How are the bearings assembled? How do I install the bearings?

The mounting method of the bearing varies according to the bearing structure, fit and conditions, and in general, because the shaft is mostly rotated, the inner ring needs an interference fit. Cylindrical bore bearings, mostly pressed into by press, or mostly used by hot filling method. In the case of taper holes, it can be installed directly on the taper shaft or with a sleeve.

When installed in the housing, there is generally a lot of clearance fit, and the outer ring has an interference amount, which is usually pressed in with a press, or there is also a cold shrink fit method for installation after cooling. When dry ice is used as a coolant, the moisture in the air will condense on the surface of the bearing. Therefore, proper anti-rust measures are required.

Depending on the type of bearing (except for the split type), there are different dies and punches, and the balls or rollers are first placed into the cage (commonly known as the "steel shovel", which is usually installed manually), and then the inner and outer bearings are pressed together with the balls or rollers on a press.

Now ordinary bearings, with cages (that is, fixed bearing rings) usually before putting in enough bearing balls, the cage is not yet, then after the ball is installed, the cage can be installed, because when there is no cage, the ball can be rolled to one side, so that the inner ring can be taken out.

As for the deep groove full of balls without cage bearings, usually in the inner ring, there is a small groove, the ball is loaded from here, after being installed, most of the bearings are glued with a metal sheet that is completely consistent with the groove, of course, there are also non-bonded, in fact, the ball has no way to come out, unless there is an external force, and if a metal sheet is bonded there, the ball is even more unlikely to come out.

As for the needle rollers. Angular contact with these bearings, basically, can be taken out casually. There are no installation issues. The installation is mainly for the Type 2 bearings mentioned above.

The principle of thermal expansion and cold contraction is used in assembly.

First, put the outer ring of the bearing in the high-temperature oil to boil, the outer ring will become larger, and then put the ball and the inner ring in turn while it is hot, and wait for the outer ring to cool down, and the fit is just right.

Some of them are pressed in, and a part of the balls is put in first, and then the rest is pressed in with a machine.

Several ways: press in.

Hot expansion and cold contraction.

The steel ball is less, and it rolls to one side and presses the cage.

Groove method. Once one ball is left, the outer ring is slightly flattened by a few microns to fit the last ball.

Mainly for the wheel bearing assembly process, to achieve automatic unmanned direct contact, safe production, medium-sized machine is mainly suitable for casters size of inch casters can be used at the same time, and do not need to change tooling, to ensure the scope of application, improve the stable operation, full completion, all kinds of caster bearing press-fitting machine.

The inner and outer traps are put together, the balls are put in, the balls are adjusted, and the cage is installed.

What about the efficiency of production? Could it be that the balls and cage are first installed on the inner ring, and then the outer ring is heated and then set?

I asked several colleagues around me but no one was clear, please teach me with a high finger.

I guess it's a small question, is there a lot of this stuff, it's hard to do it well.

Won the Healthy Harbin Science and Technology Conference.

Method of axial fixation of parts on the shaft:

1.Shoulder; Simple and reliable, preferred choice.

2.Sleeve: used for axial fixation of adjacent parts on the shaft, simple structure, more applications.

3.Round nut: When the two adjacent parts on the shaft are far away and cannot be fixed with a sleeve, a round nut is selected, and a fine thread is generally used to avoid weakening the strength of the shaft too much.

4.Shaft end retaining ring: An on-shaft part that is used to secure the shaft end.

5.Retaining rings: Used when the axial force is small, or only to prevent the part from moving in the axial direction occasionally.

6.Set screw: Used when the axial force is small.

Circumferential fixation method of parts on the shaft:

1.Key connection (mainly flat key and dry connection): simple structure, reliable work, easy assembly and disassembly, widely used in machinery.

2.Spline connection: high bearing capacity, small stress concentration, less weakening of the strength of the shaft and the hub, good alignment and guidance of the parts on the shaft and the shaft. Disadvantages: special equipment is required for processing, and the cost is high.

3.Pin connections without pins, e.g., can transmit small radial and axial loads at the same time, and can also be used as an overload shear element in safety devices.

4.Expansion connection.

5.Interference fit connection.

1. Use special tools for bearing installation and disassembly.

Advanced installation tools can avoid bearing damage caused by improper installation of tools and operations, for example, when installing the bearing, the staff adopts the copper rod percussion method, the bearing axial force is uneven, the cage is deformed, the rolling element is damaged, the clearance becomes larger, the copper rod is struck, the copper dust flies into the bearing cage, and the bearing failure is easy to occur.

2. Check the bearing before installation.

The old bearing needs to check whether there are burrs, scars, cracks on the surface of the ball (column), the radial clearance of the old bearing, and whether the axial clearance is qualified, and generally only the radial clearance is measured. For new bearings, first of all, check whether the new bearing type is correct, and refer to Table 1 for the radial clearance standard of rolling bearings. For example, the model 6318 deep groove ball bearing, with an inner bearing diameter of 90mm, has a radial clearance range of and a maximum bearing wear of .

3. Check the matching size of the bearing and the rotor shaft.

When assembling the motor, the mating dimensions of the bearing and the rotor shaft (Table 2).

4. Control the quantity of oil in the bearing and bearing chamber.

Excessive oil volume in the bearing and box, the bearing rolling element slides, the rolling element changes from rolling friction to sliding friction, the bearing rolling element is damaged, the bearing oil volume is excessive, the free space in the bearing box is small, the bearing operating temperature rises, and the general motor end cover side is equipped with a bearing oil chamber (except for the motor designed as a double sealed bearing) According to the speed of the motor, the oil injection amount of the bearing chamber can be implemented with reference to the following standards, when the motor speed < 1500rmin, add oil, and the amount is 2 3 of the bearing chamber volume. The rotational speed between 1500 and 3000r min is 1 2 of the bearing volume. Rotational speed & common; At 3000r min, the bearing volume is less than 1 3.

In the actual working process, for the bearings running at high temperature and high speed, try not to use the bearing with the sealing surface, increase the oil volume of the motor oil cap, and install the grease nozzle, which can improve the operating life of the motor bearing.

5. Ensure that the insulation is intact.

The outer ring has an insulation design of the bearing, when the insulation is damaged when the insulation is intact, the thin bearing oil film is destroyed by the shaft voltage, and the lubrication condition of the rolling element is destroyed after the oil film is destroyed. Not only is it poor, but the resulting electric spark causes galvanic corrosion on the rolling elements of the bearing, which not only accelerates the wear of the bearing.

Flat bearings are relatively simple to install.

1. Prepare a simple plane bearing parts, including loose rings, tight rings, and protective frame balls, as shown below.

2. Relaxation ring (this part is close to the stationary part in practical application), as shown in the following figure.

3. Put the balls framed by the protective frame, as shown in the figure below.

4. Tighten the ring, as shown below.

5. A simple plane bearing is installed, as shown in the figure below.

1. Distinguish the tight ring and loose ring of the bearing (judging according to the size of the inner diameter of the bearing, the hole diameter is different;

2. Distinguish the stationary parts of the mechanism (i.e., the parts that do not move, and the main body refers to the assembly);

3. No matter what the situation, the loose ring of the bearing should always lean on the end face of the stationary part.

Common problem: The tension ring and loose ring of the flat bearing are installed in the opposite position, which will make the bearing useless, and the journal will be worn out very quickly.

Solution: Re-switch the loose ring and tight ring to the next position.

There are three ways to assemble bearings: stool parsley.

1. Hammering method.

The method of hammering with a hammer pad copper rod and some relatively soft materials, be careful not to let foreign objects such as copper dust fall into the bearing raceway, and do not directly use a hammer or drum to directly hit the inner and outer rings of the bearing, so as not to affect the matching accuracy of the bearing or cause damage to the bearing.

2. Screw press or hydraulic press assembly method.

For bearings with large interference tolerances, they can be assembled with a screw press or hydraulic press. Before pressing, the shaft and bearing should be flattened, and a little lubricating oil should be applied, the pressing speed should not be too fast, and the pressure should be quickly removed after the bearing is in place to prevent damage to the bearing or shaft.

3. Hot charging method.

The hot loading method is to heat the bearing in oil to 80 -100, so that the inner bore of the bearing is enlarged and then set on the shaft, which can prevent the shaft and bearing from damage. Bearings with shields and seals that are already filled with grease are not suitable for hot mounting.