SU634693A3 - Shaft sealing cup - Google Patents

Description

(54) CANDS FOR SEAL SHAFT

This invention relates to sealing technology.

The known cuff for sealing the shaft with a sealing edge, on the working surface of which there are ribs or grooves in the form of a spiral thread; 1, and an additional seal that does not come into contact with the shaft surface with the spiral edges or grooves directed with the opposite inclination l. An additional rim when changing the direction of rotation of the compacted shaft, i.e. when the pumping action of the spiral grooves or ribs occurs on the working surface of the sealing rim, creates air flow in the axial direction to the sealing rim of the seal and pushes the fluid back into the sealed cavity. Such cuffs are used to seal the shaft irrespective of the direction of rotation.

In addition, there is a known sealing cuff for shafts with main and additional protrusions, and on these projections there are made twisted or cross-facing grooves for pushing the sealing medium. The suppressing effect of the grooves to the additional rim exceeds the pushing effect of the grooves in the main rim, so that when the shaft rotates in the space between the secondary and main ribs, an increased pressure is created which must push the compressed medium 2.

In known cuffs, the return devices on the additional protrusions are often clogged due to the deposition of contaminants and no longer work. In addition, the twisted ribs on the sliding surface of the main protrusion on the air side form

5, their acute angle to the surface, as a result, a relatively wide sliding zone on the sealing lip and, consequently, a relatively low sealing pressure is obtained.

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The purpose of the invention is to improve the efficiency of compaction.

For this, in the proposed cuff, a return device is installed between the main and additional heights.

A return device installed separately from the main and additional protrusions allows the main projection to be freely formed, especially the profile.

Claims (2)

Its cross sections, in order to achieve an optimal sealing effect without adverse side effects, occurring in the cuff with re-attachments on the main protrusion. At the same time, the additional protrusion, usually intended for protection against dust, fulfills only its initial purpose, namely, it keeps particles on the air side of the soil from getting into the proper edge of the main protrusion. To reduce friction and wear of the return device, as well as to avoid the pressure potentials in the space of the return device, the spaces between the main and additional protrusions do not touch the shaft surface, i.e. that there is an open axial gap between them. On the inner circumference of the surface of the return device, recesses can be made in which the flowing liquid can collect, forming a protective cushion with a hydrodynamic effect. The recesses are preferably made rhomboid so that they are confined at an acute angle in the circumferential direction, which improves the formation of a hydrodynamic fluid cushion. In order to improve the restoring effect, the inner circumference of the returning device can be stepped with increasing clearance from the surface of the shaft towards the main protrusion. The return device can be made of an integral element reinforcing the cuff or in the form of a protrusion of the cuff a of elastic material, while the base of the protrusion is made in one piece with the body of the cuff; the protrusion directed inward from the common place of fixing the main and additional protrusions does not interfere with the radial mobility neither main nor additional protrusions. Finally, the return device can be made as a separate structural element and be connected without gaps to the sealing heights with the help of a radial appendage formed on it, which can be inserted into the corresponding recess between the main and additional protrusions. FIG. 1-3 depict the types of cuffs offered. The body 1 of the cuff (figure 1) is made of a rubber-elastic material with a vulcanized angular ring 2 stiffness, on the radial inner end of which 3 the main protrusion 4 is vulcanised, the additional protrusion 5 and another projection b. The protrusions 4, 5, 6 form one common attachment unit 7 relative to the ring 2. The main protrusion 4, facing the sealed cavity 8, is hung with a radial mobility on a part of the rubber body, which can be called an elastic diaphragm 9, and compresses under radial pressure nat With its edge 11, shown by the dashed line, the surface of the shaft 12 against the protruding fluid. Additional protrusion 5 faces the atmosphere 13 and protects the working surface of main projection 4 from dust and contaminating particles. The return device is made in the form of protrusion b located between main 4 and additional 5 protrusions, b. the inner circumferential surface 14 of which does not touch the surface of the shaft 12, i.e. is located at a distance from the shaft surface. To return the appearing fluid back, the axial O1 binder edge 15 of the protrusion b on the side facing the liquid runs zigzag in the circumferential direction around the sealing edge 11. The bottom of the cushion with hydrodynamic action, as well as the accumulation of the flowing liquid, are diamond-shaped grooves 16 in the circumferential surface 14 the protrusion 6. At the same time, the axial limiting edges 17, 18 of the recesses 16 are standing at an acute angle in the circumferential direction and thus favor the formation of liquid pillows in places 19 of the circumferential surface 14, Ino cuff variant of Fig. 2 differs from that shown in Fig. 1 in that the stiffening ring 2 is extended further along the radius of 1 foot and is bent into the axial shoulder 20. Wavy edges 21, 22 serve to push the flowing liquid back in the circumferential direction and formed by the Mi-i steps, respectively, on the inner circumference of the surface 23 of the arm 20, due to the waviness (in FIG. 1, zigzag) of the edges 21, 22, their backward action is completely independent of the direction of rotation of the shaft . The return device can be made in the form of a separate structural element 24 (Fig. 3), for example of plastic, which is installed with an appendage 25 projecting radially outward in an axial recess 26 which is made axially between the main and additional protrusions. Embed element 24 can be easily removed or replaced. Claim 1. Cuff for shaft sealing, comprising a main protrusion on the side, 5 Facing the sealable cavity, and an additional protrusion on the side facing the atmosphere, and a device for returning the sealable medium flowing under the main protrusion, about l and This means that, in order to increase the efficiency of compaction, the return device is placed between the main and additional protrusions, 2. Cuff pop. 1, characterized in that the return device is arranged with a gap relative to the shaft surface. 3. The cuff according to claims 1 and 2, characterized in that recesses of a mainly rhomboid shape are made on the inner peripheral surface of the return device. 4. The cuff on PP. 1.2 and 3, characterized in that the inner peripheral surface in the direction of the main protrusion is stepped with an increasing gap. 3 5. The cuff according to pp. 1, 2, 3 and 4, about the fact that the return device is made in the form of an integral reinforcing element of the cuff. 6. Cuff on PP. 1,2,3 and 4, in contrast to the fact that the return device is made in the form of a protrusion of the cuff, while the base of the protrusion is made in one piece with the body of the cuff. 7. Mangeta on PP. 1,2,3 and 4, that is, the return device is made as a separate structural element adjacent to the inner surface of the cuff. Sources of information taken into account in the examination: 1. US patent number 3640542, l, 277-134, 1974. 2. The patent of Germany 2008689, l. 47 i 215/32, 1975. i / z. one FIG. g