JP2006322594A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact rolling bearing capable of allowing lubricant sealed inside of the bearing to scatter in the prescribed direction by controlling airflow inside of the rolling bearing with a simple constitution. <P>SOLUTION: In this rolling bearing comprising a pair of bearing rings relatively rotatably mounted in opposition to each other, a plurality of rolling elements rollably built in between raceway grooves respectively formed on opposite faces of the bearing rings, and a circular cage 2 retaining the rolling elements, the cage has an opening 6 for inserting each of the rolling elements into pockets 4 at one side and closed at the other side, and a plurality of blades 10 generating the airflow inside of the bearing by the rotation of the cage are mounted at an opening side of the cage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rolling bearing used in an apparatus used in a clean environment such as a robot driving motor and an optical rotary encoder.

  Conventionally, for example, the bearing ring (outer ring 30 and inner ring 32), the rolling element 34, and the retainer 36 constituting the rolling bearing as shown in FIG. 4 are reduced in friction and wear, and seizure prevention and rolling. Rolling bearings are lubricated for the purpose of extending the fatigue life of bearings. Such lubrication is performed by enclosing a lubricant inside the rolling bearing, and examples of the lubricant used at that time include lubricating oil and grease.

  However, when the rolling bearing rotates with the lubricant enclosed inside, the enclosed lubricant leaks to the outside of the rolling bearing due to the centrifugal force due to rotation, or foreign matter (for example, water, dust) from the outside Intrusion of lubricant may deteriorate the enclosed lubricant. In such a case, for example, by attaching a sealing plate (shield or non-contact or contact seal) (not shown) to the end of the race (outer ring 30 or inner ring 32), the leakage of the lubricant to the outside of the rolling bearing can be prevented. Intrusion of foreign matter into the bearing can be prevented (see Patent Document 1).

  However, for example, in a rolling bearing attached with a shield or a non-contact seal, there is a gap between the sealing plate and the race (the outer ring 30 or the inner ring 32), so the rotation of the rolling bearing (particularly the rotation of the rolling element 34). In some cases, the lubricating oil droplets or grease mist generated by the splatter may be scattered from the clearance to the outside of the rolling bearing. Even in a rolling bearing with a contact seal attached, the lubricant attached to the lip portion becomes mist due to sliding of the lip portion of the seal due to the rotation of the rolling bearing, and is scattered outside the rolling bearing. May end up.

In this way, when oil (for example, lubricating oil droplets or grease mist) scatters from the inside of the rolling bearing, the following problems may occur for industrial machines that are becoming smaller and more precise.
For example, a motor for driving a robot is provided with a function for quickly stopping inertial rotation by a brake and a function for controlling power transmission by a clutch.When oil is attached to the brake or the clutch, the disk slips, These functions may be impaired. The optical rotary encoder also has a function to detect the encoding position by turning the aluminum plate with slits or a transparent disc plate with a pattern that partially blocks light and reading the presence or absence of light with a sensor. If an oil component adheres to the aluminum plate or the disk plate, a reading error may occur and the detection function may be impaired.

As a measure for avoiding such a problem, for example, a seal that blocks scattered oil or a scattered oil between a rolling bearing and a member that causes a problem when oil such as a brake adheres (hereinafter referred to as a protective member). It is conceivable to provide an absorbent material. However, in this measure, it is necessary to secure an installation space for the seal and the absorbent material, and the number of these parts increases, resulting in an increase in manufacturing cost. Further, it is conceivable to control the airflow inside the machine so that the airflow is directed in the direction opposite to the direction in which the protective member is located, and the oil component is scattered in the direction opposite to the direction in which the protective member is located. However, in this measure, the apparatus configuration for airflow control is complicated, and a space for it must be secured.
Japanese Patent Laid-Open No. 9-177771

  The present invention has been made in order to solve such a problem, and the object thereof is to control the air flow inside the rolling bearing with a simple configuration, thereby scattering the lubricant enclosed in the bearing in a predetermined direction. It is to provide a compact rolling bearing capable of achieving the above.

  In order to achieve such an object, the rolling bearing according to the first embodiment of the present invention is formed on a pair of bearing rings arranged so as to be relatively rotatable and opposed surfaces of both the bearing rings, respectively. A plurality of rolling elements that are rotatably incorporated between the raceway grooves, and an annular retainer that holds the rolling elements. In such a configuration, the cage has an opening for inserting each rolling element into the pocket on one side and is closed on the other side, and a bearing is provided on the opening side of the cage by the rotation of the cage. A plurality of blades for generating an air flow are provided inside.

  In addition, the rolling bearing according to the second embodiment of the present invention is freely rollable between a pair of race rings arranged to face each other so as to be relatively rotatable and raceway grooves respectively formed on opposing surfaces of both race rings. A plurality of rolling elements incorporated in the ring, and an annular cage for holding the rolling elements. In such a configuration, the cage has an opening for inserting each rolling element into the pocket on one side, the other side is closed, and a bearing is provided on the closed side of the cage by the rotation of the cage. A plurality of blades for generating an air flow are provided inside.

  In each of the rolling bearings described above, the blades extend between the facing surfaces of the pair of race rings, and the airflow is passed to the facing surfaces of the race rings located in the extending direction of the blades. A guide portion for guiding the outside is formed.

  In this case, the guide portion is an inclined surface formed on at least one opposing surface of each race, and the inclined surface is formed so that the distance to the other opposing surface increases as it goes to the outside of the rolling bearing. ing.

  In this case, the guide portion is formed as a groove along the circumferential direction on at least one facing surface of each race.

  According to the rolling bearing of the present invention, by controlling the airflow inside the rolling bearing with a simple configuration, the lubricant enclosed in the bearing is scattered in a predetermined direction, whereby the mechanical device using the rolling bearing is used. Can continue to operate normally

Hereinafter, a rolling bearing according to an embodiment of the present invention will be described with reference to the accompanying drawings.
As the rolling bearing, for example, a thrust bearing or a radial bearing can be applied. Here, a radial bearing is assumed as an example. Moreover, although a roller and a ball | bowl can be applied as a rolling element, a ball | bowl is assumed as an example here.

First, the rolling bearing according to the first embodiment will be described.
As shown in FIGS. 1 (a) and 1 (b), the rolling bearing of this embodiment includes a pair of race rings (an outer ring and an inner ring not shown) opposed to each other so as to be relatively rotatable, and an outer ring and an inner ring facing each other. A plurality of rolling elements (not shown) that are rotatably incorporated between raceway grooves formed on the respective surfaces, and each of the rolling elements is rotatably held by the rolling bearing. An annular cage 2 in which a plurality of pockets 4 are formed is provided.
As an example, the cage 2 applied to the present embodiment assumes a crown-shaped cage 2 having an opening 6 for inserting a rolling element into a pocket 4 on one side and closed on the other side.

  The crown-shaped cage 2 is provided with a pair of claw portions 8a and 8b protruding so as to partially cover the opening 6, and the rolling elements inserted into the pockets 4 are sandwiched between the claw portions 8a and 8b. In this state, it is held in the pocket 4. Of the pair of claws 8a and 8b, a blade 10 is provided at the tip of one of the claws 8a, and each blade 10 rotates with the rotation of the cage 2 to generate an air flow inside the bearing. Can be made.

  In the present embodiment, as an example, the blade 10 is formed so as to tilt backward at a predetermined angle with respect to the rotation direction of the cage 2 (so as to expand the opening 6 by being connected to the tip of the claw portion 8a). ing. Here, the inclination angle of the blade 10 is not particularly limited, but when the inclination angle is small (the blade 10 is almost lying), the blade 10 can scratch the air inside the bearing (push out the air). Therefore, it is not possible to generate an air flow inside the bearing. Further, there is a concern that the cage 2 is difficult to be detached from the mold during the injection molding of the cage 2. On the other hand, when the inclination angle is large (the blade 10 is standing substantially vertically), the air resistance received by the blade 10 is increased, and the rotational torque of the bearing is also increased. For this reason, it is preferable that the said inclination angle exists in the range of 40-85 degree | times when the above is considered.

  According to such a configuration, during rotation of the rolling bearing, the blade 10 rotated together with the cage 2 scratches the air inside the bearing and pushes the air in the rotation direction M of the cage 2. The extruded air is sent in the axial direction along the inclination of the blade 10. Since this is continuously repeated, an airflow is generated in the axial direction in the rolling bearing.

  When the rotation direction of the rolling bearing is limited (for example, the rotation direction M), the air pushed out by the blade 10 is sent from the closed side of the cage 2 to the opening 6 side along the inclination of the blade 10. . For this reason, the air flow generated inside the rolling bearing always flows in the direction (air flow direction W) from the closed side toward the opening 6 side. Thereby, the direction of the airflow generated inside the rolling bearing can be controlled (limited) in one direction (for example, the airflow direction W) with a simple configuration (blade 10).

  Here, when the bearing is rotated in a state where a lubricant (for example, lubricating oil or grease) is sealed inside the rolling bearing, as described above, lubricating oil droplets and grease mist are generated. In this case, the generated oil (lubricating oil droplets or grease mist) is scattered by the air current. However, since the airflow always flows in the airflow direction W, the oil scattering direction can be limited to the airflow direction W.

  Therefore, a member (for example, a brake or a clutch provided in a motor for driving the robot; hereinafter referred to as a protective member) outside the rolling bearing that causes a problem when oil is attached is positioned on the windward side in the airflow direction W. If it is arranged, even if oil is scattered from the inside of the rolling bearing, it can be prevented from adhering to the protective member, and the mechanical device (e.g., robot) in which the rolling bearing is used normally Can continue to operate.

In the present embodiment, the blade 10 is provided only at the tip of one claw 8a out of the pair of claws 8a, 8b, but may be provided only at the tip of the other claw 8b. You may provide in the front-end | tip of nail | claw part 8a, 8b. Moreover, you may provide in some claw parts 8a and 8b, without providing in all the claw parts 8a and 8b. Furthermore, instead of the tips of the claw portions 8a and 8b, for example, the claw portions 8a and 8b may be provided so as to branch from the middle. Furthermore, you may provide in the holder | retainer 2 as a different body from the nail | claw part 8a, 8b.
Moreover, in this embodiment, although it was set as the structure which only provided the blade | wing 10 in the opening 6 side of the holder | retainer 2, it replaces with such a structure, and while providing the said blade | wing 10, it mentions later on the opposing surface of a bearing ring. The guide portion 18 may be formed. According to such a configuration, the airflow direction can always be controlled (limited) in one direction (for example, the airflow direction W) regardless of the rotation direction of the rolling bearing (the cage 2 and the blade 10).

Next, the rolling bearing according to the second embodiment will be described.
In 1st Embodiment mentioned above, although the blade | wing 10 was provided in the opening 6 side of the holder | retainer 2, in this embodiment, several blade | wing 10 is provided in the obstruction | occlusion side (opposite side to the opening 6 side) of the holder | retainer 2. ing. As shown in FIGS. 2 (a) and 2 (b), in this embodiment, the blade 10 extends from the closed side of the cage 2 along the opposing surfaces 12a, 14a of the outer inner rings 12, 14, By rotating together with the cage 2, an airflow can be generated inside the bearing. More specifically, the blade 10 extends from the closed end surface 2 a of the cage 2 toward the facing surface 12 a of the outer ring 12. In this case, the blades 10 are arranged so as to be located in the middle of the adjacent pockets 6 (in the middle of the adjacent rolling elements 16). In addition, each blade | wing 10 is comprised by the flat form extended over the side surface 2b from the end surface 2a of the holder | retainer 2, and the said flat blade 10 is substantially perpendicular to the end surface 2a and the side surface 2b. It is extended.

  Further, a guide portion 18 for guiding the airflow is formed on the facing surface 12a of the outer ring 12. In the present embodiment, as an example, the guide portion 18 is formed on the facing surface 12a of the outer ring 12 on the side where the above-described blade 10 is provided, and a predetermined angle along the extending direction of the blade 10. An inclined surface 18a inclined at the above is formed. In this case, the inclined surface 18a is formed so that the distance from the opposing surface 14a of the inner ring 14 gradually increases as it goes to the outside of the rolling bearing (so-called counterbore state).

  According to such a structure, the blade | wing 10 rotated with the holder | retainer 2 scratches the air inside a bearing, and pushes the said air to the rotation direction of the holder | retainer 2 during rotation of a rolling bearing. The pushed-out air is pressed against the inclined surface 18a, and is sent (guided) in the axial direction along the inclination of the inclined surface 18a. Since this is continuously repeated, an airflow is generated in the axial direction in the rolling bearing.

  In the present embodiment, as described above, the inclined surface 18a is inclined such that the distance to the facing surface 14a of the inner ring 14 gradually expands toward the outer side of the rolling bearing, and therefore the air pushed out by the blade 10 Is pressed against the inclined surface 18a and is sent (guided) along the inclination of the inclined surface 18a from the inside to the outside of the rolling bearing (from the opening 6 side of the cage 2 to the closing side). In this case, the air is sent from the inside to the outside of the rolling bearing regardless of the rotation direction of the rolling bearing (the cage 2 and the blade 10). As a result, the airflow generated inside the rolling bearing always flows in the direction from the inside to the outside of the rolling bearing (airflow direction W). Therefore, regardless of the rotation direction of the rolling bearing (the cage 2 and the blade 10), the air flow direction is controlled (limited) in one direction (for example, the air flow direction W) with a simple configuration (the blade 10 and the inclined surface 18a). can do.

Therefore, when a lubricant (for example, lubricating oil or grease) is sealed inside the rolling bearing and rotated, the scattering direction of the generated oil (lubricating oil droplets or grease mist) may be limited to the airflow direction W. it can.
For this reason, if it arrange | positions so that a protection member may be located in the windward side of the airflow direction W, even if an oil component scatters from the inside of a rolling bearing, it can prevent that the said oil component adheres to a protection member, The mechanical device (for example, robot) in which the rolling bearing is used can be continuously operated.

Moreover, this invention is not limited to 2nd Embodiment mentioned above, It can change as follows. In this case, the basic configuration is the same as that of the rolling bearing according to the second embodiment described above (FIG. 2A), and therefore, only the characteristic part of the present modification will be described below. In the description of this modification, the same components as those of the rolling bearing in FIG. 2A are denoted by the same reference numerals in the drawing, and the description thereof is omitted.
For example, as shown in FIG. 3, instead of forming the inclined surface 18a (FIG. 2 (a)) as the guide portion 18 on the facing surface 12a of the outer ring 12 of the rolling bearing, a groove 20 is formed along the circumferential direction. May be. In this case, the groove 20 may be newly formed, but the sealing plate mounting grooves 20 and 22 formed on the facing surfaces 12a and 14a of the outer and inner rings 12 and 14 in order to attach the sealing plate 24 are used as they are. May be. Of the grooves 20, a seal (sealing plate) 24 is attached to the groove 20 located on the opening 6 side of the cage 2. In this case, the base end of the seal 24 is supported by the groove 20, and the front end of the seal 24 extends in the direction of the groove 22 of the inner ring 14.

According to such a configuration, during the rotation of the rolling bearing (the cage 2 and the blade 10), the air pushed out to the blade 10 is pressed against the groove 20 and is sent in the axial direction along the inclination of the groove 20. Be (guided). Since this is continuously repeated, an airflow is generated in the axial direction in the rolling bearing.
In the present modification, the groove 20 is inclined so that the distance from the facing surface 14a of the inner ring 14 increases toward the outside of the rolling bearing, so that the air pushed out by the blades 10 is pressed against the groove 20. Then, along the inclination of the groove 20, it is sent (guided) from the inside to the outside of the rolling bearing (from the opening 6 side of the cage 2 to the closing side). In this case, the air is sent from the inside to the outside of the rolling bearing regardless of the rotation direction of the rolling bearing (the cage 2 and the blade 10). As a result, the airflow generated inside the rolling bearing always flows in the direction from the inside to the outside of the rolling bearing (airflow direction W). For this reason, regardless of the rotation direction of the rolling bearing (the cage 2 and the blade 10), the air flow direction is controlled (limited) in one direction (for example, the air flow direction W) with a simple configuration (the blade 10 and the groove 20). be able to.

Therefore, when a lubricant (for example, lubricating oil or grease) is sealed inside the rolling bearing and rotated, the scattering direction of the generated oil (lubricating oil droplets or grease mist) may be limited to the airflow direction W. it can. In this modification, the airflow is throttled by the gap between the tip of the seal 24 and the groove 22 of the inner ring 14, and the speed of the air passing through the gap increases. Become bigger.
For this reason, if it arrange | positions so that a protection member may be located in the windward side of the airflow direction W, even if an oil component scatters from the inside of a rolling bearing, it can prevent that the said oil component adheres to a protection member, The mechanical device (for example, robot) in which the rolling bearing is used can be continuously operated.

In this modification, the seal 24 is provided only on one side of the facing surface 12a of the outer ring 12, but the seal 24 may be provided on both sides. In this case, it is preferable to have a seal shape that does not disturb the airflow, but it is arbitrarily configured depending on, for example, the type and size of the bearing or the shape of the facing surfaces 12a, 14a of the outer inner rings 12, 14. Therefore, the seal shape is not particularly limited here. Further, the base end of the seal 24 is supported by the groove 20 of the outer ring 12, but may be supported by the groove 22 of the inner ring 14.
In this modification, as an example, a non-contact seal is applied to the seal 24 so that the tip thereof does not contact the groove 22 of the inner ring 14 (a gap exists between the tip of the seal 24 and the groove 22). A contact seal may be applied. The material of the seal 24 is not particularly limited. For example, the seal 24 formed by combining a metal plate made of a steel plate and the like with rubber or the like can be applied. Furthermore, instead of the seal 24, for example, a shield (sealing plate) press-formed from a thin metal plate such as a stainless steel plate, a steel plate, or an iron plate may be applied.

  Moreover, in 1st Embodiment, 2nd Embodiment, and the modification which were mentioned above, although the material of the holder | retainer 2 was not specifically limited, For example, various holders 2, such as metal, resin, and plastic, are applied. can do. In this case, if it is made of resin or plastic, the blade 10 can be easily formed as compared with metal or the like.

It is a figure which shows the structural example of the holder | retainer of the rolling bearing which concerns on 1st Embodiment of this invention, Comprising: (a) is a perspective view, (b) is the side view seen from the radial direction. It is a figure which shows the structural example of the rolling bearing which concerns on 2nd Embodiment of this invention, Comprising: (a) is sectional drawing along the AA of (b), (b) is a holding | maintenance of (a). The top view which looked at the structural example of the rolling device and the rolling element from the axial direction. Sectional drawing which shows the structural example of the rolling bearing which concerns on the modification of 2nd Embodiment. The perspective view which shows the structural example of the conventional rolling bearing.

Explanation of symbols

2 Cage 4 Pocket 6 Opening 8a, 8b Claw part 10 Blade 12 Outer ring 14 Inner ring 16 Rolling element 18 Guide part 18a Inclined surface 20, 22 Groove 24 Seal (sealing plate)
M Rotation direction W Airflow direction

Claims (5)

A pair of races arranged opposite to each other so as to be relatively rotatable;
A plurality of rolling elements rotatably incorporated between raceway grooves formed on opposite surfaces of both raceways,
In a rolling bearing provided with an annular cage for holding a rolling element,
The cage has an opening for inserting each rolling element into the pocket on one side, and the other side is closed. On the opening side of the cage, an air flow is generated inside the bearing by the rotation of the cage. A rolling bearing comprising a plurality of blades. A pair of races arranged opposite to each other so as to be relatively rotatable;
A plurality of rolling elements rotatably incorporated between raceway grooves formed on opposite surfaces of both raceways,
In a rolling bearing provided with an annular cage for holding a rolling element,
The cage has an opening for inserting each rolling element into the pocket on one side, and the other side is closed. On the closed side of the cage, an air flow is generated inside the bearing by the rotation of the cage. A rolling bearing comprising a plurality of blades.   The blades extend along the facing surfaces of the pair of race rings, and guide portions for guiding the airflow to the outside of the rolling bearings on the facing surfaces of the race rings located in the extending direction of the blades. The rolling bearing according to claim 1, wherein the rolling bearing is formed.   The guide portion is an inclined surface formed on at least one facing surface of each race, and the inclined surface is formed so that the distance to the other facing surface increases as the distance from the rolling bearing increases. The rolling bearing according to claim 3. The rolling bearing according to claim 3, wherein the guide part is a groove formed along a circumferential direction on at least one facing surface of each race.

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