How to disassemble bearings?

1. It is best to conduct it with experienced personnel or under their guidance

2. Before disassembling, determine the specific method to be disassembled.

3. Prepare necessary bearing disassembly tools at hand

4. When reusing or inspecting disassembled bearings, be careful not to scratch or damage the bearing raceway or rolling element. When disassembling bearings from the bearing seat, the disassembly force is applied to the outer ring: when disassembling bearings from the shaft, the disassembly force is applied to the inner ring

The main method for disassembling bearings?

1. Using hand or hydraulic pressure

2. Only use a special wrench

3. Using a puller

4. Using induction heating equipment (inner ring)

5. Using the oil injection method

How to select different tools?

Dismantling bearings installed on cylindrical shaft diameter

Cold disassembly

When disassembling smaller bearings, a suitable punch can be used to gently tap the side of the bearing collar to remove it from the shaft, preferably using a mechanical puller. Pull and grip should act on the inner ring or adjacent components. If grooves are reserved on the shoulder of the shaft and the shoulder of the bearing seat hole to accommodate the puller's grip, the disassembly process can be simplified. In addition, some threaded holes are machined at the shoulder of the hole to facilitate the bolt pushing out the bearing.

The force required for large and medium-sized bearings is usually greater than what mechanical tools can provide. Therefore, it is recommended to use hydraulic power tools or oil injection methods, or both. This means that oil holes and grooves need to be designed on the shaft.

Hot disassembly

When disassembling the inner race of needle roller bearings or NU, NJ, and NUP cylindrical roller bearings, hot disassembly methods are suitable. Two commonly used heating tools: heating ring and adjustable induction heater.

The heating ring is usually used for installing and disassembling the inner ring of small and medium-sized bearings of the same size. The heating ring is made of light alloy. The heating ring belt has radial grooves and is equipped with an electrically insulated handle.

If inner rings with different diameters are frequently disassembled, it is recommended to use a adjustable induction heater. These heaters can quickly heat the inner ring without causing the shaft to heat up. When disassembling the inner ring of large cylindrical roller bearings, special fixed induction heaters can be used.

Dismantling the bearings installed on the conical shaft diameter

Small bearings can be removed by using a mechanical or hydraulic power puller to pull on the inner ring. Some pullers are equipped with a hood operating arm, and using this self aligning puller can simplify the program and avoid damaging the journal. If the puller claw cannot be used on the inner ring, the bearing should be removed through the outer ring or by combining the puller with the puller plate.

When using the oil injection method, the disassembly of medium and large bearings will be safer and simpler. This method injects hydraulic oil between two conical mating surfaces through oil holes and grooves under high pressure. The friction between the two surfaces is significantly reduced and an axial force is generated that separates the bearing and shaft diameter.

Dismantle the bearing on the tightening sleeve

For small bearings installed on a fixed sleeve with a straight shaft, a hammer can be used to knock on a small steel block that evenly acts on the end face of the bearing inner ring for disassembly. Before this, it is necessary to loosen the locking nut of the locking sleeve by several turns.

For small bearings installed on the stepped shaft of the locking sleeve, a hammer can be used to knock on the small end face of the locking nut of the locking sleeve through a special sleeve to disassemble. Before this, it is necessary to loosen the locking nut of the locking sleeve by several turns.

For bearings installed on stepped shafts with tight sleeves, using hydraulic nuts can make bearing disassembly easier. To achieve this, a suitable stop device must be installed in the position next to the hydraulic nut piston. The oil injection method is a simpler method, but a locking sleeve with oil holes and grooves must be used.

Dismantle the bearing on the disassembly sleeve

When disassembling the bearing on the disassembly sleeve, the locking device must be removed. For small and medium-sized bearings, such as locking nuts, end plates, etc., locking nuts, hook wrenches, or impact wrenches can be used for disassembly.

For large and medium-sized bearings installed on the disassembly sleeve, hydraulic nuts can be easily disassembled. It is recommended to install a stop device behind the liquid nut at the shaft end. This stop device can prevent the release sleeve and hydraulic nut from flying out of the shaft when the release sleeve suddenly separates from the mating position.

These key points need to be noted

1. Be sure to check for cracks, sharp sources, fractures, fragments, or deformation before disassembly work;

When using the press, all components should be stable and not shake or vibrate; When pressing the shaft, the center of the shaft must be aligned with the center of the hammer 2. Do not hold the shaft with your hands when using force: place a connecting plate to catch the shaft or bearing to prevent it from falling to the ground:

3. When using the puller, ensure that the claw of the puller is firmly clamped on the side of the bearing; Align the end of the load bolt on the puller with the shaft; If the gripper becomes loose during operation, immediately stop and secure it in a different position before resuming operation; If the bearing fails to detach after applying normal disassembly force, do not apply excessive force to the puller and use other methods instead

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

5. When using the bearing oil injection method, slowly inject oil, and immediately stop oil injection when the inner ring moves axially; The tapered hole bearing may fly off the bearing at high speed, so it is important to install a nut at the end of the shaft to prevent it from flying off:

6. When using induction heating equipment, do not place flammable materials (such as oil or gas) near the work area; When reusing bearings or requiring inspection, do not heat them above 120C; Do not touch heated bearings or surrounding parts without gloves; After heating, immediately remove the bearing (inner race) from the shaft; If the bearing inner race is difficult to move during early disassembly, stop the operation, reheat the bearing (inner race), and then continue the operation.