KR102448407B1 - Cooling structure of bearing device - Google Patents

Abstract

A stationary-side spacer 4 and a rotating-side spacer 5 are provided adjacent to the fixed-side raceway 2 and the rotating-side raceway 3, respectively, opposite to the inside and outside of the rolling bearing 1, and the fixed-side raceway ring (2) and the fixed-side spacer 3 are provided on the fixed member 6, and the rotating-side raceway wheel 3 and the rotating-side spacer 5 are provided on the rotating member 7 for cooling the bearing device J is the structure An annular fixed-side concave portion 13 is formed on a peripheral surface of the fixed-side spacer (4) opposite to the rotating-side spacer (5), and the fixed-side spacer (4) in the rotating-side spacer (5). An annular rotation-side recessed portion 14 is formed at a position in the axial direction opposite to the stationary-side recessed portion 13 on the peripheral surface opposite to . A nozzle hole 15 for discharging compressed air A from an outlet 15a opened in the bottom surface of the fixed-side concave portion 13 toward the bottom surface of the rotating-side concave portion 14 is provided with a rotation-side spacer 5 . ) is inclined forward in the direction of rotation.

Description

Cooling structure of bearing device

This application claims priority to Patent Application No. 2016-176547 filed on September 9, 2016, the entirety of which is incorporated herein by reference.

The present invention relates to a cooling structure of a bearing device, for example, a main shaft of a machine tool and a cooling structure of a bearing included in the main shaft.

In the spindle device of a machine tool, in order to ensure processing precision, it is necessary to suppress the temperature rise of the apparatus small. However, in recent machine tools, there is a tendency to increase in speed in order to improve machining efficiency, and heat generation from bearings supporting the main shaft is also increasing along with the increase in speed. In addition, so-called motor built-in types including a driving motor are increasing in the device, which is also a factor of heat generation of the device.

The increase in the bearing temperature due to heat generation results in an increase in the preload, and should be suppressed as much as possible in consideration of the high speed and high precision of the main shaft. As a method of suppressing the temperature rise of a spindle device, there exists a method of sending compressed air for cooling to a bearing, and cooling a shaft and a bearing (for example, patent document 1, patent document 2). In patent document 1 and patent document 2, a shaft and a bearing are cooled by injecting a cold wind into the space between two bearings at an angle to a rotation direction, and setting it as a swirling flow.

Japanese Laid-Open Patent Publication No. 2000-161375 Japanese Laid-Open Patent Publication No. 2015-183738

In machine tools, compressed air is used for air seals for preventing foreign substances from entering the spindle, air oil for bearing lubrication, oil mist, and the like. These compressed air are made with a compressor. Usually, one compressor is used for one machine tool. When cooling a bearing, a shaft, etc. with compressed air, compressed air generated by a compressor is also used for cooling compressed air for this purpose.

In cooling by compressed air like Patent Document 1, the cooling effect increases as the amount of compressed air supplied is increased. However, in order to increase the supply amount of compressed air, it is necessary to employ a compressor having a larger capacity. For this reason, if the improvement of a cooling effect is aimed at, the enlargement of a machine tool and the increase of energy consumption will be brought about.

Patent document 2 is a proposal made in order to solve the said subject. That is, in the bearing device J in which the outer ring spacer 104 and the inner ring spacer 105 are provided between a pair of rolling bearings 101 and 101, as shown in FIG. 12, the inner peripheral surface of the outer ring spacer 104 is surface), and from the nozzle hole 115 formed in the outer ring spacer 104 , the compressed air A for cooling is sprayed toward the outer peripheral surface of the inner ring spacer 105 . When the compressed air A is discharged at once from the narrow nozzle hole 115 to the wide space 120 mainly composed of the recess 113, the compressed air A adiabatically expands, and the compressed air A As the temperature falls, the flow rate also increases. By spraying this compressed air A to the inner ring spacer 105, the inner ring spacer 105 and the rolling bearing 101 are cooled efficiently.

Thus, according to the structure of patent document 2, since a cooling effect improves, it becomes possible to suppress the temperature rise of a bearing etc. with less compressed air than the structure like patent document 1. However, it is desirable to efficiently cool a bearing or the like with less compressed air.

It is an object of the present invention to provide a cooling structure for a bearing device capable of efficiently cooling a bearing or the like even with a small amount of compressed air and suppressing the amount of compressed air used.

In the cooling structure of the bearing device of the present invention, a fixed-side spacer and a rotating-side spacer are provided adjacent to each of a fixed raceway ring and a rotating raceway ring facing inside and outside of a rolling bearing, the fixed-side raceway ring and the fixed-side spacer is provided on a fixed member of the fixed member and the rotating member, and the rotating-side raceway and the rotating-side spacer are provided on a rotating member of the fixed member and the rotating member. ,

An annular fixed-side recess is formed in a circumferential surface of the fixed-side spacer opposite to the rotating spacer, and in the rotating-side spacer, in the circumferential surface opposite to the fixed spacer, An annular rotation-side concave portion is provided at an axial position opposite to the fixed-side concave portion, and a nozzle hole for discharging compressed air from an outlet opened in the bottom surface of the fixed-side concave portion toward the bottom surface of the rotation-side concave portion; It is characterized in that it is inclined forward in the rotation direction of the rotation-side spacer.

For example, the fixed-side raceway is an outer race, and the rotation-side raceway is an inner race. In that case, the fixing member and the rotating member are, for example, a housing and a shaft, respectively.

According to the above configuration, the compressed air for cooling is discharged from the nozzle hole formed in the fixed-side spacer toward the bottom surface of the rotating-side recess formed in the rotating-side spacer. Compressed air adiabatically expands when compressed air is discharged from the narrow nozzle hole to a wide space mainly composed of the stationary-side recessed portion and the rotating-side recessed portion. Due to this adiabatic expansion, the flow velocity of the compressed air increases and the temperature decreases. Therefore, the rotation-side spacer is efficiently cooled. By forming not only the recessed part in the fixed-side spacer as in the prior art, but also the recessed part in the rotation-side spacer, the space through which the compressed air is discharged is wider than in the conventional configuration. Thereby, the adiabatic expansion of compressed air is accelerated|stimulated, and since the flow velocity of compressed air further increases and temperature falls, a cooling effect improves further.

Further, since the nozzle hole formed in the fixed-side spacer is inclined forward in the rotational direction of the rotating-side spacer, the compressed air discharged from the nozzle hole flows in the axial direction while turning along the peripheral surface of the rotating-side spacer and discharged to the outside of the bearing . Since the compressed air rotates, the time during which the compressed air is in contact with the peripheral surface of the rotation-side spacer is longer compared to the case where the compressed air flows directly in the axial direction, and the rotation-side spacer can be cooled more efficiently.

In this way, since the rotation-side spacer is efficiently cooled, the rotation-side raceway and the rotation shaft of the rolling bearing can be effectively cooled through the rotation-side spacer. Therefore, the usage-amount of compressed air can be suppressed.

In this invention, it is preferable that the axial length of the said rotation-side recessed part is twice the hole diameter of the said nozzle hole or more.

If the axial length of the rotary-side recess is smaller than twice the hole diameter of the nozzle hole, compressed air does not smoothly flow into the rotary-side recess, and the compressed air discharged from the nozzle hole cannot be sufficiently adiabatic to expand.

In the present invention, it is preferable that the radial depth of the rotation-side concave portion is in the range of 10% to 50% of the radial thickness of the rotation-side spacer.

If the radial depth of the rotation-side recessed portion is less than 10% of the radial thickness of the rotation-side spacer, the volume of the rotation-side recessed portion is small, and the volume of the compressed air cannot be sufficiently increased. In addition, when it exceeds 50%, the radial thickness of the rotating-side spacer becomes too thin, and there is a risk that the rotating-side spacer may be damaged due to an axial load applied when assembling the bearing to the shaft or during operation.

In the present invention, a cross-groove or striped-groove concave portion may be formed on the bottom surface of the rotation-side concave portion. In addition, a plurality of circumferential grooves may be formed on the bottom surface of the rotation-side recessed portion.

In these cases, the bottom surface of the concave portion on the rotation side becomes an uneven surface and the surface area of the bottom surface becomes large, so that heat exchange between the rotation side spacer and the compressed air is performed efficiently, and the cooling effect is further enhanced.

In the present invention, when the fixed-side spacer has a fixed-side spacer body in which the nozzle hole is formed, and a lubricant hole forming member in which a lubricant hole for supplying lubricant to the rolling bearing is formed, the peripheral surface of the fixed-side spacer body The bottom surface of the fixed-side concave portion may be the bottom surface, and the side surface of the lubricant hole forming member may be a side wall surface of the fixed-side concave portion.

When the fixed-side recessed portion is constituted by the peripheral surface of the fixed-side spacer body and the side surface of the lubricant hole forming member in this way, the fixed-side recessed portion is formed only by combining the fixed-side spacer body and the lubricant hole forming member. This is unnecessary.

Any combination of at least two configurations disclosed in the claims and/or specification and/or drawings is encompassed by the present invention. In particular, any combination of two or more of each of the claims is encompassed by the present invention.

The present invention will be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for the purpose of simple illustration and description, and should not be used to delimit the scope of the present invention. The scope of the present invention is defined by the appended claims. In the accompanying drawings, the same part number in a plurality of drawings indicates the same part.
BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the machine tool spindle apparatus provided with the cooling structure of the bearing apparatus which concerns on 1st Embodiment of this invention.
[ Fig. 2] Fig. 2 is an enlarged cross-sectional view of an essential part of the cooling structure of the bearing device according to the first embodiment of the present invention.
[FIG. 3] It is a cross-sectional view III-III of FIG.
[FIG. 4A] It is explanatory drawing for comparing the area of the space through which compressed air is discharged.
[FIG. 4B] Another explanatory diagram for comparing the width of a space through which compressed air is discharged.
It is sectional drawing of the principal part of the cooling structure of the bearing apparatus which concerns on 2nd Embodiment of this invention.
It is sectional drawing of the principal part of the cooling structure of the bearing apparatus which concerns on 3rd Embodiment of this invention.
It is sectional drawing of the principal part of the cooling structure of the bearing apparatus which concerns on 4th Embodiment of this invention.
It is sectional drawing of the principal part of the cooling structure of the bearing apparatus which concerns on 5th Embodiment of this invention.
It is sectional drawing of the principal part of the cooling structure of the bearing apparatus as a comparative example.
It is sectional drawing of the principal part of the cooling structure of the bearing apparatus as another comparative example.
Fig. 11 is a cross-sectional view of an essential part of a cooling structure of a bearing device as another comparative example.
12] It is sectional drawing of the principal part of the cooling structure of the conventional bearing apparatus.

The cooling structure of the bearing apparatus which concerns on 1st Embodiment of this invention is demonstrated with FIGS.

1 : is sectional drawing of the machine tool spindle apparatus provided with the cooling structure of the said bearing apparatus. In this example, although it is applied to the spindle device of a machine tool, it is not limited only to the spindle device of a machine tool.

The bearing device (J) comprises two rolling bearings (1, 1) arranged in an axial direction, between the outer rings (2, 2) and between the inner rings (3, 3) of each of the rolling bearings (1, 1); The outer ring spacer 4 and the inner ring spacer 5 are respectively interposed therebetween. The outer ring 2 and the outer ring spacer 4 are provided in the housing 6 , and the inner ring 3 and the inner ring spacer 5 are fitted to the main shaft 7 . The rolling bearing 1 is an angular ball bearing, and a plurality of rolling elements 8 are interposed between the raceway surfaces of the outer ring 2 and the inner ring 3 . Each rolling element 8 is hold|maintained at equal intervals in the circumferential direction by the retainer 9. As shown in FIG. The two rolling bearings 1 and 1 are arranged in a rear combination, and the initial preload of each of the rolling bearings 1 and 1 is reduced by the difference in width between the outer ring spacer 4 and the inner ring spacer 5 . used to set.

In this embodiment, the rolling bearing 1 is used for inner ring rotation. Therefore, the outer ring 2 and the inner ring 3 are also called "fixed side raceway" and "rotation side raceway", respectively, and the outer ring spacer 4 and inner ring spacer 5 are respectively called "fixed side spacer" and " Also called "rotation side spacer". In addition, the main shaft 7 is also called a "rotation member", and the housing 6 is also called a "fixing member". The same applies to other embodiments shown later.

The outer rings 2, 2 and the outer ring spacer 4 are, for example, in a loose fit with respect to the housing 6, with a stepped portion 6a of the housing 6 and an end cover ( The positioning in the axial direction is performed by the end face cover (40). In addition, the inner rings 3 and 3 and the inner ring spacer 5 are made, for example, by an interference fit with respect to the main shaft 7, and are aligned in the axial direction by the positioning spacers 41 and 42 on both sides. positioning is determined. Then, the positioning spacer 42 on the left side of the drawing is fixed by a nut 43 screwed to the main shaft 7 .

The cooling structure will be described.

As shown in Fig. 2, the outer ring spacer 4 is a ring-shaped lubricating oil hole forming member 12, 12 composed of an outer ring spacer body 11, which is a fixed-side spacer body, and a member separate from the outer ring spacer body 11. ) has The outer ring spacer body 11 is formed in a substantially T-shape in cross section, and lubricant hole forming members 12 and 12 are fixed to both sides of the outer ring spacer body 11 in the axial direction in a symmetrical arrangement. FIG. 2 is a partially enlarged view of FIG. 1 . However, the cut surface of the rolling bearing 1 on one side in FIGS. 1 and 2 is different.

The inner diameter dimension of the outer ring spacer body 11 is larger than the inner diameter dimension of the lubricant hole forming members 12 and 12 . Thereby, on the inner circumferential surface of the outer ring spacer 4, a fixed-side recessed portion 13 composed of the inner circumferential surface of the outer ring spacer body 11 and the side surfaces of the lubricant hole forming members 12 and 12 continuing to the inner circumferential surface is formed. have. The inner peripheral surface of the outer ring spacer body 11 is the bottom surface of the fixed-side concave portion 13 , and the side surfaces of the lubricant hole forming members 12 and 12 are the side wall surfaces of the fixed-side concave portion 13 . When the fixed-side recessed portion 13 is formed on the inner circumferential surface of the outer ring spacer body 11 and the side surfaces of the lubricant hole forming members 12 and 12 in this way, the outer ring spacer body 11 and the lubricant hole forming members 12 and 12 are formed. Since the fixed-side concave portion 13 is formed only by combining , processing of the fixed-side concave portion 13 is unnecessary.

The fixed-side recessed portion 13 is an annular groove having a substantially rectangular cross section. The side inner-diameter end portions 12a, 12a of the lubricant hole forming members 12 and 12 are cut obliquely so that the distance between them becomes wider as they go toward the inner-diameter side. The inner peripheral surface of the outer ring spacer 4 other than the fixed-side recessed portion 13, that is, the inner peripheral surface of the lubricating oil hole forming members 12 and 12, and the outer peripheral surface of the inner ring spacer 5, pass through the minute radial gap ?a. are facing

An annular rotation-side recessed portion 14 is formed on the outer peripheral surface of the inner ring spacer 5 to face the inner peripheral surface of the outer ring spacer body 11 . The rotation-side recessed portion 14 is an annular groove having a rectangular cross section. The axial width Y of the rotation-side recessed portion 14 is the same as the inner peripheral surface of the outer ring spacer body 11 . Further, the depth Z of the rotation-side recessed portion 14 is within the range of 10% to 50% of the thickness T of the inner ring spacer 5 in the radial direction.

The outer ring spacer body 11 is provided with a nozzle hole 15 for discharging the compressed air A for cooling toward the bottom surface of the rotation-side recessed portion 14 of the inner ring spacer 5 . The outlet 15a of the nozzle hole 15 is opened in the bottom surface of the concave portion 13 on the rotation side of the outer ring spacer 4 . In this example, a plurality of (for example, three) nozzle holes 15 are formed, and are arranged at equal intervals in the circumferential direction.

As shown in FIG. 3 , each nozzle hole 15 is inclined forward in the rotational direction of the inner ring spacer 5 . In other words, it is at a position offset from a straight line L in an arbitrary radial direction in a cross section perpendicular to the axis of the outer ring spacer 4 in a direction orthogonal to the straight line L. The reason for offsetting the nozzle hole 15 is to make the compressed air A act as a swirling flow in the rotational direction of the inner ring spacer 5, and to improve a cooling effect. In addition, in FIG. 1, FIG. 2, the outer ring spacer 4 is represented by the cross section passing through the center line of the nozzle hole 15. As shown in FIG.

In the outer peripheral surface of the outer ring spacer body 11, an introduction groove 16 for introducing compressed air A into each nozzle hole 15 from the outside of the bearing is formed. This introduction groove 16 is formed in the axial direction intermediate part in the outer peripheral surface of the outer ring spacer 4, and is formed in the arc shape which communicates with each nozzle hole 15. As shown in FIG. The introduction groove 16 is formed on the outer peripheral surface of the outer ring spacer body 11 over an angular range α representing most of the circumferential direction except for a circumferential position where a lubricating oil supply path (not shown), which will be described later, is provided. . As shown in FIG. 1 , a compressed air introduction path 45 is provided in the housing 6 , and the introduction groove 16 is configured to communicate with the compressed air introduction path 45 . An air supply device (not shown) for supplying the compressed air A to the compressed air introduction hole 45 is provided outside the housing 6 .

The lubrication structure will be described.

As shown in FIG. 1, the outer ring spacer 4 has the said lubricating oil hole forming members 12 and 12 for supplying lubricating oil in a bearing. In this example, air oil is used as the lubricating oil. Each lubricating oil hole forming member 12 has a base portion 12b whose inner circumferential surface is opposed to the inner ring spacer 5 through the radial gap ?a, and an inner ring protruding outward from the base portion 12b in the axial direction. It consists of the flange-shaped front-end|tip part 30 which opposes between the outer peripheral surface of (3) through the annular gap (delta)b for air oil passage. In other words, the tip 30 of the lubricating oil hole forming member 12 enters the bearing so as to cover the outer peripheral surface of the inner ring 3 and is disposed. In addition, the tip 30 of the lubricant hole forming member 12 is disposed radially inside the inner peripheral surface of the retainer 9 .

2, in the lubricant hole forming member 12, a lubricant hole 31 for supplying air oil to the annular gap δb between the lubricant hole forming member 12 and the outer peripheral surface of the inner ring 3 is formed. This lubricating oil hole 31 inclines so as to reach the inner diameter side as it goes toward the bearing side, and the outlet is opened in the inner peripheral side of the front-end|tip part 30. As shown in FIG. Air oil is supplied to the lubricating oil hole 31 through a lubricating oil supply path (not shown) provided in the housing 6 and the outer ring spacer body 11 . An annular recessed portion 3a is formed at a location on the extension line of the lubricating oil hole 31 on the outer peripheral surface of the inner ring 3 .

Oil of the air oil discharged from the lubricating oil hole forming member 12 accumulates in the annular concave portion 3a, and this oil is caused by the centrifugal force accompanying the rotation of the inner ring 3, and the outer circumferential surface of the inner ring 3, which is an inclined surface, is along the bearing center.

The exhaust structure will be described.

As shown in FIG. 1, the exhaust path 46 which exhausts compressed air for cooling and air oil for lubrication is provided in this bearing device J. The exhaust path 46 includes an exhaust groove 47 formed in a part of the outer ring spacer body 11 in the circumferential direction, and a radial exhaust hole formed in the housing 6 and communicating with the exhaust groove 47 ( 48) and an axial exhaust hole 49. The exhaust groove 47 of the outer ring spacer body 11 is formed over a position in the circumferential direction opposite to the position where the lubricant supply path is provided.

The effect|action of the cooling structure of the bearing apparatus which consists of the said structure is demonstrated.

From the nozzle hole 15 formed in the outer ring spacer 4, the compressed air A for cooling is injected toward the bottom surface of the rotation-side recessed part 14 of the inner ring spacer 5. As shown in FIG. At this time, the compressed air A is discharged from the inside of the narrow nozzle hole 15 to the wide space 20 mainly composed of the stationary-side recessed portion 13 and the rotating-side recessed portion 14, whereby the compressed air A is expands adiabatically. To be precise, the space 20 includes a stationary-side recessed portion 13 , a rotating-side recessed portion 14 , and the radial gap interposed between the stationary-side recessed portion 13 and the rotating-side recessed portion 14 . (δa) It is the size that fits the space of the width.

When the volume of the compressed air A in the nozzle hole 15 is V1 and the temperature is T1, the volume of the compressed air in the space 20 is V2, and the temperature is T2, the state of the gas From the equation, the first law of thermodynamics, V1<V2, T1>T2. That is, in the space 20, the temperature of the compressed air A decreases and the volume increases. As the volume increases, the flow rate of the compressed air A increases. In this way, the inner ring spacer 5 is efficiently cooled by blowing the high-speed compressed air A at low temperature to the inner ring spacer 5 .

In the cooling structure of the conventional bearing apparatus shown in FIG. 12, the volume of the space 120 from which the compressed air A is discharged is the magnitude|size of the volume (FIG. 4A) of the recessed part 113 substantially. In contrast, in the cooling structure of the bearing device of FIG. 2 , the volume ( FIG. 4B ) of the space 20 through which the compressed air A is discharged is approximately equal to the volume of the stationary-side recessed portion 13 and the rotating-side recessed portion 14 . ) is the sum of the volumes. When the volume of the recessed part 113 and the volume of the stationary side recessed part 13 are the same, the space 20 of the cooling structure of the bearing device of FIG. 2 is larger than the space 120 of the cooling structure of the bearing device of FIG. It is as large as the volume of the rotation-side concave portion 14 . Therefore, in the cooling structure of the bearing device of Fig. 2, the expansion rate of the compressed air A discharged from the nozzle hole 15 is large, and the temperature drop and volume increase of the compressed air A are further promoted, so that the cooling effect is improved. rises

In the present embodiment, the axial width Y of the rotation-side concave portion 14 is the same width as the inner circumferential surface of the outer ring spacer body 11 . However, the axial width Y of the rotation-side concave portion 14 is the outer ring spacer body 11 . ) may not have the same width as the inner circumferential surface. However, even in that case, it is preferable that the axial length Y of the rotation-side recessed portion 14 is at least twice the hole diameter D of the nozzle hole 15 . If, as shown in FIG. 9 , the axial length Y of the rotary-side recessed portion 14 is smaller than twice the hole diameter D of the nozzle hole 15 , the compressed air A is drawn into the rotary-side recessed portion 14 . It does not flow well into the air, and the compressed air A discharged from the nozzle hole 15 cannot be sufficiently adiabatically expanded.

The reason why the radial depth Z of the rotation-side recessed portion 14 is within the range of 10% to 50% of the radial thickness T of the rotation-side spacer 5 is for the following reasons. That is, as shown in Fig. 10, when the radial depth Z is less than 10% of the thickness T, the volume of the rotation-side recessed portion 14 is small, and the volume of the compressed air A cannot be sufficiently increased. In addition, as shown in Fig. 11, when it exceeds 50%, the thickness T-Z of the portion where the rotary-side concave portion 14 is formed becomes thin, and when the rolling bearing 1 is assembled to the main shaft 7 or during operation, There is a possibility that the rotation-side spacer 5 may be damaged by the axial load.

Since the nozzle hole 15 is inclined forward in the rotational direction of the inner ring spacer 5, the compressed air A discharged from the nozzle hole 15 flows in the axial direction while turning along the outer peripheral surface of the inner ring spacer 5. , is discharged to the outside of the bearing through the exhaust path (46). Since the compressed air A rotates, the time during which the compressed air A is in contact with the outer peripheral surface of the inner ring spacer 5 is longer compared to the case where it flows directly in the axial direction, and the inner ring spacer 5 can be moved more efficiently can be cooled.

In this way, since the inner ring spacer 5 is cooled efficiently, the inner ring 3 and the main shaft 7 of the rolling bearing 1 can be effectively cooled through the inner ring spacer 5 . This cooling structure forms an annular fixed-side concave portion 13 and a rotation-side concave portion 14 in the outer ring spacer 4 and the inner ring spacer 5, respectively, and further inclines the nozzle hole 15. Since cooling efficiency can be improved only by devising, it is not necessary to increase the output of the air supply device which supplies compressed air A, and power consumption can be suppressed.

In addition, if the stationary-side recessed part 13 and the rotation-side recessed part 14 are formed, the following effect also exists. That is, the compressed air A discharged into the space 20 between the outer ring spacer 4 and the inner ring spacer 5 passes through the radial gap δa between the outer ring spacer 4 and the inner ring spacer 5 . discharged to the outside of the bearing. At that time, at least a part of compressed air A flows into the bearing. Since the radial gap δa is narrower than the space 20, the flow velocity at each part in the circumferential direction of the compressed air A flowing through the radial gap δa is equalized, and the compression flowing into the bearing The flow rate of air (A) becomes uniform. Thereby, the collision sound of the compressed air A and the rolling element 8 during rotation can be made small.

As for the bearing device J shown in FIG. 2, although the rotation side recessed part 14 formed in the inner ring spacer 5 has a rectangular cross section, the shape of the rotation side recessed part 14 is not limited to this. For example, like 2nd Embodiment shown in FIG. 5, the corner part 21 of the rotation-side recessed part 14 may become an inclined surface. Moreover, like 3rd Embodiment shown in FIG. 6, the cross section of the bottom surface of the rotation-side recessed part 14 may be circular arc shape.

Further, as in the fourth embodiment shown in Fig. 7, a cross-groove or stripe-groove concave portion 22 is formed on the bottom surface of the rotation-side concave portion 14 by knurling or the like, or in Fig. 8 As in the fifth embodiment shown, a plurality of circumferential grooves 23 are formed on the bottom surface of the rotation-side recessed portion 14, and the bottom surface of the rotation-side recessed portion 14 is made an uneven surface, thereby increasing the surface area of the bottom surface. You can do it. By increasing the bottom surface area of the rotation-side concave portion 14 in this way, heat exchange between the inner ring spacer 5 and the compressed air A is performed efficiently, and the cooling effect is further enhanced.

In each of the above embodiments, the case in which the rolling bearing 1 is used for rotation of the inner ring is shown, but the present invention can also be applied to the case where the rolling bearing 1 is used for rotation of the outer ring. In that case, for example, a shaft (not shown) fitted to the inner periphery of the inner ring 3 is a stationary member, and a roller (not shown) fitted to the outer periphery of the outer ring 2 is a rotating member.

As described above, the preferred embodiment has been described with reference to the drawings, but those skilled in the art will readily assume various changes and modifications within the scope apparent from the specification of the present application. Accordingly, such changes and modifications are to be construed as being within the scope of the present invention as defined by the appended claims.

1: Rolling bearing
2: Outer ring (fixed side raceway)
3: Inner ring (rotation side raceway)
4: Outer ring spacer (fixed side spacer)
5: Inner ring spacer (rotation side spacer)
6: housing (fixing member)
7: main shaft (rotating member)
11: Outer ring spacer body (fixed side spacer body)
12: lubricating oil hole forming member
31: lubricant hole
13: fixed side recess
14: concave portion on the rotation side
15: nozzle hole
15a: exit
22: grooved concave part
23 : Circumference groove
A: compressed air
J: Bearing device

Claims (6)

A fixed-side spacer and a rotating-side spacer are installed adjacent to a fixed raceway ring and a rotating raceway which are opposed to the inside and outside of the rolling bearing, respectively, wherein the fixed-side raceway ring and the fixed-side spacer include a fixed member and A cooling structure of a bearing device provided on the fixed member of the rotating member, wherein the rotating side raceway and the rotating side spacer are provided on the rotating member of the fixed member and the rotating member,
An annular fixed-side recess is formed in a circumferential surface of the fixed-side spacer opposite to the rotating spacer, and in the rotating-side spacer, in the circumferential surface opposite to the fixed spacer, An annular rotation-side concave portion is formed at an axial position opposite to the fixed-side concave portion over the entire periphery, and compressed air is supplied from an outlet opened in the bottom surface of the fixed-side concave portion toward the bottom surface of the rotation-side concave portion. a nozzle hole for discharging is formed inclined forward in the rotational direction of the rotation-side spacer;
The cooling structure of the bearing device. According to claim 1,
A cooling structure of a bearing device, wherein an axial length of the rotation-side recessed portion is at least twice a bore diameter of the nozzle hole. 3. The method of claim 1 or 2,
A cooling structure for a bearing device, wherein a radial depth of the rotation-side concave portion is within a range of 10% to 50% of a radial thickness of the rotation-side spacer. 3. The method of claim 1 or 2,
A cooling structure of a bearing device, wherein a cross groove or striped groove concave portion is formed on a bottom surface of the rotation side concave portion. 3. The method of claim 1 or 2,
A cooling structure for a bearing device, wherein a plurality of circumferential grooves are formed on a bottom surface of the rotation-side recessed portion. 3. The method of claim 1 or 2,
The fixed-side spacer has a fixed-side spacer body in which the nozzle hole is formed, and a lubricant hole forming member in which a lubricant hole for supplying lubricant to the rolling bearing is formed, and a peripheral surface of the fixed-side spacer body is formed in the fixed-side recessed portion. The cooling structure of the bearing device is the bottom surface, and the side surface of the lubricating oil hole forming member is a side wall surface of the fixed-side recessed portion.

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