RU2443912C1 - Key connection - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: key connection includes the connected parts of the items, which consist of external and internal stiffening rings into the annular cavity between which there installed through an opening in external stiffening ring are keys, and the opening is closed with a retention pin fixed on external stiffening ring. On side surfaces of the key there made are projections with support surfaces in radial direction, which are in contact with mating surfaces of stiffening rings; one of them contacts the surface of external stiffening ring, and the other one contacts the surface of the internal one, and retention pin has inner radial projection the height of which equals to thickness of external stiffening ring.

EFFECT: uniform contact stresses between connected elements and key, which almost eliminates the appearance of crushed sections of the parts.

3 dwg

Description

The invention relates to the field of mechanical engineering and can be used in rocket and space technology for interconnecting various components of products (bodies, nozzles, bottoms, compartments, etc.), as well as in other areas.

The keyed joints used for joining together the solid propellant elements are widely known (see Designs of solid propellant rocket engines / Under the General Editor’s Corresponding Member of the Russian Academy of Sciences, Doctor of Technical Sciences, Professor L.N. Lavrov. - M .: Engineering, 1993. - P. 70 (Fig. 2.23g); P. 118 (Fig. 2.51)).

The main disadvantage of this design is the rotation of the keys in the annular cavity within the specified tolerances under the action of axial load, as a result of which the contact of the connected elements with the key occurs along the lines, and not along the side platforms of the keys. In this regard, the metal is crushed along the contact lines of the connected elements and, as a result, the subsequent disassembly of the joint is difficult (for example, after testing) and completion of the connection details is required.

An object of the present invention is to prevent the key from turning in the annular cavity and to ensure uniform contact pressure between the key and the connected elements.

The technical result is achieved by the fact that in the key connection, which includes the connected parts of the products, consisting of the outer and inner frames, in the annular cavity between which dowels are installed through the window in the outer frame, and the window is closed with a latch fixed to the outer frame, on the side surfaces the dowels are made with ledges with radially supporting surfaces that are in contact with the mating surfaces of the frames, one of them is in contact with the surface of the outer frame a, the other with the inner surface, and the latch has an internal radial protrusion, the height of which is equal to the thickness of the outer frame.

Figure 1 shows a cross section of a known key connection during operation.

Figure 2 shows the main section of the proposed keyway.

Figure 3 shows a cross section of the proposed connection in the area of the window for installing the keys.

When the known key connection (Fig. 1) is operating at a shear load T acting on the outer 1 and inner 2 frames, the key 3 can be deployed within specified tolerances. At the same time, the operation scheme of the connection is not calculated, since the contact of the connected elements with the key occurs along two circles 4. This significantly increases the local contact pressure and ultimately leads to crushing of the metal on the connected elements and on the key itself.

To ensure uniform contact pressure between the key and the connected elements, it is necessary to exclude the turn of the keys. This is achieved due to the fact that on the side surfaces 5 of the key 3 (figure 2) there are ledges with radially abutting surfaces 6, which are in contact with the mating surfaces of the outer 1 and inner 2 frames.

The window 7 (figure 3) for installing the keys 3 is closed by a latch 8, which on the inner surface has a radial protrusion 9. The height of the protrusion is equal to the thickness of the outer frame h. The latch 8 is fixed with screws 10 on the outer surface of the frame 1.

The keyway operation is as follows.

When a shear load acts on the frames 1, 2 on the key 3 (Fig. 2), a torque arises from the contact forces T acting on the side surfaces 5. The supporting surfaces 6 come into contact with the mating surfaces of the frames 1, 2. Reaction forces R, acting on the supporting surfaces 6, create an oppositely directed torque that prevents the turn of the dowel 3. In this case, the forces T, R are evenly distributed on the contact surfaces 5, 6, respectively.

Thus, the proposed technical solution ensures uniform contact stress between the connected elements and the key and virtually eliminates the occurrence of areas of crushing parts.

Claims (1)

The key connection, which includes the connected parts of the products, consisting of the outer and inner frames, in which the dowels are installed in the annular cavity through the window in the outer frame, and the window is closed by a latch fixed to the outer frame, characterized in that the ledges are made on the side surfaces of the dowel with radially supported surfaces that are in contact with the mating surfaces of the frames, one of them is in contact with the surface of the outer frame, the other is in contact with the surface th inner and retainer has an internal radial projection, whose height is equal to the thickness of the outer frame.

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