JPH11303875A - Cage - Google Patents

Abstract

(57) [Problem] To provide a retainer capable of reducing cost, preventing surface peeling, and preventing an increase in pocket gap due to wear. SOLUTION: This is a metal cage for rotatably holding a rolling element interposed between an inner ring of a bearing and an exporter, the surface of which is made of iron, phosphorus and oxygen which are bases, manganese, It is formed of a crystalline reaction film with at least one of zinc and calcium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing suitable for a high-speed rotating bearing such as a bearing for a generator, a flywheel bearing, a bearing for a main shaft of a centrifuge, a high-frequency motor and an aircraft engine, or a bearing for a supercharger. About the vessel.

[0002]

2. Description of the Related Art A conventional cage of this type is generally formed by subjecting an SAE4340 material, which is a cage material, to strike plating of copper and nickel, followed by two-layer plating of silver plating having a thickness of 40 to 50 μm. ing.

[0003]

However, in such a conventional cage, the plating process is complicated and the production cost is high, and the adhesion at the interface between the plating layer and the base material is weak. There is a disadvantage of peeling.

Further, since silver plating is thick and soft, it causes plastic deformation due to contact with the rolling elements when the bearing is used, and the pocket gap becomes large, resulting in a disadvantage that skew occurs.

The present invention has been made to solve such inconveniences, and can reduce costs, prevent surface peeling, and prevent an increase in pocket gap due to abrasion. It is an object of the present invention to provide a retainer capable of performing the following.

[0006]

In order to achieve the above object, a cage according to the present invention is provided with a metal cage for rollingly holding a rolling element interposed between an inner ring of a bearing and an exporter. A retainer, the surface of which is iron, phosphorus and oxygen as bases;
It is characterized by being formed of a crystalline reaction film with at least one of manganese, zinc and calcium.

Here, the material of the cage is, for example, S
AE 4340 or 4320 can be used. As for the weight ratio of each element of the crystalline reaction film, iron is desirably 35% by weight or less, manganese is 12 to 20% by weight,
As for zinc and calcium, 5-35% by weight is desirable. Further, the film thickness is desirably 2 to 10 μm, and 2 to 6 μm
Is more desirable.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. A baking test was performed by rotating a pin (specimen: SAE4340) pressed against the V block using a Phalex testing machine based on ASTM D2625 to evaluate the load resistance and the durability time.

The test conditions are shown below. Rotation speed: 191 rpm Slip speed: 0.1 m / s, load: 50 kgf / min Step load method (load is increased every minute.) Lubrication: Mobile (Larus 1026) Evaluation method: 50 kgf / min from no load The torque was detected while a load was applied, and the load when the load reached 140 kgf · cm was taken as the seizure load (withstand load), and the time until the seizure load was reached was taken as the durability time.

The test specimens were Comparative Examples 1 and 2 and Example A of the present embodiment.
Comparative Example 1 is an untreated pin, Comparative Example 2
The silver plating was formed on the surface of the pin with a thickness of 40 μm. In Embodiment A, a chemical conversion solution PF-M1A manufactured by Nippon Parkerizing Co., Ltd. was used.
A compound layer of iron, phosphorus, manganese, and oxygen (crystalline reaction film layer: film thickness: 5 μm, iron content: 22% by weight, manganese content: 15% by weight) ) Was evaluated under the same conditions. Table 1 shows the results.

Here, the total acidity is defined as a value of 0.1 required for titration of total phosphoric acid in 10 ml of a reaction solution using phenolphthalein.
It represents the amount of 1N caustic soda, and the free acidity means the reaction solution 1
Only the primary dissociation amount of 0 ml of phosphoric acid is the amount of 0.1 N sodium hydroxide required for titration with bromophenol green.

[0012]

[Table 1]

As is clear from Table 1, the embodiment A of the present embodiment
It can be seen that the test specimen of No. 1 is superior to Comparative Examples 1 and 2 in both the load resistance and the durability time. Next, various types of specimens having a crystalline reaction film layer having different iron content, manganese content and film thickness formed on the surface of the pin were prepared, and for each specimen,
The relationship between the chemical composition of the crystalline reaction film layer and the durability time, and the relationship between the film thickness and the surface roughness were investigated.

The chemical composition is EDS (Energy d
ZAF correction is performed by ispersive spectroscopy, and the acceleration voltage is 15 kV and the quantitative area is 0.01 mm ^2.
Weighed for seconds and determined by weight ratio. The endurance time was measured using the Falex tester under the same test conditions.

FIG. 1 shows the relationship between the manganese content and the durability time, FIG. 2 shows the relationship between the iron content and the durability time, and FIG. 3 shows the relationship between the film thickness and the surface roughness. As is clear from FIGS. 1 and 2, when the four components of oxygen, phosphorus, manganese, and iron are quantified, the manganese content is 12 to 20 as a weight ratio of each element of the crystalline reaction film layer. It is found that the weight% and the iron content are preferably 35% by weight or less. If the weight ratio of manganese is less than 12% by weight, a dense crystal is not formed on the entire surface, so that the underlying metal is exposed. On the other hand, if it exceeds 20% by weight, sludge (crystal debris) is inferior in reactivity with the underlying material. ) Is increased, so that the durability time is shortened.

On the other hand, when the iron content exceeds 35% by weight,
Since the crystal growth is not uniform and the lubricating oil adsorption is poor, the durability time is short and the seizure load is small. As is apparent from FIG. 3, the thickness of the crystalline reaction film layer is 2 to 10 μm.
It is understood that 2 to 6 μm is more desirable.
When the film thickness exceeds 10 μm, the surface roughness of the cage surface deteriorates due to a chemical reaction, and when the film thickness is less than 2 μm, abrasion easily occurs and the function of the cage is easily impaired.

Next, three types of angular contact bearings (inner diameter 50 mm, outer diameter 110 mm, width 27) in which the cages of Comparative Examples 3 and 4 and Embodiment B of the present embodiment are respectively incorporated.
mm) were used in a single row in front of each other, and a rotation test of each cage was performed using the test pieces as test samples to evaluate the wear depth of the rolling element contact portion (pocket portion) and the guide surface.

The test conditions are shown below. Number of revolutions: 12000 rpm Load (axial direction): 120 kgf Temperature: Room temperature Lubrication: 10 cc / h (lubrication) Test time: 720 hours All cages have the same shape, and the outer surface of the cage and the inner surface of the outer ring are in contact ( Outer ring guide retainer), and the retainer material is SAE4340 at 600 ° C. after heat treatment (stress removal) for dimensional stabilization, followed by cutting. In Example 4, silver plating was formed to a thickness of 40 μm on the surface, and in Embodiment B, a compound layer of iron, phosphorus, manganese, and oxygen (crystal) was formed on the surface in the same manner as in Embodiment A described above. (Active reaction film layer: a layer having a thickness of 5 μm, an iron content of 25% by weight, and a manganese content of 17% by weight) was used.

The evaluation tester is a system in which a shaft supported by a specimen is rotated by a motor via a coupling, and an axial load (axial load) is applied by hydraulic pressure. Lubrication is performed using turbine oil VG32 (SAE10W-3).
0), oil was mixed into the compressed air, and supplied to the rolling surface from the bearing end surface in a mist state. Table 2 shows the evaluation results.

[0020]

[Table 2]

As is clear from Table 2, this embodiment B
It can be seen that the test specimen of No. 1 has superior wear resistance of the rolling element contact portion (pocket portion) and the guide surface as compared with Comparative Examples 3 and 4. As is clear from the above description, in this embodiment, since a crystalline reaction film layer with iron as a base is formed on the cage surface by a chemical reaction, the strength is high, and the crystal on the surface Since the unevenness of the quality is increased and the interface area is increased, it is possible to prevent the surface peeling of the reaction film layer when it is strong.

Further, since there are many crystalline irregularities on the surface, the oil adsorbing property (lipophilicity) at the sliding portion can be increased and the seizure resistance can be improved. ~
Since the wear can be reduced as compared with the conventional cage provided with 50 μm, it is possible to prevent the skew of the rolling element at the rolling element contact portion (pocket portion) and to reduce the slip of the guide surface. As a result, a long-life bearing can be obtained.

Furthermore, because of the chemically reactive crystal film layer, the manufacturing process (degreasing washing → water washing → immersion treatment → washing process) becomes simpler than that of a conventional cage having silver plating of 40 to 50 μm. Cost can be reduced.

In the above embodiment, the case where manganese is reacted with iron, phosphorus and oxygen which are bases is taken as an example. However, instead of manganese, one of zinc or calcium, or manganese and zinc is used. The same action and effect as described above can be obtained by using two kinds of the above, two kinds of zinc and calcium, two kinds of manganese and calcium, and three kinds of manganese, zinc and calcium.

[0025]

As is apparent from the above description, according to the present invention, the cost can be reduced, the surface can be prevented from peeling, and the increase in the pocket gap due to wear can be prevented. Can be provided.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the manganese content and the durability time.

FIG. 2 is a graph showing the relationship between iron content and durability time.

FIG. 3 is a graph showing the relationship between film thickness and surface roughness.

Claims (1)

[Claims] 1. A metal cage for rotatably holding a rolling element interposed between an inner ring of a bearing and an external bearing, the surface of which is made of iron, phosphorus and oxygen serving as bases, and manganese. A retainer formed of a crystalline reaction film with at least one of zinc, calcium and calcium.