The method of joining parts of the shaft-bush

 

(57) Abstract:

Usage: in mechanized production when building connections with tension longitudinally-pressing method. The inventive in the sleeve over its entire length on the side opposite injected shaft injected with a gap of the auxiliary shaft. In recent excite longitudinal ultrasonic oscillations with an amplitude of providing compensation for the sum of the values of tightness in the connection gap, which is introduced into the sleeve supporting the shaft, and the amplitude of ultrasonic vibrations injected shaft. Then to the auxiliary shaft apply axial force to ensure its removal from the sleeve, which is produced simultaneously with the injection. The speed of the shot and the auxiliary output shaft set equal. 3 Il.

The invention relates to a mechanical Assembly production and can be used to build connections with tension longitudinally-pressing method.

One of the problems of modern engineering is to increase the contact stiffness of joints, which is defined as a deformation of the surface layer under the action of external loads. Large deformations lead to a loss of accuracy of the bones of the compounds displace the beginning of deformation in a zone of higher loads by applying a hardening technology for example, surface plastic deformation (SPD), in which the contacting surfaces reinforce ball, roller, diamond smoothing, thereby introducing additional operations in the process.

Known methods of joining parts, which increases the operational characteristics of the compounds, including the contact stiffness. A known method according to which after the shaft and bushing affect the shaft ultrasonic vibrations, producing friction hardening of surfaces [1] the Disadvantage of this method is the low productivity related to the fact that the hardening lead after Assembly of the connection, increasing the time for the operation.

The closest in technical essence is the way in which the details of the report in the Assembly of ultrasonic vibrations, creating a shock due to a change in the diametrical sizes of the connected components and producing due to this hardening of the mating surfaces [2]

The downside of it is uneven hardening of the surfaces of the parts, because with the passage of the shaft into the hole of the sleeve inner surface, located on the injected side of the shaft, will receive and the speed of pressing 1 mm/s and the length of the bushing 10 mm bore-side injected shaft will be subjected to shock loads during the whole time of fitting (10), and the opposite side is just 1 that when the frequency of ultrasonic vibrations 2000-1respectively 20000 200000 and shock.

The technical problem to be solved by the present invention is directed, is to increase productivity and contact stiffness of joints in the Assembly.

This goal is achieved by the fact that after centering parts opposite injected the shaft into the sleeve with a gap introducing auxiliary shaft the full length of the sleeve, the sleeve serves transverse ultrasonic vibrations (ultrasonic testing), and on the longitudinal shafts, and the amplitude of the ultrasonic inspection of the auxiliary shaft is prescribed such that a change in its transverse dimensions compensated the sum of the values of tightness in the connection gap, which is introduced into the sleeve supporting the shaft, and the amplitude of the ultrasonic inspection injected shaft, injected to the shaft make the effort and make the injection, simultaneously applying force to the auxiliary shaft, remove it from the hole, and the velocity of the shot and the auxiliary output shaft are equal.

These steps allow you to obtain a uniformly hardened surface of the bushing at the moment of Assembly operations that results in the and circuit, explaining the proposed method, where the following notation: 1 bushing, 2 injected shaft, 3 - auxiliary shaft; Fig. 2 change in strain hardening along the length of the sleeve when the Assembly according to the method of Fig. 3 the change in the degree of hardening along the length of the sleeve on the proposed method.

The method is as follows (see Fig. 1).

1. Produce the centering of the shaft 2 and the shaft 3 relative to the holes in the sleeve 1.

2. The shaft 3 is injected with a clearance hole for the entire length of the sleeve.

3. Served on the sleeve transverse ultrasonic oscillations, and on the shafts of the longitudinal oscillations, and the amplitude of oscillation of the shaft 3 is set to

< / BR>
where d is the gap between the sleeve and the auxiliary shaft;

D tightness in the connection;

x the amplitude of ultrasonic vibrations of the shaft;

m Poisson's ratio.

4. Applied to the shaft 2, the force P1and to the shaft 3, the force P2and produce movement of the shafts at the same speed.

The analysis of the distinctive characteristics and mechanism of way.

1. The use of the method according to ed. St. N 1344566 leads to uneven hardening the surface of the sleeve (Fig. 2). This is due to the fact that zapressovana. When this shock loads caused by cross-resize shaft and bushings under the action of ultrasound, are provided in the upper surface of the sleeve more often than the bottom.

To address this we used the auxiliary shaft 3 is entered with a gap over the entire length of the sleeve, which are communicated to the ultrasonic vibrations with an amplitude of:

< / BR>
where d is the gap size;

x the amplitude of the ultrasonic vibrations injected shaft;

D tightness in the connection.

This amplitude changes the diameter of the auxiliary shaft to the value:

Dd =1= ++

The necessity of keeping this ratio is associated with creating a uniform contact pressure on the surface of the sleeve from both injected shaft, and auxiliary.

2. The speed of the auxiliary output shaft must be equal to the velocity offset for each point of the inner surface of the sleeve have the same number of strokes as you resize the shafts, which contributes to the same degree of hardening (the frequency of oscillation of the shafts and bushings with 20000-1).

Were pressing shaft diameter 10 mm of soft steel 45 in the sleeve of the same material. The tightness in connect the oscillation sleeve was 0.01 mm, and pressed the shaft of 0.005 mm

Auxiliary shaft was reported oscillations amplitude

.

The speed of the shot was 1 mm/s

Measurement of the microscopic irregularities of the surface of the sleeve after fitting allowed us to obtain the results shown in Fig. 3. Surface microproject of the sleeve hole increased by 25% compared to pressing by a known method, and the entire length of the sleeve it was constant and amounted to 240 MPa. Thus, the application of the method not only managed to get a uniformly hardened surface, but also to increase the degree of hardening, which leads to higher contact stiffness of the connection.

The method of Assembly of the connection parts of the shaft-sleeve method of pressing, including centering connected details, message them of ultrasonic vibrations and the application of axial force to one of the components, characterized in that the sleeve opposite injected shaft, with a gap introducing auxiliary shaft the full length of the sleeve, inform him of longitudinal ultrasonic vibrations with an amplitude of providing compensation for the sum of the values of tightness in the connection gap, which is introduced into the sleeve spanogle apply axial force to ensure its removal from the sleeve, produced simultaneously with the pressing, and the speed of the shot and the auxiliary output shaft set equal.

 

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