Oil duct balance type bearing

Abstract

The invention discloses an oil duct balance type bearing. The oil duct balance type bearing comprises a bearing base, a tilting fillet, a positive thrust disc, a first oil cavity, a second oil cavity, a cooler and a cover with oil, wherein the tilting fillet is fixedly arranged on the bearing base; a supporting pad is arranged at the inner radial side of the tilting fillet; a positive thrust pad is arranged at the front side of the tilting fillet; the second oil cavity communicates with the first oil cavity through a hot oil inlet; the cooler is mounted in the second oil cavity; the cover with oil and the positive thrust disc form a cavity with oil; an oil injecting slot is formed in the inner radial side of the supporting pad; an oil throwing cavity is arranged at the inner radial side of the positive thrust pad; the cavity with oil comprises a high-pressure oil outlet and an oil pumping hole; the oil pumping hole communicates with the second oil cavity; the high-pressure oil outlet separately communicates with the oil injecting slot and the oil throwing cavity through a first oil duct and a second oil duct; and a first flow regulating valve and a second flow regulating valve are separately arranged in the first oil duct and the second oil duct. The oil duct balance type bearing has relatively high heat exchange efficiency, and can prevent a bearing bush from being burnt.

Description

technical field [0001] The invention relates to the field of bearing devices, in particular to generator or motor bearings. Background technique [0002] Bearings are an important part of contemporary mechanical equipment. Its main function is to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its rotation accuracy. According to the different friction properties of moving elements, bearings can be divided into two categories: rolling bearings and sliding bearings. [0003] Rolling bearings are generally composed of four parts: inner ring, outer ring, rolling body and cage. The function of the inner ring is to cooperate with the shaft and rotate together with the shaft; the function of the outer ring is to cooperate with the bearing seat to play a supporting role; The cage evenly distributes the rolling elements between the inner ring and the outer ring, and its shape, size and quantity directly affect the performance an...

AI Technical Summary

Problems solved by technology

[0013] Since the existing cooling oil mainly adopts No. 46 turbine oil or No. 32 turbine oil, the kinematic viscosity of No. 46 turbine oil at 40°C is 45.8, and its optimal operating temperature range is 44-46°C; The kinematic viscosity at 40°C is 32, and the optimal operating temperature range is 38-40°C; the existing cooling oil needs to be controlled below 65°C during operation. When the temperature of the cooling oil is too high, the viscosity becomes smaller and will Lead to poor lubrication, larger friction coefficient, increased frictional heat generation, rapid rise in oil temperature, and high oil temperature, aggravating the wear of the sliding friction surface; existing bearings adopt this cooling structure, in order to prevent excessive oil temperature from causing wear Watt, it is necessary to monitor the oil temperature in the bearing. When the temperature is too high, it is necessary to increase the water flow of the cooling body. When the temperature is too high, an alarm is given and the operation is stopped.

[0014] Due to the low heat exchange efficiency of the existing hydraulic generator bearings, the generator is prone to alarm shutdown, which not only affects the output efficiency and economic benefits of the power station, but also affects other equipment in the power station during the shutdown and start-up process of the power station. Great impact on service life

[0015] The reason for the above problems is that the density and viscosity of the cooling oil are greatly affected by the change of oil temperature. The higher the temperature of the cooling oil, the smaller the density and viscosity. After the cooling oil is cooled by the cooling copper tube a71, The cooling oil with a larger cooling capacity sinks, and the flow rate becomes smaller, and the cooling oil with a smaller cooling capacity floats up, causing the cooling oil with a larger cooling capacity in the lower area of ​​the second oil chamber a6 to stay, while the cooling oil in the upper area The flow rate of the smaller cooling oil becomes faster and flows out from the oil outlet a62, resulting in the high temperature of the cooling oil flowing out of the oil outlet a62

[0016] In addition, the bearings in the prior art also have the following problems: 1. The oil injection groove inside the support pad is designed at the top, and the inside of the support pad needs to be scraped to form small oil storage pits to improve lubrication. Because the cooling oil in the support tile is brought from the oil injection groove to the small oil storage pit on the sliding friction surface through the rotation of the main shaft, the amount of cooling oil brought in is small, and the cooling oil exchange rate is low, resulting in heat exchange in the bottom area of ​​the support tile. The speed is small, and because the standard of scraping tiles is generally two to three contact points per square centimeter, the tile scraping process is time-consuming and labor-intensive; 2. Since the existing oil drainage holes are generally designed at one end of the supporting tile, The oil circuit at the other end of the support pad is blocked, and there is a large temperature difference between the two ends of the support pad, which easily causes the deformation of the support pad and causes the phenomenon of pad wear; 3. The cooling between the thrust pad and the thrust disc of the existing thrust bearing The oil is directly pressed in from the outer diameter side of the thrust pad through the oil pump. This method has a simple structure, but due to the obstruction of centrifugal force, it is difficult for the cooling oil to be pressed into the inner diameter side of the thrust pad, which may easily lead to high temperature on the inner diameter side of the thrust pad. ;4. After manual scraping, there is a big difference in the quality of scraping tiles. For tiles with poor quality scraping tiles, there are large distribution differences in the area of ​​contacts and the depth of oil storage points, resulting in sliding friction of the supporting tiles. There are problems of uneven oil film thickness and uneven oil film flow rate on the surface. There are high-temperature points on the sliding friction surface, which are prone to produce impurities and cause unstable friction coefficients; 5. The large parts of the bearing adopt casting technology, and the national standard casting process allows 2% defects. The service life of its components is short, which greatly affects the stability of the whole machine after installation; 6. The bearing pad mounting frame is fixed by two screws on the left and right, and radial vibration will occur when the hydroelectric generator fails, resulting in loose bearing pads , the main shaft is prone to polarization, resulting in deformation of the main shaft; 7. The bearing pad seat is an annular solid body with a large thickness, is not easy to dissipate heat, and is bulky. It is usually necessary to use a crane to lift the upper half during installation, and then rotate to take out the other half. Due to the weight It is very inconvenient to take out; 8. In the existing combined bearings, there are support pads for radial force and thrust pads for axial force. It is good for realizing heat exchange, but because the oil resistance of the oil circuit is greatly affected by temperature, the oil resistance is easy to change, which may cause unstable oil supply in the oil circuit, affect the stability of heat exchange efficiency, and cause the temperature of the tile body to rise

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