GQZ Technology Knowledge: Design of Cage for Tapered Roller Bearing with High Load
Hot tags: tapered roller bearing(7)
The solid roller pillar welded cage solves the problem that the raceway cannot be checked after the assembly and use of tapered roller bearing.
Abstract: in view of the contradictory relationship between tapered roller bearing cage and load, a new type of solid roller pillar welded cage is provided, which effectively solves the problem that small-size tapered roller bearing cannot adopt pillar welded cage.
Key words: double row tapered roller bearing; Pillar welding cage; Solid roller; Detachable pillar
Tapered roller bearings are usually separate type, that is, the inner ring assembly with roller and cage assembly can be installed separately from the outer ring. Because tapered roller bearings can bear large axial and radial loads, they are widely used in automobile, rolling mill, mining, metallurgy, plastic machinery and other industries. In rolling mills and some special occasions, tapered roller bearings are required to not only have high bearing capacity, but also regularly check the raceway, so as to grasp the damage of the raceway in time. At present, for tapered roller bearings with small roller diameter, due to size constraints, pillar welded cages cannot be used, but the use of stamping cages will reduce the bearing capacity of the bearings, and it is not convenient to observe the raceway after installation and use. A new structure cage which can effectively solve the above problems is introduced below.
1. Bearing structure
The cages of tapered roller bearings include stamping cages (Fig. 1) and pillar welding cages (Fig. 2). In the design, for the consideration of stress and process, when the diameter DW of the large end of the tapered roller is ≤ 30mm, the steel plate stamping cage is adopted; When the outer diameter dimension of the bearing d > 650mm, the column welded cage is generally used.
Fig. 1 press cage tapered roller bearing
Fig. 2 tapered roller bearing of pillar welded cage
The steel plate stamping cage shrinks the diameter of the big end after the roller is assembled in the inner ring. Because the cage is inconvenient to disassemble and cannot be disassembled for many times, the tapered roller bearing of this structure is not applicable in the field where the raceway needs to be repaired; And in the design, in order to ensure the strength of the stamped cage, the pocket beam width of the cage should be greater than a certain value. Therefore, compared with the bearing using the pillar welded cage, the number of rollers is less and the corresponding rated load is also low.
At present, the general pillar welding cage structure of tapered roller bearing is shown in Fig. 2 The pillar (Fig. 3) passes through the pillar hole (Fig. 4) of the hollow roller and is connected with the two gaskets of the cage. The connection mode is that the threaded end of the pillar is connected with the threaded hole of the large gasket of the cage, and the grooved end of the pillar is welded and fixed with the small gasket of the cage. Because the structure needs to process the pillar hole in the roller center, the roller diameter DW is generally required to be more than 30mm. If the roller diameter is less than 30mm, the pillar strength selected is not enough because the machinable pillar hole is too small. If the processed pillar hole is too large, the stress on the pillar hole is large when the roller is loaded, which is easy to lead to the fragmentation of the roller.
Fig. 3 pillar
Fig. 4 hollow tapered roller
When the tapered roller diameter DW ≤ 30mm, in order to increase the number of rollers and improve the rated load, the solid roller pillar welded cage structure can be adopted, as shown in Figure 5. The structure is to connect the pillar with two gaskets through the outside of the roller, so as to limit the roller installed in the inner ring, as shown in Figure 6.
1. pillar 2. Cage large gasket 3. Roller
4. Outer ring 5. Small gasket of cage 6. Inner ring
Fig. 5 tapered roller bearing with welded cage of solid roller pillar
1. Large gasket of cage 2. Pillar 3. Roller 4. Small gasket of cage
Fig. 6 schematic diagram of pillar installation position
2. Design of welded cage for solid roller pillar
The cage structure adopts a fully loaded solid tapered roller and a pillar welded cage, a sufficient number of solid tapered rollers are installed in the inner ring raceway, the connecting pillars are placed outside the rollers and welded with the large and small gaskets of the cage, and two adjacent pillars in each group of cages are installed in a detachable way without welding. The installation position of the pillar is shown in Fig. 6 and Fig.7.
Fig.7 roller and cage pillar position
In the design, the average clearance s between rollers is determined according to the bearing size, which is generally 0.7 ~ 2.5mm. The clearance S1 between the pillar and adjacent rollers is generally guaranteed not to jam the roller but slightly less than the value S. the inclination angle of the pillar hole of the cage gasket is the inclination angle of the cage welded on the hollow roller pillar α Increase the roller half cone angle on the basis of β Value is α+β，The cage is guided by rollers. The diameter of the pillar and the thickness of the cage gasket are determined according to the strength requirements.
As shown in Fig. 8, a circular through hole is machined at its concave end on the basis of the pillar (Fig. 3), and the pillar is fixed with steel wire perforation. The size of through hole is generally 1.5mm.
Fig. 8 removable pillar
Fig. 9 small gasket pillar hole of cage
The pillar hole on the end face of the small gasket of the cage is shown in Fig. 9. There is no chamfer at the removable hole, and the rest adopts large chamfer. In order to ensure the welding quality, it can also be countersunk for the pillar to be welded with; A groove is opened at the center of the through hole of the detachable pillar hole, and the groove depth is so deep that after it is installed with the detachable pillar, the metal wire can be inserted into the through hole of the end face of the pillar groove for fastening and disassembly.
During assembly, the two gaskets of the cage are connected by pillars, two removable pillars in each column, and the rest are welded pillars (Fig. 3). The pillars pass through the through hole on the end face of the small gasket of the cage, and the threaded end of the pillar is connected with the thread of the large gasket of the cage. After the connection is fastened, the groove section of the pillar is welded and fixed with the outer side of the small gasket of the cage. The two detachable pillars are installed in the two detachable mounting holes of the small gasket of the cage. After they are installed in place, the hard metal wire passes through the circular through hole at the groove end and is placed in the deep groove machined on the end face of the small gasket of the cage for fixation. When it is necessary to check the raceway after the bearing works, take out the metal wire. After screwing out the two removable pillars, take out the limited three rows of rollers and observe the use of the raceway, as shown in Fig. 5.
The solid roller pillar welded cage solves the problem that the raceway cannot be checked after the assembly and use of tapered roller bearing, fundamentally solves the contradiction between the stamping cage and the rated load of bearing, and improves the bearing capacity and service life of bearing. In actual production, the pillar welded cage for small batch and small diameter tapered roller bearings can save a lot of cage mold cost and reduce the bearing manufacturing cost and manufacturing cycle.
More about GQZ high performanceTapered Roller Bearing:
GQZ precious-quality tapered roller bearing with reasonable price for customers all over the world and first-class service and unrivaled products.
GQZ tapered roller bearings feature a cup and cone assembly. The cup is comprised of the outer ring and the cone assembly consists of inner ring, rollers, and cage. This bearing construction accommodates combined loads and provides low friction during operation. By adjusting one single row tapered roller bearing against a second tapered roller bearing and applying a preload, a rigid bearing application can be achieved.
Previous: Fastest Bearing Finish in the World