A water-lubricated thrust bearing with tilting pads based on a small amount of second lubricating medium

Abstract

This invention belongs to the field of thrust bearing technology and relates to a water-lubricated thrust bearing with tilting pads based on a trace amount of secondary lubricating medium. The main structure includes a thrust disc, tilting pads, an oil reservoir, and a support ring. The support ring is annular and supports the tilting pads and the oil reservoir. The tilting pads are circumferentially and evenly spaced on the support ring via fixed fulcrums. The oil reservoir is located between the tilting pads and the support ring. The tilting pads have inner holes corresponding to the positions of the oil reservoirs to accommodate the oil outlet pipe at the top of the oil reservoir. The thrust disc is fixedly connected to the rotating shaft. The support ring is located directly below the thrust disc. When operating conditions change, the tilting pads compress the oil reservoir, and the secondary lubricating medium inside the oil reservoir flows through the oil outlet pipe to the gap between the thrust disc and the tilting pads. This invention achieves the supply of the secondary lubricating medium by setting up the oil reservoir, reducing bearing friction and wear, and extending service life. Its overall structure is simple, easy to implement, and low in cost, suitable for large-scale promotion, and has broad market prospects.

Description

Technical fields:

[0001] This invention belongs to the field of thrust bearing technology and relates to a water-lubricated thrust bearing based on a micro-volume second lubricating medium, specifically a water-lubricated thrust bearing formed by the coordinated work of the tilting pad and the oil reservoir, which can provide micro-volume lubricating oil replenishment and reduce friction and wear. Background technology:

[0002] Currently used water-lubricated thrust bearings are mainly of two types: fixed pad bearings and tilting pad bearings. Fixed pad water-lubricated thrust bearings have a simple structure, but it is difficult to maintain a uniform water film, especially under high load and high speed conditions. Tilting pad bearings typically consist of multiple arc-shaped pads that can tilt freely at the fulcrum. The pads can automatically adjust according to the load and other operating conditions to maintain the uniformity of the water film, and the pressure of each water film always points towards the center, exhibiting high stability. This is suitable for units with infrequent changes in operating conditions. However, water has low viscosity and poor film-forming ability. In situations with large load or speed fluctuations or where frequent adjustments to operating conditions are required, such as in ship propulsion systems, the water film formed between the pads and the thrust disc is prone to rupture, causing bearing wear and failure. These conditions can also cause bearing vibration noise, affecting the stealth capability of ships. Therefore, it is essential to research effective measures to reduce friction and wear in water-lubricated thrust bearings. Summary of the Invention:

[0003] The purpose of this invention is to overcome the problem that traditional tilting pad water-lubricated thrust bearings are prone to water film rupture and bearing friction and wear under harsh working conditions, and to provide a water-lubricated thrust bearing in which the tilting pad and oil reservoir work together to replenish a small amount of lubricating oil.

[0004] To achieve the above objectives, the present invention provides a water-lubricated thrust bearing based on a micro-volume second lubricating medium, comprising a thrust disc, tilting pads, an oil reservoir, and a support ring. The support ring has an annular structure, and the tilting pads are uniformly spaced circumferentially on the support ring via fixed fulcrums. The oil reservoir is located between the tilting pads and the support ring. One oil reservoir is arranged on each side of the fixed fulcrum under each tilting pad, and the oil reservoir is fixed to the support ring. The tilting pads have inner holes corresponding to the positions of the oil reservoirs for accommodating the oil outlet pipes at the top of the oil reservoirs. When the oil reservoir is squeezed by the tilting pads, the second lubricating medium inside the oil reservoir flows through the oil outlet pipes to the gap between the thrust disc and the tilting pads. The thrust disc is fixedly connected to a rotating shaft, which drives the thrust disc to rotate. The support ring is located directly below the thrust disc.

[0005] The oil reservoir also includes an oil inlet pipe located on the side of the oil reservoir. The oil inlet pipe is connected to an external second lubricating medium supply device. When the oil level in the oil reservoir decreases, the external second lubricating medium supply device supplies oil to the oil reservoir through the oil inlet.

[0006] The second lubricating medium is an environmentally friendly lubricating oil.

[0007] The oil outlet pipe is equipped with two small baffles in an inverted V shape, which can automatically open according to the pressure on the oil reservoir to determine the oil output and achieve autonomous flow control. Moreover, the baffles can only be opened in one direction, so that the lubricating oil can flow out in one direction and external water cannot flow into the oil reservoir.

[0008] The oil reservoir, its oil outlet pipe, and its oil inlet pipe are all made of thermoplastic polyurethane elastomer.

[0009] The size of the oil reservoir is designed based on the size and tilt angle of the tilting pad, and the height of the oil reservoir is such that it does not contact the bottom of the tilting pad under normal working conditions.

[0010] The tilting pad water-lubricated thrust bearing based on a trace amount of second lubricating medium described in this invention can achieve optimal load-bearing capacity within a certain operating range, thereby improving the bearing's performance under varying operating conditions and reducing friction and wear under these conditions.

[0011] The working principle of the tilting pad water-lubricated thrust bearing based on a micro-volume second lubricating medium described in this invention is as follows: Two micro-oil reservoirs are arranged on both sides of the support point under each tilting pad. Both the tilting pad and the oil reservoirs are circumferentially mounted on the support ring. In a water environment, under normal operating conditions, the bearing operates stably, and the tilting pad does not contact the oil reservoirs. After the operating conditions change, the tilting pad angle changes, squeezing the oil reservoirs. The two oil reservoirs release the second lubricating medium through the oil outlet pipe. The second lubricating medium directly enters the contact area, increasing the viscosity of the water lubricant and participating in the bearing lubrication. This helps the tilting pad adjust its tilt angle, allowing a liquid film force equal to the external load to be quickly formed between the tilting pad and the thrust disc, reducing the friction and wear of the tilting pad and extending the service life of the tilting pad thrust bearing. Once the operating conditions of the water-lubricated bearing stabilize, the tilting pad no longer squeezes the oil reservoirs, and the oil outlet pipe stops releasing the second lubricating medium. The second lubricating medium supply device replenishes the second lubricating medium in the oil reservoirs through the oil inlet according to the amount released each time.

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

[0013] 1. When the operating conditions of a water-lubricated bearing change, the tilting pad angle changes, compressing the oil reservoir and releasing a small amount of lubricating oil. This improves the lubrication effect of the bearing under abnormal operating conditions, reduces bearing friction and wear, and extends its service life. It is particularly suitable for applications such as ships that are frequently subjected to changing operating conditions.

[0014] 2. An inverted V-shaped baffle is installed inside the oil outlet pipe of the oil reservoir. It can automatically open according to the pressure on the oil reservoir to determine the oil output and achieve autonomous flow control. Moreover, the baffle can only be opened in one direction to achieve one-way flow of lubricating oil, and external water cannot flow into the oil reservoir.

[0015] 3. Since auxiliary lubrication is only required in small amounts when water-lubricated bearings encounter severe operating conditions, this means short oil supply time and low oil consumption. Furthermore, the use of environmentally friendly lubricating oil reduces environmental pollution. TPU oil reservoirs are simple to manufacture and inexpensive, thus possessing significant market potential.

[0016] In summary, this invention achieves the supply of a second lubricating medium by setting up an oil reservoir, thereby reducing bearing friction and wear and extending service life. Its overall structure is simple, easy to implement, and low in cost, making it suitable for large-scale promotion and with broad market prospects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium, which is the subject of this invention.

[0018] Figure 2 This is a schematic diagram illustrating the positional relationship between the tilting pad and the oil reservoir in the present invention.

[0019] Figure 3 This is a schematic diagram of the tilting tile structure principle involved in the present invention.

[0020] Figure 4 This is a schematic diagram of the oil reservoir structure principle involved in the present invention.

[0021] Figure 5 This is a schematic diagram of the oil outlet structure principle involved in the present invention.

[0022] Figure 6 This is a schematic diagram illustrating the installation principle of the oil reservoir bladder involved in this invention. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0024] Example 1:

[0025] This embodiment relates to a tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium. Its main structure, from top to bottom, includes a pressure head 1, a thrust plate 2, a tilting pad 3, an oil reservoir 5, and a support ring 6. The pressure head 1 houses a rotating shaft, which is connected to the shaft via a keyway. Specifically, the shaft has a keyway, and the pressure head has a corresponding protrusion or groove. The keyway and the protrusion / groove fit together to connect the pressure head and the shaft. The thrust plate 2 is located below the pressure head 1 and is fixedly connected to the shaft. The thrust plate, pressure head, and shaft are coaxially fixed together. The support ring 6 is located directly below the thrust plate 2 and is circular in shape. The support ring and the thrust plate are on the same axis and are used for support. The tilting pad 3 and the oil reservoir 5 are provided. Multiple fixed fulcrums 8 are evenly spaced around the upper surface of the support ring 6. The tilting pad 3 is mounted on the top of each fixed fulcrum 8, allowing it to swing up and down around the fixed fulcrum 8. An oil reservoir 5 is installed on each side of the support ring 6 at each fixed fulcrum 8 to store a second lubricating medium. The oil reservoir 5 is fixed to the support ring 6 by positioning screws 4. The oil reservoir 5 is located below the tilting pad 3, and its height is such that it does not contact the bottom of the tilting pad 3 under normal operating conditions. The tilting pad 3 has inner holes 10 on its left and right sides corresponding to the positions of the oil reservoir 5, for housing the oil outlet pipe 7 at the top of the oil reservoir 5. The oil outlet pipe 7 of the oil reservoir 5 is located within the inner holes 10 on the tilting pad 3, and the top surface of the oil outlet pipe 7 is slightly lower than the upper surface of the tilting pad 3 to accommodate the up-and-down swing of the tilting pad.

[0026] The oil reservoir 5 also includes an oil inlet pipe 9, which is located on the side of the oil reservoir 5. The oil inlet pipe 9 is connected to an external second lubricating medium supply device. When the oil level in the oil reservoir decreases, the external second lubricating medium supply device supplies oil to the oil reservoir through the oil inlet.

[0027] The oil outlet pipe 7 is equipped with two small baffles 12 in an inverted V shape, which can automatically open according to the pressure on the oil reservoir 5 to determine the oil output and achieve autonomous flow control. Moreover, the baffle 12 can only be opened in one direction to achieve unidirectional flow of lubricating oil, and external water cannot flow into the oil reservoir 5.

[0028] The support ring 6 is fixed to the base or the machine's support structure and is typically made of a robust metal material to provide sufficient support and rigidity to support the bearing and transmit axial thrust loads. The structural design and location of the support ring can vary depending on the specific machine or equipment requirements and the actual needs of the bearing manufacturer.

[0029] The height of the oil outlet pipe 7 in the inner hole 10 of the tilting pad 3 can be adjusted according to the actual situation, so as not to affect the water flow field between the thrust plate and the tilting pad and to deliver the second medium lubricating oil to the gap between the tilting pad 3 and the thrust plate 2.

[0030] The oil reservoir is made of thermoplastic polyurethane elastomer (TPU), which has high strength, high toughness, wear resistance and seawater corrosion resistance. It can be deformed under pressure and can return to its original shape after the pressure is removed. It is a mature and environmentally friendly material. The size of the oil reservoir is designed according to the size of the tilting tile and the tilt angle.

[0031] The oil outlet and inlet pipes of the oil reservoir are also made of TPU material.

[0032] The oil reservoir 5 also includes an oil reservoir positioning hole 11, and a corresponding positioning threaded hole 13 is provided on the support ring 6. The positioning screw 4 is passed through the oil reservoir positioning hole 11 and screwed into the positioning threaded hole 13 to fix the oil reservoir 5 on the support ring 6.

[0033] The height of the oil reservoir is determined based on the height between the tilting pad and the support ring. Both the tilting pad and the oil reservoir are circumferentially mounted on the support ring. Each tilting pad can make slight oscillations around a fixed fulcrum to adapt to a suitable working position, allowing each pad to form a converging oil wedge. The oil wedge formed between the pad and the thrust disc can automatically adjust the established liquid film pressure distribution when operating parameters (load, speed, lubricant viscosity, etc.) change, until a liquid film force equal to the external load is formed, allowing the bearing to return to a stable working state.

[0034] The working principle of the tilting pad water-lubricated thrust bearing based on a trace amount of secondary lubricating medium described in this embodiment is as follows:

[0035] The bearing operates in an aquatic environment. Under normal operating conditions, the shaft drives the thrust disc 2 to rotate, and water is drawn into the gap between the thrust disc 2 and the tilting pad 3. Through hydrodynamic pressure, a bearing wedge is formed on the upper surface of the tilting pad and the lower surface of the thrust disc, causing the two surfaces to completely separate. A water film pressure is established between the thrust disc and the tilting pad, forming a water film force opposite to the load direction. The pressure acting on the tilting pad 3 forces it to tilt freely along the fixed fulcrum 8. The fluid film thickness ratio h1 / h2 at the inlet and outlet of the bearing wedge is the gap ratio and is a major parameter affecting the load-bearing capacity of the tilting pad. When operating parameters are constant, the liquid film thicknesses h1 and h2 remain unchanged, meaning the clearance ratio remains constant, and the tilting pad is in the optimal position to withstand pressure. The water film pressure distribution changes accordingly, resulting in a change in water film force. Under normal operating conditions, the water film force is equal to the external load, and the bearing operates stably; at this time, the tilting pad will not contact the oil reservoir. When external operating conditions (speed or load) change, the water film pressure changes, the liquid film thicknesses h1 and h2 change, and the angle of the tilting pad 3 changes, squeezing the lower oil reservoir 5. The lubricating oil released from the oil reservoir 5 through the oil outlet pipe 7 directly enters the gap between the tilting pad 3 and the thrust plate 2, forming an oil-water mixed lubrication. This increases the viscosity of the water lubricant, helping the tilting pad 3 adjust its tilt angle, allowing a liquid film force equal to the external load to quickly form between the tilting pad 3 and the thrust plate 2, until a water film force equal to the load after the change in operating conditions is formed, and the bearing returns to a stable operating state. In summary, the release amount of this structure's trace second lubricating medium can adaptively change with operating conditions, exhibiting optimal load-bearing capacity within a given operating range. In addition, the oil film formed by the mixed lubricant not only reduces the direct contact and wear between the tilting pad and the thrust plate, but also carries away the heat generated by friction, thus playing a role in lubrication and cooling.

Claims

1. A water-lubricated tilting pad thrust bearing based on a small amount of a second lubricating medium, characterized in that The main structure includes a tilting pad, an oil reservoir, and a support ring. The support ring is an annular structure used to support the tilting pad and the oil reservoir. The tilting pads are installed on the support ring at uniform intervals around the circumference through fixed fulcrums. The oil reservoir is located between the tilting pads and the support ring. The tilting pads have inner holes corresponding to the positions of the oil reservoirs to accommodate the oil outlet pipe at the top of the oil reservoir. When the oil reservoir is squeezed by the tilting pads, the second lubricating medium inside the oil reservoir flows through the oil outlet pipe to the gap between the thrust plate and the tilting pads. The oil outlet pipe is equipped with two small baffles in an inverted V shape, which can automatically open according to the pressure on the oil reservoir to determine the oil output and achieve autonomous flow control. Moreover, the baffles can only be opened in one direction, so that the lubricating oil can flow out in one direction and external water cannot flow into the oil reservoir.

2. The tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium according to claim 1, characterized in that, Each tilting pad has two oil reservoirs located on either side of the fixed support point.

3. The tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium according to claim 1, characterized in that, The oil reservoir also includes an oil inlet pipe located on the side of the oil reservoir. The oil inlet pipe is connected to an external second lubricating medium supply device. When the oil level in the oil reservoir decreases, the external second lubricating medium supply device supplies oil to the oil reservoir through the oil inlet pipe.

4. The tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium according to claim 1, characterized in that, The thrust disk is fixedly connected to the rotating shaft, which drives the thrust disk to rotate; the support ring is located directly below the thrust disk.

5. The tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium according to claim 1, characterized in that, The oil reservoir is positioned so that it does not contact the bottom of the tilting pad under normal operating conditions.

6. The tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium according to claim 1, characterized in that, The oil reservoir, its oil outlet pipe, and its oil inlet pipe are all made of thermoplastic polyurethane elastomer.

7. The tilting pad water-lubricated thrust bearing based on a trace amount of a second lubricating medium according to claim 1, characterized in that, The second lubricating medium is lubricating oil.

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