FI93894B - Directionally independent mechanical seal - Google Patents

Abstract

A mechanical seal, independent of the direction of rotation, for a shaft duct having a sliding ring (2) rotating with the shaft, an opposing ring (3), fixed to the housing, a driver ring (4) and a spring arrangement (5) between the driver ring (4) and the sliding ring (2). The driver ring (4) can be fixed on the shaft (1). The spring arrangement (5) presses the mechanical seal (2) against the opposing ring (3) with a lubricant film between them. The spring arrangement (5) has positively locking elements (8) which interact in a driving manner with positively locking opposing elements (9) on the opposing ring (3) and on the mechanical seal (2). The spring arrangement (5) consists of at least one sprung corrugated ring with corrugation peaks (10) and corrugation troughs (11), which surrounds the shaft (1) and has positively locking elements (8) which project from the ring surface and are distributed evenly around the circumference. These positively locking elements (8) engage in positively locking recesses (9) on the opposing ring (3) and on the mechanical seal (2). <IMAGE>

Description

93894

Directionally independent mechanical seal

The invention relates to a non-rotating slip ring seal for passing through a shaft, comprising a sliding ring rotating with 5 shafts, a counter ring fixed in the housing, a torsion ring and a spring device between the torsion ring and the slip ring. in addition, the spring device comprises shape-locking elements which interact with the shape-locking counter-elements on the crank ring and the slip ring, taking these into account.

Different types of mechanical seals are known from US 3,953,038, GB 2,007,776, GB 965,237 15 and DD 216,772. In the solutions according to the first and last publication, the spring device does not provide any torque transfer. In the solution according to GB 956 237, the torque is transmitted by means of a force lock and not by a form lock. In the solution disclosed in GB 2 007 776, the transfer of torque takes place by means of shape locking, but in other respects this known solution differs crucially from the present invention.

In connection with the known mechanical seal from which the invention is derived, the spring device is a helical spring which surrounds the shaft at a sufficient distance. Its ends are made as shape-locking elements and press against the counter-supports which form the shape-locking counter-elements on the slip ring and the crank ring. This has disadvantages because, depending on the torque to be transmitted and the direction of rotation, the diameter I of the helical spring threads changes and then the spring force acting on the slip ring in the axial direction changes undesirably. The characteristic curve of the spring is thus not unambiguously determined. 35 93894 2

The following has been presented with regard to the mechanical seal described in detail and having a different structure.

In connection with all the above-mentioned slip ring seals 5, a sealing gap is formed between the slip ring fixedly housed in the housing and the slip ring with a suitable sealing agent, in which the lubricant film is located. The lubricant film in this sealing gap can be formed of both gaseous and liquid lubricant. According to the friction conditions, different circumferential forces are generated, which can be subject to strong temporal fluctuations. To transfer the circumferential forces, torque supports are arranged between the slip ring and the counter ring. In connection with the embodiment described at the beginning, the form-locking elements and the form-locking counter-elements on the counter ring and the slip ring form the torque supports. In addition, it is necessary to compensate both the lateral deviations of the shaft due to the machine and also the oscillations of the shaft in both the radial and axial directions. Also for this reason, a spring device between the crank ring and the slip ring is required. In connection with a mechanical seal, regular operation is achieved essentially in such a way that the Liu ring is adapted to be freely movable and resiliently flexible with respect to the shaft and the crank-25 ring in all operating situations. Only when these conditions are met is a freely resiliently flexible contact with the lubricant film guaranteed and thus control of the forces by the lubricant film interface. In this case, the characteristic curve of the spring device must not change uncontrolled. However, it does so, 30 if you work with a screw spring as explained at the beginning. In addition, it is detrimental that the helical spring be built for a relatively long time.

The object of the invention is to further develop the slip ring seal described at the beginning so that the sealing device 35 operates in all conditions of use in accordance with the characteristic curve defined in December 3 93894, which also does not change with different torques or different directions of rotation.

This object is solved according to the invention in that the spring device consists of at least one flexible corrugated ring with corrugated ridges and corrugated bottom, which corrugated ring surrounds the shaft and -vennyksiin. Such corrugated rings are known per se (e.g. US 3,953,038), but are used for other elastic tasks and are not suitable and are not intended for torque transmission.

15 With regard to details, there are several possibilities for further development and design within the scope of the invention. Thus, the spring device may consist of a single corrugated ring constructed, viewed from the side, of three identical corrugated ridges and three identical corrugated bases of equal length, each side being fitted with three shape-locking elements always at the highest point of the corrugated ridges. But the spring device can also be constructed from two counter-assembled corrugated rings with shape-locking elements on the corrugations of the outer ring surfaces. Also in this case, it is advantageous to use corrugated rings, each of which has three identical corrugated brushes and three identical corrugated bases, in which case, in addition, both corrugated rings also correspond to each other in each other, except for the installation phase. The shape-locking elements can be arranged on a corrugated ring or on corrugated rings, for example welded to them. However, it is also possible to form the shape locking elements on the corrugated ring or corrugated rings.

The invention will now be described in more detail in connection with a drawing showing only one exemplary embodiment. In this case, Fig. 4 93894 shows a view of a sealing device according to the invention from a rectangular axis with partial section, Fig. 2 shows a corrugated ring of the object of Fig. 1 as a cover 5, Fig. 4 is a view of a spring device consisting of two corrugated rings connected in opposite stages, and Fig. 6 is a planar application of the spring device of Fig. 5.

The mechanical seals shown in the figures are independent of the direction of rotation and are intended for export through the shaft. The slip ring seal consists of a slip ring 2 rotating with the shaft 1 and a counter ring 3 attached to the housing. The housing is not shown. A crank ring 4 is arranged in connection with the slip ring 2. The spring device 5 works between the crank ring 4 and the slip ring 2. The torsion ring 4 is fastened to the shaft 1 by means of a screw fastening 6. The spring device 5 presses the slip ring 2 with an intermediate connection of the lubricant film at point 7 against the counter ring 3. The spring device 5 comprises shape-locking elements 8 which interact with the shape-locking counter-elements 9 on the crank ring 4 and the slip ring 2 25, taking these 1 with them. This is done to support the torque explained at the beginning.

A comparative examination of Figures 1-3 shows that the spring device 5 consists of a corrugated ring with corrugations of wave-30 10 and corrugations 11, which corrugated ring and the like; snaps the shaft 1 and has shape-locking elements 8 projecting from the ring surface. These shape-locking elements 8 engage the shape-locking recesses 9 on the crank ring 4 and on the slip ring 2. How the corrugation 10, 11 passes 35 and how the shape-locking elements 8 are arranged

II

5 93894, in particular for the plane application shown in Fig. 3, which repeats linearly over a circumferential distance of 360 ° of the corrugated ring 5. In the embodiment according to Figures 1-3, the corrugated ring 5 consists, seen from the side, of three similar corrugated ridges 10 and three similar corrugated bases 11 which are of equal length in the circumferential direction. Each side has three shape-locking elements 8, always at the highest point and opposite the deepest point, as can be seen in particular from Figure 3. The torque support provided according to the invention can be implemented completely without friction.

In the embodiment according to Figures 4-6, the spring device 5 consists of two counter-mounted corrugated rings 5a, 5b, which are connected to each other by forming shape locking elements 8 on the corrugations 10 of the outer ring surfaces. In this respect, reference is made in particular to the planar view shown in Fig. 6. The two corrugated rings 5a, 5b are placed as if the wave bases 11 are against each other and connected. Also in this case 20 there are in each case three corrugated ridges 10 and three corrugated bases 11. The shape locking elements 8 are placed on the corrugated ring 5 or on the corrugated rings 5a, 5b, they could also be welded. But on the other hand, they could also be shaped from the material of the corrugated rings 5 or 5a, 5b.

The invention also comprises a kinematic reversal in which the slip ring is fixedly mounted in the housing and the counter ring rotates.

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Claims (5)

6 93894 A direction-independent slip ring seal for passing through a shaft, comprising a sliding ring (2) rotating with the shaft (1), a counter ring (3) attached to the housing, a crank ring (4) and a spring device (5) between the crank ring (4) and the slip ring (2). ), Wherein the torsion ring (4) is attachable to the shaft (1) and the spring device (5) presses the slip ring (2) by intermediate connection of the lubricant film 10 against the mating ring (3) And wherein the spring device (5) further comprises shape locking elements (8) interacting with the torsion ring ) and the slit-locking counter-elements on the Liu-ring (2), characterized in that the spring-15 device (5) consists of at least one flexible corrugated ring with corrugated ridges (10) and corrugated base (11), which corrugated ring surrounds the shaft (1) and having shape-locking elements (8) projecting from the annular surface evenly distributed on the circumference, and that the shape-locking element tit 20 (8) engage the form-locking recesses (9) on the crank ring (4) and the slip ring (2). Non-rotating mechanical seal according to Claim 1, characterized in that the corrugated ring (5) consists, viewed from the side, of three identical corrugations (10) and three identical corrugations (11) of equal length, and that three shape-locking elements (8) are arranged on each side. Sliding ring seal independent of the direction of rotation 30 according to Claim 1, characterized in that the spring device (5) consists of two identical corrugated rings (5a, 5b) which are assembled in opposite phases. having shape locking elements (8) on the corrugations (10) of the outer ring surfaces and in each case preferably comprising three corrugations (10) and three corrugations 11). Il 7 93894 Non-rotating mechanical seal according to one of Claims 1 to 3, characterized in that the shape-locking elements (8) are arranged on the corrugated ring (5) or on the corrugated rings (5a, 5b). Non-rotating mechanical seal according to one of Claims 1 to 3, characterized in that the form-locking elements (8) are formed on a corrugated ring (5) or corrugated rings (5a, 5b). 4 t 8 93894