Mechanical seal for tail shaft of pod propeller

Abstract

The utility model provides a mechanical seal for a tail shaft of a pod propeller, which relates to the field of mechanical seals and comprises a transmission shaft sleeve, a movable ring seat is arranged on the outer side of one end of the transmission shaft sleeve, and a mounting flange is sleeved outside the other end of the transmission shaft sleeve; one end of the mounting flange is connected with a static ring seat, the other end of the mounting flange is connected with a motor cabin, and a sealing assembly is assembled between the static ring seat and the moving ring seat; two framework oil seals are arranged between the inner hole wall of the static ring seat and / or the mounting flange and the peripheral wall of the transmission shaft sleeve, a flushing ring is arranged between the two framework oil seals, a flushing channel is reserved between the inner wall of the flushing ring and the outer wall of the transmission shaft sleeve, and flushing holes are formed in the flushing ring. The mounting flange is provided with an oil inlet channel and an oil outlet channel which are respectively communicated with the flushing hole; oil pressure in the flushing channel is larger than equipment oil pressure on the motor cabin side and sealing cavity pressure. According to the mechanical seal for the tail shaft of the pod propeller, sealing of external seawater can be achieved, oil liquid at the equipment end can be prevented from leaking out and entering a sealing cavity, and the stable sealing performance is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of mechanical seals, in particular to a mechanical seal for a tail shaft of a pod thruster. Background Art

[0002] Pod thrusters integrate propulsion and steering devices, greatly increasing the flexibility of ship design, construction and use, and making the superiority of electric propulsion more fully manifested. They are a new type of propulsion device that has attracted extensive attention from the world's shipbuilding industry. Pod thrusters place the propulsion motor outside the cabin and directly connect it to the propeller. They can rotate horizontally within 360° to achieve vector propulsion. They are generally composed of a permanent magnet motor, a duct, a propeller and a controller.

[0003] The pod is usually composed of a davit and a propulsion module, wherein the propulsion module includes a propeller, a sealing device, a propeller shaft, a motor housing, a motor, etc. In order to ensure the reliable operation of the motor, no seawater leakage is allowed in the motor cabin, so special consideration needs to be given to the sealing device, especially the seal between the motor housing and the external seawater.

[0004] The following are some of the most widely used traditional sealing structures:

[0005] 1. Traditional packing seals are in contact with the shaft for a long time, which is easy to wear and cause seawater leakage, and the reliability is not high.

[0006] 2. Traditional single three- or four-pass lip seals often wear out the propeller shaft severely, have a short lifespan, and are prone to failure.

[0007] 3. Traditional mechanical seals can often only cope with a small amount of axial movement and circumferential shaft runout. Although pod thrusters often have a relatively low rotation speed, the large shaft diameter will cause high end face heat generation, resulting in a short seal service life. In addition, the existing mechanical seal structure lacks an effective solution for the seal between the sealing chamber and the motor compartment, that is, there is a risk of the bearing box oil on the motor compartment side leaking into the sealing chamber, and the leakage of the bearing box oil into the sealing chamber will affect the sealing performance. Utility Model Content

[0008] In order to overcome at least one defect in the above prior art, the utility model provides a mechanical seal for the tail shaft of a pod thruster, which can not only seal the external seawater, but also prevent the oil at the equipment end from leaking into the sealing cavity, thereby ensuring stable sealing performance.

[0009] The utility model provides a mechanical seal for a tail shaft of a pod propeller: comprising a transmission sleeve sleeved on the outside of the propeller tail shaft, a dynamic ring seat is arranged on the outer side of the transmission sleeve close to one end of a propeller assembly, a mounting flange is sleeved on the outside of the other end of the transmission sleeve, one end of the mounting flange close to the dynamic ring seat is connected to a static ring seat, the other end of the mounting flange is connected to a motor cabin, a sealing assembly is arranged between the static ring seat and the dynamic ring seat; two skeleton oil seals are arranged between the inner hole wall of the static ring seat and / or the mounting flange and the outer peripheral wall of the transmission sleeve, and a flushing ring is arranged axially between the two skeleton oil seals, a flushing channel is reserved between the inner wall of the flushing ring and the outer wall of the transmission sleeve, a flushing hole is arranged on the flushing ring and penetrates along its radial direction, and an oil inlet channel and an oil outlet channel which are respectively connected to the flushing hole are arranged on the mounting flange; the oil pressure in the flushing channel is greater than the equipment oil pressure on the motor cabin side and the sealing chamber pressure.

[0010] Compared with the prior art, the pod thruster tail shaft mechanical seal of the utility model has the following advantages:

[0011] Compared with the traditional packing seal or the single multi-pass lip seal structure, the mechanical seal structure of the tail shaft of the pod thruster of the utility model has more stable sealing performance and longer service life; in addition, a sealing component is arranged between the stationary ring seat and the dynamic ring seat, and a sealing cavity is formed between the sealing component and the outer wall of the transmission shaft sleeve; two skeleton oil seals are arranged between the inner hole wall of the stationary ring seat and / or the mounting flange and the outer peripheral wall of the transmission shaft sleeve, and a flushing ring is arranged axially between the two skeleton oil seals, and a flushing channel is reserved between the inner wall of the flushing ring and the outer wall of the transmission shaft sleeve, and a flushing ring is arranged on the flushing ring along its radial penetration. There are flushing holes connected to the sealing chamber, and the mounting flange is provided with an oil inlet channel and an oil outlet channel connected to the flushing holes respectively, that is, the space between the two skeleton oil seals is filled with clean isolation oil, and the oil pressure here in this structure is greater than the oil pressure of the bearing box on the motor compartment side, and is also greater than the sealing chamber pressure; in other words, even if the sealing component leaks and external seawater medium enters the sealing chamber, it will not leak toward the bearing box due to the oil pressure between the skeleton oil seals; at the same time, the oil in the bearing box will not enter the sealing chamber, thereby preventing the oil in the bearing box from entering the sealing chamber and affecting the sealing performance.

[0012] As an improvement, an annular groove extending in the circumferential direction is provided on the outer peripheral wall of the flushing ring, and a plurality of flushing holes distributed in the circumferential direction and radially connected to the flushing channel are provided at the bottom of the annular groove, and the oil inlet channel and the oil outlet channel are respectively connected to the annular groove. In the above improved structure, the annular groove is provided to ensure that the isolation oil is fully circulated and flushed, and the performance of the skeleton oil seal is stable.

[0013] As a further improvement, a first mounting groove and a second mounting groove are respectively provided inside the opposite sides of the stationary ring seat and the mounting flange, and the ends of the two skeleton oil seals facing away from each other are respectively mounted in the first mounting groove and the second mounting groove, and the ends of the two skeleton oil seals close to each other are respectively abutted against the two ends of the flushing ring.

[0014] Furthermore, the sealing assembly includes a dynamic ring and a static ring, one end of the dynamic ring is mounted on the dynamic ring seat, and a static ring groove is provided at one end of the static ring seat away from the mounting flange, one end of the static ring is slidably mounted in the static ring groove along the axial direction, and the other end of the static ring is circumferentially rotatably abutted against the other end of the dynamic ring, and an elastic compensation piece is provided between the static ring and the bottom of the static ring groove so that the static ring always has a tendency to move toward the dynamic ring.

[0015] As a further improvement, one end of the moving ring seat is concavely provided with an annular moving ring groove, the end of the moving ring away from the static ring is fitted in the moving ring groove, and a first sealing ring is provided between the end of the moving ring away from the static ring and the bottom of the moving ring groove, and a second sealing ring is provided between the radial outer end of the moving ring and the inner wall of the moving ring groove.

[0016] Furthermore, the elastic compensation part includes multiple springs, and the bottom of the static ring groove is provided with multiple spring holes. One end of each spring is respectively mounted in the multiple spring holes, and the other end is abutted against one end of the static ring away from the dynamic ring.

[0017] As a further improvement, the stationary ring seat is provided with an air inlet hole and an air outlet hole respectively connected to the stationary ring groove, and the mounting flange is provided with an air inlet channel and an air outlet channel respectively connected to the air inlet hole and the air outlet hole.

[0018] Preferably, the dynamic ring is made of porous silicon carbide material, and the static ring is made of reactive silicon carbide material.

[0019] Other improved features and advantages of the utility model will be described in the subsequent specific embodiments, and partly become apparent from the description, or understood by implementing the utility model. The purpose and other advantages of the utility model can be achieved and obtained through the structures specifically pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional diagram of the mechanical seal of the tail shaft of the pod thruster of the utility model;

[0021] Figure 2 This is a front view of the mechanical seal of the tail shaft of the pod thruster of the utility model;

[0022] Figure 3 for Figure 2 Middle AA section view;

[0023] Figure 4 for Figure 3 The structure diagram is enlarged at the X in the middle;

[0024] Figure 5 for Figure 3 The structure diagram at Y in the middle is enlarged;

[0025] Figure 6 It is a structural schematic diagram of the flushing ring in the utility model.

[0026] Description of reference numerals:

[0027] 1. Transmission sleeve; 2. Dynamic ring seat; 3. Mounting flange; 4. Stationary ring seat; 5. Skeleton oil seal; 6. Flushing ring; 7. Flushing hole; 8. Oil inlet channel; 9. Oil outlet channel; 10. Annular groove; 11. First mounting groove; 12. Second mounting groove; 13. Dynamic ring; 14. Stationary ring; 15. Stationary ring groove; 16. Elastic compensation part; 17. Dynamic ring groove; 18. First sealing ring; 19. Second sealing ring; 20. Air inlet hole; 22. Air inlet channel; 23. Air outlet channel; 24. Connecting sleeve. DETAILED DESCRIPTION

[0028] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0029] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "fixed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0030] The present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] See also Figure 1 to Figure 5As shown, an embodiment of the present application discloses a mechanical seal for a pod propeller tail shaft, which includes a transmission sleeve 1 sleeved on the outside of the propeller tail shaft, one end of which is directly connected to the propeller assembly of the propeller through a connecting sleeve 24. This structure saves other forms of transmission methods and eliminates the risk of failure in other transmission aspects; and a dynamic ring seat 2 is provided on the outer side of the transmission sleeve 1 near the propeller assembly. In this embodiment, the dynamic ring seat 2 and the transmission sleeve 1 are an integrally formed structure. In some other embodiments, the dynamic ring seat 2 can also be connected and fixed to the outside of one end of the transmission sleeve 1 in the form of a sleeve.

[0032] The other end of the transmission sleeve 1 is covered with a mounting flange 3, one end of the mounting flange 3 near the dynamic ring seat 2 is connected to a stationary ring seat 4, the other end of the mounting flange 3 is fixedly connected to the motor cabin, a sealing assembly is arranged between the stationary ring seat 4 and the dynamic ring seat 2, and a sealing cavity is formed between the sealing assembly and the outer wall of the transmission sleeve 1; two skeleton oil seals 5 are arranged between the inner hole wall of the stationary ring seat 4 and / or the mounting flange 3 and the outer peripheral wall of the transmission sleeve 1, and a flushing ring 6 is arranged axially between the two skeleton oil seals 5, a flushing channel is left between the inner wall of the flushing ring 6 and the outer wall of the transmission sleeve 1, and a flushing ring 6 is arranged along its diameter. The mounting flange 3 is provided with an oil inlet channel 8 and an oil outlet channel 9 which are respectively connected to the flushing hole 7, that is, the space between the two skeleton oil seals 5 is filled with clean isolation oil, and the oil pressure here in this structure is greater than the oil pressure of the bearing box on the motor compartment side, and is also greater than the sealing chamber pressure; in other words, even if the sealing component leaks and external seawater medium enters the sealing chamber, it will not leak toward the bearing box due to the oil pressure between the skeleton oil seals 5; at the same time, the oil in the bearing box will not enter the sealing chamber, thereby preventing the oil in the bearing box from entering the sealing chamber and affecting the sealing performance.

[0033] See attached Figure 5 , 6 In this embodiment, an annular groove 10 extending in the circumferential direction is provided on the outer peripheral wall of the flushing ring 6, and a plurality of flushing holes 7 distributed in the circumferential direction and radially connected to the flushing channel are provided at the bottom of the annular groove 10 to form a multi-point distributed flushing channel. The oil inlet channel 8 and the oil outlet channel 9 are respectively connected to the annular groove 10. This structure ensures that the isolation oil is fully circulated and flushed, thereby ensuring the stable performance of the skeleton oil seal 5.

[0034] In addition, a first mounting groove 11 and a second mounting groove 12 are respectively provided inside the opposite sides of the stationary ring seat 4 and the mounting flange 3, and the ends of the two skeleton oil seals 5 that are away from each other are respectively mounted in the first mounting groove 11 and the second mounting groove 12, and the ends of the two skeleton oil seals 5 that are close to each other are respectively abutted against the two ends of the flushing ring 6; in this structure, the flushing ring 6 also plays a role in limiting the position of the two skeleton oil seals 5, and the two skeleton oil seals 5 are respectively mounted on the stationary ring seat 4 and the mounting flange 3, which makes installation, maintenance and disassembly more convenient.

[0035] See the attached Figure 4 In this embodiment, the sealing assembly includes a dynamic ring 13 and a static ring 14, wherein one end of the dynamic ring 13 is mounted on the dynamic ring seat 2, and a static ring groove 15 is provided at one end of the static ring seat 4 away from the mounting flange 3, and one end of the static ring 14 is slidably mounted in the static ring groove 15 along the axial direction, and a third sealing ring is provided between the radial outer end of the static ring 14 and the inner wall of the static ring groove 15; the other end of the static ring 14 is rotatably abutted with the other end of the dynamic ring 13 along the circumferential direction to form a sealing grinding surface; in addition, an elastic compensation member 16 is provided between the static ring 14 and the bottom of the static ring groove 15, so that the static ring 14 always has a tendency to move toward the dynamic ring 13, that is, when the sealing grinding surface is worn, under the action of the elastic compensation member 16, the static ring 14 can always abut against the dynamic ring 13 to ensure stable sealing performance. In this structure, the static ring 14 compensation structure is adopted to avoid the defect that the compensation ring cannot follow up at high linear speed, and better ensure the sealing performance.

[0036] See attached Figure 4 More specifically, one end of the dynamic ring seat 2 is concavely provided with an annular dynamic ring groove 17, and one end of the dynamic ring 13 away from the static ring 14 is fitted in the dynamic ring groove 17, and a first sealing ring 18 is provided between the end of the dynamic ring 13 away from the static ring 14 and the bottom of the dynamic ring groove 17, and a second sealing ring 19 is provided between the radial outer end of the dynamic ring 13 and the inner wall of the dynamic ring groove 17. Preferably, the first sealing ring 18 and the second sealing ring 19 are both O-rings, and the back of the dynamic ring 13 has an O-ring support, so that even if there is a huge axial displacement, the dynamic ring 13 will not have a rigid contact, ensuring that the sealing surface is not deformed.

[0037] In addition, in the above structure, at least one axially extending transmission pin (not shown in the figure) is arranged at the bottom of the dynamic ring groove 17, and a transmission pin groove is correspondingly arranged at the tail end of the dynamic ring 13 to prevent circumferential rotation between the dynamic ring 13 and the dynamic ring seat 2. In addition, a nylon protective sleeve is mounted on the outside of the transmission pin to prevent the dynamic ring 13 from breaking at the transmission pin groove under large torque.

[0038] Similarly, the same pin groove structure is also provided at the tail end of the stationary ring 14 and the bottom of the stationary ring groove 15, which will not be elaborated here. It is mainly to prevent the stationary ring 14 from rotating relative to the stationary ring seat 4 under the circumferential rotation force of the dynamic ring 13, thereby affecting the sealing performance.

[0039] In the above structure, the elastic compensation member 16 includes a plurality of springs, and a plurality of spring holes are provided at the bottom of the stationary ring groove 15. One end of each spring is respectively fitted in the plurality of spring holes, and the other end is in contact with the end of the stationary ring 14 away from the dynamic ring 13. Preferably, the spring is a small cylindrical spring, and a plurality of circumferentially arranged cylindrical springs are selected as compensation elements, so that the axial compensation force is more balanced, and the sealing performance is stable; in addition, the spring hole setting makes the spring limit stable, and the position will not be cheap during the expansion and contraction process, thereby ensuring that the elastic compensation force is stable and reliable.

[0040] See attached Figure 4 In this embodiment, the stationary ring seat 4 is provided with an air inlet hole 20 and an air outlet hole (not shown in the figure) which are respectively connected to the stationary ring groove 15, and the mounting flange 3 is provided with an air inlet channel 22 and an air outlet channel 23 which are respectively connected to the air inlet hole 20 and the air outlet hole; in this structure, when a slight leakage occurs on the sealing grinding surface, the leaked liquid can be blown out from the air outlet channel 23 by blowing air into the air inlet channel 22.

[0041] Preferably, the dynamic ring 13 is made of porous silicon carbide, and the static ring 14 is made of reactive silicon carbide. The dynamic ring 13 is made of silicon carbide with pores, and the porous silicon carbide can effectively maintain the full lubrication of the liquid film and increase the practical life of the mechanical seal.

[0042] In addition, see Appendix Figure 4 , 5 It can be seen that the outer ends of the oil inlet channel 8, the oil outlet channel 9, the air inlet channel 22 and the air outlet channel 23 in this embodiment are all arranged on the end face of the mounting flange 3 away from the static ring groove 15, and corresponding inlet and outlet holes are opened on the outer wall of the mounting flange 3 on the motor compartment side to realize the inlet and outlet circulation of the isolation oil and the purge air, which is not shown in the figure because the mounting flange 3 on the motor compartment side does not actually belong to the structure of the mechanical seal part. This part of the structure is actually designed by other manufacturers to cooperate with the corresponding channel outer port on the mounting flange 3 of the mechanical seal.

[0043] In the description of the present application, the description with reference to the terms "present embodiment", "some embodiments", etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradicting each other.

[0044] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A mechanical seal for a tail shaft of a pod thruster, characterized in that: The invention comprises a transmission sleeve (1) which is sleeved on the outside of the propeller tail shaft, wherein a dynamic ring seat (2) is arranged on the outer side of the transmission sleeve (1) near one end of the propeller assembly, and a mounting flange (3) is sleeved on the outside of the other end of the transmission sleeve (1), and a stationary ring seat (4) is connected to one end of the mounting flange (3) near the dynamic ring seat (2), and the other end of the mounting flange (3) is connected to the motor cabin, and a sealing component is arranged between the stationary ring seat (4) and the dynamic ring seat (2); the inner hole wall of the stationary ring seat (4) and / or the mounting flange (3) is in contact with the transmission sleeve (1); Two skeleton oil seals (5) are arranged between the outer peripheral walls of the moving shaft sleeve (1), and a flushing ring (6) is arranged axially between the two skeleton oil seals (5), a flushing channel is reserved between the inner wall of the flushing ring (6) and the outer wall of the driving shaft sleeve (1), the flushing ring (6) is provided with a flushing hole (7) penetrating along its radial direction, and the mounting flange (3) is provided with an oil inlet channel (8) and an oil outlet channel (9) respectively connected to the flushing hole (7); the oil pressure in the flushing channel is greater than the equipment oil pressure on the motor cabin side and the sealing chamber pressure.

2. The pod propeller tail shaft mechanical seal according to claim 1, characterized in that: An annular groove (10) extending in the circumferential direction is provided on the outer peripheral wall of the flushing ring (6), and a plurality of flushing holes (7) distributed in the circumferential direction and radially connected to the flushing channel are provided at the bottom of the annular groove (10), and the oil inlet channel (8) and the oil outlet channel (9) are respectively connected to the annular groove (10).

3. The pod propeller tail shaft mechanical seal according to claim 1 or 2, characterized in that: A first mounting groove (11) and a second mounting groove (12) are respectively arranged inside the opposite sides of the stationary ring seat (4) and the mounting flange (3); the ends of the two skeleton oil seals (5) which are away from each other are respectively mounted in the first mounting groove (11) and the second mounting groove (12); and the ends of the two skeleton oil seals (5) which are close to each other are respectively abutted against the two ends of the flushing ring (6).

4. The pod propeller tail shaft mechanical seal according to claim 1, characterized in that: The sealing assembly comprises a dynamic ring (13) and a static ring (14), one end of the dynamic ring (13) is mounted on the dynamic ring seat (2), and a static ring groove (15) is provided at one end of the static ring seat (4) away from the mounting flange (3). One end of the static ring (14) is axially slidably mounted in the static ring groove (15), and the other end of the static ring (14) is circumferentially rotatably abutted against the other end of the dynamic ring (13), and an elastic compensation piece (16) is provided between the static ring (14) and the bottom of the static ring groove (15) so that the static ring (14) always has a tendency to move toward the dynamic ring (13).

5. The pod propeller tail shaft mechanical seal according to claim 4, characterized in that: One end of the moving ring seat (2) is concavely provided with an annular moving ring groove (17), and the end of the moving ring (13) away from the static ring (14) is fitted in the moving ring groove (17), and a first sealing ring (18) is provided between the end of the moving ring (13) away from the static ring (14) and the bottom of the moving ring groove (17), and a second sealing ring (19) is provided between the radial outer end of the moving ring (13) and the inner wall of the moving ring groove (17).

6. The pod propeller tail shaft mechanical seal according to claim 4, characterized in that: The elastic compensation member (16) includes a plurality of springs. A plurality of spring holes are provided at the bottom of the stationary ring groove (15). One end of each of the springs is respectively fitted in the plurality of spring holes, and the other end is in contact with an end of the stationary ring (14) away from the dynamic ring (13).

7. The pod propeller tail shaft mechanical seal according to claim 4 or 6, characterized in that: The stationary ring seat (4) is provided with an air inlet hole (20) and an air outlet hole respectively connected to the stationary ring groove (15), and the mounting flange (3) is provided with an air inlet channel (22) and an air outlet channel (23) respectively connected to the air inlet hole (20) and the air outlet hole.

8. The pod propeller tail shaft mechanical seal according to claim 4, characterized in that: The dynamic ring (13) is made of porous silicon carbide material, and the static ring (14) is made of reactive silicon carbide material.

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