• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A wiper ring (2) for wiping oil off a translationally oscillating piston rod (7) has at least one outer circumferential groove (17) for receiving an annular spring (21) for radially prestressing the wiper ring (2). A plurality of sealing sections (14), each with a wiper edge (15), are provided on the radially inner circumferential surface of the wiper ring (2). Adjacent sealing sections (14) are each axially spaced apart by an inner circumferential groove (16). At least one recess (18) radially penetrating the scraper ring (2) is provided on the circumference of the scraper ring (2) in order to ensure adjustability of the scraper ring (2) in the circumferential direction. At least one groove-shaped drainage opening (19, 19a, 19b) is provided on the outer circumferential surface of the scraper ring (2) and is connected to a plurality of inner circumferential grooves (16) in order to discharge stripped oil from the inner circumferential grooves (16).
    公开号:AT521716A1
    申请号:T50808/2018
    申请日:2018-09-20
    公开日:2020-04-15
    发明作者:
    申请人:Hoerbiger Wien Gmbh；
    IPC主号:
    专利说明:

    Oil scraper ring for a piston rod
    The invention relates to a scraper ring for stripping oil from a translationally oscillating piston rod with at least one outer circumferential groove provided on the radially outer circumferential surface for receiving an annular spring for radially prestressing the scraper ring. The invention further relates to a sealing packing and a piston compressor.
    Especially with large, relatively slow-running reciprocating machines, e.g. Natural gas compressors or large gas / or diesel engines are mainly used in the so-called crosshead concept. The crosshead is a joint that couples a purely translationally oscillating piston rod connected to the piston to a combined translatory / rotationally oscillating push rod. The crosshead is rigidly connected to the piston rod and the piston and is usually supported by its own guide in the crankcase. The advantages of this concept are, for example, that a double-acting piston can be used that works on two sides in the same cylinder, or that different lubricants can be used to lubricate the piston and the crankshaft due to the spatial separation of cylinder and crankcase (also with compressors dry-running pistons). Due to the purely translatory movement of the piston rod, the piston is also free of lateral forces, which is why there is no piston tilting at top dead center; the piston can therefore be made structurally simpler compared to concepts with a direct connection of the push rod to the piston.
    In piston compressors, there is usually lubricating oil in the crankcase for lubricating the moving parts of the piston compressor, in particular the crank mechanism. The lubricating oil also gets onto the piston rod and would be transported along the piston rod into the compression space in the cylinder, which is undesirable, since on the one hand this represents a significant oil leak and an associated oil loss. On the other hand, some of the lubricating oil would also be removed with the compression medium and contaminate it. In order to avoid this, several so-called (oil) wiper rings are usually provided in the area of the piston rod, which should wipe off the oil film on the piston rod. So-called oil scraper packs are often used, which contain several oil scraper rings. For an improved wiping action, several wiping rings per pack are generally required, which are supported by means of suitable support rings in order not to be damaged by the oscillating piston rod, in particular to be extruded into the gap between the piston rod and the wiping pack. Such designs are relatively complex and therefore expensive. In addition, due to the serial arrangement of several -12/28
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    Scraper rings with intermediate support rings limited in size reduction, which is disadvantageous.
    Wiper rings are often also installed in so-called sealing packs. A number of sealing rings are provided in a sealing packing, through which the crank rod is passed and which seal the crankcase against the compression space. Such sealing packs and sealing rings in various designs are well known.
    Known scraper rings are e.g. metallic radially cut rings with a sharp scraper edge, which surround and touch the piston rod in the circumferential direction. Such cut scraper rings are held together by a circumferential ring spring and activated by this, i.e. the ring spring generates a radial contact pressure in order to enable the wiper ring to function properly. In order to seal the radial cuts, two radially cut rings are often used and are offset in the circumferential direction from one another and secured against rotation. Arrangements of a radial and a tangentially cut scraper ring are also known. When using two staggered rings, in some cases only one scraper edge covers another, or if there are two scraper edges per ring, only the two following scraper edges cover the gap of the first ring, which can lead to increased oil leakage. The additional manufacturing and assembly effort when designing as a module with several rings, which must be secured against rotation, is an additional source of error for classic stripping solutions.
    Conventional scraper rings generally have oil drain holes and / or oil drain grooves on the circumference in order to discharge the stripped oil. Often, however, these are dimensioned too small, which results in a backflow or continuous wetting of the piston rod by the lubricated oil that has already been stripped off, which reduces the oil wiping performance of the next wiping edge.
    Another problem with such metallic wiper rings is that the sharp wiper edge scratches the piston rod and can damage it. The scraper edge must therefore also be manufactured with very precise manufacturing tolerances to prevent excessive damage to the piston rod. But this increases the manufacturing effort of conventional scraper rings.
    Scraper rings are often split in some way to enable wear adjustment, to compensate for thermal expansion, to be easily mounted on the piston rod and to ensure a uniform scraping effect along the circumference of the piston rod / 28 2 '
    860 AT can. But there are also uncut scraper rings. However, these rings always suffer from the problems of not being able to adjust wear, or only being able to do so to a limited extent, and of being able to compensate for thermal expansion inadequately due to different thermal expansion coefficients of the material of the piston rod and of the wiper ring.
    The wiper rings mentioned are e.g. known from EP 2 369 205 B1, EP 2 360 400 B1, US 3,542,374 A. A sealing packing with a scraper ring is shown, for example, in WO 2010/079227 A1 or EP 2 489 907 B1.
    Accordingly, it is an object of the present invention to provide a scraper ring which eliminates the disadvantages mentioned. In particular, a reduction in the rings used per wiper pack should be made possible and oil leakage in the cylinder should be avoided. Sufficient removal of the stripped lubricating oil should also be made possible, and surface damage to the piston rod by the scraper ring should be avoided.
    According to the invention, the object is achieved in that a plurality of sealing sections, each with a scraping edge, are provided on the radially inner circumferential surface of the scraper ring, the sealing sections being axially spaced apart from one another by inner circumferential grooves, that at least one recess radially penetrating the scraper ring is provided on the circumference of the scraper ring which extends at least partially from a first axial ring end of the scraper ring to a second axial ring end of the scraper ring in order to produce an adjustability of the scraper ring in the circumferential direction at least in the region of a plurality of sealing sections at the first axial end of the scraper ring, the recess at least in sections in a direction deviating from the axial direction of the scraper ring and that at least one drainage opening is provided on the outer circumferential surface of the scraper ring and is connected to at least one inner circumferential groove in order to drain oil from the inner circumferential groove. Depending on the number of sealing sections, the scraper ring according to the invention can thus replace a plurality of separate scraper rings arranged axially one behind the other. Since the sealing sections of the scraper ring are connected to one another, no separate anti-rotation device is required, as is the case with separate scraper rings in the prior art.
    The recess preferably extends continuously from the first axial ring end to the second axial ring end of the scraper ring, the scraper ring being completely interrupted at least once by the at least one recess. The fact that the scraper ring is interrupted at least once makes it easy to mount the scraper ring on the piston rod without having to detach the piston rod from the crosshead
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    860 AT and the adjustability in the circumferential direction is improved, whereby wear of the scraper ring can be better compensated.
    The at least one drainage opening preferably extends in a groove shape from the first axial ring end of the wiper ring partially in the direction of the second axial ring end and is connected to a plurality of inner circumferential grooves. This improves the removal of oil and simplifies the manufacture of the scraper ring.
    However, at least two recesses are preferably provided, through which the scraper ring is completely interrupted at least twice, the at least two recesses being preferably spaced apart from one another at constant angular intervals on the circumference of the scraper ring. As a result, the scraper ring is divided into at least two ring segments, which makes it easier to mount the scraper ring on the piston rod. In addition, the wear adjustment with continuous wear of the scraper ring, which results from the relative movement between the piston rod and the scraper ring, is improved by the at least two ring segments.
    At least one recess preferably runs helically along the outer circumferential surface of the scraper ring, the pitch of the helix preferably being between 0.1 and 10. This results in a continuous overlap of the sealing sections, which leads to a good wiping effect and little leakage.
    According to an advantageous embodiment, at least one recess extends in a step-like or labyrinthine manner, the recess preferably having at least three axially extending recess sections and at least two circumferentially extending recess sections which are arranged alternately. This further improves the oil wiping effect and reduces leakage.
    At least two drainage openings are preferably provided on the outer circumference of the scraper ring. This ensures that a sufficiently large amount of lubricating oil can be drained radially outwards from the inside.
    At least one drainage opening preferably has a helical shape, which improves the removal of lubricating oil.
    If at least one drainage opening runs parallel to the at least one recess, the drainage openings can be adapted to the course of the recesses, as a result of which a uniform distribution of ring material on the circumference of the scraper ring can be achieved.
    The scraper ring is preferably made of plastic, which enables simple manufacture and ensures that the surface of the piston rod is not damaged by the scraper ring.
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    The scraper ring can advantageously be produced by means of a machining production method, preferably by means of milling and / or by means of a generative production method, preferably by means of 3D printing, selective laser sintering or stereolithography.
    The present invention is explained in more detail below with reference to FIGS. 1 to 8e, which show exemplary, schematic and non-limiting advantageous embodiments of the invention. It shows
    1 shows a piston compressor,
    2 shows a wiper ring of a preferred embodiment in an isometric view,
    3 shows a wiper ring of a preferred embodiment in a side view,
    4 shows a preferred embodiment of a recess in the wiper ring,
    5a-5c preferred configurations of the recess of the scraper ring,
    6 shows a cross section of a scraper ring,
    7 shows a preferred embodiment of a drainage opening of the scraper ring,
    8a-e different cross-sectional shapes of a sealing section with scraping edge.
    1 shows an example of a piston compressor 1 in which the scraper ring 2 according to the invention (see FIG. 2) can be used. The piston compressor 1 has a compressor housing 3 (crankcase) in which a crankshaft 4 is rotatably mounted. A push rod 5 is rotatably supported at one end on a crank pin (not shown) of the crankshaft 4 and is rotatably arranged at a cross head 6 at the other end. The crosshead is axially movably mounted in the compressor housing 3 and is provided to support the lateral forces acting on the crosshead 6 radially on the compressor housing 3 due to the rotary and translational oscillation of the push rod 5. At the crosshead 6, one end of a piston rod 7 is arranged, the opposite end is connected to a piston 8, which is arranged in a cylinder liner 9 of a cylinder 10. From the crosshead 6, only a translatory movement is transmitted to the piston 8 via the piston rod 7, as a result of which the piston 8 executes an essentially purely translationally oscillating movement in the cylinder bushing 9 without radial side forces acting on the cylinder bushing 9. The piston compressor 1 is designed in the example shown as a double-acting compressor, which means that 8 compression work is carried out in the cylinder 10 on both axial sides of the piston. Of course, a single-acting compressor could be used or another piston machine such as an internal combustion engine. On the cylinder 10 suction and pressure valves 11 are provided radially on the outside, which for the
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    Supply of medium to be compressed to the cylinder 10 (sucking valve) and discharge of compressed medium from the cylinder 10 (pressure valve) are provided. The suction and pressure valves 11 can of course also be designed differently and can also be arranged elsewhere.
    Between the cylinder 10 and the compressor housing 3, a sealing packing 12 is generally provided, which serves to seal the high pressure in the cylinder from the relatively low pressure in the compressor housing 3. This packing 12 usually comprises a number of sealing rings arranged axially one behind the other, e.g. formed in a known manner from radially and / or tangentially cut or segmented packing rings, possibly in combination with support rings, which are each arranged in a chamber disc. The sealing packing 12 could also have an axial end, for example on one end face or on both sides, e.g. in the form of an annular disc. Furthermore, such sealing packings 12 of the piston rod 7 generally have a plurality of wiper rings arranged axially one behind the other. However, the wiper rings can also be arranged in their own wiper pack and separately from the sealing pack. These serve to avoid that the lubricating oil used to lubricate the moving parts in the crankcase, in particular the crankshaft 4 and the push rod 5, which adheres to the piston rod 7, does not get into the cylinder 10. This ensures that the compressed medium is not contaminated by lubricating oil, which is particularly important for natural gas compressors and air compressors, but also for dry-running compressors. The lubricating oil adhering to the piston rod 7 is stripped off by the scraper ring during the relative movement between the piston rod 7 and the scraper rings. The stripped lubricating oil can then be collected and, if necessary, returned to the crankcase for lubrication. In order to improve this scraper effect, a scraper ring 2 is provided according to the invention, which is described in more detail below with reference to FIG.
    The scraper ring 2 in FIG. 2 has a central cylindrical opening 13, in which the piston rod 7, for example of the piston compressor 1, is carried out in the assembled state and oscillates translationally during operation. At least three sealing sections 14, each with a wiping edge 15 for wiping oil off the piston rod 7, are provided on the radially inner circumferential surface of the wiper ring 2. When using the scraper ring 2, the scraper edges 15 generally face the oil-carrying side, here, for example, the crankcase. The sealing sections 14 are axially spaced apart from one another by inner circumferential grooves 16. To improve the wiping effect, more than three sealing sections 14 can of course also be provided, in the illustrated embodiment the wiping ring 2 has e.g. seven sealing sections 14. It should be noted that an increase in the number of sealing sections 14 (at -6
    7/28
    860 AT constant sealing section width b - see Fig. 4) also increased the axial length of the scraper ring 2. On the radially outer circumferential surface of the scraper ring 2, at least one outer circumferential groove 17 is provided in a known manner, which is used to receive an annular spring (not shown) for radially prestressing the scraper ring 2 on the piston rod 7. If a plurality of sealing sections 14 are provided on the scraper ring 2, as in the example shown, it is of course advantageous if the number of outer circumferential grooves 17 is increased accordingly in order to ensure that the prestress against the piston rod 7 is as uniform as possible over the axial length of the scraper ring 2 to be able to. In the embodiment shown, e.g. six outer circumferential grooves 17 are provided, but of course more or less could also be provided. In the assembled state, a first axial ring end E1 of the scraper ring 2 faces the piston 8, which means that, when the piston compressor 1 is in operation, the scraper ring 2 is acted upon by lubricating oil from the opposite second axial ring end E2 which adheres to the piston rod 7. Accordingly, the stripping edges 15 on the sealing sections 14 face the second axial ring end E2. In order to improve the stripping effect, the sealing sections 14 can be designed differently in order to produce different stripping edges 15, as will be explained in detail later with reference to FIG. 8.
    At least one recess 18 is provided on the circumference of the scraper ring 2, which radially penetrates the scraper ring 2 and which extends at least partially from the first axial ring end E1 in the direction of the second axial ring end E2. The length of the recess 18 is to be dimensioned such that a certain adjustability of the scraper ring 2 is ensured in the circumferential direction. This adjustability is important that the scraper ring 2 can be preloaded radially against the piston rod 7 in the assembled state by the annular springs 21 arranged on the circumference in the circumferential grooves 17, so that the scraper ring 2 can develop its scraper effect. For this purpose, the axial length of the recess 18 can be dimensioned such that the scraper ring 18 can deform due to the action of the ring springs 21 in order to be able to be prestressed against the piston rod 7, at least in the region of the first axial ring end E1. Preferably, only a very small web remains at the second ring end E2, for example in the area of the inner circumferential groove width a or sealing section width b (as indicated in FIG. 4, in which a continuous web is shown at the second ring end E2), so that the scraper ring 2 is sufficiently flexible is.
    In principle, a material with suitable strength properties can also be used as the material for the scraper ring 2, which on the one hand allows the scraper ring to have a sufficiently high stability and on the other hand has a certain elasticity to enable the scraper ring 2 to be adjusted. For example, the / 28 7 '
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    With a relatively high rigidity of the material, the recess 18 can extend further from the first axial ring end E1 in the direction of the second axial ring end E2 than in the case of a relatively elastic material, in order to ensure sufficient deformability of the scraper ring 2.
    The recess 18 extends at least in sections in a direction deviating from the axial direction of the scraper ring 2, so that the sealing sections 14 at least partially overlap in the axial direction, which prevents stripped lubricating oil from flowing axially unhindered through the recess 18, which improves the scraper effect becomes.
    According to an advantageous embodiment of the invention, the recess 18 extends, as shown in FIG. 2, not only partially but continuously from the first axial ring end E1 to the second axial ring end E2 of the scraper ring 2. The circumference of the scraper ring 2 is therefore thereby completely interrupted at least once (circumferentially and radially). This in particular improves the adjustability of the scraper ring 2 in the circumferential direction, as a result of which a very uniform prestressing of the scraper ring 2 by the ring springs 21 is achieved in the axial direction. This achieves a uniform wiping effect and also enables simple wear compensation. In order to facilitate the assembly of the scraper ring 2, a plurality of recesses 18 can also be provided, these preferably being provided at constant angular distances from one another on the circumference of the scraper ring 2. In the example shown, two diametrically opposite recesses 18 are arranged, which results in two separate ring segments 2a, 2b.
    So that the lubricating oil to be stripped from the piston rod 7 cannot flow unhindered in the axial direction through the recesses 18, which would reduce the stripping effect, it is provided that the direction of the recesses 18 deviate at least in sections from the axial direction (longitudinal axis) of the stripping ring 2. In the example shown, the two recesses 18 run helically along the outer circumferential surface of the scraper ring 2, the pitch of the helix preferably being between 0.1 and 10, particularly preferably between 0.7 and 1.4. The helical course has proven to be advantageous, but is not absolutely necessary. It is only important that the at least one recess 18 does not run axially at least in sections, so that there is a certain overlap of the sealing sections 14, in particular the wiping edges 15 provided thereon, in the axial direction.
    For example, the recess 18 could also run along a straight line from the first axial ring end E1 of the scraper ring 2 to the second axial ring end E2, which runs at a certain angle to the longitudinal axis of the scraper ring 2 (FIG. 5c). Around the -89/28
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    To further increase the blocking effect, i.e. to prevent the unimpeded flow of lubricating oil from the first axial ring end E1 to the second axial ring end E2 of the scraper ring 2, it is advantageous if the at least one recess 18 is step-like (Fig. 4 + 5a) or labyrinthine (Fig. 5b), with changing circumferential directions of the recess 18, wherein the step-shaped or labyrinth-shaped course can also be combined with the helical or straight alignment, as shown in FIG. 2 using a step-shaped course and explained in detail with reference to FIG becomes.
    On the outer circumferential surface of the scraper ring 2, a plurality of drainage openings 19 are provided, which connect the inner circumferential grooves 16 to the outer circumferential surface of the scraper ring 2 in order to be able to discharge lubricating oil stripped off via the drainage openings 19. The drainage openings 19 can be designed differently, for example as bores, grooves, etc.
    In the preferred embodiment shown, the groove-shaped drainage openings 19 each extend in the axial direction from the first axial ring end E1 of the scraper ring 2 in the direction of the second axial end E2. The drainage openings 19 are connected to the inner circumferential grooves 16 in that the groove-shaped drainage openings 19 intersect the inner circumferential grooves 16. Ring sections 26, which are connected to the sealing sections 14, are formed by the groove-shaped drainage openings 19 between the drainage openings 19. The ring sections 26 give the scraper ring 2 the necessary stability and ensure that the position of the sealing sections 14 does not change in the axial direction and in the circumferential direction. This works essentially analogously to an anti-rotation device that was previously required in the prior art when using several conventional scraper rings, and analogously to an axial fixation that was previously achieved, for example, by means of support rings. At the second axial ring end E2, the ring sections 26 can be connected to the circumferential shoulder 20. The drainage openings serve to discharge lubricating oil stripped from the stripping edges 15 radially outward from the inner peripheral surface of the stripping ring 2 through the inner peripheral grooves 16. In order to make this possible, it is important that the drainage openings 19 extend from the first axial ring end E1 of the scraper ring 2 only partially and not completely to the second axial ring end E2. On the scraper ring 2 in FIG. 2, a radially outwardly extending circumferential shoulder is provided on the second axial ring end E2, which axially delimits the drainage openings 19 and at the same time can serve to fix the axial position of the scraper ring 2. As shown in the example shown, the drainage openings 19 can be analogous to the at least one recess 18 e.g. helical or straight on the outer peripheral surface of the scraper ring 2 are provided. Drainage openings 19 lying next to one another are preferably arranged at constant angular distances from one another. The following are therefore excluded: -910/28
    860 AT those drainage openings 19, between which the at least one recess 18 is located. In the exemplary embodiment shown, these are the two drainage openings 19a and 19b. Furthermore, it is advantageous if the drainage openings 19 run parallel to the at least one recess 18 in order to achieve the most uniform possible stability of the scraper ring 2.
    In Figure 3, the scraper ring 2 shown in Figure 2 is shown in a frontal view. In the outer circumferential grooves 17, ring springs 21 are indicated here, which press the scraper ring 2 radially against the piston rod 7 in the assembled state. Such ring springs 21 and their assembly are well known, which is why it is not discussed in detail. It can be seen that the drainage openings 19 have a helical shape and extend from the first axial ring end E1 of the scraper ring 2 to the circumferential shoulder 20 which is provided on the second axial ring end E2. It can also be seen that the drainage openings 19 intersect the inner circumferential grooves 16. The drainage openings 19 form the intermediate ring sections 26, which are connected radially on the inside to the sealing sections 14 in order to give the scraper ring 2 the necessary stability. As already described, the at least one recess 18 (not shown in FIG. 3) extends completely, and at least in sections in the non-axial direction, from the first axial ring end E1 to the second axial ring end E2 of the scraper ring 2. As a result, the scraper ring 2 is at least once complete interrupted at the perimeter. In contrast to the recess 18, the drainage openings 19 could also have an axial course because they are axially delimited by the circumferential shoulder 20, as a result of which no lubricating oil can reach the second axial ring end E2 of the scraper ring 2. However, the helical shape of the drainage openings 19 has proven to be advantageous, in particular if the drainage openings 19 run parallel to the at least one recess 18. 3 shows the sealing sections 14 which are axially spaced apart from one another by the inner circumferential grooves 16. The inner circumferential grooves 16 are in turn connected to the drainage openings 19 in order to be able to transport the stripped lubricating oil radially outward. An advantage of these preferred groove-shaped drainage openings 19 is that a sufficiently large space is created for the removal of the lubricating oil so that a build-up of lubricating oil between the piston rod 7 and the scraper ring 2 can be reliably avoided, which could possibly have a negative effect on the scraper effect of the scraper ring 2.
    The scraper ring 2 can, for example, by mechanical production, in particular machining, or by additive manufacturing processes, such as 3D printing, selective laser sintering or stereolithography, and is preferably made of a suitable, in particular tribologically optimized plastic, or also of metal. Such production methods are known in the prior art, which is why, -1011/28
    860 AT this point is not discussed in detail. A combination of additive and machining production would of course also be conceivable. For example, a base body of the scraper ring 2 could be produced by means of 3D printing, which essentially has only the central cylindrical opening 13 and the sealing sections 14 which are axially spaced apart by the inner circumferential grooves 16. The desired number of drainage openings 19 and recesses 18 can be arranged on the base body in a second step, for example by means of a suitable CNC milling method. If the scraper ring 2 has more than one recess 18, the resulting number i of ring segments 2a-2i could, of course, also be produced separately and only joined together during assembly. In the example shown in FIG. 2, the scraper ring 2 has, for example, two recesses 18 and consequently consists of two ring segments 2a, 2b. With three recesses 18, it would correspond to three ring segments 2a-2c, etc. The material used is preferably a tribologically optimized plastic, for example a PTFE-based plastic with suitable strength properties; in particular, the plastic should also be temperature-resistant in order to withstand the expected temperatures in To withstand operation. The plastic should also be sufficiently resistant to the medium to be compressed and in particular to the lubricating oil to be stripped off the piston rod. Of course, it would also be conceivable for the wiper ring to be produced in sections from different materials, in particular plastics, which have different properties. For example, the sealing sections 14, in particular the scraping edges 15, could be made of a suitable, relatively soft, elastic material so as not to damage the surface of the piston rod 7. The remaining scraper ring 2 could be made of another material, for example a more stable plastic or a metal.
    4 shows a detail of the scraper ring 2 in the region of a recess 18 in a frontal view. A drainage opening 19 provided on the radially opposite side of the scraper ring 2 can be seen in the background. In the exemplary embodiment shown, the wiper ring 2 has seven sealing sections 14, which are spaced apart from one another in the axial direction by the inner circumferential grooves 16. Of course, more or fewer sealing sections 14 and inner circumferential grooves 16 could also be provided. It would be conceivable, for example, that the sealing section width b of the sealing sections 14 and the inner circumferential groove width a of the inner circumferential grooves 16 are changed at a constant axial overall height L of the scraper ring 2, or that the sealing section width b of the sealing sections 14 and the inner circumferential groove width a of the inner circumferential grooves 16 are changed, as a result of which the axial Height L of the scraper ring 2 changed. Of course, the individual sealing sections 14 do not have to have the same sealing section width b, -1112/28
    860 AT, also the individual inner circumferential grooves 16 do not have to have the same inner circumferential groove width a.
    The recess 18 extends from the first axial ring end E1 to the second axial ring end E2 of the scraper ring 2 and here has a helical shape. In addition, the recess 18 is of stepped design, that is, starting from the first axial ring end E1, alternately has an (here) axial recess section A and a (here) recess section B running normal to it, as symbolized by the dashed areas in FIG. Of course, the recess sections A, B do not have to be normal to one another, but could, for example, also be arranged at a certain angle to one another. The number n of axial recess sections A and number m of recess sections B can essentially be chosen arbitrarily and is directed e.g. according to the size of the scraper ring 2, according to the nature of the lubricating oil, according to the pressure conditions, etc. The number m of the recessed sections B is generally m = n-1, preferably at least n = 2 axial recessed sections A being arranged and consequently m = 1 Recess sections B. In addition to the helical and step-shaped course of the recess 18, other courses would of course also be conceivable, for example a labyrinthine course (Fig.5b) or a course in the form of various curves. The structural design of the recess (s) 18 is preferably selected such that, on the one hand, the flow of lubricating oil between the axial ends E1, E2 is reliably limited and, on the other hand, that production is made as simple and inexpensive as possible.
    5a-5c schematically show further advantageous courses of the recess (s) 18, the course in FIG. 5a essentially corresponding to the course shown in FIG. The recess 18 has a recess width s in the circumferential direction, which is between 0 mm and 10 mm, preferably between 0.2 mm and 7 mm, particularly preferably between 0.4 mm and 3 mm. The recess width s essentially depends on the size and the field of application of the scraper ring 2, e.g. the diameter of the cylindrical opening 13 (which essentially corresponds to the diameter of the piston rod 7), the axial overall height L, the sealing section width b or an expected viscosity of the lubricating oil. The recess width s need not be constant over the entire length of the recess 18 in any embodiment of the recess 18. The step-shaped recess 18 in FIG. 5 a runs essentially continuously increasing from the first axial ring end E1 to the second axial ring end E2. This means that the steps formed by the axial recess sections A and normal recess sections B standing thereon are arranged uniformly. The second opening at the second axial ring end E2
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    The recess end AE2 of the recess 18 is thus offset in the circumferential direction by a certain recess offset AV from the first recess end AE1, which opens into the first axial ring end E1. The width of the recess sections B is constant here. In the example shown in FIG. 5 a, the recess offset AV is consequently formed by the number m of recess sections B and the recess section width b B of a recess section B, the recess section width b B being constant in the example shown (which does not necessarily have to be the case). The following generally applies to the recess offset AV of the step-like profile AV = m * b B.
    The recess 18 in FIG. 5b has a so-called labyrinthine course, with n = 3 axial recess sections A and m = 2 recess sections B running in the circumferential direction, it also being possible, of course, to arrange a larger number n, m of recess sections A, B. Starting from the first axial ring end E1, the labyrinth-shaped recess 18 in FIG. 5b first has a first axial recess section A1 with a first recess section length I A1 and then a first circumferential recess section B1 with a first recess section width b B1 . A second axial recess section A2 with a recess section length l A2 adjoins the first recess section B1 running in the circumferential direction. This is followed by a second circumferential recess section B2 with a first recess section width b B2 , which is followed by a third axial recess section A3 with a recess section length l A3 , which opens into the second axial ring end E2.
    In contrast to the step-shaped course running continuously in the circumferential direction in FIG. 5 a, the recess sections B2 running in the circumferential direction extend at least partially alternately in the opposite tangential direction. In the example shown in FIG. 5b, the recess offset AV thus corresponds to the difference between the recess section widths b B1 , b B2 of the two tangential recess sections B1, B2 (AV = b B1 -b B2 ). The following generally applies to the recess offset AV of the labyrinth-shaped course AV = | ΣΖ> ΰ / -Σό ΰ7 | with Bi = odd circumferential recess sections B1, B3, ... Bi and Bj = even circumferential recess sections B2, B4, ... Bj. It is of course also conceivable to combine the step-shaped course and the labyrinth-shaped course.
    The recess 18 in FIG. 5c has a simple straight course and is arranged at a recess angle α to the circumferential direction. The recess angle α is between 5 ° and 85 °. Preferably between 20 ° and 60 °, particularly preferably between 24 ° and 52 °.
    , -1314/28
    860 AT
    Of course, other configurations than those shown in FIGS. 5a-5c would also be possible for the course of a recess 18.
    6 shows a simplified cross section of the scraper ring 2 at a point without a recess 18 and drainage opening 19 and serves to illustrate the most important dimensions. The scraper ring 2 has an axial overall height L and a ring width RB at the first axial ring end E1. At the second axial ring end E2, the scraper ring 2 has an increased shoulder width SB due to the circumferential shoulder 20 compared to the ring width RB. On the outer circumference, the scraper ring 2 has at least one outer circumferential groove 17 for arranging an annular spring 21, here three outer circumferential grooves 17. The shown scraper ring 2 has four sealing sections 14 with a sealing section width b and three intermediate inner circumferential grooves 16 with an inner circumferential groove width a and an inner circumferential groove depth t.
    On the sealing sections 14, the second axial ring end E2 wiping edges 15 are provided for wiping lubricating oil. The inner circumferential grooves 16 and sealing sections 14 are here essentially rectangular. This means that a stripping angle δ is formed between the radially inner circumferential surfaces 22 of the sealing sections 14 and first sealing section surfaces 23 facing the second axial ring end E2, which corresponds to an angle of 90 ° here. The shape of the sealing sections 14 thus determines the shape of the inner circumferential grooves 16 and vice versa, and thus also the shape of the wiping edges 15. However, the wiping angle δ need not be a right angle, but different configurations of the wiping edge 15 and consequently the wiping angle δ are possible, such as 8a-e is shown below.
    7 shows a schematic illustration of advantageous drainage openings 19. Starting from the first axial ring end E1, the drainage openings 19 extend partially in the direction of the second axial ring end E2 and are connected radially on the inside to the inner circumferential grooves 16 in order to discharge stripped lubricating oil from the inside to the radially outside . Between the drainage openings 19, the ring sections 26 are formed, which are connected radially on the inside to the sealing sections 14 and are connected to the circumferential shoulder 20 at the second axial ring end E2 in order to give the scraper ring 2 the necessary stability. At least one drainage opening 19 is provided on the scraper ring 2, but preferably several, in particular at least seven drainage openings 19. The drainage openings 19 each have a drainage opening width k in the circumferential direction and are spaced apart from one another on the circumference at a drainage distance p. The ratio k / p of the drainage width k to the drainage distance p is preferably between k / p = 0.1 and k / p = 1.5, particularly preferably between 0.6 and 0.7, in order to ensure that there is sufficient ring material between the Drainage openings 19 are provided in order to ensure a sufficiently high stability of the scraper ring 2. Depending on the material used, you can
    15/28
    860 AT, of course, other values for the ratio k / p can also be provided. The drainage openings 19 can run in the axial direction, but they are preferably arranged at a certain drainage angle β to the circumferential direction, as shown in FIG. The drainage angle β is advantageously between 5 ° and 90 °, preferably between 20 ° and 60 °, particularly preferably between 24 ° and 52 °. In particular, it is advantageous if the drainage openings 19 run parallel to the at least one recess 18 in order to achieve the most uniform possible course of ring material in the axial and tangential direction, which is advantageous for a uniform stability of the scraper ring 2.
    Finally, FIGS. 8a-e show several forms of sealing sections 14 and the stripping edges 15 arranged thereon. The arrow on the left symbolizes the direction from which oil is applied to the scraper ring 2 (the second axial ring end E2 in the versions shown so far). The sealing section 14 in FIG. 8a essentially corresponds to the example shown in FIG. 6 with a wiping angle δ of 90 °. The sealing section 14 in FIG. 8b likewise has a wiping angle δ of 90 °, but in addition a chamfer 24 is provided between the radially inner circumferential surface 22 and a second sealing section surface 25 facing the first axial ring end E1 in order to improve the outflow of lubricating oil . 8c-e show further configurations of sealing sections 14 and in particular wiping edges 15 with different wiping angles δ. In general, the wiping angle δ is in the range between 5 ° and 135 °, preferably between 20 ° and 110 °, particularly preferably between 30 ° and 100 °. However, the radially inner circumferential surface 22 of a sealing section 14 does not necessarily have to run in the axial direction, that is, it must be cylindrical, but could, for example, be arranged at a certain angle of inclination ε to the axial direction, as shown in FIG. 8c. Of course, several different configurations of sealing sections 14 with different wiping edges 15, in particular wiping angles δ and inclination angles ε could also be combined on a wiper ring 2.
    The exemplary embodiments of the scraper ring 2 shown with reference to FIGS. 2-8e are, of course, only to be understood as examples; the specific structural design is left to the person skilled in the art, since this depends on a large number of influencing parameters, such as, for example, the lubricating oil used, the expected compression pressure of the compressor (or internal combustion engine), the temperature to be expected in the compressor housing (or motor housing), the size and surface condition of the piston rod 7, the compression medium used, etc.
    权利要求:
    Claims (15)
    [1]
    Claims
    1. wiper ring (2) for wiping oil from a translationally oscillating piston rod (7) with at least one outer circumferential groove (17) provided on the radially outer circumferential surface for receiving an annular spring (21) for radially prestressing the wiper ring (2), characterized in that that on the radially inner circumferential surface of the scraper ring (2) a plurality of sealing sections (14) are provided, each with a scraper edge (15), the sealing sections (14) being axially spaced apart from one another by inner circumferential grooves (16), that on the circumference of the scraper ring ( 2) at least one recess (18) radially penetrating the scraper ring (2) is provided, which extends at least partially from a first axial ring end (E1) of the scraper ring (2) to a second axial ring end (E2) of the scraper ring (2) extends to adjust the scraper ring (2) at least in the area of a plurality of sealing sections (14) at the first axial end (E1) of the scraper ring (2) to produce in the circumferential direction, the recess (18) running at least in sections in a direction deviating from the axial direction of the scraper ring (2) and that at least one drainage opening (19) is provided on the outer circumferential surface of the scraper ring (2), which is provided with at least an inner peripheral groove (16) is connected to discharge stripped oil from the inner peripheral grooves (16).
    [2]
    2. scraper ring (2) according to claim 1, characterized in that the recess (18) extends continuously from the first axial ring end (E1) to the second axial ring end (E2) of the scraper ring (2), the scraper ring (2) through the at least one recess (18) is completely interrupted at least once.
    [3]
    3. scraper ring (2) according to claim 1 or 2, characterized in that the at least one drainage opening (19) extends groove-shaped from the first axial ring end (E1) of the scraper ring (2) partially in the direction of the second axial ring end (E2) and with a plurality of inner circumferential grooves (16) is connected.
    [4]
    4. scraper ring (2) according to one of claims 1 to 3, characterized in that at least two recesses (18) are provided on the scraper ring (2).
    [5]
    5. scraper ring (2) according to claim 4, characterized in that the at least two recesses (18) are provided at constant angular intervals, spaced from one another on the circumference of the scraper ring (2).
    [6]
    6. wiper ring (2) according to any one of claims 1 to 5, characterized in that at least one recess (18) helically along the outer peripheral surface of the -1617/28
    860 AT
    Scraper ring (2) extends, the slope (k) of the helix preferably being between 0.1 and 10.
    [7]
    7. scraper ring (2) according to any one of claims 1 to 6, characterized in that at least one recess (18) extends step-like or labyrinthine, the recess (18) preferably at least three axially extending recess sections (A) and at least two extending in the circumferential direction Has recess sections (B) which are arranged alternately.
    [8]
    8. wiper ring (2) according to one of claims 1 to 7, characterized in that at least two drainage openings (19) are provided on the outer circumference of the wiper ring (2).
    [9]
    9. wiper ring (2) according to one of claims 3 to 8, characterized in that at least one drainage opening (19) extends helically.
    [10]
    10. wiper ring (2) according to one of claims 3 to 9, characterized in that at least one drainage opening (19) runs parallel to the at least one recess (18).
    [11]
    11. wiper ring (2) according to one of claims 1 to 10, characterized in that the wiper ring (2) is at least partially made of plastic.
    [12]
    12. scraper ring (2) according to one of claims 1 to 11, characterized in that the scraper ring (2) is produced by means of a machining manufacturing process, preferably by milling and / or that the scraper ring (2) is manufactured by means of a generative manufacturing process, preferably using 3D printing, selective laser sintering or stereolithography.
    [13]
    13. sealing packing (12) for sealing a translationally oscillating piston rod (7), with a packing housing in which a number of sealing rings arranged axially one behind the other is provided and with at least one scraper ring (2) for stripping oil from the piston rod (7) one of claims 1 to 12.
    [14]
    14. Piston compressor (1) with a compressor housing (3) and at least one cylinder housing (10) arranged thereon, in which a piston (8) oscillates translationally, which is connected to a piston rod (7) and with at least one in the compressor housing (3) arranged scraper ring (2) according to one of claims 1 to 12 for stripping oil from the piston rod (7).
    [15]
    15. Piston compressor according to claim 14, characterized in that in the compressor housing (3) a sealing packing (12) is provided with a packing housing in which a number of sealing rings arranged axially one behind the other is provided, the scraper ring (2) in the sealing packing (12 ) is arranged.
    类似技术:
    公开号 | 公开日 | 专利标题
    DE1601388C3|1975-01-23|Sealing arrangement for a piston of an internal combustion engine
    DE3540441C2|1991-07-11|
    EP0139965A1|1985-05-08|Seal ring for piston rods
    EP2570705B1|2016-04-27|Stripping ring and stripping blade
    EP2050946A1|2009-04-22|Cylinder with devices for containing lubricants
    EP0985108B1|2004-02-25|Sealing element for dry-running systems and the use thereof
    AT402327B|1997-04-25|PISTON FOR AN INTERNAL COMBUSTION ENGINE
    EP1356221B1|2006-04-12|Ring-shaped seal
    DE3005720A1|1980-08-28|LUBRICATION SYSTEM FOR THE CYLINDER OF AN INTERNAL COMBUSTION ENGINE
    EP3636967A1|2020-04-15|Oil scraping ring for a piston rod
    EP2236800B1|2019-05-29|Cylinder with devices for distributing lubricants
    DE102017205345A1|2017-10-05|Piston ring for improved lubricating oil consumption
    DE2921291A1|1979-11-29|PISTON CYLINDER MACHINE
    DE102013002311A1|2014-05-08|RB rotary engine
    DE3207810C2|1983-12-01|Arrangement for sealing a piston in a cylinder
    DE19808483C2|1999-12-16|Oil scraper piston ring
    DE4129892C2|1995-10-19|Axial piston machine with pistons with sliding rings
    DE19913889B4|2010-01-21|reciprocating engine
    DE112012001145B4|2020-06-18|Motor arrangement for improved cooling
    WO2018172144A1|2018-09-27|Cylinder liner
    DE102017118773A1|2019-02-21|Piston ring set, piston and internal combustion engine
    DE102016111951A1|2017-01-12|Bearing interface with recesses to reduce friction
    DE102018005361A1|2020-01-09|Hydraulic gear pump with variable delivery volume
    DE3645157C2|1990-08-02|Valve timing setting mechanism
    DE10296964B4|2006-04-06|Displacement element and sealing arrangement for Stirling cycle machines
    同族专利:
    公开号 | 公开日
    EP3636967B1|2020-12-16|
    EP3636967A1|2020-04-15|
    CN110925113A|2020-03-27|
    AT521716B1|2020-07-15|
    US20200096104A1|2020-03-26|
    ES2845251T3|2021-07-26|
    JP2020046072A|2020-03-26|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE560789C|1929-03-15|1932-10-07|Demag Akt Ges|Device for sealing the piston rod on briquette extrusions|
    GB995683A|1963-05-24|1965-06-23|Us Metallic Packing Company Lt|Improvements in packings|
    EP0139965A1|1983-08-25|1985-05-08|Alfred F. Schirmer|Seal ring for piston rods|
    EP0473737B1|1990-03-23|1994-09-07|MUELLER & BRAUCHLI AG.|Stuffing box seal for piston rods|
    DE19505404A1|1995-02-17|1996-08-29|Renk Ag|Sealing device for shafts|
    EP2489907A1|2011-02-17|2012-08-22|Hoerbiger Kompressortechnik Holding GmbH|Seal for a moving piston rod of a piston compressor|
    EP2570705A1|2011-09-19|2013-03-20|Wärtsilä Switzerland Ltd.|Stripping ring and stripping blade|
    CN205225624U|2015-12-24|2016-05-11|温州市建庆实业公司|Three lamella scraper rings in double knives mouth|
    US3542374A|1968-04-24|1970-11-24|Worthington Corp|Packing for piston rods in high pressure nonlube reciprocating compressors|
    AT507564B1|2009-01-12|2010-06-15|Hoerbiger Kompressortech Hold|SEAL ASSEMBLY FOR SEALING A PISTON ROD OF A PISTON COMPRESSOR|
    AT508782B1|2010-02-15|2011-04-15|Hoerbiger Kompressortech Hold|CIRCUIT ARRANGEMENT AND COMPRESSOR WITH SUCH A CUT-OFF ARRANGEMENT|DE102020112664A1|2020-05-11|2021-11-11|OET GmbH|Reciprocating compressor for generating oil-free compressed air|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    ATA50808/2018A|AT521716B1|2018-09-20|2018-09-20|Oil scraper ring for a piston rod|ATA50808/2018A| AT521716B1|2018-09-20|2018-09-20|Oil scraper ring for a piston rod|
    US16/573,685| US20200096104A1|2018-09-20|2019-09-17|Oil scraper ring for a piston rod|
    EP19197917.8A| EP3636967B1|2018-09-20|2019-09-18|Oil scraping ring for a piston rod|
    ES19197917T| ES2845251T3|2018-09-20|2019-09-18|Oil scraper ring for a piston rod|
    JP2019170373A| JP2020046072A|2018-09-20|2019-09-19|Oil scraping ring for piston rod|
    CN201910889624.6A| CN110925113A|2018-09-20|2019-09-20|Oil scraper ring for piston rod|
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