Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of the invention:
AN APPARATUS FOR TESTING A SEAL DEVICE

Applicant:
GOA SHIPYARD LIMITED
(A Govt. of India Undertaking-Ministry of Defence)
Having address as:
GOA SHIPYARD LIMITED
Vasco-Da-Gama, GOA - 403802, India

The following specification particularly describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application does not claim priority from any patent application.

TECHNICAL FIELD
[002] The present disclosure in general relates to field of sea seals. More particularly, the present disclosure relates to an apparatus for testing a seal device used in stern gear system.
BACKGROUND
[003] Generally, propeller of a ship is fitted at shaft and attached to a crankshaft coming from main engine, so that the rotating motion of the main engine can be converted into thrust to propel the ship. The propeller shaft or tail shaft is supported by a bearing arrangement which acts as an intermediate phase between the sea and the ship. Stern gear system comprising a stern tube is a hollow tube passing at lower stern part of the ship carrying tail shaft and connecting it to the propeller out at sea, bearing for the tail shaft, lubrication arrangement and most importantly the sealing arrangements. The stern tube bearing arrangement and sealing plays a vital role in ship’s operation and pollution prevention.
[004] Deep sea seal is a most critical component of the stern gear system. The deep-sea seal may be installed and tested after the complete installation of the shafts and bolting down of the Gear box and main engine. However, there is a small chance of failure of the deep-sea seals while testing onboard. In case of failure, amount of work involved in installation of new deep-sea seal and time delay is quite high.

SUMMARY
[005] Before the present apparatus for testing a seal device is described, it is to be understood that this application is not limited to the particular composition, and methodologies described, as there can be multiple possible embodiments which are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.
[006] In one implementation, an apparatus for testing a seal device is disclosed. The apparatus comprises a holding plate, a cover plate and dummy shaft. The holding plate comprising foundation legs and the holding plate is having a hole in center of the holding plate for allowing passage of the dummy shaft. The holding plate is mounted with a stator part of the seal device to be tested. The cover plate is arranged for holding water on an inner side of the seal device to be tested and the cover plate is arranged to be attached to other side of the holding plate. The dummy shaft is attached to the center of the cover plate such that dummy shaft passes through the center of the holding plate.

BRIEF DESCRIPTION OF DRAWINGS
[007] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.
[008] Figure 1(a) illustrates a schematic diagram of an apparatus (100) for testing a seal device, in accordance with an embodiment of the present subject matter;
[009] Figure 1(b) illustrates a schematic diagram of a holding plate (102) assembled in the apparatus (100) of Figure 1(a), in accordance with an embodiment of the present subject matter;
[0010] Figure 1(c) illustrates a schematic diagram of a cover plate (104) assembled in the apparatus (100) of Figure 1(a), in accordance with an embodiment of the present subject matter;
[0011] Figure 1(d) illustrates a schematic diagram of a dummy shaft (106) used in the apparatus of Figure 1(a), in accordance with an embodiment of the present subject matter; and
[0012] Figure 2 illustrates a schematic diagram showing the apparatus (100) with a seal device (202) to be tested mounted over the apparatus (100).
DETAILED DESCRIPTION
[0013] Some embodiments of the present disclosure, illustrating all its features, will now be discussed in detail. Herein, the conjunction “or” is not intended to be exclusive unless otherwise noted. For example, the phrase “or alternatively” is intended to be exclusive. Further, when used in connection with chemical substitution at a specific position, the conjunction “or” is intended to be exclusive. As used herein, the adjective “exemplary” is used simply to point to an example and is not meant to indicate preference. It must also be noted that as used herein and in the appended claims, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. Terms such as “inner”, “outer”, “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
[0014] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure of an apparatus for testing a seal device is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
[0015] Sea seal is a most critical component of the stern gear system. The sea seal may be installed and tested after the complete installation of the shafts and bolting down of the Gear box and main engine. However, there is a small chance of failure of the sea seals while testing onboard. In case of failure, amount of work involved in installation of new sea seal and time delay is quite high. Hence, testing the sea seals prior completion of installation of the stern gear systems will ensure nil failure after installation onboard.
[0016] The present subject matter overcomes the problems involved in the existing art. In order to address the above challenges, the present subject matter develops an apparatus for testing a seal device (also referred as a deep-sea seal device).
[0017] Generally, sea seal provides a primary sealing action through two mating rings. The mating ring comprises different material depending on the manufacturer and application. Out of the two mating rings, one mating ring is stationery and mounted on stern tube of shaft and other mating ring is mounted on the shaft and rotates along with it. Both the mating rings are held together by compressive load. Secondary sealing action is executed when primary sealing action fails. The secondary sealing action is done through inflatable tube concealed under the stator part of the sea seal. The sealing action happens when the inflatable tube is inflated to a preset pressure (as per OEM).
[0018] Referring now to the drawings, and more particularly to Figures 1(a) through Figure 2, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0019] Referring now to Figure 1 (a), Figure 1 (b), Figure 1 (c), Figure 1 (d) in combination, Figure 1 (a) illustrates a schematic diagram of an apparatus 100 for testing a seal device (not shown in Figures).
[0020] In an embodiment, the apparatus 100 for testing a seal device comprises a holding plate 102, a cover plate 104 and a dummy shaft 106. As shown in Figure 1 (a), the holding plate 102 comprising foundation legs 108. The foundation legs 108 are selected in a predefined dimension. The holding plate 102 is having a hole 110 in center of the holding plate 102 for allowing passage of the dummy shaft 106. The hole 110 is selected in a predefined dimension.
[0021] The holding plate 102 is mounted with a stator part of the seal device 202 to be tested. The seal device 202 comprises a new seal device to be tested or a repaired seal device to be tested. The holding plate 102 is selected in a predefined dimension. As shown in Figure 1 (b), diameter of the holding plate is (3D x 3D) mm. The predefined dimension of the hole 110 comprises (D+50) mm. "D” is a variable and denotes as diameter of the dummy shaft 106, which is detected by the OEM. Diameter D of the dummy shaft 106 is equal to the diameter of an actual shaft and D is selected in a range of 200 mm to 500 mm. Thickness of the holding plate 102 comprises D/10.
[0022] The holding plate 102 is made of a preselected material. The preselected material may include and not limited to steel.
[0023] The cover plate 104 is arranged for holding water on an inner side of the seal device 202 to be tested. The cover plate 104 is arranged to be attached to other side of the holding plate 102. The cover plate 104 is selected in a predefined dimension. Back of the cover plate 104 comprising the dimension as (2D x 2D) mm and Back of the cover plate 104 comprising the dimension as (2D+100 x 2D+100) mm, wherein "D” is a variable and denotes as diameter of a dummy shaft 106, which is detected by the OEM. D comprises a range of 200 mm to 500 mm. Thickness of the holding plate 102 comprises D/10. Minimum thickness of holding plate 102 should not be less than 20 mm.
[0024] The dummy shaft 106 is attached to the center of the cover plate 104 such that the dummy shaft 106 passes through the center of the holding plate 102. Diameter of the dummy shaft 106 is equal to the diameter of actual shaft (not shown in Figures). By changing diameter of the dummy shaft 106, seal devices 202 of different size may be tested. Dimension of the dummy shaft 106 comprises (3D x D) mm. "D” is a variable and denotes as diameter of the dummy shaft 106, which is detected by the OEM. The dummy shaft 106 is to be welded to the center of the cover plate 104. Minimum thickness of cover plate 104 should not be less than 20 mm.
[0025] Seal mounting PCD is to be drilled and tapped as per the seal device to be tested.
[0026] Figure 1(b) illustrates a schematic diagram of the holding plate 102.
[0027] Figure 1(c) illustrates a schematic diagram of the cover plate 104.
[0028] Figure 1(d) illustrates a schematic diagram of the dummy shaft 106.
[0029] In accordance with an embodiment, Figure 2 illustrates a schematic diagram 200 showing the apparatus 100 with a seal device 202 to be tested mounted on the apparatus 100. As shown in Figure 2, the seal device 202 provides a primary sealing action through two mating rings 208. The mating ring 208 comprises different material depending on the manufacturer and application. Out of the two mating rings 208, one mating ring 208 is stationery and mounted on stern tube of the dummy shaft 106 and other mating ring 208 is mounted on the dummy shaft 106 and rotates along with the dummy shaft 106. Both the mating rings 208 are held together by compressive load 210. Secondary sealing action is executed when primary sealing action fails. The secondary sealing action is done through inflatable tube (not shown in Figure 2) concealed under the stator part 204 of the seal device 202. The sealing action happens when the inflatable tube is inflated to a preset pressure (as per OEM).

[0030] In an embodiment, the seal device comprises stator part 204 and rotor part 206. The stator part 204 needs to be mounted on the holding plate 102 and the rotor part 206 needs to be mounted on the dummy shaft 106. The stator part 204 and the rotor part 206 may be installed as per OEM installation manual. Water may be filled by using a poker gauge port 212 of the seal device 202 till the entire water holding cover is filled, which simulates the onboard conditions. In case any leakage is found between mating rings 208 of the seal device 202, the leakage may then be aligned as per the OEM installation manual. Once the testing of the seal device 202 through the apparatus 100 is completed, the seal device 202 is tested further as per OEM requirements.
[0031] The seals or seal device 202 may be mounted on the apparatus 100 and is tested as per manufactures requirement. Any seal defects can be rectified during early-stage prior installing onboard.
[0032] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, the advantages may include those provided by the following features.
[0033] The proposed apparatus provides testing seals of the seal devices prior completion of installation of the stern gear systems which ensure nil failure after installation onboard.
[0034] Some embodiments of the apparatus 100 follow convenient manufacturing process requiring bare minimum capital equipment and cost is low.
[0035] Although an exemplary embodiment of the present embodiment has been described in detail, the scope of the present embodiment is not limited thereto but various modifications and improvements made by those skilled in the art using the basic concepts of the present embodiment defined in the appended claims also pertain to the scope of the present embodiment.
, Claims:
1. An apparatus (100) for testing a seal device (202), the apparatus (100) comprising:
a holding plate (102) comprising foundation legs, wherein the holding plate (102) is having a hole (110) in center of the holding plate (102) for allowing passage of a dummy shaft (106), and wherein the holding plate (102) is mounted with a stator part of the seal device (202) to be tested; and
a cover plate (104) arranged for holding water on an inner side of the seal device (202) to be tested, the cover plate (104) is arranged to be attached to other side of the holding plate (102);
wherein the dummy shaft (106) is attached to the center of the cover plate (104) such that dummy shaft (106) passes through the center of the holding plate (104).
2. The apparatus (100) as claimed in claim 1, wherein the seal device (202) comprises a new seal device (202) to be tested or a repaired seal device (202) to be tested.
3. The apparatus (100) as claimed in claim 1, wherein the holding plate (102) is selected in a predefined dimension selected according to dimension of the dummy shaft (106).
4. The apparatus (100) as claimed in claim 1, wherein the holding plate (102) is made of a preselected material comprising steel.
5. The apparatus (100) as claimed in claim 1, wherein the foundation legs (108) are selected.in a predefined dimension according to dimension of the dummy shaft (106).
6. The apparatus (100) as claimed in claim 1, wherein the hole (110) is selected in a predefined dimension according to dimension of the dummy shaft (106).
7. The apparatus (100) as claimed in claim 1, wherein the cover plate (104) is selected in a predefined dimension according to dimension of the dummy shaft (106).