Bidirectional thrust bearing

Abstract

The invention discloses a bidirectional thrust bearing which comprises a bearing seat, a bearing cover, a bushing seat, a first thrust disc, a second thrust disc, a first oil cavity, a second oil cavity, a cooler and an oil-carrying cover, wherein the bushing seat is fixed on the bearing seat; a supporting bushing is arranged on the inner diameter side of the bushing seat; a first thrust bushing is arranged on the front side of the bushing seat; a second thrust bushing is arranged on the rear side of the bushing seat; the oil inlet end of the second oil cavity communicates with the first oil cavity; the cooler is installed in the second oil cavity; the oil-carrying cover and the outer diameter side of the first thrust disc form an oil-carrying cavity; an oil injection groove is formed in the inner diameter side of the supporting bushing; a first oil-throwing cavity is formed in the inner diameter side of the first thrust bushing; a second oil-throwing cavity is formed in the inner diameter side of the second thrust bushing; the oil-carrying cavity comprises a high-pressure oil outlet and an oil pumping opening; the oil pumping opening communicates with the oil outlet end of the second oil cavity; and the high-pressure oil outlet is divided into three oil passages which communicate with the oil injection groove, the first oil-throwing cavity and the second oil-throwing cavity correspondingly. The bidirectional thrust bearing has high heat exchange efficiency, and can greatly lower oil temperature.

Description

technical field [0001] The invention relates to the field of bearing devices, in particular to a two-way thrust bearing of a generator or an electric motor. Background technique [0002] Bearings are an important component in contemporary machinery and 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 qu...

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 scraping standard generally has two to three contact points per square centimeter, the scraping process is time-consuming and labor-intensive; 2. The existing oil drainage holes are generally designed at one end of the supporting tile, resulting in The oil path 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 may easily cause the deformation of the support pad and cause the phenomenon of pad wear; 3. The cooling oil between the thrust pad and the thrust plate of the existing thrust bearing Press directly through the oil pump from the outer diameter side of the thrust pad. This method has a simple structure, but due to the hindrance 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. The surface of tiles with poor quality scraping tiles has a large distribution difference in the area of ​​contacts and the depth of oil storage points, which leads to the sliding friction surface of the supporting tiles. There are problems of uneven oil film thickness and uneven oil film flow rate. 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. The service life of the 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 hydro-generator fails, resulting in loosening of the bearing pad. The main shaft is prone to polarization, which leads to the deformation of the main shaft; 7. The bearing pad seat is an annular solid body with a large thickness, which is not easy to dissipate heat and is bulky. During installation, it is usually necessary to use a crane to lift the upper half, and then rotate to take out the other half. 8. The existing combined bearings include support pads for radial force and thrust pads for axial force. Both support pads and thrust pads must have oil passages through them for Realize 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 easily 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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