JP2011069456A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing improving reliability of discharge of a base oil from a grease sump, and preventing outflow of a discharged lubricating oil from the inside of the bearing. <P>SOLUTION: The rolling bearing has an inner ring 1, an outer ring 2, and a plurality of rolling elements 3 interposed between the track surfaces 1a, 2a of the inner and outer rings 1, 2. It also has the annular grease sump 4 partially fitted in a peripheral surface of a fixed side track ring not rotated out of the inner ring 1 and the outer ring 2, storing grease inside thereof, and having a base oil discharge port for oozing the base oil of the grease in the inner end. The grease sump 4 is made by dividing the inside space 11 for storing the grease into a plurality of tanks. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rolling bearing that is used for supporting a machine tool spindle and the like and is grease lubricated.

  As a lubrication method for machine tool spindle bearings, grease lubrication that can be used maintenance-free, air-oil lubrication in which lubricating oil is mixed with carrier air and oil is injected into the bearing from the nozzle, jet that injects lubricating oil directly into the bearing There are methods such as lubrication. In recent machine tools, in order to increase machining efficiency, there is a trend toward higher speed, and lubrication of main shaft bearings is also relatively inexpensive and air-oil lubrication that can be easily increased in speed is often used. However, this air oil lubrication method has a problem from the viewpoint of cost, noise, energy saving, and resource saving because it requires an air oil supply device as ancillary equipment and requires a large amount of air. There is also a problem of deteriorating the environment due to the scattering of oil. In order to avoid these problems, recently, speeding up by grease lubrication has begun to attract attention, and requests have been increasing.

Since grease lubrication is performed only with the grease enclosed at the time of bearing assembly, high-speed operation leads to excessive temperature rise at an early stage due to deterioration of the grease due to heat generation from the bearing and oil film breakage on the raceway surface, especially the inner ring. There is a case. In particular, in a high-speed rotation region where the dn value exceeds 1,000,000 (bearing inner diameter mm × rotational speed min ⁻¹ ), it is difficult to guarantee normal operation.
As a means for extending the grease life, there is a proposal aiming at high speed and long life by providing a grease reservoir in contact with the fixed-side raceway (Patent Document 1).

JP 2009-103232 A

In the proposed technique, if grease is not sufficiently filled and a gap is generated inside the grease reservoir when the grease is filled, the base oil separated from the thickener in the grease is used to replenish the internal gap, It becomes difficult to be discharged.
In the horizontal spindle SU1 shown in FIG. 13, the base oil supplied into the bearings B1 and B1 accumulates on the lower rolling surface and continues to contribute to lubrication for a long time. On the other hand, in the vertical spindle SU2 shown in FIG. 14, the discharged lubricating oil moves downward due to gravity and easily flows out of the bearing B1. Therefore, there is a possibility of poor lubrication.

  An object of the present invention is to provide a rolling bearing capable of improving the reliability of discharging base oil from a grease reservoir and preventing the discharged lubricating oil from flowing out of the bearing.

  The rolling bearing according to the present invention is a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed between the raceways of the inner and outer rings. An annular grease reservoir having a base oil discharge port for storing grease inside and storing grease at the inner end and leaching out the base oil of the grease is provided. It is divided into tanks.

According to this configuration, the base oil is separated from the thickener in each tank due to a temperature rise during operation, and at the same time, the internal pressure of each tank in the sealed grease reservoir increases. Due to this internal pressure, the separated base oil is discharged from the base oil discharge port provided in each tank toward the raceway surface of the fixed-side raceway. When the temperature rises and reaches a steady state, the internal pressure increase factor disappears, so that the internal pressure gradually decreases in parallel with the base oil discharge, and the base oil discharge amount per unit time also decreases.
At this time, if there is a clearance due to poor filling of the grease in the grease reservoir, the base oil is used for replenishing the clearance, and the base oil is difficult to be discharged to the outside. In the present invention, in particular, the internal space of the grease reservoir is divided into a plurality of tanks, and a so-called parallel system that discharges base oil in parallel from each tank is provided. For this reason, the effect of grease filling failure can be limited to each tank, and the reliability of base oil discharge can be improved as a whole grease reservoir. Further, when the base oil discharge port is made smaller than the conventional base oil discharge port, the pressure in the grease reservoir can be increased, and the base oil discharge can be made more reliable.

  The grease reservoir has an oil passage groove that communicates the base oil discharge port and the internal space, and a base oil discharge port and an oil passage groove are provided in each tank of the grease reservoir, respectively. May be. In this case, due to the temperature rise during operation, the base oil is separated from the thickener in each tank, and at the same time, the internal pressure of each tank increases. In each tank, the separated base oil is discharged toward the raceway surface of the stationary raceway through the oil passage groove. For example, even if there is a base oil discharge failure due to grease filling failure in some tanks, the base oil separated in other tanks is directed to the raceway surface of the stationary side raceway through the oil passage groove. Discharged. In this way, the base oil can be discharged more reliably.

  The grease reservoir may be formed of a resin material or a magnesium alloy by injection molding or machining. When the grease reservoir is injection-molded using a resin material or a magnesium alloy, the manufacturing cost can be reduced as compared with a machined one.

  Each tank of the grease reservoir may be provided with a grease sealing hole for sealing grease and an air vent hole. When each tank is filled with grease, air can be smoothly extracted from the air vent hole in each tank. In this case, the possibility of grease filling failure can be reduced as compared with the case where only the grease sealing hole is provided in each tank.

The inner ring may be a rotation-side raceway, and an inclined surface having a larger diameter as it approaches the center from the bearing end face side may be provided on the outer diameter surface of the inner ring. In this case, when the inner ring rotates, the lubricating oil adhering to the outer diameter surface of the inner ring moves to the larger diameter side while adhering to the slope due to centrifugal force and surface tension (hereinafter referred to as “attachment flow”). . Thereby, lubricating oil can be used effectively.
The grease reservoir may be provided with a slope facing the slope provided on the outer diameter surface of the inner ring and parallel to the slope. In this case, the slope of the grease reservoir and the slope of the outer surface of the inner ring provide a sealing effect, and the lubricating oil that is about to flow out is effectively guided to the outer surface of the inner ring and returned to the inside of the bearing by the adhering flow. Increased amount of lubricating oil.

  The outer ring may be provided with a slope that faces and is parallel to the slope provided on the outer diameter surface of the inner ring. In this case, in addition to having a sealing effect, the lubricating oil about to flow out to the outside is effectively guided to the outer surface of the inner ring, and the amount of lubricating oil returned to the inside of the bearing by the adhering flow increases. In this way, it is possible to prevent the lubricating oil from flowing out from the inside of the bearing.

The grease reservoir may be provided with a non-contact seal having a slope facing the slope provided on the inner ring outer diameter surface.
The outer ring may be provided with a non-contact seal having a slope facing the slope provided on the outer diameter surface of the inner ring.
In these cases, the outflow of the lubricating oil to the outside of the bearing can be reduced by the sealing effect of the non-contact seal. Moreover, since it is a non-contact seal, it can respond to high-speed operation.

  The inner ring may be a rotating raceway, an inner ring spacer disposed adjacent to the inner ring may be provided, and a spiral groove that causes an air flow from the outside of the bearing to the inside may be provided on the outer peripheral surface of the inner ring spacer. . In this case, when the inner ring and the inner ring spacer are rotated, the surrounding air is moved by a viscous pump action along a spiral groove provided on the outer peripheral surface of the inner ring spacer. During operation, the spiral groove can generate an air flow from the outside to the inside of the bearing, thereby preventing the lubricating oil from flowing out from the bearing.

  The cage has a plurality of rolling elements, and the cage is guided by the inner surface of the outer ring, and increases toward one side of the outer diameter surface of the cage from the cage end surface side toward the center. A slope having a diameter may be provided. In this case, when the cage rotates, the lubricating oil adhering to the slope can be returned to the inside of the bearing by the adhering flow. Therefore, the lubricating oil adhering to the outer diameter surface of the cage can be used effectively.

  The cage has a retainer for holding the plurality of rolling elements, and the retainer is guided by the inner ring outer diameter surface or the rolling element, and is centered from the cage end surface side on both sides of the outer diameter surface of the retainer. You may provide the slope which becomes large diameter, so that it approaches. In this case, when the cage rotates, the lubricating oil adhering to the slope provided on the outer diameter surface of the cage can be returned to the inside of the bearing by the adhering flow. Therefore, the lubricating oil adhering to the outer diameter surface of the cage can be used effectively.

  The grease reservoir may be provided with a slope facing the slope provided on the outer diameter surface of the cage and parallel to the slope. In this case, the lubricating oil that tends to flow to the outside attached to the slope of the grease reservoir is effectively guided to the slope provided on the outer diameter surface of the cage. Thereafter, the adhering flow can return the lubricating oil adhering to the slope of the cage to the inside of the bearing.

  The outer ring inner diameter surface may be provided with a slope facing and parallel to the slope provided on the outer diameter face of the cage. In this case, the lubricating oil that tends to flow to the outside attached to the inclined surface of the inner surface of the outer ring is effectively guided to the inclined surface provided on the outer surface of the cage. Thereafter, the adhering flow can return the lubricating oil adhering to the slope of the cage to the inside of the bearing.

The inner ring spacer may position the axial position of the inner ring.
The outer ring is a fixed raceway, and the grease reservoir is an outer ring lid spacer that fits at least on the inner peripheral surface of the outer ring, and a grease that forms an internal space for storing grease in cooperation with the outer ring lid spacer. It may have a pool forming part. According to this configuration, either or both of the outer ring lid spacer and the grease reservoir forming part can be formed by, for example, injection molding. In this case, a partition plate or the like that divides the internal space for storing grease into a plurality of tanks can be integrally formed on either the outer ring lid spacer or the grease reservoir forming component.

  The grease pool forming component has an in-bearing insertion portion that protrudes toward the inside of the bearing and is inserted to the vicinity of the raceway surface of the outer ring, and an inner peripheral surface of a tip portion that is inserted into the bearing of the outer ring lid spacer. The base oil discharge port may be provided between the bearing insertion portion and the outer peripheral surface in the vicinity of the raceway surface.

The rolling bearing may be an angular ball bearing that supports a machine tool spindle.
The rolling bearing may be a cylindrical roller bearing that supports a machine tool main shaft.
The rolling bearing may be a tapered roller bearing that supports a machine tool main shaft.

  The rolling bearing according to the present invention is a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed between the raceways of the inner and outer rings. An annular grease reservoir having a base oil discharge port for storing grease inside and storing grease at the inner end and leaching out the base oil of the grease is provided. Since it is divided into tanks, the reliability of base oil discharge from the grease reservoir is improved, and the shape of the bearing and grease reservoir is made so that the lubricating oil is returned to the inside of the bearing by the adhering flow. It can be prevented from flowing out.

It is sectional drawing of the rolling bearing which concerns on one Embodiment of this invention. It is an expanded sectional view of the principal part of the rolling bearing. It is sectional drawing of the grease reservoir of the rolling bearing. It is a top view of the grease reservoir. It is sectional drawing of the principal part of the rolling bearing which concerns on other embodiment of this invention. It is sectional drawing of the principal part of the rolling bearing which concerns on further another embodiment of this invention. It is sectional drawing of the principal part of the rolling bearing which concerns on further another embodiment of this invention. It is sectional drawing of the principal part of the rolling bearing which concerns on further another embodiment of this invention. It is sectional drawing of the principal part of the rolling bearing which concerns on further another embodiment of this invention. It is sectional drawing of the principal part of the rolling bearing which concerns on further another embodiment of this invention. It is sectional drawing which applied the rolling bearing which concerns on any embodiment of this invention to the horizontal spindle apparatus. It is sectional drawing which applied the rolling bearing which concerns on any embodiment of this invention to the vertical spindle apparatus. It is sectional drawing of the horizontal spindle apparatus of a prior art example. It is sectional drawing of the vertical spindle apparatus of a prior art example.

An embodiment of the present invention will be described with reference to FIGS.
First, a schematic configuration of the rolling bearing will be described, and a structure for improving the reliability of base oil discharge from the grease reservoir and a structure for preventing the lubricant oil from flowing out from the bearing will be sequentially described.
The rolling bearing according to this embodiment includes an inner ring 1, an outer ring 2, and a plurality of rolling elements 3 interposed between the raceway surfaces 1 a and 2 a of the inner and outer rings 1 and 2. An annular grease reservoir 4 is provided adjacent to the outer ring 2 serving as the stationary raceway ring. The plurality of rolling elements 3 are held by the cage 5. The cage 5 is guided by the outer ring inner diameter surface 2b, and a slope 5a having a larger diameter is provided on one side of the outer diameter surface of the cage 5, that is, on the left side of FIG. ing.

  One end of the bearing space between the inner and outer rings 1 and 2 is sealed with a non-contact seal 6. This rolling bearing is an angular ball bearing, the non-contact seal 6 is provided at the end on the bearing back side, and the grease reservoir 4 is provided on the bearing front side. For example, the inner ring 1 of the rolling bearing can be rotated by being fitted to a machine tool spindle (not shown), and the outer ring 2 is fixedly supported in a fitted state on the inner periphery of a housing (not shown) in the spindle unit. The outer ring 2 is provided with a step surface 2c that extends from the raceway surface 2a to the outer diameter side and faces the outer ring front side. The step surface 2c is provided so as to follow the outer ring front side away from the rolling element 3, that is, the edge on the opposite side to the direction in which the contact angle occurs on the raceway surface 2a.

(1) A structure for improving the reliability of discharging base oil from a grease reservoir will be described.
As shown in FIGS. 2 and 3, the grease reservoir 4 is configured as a separate part from the rolling bearing, and a part of the grease reservoir 4 is fitted to the inner peripheral surface 2d of the outer ring 2 to store the grease Gr inside. A base oil discharge port 7 through which grease base oil oozes out is provided at the end. The grease reservoir 4 includes an outer ring lid spacer 8, a grease reservoir forming component 9, and a partition plate 10. The outer ring lid spacer 8 and the grease reservoir forming component 9 cooperate to form an internal space 11 for storing the grease Gr. The internal space 11 for storing the grease Gr is divided into a plurality of tanks 11a to 11d (four tanks in this example) by the partition plate 10 as shown in FIG. 4 (AOB cross section in FIG. 3).

As shown in FIG. 1, the partition plate 10 is formed in a rectangular plate shape, one side of the rectangular plate is fixed to the inner wall surface 8 a on the base end side of the outer ring lid spacer 8, and another piece of the rectangular plate Is fixed to the inner peripheral surface 8b following the inner wall surface 8a of the outer ring lid spacer 8. Further, the other side of the rectangular plate is fixed to the bottom surface 9 a of the grease reservoir forming component 9, and the remaining one side of the rectangular plate is fixed to the inner wall surface 9 b on the tip side of the grease reservoir forming component 9.
As shown in FIG. 4, the internal space 11 is equally divided into four tanks 11a to 11d in the circumferential direction. The grease reservoir 4 has an oil passage groove 12 that connects the base oil discharge port 7 and the internal space 11, and the base oil discharge port 7 and the oil passage groove 12 are provided in each of the tanks 11 a to 11 d. ing. Each tank 11a to 11d is provided with a grease sealing hole 13 for sealing grease and an air vent hole 14, respectively. In this example, in each of the tanks 11a to 11d, the grease sealing hole 13 and the air vent hole 14 are formed so as to penetrate the wall surface of the outer ring lid spacer 8 in the axial direction. Further, the grease sealing hole 13 is disposed on one end side of the arc in each of the tanks 11a to 11d, and the air vent hole 14 is disposed on the other end side of the arc in each of the tanks 11a to 11d. After the grease is filled in the respective tanks 11a to 11d of the grease reservoir 4 from the grease filling hole 13, the grease filling hole 13 and the air vent hole 14 are respectively filled with plugs not shown.

As shown in FIG. 2, the outer ring lid spacer 8, the grease reservoir forming component 9, and the partition plate 10 are formed by injection molding using, for example, a resin material or a magnesium alloy. As the resin material, for example, various resin materials such as polyphenylene sulfide resin (abbreviation PPS) can be applied. In this case, the partition plate 10 is formed integrally with either the outer ring lid spacer 8 or the grease pool forming component 9. After the injection molding, the outer ring lid spacer 8, the grease reservoir forming component 9, and the partition plate 10 are assembled. A sealing material 15 is interposed on the mating surface between the base end portion of the grease reservoir forming component 9 and the base end portion of the outer ring lid spacer 8. The sealing material 15 is made of, for example, an O-ring, and is fitted in a circumferential groove 9 c formed on the outer peripheral surface of the base end portion of the grease reservoir forming component 9. The grease pool forming component 9 may be joined to the outer ring lid spacer 8 by using an adhesive without providing the circumferential groove 9c.
The outer peripheral surface of the tip portion of the outer ring lid spacer 8 in the grease reservoir 4 is fitted to the inner peripheral surface 2 d of the outer ring 2. A sealing material 16 made of, for example, an O-ring is interposed between these fitting surfaces. The sealing material 16 is fitted in a circumferential groove formed on the outer peripheral surface of the distal end portion of the outer ring lid spacer 8. These sealing materials 15 and 16 prevent grease leakage from the grease reservoir 4.

As shown in FIGS. 1 and 2, the grease reservoir forming component 9 has an in-bearing insertion portion 17 that protrudes into the bearing and is inserted to the vicinity of the raceway surface 2 a of the outer ring 2. A base oil discharge port 7 is provided between the inner peripheral surface of the tip portion inserted into the bearing in the outer ring lid spacer 8 and the outer peripheral surface of the inner insert portion 17 in the vicinity of the raceway surface 2a. Yes.
An axial clearance for soaking out grease base oil, a so-called step surface clearance δ1, is formed between the front end surface of the bearing insertion portion 17 and the step surface 2 c of the outer ring 2. Further, since the base oil discharge port 7 and the space 11 inside the grease reservoir are communicated by the oil passage groove 12, the space 11 inside the grease reservoir is connected via the oil passage groove 12 and the base oil discharge port 7. It communicates with the step surface gap δ1.

(2) A structure for preventing the lubricating oil from flowing out of the bearing will be described.
As shown in FIG. 2, slopes 1 b and 1 b that have larger diameters as they approach the center from the bearing end face side are provided on the outer surface of the inner ring. In this case, when the inner ring 1 rotates, the lubricating oil adhering to the outer surface of the inner ring causes an adhering flow that moves to the larger diameter side while adhering to the inclined surface 1b due to centrifugal force and surface tension. Thereby, lubricating oil can be used effectively. Also, the tip surface 6a on the inner diameter side of the non-contact seal 6 fitted and fixed to the outer ring 2 is a slope facing the slope 1b on the right side of FIG. 2 provided on the outer diameter surface of the inner ring and parallel to the slope 1b. A predetermined radial gap δ2 is formed between the tip surface 6a of the non-contact seal 6 and the inclined surface 1b of the inner ring outer diameter surface.

The grease pool forming component 9 includes a grease pool slope forming component 18 that includes a slope 18a that faces the slope 1b on the left side of the outer surface of the inner ring and is parallel to the slope 1b. The grease reservoir slope forming part 18 is formed of a non-contact seal and is formed in a substantially L-shaped cross section. The tip surface on the inner diameter side of the grease reservoir slope forming component 18 is provided opposite to and parallel to the left slope 1b. A predetermined radial gap δ3 is formed between the slope 18a of the grease pool slope forming part 18 and the slope 1b on the left side of the inner ring outer diameter surface.
The grease reservoir slope forming component 18 is integrated with the grease reservoir forming component 9 and can be formed by, for example, injection molding. However, it is not limited to injection molding. The grease reservoir slope forming component 18 may be a separate structure from the grease reservoir forming component 9, and both may be fixed by a fixing means such as a bolt or an adhesive.

  The outer ring guide cage 5 is provided on one side of the outer diameter surface, on the left side in the example of FIG. 2, with a slope 5a having a larger diameter as it approaches the center from the cage end surface side. Further, in the grease reservoir forming component 9, an inner diameter surface 9d facing the inclined surface 5a of the cage 5 is formed in parallel to the inclined surface 5a of the cage 5 with a predetermined radial gap δ4 therebetween.

As shown in FIGS. 1 and 2, an inner ring spacer 19 is provided adjacent to the inner ring 1 to position the axial position of the inner ring 1, and the outer ring surface of the inner ring spacer 19 extends from the outside of the bearing to the inside. The spiral groove 19a for generating the air flow is provided. The spiral groove 19a is formed so as to generate an air flow from the outside of the bearing toward the inside during operation in consideration of the rotation direction of the main shaft.
In this case, when the inner ring 1 and the inner ring spacer 19 rotate, the surrounding air moves by a viscous pump action along the spiral groove 19 a provided on the outer peripheral surface of the inner ring spacer 19. During operation, the spiral groove 19a causes an air flow from the outside to the inside of the bearing, thereby preventing the lubricating oil from flowing out from the bearing.

The operation and effect of the rolling bearing in which the grease reservoir 4 is assembled as shown in FIGS. 1 and 2 are as follows. When a bearing is incorporated into a main shaft or the like not shown, each tank 11a to 11d of the grease reservoir 4, the oil passage groove 12, the base oil discharge port 7, and the stepped surface gap δ1 have grease filling holes of the tanks 11a to 11d. 13 is filled with grease Gr. Further, grease is sealed in the bearing for initial lubrication.
Since the outer peripheral surface of the front end portion of the outer ring lid spacer 8 is fitted into the inner peripheral surface 2d following the step surface 2c of the outer ring 2 and inserted into the bearing, the grease Gr is inserted into the grease reservoir 4 from the grease sealing hole 13. When the outer ring lid spacer 8 is sealed, grease leakage from the mating surface of the end surface of the outer ring 2 and the end surface of the outer ring fixing spacer (not shown) can be prevented. At the same time, the outer ring lid spacer 8 can prevent intrusion of dust and foreign matters from the outside of the bearing.

As the temperature rises during operation, the base oil is separated from the thickener in each of the tanks 11a to 11d, and at the same time, the internal pressure of each of the tanks 11a to 11d in the sealed grease reservoir 4 increases. Due to this internal pressure, the separated base oil is discharged from the base oil discharge port 7 provided in each of the tanks 11 a to 11 d toward the raceway surface 2 a of the outer ring 2. When the temperature rises and reaches a steady state, the internal pressure increase factor disappears, so that the internal pressure gradually decreases in parallel with the base oil discharge, and the base oil discharge amount per unit time also decreases.
At this time, if there is a gap due to poor filling of grease in the grease reservoir 4, the base oil is used for replenishing the gap, and the base oil is difficult to be discharged to the outside. In the embodiment of the present invention, in particular, the space 11 inside the grease reservoir 4 is divided into a plurality of tanks 11a to 11d, and base oil is discharged from each of the tanks 11a to 11d in parallel. For this reason, the influence of the filling failure of grease can be limited to each tank, and the reliability of the base oil discharge can be improved as the entire grease reservoir 4. For example, even if there is a discharge failure of the base oil due to a poor filling of grease in some tanks, the base oil separated in the other tanks passes through the oil passage 12 and the base oil discharge port 7 to the outer ring 2. Is discharged toward the track surface 2a. In this configuration, when the base oil discharge port 7 is made smaller than the conventional base oil discharge port, the pressure in the grease reservoir 4 can be increased and the base oil discharge can be made more reliable.

  Since the grease reservoir 4 is formed by injection molding using a resin material or a magnesium alloy, the manufacturing cost can be reduced as compared with a machined product. Since each of the tanks 11a to 11d of the grease reservoir 4 is provided with a grease sealing hole 13 for sealing grease and an air vent hole 14, each of the tanks 11a to 11d is filled with grease when the grease is filled with the grease. The air can be smoothly extracted from 14. In this case, compared with the case where only the grease sealing hole 13 is provided in each of the tanks 11a to 11d, the possibility of grease filling failure can be reduced.

Since the grease reservoir 4 is provided with the grease reservoir slope forming component 18 that includes the slope 18a facing and parallel to the slope 1b provided on the inner ring outer diameter surface, the slope 18a and the slope 1b of the inner ring outer diameter surface As a result, a sealing effect is obtained, and the lubricating oil about to flow out to the outside is effectively guided to the outer surface of the inner ring, and the amount of lubricating oil returned to the inside of the bearing by the adhering flow increases. As a result, high speed operation and long life can be achieved.
Since the outer ring 2 is provided with the non-contact seal 6 having an inclined surface facing the inclined surface 1b provided on the outer surface of the inner ring, the non-contact seal 6 can reduce the outflow of lubricating oil to the outside of the bearing. Moreover, since it is the non-contact seal 6 which does not contact an inner ring outer diameter surface, it can respond also to a high-speed driving | operation.
In the outer ring guide cage 5, a slope 5 a that increases in diameter as it approaches the center from the cage end surface side is provided on the left side of the outer diameter surface, and the grease reservoir forming component 9 faces the slope 5 a of the cage 5. An inner diameter surface 9d is formed in parallel to the inclined surface 5a of the cage 5 with a predetermined radial gap δ4 therebetween. Thereby, the lubricating oil adhering to the inner diameter surface 9d is effectively guided to the outer diameter surface of the cage, and when the cage 5 rotates, the lubricating oil adhering to the inclined surface 5a can be returned to the inside of the bearing by the adhering flow. Therefore, the lubricating oil adhering to the outer diameter surface of the cage 5 can be used effectively.

Next, another embodiment of the present invention will be described.
In the following description, the same reference numerals are given to portions corresponding to the matters described in the preceding forms in each embodiment, and overlapping description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  The rolling bearing shown in FIG. 5 uses the cage 5A as an inner ring guide or a rolling element guide, and is provided with slopes 5Aa and 5Aa that increase in diameter toward the center from the cage end surface side on both sides of the outer diameter surface of the cage 5A. ing. A slope 2e is formed on the inner surface of the outer ring so as to face the slope 5Aa on the right side of the cage 5A and to be parallel to the slope 5Aa with a predetermined radial gap δ5 therebetween. According to this configuration, the lubricating oil adhering to the outer ring inner diameter surface 2e is effectively guided to the outer diameter surface of the cage. When the cage 5A rotates, the lubricating oil adhering to the slope 5Aa on the right side of the cage 5A can also be returned to the inside of the bearing by the adhering flow.

In the configuration of FIG. 2, a general outer ring guide type cage in which a slope is not formed on the outer diameter surface of the cage 5 may be applied. In this case, the inner peripheral surface of the tip portion of the grease reservoir forming component 9 does not need to be a slope. In the configuration of FIGS. 2 and 5, it is possible to omit the grease reservoir slope forming component 18 made of a non-contact seal. In this case, the slope 1b on the left side of the outer surface of the inner ring may be flat. As the non-contact seal 6 fitted and fixed to the outer ring 2, it is also possible to apply one having no inclined surface formed on the tip surface 6 a on the inner diameter side.
In the configuration of FIG. 5, a general inner ring guide or rolling element guide cage in which a slope is not formed on the outer diameter surface of the cage may be applied. A plurality of grooves may be formed on the outer peripheral surface of the inner ring spacer instead of the spiral groove.

  As shown in FIG. 6, the outer ring 2 is not provided with a stepped surface, and the outer ring lid spacer 8 is fitted along the inner peripheral surface 2 d on the front side of the outer ring 2 which is a tapered surface. Between the tapered outer peripheral surface and the inner peripheral surface 2d on the front side of the outer ring 2, an inclined gap δ6 communicating with each of the tanks 11a to 11d (FIG. 4) of the grease reservoir 4 may be formed. Also in this configuration, by dividing the inside of the grease reservoir 4 into a plurality of tanks, the reliability of the base oil discharge can be improved as the entire grease reservoir 4.

  As shown in FIG. 7, the grease reservoir 4 may not be provided with an outer ring lid spacer. In this configuration, the grease is stored in the internal space 11 sandwiched between the outer ring fixed spacer 20 and the outer ring inner peripheral surface 2 d and the grease pool forming component 9. Also in this configuration, the reliability of the base oil discharge can be improved as a whole of the grease reservoir 4 by dividing the inside of the grease reservoir 4 into a plurality of tanks 11a to 11d (FIG. 4).

As shown in FIG. 8, instead of providing the outer ring fixing spacer, a race ring extension 2 f extending in the width direction for forming the grease reservoir 4 may be provided on the outer ring 2. The grease reservoir 4 is formed by the bearing ring extension 2f of the outer ring 2 and an integral grease reservoir forming component 9 provided on the bearing space side of the bearing ring extension 2f. The grease reservoir forming component 9 has a side wall portion 9e opposite to the inside of the bearing in contact with the positioning step surface 2g provided on the inner diameter surface of the bearing ring extension 2f and provided in the vicinity of the positioning step surface 2g. The outer ring 2 is fixed in a normal axial position by the retaining ring 21 fitted in the retaining ring groove formed. A tapered notch 22 is provided on the outer diameter edge of the side wall portion 9e of the grease reservoir forming component 9 on the bearing outward surface, and a sealing material 23 is interposed between the notch 22 and the retaining ring 21. It is. The sealing material 23 is made of an O-ring.
As shown in the figure, the inner ring 1 may have the same width as that of the outer ring 2 including the race ring extension 2f, or may have a width without the race ring extension.
In each of the above embodiments, the grease reservoir 4 may be formed by machining.

  In each of the above embodiments, a cylindrical roller bearing can be adopted as the rolling bearing as shown in FIG. 9, and a tapered roller bearing can also be adopted as the rolling bearing as shown in FIG. It is also possible to provide grease reservoirs 4 on both axial sides of these bearings.

11 and 12 show examples of a machine tool spindle device using the rolling bearing according to any of the above embodiments. In the horizontal spindle device of FIG. 11 and the vertical spindle device of FIG. 12, two of the rolling bearings are used as a back surface combination. The two rolling bearings BR1 and BR1 rotatably support both ends of the main shaft 25 in the housing 24.
In the vertical spindle device shown in FIG. 12, the discharged lubricating oil moves downward due to gravity and easily flows out of the bearing, which may result in poor lubrication. By using the structure (2) above, , Lubricant outflow to the outside of the bearing can be reduced. Further, by dividing the inside of the grease reservoir 4 into a plurality of tanks, the reliability of the base oil discharge can be improved as the entire grease reservoir 4. Therefore, even in the vertical spindle device, stable high speed operation and long life can be achieved. The horizontal spindle device also achieves the same effect by adopting the structure (2) for preventing the lubricating oil from flowing out from the inside of the bearing and the structure for dividing the inside of the grease reservoir 4 into a plurality of tanks.
The rolling bearing according to each of the embodiments may be a cylindrical roller bearing that supports the machine tool main shaft. The rolling bearing may be a tapered roller bearing that supports a machine tool main shaft.

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a ... Raceway surface 2 ... Outer ring 2a ... Raceway surface 3 ... Rolling element 4 ... Grease reservoir 5 ... Cage 6 ... Non-contact seal 7 ... Base oil discharge port 8 ... Outer ring lid spacer 9 ... Grease reservoir formation component 10 ... Partition plate 11 ... Spaces 11a to 11d ... Tank 12 ... Oil passage groove 13 ... Grease sealing hole 14 ... Air vent hole 17 ... Bearing insertion portion 19 ... Inner ring spacer 19a ... Spiral groove 25 ... Main shaft

Claims (20)

In a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed between raceway surfaces of these inner and outer rings,
Of the inner ring and outer ring, an annular grease having a base oil discharge port that is partially fitted to the peripheral surface of a non-rotating fixed raceway to store grease inside and to exude grease base oil at the inner end A rolling bearing having a reservoir, wherein the grease reservoir is obtained by dividing an internal space for storing grease into a plurality of tanks.   2. The grease reservoir according to claim 1, wherein the grease reservoir has an oil passage groove that communicates the base oil discharge port and the internal space, and the base oil discharge port and the oil passage groove are respectively provided in each tank of the grease reservoir. Rolling bearing provided.   The rolling bearing according to claim 1 or 2, wherein the grease reservoir is formed of a resin material or a magnesium alloy by injection molding or machining.   The rolling bearing according to any one of claims 1 to 3, wherein each of the grease reservoirs is provided with a grease sealing hole for sealing grease and an air vent hole.   The rolling bearing according to any one of claims 1 to 4, wherein the inner ring is a rotating side race ring, and an inner ring outer diameter surface is provided with a slope whose diameter becomes larger as approaching the center from the bearing end surface side.   The rolling bearing according to claim 5, wherein the grease reservoir is provided with a slope facing the slope provided on the outer diameter surface of the inner ring and parallel to the slope.   7. The rolling bearing according to claim 5 or 6, wherein the outer ring is provided with an adjacent inclined surface that faces the inclined surface provided on the outer diameter surface of the inner ring and is parallel to the inclined surface.   The rolling bearing according to claim 5, wherein the grease reservoir is provided with a non-contact seal having a slope facing a slope provided on the outer diameter surface of the inner ring.   9. The rolling bearing according to claim 5 or 8, wherein the outer ring is provided with a non-contact seal having a slope opposite to the slope provided on the outer diameter surface of the inner ring.   5. The inner ring spacer according to claim 1, wherein the inner ring is a rotating raceway, and an inner ring spacer is provided adjacent to the inner ring. Rolling bearing with a spiral groove that causes air flow to the inside.   11. The holder according to claim 1, further comprising a cage that holds the plurality of rolling elements, the cage being guided by an inner diameter surface of the outer ring, and an outer diameter surface of the cage. A rolling bearing provided with a slope having a larger diameter toward the center from the end face side of the cage.   11. The holder according to claim 1, further comprising a cage that holds the plurality of rolling elements, wherein the cage is guided by the inner ring outer diameter surface or the rolling element. Rolling bearings provided with slopes that increase in diameter toward the center from the cage end face side on both sides of the outer diameter surface of the bearing.   The rolling bearing according to claim 11 or 12, wherein the grease reservoir is provided with a slope facing and parallel to the slope provided on the outer diameter surface of the cage.   The rolling bearing according to claim 12, wherein an outer ring inner diameter surface is provided with a slope facing the slope provided on the outer diameter face of the cage and parallel to the slope.   The rolling bearing according to claim 10, wherein the inner ring spacer is used to position an axial position of the inner ring.   16. The outer ring lid spacer according to claim 1, wherein the outer ring is a stationary side race ring, and the grease reservoir is at least an outer ring lid spacer fitted to an inner peripheral surface of the outer ring, and the outer ring lid spacer. A rolling bearing having a grease reservoir forming part that cooperates to form an internal space for storing grease.   17. The grease reservoir forming component according to claim 16, wherein the grease reservoir forming component has an insertion portion in the bearing that protrudes into the bearing and is inserted to the vicinity of the raceway surface of the outer ring, and a tip portion that is inserted into the bearing in the outer ring lid spacer. A rolling bearing in which the base oil discharge port is provided between the inner peripheral surface of the bearing and the outer peripheral surface in the vicinity of the raceway surface in the bearing insertion portion.   18. The rolling bearing according to claim 1, wherein the rolling bearing is an angular ball bearing that supports a machine tool main shaft.   The rolling bearing according to any one of claims 1 to 17, wherein the rolling bearing is a cylindrical roller bearing that supports a machine tool main shaft.   The rolling bearing according to any one of claims 1 to 10, and 15 to 17, wherein the rolling bearing is a tapered roller bearing for supporting a machine tool main shaft.

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