JPH11303876A - Barrel polishing media for metal machined cage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of abrasion of a rolling element even in the case where the abrasive grains are left in the embedded condition, by barrel polishing while setting the degree of hardness of the polishing abrasive grains at the nearly same degree of hardness as the degree of hardness of the rolling element. SOLUTION: In case of barrel polishing of a cage main body, polishing media 12 composed of the abrasive grains 13 having 500-850 Hv of degree of hardness and the binder 14 are used so as to perform the polishing with a centrifugal flow barrel polishing device, and the burr formed in an edge of a cage pocket is eliminated for chamfering. The cage main body is washed after the polishing, and even in the case where the abrasive grains 13 of the polishing media 12 is left in the cage main body, since the degree of hardness of the abrasive grains 13 is the nearly same with the degree of hardness of a cylindrical roller housed in the rocket, abrasion of the cylindrical roller due to a contact with the abrasive grains 13 can be restricted. Deterioration of the grease due to mixing with the abrasion powder is remarkably reduced, and the lifetime of a bearing and reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing medium used for barrel-polishing a metal machined cage for holding a rolling element of a rolling bearing.

[0002]

2. Description of the Related Art In general, a main motor mounted on a railway vehicle has a large load torque at the time of starting and is subjected to vibration and impact at high speed rotation. Large capacity cylindrical roller bearings are used.

[0003] In the above-described cylindrical roller bearing for high-speed rotation having a large load capacity, a metal hollow cage made of a high-strength brass casting or the like is usually employed.

[0004] This retainer is entirely formed by stamping, including a pocket for accommodating a cylindrical roller. In this milled cage, since burrs occur at the edges and the like at the openings of the pockets on the inner diameter side and the outer diameter side of the cage, an appropriate deburring operation is performed after the milling process, and a polishing process is further performed. I try to remove the burr.

As a polishing machine for polishing a metal cage, a centrifugal flow barrel polishing machine is known.

As shown in FIG. 7 (I), a centrifugal flow barrel polishing machine is arranged such that a plurality of barrel tanks 22 are arranged at equal intervals on a concentric circle of a rotation axis at an outer peripheral portion of a turret disk 21 so as to be rotatable. The barrel turret 22 is caused to carry out planetary movement by the rotation of the turret disk 21.

When polishing the cage, the cage, polishing media, compound, water, rust inhibitor and the like are put into the barrel tank 22, and then the turret disk 21 is rotated to cause the barrel tank 22 to perform a planetary motion. .

[0008] During the planetary movement of the barrel tank 22, the filler 23 such as abrasive media filled therein moves to the outer peripheral side in the barrel tank 22 by centrifugal force, and forms a surface layer in contact with the space in the barrel tank 22. A fluid tank 24 that flows in the swirling direction is formed, and the retainer is polished by contact with the polishing media in the fluid tank 24, and burrs and the like are removed by the polishing.

[0009] After the polishing, the retainer is removed by washing such as water washing or ultrasonic washing. After that washing,
It is immersed in hot water of about 50 ° C., and then dried by blowing air or the like.

[0010]

In the above-mentioned polishing treatment of the cage, a polishing medium mainly containing aluminum oxide (alumina) has been generally used as a polishing medium. This aluminum oxide is 1700-
Since the retainer has a hardness of about 2000 Hv, the retainer can be very effectively polished, but fine aluminum oxide may remain in the surface of the retainer.

As described above, the retainer removes the deposits by washing after the polishing process. However, as described above, if the aluminum oxide is buried, it cannot be removed. .

Therefore, in a cylindrical roller bearing in which a cylindrical roller is held by a cage which has been barrel-polished by a polishing medium mainly composed of aluminum oxide, the cylindrical roller wears due to contact with aluminum oxide remaining in the cage. In some cases, problems such as grease deterioration may occur due to the induction of the grease or the mixing of the wear powder into the grease.

Generally, rolling bearings and the like for supporting a rotating shaft of a main motor mounted on a railway vehicle are regularly inspected when a predetermined traveling distance is reached to inspect the rolling bearings. In order to extend the period and reduce maintenance and inspection costs, there is a demand for a highly reliable rolling bearing for high load and high speed rotation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a polishing medium for barrel polishing in which abrasion of rolling elements is hardly induced even if the polishing medium remains in the barrel-polished machined cage.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a polishing medium for barrel-polishing a metal hollow cage for holding a rolling element of a rolling bearing. A configuration in which the hardness is almost equal to the hardness of the rolling element is adopted.

Here, the hardness of the rolling element of the rolling bearing is 65.
Since it is about 0 to 800 Hv, the abrasive grain is 500 to
The hardness is about 850 Hv.

Examples of such abrasive grains include natural silica sand containing silicon oxide as a main component.

When the polishing media having the above-described configuration is put into a barrel polishing machine such as a centrifugal barrel polishing machine or a vibration tumbler, the punching cage is barrel-polished, whereby the punching cage is polished by contact with the polishing media. You.

Here, since the abrasive grains of the polishing media for polishing the machined cage have the same hardness as the rolling elements,
Even if abrasive grains remain in the machined cage after polishing in a state where they are buried, it is necessary to suppress the abrasion of the rolling elements due to contact with the abrasive grains and to prevent the grease from being deteriorated due to mixing of wear powder. Can be. Therefore, the life and reliability of the bearing are improved, and the maintenance and inspection organization can be extended and the maintenance and inspection costs can be reduced.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a cylindrical roller bearing as a rolling bearing. This cylindrical roller bearing comprises an outer ring 1, an inner ring 2, a cylindrical roller 3 as a rolling element incorporated between the two wheels 1, 2, and a retainer 4 for holding the cylindrical roller 3.

The cylindrical roller 3 is made of high carbon chromium bearing steel or the like and is quenched and has a surface hardness of 650 to 800H.
v. On the other hand, the retainer 4 is made of a high-strength brass casting and has a hardness of about 100 Hv.

As shown in FIGS. 2 to 4, the retainer 4
A plurality of pockets 5 are formed in the cage body 4a at equal intervals in the circumferential direction, and are provided between adjacent pockets 5. The cage body 4a includes a cylindrical retainer body 4a and a ring plate 4b abutted on the end surface thereof. A pin hole 7 penetrating through both end surfaces of the pillar 6 is formed. On the other hand, the ring plate 4b has
A pin hole 8 is formed at a position facing the pin hole 7, and the retainer main body 4a and the ring plate 4b are integrated by caulking a pin 9 inserted into the pin holes 7, 8. The cylindrical roller 3 includes a retainer body 4a and a ring plate 4
In a stage before the integration with b, it is inserted into the pocket 5 of the retainer main body 4a.

The pocket 5 of the retainer main body 4a is formed by cutting. In forming the retainer main body 4a, the outer diameter surface and the inner diameter surface of the cylindrical material 10 shown in FIG. 5 (I) are turned to a predetermined size and shape, and then one end surface of the cylindrical material 10 is formed. From the fir
As shown in FIG. 5 (II), a plurality of pockets 5 are formed. As described above, when the retainer body 4a is cut out,
For example, as shown in FIG.
1 is formed.

In order to remove the burrs 11, the retainer main body 4a after the deburring is subjected to an appropriate deburring operation, and further barrel-polished. After the barrel polishing, the retainer body 4a
Is washed, immersed in warm water of about 50 ° C. to remove oil, and then dried by blowing air.

Here, in barrel polishing of the retainer body 4a, a centrifugal flow barrel polishing machine 20 shown in FIG. 7 (I) is used. In the barrel polishing, if the hardness of the abrasive grains of the polishing media is too low, the burrs 11 cannot be effectively removed, and a long time is required for polishing. On the other hand, if the hardness is too high, as described above, the abrasive grains of the polishing media buried in the retainer body 4a cannot be removed by washing, and wear is induced on the cylindrical rollers 3 by contact with the remaining abrasive grains. Problem may occur.

In order to solve the problem, the polishing media is formed by abrasive grains having a hardness of about 500 to 850 Hv. Such abrasives include natural silica sand. Table 1 shows the components of the natural silica sand and contains silicon oxide as a main component.

[0027]

[Table 1]

The natural silica sand containing silicon oxide as a main component as described above contains a small amount of aluminum oxide.
This is not a problem. This natural silica sand is mixed with a binder and formed into a predetermined shape. As the binder, an unsaturated polyester resin can be used. The unsaturated polyester and the above-mentioned natural silica sand are blended by 50%, and the mixture is formed into a bullet having a size of, for example, about 6 mm to form an abrasive medium. I do. FIG. 7 (II) shows the formed polishing media 12, 13 indicates abrasive grains, and 14 indicates a binder. By polishing using the polishing media 12 with a centrifugal flow barrel polishing machine, as shown in FIG. 6 (II), the burrs formed on the edges and the like of the pockets 5 are removed and rounded.

After the polishing, the retainer body 4a is cleaned in the same manner as described above. Even if the abrasive grains 13 of the polishing media remain in the retainer main body 4a due to the washing, the hardness of the abrasive grains 13 is substantially the same as the hardness of the cylindrical roller 3 housed in the pocket 5, so that the abrasive grains 13 Abrasion of the cylindrical roller 3 due to contact of the roller 3 can be suppressed. Also, the amount of abrasion powder mixed in can be reduced to about 1/2 to 1/3 as compared with a cage polished using a polishing medium mainly containing aluminum oxide,
Problems due to deterioration of the grease due to the mixing of the wear powder are extremely reduced, and the life and reliability of the bearing can be improved.

In the embodiment, a cylindrical roller bearing having an outer ring 1 and an inner ring 2 has been described as a cylindrical roller bearing, but the type of the cylindrical roller bearing is not limited to this. For example, FIG.
As shown in (I), an inner ring 2 having a raceway surface formed on the outer periphery, a cylindrical roller 3 and a machined cage 4,
As shown in FIG. 8 (II), it may be composed of an outer ring 1 having a raceway surface formed on the inner periphery, a cylindrical roller 3 and a machined cage 4. Alternatively, as shown in FIG.
It may be composed of a cylindrical roller 3 and a punching retainer 4.

Further, in the embodiment, the cylindrical roller bearing has been described as an example of the rolling bearing. However, the rolling bearing is not limited to this. You may.

[0032]

As described above, according to the present invention, the hardness of the polishing media for barrel-polishing the metal-made metal-cage retainer is substantially the same as that of the rolling element of the rolling bearing, so that the metal is retained by cleaning after barrel-polishing. Even if abrasive media remains in the grinding machine, it is possible to suppress wear of the rolling elements due to contact with the remaining abrasive media and deterioration of grease due to mixing of abrasion powder. Can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a rolling bearing according to the present invention.

FIG. 2 is a cross-sectional view of a state where the retainer is cut at a pillar portion of the cage.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is an exploded perspective view showing a part of the cage.

FIGS. 5 (I) and (II) are perspective views showing steps of manufacturing the retainer main body according to the embodiment.

FIG. 6 (I) is a cross-sectional view showing a state after the pocket is removed, and (II) is a cross-sectional view showing the state after barrel polishing.

FIG. 7 (I) is a schematic view of a centrifugal flow barrel polishing machine, (I)
I) is an enlarged sectional view of the polishing media

8 (I), (II) and (III) are cross-sectional views showing another example of the cylindrical roller bearing.

[Explanation of symbols]

 3 Cylindrical roller 4 Cage 13 Abrasive

Claims (4)

[Claims] 1. A polishing media for barrel-polishing a metal hollow cage for holding a rolling element of a rolling bearing,
A polishing medium for barrel polishing of a metal machined retainer, wherein the hardness of the abrasive grains is substantially equal to the hardness of the rolling elements. 2. The polishing media for barrel polishing of a metal machined holder according to claim 1, wherein the hardness of the abrasive grains is 500 to 850 Hv. 3. The polishing media for barrel polishing of a metal machined retainer according to claim 1, wherein the abrasive grains contain silicon oxide as a main component. 4. The polishing media for barrel polishing of a metal machined retainer according to claim 1, wherein said abrasive grains are made of natural silica sand.