Oil-gas lubrication structure of rolling bearing

Abstract

An oil-gas lubrication structure of a rolling bearing is provided with a rolling bearing (1) and a lubrication device (2) for supplying oil gas to the rolling bearing (1). The lubricating device (2) is provided with: an outer ring spacer (11) provided adjacent to the outer ring end surface (7b) of the rolling bearing (1) and having an oil gas supply hole (14); and a nozzle spacer (12) that is fixed to the outer ring spacer (11) via a joining surface (12a), has an oil gas supply hole (17) communicating with the oil gas supply hole (14), and ejects oil gas from the oil gas supply hole (17) toward the rolling bearing (1). And a flat and straight surface securing means (13) for securing a flat and straight surface (f2) between the boundary section (19) and a seal groove (18) provided in the joining surface (12a) and located on the outside of the oil gas supply hole (14) and the oil gas supply hole (17), while securing a contact surface (f1) between the outer ring spacer (11) and the outer ring end surface (7b), so as to ensure that the area of the flat and straight surface (f2) is greater than or equal to a predetermined area.

Description

Technical Field

[0001] The present invention relates to an oil - air lubrication structure for rolling bearings such as angular contact ball bearings suitable for high - speed rotation, for example, for supporting a spindle of a machine tool etc. Background Art

[0002] The spindle device of a machine tool has a tendency to be high - speed, and an oil - air lubrication structure is applied (for example, Patent Documents 1 and 2). This oil - air lubrication is a lubrication method in which lubricating oil is mixed in the supplied air and directly sprayed onto the inner ring. As Figure 6 shown, this oil - air lubrication structure includes: a rolling bearing 52 having a counterbore 50 as an inclined surface portion provided on the outer diameter of the inner ring, and an oil groove 51 provided in the counterbore 50; an outer - ring spacer 53; and a nozzle spacer 54.

[0003] Oil - air is sprayed from a housing 55 as a customer part, via the outer - ring spacer 53 and the nozzle spacer 54, into the oil groove 51 of the inner ring. Through the centrifugal force generated by the rotation of the inner ring and the surface tension of the oil, lubrication is spread along the counterbore 50 to the rolling surface 56. The nozzle spacer 54 of the outer - ring spacer 53 and the nozzle spacer 54 is fixed to the outer - ring spacer 53 by bolts or the like. The outer - ring spacer 53 and the nozzle spacer 54 communicate with the oil supply hole 57, and an O - ring 58 is installed at their junction to prevent oil - air leakage.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 4261083

[0007] [Patent Document 2] Japanese Patent Publication No. 4289875 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] · In the spacer of this oil - air lubrication structure, the nozzle spacer 54 is fixed to the outer - ring spacer 53 with bolts, and the outer - ring spacer 53 contacts the bearing outer ring 59.

[0010] · If the radial cross - sectional height h of the nozzle spacer 54 is too large relative to the ball diameter of the bearing, the contact surface between the outer - ring spacer 53 and the bearing outer ring 59 cannot be ensured. Even if the radial cross - sectional height h of the nozzle spacer 54 is too small relative to the ball diameter, the straight surface between the O - ring groove and the oil supply hole cannot be ensured and it does not hold. In the case where the specified straight surface cannot be ensured, even when the O - ring 58 is not installed or the O - ring 58 is installed, it is possible that the function of the O - ring 58 cannot be exerted and oil - air cannot be smoothly supplied to the rolling bearing 52. Therefore, the radial cross - sectional height h of the nozzle spacer 54 relative to the ball diameter must be set optimally.

[0011] An object of the present invention is to provide an oil-air lubrication structure for a rolling bearing that can smoothly supply oil and gas.

[0012] Technical solution for solving the problem

[0013] The oil-air lubrication structure of the rolling bearing of the present invention has a rolling bearing and a lubrication device for supplying oil and gas to the rolling bearing;

[0014] The lubrication device includes: an outer ring spacer, which is arranged adjacent to the end face of the outer ring of the rolling bearing and has an oil and gas supply hole; and a nozzle spacer, which is fixed to the outer ring spacer via a joint surface and has an oil and gas supply hole communicating with the oil and gas supply hole, and sprays oil and gas from the oil and gas supply hole to the rolling bearing;

[0015] It also has a flat surface ensuring mechanism, which while ensuring contact between the outer ring spacer and the outer ring end face, ensures that the flat surface between the sealing groove, which is located outside the oil and gas supply hole and the oil and gas supply hole and is arranged in a ring shape in the joint surface, and the oil and gas supply hole has a certain area or more.

[0016] The oil and gas is lubricating oil mixed with conveying air.

[0017] The "certain area" is an area arbitrarily determined by design, etc., for example, an appropriate area is obtained through either or both of experiments and simulations to determine.

[0018] According to this structure, the contact surface between the outer ring spacer and the outer ring end face is ensured. At the same time, by ensuring that the flat surface between the sealing groove in the joint surface and the oil and gas supply hole has a certain area or more, not only can a seal be installed on the sealing groove, but also the sealing function can be exerted. Therefore, oil and gas can be smoothly supplied from the lubrication device to the rolling bearing.

[0019] Alternatively, the rolling bearing is a ball bearing, and the following relationship exists between the cross-sectional height h of the nozzle spacer and the ball diameter Dw in the flat surface ensuring mechanism:

[0020] 0.8 ≦ h / Dw ≦ 2.0

[0021] The cross-sectional height h of the nozzle spacer is the radial cross-section of the nozzle spacer.

[0022] By satisfying the above relationship, the contact surface between the outer ring spacer and the outer ring end face can be ensured, and a seal can be reliably installed on the sealing groove.

[0023] Alternatively, the following relationship exists between the pitch diameter d3 of the oil supply hole of the nozzle spacer and the pitch circle diameter PCD of the rolling bearing:

[0024] 0.9 ≦ d3 / PCD ≦ 1.1

[0025] By satisfying the relationship between the pitch diameter d3 of the oil supply holes and the pitch circle diameter PCD, it is possible to aim at a specified position on the inner ring and spray oil and gas. Thereby, it is possible to supply oil and gas from the lubricating device to the rolling bearing more smoothly.

[0026] Alternatively, the nozzle diameter A of the nozzle spacer and the oil supply hole diameter B may be in the following relationship:

[0027] 1.0 ≦ B / A ≦ 4.0

[0028] The nozzle diameter A is the oil supply hole diameter on the downstream side facing the rolling bearing in the oil and gas supply holes. The oil supply hole diameter B is the oil supply hole diameter on the upstream side communicating with the oil and gas supply holes of the outer ring spacer.

[0029] By satisfying the relationship between the nozzle diameter A and the oil supply hole diameter B, it is possible to appropriately maintain the relationship between the air velocity and the air pressure, and even when the free margin of the radial dimension around the seal groove is small, it is possible to provide an O-ring (seal) mechanism.

[0030] Alternatively, the oil supply hole diameter B of the nozzle spacer and the inner diameter C of the seal groove may be in the following relationship.

[0031] 1.0 < C / B ≦ 2.5

[0032] By satisfying the relationship between the oil supply hole diameter B and the inner diameter C of the seal groove, it is possible to improve the functionality of the O-ring (seal) and enable smoother oil and gas lubrication.

[0033] Alternatively, the inner diameter C of the seal groove and the seal inner diameter D of the seal member inserted into the seal groove may be in the following relationship:

[0034] 0.7 ≦ D / C ≦ 1.0

[0035] By satisfying the relationship between the inner diameter C of the seal groove and the seal inner diameter D, it is possible to suppress the rebound of the seal member installed in the seal groove, improve the assemblability of the lubricating device, and enable smoother oil and gas lubrication. The seal member has a slight interference fit with the seal groove and will not fall freely. Therefore, since the seal member is installed on the nozzle spacer and it is difficult to disengage when fixing the outer ring spacer and the nozzle spacer, the assemblability of the seal member is also improved. In addition, by satisfying these relationships, it is possible to use standard products as the seal members, so compared with using special seal members, cost reduction can be achieved.

[0036] The rolling bearing may also be an angular contact ball bearing. For the angular contact ball bearing of this oil and gas lubrication structure, in order to supply oil and gas, a tapered hole with an inclined surface portion on one side of the outer peripheral surface of the inner ring is formed.

[0037] Any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of more than two of the respective claims in the claims is included in the present invention. Description of the Drawings

[0038] The present invention will be more clearly understood from the following description of preferred embodiments with reference to the drawings. However, the embodiments and the drawings are only for illustration and explanation, and should not be used to limit the scope of the present invention. The scope of the present invention is determined by the claims. In the drawings, the same reference numerals in multiple drawings denote the same or corresponding parts.

[0039] Figure 1 is a longitudinal sectional view of an oil-air lubrication structure of a rolling bearing according to a first embodiment of the present invention.

[0040] Figure 2 is Figure 1 a partial enlarged view of the main part of

[0041] Figure 3A is a partial enlarged view of a nozzle spacer of the oil-air lubrication structure as observed axially.

[0042] Figure 3B is a side view of a seal installed in a seal groove of the nozzle spacer.

[0043] Figure 4A is a partial enlarged view of the main part of the oil-air lubrication structure with a partial change.

[0044] Figure 4B is a longitudinal sectional view of an oil-air lubrication structure of a rolling bearing according to a second embodiment of the present invention.

[0045] Figure 5 is a sectional view of a spindle device adopting any one of the oil-air lubrication structures.

[0046] Figure 6 is a longitudinal sectional view of an oil-air lubrication structure of a rolling bearing in a conventional example. Detailed Description of the Invention

[0047] [First Embodiment]

[0048] Together with Figures 1 to 3B , Figure 5 the oil-air lubrication structure of the rolling bearing according to the embodiment of the present invention will be described. The oil-air lubrication structure of the rolling bearing according to this embodiment is applicable to, for example, an angular contact ball bearing that rotatably supports a machine tool spindle.

[0049] As Figure 1 shown, the oil-air lubrication structure of the rolling bearing has an angular contact ball bearing 1 and a lubrication device 2 that supplies oil and gas to the angular contact ball bearing 1. As a rotating body, a spindle 5 (Figure 5 ) is rotatably supported on the housing 3 via the angular contact ball bearing 1, the lubrication device 2, the inner ring spacer 4, etc. Figure 5 ) When a plurality of angular contact ball bearings 1, lubrication devices 2, and inner ring spacers 4 are assembled to the housing 3 Figure 5 ) and the main shaft 5 Figure 5 ), a specified positioning preload or constant pressure preload is applied to the angular contact ball bearing 1.

[0050] <Rolling bearing>

[0051] As the rolling bearing, the angular contact ball bearing 1 has an inner ring 6, an outer ring 7 as a fixed-side raceway ring, a plurality of rolling elements 8 interposed between the rolling surfaces 6a, 7a of the inner and outer rings 6, 7, and a cage 9 for holding these rolling elements 8. The rolling elements 8 are formed of balls and are held in the pockets 9a of the cage 9. In the inner peripheral surface of the cage 9, the portion 9b located on the width surface side rather than the pockets 9a is a conical surface whose diameter on the width surface side is larger than the center in the width direction of the cage. The outer peripheral surface of the outer ring 7 is fitted into the fitting hole of the housing 3 Figure 5 ), and the inner peripheral surface of the inner ring 6 is fitted into the outer peripheral surface of the main shaft 5 Figure 5 ).

[0052] As Figure 2 shown, on the outer peripheral surface of the inner ring 6 on the anti-load side, there is provided an inclined surface portion 6b connected to the rolling surface 6a, that is, a tapered hole. The inclined surface portion 6b is a tapered shape whose diameter gradually decreases from the rolling surface 6a side toward the inner ring spacer 4 side. A circumferential groove 10 is provided on the inclined surface portion 6b. The circumferential groove 10 is formed in an annular shape with a V-shaped cross section.

[0053] <Lubrication device>

[0054] The lubrication device 2 includes an outer ring spacer 11 and a nozzle spacer 12. The lubrication device 2 includes a flat surface ensuring mechanism 13 described later. The outer ring spacer 11 is disposed adjacent to the outer ring end face 7b of the angular contact ball bearing 1 and has an oil and gas supply hole 14. The oil and gas supply hole 14 is connected by piping to an oil and gas supply source via the oil and gas supply path 15 Figure 5 ) of the housing 3 Figure 5 ). The outer ring end face 7b is the back surface of the outer ring on the side supporting the axial load. An annular communication groove 16 communicating with the oil and gas supply path is provided on the outer peripheral surface of the outer ring spacer 11, and the communication groove 16 communicates with the oil and gas supply hole 14. The oil and gas supply hole 14 includes an upstream supply hole portion 14a and a downstream supply hole portion 14b. The upstream supply hole portion 14a extends a specified length in the radial direction communicating with the communication groove 16, and the downstream supply hole portion 14b extends a specified length in the axial direction communicating with the upstream supply hole portion 14a.

[0055] The nozzle spacer 12 is fixed to the outer ring spacer 11 via a joint surface 12a, and has an oil and gas supply hole 17 communicating with a supply hole portion 14b on the downstream side of the oil and gas supply hole 14 of the outer ring spacer 11. The joint surface 12a is along a plane perpendicular to the bearing center line C1 ( Figure 1 ) of the rolling bearing 1. The nozzle spacer 12 ejects oil and gas from the oil and gas supply hole 17 toward the rolling bearing 1. An annular cutout recess 11a is formed in an inner diameter side portion of one side surface of the outer ring spacer 11, and the nozzle spacer 12 is fixed to the cutout recess 11a with bolts.

[0056] The nozzle spacer 12 is provided at a prescribed gap δ along the inclined surface portion 6b of the inner ring 6. The front end portion 12ba of the nozzle spacer 12 is positioned near the rolling elements 8 between the inner peripheral surface of the cage 9 and the outer peripheral surface of the inner ring 6. The nozzle spacer 12 is an annular member, is disposed adjacent to the rolling bearing 1 in the axial direction, and has a flange-shaped portion 12b extending axially from an inner diameter side portion of the side surface. The inner peripheral surface of the outer bearing portion of the nozzle spacer 12 faces the outer peripheral surface of the inner ring spacer 4 with a prescribed radial gap therebetween. In this specification, the "axial direction" means the direction along the bearing center line C1 ( Figure 1 ) of the rolling bearing 1. The "radial direction" means a direction orthogonal to the straight line constituting the "axial direction".

[0057] The flat inner peripheral surface of the flange-shaped portion 12b is formed as an inclined surface at the same angle as the inclined surface portion 6b of the inner ring 6 and extends directly below the cage 9. The front end of this flange-shaped portion 12b becomes the front end portion 12ba of the nozzle spacer 12. Considering the fitting of the inner ring 6 to the shaft and the expansion of the inner ring 6 due to temperature rise and centrifugal force, the gap δ between the flange-shaped portion 12b and the inclined surface portion 6b is set within a range where they do not contact during operation.

[0058] On the nozzle spacer 12, the oil and gas supply hole 17 is provided which faces the circumferential groove 10 of the inner ring 6 and has a spout 17ba opened. The oil and gas supply hole 17 is provided at one or more locations in the circumferential direction of the nozzle spacer 12. The oil and gas supply hole 17 has an upstream supply hole 17a communicating with the oil and gas supply hole 14 of the outer ring spacer 11 and a downstream nozzle hole 17b forming the spout 17ba.

[0059] The upstream supply hole 17a extends axially for a prescribed length, and its front end portion communicates with the downstream supply hole 17b. The downstream nozzle hole 17b is provided such that the oil and gas ejection direction of the spout 17ba faces the circumferential groove 10 and has a definite inclination angle with respect to the axial direction. Thereby, the oil and gas ejected from the spout 17ba can be directly blown onto the circumferential groove 10. In addition, the side wall inclined surface 10a of the circumferential groove 10 close to the rolling surface 6a is set to have an inclination angle with respect to the axial direction larger than that of the inclined surface portion 6b of the inner ring 6.

[0060] <Flat surface ensuring mechanism>

[0061] The flat surface ensuring mechanism 13 ensures the contact surface f1 between the outer ring spacer 11 and the end face 7b of the outer ring, and ensures that the flat surface f2 between the sealing groove 18 and the boundary portion 19 between the oil and gas supply hole 14 and the oil and gas supply hole 17 has an area above a certain value. That is, the flat surface ensuring mechanism 13 ensures the contact surface f1 and ensures that the flat surface f2 between the sealing groove 18 and the oil and gas supply hole 17 has an area above a certain value. The contact surface f1 is the contact surface between the end face 7b on the back side of the outer ring and one side surface of the outer ring spacer 11 facing the end face 7b of the outer ring.

[0062] A ring-shaped sealing groove 18 is provided on the joint surface 12a of the nozzle spacer 12 and the outer ring spacer 11. The ring-shaped sealing groove 18 is located radially outside the boundary portion 19 around the base end portion of the upstream oil supply hole 17a. In addition, as Figure 3A shown, the ring-shaped sealing groove 18 is provided concentrically with the oil supply hole 17a. An O-ring or other sealing member 20 as shown in Figure 3B is embedded in the ring-shaped sealing groove 18. As shown in Figure 2 the outer ring spacer 11 and the nozzle spacer 12 are fixed by fasteners (not shown) such as bolts. The sealing member 20 is elastically deformed in the sealing groove 18 to seal the periphery of the boundary portion 19, thereby preventing the leakage of oil and gas from the boundary portion 19. The O-ring is, for example, a standard product specified by ISO or other international standardization organizations.

[0063] <Regarding parameters, etc.>

[0064] If the radial cross-sectional height h of the nozzle spacer 12 is too large relative to the ball diameter of the rolling bearing 1, the contact surface f1 between the outer ring spacer 11 and the outer ring 7 cannot be ensured. Even if the radial cross-sectional height h of the nozzle spacer 12 is too small relative to the ball diameter, the flat surface f2 between the O-ring groove 18 and the oil supply hole cannot be ensured and it does not hold. Therefore, it is necessary to optimally set the nozzle spacer cross-sectional height h relative to the ball diameter Dw.

[0065] Specifically, in the flat surface ensuring mechanism 13, the nozzle spacer cross-sectional height h and the ball diameter Dw are in the following relationship:

[0066] 0.8 ≦ h / Dw ≦ 2.0

[0067] In addition, oil and gas are sprayed from the outer ring spacer 11 through the nozzle spacer 12 into the oil groove 10 of the inner ring 6. The nozzle hole A of the nozzle spacer 12 has a certain angle with respect to the radial vertical line. Therefore, if the pitch diameter d3 of the oil supply hole of the nozzle spacer 12 is not in the optimal positional relationship with respect to the pitch circle diameter PCD of the rolling bearing 1, the structure in which the front end of the nozzle hole aims at the oil groove 10 of the inner ring 6 cannot be formed. That is, the relationship between the pitch diameter d3 of the oil supply hole and the bearing PCD is important.

[0068] Therefore, the pitch diameter d3 of the oil supply holes of the nozzle spacer 12 and the pitch circle diameter PCD of the rolling bearing 1 have the following relationship.

[0069] 0.9 ≦ d3 / PCD ≦ 1.1

[0070] The O-ring used for the nozzle spacer 12 is an O-ring with a very small diameter due to size limitations.

[0071] In order to reduce costs, the O-ring should use the manufacturer's standard product.

[0072] Considering the assemblability, it is preferable that the O-ring has the same value or a slightly excessive interference with respect to the inner diameter of the O-ring groove.

[0073] However, the dimensions of the periphery of the O-ring groove are sometimes designed with a small free margin in the radial dimension and a large interference.

[0074] Therefore, even if the inner diameter of the O-ring groove is reduced to reduce the interference, there is an oil supply hole 17a in the center of the O-ring groove 18, and a flat portion between the oil supply hole 17a and the inner diameter of the O-ring groove must be ensured, so the dimension setting is difficult.

[0075] If the interference of the O-ring is too large, there will be a springback when inserting the O-ring, and the O-ring will be fastened while floating from the groove, and the O-ring may be worn.

[0076] If wear occurs, the function of the O-ring may not be properly exerted, resulting in leakage.

[0077] Thus, the relationships among (1) the nozzle aperture A and the oil supply aperture B, (2) the oil supply aperture B and the inner diameter C of the O-ring groove, and (3) the inner diameter C of the O-ring groove and the inner diameter D of the O-ring need to be set to optimal dimensions.

[0078] In summary, the various parameters are set as follows.

[0079] The nozzle diameter A of the nozzle spacer 12 and the oil supply aperture B are in the following relationship:

[0080] 1.0 ≦ B / A ≦ 4.0

[0081] The oil supply aperture B of the nozzle spacer 12 and the inner diameter C of the sealing groove 18 are in the following relationship:

[0082] 1.0 < C / B ≦ 2.5

[0083] The inner diameter C of the sealing groove 18 and the sealing inner diameter D of the seal 20 embedded in the sealing groove 18 are in the following relationship:

[0084] 0.7 ≦ D / C ≦ 1.0

[0085] <Comparison between this embodiment and the comparative example>

[0086] Here, in order to evaluate the oil - air lubrication structure of the rolling bearings of Examples 1 - 4 and the oil - air lubrication structure of the rolling bearings of the comparative example, as shown in Table 1, comparisons were made on air velocity, air pressure, O - ring part design, O - ring functionality, O - ring assemblability, etc. In Table 1, ◎ indicates feasible and excellent effect, ○ indicates feasible and good effect, △ indicates feasible, and × indicates poor effect.

[0087] [Table 1]

[0088]

[0089] <Effect>

[0090] According to the oil - air lubrication structure of the rolling bearing described above, the oil - air supplied from the oil - air supply hole 14 is sprayed into the circumferential groove 10 of the inner - ring inclined surface portion 6b through the oil - air supply hole 17 of the nozzle spacer 12. The oil adhering to the circumferential groove 10 is guided along the inner - ring inclined surface portion 6b by the action of centrifugal force and flows into the interior of the angular contact ball bearing 1 as lubricating oil.

[0091] The flat - surface and other ensuring mechanism 13 ensures the contact surface f1 between the outer - ring spacer 11 and the outer - ring end surface 7b. Thus, in the state where a plurality of angular contact ball bearings 1, the lubrication device 2, and the inner - ring spacer 4 are assembled to the housing 3 ( Figure 5 ) and the main shaft 5 ( Figure 5 ), a prescribed pre - load can be applied to the angular contact ball bearing 1, and a prescribed gap δ between the nozzle spacer 12 and the inclined surface portion 6b of the inner - ring 6 can be ensured. At the same time, by ensuring that the flat surface f2 between the seal groove 18 and the oil - air supply hole 19 in the joint surface 12a is above a certain area, a seal member 20 can be installed on the seal groove 18, and the function of the seal member 20 can be exerted. Therefore, oil - air can be smoothly supplied from the lubrication device 2 to the rolling bearing 1.

[0092] In the flat - surface and other ensuring mechanism 13, the following relationship exists between the cross - section height h of the nozzle spacer and the ball diameter Dw:

[0093] 0.8 ≤ h / Dw ≤ 2.0

[0094] By satisfying the above relationship, the contact surface f1 between the outer - ring spacer 11 and the outer - ring end surface 7b can be ensured, and the seal member 20 can be reliably installed on the seal groove 18.

[0095] The following relationship exists between the pitch diameter d3 of the oil - supply holes of the nozzle spacer 12 and the pitch - circle diameter PCD of the rolling bearing 1:

[0096] 0.9 ≤ d3 / PCD ≤ 1.1

[0097] By satisfying the relationship between the pitch diameter d3 of the oil supply hole and the pitch circle diameter PCD, it is possible to aim at a specified position of the inner ring 6 and inject oil and gas. As a result, it is possible to supply oil and gas from the lubricating device 2 to the rolling bearing 1 more smoothly.

[0098] The nozzle diameter A of the nozzle spacer 12 and the oil supply hole diameter B are in the following relationship:

[0099] 1.0 ≦ B / A ≦ 4.0

[0100] By satisfying the relationship between the nozzle diameter A and the oil supply hole diameter B, it is possible to appropriately maintain the relationship between the air velocity and the air pressure, and even when the free margin of the radial dimension around the seal groove is small, it is possible to provide an O-ring (seal) mechanism.

[0101] The oil supply hole diameter B of the nozzle spacer 12 and the inner diameter C of the seal groove 18 are in the following relationship:

[0102] 1.0 < C / B ≦ 2.5

[0103] By satisfying the relationship between the oil supply hole diameter B and the inner diameter C of the seal groove 18, it is possible to improve the functionality of the O-ring (seal) and enable smoother oil and gas lubrication.

[0104] The inner diameter C of the seal groove 18 and the seal inner diameter D of the seal member 20 inserted into the seal groove 18 are in the following relationship:

[0105] 0.7 ≦ D / C ≦ 1.0

[0106] By satisfying the relationship between the inner diameter C of the seal groove 18 and the seal inner diameter D, it is possible to suppress the rebound of the seal member 20 installed in the seal groove 18, improve the assemblability of the lubricating device 2, and enable smoother oil and gas lubrication. The seal member 20 has a slight interference fit with respect to the seal groove 18 and does not fall freely. Therefore, since the seal member 20 is installed on the nozzle spacer 12 and it is difficult to come off when fixing the outer ring spacer 11 and the nozzle spacer 12, the assemblability of the seal member 20 is also improved. In addition, by satisfying these relationships, it is possible to use standard products as the seal member 20, so cost reduction can be achieved compared to using special seal members.

[0107] The rolling bearing is an angular contact ball bearing 1. The angular contact ball bearing 1 of this oil and gas lubrication structure has a tapered hole with an inclined surface portion 6b on one side of the outer peripheral surface of the inner ring 6 for supplying oil and gas.

[0108] <Regarding other embodiments>

[0109] In the following description, the same reference numerals are assigned to the parts corresponding to those previously described in each embodiment, and repeated descriptions are omitted. When only a part of the structure is described, unless otherwise specified, the other parts of the structure are the same as those of the previously described embodiment. The same structure has the same function and effect. Not only the combinations of the parts specifically described in each embodiment, but also the combinations of the embodiments with each other are possible, especially if the combinations do not cause any obstacles.

[0110] [Example of providing a sealing groove in the outer ring spacer, Figure 4A

[0111] As Figure 4A shown, a ring-shaped sealing groove 18 may also be provided on the joint surface 11b of the outer ring spacer 11 and the nozzle spacer 12. The ring-shaped sealing groove 18 is located radially outside the boundary portion 19 around the downstream side portion of the downstream supply hole portion 14b. The ring-shaped sealing groove 18 is provided concentrically with the downstream supply hole portion 14b. A sealing member 20 such as an O-ring is fitted into the ring-shaped sealing groove 18.

[0112] In this case, the same function and effect as those of the above-described embodiment are also achieved.

[0113] [Second Embodiment: Cylindrical Roller Bearing, Figure 4B

[0114] As Figure 4B shown, a cylindrical roller bearing 1A may also be used as a rolling bearing. On the outer peripheral surface of the inner ring 6 of the cylindrical roller bearing 1A, an inclined surface portion 6b connected to the rolling surface 6a is provided. A circumferential groove 10 is provided on one inclined surface portion 6b. The nozzle spacer 12 is provided at a prescribed gap δ along the inclined surface portion 6b on one side of the inner ring 6. In the second embodiment, the same function and effect as those of the above-described embodiments are also achieved.

[0115] <Example of Application to a Spindle Device, Figure 5 >

[0116] Figure 5 An example of a spindle device having an oil-air lubrication structure using the rolling bearing of the first embodiment is shown. This spindle device is applied to a machine tool, and a chuck for mounting a tool or a workpiece is attached to the end of the spindle 5. The spindle 5 is supported by a plurality of (in this example, a pair of) rolling bearings 1, 1 separated in the axial direction. The pair of rolling bearings 1, 1 are arranged facing each other. Each inner ring 6 is fitted to the outer peripheral surface of the spindle 5, and each outer ring 7 is fitted to the inner peripheral surface of the housing 3. These inner and outer rings 6, 7 are fixed to the spindle 5 and the housing 3 by an inner ring pressing member 21 and an outer ring pressing member 22, respectively.

[0117] ​​The housing 3 has a double structure with an inner peripheral housing 3A and an outer peripheral housing 3B, and a cooling medium flow path 32 is formed between the inner and outer housings 3A and 3B. An oil-gas supply path 15 and its oil-gas supply port 15a are provided on the inner peripheral housing 3A. The housing 3 is fixed to the support table 37. An oil-gas exhaust path 39 is provided in the housing 3, and oil-gas exhaust grooves 34 are provided near the installation portions of the respective bearings 1 on the inner peripheral surface, opening to the atmosphere from the oil-gas exhaust grooves 34.

[0118] Figure 1 The nozzle spacer 12 shown in etc. is an annular member, but depending on the use and usage conditions, it may also be an arc-shaped member extending a predetermined length in the circumferential direction.

[0119] The oil-gas lubrication structure of each rolling bearing can also be applied to uses other than machine tool uses.

[0120] As described above, the preferred embodiments have been described with reference to the drawings, but various additions, changes, and deletions can be made without departing from the gist of the present invention. Therefore, such cases are also included in the scope of the present invention.

[0121] [Reference Signs]

[0122] 1…Angular contact ball bearing (rolling bearing)

[0123] 1A…Cylindrical roller bearing (rolling bearing)

[0124] 2…Lubrication device

[0125] 7b…Outer ring end face

[0126] 11…Outer ring spacer

[0127] 11b…Joint surface

[0128] 12…Nozzle spacer

[0129] 12a…Joint surface

[0130] 13…Flat surface ensuring mechanism etc.

[0131] 14…Oil-gas supply hole

[0132] 17…Oil-gas supply hole

[0133] 18…Sealing groove

[0134] 19…Boundary portion

[0135] f1…Contact surface

[0136] f2…Flat surface.

Claims

1. An oil-gas lubrication structure for a rolling bearing, comprising a rolling bearing and a lubricating device for supplying oil and gas to the rolling bearing; wherein: The lubricating device comprises: an outer ring spacer, which is arranged adjacent to the outer ring end face of the rolling bearing and has an oil and gas supply hole; and a nozzle spacer, which is fixed to the outer ring spacer via a joint surface and has an oil and gas supply hole connected to the oil and gas supply hole, and sprays oil and gas from the oil and gas supply hole to the rolling bearing; It also has a ensuring mechanism such as a flat surface, which ensures that the outer ring spacer is in contact with the outer ring end face, and at the same time ensures that the flat surface between the sealing groove in the joint surface located on the outside of the oil and gas supply hole and the oil and gas supply hole and arranged in an annular shape and the oil and gas supply hole is larger than a certain area.

2. The oil-gas lubrication structure of a rolling bearing according to claim 1, characterized in that: The rolling bearing is a ball bearing, and the flat surface ensures that in the mechanism, the nozzle spacer cross-sectional height h and the ball diameter Dw are in the following relationship: 0.8≦h / Dw≦2.

0.

3. The oil-gas lubrication structure of a rolling bearing according to claim 1 or 2, characterized in that: The pitch diameter d3 of the oil supply hole of the nozzle spacer and the pitch circle diameter PCD of the rolling bearing are in the following relationship: 0.9≦d3 / PCD≦1.

1.

4. The oil-gas lubrication structure of a rolling bearing according to claim 1 or 2, characterized in that: The nozzle diameter A and the oil supply aperture B of the nozzle spacer are in the following relationship: 1.0≦B / A≦4.

0.

5. The oil-gas lubrication structure of a rolling bearing according to claim 4, characterized in that: The oil supply aperture B of the nozzle spacer and the inner diameter C of the sealing groove are in the following relationship: 1.0<C / B≦2.

5.

6. The oil-gas lubrication structure of a rolling bearing according to claim 4 or 5, characterized in that: The inner diameter C of the sealing groove and the sealing inner diameter D of the sealing member embedded in the sealing groove are in the following relationship: 0.7≦D / C≦1.

0.

7. The oil-gas lubrication structure of a rolling bearing according to claim 1 or 2, characterized in that: The rolling bearing is an angular contact ball bearing.

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