DE2339995C3 - Process for the production of anti-graze elements - Google Patents

Description

Keeping the and / or carburizing atmosphere and / or io as small as possible was further proposed

to coat the inside of the stator walls with a relatively soft layer, which is removed by the grazing Ro torschaufeln. Such layers exist ζ. B. from graphite, from injected or sintered poiose nickel-chrome alloys or nickel-graphite materials, from honeycomb cells, etc. and are referred to as abrasive sire protection layers. In any case, efforts were made to make these anti-streak layers as constant as possible in shape, so that no signs of growth occur under the influence of the ambient temperature and / or the ambient atmosphere.

These designs therefore have the disadvantage. that the soft layers or the sharpened ones

be produced under the influence of heat growing material and that they are before their use subject to a treatment under the aforementioned conditions and, if necessary, a final one To be subjected to customization.

2. The method according to claim 1, characterized in that the pretreatment with regard to the growth rate intensified in comparison to the later operating conditions Growing conditions is carried out.

3. The method according to claim 1, characterized in that the anti-slip elements are melt metallurgically getting produced.

4. The method according to claim 1, characterized

draws that the Streifschulz elements 25 blade ends an irreversible one in a grazing

Experienced change in shape by being bent or abraded will. In addition, there is the corrosion and erosion of the blade ends or the cell wall ends and the stator wall, so that in long-term operation the clearance between the rotor and the stator constantly increases and the efficiency of the machine decreases.

The present invention sets itself the task. To create anti-stripe elements, which through

characterized in that the protective lining elements before the comparison 35 striation, erosion or corrosion is generated in the game application at 600 to 700 ⁰ C annealed. Reduce operation again in such a way that

8. The method as claimed in claim 4, characterized in that the balance between the clearance increases

Wear and play reduction evenly maintained over the longest possible operating period.

9. The method as claimed in claim 4, characterized in that it remains, according to the invention, this object is drawn that the anti-slip elements made of copper solved by that the anti-slip elements from one

known per se, in an oxidizing, embroidering, sulfurizing and / or radiant atmosphere and / or growing under the influence of heat

draws that the anti-stripe elements are made of copper, 45 material and that they are in front of their Carbon, nickel and tin are produced. Using a treatment among the foregoing

subject to the highest conditions and, if necessary, subjected to a final dimensional processing.
This solution is based on the fact that the growth of the mentioned materials under constant conditions basically follows an initially stronger and then increasingly weaker rising curve, the curvature of this curve, ie the deviation from a linear course, corresponding to the desired uniform growth as the growth process progresses. If the anti-slip or growth elements were used immediately, an excessively high rate of growth would initially have to be accepted with a corresponding risk from excessive pressure between the parts moving against one another, in order to obtain the growth rate suitable for continuous operation only later. The reverse would be the rate of growth in the course

Powder metallurgically produced willows.

5. The method according to claim 3, characterized in that that the anti-graze elements are made of near-eutectic or hypereutectic cast iron.

6. The method according to claim 5, characterized in that the anti-slip elements are annealed ^{at at least 50O 0 C before use.}

7. The method according to claim 6, characterized in that the anti-slip elements made of copper. Carbon and nickel are produced.

fer. Carbon nickel and iron are produced.

10. The method according to claim 4, characterized

11. The method according to claim 9 or 10, characterized characterized in that the anti-slip elements are annealed at at least 250 ° C before use will.

The present invention relates to a Verhren for the production of Streifschul / .elemente for devices with two jilen moved relative to one another, in particular one rotating part and one ator part.

The efficiency of turbines, compressors, ruLkwclenmaschinen etc. decreases with increasing ) iel between rotor and stator. It is therefore always: r seeks the play between the rotor on the one hand and

: m to keep the stator as small as possible on the other hand. The 65 of continuous operation drop undesirably if they are in Mimalc game size is set to optimal values based on the material in the initial stage.

The effect in the machine depends on the absolute speed of growth in the prostitute

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• the size, the manufacturing technology and the ■ of the rotor and the stator, as well as due to the

sion length / time. by dimensioning the thickness of the Anti-slip elements adjustable, but otherwise proportional to the relative growth rate in% / time with their factory-related saturation curve is. The method according to the invention thus enables the absolute growth rate to a desired continuous operation according to the known relative growth curve of the material in question and the resulting higher and strongly changing initial growth rate in an aging process - preferably under forced growth conditions - to be anticipated.

The invention is explained by way of example with the aid of the schematic drawings. It shows _{) 5}

Fig.! a section of the longitudinal section through a turbine with a protection element,

F i g. 2 shows a detail from the longitudinal section a pressure wave machine with a streak protection element,

F 1 g. 3 two growth curves of two graphite metal sintered materials and

F 1 g. 4 the growth curves of three types of gray cast iron.

F 1 g. 1 shows a detail of an axial section? $ Through a turbine, comprising a stator 1 and a rotor 2, which on its periphery rotor blades 3 comprises the stator 1 and the rotor 2 consist of a volume-resistant material, / .. as steel. In order to keep the distance 4 between the ends of the rotor blades 3 and the stator 1 as small as possible, a segmented ring 5 made of a growing material, preferably gray cast iron, is mechanically attached to the inner surface of the stator 1 and opposite the rotor blade ends. If the rotor blade ends streak the ring 5, they will be bent if they are sharpened, or the segments, if they are soft, will be worn away on the rotor side. Due to the oxidizing operating atmosphere on the one hand and the operating temperature on the other hand, the ring segments 5 also grow in the direction of the rotor axis. Here, the play 6 created by stripes and the corrosion / erosion effect is reduced. This eliminates corrosion and erosion as well as abrasion in the event of unpredictable vibrations and temperature increases.

F i g. 2 shows a cross section through a pressure wave machine with a stator 7 made of spheroidal graphite cast iron and a rotor 8 made of Ni alloy. In machines of this type, the front side is between the rotor 8 and the stator 7 to keep the distance 9 and the game 10 as small as possible. For this purpose, im Stator 7 has a plate 12 made of a growing material, preferably made of a soft gray cast iron. Here, too, the plate 12 grows, due to the oxidizing operating atmosphere on the one hand and the Operating temperature on the other hand, against the rotor 8.

In contrast to the application example according to FIG. 2, the plate 12 can, for example, firmly with the Front side of the rotor 8 be connected so that they are in <k> Direction of the Rotorachsc against the stator 7 grows. Basically you are free to work on the rotor and / or on the Sta tor to attach a growing F.lcmcnt. Because the rotor parts are usually a strong mechanical bean are subject to a claim, it seems appropriate. (>: ·, to provide only the stator parts with growing elements.

Drr Wachsnumsvcrlusi of three different gray cast iron during annealing at a temperature of 650 ⁰ C in air is g i in F. 4 shown. The growth of the gray cast iron used to manufacture the plate 12 or the segment ring 5, hereinafter referred to as the element, can be varied within wide limits, e.g. B. by the choice of its composition, by changing the cooling rate during casting of the element, by a heat treatment of the element after casting, etc. In addition, the growth of an element made of gray cast iron is of its shape, of the type of attachment to the base material, of the Stress, dependent on the operating temperature and the operating atmosphere, but in any case the growth curve has the indicated course with decreasing curvature, ie increasing approximation to a linear course with an approximately constant growth rate.

Instead of gray cast iron, other types of cast iron, such as ζ Β. Malleable cast iron. Cast iron with partly globular and partly lamellar graphite etc. will be used, depending on which properties are required of the element.

The elements are fastened to the supporting base material of the stator or the rotor using conventional methods Connection technology such. B. mechanically, by soldering, welding, pouring, sintering, etc.

Instead of cast iron, the elements 5 and 12 can consist of other materials, which are higher Temperatures due to oxidation show growth. Sintered graphite-metal materials are particularly suitable for this purpose, the metal phase being nickel. Comprises copper, iron, tin, lead, antimony and / or zinc. As the growth curves in FIG. 3 show, the more growth occurs in air, the faster the metal phase contains easily oxidizable elements such as copper and tin. In principle, can be used to manufacture of elements 5, 12 all materials are used that are under the influence of chemical elements or connections of the environment z. B. by carburizing. Nitrification, sulphurisation, oxidation, etc. or grow through a structural change under the effect of the ambient temperature.

As the F i g. 3 and 4 show, the growth curves at the beginning of the annealing treatment show a stronger growth per unit of time than is the case with an advanced annealing time. Furthermore, the higher the annealing temperature, the stronger the growth. In order to achieve at least an approximately constant growth rate of the elements during operation, provision is therefore made to utilize only that growth area which is characterized by an approximately constant growth rate and which is shown in FIGS. 3 and 4 correspond to that curve which extends from an annealing time of about 250 hours to an annealing time of about 1000 hours. In any case, depending on the material used, the annealing temperature and the annealing time must be coordinated so that the growth rate at the end of the heat treatment is approximately constant or shows a smaller change than in the initial price. If cast iron is used to manufacture the elements, annealing temperatures of at least are required. ¹ JOOT is useful to shorten the aging process in the interests of economy. When using a material based on copper, in accordance with the procedures shown in FIG. 3 is the application of

Glow temperatures of at least 250 "C are suitable. Through a suitable, aggressive atmosphere, its composition can possibly deviate from those of the operating conditions in the direction of the accelerated growth rate, the time required can be reduced further reduce for aging.

For this purpose 3 sheets of drawings

Claims (1)

Patent claims: I. Process for the production of anti-graze elements, which are caused by grazing, erosion or corrosion reduce the resulting play in operation again, characterized in that the anti-slip elements are made of a known, in an oxidizing, embroidering, sulphurizing operating condition to which the machine was subjected is defined. In order to keep the play between the rotor and the statoi as small as possible, it was proposed that the Ro to provide door shovels on the head with a sharpening. If the blades strip the stator, the dit sharpened blade ends bent or abraded ben, so that no harmful grazing forces occur. To the play between the rotor and the statoi