JP2001050264A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing realizing torque reduction by suppressing spin slip and reducing rolling resistance of a rolling body and a raceway groove, and capable of receiving a radial load, an axial load in both directions, and a moment load. SOLUTION: A plurality of rolling bodies 5 wherein an outer diameter 5a forming a rolling contact face also has a curvature in an axial direction and a radius is smaller than a radius of a raceway surface, are incorporated in a raceway groove 3 between outer and inner rings 1 and 2. Adjacent rolling bodies 5 are each arranged so as to mutually cross, and the outer diameter 5a of each rolling body 5 constantly contact two points at raceway surfaces 1a or 1b of one race 1 and raceway surfaces 2b or 2a of another race 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing capable of receiving a radial load, an axial load in both directions, and a moment load, such as an industrial machine, a robot, a medical device, a semiconductor / liquid crystal manufacturing device, an optical and optoelectronic device, and the like. Used for

[0002]

2. Description of the Related Art Conventionally, cross roller bearings and four-point contact ball bearings are known as bearings capable of receiving a radial load, an axial load in both directions, and a moment load with one bearing. In a conventional cross roller bearing, a cylindrical roller 300 is interposed between an inner ring 100 and an outer ring 200 (FIG. 1).
8). In the four-point contact ball bearing, a ball 400 is interposed between an inner ring 100 and an outer ring 200 (FIG. 19).

[0003]

However, the conventional cross roller bearing and four-point contact bearing have the following problems. The cross roller bearing has a rolling element of a cylindrical roller 300
Since the rolling contact surface 301 is in line contact with the raceway groove 500, the torque is large. Since the rolling element of the four-point contact ball bearing has a ball 400, when receiving a pure axial load or when the axial load is more dominant than the radial load, the torque is smaller than that of the cross roller bearing of the same size, but the radial load is smaller than the axial load. Is dominant or is subject to pure radial loads,
Each ball 400 has a track groove 500 and four points 401
Due to the contact at 401, there is a problem that the spin sliding between the ball 400 and the raceway groove 500 is large and the torque is large.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to suppress the spin slip between the rolling elements and the raceway grooves and to reduce the rolling resistance. An object of the present invention is to provide a rolling bearing capable of receiving a radial load, a biaxial axial load, and a moment load that realize low torque.

[0005]

In order to achieve the above object, the present invention provides a technical means in which a plurality of rolling elements are incorporated between a pair of races, and each of the races has a radius of the rolling race. Each has a raceway groove composed of two larger diameter raceway surfaces,
In each of the rolling elements, the outer diameter serving as a rolling contact surface also has a curvature in the axial direction, and continuous rolling elements are arranged alternately in an intersecting manner, and the outer diameter of each rolling element is always opposite. And that of the other raceway is in two-point contact.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a rolling bearing according to an embodiment of the present invention. The present embodiment is merely an embodiment disclosed in the description of the rolling bearing of the present invention, is not limited in any way, and can be freely changed within the scope of the present invention.

In the rolling bearing, a plurality of rolling elements 5, 5,... Are incorporated in a raceway groove 3 formed between an inner diameter of a raceway (outer ring) 1 and an outer diameter of a raceway (inner race) 2. Track ring 1,2
Are the respective raceway surfaces 1a and 1 formed on the inner diameter of one raceway (outer ring) 1 and the outer diameter of the other raceway (inner race) 2.
A raceway groove 3 having a desired shape is formed by b, 2a and 2b, and either or both of raceways 1 and 2 are axially divided at the center in the width direction into two types. The type in which the wheels 1 and 2 are not divided is also used. Also, the two-piece type may be assembled integrally with bolts / rivets 4 or the like.

The raceway groove 3 is formed by raceway surfaces 1a, 1b, 2a, 2b having a radius larger than the radius of the rolling element 5. As long as the shape of each raceway surface 1a, 1b, 2a, 2b has a shape suitable for rolling of the rolling element 5,
The cross section may be any shape such as an arch shape or a V shape, and may be any shape such as a curved shape or a straight shape, and is not particularly limited. For example, a gothic arch is applied.

The rolling element 5 has an outer diameter 5a serving as a rolling contact surface.
Have a curvature in the axial direction, and the raceway surfaces 1a, 1b, 2a,
2b, the rolling elements 5 are arranged in an arbitrary shape having a radius smaller than the respective radii, and the adjacent rolling elements 5 are alternately arranged in an intersecting manner, and the outer diameter 5a of each rolling element 5 is always Two contact points are made between the raceway surfaces 1a and 1b of one raceway 1 and the raceway surfaces 2b and 2a of the other raceway 2.

For example, the rolling element 5 has a pair of relative surfaces 5b,
A vertically-cut ball having a cut surface 5b (having a structure in which the upper and lower portions of the ball are cut to form relative surfaces 5b, 5b; the same applies hereinafter), and a rotation center axis 5 perpendicular to the relative surfaces 5b, 5b.
are assembled so that the c crosses each other, and the outer diameter 5a of each rolling element 5 is always equal to the raceway surfaces 1a, 1b of one race 1 and the other race 2 At two points on the raceway surfaces 2b and 2a.

The upper and lower cutting widths of the rolling element 5 are not particularly limited, and the upper and lower cutting ratios may be equal or not uniform, and may be arbitrarily selected within the scope of the present invention. That is, the relative surfaces 5b, 5b of the rolling elements 5
Both symmetric and asymmetric may be within the scope of the present invention.

Incidentally, the overall shape of the rolling element 5 and the relative surfaces 5b, 5
The presence or absence of b and the magnitude of the curvature in the axial direction at the outer diameter 5a are not limited to the above specific shape at all, and can be arbitrarily changed within the scope of the present invention. That is, for example, instead of the relative surfaces 5b, 5b, non-parallel surfaces may be provided, and a rotation center axis 5c perpendicular to the both surfaces may be provided.

The rolling elements 5, 5... Are assembled by the relative surfaces 5b, 5b, 5b, 5 of the adjacent rolling elements 5, 5.
The rotation center axes 5c, 5c perpendicular to b are alternately crossed, and the crossing state may be either orthogonal or non-orthogonal.

The method of arranging the rolling elements 5 in an intersecting manner is not particularly limited as long as the numbers are the same in both cases, that is, the rolling elements 5 may intersect one by one, or may intersect one by one. If the number is the same in both cases even if they do not intersect, they may intersect two by two or intersect each other, such as one by one, and both are within the scope of the present invention.

The movement of each rolling element 5, 5 is controlled by a cage 6, 6 '.
Alternatively, it is guided by a separator (spacer) 8. The retainers 6, 6 'and the separator (spacer) 8 are not particularly limited as long as they have a holding portion 7 for holding and guiding the rolling element 5, a pocket 13, or a groove 9 respectively. Instead, it can be arbitrarily selected and changed within the scope of the present invention.
The method of guiding the retainers 6, 6 'is not particularly limited, and may be inner ring guide, outer ring guide, or rolling element guide. The configuration of the retainers 6, 6 'is not particularly limited, and may be an integral type or formed from several parts.

For example, the cage 6 alternately arranges the adjacent rolling elements 5, 5 such that the rotation center axes 5c, 5c perpendicular to the relative surfaces 5b, 5b, 5b, 5b respectively cross each other as described above. .. (And pockets 13, 13,... In the retainer 6 ') are alternately formed in the circumferential direction. The separator 8 has a smaller diameter than the diameter of the rolling element 5, and the rotating center axes 5c, 5c perpendicular to the relative surfaces 5b, 5b, 5b, 5b of the rolling elements 5, 5 held adjacent to each other as described above, respectively. Concave arc grooves 9, 9 that are held in an intersecting manner are formed in an intersecting manner on the relative surfaces 10, 10. The curvature of the arc groove 9 may be substantially the same as or larger than the curvature of the rolling element outer diameter 5a, and may be arbitrary.

The state in which the preload is applied between the rolling element and the raceway surface is not particularly limited. That is, the preload may or may not be applied in the manufacturing stage, and both are within the scope of the present invention. .

As the material of the orbital wheels 1 and 2 and the rolling elements 5 of these bearings, a bearing steel is usually used. However, in order to improve the corrosion resistance and the heat resistance according to the use environment, stainless steel and ceramics are used. It is appropriately selected. In addition, cage 6
As the material of 6 ', a machined cage, a press cage,
Since the resin retainer and the like are appropriately selected, metals such as brass and iron, and synthetic resins such as polyamide 66 (nylon 66) and polyphenylene sulfide (PPS) are selected within the scope of the present invention.

[0019]

Next, a specific embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a rolling bearing according to a first embodiment of the present invention. The rolling elements 5, 5 are upper and lower cut balls having a pair of relative surfaces 5b, 5b as shown in FIG. 2, and include an outer ring 1 of a bearing formed integrally and an inner ring 2, 2 divided into two. Are interposed in the raceway groove 3 formed between them. The raceway groove 3 of the present embodiment has two raceway surfaces 1a, 1b and 2a having a radius larger than the radius of the rolling element 5.
A gothic arch composed of 2b, and the relative surfaces 5b and 5b of the rolling element (vertical cut ball) 5 are symmetric.

The rotation centers 5c, 5c of the rolling elements 5, 5 perpendicular to the relative surfaces 5b, 5b are arranged so as to intersect alternately. Guided in parts 7,7. The retainer 6 is a retainer capable of alternately incorporating the adjacent rolling elements 5, 5 such that the rotation center axes 5c, 5c perpendicular to the relative surfaces 5b, 5b, 5b, 5b intersect, respectively, as described above. 7, 7 are alternately formed in the circumferential direction.

Therefore, according to the first embodiment, the outer diameter 5a of the rolling element 5 makes point contact with the raceway surface 1a of the outer race 1 and the raceway surface 2b of the inner race 2 (the contact points are indicated by 11, 11). )
Then, the adjacent rolling elements 5 make point contact with the raceway surface 1b of the outer race 1 and the raceway surface 2a of the inner race 2 (contact points are indicated by 12 and 12).
I do.

Since the contact angles of the rolling elements 5 and 5 alternately intersect, a single bearing can receive a radial load and an axial load and a moment load in both directions. Also, the rolling element 5 is in point contact with only two places on the raceway surfaces 1a and 2b and the other rolling element 5 is on the raceway surfaces 1b and 2a (11, 11, 1).
Since 2 ・ 12) is not performed, large spin in the conventional four-point contact bearing can be eliminated.

Further, since the contact form between the rolling elements 5 and 5 and the outer and inner rings 1 and 2 is the same as that of a general ball bearing, the rolling resistance is lower and a lower torque can be realized as compared with a cross roller.

[Second Embodiment] FIG. 3 shows a second embodiment. In this embodiment, the two inner rings 2, 2 in the first embodiment are fixed with bolts or rivets 4, so that adjustment of preload or clearance is not required. The other configuration and operation and effect are the same as those of the first embodiment.

"Third Embodiment" FIG. 4 shows a third embodiment. In this embodiment, the outer ring 1 and the inner ring 2 are of an integral type instead of the outer ring 1 and the inner ring 2 and the two-partition type of the first embodiment. The other configuration and operation and effect are the same as those of the first embodiment.

"Fourth Embodiment" FIG. 5 shows a fourth embodiment. In this embodiment, the divided outer races 1, 1 in the third embodiment are fixed by bolts or rivets 4, so that adjustment of preload or clearance is not required. The other configuration and operation and effect are the same as those of the first embodiment.

"Fifth Embodiment" FIG. 6 shows a fifth embodiment. In this embodiment, as shown in the figure, the outer ring 1 and the inner ring 2 are formed integrally with each other, the outer ring 1 is provided with a hole for a rolling element, and instead of the retainer 6 in the first embodiment, The rolling elements 5 and 5 are guided by a separator (spacer) 8 as shown enlarged in FIG. Such a structure allows the bearing to be more compact. The other configuration and operation and effect are the same as those of the first embodiment.

The separator 8 has a smaller diameter than the diameter of the rolling element 5 and holds the rolling elements 5, 5 held adjacent to each other, as described above, with the rotation center axis 5 perpendicular to the relative surfaces 5b, 5b, 5b, 5b.
Concave arc grooves 9, 9 for holding c and 5c in an intersecting shape are formed in the intersecting surfaces 10 and 10 in an intersecting shape.

"Sixth Embodiment" FIG. 8 shows a sixth embodiment. This embodiment is used for high-speed rotation. Rolling member 5 having symmetrical relative surfaces 5b in the first embodiment
Instead of the asymmetrical relative surfaces 5b ', 5b shown in FIG.
d 'is used, and the large end 5d' of the relative surfaces 5b 'and 5d' is the inner ring 2 of the bearing.
, The rotation of the rolling elements 5 'becomes more stable, and a lower torque can be realized. The other configuration and operation and effect are the same as those of the first embodiment.

"Seventh Embodiment" FIG. 10 shows a seventh embodiment. In the present embodiment, the inner ring 2, 2 divided into two parts in the sixth embodiment is fixed with bolts or rivets 4, so that adjustment of preload or clearance is not required. Other configurations, functions and effects are the same as those of the sixth embodiment.

[Eighth Embodiment] FIG. 11 shows an eighth embodiment. In this embodiment, the outer ring 1 and the inner ring 2 are of an integral type instead of the outer ring 1 and the inner rings 2 and 2 of the sixth embodiment which are divided into two. Other configurations, functions and effects are the same as those of the sixth embodiment.

Ninth Embodiment FIG. 12 shows a ninth embodiment. In the present embodiment, the outer ring 1, 1 divided into two parts in the eighth embodiment is fixed with bolts or rivets 4, so that adjustment of preload or clearance is not required. Other configurations, functions and effects are the same as those of the sixth embodiment.

"Tenth Embodiment" FIG. 13 shows a tenth embodiment. In this embodiment, as shown in the figure, the outer ring 1 and the inner ring 2 are formed integrally with each other, the outer ring 1 is provided with a hole for a rolling element, and instead of the retainer 6 in the first embodiment, The rolling elements 5 and 5 are guided by a separator (spacer) 8 as shown enlarged in FIG. Such a structure allows the bearing to be more compact. Other configurations, functions and effects are the same as those of the sixth embodiment.

"Eleventh Embodiment" FIGS. 15 to 17 show the eleventh embodiment. FIG. 15 is a longitudinal sectional view showing the rolling bearing of this embodiment with a part omitted, FIG. 16 is an enlarged perspective view showing an embodiment of a cage, and FIG. 17 is an enlarged perspective view showing one embodiment of a rolling element. . This embodiment is an example of an embodiment using a machined cage (annular cage) 6 ′ as shown in FIG. 16 instead of the cage 6 used in the first embodiment and the like. By 6 ', the posture of each rolling element 5 is maintained.

The retainer 6 'is provided with a rotating central axis 5 perpendicular to the relative surfaces 5b, 5b, 5b, 5b.
The pockets 13 which can be incorporated alternately so that c and 5c are respectively intersected are arranged at equal intervals and alternately in an intersecting manner at the same number as the number of rolling elements 5 on the circumference of the annular body. It is configured. The axial side surfaces 13a and 13b of the pockets 13 are alternately parallel to each other and neither perpendicular nor parallel to the rotation axis of the bearing, and have a constant angle (inclined) at the same level as the contact angle of the rolling element 5. ing. Each pocket 13 ...
The distance between both side surfaces 13a and 13b in the axial direction of
Is slightly larger than the width. Above pocket 13
The shape of the pocket has an inclined parallel side surface 13a, 13b, and if the distance between both side surfaces 13a, 13b is formed slightly larger than the width of the rolling element 5, the overall shape of the pocket is It should not be construed that the invention is particularly limited, and can be modified within the scope of the present invention. In this embodiment,
On the circumference, the rolling elements 5... The same number of pockets 13... Are arranged at equal intervals and alternately in an intersecting manner, but are not particularly limited. Intersecting or intersecting such as two by one is within the scope of the present invention. The material of the retainer 6 'is not particularly limited, and may be a metal such as brass or iron, or a plastic such as a synthetic resin. For example,
Polyamide 66 (nylon 66) and polyphenylene sulfide (PPS) are selected. The guide method of the retainer 6 'is not particularly limited, and may be inner ring guide, outer ring guide, or rolling element guide. Also, the configuration of the retainer 6 'is not particularly limited, and may be an integral type or formed from several parts.

Under the influence of various factors, there is a possibility that spin or skew may occur in the rolling element during rotation. If the attitude of the rolling element cannot be controlled well, the rotational resistance of the bearing will increase or smooth rotation will occur. May not be possible. Therefore, according to the present embodiment, the pocket 13 of the retainer 6 'is provided with the parallel side surfaces 13a and 13b which are substantially the same as a fixed angle of the same level as the contact angle of the rolling element 5 and the pocket side surfaces 13a. , 13b, the rolling element 5
Therefore, a change in the posture of the rolling element 5 due to spin, skew, or the like is suppressed, and the posture of the bearing can be maintained, so that a lower torque of the bearing can be realized.

The other constructions and operational effects are the same as those of the first to fourth embodiments and the sixth to ninth embodiments. That is, in the present embodiment, the outer ring 1 and the inner ring 2
Is an integral type, but is not particularly limited, and one or both of the outer rings 1 and 2 are divided into two in the axial direction at the center in the width direction. Are often selected within the scope of the present invention. Some of the split types are assembled integrally with bolts / rivets 4 or the like. In this embodiment, as shown in FIG. 17, a rolling element similar to that of the first embodiment is used as the rolling element 5, but the rolling element 5 'used in the sixth to ninth embodiments is used. Can also be used. That is,
A rolling element (vertical cut ball) 5 'having asymmetrical relative surfaces 5b', 5d 'is used, and the large end 5d' of the relative surfaces 5b ', 5d' is arranged to face the inner ring 2 of the bearing. It is also within the scope of the present embodiment that the rotation of the rolling element 5 'becomes more stable and lower torque can be realized.

[0039]

According to the present invention, because of the above-mentioned configuration, a single bearing can receive a radial load, an axial load and a moment load in both directions.

According to the present invention, the following effects can be obtained in addition to the above effects. Since each rolling element is always in two-point contact with the raceway groove of the raceway, an increase in torque due to a large spin of the ball in the conventional four-point contact bearing can be suppressed. Furthermore, since the outer diameter of the rolling element as a rolling contact surface is also formed with a curvature in the axial direction, the rolling resistance is lower and the torque can be reduced as compared with the cross roller.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view partially showing a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing one embodiment of a rolling element.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention with a part omitted;

FIG. 4 is a longitudinal sectional view partially showing a third embodiment of the present invention;

FIG. 5 is a longitudinal sectional view partially showing a fourth embodiment of the present invention;

FIG. 6 is a longitudinal sectional view partially showing a fifth embodiment of the present invention;

FIG. 7 is an enlarged perspective view showing one embodiment of a separator.

FIG. 8 is a longitudinal sectional view showing a sixth embodiment of the present invention with a part omitted;

FIG. 9 is an enlarged perspective view showing another embodiment of the rolling element.

FIG. 10 is a longitudinal sectional view showing a seventh embodiment of the present invention with a part being omitted;

FIG. 11 is a longitudinal sectional view partially showing the eighth embodiment of the present invention;

FIG. 12 is a longitudinal sectional view showing a ninth embodiment of the present invention with a part omitted;

FIG. 13 is a longitudinal sectional view partially showing the tenth embodiment of the present invention;

FIG. 14 is an enlarged perspective view showing another embodiment of the separator.

FIG. 15 is a vertical cross-sectional view partially showing the eleventh embodiment of the present invention.

FIG. 16 is an enlarged perspective view showing another embodiment of the cage.

FIG. 17 is an enlarged perspective view showing one embodiment of a rolling element.

FIG. 18 is a longitudinal sectional view of a cross roller bearing according to an example of the related art.

FIG. 19 is a longitudinal sectional view of a four-point contact ball bearing as an example of the prior art.

[Explanation of symbols]

 1: outer ring 2: inner ring 3: raceway groove 5: rolling element 5a: outer diameter 5b: relative surface 5c: rotation center axis 6, 6 ': retainer 8: separator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16C 33/60 F16C 33/60 F-term (Reference) 3J101 AA13 AA15 AA25 AA26 AA32 AA33 AA42 AA54 AA62 BA02 BA13 BA34 BA44 BA53 BA54 BA64 FA02 GA32 GA53 GA55

Claims (1)

[Claims] A plurality of rolling elements are incorporated between a pair of races, each of the races has a raceway groove composed of two raceway surfaces having a diameter larger than the radius of the rolling bodies, and The moving body is
The outer diameter serving as a rolling contact surface also has a curvature in the axial direction, and continuous rolling elements are arranged alternately in an intersecting manner, and the outer diameter of each rolling element is always equal to the raceway surface of one of the raceways. A rolling bearing having two points of contact with the raceway surface of the other raceway.