How To Adjust The Clearance Of The Reducer Bearing?

The reducer is the most widely used transmission device in industrial enterprises, and the adjustment of the bearing clearance of each shaft in the reducer is the key to the continuous and stable operation of the reducer.

After the reducer has been running for a period of time, due to the mutual wear of the various components, the bearing gap will increase. In order to ensure the continuous and stable work of the reducer, we must perform Adjust the bearing clearance. Introduce two types of end caps for adjusting the bearing clearance of reducer.
The bearing end cover used for fixing the reducer is generally divided into two types: external mounting type and embedded mounting type. The structure is simple, but the sealing performance is better. When adjusting the bearing gap, the box cover should be opened, and it is mostly used to fix the non-adjustable gap bearing. When using an external end cover to fix the bearing, the adjusting gasket can be used to adjust the bearing gap and strengthen the sealing performance, which is convenient for assembly and disassembly, but the length of the shaft section is increased.
The embedded end cover is easy to adjust due to the use of adjusting bolts, and can be used to fix bearings with adjustable gaps and reducers with high sealing requirements.
1. Fixing method at both ends of the shaft system: This structure often uses end caps to fix the outer ring of the bearing, which is simple in structure and convenient to use. It is more common in general gear reducers and worm reducers with bearing support point span <300mm. (1) The bearing clearance adjustment of the reducer with the external end cover adopts the reducer with the external end cover fixed to the outer ring of the bearing, which has a simple structure and is easy to use. This method is widely used in reducers. Gear shafting structure fixed by external end cover. For this kind of fixing method, most of them leave a proper amount of axial clearance at both ends when leaving the factory to ensure the flexible operation of the bearing and the thermal elongation of the shafting parts. The gap should not be too large, generally within the range of 0.25mm~0.4mm, otherwise the rolling elements will be unevenly loaded and cause more serious axial movement. Therefore, it is necessary to adjust the bearing clearance to ensure a certain axial clearance. When adjusting the shaft system of this kind of fixed method, first open the observation hole of the reducer, check the meshing of the gears, and then determine the direction from which the shafting moves to the clearance. If you have determined that the high-speed axial input side adjusts the gap, then remove the blank cover of the high-speed shaft, use a depth vernier caliper to measure the depth of the bearing from the end cover plane and record; then use a crowbar tool to move the shaft to the input side Move, and then measure the depth of the bore end bearing from the end cover plane. The difference between the two depth dimensions is the amount of bearing movement. After moving the shaft system, add a spacer equal to the amount of movement on the bearing hole, and finally install the blanking cover. After all the parts are assembled, gently rotate the reducer to check whether the rotation of each axis is flexible and whether there is jamming. If there is still jamming, the thickness of the added gasket can be reduced appropriately. Until the rotation of each axis of the reducer is adjusted to be flexible. According to the actual situation, the bearing end cover installed on the box can also be cut, and the cutting depth is 0.20mm of the bearing movement or slightly larger than the movement. If the cutting depth is greater than 1/3 of the plane thickness of the end cap, the end cap is too thin and the strength is weakened, and the end cap needs to be reworked. For radial thrust bearings with adjustable clearance, the required bearing clearance can be obtained by adjusting the relative position of the outer ring of the bearing. This kind of clearance is generally relatively small to ensure the rigidity of the bearing and reduce noise and vibration. For bearings with non-adjustable clearance (such as radial ball bearings), you can adjust during assembly to leave a proper amount of clearance between the fixed end cover and the end surface of the outer ring of the bearing to allow the thermal elongation of the shafting. In the bevel gear reducer, the shaft system of the cantilever pinion bevel gear is required to have good rigidity, and the axial position of the shaft system can be adjusted to achieve the coincidence of the bevel tops of the two gears. Therefore, the entire shaft system is often installed in the collar to form an independent component. The shoulder of the cup serves to fix the bearing. The shoulder should not be too high to facilitate the disassembly of the bearing. The flange of the cup and the end cover of the bearing are equipped with gaskets to adjust the bearing clearance and adjust the axial position of the shaft system. When the bevel gear shaft system adopts the centripetal thrust bearing, the bearing has two layout schemes: positive installation and reverse installation. The structure in which the bearing is being installed has a small fulcrum span and poor rigidity, but it is more convenient to adjust it with a gasket. The structure of bearing reverse installation, this kind of mechanism is inconvenient to install the bearing, and it is more troublesome to adjust with round nut, but the fulcrum span is larger and the rigidity is better. This structure is often used when the two bearings are required to be arranged compactly and the rigidity of the shaft system needs to be improved. (2) The bearing gap adjustment of the reducer with the embedded end cover adopts the embedded end cover. When the bearing gap adjustment is carried out, the adjustment of the bearing gap is mainly realized through the adjustment end cover of the reducer itself. There is no need to disassemble the parts of the reducer. The way to adjust the gap of the reducer bearing (tapered roller bearing) is very simple. When the reducer runs for a period of time, the gap of the tapered roller bearing will vary with the increase of the equipment running time. Increase, which may cause the noise and vibration of the reducer to increase, and even cause damage to the bearings and gears and failure of the reducer. In order to avoid such accidents, the operation of the reducer equipment should be monitored during the production process, and the gearbox bearing clearance should be adjusted by stopping the machine during the production gap. If the load on the output end can be discharged, the adjustment will be more precise. When adjusting, you can use the adjusting bolts on the adjusting end cover to adjust. After adjusting, gently turn the reducer to check whether the rotation of each axis is flexible and whether there is jamming. If there is still jamming, adjust again. Repeatedly, a better bearing clearance can be obtained, until the rotation of each shaft of the reducer is adjusted to be flexible without obvious axial movement. 2. One end of the shafting system is fixed and the other end is swimming. The shaft system is fixed at one end and the other end is swimming. The shafting structure is more complicated, but it can tolerate greater thermal elongation of the shafting. It is mostly used in shaft systems with large bearing fulcrum span and high temperature rise. When arranging the support, the end receiving the smaller radial force should be used as the swimming end to reduce the friction during axial swimming. If the radial forces of the two fulcrums are similar, the shaft extension end is often selected as the free end.

A worm shaft system with one end fixed and one end moving. The fixed end support is composed of a combined bearing. The two rings of the combined bearing are fixed in both directions by a cup shoulder and a bearing end cover. The two inner rings are made of on-shaft parts, shoulders or rounds. The nut is fixed in both directions. Because the bearing of the fixed section bears the axial force, the elastic retaining ring is generally not used as the fixed part. When fixing the bearing inner ring with a round nut, the thread diameter should be smaller than the bearing inner diameter, the diameter should be smaller than the gasket size, and the position of the gasket in the groove should be lower than the thread inner diameter. When using tapered roller bearings. In order to prevent the nut from contacting the bearing cage, a spacer should be added between the nut and the bearing.

Radial ball bearings or radial roller bearings can be selected for the support of the floating end. For radial ball bearings, both sides of the inner ring can be fixed by the shoulders and parts on the shaft, while the outer ring is not fixed, so it can move axially in the bearing seat hole. For radial roller bearings, both inner and outer rings are fixed. Need to be fixed. The axial movement is achieved by the axial displacement of the roller relative to the outer ring.

The adjustment of the bearing clearance of each shaft system of the reducer is very important to whether the reducer can work normally and stably. In order to ensure that the reducer gets a good working condition, we must pay attention to the following points.

(1) When adjusting the bearing clearance of the reducer, it must be based on gear meshing, and must meet the requirements of the contact spots of the two gears, the side clearance and the top clearance of the gears, that is, the speed of the reducer must be light and flexible.

(2) When adjusting the bearing clearance of the reducer, the bearing clearance must be within the adjustable range. If the bearing clearance is already in a scrapped state, it is meaningless to adjust the clearance again.

(3) Check the operation at any time, improve the quality of maintenance and repair, and extend the service life of the equipment.
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