the crankshaft journal (432) is mounted, and / or - On the connecting rod (P2) of the piston (K2) is formed or held by a piston holder (K11) of the piston (K1).

4. Reciprocating piston engine according to one of claims 1 to 3, characterized in that a first along a first connecting rod axis (Pa) extending connecting rod (P1) directly by means of the crankshaft journal (432) is movable and a second along a second connecting rod axis (Pb) extending connecting rod (P2) indirectly by means of the crankshaft journal (432), in particular by means of the first connecting rod (P1), is movable, preferably the second connecting rod (P2) as Schlepppleuel from the first connecting rod (P1) is movable as a drive connecting rod.

5. Reciprocating piston engine according to one of claims 1 to 4, characterized in that at least one first or second connecting rod bearing (L1, L2) of the at least one first or second connecting rod (P1, P2) so offset from the radially aligned cylinder axis (Z) stored is that thereby the first or second connecting rod axis (Pa, Pb) is tilted against the radially oriented cylinder axis (Z), in particular outside this, in particular such that the at least one first or second connecting rod bearing (L1, L2) is biased ,

6. Reciprocating piston engine according to one of claims 1 to 5, characterized in that the at least one connecting rod bearing (L1, L2), in particular a first connecting rod bearing (L1) of a first connecting rod (P1), mounted directly on the crankshaft journal (432) and radially aligned Cylinder axis (Z) is offset, in particular such that the at least one connecting rod bearing (L1) is biased.

7. A reciprocating engine according to one of claims 1 to 6, characterized in that the at least one connecting rod bearing (L1, L2), in particular a second connecting rod bearing (L2) of a second connecting rod (P2), indirectly on the crankshaft journal (432), in particular on the first connecting rod (P1), mounted and offset from the radially oriented cylinder axis (Z), in particular such that the at least one, in particular second, connecting rod bearing (L2) is biased.

8. A reciprocating engine according to one of claims 1 to 7, characterized in that

- A first connecting rod bearing (L1) is mounted directly on the crankshaft journal (432) and an offset (Δ χ, Fig.4) consists between the radially oriented cylinder axis (Z) and a bearing section plane of the first connecting rod bearing (L1), and / or

a second connecting rod bearing (L2) is mounted indirectly on the crankshaft journal (432), in particular directly on the first connecting rod (P1), and there is an offset between the radially oriented cylinder axis (Z) and a bearing sectional plane of the second connecting rod bearing (L2) , especially

- An offset exists between the radially oriented cylinder axis (Z) and a ring plane of a through the first connecting rod bearing (L1) formed ring ball bearing and / or a center axis of a sliding bearing formed by the second connecting rod bearing.

9. Reciprocating piston engine according to one of claims 1 to 8, characterized in that the connecting rod axis (Pa, Pb) of the connecting rod (P1, P2) is tilted against the radially oriented cylinder axis (Z), such that the at least one connecting rod bearing ( L1, L2) is biased.

10. A reciprocating engine according to one of claims 1 to 9, characterized in that

- The connecting rod (Pa) of the at least one connecting rod (P1) is tilted so far against the radially oriented cylinder axis (Z) to the shaft axis (E) that

- The at least one connecting rod bearing (L1) with the connecting rod axis (Pa) outside the radially oriented cylinder axis (Z) is mounted, whereby

- The at least one connecting rod bearing (L1) is biased.

11. A reciprocating engine according to one of claims 1 to 10, characterized in that the bearing clearance of the connecting rod bearing (L1, L2) is reduced to an upper limit, which is below the free bearing clearance in the unstressed state.

12. A reciprocating engine according to one of claims 1 to 11, characterized in that

- The connecting rod (Pa) against the radially oriented cylinder axis (Z) inwardly to the crankshaft journal (432), in particular inwardly to the drive shaft coupling, tilted, and / or - The at least one connecting rod bearing (L1) is offset inwardly towards the crankshaft journal (432), in particular offset inwardly to the drive shaft coupling and / or to the drive.

13. A reciprocating engine according to any one of claims 1 to 12, characterized in that a tilt angle ( ^a ) of the tilt between more than 0 ° and less than 5 °.

14. A reciprocating engine according to one of claims 1 to 13, characterized in that

- A first connecting rod (P1) by means of a first connecting rod bearing (L1) is mounted directly on the crankshaft journal (432) and on the first connecting rod (P1) by means of a piston holder (K1 1) a first piston (K1) is held, and

- A second connecting rod (P2) by means of a second connecting rod bearing (L2) and a coupling element on the first connecting rod (P1) is fixed and on the second connecting rod (P2), a second piston (K2) is formed.

15. A reciprocating engine according to claim 14, characterized in that

- The first connecting rod bearing (L1) is a ring-ball bearing, in particular a grooved or rolling bearing of any kind, in particular in the form of a ring-ball bearing on the crankshaft journal (432), and / or

- The second connecting rod bearing (L2) is a joint bearing, in particular in the form of a plain bearing or rolling bearing on the first connecting rod (P1).

16. A reciprocating engine according to one of claims 1 to 15, characterized in that

- The reciprocating compressor (400) is formed as a two-stage compressor with a first and second compressor stage (401, 402), in particular as a TWIN compressor, wherein:

- A first connecting rod (P1) of the second, in particular high-pressure, compressor stage is formed, wherein the first connecting rod (P1) by means of a first connecting rod bearing (L1) is mounted directly on the crankshaft journal (432), and / or - A second connecting rod (P2) of the first, in particular low-pressure, compressor stage (401) is formed, wherein the second connecting rod (P2) by means of a second connecting rod bearing (L2) and a coupling element directly on the first connecting rod (P1) is mounted.

17. A reciprocating engine according to one of claims 1 to 16, characterized in that

- The at least one connecting rod bearing (L1, L2), in particular a first connecting rod bearing (L1) and / or a second connecting rod bearing (L2), in particular a ring-ball bearing and / or a spherical plain bearing, along the radially oriented cylinder axis (Z) has detected radial bearing clearance, which varies in one direction along the axially aligned shaft axis (E) of the crankshaft journal (432), and / or

- At least one connecting rod bearing (L1, L2), in particular a first (L1) and / or a second connecting rod bearing (L2), in particular a ring ball bearing and / or a joint bearing, along the axially aligned shaft axis (E) of the crankshaft journal (432) has a detected axial bearing clearance that varies in a direction along the axially aligned shaft axis (E).

18. A reciprocating engine according to claim 17, characterized in that the axial bearing clearance and / or the radial bearing clearance away from the crankshaft journal (432), in particular outside, is greater than near the crankshaft journal (432), in particular greater than inside.

19. A reciprocating engine according to claim 17 or 18, characterized in that at the at least one connecting rod bearing (L1) the thrust bearing play in the range of 0.1 - 0.3 mm and / or the radial play in the range of 0.05 - 0.08 mm

20 compressed air supply system (1001) for operating a pneumatic system (1002), in particular an air spring system of a vehicle, preferably a passenger car, with a compressed air flow (DL), comprising:

- An air dryer assembly (100) in a pneumatic main line (200) which pneumatically connects a compressed air supply (1) from an air compressor (400) and a compressed air connection (2) to the pneumatic system (1002), and

- One to the pneumatic main line (200) pneumatically connected valve assembly (300) for controlling the compressed air flow (DL) and an air dryer (101) in the main pneumatic line (200), wherein - To the compressed air supply (1) an air compressor (400, 400 ') with a reciprocating engine, in particular a one-, two- or multi-stage piston compressor or a one-, two- or multi-cylinder compressor, the claims 1 to 19 is connected.

21 compressed air supply system (1000) with a pneumatic system (1002) and with a compressed air supply system (1001) according to claim 20 for operating the pneumatic system (1002) with a compressed air flow (DL), in particular an air spring system of a vehicle, preferably a car, the pneumatic main ( 1002) a compressed air supply (1) from an air compressor (400, 400 ') with a reciprocating engine, in particular a one-, two- or multi-stage piston compressor (400, 400'), the claims 1 to 17 and a compressed air connection (2) to the Pneumatic system (1002) pneumatically connects.

22, vehicle, in particular passenger car, with a pneumatic system (1002), in particular an air spring system, and a compressed air supply system (1001) according to claim 20 for operating the pneumatic system (1002) with a compressed air flow.

23. A method for assembling and / or operating a reciprocating piston engine, in particular according to one of claims 1 to 19, in particular with a one-, two- or multi-stage piston compressor (400, 400 ') or a one, two or mehrzylindri- gene Compressor, in particular on a compressed air supply system (1001), comprising:

- At least one cylinder (410, 420) and at least one respective cylinder (410, 420) associated piston (K1, K2), wherein in operation the piston (K1, K2) along a radially oriented cylinder axis (Z) in a Zylinderhubraum (41 1, 421) of the cylinder (410, 420) is deflected,

an operable crankshaft (430) having a crankshaft journal (432) disposed eccentrically to a shaft axis (E) of the crankshaft (430) and a drive shaft coupling (431) adapted for coupling a drive shaft (501), in particular of a drive motor (M), designed to drive the crankshaft (430),

- At least one each for deflecting the at least one piston (K1, K2) formed and along a connecting rod axis (Pa, Pb) extending connecting rod (P1, P2), which is movable by means of the crankshaft journal (432), characterized in that - The crankshaft journal (432) and / or the drive shaft coupling (431) along an axially aligned shaft axis (E) of the crankshaft journal (432) is aligned, which is perpendicular to the radially oriented cylinder axis (Z), and

- The connecting rod axis (Pa) of the connecting rod (P1) tilted against the radially oriented cylinder axis (Z) mounted and / operated, so that the bearing clearance of at least one connecting rod bearing (L1) is reduced, in particular such that at least one connecting rod bearing ( L1) is biased.

24. The method according to claim 23, characterized in that at least one connecting rod (Pa) is set parallel to the cylinder axis (Z) and then a set axis position of the connecting rod (Pa) of the connecting rod (P1) against the radially oriented cylinder axis ( Z) tilted mounted and / operated, in particular such that at least one connecting rod bearing (L1) is biased.