Bearing for conveyor roller is surface contact, so it is necessary to maintain a certain oil film between the contact surfaces, so the following problems should be paid attention to in the design.
1, it is necessary to make the oil film enter the friction surface smoothly.
2, the oil should enter the bearing from the non bearing area.
3, do not open the full ring oil tank in the middle of the bearing.
4, such as oil tiles, seam opening oil ditch.
5, it is necessary to make the oil ring fully reliable.
6, the filling hole not blocked.
7, do not form an oil non flow zone.
8, prevent the sharp edge and angle of cutting oil film.
Bearing for conveyor roller is also lubricated with grease, and the following points should be taken into consideration when selecting grease.
(1) when the bearing load is large and the rotation speed is low, the small cone penetration grease should be chosen, and the cone penetration should be chosen. The high speed bearing selects the lubricating grease with smaller cone penetration and good mechanical stability. It is particularly noted that the viscosity of the base oil of the grease is lower.
(2) the dropping point of the selected grease is generally higher than that of the working temperature of 20-30 degrees C. when the high temperature is running continuously, it is not to exceed the allowable temperature range of grease.
(3) when bearing for conveyor roller works in a wet or wet environment, a calcium based, aluminum or lithium base grease with good water resistance should be selected.
(4) choose the lubricating grease with good adhesion.
The choice of grease for 2, bearing for conveyor roller:
The load <1MPa, the circumferential velocity of the neck of the shaft is below 1m/s, the maximum working temperature is 75 degrees C, and No. 3 calcium base fat is selected.
The load 1-6.5MPa, the circumferential velocity of the neck of the shaft is 0.5-5m/s, the maximum working temperature is 55 degrees C, and No. 2 calcium base fat is selected.
The load >6.5MPa, the circumferential velocity of the neck of the shaft is below 0.5m/s, the maximum working temperature is 75 degrees C, and No. 3 calcium base fat is selected.
Load <6.5MPa, shaft neck circumference speed 0.5-5m/s, maximum working temperature of 120 DEG C, the No. 2 lithium grease;
The load >6.5MPa, the circumferential velocity of the neck of the shaft is below 0.5m/s, the maximum working temperature is 110 degrees C, and No. 2 calcium sodium base grease is selected.
Load 1-6.5MPa, shaft neck circumference speed below 1m/s, the maximum working temperature of 50-100 DEG C, the No. 2 lithium grease;
The circumferential velocity of the load >5MPa axle neck is 0.5m/s, the maximum working temperature is 60 degrees C, and No. 2 calender is selected.
In the wet environment, under the condition of 75-120 C, the grease of calcium sodium base grease should be considered. In wet environment, the working temperature is below 75 centigrade, no 3 calcium base fat, and aluminum base grease can also be used. The temperature at 110-120 DEG C, available barium grease or grease. When concentrated in lubrication, the consistency is smaller.
3, bearing for conveyor roller used lubricating grease lubrication period:
Accidental work, not important parts: shaft speed <200r/min, lubrication cycle 5 days once; shaft speed >200r/min, lubrication cycle 3 days.
Discontinuous work: the shaft speed is <200r/min, the lubrication period is 2 days; the shaft speed is >200r/min, and the lubrication period is 1 days.
Continuous work, the working temperature is less than 40 degrees C: shaft speed <200r/min, lubrication cycle 1 days; shaft speed >200r/min, lubrication cycle every time.
Continuous work, working temperature 40-100 degrees: shaft speed <200r/min, lubrication cycle per class, shaft speed >200r/min, lubricating cycle two times per class.
Both the shaft neck and the bearing for conveyor roller should be evenly and finely contacted, and there is also a certain coordination gap.
It refers to the center angle of the contact surface between the neck of the shaft and the bearing for conveyor roller. The contact angle should not be too large or too small. If contact angle is too small, the pressure of bearing for conveyor roller will increase. When severe, it will cause large deformation of bearing for conveyor roller, accelerate wear and shorten service life. Contact angle is too large, which will affect the formation of oil film and get no good liquid lubrication.
The experimental study shows that the limit of the contact angle of bearing for conveyor roller is 120 degrees. When the bearing for conveyor roller is worn to this contact angle, the liquid lubrication will be destroyed. Therefore, the smaller the pressure condition of bearing for conveyor roller, the smaller the contact angle is. From the analysis of friction theory, when the contact angle is 60 degrees, the minimum friction torque, therefore suggested that the speed is higher than that of 500r/min bearing for conveyor roller, the contact angle of 60 degrees, the speed is lower than 500r/min bearing for conveyor roller, the contact angle of 90 degrees can be used, also can use 60 degrees.
The actual contact between the shaft neck and the surface of the bearing for conveyor roller can be expressed by the actual contact points on the unit area. The more and more contact points, the better the bearing for conveyor roller scraping, and vice versa, it means bearing for conveyor roller scraping is not good. Generally speaking, the more close the contact point is, the more difficult it is to scrape and study. In production, contact points should be determined according to the performance and working conditions of bearing for conveyor. The data listed in the table below are available for reference.
Bearing for conveyor roller speed (r/min) contact point
(the number of contact points per 25 * 25 millimeter area)
Less than 100 3~5
100~500 10~15
500~1000 15~20
1000~2000 20~25
Over 2000 and more than 25
The first and second class precision machines can use the upper table data, and the grade III precision can be reduced by half according to the data of the upper table.
1, it is necessary to make the oil film enter the friction surface smoothly.
2, the oil should enter the bearing from the non bearing area.
3, do not open the full ring oil tank in the middle of the bearing.
4, such as oil tiles, seam opening oil ditch.
5, it is necessary to make the oil ring fully reliable.
6, the filling hole not blocked.
7, do not form an oil non flow zone.
8, prevent the sharp edge and angle of cutting oil film.
Bearing for conveyor roller is also lubricated with grease, and the following points should be taken into consideration when selecting grease.
(1) when the bearing load is large and the rotation speed is low, the small cone penetration grease should be chosen, and the cone penetration should be chosen. The high speed bearing selects the lubricating grease with smaller cone penetration and good mechanical stability. It is particularly noted that the viscosity of the base oil of the grease is lower.
(2) the dropping point of the selected grease is generally higher than that of the working temperature of 20-30 degrees C. when the high temperature is running continuously, it is not to exceed the allowable temperature range of grease.
(3) when bearing for conveyor roller works in a wet or wet environment, a calcium based, aluminum or lithium base grease with good water resistance should be selected.
(4) choose the lubricating grease with good adhesion.
The choice of grease for 2, bearing for conveyor roller:
The load <1MPa, the circumferential velocity of the neck of the shaft is below 1m/s, the maximum working temperature is 75 degrees C, and No. 3 calcium base fat is selected.
The load 1-6.5MPa, the circumferential velocity of the neck of the shaft is 0.5-5m/s, the maximum working temperature is 55 degrees C, and No. 2 calcium base fat is selected.
The load >6.5MPa, the circumferential velocity of the neck of the shaft is below 0.5m/s, the maximum working temperature is 75 degrees C, and No. 3 calcium base fat is selected.
Load <6.5MPa, shaft neck circumference speed 0.5-5m/s, maximum working temperature of 120 DEG C, the No. 2 lithium grease;
The load >6.5MPa, the circumferential velocity of the neck of the shaft is below 0.5m/s, the maximum working temperature is 110 degrees C, and No. 2 calcium sodium base grease is selected.
Load 1-6.5MPa, shaft neck circumference speed below 1m/s, the maximum working temperature of 50-100 DEG C, the No. 2 lithium grease;
The circumferential velocity of the load >5MPa axle neck is 0.5m/s, the maximum working temperature is 60 degrees C, and No. 2 calender is selected.
In the wet environment, under the condition of 75-120 C, the grease of calcium sodium base grease should be considered. In wet environment, the working temperature is below 75 centigrade, no 3 calcium base fat, and aluminum base grease can also be used. The temperature at 110-120 DEG C, available barium grease or grease. When concentrated in lubrication, the consistency is smaller.
3, bearing for conveyor roller used lubricating grease lubrication period:
Accidental work, not important parts: shaft speed <200r/min, lubrication cycle 5 days once; shaft speed >200r/min, lubrication cycle 3 days.
Discontinuous work: the shaft speed is <200r/min, the lubrication period is 2 days; the shaft speed is >200r/min, and the lubrication period is 1 days.
Continuous work, the working temperature is less than 40 degrees C: shaft speed <200r/min, lubrication cycle 1 days; shaft speed >200r/min, lubrication cycle every time.
Continuous work, working temperature 40-100 degrees: shaft speed <200r/min, lubrication cycle per class, shaft speed >200r/min, lubricating cycle two times per class.
Both the shaft neck and the bearing for conveyor roller should be evenly and finely contacted, and there is also a certain coordination gap.
It refers to the center angle of the contact surface between the neck of the shaft and the bearing for conveyor roller. The contact angle should not be too large or too small. If contact angle is too small, the pressure of bearing for conveyor roller will increase. When severe, it will cause large deformation of bearing for conveyor roller, accelerate wear and shorten service life. Contact angle is too large, which will affect the formation of oil film and get no good liquid lubrication.
The experimental study shows that the limit of the contact angle of bearing for conveyor roller is 120 degrees. When the bearing for conveyor roller is worn to this contact angle, the liquid lubrication will be destroyed. Therefore, the smaller the pressure condition of bearing for conveyor roller, the smaller the contact angle is. From the analysis of friction theory, when the contact angle is 60 degrees, the minimum friction torque, therefore suggested that the speed is higher than that of 500r/min bearing for conveyor roller, the contact angle of 60 degrees, the speed is lower than 500r/min bearing for conveyor roller, the contact angle of 90 degrees can be used, also can use 60 degrees.
The actual contact between the shaft neck and the surface of the bearing for conveyor roller can be expressed by the actual contact points on the unit area. The more and more contact points, the better the bearing for conveyor roller scraping, and vice versa, it means bearing for conveyor roller scraping is not good. Generally speaking, the more close the contact point is, the more difficult it is to scrape and study. In production, contact points should be determined according to the performance and working conditions of bearing for conveyor. The data listed in the table below are available for reference.
Bearing for conveyor roller speed (r/min) contact point
(the number of contact points per 25 * 25 millimeter area)
Less than 100 3~5
100~500 10~15
500~1000 15~20
1000~2000 20~25
Over 2000 and more than 25
The first and second class precision machines can use the upper table data, and the grade III precision can be reduced by half according to the data of the upper table.
