Piston Compressor

Abstract

The present invention relates to a piston compressor comprising a piston (1) guided in a compressor cylinder (2), the piston and the compressor cylinder forming a compressor chamber (3) for compressing a fluid, a shaft (4) arranged rotatably about its axis, and a stroke member (6, 13) arranged eccentrically with respect to the axis of the shaft and fixedly mounted on the shaft, the stroke member and the piston being arranged such that, when the shaft rotates about its axis, the piston undergoes a movement between a maximum stroke position and a minimum stroke position.

Description

[Technical Field]

[0001] The present invention relates to a piston compressor.

[0002] A piston compressor includes one or more pistons, each guided in a compressor cylinder, where the pistons and compressor cylinder form a compressor chamber for compressing a fluid. During operation of the compressor, the pistons are moved along the axis of the compressor cylinder between a maximum stroke position and a minimum stroke position, where the compressor chamber has its minimum volume when the piston is in the maximum stroke position and its maximum volume when the piston is in the minimum stroke position. Preferably, the fluid to be compressed is supplied to and discharged from the compressor chamber through a port controlled by a valve.

[0003] The piston compressor according to the invention operates according to this principle.

[0004] Vehicles, especially commercial vehicles, require a supply of compressed fluid, especially compressed air, for various systems of the vehicle. For example, air is required for the vehicle's fuel cell or is stored in a compressed air reservoir for the pneumatic braking system or pneumatic air suspension and / or other consumer devices. The compressed air is, as mentioned above, especially generated by a piston compressor.

[0005] Since installation space in a vehicle is limited, the present invention has the object of reducing the installation space required for a piston compressor by shortening its extension in at least one direction. Another object of the present invention is to reduce the design complexity of the piston compressor.

[0006] These problems are solved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

[0007] According to the present invention there is provided a piston compressor comprising: a piston guided in a compressor cylinder, the piston and the compressor cylinder forming a compressor chamber for compressing a fluid; a shaft rotatable about an axis; a stroke member disposed eccentrically with respect to the axis of the shaft and fixed to the shaft; Including, A piston compressor is provided in which the stroke member and piston are configured such that as the shaft rotates about its axis, and in particular as it rotates through a full rotation, the piston moves between a maximum stroke position and a minimum stroke position.

[0008] The expression "movement" is to be understood in particular to mean "at least one movement." Preferably, the piston performs two movements between a maximum stroke position and a minimum stroke position when the shaft performs a full rotation about its axis, for example from the maximum position to the minimum position and back from the minimum position to the maximum position.

[0009] In particular, due to the eccentric arrangement of the stroke member relative to the axis of the shaft, the stroke movement performed by the stroke member is transmitted to the piston.

[0010] Preferably, the stroke member includes a cylindrical member, the axis of which is eccentrically disposed relative to the axis of the shaft. Preferably, to reduce weight, the stroke member does not include a solid cylindrical member. For example, the cylindrical member has an inner ring through which the shaft extends and an outer ring eccentrically disposed relative to the inner ring. The two rings may be connected via multiple members extending radially outward from the inner ring to the outer ring. The cylindrical member may be configured as a disk, the height of which is smaller than the radius of the cylindrical member, thereby reducing the extension length of the compressor in the axial direction of the shaft. The disk or cylindrical shape of the stroke member is particularly advantageous because it allows the connecting rod's mounting portion to be connected to the stroke member via a relatively large rolling bearing, which is more resistant to heat and torque fluctuations than a small rolling bearing, such as is used in the case of a stroke member realized by a crank pin connected to the shaft by a crank shoulder.

[0011] In general, the stroke member may include a member having other shapes, so long as the stroke member is capable of transferring the stroke motion of the stroke member to the piston, thereby lifting the piston. In particular, the stroke member may include a partially cylindrical member.

[0012] Preferably, the stroke member and the piston are directly connected to each other or connected via an intermediate member.

[0013] Preferably, the compressor includes at least one separate piston guided in one separate compressor cylinder. Particularly preferably, the compressor includes at least two separate pistons, preferably two to eight, more preferably two to five, even more preferably exactly two or five, and most preferably exactly two, each separate piston guided in one separate compressor cylinder. In other words, the compressor preferably includes a total of three to nine, preferably three to six, more preferably exactly three, six, or nine, and most preferably exactly three pistons, each piston guided in one compressor cylinder. The use of three pistons in particular has proven particularly advantageous, since it allows the pistons to be arranged in an angular arrangement in the form of a Y-shaped arrangement. The Y-shaped arrangement has proven particularly advantageous with regard to the reduction of noise and vibration emissions from the compressor. This makes the compressor particularly suitable as an air compressor, in particular for braking systems, in particular for braking systems of vehicles, in particular commercial or rail vehicles.

[0014] When describing features relating to a compressor cylinder and another compressor cylinder, or a piston and another piston, each feature is intended to apply equally to preferred embodiments having at least two separate pistons and cylinders, preferably two to eight, more preferably two to five, more preferably exactly two or five, and most preferably exactly two separate pistons and cylinders. In addition to this description, this is additionally indicated by the " / s" at the end after the word "additional piston" or "additional "cylinder".

[0015] Preferably, the compressor cylinder and the further compressor cylinder are arranged one on top of the other, i.e., such that the distance between the axis of the compressor cylinder and the axis of the further compressor cylinder, in particular between adjacent cylinders, in the direction of the axis of the shaft, is smaller than the sum of the outer radii of the outer dimensions of the compressor cylinder and the outer radii of the outer dimensions of the further compressor cylinder. As a result, the compressor cylinders are not arranged in a line, in which case the extension length of the compressor in the direction of the axis of the shaft is reduced. Additionally or alternatively, preferably additionally, the compressor cylinder and the further compressor cylinder are arranged such that the axes of the cylinders are spaced apart from each other in the direction of the axis of the shaft. Additionally or alternatively, preferably additionally, the compressor cylinder and the further compressor cylinder are arranged such that the distance between the axis of the compressor cylinder and the axis of the further compressor cylinder, in particular between adjacent cylinders, in the direction of the axis of the shaft, is greater than the extension length of one, in particular each, intermediate member, in particular a connecting rod, connecting the piston to the shaft. This allows each piston to be connected to the shaft via an individual stroke member or stroke member portion, preferably via an individual connecting rod and preferably via an individual bearing means, in particular a rolling bearing. Due to the spacing between the cylinders in the axial direction of the shaft, the pistons can be coupled to the shaft by rolling bearings. This allows for oil-free bearings in the crankcase, unlike oil-lubricated bearings, so that the air to be compressed by the compressor can be drawn from the crankcase without the risk of the air being contaminated with oil. Furthermore, due to the spacing between the cylinders in the axial direction of the shaft, it is possible to use relatively large pistons and / or increase the compressor's resistance to thermal and torque fluctuations, making the compressor particularly suitable as an air compressor, in particular for braking systems, in particular for vehicles, in particular commercial or rail vehicles. In particular, the preferred angular arrangement described below, combined with the small axial spacing described above, allows for a small-sized compressor with increased resistance to thermal and torque fluctuations.

[0016] Preferably, each piston is connected to the shaft by a stroke member, preferably by a connecting rod. Preferably, each connecting rod is connected to its piston by oil-free bearing means, particularly preferably a ball bearing. Additionally or alternatively, each connecting rod is connected to the shaft, particularly via its own bearing means, particularly oil-free bearing means, particularly preferably a rolling bearing. Preferably, each connecting rod is connected to the stroke member via its own stroke member or a stroke member portion. Preferably, the piston compressor has one stroke member or stroke member portion for each piston, particularly one disk-shaped stroke member or stroke member portion for each piston, and the stroke member or stroke member portion and piston are configured so that the pistons move between a maximum stroke position and a minimum stroke position when the shaft rotates about its axis.

[0017] Preferably, the compressor cylinder and the other compressor cylinders are arranged in an angular arrangement, where the angle between the axes of the compressor cylinders is 0° to 180°, in particular greater than 0° to 180°, preferably 10° to 160°, more preferably 30° to 140°, and most preferably 60° to 120°, similar to a V-engine, a boxer engine, or a radial engine. Preferably, the compressor cylinder and the at least two other compressor cylinders are arranged in an angular arrangement such that their axes have different angles relative to a reference angular position. Particularly preferably, the compressor cylinder and the at least two other compressor cylinders are arranged in an angular arrangement such that the maximum angular space between two of their axes that are adjacent to each other in the circumferential direction is 10° to 160°, preferably 30° to 140°, more preferably 60° to 120°, even more preferably 60° or 120°, and most preferably 120°. Preferably, the compressor cylinder and the at least two further compressor cylinders are arranged in a star configuration around the axis, preferably in a Y configuration, and preferably the angular spacing between the legs of the star or Y configuration is between 10° and 160°, preferably between 30° and 140°, more preferably between 60° and 120°, even more preferably 60° or 120°, most preferably 120°.

[0018] In one advantageous embodiment of the invention, characterized by smooth and balanced operation of the compressor, the compressor includes three or six compressor cylinders spaced 120° or 60° apart from each other.

[0019] In an advantageous embodiment, the axis of the compressor cylinder and the axis of the further compressor cylinder are arranged in the same plane, with the shaft axis being oriented perpendicular to this plane, resulting in a compressor with a reduced extension in the direction of the shaft axis.

[0020] In an alternative embodiment, if one wishes to reduce the extension length of the compressor transverse to the shaft axis, the compressor cylinder and another compressor cylinder may be arranged in line.

[0021] Angular and row arrangements of the compressor cylinders may be combined, for example, at least two compressor cylinders may be arranged in a row along the axis of the shaft, with at least two other compressor cylinders arranged in another row, both rows being arranged in an angular arrangement about the axis of the shaft.

[0022] Generally, the compressor may include two or more separate compressor cylinders. Preferably, the compressor includes three compressor cylinders, with the angle between the axes of each compressor cylinder about the shaft axis being 120°. In another embodiment, the compressor includes six compressor cylinders, with the angle between the axes of each compressor cylinder about the shaft axis being 60°, i.e., similar to a V-engine or radial engine.

[0023] Preferably, the at least one further piston is connected to the stroke member directly or via an intermediate member, so that the at least one further piston moves between a maximum stroke position and a minimum stroke position when the shaft rotates about its axis, in particular when it makes a full rotation. Preferably, the extension length of the stroke member in the direction of the axis of the shaft is selected so that the pistons can each be connected to the stroke member, with the positions of the axes of the pistons being spaced apart from one another in the direction of the axis of the shaft. Particularly preferably, the extension length of the stroke member is at least as large as, and preferably larger than, the sum of the extension lengths of the intermediate members of each piston.

[0024] Preferably, the shaft has a cylindrical shape. Particularly preferably, the stroke member has a hollow cylindrical shape, the inner diameter of the hollow cylinder corresponding to the outer diameter of the shaft and the outer diameter of the hollow cylinder corresponding to the inner diameter of a bearing means, in particular a rolling bearing, for connecting the stroke member to an intermediate member, in particular a connecting rod. Preferably, the extension of the stroke member is arranged eccentrically with respect to the shaft. This embodiment is preferably combined with the angular arrangement described above. Preferably, the stroke member is constructed as one piece, in particular formed in one piece, for example by casting.

[0025] In particular, the intermediate member, preferably each intermediate member, is a connecting rod. Preferably, the connecting rod, in particular each connecting rod, has a mounting portion for connecting the connecting rod to a shaft, in particular a crankshaft, and a rod portion for connecting, in particular coupling, the connecting rod to a piston. The mounting portion can be configured to realize the connection with the shaft in various ways. For example, the mounting portion may have a bore configured to receive a crank pin connected to the shaft via a crank shoulder. However, the inventors have discovered that it is advantageous to realize the connection between the connecting rod and the shaft by a bore configured to receive the shaft. Particularly preferably, the bore is configured to receive the shaft and the eccentric. Preferably, the eccentric is rotationally symmetric, in particular disk-shaped or cylindrical. In particular, the bore of the mounting portion has a diameter corresponding to the sum of the radial extension of the eccentric and the radial extension of a bearing means between the eccentric and the mounting portion. Particularly preferably, the bearing means includes a rolling bearing.

[0026] The rod portion can be configured to couple with the piston in various ways. "Coupling" particularly means that forces can be transmitted from the connecting rod to the piston and vice versa. The piston and the connecting rod do not necessarily have to be separate components. On the contrary, the piston and the rod portion or at least a portion of the rod portion, preferably the portion of the rod portion facing the piston, can be configured as one piece or as separate pieces. Preferably, they are configured as one piece, in particular, molded integrally, for example, by casting, and / or there is no joint between them. Alternatively, the piston and the connecting rod can be manufactured from two pieces and connected to each other by a connecting means that allows rotational movement between the rod portion and the piston (rotatable connection) or prevents such movement (rigid connection). For a rotatable connection, a wrist pin bearing can be used as a connecting means. Such a wrist pin bearing can be realized by a wrist pin connected to the rod portion and a corresponding receiving portion, in particular a bore, of the cylinder, or vice versa. For a fixed connection, the connecting means may have a bore extending from the piston into the rod portion. The interior of the piston and the interior of the rod portion may be provided with threads for screwing the two parts together. Alternatively, second bores may be provided, e.g., one bore in the piston and one bore in the rod portion, so that a screw can be inserted through one of the bores and a threaded nut can be inserted through the other to connect the two parts together. Particularly preferably, one bore may extend radially through the piston, in particular from the surface of the piston facing the cylinder in the radial direction, to the rod portion. The bore in the rod portion may extend perpendicular to the bore in the piston. In the case of the preferred one-piece construction of the piston and the rod portion, the aforementioned bore may advantageously be used to connect a valve, in particular a reed valve, to the piston, thereby allowing air to be drawn through the piston, in particular from inside the crankcase.

[0027] Alternatively, this embodiment allows for two or more compressor cylinders to be arranged in the same plane, i.e., in the case of two compressor cylinders, arranged at an angle of 180°, with the shaft axis oriented perpendicular to this plane. Furthermore, it is even possible to arrange more compressor cylinders in the same plane by connecting them to the same stroke member.

[0028] Preferably, the crankcase further includes a split crankcase having two separate parts that can be connected to each other along a connecting surface, particularly by threading, and in which the mounting opening defined by the connecting surface is dimensioned such that, before the separate parts are connected to each other, a pre-assembled crank drive including a shaft, a stroke member, particularly one of the aforementioned or later-described stroke members, and a piston, preferably a piston and at least one additional piston, can be inserted into one of the separate parts through the mounting opening. This can be achieved, for example, by the connecting surface extending in the direction of the axis of the shaft, particularly parallel to the direction of the axis of the shaft, and preferably by at least one of the cylinders being connected to one separate part while the remaining cylinders are connected to the other part. Alternatively, this can be achieved by the connecting surface extending at an angle, particularly perpendicular to the axis of the shaft, and particularly by the connecting surface separating each cylinder opening in the crankcase for each cylinder into two parts.

[0029] Based on the split crankcase described above, the crank drive can be completely pre-assembled outside the crankcase, so that the piston is already connected to the shaft. This provides a suitable fit between the crank drive components, making the compressor particularly suitable as an air compressor, in particular for braking systems, in particular for braking systems of vehicles, in particular commercial or rail vehicles. In particular, the angular arrangement described above, combined with the small axial space described above, allows for a compressor of small dimensions with increased resistance to heat and torque fluctuations.

[0030] Alternatively, at least one, preferably each, further piston of one further compressor cylinder is directly connected or connected via an intermediate member to one further stroke member arranged on the shaft, in particular one further stroke member for each piston, so that the at least one further piston moves between a maximum stroke position and a minimum stroke position when the shaft rotates about its axis, in particular when it makes a full rotation.

[0031] Preferably, the stroke member and the further stroke member are each constructed as separate pieces, with the stroke member and the shaft being torque-transmittingly coupled to one another by a coupling force acting in the direction of the shaft axis, preferably provided by a biasing means for biasing the shaft and the stroke member toward one another in the direction of the shaft axis, preferably comprising a threaded nut cooperating with a corresponding thread on the shaft. Particularly preferably, each stroke member has a hole, preferably disk-shaped, for receiving the shaft, preferably with the holes of each stroke member aligned with one another so that a particularly cylindrical shaft can be inserted through the hole in the direction of the shaft axis, particularly when the stroke members are already pre-assembled in the crankcase of the compressor, whereby each stroke member is already connected to a piston. Preferably, abutment surfaces are provided protruding from the shaft in a radial direction relative to the shaft axis, allowing the coupling force to be transmitted from the shaft to the stroke member.

[0032] Due to the fact that the stroke member is a separate part, it can be pre-assembled separately to the piston outside the crankcase, which allows for a strong fit, in particular a press fit, between the piston and the stroke member, particularly preferably between the rolling bearing that connects the stroke member to the piston via the connecting rod. Due to the fact that the stroke member is a separate part, it can be inserted into the crankcase pre-assembled to the piston, in particular through a piston opening, in particular a bore, in the crankcase. This makes it possible in particular to combine the advantages of pre-assembling the piston and stroke member outside the crankcase with a one-piece crankcase.

[0033] Based on the force-transmitting connection between the shaft and the stroke members by a connecting force acting in the axial direction, the stroke members may be pre-assembled in a one-piece crankcase, whereby the stroke members are preferably already connected to pistons already assembled in their cylinders, and the crankshaft can then be inserted in the direction of the shaft axis through aligned holes in each stroke member. Torque transmission from the motor, in particular the electric motor, to the shaft can be provided, for example, by a clutch connection or by directly attaching the compressor shaft to the motor shaft. One advantage of the above-mentioned design is the freedom to choose the orientation of the stroke members in the circumferential direction relative to the shaft axis.

[0034] Preferably, the stroke members are arranged eccentrically with respect to the axis of the shaft and are preferably fixed to the shaft, and are aligned with one another so that the angle between them, in particular the angle between their axes of symmetry, is less than 180°, preferably less than 90°, more preferably less than 60°, even more preferably less than 30°, and most preferably less than 10°, and in particular the stroke members are arranged in a row, in particular the stroke members share a common axis of symmetry. In the preferred case where the stroke members are disk-shaped, the axis of symmetry relates in particular to the axis of rotational symmetry of the stroke members. Arranging the stroke members eccentrically with respect to the axis of the shaft means in particular that the axis of symmetry of the stroke members is spaced apart from the axis of the shaft in a radial direction relative to the axis of the shaft.

[0035] Preferably, the stroke member and the further stroke member are arranged to abut against each other in the axial direction of the shaft, which advantageously reduces the extension length of the compressor in the direction of the shaft axis, for example, at least one stroke member has a sleeve attached to the shaft, in which case the shaft abuts against the further stroke member.

[0036] Preferably, a space is provided between one stroke member and another stroke member, in particular for cooling purposes, since the stroke members have permanently lubricated bearings, cooling is important to avoid overheating of the lubricant and therefore its escape from the bearings.

[0037] Preferably, the stroke member, preferably each of the stroke members, and the shaft are constructed in one piece, for example by casting. Preferably, the shaft has a cylindrical shape. Additionally or alternatively, the stroke member, in particular each of the stroke members, has a disk or cylindrical shape.

[0038] Preferably, the pistons, in particular each piston, are connected to a stroke member, in particular to its own stroke member or stroke member portion, via a connecting rod.

[0039] Preferably, the stroke members, and in particular each stroke member, comprises a circular disc, which is mounted on the shaft eccentrically with respect to the axis of the shaft.

[0040] Preferably, a rolling or plain bearing is provided between the stroke member, in particular each stroke member, and the piston, in particular each piston, in particular between the stroke member and an intermediate member, for example a connecting rod. In particular, the bearing can be formed by the stroke member and a connecting member surrounding the stroke member, in which case a space containing roller members, such as balls or needles, is formed between the two members to form the rolling bearing. To form a plain bearing, the space between the stroke member and the connecting member is configured so that the two members can slide relative to each other. In all embodiments, the space may contain a lubricant, in particular a permanent lubricant.

[0041] Preferably, the fluid is a gas, in particular air, or a liquid, in particular a hydraulic liquid.

[0042] Preferably, the compressor includes two or more stroke members, in which case at least one stroke member is configured as described above.

[0043] The stroke members may be eccentric relative to the axis of the shaft, with the centres of each stroke member being at a predetermined angular orientation about the axis of the shaft, with the angle between the centres being between 0° and 180°. In one preferred embodiment, the eccentric stroke members have the same angular orientation or are joined together to form a single stroke member.

[0044] In one embodiment of the present invention, the compressor is configured as a multi-tumble piston compressor. Multiple compressor cylinders are preferred to meet low vibration requirements and minimize reciprocating noise. Thus, the compressor may include three, four, five, six, seven, eight, or more compressor cylinders, and more preferably, may be arranged in a radial engine-like configuration. However, two, one, or more than eight compressor cylinders are equally possible.

[0045] According to another aspect of the present invention, there is provided a vehicle having a compressor as described above.

[0046] Preferably, the compressor is connected to these systems of the vehicle, i.e. -Fuel cells, -Air braking system, -Air suspension, -Compressed air reservoir The air supply is configured to supply air to at least one of the

[0047] Preferably, the vehicle is configured as a commercial vehicle, truck, trailer, passenger car, and / or a tow vehicle and trailer combination.

[0048] Additionally or alternatively, the vehicle may be configured as an electric vehicle, a hybrid vehicle, or a conventional vehicle. As an electric or hybrid vehicle, the vehicle may be powered by a fuel cell-based system and / or a battery system.

[0049] In particular, the compressor can preferably serve exclusively as an air supply unit for a trailer, in which case the compressor is mounted in the trailer or in the corresponding towing vehicle.

[0050] Hereinafter, some preferred embodiments of the present invention will be described with reference to the drawings. [Brief explanation of the drawings]

[0051] [Figure 1a] 1 is a schematic diagram of a piston compressor according to the present invention, the piston being in its maximum stroke position; [Figure 1b] 1b shows the compressor shown in FIG. 1a with the piston in its minimum stroke position. [Figure 2a] 10 shows another embodiment of the shaft and one stroke member of the piston compressor according to the present invention. FIG. [Figure 2b]10 shows yet another embodiment of the shaft and one stroke member of the piston compressor according to the present invention. FIG. [Figure 2c] 10 shows yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention; FIG. [Figure 2d] 10 shows yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention; FIG. [Figure 2e] 10 shows yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention; FIG. [Figure 2f] 10 shows yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention; FIG. [Figure 3] 1 is a schematic side view of a compressor according to the present invention; [Figure 4] 1 is a schematic front view of a compressor according to the present invention; [Figure 5] 4 is a schematic side view showing the compressor shown in FIG. 3 together with a crankcase and an air passage. FIG.

[0052] 1a and 1b show a schematic diagram of a piston compressor according to the invention, with the piston in its maximum stroke position.

[0053] The illustrated piston 1 is guided within a compressor cylinder 2. The compressor cylinder 2 extends vertically upward in this illustration, so that its axis 10 is oriented vertically. The piston 1 is disposed within the compressor cylinder 2 so as to be movable along the axis 10 from a maximum stroke position as shown in FIG. 1a to a minimum stroke position as shown in FIG. 1b. The piston 1 and the compressor cylinder 2 form a compressor chamber 3, in which movement of the piston 1 compresses a fluid.

[0054] Furthermore, the illustrated shaft 4 extends perpendicularly from the plane of the drawing. Accordingly, the axis 5 of the shaft 4 also extends perpendicularly from the plane of the drawing. The shaft 4 is configured to rotate about its axis 5.

[0055] The shaft 4 is provided with a stroke member 6. The stroke member 6 comprises a circular or cylindrical member having an axis oriented parallel to the axis 5 of the shaft 4 but offset from this axis 5. Thus, the stroke member 6 is provided eccentrically with respect to the shaft 4.

[0056] When the shaft 4 rotates about its axis 5, the stroke member 6 also rotates about this axis, due to the fact that the stroke member 6 is fixedly connected to the shaft 4.

[0057] A connecting member 7 is provided around the stroke member 6. The connecting member 7 comprises a circular or cylindrical member that is coaxial with the stroke member 6. The stroke member 6 and the connecting member 7 define a space 8 therebetween.

[0058] The space 8 may be configured such that the stroke member 6 slides on the inner surface of the connecting member 7 while the shaft 4 rotates about its axis 5. A sliding bearing is thus formed by the stroke member 6, the connecting member 7 and the space 8. In this embodiment, a lubricant may be provided in the space 8 to reduce friction between the stroke member 6 and the connecting member 7.

[0059] In another embodiment, a roller member such as a ball or needle is provided in the space 8. Thus, a rolling bearing is formed by the stroke member 6, the connecting member 7, and the space 8 containing the roller member. In this embodiment, a lubricant can be supplied into the space 8 to reduce friction between the stroke member 6, the roller member, and the connecting member 7.

[0060] The stroke member 6 is arranged eccentrically relative to the axis 5, so that the stroke member 6 and the connecting member 7 perform a stroke movement when the shaft 4 rotates about its axis 5, in particular when it makes a full rotation.

[0061] An intermediate member 9 including a connecting rod is rotatably mounted at one end of the connecting member 7, the other end of which is rotatably mounted to the piston 1. The intermediate member 9 is configured such that when the shaft 4 rotates about the axis 5, in particular when it rotates fully, the intermediate member 9 transmits the stroke motion of the connecting member 7 to the piston 1.

[0062] This stroke motion can be seen by comparing Figure 1a, which shows the piston 1 in its maximum stroke position (Figure 1a), with Figure 1b, which shows the piston 1 in its minimum stroke position (Figure 1b).

[0063] Other components of the compressor, particularly ports or valves, are not shown to keep the drawings simple.

[0064] The embodiment shown in Figures 1a and 1b represents only one embodiment according to the invention. Other embodiments can be formed by providing more than one piston. For example, two or more pistons can be arranged around the axis 5 of the shaft 4. Preferably, these pistons are arranged at regular intervals. For example, three or six pistons can be arranged around the shaft 4, in particular at intervals of 120° or 60°, respectively.

[0065] Below are several embodiments of the shaft and one or more stroke members.

[0066] In FIG. 2a an embodiment of the shaft and one stroke member of a piston compressor according to the invention is shown.

[0067] A shaft 4 having an axis 5 as shown extends from left to right. A stroke member 6 is provided on the shaft 4, and the stroke member 6 is shown in cross section. The shaft 4 and the stroke member 6 are provided as two separate members.

[0068] The stroke member 6 is arranged eccentrically with respect to the axis 5 of the shaft 4, so that when the shaft 4 rotates about its axis 5, in particular when it makes a full rotation, the stroke member 6 performs a stroke motion.

[0069] Around the stroke member 6, one or more pistons can be arranged, each guided in a compressor cylinder as described above. The pistons can be arranged in the same plane as the vertically oriented axis 5, i.e., the axes of the compressor cylinders can be arranged in this plane.

[0070] In FIG. 2b another embodiment of the shaft and one stroke member of a piston compressor according to the invention is shown.

[0071] In contrast to the embodiment shown in Figure 2a, the stroke member 6 has a greater extension in the direction of the axis 5. This makes it possible to arrange more pistons in the direction of the axis 5 that can be moved by one stroke member 6. This makes it possible to provide several compressor cylinders in a row, whose pistons are controlled by the same stroke member 6.

[0072] In figure 2c yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention is shown.

[0073] 2a, in which a further stroke member 13 is provided on the shaft 4. A space 11 is formed between the two stroke members 6, 13 in the direction of the axis 5. Since the stroke members 6, 13 are connected to the connecting member 7 shown in FIGS. 1a and 1b, which forms part of a rolling bearing or a plain bearing, respectively, the space 11 is used to cool the stroke members 6, 13. In particular, cooling of the permanent lubricant can be ensured, and leakage of the lubricant from the bearing due to excessive fluidity of the lubricant is avoided.

[0074] In figure 2d yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention is shown.

[0075] This embodiment corresponds to the embodiment shown in Figure 2c, in which the further stroke member 13 includes a sleeve 12 through which the shaft 4 extends. The sleeve 12 abuts the stroke member 6. A portion of the further stroke member 13 is thinner than the portion including the sleeve 12, so that a space 11 is formed between the stroke members 6, 13. This space 11 is used for cooling purposes, as described above with reference to Figure 2c.

[0076] In figure 2e yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention is shown.

[0077] This embodiment corresponds to the embodiment shown in Fig. 2d, in which the sleeve 12 is configured as a separate component, and therefore the manufacturing of the stroke members 6, 13 and the sleeve 12 is easier, since the geometry of each of the components 6, 12, 13 is simplified.

[0078] In figure 2f yet another embodiment of the shaft and two stroke members of a piston compressor according to the invention is shown.

[0079] This embodiment substantially corresponds to the embodiment shown in Figure 2c. In contrast, the stroke members 6, 13 and the shaft 4 are constructed as one piece. Advantageously, the stroke members 6, 13 do not have to be attached to the shaft 4 in a separate assembly step.

[0080] The embodiments shown in Figures 1a, 1b, and 2a-2f are not intended to limit the subject matter of the present invention. Instead, the intent of these figures is to illustrate some aspects of the present invention in more detail. Furthermore, many more embodiments can be formed by combining some or all of the illustrated embodiments.

[0081] 3 to 5 will be described in detail below, and different names may be used for the same parts. For example, the part of the connecting member 7 is partly called the connecting member 7, partly called the ecce rod, and partly called the connecting rod.

[0082] FIG. 5 shows a schematic cross-section of a compressor 14, particularly an air compressor 14, according to the present invention. The compressor 14 includes a shaft 4 rotatably mounted about a rotation axis 17 by a plurality of rolling bearings 15. The illustrated compressor 14 includes three compressor units 19, each of which includes a cylinder 23 and a piston 21. As can be seen from the front view shown in FIG. 4, the compressor units 19, particularly the pistons 21 and cylinders 23 of the compressor units 19, are circumferentially spaced apart by 120° from one another. To simplify the drawing, only one compressor unit 19 is shown in FIG. 5.

[0083] The compressor 14 further comprises three crank mechanisms 25 for converting the rotational movement 27 of the shaft 4 into a reciprocating movement 29 of the pistons 21. Each crank mechanism 25 comprises a stroke member 31 in the form of an eccentric 31, in particular a disk-shaped eccentric 31. Furthermore, each crank mechanism comprises a connecting rod 33 connected to the shaft 4 by a rolling bearing 36. The rolling bearing 36 surrounds the shaft 4 (crankshaft 4). In particular, the rolling bearing 36 is attached to and surrounds the disk-shaped eccentric 31. The shaft 4 and the eccentric 31 are surrounded by the rolling bearings 36 in a circumferential direction U. The axial direction A is designated A. The radial direction is designated R.

[0084] As can be best seen in Figures 3 and 5, the shaft 4 is not provided with a counterweight, and a number of flywheels 35 are mounted between the crank mechanisms 25 in the axial direction A, in particular between disk-shaped stroke members 31 and connecting rods 33 attached to the stroke members 31 by means of rolling bearings 36. In particular, the crank mechanisms 25, and in particular the stroke members 31, are arranged directly adjacent to one another in the axial direction A. The stroke members 31 are realized as eccentrics 31, in particular as disk-shaped eccentrics 31. In the illustrated case, the disk-shaped eccentrics 31 are manufactured as separate parts relative to one another and to the shaft. However, the stroke members 31 are fixedly connected to the shaft 4, so that they rotate at the same rotational speed as the shaft. In the illustrated case, this is achieved by a threaded nut 90, which engages with a thread 92 on the shaft 4 and couples the stroke member 31 in a force-fit manner, i.e., by a compressive force 94 acting in the axial direction A. In this case, the compressive force 94 compresses the stroke member 31, the flywheel 35, and the annular shoulder 96 against one another. The annular shoulder 96 provides an abutment surface that projects radially from the shaft, allowing the coupling force to be transmitted from the shaft 4 to the stroke member 31, in particular from the threaded nut 90 via the annular shoulder 96 through the flywheel 35 to the stroke member 31. The annular shoulder 96 can be coupled to the shaft by any mounting method, in particular by press-fit. Alternatively, the stroke member 31 and the shaft can be manufactured in one piece, for example by casting. Alternatively, only the three stroke members 31 can be manufactured as one single piece, in particular in the form of a perforated cylinder, which has a cylindrical bore offset from the axis of symmetry of the cylinder and can therefore act as an eccentric. Such a perforated cylindrical eccentric 31 can be fixed to the shaft 4, for example by press fitting.

[0085] As can be best seen in Figures 3 and 5, the compressor units 19, in particular the central axes of their pistons 21, and / or the crank mechanism 25, in particular the stroke member 31 and connecting rod 33, are arranged between the rolling bearings 15 in the axial direction A. In particular, the rolling bearings 15 are spaced apart from one another in the axial direction A, thereby providing space for the compressor units 19, in particular between the central axes of the pistons 21 and the crank mechanism 25, in particular the stroke member 31. As can further be seen in Figure 5, the rolling bearings 15 rotatably mounting the shaft 4 are preferably spaced apart from one another in the axial direction A, thereby providing space for the crank mechanism 25, the compressor units 19 and the flywheel 35 between the rolling bearings 15. In particular, the flywheel 35, the crank mechanism 25 and the compressor unit 19 are arranged axially between the rolling bearings 15 of the shaft 4.

[0086] Compressor 14 further includes two flywheels 35 configured to counteract mass forces 37, 39, 41 acting on shaft 4, particularly rotational mass force 37 and alternating mass forces 39, 41. This is achieved, inter alia, by configuring the flywheels to provide a counterweight function in addition to their flywheel function (flattening the compressor's torque curve). This is achieved, inter alia, by configuring flywheels 35 so that their centers of gravity 43 are spaced radially R from rotational axis 17 and are circumferentially disposed relative to stroke member 31, connecting rod 33, and piston 21, such that the resulting rotational mass force 45 of flywheel 35 counteracts mass forces 37, 39, and 41 of stroke member 31, connecting rod 33, and / or piston 21. As can be seen in FIG. 3 , the centers of gravity 43 of each flywheel 35 are aligned with one another in circumferential direction U. In other words, the spacing between the centers of gravity 43 of each flywheel 35 in the circumferential direction U is zero. Additionally, the centers of gravity 43 of each flywheel 35 are spaced an equal distance from the rotation axis 7 of the shaft 4.

[0087] The flywheel 35 shown in Figures 3, 4, and 5 is configured to cancel the rotational mass force 37 of the eccentric 31. This is achieved, inter alia, by configuring the flywheel 35 so that the center of gravity 43 of the flywheel 35 is spaced radially R from the rotational axes 17, 55 of the shaft 4 and the flywheel 35, and so that the center of gravity 77 of the eccentric 31 is spaced 180° from the center of gravity 43 of the flywheel 35 in the circumferential direction U. In other words, the center of gravity 77 of the eccentric 31 is located circumferentially opposite the rotational axes 17, 55 of the shaft 4 and the flywheel 35. Because the flywheel 35 and the eccentric are coupled to the shaft 4 so as to rotate at the same rotational speed as the shaft, their relative positions in the circumferential direction U remain constant during rotation of the shaft 4. Therefore, the rotational mass force 37 of the eccentric 31 acts in the radial direction R, opposite to the rotational mass force 45 of the flywheel 35, and thus cancel each other out.

[0088] The flywheel 35 is further configured to counteract the alternating mass forces 39, 41 of the pistons 21. As can be seen in FIG. 4 , each piston 21 generates an alternating mass force 39 acting in a direction parallel to the movement 29 of the piston 21. The alternating mass force 39 includes a parallel force component 41 acting parallel to the rotational mass force 37 of the stroke member 31 and an orthogonal force component 40 acting perpendicular to the rotational mass force 37 of the stroke member 31. The circumferential positions of the pistons 21 and stroke member 31 are selected relative to one another so that the alternating mass forces 39, 40, 41 of each piston 21 at least partially cancel each other, and in particular so that the orthogonal components 40 at least partially cancel each other. In particular, their circumferential positions are selected relative to one another so that the alternating mass forces 39, 40, 41 superimpose on one another to form a superimposed force 79 having a variable amplitude that acts parallel to the rotational mass force 37 of the stroke member 31. This is achieved in particular by combining the radial arrangement of the pistons 21, circumferentially offset by 120° from one another, with the alignment of the centers of gravity 77 and / or axes of symmetry of the eccentric bodies 31 with one another, as shown in Figure 4. Based on this superimposed alternating mass force 79, the center of gravity 43 of the flywheel 35 can be spaced away from the rotation axis 7 of the shaft 13 in the direction opposite to the superimposed force 79. This allows the flywheel 35 to be used to counteract both the rotational mass force 37 of the stroke member 31 and at least a portion of the parallel force component 41 of the alternating mass force 39 of the pistons 21.

[0089] 5 shows a preferred embodiment of the compressor 14 that draws air from inside the crankcase 81. The crankcase 81 includes a housing 83 in which the shaft 4, the stroke member 31, and at least a portion of the connecting rod 33 are disposed. The shaft 4 is rotatably mounted to the housing 83 and a cover 91 of the crankcase 81 via a rolling bearing 15. The housing 83 has one hole 85 for each piston 21, through which the connecting rod 33 and piston 21 can protrude from the housing 83. The crankcase 81 further includes a cylinder 23 for each piston 21. The cylinder 23 may be disposed above the hole 85 in the radial direction R.

[0090] The crankcase housing 83 may further include a mounting opening 89 for inserting the shaft 4 into the housing 83 in the axial direction A, in particular with the eccentric 31 previously mounted thereon. The crankcase 81 further includes a cover 91 for closing the mounting opening 89 after the shaft 4 and in particular the crank mechanism and the compressor unit have been mounted. The shaft 4 may be supported in the radial direction R relative to the cover 91 by means of a rolling bearing 15. Both the cover 91 and the housing 83 have holes with the same diameter and the same axis of rotation, in particular the axis of rotation 17 of the shaft, via which the rolling bearing 15 is rotatably mounted in the housing 83 and the cover 91.

[0091] The compressor 14 further includes an air filter 95 for filtering air before it enters the crankcase 81. The air filter 95 is mounted between the cover 91 and the filter cover 99 in the axial direction A. The air filter 95 may be hollow and cylindrical. An air flow 97 through the compressor 14 is indicated generally by the reference numeral 97. From left to right, air passes through an opening (not shown) in the air filter cover 99 and into the hollow, cylindrical air filter 95, where the air 97 passes through the air filter 95 in the radial direction R. After leaving the air filter 95, the filtered air 97 flows into the crankcase housing 83 through an opening (not shown) in the cover 91. The air then passes through a plurality of openings (holes) 101 in the piston 21 and into an air compression chamber defined by the piston 21 and the cylinder 23. The cylinder 23 has a plurality of openings (holes) 103 that lead to an exhaust passage system 105. The discharge passage system 105 includes an annular air collection passage 107 in which compressed air from the three compressor units 19 is collected and then guided to a compressed air consumer, such as an air braking system. The collection passage 107 has cooling fins 108. The collection passage 107 is fluidly connected to each compressor unit 19 by individual discharge passages (pipes) 109. The individual discharge passages 109 may be defined radially inward by the cylinder 23 and radially outward by the cylinder cover 111. Furthermore, the individual discharge passages 109, particularly in their radial direction R, may be realized by holes extending through the cylinder 23 in the axial direction of the shaft outside the compression chambers. Furthermore, the individual discharge passages 109 and / or the collection passage 107 may be integrated into the crankcase housing 83.

[0092] In one embodiment of the compressor 14 shown in FIG. 5 , the stroke member 31 and the other stroke member 31 are constructed as separate pieces, and in this case, the stroke member 31 and the shaft 4 are torque-transmittingly coupled to each other by a coupling force 94 acting in the direction A of the axis 17 of the shaft 4. The force 94 is provided by biasing means 90, 92 that urge the shaft 4 and the stroke member 31 toward each other in the direction A of the axis 17 of the shaft 4. The biasing means includes a threaded nut 90 and a corresponding cooperating thread 92 on the shaft 4. The stroke members 31 are each disk-shaped and have a hole 114 for receiving the shaft 4. The holes 114 of the stroke members 31 are aligned with each other so that the shaft 4 can be inserted through the hole 114 in the direction of the axis of the shaft 4. This allows the stroke members 31 to be pre-assembled in the crankcase 81 of the compressor 14 with the pistons 21 already coupled to them. The compressor further includes an annular shoulder 96 providing an abutment surface 116 projecting from the shaft in a radial direction relative to the axis of the shaft, thereby enabling the coupling force 94 to be transmitted from the shaft 4 to the stroke member 31.

[0093] Due to the fact that each stroke member 31 is a separate part, the stroke members 31 can be pre-attached individually to the pistons 21 outside the crankcase 81, which allows for a strong fit, in particular a press fit, between the connecting rods 33 and the stroke members 31, in particular via the rolling bearings 36 that connect the stroke members 31 to the pistons via the connecting rods 33. Furthermore, due to the stroke members being separate parts, the stroke members can be inserted into the crankcase 81 through piston openings, in particular holes 85, in the crankcase 81. This makes it possible, in particular, to combine the advantages of pre-assembling the pistons 21 and stroke members 31 outside the crankcase 81 with a one-piece crankcase 81. Torque transmission from the motor, in particular the electric motor, to the shaft 4 can be provided, for example, by coupling via a clutch 118.

[0094] In an alternative embodiment, the crankcase may be a split crankcase, as indicated by section lines 120 and 122 in FIG. 5 . Split line 120 indicates an embodiment in which the split line extends in the axial direction A. Split line 122 indicates an alternative embodiment in which the split line extends in the radial direction R. Separate sections of the crankcase may be joined together along split lines 120, 122. By selecting split lines, such as those indicated by split lines 120 and 122, a crank drive including a pre-assembled shaft 4, stroke member 31, connecting rod 33, and pistons 21 can be inserted into one of the separate crankcase sections through an attachment opening. This allows for pre-assembly of the entire crank drive with the pistons 21 and / or stroke members 31 in one piece outside of the crankcase 81, while still allowing for easy assembly of the compressor 14.

[0095] The features disclosed in the above description, in the drawings and in the claims may be important for realizing different embodiments of the invention both individually and in any combination. [Explanation of symbols]

[0096] 1 piston 2 Compressor cylinder 3 Compressor room 4th axis 5 axis 6. Process parts 7 Connecting members 8 spaces 9 Intermediate parts 10 Axis of compressor cylinder 11 Space 12 sleeves 13 Process parts 14 Compressor 15 Rolling bearings 17.55 Rotation axis 19 Compressor unit 21 Piston 23 cylinders 25 Crank mechanism 27 Rotational Motion 29 Reciprocating motion 31 Eccentric body 33 Connecting rod 35 Flywheel 36 Rolling bearings 37 Rotational Mass Force 39 Alternating mass force on a piston 40 Orthogonal force components 41 Parallel force components 43 Flywheel center of gravity 45 Rotational Mass Force 77 Center of gravity of eccentric body 79 Superposition Force 81 Crankcase 83 Housing 85 holes 89 Mounting opening 90 threaded nut 91 Cover 92 threads 94 Compression force 95 Air Filter 96 Circular Shoulder 97 Airflow 99 Filter Cover 101,103 Opening (hole) 105 Discharge passage system 107 Collection Passage 108 Cooling fin 109 Individual discharge passages 111 Cylinder head (cover) 114 holes 116 Contact surface 118 Clutch 120,122 cutting line R Radial direction A Axial direction U circumferential direction

Claims

1. A piston compressor, a piston (1) guided in a compressor cylinder (2), the piston (1) and the compressor cylinder (2) forming a compressor chamber (3) for compressing a fluid; a shaft (4) rotatably provided around an axis (5); a stroke member (6, 13) disposed eccentrically with respect to the axis (5) of the shaft (4) and fixed to the shaft (4); Including, The stroke member (6, 13) and the piston (1) are configured such that a full rotation of the shaft (4) about its axis (5) causes the piston (1) to move between a maximum stroke position and a minimum stroke position; the piston compressor includes at least one separate piston guided in one separate compressor cylinder, the at least one further piston is connected directly or via an intermediate member to one further stroke member (13) arranged on the shaft (4) in such a manner that the at least one further piston is adapted to move between the maximum stroke position and the minimum stroke position when the shaft (4) makes a full rotation about its axis; A piston compressor, a space (11) for cooling by the other stroke member (13) having a sleeve (12) through which the shaft (4) passes and which abuts against the stroke member (6) is provided between the stroke member (6) and the other stroke member (13); The stroke member (6, 13) comprises a circular disk mounted on the shaft (4) eccentrically with respect to the axis (5) of the shaft (4). Piston compressor.

2. 2. A piston compressor according to claim 1, wherein the stroke member (6, 13) and the piston (1) are connected to each other directly or via an intermediate member (9).

3. 3. A piston compressor according to claim 1 or 2, wherein the piston compressor comprises at least two separate pistons, each of which is guided in one separate compressor cylinder.

4. The compressor cylinder (2) and the other compressor cylinder are arranged such that the distance between the axis (10) of the compressor cylinder (2) and the axis (10) of the other compressor cylinder in the direction of the axis (5) of the shaft (4) is: and / or so that the extension length is greater than the extension length of one intermediate member (9) connecting the piston to the shaft.

3. The piston compressor according to claim 1, wherein the piston is arranged in a direction perpendicular to the axis of rotation.

5. 3. The piston compressor according to claim 1, wherein the compressor cylinder (2) and the further compressor cylinder are arranged in an angular arrangement, the angle between the axes of the compressor cylinders being greater than 0° and 180°.

6. 4. The compressor of claim 3, wherein the compressor cylinder (2) and the further compressor cylinder are arranged in line along the axis (5) of the shaft (4).

7. 3. A piston compressor according to claim 1, wherein the shaft has a cylindrical shape and the stroke member (6, 13) has a hollow cylindrical shape.

8. 3. The piston compressor of claim 1, further comprising a split crankcase having two separate sections connectable to one another along a connecting surface, wherein, prior to connecting the separate sections to one another, an attachment opening defined by the connecting surface is sized so that a pre-assembled crank drive including each of the shaft, the stroke member, and the piston can be inserted into one of the separate sections through the attachment opening.

9. the coupling surface extends in the direction of the axis of the shaft; or 9. The piston compressor of claim 8, wherein the coupling surface extends at an angle relative to the axis of the shaft.

10. 4. The piston compressor according to claim 3, wherein the at least one further piston is connected directly to one of the further stroke members (6, 13) arranged on the shaft (4) or via the intermediate member, such that the at least one further piston is configured to move between the maximum stroke position and the minimum stroke position when the shaft (4) rotates about its axis.

11. 11. A piston compressor according to claim 10, wherein the stroke member (6) and the further stroke member (13) are each constructed as separate pieces.

12. 12. A piston compressor according to claim 11, wherein each of said stroke members (6, 13) has a hole for receiving said shaft.

13. 11. A piston compressor according to claim 10, wherein the stroke members (6, 13) are arranged eccentrically with respect to the axis (5) of the shaft (4), such that the angle between each of the stroke members is less than 180°.

14. The stroke member (6, 13) and the shaft (4) are constructed as one piece.

3. The piston compressor according to claim 1 or 2.

15. the piston (1) is connected to the stroke member (6, 13) via a connecting rod; and / or a rolling or plain bearing is provided between the stroke member (6, 13) and the piston (1); and / or The fluid is a gas or a liquid.

3. The piston compressor according to claim 1 or 2.

16. A vehicle having the piston compressor according to claim 1 or 2.

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