JP2010014169A - Grease supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grease supply device discharging a base oil smoothly by increasing the sealing property of an enclosed grease and extending the life of grease lubrication. <P>SOLUTION: The grease supply device 4, which is provided in a fixed state to an outer ring 2, has an annular container part 11, the inner part of which becomes a grease reservoir, and an in-bearing insertion part 12, which protrudes from the container part 11 and which is inserted up to near the raceway surface 2a of the outer ring 2 to form a gap which makes the grease base oil ooze out to the tip. A grease sealing hole 13b which seals the grease, is provided in the container part 11 and a male screw member 16 which is screwed to this grease sealing hole 13b to seal the grease sealing hole 13b, is provided. The male screw member 16 is formed of a material having a larger thermal expansion coefficient than the container part 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a grease supply device used for a machine tool spindle or the like used for grease lubrication.

  As a lubrication method for machine tool spindle bearings, grease lubrication that can be used without maintenance, air-oil lubrication in which lubricating oil is mixed with the carrier air, and oil is injected into the bearing from the nozzle, bearing oil is directly injected into the bearing. There are methods such as jet lubrication. In recent machine tools, in order to increase machining efficiency, there is a tendency for higher speed, and lubrication of main shaft bearings is also relatively inexpensive and air-oil lubrication that can be speeded up easily 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 may lead to premature seizure due to deterioration of the grease due to heat generation of the bearing and oil film breakage on the raceway surface, especially the inner ring. It is done. In particular, it is difficult to guarantee the grease life in a high-speed rotation region where the dn value exceeds 1,000,000 (bearing inner diameter dmm × rotation number nrpm).

New proposals have been introduced as a means of extending the life of grease. For example, there is a proposal (Patent Document 1) aiming at high speed and long life by providing a grease reservoir on the outer ring raceway surface. In addition, there is a proposal (Patent Document 2) in which a bearing is properly lubricated and lubricated by a grease replenishing device provided outside the spindle.
Japanese Patent Laid-Open No. 11-108068 JP 2003-113998 A JP 2006-132765 A

However, the technologies of the above proposed examples are not satisfactory in consideration of the use rotation speed (dn value> 1.5 million) equivalent to air-oil lubrication and maintenance-free.
The present applicant has proposed a technique (Patent Document 3) obtained by developing the technique of Patent Document 1. In Patent Document 3, when the bearing is stopped, the grease base oil moves from the flow path to the minute gap due to the capillary action of the thickening agent in the grease and the stepped surface of the outer ring. In combination with the surface tension, the base oil is held in oil in the minute gaps.
When the bearing is operated, the base oil stored in the minute gap is discharged from the minute gap due to the volume expansion caused by the temperature increase of the outer ring caused by the operation and the air flow generated by the revolution / spinning of the rolling element. It moves while adhering to the raceway surface and is continuously supplied to the rolling element contact portion.

In this Patent Document 3, for example, after a grease pool forming component is assembled in the outer ring fixed spacer, grease is sealed in the grease pool forming component through a screw hole formed in the grease pool forming component. Thereafter, a structure is employed in which a screw is screwed into this screw hole and sealed to prevent leakage of grease.
In this structure, it is important to maintain the sealed state of the grease reservoir that was initially sealed, because the state of the grease reservoir sealed has an effect on the base oil discharge. Done and contribute to the grease lubrication life.

An object of the present invention is to provide a grease supply device that can enhance the hermeticity of encapsulated grease so that base oil can be discharged smoothly, and can extend the life of grease lubrication.

  The grease supply apparatus according to the present invention is a grease supply apparatus that supplies a base oil of grease to 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. A grease supply device is provided in a fixed state with respect to the fixed-side raceway, and this grease supply device is inserted into the annular container portion in which the grease is stored inside and the vicinity of the raceway surface of the fixed-side raceway. And a grease insertion hole for enclosing grease in the container portion, and screwing into the grease sealing hole to form a grease sealing hole. A male screw member for sealing is provided, and the male screw member is formed of a material having a thermal expansion coefficient larger than that of the container portion.

According to this configuration, the grease is sealed in the container portion from the grease sealing hole in a state where the grease supply device is fixed to the stationary race. Thereafter, the male screw member is screwed into the grease sealing hole and sealed. When the bearing is operated in this grease filled state, the grease base oil is separated from the thickener due to the temperature rise during operation. The separated base oil is discharged through the gap and the like toward the raceway surface of the fixed-side raceway.
In addition, when the temperature rises during operation, a difference in expansion occurs between the container part and the male screw member due to a difference in thermal expansion coefficient between the container part and the male screw member. Thereby, the displacement amount by which the external thread portion of the external thread member expands radially outward becomes larger than the displacement amount by which the internal thread portion of the grease sealing hole of the container portion expands radially outward. Therefore, the sealability between the grease sealing hole and the male screw member can be improved. Further, the difference in thermal expansion coefficient between the container portion and the male screw member causes a difference in expansion between the container portion and the male screw member. As a result, the male screw member expands in the axial direction in the container portion, and contributes to smooth discharge of the base oil separated in the grease reservoir.
Therefore, it is possible to prevent grease leakage from the container portion. In this way, it is possible to smoothly discharge the base oil by enhancing the hermeticity of the sealed grease and expanding the male screw member in the axial direction in the container portion. Therefore, the grease lubrication life can be extended. Can do.

Based on the difference in thermal expansion coefficient between the container portion and the male screw member, the amount of displacement of the male screw member expanding radially outward is larger than that of the female screw portion of the grease sealing hole, and the male screw member is moved in the axial direction. You may comprise so that it may expand | swell and the pressure in a container part may be raised. When the temperature rises during operation, the pressure in the container is increased by expanding the male screw member in the axial direction after improving the radial sealing between the grease sealing hole and the male screw member. As a result, the base oil separated in the grease reservoir is discharged smoothly and continuously. Therefore, the grease base oil can be reliably discharged without using a complicated mechanism.
The male screw member may be formed of a material made of polyetheretherketone or polycarbonate. When these materials are applied, since the dimensional change of the male screw member is small and the water supply rate is low, the displacement amount of the male screw member in the radial direction accompanying the temperature change is stabilized. Therefore, the sealing property between the grease sealing hole and the male screw member in the container portion can be improved more reliably.

  You may provide a sealing material in the external thread part of the said external thread member. A sealing tape or the like can be applied as the sealing material. When a sealing material is wound around the male screw portion and the male screw portion with the sealing material is screwed into the female screw portion of the grease sealing hole, the sealing material is buried in the gap between the female screw portion and the male screw portion. When the temperature rises during operation, the sealing material is pressed against the female screw portion and the male screw portion and elastically deforms. Thereby, it becomes possible to improve the sealing property between the grease sealing hole and the male screw member in the container part more reliably.

The rolling bearing device may be used for supporting the spindle of a machine tool. In this case, since the grease lubrication life can be extended, the trouble of maintaining the machine tool can be further omitted.
An annular groove is provided around the opening of the grease sealing hole on the outer surface of the container portion, a seal member is provided in the annular groove, and the seal member is interposed between the male screw member or the container portion and the male screw member. You may seal with a member. In this case, the reliability of preventing grease leakage can be further improved.

  The grease supply apparatus according to the present invention is a grease supply apparatus that supplies a base oil of grease to 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. A grease supply device is provided in a fixed state with respect to the fixed-side raceway, and this grease supply device is inserted into the annular container portion in which the grease is stored inside and the vicinity of the raceway surface of the fixed-side raceway. And a grease insertion hole for enclosing grease in the container portion, and screwing into the grease sealing hole to form a grease sealing hole. Since the male screw member is provided with a material having a thermal expansion coefficient larger than that of the container portion, the hermeticity of the sealed grease is improved. Preparative Preparative male screw member in the container part can perform base oil discharge smoothly by expansion in the axial direction, it is possible to extend the life of the grease lubrication life.

A first embodiment of the present invention will be described with reference to FIGS.
The rolling bearing device according to the first 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, and is adjacent to the outer ring 2. A grease supply device 4 is arranged. The plurality of rolling elements 3 are held by a cage 5, and one end of the bearing space between the inner and outer rings 1 and 2 is sealed by a seal 6. This rolling bearing is an angular ball bearing, the seal 6 is provided at the end portion on the bearing back side, and the grease supply device 4 is provided on the bearing front side. The grease supply device 4 also serves as a seal on the front side of the bearing, preventing grease leakage from the front side of the bearing. For example, the inner ring 1 of the rolling bearing can be rotated by being fitted to a machine tool spindle 7 shown in FIG. 3, and the outer ring 2 is fixedly supported in a fitted state on the inner periphery of a housing 8 shown in FIG. The

  As shown in FIG. 2A, the outer ring 2 that is a fixed-side raceway is provided with a step surface 2 b that follows the raceway surface 2 a on the front side of the outer race that is separated from the rolling elements 3. Further, the step surface 2b is a surface that extends from the raceway surface 2a to the outer diameter side and faces the outer ring front side.

  As shown in FIG. 1, the grease supply device 4 is configured as a separate part from the rolling bearing. The grease supply device 4 is provided in a fixed state with respect to the fixed-side raceway, and is disposed on the outer diameter side of the inner ring positioning spacer 9 by being provided in contact with the front side width surface of the outer ring 2. . In this example, the grease supply device 4 includes an outer ring fixing spacer 10 provided in contact with a front width surface, that is, an end surface of the outer ring 2, and an annular container portion 11 fitted to an inner diameter surface of the outer ring fixing spacer 10. And an in-bearing insertion portion 12 that protrudes from the container portion 11 and is inserted to the vicinity of the raceway surface 2a of the outer ring 2 to form a gap δ1 (FIG. 2A) at which the grease base oil is oozed out.

  As shown in FIG. 1, the annular container portion 11 has a grease reservoir in the inside sandwiched between the outer ring fixed spacers 10. The outer ring fixed spacer 10 has an engaging step 10a at the end opposite to the outer ring 2 on the inner diameter surface. The outer diameter side tip 13a of the side wall part 13 of the container part 11 can be fitted to the engaging step part 10a. The side wall portion 13 of the container portion 11 is engaged with the engaging step portion 10a of the outer ring fixing spacer 10 and a fixing part or the like not shown is used on the inner diameter surface of the engaging step portion 10a. In contrast, the container part 11 is fixed in the axial direction. The outer ring fixed spacer 10 and the container part 11 are made of a metal material such as steel. However, non-ferrous metal materials can also be applied. In particular, the container part 11 is formed of a material having a smaller thermal expansion coefficient than a male screw member described later. As a material of the outer ring fixed spacer 10 and the container portion 11, for example, a material such as iron, novinite cast iron, invar, ceramics, or the like is applied.

The in-bearing insertion portion 12 is disposed along the inner diameter surface 2 c of the outer ring 2. This in-bearing insertion portion 12 is a ring-shaped member in which, for example, a part of the tip in the circumferential direction is in contact with the stepped surface 2b and forms a flow path 14 and a gap δ1 with the outer ring 2. The in-bearing insertion portion 12 is formed integrally with the container portion 11. That is, it extends integrally from the outer diameter end of the side wall 15 of the container 11 adjacent to the bearing.
As shown in FIG. 2A, a flow path 14 extending in the axial direction by a predetermined small distance is formed by the peripheral wall at the tip of the bearing insertion portion 12 and the inner diameter surface 2c of the outer ring 2 facing this. The base portion of the in-bearing insertion portion 12 has a smaller diameter than the tip. A portion (annular portion 15) surrounded by the outer diameter surface of the base portion and the inner diameter surface 2 c of the outer ring 2 communicates with the container portion 11 and with the flow path 14.
Further, the front end surface 12a of the in-bearing insertion portion 12 forms the gap δ1 so-called step surface gap δ1 for oozing out grease base oil between the step surface 2b of the outer ring 2. As a result, the grease reservoir in the container portion 11 of the grease supply device 4 communicates with the step surface gap δ1 through the annular portion 15 and the flow path 14.

  As shown in FIG. 1, in the side wall part 13 of the container part 11, the grease enclosure hole 13b which encloses grease in the container part 11 is provided, for example in the circumferential direction several places. The grease sealing hole 13b is a hole that penetrates the side wall portion 13 in the axial direction. However, the grease sealing hole 13b is not limited to a plurality of locations in the circumferential direction, and may be provided only at one location in the circumferential direction. A male screw member 16 is provided which is screwed into each grease sealing hole 13b to seal the grease sealing hole 13b. That is, a female screw part is formed in the grease sealing hole 13b, and the male screw part 16a of the male screw member 16 can be screwed into the female screw part.

As the male screw member 16, for example, various screws such as a hexagon socket head cap screw, a hexagon head bolt, and a hexagon socket head set screw can be applied. The male screw member 16 is preferably made of a resin material such as polyetheretherketone (PEEK) or polycarbonate (PC) having a small dimensional change and a low water supply rate. However, the screw material is not necessarily limited to these resin materials, and any material having a thermal expansion coefficient larger than that of the container portion 11 is sufficient.
Here, the thermal expansion coefficients at 20 ° C. of various resin materials are as follows.
PEEK 3.1 × 10 ⁻⁵ / ° C, PC 6.5 × 10 ⁻⁵ / ° C

  In the case of FIG. 1B, the male screw member 16 is a hexagon socket head bolt, and a washer 17 is interposed between the seat surface of the bolt head and the side wall portion 13. As the washer 17, a spring washer, a plain washer, etc. are applicable. In some cases, the washer 17 is not interposed. When a hexagon socket set screw is applied as the male screw member 16, the screw head does not protrude from the side wall portion 13 of the container portion 11. Therefore, the outer ring presser cover 18 for positioning and fixing the outer ring fixing spacer 10 in the housing 8 shown in FIG. No longer interferes with the screw head. Therefore, the axial dimension of the main shaft 7 can be further shortened, and the rigidity of the spindle unit can be increased.

  According to the rolling bearing device described above, in a state where the grease supply device 4 is fixed to the outer ring 2, grease is sealed in the container portion 11 from the grease sealing hole 13b using a grease gun or the like not shown. . Thereafter, the male screw member 16 is screwed into the grease sealing hole 13b and sealed. When the bearing is operated in this grease-filled state, the grease base oil is separated from the thickener due to the temperature rise during operation in the grease stored in the sealed grease reservoir. The separated grease base oil is discharged to the raceway surface 2a of the outer ring 2 through the step surface gap δ1. When the temperature rises to a steady state, it gradually decreases in parallel with the grease base oil discharge, and the base oil discharge amount per unit time also decreases.

Further, when the temperature rises during the bearing operation, for example, from 20 ° C. to 40 ° C., a difference in expansion occurs between the container part 11 and the male screw member 16 due to a difference in thermal expansion coefficient between the container part 11 and the male screw member 16. Thereby, the displacement amount by which the external thread portion 16a of the external thread member 16 expands radially outward becomes larger than the displacement amount by which the internal thread portion of the grease sealing hole 13b of the container portion 11 expands radially outward. Therefore, the sealing property between the grease sealing hole 13b and the male screw member 16 in the container part 11 can be improved. Further, when the male screw member 16 expands in the axial direction in the container portion 11, the base oil separated from the grease reservoir can be smoothly supplied as the lubricating oil for the bearing.
Therefore, the grease leakage from the container part 11 can be prevented with a simple configuration. In this way, it is possible to smoothly discharge the base oil by enhancing the hermeticity of the sealed grease and expanding the male screw member in the axial direction in the container portion. Therefore, the grease lubrication life can be extended. Can do.

  Thereafter, when the bearing operation is stopped, the temperature of the grease supply device 4 and the like decreases, and thereby, the grease base oil is not discharged due to the temperature increase of the grease supply device 4, and the gap surface gap δ1 has no grease base. Filled with oil. Therefore, the grease supply device 4 is in a sealed state when the operation is stopped. At the same time, the container 11 and the male screw member 16 eliminate the expansion difference. Therefore, the contact surface pressure generated in each screw thread can be reduced, and the male screw member 16 can be easily and smoothly removed from the grease sealing hole 13b. Thereby, it is possible to easily perform the replacement of the grease and the inspection of the deterioration state.

Thereafter, when the bearing operation is resumed, the temperature of the grease supply device 4 rises again, and the container portion 11 and the male screw member 16 cause an expansion difference.
The sealability between the grease sealing hole 13b and the male screw member 16 in the container part 11 can be improved. Further, when the male screw member 16 expands in the axial direction in the container portion 11, the base oil separated from the grease reservoir can be smoothly supplied as the lubricating oil for the bearing.
The temperature change in the grease supply device 4 is repeated by such a heat cycle of temperature increase and decrease, and the grease base oil separated from the grease is surely moved to the stepped surface gap δ1, and the raceway surface 2a of the outer ring 2 is reached. Repeatedly supplied. Moreover, the expansion | swelling difference of the container part 11 and the external thread member 16 can be repeatedly produced by the said heat cycle. Therefore, grease leakage can be prevented during the operation of the bearing, and the grease lubrication life can be extended.

In addition to the base oil discharge action by the heat cycle, a base oil discharge action by the capillary phenomenon shown below is also added. That is, when the operation of the bearing is stopped, the grease base oil moves to the stepped surface gap δ1 through the flow path 14 due to the thickener in the grease and the capillary phenomenon of the stepped surface gap δ1. In combination with the surface tension, the grease base oil is held in oil in the step surface gap δ1.
When the bearing is operated, the grease base oil stored in the stepped surface gap δ1 is removed from the stepped surface gap δ1 by the volume expansion caused by the temperature increase of the outer ring 2 generated by the operation and the air flow generated by the revolution and rotation of the rolling element 3. It is discharged, moves while adhering to the raceway surface 2a of the outer ring 2, and is continuously supplied to the rolling element contact portion. Thus, since the grease base oil is discharged to the raceway surface 2a of the outer ring 2 also by the capillary phenomenon described above, the lubrication is further ensured. This makes it possible to achieve high speed, long life, and maintenance-free operation using only the grease sealed in the rolling bearing device.

As shown in FIG. 2B, based on the difference in thermal expansion coefficient between the container portion 11 and the male screw member 16, the displacement of the male screw member 16 expanding radially outward from the female screw portion of the grease sealing hole 13b. While the amount is increased and the male screw member 16 is expanded in the axial direction to increase the pressure in the container portion 11, the following effects are obtained. When the temperature rises during operation, the sealability in the radial direction between the grease sealing hole 13b and the male screw member 16 is increased, and then the male screw member 16 is expanded in one axial direction represented by arrow A1 in FIG. Thereby, the pressure in the container part 11 increases. As a result, the base oil separated in the grease reservoir is discharged smoothly and continuously. Therefore, the grease base oil can be reliably discharged without using a complicated mechanism.
When the male screw member 16 is formed of a material made of polyetheretherketone or polycarbonate, since the dimensional change of the male screw member 16 is small and the water supply rate is low, the amount of displacement in the radial direction of the male screw member 16 accompanying the temperature change is stabilized. Therefore, the sealing property between the grease sealing hole 13b and the male screw member 16 in the container part 11 can be improved more reliably.
In the side wall part 13 of the container part 11, when the grease sealing holes 13 b are provided at a plurality of locations in the circumferential direction, it is possible to reduce the work of allowing the grease after sealing to conform to the entire circumferential direction of the container part 11. In addition, it is possible to easily visually check the grease-filled state from the plurality of grease-filled holes 13b before screwing.

In this embodiment, the rolling bearing is an angular ball bearing, and the stepped surface 2b is formed following the edge opposite to the direction in which the contact angle occurs on the raceway surface 2a. It becomes easy to arrange directly under the rolling elements 3. Thereby, the step surface 2b can be brought close to the center of the rolling element 3, and the base oil can be supplied from the step surface gap δ1 to the raceway surface 2a more efficiently.
When the rolling bearing device is used to support the spindle 7 of the machine tool as shown in FIG. 3, the grease lubrication life can be extended, so that the trouble of maintaining the machine tool can be further omitted. Become.

Next, a second embodiment of the present invention will be described with reference to FIGS.
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.

  As shown in FIGS. 4 and 5, in the rolling bearing device according to the second embodiment, in particular, an annular groove 19 is provided in the container portion 11, and a seal member 20 is provided in the annular groove 19. As the seal member 20, for example, an O-ring can be applied. The annular groove 19 is provided at a radially outward position of the grease sealing hole 13b in the container portion 11 and so as to face outward in the axial direction. A lid member 21 that closes the annular groove 19 and the grease sealing hole 13b is firmly fixed to the side wall portion 13 of the container portion 11. A through hole 21 a through which the male screw member 16 is passed is provided in the lid member 21, and the male screw member 16 is screwed into the grease sealing hole 13 b of the container portion 11 via the lid member 21. In the screwed state, the seal member 20 is pressed between the annular groove 19 and the lid member 21 to be elastically deformed, thereby preventing grease leakage from between the side wall portion 13 and the lid member 21. it can. In this way, the reliability of preventing grease leakage can be further improved. Other configurations are the same as those of the first embodiment, and the same effects as those of the first embodiment are achieved. Note that the annular groove 19 and the grease sealing hole 13b may be closed by a seat surface or a washer of the screw head of the male screw member 16. In this case, the number of parts can be reduced by the amount that the lid member 21 is unnecessary.

  As other embodiment of this invention, as shown in FIG. 6, you may provide the sealing material 22 in the external thread part 16a of the external thread member 16. As shown in FIG. As the sealing material 22, for example, a sealing tape or the like can be applied. When the sealing material 22 is wound around the male threaded portion 16a, it is desirable to wind the sealing material 22 slightly stronger in a spiral shape with the oil and the like adhering to the male threaded portion 16a being removed. In this case, the sealing material 22 is wound in the direction opposite to the direction in which the male screw member 16 is rotated. Thereby, peeling of the sealing material 22 when the male screw member 16 is tightened can be prevented.

As another embodiment of the present invention, as shown in FIG. 7, instead of providing the outer ring fixed spacer 10, the outer ring 2 may be provided with a race ring extension 2 d for providing the grease supply device 4. In this case, of the container part 11 of the grease supply device 4, the side wall part 13 on the opposite side to the inside of the bearing is in contact with the positioning step surface 2da provided on the inner diameter surface of the bearing ring extension 2d and is used for positioning. The outer ring 2 is fixed in a normal axial position by a retaining ring 23 fitted in a retaining ring groove provided in the vicinity of the step surface 2da. A tapered notch 13c is provided at the outer diameter edge of the side wall 13 on the bearing outward surface, and a sealing material 24 is interposed between the notch 13b and the retaining ring 23. The sealing material 24 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 bearing ring extension 2d, or may have a width without the bearing ring extension as in FIG.

  In this way, when the bearing ring extension 2d for forming the grease reservoir is provided and the portion corresponding to the outer ring fixed spacer is integrated with the outer ring 2, oil leakage as in the case of providing a separate spacer is provided. The resulting mating surface is eliminated. Therefore, the problem of leakage of the grease base oil from the mating surface does not occur. Further, since the bearing ring extension 2d, which corresponds to the spacer, is integrated with the outer ring 2 to form a grease reservoir, the assembly of the bearing is improved and the assembly accuracy can be improved by reducing the number of parts. In addition, the same operational effects as those of the above-described embodiment are obtained.

In the said embodiment, although the level | step difference surface 2b is provided in the outer ring | wheel 2, it is not limited to this form. For example, as shown in FIG. 8, the outer ring 2 is not provided with a stepped surface, but is provided by inserting an in-bearing insertion portion 12 along the front-side inner peripheral surface 2 ca of the outer ring 2 having a tapered surface. This may be applied to a configuration example in which an inclined gap communicating with the annular portion 15 is formed between the tapered outer peripheral surface 12b at the tip of the outer ring 2 and the front-side inner peripheral surface 2ca of the outer ring 2.
In this configuration example, since the outer ring 2 is not provided with a stepped surface, the thickness of the outer ring 2 is increased, so that the rigidity of the rolling bearing device can be made higher than that of the other embodiments. Moreover, since the number of processing steps can be reduced, the manufacturing cost can be reduced. In addition, the same operational effects as those of the above-described embodiment are obtained.

In each of the above embodiments, an example in which an angular ball bearing is used as the rolling bearing has been described. However, various rolling bearings such as a tapered roller bearing, a cylindrical roller bearing, and a deep groove ball bearing can be applied.
As other embodiments, in machine tools other than the spindle unit, industrial robots, and the like, the inner ring may be a fixed-side raceway and the outer ring may be a rotation-side raceway.

(A) It is sectional drawing of the rolling bearing apparatus which concerns on 1st Embodiment of this invention, (B) It is an expanded sectional view of the principal part of the grease supply apparatus of the rolling bearing apparatus. (A) It is an expanded sectional view expanding and showing the important section of Drawing 1 (A), and (B) An expanded sectional view of the important section of a grease supply device at the time of temperature rise. It is a half sectional view of the spindle device for machine tools using the rolling bearing device. It is sectional drawing of the rolling bearing apparatus which concerns on 2nd Embodiment of this invention. It is an expanded sectional view of the principal part of the rolling bearing device. It is sectional drawing of the principal part of the rolling bearing apparatus which concerns on other embodiment of this invention. It is sectional drawing of the rolling bearing apparatus which concerns on other embodiment of this invention. It is sectional drawing of the rolling bearing apparatus which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a ... Raceway surface 2 ... Outer ring 2a ... Raceway surface 3 ... Rolling element 4 ... Grease supply device 7 ... Machine tool spindle 11 ... Container part 12 ... Bearing insertion part 13b ... Grease filling hole 16 ... Male screw member 19 ... Ring Groove 20 ... Sealing member 22 ... Sealing material

Claims (6)

In a grease supply device for supplying a base oil of grease to a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed between raceway surfaces of the inner and outer rings,
A grease supply device is provided in a fixed state with respect to a fixed-side raceway that does not rotate among the inner and outer rings. The grease supply device includes an annular container portion in which the inside is a reservoir for grease, and projects from the container portion to An insertion part in the bearing that is inserted to the vicinity of the raceway surface and forms a gap that causes grease base oil to ooze out at the tip,
A material having a thermal expansion coefficient larger than that of the container portion is provided with a grease sealing hole for sealing grease in the container portion, and provided with a male screw member that is screwed into the grease sealing hole to seal the grease sealing hole. A grease supply device formed by the method described above. In claim 1, based on the difference in thermal expansion coefficient between the container portion and the male screw member,
A grease supply device configured to increase a displacement amount in which the male screw member expands radially outward than the female screw portion of the grease sealing hole and to increase the pressure in the container portion by expanding the male screw member in the axial direction.   3. The grease supply device according to claim 1, wherein the male screw member is formed of a material made of polyetheretherketone or polycarbonate.   4. The grease supply device according to claim 1, wherein a sealing material is provided on a male screw portion of the male screw member. 5.   5. The grease supply device according to any one of claims 1 to 4, which is used for supporting a spindle of a machine tool.   In any one of Claims 1 thru | or 5, An annular groove is provided around the opening of the grease enclosure hole in the outer surface of the said container part, A sealing member is provided in this annular groove, This sealing member is an external thread member, Or the grease supply apparatus sealed with the cover member interposed between the container part and the external thread member.

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