Bearing oil mist prevention device

Abstract

The utility model discloses a bearing oil mist prevention device which comprises an oil retainer used for being arranged outside a bearing in a sleeving mode, an oil discharging groove used for guiding oil liquid to flow back and an annular installation groove used for being connected with a sealing ring plate in a clamping mode are formed in the inner side, close to the bearing, of the oil retainer, and the installation groove is located above the oil discharging groove. According to the utility model, the sealing structure is additionally arranged above the oil discharge groove, so that the sealing problem between the main shaft bearing and the oil deflector ring is solved, and the phenomenon that oil mist overflows is effectively prevented.

Description

Technical Field

[0001] The utility model relates to an axial sealing device, in particular to an oil mist prevention device for bearings. Background Art

[0002] The bearing devices of mixed-flow pumps and turbines often adopt a split-type rotating oil sump structure, and a wool seal ring is used for sealing above the oil sump. The disadvantages of this structure are as follows: both mixed-flow pumps and turbines are applied to high-lift or high-head and high-speed operating conditions. Due to the excessive speed of the unit, under the action of the centrifugal force of the unit, oil splashing will occur at the rotating oil sump part. The wool seal ring used for sealing has a certain plasticity, and there is a certain swing of the main shaft during the operation of the unit. Under the long-term back-and-forth swing, the gap between the wool felt and the contact surface will gradually become larger, and air enters the oil sump through the gap and rotates at high speed together with the turbine oil. As the oil temperature rises, oil bubbles and oil mist are generated, resulting in the turbine oil in the rotating oil sump exceeding the designed oil level. Eventually, oil splashing, oil overflowing, and oil mist overflowing often occur above the rotating oil sump, and it is necessary to frequently stop the machine to replace the wool seal ring, clean the oil stain, and re-add turbine oil, which has a great impact on the operation of the unit at the power station site. The utility model patent application with the publication number CN203516475 U discloses a rotating oil sump structure of a bearing, and the utility model patent application with the publication number CN214366513 U discloses a sealing device for the upper cover of the water guide oil sump of a turbine. In these two solutions, by arranging a circular ring / oil baffle between the rotating oil sump and the bearing bush / bearing, when the oil mist generated inside the rotating oil sump contacts the circular ring / oil baffle, it condenses and flows back to solve the problem of oil splashing in the rotating oil sump, but neither of these two solutions solves the sealing problem between the bearing bush and the circular ring / oil baffle. Summary of the Utility Model

[0003] Purpose of the utility model: The purpose of the utility model is to provide an oil mist prevention device for bearings that solves the sealing problem between the bearing and the rotating oil sump on both sides of the oil baffle.

[0004] Technical solution: An oil mist prevention device for bearings described in the utility model includes an oil baffle ring located between the bearing and the rotating oil sump, which is provided with an annular installation groove for clamping a sealing ring plate and an oil discharge groove for guiding the oil liquid to flow back, and the installation groove is located above the oil discharge groove.

[0005] In the utility model, by adding a sealing structure above the oil discharge groove, the sealing problem between the main shaft bearing and the oil baffle ring is solved, and the phenomenon of oil mist overflow is effectively prevented.

[0006] Preferably, the inner diameter of the oil baffle ring is larger than the outer diameter of the bearing, so as to form an oil film gap between the oil baffle ring and the bearing.

[0007] Preferably, a sealing ring plate is further included. The inner diameter of the sealing ring plate is smaller than that of the oil baffle ring, and the sealing ring plate is a phenolic laminated cloth board, which ensures mechanical strength, moisture resistance and heat resistance.

[0008] Preferably, the installation groove and the oil discharge groove are communicated through an oil film gap.

[0009] Preferably, in order to better return the rising oil, reduce the pressure in the oil discharge groove and effectively inhibit oil splashing: the bottom of the oil baffle ring extends into the rotating oil basin, and a rectangular thread is provided on the inner side of the bottom of the oil baffle ring, and the rectangular thread is communicated with the oil discharge groove through the oil film gap.

[0010] Preferably, a shoulder ring for connecting with the top of the rotating oil basin is provided on the outer periphery of the oil baffle ring. The shoulder ring is embedded in the upper surface of the rotating oil basin.

[0011] Preferably, an elastic sealing ring for connecting with the rotating oil basin is provided on the outer side of the oil baffle ring close to the rotating oil basin.

[0012] Preferably, the cross-section of the oil discharge groove is an inverted triangle, a drain hole inclined outward to the oil baffle ring is provided at the bottom of the oil discharge groove, and the number of the oil discharge grooves is not less than 2. The oil discharge grooves are communicated with each other.

[0013] Beneficial effects: Compared with the prior art, the utility model has the following advantages: 1. Ensure effective sealing between the main shaft bearing and the oil baffle ring: ensure that the oil circuit is smoother during the operation of the unit, improve the oil sealing effect, and ensure that no oil mist is ejected; 2. Increase the operation reliability of the mixed-flow pump and the water turbine under the conditions of high head, high water head and high speed; 3. Extend the service life of the bearing: effectively seal, avoid the dry film or bearing burning caused by the decrease of the oil level in the rotating oil basin; 4. Greatly extend the operation time: the actual cumulative use exceeds 8000 hours without any abnormal conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of the assembled state of the utility model;

[0015] Figure 2 is Figure 1 the enlarged view of part A in DETAILED DESCRIPTION OF THE INVENTION

[0016] The technical solution of the utility model will be further described below with reference to the drawings.

[0017] As Figures 1 to 2, which is the bearing anti-oil mist device of the present utility model. The main body of the anti-oil mist device is the oil baffle ring 2. The oil baffle ring 2 is sleeved outside the bearing 6 and is located between the bearing 6 and the rotating oil basin 1. The side of the oil baffle ring 2 close to the bearing 6 is the inner side, and the side close to the rotating oil basin is the outer side. The inner diameter of the oil baffle ring 2 is larger than the outer diameter of the bearing 6, so that an oil film gap 5 can be formed between the oil baffle ring 2 and the bearing 6. An installation groove and a drain groove are successively arranged on the inner side of the oil baffle ring 2. The installation groove and the drain groove are distributed up and down. The installation groove is annular and is used for installing the sealing ring plate 3. The drain groove is also an annular groove with an inverted triangular cross section to make the oil liquid flow back. There is a drain hole 22 at the bottom of the drain groove, and the drain hole leads to the outside of the oil baffle ring 2. When there are no less than 2 drain grooves, the upper and lower drain grooves are communicated, and the installation groove and the drain groove are communicated through the oil film gap 5.

[0018] The sealing ring plate 3 is located in the installation groove and is an electrical phenolic laminated cloth board made of phenolic resin and cotton cloth. It has high mechanical strength, excellent moisture resistance and heat resistance, is easy to process, and can effectively seal to prevent oil mist from overflowing. The inner diameter of the sealing ring plate 3 is slightly larger than the outer diameter of the bearing 6 and smaller than the inner diameter of the oil baffle ring 2. There is a clearance fit between the sealing ring plate 3 and the bearing 6. The external dimensions of the sealing ring plate 3 are determined according to the internal gear of the installation groove of the oil baffle ring 2. The sealing ring plate 3 and the oil baffle ring are in a tight fit to prevent the sealing ring plate 3 from loosening when rotating with the rotating oil basin 1. Compared with the wool felt ring, the sealing ring plate 3 as a whole reduces the gap between the oil basin and the bearing bush, improving the sealing effect and service life during use.

[0019] The bottom of the oil baffle ring 2 is lengthened and extends into the interior of the rotating oil basin 1. There is a rectangular thread 21 on the inner side of the bottom of the oil baffle ring 2, and the top of the rectangular thread 21 is communicated with the drain groove through the oil film gap 5. When the oil baffle ring 2 and the oil basin rotate with the main shaft 7, the oil liquid will rise along the rectangular thread 21 to lubricate the bearing 6 / bearing bush to form an oil film. After the oil liquid rises, it encounters the drain groove and then flows back to the oil basin 1 through the drain hole 22, circulating repeatedly. The rectangular thread 21 has a certain pressure-reducing function and can reduce the oil film pressure.

[0020] The outer circumference of the top of the oil baffle ring 2 is a shoulder ring. The shoulder ring is connected to the top of the rotating oil basin 1 through bolts, so that the oil baffle ring 2, the rotating oil basin 1 and the main shaft 7 rotate synchronously. During installation, the shoulder ring is embedded in the upper surface of the rotating oil basin 1. An elastic sealing ring 4 is arranged between the outer side of the oil baffle ring 2 and the rotating oil basin 1. The sealing ring 4 forms a seal between the oil baffle ring 2 and the rotating oil basin 1 to prevent the turbine oil from leaking out from the bolt joint surface. There is an installation groove on the side wall of the rotating oil basin 1 for restricting the position of the sealing ring 4.

[0021] Effect verification: Taking a hydropower station as an example, the model is HL124-LJ-260, the rated power is 36.08MW, the supporting motor is SF35-18 / 4800, and the water head is 177m. The power station adopts a split-type rotating oil sump structure, and the rotating oil sump is sealed with a wool seal ring above. After the unit has run (accumulative number) for 4500 hours, the oil leakage above the bearing gradually increases. After the power station stops running and disassembles the bearing, it is found that: the wool seal ring above the rotating oil sump is severely deformed, the turbine oil in the bearing oil sump is thrown out from above, and there is an oil mist phenomenon. After analysis, the reason is the high water head of the power station and long-term operation. After excluding other adverse factors, it is decided to adopt this bearing device. After running for 8000 hours accumulatively, no abnormal situation is found, which brings great convenience to the operation of the power station.

Claims

1. An oil mist prevention device for a bearing, characterized in that, It includes an oil baffle ring (2) located between the bearing and the rotating oil sump. An annular mounting groove for clamping a sealing ring plate and an oil discharge groove for guiding the oil fluid to flow back are provided on the inner side of the oil baffle ring (2) close to the bearing. The mounting groove is located above the oil discharge groove. The sealing ring plate (3) is located in the mounting groove. The sealing ring plate (3) is a phenolic laminated cloth board. The inner diameter of the sealing ring plate (3) is smaller than the inner diameter of the oil baffle ring (2).

2. The bearing oil mist prevention device according to claim 1, characterized in that, The inner diameter of the oil baffle ring (2) is larger than the outer diameter of the bearing, so that an oil film gap (5) is formed between the oil baffle ring (2) and the bearing.

3. The bearing oil mist prevention device according to claim 2, wherein, The sealing ring plate (3) and the bearing (6) are in clearance fit.

4. The bearing oil mist prevention device according to claim 2, characterized in that, The mounting groove and the oil discharge groove are communicated through the oil film gap (5).

5. The bearing oil mist prevention device according to claim 2, characterized in that, The bottom of the oil baffle ring (2) extends into the rotating oil sump. A rectangular thread (21) is provided on the inner side of the bottom of the oil baffle ring (2). The rectangular thread (21) is communicated with the oil discharge groove through the oil film gap (5).

6. The bearing anti-oil mist device according to claim 1, characterized in that, A shoulder ring for connecting with the top of the rotating oil sump is provided on the outer periphery of the oil baffle ring (2).

7. The bearing oil mist prevention device according to claim 6, characterized in that, An elastic sealing ring (4) for connecting with the rotating oil sump is provided on the outer side of the oil baffle ring (2) close to the rotating oil sump.

8. The bearing oil mist prevention device according to claim 1, characterized in that, The cross section of the oil discharge groove is an inverted triangle, and an oil discharge hole (22) extending towards the outer side of the oil baffle ring (2) is provided at the bottom of the oil discharge groove.

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