JP2011174523A - Multipoint contact ball bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multipoint contact ball bearing whose joined inner rings are not separated with a retainer, without increasing the number of components. <P>SOLUTION: The multipoint contact ball bearing includes inner and outer rings 2 and 4 which are relatively rotatably disposed facing each other, two or more balls 6 which roll between track grooves 2a and 4a which are formed in the inner and outer rings, and a retainer 8 which rotates between the track grooves while each ball is inserted in two or more pockets 82 which are arranged in its circumferential direction, wherein the outer ring contacts with each ball at one or two points in its track groove, the inner ring is constructed by assembling two annular bodies 22 and 24 which can be separated, and the annular bodies are formed with track grooves 22a and 24a which respectively contact with each ball at one point. The retainer is provided with a drop-off preventing portions 86 for preventing the ball inserted in the pocket from dropping-off depending on its own weight to the inner diameter side, and a plurality of clicks 88 in inner peripheries on both sides which project in a diameter reduction direction. The inner ring is provided with a depressions 2b (groove 22b and step 24b) formed by reducing the diameter of outer peripheries on both sides. The clicks are engaged with the depressions to assemble the two annular bodies. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rolling bearing in which balls, which are rolling elements, are in contact with a raceway (for example, inner and outer races) at three or more points. Specifically, the inner race has two annular bodies (annular bodies with raceways). The present invention relates to an inner ring non-separation technique in a combined inner ring bearing that is assembled.

Typical forms of multi-point contact ball bearings in which balls, which are rolling elements, contact the raceway at multiple points include 4-point contact ball bearings and 3-point contact ball bearings. Of these, the four-point contact ball bearing is a single-row angular contact ball bearing with separated inner and outer rings, or a structure in which the inner ring and / or outer ring, or both, are divided into two on a plane perpendicular to the central axis, and with a small axial clearance. Axial loads in both directions can be applied. For this reason, it is used for applications that require axial rigidity in both directions, such as a pinion front bearing for rack and pinion steering.
Multi-point contact ball bearings can be assembled in the same way as deep groove ball bearings (assembling method in which the inner and outer rings are brought together) by making the number of balls the same as deep groove ball bearings. However, in applications where both downsizing and rigidity are required, a separate inner ring (two annular bodies) is assembled and integrated in order to increase the number of balls (matched inner ring structure). It is necessary to adopt. On the other hand, when the combined inner ring structure is adopted, the inner ring is separated without any resistance, and there are not a few cases that hinder transportation, handling and assembly. This situation is the same for the three-point contact ball bearing.
Therefore, various measures have been conventionally taken in order to prevent such inner ring separation. For example, in Patent Document 1, as shown in FIG. 6, a combined inner ring 50 is integrated by using a connection ring 56 for connecting a pair of annular bodies 52 and 54 constituting the inner ring 50, and the separation is performed. A technique for preventing the above is disclosed.

JP 2003-172342 A

  Thus, according to the measure disclosed in Patent Document 1 described above, it is possible to reliably achieve non-separation of the inner ring 50. On the other hand, in this measure, a new part called the connection ring 56 is generated, and the engagement groove 58 of the connection ring 56 needs to be formed on the inner ring inner diameter surface. It is assumed that the fitting surface is reduced and creep is likely to occur.

  The present invention has been made to solve such a problem, and the object thereof is to increase the number of parts and to make the inner ring non-separated by using a cage. It is to provide a point or four point contact ball bearing.

  In order to achieve such an object, the multi-point contact ball bearing according to the present invention (particularly, a three-point or four-point contact ball bearing) includes an inner ring and an outer ring that are opposed to each other so as to be relatively rotatable about a rotation axis. And a plurality of balls that are respectively formed on the inner and outer rings and roll between the mutually facing raceway grooves, and the balls between the raceway grooves in a state where the balls are inserted one by one into a plurality of pockets arranged in the circumferential direction. A rotating cage is provided, the outer ring is in contact with each ball at one or two points in the raceway groove, and the inner ring is configured by assembling two separable annular bodies, The raceway grooves that contact each ball at one point are formed. In such a multi-point contact ball bearing, the retainer is provided with a drop-off preventing portion that does not drop the ball inserted into the pocket to the inner diameter side by its own weight, and the diameter is reduced at both inner peripheral edges in the rotation axis direction. A plurality of claw portions projecting in the direction are provided, and the inner ring is provided with a concave portion formed by reducing the outer peripheral edges on both sides in the rotation axis direction, and by engaging the claw portion with the concave portion. The two annular bodies are assembled.

  In this case, the cage is provided with a pocket having an opening for inserting the ball on one side in the rotation axis direction and a column portion connecting adjacent pockets alternately along the circumferential direction, The claw portion is made of a resin having a bottom ring portion that closes the other side in the rotation axis direction, and the claw portion has one inner peripheral edge in the rotation axis direction of the column portion, and the other in the rotation axis direction of the bottom ring portion. It is possible to arrange | position to the side inner periphery, without mutually overlapping in the said rotating shaft direction.

In the multi-point contact ball bearing as described above, the inner ring may be formed in a tapered shape in which the diameter of the raceway groove gradually increases as it goes toward the recess.
Moreover, as said recessed part, what is necessary is just to form the level | step difference from the groove shoulder part of the said inner ring | wheel which continues in the circumferential direction, or the groove | channel shoulder part of the said inner ring | wheel which continues in the circumferential direction, as the said fall part, For example, a plurality of protrusions protruding from the inner peripheral edge of the pocket may be provided.

  According to the multi-point contact ball bearing of the present invention, it is possible to prevent the inner ring from being separated by using a cage without increasing the number of parts, and to achieve non-separation of the inner ring easily and at low cost. Can do. As a result, it is possible to improve convenience without hindering the transportation, handling and assembly of the multipoint contact ball bearing.

It is a figure which shows the structure of the 4-point contact ball bearing which concerns on 1st Embodiment of this invention, Comprising: (a) is principal part sectional drawing, (b) is a principal part top view which shows the structure of a holder | retainer. . It is a figure which shows the structure of the 4-point contact ball bearing which concerns on 2nd Embodiment of this invention, Comprising: (a) is principal part sectional drawing, (b) is a principal part perspective view which shows the structure of a holder | retainer, c) is a cross-sectional view showing a configuration of an inner ring (annular body) having a groove shoulder tapered. It is a figure for demonstrating the assembly operation procedure of the 4-point contact ball bearing which concerns on 1st Embodiment of this invention, Comprising: (a) is a figure which shows the procedure which comprises an outer ring ball holder set, (b) is It is a figure which shows the integration procedure of the integration of an inner ring, and an inner ring and an outer ring ball cage set. It is a figure for demonstrating the assembly operation | movement procedure of the 4-point contact ball bearing which concerns on 2nd Embodiment of this invention, Comprising: (a) shows the procedure which comprises the assembly | attachment body of an outer ring, one annular body, and a ball | bowl. (B) is a diagram showing a procedure for inserting a ball into the pocket of the cage, (c) is a diagram showing a state in which an outer ring, an annular body, a ball and an assembly of the cage are configured. ) Is a diagram showing the integration procedure of the inner ring and the bearing. When the groove shoulder part of an outer ring | wheel is high, the procedure which inserts a ball | bowl in the pocket of a holder | retainer is shown. It is principal part sectional drawing which shows the structure of the inner ring | wheel non-separation in the conventional 4-point contact ball bearing of a matching inner ring structure.

First, the general form of the multipoint contact ball bearing according to the present invention will be described. The inner ring of a multi-point contact ball bearing is configured by combining two separable annular bodies (so-called mating inner ring structure), and the raceway grooves of these annular bodies are both centered on the grooves (as an example, left and right). It is offset from the center of the outer ring, and is formed in a Gothic arch shape in which both grooves (so-called R-shaped concave curved surfaces) intersect. On the other hand, the outer ring has a single circular arc shape in which the groove center coincides with the width center of the outer ring, or both (for example, left and right) groove centers are offset from the outer ring center, and both grooves (so-called R-shaped). The outer ring raceway groove is formed over the entire circumference of the inner peripheral portion so as to form a Gothic arch shape intersecting the concave curved surfaces).
A combination of an outer ring whose outer ring raceway groove forms the single arc shape and the inner ring (matching inner ring) is called a three-point contact ball bearing, and an outer ring whose inner ring raceway groove forms the Gothic arch shape and the inner ring (matching inner ring). The combination of these is called a four-point contact ball bearing. These ball bearings are provided with a slight radial clearance, and support the load while having different contact angles depending on the axial load direction. The gist (technical idea) of the present invention relates to the combined inner ring and is not limited to the form of the outer ring. In the following, a four-point contact ball bearing is assumed as an example of a multi-point contact ball bearing, and an embodiment thereof will be described. However, the present invention provides a three-point contact ball bearing or a contact portion exceeding four points. It is applicable also to the ball bearing which has.

Hereinafter, a four-point contact ball bearing (hereinafter also simply referred to as a bearing) according to the present invention will be described with reference to the accompanying drawings.
FIG. 1A shows the configuration of a four-point contact ball bearing according to the first embodiment of the present invention. The bearings are respectively formed on an inner ring 2 and an outer ring 4, and inner and outer rings 2 and 4 that are opposed to each other so as to be relatively rotatable around a rotation shaft (a shaft (not shown) extending in the horizontal direction in the figure). Track with a plurality of balls 6 rolling between the facing race grooves (inner ring raceway groove 2a and outer ring raceway groove 4a) and one ball 6 inserted into each of a plurality of pockets 82 arranged in the circumferential direction. A cage 8 that rotates between the grooves 2a and 4a is provided.

In the outer ring 4, an outer ring raceway groove 4a is formed over the entire circumference of the inner peripheral part with the groove center being coincident with the width center of the outer ring 4. The outer ring 4 is connected to each ball 6 by the outer ring raceway groove 4a. Touch at two points.
On the other hand, the inner ring 2 is configured by assembling two separable annular bodies 22 and 24 (so-called combined inner ring structure), and these annular bodies 22 and 24 are in contact with each ball 6 at one point. The raceway grooves 22a and 24a are formed over the entire circumference of the outer peripheral portion so as to face the outer ring raceway groove 4a. That is, the inner ring 2 is configured by assembling the two annular bodies (annular bodies with raceways) 22 and 24, and in this state, the raceway grooves 22 a and 24 a of these annular bodies 22 and 24 are formed on the outer peripheral portion of the inner ring 2. An inner ring raceway groove 2 is formed.
As described above, the ball bearing 6 incorporated between the inner ring raceway groove 2a (the raceway grooves 22a and 24a) and the outer ring raceway groove 4a is composed of two points with these raceway grooves 2a and 4a. It is configured as a four-point contact ball bearing with a contacted inner ring structure. In FIG. 1 (a), the inner ring raceway groove 2a (track grooves 22a, 24a) and the outer ring raceway groove 4a are slightly exaggerated in order to clearly show the contact state (in FIGS. 2 to 5). The same).

The cage 8 has a cylindrical shape with a predetermined thickness, and a plurality of through holes (circular holes) are opened in the cylindrical portion 84 as pockets 82 that are slightly larger than the ball diameter (the diameter of the ball 6). Perforated at regular intervals with a caliber (so-called press type or machined type cage). The retainer 8 is provided with a drop-off prevention portion 86 that prevents the ball 6 inserted into the pocket 82 from dropping toward the inner diameter side by its own weight. FIG. 1B shows a configuration in which a plurality of protrusions protruding from the inner peripheral side peripheral portion of the pocket 82 are provided as an example of the drop-off preventing portion 86. In this case, the drop-off prevention part 86 protrudes at an inclination toward the center direction (downward in FIG. 1A) from the four places on the inner diameter side peripheral part so as to reduce the opening diameter of the pocket 82.
FIG. 1B shows a configuration in which four dropout prevention portions 86 are arranged with a phase difference of 90 degrees along the axial direction (left-right direction in the figure) and the circumferential direction (up-down direction in the figure). However, the number and phase difference are not particularly limited. For example, a configuration in which four protrusions are arranged with a phase difference of 90 degrees shifted from the axial direction and the circumferential direction, or a structure in which three protrusions are arranged at equal intervals (120 degree phase difference). Also good.

  With this configuration, the cage 8 can freely insert and remove the ball 6 into and from the pocket 82 on the outer diameter side, while the ball 6 is prevented by the drop-off prevention portion 86 on the inner diameter side. The ball 6 is prevented from falling off the pocket 82 by hooking (so-called snapping), and the ball 6 can be rotatably held in the pocket 82. In this case, the allowance (pachin allowance) for the ball 6 of the drop-off prevention unit 86 may be arbitrarily set according to the weight, material, size, etc. of the ball 6. In addition, the ball 6 can be inserted from the inner diameter side of the pocket 82 by pushing the ball 6 against the hanging allowance (pachin allowance) of the drop prevention portion 86.

In this embodiment, the claw part 88 and the recessed part 2b which can be mutually engaged are provided in the holder | retainer 8 and the inner ring | wheel 2, respectively, and the two annular bodies 22 are engaged by engaging the claw part 88 with the recessed part 2b. , 24 can be assembled.
As shown in FIG. 1, the retainer 8 is provided with a plurality of claw portions 88 that protrude in the diameter-reducing direction at the inner peripheral edges on both sides in the rotation axis direction (the left-right direction in FIG. 1A). In this case, the number, size, arrangement interval, and the like of the claw portions 88 are not particularly limited and can be arbitrarily set. Further, the number, size, and arrangement interval of the claw portions 88 may be the same on the one side inner periphery and the other side inner periphery in the rotation axis direction, or may be different. Furthermore, it does not matter whether the claw portion 88 is formed, whether it is an integral structure with the main body of the cage 8 or a separate structure. In FIG. 1 (a), protrusions projecting at equal intervals in a tapered rectangular shape with the same thickness as the cage 8 from the inner peripheral edges on both sides in the direction of the rotation axis substantially perpendicularly to the diameter reducing direction. As an example, a configuration in which a plurality of components are arranged is shown. In addition, it is also conceivable that the claw portion 88 is formed as a ridge that continues over the entire circumference in the circumferential direction.

On the other hand, the inner ring 2 is provided with recesses 2b formed by reducing the diameters of the outer peripheral edges on both sides in the rotation axis direction (the left-right direction in FIG. 1A). As the recess 2b, for example, a groove 22b continuous in the circumferential direction with the groove shoulder 2c of the inner ring 2 or a step 24b from the groove shoulder 2c of the inner ring 2 continuous in the circumferential direction may be formed. The configuration (size, shape, depth, height, etc.) of the recess 2b (the groove 22b and the step 24b) is not particularly limited as long as the claw portion 88 of the cage 8 can be engaged. In other words, the claw portion 88 of the cage 8 and the recess 2b (the groove 22b and the step 24b) of the inner ring 2 may be of any configuration as long as they can be engaged with each other.
In FIG. 1 (a), a groove 22b continuous in the circumferential direction is formed on the groove shoulder 22c of one annular body 22 (shoulder of the raceway groove 22a formed on the outer periphery), and in the circumferential direction. The configuration of the recess 2b formed with a step 24b from the groove shoulder 24c of the other continuous annular body 24 (shoulder of the track groove 24a formed on the outer peripheral portion) is shown as an example. The annular body 22 may be formed with a step 24b and the annular body 24 may be formed with a groove 22b, or the annular body 22, 24 may be formed with either the groove 22b or the step 24b (same (Concave configuration).

  As described above, the retainer 8 is provided with the claw portion 88, the recess 2b (the groove 22b and the step 24b) is formed in the inner ring 2 (annular bodies 22, 24), and the claw portion 88 is engaged with the recess 2b. The retainer 8 can effectively prevent the inner ring 2 from being separated into the annular bodies 22 and 24 without increasing the number of parts. Thereby, it is possible to easily separate the inner ring at low cost.

Here, the assembling work of the four-point contact ball bearing of the mating inner ring structure according to the present embodiment may be performed according to the procedure shown in FIG.
First, the outer ring 4 and the cage 8 are positioned on the same rotation shaft (a shaft (not shown) extending in the vertical direction in FIG. 3), and the inner diameter side of the pocket 82 of the cage 8 (the right side in the drawing). The ball 6 is positioned at (the state of the ball 6 shown by the solid line in FIG. 5A). Next, the ball 6 is pressed into the pocket 82 against the hooking allowance (pachining allowance) while being brought into contact with the drop-off preventing portion 86, and is brought into contact with the raceway groove 4a of the outer ring 4 at two points (see FIG. 3 (a)). The state of the ball 6 indicated by a broken line). Thereby, the assembly (outer ring ball holder set) of the outer ring 4, the ball 6, and the cage 8 is configured.

  And, to the outer ring ball cage set, the two annular bodies 22 and 24 are assembled from both sides in the rotational axis direction (both sides in the axial direction (upper side and lower side in FIG. 3) (FIG. 3B)), These annular bodies 22 and 24 are integrated to form the inner ring 2, and the inner ring 2 and the outer ring ball cage set are integrated to form a bearing (see FIG. 1 (a)). When the two annular bodies 22 and 24 are assembled to the outer ring ball cage set, the groove shoulder portions 22c and 24c of the annular bodies 22 and 24 are brought into contact with the claw portion 88 of the cage 8. The claw portion 88 is moved in the axial direction until it engages with the recess 2b (the groove 22b and the step 24b), whereby the two annular bodies 22 and 24 are integrated without separation (so-called snapping). Thus, the inner ring 2 (matching inner ring) is configured.

In this case, the hooking cost (pachining cost) of the claw portion 88 of the cage 8 with respect to the groove shoulder portion 2c of the inner ring 2 (groove shoulder portions 22c, 24c of the annular bodies 22, 24) is the annular body with respect to the outer ring ball cage set. The inner ring 2 (annular body 22) can be mounted without difficulty, and can be securely separated from the inner ring by engagement with the recess 2b (groove 22b and step 24b). 24) and the material and size of the cage 8 may be set arbitrarily.
For example, the inner ring 2 (annular bodies 22 and 24) can be configured to have a tapered shape in which the groove shoulder portion 2c (22c and 24c) is gradually expanded in diameter toward the recess 2b (the groove 22b and the step 24b). Yes (see FIG. 2 (c)). Accordingly, the claw portion 88 can be engaged with the concave portion 2b (the groove 22b and the step 24b) while the groove shoulder portion 2c (22c, 24c) and the claw portion 88 are smoothly in contact with each other. Assembling of the annular bodies 22 and 24 to the cage set can be performed without difficulty.

In addition, in 1st Embodiment of this invention mentioned above, although the structure (FIG. 1) in case the holder | retainer 8 is what is called a press type and a machined type was demonstrated as an example, the structure of the holder | retainer which concerns on this invention is It is not limited to this, For example, it is also possible to comprise as what is called a crown type holder | retainer as shown in FIG.
FIG. 2A shows a configuration of a four-point contact ball bearing according to a second embodiment of the present invention to which such a crown type cage is applied, and this configuration will be described below. Since the basic bearing configuration other than the cage is assumed to be the same as that of the first embodiment (FIG. 1) described above, its constituent members (inner ring (annular body), outer ring, ball) and The common members are denoted by the same reference numerals in the drawings, and the description thereof is omitted. Hereinafter, the description of the configuration characteristic of the second embodiment will be limited.

In this embodiment, as shown in FIGS. 2A and 2B, the cage 8 has an opening 80 for inserting the ball 6 on one side in the rotation axis direction (the right side in FIG. 2A). The bottom ring part 83 which is alternately provided along the circumferential direction and has the pocket 82 which has the pocket 82 which has the adjacent pocket 82, and obstruct | occludes the other side (left side of the figure (a)) of the said rotating shaft direction. It is made of resin. The column part 81 is provided with a pair of protrusions 85 protruding so as to partially cover the opening 80, and the balls 6 inserted into the pockets 82 are sandwiched by the protrusions 85 in the pockets. It is rotatably held in 82.
As in the first embodiment (FIG. 1) described above, the retainer 8 is provided with a drop-off preventing portion (not shown) that does not drop the ball 6 inserted into the pocket 82 toward the inner diameter side by its own weight. Yes. The configuration of the drop-off prevention unit, the number of arrangement, the arrangement phase difference, and the like are not particularly limited and can be arbitrarily set. For example, a plurality of protrusions as shown in FIG. 1 (b) may be projected from the inner peripheral edge of the pocket 82, or the pocket 82 is surface-shaped so as to form a concave spherical shape along the surface of the ball 6. A spherical pocket may be used, and the inner peripheral side diameter of the pocket surface may be smaller than the ball diameter (the diameter of the ball 6).

Also in the present embodiment, the cage 8 is provided with a plurality of claw portions 88 that can be engaged with the recess 2 b of the inner ring 2. In this case, the claw portions 88 are provided on one side inner periphery in the rotation axis direction of the column portion 81 (right inner periphery in FIG. 2A), and on the other side inner periphery in the rotation axis direction of the bottom ring portion 83 (same as the same). Arranged on the inner peripheral edge of the left side of the figure without overlapping each other in the direction of the rotation axis (left and right direction in the figure).
In the cage 8 shown in FIGS. 2 (a) and 2 (b), the claw portion 88 disposed on the pillar portion 81 extends beyond the projection 85 to the outside in the width direction of the cage 8, and the extension It is configured as a substantially L-shaped protrusion (hereinafter referred to as a claw portion 88a) that extends in a reduced diameter direction (inner diameter direction of the retainer 8) substantially vertically from the protruding end, and forms a plate shape with substantially the same thickness. . On the other hand, the claw portion 88 disposed on the bottom ring portion 83 extends substantially vertically from the vicinity of the deepest portion of the pocket 82 in the direction of diameter reduction (inner diameter direction of the cage 8), and the whole has substantially the same thickness. It is configured as a flat plate-like protrusion (hereinafter referred to as a claw portion 88b) having a plate shape. The configuration of the claw portions 88a and 88b shown in FIGS. 2 (a) and 2 (b) is an example thereof, and the number, size, arrangement interval, formation method of the claw portions 88a and 88b, There is no particular limitation as to whether it is an integral configuration or a separate configuration. That is, any configuration may be used as long as it can be engaged with the recess 2b of the inner ring 2. In the present embodiment, the claw portion 88a and the claw portion 88b are disposed without overlapping with each other in the rotation axis direction (axial direction (left-right direction in FIG. 2A)), and thus are held by axial draw molding. It can be integrally formed with the body of the vessel 8.

  As a result, the claw portions 88a, 88b are engaged with the recess 2b of the inner ring 2 (step 24b in the configuration shown in FIG. 2A), so that the inner ring can be used without increasing the number of parts. Non-separation can be achieved.

Here, the assembling work of the four-point contact ball bearing of the mating inner ring structure according to the present embodiment may be performed according to the procedure shown in FIG.
First, the outer ring 4 and one annular body, specifically, the annular body (corresponding to the annular body 24 shown in FIG. 2A) positioned on the opening 80 side of the cage 8 when the bearing is assembled are the same. Is positioned on the rotation axis (axis extending in the vertical direction (not shown) in FIG. 4) and the annular body 24 is moved outward in the rotation axis direction (outward in the axial direction (downward in FIG. 4)). The ball 6 is shifted and placed on the raceway groove 4a of the outer ring 4 (the state of the ball 6 shown by the solid line in FIG. 5A). From this state, the annular body 24 is moved inward in the axial direction (upward in FIG. 4) to bring the ball 6 into contact with the raceway groove 4a of the outer ring 4 at two points, and at one point with the raceway groove 24a of the annular body 24. (The state of the ball 6 shown by a broken line in FIG. 4A).

  Next, the cage 8 is positioned on the side opposite to the assembly side of the annular body 24 (upper side in FIG. 4) with respect to the assembly of the outer ring 4, the annular body 24 and the ball 6 (FIG. 4B). In this state, the protrusion 85 is pushed into the pocket 82 from the opening 80 while being in contact with the ball 6 (the state shown in FIG. 3C). At that time, while the claw portion 88a of the cage 8 is brought into contact with the groove shoulder portion 24c of the annular body 24, the claw portion 88a is moved in the axial direction until the claw portion 88a engages with the recess 2b (step 24b).

  Then, with respect to the assembly of the outer ring 4, the annular body 24, the balls 6 and the cage 8, the remaining annular body, specifically, the bottom ring portion 83 side of the cage 8 when the bearing is assembled. The annular body (corresponding to the annular body 22 shown in FIG. 2 (a)) is assembled from the side opposite to the assembly side of the annular body 24 (upper side in FIG. 4), and the assembled annular body 22 is assembled into the annular body 24. To form an inner ring 2 (state shown in FIG. 2D), and the inner ring 2 and the assembly are integrated to form a bearing (see FIG. 2A). At that time, the groove shoulder portion 22c of the annular body 22 is moved in the axial direction until the claw portion 88b engages with the concave portion 2b (step 24b) while contacting the claw portion 88b of the cage 8. Thereby, the two annular bodies 22 and 24 are integrated (so-called snapping) without being separated, and the inner ring 2 (matching inner ring) is configured.

  Also in this case, as in the case of the first embodiment described above, the groove shoulder 2c of the inner ring 2 (the groove shoulders 22c, 24c of the annular bodies 22, 24) is gradually expanded toward the recess 2b (step 24b). By making the diameter tapered (see FIG. 2C), the groove shoulder portion 2c (22c, 24c) and the claw portion 88 (88a, 88b) are smoothly brought into contact with each other while the claw portion 88 ( 88a, 88b) can be engaged with the recess 2b (step 24b) without difficulty.

In the assembly work of the bearing according to the present embodiment described above, an assembly is configured with the outer ring 4 and the ball 6 using a predetermined jig (not shown) instead of the annular body 24, and the assembly is After assembling the cage 8 and the annular body 22, the procedure may be such that the jig is pulled out and replaced with the annular body 24. In this case, the jig may be configured to have a groove or the like that allows the balls 6 to be easily arranged with the raceway groove 4a of the outer ring 4 during assembly work and can be held more stably. As a result, the assembly work of the bearing can be performed more easily.
Further, when the groove shoulder 4c of the outer ring 4 is high (the distance from the deepest part of the outer ring raceway groove 4a to the groove shoulder 4c is large), as shown in FIG. The balls 6 may be pushed into the pockets 82 from the openings 80 by moving the retainer 8 in the axial direction as it is or after assembling the annular body 24 after the 6 are placed and arranged.

As described above, according to the four-point contact ball bearing according to the first embodiment (FIG. 1) and the second embodiment (FIG. 2) of the present invention, the inner ring 2 ( It is possible to prevent the annular bodies 22 and 24) from being separated, and the inner ring can be separated easily and at low cost. As a result, the convenience can be improved without hindering the transportation, handling and assembly of the four-point contact ball bearing.
In the first embodiment (FIG. 1) and the second embodiment (FIG. 2), a four-point contact ball bearing is assumed as an example of a multipoint contact ball bearing, and the bearing configuration has been described. As described above, the present invention can also be applied to a three-point contact ball bearing, and further to a ball bearing having a contact portion exceeding four points. Also in these bearings, the first embodiment (FIG. 1) and The same effects as those of the second embodiment (FIG. 2) can be obtained.

2 Inner ring 2a Inner ring raceway groove 2b Recessed part 2b
4 outer ring 4a outer ring raceway groove 6 ball 8 cage 22, 24 annular body 22a, 24a annular body raceway groove 22b groove 24b step 82 pocket 86 drop prevention part 88 claw part

Claims (5)

An inner ring and an outer ring that are arranged opposite to each other so as to be relatively rotatable about a rotation axis, a plurality of balls that are formed on the inner and outer rings and that roll between race grooves facing each other, and a plurality of balls that are arranged in the circumferential direction A cage that rotates between the raceway grooves in a state where the balls are inserted one by one in a pocket,
The outer ring is in contact with each ball at one or two points in the raceway groove, and the inner ring is configured by assembling two separable annular bodies, each of which has one point with each ball. A multi-point contact ball bearing in which the raceway grooves that are in contact with each other are formed,
The retainer is provided with a drop prevention portion that prevents the ball inserted into the pocket from dropping to the inner diameter side by its own weight, and a plurality of claw portions that protrude in the reduced diameter direction at both inner peripheral edges in the rotation axis direction. Is provided,
The inner ring is provided with a recess formed by reducing the outer peripheral edges on both sides in the rotation axis direction,
The multi-point contact ball bearing, wherein the two annular bodies are assembled by engaging the claw portion with the recess. The retainer is alternately provided with a pocket having an opening for inserting the ball on one side in the rotation axis direction and a pillar portion connecting adjacent pockets along a circumferential direction, and the rotation axis direction Made of resin with a bottom ring portion that closes the other side of
The claw portion is disposed on the inner peripheral edge on the one side in the rotational axis direction of the column part and the inner peripheral edge on the other side in the rotational axis direction of the bottom ring part without overlapping each other in the rotational axis direction. The multi-point contact ball bearing according to claim 1, wherein:   3. The multi-point contact ball bearing according to claim 1, wherein the inner ring has a tapered shape in which a diameter of a shoulder portion of the raceway groove is gradually increased toward the concave portion.   4. The groove according to claim 1, wherein a groove is formed in the groove shoulder of the inner ring in the circumferential direction, or a step from the groove shoulder of the inner ring is formed in the circumferential direction. Multi-point contact ball bearings as described in Crab.   The multipoint contact ball bearing according to any one of claims 1 to 4, wherein a plurality of protrusions that protrude from an inner peripheral edge of the pocket are provided as the drop-off prevention part.

Images