After the bearing runs on the mechanical equipment for a period of time, it is inevitable that there will be maintenance or damage and replacement. In the early days, the popularity of professional knowledge of bearing disassembly was not enough, the awareness of safe operating procedures was not strong, and the disassembly of bearings often appeared in a “violent” way. This is easy to damage bearings or mechanical equipment, causing unnecessary economic losses, then how is the correct way to disassemble bearings?

Different types of bearings have different disassembly methods. Maxwell, the author of this article, has introduced the scientific disassembly methods of bearings in a comprehensive and detailed way from a technical point of view, please continue reading.

Remove cylindrical bearings

1. Cold disassembly method

When removing smaller bearings, they can be removed from the shaft by gently tapping the side of the bearing ring with a suitable punch, preferably using a mechanical puller. The pull should be applied to the inner ring or adjacent parts. The removal process can be simplified if the shaft shoulder and the bearing seat hole shoulder are reserved for grooves to accommodate the puller’s pull grip.

In addition, a number of threaded holes are machined in the position of the hole shoulder to facilitate the bolt to push the bearing out.

The force required by large and medium-sized bearings is usually greater than that provided by mechanical tools.

Therefore, it is recommended to use hydraulic power tools or oil injection method, or both. This means that oil holes and oil grooves need to be designed on the shaft.

2. Thermal disassembly method

When removing the inner rings of needle roller bearings or NU, NJ, and NUP cylindrical roller bearings, the thermal removal method is suitable. Two commonly used heating tools: heating ring and adjustable induction heater.

The heating ring is usually used to install and remove the inner ring of small and medium-sized bearings of the same size. The heating ring is made of light alloy. The heating ring is radially slotted and equipped with an electrically insulated handle.

If the inner rings of different diameters are often removed, it is recommended to use an adjustable induction heater.

These heaters can quickly heat the inner ring without heating the shaft.

When removing the inner rings of large cylindrical roller bearings, some special stationary induction heaters can be used.

Remove the cone bearing

Small bearings can be removed by using mechanical or hydraulic power puller to pull the inner ring. Some pullers are equipped with spring operating arms, using this puller with a self-matching core design can simplify the procedure and avoid damage to the journal. If the puller claw cannot be used on the inner ring, the bearing should be removed via the outer ring or by a puller combined with a puller.

When using the oil injection method, the disassembly of medium and large bearings will be safer and simpler. In this method, hydraulic oil is injected between two conical mating surfaces under high pressure through the oil hole and the oil tank. Friction between the two surfaces is greatly reduced, and axial forces are created that separate the bearing and shaft diameter.

Remove angular contact ball bearings

1. Push and press method

Using a press to push and disassemble angular contact ball bearings is stable and reliable, and will not damage the machine and bearing shield room. The press is divided into manual push press, hydraulic press and mechanical press.

When the bearing is disassembled, the force point of the press should be on the center point of the shaft, and can not be biased.

2. Drag out method

When installing the outer side of the bearing, the Angle of the tensile bend should be extended to the outside; When assembling the inner ring, the puller should be stuck inward over the inner ring.

1, to hook the puller on the inner ring of the bearing, but not on the outside, to prevent the bearing disassembly process loose too much or damage;

2, in the use of tension for bearing disassembly, to make the ball screw point to the core hole of the shaft, can not tilt. Also pay attention not to damage the retractor and bearing, pay attention to the force between the bearing and the retractor;

3, Pay attention to avoid dislocation of retractor during bearing disassembly;

4, pull the two feet should be lower than 90.

Remove the bearing on the return sleeve

When removing the bearing on the return sleeve, the locking device (such as lock nut, end plate, etc.) must be removed. For small and medium-sized bearings, a locking nut, hook wrench or impact wrench can be used to disassemble.

For medium and large bearings mounted on the release sleeve, hydraulic nuts can be easily removed.

It is recommended to install a stop device behind the hydraulic nut at the shaft end.

The stop device can prevent the release sleeve and the hydraulic nut from flying out of the shaft when the release sleeve is suddenly separated from the matching position.

Conclusion

Bearing disassembly work is complex and very important, before disassembly should confirm the type of bearing, according to the method described in this article, reasonable use of tools, scientific method disassembly, before disassembly should be prepared tools and follow the relevant precautions.

1, Check whether the bearing has cracks, sharp sources, fractures, fragments or deformation before disassembly.

2, When using the press, all parts are stable and do not shake or vibrate; When pressing the shaft, the center of the shaft must be aligned with the center of the hammer; Do not grip the shaft when exerting force; Place a plate to catch the removed shaft or bearing so that it does not fall to the ground.

3, When using the puller, make sure that the puller claw is stuck on the side of the bearing; Align the end of the load bolt on the drawing tool with the shaft; If the jaw becomes loose during operation, stop immediately, and resume operation after changing position. If the bearing fails to come out after applying the normal disassembly force, do not apply excessive force to the puller and use other methods.

4, When using a professional wrench (disassembling the sleeve), please use a wrench of appropriate size to lock the nut; If the lock nut is too tight, do not hit the handle of the wrench with a hammer.

5, When using the bearing oiling method, slowly inject the oil, and immediately stop the oil injection when the inner ring moves along the axis; The taper bore bearing may fly away from the bearing at high speed, and a nut must be installed at the end of the shaft to prevent it from flying away.

6, When using induction heating equipment, do not place flammable materials (such as oil or gas) near the working area; When bearings are used repeatedly or need to be inspected, do not heat more than 120 ° C; Do not touch the heated bearing or surrounding parts without gloves; After heating, remove the bearing (inner ring) from the shaft immediately; If the bearing inner ring is difficult to move during early disassembly, stop the operation, reheat the bearing (inner ring), and then continue the operation.