JPH074429A - Rolling bearing - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent wear of the guide surfaces 8a, 8a and the guided surfaces 7a, 7a. [Structure] Concave grooves 9 and 9 are formed on the guide surfaces 8a and 8a, and abrasion powder generated in the cage 6 is discharged through the concave grooves 9 and 9. By discharging the wear debris, new wear caused by the wear debris is prevented. Further, a strong oil film is formed between the both surfaces 8a, 7a through the concave grooves 9, 9 to prevent wear due to oil film breakage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The rolling bearing according to the present invention relates to an improvement of a rolling bearing that rotates at high speed such as a gas turbine and a jet engine.

[0002]

2. Description of the Related Art Rolling bearings as shown in FIGS. 9 to 10 are widely used to support various rotating parts such as a rotating shaft of a gas turbine. Each of these rolling bearings is provided between the inner ring 2 having an inner ring raceway 1 on the outer peripheral surface, the outer ring 4 having an outer ring raceway 3 on the inner peripheral surface, and between the inner ring raceway 1 and the outer ring raceway 3 so as to be freely rollable. A plurality of rolling elements 5 (rollers in the illustrated example), and a retainer 6 rotatably provided between the inner ring raceway 1 and the outer ring raceway 3 while holding the plurality of rolling elements 5. It has and.

The cage 6 rotates as the rolling element 5 rolls, but by being guided by the inner ring 2 or the outer ring 4, the cage 6 swings in the diametrical direction (vertical direction in FIGS. 9 to 10) during rotation. I try not to. That is, in the first example shown in FIG.
Guided surfaces 7 provided on the inner peripheral surfaces of both ends of the cage 6.
The so-called inner ring guide structure is formed by bringing a and 7a close to guide surfaces 8a and 8a provided on the outer peripheral surfaces of both ends of the inner ring 2 which are located outside the inner ring raceway 1. Also, FIG.
In the second example shown in FIG. 2, the guided surfaces 7b, 7b are provided on the outer peripheral surfaces of both ends of the cage 6, and the inner peripheral surfaces of both ends of the outer ring 4 are provided at the portions deviated from the outer ring raceway 3. A so-called outer ring guide structure is provided in which the guide surfaces 8b and 8b are close to each other.

In any of the guide structures, when the cage 6 is rotated, the guided surfaces 7a and 7b slide with respect to the guide surfaces 8a and 8b, so that the cage 6 is displaced in a diametrical manner. Allow things to rotate while preventing things. As described above, when the rolling bearing is used, the guided surfaces 7a, 7b are
And the guide surfaces 8a and 8b slide, but in the case of a rolling bearing that rotates at high speed such as a gas turbine bearing, the relative speed (sliding speed) between the two surfaces 7a, 7b, 8a and 8b.
Is considerably larger. For this reason, the surface of the cage 6 is plated with silver, which serves as a solid lubricating layer.
The surfaces 7a, 7b, 8a and 8b are prevented from being worn.

[0005]

However, in the case of the rolling bearing constructed and operated as described above, the guided surfaces 7a, 7a and 7b are formed.
Due to the properties of the b and the guide surfaces 8a, 8b, damages such as abrasion may occur on the both surfaces 7a, 7b, 8a, 8b. The present inventors have studied the cause of such damage and found the following.

Abrasion powder bites into and is fixed to the surface of the silver plating coated on the guided surfaces 7a and 7b, and the silver-plated layer containing the abrasion powder functions as if it were a rasp. Shave off and wear this guide surface. That is, when the rolling bearing is in operation, it is inevitable that minute wear powder is generated, but the wear powder generated inside the cage 6 causes a gap between the guided surfaces 7a and 7b and the guide surfaces 8a and 8b. When it enters, the abrasion powder bites into the soft silver-plated surface and is fixed on the silver-plated surface, causing the above-described abrasion.

Due to the whirling motion of the cage 6 during high-speed rotation, the guided surfaces 7a, 7b and the guiding surfaces 8a, 8 are formed.
The oil film is cut off between the two surfaces 7a, 7b, 8
Metal contact occurs between a and 8b, which promotes wear. That is, the center of rotation of the cage 6 and the center of gravity do not coincide completely. Therefore, when the cage 6 rotates at a high speed, the cage 6 tends to make a so-called whirling motion in which the cage 6 rotates while being displaced in the diametrical direction based on the disagreement between the center of rotation and the center of gravity. As a result, the guided surface 7
The a and 7b are strongly pressed partially toward the guide surfaces 8a and 8b, the oil film of the part is pushed away, the oil film breakage easily occurs, and the abrasion as described above easily occurs.

The present invention is intended to obtain a rolling bearing excellent in durability and reliability by preventing wear due to these causes.

[0009]

The rolling bearing of the present invention comprises:
Similar to the conventional rolling bearing described above, an inner ring having an inner ring raceway on the outer peripheral surface, an outer ring having an outer ring raceway on the inner peripheral surface, and a plurality of rollably provided between the inner ring raceway and the outer ring raceway. And a retainer rotatably provided between the inner ring raceway and the outer ring raceway while holding the plurality of rolling elements. Then, the guided surface, which is one of the peripheral surfaces of the cage, is disengaged from the track formed on the peripheral surface at a part of the peripheral surface of either the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring. The cage is guided by being brought close to the guide surface which is the open portion.

In particular, in the rolling bearing of the present invention, the guide surface has a large number of concave grooves in the circumferential direction. Each of these grooves is inclined with respect to the axial direction of the inner ring and the outer ring. And, the inclination direction of each groove is characterized in that it is a direction in which the fluid existing in the plurality of rolling element installation portions is taken into each groove based on the relative rotation of the guide surface and the guided surface. There is.

[0011]

According to the rolling bearing of the present invention having the above-described structure, the wear debris that has entered between the guide surface and the guided surface is discharged to the outside of the rolling bearing through the plurality of concave grooves. The powder does not promote wear of the guide surface and the guided surface. In addition, a sufficient amount of lubricating oil is supplied between these two sides through the above-mentioned recessed grooves, so even if the cage runs around, it will be less likely to run out of oil film, and wear due to oil film runout will also be prevented. it can.

[0012]

1 to 4 show, as a first embodiment of the present invention, an example in which the present invention is applied to a structure in which a cage 6 is supported by a so-called inner ring guide. The same parts as those of the conventional structure shown in FIG. 9 are designated by the same reference numerals, and the overlapping description will be omitted.
The characteristic part of the present invention will be described. In each of the illustrated embodiments, the outer ring 4 is fixed to the housing side and the inner ring 2 is used together with the rotating shaft. In the case of the first embodiment, the inner ring 2 rotates counterclockwise in FIGS. 2 and 4, and from right to left in FIG. The cage 6 also rotates in the same direction as the inner ring 2 with the rotation of the inner ring 2, but the rotational speed of the cage 6 is slower than the rotational speed of the inner ring 2 (usually about half). Therefore, the inner ring 2 rotates relative to the retainer 6 in the counterclockwise direction in FIGS. 2 and 4, and in the right to left direction in FIG. 3, as indicated by the arrow X in FIGS.

In the case of the rolling bearing of the present invention, a large number of recessed grooves 9, 9 are formed in the guide surfaces 8a, 8a formed at both ends of the outer peripheral surface of the inner ring 2 at equal intervals in the circumferential direction. is doing. Each of these recessed grooves 9, 9 is inclined with respect to the axial direction of the inner ring 2 and the outer ring 4. Then, the inclination direction of each groove 9, 9 is determined based on the relative rotation between the guide surfaces 8a, 8a and the guided surfaces 7a, 7a provided at both ends of the inner peripheral surface of the cage 6, respectively. The direction in which the fluid existing in the moving body installation portion is taken into the concave grooves 9 and 9 is set. That is, each of the recessed grooves 9, 9 is inclined in a direction toward the rear in the rotation direction of the inner ring 2 (to the right in FIGS. 2 to 4) from the center of the width direction toward both ends of the width direction.

According to the rolling bearing of the present invention constructed as described above, the abrasion powder that has entered between the guide surfaces 8a, 8a and the guided surfaces 7a, 7a is rolled through the plurality of concave grooves 9, 9. Since it is discharged to the outside, the guide surface 8 is
The wear of a, 8a and the guided surfaces 7a, 7a is not promoted. That is, even if the abrasion powder bites into the silver-plated surface covering the guided surfaces 7a, 7a, the abrasion powder falls off when passing through the concave grooves 9, 9. On the other hand, each groove 9,
Inside 9 is a flow that discharges the lubricating oil and air inside the cage 6 to the outside of the cage 6 by a kind of pumping action that accompanies the rotation of the inner ring 2. Therefore, the abrasion powder that has fallen off in the concave grooves 9 and 9 is discharged to the outside of the cage 6 by the flow. As a result, abrasion due to abrasion powder is prevented.

Further, the guide surfaces 8a, 8a and the guided surface 7 are
A sufficient amount of lubricating oil is supplied between a and 7a through the plurality of concave grooves 9 and 9. That is, the lubricating oil that has entered the concave grooves 9 and 9 enters the minute gap between the guide surfaces 8a and 8a and the guided surfaces 7a and 7a by the wedge action accompanying the rotation of the inner ring 2, A strong lubricating oil film due to the wedge film effect is formed between the both surfaces 8a, 7a. Therefore, even if the cage 6 swings around, the oil film is less likely to run out, and wear due to the running out of the oil film can be prevented.

Next, FIGS. 5 to 8 show, as a second embodiment of the present invention, a cage 6 supported by a so-called outer ring guide and a rolling element 5.
An example is shown in which the present invention is applied to a structure using balls as. The same parts as those of the conventional structure shown in FIG. 10 are designated by the same reference numerals, and the overlapping description will be omitted. The characteristic parts of the present invention will be described below. Also in the case of the second embodiment, the inner ring 2 rotates counterclockwise in FIG. Therefore, the cage 6 is attached to the fixed outer ring 4 in FIGS.
As shown by, the relative rotation is performed counterclockwise in FIGS. 6 and 8 and from right to left in FIG.

Guide surfaces 8b, 8 are provided at both ends of the inner peripheral surface of the outer ring 4.
b is provided, and a large number of concave grooves 9a, 9a are formed in each guide surface 8b, 8b at equal intervals in the circumferential direction. Each of these concave grooves 9a, 9a is inclined with respect to the axial direction of the inner ring 2 and the outer ring 4. And each groove 9a,
The inclination direction of 9a is based on the relative rotation between the guide surfaces 8b, 8b and the guided surfaces 7b, 7b provided at both ends of the inner peripheral surface of the cage 6, and the fluid existing in the plurality of rolling element installation portions Is the direction in which the grooves 9a, 9a are taken in. That is, the recessed grooves 9a, 9a are inclined toward the front in the rotational direction of the inner ring 2 (to the right in FIGS. 6 to 8) from the widthwise center toward the widthwise end edges.

Also in the case of this embodiment, as in the case of the first embodiment described above, the guide surfaces 8b, 8b and the guided surfaces 7b, 7b.
The wear powder that has entered between and is discharged to the outside of the rolling bearing through the plurality of recessed grooves 9a and 9a, so that the wear powder promotes the wear of the guide surfaces 8b and 8b and the guided surfaces 7b and 7b. There is no. In addition, since a sufficient amount of lubricating oil is supplied between the two surfaces 8b and 7b through the plurality of recessed grooves 9a and 9a, the oil film is unlikely to run out even when the cage is swung, Wear due to running out of oil film can also be prevented.

In each embodiment, the depths, widths, inclination angles, etc. of the concave grooves 9, 9a are determined by design in accordance with the size of the rolling bearing to be implemented, the rotational speed used, and the like. Although not shown, the plurality of concave grooves 9 and 9a are formed on the guide surface 8b,
Instead of 8b, or on the guided surfaces 7b, 7b together with the guiding surfaces 8b, 8b. However, it is necessary to reverse the inclination direction of the concave groove between the case where the concave groove is formed on the guide surfaces 8b and 8b facing each other and the case where the concave groove is formed on the guided surfaces 7b and 7b. Although not shown, the present invention can also be implemented when the inner ring 2 is fixed and the outer ring 4 is rotated. However, it is necessary to reverse the inclination direction of the plurality of concave grooves 9 and 9a with respect to the rotation direction with respect to each of the above-described embodiments.

[0020]

Since the rolling bearing of the present invention is constructed and operates as described above, it is possible to prevent the abrasion powder from remaining and suppress the occurrence of oil film breakage, thereby preventing the abrasion, thereby improving the durability, A highly reliable rolling bearing can be obtained.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a first embodiment of the present invention.

FIG. 2 is a partial side view of the same.

FIG. 3 is a view of the inner ring taken out and viewed from above in FIG.

FIG. 4 is a view seen from below in FIG.

FIG. 5 is a partial sectional view showing a second embodiment of the present invention.

FIG. 6 is a partial side view of the same.

FIG. 7 is a view of the outer ring taken out and viewed from below in FIG.

FIG. 8 is a view seen from above in FIG.

FIG. 9 is a partial sectional view showing a first example of a conventional rolling bearing.

FIG. 10 is a partial cross-sectional view showing the second example.

[Explanation of symbols]

 1 inner ring raceway 2 inner ring 3 outer ring raceway 4 outer ring 5 rolling element 6 cage 7a, 7b guided surface 8a, 8b guide surface 9, 9a concave groove

Claims (2)

[Claims] 1. An inner ring having an inner ring raceway on an outer peripheral surface, an outer ring having an outer ring raceway on an inner peripheral surface, and a plurality of rolling elements rotatably provided between the inner ring raceway and the outer ring raceway. In the state where the plurality of rolling elements are held, a retainer rotatably provided between the inner ring raceway and the outer ring raceway is provided, and a guided surface that is any peripheral surface of the retainer is provided. Guide the cage by bringing the outer peripheral surface of the inner ring and the inner peripheral surface of the outer ring into close proximity to a guide surface that is a portion off the track formed on the peripheral surface at a part of the peripheral surface. In the illustrated rolling bearing, the guide surface has a large number of grooves in the circumferential direction, and each groove is inclined with respect to the axial direction of the inner ring and the outer ring. The direction is based on the relative rotation between the guide surface and the guided surface, and the fluid existing in the plurality of rolling element installation portions is set to each of the above-mentioned directions. Rolling bearing characterized in that it is in the direction to be taken into the groove. 2. The rolling bearing according to claim 1, wherein a plurality of concave grooves are formed on the guided surface instead of or together with the guide surface.