Thrust bearing bush with three-layer structure and thrust bearing

Abstract

The thrust bearing bush comprises a steel base layer located at the bottom, a babbitt metal layer is arranged above the steel base layer, and an antifriction wear-resistant lubricating layer is arranged above the babbitt metal layer. The friction coefficient between the runner plate and the bearing bush is reduced, the wear resistance of the bush surface is improved, the friction-reducing and wear-resisting layer can ensure a smaller dry friction coefficient in the starting stage, the starting torque can be reduced, and a machine can be easily started even if a high top is cancelled; and at a low rotating speed, even if an oil film is not formed, the tile surface can be better protected by virtue of the wear-resistant characteristic of the antifriction wear-resistant layer.

Description

TECHNICAL FIELD

[0001] The utility model relates to a three -layer structure thrust bearing bush and thrust bearing belong to water -turbine generator unit with thrust bearing technical field. BACKGROUND

[0002] At present, the babbitt alloy thrust bearing for water turbine generator unit is a double -layer structure bush of steel base plus babbitt alloy. The steel base is mostly low -carbon steel, and in order to protect the mirror plate surface on the shaft from being abraded by the steel base of the bush, a certain thickness of babbitt alloy is inlaid on the surface of the bush, which benefits from the good wear resistance, corrosion resistance and embedding property of babbitt alloy. In actual work, the bush is lubricated by lubricating oil, and there is an oil film between the mirror plate and the bush to avoid direct contact between the two to produce friction. But this way has the following shortcomings:

[0003] Shortcoming one: during the start -stop stage of the unit, because the speed is low, the mirror plate and the bush cannot form an oil film, and the babbitt alloy surface of the mirror plate and the bush will be half dry friction or even dry friction, and due to the high friction coefficient under dry friction, it will cause large starting torque and cannot start the machine or burn out the bush due to a large amount of heat generated by dry friction, and the existing solution is to open a high -pressure oil chamber on the surface of the bush, and during the start -stop stage, the mirror plate and the bush are separated by the way of high -pressure oil to avoid dry friction;

[0004] Shortcoming two: after the machine is stopped, the mirror plate and the bush are in close contact, and the mirror plate on the shaft will drive the bush to displace under the action of friction when it is hot contracted, which threatens the safety of the next start;

[0005] Shortcoming three: under extreme working conditions, the bush surface and the mirror plate will occasionally scratch and rub, causing damage to the bush surface. INVENTION CONTENTS

[0006] The utility model aims at: in view of the above -mentioned problem, provide a kind of three -layer structure thrust bearing bush and thrust bearing, mirror plate and the babbitt alloy surface of bush can be avoided to directly rub under some working conditions.

[0007] The technical scheme adopted by the utility model is as follows:

[0008] A three -layer structure thrust bearing bush for water -turbine generator unit, comprising a steel base layer at the bottom, a babbitt alloy layer above the steel base layer, and a friction -reducing and wear -resistant lubricating layer above the babbitt alloy layer.

[0009] Optionally, the steel base layer, babbitt alloy layer and friction -reducing and wear -resistant lubricating layer are integrated into a composite layer structure.

[0010] Optionally, the steel base layer is made of low -carbon steel.

[0011] Optionally, the babbitt alloy layer is made of tin -based babbitt alloy.

[0012] Alternatively, the friction-reducing wear-resistant lubricating layer uses phenolic resin as the adhesive.

[0013] Alternatively, the friction-reducing wear-resistant lubricating layer uses MoS2 as the main solid lubricating phase.

[0014] Alternatively, the friction-reducing wear-resistant lubricating layer has a thickness of 25-65 μm.

[0015] A thrust bearing comprising the three-layer structure thrust bearing bush described above.

[0016] In summary, due to the adoption of the technical solutions described above, the present application has the following beneficial effects:

[0017] 1. The three-layer structure thrust bearing bush and the thrust bearing provided by the present application reduce the friction coefficient between the mirror plate and the bearing bush, increase the wear resistance of the bearing surface, and ensure a smaller dry friction coefficient of the friction-reducing wear-resistant layer during the starting stage, thereby reducing the starting torque and enabling easy starting even if the high-pressure oil chamber is removed; at low rotational speed, the friction-reducing wear-resistant layer can better protect the bearing surface even if no oil film is formed.

[0018] 2. The three-layer structure thrust bearing bush and the thrust bearing provided by the present application reduce the friction coefficient between the mirror plate and the bearing bush after the adoption of the friction-reducing wear-resistant coating, and the friction force generated by the thermal shrinkage of the mirror plate on the shaft is small, which prevents the displacement of the bearing bush; in extreme working conditions, the friction-reducing wear-resistant layer can better protect the bearing surface from damage caused by occasional scratching and rubbing of the bearing surface and the mirror plate; and since the bearing surface and the mirror plate do not need to be forcibly separated, the bearing surface does not need to be provided with a high-pressure oil chamber. BRIEF DESCRIPTION OF DRAWINGS

[0019] Fig. 1 is a sectional view of the three-layer structure thrust bearing bush and the thrust bearing.

[0020] Fig. 2 is a whole view of the three-layer structure thrust bearing bush and the thrust bearing.

[0021] Markings in the figure: 1-friction-reducing wear-resistant lubricating layer, 2-Babbitt alloy layer, 3-steel base layer. DETAILED DESCRIPTION

[0022] The present application will be described in detail below with reference to the accompanying drawings.

[0023] In order to make the purpose, technical solutions and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0024] A three-layer structure thrust bearing bush, as shown in the figure, for a hydroelectric generating unit, comprising a steel base layer 3 at the bottom, a babbitt layer 2 above the steel base layer 3, and a friction-reducing wear-resistant lubricating layer 1 above the babbitt layer 2. Figs. 1-2

[0025] The steel base layer 3 serves as the base of the thrust bearing bush, providing sufficient strength and rigidity to support the entire bush structure and prevent deformation under heavy thrust.The babbitt layer 2, with its unique microstructure, helps form an oil film during operation, reducing friction and wear. The friction-reducing wear-resistant lubricating layer 1, as a solid lubricant, has a low friction coefficient and can provide lubrication without oil, reducing direct contact between the mirror plate and the babbitt layer 2 during startup, shutdown, or abnormal conditions, preventing damage. The babbitt layer 2 is less likely to be damaged due to the protection of the friction-reducing wear-resistant lubricating layer 1, extending the service life of the bush. The low-friction coefficient lubricating layer helps improve the operating efficiency of the unit. Based on the friction-reducing wear-resistant lubricating layer 1 as a lubricant, the present scheme does not need to separate the mirror plate from the bush through lubricating oil, so it does not have a high-pressure oil chamber, making the structure more complete.

[0026] As another specific embodiment, the steel base layer 3, babbitt layer 2, and friction-reducing wear-resistant lubricating layer 1 are an integrated composite layer structure. The three layers of the entire bush have no obvious interface, forming a continuous and uniform composite layer structure. The combination strength between layers is high, the overall performance is uniform, and delamination or shedding is unlikely. This can better utilize the characteristics of each layer of material and optimize the combination of mechanical properties, wear resistance, and lubrication performance.

[0027] As another specific embodiment, the steel base layer 3 is made of low-carbon steel. Low-carbon steel has low carbon content, so it has good toughness and plasticity, which makes the bush less likely to break under impact or vibration.

[0028] As another specific embodiment, the babbitt layer 2 is made of tin-based babbitt. Tin-based babbitt has a very low friction coefficient, effectively reducing friction between the thrust bearing and the mirror plate, and reducing wear.

[0029] As another specific embodiment, the friction-reducing wear-resistant lubricating layer 1 uses phenolic resin as an adhesive. Phenolic resin as an adhesive can firmly bond the friction-reducing wear-resistant material to the babbitt layer 2, forming a uniform and stable lubricating layer. The combination of friction-reducing wear-resistant material and phenolic resin can provide good friction-reducing effect and reduce energy loss.

[0030] As another specific embodiment, the friction-reducing wear-resistant lubricating layer 1 uses MoS2 as the main solid lubricating phase. MoS2 is a solid lubricating material with a layered structure, and the van der Waals force between the layers is weak, making it easy to slide between layers, thus having an extremely low friction coefficient. It can significantly reduce the friction between the thrust pad and the mirror plate, reducing energy loss. Among them, MoS2 particles are uniformly dispersed in the adhesive to play their lubricating role.

[0031] As another specific embodiment, the friction-reducing wear-resistant lubricating layer 1 has a thickness of 25-65 μm. When designing the pad, it can be considered that the thickness of the lubricating layer will not significantly affect the overall geometric size and design of the pad. The installation and fitting size of the pad can remain unchanged, and no large-scale modification of the existing hydroelectric generating set is required.

[0032] A thrust bearing comprising a three-layer structure thrust pad as described above.

[0033] In summary, due to the adoption of the technical scheme described above, the embodiment has the following beneficial effects:

[0034] 1. The three-layer structure thrust pad and thrust bearing provided by the embodiment reduces the friction coefficient between the mirror plate and the pad, increases the wear resistance of the pad surface, and ensures a smaller dry friction coefficient during the starting stage, thereby reducing the starting torque and enabling easy starting even if the high top is removed. At low speed, even if no oil film is formed, the wear-resistant layer itself can better protect the pad surface.

[0035] 2. The three-layer structure thrust pad and thrust bearing provided by the embodiment reduces the friction coefficient between the mirror plate and the pad after adopting the friction-reducing wear-resistant coating, so that the friction force generated by the thermal contraction of the shaft mirror plate will not cause the displacement of the pad; in extreme working conditions, the friction-reducing wear-resistant layer can better protect the pad surface and prevent damage to the pad surface.

[0036] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. The present application extends to any new features or any new combinations disclosed in the specification, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the details of the technical features not disclosed in the present embodiment, such as specific structures, connection methods, etc., can be obtained from the prior art by those skilled in the art, and the present disclosure does not specifically limit this.

Claims

1. A three-layer thrust bearing, characterized in that: For use in hydro-generator sets, including a steel base layer (3) at the bottom, a Babbitt alloy layer (2) above the steel base layer (3), and a friction-reducing and wear-resistant lubricating layer (1) above the Babbitt alloy layer (2); the friction-reducing and wear-resistant lubricating layer (1) uses phenolic resin as a binder and MoS2 as the main solid lubricating phase.

2. The three-layer thrust bearing as described in claim 1, characterized in that: The steel base layer (3), the Babbitt alloy layer (2), and the friction-reducing and wear-resistant lubricating layer (1) are an integrated composite layer structure.

3. The three-layer thrust bearing as described in claim 1, characterized in that: The steel base layer (3) is made of low-carbon steel.

4. The three-layer thrust bearing as described in claim 1, characterized in that: The Babbitt alloy layer (2) is made of tin-based Babbitt alloy.

5. The three-layer thrust bearing as described in claim 1, characterized in that: The thickness of the friction-reducing and wear-resistant lubricating layer (1) is 25-65 μm.

6. A thrust bearing, characterized in that: Including the three-layer thrust bearing as described in any one of claims 1-5.

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