Oil-gas lubrication structure of rolling bearing
By optimizing the design of the nozzle septum and oil supply hole, the problem of poor oil and gas supply in the existing oil-gas lubrication structure was solved, enabling effective installation of seals and efficient operation of the lubrication device, thereby reducing costs.
Patent Information
- Application Number
- CN202422875211.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-27
- Filing Date
- 2024-11-25
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-11-25
AI Technical Summary
In existing oil-air lubrication structures, improper design of the radial section height of the nozzle septum and the oil supply hole results in the inability to ensure the contact surface between the outer ring septum and the outer ring of the bearing, and the flatness between the O-ring groove and the oil supply hole is insufficient, affecting the smooth supply of oil and air.
By designing an oil-air lubrication structure for a rolling bearing, while ensuring contact between the outer ring spacer and the outer ring end face, a flat surface and other ensuring mechanisms are set to ensure that the flat surface between the sealing groove and the oil supply hole has a defined area, and the parameter relationship of the nozzle spacer is optimized, including the nozzle spacer cross-sectional height, the pitch diameter and pitch circle diameter of the oil supply hole, and the ratio of the nozzle diameter to the oil supply hole diameter, so as to install the seal and perform the sealing function.
This ensures a smooth supply of oil and gas, guarantees the functionality and assemblability of the seals, reduces costs, and improves the reliability and efficiency of the lubrication system.
Smart Images
Figure CN223609136U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the oil gas lubrication structure of the rolling bearing such as the angular contact ball bearing such as the high -speed rotation such as the main shaft for supporting the machine tool etc. BACKGROUND
[0002] The main shaft device of machine tool has the tendency of high speed, and is suitable for oil gas lubrication structure (for example, patent document 1, 2). The oil gas lubrication is the lubrication method that mixes lubricating oil in conveying air and directly sprays to the inner ring. As shown in the figure, the oil gas lubrication structure includes: the rolling bearing 52 is provided with the counterbore 50 as the inclined surface part on the inner ring outer diameter, and the oil groove 51 is provided on the counterbore 50;Outer ring spacer 53 and nozzle spacer 54. Figure 6
[0003] The oil gas is sprayed to the oil groove 51 of the inner ring from the housing 55 as the customer component via the outer ring spacer 53, the nozzle spacer 54, and is spread lubricated along the counterbore 50 to the rolling surface 56 by the centrifugal force generated by the rotation of the inner ring and the surface tension of the oil. The outer ring spacer 53 and the nozzle spacer 54 of the nozzle spacer 54 are fixed on the outer ring spacer 53 by bolts or the like. The outer ring spacer 53 and the nozzle spacer 54 are communicated with the oil supply hole 57, and the O-ring 58 is installed at the junction thereof to prevent oil gas leakage.
[0004] PRIOR ART DOCUMENTS
[0005] PATENT DOCUMENTS
[0006] [Patent document 1] Japanese patent No. 4261083
[0007] [Patent document 2] Japanese patent No. 4289875 SUMMARY
[0008] PROBLEMS TO BE SOLVED BY THE INVENTION
[0009] In the spacer of the oil gas lubrication structure, the nozzle spacer 54 is fixed on the outer ring spacer 53 by bolts, and the outer ring spacer 53 is in contact with the bearing outer ring 59.
[0010] If the radial section height h of the nozzle spacer 54 is too large relative to the ball diameter of the bearing, the contact surface of the outer ring spacer 53 and the bearing outer ring 59 cannot be ensured. Even if the radial section height h of the nozzle spacer 54 is too small relative to the ball diameter, the flat surface (straight surface) between the O-ring groove and the oil supply hole cannot be ensured. In the case where the specified flat surface cannot be ensured, even if the O-ring 58 cannot be installed or is installed, it is possible that the function of the O-ring 58 cannot be played and the oil gas cannot be smoothly supplied to the rolling bearing 52. Therefore, the radial section height h of the nozzle spacer 54 relative to the ball diameter must be set to be optimal.
[0011] The oil gas lubrication structure of the rolling bearing can smoothly supply oil gas.
[0012] Technical solution for solving the problem
[0013] The oil gas lubrication structure of the rolling bearing comprises a rolling bearing and a lubrication device for supplying oil gas to the rolling bearing.
[0014] The lubrication device comprises an outer ring spacer provided adjacent to an outer ring end surface of the rolling bearing and having an oil gas supply hole, and a nozzle spacer fixed to the outer ring spacer via an engaging surface and having an oil gas supply hole in communication with the oil gas supply hole and from which oil gas is sprayed to the rolling bearing.
[0015] The flat surface ensuring mechanism ensures that the flat surface between the sealing groove in the engaging surface, which is located outside the oil gas supply hole and the oil gas supply hole and is provided in a ring shape, and the oil gas supply hole is above a certain area while ensuring the contact between the outer ring spacer and the outer ring end surface.
[0016] The oil gas is lubricating oil mixed with air.
[0017] The "certain area" is an area determined arbitrarily by design, for example, an appropriate area determined by either one or both of test and simulation.
[0018] According to the structure, the contact surface between the outer ring spacer and the outer ring end surface is ensured. At the same time, by ensuring that the flat surface between the sealing groove in the engaging surface and the oil gas supply hole is above a certain area, not only can a seal be installed on the sealing groove, but also the function of the seal can be played. Therefore, oil gas can be smoothly supplied from the lubrication device to the rolling bearing.
[0019] The rolling bearing can be a ball bearing, and the flat surface ensuring mechanism in the nozzle spacer cross-sectional height h and the ball diameter Dw are in the following relationship:
[0020] 0.8≦h / Dw≦2.0
[0021] The nozzle spacer cross-sectional height h is the radial cross section of the nozzle spacer.
[0022] By satisfying the relationship, the contact surface between the outer ring spacer and the outer ring end surface can be ensured, and the seal can be reliably installed on the sealing groove.
[0023] The oil supply hole pitch diameter (pitch diameter) d3 of the nozzle spacer and the pitch circle diameter PCD of the rolling bearing are in the following relationship:
[0024] 0.9 ≦ d3 / PCD ≦ 1.1
[0025] By satisfying the relation of the pitch diameter d3 of the oil supply hole and the pitch circle diameter PCD, oil gas can be injected at a prescribed position of the inner ring. Thus, oil gas can be more smoothly supplied from the lubricating device to the rolling bearing.
[0026] Also, the nozzle diameter A of the nozzle spacer and the oil supply hole diameter B can be in the following relation:
[0027] 1.0 ≦ B / A ≦ 4.0
[0028] The nozzle diameter A is the oil supply hole diameter of the oil gas supply hole on the downstream side facing the rolling bearing. The oil supply hole diameter B is the oil supply hole diameter of the oil gas supply hole on the upstream side communicating with the oil gas supply hole of the outer ring spacer.
[0029] By satisfying the relation of the nozzle diameter A and the oil supply hole diameter B, the relation of the air speed and the air pressure can be appropriately maintained, and the O-ring (seal) mechanism can be provided even in the case where the radial dimension of the seal groove periphery has a small free allowance.
[0030] Also, the oil supply hole diameter B of the nozzle spacer and the inner diameter C of the seal groove can be in the following relation.
[0031] 1.0 < C / B ≦ 2.5
[0032] By satisfying the relation of the oil supply hole diameter B and the inner diameter C of the seal groove, functional improvement of the O-ring (seal) can be achieved, and more smooth oil gas lubrication can be performed.
[0033] Also, the inner diameter C of the seal groove and the seal inner diameter D of the seal member embedded in the seal groove can be in the following relation:
[0034] 0.7 ≦ D / C ≦ 1.0
[0035] By satisfying the relation of the inner diameter C of the seal groove and the seal inner diameter D, the resilience of the seal member installed in the seal groove can be suppressed, the assembly of the lubricating device can be improved, and more smooth oil gas lubrication can be performed. The seal member has a slight interference with respect to the seal groove and does not freely fall. Thus, since the seal member is installed on the nozzle spacer, the outer ring spacer and the nozzle spacer are difficult to be detached when fixed, the assembly of the seal member is also improved. In addition, by satisfying these relations, a standard product can be used as the seal member, and thus cost reduction can be achieved compared to the use of a dedicated seal member.
[0036] The rolling bearing can also be an angular contact ball bearing. The angular contact ball bearing of the present oil gas lubrication structure has a tapered hole in which one side portion of the outer peripheral surface of the inner ring is a beveled portion for supplying oil gas.
[0037] In the present utility model, any combination of two or more of the claims is included. In particular, any combination of two or more of the claims is included in the present utility model. BRIEF DESCRIPTION OF DRAWINGS
[0038] The present utility model will be more clearly understood by the following description of preferred embodiments with reference to the accompanying drawings. The embodiments and drawings are, however, included by way of illustration and explanation only. The scope of the present utility model is not limited to the embodiments and drawings. In the drawings, identical or comparable elements are denoted by identical reference numerals in the various figures.
[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 utility model.
[0040] Figure 2 is a partial enlarged view of a main part of Figure 1 .
[0041] Figure 3A is a partial enlarged view of a nozzle spacer of the oil-air lubrication structure, viewed from an axial direction.
[0042] Figure 3B is a side view of a seal member installed in a seal groove of the nozzle spacer.
[0043] Figure 4A is a partial enlarged view of a main part of the oil-air lubrication structure, partially changed.
[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 utility model.
[0045] Figure 5 is a sectional view of a spindle device using 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 according to a prior art example. DETAILED DESCRIPTION
[0047] [First Embodiment]
[0048] The oil-air lubrication structure of a rolling bearing according to an embodiment of the present utility model will be described together with Figures 1 to 3B , Figure 5 . The oil-air lubrication structure of a rolling bearing according to the present embodiment is suitable for, for example, an angular contact ball bearing that rotatably supports a main shaft of a machine tool.
[0049] As Figure 1As shown, the oil-air lubrication structure of the rolling bearing has an angular contact ball bearing 1 and a lubricating device 2 that supplies oil-air to the angular contact ball bearing 1. A spindle 5 ( Figure 5 ) as a rotating body is rotatably supported on a housing 3 ( Figure 5 ) via the angular contact ball bearing 1, the lubricating device 2, and an inner ring spacer 4, and the like. In a state in which the plurality of angular contact ball bearings 1, the lubricating device 2, and the inner ring spacer 4 are assembled to the housing 3 ( Figure 5 ) and the spindle 5 ( Figure 5 ), a predetermined preload or a constant pressure preload is applied to the angular contact ball bearing 1.
[0050] <ROLLING BEARING>
[0051] The angular contact ball bearing 1 as the rolling bearing has an inner ring 6, an outer ring 7 as a fixed side raceway, a plurality of rolling elements 8 interposed between rolling surfaces 6a, 7a of the inner and outer rings 6, 7, and a retainer 9 that holds the rolling elements 8. The rolling elements 8 are constituted by balls and are held in pockets 9a of the retainer 9. In an inner peripheral surface of the retainer 9, a portion 9b located on a width surface side more than the pockets 9a is a tapered surface that is larger in diameter than a central portion in a retainer width direction. An outer peripheral surface of the outer ring 7 is fitted to a fitting hole of the housing 3 ( Figure 5 ), and an inner peripheral surface of the inner ring 6 is fitted to an outer peripheral surface of the spindle 5 ( Figure 5 ).
[0052] As shown in Figure 2 , on an outer peripheral surface of the inner ring 6 on a counter load side, a tapered hole, that is, a tapered surface portion 6b that is continuous with the rolling surface 6a is provided. The tapered surface portion 6b is a tapered shape in which the diameter gradually decreases from the rolling surface 6a side toward the inner ring spacer 4 side. A circumferential groove 10 is provided on the tapered surface portion 6b. The circumferential groove 10 is formed in a ring shape in a cross-sectional V shape.
[0053] <LUBRICATING DEVICE>
[0054] The lubricating device 2 includes an outer ring spacer 11 and a nozzle spacer 12. The lubricating device 2 includes a securing mechanism 13 described later. The outer ring spacer 11 is provided adjacent to an outer ring end surface 7b of the angular contact ball bearing 1 and has an oil-air supply hole 14. The oil-air supply hole 14 is connected to an oil-air supply path 15 ( Figure 5 ) of the housing 3 ( Figure 5) with a supply source of oil gas. The outer ring end surface 7b is an outer ring back surface on the side of supporting an axial load. An annular communication groove 16 which communicates with the oil gas supply passage is provided on the outer peripheral surface of the outer ring spacer 11, and the communication groove 16 communicates with the oil gas supply hole 14. The oil gas supply hole 14 includes a supply hole portion 14a on the upstream side and a supply hole portion 14b on the downstream side. The supply hole portion 14a on the upstream side extends in the radial direction by a prescribed length in communication with the communication groove 16, and the supply hole portion 14b on the downstream side extends in the axial direction by a prescribed length in communication with the supply hole portion 14a on the upstream side.
[0055] The nozzle spacer 12 is fixed to the outer ring spacer 11 via an engaging surface 12a, and has an oil gas supply hole 17 which communicates with the supply hole portion 14b on the downstream side of the oil gas supply hole 14 of the outer ring spacer 11. The engaging surface 12a is along a plane which is perpendicular to the bearing center line Cl of the rolling bearing 1. Figure 1 ) The nozzle spacer 12 sprays oil gas from the oil gas supply hole 17 toward the rolling bearing 1. An annular cutout recess 11a is formed on the inner diameter side portion of the side surface of the outer ring spacer 11, and the nozzle spacer 12 is fixed with a bolt to the cutout recess 11a.
[0056] The nozzle spacer 12 is disposed apart by a prescribed gap δ from the beveled portion 6b of the inner ring 6. The nozzle spacer 12 has its front end portion 12ba positioned in the vicinity of the rolling element 8 between the inner peripheral surface of the retainer 9 and the outer peripheral surface of the inner ring 6. The nozzle spacer 12 is an annular member disposed adjacent to the rolling bearing 1 in the axial direction, and has a flange-like portion 12b which extends in the axial direction from the inner diameter side portion of the side surface. The inner peripheral surface of the bearing outer portion of the nozzle spacer 12 opposes the outer peripheral surface of the inner ring spacer 4 with a prescribed radial gap therebetween. In this specification, the "axial direction" refers to the direction along the bearing center line Cl of the rolling bearing 1. Figure 1 ) The "radial direction" refers to the direction orthogonal to the straight line constituting the "axial direction".
[0057] The flat inner peripheral surface of the flange-like portion 12b is formed as an inclined surface at the same angle as the beveled portion 6b of the inner ring 6, and extends directly below the retainer 9. The front end of this flange-like portion 12b becomes the front end portion 12ba of the nozzle spacer 12. The gap δ between the flange-like portion 12b and the beveled portion 6b is set within a range so as not to come into contact during operation, taking into account the fitting of the inner ring 6 with the shaft, and the expansion of the inner ring 6 due to temperature rise and centrifugal force.
[0058] On the nozzle spacer 12, the oil gas supply hole 17 is provided which opposes the circumferential groove 10 of the inner ring 6 and from which the discharge port 17ba opens. The oil gas supply hole 17 is provided at one or more places in the circumferential direction of the nozzle spacer 12. The oil gas supply hole 17 has an upstream side supply hole 17a which communicates with the oil gas supply hole 14 of the outer ring spacer 11, and a downstream side nozzle hole 17b which forms the discharge port 17ba.
[0059] The upstream-side oil supply hole 17a extends in the axial direction for a prescribed length, and communicates with the downstream-side oil supply hole 17b at the front end portion thereof. The downstream-side nozzle hole 17b is provided so that the oil gas ejection direction of the ejection port 17ba is directed toward the circumferential groove 10 and has a prescribed inclination angle with respect to the axial direction. Thus, the oil gas ejected from the ejection port 17ba can be directly blown to the circumferential groove 10. In addition, the side wall inclined surface 10a of the circumferential groove 10 near the rolling surface 6a is set so as to have a larger inclination angle with respect to the axial direction than 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 fl between the outer ring spacer 11 and the outer ring end surface 7b, and ensures that the flat surface f2 between the seal groove 18 and the boundary portion 19 of the oil gas supply hole 14 and the oil gas supply hole 17 is a prescribed area or more. That is, the flat surface ensuring mechanism 13 ensures the contact surface fl, and ensures that the flat surface f2 between the seal groove 18 and the oil gas supply hole 17 is a prescribed area or more. The contact surface fl is the contact surface between the outer ring end surface 7b on the back surface side of the outer ring and one side surface of the outer ring spacer 11 facing the outer ring end surface 7b.
[0062] The annular seal groove 18 is provided on the joint surface 12a of the nozzle spacer 12 with the outer ring spacer 11. The annular seal groove 18 is located radially outward with respect to the boundary portion 19 around the base end portion of the upstream-side oil supply hole 17a. In addition, as shown in FIG. 2, the annular seal groove 18 is provided concentrically with the oil supply hole 17a. As shown in FIG. 3, an O-ring or the like seal member 20 is fitted in the annular seal groove 18. Figure 3A Figure 3B As shown in FIG. 3, the outer ring spacer 11 and the nozzle spacer 12 are fixed by a fastener (not shown) such as a bolt, and the seal member 20 is elastically deformed in the seal groove 18 to seal around the boundary portion 19, thereby preventing leakage of oil gas from the boundary portion 19. The O-ring, for example, is a standard product prescribed by ISO or the like as an international standardization organization. Figure 2
[0063] <Regarding parameters>
[0064] If the radial cross-sectional height h of the nozzle spacer 12 is too large with respect to the ball diameter of the rolling bearing 1, the contact surface fl 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 with respect to the ball diameter, the flat surface f2 between the O-ring groove 18 and the oil supply hole cannot be ensured, and thus the relationship does not hold. Therefore, the nozzle spacer cross-sectional height h with respect to the ball diameter Dw must be optimally set.
[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, the oil and gas is injected from the outer ring spacer 11 to the oil groove 10 of the inner ring 6 through the nozzle spacer 12. The nozzle hole A of the nozzle spacer 12 has a certain angle with respect to the radial vertical line. Therefore, if the oil supply hole pitch diameter d3 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 of the oil supply hole pitch diameter d3 and the bearing PCD is important.
[0068] Therefore, the oil supply hole pitch diameter d3 of the nozzle spacer 12 and the pitch circle diameter PCD of the rolling bearing 1 are in the following relationship.
[0069] 0.9≦d3 / PCD≦1.1
[0070] The O-ring used for the nozzle spacer 12 adopts a very small diameter O-ring due to the size limitation.
[0071] In order to reduce the cost, the O-ring should use the manufacturer's standard product.
[0072] Considering the assembly, it is preferable that the O-ring has the same value or a slight interference amount with respect to the O-ring groove inner diameter.
[0073] However, the size of the groove periphery of the O-ring is sometimes designed to have a small free allowance in the radial direction and a large interference amount.
[0074] Therefore, even if the O-ring groove inner diameter is reduced in order to reduce the interference amount, the oil supply hole 17a is provided in the center of the O-ring groove 18, and it is necessary to ensure the flat portion between the oil supply hole 17a and the O-ring groove inner diameter, so the size setting is difficult.
[0075] If the interference amount of the O-ring is too large, the O-ring will be in a state of floating from the groove when the O-ring is inserted, and the O-ring will be fastened in the spacer, and the O-ring can be worn.
[0076] If the wear occurs, the function of the O-ring can not be properly exerted, resulting in leakage.
[0077] Therefore, (1) the relationship of the nozzle hole diameter A and the oil supply hole diameter B, (2) the relationship of the oil supply hole diameter B and the inner diameter C of the O-ring groove, (3) the relationship of the inner diameter C of the O-ring groove and the inner diameter D of the O-ring, all of which need to be set to the optimal size.
[0078] In summary, each parameter is set as follows.
[0079] The nozzle diameter A of the nozzle spacer 12 and the oil supply hole diameter B are in the following relationship:
[0080] 1.0 ≦ B / A ≦ 4.0
[0081] 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:
[0082] 1.0 < C / B ≦ 2.5
[0083] The inner diameter C of the seal groove 18 and the seal inner diameter D of the seal 20 embedded in the seal groove 18 are in the following relationship:
[0084] 0.7 ≦ D / C ≦ 1.0
[0085] <Comparison between the present embodiments and the comparative example>
[0086] Here, in order to evaluate the oil gas lubrication structure of the rolling bearing of the present embodiments 1 to 4 and the oil gas lubrication structure of the rolling bearing of the comparative example, the air speed, the air pressure, the O-ring portion design, the O-ring functionality, the O-ring assembly, and the like were compared as shown in Table 1. In Table 1, represents that it is implementable and the effect is excellent, represents that it is implementable and the effect is good, represents that it is implementable, and represents that the effect is not good.
[0087] [Table 1]
[0088]
[0089] <Effects>
[0090] According to the oil gas lubrication structure of the rolling bearing described above, the oil gas supplied from the oil gas supply hole 14 is sprayed toward the circumferential groove 10 of the inner ring inclined surface portion 6b via the oil gas 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 or the like securing mechanism 13 secures the contact surface fl of the outer ring spacer 11 and the outer ring end surface 7b. Thereby, in a state where the plurality of angular contact ball bearings 1, the lubricating device 2, and the inner ring spacer 4 are assembled to the housing 3( Figure 5 ) and the main shaft 5( Figure 5 ), it is possible to apply a prescribed pre-press to the angular contact ball bearing 1, and it is possible to secure a prescribed gap δ between the nozzle spacer 12 and the inclined surface portion 6b of the inner ring 6. At the same time, by securing the flat surface f2 between the seal groove 18 and the oil gas supply hole 19 in the engaging surface 12a to be a certain area or more, it is possible to mount the seal 20 on the seal groove 18, and it is possible to exert the function of the seal 20. Therefore, it is possible to smoothly supply oil gas from the lubricating device 2 to the rolling bearing 1.
[0092] In the flat surface or the like securing mechanism 13, the nozzle spacer cross-sectional height h and the ball diameter Dw are in the following relationship:
[0093] 0.8 ≦ h / Dw ≦ 2.0
[0094] By satisfying the relationship, the contact surface fl of the outer ring spacer 11 and the outer ring end surface 7b can be ensured, and the seal 20 can be reliably installed on the seal groove 18.
[0095] The oil supply hole pitch diameter d3 of the nozzle spacer 12 and the pitch circle diameter PCD of the rolling bearing 1 are in the following relationship:
[0096] 0.9 ≦ d3 / PCD ≦ 1.1
[0097] By satisfying the relationship of the oil supply hole pitch diameter d3 and the pitch circle diameter PCD, the oil gas can be injected at a predetermined position of the inner ring 6. Thereby, the oil gas can be more smoothly supplied from the lubricating device 2 to the rolling bearing 1.
[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 of the nozzle diameter A and the oil supply hole diameter B, the relationship of the air speed and the air pressure can be appropriately maintained, and the O-ring (seal) mechanism can be provided even in the case where the radial dimension of the seal groove periphery has a small free margin.
[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 of the oil supply hole diameter B and the inner diameter C of the seal groove 18, the functional improvement of the O-ring (seal) can be achieved, and the oil gas lubrication can be more smoothly performed.
[0104] The inner diameter C of the seal groove 18 and the seal inner diameter D of the seal 20 embedded in the seal groove 18 are in the following relationship:
[0105] 0.7 ≦ D / C ≦ 1.0
[0106] By satisfying the above relationships of the inner diameter C of the seal groove 18 and the seal inner diameter D, the resilience of the seal 20 installed in the seal groove 18 can be suppressed, the assembly of the lubricating device 2 can be improved, and smoother oil-air lubrication can be performed. The seal 20 has a slight interference with respect to the seal groove 18 and does not freely fall. Therefore, since the seal 20 is difficult to be detached when the seal 20 is installed on the nozzle spacer 12 and the outer ring spacer 11 and the nozzle spacer 12 are fixed, the assembly of the seal 20 is also improved. In addition, by satisfying the above relationships, a standard product can be used as the seal 20, and thus cost reduction can be achieved compared to the use of a dedicated seal.
[0107] The rolling bearing is an angular contact ball bearing 1. The angular contact ball bearing 1 of the present oil-air lubrication structure is a taper hole in which one side portion of the outer peripheral surface of the inner ring 6 is a bevel portion 6b, for supplying oil-air.
[0108] <Regarding Other Embodiments>
[0109] In the following description, the same reference numerals are assigned to portions corresponding to matters described in advance in each embodiment, and repeated description is omitted. In a case where only a part of the structure is described, unless specifically described, other portions of the structure are the same as the embodiment described in advance. The same structure functions to achieve the same effects. Not only a combination of the portions specifically described in each embodiment, but also embodiments can be partially combined with each other, particularly if the combination does not cause an obstacle.
[0110] [Example in which a seal groove is provided on an outer ring spacer, Figure 4A ]
[0111] As Figure 4A indicated, a ring-shaped seal groove 18 can also be provided on the joint surface 11b of the outer ring spacer 11 with the nozzle spacer 12. The ring-shaped seal groove 18 is located radially outward of the boundary portion 19 around the downstream side portion of the downstream side supply hole portion 14b. The ring-shaped seal groove 18 is concentrically provided with the downstream side supply hole portion 14b. A seal 20 such as an O-ring is fitted in the ring-shaped seal groove 18.
[0112] In this case, the same effects as those of the above-described embodiment are also achieved.
[0113] [Second Embodiment: Cylindrical Roller Bearing, Figure 4B ]
[0114] As Figure 4BAs shown, the cylindrical roller bearing 1A can also be used as a rolling bearing. On the outer circumferential surface of the inner ring 6 of the cylindrical roller bearing 1A, a beveled portion 6b connected to the rolling surface 6a is provided. A circumferential groove 10 is provided on one side of the beveled portion 6b. The nozzle septum 12 is provided at a predetermined gap δ along the beveled portion 6b on one side of the inner ring 6. In the second embodiment, it also achieves substantially the same effect as in the embodiments described above.
[0115] <Example of application for spindle assembly,> Figure 5 >
[0116] Figure 5 This illustrates an example of a spindle assembly employing the oil-air lubrication structure of the rolling bearings according to the first embodiment. This spindle assembly is used in a machine tool, where a chuck for a tool or workpiece is mounted at the end of the spindle 5. The spindle 5 is supported by a plurality of (in this example, a pair) rolling bearings 1, 1 separated axially. The pair of rolling bearings 1, 1 is configured to face the back. Each inner ring 6 engages with the outer circumferential surface of the spindle 5, and each outer ring 7 engages with the inner circumferential surface of the housing 3. These inner and outer rings 6, 7 are respectively fixed to the spindle 5 and the housing 3 by inner ring pressing members 21 and outer ring pressing members 22.
[0117] The housing 3 has a dual structure consisting of an inner circumferential housing 3A and an outer circumferential housing 3B, with a cooling medium flow path 32 formed between the inner and outer housings 3A and 3B. An oil / gas supply path 15 and an oil / gas supply port 15a are provided on the inner circumferential housing 3A. The housing 3 is fixed to a support platform 37. An oil / gas exhaust path 39 is provided within the housing 3, and oil / gas exhaust grooves 34 are provided near the mounting portions of each bearing 1 on the inner circumferential surface, opening to the atmosphere from the oil / gas exhaust grooves 34.
[0118] Figure 1 The nozzle septum 12 shown is a ring-shaped component, but depending on the application and operating conditions, it can also be an arc-shaped component extending a specified length in the circumferential direction.
[0119] The oil-air lubrication structure of each rolling bearing can also be applied to uses other than machine tools.
[0120] As described above, preferred embodiments have been illustrated with reference to the accompanying drawings. However, various additions, modifications, and deletions can be made without departing from the spirit of this invention. Therefore, such modifications are also included within the scope of this invention.
[0121] [Symbol Explanation]
[0122] 1… Angular contact ball bearings (rolling bearings)
[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
[0131] 14 … oil gas supply hole
[0132] 17 … oil gas supply hole
[0133] 18 … seal groove
[0134] 19 … boundary portion
[0135] f1 … contact surface
[0136] f2 … flat surface
Claims
1. An oil gas lubrication structure of a rolling bearing, having a rolling bearing and a lubricating device that supplies oil gas to the rolling bearing; characterized by, the lubricating device including: an outer ring spacer that is disposed adjacent to an outer ring end surface of the rolling bearing and has an oil gas supply hole; and a nozzle spacer that is fixed to the outer ring spacer via an engaging surface and has an oil gas supply hole that communicates with the oil gas supply hole and from which oil gas is sprayed toward the rolling bearing; further having a flat surface securing mechanism that secures a flat surface between a seal groove that is located outside the oil gas supply hole and the oil gas supply hole and is disposed annularly in the engaging surface and the oil gas supply hole to be a certain area or more while securing contact of the outer ring spacer with the outer ring end surface.
2. The oil gas lubrication structure of a rolling bearing according to claim 1, wherein the rolling bearing is a ball bearing, and in the flat surface securing mechanism, a nozzle spacer cross-sectional height h and a 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, an oil supply hole pitch diameter d3 of the nozzle spacer and a 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, a nozzle diameter A of the nozzle spacer and an oil supply hole diameter B 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, wherein the oil supply hole diameter B of the nozzle spacer and an inner diameter C of the seal 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 5, wherein the inner diameter C of the seal groove and a seal inner diameter D of a seal member that is fitted in the seal groove are in the following relationship: 0.7 ≦ D / C ≦ 1.
0.
7. The oil gas lubricating structure of a rolling bearing according to claim 1 or 2, wherein the rolling bearing is an angular contact ball bearing.