Mechanical seal arrangement with a bellows element

Abstract

The invention relates to a mechanical seal arrangement, comprising a rotating slide ring (11) and a stationary slide ring (12), which define a sealing gap (13) in between them, and a bellows unit (2) with a bellows element (3) and an intermediate disc (4), wherein the bellows element (3) has a first connector area (31), a second connector area (32), and a bellows intermediate area (33), wherein the bellows element (3) is made of an elastomer material and provides a connection between the rotating slide ring (11) and a rotating structural component (10), wherein the intermediate disc (4) is arranged between the bellows element (3) and the rotating slide ring (11), and wherein the intermediate disc (4) has at least one slit (47) that has a slit width (B) that is smaller than a slit length (S), and wherein the slit (47) is closed at one side, so that a connection area (49) remains at the slit (47) at the intermediate disc (4).

Claims

1. Mechanical seal arrangement, comprising a rotating slide ring and a stationary slide ring which define a sealing gap in between them, and a bellows unit with a bellows element and an intermediate disc, wherein the bellows element has a first connector area, a second connector area, and a bellows intermediate area, wherein the bellows element is made of an elastomer material and provides a connection between the rotating slide ring and a rotating structural component, wherein the intermediate disc is arranged between the bellows element and the rotating slide ring, and wherein the intermediate disc has at least one slit that has a slit width (B) that is smaller than a slit length, and wherein the slit is closed on one side, so that a connection area remains at the slit at the intermediate disc, and wherein a plurality of recesses is provided at an inner circumferential area of the intermediate disc, wherein each of the recesses includes a width and a depth, wherein the width of each of recesses is greater than the width of the slit, and wherein the length of each of the recesses is less than the slit length.

2. Mechanical seal arrangement according to claim 1, wherein the slit begins at the inner circumferential area of the intermediate disc.

3. Mechanical seal arrangement according to claim 1, wherein exactly one slit is provided at the intermediate disc.

4. Mechanical seal arrangement according to claim 1, wherein a slit width (B) corresponds to a radial length of the connection area.

5. Mechanical seal arrangement according to claim 1, wherein a ratio of the slit width (B) to the slit length (S) is in a range of 0.05 to 0.35.

6. Mechanical seal arrangement according to claim 5, wherein the ratio of the slit width (B) to the slit length (S) is approximately 0.17.

7. Mechanical seal arrangement according to claim 1, wherein a ratio of the slit length (S) to a ring width (R) of the intermediate disc is in a range of 0.7 to 0.95.

8. Mechanical seal arrangement according to claim 7, wherein the ratio of the slit length (S) to the ring width (R) of the intermediate disc is 0.85.

9. Mechanical seal arrangement according to claim 1, wherein the recesses are arranged at regular distances at the inner circumferential area of the intermediate disc, and/or that the intermediate disc has an uneven number of recesses.

10. Mechanical seal arrangement according to claim 1, wherein the slit extends from the inner circumferential area beginning at one of the recesses.

11. Mechanical seal arrangement according to claim 1, wherein the intermediate disc has a plurality of axially projecting ledges which are formed alternatingly with the recesses at the inner circumferential area of the intermediate disc.

12. Mechanical seal arrangement according to claim 1, wherein the bellows unit further comprises a first Z profile angle and a second Z profile angle, wherein the first Z profile angle is arranged at an outer side of the first connector area, and wherein the second Z profile angle is arranged at an outer side of the second connector area.

13. Mechanical seal arrangement according to claim 12, wherein the second Z profile angle ends at the same height in the axial direction (X-X) as the second connector area.

14. Mechanical seal arrangement according to claim 12, wherein a first radially inward facing area of the first Z profile angle overlaps with an end of the first connector area that faces towards the bellows intermediate area, and/or that a second radially inward facing area of the second Z profile angle overlaps with an end of the second connector areas that faces the bellows intermediate area.

15. Mechanical seal arrangement according to claim 12, further comprising a pre-tensioning element which pre-tensions the bellows unit in the axial direction (X-X), wherein the pre-tensioning element is supported at a first end area at the first Z profile angle, and is supported with a second end area at the second Z profile angle.

16. Mechanical seal arrangement according to claim 1, wherein the intermediate disc includes a first side having a single elevation, and a second side having a single elevation.

17. Mechanical seal arrangement according to claim 1, wherein the intermediate disc includes a single outer circumference.

18. Mechanical seal arrangement, comprising a rotating slide ring and a stationary slide ring which define a sealing gap in between them, and a bellows unit with a bellows element and an intermediate disc, wherein the bellows element has a first connector area, a second connector area, and a bellows intermediate area, wherein the bellows element is made of an elastomer material and provides a connection between the rotating slide ring and a rotating structural component, wherein the intermediate disc is arranged between the bellows element and the rotating slide ring, and wherein the intermediate disc has at least one slit that has a slit width (B) that is smaller than a slit length, and wherein the slit is closed on one side, so that a connection area remains at the slit at the intermediate disc, and wherein a plurality of recesses is provided at an inner circumferential area of the intermediate disc, wherein the intermediate disc includes a single outer circumference.

Description

(1) In the following, preferred exemplary embodiments of the invention are described in detail by referring to the accompanying drawing, with identical parts or parts having identical functions being indicated by the same reference signs. In the drawing:

(2) FIG. 1 shows a schematic longitudinal section view of a mechanical seal arrangement according to a first exemplary embodiment of the invention,

(3) FIG. 2 shows an enlarged detailed view of FIG. 1,

(4) FIG. 3 shows a schematic top view of an intermediate disc according to the first exemplary embodiment of the invention,

(5) FIG. 4 shows a perspective view of the intermediate disc of FIG. 3,

(6) FIG. 5 shows a sectional view of the intermediate disc of FIG. 3,

(7) FIG. 6 shows a schematic view of a mechanical seal arrangement according to a second exemplary embodiment of the invention,

(8) FIG. 7 shows a schematic top view of the intermediate disc of FIG. 6,

(9) FIG. 8 shows a perspective view of the intermediate disc of FIG. 7, and

(10) FIG. 9 shows a schematic sectional view of the intermediate disc of FIG. 7.

(11) In the following, a mechanical seal arrangement 1 according to a first exemplary embodiment of the invention is described in detail by referring to FIGS. 1 to 5.

(12) As can be seen in FIG. 1, the mechanical seal arrangement 1 comprises a rotating slide ring 11 and a stationary slide ring 12 which define a sealing gap 13 in between them in the known manner. The mechanical seal arrangement 1 serves for sealing a first space 8 against a second space 9.

(13) The rotating slide ring 11 is connected to a rotating structural component 10, which in this exemplary embodiment is a shaft, and rotates together with the same. The stationary slide ring 12 is connected to a stationary housing 14. The reference sign 15 indicates a secondary sealing element for sealing the stationary slide ring 12 against the housing 14.

(14) The mechanical seal arrangement 1 further comprises a bellows unit 2, which establishes the connection between the rotating slide ring 11 and the rotating structural component 10. The bellows unit 2 comprises a bellows element 3 and a single-part intermediate disc 4. The bellows element 3 is made of an elastomer material and comprises a first connector area 31, a second connector area 32, and a bellows intermediate area 33 that is located between the two connector areas 31, 32. The bellows intermediate area 33 is flexible and facilitates an elongation and shortening of the bellows element 3 in the axial direction X-X.

(15) As can be seen from FIG. 1, the bellows element 3 is a single-part structural component and serves for providing a sealing at the rotating slide ring 11. Further, the bellows unit 2 takes over a torque transmission from the rotating structural component 10 to the rotating slide ring 11.

(16) The bellows unit 2 further comprises a first Z profile angle 5 and a second Z profile angle 6. The first Z profile angle 5 is arranged at the first connector area 31 at its outer diameter. The second Z profile angle 6 is arranged at the second connector area 32 at its outer diameter. In section, the two Z profile angles 5, 6 have a Z profile.

(17) The first Z profile angle 5 comprises a first radially outward facing area 51, a first radially inward facing area 52, and a first axial area 53. The second Z profile angle 6 comprises a second radially outward facing area 61, a second radially inward facing area 62, and a second axial area 63 (cf. FIG. 2). Here, the first radially inward facing area 52 of the first Z profile angle overlaps with an end of the first connector area 31 that is facing towards the bellows intermediate area 33. The second radially inward facing area 62 of the second Z profile angle 6 overlaps with an end of the second connector area 32 (cf. FIG. 1) that is facing towards the bellows intermediate area 33. Here, the two axial areas 53, 63 of the two Z profile angles 5, 6 rest on the outer diameters of the first and second connector areas 31, 32. In this manner, the elastomer connector areas 31, 32 are crimped.

(18) Further, an end of the second connector area 32 and the second radially outward facing area 61 of the second Z profile angle 6 are positioned at the same height in the axial direction X-X, thus resulting in an even end surface.

(19) The bellows element 3 further comprises a ledge 34 at its inner circumference. As can be seen from FIG. 2, the intermediate disc 4 abuts a face-side contact surface 35. An inner circumferential area 40 of the intermediate disc has a distance to the outer circumference of the rotating structural component 10. The result is a ring-shaped gap 48 between the inner circumferential area 40 of the intermediate disc 4 and the rotating structural component 10. In this manner, a continuous connection of the rotating slide ring 11 to the area between the bellows element 3 and the rotating structural component 10 is ensured.

(20) FIGS. 3 to 5 show a detailed illustration of the intermediate disc 4. As can be seen from FIG. 3, a plurality of recesses 41 is provided at the inner circumferential area of the intermediate disc 4, with the recesses 41 enlarging the passage cross section at the bellows element. In this manner, the axial readjusting behavior of the bellows element is maintained at all times.

(21) Further, the intermediate disc 4 has a slit 47. The slit 47 extends radially outward, beginning at the inner circumferential area 40 of the intermediate disc 4. At that, the slit 47 is not formed continuously up to the outer circumferential area 46 of the intermediate disc 4. A connection area 49 remains at the intermediate disc. Thus, the intermediate disc still has a material area that is located between the outer and the inner circumference, whereby a certain stability of the intermediate disc is ensured, and any widening of the intermediate disc is prevented.

(22) The slit 47 has a width B and a slit length S, namely in such a manner that a ratio of the slit width B to the slit length S is approximately 0.12. The slit width B also approximately corresponds to the radial length of the connection area 49. Thus, the width B of the slit 47 is chosen to be equal to a width V of the connection area 49. In this exemplary embodiment, the slit 47 is arranged at an intermediate area between two recesses 41. Here, a maximum ring width R of the intermediate disc and the slit length S are chosen in such a manner that a ratio of the slit length to the ring width is approximately 0.9.

(23) As can be seen from FIG. 2, the ring-shaped intermediate disc 4 is arranged between the rotating slide ring 11 and the bellows element 3 in such a manner that the intermediate disc 4 abuts a first side 43 at a rear side of the rotating slide ring 11, and abuts a second side 44 at the face-side contact surface 35 of the bellows element 3. The intermediate disc 4 further has a constant width.

(24) The bellows unit 2 further comprises a pre-tensioning element 7, which in this exemplary embodiment is a barrel spring. Here, the pre-tensioning element 7 is supported between the first Z profile angle 5 and the second Z profile angle 6, providing a permanent pre-tensioning of the bellows unit 2.

(25) By providing the rigid intermediate disc 4 between the elastomer bellows element 3 and the rotating slide ring 11 according to the invention, an improved axial readjusting behavior of the mechanical seal arrangement 1 can now be facilitated according to the invention. In particular through the slit ring-shaped intermediate disc 4, an axial readjusting behavior of the bellows element can be ensured in all operational states. The intermediate disc 4 expands at high temperatures, so that the gap 48 between the inner circumferential area 40 of the intermediate disc 4 and the rotating structural component is sufficiently large. When cooling down, the intermediate disc contracts radially inward. However, in the course of this process, the slit 47 extending from the inner circumferential area 40 now also facilitates contraction of the inner circumferential area when it cools down, without the intermediate disc 4 shrinking onto the rotating structural component 10 as a result of that. In this manner, the axial adjusting capacity of the bellows element is maintained even at low temperatures.

(26) According to the invention, the intermediate disc that is slit only partially thus provides a simple and cost-effective solution for temperature-related changes in the dimensions of the intermediate disc 4.

(27) Further, in the event of the intermediate disc widening, the connection area 49 provided radially at the end of the slit 47 in the intermediate disc prevents any damage to the elastomer bellows element 3 by an edge at the outer circumferential area.

(28) Thus, according to the invention, the problem of the intermediate disc 4 shrinking onto the rotating structural component 10 can be solved without any damage to the bellows element occurring as a result, and without causing any disadvantages with respect to the axial readjusting behavior of the bellows element 3.

(29) In contrast, the intermediate disc 4, which may for example be made of a stable synthetic material, can move on the outer circumference of the rotating structural component 10 without any adhesion effects, and also remove any contaminations off the surface of the rotating structural component. Thus, the disadvantage that has so far been present in the state of the art in elastomer bellows elements with resect to their readjusting behavior after a certain operating time can be overcome by proficiently providing the intermediate disc 4. Further, a leakage at the sealing gap 13 can be significantly reduced according to the invention, since an axial readjusting of the mechanical seal is always possible, and the sealing gap width can be kept as small as possible.

(30) Further, the intermediate disc 4 also has the advantage that a considerable shortening of the mechanical seal arrangement is possible in the axial direction X-X, because the support shoulder, which has so far been necessary for elastomer bellows elements in the state of the art and which has been provided in the area of the second connector area 32, supporting the bellows element 3 on the rotating structural component 10, can be foregone. As a result, axial installation space is saved. At the same time, the use of the intermediate disc 4 also creates the possibility of clamping the rotating slide ring 11 in the axial direction X-X over a longer axial area 63 of the second Z profile angle 6 across a longer axial direction (clamping length L), and of thus reducing a radial crimping of the rotating slide ring 11 (cf. FIG. 2). This results in positive effects on the rotating slide ring 11 in particular with respect to a possible undesired deformation of the sliding surface of the rotating slide ring 11. This deformation can lead to an additional undesired leakage at the mechanical seal during operation.

(31) The bellows unit 2 according to the invention thus facilitates a number of surprising advantages when elastomer bellows elements 3 are used. Here, the bellows unit 2 can be built in an even more compact manner in the axial direction X-X. The option of shortening the seal installation length in the axial direction X-X thus results in an extremely great competitive edge. Further, the bellows unit 2 according to the invention can also easily dampen the vibrations that may occur during operation, performing even after a log operating time thanks to axial adjusting motions being possible at all times.

(32) FIGS. 6 to 9 show a mechanical seal arrangement according to a second exemplary embodiment in which the intermediate disc 4 additionally comprises projecting ledges 45 in the axial direction X-X. These projecting ledges 45 are formed at the inner circumferential area 40 of the intermediate disc 4. Here, a recess 41 and an axially projecting ledge 45 are respectively alternatingly provided at the inner circumferential area 40 (cf. FIG. 8). At that, a number of recesses 41 and a number of the axially projecting ledges 45 is uneven. In this exemplary embodiment, respectively nine recesses 41 and nine ledges 45 are provided. At that, the slit 47 is formed radially outward, beginning at a recess 41.

(33) The recesses 41 are again provided to be bow-shaped. As can be seen in FIG. 9, the intermediate disc 4 thus has an L-shape in section when the section is made through the axially projecting ledge 45.

(34) At that, the axially projecting ledges 45 facilitate a stable support of the bellows element 3. In this manner, it is further ensured that the bellows element 3 cannot come into contact with the rotating structural component 10 in the area of the second connector area 32 and compromise an axial readjusting behavior of the bellows element 3, for example. The ledges 45 thus provide a support of the elastomer bellows element 3 without compromising the ability of the intermediate disc 4 according to the invention to contract at the inner circumferential area 40 when cooling off.

PARTS LIST

(35) 1 mechanical seal arrangement

(36) 2 bellows unit

(37) 3 bellows element

(38) 4 intermediate disc

(39) 5 first Z profile angle

(40) 6 second Z profile angle

(41) 7 pre-tensioning element

(42) 8 first space

(43) 9 second space

(44) 10 rotating structural component/shaft

(45) 11 rotating slide ring

(46) 12 stationary slide ring

(47) 13 sealing gap

(48) 14 housing

(49) 15 secondary sealing element/O-ring

(50) 31 first connector area

(51) 32 second connector area

(52) 33 bellows intermediate area

(53) 34 ledge

(54) 35 face-side contact surface of the bellows element

(55) 40 inner circumferential area

(56) 41 recess

(57) 42 projecting areas

(58) 43 first side

(59) 44 second side

(60) 45 ledge

(61) 46 outer circumferential area

(62) 47 slit

(63) 48 ring-shaped gap

(64) 49 connection area

(65) 51 first radially outward facing area

(66) 52 first radially inward facing area

(67) 53 first axial area

(68) 61 second radially outward facing area

(69) 62 second radially inward facing area

(70) 63 second axial area

(71) B width of the slit

(72) L axial clamping length

(73) S length of the slit

(74) R maximum ring width of the intermediate disc

(75) V radial width of the connection area

(76) X-X axial direction