JP2019070428A - Cooling structure of bearing device - Google Patents

Abstract

To provide a cooling structure of a bearing device capable of eliminating or reducing troubles caused by flowing of much compressed air to the inside of a rolling bearing by smoothly discharging the compressed air sucked between a stationary-side spacer and a rotary-side space for cooling the bearing, from a discharge port formed on the stationary-side spacer.SOLUTION: A bearing device J is provided with an outer ring spacer 4 and an inner ring spacer 5 respectively in adjacent to an outer ring and an inner ring of a rolling bearing. A nozzle hole 15 is formed for discharging compressed air A from an outlet 15a opened on an inner peripheral face of the outer ring spacer 4 toward an outer peripheral face of the inner ring spacer 5, and an exhaust port 17 for the compressed air A discharged from the nozzle hole 15, is formed on an axial end face of the outer ring spacer 4. The nozzle hole 15 is inclined to a front part in a rotating direction, of the inner ring spacer 5, and the exhaust port 17 is inclined to a front part in the rotating direction of the inner ring spacer 5.SELECTED DRAWING: Figure 4

Description

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

  In a spindle device of a machine tool, it is necessary to keep the temperature rise of the device small in order to secure machining accuracy. However, recent machine tools tend to increase in speed in order to improve processing efficiency, and heat generation from the bearing that supports the main shaft is also increasing with the increase in speed. In addition, so-called motor built-in type in which a drive motor is incorporated inside the device is increasing, and this is also a heat generation factor of the device.

  The temperature rise of the bearing due to heat generation results in an increase in preload, and we would like to minimize the increase in speed and accuracy of the main shaft. As a method of suppressing the temperature rise of the spindle device, there is a method of feeding compressed air for cooling to a bearing to cool the bearing (for example, Patent Document 1). In Patent Document 1, compressed air is injected from the nozzle holes provided in the outer ring spacer into the space between the outer ring spacer and the inner ring spacer. The inner ring spacer and the inner ring are cooled more effectively by injecting the compressed air in a rotational direction at an angle to form a swirl flow. The compressed air that has passed through the inner ring spacer is discharged to the outside after passing through an exhaust port provided on the end face of the outer ring spacer adjacent to the rolling bearing and the inside of the bearing.

JP, 2015-183738, A

  Cooling by compressed air can be applied, for example, when lubricating oil is mixed with compressed air to lubricate a rolling bearing. It is so-called air oil lubrication or oil mist lubrication. In this case, if the amount of compressed air passing through the inside of the bearing is too large, smooth air supply and exhaust such as air oil may be hindered. In addition, the compressed air may collide with the film of the air curtain-like air flow generated in the vicinity of the shaft end of the rolling bearing by rotation and the rolling elements during rotation, and thus the noise may be increased.

  Cooling by compressed air can also be applied to grease lubrication of bearings. In that case, if the amount of compressed air passing through the inside of the bearing is large, the compressed air may discharge the grease inside the bearing, which may lead to a lubrication failure.

  It is an object of the present invention to smoothly discharge compressed air blown between a fixed space and a rotating space for bearing cooling from an outlet provided in the fixed space. It is an object of the present invention to provide a cooling structure of a bearing device capable of eliminating or reducing the adverse effect of a large amount of air flowing inside the rolling bearing.

According to the cooling structure of the bearing device of the present invention, the fixed side bearing ring and the rotary side spacer are provided adjacent to the fixed side bearing ring and the rotating side bearing ring facing the inside and outside of the rolling bearing, The stationary side spacer is installed on a stationary member of the stationary member and the rotating member, and the rotating side race ring and the rotating side spacer are installed on a rotating member of the stationary member and the rotating member In the bearing device,
There is provided a nozzle hole for discharging compressed air from the outlet opening in the peripheral surface facing the rotary side spacer in the stationary side spacer to the peripheral surface facing the stationary side spacer in the rotary side spacer And, an exhaust port of the compressed air discharged from the nozzle hole is provided on an axial end face of the fixed side spacer, and the nozzle hole is provided to be inclined forward in the rotational direction of the rotating side spacer And the exhaust port is inclined forward in the rotational direction of the rotation-side spacer.
For example, the fixed bearing ring is an outer ring, and the rotating bearing ring is an inner ring. In that case, the fixed member and the rotating member are, for example, a housing and a shaft, respectively.

  According to this configuration, the compressed air for cooling is discharged toward the circumferential surface of the rotation-side spacer from the nozzle holes provided in the fixed-side spacer. Since the nozzle holes are inclined forward in the rotational direction of the rotary side spacer, the compressed air discharged from the nozzle holes flows in the axial direction while rotating along the circumferential surface of the rotary side spacer, and the rotation is made between them. Cool the spacer. Since the compressed air swirls, the time during which the compressed air is in contact with the circumferential surface of the rotary side spacer is longer than when flowing straight in the axial direction, and the rotary side spacer can be cooled efficiently.

The compressed air which has passed through the circumferential surface of the rotary side spacer is discharged to the outside through an exhaust port provided on an axial end surface of the stationary side spacer and the inside of the rolling bearing. Since the exhaust port is also inclined forward in the rotational direction of the rotation-side spacer, the compressed air which is a swirl flow is smoothly discharged from the exhaust port. As a result, the amount of compressed air passing through the inside of the rolling bearing can be reduced, thereby eliminating or reducing the adverse effect of the large amount of compressed air flowing through the inside of the rolling bearing.
Specifically, when the rolling bearing is subjected to air oil lubrication or oil mist lubrication, it is possible to prevent smooth air supply and exhaust from being disturbed such as air oil, and a film of air curtain-like air flow generated near the shaft end of the rolling bearing. And, the noise due to the compressed air colliding with the rolling elements in rotation can be suppressed. In addition, when the rolling bearing is grease-lubricated, compressed air can be prevented from discharging the grease inside the bearing.

In the present invention, it is preferable that the number of the nozzle holes and the number of the exhaust ports are the same and a plurality of the nozzle holes and the exhaust ports are equally distributed in the circumferential direction.
In this case, the rotation-side spacer can be cooled uniformly in the circumferential direction by the compressed air discharged from the nozzle holes. Further, the compressed air which has passed through the circumferential surface of the rotary side spacer is discharged uniformly from the respective exhaust ports. For this reason, discharge of compressed air is performed smoothly.

The arrangement of the nozzle hole and the exhaust port, the circumference from the outlet of any one of the nozzle holes to the exhaust port located on the front side of the rotation side spacer in the rotational direction with respect to the nozzle hole The distance in the direction is longer than the circumferential distance from any one of the exhaust ports to the outlet of the nozzle hole located on the front side in the rotational direction of the rotation-side spacer relative to the exhaust port Is desirable.
With such a positional relationship between the nozzle hole and the exhaust port, the time during which the compressed air is in contact with the circumferential surface of the rotation-side spacer is long, and the cooling effect is high.

In the present invention, when the rolling bearing is lubricated by grease enclosed in the bearing between the stationary bearing ring and the rotating bearing ring, the rolling bearing is adjacent to the stationary bearing ring at the rotating side spacer It is preferable that an obstacle wall is provided at an end in the axial direction to project toward the stationary side spacer and prevent the compressed air discharged from the nozzle hole from flowing into the inside of the bearing.
The presence of the barrier prevents the compressed air from flowing into the interior of the rolling bearing. For this reason, the grease enclosed inside the bearing is prevented from being removed by the compressed air, and a good lubrication state can be maintained.

  According to the cooling structure of the bearing device of the present invention, the fixed side bearing ring and the rotary side spacer are provided adjacent to the fixed side bearing ring and the rotating side bearing ring facing the inside and outside of the rolling bearing, The stationary side spacer is installed on a stationary member of the stationary member and the rotating member, and the rotating side race ring and the rotating side spacer are installed on a rotating member of the stationary member and the rotating member In a bearing device, a nozzle that discharges compressed air from an outlet opening in a circumferential surface facing the rotary side spacer in the stationary side spacer toward a circumferential surface facing the stationary side spacer in the rotary side spacer A hole is provided, and an exhaust port of the compressed air discharged from the nozzle hole is provided on an axial end face of the fixed side spacer, and the nozzle hole is inclined forward in the rotational direction of the rotary side spacer. Set up And the exhaust port is inclined forward in the rotational direction of the rotary spacer, so that compressed air blown between the fixed spacer and the rotary spacer for bearing cooling is provided. By smoothly discharging the air from the discharge port provided in the fixed side spacer, it is possible to eliminate or reduce the adverse effect due to the large amount of compressed air flowing inside the rolling bearing.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the machine tool main spindle apparatus provided with the cooling structure of the bearing device which concerns on 1st Embodiment of this invention. It is an expanded sectional view of the principal part of the bearing device. It is the figure which expanded and represented a part of outer ring | wheel spacer of the bearing apparatus. It is IV-IV sectional drawing of FIG. 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 the VI-VI sectional view of FIG. 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 the elements on larger scale of FIG. 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 the elements on larger scale of FIG.

Embodiments of the present invention will be described with reference to the drawings.
First Embodiment
1 to 4 show a cooling structure of a bearing device according to a first embodiment of the present invention. The cooling structure of the bearing device in this example is applied to a spindle device of a machine tool. However, the invention is not limited to the spindle device of the machine tool.

  As shown in FIG. 1, the bearing device J includes two rolling bearings 1, 1 arranged in the axial direction, and an outer ring spacer 4 between the outer rings 2, 2 and the inner rings 3, 3 of the rolling bearings 1, 1. And an inner ring spacer 5 are respectively interposed. The outer ring 2 and the outer ring spacer 4 are installed 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 raceways of the outer ring 2 and the inner ring 3. Each rolling element 8 is held circumferentially equidistantly by the cage 9. The two rolling bearings 1, 1 are arranged in a back-to-back combination with each other, and are used by setting the initial preload of each rolling bearing 1, 1 by the width dimension difference between the outer ring spacer 4 and the inner ring spacer 5.

  In this embodiment, the rolling bearing 1 is used in inner ring rotation. Therefore, the outer ring 2 and the inner ring 3 respectively correspond to the "fixed side bearing ring" and the "rotation side bearing ring" in the claims, and the outer ring spacer 4 and the inner ring spacer 5 are "fixed side spacer" and "rotational ring It corresponds to the "space interspace". Moreover, the main shaft 7 corresponds to a "rotating member", and the housing 6 corresponds to a "fixing member". The same applies to the other embodiments described later.

  The outer rings 2 and 2 and the outer ring spacer 4 are, for example, clearance fit with respect to the housing 6, and are positioned in the axial direction by the step 6 a of the housing 6 and the end face lid 40. Also, the inner ring 3, 3 and the inner ring spacer 5 are, for example, an interference fit with the main shaft 7, and are positioned in the axial direction by the positioning spacers 41, 42 on both sides. The positioning spacer 42 on the left side of the figure is fixed by a nut 43 screwed to the main shaft 7.

The cooling structure will be described.
FIG. 2 is an enlarged cross-sectional view of the main part of the cooling structure of the bearing device. The outer ring spacer 4 has an outer ring spacer main body 11 and ring-shaped lubrication nozzles 12 and 12 which are separate members from the outer ring spacer main body 11. The outer ring spacer main body 11 is formed to have a substantially T-shaped cross section, and lubricating nozzles 12 are fixed to both axial sides of the outer ring spacer main body 11 in a symmetrical arrangement, respectively. The inner diameter of the outer ring spacer main body 11 is larger than the inner diameter of the lubrication nozzles 12, 12. As a result, a recess 13 is formed on the inner peripheral surface of the outer ring spacer 4 by the inner peripheral surface of the outer ring spacer main body 11 and the side surfaces of the lubrication nozzles 12 and 12 following the inner peripheral surface. There is. The recess 13 is an annular groove having a rectangular cross section. The inner peripheral surface of the outer ring spacer 4 other than the recessed portion 13, that is, the inner peripheral surfaces of the lubricating nozzles 12 and 12, and the outer peripheral surface of the inner ring spacer 5 are opposed via a minute radial gap δa. . Thus, a space 14 wider in the radial direction than the other is formed between the recess 13 and the outer peripheral surface of the inner ring spacer 5.

  The outer ring spacer main body 11 is provided with a nozzle hole 15 for discharging the compressed air A for cooling toward the outer peripheral surface of the inner ring spacer 5. The outlet 15 a of the nozzle hole 15 is open to the recess 13 on the inner peripheral surface of the outer ring spacer 4. In this example, a plurality of (for example, three) nozzle holes 15 are provided, and they are arranged at equal intervals in the circumferential direction.

  As shown in FIG. 4 which is a cross-sectional view taken along the line IV-IV of FIG. 1, each nozzle hole 15 is inclined forward in the rotational direction of the inner ring spacer 5. That is, it is at a position offset in a direction orthogonal to the straight line L from an arbitrary radial straight line L in a cross section perpendicular to the axial center of the outer ring spacer 4. The reason for offsetting the nozzle holes 15 is to cause the compressed air A to act as a swirling flow in the rotational direction of the inner ring spacer 5 to improve the cooling effect. In FIGS. 1 and 2, the outer ring spacer 4 is represented by a cross section passing through the center line of the nozzle hole 15.

  An introduction groove 16 for introducing the compressed air A into each nozzle hole 15 from the outside of the bearing is formed on the outer peripheral surface of the outer ring spacer main body 11. The introduction groove 16 is provided in an axially intermediate portion on the outer peripheral surface of the outer ring spacer 4 and is formed in an arc shape communicating with each nozzle hole 15. The introduction groove 16 is provided on an outer peripheral surface of the outer ring spacer main body 11 over an angle range showing most of the circumferential direction except the circumferential position where the air oil supply path (not shown) described later is provided. As shown in FIG. 1, the housing 6 is provided with a compressed air introduction path 45, and the introduction groove 16 is in communication with the compressed air introduction path 45. An air supply device (not shown) for supplying compressed air A to the compressed air introduction hole 45 is provided outside the housing 5.

The lubrication structure will be described.
As shown in FIG. 1, the outer ring spacer 4 has the lubricating nozzles 12, 12 for supplying air oil to the inside of the bearing of the rolling bearing 1. Each of the lubricating nozzles 12 includes a tip 30 that protrudes inside the bearing and faces the outer circumferential surface of the inner ring 3 via an annular gap δb for air oil passage. In other words, the tip end portion 30 of the lubrication nozzle 12 is disposed to enter the inside of the bearing so as to cover the outer peripheral surface of the inner ring 3. Further, the tip end portion 30 of the lubricating nozzle 12 is disposed radially inward of the inner peripheral surface of the cage 9.

As shown in FIG. 2, the lubricating nozzle 12 is provided with an air oil supply hole 31 for supplying air oil to the annular gap δb between the lubricating nozzle 12 and the outer peripheral surface of the inner ring 3. The air oil supply hole 31 is inclined so as to reach the inner diameter side as it goes to the bearing side, and the outlet is opened on the inner peripheral side of the tip portion 30. Air oil is supplied to the air oil supply hole 31 through an air oil supply path (not shown) provided in the housing 6 and the outer ring spacer main body 11. An annular recess 3 a is provided at a location on the extension of the air oil supply hole 31 in the outer peripheral surface of the inner ring 3.
The oil of air oil discharged from the lubricating nozzle 12 is accumulated in the annular recess 3a, and this oil is directed to the bearing center along the outer peripheral surface of the inner ring 3 which is the inclined surface by the centrifugal force accompanying the rotation of the inner ring 3. It is led.

The exhaust structure will be described.
An exhaust port 17 is provided at an axial end of the outer ring spacer main body 11. The exhaust port 17 has, for example, a rectangular shape as shown in the developed view of FIG. 3, and the outer ring 2 of the rolling bearing 1 is disposed adjacent to the outer ring spacer main body 11. It has an opening shape that communicates the inside and the outside. The number of the exhaust ports 17 is the same as the number of the nozzle holes 15 (for example, three), and similarly to the nozzle holes 15, the exhaust ports 17 are provided equidistantly in the circumferential direction. Further, the exhaust port 17 is also inclined forward in the rotational direction of the inner ring spacer 5 as in the nozzle hole 15.

Although the nozzle hole 15 and the exhaust port 17 are illustrated in the same cross section in FIG. 2, actually, as shown in FIG. 4, the positions of the nozzle hole 15 and the exhaust port 17 are shifted in the circumferential direction. The nozzle holes 15 and the exhaust ports 17 are arranged circumferentially as follows. That is, the circumferential distance M from the outlet 15a of any one nozzle hole 15 to the exhaust port 17 positioned on the front side of the rotation direction of the inner ring spacer 5 with respect to the nozzle hole 15 is any one It is longer than the circumferential distance N from the exhaust port 17 to the outlet 15 of the nozzle hole 15 located on the front side of the rotational direction of the inner ring spacer 5 with respect to the exhaust port 17. Here, the position of the nozzle hole 15 is the circumferential position of the center of the outlet 15a. Further, the position of the exhaust port 17 is at the circumferentially central position of the inner diameter end of the exhaust port 17.
By arranging the nozzle holes 15 and the exhaust port 17 in this manner, the compressed air A can be retained in the bearing device J for as long as possible.

  In FIG. 1, the housing 6 is provided with an exhaust path 46 for exhausting compressed air for cooling and air oil for lubrication from the bearing device J. The exhaust passage 46 has a radial exhaust hole 48 communicating with the exhaust port 17 and an axial exhaust hole 49 communicating with the radial exhaust hole 48.

The operation of the cooling structure of the bearing device configured as described above will be described.
The compressed air A for cooling is blown toward the outer peripheral surface of the inner ring spacer 5 from the nozzle holes 15 provided in the outer ring spacer 4. At this time, the compressed air A is discharged from the inside of the narrow nozzle hole 15 into the wide space 14 so that the compressed air A is adiabatically expanded. Assuming that the volume of compressed air in the nozzle hole 15 is V1, the temperature is T1, the volume of compressed air in the space 14 is V2, and the temperature is T2, according to the equation of state of gas and the first law of thermodynamics, V1 < It becomes V2, T1> T2. That is, in the space 14, as the temperature of the compressed air A decreases, the volume increases. As the volume increases, the flow velocity of the compressed air A increases. Thus, the inner ring spacer 5 is efficiently cooled by blowing the low temperature and high speed compressed air A onto the inner ring spacer 5.

  The compressed air A coming out of the space 14 flows axially outward along the outer peripheral surface of the inner ring spacer 5 and the outer peripheral surface of the inner ring 3. Also during this time, the inner ring spacer 5 and the inner ring 3 are cooled. Since the nozzle holes 15 are inclined forward in the rotational direction of the inner ring spacer 5, the compressed air A flows axially while turning along the outer peripheral surface of the inner ring spacer 5 and the outer peripheral surface of the inner ring 3. If it flows in the axial direction while turning, the time during which the compressed air A is in contact with the outer peripheral surface of the inner ring spacer 5 and the outer peripheral surface of the inner ring 3 becomes longer than in the case of flowing straight in the axial direction. Further, as described above, the nozzle holes 15 and the exhaust ports 17 are arranged in the circumferential direction (M> N) so that the compressed air A stays in the inside of the bearing device J as long as possible. From these things, the inner ring spacer 5 and the inner ring 3 can be cooled more efficiently.

  The compressed air A which has passed through the outer peripheral surface of the inner ring spacer 5 and the outer peripheral surface of the inner ring 3 is discharged to the outside through the exhaust port 17 provided on the axial end face of the outer ring spacer 4 and the inside of the rolling bearing 1 Ru. The exhaust port 17 is also inclined forward in the rotational direction of the inner ring spacer 5 in the same manner as the nozzle hole 15, so the compressed air A, which is a swirling flow, is smoothly discharged from the exhaust port 17. As a result, the amount of compressed air A passing through the inside of the rolling bearing 1 can be reduced to eliminate or reduce the adverse effect of the compressed air A flowing through the inside of the rolling bearing 1. As in this embodiment, when the rolling bearing 1 is subjected to air oil lubrication, it is possible to prevent smooth air supply and exhaust of the air oil from being impeded. Further, as in this embodiment, when the tip end portion 30 of the lubricating nozzle 12 is in the inside of the bearing, noise due to the compressed air A colliding with the rolling element 9 in rotation can be reduced.

  Since the number of the nozzle holes 15 and the number of the exhaust ports 17 are the same, and the nozzle holes 15 and the exhaust ports 17 are provided equally in the circumferential direction, compressed air A discharged from the nozzle holes 17 is provided. Thus, the inner ring spacer 5 and the inner ring 3 can be cooled uniformly in the circumferential direction. Further, the compressed air A which has passed through the outer peripheral surface of the inner ring spacer 5 and the outer peripheral surface of the inner ring 3 is discharged uniformly from the exhaust ports 17. Therefore, the discharge of the compressed air A is performed more smoothly.

Second Embodiment
5 and 6 show a second embodiment of the present invention. Although this bearing device J also air-oil lubricates the rolling bearing 1, unlike the first embodiment, as shown in FIG. 5, the nozzle hole 15 and air oil for discharging the compressed air A to the integral outer ring spacer 4 A supply hole 31 is provided.

  In this bearing device J, a recess 13 (see FIG. 2) like the outer ring spacer 4 of the first embodiment is formed on the inner peripheral surface of the outer ring spacer 4 where the outlet 15a of the nozzle hole 15 opens. Absent. Instead, the inner ring spacer 5 is provided with a plurality (10 in this example) of holes 20 penetrating the outer peripheral surface and the inner peripheral surface in the circumferential direction. Each hole 20 is provided at an axially intermediate portion of the inner ring spacer 5. The shape of the hole 20 is, for example, a round hole shape. The hole 20 is also inclined forward in the rotational direction of the inner ring spacer 5 as it goes to the inner diameter side. By providing the holes 20, a part of the compressed air A discharged from the nozzle holes 15 comes into contact with the outer peripheral surface of the main shaft 7.

  The air oil supply hole 31 opens in the side surface portion of the outer ring spacer 4 and faces the inside of the rolling bearing 1. As in the first embodiment, the portion of the outer ring spacer 4 provided with the air oil supply hole 31 does not protrude into the bearing. The air oil supply hole 31 is inclined so as to be positioned on the inner diameter side toward the rolling bearing 1 so that the discharged air oil hits the boundary between the raceway surface of the inner ring 3 and the rolling element 8. Air oil is supplied to the air oil supply hole 31 from an air oil supply path (not shown) provided in the housing through a radial direction hole 21 (FIG. 6) provided in the outer ring spacer 4.

  As in the first embodiment, an exhaust port 17 is provided on the axial end face of the outer ring spacer 4. The shape of the exhaust port 17 is the same as described above. The number of exhaust ports 17 is the same as that of the nozzle holes 15 (for example, three). As shown in FIG. 6, the nozzle holes 15 and the exhaust ports 17 are provided equally in the circumferential direction. Further, both the nozzle hole 15 and the exhaust port 17 are inclined forward in the rotational direction of the inner ring spacer 5. The circumferential arrangement of the nozzle holes 15 and the exhaust ports 17 is the same as that of the first embodiment.

  In the case of the cooling structure of this bearing device, the compressed air A for cooling is blown to the outer peripheral surface of the inner ring spacer 5 from the nozzle hole 15 to cool the inner ring spacer 5 and a part of the compressed air A is the inner ring spacer 5 The main shaft 7 is directly cooled by striking the main shaft 7 through the holes 20 formed in the. Thereafter, the compressed air A flows axially outward along the outer peripheral surface of the inner ring spacer 5. Since the nozzle holes 15 are inclined forward in the rotational direction of the inner ring spacer 5, the compressed air A flows axially while swirling along the outer peripheral surface of the inner ring spacer 5, and between the inner ring spacer 5 the efficiency Cool well.

  After the inner ring spacer 5 is cooled, the compressed air A is discharged to the outside through the exhaust port 17 of the outer ring spacer 4 and the inside of the rolling bearing 1. Since the exhaust port 17 is also inclined forward in the rotational direction of the inner ring spacer 5, the compressed air A, which is a swirling flow, is smoothly discharged from the exhaust port 17. As a result, the amount of compressed air A passing through the inside of the rolling bearing 1 can be reduced to eliminate or reduce the adverse effect of the compressed air A flowing through the inside of the rolling bearing 1. As in this embodiment, when the rolling bearing 1 is subjected to air oil lubrication, it is possible to prevent smooth air supply and exhaust of the air oil from being hindered. Further, as in this embodiment, when a part of the outer ring spacer 4 does not protrude inside the bearing, the compressed air A collides with the film of the air curtain-like air flow generated near the shaft end of the rolling bearing 1 by rotation. Noise can be reduced.

  Although each of the above-described embodiments is of the type in which the rolling bearing 1 is air-oil lubricated, the present invention can also be applied to the type of grease-growing the rolling bearing.

Third Embodiment
FIG. 7 is a cross-sectional view of a bearing device that is grease lubricated, and FIG. 8 is a partially enlarged view thereof. Similar to the air-oil lubrication bearing device, the bearing device J also includes the outer ring spacer 4 and the inner ring spacer 5 between the outer rings 2 and 2 and between the inner rings 3 and 3 of the plurality of rolling bearings 1 aligned in the axial direction. Each is intervened. An angular ball bearing is used as each rolling bearing 1. A plurality of rolling elements 8 are interposed between the raceway surfaces of the outer ring 2 and the inner ring 3, and the rolling elements 8 are held circumferentially equidistantly by the cage 9. In addition, seal members 51, 52 for sealing the bearing internal space S1 between the outer ring 2 and the inner ring 3 are attached to both axial ends of the outer ring 2 in the bearing device J which is grease lubrication.

  The outer ring spacer 4 is substantially T-shaped in cross section, and the inner peripheral surface of the inner projecting portion 4a, which is a vertical line portion of the T, and the outer peripheral surface of the inner ring spacer 5 face each other through the radial gap δ1. ing. The outer ring spacer 4 is provided with a nozzle hole 15 for discharging the compressed air A for cooling toward the outer peripheral surface of the inner ring spacer 5 by opening the outlet 15a on the inner peripheral surface of the inner diameter side protruding portion 4a There is. The number of the nozzle holes 15 is, for example, three, and the nozzle holes 15 are equally distributed in the circumferential direction. Further, although not shown, each nozzle hole 15 is inclined forward in the rotational direction of the inner ring spacer 5.

  An introduction groove 16 for introducing compressed air A into the nozzle holes 15 from the outside of the bearing device J is formed on the outer peripheral surface of the outer ring spacer 4. In addition, a discharge port 17 of the compressed air A discharged from the nozzle hole 15 is provided on an axial end surface of the outer ring spacer 4. The discharge port 17 has a notch shape similar to that of the first embodiment, and is inclined forward in the rotational direction of the inner ring spacer 5 as with the nozzle hole 15.

  The inner ring spacer 5 has obstacle walls 53 projecting outward in the axial direction at both ends. In this example, the obstacle wall 53 has a tapered shape in which the amount of protrusion toward the outer diameter side is larger toward the side closer to the rolling bearing 1 in the axial direction. Note that the inner ring spacer 5 of this configuration has two axially middle portions divided in order to allow assembly of the outer ring spacer 4, that is, to prevent interference between the inner periphery of the outer ring spacer 4 and the obstacle wall 53. Consists of two inner ring segments.

  As shown in FIG. 8, the outer diameter end of the obstacle wall 53 is opposed to the inner peripheral surface of the outer ring spacer 4 via a slight radial gap δ2. Further, the end face of the obstacle wall 53 is opposed to the seal member 51 on the inner side in the axial direction via a slight axial gap δ3. Thus, a labyrinth seal portion 55 having a labyrinth seal effect is constructed by the seal member 51 and the obstacle wall 53, and the bearing inner space S1 and the spacer space S2 are separated by the labyrinth seal portion 55.

  In the bearing device J, the compressed air A for cooling, which is fed from a compressed air supply device provided outside the bearing device J during operation, etc., passes from the nozzle hole 15 of the outer ring spacer 4 to the outer peripheral surface of the inner ring spacer 5 Will be supplied towards the After the compressed air A collides with the inner ring spacer 5, it flows axially to both sides along the outer peripheral surface of the inner ring spacer 5, and further along the tapered outer diameter surface of the obstacle wall 53 of the inner ring spacer 5. It is guided to the radial side and discharged from the exhaust port 17 of the outer ring spacer 5. In addition to guiding the compressed air A to the outer diameter side by the obstacle wall 53, the exhaust port 17 is inclined forward in the rotational direction of the inner ring spacer 5 in the same manner as the nozzle hole 15. The flow of the compressed air A and the discharge of the compressed air A from the spacer space S2 become smooth. While the compressed air A passes through the spacer space S2, the heat of the bearing device J and the main shaft 7 supported by the bearing device J is removed. Thereby, the bearing device J and the main shaft 7 are cooled efficiently.

  The provision of the barrier walls 53 at both axial ends of the inner ring spacer 5 prevents the compressed air A from flowing into the bearing internal space S1. In this embodiment, in particular, since the bearing internal space S1 and the spacer space S2 are separated by the labyrinth seal portion 55, the inflow of the compressed air A into the bearing internal space S1 can be more effectively prevented. Furthermore, since the compressed air A flows smoothly in the spacer space S2, the internal pressure of the spacer space S2 is lower than the internal pressure of the bearing internal space S1, and the compressed air A does not easily flow into the bearing internal space S1. From these things, it can suppress that the compressed air A flows in into bearing internal space S1 as much as possible, and it is prevented that the grease enclosed by bearing internal space S1 is eliminated by the compressed air A. FIG. Therefore, good lubrication can be maintained.

Fourth Embodiment
FIG. 8 is a sectional view of another example of the bearing device which is grease lubrication, and FIG. 9 is a partially enlarged view thereof. This bearing device J differs from the third embodiment in the shape of the obstacle wall formed on the inner ring spacer 5. Others are the same as the third embodiment.

  As shown in FIG. 9, the inner ring spacer 5 is composed of a central cylindrical body 5a and obstacle wall formers 5b, 5b on both axial sides thereof. Each obstacle wall formation body 5b is provided with the obstacle wall 61 at an axial end. The portion of the obstacle wall formation body 5b excluding the obstacle wall 61 is a cylindrical shape having the same outer diameter as the cylindrical body 5a.

  As shown in FIG. 9, the obstacle wall 61 includes a collar 61a extending to the outer diameter side and a cylindrical portion 61b extending axially inward from the outer diameter end of the collar 61a. The outer diameter end of the collar portion 61 a extends near the inner peripheral surface of the outer ring 2 of the rolling bearing 1. The axially inner end of the cylindrical portion 61b is opposed to the inner diameter side protruding portion 4a of the outer ring spacer 4 via a minute gap 62, and the labyrinth seal LS is configured by this opposed portion.

  A cooling space S3 is formed inside the cylindrical portion of the obstacle wall forming body 5b, the flange portion 61a of the obstacle wall 61, the cylindrical portion 61b, and the inner diameter side projection 4a of the outer ring spacer 4. Further, an exhaust space S4 is formed between the cylindrical portion 61b of the obstacle wall 61 and the cylindrical portion 4b which is a horizontal line portion of the T-shape in the outer ring spacer 4. The cooling space S3 and the exhaust space S4 are connected via the gap 62 configured as a labyrinth seal LS.

  The bearing internal space S1 and the cooling space S2 are completely separated by the obstacle wall 61. In addition to the fact that the outer diameter end of the collar 61a of the obstacle wall 61 extends close to the inner circumferential surface of the outer ring 3, the collar 61a of the obstacle wall 61 is slightly By facing each other through the axial gap 63, a labyrinth seal portion having a labyrinth seal effect is constructed between the bearing inner space S1 and the exhaust space S4.

  The bearing device J cools the inner ring spacer 5 by discharging compressed air A for cooling from the nozzle holes 15 of the outer ring spacer 4 toward the outer peripheral surface of the inner ring spacer 5 during operation or the like. Thereafter, the compressed air A flows along the outer peripheral surface of the inner ring spacer 5 in the axial direction. The rolling bearings 1 are provided on both sides in the axial direction. However, since the obstacle walls 61 are provided on both axial ends of the inner ring spacer 5, the compressed air A does not easily flow into the bearing. Further, since a part of the obstacle wall 61 is configured as the labyrinth seal LS, the exhaust of the compressed air A after being blown to the outer peripheral surface of the inner ring spacer 5 is suppressed, and the compressed air A flows into the cooling space S3. The remaining time is long, and the inner ring spacer 5 can be cooled efficiently. Thereby, the inner ring spacer 5 and the inner ring 3 of the rolling bearing 1 in contact therewith are cooled more efficiently.

  The compressed air A in the cooling space S3 flows to the exhaust space S4 through the gap 62 little by little with time, and is further discharged from the exhaust space S4 to the outside of the bearing device J through the exhaust port 17. Since the exhaust port 17 is inclined forward in the rotational direction of the inner ring spacer 5 in the same manner as the nozzle hole 15, the compressed air A is smoothly discharged from the exhaust port 17.

  Since the obstacle wall 61 is provided, the compressed air A does not flow directly from the cooling space S3 into the bearing internal space S1. Further, since the labyrinth seal portion is constructed between the bearing internal space S1 and the exhaust space S4, the compressed air A hardly flows into the bearing internal space S1 from the exhaust space S4. For this reason, it is prevented that the grease enclosed inside the bearing is blown off by the compressed air A, and a good lubrication state can be maintained.

  Although the case where rolling bearing 1 was used by inner ring rotation was shown in each above-mentioned embodiment, also when using by outer ring rotation, this invention is applicable. In that case, for example, a shaft (not shown) fitted on the inner periphery of the inner ring 3 is a fixing member, and a roller (not shown) fitted on the outer periphery of the outer ring 2 is a rotating member.

  As mentioned above, although the form for implementing this invention based on the Example was demonstrated, the embodiment disclosed here is an illustration and restrictive at no points. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

1 ... Rolling bearing 2 ... Outer ring (fixed side bearing ring)
3 ... Inner ring (rotation side race)
4 ... Outer ring spacer (fixed side spacer)
5 ... Inner ring spacer (rotation side spacer)
6 ... housing (fixed member)
7 ... Spindle (rotational member)
15 ... nozzle hole 15a ... outlet 17 ... exhaust port 53, 61 ... obstacle wall A ... compressed air J ... bearing device

Claims (5)

A stationary side spacer and a rotational side spacer are provided respectively adjacent to the stationary side race ring and the rotational side race ring opposed to the inside and outside of the rolling bearing, and the stationary side race ring and the stationary side seat are fixed members and In a bearing device installed on a fixed member among rotating members, wherein the rotating side race ring and the rotating side spacer are installed on a rotating member among the fixed member and the rotating member,
There is provided a nozzle hole for discharging compressed air from the outlet opening in the peripheral surface facing the rotary side spacer in the stationary side spacer to the peripheral surface facing the stationary side spacer in the rotary side spacer And, an exhaust port of the compressed air discharged from the nozzle hole is provided on an axial end face of the fixed side spacer, and the nozzle hole is provided to be inclined forward in the rotational direction of the rotating side spacer The cooling structure of a bearing device, characterized in that the exhaust port is inclined forward in the rotational direction of the rotation side spacer.   The cooling structure of the bearing device according to claim 1, wherein the fixed bearing ring is an outer ring, and the rotating bearing ring is an inner ring.   The cooling structure of a bearing device according to any one of claims 1 or 2, wherein the number of the nozzle holes and the number of the exhaust ports are the same, and the nozzle holes and the exhaust ports are in the circumferential direction. The cooling structure of the bearing device provided in equal intervals.   The cooling structure of a bearing device according to claim 3, from the outlet of any one of the nozzle holes to the exhaust port located forward of the nozzle hole in the rotational direction of the spacer on the rotating side. A circumferential distance is a circumferential distance from any one of the exhaust ports to the outlet of the nozzle hole located on the front side in the rotational direction of the rotation side spacer with respect to the exhaust port. Even long bearing cooling structure.   The cooling structure of a bearing device according to any one of claims 1 to 4, wherein the rolling bearing is made of grease enclosed in a bearing between the fixed bearing ring and the rotating bearing ring. The compressed air which is lubricated and protrudes to the side of the fixed-side spacer at the axial end adjacent to the fixed-side race ring in the rotating-side spacer and the compressed air discharged from the nozzle hole flows into the inside of the bearing The cooling structure of the bearing device provided with a barrier that prevents

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