JP2001099166A - Lubricating device for bearing and bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricating device for a bearing and the bearing capable of corresponding to high speed rotation while labor is omitted at maintenance time. SOLUTION: This device has a lubricant-contained polymer member 16 charged in a bag hole 15b provided in a spindle 15 supported by an inner ring 12 and a supply path 15c extended from the bag hole 15b toward an external periphery of the spindle 15, a lubricant coming out from the lubricant-contained polymer member 16 is supplied in a bearing 10 through a through passage 12a inserted in a radial direction in the inner ring 12 of a bearing 10 through the supply path 15c, consequently the lubricant can be supplied to the bearing 10 based on centrifugal force, thus is suitable for lubrication of the bearing rotated at a high speed. By arranging the lubricant-contained polymer member 16 in a position nearer than the bearing 10 from the axial center, its receiving centrifugal force and vibration are decreased. Necessity for providing the lubricant-contained polymer member 16 in a constitutional part of the bearing 10 or a space in the inside of the bearing 10 is eliminated, thus necessity for separating the spindle 15 and the bearing 10 is eliminated at maintenance time of the lubricant- contained polymer member 16, and labor for maintenance is omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication technique for a bearing, for example, a lubrication technique for lubricating a bearing using a polymer containing a lubricant.

[0002]

2. Description of the Related Art Generally, when a main shaft of a machine tool or the like is rotatably supported by rolling bearings, grease lubrication is generally used if it is possible to provide a compact structure without providing an oiling device or the like. is there. Such rolling bearings are often lubricated with grease excellent in high speed and low heat generation, such as grease such as Isoflex NBU15 manufactured by Cruiba.

[0003]

By the way, in order to improve the processing efficiency and the productivity, the machine tool is required to have a higher speed, and the rotational speed of the spindle tends to be higher. However, Dmn 800,000 (rpm · mm)
In order to properly lubricate a bearing corresponding to a high-speed rotation exceeding the above range, normal grease lubrication may result in insufficient lubrication.

In such a case, a lubricating device using a resin containing a lubricant (hereinafter, referred to as a lubricant-containing polymer) has been developed for the purpose of, for example, further improving the lubrication of a grease-lubricated bearing. I have. JP-A-6-31343
Japanese Patent Application Laid-Open No. 8-2 discloses a structure in which a space is sandwiched between the outer ring and the inner ring and a lubricant-containing polymer is filled therein.
No. 1450 discloses a retainer made of a polymer containing a lubricant. Further, Japanese Unexamined Patent Publication No. 7-145818
Japanese Patent Application Laid-Open No. 7-139551 discloses a structure in which a recess is provided in an outer ring, an inner ring, or a roller and filled with a lubricant-containing polymer. There is disclosed a configuration in which a lubricant-containing polymer is filled in a space and a coating film of a release agent is formed on an inner peripheral surface of an outer ring, an outer peripheral surface of an inner ring, and a surface of a rolling element.

[0005]

In conventional rolling bearings containing a lubricant-containing polymer, any of the rolling bearings in which the lubricant-containing polymer is directly filled in the bearing or the bearing components are lubricated. It is formed of an agent-containing polymer. However, since the mechanical strength of the lubricant-containing polymer is generally low, the rolling incorporating a bearing component (here, a retainer) made of the lubricant-containing polymer as disclosed in JP-A-8-21450 is disclosed. When the bearing supports the main shaft of a machine tool that rotates at high speed, the strong centrifugal force or large vibration may cause deformation or breakage of the lubricant-containing polymer.

Further, as disclosed in JP-A-6-313435 and JP-A-7-145818,
The lubricant-containing polymer is placed inside the bearing (in this case, the space surrounded by the inner ring and the outer ring) or the bearing components (here, the inner ring,
In the case of rolling bearings directly filled in the outer ring and rollers
As disclosed in JP-A-313435, in order to maintain the dimensional accuracy of the bearing and the bearing component, the tempering temperature of the bearing component filled with the lubricant-containing polymer is set to be equal to or higher than the melting point of the polymer. It is necessary to heat-treat the bearing member at a temperature higher than usual depending on the type of the lubricant-containing polymer to be used, so that there is a problem that the manufacturing cost increases. In addition, at the time of maintenance, it is necessary to perform work after separating the main shaft and the bearing, which is troublesome.

The present invention has been made in view of the above problems of the prior art,
An object of the present invention is to provide a bearing lubricating device and a bearing that can cope with high-speed rotation while saving labor for maintenance.

[0008]

In order to achieve the above object, a bearing lubricating device according to the present invention comprises an inner ring, an outer ring, and a rolling element rotatably disposed between the inner ring and the outer ring. A lubricant source provided in a shaft supported by the inner ring, and a supply path extending from the lubricant source to an outer periphery of the shaft in the shaft. The lubricant supplied from the lubricant source is supplied to the inside of the bearing via the supply passage and further through a through passage radially penetrating the inner race of the bearing.

According to the lubricating device of the present invention, a lubricant source provided in a shaft supported by the inner race, and a supply passage extending from the lubricant source to the outer periphery of the shaft in the shaft. Wherein the lubricant from the lubricant source is supplied into the bearing via the supply path and further through a through path radially penetrating the inner race of the bearing. Because the lubricant can be supplied to the bearing based on the centrifugal force,
Suitable for lubrication of high-speed rotating bearings. Further, since the lubricant source is disposed at a position closer to the axis than the bearing, the centrifugal force and vibration received by the lubricant source are reduced. Therefore, a lubricant-containing polymer or the like that is weak to external force may be used as the lubricant source. Yes, but not limited to. Further, it is not necessary to provide, for example, a lubricant-containing polymer or the like in the components of the bearing or in the space inside the bearing. When such a lubricant-containing polymer is maintained, there is no need to separate the shaft and the bearing, thereby reducing maintenance work. .

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an axial sectional view of a bearing lubrication device according to a first embodiment of the present invention. FIG. 2 is a view of the main axis of FIG. 1 viewed in the direction of arrow II. In FIG. 1, an angular contact ball bearing (hereinafter, referred to as a bearing) 10 often used to support a main shaft 15 of a machine tool rotating at high speed includes an outer ring 11 attached to a housing (not shown) and a main shaft 1.
5 comprises a plurality of balls 13 as rolling elements sandwiched between the outer ring 11 and the inner ring 12, and a retainer 14 for holding the balls 13.

On the left end surface of the cylindrical main shaft 15, four screw holes 15a are formed at equal intervals in the circumferential direction.
A bag hole 15b is formed in the back of 5a. In the blind hole 15b, a lubricant-containing polymer 16 described later is provided.
Is arranged. The blind hole 15b filled with the lubricant-containing polymer 16 is sealed by a set screw 17 screwed into the screw hole 15a.

A supply passage 15c extending radially outward from the vicinity of the bottom of the blind hole 15b is formed. Supply path 15c
Is a through passage 1 that penetrates the inner ring 12 of the bearing 10 in the radial direction.
Open to 2a. The through passage 12a is adjacent to the raceway surface and is open toward the lower side of the ball 13, but may be open toward the retainer 14.

[0013] The lubricant-containing polymer used in the present embodiment is not limited at all, and any of those conventionally used for rolling bearings can be used. The resin containing the lubricant is not particularly limited,
It is preferable that the holding performance of the lubricant is high and that the operation of filling the holding member described later is easy. For example, polyolefin resins such as polyethylene, polypropylene, and polymethylpentene are suitable. In addition, polyamide, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyether sulfone, polyether ketone, polyamide imide, polystyrene,
A mixture of ABS resin, unsaturated polyester resin, urea resin, melamine resin, phenol resin, polyimide resin, epoxy resin and the like can also be used. It is also possible to use a mixture of a high molecular weight compound and a low molecular weight compound.

The lubricant is obtained by blending various additives with a lubricating oil. Lubricating oil is not particularly limited,
Mineral oils, ether oils, ester oils, paraffinic hydrocarbon oils, naphthalene hydrocarbon oils, and the like have a high affinity for the above-mentioned polyolefin resin, and can be contained in a larger amount in the resin. Of course, other lubricating oils are possible. The additives are also not particularly limited, and known rust preventives, antioxidants, antiwear agents, defoamers, extreme pressure agents, and the like can be appropriately compounded as necessary.

The lubricant-containing polymer is obtained by mixing the above-mentioned resin and lubricant at a predetermined mixing ratio, and optionally stirring the mixture while heating to dissolve both components. As the content of the lubricant in the lubricant-containing polymer increases, the lubricating life becomes longer, which is preferable. On the other hand, the lubricant-containing polymer itself softens and becomes difficult to maintain its shape. In the present embodiment, since the lubricant-containing polymer is used in a state of being filled in the blind hole 15b of the main shaft 15, no external force is directly applied at the time of assembly or the like, and the lubricant-containing polymer is close to the shaft center. Therefore, it is hardly affected by centrifugal force and vibration, and even if a large amount of lubricant is contained, no trouble is caused and the lubrication life can be improved. The oil content is preferably 30 to 95 w
t%, more preferably 50 to 90 wt%.

Next, the operation of this embodiment will be described. When the main shaft 15 rotates, the lubricant seeps out of the lubricant-containing polymer 16 filled in the blind hole 15b, and flows through the supply passage 15c and the through passage 12a of the inner ring 12 based on the centrifugal force. Invade inside.

The lubricant that has entered the bearing 10 adheres to the ball 13 due to centrifugal force, and lubricates the raceway surface as the ball 13 rotates. The lubricant-containing polymer 16 as a lubricant source and the supply path 15c constitute a lubrication device.

According to the present embodiment, the bearing 10 can be lubricated with a simple configuration without providing a large-scale lubricating device. At the time of maintenance, set screw 1
Since the lubricant-containing polymer 16 can be replaced by replacing the lubricant-containing polymer 16 or the lubricant can be replenished in some cases, there is no need to disassemble the main shaft 15 as in the prior art, and the workability is excellent.

FIG. 3 is a sectional view similar to FIG. 1 showing the second embodiment, but the lower half is omitted. FIG. 4 is a diagram of the main shaft 25 viewed from above in the radial direction with the bearing 10 removed. The second embodiment differs from the embodiment of FIG. 1 only in the configuration of the main shaft 25. That is, in FIG. 3, the supply passage 25 c extending in the radial direction from near the bottom of the blind hole 25 b is open at the bottom of the circumferential groove 25 d formed on the outer periphery of the main shaft 25. Further, the through hole 12a of the inner race 12 is also open toward the circumferential groove 25d. The width of the peripheral groove 25d is preferably larger than the diameter of the supply passage 25c and the diameter of the through hole 12a. The other configuration is the same as that of the first embodiment, and the description is omitted.

Next, the operation of the present embodiment will be described. In accordance with the rotation of the main shaft 25, the lubricant seeps out of the lubricant-containing polymer 16 filled in the blind hole 25b, and is based on the centrifugal force. Thus, the gas enters the bearing 10 through the supply passage 25c, the peripheral groove 25d, and the through passage 12a of the inner ring 12. The lubricant that has entered the bearing 10 adheres to the ball 13 due to centrifugal force, and lubricates the raceway surface as the ball 13 rotates.

According to this embodiment, in addition to the effects of the above-described embodiment, since the circumferential groove 25d is provided, the supply passages 25c and the through holes 12a formed at equal intervals in the circumferential direction are provided.
The lubricant can be appropriately transmitted from the supply passage 25c to the through hole 12a even when the angular position of the lubricant is shifted.

FIG. 5 shows a modification of this embodiment.
It is sectional drawing similar to. This modification differs from the embodiment of FIG. 3 in that a bearing 10 is provided instead of providing a circumferential groove in the main shaft.
Is that a circumferential groove 22b is provided on the inner periphery of the inner ring 22. That is, the main shaft 15 shown in FIG. 5 is the same as the configuration of FIG.

According to the present modification, in addition to the effect of the first embodiment, since the circumferential groove 22b is provided on the inner circumference of the inner race 22, the supply passages 15c formed at equal intervals in the circumferential direction are provided. Even if the angular position with respect to the through hole 22a is shifted, the supply path 15
The lubricant can be appropriately transmitted from c to the through hole 22a.

FIG. 6 is a sectional view similar to FIG. 1 showing the third embodiment. In the third embodiment, a disk-shaped front cover 18 is attached to the left end surface of the main shaft 15 so that dust and cutting fluid do not enter the blind hole 15b. Since the configuration is the same as that of the embodiment of FIG.

FIG. 7 is a sectional view similar to FIG. 3 showing a fourth embodiment. In the fourth embodiment, FIG.
As compared with the embodiment, the configurations of the bearing 10 and the main shaft 15 are the same, but the configuration of filling the blind hole 15b is different. That is, in FIG. 7, the porous member 19 is buried in the vicinity of the bottom of the blind hole 15b over about 1/4 of the entire length of the blind hole 15b. The remaining 3/4 of the blind hole 15b is filled with a lubricant-containing polymer. The other configuration is the same as that of the first embodiment, and the description is omitted.

The operation of this embodiment will be described.
The lubricant that has oozed out of the lubricant-containing polymer 16 filled in the blind hole 15b is temporarily accumulated in the porous member 19, and is supplied to the supply path 1 based on the centrifugal force generated by the rotation of the main shaft 15.
5c and the inner ring 12 penetrate into the bearing 10 through the through passage 12a. The lubricant that has entered the bearing 10 adheres to the ball 13 due to centrifugal force, and lubricates the raceway surface as the ball 13 rotates.

FIG. 8 is a diagram showing a modification of the present embodiment.
It is sectional drawing similar to. This modification differs from the embodiment of FIG. 7 in that the porous member 19 is provided in the supply path 15c without being provided in the blind hole 15b. In this modification, the bearing 20 in which the circumferential groove 22b is formed on the inner periphery of the inner ring 22 is used, but the bearing 10 shown in FIG. 1 may be used.

Explaining the operation of this modification, the lubricant that has oozed out of the lubricant-containing polymer 16 filled in the blind hole 15b due to the centrifugal force accumulates in the porous member 19 in the supply passage 15c. Then, the gas enters the bearing 20 via the circumferential groove 22b of the inner ring 22 and the through-passage 22a. The lubricant that has entered the bearing 20 adheres to the ball 23 due to centrifugal force, and lubricates the raceway surface as the ball 23 rotates. According to this modification, since the lubricant-containing polymer member can be arranged over the entire length of the blind hole 15b, the capacity of the lubricant can be ensured.

Although the present invention has been described with reference to the embodiment, it should be understood that the present invention should not be construed as being limited to the above-described embodiment, and that modifications and improvements can be made as appropriate. is there. For example, in the present embodiment, an angular contact ball bearing has been described as an example.
It is also applicable to cylindrical roller bearings and other types of bearings.

[0030]

According to the lubricating device of the present invention, the lubricant source provided in the shaft supported by the inner race, and the inside of the shaft extends from the lubricant source toward the outer periphery of the shaft. A supply path, and the lubricant coming out of the lubricant source is supplied into the bearing via the supply path and further through a through path radially penetrating the inner race of the bearing. Since the lubricant can be supplied to the bearing based on the centrifugal force, it is suitable for lubrication of a bearing that rotates at high speed. Further, since the lubricant source is disposed at a position closer to the axis than the bearing,
Since the centrifugal force and vibration applied thereto are reduced, a lubricant-containing polymer or the like that is vulnerable to external force can be used as a lubricant source, but is not limited thereto. Further, it is not necessary to provide, for example, a lubricant-containing polymer or the like in the components of the bearing or in the space inside the bearing. When such a lubricant-containing polymer is maintained, there is no need to separate the shaft and the bearing, thereby reducing maintenance work. .

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a bearing lubrication device according to a first embodiment of the present invention.

FIG. 2 is a view of the main axis of FIG. 1 as viewed in the direction of arrow II.

FIG. 3 is a sectional view similar to FIG. 1 showing a second embodiment, but with a lower half omitted.

FIG. 4 is a diagram of the main shaft 25 viewed in a radial direction with the bearing 10 removed.

FIG. 5 is a cross-sectional view similar to FIG. 3, showing a modification of the present embodiment.

FIG. 6 is a sectional view similar to FIG. 1, showing a third embodiment.

FIG. 7 is a sectional view similar to FIG. 3, showing a fourth embodiment;

FIG. 8 is a cross-sectional view similar to FIG. 7, showing a modification of the present embodiment.

[Explanation of symbols]

 11, 21 Outer ring 12, 22 Inner ring 12a, 22a Through hole 22b Peripheral groove 13, 23 Ball 14, 24 Cage 15, 25 Main shaft 15b, 25b Bag hole 15c, 25c Supply path 25d Peripheral groove 16 Lubricant-containing polymer member 19 Porous Quality material

Claims (2)

[Claims] 1. A lubrication device for a bearing having an inner ring, an outer ring, and a rolling element rotatably disposed between the inner ring and the outer ring, wherein the lubrication device is provided in a shaft supported by the inner ring. A lubricant source, and a supply path extending from the lubricant source toward the outer periphery of the shaft in the shaft, the lubricant coming out of the lubricant source passes through the supply path, and A lubricating device for a bearing, which is supplied to the inside of the bearing via a through passage radially penetrating an inner ring of the bearing. 2. A bearing lubricated by the lubricating device according to claim 1.