SU596746A1 - Interference fit - Google Patents

Description

one

The invention relates to the field of machine building, to joints made under temperature effects on connected parts, for example pipes, rods, shafts or other parts and advantageously can be used / for connecting pipes or rods with couplings, locking parts and other connecting parts.

A compound is known which contains female parts and male parts with matching surfaces, on which a thread is made, which are protruding sideways and straight lines of a trapezoidal or rectangular profile ij.

Maphermetitao threaded connection, as it is a spiral channel through which high-pressure liquid or gas can penetrate. In addition, the thread is a relatively complex structural element, labor-intensive to manufacture.

It is also known that the one-piece connection with the tension of the preheated female part with pre-cooled

the covered part, whose mating surfaces have annular grooves and protrusions 2 inserted into each other.

A disadvantage of the known is that the female and female components of the joint include at least two mating cylindrical surfaces of different diameters. This circumstance requires increased accuracy in their manufacture. A slight misalignment of the cylindrical mating surfaces will reduce the quality of the amp and the dynenium or make it impossible.

A second similar disadvantage is that the end face of the female part abuts against the shoulder of the male part and, moreover, the parts are mated along transition conical surfaces of the chamfer type. It also requires precision machining of the mating parts in order to maintain the exact distance between the collar and the end on one side and the mating face surfaces on the other. In addition, this permanent connection, suitable only

for parts with radial dimensions exceeding the axial dimensions by three to five times and unsuitable for joining parts, such as pipes or rods, in which the axial dimensions exceed the radial ones by more than two or three gas.

The aim of the invention is to simplify the manufacturing technology while ensuring the coaxiality of the connected parts such as pipes or rods.

This is achieved in that the annular grooves are made in the female part and the annular projections on the male one, while the outer diameter of the protrusions is smaller than the external diameter of the grooves.

FIG. 1 - permanent connection with tension, longitudinal section; on fng. 2, the longitudinal envelope of FIG. 3 - covered part, longitudinal section.

The joint consists of the female part 1, on the mating surface 2 of which cola grooves 3 are made. The cavity of the female part 1 includes the connecting part of the male part 4, which also. cojjiepHcHtT coagulated surface 5, on the edge of which there are cops Shzyuky 6; The linear and diametral dimensions of the annular protrusions 6 and the grooves 3 correspond to each other in such a way that, in the assembly of the female 1 and the 4 parts covered, the protrusions 6 BX1H are connected in the grooves 3 of the joint. mi guaranteed clearance.

In order to perform the connection of parts 1 and 4, it is necessary that before the connection is made, the difference between the outer diameter of the annular projections 6 and the inner mating surface 2 is equal to the increment value of the more recent temperature of the part 1 jp at a given temperature) and ensures that the part 4 is inserted into the cavity of the heated part 1 ; or, so that the difference of these diameters is equal to the sum of the increment of the diameter of the mating surface 2 when the part 1 is heated and the size of the diameter reduction of the annular protrusions 6 when the part 4 is cooled,

The location of the annular protrusions 6 on the outer surface 5 of the male part 4, and the annular grooves 3 on the inner surface 2 of the female part 1 are caused by technological reasons for the treatment of these surfaces. The reason is that the mating surfaces 2 and 5, as well as the surface of the protrusions 6. Must be made of a higher class of accuracy than the surfaces of the grooves 3. If the protrusions 6 were splayed on the inner surface 2, then they would significantly complicate the processing

5 of this surface. The presence of the protrusions 6 on the outer surface 5 reduces these difficulties in the manufacture of surfaces. The process of connecting parts 1 and 4 is carried out by heating the child 1

About up to a predetermined temperature, providing a necessary increase in the diameter of the mating surface 2, after which the part 4 is inserted into the cavity of the female part 1 in such a way that

The 5 grooves 3 were located above the protrusions 6. After the temperatures of the parts 1 and 4 were equalized, the mating surface 2 of the female part 1 tightly compresses the mating surface 5 of the covered part 4, and the projections 6 enter into the grooves 3.

The process of joining Parts 1 and 4 can be carried out as a result of cooling the male part 4 or

5 while heating part 1 and cooling part 4 to the set temperatures.

The presence of ring protrusions and grooves in the parts to be joined, respectively

0 introduced one into the other, significantly increases the leaktightness of the joint and, in addition, reduces the cost of manufacturing parts and their elements of the proposed joint as compared to the known compounds that are more laborious for S. to perform operations on the manufacture and strengthening and control.

Ph o r u m a l o u b u re p The continuous connection with tension is foreseen; In the heated covering part with the covered part, the mating surfaces of which have annular grooves and protrusions inserted into each other, characterized in that, in order to simplify the manufacturing technology while ensuring the coaxiality of the connected parts such as pipes or rods, the annular grooves are made

Q in the female part, and the annular protrusions on the male, while the outer diameter of the protrusions is less than the outer diameter of the grooves.

Sources of information taken in

attention during examination;

1. Sherbyuk, ND, et al. Threaded connections of an oil pipe and downhole motor, Nedra, Moscow, 1974, pp. 85-90.

2. Copyright certificate № 502133, cl. F 16 B 4 / GS, 1973.

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