JP2009138897A - Rolling bearing and its lubrication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing capable of lengthening the service life, while attaining a high speed by improving lubricity. <P>SOLUTION: This rolling bearing 1 has an outer ring 3 forming a raceway surface 3a on an inner diameter surface, a plurality of rolling elements 4 rollingly contacting with the raceway surface 3a of this outer ring 3, and a cage 5 holding the plurality of these rolling elements 4 in a pocket 10. The cage 5 oppositely guide a guide object surface 5a being a part of its outer diameter surface to a guide surface 3b being part of the outer diameter surface of the outer ring 3. A tapered surface 5b being a large diameter on the central side in the axial direction is formed on the outer diameter surface of the cage 5. A lubricating oil sticking means 8 is arranged for sticking lubricating oil to the tapered surface 5b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing used for supporting a main shaft or the like of a machine tool, and a lubricating device thereof.

  Bearings used for machine tool spindles require high rotational accuracy and rigidity. In recent years, the spindle has been increased in speed in order to improve machining efficiency, and high-speed compatibility is required for the bearing. In response to such a demand, a cylindrical roller bearing using a cylindrical roller as a rolling element is used by reducing the internal clearance of the bearing after incorporation to a value almost close to zero. As a lubrication method for operating a cylindrical roller bearing at a high speed, a small amount of oil lubrication with oil mist or air oil that can suppress power loss during operation is often used.

In air oil lubrication, which is a typical lubrication method suitable for high-speed operation, a technique as disclosed in, for example, Patent Document 1 is generally employed. This technique is applied to an N-type cylindrical roller bearing having a flange portion for guiding the cylindrical roller on both axial sides of the inner ring outer diameter surface, and is an outer ring guide system in which the cage is guided to the inner diameter surface of the outer ring. The N-type cylindrical roller bearing is often used as a bearing for a machine tool main spindle because of its good workability. In Patent Document 1, by adopting an outer ring guide system for the cage, a relatively wide clearance can be secured between the inner diameter surface of the cage and the outer diameter surface of the inner ring collar portion. By injecting air oil from the lubricating oil inlet hole provided at the end of the direction, the lubricating oil is introduced into the bearing, and the centrifugal force accompanying the rotation is used to smoothly lubricate the raceway surface and the guide surface of the cage. It is described that.
JP 2002-323048 A

In order to operate the cylindrical roller bearing at a high speed, it is a problem to reliably supply the lubricating oil to a place where the lubricating oil is required. The following parts are specifically mentioned as places where the lubricating oil supply is necessary.
・ Between raceway surface of inner and outer rings and rolling surface of cylindrical roller ・ Between side surface of inner ring collar and end surface of cylindrical roller ・ Between pocket wall surface of cage and rolling surface of cylindrical roller ・ Cage guide surface of inner and outer rings Between guided surfaces of cage

  With respect to the above-described problem, Patent Document 1 describes that smooth lubrication can be performed using centrifugal force due to rotation of a bearing by supplying oil from the inner diameter side of the cage as an outer ring guide system. However, if lubrication is performed only from one axial side, lubrication oil is supplied between the raceway surface of the inner and outer rings and the rolling surface of the cylindrical roller, and between the inner ring collar and the end surface of the cylindrical roller opposite to the side where the lubricating oil introduction hole is provided. Is difficult.

Further, in the conventional general air oil lubrication, a lubricating oil introducing member having a lubricating oil introducing hole is disposed on the end face side of the bearing. When a bearing that performs forced lubrication such as air-oil lubrication is incorporated in the main spindle device, the bearing from the center of the bearing to the shaft end of the main spindle is equivalent to the amount of the lubricating oil introduction member, as compared to the case of incorporating a bearing that does not perform forced lubrication. The distance gets longer. This is disadvantageous when considering the rigidity of the spindle during machining.
The above problems and problems can be applied not only to the cylindrical roller bearing but also to other rolling bearings.

An object of the present invention is to provide a rolling bearing capable of improving lubricity and increasing the speed and life.
Another object of the present invention is to make it possible to shorten the distance from the bearing center to the shaft end of the main shaft when incorporated in the main shaft device.
Still another object of the present invention is to provide a method of lubricating a rolling bearing capable of improving lubricity and increasing the speed and life.

A rolling bearing according to the present invention includes an outer ring having a raceway surface formed on an inner diameter surface, a plurality of rolling elements that are in rolling contact with the raceway surface of the outer ring, and a cage that holds the plurality of rolling elements in a pocket, The cage is guided such that a guided surface that is a part of the outer diameter surface thereof is opposed to a guide surface that is a part of the inner diameter surface of the outer ring, and the cage is pivoted on the outer diameter surface of the cage. A taper surface having a large diameter at the center in the direction is formed, and lubricating oil adhering means for adhering lubricating oil to the taper surface is provided.
According to this configuration, when the lubricating oil adheres to the tapered surface of the cage by the lubricating oil adhesion means, the lubricating oil remains in the adhered state due to the surface tension and the centrifugal force accompanying the rotation of the cage. Move to the larger diameter side. Part of the lubricating oil that has reached the periphery of the pocket that accommodates and holds the rolling element moves to the wall surface of the pocket and lubricates between the wall surface of the pocket and the surface of the rolling element. Further, the lubricating oil that moves to the large diameter side through the pillar portion between the pockets moves to the maximum diameter portion of the tapered surface as it is, and is scattered in the outer diameter direction by centrifugal force. The lubricating oil scattered in the outer diameter direction is received by the raceway surface of the outer ring and used for lubrication between the raceway surface of the outer ring and the surface of the rolling element. Further, due to the rotation of the rolling element, the lubricating oil on the wall surface of the pocket and the lubricating oil on the raceway surface of the outer ring move toward the inner ring side, and lubricates between the raceway surface of the inner ring and the surface of the rolling element. Thereby, each part of a bearing can be lubricated with sufficient balance, and high speed and long life of the bearing can be achieved.

The lubricating oil adhering means is provided with a lubricating oil introduction hole for communicating the inner diameter side and the outer diameter side in the outer ring, and through this lubricating oil introduction hole, the lubricating oil supplied from the outside is directed toward the tapered surface of the cage. And can be jetted.
By injecting the lubricating oil toward the tapered surface of the cage through the lubricating oil introduction hole, the lubricating oil can be efficiently attached to the tapered surface. Since the lubricating oil introduction hole is provided in the outer ring, it is not necessary to provide another member for introducing lubricating oil on the end face side of the bearing. Therefore, the lubrication structure can be simplified, and the distance from the bearing center to the shaft end of the main shaft when incorporated in the main shaft device can be shortened.

The lubricating oil adhering means is provided with a lubricating oil introduction hole that communicates an inner diameter side and an outer diameter side in the outer ring, and the lubricating oil supplied from the outside is introduced into the lubricating oil introduction hole by capillary action. It is good also as what provided the particulate or fibrous core material induced | guided | derived to a taper surface.
Even in this configuration, the lubricating oil supplied from the outside can be stably attached to the tapered surface of the cage. In addition, the lubrication structure can be simplified, and the distance from the bearing center to the shaft end of the main shaft when incorporated in the main shaft device can be shortened. Further, in the case of this configuration, since the lubricating oil is not injected, the eccentric load due to the injection does not act on the cage.

In this invention, the rolling element can be a roller.
Although the present invention can be applied to any type of rolling bearing, the effect of the invention appears more significantly when the rolling element is a roller than when it is a ball. This is because the bearings in which the rolling elements are rollers tend to be structurally difficult for lubricating oil supplied from the outside to enter the raceway surface.

When the rolling element is a cylindrical roller, the guide surface of the outer ring is formed on both sides in the axial direction of the outer ring raceway surface, and the tapered surface of the cage is formed on the center side in the axial direction from the guided surface. The axial position of the inner diameter side opening of the lubricating oil introduction hole is preferably between the outer ring raceway surface and the guide surface.
If the guide surface of the outer ring and the guided surface of the cage are formed on both sides of the cylindrical roller in the axial direction, the cage is guided by the outer ring on both sides of the cylindrical roller in the axial direction, so that the cage can be guided accurately and reliably. Become. Further, if the tapered surface of the cage is formed on the axial center side with respect to the guided surface, and the axial position of the inner diameter side opening of the lubricating oil introduction hole is on the axial center side with respect to the outer ring guide surface, the outer ring The lubricating oil introduction hole can be provided without interfering with the guide surface and the guided surface of the cage.

Further, when the rolling element is a ball that contacts the outer ring raceway surface with a contact angle, the outer ring guide surface is formed on the bearing back side of the outer ring raceway surface, and the tapered surface of the cage is formed. Preferably, it is formed on the front side of the bearing with respect to the center of the pocket, and the axial position of the inner diameter side opening of the lubricating oil introduction hole is on the front side of the bearing with respect to the outer ring raceway surface.
Bearings whose rolling elements are in contact with the outer ring raceway surface with a contact angle, that is, angular contact ball bearings, the inner ring surface of the outer ring has a smaller diameter on the bearing back side and a larger diameter on the bearing front side than the raceway surface. . The guide surface of the outer ring and the guided surface of the cage are formed on the bearing back side of the ball whose outer ring has a small diameter, and the outer ring has a large diameter at the position of the tapered surface of the cage and the inner diameter side opening of the lubricating oil introduction hole. By making the bearing front side from the center of the ball, the overall balance is good and the cage can be made a simple shape.

The angle α (deg) of the tapered surface is obtained when the pitch circle diameter of the rolling element array is dm (mm) and the bearing rotational speed is n (min ⁻¹ ).
α> 0.024 × dm × n × 10 ⁻⁴ −2.2
It is better to set so that
In order to guide the lubricating oil adhering to the tapered surface of the cage to the raceway surface of the outer ring, it is necessary to reliably move to the maximum diameter portion of the tapered surface with the lubricating oil adhered. For this purpose, it was found from the test results that the above relationship should be satisfied with respect to the angle of the tapered surface of the cage.

The rolling bearing lubrication method of the present invention includes an outer ring having a raceway surface formed on an inner diameter surface, a plurality of rolling elements that are in rolling contact with the raceway surface of the outer ring, and a cage that holds the plurality of rolling elements in a pocket. The retainer is guided so that a guided surface which is a part of an outer diameter surface thereof is opposed to a guide surface which is a part of an inner diameter surface of the outer ring, and the outer diameter of the retainer A rolling bearing lubrication method in which a tapered surface having a large diameter on the axial center side is formed on the surface, and the lubricating oil supplied from the outside is attached to the tapered surface of the cage to maintain the surface tension of the lubricating oil. After the lubricating oil is moved to the axial center side of the taper surface by centrifugal force accompanying the rotation of the device, it is scattered in the outer diameter direction at the large diameter end of the taper surface to introduce the lubricating oil into the bearing. Features.
When the lubricating oil supplied from the outside adheres to the tapered surface of the cage, the lubricating oil moves to the larger diameter side of the tapered surface with the adhered state due to the surface tension and the centrifugal force accompanying the rotation of the cage. Part of the lubricating oil that has reached the periphery of the pocket that accommodates and holds the rolling element moves to the wall surface of the pocket and lubricates between the wall surface of the pocket and the surface of the rolling element. Further, the lubricating oil that moves to the large diameter side through the pillar portion between the pockets moves to the maximum diameter portion of the tapered surface as it is, and is scattered in the outer diameter direction by centrifugal force. The lubricating oil scattered in the outer diameter direction is received by the raceway surface of the outer ring and used for lubrication between the raceway surface of the outer ring and the surface of the rolling element. Further, due to the rotation of the rolling element, the lubricating oil on the wall surface of the pocket and the lubricating oil on the raceway surface of the outer ring move toward the inner ring side, and lubricates between the raceway surface of the inner ring and the surface of the rolling element. Thereby, each part of a bearing can be lubricated with sufficient balance, and high speed and long life of the bearing can be achieved.

  A rolling bearing according to the present invention includes an outer ring having a raceway surface formed on an inner diameter surface, a plurality of rolling elements that are in rolling contact with the raceway surface of the outer ring, and a cage that holds the plurality of rolling elements in a pocket, The cage is guided such that a guided surface that is a part of the outer diameter surface thereof is opposed to a guide surface that is a part of the inner diameter surface of the outer ring, and the Since a tapered surface having a large diameter at the center in the direction is formed and lubricating oil adhering means for adhering lubricating oil to the tapered surface is provided, the lubricity can be improved, and the speed and life can be increased.

  When the lubricating oil adhering means is a lubricating oil introduction hole provided in the outer ring, the distance from the bearing center to the shaft end of the main shaft when incorporated in the main shaft device can be shortened.

  The rolling bearing lubrication method of the present invention includes an outer ring having a raceway surface formed on an inner diameter surface, a plurality of rolling elements that are in rolling contact with the raceway surface of the outer ring, and a cage that holds the plurality of rolling elements in a pocket. The retainer is guided so that a guided surface which is a part of an outer diameter surface thereof is opposed to a guide surface which is a part of an inner diameter surface of the outer ring, and the outer diameter of the retainer A rolling bearing lubrication method in which a tapered surface having a large diameter on the axial center side is formed on the surface, and the lubricating oil supplied from the outside is attached to the tapered surface of the cage to maintain the surface tension of the lubricating oil. In order to introduce the lubricating oil inside the bearing by moving the lubricating oil to the axial center side of the tapered surface by the centrifugal force accompanying the rotation of the vessel, and then splashing in the outer diameter direction at the large diameter end of the tapered surface. The lubricity is improved to increase the speed and life.

  A first embodiment of the present invention will be described with reference to FIGS. The rolling bearing 1 is a cylindrical roller bearing, and includes an inner ring 2, an outer ring 3, a plurality of cylindrical rollers 4 as rolling elements interposed between the raceway surfaces 2a and 3a of the inner and outer rings 2 and 3, and each cylindrical roller. 4 and an annular cage 5 that holds 4. The inner ring 2 has a flange portion 6 projecting to the outer diameter side on both sides of the raceway surface 2a, and the outer ring 3 has no collar. A shaft (not shown) is inserted into the inner periphery of the inner ring 2, and the outer periphery of the outer ring 3 is inserted and fixed to the inner periphery of the bearing box 31.

  The inner surface of the outer ring 3 is cylindrical, and the raceway surface 3a is formed at the center in the axial direction, and guide surfaces 3b for guiding the cage 5 are formed at both sides in the axial direction. Circumferential relief grooves 7 are formed at the boundary between the raceway surface 3a and the guide surfaces 3b on both sides, and a lubricating oil introduction hole 8 having an inner diameter side opening located at the groove bottom of the relief groove 7 is formed in the outer ring 3. Is provided. The lubricating oil introduction hole 8 is lubricating oil adhering means for adhering lubricating oil to a tapered surface 5b of the cage 5 described later, and functions as a nozzle for injecting lubricating oil. In this embodiment, the lubricating oil introduction hole 8 is provided straight in the radial direction, but the lubricating oil introduction hole 8 may have other shapes. It is desirable to provide the lubricating oil introduction holes 8 at a plurality of positions in the circumferential direction at equal positions. An air oil inlet 13 is provided on the inner diameter surface of the bearing box 31 corresponding to the position of the lubricating oil inlet 8. An air oil introduction path 14 is connected to the air oil introduction port 13 to send air oil supplied from an air oil supply device provided outside to the air oil introduction port 13 side.

  As shown in FIG. 2, the cage 5 has a plurality of pockets 10 provided at predetermined intervals in the circumferential direction, and the cylindrical rollers 4 are held in the pockets 10. A portion between the pockets 10 is a pillar portion 11. At both ends of the cage 5 in the axial direction, flange-shaped guide portions 12 projecting to the outer diameter side are provided, and the outer diameter surface of the guide portion 12 is a guided surface 5 a corresponding to the guide surface 3 b of the outer ring 3. It is formed as. The guided surface 5a of the cage 5 is opposed to the guide surface 3b of the outer ring 3 with a slight clearance, and the guided surface 5a slides along the guide surface 3b when the outer ring 3 rotates. The cage 5 is guided by the outer ring 3 by contact. That is, the cage 5 has an outer ring guide structure.

The outer diameter surface on the axially central side with respect to the cage guide portion 12 is formed as a tapered surface 5b having a large diameter on the central side. A connecting portion between the side surface 5c on the center side of the guide portion 12 and the tapered surface 5b is a round surface 5d having an arcuate cross section. The angle α (deg) of the tapered surface 5b is determined when the pitch circle diameter of the rolling element array is dm (mm) and the specified rotational speed of the bearing is n (min ⁻¹ ).
α> 0.024 × dm × n × 10 ⁻⁴ −2.2 (Expression 1)
The relationship is established. The reason will be shown later.

A method of lubricating the rolling bearing 1 having this configuration will be described. For the lubrication, air oil is used in which the lubricating oil is conveyed with pressurized air and mixed with the lubricating oil and air. Air oil supplied from the outside is injected from the inner diameter side opening of the lubricating oil introduction hole 8 toward the tapered surface 5 b of the cage 5 through the air oil introduction path 14 and the air oil introduction port 13 of the bearing box 31. Part of the injected air oil flows toward the guide portion 12, and the lubricating oil in the air oil penetrates between the guide portion 3 b of the outer ring 3 and the guided portion 5 a of the cage 5 and lubricates.
Most of the injected air oil goes to the taper surface 5b, and the lubricating oil adheres to the taper surface 5b. Since the cage 5 is rotating, centrifugal force acts on the lubricating oil adhering to the tapered surface 5b. Therefore, as indicated by arrows A and B in FIG. 2, the lubricating oil moves to the larger diameter side of the tapered surface 5 b while remaining attached to the tapered surface 5 b due to the action of surface tension. Formula 1 defines an angle α of the tapered surface 5b that enables the lubricant to move along the tapered surface 5b, and was obtained by testing.

Part of the lubricating oil (arrow A) moving on the tapered surface 5 b reaches the pocket 10 and lubricates between the wall surface 10 a of the pocket 10 and the end surface 4 a of the cylindrical roller 4. Further, it travels along the end surface 4 a of the cylindrical roller 4 to the inner ring 2 side, and lubricates between the side surface 6 a (FIG. 1) of the inner ring collar portion 6 and the end surface 4 a of the cylindrical roller 4.
The lubricating oil (arrow B) that moves through the portion of the column portion 11 on the tapered surface 5b moves to the maximum diameter portion of the tapered surface 5b, and is scattered in the outer diameter direction by centrifugal force. The scattered lubricating oil is received by the raceway surface 3 a of the outer ring 3 and lubricates between the raceway surface 3 a of the outer ring 3 and the rolling surface 4 b of the cylindrical roller 4. Further, the lubricating oil moves from the outer ring 3 to the inner ring 2 by the rotation of the cylindrical roller 4, and the space between the raceway surface 2 a of the inner ring 2 and the rolling surface 4 b of the cylindrical roller 4 is also lubricated.

  Thus, by guiding the lubricating oil supplied from the outside to each part of the bearing, it is possible to reliably supply the lubricating oil to a place where the lubricating oil is required and to lubricate each part of the bearing in a well-balanced manner. For this reason, high-speed operation is possible. In addition, the bearing life can be extended. In addition, since air oil is injected to the taper surface 5b of the retainer 5 through the lubricating oil introduction hole 8, the pressure of the air oil acts as an uneven load. However, if the lubricating oil introduction holes 8 are provided at equidistant positions in a plurality of locations in the circumferential direction, the uneven load is offset and the influence on the bearing can be reduced.

  FIG. 3 shows a modification of the first embodiment. This rolling bearing 1 is provided with a particulate or fibrous core material 16 for guiding lubricating oil from the outside of the bearing to the inside of the bearing by capillary action in the lubricating oil introduction hole 8. The core material 16 has the bearing outer side communicated with an external oil tank, and the bearing inner side is in contact with the tapered surface 5 b of the cage 5. As a material of the core material 16, it is preferable that abrasion resistance is favorable, for example, what twisted carbon fiber etc. is suitable.

  In the rolling bearing 1, the lubricating oil in the external oil tank is guided to the inside of the bearing through the core member 16 and attached to the tapered surface 5 b of the cage 5. Also in this configuration, the lubricating oil supplied from the outside can be stably attached to the tapered surface 5 b of the cage 5. Further, since no lubricating oil is injected, an eccentric load due to the injection does not act on the cage 5. Therefore, the lubricating oil introduction hole 8 and the core material 16 need only be provided at one place in the circumferential direction.

  4 to 5 show a second embodiment of the present invention. The rolling bearing 101 is an angular ball bearing, and includes an inner ring 102, an outer ring 103, a plurality of balls 104 that are rolling elements interposed between the raceway surfaces 102 a and 103 a of the inner and outer rings 102 and 103, and each ball 104. And an annular cage 105 for holding. The balls 104 are in contact with the raceway surfaces 102a and 103a of the inner and outer rings 102 and 103 with a contact angle θ, and the inner ring 102 has a large-diameter portion 106 that protrudes outward from the raceway surface 102a toward the bearing front side. The outer ring 103 has a small-diameter portion 107 that protrudes toward the inner diameter side on the bearing back side with respect to the raceway surface 103a. In addition, the bearing front side is the left direction of FIG. A shaft (not shown) is inserted into the inner periphery of the inner ring 2, and the outer periphery of the outer ring 3 is inserted and fixed to the inner periphery of the bearing box 31.

  An inner diameter surface of the small-diameter portion 107 of the outer ring 103 is formed as a guide surface 103 b that guides the cage 105. A lubricating oil introduction hole 108 is provided on the bearing front side of the raceway surface 103 a of the outer ring 103. The lubricating oil introduction hole 108 is lubricating oil adhesion means, and functions as a nozzle for injecting lubricating oil. In this embodiment, the lubricating oil introduction hole 108 is provided straight in the radial direction, but the lubricating oil introduction hole 108 may have other shapes. The lubricating oil introduction holes 108 are desirably provided at a plurality of positions in the circumferential direction at equal positions. An air oil inlet 13 is provided on the inner diameter surface of the bearing housing 31 in correspondence with the position of the lubricating oil inlet 108. An air oil introduction path 14 is connected to the air oil introduction port 13 to send air oil supplied from an air oil supply device provided outside to the air oil introduction port 13 side.

  As shown in FIG. 5, the cage 105 has a plurality of pockets 110 provided at predetermined intervals in the circumferential direction, and the balls 104 are held in the pockets 110. A portion between the pockets 110 is a column portion 111. A part of the outer diameter surface of the cage 105 is a guided surface 105 a that is opposed to the guide surface 103 b of the outer ring 103 with a slight clearance, and is covered along the guide surface 103 b when the outer ring 103 rotates. The cage 105 is guided by the outer ring 103 by the sliding contact of the guide surface 105a. That is, the cage 105 has an outer ring guide structure.

  On the outer diameter surface of the cage 105, the front side of the bearing is formed as a tapered surface 105b having a larger diameter at the center side than the center of the pocket 110. However, the range of the predetermined width to the bearing front side and the back side across the center of the pocket 110 is a cylindrical surface 105c having the same diameter as the maximum diameter portion of the tapered surface 105b. As in the first embodiment, the angle α (deg) of the tapered surface 102c is set so that the relationship of the above expression 1 holds.

  The lubrication method of the rolling bearing 101 is basically the same as the lubrication method of the rolling bearing 1 of the first embodiment. That is, air oil supplied from the outside is injected from the lubricating oil introduction hole 108 toward the tapered surface 105 b of the cage 105. Then, the lubricating oil adheres to the tapered surface 105b. Since the cage 105 is rotating, centrifugal force acts on the lubricating oil adhering to the tapered surface 105b. By setting the angle α of the taper surface 105b to a value that satisfies the relationship of the above formula 1, the lubricant is attached to the taper surface 105b by the action of surface tension, as indicated by arrows A and B in FIG. It moves to the larger diameter side of the taper surface 105b.

  Part of the lubricating oil (arrow A) that moves on the tapered surface 105 b reaches the pocket 110 and lubricates between the wall surface 110 a of the pocket 110 and the surface of the ball 104. The lubricating oil (arrow B) that moves through the portion of the column portion 111 on the tapered surface 105b moves to the maximum diameter portion of the tapered surface 105b or the cylindrical surface 105c, where it is scattered in the outer diameter direction by centrifugal force. The scattered lubricating oil is received by the raceway surface 103 a of the outer ring 103 and lubricates between the raceway surface 103 a of the outer ring 103 and the surface of the ball 104. Further, the rotation of the ball 104 causes the lubricating oil to move from the outer ring 103 to the inner ring 102, and the space between the raceway surface 102 a of the inner ring 102 and the surface of the ball 104 is also lubricated. Further, the lubricating oil provided for lubrication on the raceway surface 103 a of the outer ring 103 is sent to the bearing back side by the pumping action accompanying the rotation of the ball 104, and the guide surface 103 b of the outer ring 103 and the guided surface 105 b of the cage 105. Lubricate the gap.

  Thus, by guiding the lubricating oil supplied from the outside to each part of the bearing, it is possible to reliably supply the lubricating oil to a place where the lubricating oil is required, and to lubricate each part of the bearing in a well-balanced manner. For this reason, high-speed operation is possible. In addition, the bearing life can be extended. Also in this embodiment, if the lubricating oil introduction holes 108 are provided at a plurality of positions in the circumferential direction at equal positions, the uneven load due to the injection of the air oil is offset and the influence on the bearing can be reduced.

  Also in the rolling bearing 101 of the second embodiment, in the same manner as in the modification of the first embodiment, in the lubricating oil introduction hole 108, a particulate shape that guides the lubricating oil from the outside of the bearing to the inside of the bearing by capillary action. Or it is good also as a structure which provided the fibrous core material. Even in such a case, the lubricant supplied from the outside can be stably attached to the tapered surface 105b of the cage 105.

In 1st Embodiment, the example which applied this invention to the cylindrical roller bearing which is a kind of roller bearing is shown, In 2nd Embodiment, the example which applied this invention to the angular ball bearing which is a kind of ball bearing Although shown, this invention is applicable also to bearings other than the above.
FIG. 6 shows a third embodiment, in which this invention is applied to a tapered roller bearing. The repeated description will be omitted, and only differences from the rolling bearing 1 (first embodiment) which is a cylindrical roller bearing will be described. The rolling bearing 201 which is a tapered roller bearing is a rolling element between a raceway surface 202a made of a conical surface formed on the outer periphery of the inner ring 202 and a raceway surface 203a made of a conical surface formed on the inner periphery of the outer ring 203. A certain tapered roller 204 is interposed. The inner ring 202 has a large brim portion 206 and a small brim portion 207 as outer diameter portions on both sides of the raceway surface 202a, and the outer ring 203 has no brim.

  The cage 205 has an outer ring guide structure, and the guided surface 205a of the cage 205 is opposed to the guide surface 203b of the outer ring 203 with a slight clearance. The inner diameter surface of the outer ring 203 is a conical surface throughout, and both sides of the raceway surface 203a in the axial direction are cage guide surfaces 203b. The inner diameter side opening of the lubricating oil introduction hole 208 is located at the boundary between the raceway surface 203a and the tapered roller large diameter side guide surface 203b. At both ends in the axial direction of the cage 205, rib-shaped guide portions 212 and 213 projecting to the outer diameter side are provided, and the outer diameter surfaces of these guide portions 212 and 213 are formed as guided surfaces 205a.

  A portion of the outer diameter surface of the cage 205 from the tapered roller large diameter side guide portion 212 to the axial center position of the center of the pocket 210 is a tapered surface 205c for introducing a lubricating oil having a large diameter on the small diameter side of the tapered roller. Has been. The angle α (deg) of the tapered surface 205c is also set so that the relationship of the above expression 1 is established.

  When a tapered roller bearing and a cylindrical roller bearing are compared, in the tapered roller bearing, lubricating oil tends to enter the bearing from the small diameter side of the tapered roller 204. Therefore, in the rolling bearing 201 which is this tapered roller bearing, the lubricating oil introduction hole 208 of the outer ring 203 and the lubricating oil introduction tapered surface 205c of the cage 205 are provided only on the large diameter side of the tapered roller, and only from the large diameter side. Lubricating oil is forcibly introduced into the bearing. The lubricating oil introduction hole 208 of the outer ring 203 and the tapered oil introduction tapered surface 205c of the cage 205 are provided not only on the large diameter side but also on the small diameter side so that the lubricating oil is forcibly introduced into the bearing from both sides. It may be.

  FIG. 7 shows a fourth embodiment, which is an application of the present invention to a deep groove ball bearing. The repeated description will be omitted, and only differences from the rolling bearing 101 (second embodiment) which is an angular ball bearing will be described. In the rolling bearing 301 which is a deep groove ball bearing, a ball 304 which is a rolling element is interposed between a raceway surface 302 a formed on the outer periphery of the inner ring 302 and a raceway surface 303 a formed on the inner periphery of the outer ring 303. .

  The cage 305 has an outer ring guide structure, and the guided surface 305a of the cage 305 faces the guide surface 303b of the outer ring 303 with a slight clearance. The guide surfaces 303b of the outer ring 303 are located on both sides in the axial direction of the raceway surface 303a, and a relief groove 307 is formed at the boundary between the raceway surface 303a and the guide surface 303b. The side edges are open. At both ends in the axial direction of the cage 305, a brim-shaped guide portion 312 that protrudes toward the outer diameter side is provided, and an outer diameter surface of the guide portion 312 is formed as a guided surface 305a.

  On the outer diameter surface of the cage 305, the taper surface 305c has a large diameter from the guide portion 312 to the center in the axial direction. The angle α (deg) of the taper surface 305c is also set so that the relationship of Expression 1 is satisfied.

  The deep groove ball bearing has a larger diameter on both axial sides than the inner ring raceway surface 302a and a smaller diameter on both axial sides than the outer ring raceway surface 303a. From either of these, the lubricating oil is difficult to enter the bearing. Therefore, the lubricating oil introduction hole 308 of the outer ring 303 and the tapered surfaces 305c of the cage 305 are provided on both sides in the axial direction so that the lubricating oil is forcibly introduced into the bearing from both sides in the axial direction. Depending on the state of the apparatus in which the rolling bearing 301 is incorporated, the lubricating oil introduction hole 308 of the outer ring 303 and the tapered surface 305c of the cage 305 are provided only on one side in the axial direction, so that the lubricating oil is forcibly introduced into the bearing only from one side. It may be.

  As described above, the present invention can be applied to any type of rolling bearing, but the effect of the invention appears more significantly when the rolling element is a roller than when it is a ball. This is because the bearings in which the rolling elements are rollers tend to be structurally difficult for lubricating oil supplied from the outside to enter the raceway surface. In addition, when the tapered roller bearing and the cylindrical roller bearing are compared, it can be said that the tapered roller bearing has better lubricity than the cylindrical roller because the lubricating oil easily enters the bearing from the small diameter side of the tapered roller. Therefore, it is considered that a cylindrical roller bearing is most suitable for employing the lubricating structure of the present invention.

  FIG. 8 shows an example of a high-speed spindle device including the rolling bearings 1 and 101 according to the first and second embodiments. The spindle device 30 is applied to a machine tool, and a tool or workpiece chuck is attached to the front side (machining side) end of the main shaft 25. The main shaft 25 is supported by a plurality of rolling bearings 1 and 101 separated in the axial direction. Here, the rear end portion of the main shaft 25 is formed by the rolling bearing 1 including the cylindrical roller bearing shown in FIGS. 1 and 2, and the front end portion of the main shaft 25 is formed from the angular ball bearing shown in FIGS. Are each supported by a set of two rolling bearings 101.

  The inner rings 2 and 102 of the respective rolling bearings 1 and 101 are fitted to the outer diameter surface of the main shaft 25, and the outer rings 3 and 103 are fitted to the inner diameter surface of the bearing housing 31. The two rolling bearings 101 are positioned relative to each other by the inner ring positioning spacer 32 and the outer ring positioning spacer 33. An inner ring spacer 36 and a small diameter portion 31 a of the bearing housing 31 are interposed between the rolling bearing 1 and the rear rolling bearing 101. The rolling bearing 1 is fixed in the bearing housing 31 by a fixing nut 37 and a pressing lid 33B that are screwed onto the rear end portion of the main shaft 25. A set of two rolling bearings 101 and inner and outer ring positioning spacers 31 and 32 are fixed in the bearing housing 31 by a step surface 25a of the main shaft 25 and a pressing lid 33A.

  The bearing box 31 has a double structure of an inner peripheral bearing box 31A and an outer peripheral bearing box 31B, and a cooling groove 40 is formed between the inner and outer bearing boxes 31A and 31B. Lubricating oil is applied to the presser lids 33A and 33B from an air oil supply device 60 serving as a lubricating oil supply source when the rolling bearings 1 and 101 are air-oil lubricated, or from an oil tank 61 serving as an oil supply source when utilizing capillary action. An introduction hole 42 to be introduced is provided. The introduction holes 42 communicate with a supply path 43 provided in the inner peripheral bearing box 31A, and the supply path 43 communicates with the air oil introduction path 14 (FIGS. 1 and 4). An oil supply path from the cooling oil supply device 41 communicates with the cooling groove 40 in the bearing box 31.

  The oil supplied to the cooling groove 40 in the bearing box 31 and used for cooling the bearing box 31 is circulated and collected from the drain oil outlet hole 49 of the outer peripheral bearing box 31B to the cooling oil supply device 41. In addition, oil pressure holes 50 are provided in the presser lids 33A and 33B, and these oil pressure holes 50 communicate with an oil drain passage 51 provided in the inner peripheral bearing box 31A and come out of the rolling bearings 1 and 101. The drained oil passes through the drainage passage 51 and is discharged from the drainage hole 50 to the outside.

  The spindle device 30 configured as described above uses the rolling bearings 1 and 101 that can reliably supply the lubricating oil to the places where the lubricating oil is required as bearings for supporting the main shaft 25, so that the main shaft 25 can be operated at high speed. It is. Further, since a member such as a spacer for introducing lubricating oil is not provided on the end face side of the bearing of the rolling bearing 1, the distance from the center of the rolling bearing 1 to the shaft end of the main shaft 25 can be shortened, and rigidity is increased. In addition, the apparatus can be made compact.

The spindle device 30 uses the rolling bearing 1 that is a cylindrical roller bearing and the rolling bearing 101 that is an angular ball bearing in combination. However, only one of the rolling bearings may be used. Further, instead of the rolling bearing 1 which is a cylindrical roller bearing and the rolling bearing 101 which is an angular ball bearing, a rolling bearing 201 which is a tapered roller bearing and a rolling bearing 301 which is a deep groove ball bearing may be used.
Moreover, although the rolling bearings 1, 101, 201, 301 of the above embodiment have the inner rings 2, 102, 202, 302, the present invention can also be applied to bearings that do not have an inner ring and are directly incorporated into the shaft.

It is sectional drawing of the rolling bearing concerning 1st Embodiment of this invention. It is the partial expanded view which looked at the retainer of the rolling bearing from the outer diameter side. It is sectional drawing of the rolling bearing which is a modification of 1st Embodiment. It is sectional drawing of the rolling bearing concerning 2nd Embodiment of this invention. It is the partial expanded view which looked at the retainer of the rolling bearing from the outer diameter side. It is sectional drawing of the rolling bearing concerning 3rd Embodiment of this invention. It is sectional drawing of the rolling bearing concerning 4th Embodiment of this invention. It is a block diagram of the spindle apparatus provided with the rolling bearing of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101,201,301 ... Rolling bearing 2,102,202,302 ... Inner ring 3,103,203,303 ... Outer ring 3a, 103a, 203a, 303a ... Outer ring raceway surface 3b, 103b, 203b, 303b ... Guide surface 4 ... Cylindrical rollers (rolling elements)
5, 105, 205, 305 ... cages 5a, 105a, 205a, 305a ... guided surfaces 5b, 105b, 205b, 305b ... tapered surfaces 8, 108, 208, 308 ... lubricating oil introduction holes (lubricating oil adhering means)
16 ... core material 104, 304 ... ball (rolling element)
204 ... Tapered roller

Claims (8)

  An outer ring having a raceway surface formed on an inner diameter surface, a plurality of rolling elements that are in rolling contact with the raceway surface of the outer ring, and a cage that holds the plurality of rolling elements in a pocket. A guided surface that is a part of the radial surface is guided to face a guide surface that is a part of the inner diameter surface of the outer ring, and the axial center side of the outer diameter surface of the cage has a large diameter. A rolling bearing characterized in that a taper surface is formed and lubricating oil adhering means for adhering lubricating oil to the taper surface is provided.   2. The lubricating oil adhering means according to claim 1, wherein the outer ring is provided with a lubricating oil introduction hole that communicates an inner diameter side and an outer diameter side, and through the lubricating oil introduction hole, the lubricating oil supplied from the outside is supplied to the retainer. Rolling bearing that is designed to inject toward the taper surface.   2. The lubricating oil adhering means according to claim 1, wherein the outer ring is provided with a lubricating oil introduction hole that communicates an inner diameter side and an outer diameter side, and the lubricating oil supplied from the outside is capillarized in the lubricating oil introduction hole. A rolling bearing which is provided with a particulate or fibrous core that is guided to the tapered surface of the cage.   The rolling bearing according to any one of claims 1 to 3, wherein the rolling element is a roller.   4. The rolling element according to claim 2, wherein the rolling element is a cylindrical roller, the guide surfaces of the outer ring are formed on both sides in the axial direction of the outer ring raceway surface, and the tapered surface of the retainer is formed more than the guided surface. A rolling bearing formed on an axially central side and having an axial position of an inner diameter side opening of the lubricating oil introduction hole between the outer ring raceway surface and the guide surface.   4. The rolling element according to claim 2, wherein the rolling element is a ball that contacts the raceway surface of the outer ring with a contact angle, the guide surface of the outer ring is formed on the bearing back side of the outer ring raceway surface, and the holding A rolling bearing in which a tapered surface of the container is formed on the front side of the bearing with respect to the center of the pocket, and an axial position of the inner diameter side opening of the lubricating oil introduction hole is set on the front side of the bearing with respect to the outer ring raceway surface. The angle of the taper surface is α (deg), the pitch circle diameter of the rolling element array is dm (mm), and the specified rotational speed of the bearing is n (min ⁻¹ ). If
α> 0.024 × dm × n × 10 ⁻⁴ −2.2
Rolling bearing that satisfies this relationship.   An outer ring having a raceway surface formed on an inner diameter surface, a plurality of rolling elements that are in rolling contact with the raceway surface of the outer ring, and a cage that holds the plurality of rolling elements in a pocket. A guided surface that is a part of the radial surface is guided to face a guide surface that is a part of the inner diameter surface of the outer ring, and the axial center side of the outer diameter surface of the cage has a large diameter. A method of lubricating a rolling bearing having a tapered surface, in which lubricating oil supplied from the outside is attached to the tapered surface of the cage, and lubricated by the surface tension of the lubricating oil and the centrifugal force associated with rotation of the cage. A rolling bearing lubrication method comprising: moving oil toward an axially central side of a taper surface, and then scattering the oil at an outer diameter direction at a large diameter end of the taper surface to introduce lubricating oil into the bearing.

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