JP2010002027A - Cylindrical roller bearing and cylindrical roller bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical roller bearing and a cylindrical roller bearing device, enough spreading lubricating oil to a rolling surface of a cylindrical roller and lengthening the life of a bearing. <P>SOLUTION: In this cylindrical roller bearing 1, the cylindrical roller 4 is interposed between raceway surfaces 2a, 3a of an inner ring 2 and an outer ring 3, and lubrication is performed with grease. The outside diameter surface of the cylindrical roller 4 is provided with an annular recessed part 4a continuously extending over the whole periphery. The width of the recessed part is set to 15-25% of the length of a straight part of the outside diameter surface of the cylindrical roller. The grease can be held in the vicinity of the rolling surface of the cylindrical roller 4 which has not been lubricated before by this recessed part 4a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cylindrical roller bearing and a cylindrical roller bearing device used for supporting a machine tool main shaft and the like.

  As main lubrication methods for machine tool spindle bearings, there are methods such as air-oil lubrication in which lubricating oil is mixed with transport air and discharged from a nozzle, and grease lubrication that can be used maintenance-free. However, the air oil lubrication method has a problem from the viewpoint of cost, 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 that the surrounding environment is deteriorated by scattering of oil and noise. In order to avoid these problems, in recent years, there has been an increasing demand for high speed and long life by grease lubrication, and various improvements have been made.

  As an example of improvement of the grease lubrication method, a stepped surface following the raceway surface is provided on the stationary bearing ring of a rolling bearing, and the tip of the stepped surface faces through a gap between the fixed side bearing ring and the peripheral wall. In addition, a gap forming piece for forming a flow path is provided, and a grease reservoir that communicates with the flow path is provided, so that the base oil of grease is pushed out from the gap into the bearing due to pressure fluctuation due to a temperature rise in the grease reservoir. The thing is proposed (patent document 1).

As another improvement example of the grease lubrication method, in the cylindrical roller bearing, an escape portion that avoids contact with the cylindrical roller is also used as a lubricant reservoir in the inner peripheral portion on the tip end side of the cage that holds the cylindrical roller. A provided one has also been proposed (Patent Document 2).
JP 2007-182917 A Japanese Patent Laid-Open No. 2005-163997 JP 2005-127493 A

However, in the cylindrical roller bearing, the raceway surface of the inner and outer rings and the rolling surface of the cylindrical roller are in line contact with each other, so that a larger amount of lubricating oil is consumed than in the case of a ball bearing that makes point contact. Also, the lubricating oil tends to be harder to reach the center in the axial direction of the roller rolling surface. For example, in the grease-lubricated double-row cylindrical roller bearing 31 shown in FIG. 9, the grease tends to be unevenly distributed in the portions indicated by symbols (a), (b), and (c) that deviate from the raceway surface 33 a of the outer ring 33. Therefore, those disclosed in Patent Documents 1 and 2 are insufficient for spreading the lubricating oil over the entire cylindrical roller.
As a technique for spreading lubricating oil on the rolling surface of the cylindrical roller, there is one disclosed in Patent Document 3 and the like, and the life of the cylindrical roller bearing is extended. However, further extension of the life is desired.

  An object of the present invention is to provide a cylindrical roller bearing and a cylindrical roller bearing device capable of sufficiently spreading lubricating oil to the rolling surface of the cylindrical roller and extending the life of the bearing.

The cylindrical roller bearing according to the present invention is a cylindrical roller bearing in which a cylindrical roller is interposed between the raceway surfaces of the inner ring and the outer ring, and lubrication is performed with grease. It is a thing.
According to this configuration, the grease is held in each portion of the outer ring that is off the inner raceway surface, and the grease is also held in the concave portion of the cylindrical roller. As a result, not only the space for holding the grease increases, but also the grease can be held near the rolling surface of the cylindrical roller, which was difficult to achieve lubrication in the conventional example. As a result, the grease can be sufficiently spread over the rolling surface of the cylindrical roller, and the life of the cylindrical roller bearing can be extended.

The width of the recess is 15 to 25% of the length of the straight portion of the outer diameter surface of the cylindrical roller. The straight portion length is the axial length of the straight portion that is a portion of the cylindrical surface parallel to the roller axis on the outer diameter surface of the cylindrical roller.
The concave part of the cylindrical roller is a space for holding the grease, and in order to hold the grease sufficiently, its width dimension (length in the axial direction) is better, but it is limited from the viewpoint of securing the rolling surface. There is. If the concave portion is narrower than 15% of the length of the straight portion, the grease holding ability is insufficient. On the other hand, if the concave portion is wider than 15% of the length of the straight portion, the load capacity of the bearing is insufficient. Therefore, the width of the recess is 15 to 25% of the length of the straight portion of the cylindrical roller. As a result, the grease can be sufficiently held by the annular recess while ensuring the load capacity of the bearing.

A cylindrical roller bearing device according to the present invention is a cylindrical roller bearing device in which a cylindrical roller bearing interposed between inner and outer ring raceway surfaces and lubricated with grease is press-fitted into an inner diameter surface of a housing. An annular recess is provided on the outer diameter surface of the cylindrical roller along the entire circumference, and a slit is formed in the outer ring so as to pass through in the radial direction and open at a position where the recess passes, and the housing extends in the circumferential direction. A circumferential groove communicating with the slit is provided, and the slit and the circumferential groove are filled with grease.
According to this configuration, the initial sealed grease is sealed in the cylindrical roller bearing, and the grease is filled from the circumferential groove of the housing to the slit of the outer ring. Grease base oil can be supplied to the concave portion of the radial surface. Therefore, the lubricating performance is further improved as compared with the cylindrical roller bearing according to the present invention. Thereby, the lubricating oil can be sufficiently spread over the rolling surface of the cylindrical roller, and the life of the cylindrical roller bearing can be extended.

Another cylindrical roller bearing device of the present invention is a cylindrical roller bearing device in which a cylindrical roller is interposed between raceways of an inner ring and an outer ring, and a cylindrical roller bearing that is lubricated with grease is press-fitted into an inner diameter surface of a housing. A slit that penetrates the outer ring in the radial direction and opens at a passing position of the chamfered portion of the cylindrical roller, and a circumferential groove that extends in the circumferential direction and communicates with the slit is provided in the housing, The slit and the circumferential groove are filled with grease.
Even in this configuration, the base oil of grease can be supplied to the chamfered portion of the cylindrical roller from the circumferential groove of the housing through the slit of the outer ring by capillary action, so that the lubricating oil can be sufficiently distributed to the rolling surface of the cylindrical roller. Therefore, the life of the cylindrical roller bearing can be extended.

In the cylindrical roller bearing device according to each of the above configurations of the present invention, the slit is formed on one of the two width surfaces facing each other obtained by dividing the outer ring by a plane perpendicular to the axis. It is good also as what consists of a clearance gap comprised by an uneven | corrugated | grooved part and the other width surface.
In the case of this configuration, the slit can be easily processed as compared with the case where the slit is processed by making a cut directly in the outer ring.

In the cylindrical roller bearing device according to the present invention, instead of providing the slit in the outer ring, the slit is provided in a part different from the outer ring, and the outer ring is obtained by dividing the outer ring by a plane perpendicular to the axis. The separate part may be sandwiched between two width surfaces.
In this way, when a slit is provided in a separate part from the outer ring and this separate part is sandwiched between two width surfaces obtained by dividing the outer ring, when the slit is machined by directly cutting the outer ring In comparison, the slit can be easily processed.

In the case of each of the configurations in the present invention, it is desirable that the width of the slit is 0.05 to 0.1 mm.
In order to supply the base oil of grease from the circumferential groove of the housing through the slit of the outer ring to the cylindrical roller by capillary action, the width dimension of the slit of the outer ring is preferably set to about 0.05 to 0.1 mm. If the width dimension of the slit is larger than 0.1 mm, the pressure inside the grease reservoir is difficult to increase and the force for pushing out the oil becomes weak. Conversely, if the width dimension of the slit is small, processing is difficult, and 0.05 mm is the limit when forming the slit by wire cutting.

  In the cylindrical roller bearing device according to each of the above-described configurations of the present invention, a plurality of the slits are provided separately in the circumferential direction of the outer ring, and the circle is provided in the housing at the same phase as the slits in the circumferential direction. You may provide the some housing side slit which makes a surrounding groove communicate with each said slit. In the case of this configuration, the lubricating oil can be evenly distributed to all the cylindrical rollers.

In this invention, the total angle that the plurality of slits occupy in the circumferential direction of the outer ring may be 180 to 340 °.
In the case of this configuration, the lubricating oil can be evenly distributed to all the cylindrical rollers, and the strength of the outer ring can be sufficiently secured.

The cylindrical roller bearing according to the present invention is a cylindrical roller bearing in which a cylindrical roller is interposed between the raceway surfaces of the inner ring and the outer ring, and lubrication is performed with grease. Therefore, the lubricating oil can be sufficiently spread over the rolling surface of the cylindrical roller, and the life of the bearing can be extended. Further, since the width of the recess is 15 to 25% of the length of the straight portion of the outer diameter surface of the cylindrical roller, grease can be held by the annular recess while ensuring the load capacity of the bearing.
The cylindrical roller bearing device of the present invention is a cylindrical roller bearing device in which a cylindrical roller is interposed between raceway surfaces of an inner ring and an outer ring, and a cylindrical roller bearing that is lubricated with grease is press-fitted into an inner diameter surface of a housing. An annular recess is provided on the outer diameter surface of the cylindrical roller along the entire circumference, and a slit is formed in the outer ring so as to pass through in the radial direction and open at a position where the recess passes. The slit extends in the circumferential direction of the housing. Since the circumferential groove communicated with is provided and grease is filled in the slit and the circumferential groove, the lubricating oil can be sufficiently distributed to the rolling surface of the cylindrical roller, and the life of the bearing can be extended.
Another cylindrical roller bearing device according to the present invention is a cylindrical roller bearing device in which a cylindrical roller is interposed between raceway surfaces of an inner ring and an outer ring, and a cylindrical roller bearing that is lubricated with grease is press-fitted into an inner diameter surface of a housing. The outer ring is provided with a slit that penetrates in the radial direction and opens at a passing position of the chamfered portion of the cylindrical roller, and the housing is provided with a circumferential groove that extends in the circumferential direction and communicates with the slit. Since the circumferential groove is filled with grease, the lubricating oil can be sufficiently distributed to the rolling surface of the cylindrical roller, and the life of the bearing can be extended.

  A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a half sectional view of a double row cylindrical roller bearing of this embodiment. This cylindrical roller bearing 1 has two rows of cylindrical rollers 4 interposed between a raceway surface 2 a formed on the outer periphery of the inner ring 2 and a raceway surface 3 a formed on the inner periphery of the outer ring 3. Then, lubrication is performed with grease. Each row of cylindrical rollers 4 is held by a cage 5. Here, a case is shown in which the inner ring 2 is a rotating raceway and the outer ring 3 is a stationary raceway.

  The cylindrical roller 4 is made of bearing steel or ceramic, and an annular recess 4a is provided at the center in the axial direction on the outer diameter surface serving as a rolling surface. The recess 4a is a space for holding the grease, and in order to hold the grease sufficiently, the width dimension (length in the axial direction) should be long. However, there is a limitation in securing the rolling surface. is there. When the concave portion 4a is narrower than 15% of the length of the straight portion of the cylindrical roller 4, the grease holding ability is insufficient. On the other hand, if the concave portion 4a is wider than 15% of the length of the straight portion, the load capacity of the bearing is insufficient. Note that the load capacity was insufficient when the load capacity decreased to 20% or less. Therefore, the width dimension of the recess 4a is desirably 15 to 25% of the length of the straight portion of the cylindrical roller 4. The straight portion length is the axial length of the straight portion that is a portion of the cylindrical surface parallel to the roller axis on the outer diameter surface of the cylindrical roller. For example, when the cylindrical roller 4 has an axial length of 11 mm and the straight portion length is 50% of the roller axial length, the straight portion length is 5.5 mm. Therefore, the width dimension of the concave portion 4a is 0. 825 mm (15%) to 1.375 mm (25%) is desirable.

According to the cylindrical roller bearing 1 having this configuration, since the annular recess 4a is provided on the outer diameter surface of the cylindrical roller 4 along the entire circumference, similarly to the conventional example shown in FIG. In addition to the grease being held at each part (denoted by symbols a, b, c) as in the case of FIG. 9, the grease is also held at the recess 4 a of the cylindrical roller 4. Thereby, not only the space for holding the grease increases, but also the grease can be held in the vicinity of the rolling surface of the cylindrical roller 4 where lubrication was difficult to reach in the conventional example.
In other words, the initial sealed grease moves to the stationary space by the running-in operation, but the concave portion 4a becomes a stationary space. Therefore, even if the cylindrical roller 4 rotates and revolves, the grease is not stepped on and discharged. The grease accumulated in the recess 4a is actually adhered to the raceway surface 3a of the outer ring 3 that is a stationary raceway. Therefore, grease is held near the rolling surface of the cylindrical roller 4 and can contribute to lubrication. As a result, the lubricating oil can be sufficiently spread over the rolling surface of the cylindrical roller 4 and the life of the cylindrical roller bearing 1 can be extended.

  Although it is conceivable to provide the inner ring 2 and the outer ring 3 with a recess similar to the recess 4a of the cylindrical roller 4, in the case of the inner ring 2 that is the rotating raceway, it is difficult to hold the grease because centrifugal force acts. . In addition, if the outer ring 3 that is the fixed-side raceway is provided with a recess, it is possible to retain the grease, but the grease base oil must move over the recess so that it can be used in a horizontal axis position. Cannot be expected.

  2 and 3 show another embodiment of the present invention. FIG. 2 is a front sectional view of an example of a spindle device for a machine tool using the cylindrical roller bearing device of this embodiment. In the spindle device 24 for machine tools, a tool or workpiece chuck is attached to the front side end portion (left side in the figure) of the main shaft 25. The front side of the main shaft 25 is supported by a double row cylindrical roller bearing 1A. In the double-row cylindrical roller bearing 1A, the same reference numerals are given to constituent members having the same functions as those of the cylindrical roller bearing 1 of the embodiment shown in FIG.

  The cylindrical roller bearing 1A in this case has the same configuration as that of the embodiment of FIG. 1 except for the outer ring 3, and two rows of cylindrical rollers 4 include the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3. The cylindrical rollers 4 in each row are held by cages 5 respectively. An annular recess 4a is provided at the central position in the axial direction on the outer diameter surface serving as the rolling surface of the cylindrical roller 4. In particular, in this cylindrical roller bearing 1A, the outer ring 3 is provided with two rows of slits 6 penetrating in the radial direction and opening at the passage positions of the recesses 4a of the respective rows of cylindrical rollers 4. In this case, the slit 6 is formed by cutting the outer ring 3 in the radial direction. A plurality of slits 6 in each row are provided separately in the circumferential direction of the outer ring 3. The width dimension (axial length) of the slit 6 of the outer ring 3 is set to about 0.05 to 01 mm (50 to 100 μm).

  The inner ring 2 of the cylindrical roller bearing 1A is press-fitted to the outer diameter surface of the main shaft 25, and the outer ring 3 is press-fitted to the inner diameter surface of the housing 26. The inner ring 2 is positioned in the axial direction by being sandwiched between a bearing fixing nut 27 and an inner ring spacer 28 screwed onto the main shaft 25. The outer ring 3 is positioned in the axial direction by being sandwiched between an outer ring retainer 29 provided at the end of the housing 26 and a stepped portion 26 a on the inner diameter surface of the housing 26. The housing 26 has a double structure including an inner peripheral housing 26A and an outer peripheral housing 26B.

  On the outer periphery of the inner peripheral housing 26A, circumferential grooves 7 extending in the circumferential direction are provided at axial positions corresponding to the two rows of slits 6 of the outer ring 3 in the cylindrical roller bearing 1A. The cylindrical groove 7 is a space that serves as a grease reservoir. Further, the inner peripheral housing 26 </ b> A has a plurality of housing-side slits 8 communicating the respective circumferential grooves 7 with the corresponding rows of slits 6 of the outer ring 3, and the slits of the outer ring 3 in the circumferential direction of the housing 26. 6 is provided at the same phase as that of FIG. FIG. 3 shows a positional relationship in the circumferential direction of the slit 6, the housing side slit 8, and the circumferential groove 7 of the outer ring 3 as a cross-sectional view taken along the line AA in FIG. The circumferential groove 7 has an annular shape that extends around the entire circumference. Here, the number of slits 6 and housing side slits 8 of the outer ring 3 in each row is six, but the number is not particularly defined.

  The initially filled grease is sealed in the cylindrical roller bearing 1A in a normal manner, and the slit 6, the housing side slit 8, and the circumferential groove 7 of the outer ring 3 are filled with grease. A hatched portion in FIG. 3 indicates a portion filled with grease.

  In the cylindrical roller bearing device having the above-described configuration, when a heat cycle in which the temperature rises and falls in the circumferential groove 7 serving as the grease reservoir portion acts, the base oil of the grease is caused to change by pressure fluctuation due to the temperature rise in the circumferential groove 7. 3 is extruded from the slit 6. As a result, the base oil of the grease filled in the circumferential groove 7, the housing-side slit 8, and the slit 6 of the outer ring 3 and the initial sealed grease in the cylindrical roller bearing 1A are connected, and the base is caused by the capillary action of the thickener. Oil flows into the recess 4 a of the cylindrical roller 4. Since the width dimension of the slit 6 of the outer ring 3 is set to about 50 to 100 μm, the capillary action can be applied. When the width dimension of the slit 6 is larger than 0.1 mm (100 μm), the pressure inside the grease reservoir is difficult to increase and the force for pushing out the oil becomes weak. Conversely, when the width dimension of the slit 6 is small, processing is difficult, and when the slit 6 is formed by wire cutting, 0.05 mm (50 μm) is the limit.

  Thus, according to this cylindrical roller bearing device, the base oil of grease passes from the circumferential groove 7 of the housing 26 through the housing side slit 8 and the slit 6 of the outer ring 3 to the concave portion 4a of the outer diameter surface of the cylindrical roller 4 by capillary action. Therefore, the lubricating performance is further improved as compared with the case of the cylindrical roller bearing 1 of the embodiment shown in FIG. Thereby, lubricating oil can fully be spread over the rolling surface of the cylindrical roller 4, and the life of the cylindrical roller bearing 1A can be extended.

  In this embodiment, there are six slits 6 in the outer ring 3 in each row. However, the slit 6 occupies the circumferential direction of the outer ring 3 so that the base oil of the grease can be sufficiently supplied to the recess 4a of the cylindrical roller 4. The total angle is preferably 180 to 340 °. The remaining portion of the outer ring 3 where the circumferential slit 6 is not positioned is placed at an even position so that the base oil of grease spreads evenly over the recess 4a of the cylindrical roller 4 over the entire circumference. It is desirable to do.

  As described above, the slit 6 of the outer ring 3 is formed by cutting the outer ring 3 in the radial direction, and the outer ring 2 is perpendicular to the axis thereof as shown in FIG. You may form by dividing | segmenting on a plane. That is, of the two width surfaces 3b and 3b facing each other obtained by dividing the outer ring 3 by a plane perpendicular to the axis, the uneven portions 3ba and 3bb formed on one width surface and the other width surface 3b. It is good also considering the clearance gap comprised by these as the slit 6. FIG. In this case, the outer ring 3 is divided into three parts in order to form the slits 6 for two rows. The concavo-convex portions 3ba and 3bb are formed so as to extend in the radial direction, and the concave portions 3ba and the convex portions 3bb are arranged in the circumferential direction at substantially equal intervals. Since the gap between the concave and convex portions 3ba and 3bb is the width of the slit 6, it is desirable to manage the gap between 50 and 100 μm. Thus, when the outer ring 3 is divided to form the slit 6, the slit 6 can be processed more easily than when the slit 6 is processed by cutting directly into the outer ring 3.

  In addition, as shown in FIGS. 5 and 6, the slit 6 is provided in a component 9 separate from the outer ring 3, and the separate parts are formed by the two width surfaces 3b and 3b of the outer ring 3 obtained by dividing as described above. 9 may be sandwiched. That is, in this case, an unevenness is applied to each width surface 3b so that, for example, a T-shaped gap with an outer diameter side end serving as a widened portion is formed between the two width surfaces 3b, 3b of the outer ring 3 facing each other. . Further, as shown in FIG. 6, the separate part 9 is processed into a shape having a T-shaped cross section having a flange portion 9 a at the outer diameter side end and a slit 6 penetrating in the radial direction at the center thereof. Is inserted into a gap having a T-shaped cross section between the two width surfaces 3, 3b of the outer ring 3. As the material of the separate part 9, it is preferable from the viewpoint of processing the slit 6 to use a material that is relatively easy to process, such as gun metal. Also in this case, it is desirable that the width dimension of the slit 6 is 50 to 100 μm.

  As described above, when the slit 6 is provided in the separate part 9 from the outer ring 3 and the separate part 9 is sandwiched between the two width surfaces 3 b and 3 b obtained by dividing the outer ring 3, the slit is directly cut into the outer ring 3. The slit 6 can be processed more easily than when the slit 6 is processed by inserting

  FIG. 7 shows still another embodiment of the present invention. In this embodiment, in the cylindrical roller bearing device shown in FIGS. 2 and 3, the slit 6 of the outer ring 3 of the cylindrical roller bearing 1 </ b> A is disposed so as to open at a passing position of the chamfered portion 4 b of the cylindrical roller 4. . In this embodiment, the concave portion 4a on the outer diameter surface of the cylindrical roller 4 is omitted. Other configurations are the same as those of the cylindrical roller bearing device shown in FIGS. 2 and 3, and initial grease is sealed in the cylindrical roller bearing 1 </ b> A in the same manner as usual, and the circumferential groove 7, the housing side slit 8, The slit 6 of the outer ring 3 is also filled with grease. The width dimension of the slit 6 of the outer ring 3 is desirably about 50 to 100 μm, as in the case of the embodiment of FIGS. In addition, the BB arrow sectional drawing in FIG. 7 becomes substantially the same as the case of FIG.

  Also in this embodiment, since the grease base oil can be supplied from the circumferential groove 7 of the housing 26 to the chamfered portion 4b of the cylindrical roller 4 by the capillary phenomenon through the housing side slit 8 and the slit 6 of the outer ring 3, the cylindrical roller 4 Thus, the lubricating oil can be sufficiently spread over the rolling surface, and the life of the cylindrical roller bearing 1A can be extended.

  In this embodiment, two rows of slits 6 are provided so that the slits 6 are opened at the passing position of one chamfered portion 4b of each cylindrical roller 4. However, the passage of both chamfered portions 4b of each cylindrical roller 4 is provided. Four rows of slits 6 may be provided so that the slits 6 are opened at positions. The slit 6 of the outer ring 3 may be configured by forming the uneven portions 3ba and 3bb on one of the two width surfaces 3b obtained by dividing the outer ring 3 as shown in FIG. In this case, if four rows of slits 6 are provided, the outer ring 3 is divided into five.

  FIG. 8 shows still another embodiment of the present invention. In this embodiment, in the cylindrical roller bearing device shown in FIG. 7, a concave portion 4a similar to that in the embodiment of FIG. 1 is provided on the outer diameter surface of the cylindrical roller 4 of the cylindrical roller bearing 1A. Other configurations are the same as those in the embodiment of FIG. In addition, CC sectional drawing in FIG. 8 becomes substantially the same as the case of FIG.

  In the case of this embodiment, the base oil of grease can be supplied from the circumferential groove 7 of the housing 26 to the chamfered portion 4b of the cylindrical roller 4 by capillary action through the housing side slit 8 and the slit 6 of the outer ring 3, and the cylindrical roller 4 Since the grease is also retained in the recess 4a, the lubricating oil can be sufficiently spread over the rolling surface of the cylindrical roller 4, and the life of the cylindrical roller bearing 1A can be extended.

1 is a half sectional view of a cylindrical roller bearing according to a first embodiment of the present invention. It is a fragmentary sectional view of the spindle apparatus for machine tools provided with the cylindrical roller bearing apparatus concerning other embodiment of this invention. It is AA arrow sectional drawing in FIG. It is an expanded view which shows the other structural example of the outer ring slit in the cylindrical roller bearing device. It is sectional drawing which shows the further another structural example of the outer ring | wheel slit in the cylindrical roller bearing apparatus. (A) is a perspective view of another part which has the outer ring | wheel slit, (B) is ZZ arrow sectional drawing in (A). It is a fragmentary sectional view of the spindle apparatus for machine tools provided with the cylindrical roller bearing apparatus concerning further another embodiment of this invention. It is a fragmentary sectional view of the spindle apparatus for machine tools provided with the cylindrical roller bearing apparatus concerning further another embodiment of this invention. It is half sectional drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A ... Cylindrical roller bearing 2 ... Inner ring 2a ... Race surface 3 ... Outer ring 3a ... Race surface 3b ... Width surface 3ba, 3bb ... Uneven portion 4 ... Cylindrical roller 4a ... Recess 4b ... Chamfer 6 ... Outer ring slit 7 ... Circumference Groove 8 ... Housing side slit 9 ... Separate part 26 ... Housing

Claims (8)

  In a cylindrical roller bearing in which a cylindrical roller is interposed between the raceway surfaces of the inner ring and the outer ring and lubricated with grease, an annular recess is provided on the outer diameter surface of the cylindrical roller along the entire circumference, and the width dimension of the recess is A cylindrical roller bearing characterized by being 15 to 25% of the length of the straight portion of the outer diameter surface of the cylindrical roller. In a cylindrical roller bearing device in which a cylindrical roller bearing, in which a cylindrical roller is interposed between the raceway surfaces of the inner ring and the outer ring and lubricated with grease, is press-fitted into the inner diameter surface of the housing,
An annular recess is provided on the outer diameter surface of the cylindrical roller, and the outer ring is provided with a slit that penetrates in the radial direction and opens at a position where the recess passes, and the housing extends in the circumferential direction. A cylindrical roller bearing device, characterized in that a circumferential groove communicating with the slit is provided, and grease is filled in the slit and the circumferential groove. In a cylindrical roller bearing device in which a cylindrical roller bearing, in which a cylindrical roller is interposed between the raceway surfaces of the inner ring and the outer ring and lubricated with grease, is press-fitted into the inner diameter surface of the housing,
The outer ring is provided with a slit that penetrates in the radial direction and opens at a passing position of the chamfered portion of the cylindrical roller, and the housing is provided with a circumferential groove that extends in the circumferential direction and communicates with the slit. A cylindrical roller bearing device characterized in that a circumferential groove is filled with grease.   In claim 2 or claim 3, the slit is an uneven portion formed on one of the two width surfaces facing each other obtained by dividing the outer ring by a plane perpendicular to the axis, A cylindrical roller bearing device comprising a gap formed by being sandwiched between the other width surface.   4. The slits according to claim 2, wherein the slits are provided in a part different from the outer ring, instead of being provided in the outer ring, and are opposed to each other obtained by dividing the outer ring by a plane perpendicular to the axis. A cylindrical roller bearing device in which the separate part is sandwiched between two width surfaces.   6. The cylindrical roller bearing device according to claim 2, wherein the slit has a width of 0.05 to 0.1 mm.   7. The slit according to claim 2, wherein a plurality of the slits are provided separately in a circumferential direction of the outer ring, and the housing has the same phase as the slits in the circumferential direction. A cylindrical roller bearing device provided with a plurality of housing-side slits that allow circumferential grooves to communicate with the respective slits.   The cylindrical roller bearing device according to claim 7, wherein a total angle occupied by the plurality of slits in a circumferential direction of the outer ring is 180 to 340 °.

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