JP2002250352A - Small-amount oil lubrication bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device being supplied with the large amount of lubricant into a bearing when bearing temperature rises. SOLUTION: This bearing device is provided with a spacer 8 fitted into a rotating shaft 1 adjacent to a bearing inner ring 4 fitted into the shaft 1 and a lubricant supply mechanism 10 for supplying lubricant 9 into the bearing 2 (rolling space 5 on inner ring side). The mechanism 10 has a lubricant chamber 11 provided in the spacer 8, a lubricant flow passage 15 supplying the lubricant into the rolling space 5 on an inner ring side from the lubricant chamber 11, a lubricant discharge hole 14, and a lubricant supply groove 13. The lubricant chamber 11 is provided with a pressure-adjusting mechanism 16 for the pressure in the lubricant chamber capable of being communicatable or uncommunicatable with an atmospheric side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device in which a spindle unit used for a machine tool or the like can be stably operated without lubrication for a certain period of time.

[0002]

2. Description of the Related Art A conventional micro oil lubricated bearing device 100 used for inner ring rotation is provided with a lubricant (oil / oil) in a lubricant reservoir 500 provided inside a spacer 200 as shown in Japanese Utility Model Laid-Open No. 6-35659.
(Grease) 300 was sealed, and the lubricant 300 was supplied to the bearing rolling surface 401 from the lubricant reservoir 500 by centrifugal force (see FIG. 5).

[0003]

However, in the conventional method, when the spacer 200 rotates, the lubricant 300 sticks to the outside of the lubricant reservoir 500 by centrifugal force, and the lubricant 300 is supplied to the bearing 400. A space 501 is formed inside the lubricant reservoir 500 by the amount of the supplied lubricant 300.
This space 501 has a pressure lower than that of the atmosphere due to the closed structure, so that the lubricant 300 does not easily come out on the bearing rolling surface 401.

[0004] The present invention has been made in view of the above-mentioned problems of the prior art.
An object of the present invention is to provide a bearing device in which a lubricant easily flows into a bearing rolling space.

[0005]

In order to achieve the above-mentioned object, the present invention provides a technical solution comprising a bearing having an inner ring fixed to a rotating shaft and a bearing arranged adjacent to the inner ring or the inner ring. Provided in one or both of the possible spacers,
A lubricant supply structure that increases the amount of lubricant supplied into the bearing when the temperature of the rotating shaft system such as the inner ring, the spacer, and the rotating shaft increases with an increase in the bearing temperature. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the rolling bearing device of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment, and FIG. 3 shows a second embodiment.

The drawings of the first embodiment show a part of a spindle unit incorporating a bearing device of the present invention. In the bearing device, an inner ring 4 of a bearing 2 is fitted to a shaft (rotating shaft) 1 and the inner ring is formed. A lubricant supply structure (including a lubricant supply mechanism 10 and a lubricant chamber pressure adjusting mechanism 16) for supplying a lubricant 9 into the bearing 2 is provided. 21). Note that this embodiment is merely an embodiment of the bearing device of the present invention, and is not to be construed as limiting in any way, and can be appropriately changed within the scope of the present invention.

The bearing 2 comprises an inner ring 4 and an outer ring 3, a plurality of rolling elements 6 incorporated between the inner ring 4 and the outer ring 3, and a retainer 7 in which the rolling elements 6 are equally arranged. 1 shows an embodiment of a single-row angular contact ball bearing in which the groove shoulder on one side is dropped. In addition, the bearing 2 shown in this embodiment is only one embodiment and is not limited, and can be appropriately changed within the scope of the present invention. In the present embodiment, a ball bearing will be described, but a roller bearing is also within the scope of the present invention.

The inner race 4 is formed in a narrow annular shape lacking a non-load side portion, and a spacer 8 is disposed adjacent to the lacking side, and the rolling space on the inner ring 4 side together with the spacer 8 is arranged. 5. That is, the rolling space 5 on the inner ring 4 side (hereinafter, also referred to as the inner ring rolling space) 5 is a track 4 provided on the inner ring outer diameter surface 4b.
a and a rolling element separation preventing tapered surface 8a provided around the outer periphery of the shoulder portion of the spacer 8. In the present embodiment, the rolling element separation preventing tapered surface 8a of the spacer 8 is formed of a tapered surface, but may be a curved surface having the same curvature as the raceway 4a on the inner ring 4 side. Can be selected arbitrarily.

The spacer 8 is formed in an annular shape formed to be wider in the axial direction than the inner ring 4.
A rolling element separation preventing taper surface 8a constituting the inner ring side rolling space 5 is provided around the shoulder portion on the inner ring adjacent side, and a lubricant supply mechanism 10 for supplying a lubricant 9 to the rolling space 5 is provided. Have. Further, between the spacer 8 and the shaft 1 is fixed by an interference fit or the like so that the lubricant 9 sealed in the lubricant supply mechanism 10 does not leak. The lubricant 9 is not particularly limited and is not particularly limited to general grease, lubricating oil and the like, and well-known ones can be appropriately selected within the scope of the present invention.

The lubricant supply mechanism 10 has, for example, the following configuration. Note that this embodiment is merely an example, and is not to be construed as limiting. A lubricant chamber 11 for holding a lubricant (oil) 9 is uniformly and continuously provided on the circumference of the spacer inner diameter 8c, and the lubricant chamber 11 A plurality of lubricant supply paths 12 for supplying 9 are provided in the circumferential direction. The depth of the lubricant chamber 11
The design of the shape and the like can be changed as appropriate.

In the present embodiment, the lubricant supply path 12
The lubricant supply groove 13 provided on the side adjacent to the inner ring 4 and connected to the inner ring side rolling space 5, the lubricant discharge hole 14 penetrating the groove 13, the hole 14 and the lubricant chamber 11 are formed. The lubricant 9 is formed of a lubricant flow path 15 that communicates with the lubricant chamber 11 and is supplied to the inside of the bearing 2 (the inner race-side rolling space 5).

In the present embodiment, the lubricant supply groove 13 is provided at the upper end of the side surface 8 d of the spacer 8 in contact with the inner race 4, at the upper end of the inner race side rolling space 5
Is formed in a desired shape so as to open at the end of the rolling element separation preventing taper surface 8a constituting the rolling element. In the embodiment, it is formed perpendicular to the axial direction, but may be formed so as to be inclined so as to open in the rolling element separation preventing tapered surface 8a.

In the present embodiment, the lubricant discharge hole 14 is provided in a desired shape near the axis 1 of the lubricant supply groove 13. However, the lubricant discharge hole 14 may be arbitrarily selected such as a hole position, a hole shape, and a hole diameter shown in the present embodiment. Alternatively, the hole 14 may be constituted by a plurality of fine holes, which is within the scope of the present invention.

In the present embodiment, the lubricant flow path 15 is provided in a desired shape in an inclined manner from the upper end of the lubricant chamber 11 near the inner ring 4 to the lubricant discharge hole 14. In the present embodiment, the flow path 15 is inclined, but the inclination angle can be appropriately changed in design.
It may be provided perpendicular to the radial direction from 1 to the inner ring side rolling space 5 and is within the scope of the present invention. It is also within the scope of the present invention that the contact point with the lubricant chamber 11 is not limited and the design can be changed as appropriate.

In the present embodiment, the lubricant supply paths 12 are provided at a plurality of locations (three locations) evenly in the circumferential direction. However, the lubricant supply paths 12 may not be equally distributed as in the present embodiment. Also,
This does not hinder the use of a single lubricant supply path 12. Further, the lubricant chamber 11 is not provided continuously in the circumferential direction as in the present embodiment, but is
It is also possible to provide a plurality of by intermittently providing in the circumferential direction,
In the case of such a configuration, each lubricant chamber 11
A configuration in which the lubricant supply path 12 is provided for each is also possible, which is within the scope of the present invention. In this case, each lubricant chamber 1
One or more lubricant supply paths 12 can be provided for each one.

The lubricant chamber pressure adjusting mechanism 16 is connected to the lubricant chamber 1 via an air introduction groove 17 provided on the inner diameter 8c side of the spacer 8.
1 and an air introduction hole 18 for bringing the lubricant chamber 11 to atmospheric pressure, and normally closing the air introduction hole 18 to seal the lubricant chamber 11 and deforming when the shaft temperature rises,
8 is provided with a plug 19 made of a shape memory alloy communicating with the atmosphere side.

In the present embodiment, a plurality of lubricant chamber pressure adjusting mechanisms 16 are provided equidistantly in the circumferential direction of the spacer 8. The lubricant chamber pressure adjusting mechanism 16 may be provided only one in the circumferential direction of the spacer 8, or in a case where a plurality of the lubricant supply mechanisms 10 are provided in the circumferential direction of the spacer 8. Are provided with the lubricant chamber pressure adjusting mechanisms 16 in a number corresponding to the respective lubricant supply mechanisms 10.

The stopper 19 has one end 19a fixed to the spacer outer diameter 8b with a bolt 20 so as to be openable and closable on the atmosphere introducing hole 18. However, the shape and the like are not particularly limited and are optional within the scope of the present invention. The design can be changed. The method of fixing the one end of the plug 19 is not particularly limited and is arbitrary.

In this embodiment, the air introduction hole 18 is provided so as to vertically communicate with a desired diameter in the radial direction over the atmosphere introduction groove 17 recessed in the spacer inner diameter 8c and the spacer outer diameter 8b. However, the present invention is not particularly limited, and it is within the scope of the present invention to form an inclined shape at a desired angle.

Therefore, according to the present embodiment, when the shaft 1 rotates, the lubricant 9 flows through the lubricant chamber 11 → the lubricant flow path 15 → the lubricant discharge hole 14 → the lubricant supply groove 13 by the centrifugal force. It is supplied to the inside of the bearing 2, that is, to the inner ring side rolling space 5. At a low temperature, the plug 19 of the lubricant chamber pressure adjusting mechanism 16 closes the air introduction hole 18 to form the lubricant chamber 11 in a closed structure. Therefore, as the amount of the lubricant 9 decreases, the pressure in the chamber 11 becomes lower than the atmospheric pressure. . Therefore, the amount of the lubricant 9 supplied into the bearing 2 through the lubricant discharge hole 14 is reduced.

On the other hand, when the temperature of the shaft 1 becomes high due to heat generation of the bearing 2 or the like, the plug 19 made of a shape memory alloy is deformed and a clearance is formed at the entrance of the air introduction hole 18 (the state shown by the phantom line in FIG. 1). Then, the atmosphere enters the lubricant chamber 11 from the atmosphere introduction hole 18 through the atmosphere introduction groove 17. As a result, the pressure in the lubricant chamber 11 rises, so that the lubricant 9 passes through the lubricant chamber 11 → the lubricant flow path 15 → the lubricant discharge hole 14 → the lubricant supply groove 13 to the inside of the bearing 2, that is, the inner ring side rotation. The amount supplied to the running space 5 is increased, sufficient lubrication is possible, and an excessive rise in temperature of the bearing 2 can be suppressed.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to the drawings.

In the present embodiment, the inner race 4 is replaced with a structure in which the lubricant supply mechanism 10 is provided on the spacer 8 of the first embodiment.
And a lubricant supply mechanism 10.

The details are as follows. The drawing shows a part of a spindle unit incorporating the bearing device of the present invention. In the bearing device, an inner ring 4 of a bearing 2 is fitted on a shaft (rotating shaft) 1 and a lubricant 9 is supplied into the bearing 2. (A lubricant supply mechanism 10 and a lubricant chamber pressure adjusting mechanism 16). Note that this embodiment is merely an embodiment of the bearing device of the present invention, and is not to be construed as limiting in any way, and can be appropriately changed within the scope of the present invention.

The bearing 2 includes an inner ring 4 and an outer ring 3, a plurality of rolling elements 6 incorporated between the inner ring 4 and the outer ring 3, and a retainer 7 in which the rolling elements 6 are equally arranged. 1 shows an embodiment of a single-row angular contact ball bearing in which the groove shoulder on one side is dropped. In addition, the bearing 2 shown in this embodiment is only one embodiment and is not limited, and can be appropriately changed within the scope of the present invention. In the present embodiment, a ball bearing will be described, but a roller bearing is also within the scope of the present invention.

The inner race 4 is formed in an annular shape having the same width as the outer race 3 in the axial direction, and a lubricant chamber 11 for holding the lubricant 9 is continuously formed on the circumference at the center of the inner diameter. The inner ring side rolling space 5 is provided in the largest diameter portion 11b of the lubricant chamber 11.
A plurality of lubricant supply paths 12 for supplying the lubricant 9 are provided in the circumferential direction. Note that the design of the lubricant chamber 11 can be changed as appropriate in regard to the depth and shape thereof.

The lubricant 9 sealed in the lubricant chamber 11
The inner ring 1 and the shaft 4 are fixed with an interference fit or the like so as not to leak. The lubricant 9 is not particularly limited and is not particularly limited to general grease, lubricating oil and the like, and well-known ones can be appropriately selected within the scope of the present invention.

The lubricant supply mechanism 10 has, for example, the following configuration. Note that this embodiment is merely an example, and is not to be construed as limiting. A lubricant chamber 11 for holding a lubricant (oil) 9 is uniformly and continuously provided around the inner diameter of the inner ring 4, and the lubricant chamber 11 is provided in the inner ring side rolling space 5 with the lubricant 9. Are provided at a plurality of locations in the circumferential direction. Note that the design of the lubricant chamber 11 can be changed as appropriate in regard to the depth and shape thereof.

In the present embodiment, the lubricant supply path 12
A lubricant discharge hole 14 connected to the inner ring side rolling space 5, and a lubricant passage 15 connecting the hole 14 and the lubricant chamber 11.
The lubricant 9 filled in the lubricant chamber 11 is supplied to the inside of the bearing 2 (the inner ring side rolling space 5).

In the present embodiment, the lubricant discharge hole 14 is provided on the non-load side 4a 'of the inner raceway 4a which forms the inner raceway space 5.
Are provided so as to open in a desired shape. The hole position is preferably provided on the non-load side 4a 'of the inner raceway 4a, but is not limited. The hole position, hole shape, hole diameter and the like shown in the present embodiment may be arbitrarily set, and the hole 14 may be constituted by a plurality of fine holes, which is within the scope of the present invention.

In the present embodiment, the lubricant passage 15 extends from the largest diameter portion 11 b of the lubricant chamber 11 to the lubricant discharge hole 14.
It is provided in a desired shape in an inclined manner over, but optionally, such as the flow path shape, flow path diameter, flow path length shown in the present embodiment,
Further, in the present embodiment, the flow path 15 is inclined, but the design of the inclination angle can be appropriately changed.
It may be provided perpendicular to the radial direction from 1 to the inner ring side rolling space 5 and is within the scope of the present invention.

In the present embodiment, a plurality of (three) lubricant supply paths 12 are provided in the circumferential direction at equal intervals, but the lubricant supply paths 12 may not be arranged at equal intervals as in the present embodiment. Also,
This does not hinder the use of a single lubricant supply path 12. Further, the lubricant chamber 11 is not provided continuously in the circumferential direction as in the present embodiment, but is
It is also possible to provide a plurality of by intermittently providing in the circumferential direction,
In the case of such a configuration, each lubricant chamber 11
A configuration in which the lubricant supply path 12 is provided for each is also possible, which is within the scope of the present invention. In this case, each lubricant chamber 1
One or more lubricant supply paths 12 can be provided for each one.

In the present embodiment, the lubricant flow path 15 is provided at a desired diameter and inclined from the maximum diameter portion 11b of the lubricant chamber 11 to the inner ring side rolling space 5, but is not interpreted as being limited in any way. The connecting position on the side of the medicine chamber 11 and the connecting position on the side of the inner ring-side rolling space 5 can be arbitrarily changed in design, and does not impede the provision of the connecting position vertically in the axial direction.

The lubricant chamber pressure adjusting mechanism 16 is connected to the lubricant chamber 11 through an atmosphere introduction groove 17 provided on the inner diameter side of the inner ring 4 and has an atmosphere introduction hole 18 for bringing the lubricant chamber 11 to atmospheric pressure. Usually, the lubricant chamber 11 is closed by closing the air introduction hole 18, and is provided with a plug 19 made of a shape memory alloy which is deformed when the shaft temperature rises and communicates the air introduction hole 18 with the atmosphere side.

In this embodiment, a plurality of lubricant chamber pressure adjusting mechanisms 16 are provided equidistantly in the circumferential direction of the inner ring 4. The lubricant chamber pressure adjusting mechanism 16 may be only one in the circumferential direction of the inner ring 4, or in a case where a plurality of the lubricant supply mechanisms 10 are provided in the circumferential direction of the inner ring 4, The lubricant chamber pressure adjusting mechanisms 16 are provided by the number corresponding to the respective lubricant supply mechanisms 10.

The stopper 19 is fixed at one end 19a to the side surface of the inner race 4 with a bolt 20 so that the stopper 19 can be opened and closed on the air introduction hole 18. However, the shape and the like are not particularly limited, and are arbitrarily designed within the scope of the present invention. Can be changed.

In the present embodiment, the air introduction hole 18 is formed to be inclined with a desired diameter over the air introduction groove 17 recessed in the inner diameter of the inner ring 4 and the side surface of the inner ring 4, but the inclination angle is particularly limited. Instead, the inclination angle can be arbitrarily changed.

Therefore, according to the present embodiment, when the shaft 1 rotates, the lubricant 9 flows through the lubricant chamber 11 → the lubricant flow path 15 → the lubricant discharge hole 14 in the bearing 2, that is, the inner ring by the centrifugal force. It is supplied to the side rolling space 5. At a low temperature, the plug 19 of the lubricant chamber pressure adjusting mechanism 16 closes the air introduction hole 18 to make the lubricant chamber 11 a closed structure. Therefore, as the amount of the lubricant 9 decreases, the pressure in the lubricant chamber 11 becomes higher than the atmospheric pressure. Lower. Therefore, the amount of the lubricant 9 supplied into the bearing 2 through the lubricant discharge hole 14 is reduced.

On the other hand, when the temperature of the shaft 1 becomes high due to heat generation of the bearing 2 or the like, the plug 19 made of a shape memory alloy is deformed and a clearance is formed at the inlet of the air introduction hole 18 (FIG. 4). And enters the lubricant chamber 11 through the air introduction groove 17. As a result, the pressure in the lubricant chamber 11 increases, so that the lubricant 9 is supplied to the inside of the bearing 2, that is, the inner ring side rolling space 5 through the lubricant chamber 11 → the lubricant flow path 15 → the lubricant discharge hole 14. Therefore, sufficient lubrication becomes possible and an excessive rise in temperature of the bearing 2 can be suppressed.

In the first embodiment described above, the spacer 8 provided with the lubricant supply structure 21 has been described.
The structure may be provided on the bearing inner ring 4 side. In this case, the lubricant supply structure 21 of the above-described second embodiment may be employed, and may be provided on both the spacer 8 and the inner ring 4. . In the above-described second embodiment, the lubricant supply structure 21 may be provided in the inner race 4 even if the bearing is a double-row bearing.

[0042]

As described above, according to the present invention, when the temperature of the bearing rises, more lubricant can be supplied into the bearing when the temperature of the bearing rises, sufficient lubrication becomes possible, and the temperature rise of the bearing is reduced. I can do it.

[Brief description of the drawings]

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

FIG. 2 is a side view showing a main part of the spacer as viewed from a lubricant discharge hole direction.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a conventional technique.

[Explanation of symbols]

 1: Shaft 2: Bearing 3: Outer ring 4: Inner ring 4a: Track (inner ring side) 5: Rolling space (inner ring side) 8: Spacer 8a: Track (spacer side) 9: Lubricant 10: Lubricant supply mechanism 11: Lubricant chamber 12: Lubricant supply path 16: Lubricant chamber pressure adjusting mechanism 21: Lubricant supply structure

Claims (1)

[Claims] An inner ring is provided on one or both of a bearing in which an inner ring is fixed to a rotating shaft and a spacer which may be disposed adjacent to the inner ring. seat,
A lubricant supply structure for increasing the amount of lubricant supplied into the bearing when the temperature of the rotating shaft system such as the rotating shaft rises.