Source:Sheng Wei networkAuthor:admin Addtime:2019/11/28 Click:
Points for attention
From the perspective of use, the following points should be paid attention to to to ensure that the bearing can work reliably:
1. Improve the lubrication quality, control the pressure, temperature and flow of the engine oil, and strengthen the engine oil filtration.
2. Use fuel oil and lubricating oil that meet the requirements.Cylindrical roller bearing
3. It is unfavorable to control the temperature state of diesel generator set and work under the condition of supercooling and overheating. In cold weather, the diesel engine shall be preheated before starting, and the engine oil shall enter the friction surface by turning the crankshaft by hand.
4. The surface quality and geometry of bearing and journal shall be strictly guaranteed.
5. The bearing clearance shall be appropriate. If the generator set is too large, it will have impact. If it is too small, it will have poor lubrication and may burn tiles.
How to ensure the reliable operation of bearings
Generally speaking, we should pay attention to the following points from the perspective of use:
1. The bearing clearance shall be appropriate, too large will produce impact, too small will result in poor lubrication, and may burn the tiles;
2. The surface quality and geometry of bearing and journal shall be strictly guaranteed;
3. Improve the lubrication quality, control the pressure, temperature and flow of the engine oil, and strengthen the engine oil filtration;
4. Use fuel oil and lubricating oil that meet the requirements.
In order to give full play to the bearing and maintain its proper performance for a long time, regular maintenance (regular inspection) must be carried out. It is very important for improving productivity and economy to find faults early and prevent accidents in advance through proper regular inspection.
Whether the bearing is installed correctly affects the accuracy, service life and performance. Therefore, the design and assembly department should fully study the bearing installation. It is expected to be installed in accordance with the work standards. The items of operation standard are generally as follows:
(1) clean bearings and bearing related parts
(2) check the size and finishing of related parts
(4) inspection after bearing installation
(5) lubricant supply
It is hoped that the bearing package will not be opened until shortly before installation. General grease lubrication, do not clean, directly fill grease. It is not necessary to clean the lubricating oil for lubrication. However, the bearings for instrument or high-speed use shall be cleaned with clean oil to remove the rust inhibitor applied on the bearings. The bearing with antirust agent removed is easy to rust, so it can't be ignored. Moreover, the bearing which has been sealed with grease can be used directly without cleaning.
The installation method of the bearing varies according to the bearing structure, fit and conditions. Generally, the inner ring needs interference fit due to the shaft rotation. Cylindrical hole bearing, press in with a press, or heat installation method. In the case of taper hole, it is directly installed on the taper shaft or installed with sleeve.
When it is installed to the shell, there are many clearance fits, and the outer ring has interference, so it is usually pressed in with a press, or there is also a cold shrink fit method installed after cooling. When dry ice is used as coolant and cold shrink is used for installation, the moisture in the air will condense on the surface of the bearing. Therefore, appropriate anti rust measures are needed.
The disassembly of bearing is regular maintenance, and the bearing is replaced. After disassembly, if it is necessary to continue to use or check the state of the bearing, the disassembly shall also be carried out with the same care as the installation. Pay attention not to damage the bearing parts, especially the disassembly of the interference fit bearing, which is difficult to operate.
It is also very important to design and make disassembly tools according to the needs. During disassembly, the disassembly method, sequence and coordination condition of the bearing shall be studied according to the drawings, so as to obtain the safe disassembly operation.
For the outer ring disassembly of interference fit, set several screws for outer ring extrusion screw on the circumference of the shell in advance, tighten the screw equally on one side, and disassemble at the same time. These screw holes are usually covered with separate bearings such as blind plugs, tapered roller bearings, etc., and several notches are set on the shoulder of the housing block. The cushion block is used to dismantle them with a press or gently knocked.
The inner ring can be easily removed by a press. At this time, pay attention to let the inner ring bear its pulling force. Moreover, the pull-out clamps shown are mostly used. No matter what kind of clamps are used, they must be firmly clamped on the side of the inner ring. Therefore, it is necessary to consider the size of the shaft shoulder, or to study the processing of the upper groove at the shoulder, so as to use the drawing fixture.
The inner ring of large bearing is disassembled by oil pressure method. The oil pressure is applied through the oil hole of the bearing to make it easy to pull. For bearings with large width, oil pressure method and drawing fixture shall be used together for disassembly.
The inner ring of cylindrical roller bearing can be disassembled by induction heating method. The method of drawing after heating the part in a short time to expand the inner ring. Induction heating is also used where a large number of such bearing cones need to be installed.
When the bearing is removed for inspection, first make appearance records by photography and other methods. In addition, confirm the amount of residual lubricant and sample the lubricant before cleaning the bearing.
A. bearing cleaning can be divided into rough cleaning and fine cleaning, and metal grid can be placed at the bottom of the used container.
B. during rough cleaning, use a brush to remove the grease or adhesive in the oil. At this time, if the bearing is rotated in the oil, pay attention to damage the rolling surface due to foreign matters.
C. during fine cleaning, rotate the bearing slowly in the oil, and conduct it carefully.
Generally, the detergent used is neutral diesel oil or kerosene without water, and warm alkaline solution is sometimes used as required. No matter what kind of cleaning agent is used, always filter and keep clean.
After cleaning, apply antirust oil or grease on the bearing immediately.