A bidirectional thrust unit for a ship propeller

Abstract

The utility model discloses a kind of two-way thrust units for ship propeller, comprising: being sleeved on propeller shaft and being located between first thrust bearing and second thrust bearing, bearing seat, fixedly connected on gear box pedestal, bearing seat inside is equipped with the installation cavity of containing first thrust bearing and second thrust bearing, bearing gland, through bolt fixed in the one side of bearing seat, and contact with the outer ring of first thrust bearing, bearing cover, through bolt fixed in the other side of bearing seat, with bearing gland jointly close both ends of bearing seat, whereby compared with the design of multiple independent bearing combination in prior art, the two-way thrust bearing unit of the utility model occupies smaller space, only need to be fixed in gear box pedestal by flange and positioning pin when installing, without complex debugging process, greatly improve installation efficiency, also convenient for later maintenance and replacement.

Description

Technical Field

[0001] This utility model relates to the field of ship propeller technology, specifically a bidirectional thrust unit for ship propellers. Background Technology

[0002] In marine propulsion systems, the propeller shaft system is a key component for transmitting power. During its operation, it generates bidirectional axial thrust and unidirectional radial force. To withstand these forces, traditional marine propeller shaft systems typically employ a structure combining multiple bearings. For example, in existing technologies, a double-row self-aligning roller bearing is often used to withstand the radial force, while two independent spherical roller bearings are used to withstand the positive and negative axial thrust, respectively. Although this structure can meet the basic force requirements, its design is complex, the installation and commissioning process is cumbersome, and it needs to be manufactured and installed simultaneously with the propeller shaft and gearbox base, resulting in a long production cycle and high cost.

[0003] However, the existing technology has obvious drawbacks. First, due to the use of multiple independent bearing combinations, the structure is relatively loose and occupies a large space, which is not conducive to the compact design of ship equipment. Second, the installation and commissioning of the bearings in the existing technology need to be carried out after the propeller shaft and gearbox base are manufactured, which makes it impossible to achieve modular production and pre-assembly, resulting in low production efficiency. In addition, the bearing combination of the existing technology is prone to loosening or wear during long-term operation, which affects the stability and service life of the system.

[0004] Therefore, this utility model provides a bidirectional thrust unit for ship propellers. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a bidirectional thrust unit for ship propellers to solve the aforementioned problems.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a bidirectional thrust unit for a ship propeller, comprising: a propeller shaft extending axially; a first thrust bearing and a second thrust bearing symmetrically mounted face-to-face on the propeller shaft; a spring disposed between the first and second thrust bearings; a spacer ring sleeved on the propeller shaft and located between the first and second thrust bearings; a bearing housing fixedly connected to a gearbox base, the bearing housing having an internal mounting cavity for accommodating the first and second thrust bearings; a bearing cap fixed to one side of the bearing housing by bolts and in contact with the outer ring of the first thrust bearing; and a bearing cover fixed to the other side of the bearing housing by bolts, together with the bearing cap sealing both ends of the bearing housing.

[0007] Preferably, both the first thrust bearing and the second thrust bearing are spherical roller thrust bearings, and their outer rings are in contact with both ends of the spring.

[0008] Preferably, the outer diameter of the spacer ring is clearance-fitted with the inner wall of the mounting cavity of the bearing seat, and its axial length matches the free length of the spring.

[0009] Preferably, the inner end faces of the bearing cap and the bearing cover abut against the outer rings of the first thrust bearing and the second thrust bearing, respectively.

[0010] Preferably, the connection surface between the bearing housing and the gearbox base is provided with a flange structure, and the flange structure is aligned by a locating pin.

[0011] Beneficial effects

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] (1) This utility model integrates the first thrust bearing and the second thrust bearing face-to-face in the bearing housing, and uses springs and spacer rings to achieve preload and clearance control, which significantly simplifies the structural layout of the bearing unit. Compared with the design of the prior art that requires multiple independent bearing combinations, the bidirectional thrust bearing unit of this utility model occupies less space. During installation, the bearing housing only needs to be fixed to the gearbox base by flanges and positioning pins, without complicated debugging process, which greatly improves the installation efficiency and facilitates later maintenance and replacement.

[0014] (2) This utility model does not rely on the synchronous production of the propeller shaft and gearbox base, realizing modular production. This design not only shortens the production cycle but also reduces manufacturing costs. In addition, the dual-bearing integrated structure and pre-tightening mechanism reduce the number of bearings and installation steps, further improving production efficiency and solving the problems of long production cycles and high costs in the prior art. Attached Figure Description

[0015] Figure 1 This is a perspective view of the present invention.

[0016] In the diagram: 1. Propeller shaft; 2. First thrust bearing; 3. Second thrust bearing; 4. Spring; 5. Spacer ring; 6. Bearing cover; 7. Bearing gland; 8. Bearing housing; 9. Gearbox base. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figure 1 A bidirectional thrust unit for a ship propeller, comprising:

[0019] A propeller shaft 1 extends axially; a first thrust bearing 2 and a second thrust bearing 3 are symmetrically mounted on the propeller shaft 1 in a face-to-face manner; a spring 4 is disposed between the first thrust bearing 2 and the second thrust bearing 3; a spacer ring 5 is sleeved on the propeller shaft 1 and located between the first thrust bearing 2 and the second thrust bearing 3; a bearing housing 8 is fixedly connected to the gearbox base 9, and the bearing housing 8 has an internal mounting cavity for accommodating the first thrust bearing 2 and the second thrust bearing 3; a bearing cap 7 is fixed to one side of the bearing housing 8 by bolts and contacts the outer ring of the first thrust bearing 2; a bearing cover 6 is fixed to the other side of the bearing housing 8 by bolts, and together with the bearing cap 7, seals both ends of the bearing housing 8.

[0020] It should be noted that the propeller shaft 1 described in this embodiment is a cylindrical hollow shaft made of high-strength alloy steel, with its two ends connected to the ship's propeller and gearbox output shaft, respectively. The inner rings of the first thrust bearing 2 and the second thrust bearing 3 are fixed to the axial middle section of the propeller shaft 1 by an interference fit, and their outer rings face opposite directions. The spring 4 is a cylindrical helical compression spring, sleeved on the propeller shaft 1 and located between the inner rings of the first thrust bearing 2 and the second thrust bearing 3, with both ends of the spring abutting against the end faces of the inner rings of the two bearings. The spacer ring 5 is an annular metal part with a clearance fit between its inner hole and the propeller shaft 1, and a clearance of 0.1-0.3 mm between its outer circumferential surface and the inner wall of the mounting cavity of the bearing seat 8. Its axial length is designed to be 1.2 times the length of the spring after compression, based on the free length of the spring 4, to ensure stable preload. The bearing housing 8 is a split-type cast structure. Its bottom flange is connected to the flange face of the gearbox base 9 by bolts. The bearing housing has stepped mounting cavities machined inside. The outer rings of the first thrust bearing 2 and the second thrust bearing 3 are respectively embedded in the stepped surfaces on both sides of the mounting cavity. The bearing cap 7 and the bearing cover 6 are both annular flange structures, which are fixed to both ends of the bearing housing 8 by eight circumferentially distributed bolts. The inner end faces of both are tightly fitted to the end faces of the outer rings of the first thrust bearing 2 and the second thrust bearing 3, respectively.

[0021] The first thrust bearing 2 and the second thrust bearing 3 are both spherical roller thrust bearings, and their outer rings are in contact with both ends of the spring 4.

[0022] It should be noted that the spring 4 described in this embodiment has annular grooves machined on both ends, and the outer ring end faces of the spherical roller thrust bearings 2 and 3 are provided with flanges that match the grooves. The axial positioning of the spring 4 and the outer ring is achieved through the engagement of the grooves and flanges. In addition, the outer ring surface is coated with a polytetrafluoroethylene wear-resistant coating to reduce frictional wear on the contact surface with the spring.

[0023] The outer diameter of the spacer ring 5 is clearance-fitted with the inner wall of the mounting cavity of the bearing housing 8, and its axial length matches the free length of the spring 4. The inner end faces of the bearing cap 7 and the bearing cover 6 respectively abut against the outer rings of the first thrust bearing 2 and the second thrust bearing 3.

[0024] It should be noted that the outer end face of the bearing cover 6 described in this embodiment is provided with an annular sealing groove, in which a nitrile rubber sealing ring is embedded to form a radial seal with the end face of the bearing seat 8 to prevent lubricating oil leakage.

[0025] The connection surface between the bearing housing 8 and the gearbox base 9 is provided with a flange structure, and the flange structure is aligned by a locating pin.

[0026] It should be noted that the flange contact surface described in this embodiment is coated with molybdenum disulfide grease to reduce frictional resistance during assembly.

[0027] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0028] Working Principle: A first thrust bearing 2 and a second thrust bearing 3, symmetrically mounted on the propeller shaft 1, are fixed face-to-face within the stepped mounting cavity of the bearing housing 8. The inner rings of the two bearings are connected to the propeller shaft 1 via an interference fit, while the outer rings are pressed against the stepped surface of the bearing housing 8 by the preload of springs 4. A spacer ring 5 limits the installation gap between the two bearings and matches the compression length of springs 4. Bearing caps 7 and 6 are bolted to both ends of the bearing housing 8, with their inner end faces abutting against the outer rings and their outer end faces forming a radial seal through sealing rings 10. When the propeller rotates, the bidirectional axial thrust is borne separately by the two bearings, while the radial force is shared by both bearings. Springs 4 and spacer rings 5 ​​work together to maintain the bearings in a preloaded state, preventing loosening. This design replaces the traditional multi-bearing combination with a dual-bearing integrated structure, simplifying the installation process and enabling modular production. Simultaneously, the compact layout and preload mechanism solve the problems of loose structure, long production cycle, and easy loosening and wear in existing technologies.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bidirectional thrust unit for a ship propeller, characterized in that, include: The propeller shaft (1) extends axially; The first thrust bearing (2) and the second thrust bearing (3) are symmetrically mounted on the propeller shaft (1) in a face-to-face manner; A spring (4) is disposed between the first thrust bearing (2) and the second thrust bearing (3); A spacer ring (5) is fitted onto the propeller shaft (1) and located between the first thrust bearing (2) and the second thrust bearing (3); The bearing housing (8) is fixedly connected to the gearbox base (9), and the bearing housing (8) has an installation cavity inside to accommodate the first thrust bearing (2) and the second thrust bearing (3); The bearing cap (7) is fixed to one side of the bearing housing (8) by bolts and contacts the outer ring of the first thrust bearing (2); The bearing cover (6) is fixed to the other side of the bearing seat (8) by bolts, and together with the bearing cover (7), seals both ends of the bearing seat (8).

2. The bidirectional thrust unit for a ship propeller according to claim 1, characterized in that, The first thrust bearing (2) and the second thrust bearing (3) are both spherical roller thrust bearings, and their outer rings are in contact with the two ends of the spring (4).

3. The bidirectional thrust unit for a ship propeller according to claim 1, characterized in that, The outer diameter of the spacer ring (5) is clearance-fitted with the inner wall of the mounting cavity of the bearing seat (8), and its axial length matches the free length of the spring (4).

4. The bidirectional thrust unit for a ship propeller according to claim 1, characterized in that, The inner end faces of the bearing cap (7) and bearing cover (6) respectively abut against the outer rings of the first thrust bearing (2) and the second thrust bearing (3).

5. The bidirectional thrust unit for a ship propeller according to claim 1, characterized in that, The connection surface between the bearing housing (8) and the gearbox base (9) is provided with a flange structure, and the flange structure is aligned by a locating pin.

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