SU1439311A1 - Safety elastic coupling - Google Patents

Abstract

The invention relates to mechanical engineering and can be applied in instrument engineering for the transmission of torque of a limited magnitude, damping of torsional vibrations and compensation of misalignments of connected shafts. The invention is an extension of functionality. The coupling consists of a leading 1 and a driven 2 half couplings with end cylindrical grooves in which liners 3 are made with tension, made of elastic friction organic material. The inner surface of the liners is spherical and forms friction pairs with steel heads 4 fingers 5. Screw grooves are made into the cylindrical surface of the fingers 5, into which the bearing turns of the torsion spring 6 are connected, which connects the driving and driven half-couplings. In the assembled clutch, the torsion spring is in the compressed state and provides the necessary pressure force in the friction pairs. The design of the coupling provides for adjusting the spring compression force by tightening the strings 9 with screws 7 and sleeves 8, in which the ends of the strings 9 are fixed. 3 sludge. S 0t / S.1

Description

114

The invention relates to maiginating and can be used in instrument engineering for the transmission of torque, limited torque, damping of torsional oscillations and misalignment joints (angular, radial and axial) of connected shafts

The purpose of the invention is to enhance the functionality by transmitting a torque of an adjustable limited value and compensating for the displacement of the connected shafts about

Fig. 1 shows a coupling, a longitudinal section i in Fig. 2 a section A-A in Fig. 1j in Fig. 3 shows a coupling connecting radially offset shafts.

The coupling consists of a master 1 and a slave 2 half couplings, on the inner ends of which cylindrical recesses are made. In these recesses, with tension, there are inserted liners 3, the inner surface of which is made with a spherical recess. Inserts 3 are made of elastic friction organic material (for example, rubber resin, acrylonitrile-butadiene copolymer, etc.) and form spherical friction pairs with steel heads 4 fingers 5 located on the axis of rotation of the coupling, while the coefficient of friction in the friction a pair may be 0.25-0.5. In order to facilitate the insertion of the inserts 3 into the recesses of the half couplings 1 and 2, central technological holes are made in the inserts 3. On the cylindrical surface of the sleeves 5, there are screw grooves into which the support (end) turns of the torsion spring 6 connecting the drive and driven coupling halves are inserted. In the assembled clutch, the torsion spring 6 is in the compressed state and creates the necessary pressure force in the friction pairs.

The compression force of the spring 6 is regulated by a special mechanism consisting of adjusting screws 7, screwed into bronze bushings 8, freely set in the holes in the flange of the driven coupling half 2, and strings 9 (flexible rods), which are terminated at one end in conical holes of the bushings 8, and the other on the ring 10 of the axial ball bearing 11 mounted on the leading coupling half 1 (ring

0

5 O -.

five

five

12

10 mounted on the half coupling 1 with a guaranteed clearance). In order to ensure the mobility of the coupling in the axial direction in one of the coupling halves 1 and 2 (or both), the slots are made. The mechanism for adjusting the compression forces of the spring 6 of the torsion provides the setting of the coupling for any limiting torque, the value of which is in the range determined by the design parameters of the coupling.

The transmission of rotation from the leading coupling half 1 to the driven 2 can only be carried out in one direction, in the direction of the tightening of the spring 6.

The clutch works as follows.

At start-up, the heads of the 4 fingers 5 slip through the friction material of the liners 3. In the steady state under the action of the nominal (calculated) torque, the coupling half 1 and 2 are twisted by a certain angle depending on the pre-selected spring 6 parameters. For some reason the torque moment becomes greater than the limiting moment to which the clutch is tuned, then due to the slip in the friction pairs, the relative rotation of the coupling halves 1 and 2 occurs.

The angular displacements of the half couplings 1 and 2 are compensated for by rotating the head 4 of the fingers 5 relative to the contribution 3 of the half 1 "sleeves 1 or 2, and the radial displacements due to the skewing of both fingers 5 together with the torsion spring 6 relative to the half couplings 1 and 2 (Fig .G)

Thus, when compensating for the angular and radial displacements of the shafts, additional stresses in the elastic element (spring 6) do not occur and the coupling capacity does not decrease.

The circumferential engagement force of the coupling can be determined from the following relationship:

L)

fR

Bz - AZ

where M is the design torque,

R is the radius of the spherical head 4j f is the coefficient of friction in the friction pair (f 0.25-0.5); a is the ratio of the radius of the hole of the CG liner (to the radius of the spherical head R;

B D ratio of the radius contour to

314

the spherical recess of the liner 3r2 to the radius of the head R (Fig. 1), and b 1.

In order to avoid jamming of the coupling, it is necessary to observe the condition b cos arctg f.

So, with a friction coefficient of f 0.25, b is obtained, and with f 0.5 b, it is 0.89.

In order to prevent the clutch from losing its stability under the action of centrifugal forces, as well as to evenly wear the friction liners 3, the centers of the weight of the fingers 5 must always be on the axis of rotation of the clutch during operation. In the presence of angular or radial displacements of the shafts, the fingers 5 are rotated at a certain angle relative to the axes of the half couplings 1 and 2 (Fig. 3). Only the centers of the spherical heads 4 remain stationary, which, with any misalignment, are located on the axles of their coupling halves 1 and 2. Thus, to achieve the above objectives, the centers of gravity of the fingers 5 must coincide with the geometric centers of the spherical heads 4i parts of the fingers 5 should be chosen by

formula

L 4, R

3fr D

where L is the length of the cylindrical part

fingertips

D is the diameter of the finger 3 R is the radius of the spherical head 4. If the obtained length L is not sufficient to wind the required number of turns of the spring 6 of the torsion on the finger 5, it increases to the required value, and the corresponding axial force is performed in the finger 5 hole.

We offer safety

elastic coupling with torsion spring has safety properties,

0

31

five

0

five

0

five

about

45

one

moreover, it can be adjusted for any limiting torque (within the limits of permissible pressure in hydraulic couples). In addition, the eye is more durable, since there are no stress concentrators in its design, and the adjusting mechanism provides reliable compensation for wear of the rubbing surfaces, possesses anti-vibration properties (due to the use of elastic organic inserts and flexible connecting rods at the strings). The constructive design of the clutch provides ease of assembly and compensation of the angular and radial displacements of the connected shafts.

Claims (1)

Invention Formula The safety elastic coupling, containing the leading and driven flange half feet, connected by means of a torsion spring, is characterized in that, in order to expand its functionality, it is equipped with a spring force regulating mechanism, inserts made of an elastic friction material, fingers with spherical heads and screw grooves on their cylindrical surface, inserts made with spherical depressions and fixed on flanges of coupling heads facing each other are located in depressions x inserts, the ends of the springs are located in the helical grooves of the fingers, and the mechanism for adjusting the compressive force of the spring is made in the form of a ring and flexible rods, one ends of which are placed in the flange of the driven half-coupling with the help of an adjustable screw pair, and the second ends are fixed in the ring mounted with possibility of movement in the circumferential direction relative to the leading coupling half. Ф14г.1 s 9l4, z.