JP6460368B2 - Rolling bearing device - Google Patents

Description

  The present invention relates to a rolling bearing device.

Conventionally, grease lubrication has been widely used as a lubrication method for rolling bearing devices.
In grease lubrication, in order to maintain the lubrication performance even under severe lubrication conditions such as high temperature, high speed rotation, and heavy load, a grease reservoir is provided in the outer ring spacer of the bearing, and the base oil contained in the grease held in the grease reservoir Is supplied into the bearing. As rolling bearing devices having this type of mechanism, for example, Patent Documents 1 and 2 below are known.

  Patent Document 1 discloses an inner ring, an outer ring, a plurality of balls as rolling elements interposed between the inner ring and the outer ring, a cage for holding the plurality of balls at predetermined intervals along the circumferential direction, and the inner ring. A seal that seals one axial end of the annular space between the outer ring and the outer ring, and an annular grease reservoir that is provided close to the annular groove adjacent to the guide surface of the outer ring that guides the rotation of the cage. A rolling bearing device comprising a member is disclosed.

  Patent Document 2 discloses communication between an inner ring, an outer ring, a plurality of rolling elements interposed between raceways of the inner and outer rings, a grease pool forming component provided in contact with the outer ring, and the vicinity of the raceway surface of the outer ring from the grease pool. A rolling bearing provided with a gap forming piece that forms a gap along the inner surface of the outer ring is disclosed.

International Publication No. 2010/010897 JP 2005-180629 A

  If you continue to use a grease-filled type rolling bearing device, cracks (voids) may occur near the communication path between the grease reservoir and the bearing as the base oil contained in the grease in the grease reservoir is supplied. There is. If the cracks continue over the entire circumference, there is a problem that the supply of base oil to the rolling bearing is interrupted despite the grease remaining in the grease reservoir. When the supply of the base oil is interrupted, the lubrication performance of the bearing is lost when the base oil in the rolling bearing is completely consumed, and thereafter it is difficult to use the rolling bearing device for a long period of time.

  On the other hand, Patent Document 2 discloses a structure in which a minute gap is formed between an outer ring and a gap forming piece, so that the base oil of grease can be supplied to the vicinity of the raceway surface of the outer ring. Attempts to achieve this are disclosed. However, the technique disclosed in Patent Document 2 has a problem that the structure is complicated because it is necessary to precisely design the shape of the gap forming piece to form a minute gap.

  Accordingly, an object of the present invention is to provide a rolling bearing device that has a simple structure and can continue to supply the base oil contained in the grease to the bearing over a long period of time, thereby realizing a long life. It is.

The invention according to claim 1 for achieving the above object, the inner ring (5), outer ring (6), a plurality of rolling elements arranged between these inner and outer (7), and has an outer peripheral surface A rolling bearing (3) having a cage that holds the plurality of rolling elements in a rollable manner, and is adjacent to one side in the axial direction of the rolling bearing and formed in a groove shape along the circumferential direction. A grease reservoir (25) in which G) is stored, and a spacer (4, 15, 16, 18) in which a flow passage (24) for communicating the grease reservoir and the inside of the rolling bearing is formed, The spacer has an annular wall surface (23, 23A) that defines an inner periphery of the grease reservoir, and an end of the grease reservoir on the annular bearing side in the axial direction of the annular reservoir is the portion of the spacer. It is continuous with the facing end face (16A) facing the rolling bearing, Serial and the entire region of the annular wall is formed by a flat cylindrical surface, the radial dimension of the annular wall is greater than the maximum radial dimension of the outer peripheral surface of the retainer to provide a rolling bearing device (1) .

The invention according to claim 2 is the rolling bearing device according to claim 1, wherein the annular wall surface has a cylindrical surface (23) centered on the axis of the spacer.
The invention according to claim 3 is the rolling according to claim 1, wherein the annular wall surface has a conical surface (23 </ b> A) centering on the axis of the spacer, the diameter of the annular wall surface being reduced toward the rolling bearing side. It is a bearing device.

According to a fourth aspect of the present invention, an inner periphery of the grease reservoir is linearly formed in a sectional view in the axial direction of the spacer, and the grease reservoir is the rolling bearing in the axial direction of the spacer. 4. The rolling bearing device according to claim 1, wherein a radial dimension on the side is the same as or larger than a side opposite to the rolling bearing side in the axial direction of the spacer.
In the above description, numbers in parentheses represent reference numerals of corresponding components in the embodiments described later, but the scope of the claims is not limited by these reference numerals.

  According to the present invention, the annular wall surface is continuous with the opposed end surface facing the rolling bearing of the spacer. The annular wall surface extends from the end of the grease reservoir spacer on the side of the rolling bearing in the axial direction to the opposite side of the grease reservoir in the axial direction of the rolling bearing. Further, the entire area of the annular wall surface is formed by a flat surface. The base oil contained in the grease in the grease reservoir moves toward the flow path inside the grease reservoir. However, since the entire area of the annular wall surface is formed by a flat surface, the base oil formed in the grease reservoir is formed. The oil flow is only in one direction along the annular wall surface. That is, it is possible to avoid a distribution in the ease of flow of the base oil inside the grease reservoir. Therefore, the occurrence of grease cracking can be effectively suppressed or prevented. Thereby, the base oil contained in the grease can be continuously supplied to the rolling bearing over a long period of time, and the life of the rolling bearing can be extended. In addition, since it is only necessary to form the entire area of the annular wall surface defining the grease reservoir on a flat surface, it is possible to prevent the structure of the rolling bearing device from becoming complicated.

It is sectional drawing of the rolling bearing apparatus which concerns on the 1st Embodiment of this invention. It is sectional drawing to which the principal part of FIG. 1 was expanded. It is an enlarged view for demonstrating the flow of the base oil contained in grease based on a reference form. It is sectional drawing of the rolling bearing apparatus which concerns on the modification of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a rolling bearing device 1 according to a first embodiment of the present invention.
The rolling bearing device 1 is a device that supports, for example, a main shaft (a shaft on which a rolling bearing is supported) 2 of a machine tool.
Referring to FIG. 1, a rolling bearing device 1 includes a rolling bearing 3 composed of an angular ball bearing, and a grease storage member 4 as an example of a spacer of the present invention provided adjacent to the rolling bearing 3.

  As shown in FIG. 1, the rolling bearing 3 is interposed between an inner ring 5 fitted on the main shaft 2, an outer ring 6 fitted on a housing (not shown) of a machine tool, and the inner ring 5 and the outer ring 6. Rolling element 7, cylindrical retainer 8 that holds the plurality of rolling elements 7 at regular intervals in the circumferential direction Y, and the axial direction of the annular space between the inner ring 5 and the outer ring 6 (axial direction of the main shaft 2) And a seal 9 that seals one end of X (the right end in FIG. 1 and the end opposite to the grease storage member 4). In FIG. 1, an angular ball bearing is employed as the rolling bearing 3, but a deep groove ball bearing may be employed instead of this, and a cylindrical roller bearing, a tapered roller bearing, or the like may also be employed.

An inner ring raceway surface 10 for rolling the rolling elements 7 is formed at the center in the axial direction X of the outer periphery of the inner ring 5. Further, first seal grooves 11 are formed at both ends in the axial direction X of the outer periphery of the inner ring 5. An inner peripheral portion (seal lip) of the seal 9 is fitted in the first seal groove 11 on the side farther from the grease storage member 4 in the axial direction X (right side in FIG. 1).
An outer ring raceway surface 12 for rolling the rolling elements 7 is formed at the center in the axial direction X of the inner periphery of the outer ring 6. Second seal grooves 13 are formed at both ends in the axial direction X of the inner periphery of the outer ring 6. The outer peripheral portion (seal lip) of the seal 9 is fitted in the second seal groove 13 on the side farther from the grease storage member 4 in the axial direction X (right side in FIG. 1).

  The second seal groove 13 on the side close to the grease storage member 4 (left side in FIG. 1) in the axial direction X functions as an annular groove 14 for storing the grease G. The annular groove 14 is constituted by an annular step portion 28 formed at the end of the outer ring 6 on the side close to the grease storage member 4. The step portion 28 is connected to the outer ring raceway surface 12. The annular groove 14 is filled with grease G for initial lubrication in advance.

As shown in FIG. 1, the grease storage member 4 surrounds the inner ring spacer 15 so that an annular space 17 is formed between the inner ring spacer 15 fitted on the main shaft 2 and the inner ring spacer 15. An outer ring spacer 16 formed and fitted in a machine tool housing (not shown), and a grease containing ring 18 disposed in an annular space 17 between the inner ring spacer 15 and the outer ring spacer 16 are included.
The inner ring spacer 15 is formed in a cylindrical shape in contact with the outer peripheral surface of the main shaft 2. As shown in FIG. 1, the inner ring spacer 15 externally fitted to the main shaft 2 is positioned in a state where one end face in the axial direction X (the right end face in FIG. 1) is in contact with the end face of the inner ring 5. This positioning is performed by spacers K1 and K2 that sandwich a cylindrical body including the inner ring 5 and the inner ring spacer 15 from both sides in the axial direction X. The spacers K1 and K2 are fixed to the main shaft 2, respectively.

  The outer ring spacer 16 is integrally provided with a cylindrical peripheral wall 19 and an annular plate-shaped bottom wall 20 that extends radially inward from a peripheral edge on the one end side in the axial direction (the right end edge in FIG. 1) of the peripheral wall 19. It is formed in a cylindrical shape. By fitting the outer ring spacer 16 to the inner ring spacer 15 through the central opening of the bottom wall 20, the side facing the rolling bearing 3 is opened between the outer ring spacer 16 and the inner ring spacer 15. An annular space 17 is defined in which the opposite side is closed by the bottom wall 20. In the following description, the “axial direction of the outer ring spacer 16” refers to the axial direction of the peripheral wall 19 of the outer ring spacer 16 and corresponds to the axial direction X of the main shaft 2 in this embodiment.

Further, as shown in FIG. 1, the outer ring spacer 16 is positioned in a state in which the end face on the axial rolling bearing 3 side (the right end face in FIG. 1) is in contact with the end face of the outer ring 6. This positioning is performed, for example, by a positioning member (not shown) fixed to a housing (not shown).
The grease containing ring 18 includes a cylindrical portion 21 along the inner ring spacer 15 that forms the inner peripheral surface of the annular space 17, and the opposite side of the cylindrical portion 21 from the axial rolling bearing 3 of the outer ring spacer 16 ( An annular plate-like rear flange portion 22 that extends radially outward from the periphery of the left side in FIG. 1 is integrally provided. The peripheral wall 19 of the outer ring spacer 16, the cylindrical portion 21 constituting the grease containing ring 18, and the rear flange portion 22 divide a grease reservoir 25 having a substantially U-shaped annular section having an opening 24 facing the rolling bearing 3. Yes.

The rear flange portion 22 is formed to have a diameter that is substantially contained in the annular space 17 so that the outer peripheral surface thereof is in contact with the peripheral wall 19 of the outer ring spacer 16 when the grease accommodating ring 18 is accommodated in the annular space 17.
On the other hand, the cylindrical portion 21 has an annular wall surface 23 having a smaller diameter than the rear flange portion 22. An inner wall of the grease reservoir 25 is defined by the annular wall surface 23. The end of the annular wall surface 23 on the side of the rolling bearing 3 in the axial direction of the outer ring spacer 16 is continuous with the facing end surface 18 </ b> A of the grease containing ring 18 that faces the cage 8. Further, the end of the annular wall surface 23 opposite to the rolling bearing 3 in the axial direction of the outer ring spacer 16 is connected to the back flange 22. Further, the entire area of the annular wall surface 23 is formed by a cylindrical surface centered on the central axis of the outer ring spacer 16. In other words, the inner periphery of the grease reservoir 25 is configured in a straight line in a sectional view in the axial direction of the outer ring spacer 16, and the grease reservoir 25 is the radial direction of the outer ring spacer 16 on the side of the rolling bearing 3. The dimensions are the same as the radial dimensions of the outer ring spacer 16 on the opposite side of the rolling bearing 3 in the axial direction.

  The end of the annular wall surface 23 on the side of the rolling bearing 3 in the axial direction of the outer ring spacer 16 (the right end in FIG. 1) enters the inside of the rolling bearing 3, that is, between the inner ring 5 and the outer ring 6 to form an annular groove. 14 in the inner region. An annular gap defined by the end of the annular wall surface 23 in the axial direction on the rolling bearing 3 side and the annular groove 14 allows circulation between the grease reservoir 25 and the inside of the rolling bearing 3 (annular groove 14). An opening 24 is formed as an example of the flow passage of the invention.

  Further, the grease storage member 4 is formed with a screw hole 26 formed across the bottom wall 20 of the outer ring spacer 16 and the cylindrical portion 21 of the grease containing ring 18. The grease receiving ring 18 is fixed to the outer ring spacer 16 by screwing the screwed portion of the bolt 27 into the screw of the screw hole 26. The screw hole 26 partially overlaps the position of the grease reservoir 25 when viewed from the radial direction of the outer ring spacer 16. Since the screw hole 26 is provided not in the back flange portion 22 but in the thick tubular portion 21, the depth of the screw hole 26 can be provided longer than in the case where the screw hole 26 is provided in the back flange portion 22. . Thereby, fixation with the volt | bolt 27 can be performed firmly.

  As the grease G filled in the grease reservoir 25 and the annular groove 14, a grease compound containing urea compound, Ba complex soap, Li complex soap, or the like as a thickener and ester, polyalphaolefin, or the like as a base oil can be used. . In order to supply the base oil to the rolling bearing 3 over a long period of time, it is necessary to keep the grease G in the grease reservoir 25. Therefore, in order to suppress the flow of the grease G, the grease G has a certain degree of viscosity. It is preferable to have

FIG. 2 is an enlarged cross-sectional view of a main part of FIG. The flow of the base oil of the grease G filled in the grease reservoir 25 will be described with reference to FIG.
As shown in FIG. 2, in the rolling bearing device 1, the grease G for initial lubrication is filled in the annular groove 14 of the rolling bearing 3, and the grease G for replenishment is filled in the grease reservoir 25. The grease G in the annular groove 14 and the grease G in the grease reservoir 25 are connected to each other. Therefore, when the base oil of the grease G in the annular groove 14 is consumed by the operation of the rolling bearing 3, the base oil of the grease G stored in the grease reservoir 25 permeates and moves toward the rolling bearing 3 according to the consumption. To do.

In this case, as indicated by a solid line arrow in FIG. 2, a base oil flow is formed in the axial direction of the outer ring spacer 16 from the inner side of the grease reservoir 25 toward the opening 24.
FIG. 3 is an enlarged view for explaining the flow of the base oil contained in the grease G according to the reference embodiment. Parts that are the same as those shown in FIGS. 1 and 2 are given the same reference numerals, and descriptions thereof are omitted.

  The rolling bearing device 201 shown in FIG. 3 includes a grease accommodating ring 218 as described below. The grease containing ring 218 is formed in a radial direction from a peripheral portion of the cylindrical portion 221 along the inner ring spacer 15 and the opposite side (left side in FIG. 3) of the cylindrical portion 221 to the axial bearing of the outer ring spacer 16 (not shown). An annular plate-like rear flange portion 222 extending outward, and an annular plate-like portion extending radially outward from the peripheral edge of the cylindrical portion 221 on the side of the axial bearing of the outer ring spacer 16 (right side in FIG. 3) A supply-side flange portion 223 is integrally provided. An annular integral grease reservoir 225 having an opening 224 facing the rolling bearing is defined by the peripheral wall 19 of the outer ring spacer 16, the cylindrical portion 221 constituting the grease containing ring 218, the back side flange portion 222 and the supply side flange portion 223. ing.

  In such a grease reservoir 225, as indicated by a solid line arrow in FIG. 3, normally, the other axial side of the outer ring spacer 16 (left side in FIG. 3) to one axial side (rolling bearing side; right side in FIG. 3). In the region of the grease reservoir 225 that is radially inward of the opening 224 and close to the supply side flange 223, the outer ring spacer is formed along the inner wall of the supply side flange 223. Another base oil flow from the radially inner side to the radially outer side of 16 is also formed.

  If the rolling bearing device 201 shown in FIG. 3 is continuously used, grease cracks may occur in the vicinity of the opening 224. As one of the mechanisms for the occurrence of such grease cracking, the present inventor considers the following mechanism. That is, the flow of base oil from the other side in the axial direction of the outer ring spacer 16 (left side in FIG. 3) to the one side in the axial direction (right side in FIG. 3) having directions intersecting each other in the vicinity of the opening 224 of the grease reservoir 225. And the flow of the base oil from the radially inner side of the outer ring spacer 16 toward the radially outer side interfere with each other. As a result, the flow rate of the base oil at the opening 224 decreases, thereby causing a grease crack. It is. That is, since the grease containing ring 218 includes the supply-side flange portion 223, there is a distribution in the ease of the flow of gas oil in the grease reservoir 225, and this is a cause of occurrence of grease cracking. The inventor thinks.

  Returning to FIG. 2, the annular wall surface 23 connects the opposite end face 18 </ b> A of the grease containing ring 18 facing the cage 8 and the rear flange portion 22. Further, the entire area of the annular wall surface 23 is formed by a cylindrical surface. The base oil contained in the grease G of the grease reservoir 25 moves inside the grease reservoir 25 toward the flow passage 24, but the entire area of the annular wall surface 23 is formed by a cylindrical surface. The flow of the base oil formed inside is only a one-way flow along the annular wall surface 23. That is, it is possible to avoid the occurrence of distribution in the ease of flow of the base oil inside the grease reservoir 25. Therefore, the occurrence of grease cracking can be effectively suppressed or prevented. Thereby, the base oil contained in the grease G can be continuously supplied to the rolling bearing 3 for a long time, and the life of the lubricating performance of the rolling bearing 3 can be increased. In addition, since it is only necessary to form the entire area of the annular wall surface 23 defining the grease reservoir 25 on a flat surface, it is possible to prevent the structure of the rolling bearing device 1 from becoming complicated.

FIG. 4 is a cross-sectional view of a rolling bearing device according to a modification of the present invention.
In the modification shown in FIG. 4, the inner periphery of the grease reservoir 25 is partitioned by the annular wall surface 23 </ b> A. The end of the annular wall surface 23 </ b> A on the side of the rolling bearing 3 in the axial direction of the outer ring spacer 16 is continuous with the facing end surface 18 </ b> A of the grease containing ring 18 that faces the cage 8. Further, the end of the annular wall surface 23 </ b> A opposite to the rolling bearing 3 in the axial direction of the outer ring spacer 16 is connected to the back flange 22. The entire area of the annular wall surface 23 </ b> A of the cylindrical portion 21 is formed by a conical surface centered on the central axis of the outer ring spacer 16. The conical surface is reduced in diameter toward the rolling bearing 3 in the axial direction of the outer ring spacer 16. In other words, the inner periphery of the grease reservoir 25 is configured in a straight line in a sectional view in the axial direction of the outer ring spacer 16, and the grease reservoir 25 is the radial direction of the outer ring spacer 16 on the side of the rolling bearing 3. The dimension is larger than the radial dimension of the outer ring spacer 16 on the side opposite to the rolling bearing 3 side in the axial direction. An annular gap defined by the end of the annular wall surface 23 </ b> A of the outer ring spacer 16 in the axial direction on the rolling bearing 3 side and the annular groove 14 forms an opening 24.

  The annular wall surface 23 </ b> A connects the opposite end face 18 </ b> A of the grease containing ring 18 facing the cage 8 and the rear flange portion 22. Since the entire area of the annular wall surface 23A is formed as a conical surface, the flow of the base oil formed inside the grease reservoir 25 is only a one-way flow along the annular wall surface 23A (indicated by a solid arrow in FIG. 4). It is. Therefore, it is possible to avoid the distribution in the ease of flow of the base oil in the grease reservoir 25. Therefore, occurrence of grease cracking can be effectively suppressed or prevented. Thereby, the base oil contained in the grease G can be continuously supplied to the rolling bearing 3 for a long time, and the life of the lubricating performance of the rolling bearing 3 can be increased. In addition, since it is only necessary to form the entire area of the annular wall surface 23A defining the grease reservoir 25 in a conical shape, it is possible to prevent the structure of the rolling bearing device 1 from becoming complicated.

As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.
For example, as an example of the grease reservoir 25, the case where the grease reservoir 25 is annular and integrated has been described as an example. However, the grease reservoir 25 is structured to be separated into a plurality of chambers along the circumferential direction of the outer ring spacer 16. It may be.

  In the above-described embodiment, the inner ring 5 and the inner ring spacer 15 are on the rotating side that rotates with the main shaft 2, and the outer ring 6 and the outer ring spacer 16 are fixed in a stationary state in which they are fixed to a housing (not shown). The case of a fixed side has been described as an example. However, the present invention can also be applied to the case where the outer ring 6 and the outer ring spacer 16 are on the rotating side and the inner ring 5 and the inner ring spacer 15 are on the fixed side.

  In addition, various modifications can be made within the scope of the claims.

DESCRIPTION OF SYMBOLS 1 ... Rolling bearing apparatus, 3 ... Rolling bearing, 4 ... Grease storage member, 5 ... Inner ring, 6 ... Outer ring, 7
DESCRIPTION OF SYMBOLS ... Rolling element, 15 ... Inner ring spacer, 16 ... Outer ring spacer, 18 ... Grease housing ring, 21 ... Cylindrical part, 22 ... Back flange part, 23 ... Ring wall surface, 23A ... Ring wall surface, 24 ... Opening, 25 ... grease reservoir

Claims (4)

An inner ring, an outer ring, a plurality of rolling elements disposed between the inner and outer rings, and a rolling bearing having a peripheral surface and a retainer that holds the plurality of rolling elements in a rollable manner;
Adjacent to one side in the axial direction of the rolling bearing and formed in a groove shape along the circumferential direction, a grease reservoir in which grease is stored, and a flow passage for communicating the grease reservoir and the inside of the rolling bearing are formed. A spacer, and
The spacer has an annular wall surface defining an inner periphery of the grease reservoir,
An end of the annular wall on the rolling bearing side in the axial direction of the grease reservoir is continuous with an opposed end surface of the spacer facing the rolling bearing,
A rolling bearing device, wherein the entire annular wall surface is formed of a flat cylindrical surface, and the radial dimension of the annular wall surface is larger than the maximum radial dimension of the outer peripheral surface of the cage.   The rolling bearing device according to claim 1, wherein the annular wall surface has a cylindrical surface centered on an axis of the spacer.   2. The rolling bearing device according to claim 1, wherein the annular wall surface has a conical surface centering on an axis of the spacer, the diameter of which decreases toward the rolling bearing side. The inner periphery of the grease reservoir is configured linearly in a sectional view in the axial direction of the spacer,
4. The grease reservoir according to claim 1, wherein a radial dimension of the rolling bearing side in the axial direction of the spacer is the same as or larger than an opposite side of the rolling bearing side in the axial direction of the spacer. The rolling bearing device according to one item.

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