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Bearing Capacity Of Sliding Bearing
- Jul 25, 2017 -

Plain bearings are bearings that work under sliding friction. Plain bearings work smoothly, reliably and without noise. Under the condition of liquid lubrication, the sliding surface is separated by lubricating oil without direct contact, and the friction loss and surface wear can be greatly reduced, Slide Bearings and the oil film also has a certain vibration absorption ability. But the friction resistance of starting is larger. The shaft, which is supported by the bearing, is called the axle neck, and the part matching the axle neck is called the bearing. In order to improve the friction property of the bearing surface, Slide Bearings the antifriction material layer which is cast on the inner surface is called bearing liner. The material of bearing liner and bushing is referred to as sliding bearing material. Plain bearings are generally used in low speed and heavy duty conditions, or the maintenance and filling of lubricating oil difficult operation parts.

Plain bearings are usually said to be plain, with a simple form, large contact area, if the lubrication remains good, anti-wear performance will be very good, bearing life will be very long. The bearing capacity of sliding bearing is large, the rotary precision is high, Slide Bearings and the lubricating film has an impact-resisting effect. So it has been widely used in engineering. But his biggest drawback is the inability to maintain sufficient oil reserves and, once the lubricant is insufficient, it immediately causes severe wear and failure.

Sliding bearing according to the direction of bearing load can be divided into: thrust sliding bearings and radial bearings

According to the lubrication film formation principle is divided into: dynamic pressure sliding bearing and hydrostatic bearing

According to the structure of different types can be divided into: integral sliding bearing split

Characteristics´╝Ü

Compared with rolling bearings, Slide Bearings sliding bearing has the characteristics of high bearing capacity, good seismic resistance, stable and reliable work, low noise and long life. It is widely used in internal combustion engines, rolling mills, large motors and meters, radars, telescopes and so on.

Working mechanism and function of sliding bearing

(1) Basic work handling

The sliding bearing is lubricated by hydrodynamic fluid, Slide Bearings and when the rotating shaft rotates, an oil wedge is formed between the shaft and the bearing. Note that it is necessary to put the shaft together a eccentric positions, shaft and bearing gap between, otherwise it is impossible to build a load wedge.

(2) Structure of sliding bearing

The use of sliding bearing motor, its bearing parts are bearings, oil rings, C-shaped shell, inside and outside oil seals, inner air protection ring, vents (embedded oil-proof or sealed shell) and internal pressure transport pipe and container (depending on the size and speed of the motor)

Plain bearings are commonly used in oil seals with rigid labyrinth ring, floating labyrinth ring, baffle seal. Both sides of the bearing (inside and outside of the motor) are oil seals. Slide Bearings Some motor (such as open motor) internal approximate vacuum, will try to pump oil into the motor rotor. A lot of time, vacuum (pressure) is too large, separate labyrinth ring seals can not prevent the leakage of oil, at this time, Slide Bearings in the Labyrinth ring seal between the establishment of a external inlet. For large or high speed motors, add an internal fan pressure seal Chamber.

(3) Type of sliding bearing

There are five basic types of plain bearings: ordinary cylindrical inner cavity bearing, two-angle inner cavity (lemon-shaped) bearing, four-corner inner cavity bearing, 4 liner bearing bearings, 5 liner bearing bearings. The most common and most commonly used is the standard cylindrical plain bearings, Slide Bearings cylindrical bearings only a local arc bearing the upper half of the other two parts of the arc bearings to limit the movement of the upper part of the shaft, therefore, is called part of the circular cylindrical plain bearings.

(4) Life of sliding bearing

It is theoretically believed that the life of sliding bearing is infinitely long, and if it is maintained well, its life will be longer. The correct maintenance of the sliding bearing only in the long-term low-speed operation will be obvious wear. During low-speed operation, the oil film is not in the desired thickness, which increases the wear and tear of the bearing. At rest, the oil film thickness is zero. This happens during slow start and inertia parking, and if this happens frequently, it is recommended that the hydraulic jack be used to minimize bearing wear. Slide Bearings The hydraulic jack is positioned before the shaft starts to rotate, and the oil-film thickness is ensured at a very low rotational speed (down to 0) by pressing the shaft neck from the lower part of the bearing to the bearing. Hydraulic jacks are generally used only in very large motors.

The calculation of bearing life is generally based on the following four assumptions:

1. Lubricate the bearing with the appropriate amount of lubricating oil;

2. Install bearings without damaging the bearing;

3. The dimension of the bearing is correct;

4. Bearings are not defective.

(5) Lubrication of plain bearings

Bearing lubrication is very important if the lubrication is improper, sliding bearing can be early warning, especially with bearing check thermometer bearings. The oil film thickness, heating and bearing performance must be taken into account when choosing viscosity of oil.

The sliding bearing is lubricated by high quality steam turbine oil, Slide Bearings and the viscosity of oil is very important. If the viscosity of the oil used is different from that of the bearing design, several conditions will occur: the rotor dynamic performance differential bearing oil film thickness change or bearing heating increase.

The compatibility of oil and paint with the sealing system must be verified. Incompatible oil and paint will react with the sealing system, causing oil spills and impurities into the bearing, causing serious damage to the bearings. The liquid surface of the oil must be kept in a suitable position, Slide Bearings and the marking on the oil or window can indicate the liquid surface. In addition, the constant water level oiler can be used to ensure the oil surface of the motor. The deviation tolerance of the oil surface should be kept to a minimum, if the liquid surface is too high, the oil will spill, or slow down the oil ring to a low point, the axle neck (bearing) can not be transmitted to the required oil; if it is less than 6, then there will be an accident.

Sliding bearing lubrication method has oil ring lubrication immersion lubrication, oil ring lubrication can be used for cylindrical bearings, two-angle bearings, four-square-shaped bearings, but generally can not be used for bearing bearings.