Device for preventing wear on rod guides of pistons, valves, or the like.

Description

[0001] Device for preventing wear of rod guides of pistons, slides or the like. In pistons, but mainly in In slides, the body diameter is usually only a very small amount (up to 2 mm) smaller than the diameter of the cylinder or the Slide bushing. Here, it is of particular importance to always move the piston or slide with geometric accuracy and in a centered position. otherwise the wall of the cylinder or bushing will be scraped away, which will result in the sealing effect of the piston rings ceasing and The overflow losses are constantly increasing. In this case, only further drilling can remedy the situation, but this is a costly and time-consuming process. This represents a situation where the difficulties are further increased by the fact that reboring the cylinder or bushing also affects the dimensions of the The sealing rings need to be modified.

[0002] The eccentric movement of the pistons and slides in the housing usually arises because the rod guides become misaligned over time. wear and tear. The heavier the piston or slide, the sooner this occurs.

[0003] Although these problems and their causes have long been generally known, there is still a lack of guidance - for the Rods of pistons, valves, and the like, which even remotely meet the operational requirements. It has indeed been suggested, In locomotives, a support wedge is attached to the guide of the piston rod, which can be constantly readjusted by screws. The intention is that the rod guide should remain unloaded. However, this well-known device is practically ineffective. Firstly, the rod guide is in all In some cases, adjustment is inaccessible during operation, and in the case of locomotives, it is even impossible to reach. Therefore, adjustment is always only possible after the fact. can be carried out after shutdown if the wear of the support wedge is already advanced, so that for a A considerable part of the operation already had to bear the load from the rod guide. "Run even after the operation..." If the wedge can be readjusted, it must be taken into account that this process is repeated in every operating period. that the wear of the rod guide gradually progresses through accumulation to such an extent that over time the inner wall of the cylinder or bushing is also affected. is affected and needs to be re-drilled or replaced. On the other hand, the well-known facility never had one. a reliable guarantee that, if the support wedge has been adjusted so that the rod guide is relieved of stress, so that also the actual goal; the centric movement of the piston or slide in the cylinder or bushing, was achieved, because as a result Diversity The degree of wear on the rod guide depends on the surface loads and the material of the sliding parts. Scraping of the cylinder or inner wall of the bushing always deviates, so that the conditions for restoring a reasonably concentric alignment The movement of the rod guide and the piston or slide are different from each other.

[0004] The proposal to connect a relief wedge to the rod guide therefore represents, in the best case, a device for the approximately centered readjustment of the rod in its guide, but this readjustment of the rod always results in an incorrect @#Re-adjustment of the piston or slide that has come into an eccentric position due to wear of the guide in relation to the cylinder or the A rifle in tow. Furthermore, the well-known system suffers from the fundamental flaw that the need for any necessary follow-up only becomes apparent after the wear and tear of the rod guide can only be detected when it is already too late.

[0005] According to the invention, all these disadvantages are avoided by a device that acts preventively, so that when switched on this device is characterized by the mutual position and shape of the circularly rotated and concentrically mounted pistons, bz-,v. slide, rod and the rod guidance can no longer be changed during operation. This is achieved by the piston or slide rod resting on supports, which is pressed against the rod by means of a spring, a gaseous or liquid pressure medium, with practically constant pressure, such that the The rod guide remains automatically unloaded even if the support wears down, thus preventing eccentric wear. Rod guide and thus for the eccentric adjustment of the piston which is mounted concentrically in the cylinder or bushing from the outset or The slide cannot occur; the piston or slide therefore always moves automatically, even with a horizontal axis arrangement in the housing. balanced in the same way as in a vertical arrangement, so that the parts can withstand several years of operation without replacement.

[0006] The absorption of pressures and weights by means of springs or pressure media is known in mechanical engineering for shafts. The invention orders In contrast, the peculiar use of machine elements that constitute a common good for solving a back-and-forth problem a special task arising in moving machine parts, which despite its importance has so far remained unsolved.

[0007] The drawing shows slide rod guides as exemplary embodiments. Fig. z shows a view of one guided by a Locomotive control moving slide, the associated bushing and the guides in longitudinal section.

[0008] Fig. 2 shows the guide according to Fig. i on a larger scale.

[0009] Fig. - is a section according to A--4 of Fig. a. Fig. .1 shows the relief of the guide according to another embodiment.

[0010] The well-known slide elements b are located on the slide rod a, which separate the vapor inlet chamber c from the Steam outlet chambers d separate. - Precisely fitted sleeves are located on the front and rear covers e and e, respectively, of the valve chest. f are provided, which guide the slide rod. To relieve stress on the guide sleeves f, two-part constructions are expediently used. Support ep. or sleeves g are attached, which in the arrangement according to Figs. i to 3 with a spring arranged below a spring plate 1a j are loaded. The front and rear relief springs i are individually approximately half as strong as the combined weight of the slide and Rod. A screw 1z is used to tension the spring, which is secured against rotation, e.g., by a plate L. It goes without saying that the relief spring can be arranged differently from the example shown in the drawing.

[0011] The last link of the control system and the slide rods ca are expediently connected by a hinge, because in the case of rigid connections the Wear and tear on the guides would also adversely affect the guides of the slide rod.

[0012] The arrangement according to Fig. 1 is basically the same as the one described, with the exception that the lower part of the Relief sleeve g by an auxiliary piston o held upwards under the influence of a gaseous medium (steam, compressed air or the like). is pressed. In locomotives, the boiler steam is a very suitable means; but especially the compressed air of the braking system. The area of ​​the The auxiliary piston must be determined such that the piston force compensates for half the weight of the slide and the rod. It goes without saying that that instead of the auxiliary piston, a membrane-like component or the like can be used.

[0013] In both arrangements, the two halves of the relief sleeve g are interchangeable after wear. An opening h serves for the introduction of lubricant. The longitudinal movement of the relief sleeve is controlled internally by the guide sleeve f, and externally by a Lid Y prevents this.

[0014] Since the rod guides in the described device are located in the outflow chamber, a special rod= Sealing is omitted, but it is clear that a rod seal of any system adjoining the guides inside, in the middle or outside is required. The invention does not change anything.

[0015] The described rod guide is also suitable for piston rods (steam engines, gas engines, pumps, compressors, etc.) and the like. suitable, namely it can end at one end of the rod guide in a closed sleeve or be connected with a rod seal. to be. The essence is always explicitly that the object under the influence of a force or an auxiliary piston or a membrane or the like, The relieving rod support approximately compensates for the weight of those structural components that would otherwise load the rod guide, thereby The abduction of the pole support is prevented.

Claims

[0016] PATENT-fANsI'i:L7ci1: Device for preventing wear of rod guides of pistons, slides or the like, in particular of steam engines, characterized in that a rod guide is fitted under the influence of any pressure medium with practically The support (g) is switched on with constant pressure against the rod.