JP2004324810A - Rolling bearing device and lubricating method for it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device of grease lubrication type capable of eliminating inconvenience such that the agitating resistance of rolling elements enlarges in case the grease is replenished anew. <P>SOLUTION: According to the rolling bearing device and a lubricating method for it, not the grease G itself but its base oil 30 is solely replenished to the rolling bearing device 1, so that an increase in the amount of a thickening agent will never occur, and the rise of the agitating resistance of the balls 8 can be suppressed, and at the same time, in particular the conventional inconvenience such as heat emission etc. associated with a shorter lifetime of the grease G in the bearing used in a high speed operation can easily be eliminated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rolling bearing device used for, for example, a main shaft of a machine tool and a lubrication method for the rolling bearing device.
[0002]
[Prior art]
BACKGROUND ART In a rolling bearing device used for a main shaft or the like of a machine tool, there is an oil lubrication type device that lubricates the inside of a bearing by injecting or spraying a lubricating oil between an inner ring member and an outer ring member (for example, And Patent Document 1).
[0003]
In this rolling bearing device, an annular groove is formed on an end surface of an inner ring member, and a lubrication heading toward a rolling element is formed by communicating a bottom portion of the annular groove with each of a plurality of openings formed at intervals in a circumferential direction of an inner ring raceway surface. And a hole. Further, a relief portion is provided on the peripheral edge of the opening to form a clearance for releasing the lubricating oil between the opening and the rolling element passing through the opening.
[0004]
In the lubricating operation of the above-mentioned conventional rolling bearing device, the air flow containing the lubricating oil jetted from the nozzle into the annular groove toward the bottom is blown toward the rolling element through an oil supply hole opened at the bottom.
[0005]
In addition, there is a grease lubrication type rolling bearing device in which grease is previously sealed in a bearing and used.
[0006]
[Patent Document 1]
JP-A-11-182560 (FIG. 1)
[0007]
[Problems to be solved by the invention]
Especially when the above-mentioned grease lubricated type rolling bearing device is used under high-speed rotation, if the lubricating grease changes during use, problems such as seizure may occur. Was needed. However, when lubricating grease is newly supplied to the rolling bearing device, the rolling resistance of the rolling element changes from before (the stirring resistance increases), which is not preferable. Alternatively, disadvantages are pointed out, such as the necessity of disassembling the machine tool accompanying the replenishment operation.
[0008]
[Means for Solving the Problems]
The rolling bearing device of the present invention is an inner ring member through which a shaft is inserted and rotatably supported around the axis, an outer ring member concentrically arranged with the inner ring member, and an inner ring raceway surface of the inner ring member. And a plurality of rolling elements rotatably arranged between outer raceway surfaces of the outer race member, lubricating grease is sealed between the inner race member and the outer race member, and an axial end face of the inner race member. A retaining groove is formed along the circumferential direction of the inner race member, and a lubrication hole is formed in the inner race member for communicating the retaining groove with an opening formed at a predetermined position near the inner raceway surface or in the vicinity thereof. A holding member for holding oil to be supplied to the lubricating grease is mounted in the holding groove, and is provided integrally with the inner race member so as to rotate.
[0009]
In the above configuration, when the oil content of the grease decreases with use, the oil content of the lubricating grease is supplied to and held by the holding member, and the oil content is reduced by centrifugal force accompanying the rotating operation of the inner ring member. The oil is supplied from the holding member toward the opening to lubricate the inside of the bearing, and the oil is dispersed and held in the thickening agent of the lubricating grease. The oil is supplied to the inside of the bearing as needed, and the inside of the bearing is lubricated. .
[0010]
The lubrication method of the present invention includes an inner ring member through which a shaft body is inserted and rotatably supported around the axis, an outer ring member concentrically arranged with the inner ring member, an inner ring raceway surface of the inner ring member, and A rolling bearing device including a plurality of rolling elements rotatably arranged between outer ring raceway surfaces of an outer ring member, wherein lubricating grease is sealed between the inner ring member and the outer ring member; According to the loss of the oil content of the lubricating grease accompanying the rotation of the member, only the oil content of the lubricating grease is supplied to the holding member provided integrally with the inner ring member for rotation, and the rotation operation of the inner ring member is performed. The centrifugal force causes the oil of the lubricating grease to be supplied from the holding member toward the opening.
[0011]
According to this lubrication method, when the oil content of the grease decreases with use, if the oil content of the lubricating grease is supplied to and held by the holding member, the oil content is opened to the opening by centrifugal force accompanying the rotating operation of the inner ring member. The oil is supplied to the inside of the bearing to lubricate the inside of the bearing, and the oil is dispersed and held in the thickening agent of the lubricating grease, and the oil is supplied to the inside of the bearing as needed to lubricate the inside of the bearing.
[0012]
For this reason, lubrication inside the bearing can be easily ensured without disassembling the machine tool or the like. In addition, by replenishing the oil inside the bearing with the insufficient oil, the remaining oil inside the bearing increases. Since the oil is also supplied to the thickener, it is not necessary to pre-fill the lubricating grease in an excessive amount, and the amount of lubricating grease used can be reduced.
[0013]
In this way, the thickener is used as is without replenishing the lubricating grease itself, and only the oil is replenished.Therefore, it is possible to avoid problems such as an increase in stirring resistance that occurred when replenishing lubricating grease as in the past. In addition to the above, it is possible to eliminate problems such as heat generation due to shortening of the life of lubricating grease particularly in a bearing used at high speed.
[0014]
Preferably, the holding member is made of a porous material such as a sintered material or a phenol resin.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a rolling bearing device according to an embodiment of the present invention will be described with reference to the drawings, taking an angular ball bearing as an example. FIG. 1 is a sectional view showing a state in which a rolling bearing device of the present invention is mounted on a machine tool, FIG. 2 is a single sectional view showing the entire configuration of the rolling bearing device, FIG. 3 is an enlarged sectional view showing a using state, and FIG. It is a partially enlarged front view of a bearing device.
[0016]
As shown in FIG. 1, a rolling bearing device 1 according to this embodiment is of a grease lubrication type and has a predetermined axial spacing in an annular space between a housing 2 of a machine tool and a drive shaft (shaft) 3. Are arranged in pairs. In addition, since the structure of these rolling bearing devices 1 is a left-right symmetrical shape, only the structure of one rolling bearing device 1 is shown in FIGS.
[0017]
The rolling bearing device 1 includes an inner race member 4 into which the drive shaft 3 is press-fitted, an outer race member 5 disposed concentrically with the inner race member 4 and press-fit into the housing 2, and, as shown in FIG. A plurality of balls (rolling elements) 8 which are rotatably arranged between an inner raceway surface 6 formed on the outer peripheral surface and an outer raceway surface 7 formed on the inner peripheral surface of the outer race member 5; And a retainer 9 for holding the lubrication grease at equal positions in the circumferential direction, and lubricating grease (hereinafter simply referred to as “grease”) G is provided in advance in the bearing.
[0018]
As a thickener for grease G, for example, a urea-based, Ba-based, or Li-based is used, and an ester + synthetic hydrocarbon-based is used as the base oil 30. Its viscosity is 20 to 30 mm ² / s at 40 ° C. The consistency of grease G is equivalent to NLGI 2.
[0019]
As shown in FIG. 1, an outer race spacer 10 is arranged between the outer race members 5, and an inner race spacer 11 is arranged between the inner race members 4. The outer ring members 5 of each rolling bearing device 1 are sandwiched between a pair of spacers 12 in the axial direction. A stepped portion 15 is formed on one axial side of the support hole 14 at the center of the housing 2.
[0020]
A restraining ring 16 is attached to the other axial opening of the stepped portion 15 and the support hole 14, and the outer race spacer 10, the outer ring member 5, and the spacer 12 are sandwiched between the stepped portion 15 and the restraining ring 16. ing.
[0021]
The inner race spacer 11 and the inner race member 4 of the rolling bearing device 1 are sandwiched by spacers 13. The spacers 13 are provided with a holding nut member 17 screwed to one axial side of the drive shaft 3, and a drive shaft. 3 and a flange 18 formed on the other side in the axial direction.
[0022]
As shown in FIG. 3, a first oil supply hole 20 is formed in a portion of the housing 2 facing the outer race spacer 10 along a radial direction. A second oil supply hole 21 is formed in the outer race spacer 10 so as to communicate with the first oil supply hole 20 and extend along the radial direction.
[0023]
An annular holding groove 23 having a rectangular cross section and extending along the circumferential direction is formed on the opposed axial end face 22 of each inner ring member 4. The radially inward portion of the second oil supply hole 21 is formed by being bent in the axial direction so as to be open facing the holding groove 23 of the inner race member 4 of the rolling bearing device 1. More specifically, the second oil supply hole 21 is formed of a large diameter portion 21a directly communicating with the first oil supply hole 20 and a small diameter portion 21b formed by bending the large diameter portion 21a. ing.
[0024]
An annular V-shaped groove 24 having a substantially V-shaped cross section is formed along the peripheral edge on the side opposite to the side on which the inner raceway surface 6 is offset. The V-shaped groove 24 is formed at a position to avoid a contact portion of the ball 8 on the inner raceway surface 6.
[0025]
At the corner of the holding groove 23, a third oil supply hole 25 opened to the V-shaped groove 24 and communicating the holding groove 23 and the V-shaped groove 24 is provided at predetermined intervals in the circumferential direction of the inner ring member 4 (for example, 6 to 24). Location). An annular gap 26 is provided between a radially outer side portion of the ball 8 side opening of the third oil supply hole 25 and the rolling surface of the ball 8.
[0026]
An annular holding member 31 that holds the base oil 30 is fitted into the holding groove 23 without any gap. The holding member 31 has a function of supplying the base oil 30 toward the opening by centrifugal force accompanying the rotation of the inner ring member 4 about the axis. The holding member 31 is formed of a porous material such as a sintered material or a phenol resin.
[0027]
Next, the lubrication operation of the rolling bearing device 1 will be described. When the inner ring member 4 rotates with the use of the rolling bearing device 1, in other words, with the rotation of the drive shaft 3 about the axis, the inside of the bearing is preliminarily provided by the base oil 30 of the grease G provided inside the bearing. Lubricated.
[0028]
By the way, with the use of the rolling bearing device 1, the amount of the base oil 30 of the grease G gradually decreases from inside the bearing, and the thickener remains inside the bearing. Therefore, in the embodiment of the present invention, only the insufficient amount of the base oil 30 is supplied into the bearing.
[0029]
At this time, the base oil 30 is supplied to the first oil supply hole 20 from a predetermined position outside the rolling bearing device 1. The base oil 30 supplied to the first oil supply hole 20 passes through the large diameter portion 21a of the second oil supply hole 21, reaches the small diameter portion 21b of the second oil supply hole 21, and is discharged from the small diameter portion 21b. It is absorbed and retained by the porosity.
[0030]
When the drive shaft 3 is rotated by the driving of the machine tool, the inner race member 4 is rotated around the axis together with the drive shaft 3, and a centrifugal force acts on the base oil 30 in a radially outward direction. Then, the base oil 30 gradually comes out of the holding member 31 according to the magnitude of the centrifugal force, and reaches the V-shaped groove 24 when reaching the third oil supply holes 25.
[0031]
Then, while a certain amount of the base oil 30 is secured in the V-shaped groove 24, the base oil 30 is held by the thickener, and the base oil 30 is used with the rotation of the inner ring member 4, Lubricate the inside of the bearing.
[0032]
Since the third oil supply hole 25 is communicated with the V-shaped groove 24 having an area larger than the opening area, the base oil 30 once absorbed and held by the holding member 31 can be easily converted to V by the centrifugal force. The groove 24 can be reached. Even if an excessive amount of the base oil 30 is supplied to the inside of the bearing, the excessive amount of the base oil 30 that has reached the V-shaped groove 24 is discharged from the gap 26 to the outside of the bearing. Is done.
[0033]
As described above, according to the embodiment of the present invention, the supply path of the base oil 30 is provided in the rolling bearing device 1 so that only the insufficient base oil 30 of the grease G is supplied into the bearing. The lubricating oil, that is, the base oil 30, can be easily supplied without decomposing the oil. For this reason, it is possible to greatly reduce the time and effort as compared with the conventional case where the machine tool is disassembled and grease G is supplied inside the bearing.
[0034]
Further, since only the base oil 30 is replenished instead of the grease G itself, the amount of the thickener does not increase, and therefore, the rise of the stirring resistance of the ball 8 can be suppressed. In addition, problems such as heat generation due to the shortened life of the grease G in a bearing used at high speed can be easily eliminated.
[0035]
In addition, since sufficient lubricity can be ensured by replenishing the base oil 30, it is not necessary to increase the amount of grease G to be sealed in advance, and therefore, the initial amount of grease G itself can be reduced.
[0036]
【The invention's effect】
As is clear from the above description, according to the present invention, the oil is dispersed and held in the thickener of the lubricating grease, and the oil is supplied to the inside of the bearing as needed to lubricate the inside of the bearing. Problems such as heat generation due to shortening of grease life in a bearing used at high speed can be easily eliminated.
[Brief description of the drawings]
FIG. 1 is a sectional view of a rolling bearing device according to an embodiment of the present invention in a used state in which the rolling bearing device is mounted on a machine tool.
FIG. 2 is a single sectional view showing the entire configuration of the rolling bearing device.
FIG. 3 is an enlarged sectional view showing a state of use similarly.
FIG. 4 is a partially enlarged front view of the rolling bearing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolling bearing device 2 Housing 3 Drive shaft 4 Inner ring member 5 Outer ring member 6 Inner ring raceway surface 7 Outer ring raceway surface 8 Ball 20 First oil supply hole 21 Second oil supply hole 21a Large diameter portion 21b Small diameter portion 23 Holding groove 24 V-shaped groove 25 Third oil supply hole 26 Gap 30 Base oil 31 Holding member G Grease

Claims (2)

An inner ring member through which the shaft body is inserted and rotatably supported around the axis, an outer ring member arranged concentrically with the inner ring member, an inner raceway surface of the inner race member, and an outer raceway surface of the outer race member A rolling bearing device comprising a plurality of rolling elements disposed so as to be freely rotatable therebetween, wherein lubricating grease is sealed between the inner ring member and the outer ring member.
A retaining groove is formed on the axial end surface of the inner ring member along a circumferential direction of the inner ring member, and an oil supply hole for communicating the retaining groove and an opening formed at a predetermined position near the inner raceway surface or in the vicinity thereof. Is formed on the inner ring member,
A rolling bearing device, wherein a holding member for holding oil to be supplied to the lubricating grease is mounted in the holding groove, and is provided integrally with the inner race member so as to rotate. An inner ring member through which the shaft body is inserted and rotatably supported around the axis, an outer ring member arranged concentrically with the inner ring member, an inner raceway surface of the inner race member, and an outer raceway surface of the outer race member A method of lubricating a rolling bearing device, comprising: a plurality of rolling elements disposed so as to be freely rotatable therebetween, wherein lubricating grease is sealed between the inner ring member and the outer ring member.
In accordance with the loss of oil of the lubricating grease accompanying the rotation of the inner ring member, only the oil of the lubricating grease is supplied to a holding member provided integrally with the inner ring member for rotation, and the rotation of the inner ring member is caused by the rotation of the inner ring member. A method of lubricating a rolling bearing device, characterized in that an oil component of the lubricating grease is supplied from the holding member toward an opening by a centrifugal force.

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