JP2002206526A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing capable of receiving a radial load, axial loads in both directions, and a moment load by one bearing capable of improving a characteristic of resistance against spin wear, providing high moment rigidity, and reducing torque. SOLUTION: This rolling bearing consists of a bearing ring 1 having a raceway surface 4, a bearing ring 2 having a raceway surface 5, and a rolling body 6 incorporated between inner and outer rings 1 and 2. The raceway surface 4 of at least one bearing ring 1 is composed of two raceway surfaces 4a, 4b, which are constituted to have large diameters than a radius of the rolling body 6. Each rolling body is constituted such that an outside diameter 6a which becomes a rolling contact face has a curvature in the axial direction and is arranged in a crossing manner alternately on circumference. The outside diameter 6a of each rolling body 6 comes into contact at two points in total, namely, at one point of the raceway surface 4a of the bearing ring 1 on one side and the raceway surface 5 of the bearing ring 2 on the other side which oppose mutually and at one point of the raceway surface 4b of the bearing ring 1 on one side and the raceway surface 5 of the bearing ring 2 on the other side, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as a bearing capable of receiving a radial load, an axial load and a moment load in both directions, a cross roller bearing as shown in FIG. 8, a four-point contact ball bearing as shown in FIG. Alternatively, a three-point contact ball bearing as shown in FIG. 10 is known. In the cross roller bearing, the rolling elements 300 incorporated between the races (the inner ring 100 and the outer race 200) are rollers, and the rolling elements 300 and the race 1
Since 00 and 200 are in line contact at two locations, they have the advantage of high moment rigidity. In the four-point contact ball bearing or the three-point contact ball bearing, the rolling element 400 incorporated between the races (the inner ring 100 and the outer ring 200) is a ball, and the rolling element 400 and the race 10
It has the advantages of low torque and smooth operation because it comes in point contact with 0.20 at four or three points.

[0003]

However, the cross roller bearing has the advantage of large moment rigidity, but has the disadvantage of large torque and torque fluctuation because the rolling element 300 and the races 100 and 200 are in line contact. A four-point contact ball bearing or a three-point contact ball bearing
Since 0 is a ball, there is an advantage that torque is smaller than a cross roller of the same size, but there is also a disadvantage that moment rigidity is small. In addition, when the radial load is dominant over the axial load or when a pure radial load is applied, each ball 400 comes into contact with the orbital rings 100 and 200 at four or three places, so that the ball has a large spin and a small spin wear. No performance is obtained. Further, the gap between the bearings is usually set to a positive value in order to improve the spin wear performance as much as possible, and as a result, the moment rigidity of the bearing is reduced.

The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to realize high moment stiffness and low torque while improving spin wear resistance. An object of the present invention is to provide a rolling bearing capable of receiving a radial load, an axial load in both directions, and a moment load with one bearing.

[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 having a larger diameter raceway surface, in which at least one raceway ring has two raceway surfaces, and each of the rolling elements has an outer diameter that becomes a rolling contact surface also in the axial direction. It has a curvature and is arranged alternately in an intersecting manner on the circumference, and the outer diameter of each rolling element is always one point on the raceway surface of one raceway and the raceway surface of the other raceway that are always opposed. That is, contact at a total of two points.

[0006]

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

In the rolling bearing, a plurality of rolling elements 6, 6,... 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. As the bearing rings 1 and 2, a type in which one or both of them are divided into two parts in an axial direction at an arbitrary position in the width direction, and a type in which neither the bearing rings 1 and 2 are divided. Some of the two-split types are assembled integrally with bolts and rivets.

The raceway groove 3 is formed by raceway surfaces 4 and 5 having a radius larger than the radius of the rolling element 6. Further, the raceway groove 3 of at least one of the raceways 1 and 2 is composed of two raceway surfaces 4a and 4b or 5a and 5b. The shape of each of the raceway surfaces 4 (or 4a and 4b) and 5 (or 5a and 5b) may be arch-shaped or V-shaped as long as it has a shape suitable for rolling of the rolling element 6.
The shape may be arbitrarily shaped such as a character, or may be any shape such as a curved shape or a linear shape, and is not particularly limited.

The rolling element 6 has an outer diameter 6a serving as a rolling contact surface.
Have a curvature in the axial direction, and the raceway surface 4 (or 4a
4b) and 5 (or 5a and 5b), each having an arbitrary shape having a smaller radius than each of the rolling elements 6. The rolling elements 6 are arranged such that adjacent rolling elements 6 are alternately arranged in an intersecting manner. The outer diameter 6a of the moving body 6 is always equal to the raceway surface 4 of one race 1
(Or 4a, 4b) and the raceway surface 5 of the other raceway 2
(Or 5a and 5b), each of which is in contact with one point at a total of two points.

For example, the rolling element 6 includes a pair of relative surfaces 6b,
A vertically-cut ball having a vertical cutting surface 6b (having a structure in which the upper and lower portions of the ball are cut to form relative surfaces 6b, 6b; the same applies hereinafter).
Each of the rolling elements 6, 6... is assembled so that c has an intersecting shape, and the outer diameter 6a of each of the rolling elements 6 is always equal to the raceway surface 4 (or 4a, 4b) of one race 1 and the other. Are in contact with each other on the raceway surface 5 (or 5a, 5b) of the raceway ring 2 at a total of two points.

The upper and lower cutting widths of the rolling element 6 are not particularly limited, and the upper and lower cutting ratios may be equal or unequal, and can be arbitrarily selected within the scope of the present invention. That is, the relative surfaces 6b, 6b of the rolling elements 6
Both symmetric and asymmetric may be within the scope of the present invention.

Incidentally, the overall shape of the rolling element 6 and the relative surfaces 6b, 6
The presence or absence of b and the magnitude of the curvature in the axial direction at the outer diameter 6a 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, in place of the relative surfaces 6b, 6b, non-parallel surfaces may be provided, and a rotation center axis 6c perpendicular to the both surfaces may be provided.

The rolling elements 6, 6... Are assembled by the relative surfaces 6b, 6b, 6b, 6 of the adjacent rolling elements 6, 6.
The rotation center axes 6c, 6c perpendicular to b are alternately crossed, but the crossing state may be orthogonal or non-orthogonal.

The method of arranging the rolling elements 6 in an intersecting manner is not particularly limited as long as the numbers are the same in both cases, that is, the rolling elements 6 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 6, 6 is guided by a cage 7 or a separator (spacer) 9.

The retainer 7 and the separator (spacer) 9
Pockets 8 for holding and guiding the rolling elements 6 or grooves 1
The shape is not particularly limited as long as it has a shape of 0 and 10, and can be arbitrarily selected and changed within the scope of the present invention. The guide system of the retainer 7 is not particularly limited, and may be inner ring guide, outer ring guide, or rolling element guide. Further, the configuration and shape of the retainer 7 are not particularly limited, and may be, for example, an integral type or formed from several parts.

For example, the cage 7 can incorporate the adjacent rolling elements 6, 6 alternately so that the rotation center axes 6c, 6c perpendicular to the relative surfaces 6b, 6b, 6b, 6b, respectively, cross each other. The pockets 8 are placed on the rolling elements 6 on the circumference of the annular body.
.. Are arranged at equal intervals and alternately in an intersecting manner with the same quantity as the quantity. The axial side surfaces 8a and 8b of the pockets 8 are alternately parallel to each other, 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 6. ing.

Both side surfaces 8a, 8 in the axial direction of each pocket 8.
The distance between b is slightly larger than the width of the rolling element 6. If the pocket 8 has slanted parallel side surfaces 8a and 8b, and the distance between the side surfaces 8a and 8b is formed to be slightly larger than the width of the rolling element 6, the pocket 8 may have the same shape. The overall shape is not particularly limited and can be changed within the scope of the present invention.

In this embodiment, the rolling elements 6 are arranged on the circumference.
The same number of pockets 8 are arranged at equal intervals and alternately in an intersecting manner, but are not particularly limited. If both have the same number, they intersect two by two or one by one. 2
They may intersect as if they are within the scope of the present invention.

Due to the influence of various factors, there is a possibility that spin or skew may occur in the rotating rolling element. If the attitude of the rolling element cannot be controlled well, the rotational resistance of the bearing may increase or the rotation may occur smoothly. May not be possible. Therefore, according to the present embodiment, the pocket 8 of the retainer 7 is provided with the parallel side surfaces 8a and 8b which are substantially the same as a fixed angle of the same level as the contact angle of the rolling element 6, and the pocket side surfaces 8a and 8b are formed. 8b suppresses a change in the attitude of the rolling element 6 due to spin, skew, or the like of the rolling element 6, and can maintain the attitude of the bearing. Therefore, it is possible to reduce the torque of the bearing.

The separator 9 has a smaller diameter than the diameter of the rolling element 6, and the rotating center axis 6 perpendicular to the relative surfaces 6b, 6b, 6b, 6b holds the adjacent rolling elements 6, 6 as described above.
Concave arc grooves 10, 10 for holding c and 6c in an intersecting shape, respectively, are formed in an intersecting manner on the relative surfaces 11, 11. The radius of curvature of the arc groove 10 may be substantially the same as or larger than the radius of curvature of the rolling element outer diameter 6a, and is arbitrary. By using the separator 9 in this manner, the entire bearing can be made compact.

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 bearing rings 1 and 2 and the rolling elements 6 of these bearings, bearing steel is usually used. However, in order to improve the corrosion resistance and heat resistance according to the use environment, a corrosion-resistant coating,
Stainless steel, heat-resistant steel (for example, M50, etc.), ceramic, and the like are appropriately selected and are not particularly limited. Further, as the material of the retainer 7, an extruded retainer, a press retainer,
Since a 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. Not done.

FIG. 3 shows an embodiment of a rolling element having an asymmetrical relative surface. The rolling element 6 'of this embodiment is used particularly in the case of high-speed rotation. The rolling element 6 'of the present embodiment is a rolling element (a vertically cut ball) having asymmetrical relative surfaces 6b' and 6d '.
6 ', by arranging the large ends 6d' of the relative surfaces 6b ', 6d' so as to face the inner ring 2 of the bearing, the rotation of the rolling elements 6 'becomes more stable and lower torque can be realized. it can.
6a 'indicates the outer diameter, and 6c' indicates the rotation center axis. The other configuration and effects are the same as those of the rolling element 6 described above, and the description thereof is omitted.

The internal clearance of the bearing is set to be small or negative as necessary. Thereby, higher moment rigidity of the bearing can be realized.

In the drawing, reference numeral 14 denotes a sealing plate.
Corresponds to either a contact type seal or a non-contact type seal, or a non-contact type shield, and the shape thereof is not particularly limited, and a known shape is appropriately selected within the scope of the present invention. . In the drawing, 14a is the inner ring seal groove 2a.
3 shows a sealing surface of a sealing plate 14 which is in close contact with the inner bottom and serves as a sealing surface.

The method of arranging the sealing plate 14 is not particularly limited, and may be arranged on both sides or on one side, if necessary, and both are within the scope of the present invention. Both the outer ring side and the inner ring side of the sealing surface are within the scope of the present invention. The shape of the seal, for example, the lip shape is not particularly limited, and even in line contact with the sealing surface, even in surface contact,
Either is within the scope of the present invention. Further, the presence or absence of the core metal is free, and the type having the core metal and the type without the core metal may be properly used as needed, and are not particularly limited. Also, the seal groove structure of the outer ring 1 and the inner ring 2 is not particularly limited, and can be appropriately changed within the scope of the present invention.
The presence or absence of the sealing plate 14 is not particularly limited, and it is within the scope of the present invention whether or not it is installed as necessary.

[0028]

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 6, 6 are upper and lower cut balls having a pair of relative surfaces 6b, 6b, respectively, as shown in FIG. 2, and the inner ring formed integrally with the outer ring 1.1 of the bearing divided into two. 2 and 3 are interposed in the raceway grooves 3.3 formed. In the present embodiment, the raceway groove 3 composed of two raceway surfaces 4a and 4b each having a radius larger than the radius of the rolling element 6 and the radius larger than the radius of the rolling element 6 are formed. The raceway groove 3 has one raceway surface 5 and the relative surfaces 6b, 6b of the rolling elements (upper and lower cut balls) 6 are symmetrical.

The rotation center axes 6c, 6c of the rolling elements 6, 6 perpendicular to the relative surfaces 6b, 6b are arranged so as to intersect alternately. Guided at 8,8. The retainer 7 has a pocket 8 in which the adjacent rolling elements 6, 6 can be alternately assembled so that the rotation center axes 6c, 6c perpendicular to the relative surfaces 6b, 6b, 6b, 6b cross each other as described above. Are arranged at equal intervals and alternately in an intersecting manner with the same number of rolling elements 6 on the circumference of the annular body.

Therefore, according to the first embodiment, the outer diameter 6a of the rolling element 6 contacts the raceway surface 4a of the outer race 1 and the raceway surface 5 of the inner race 2 which are opposed to each other at a total of two points. 1
2 and 12), and the adjacent rolling elements 6 contact the raceway surface 4b of the outer race 1 and the raceway surface 5 of the inner race 2 at one point each, for a total of two points (contact points 13 and 13).

Since the contact angles of the rolling elements 6 and 6 alternately intersect, a single bearing can receive a radial load and an axial load and a moment load in both directions. The rolling element 6 is at one point on each of the raceway surfaces 4a and 5 and the other rolling element 6 is at one point on each of the raceway surfaces 4b and 5, and only two points (two points) are in point contact (12.12, 12). 13.13), large spin in the conventional four-point contact bearing can be eliminated.

Furthermore, since the contact form between the rolling elements 6, 6 and the outer and inner rings 1, 2 is the same as that of a general ball bearing, the rolling resistance is lower and the torque can be reduced as compared with a cross roller.

"Second Embodiment" FIG. 6 shows a second embodiment. In this embodiment, the outer ring 1 has one raceway surface, the inner ring 2 has two raceway surfaces, the outer ring 1 is integrated, and the inner ring 2 is of a two-part type. The other configuration and operation and effect are the same as those of the first embodiment.

"Third Embodiment" FIG. 7 shows a third embodiment. In this embodiment, both the outer race 1 and the inner race 2 have two raceway surfaces 1a and 1b, 2a and 2b, and the outer race 1 is divided into two parts.
The inner ring 2 is an integral type. The other configuration and operation and effect are the same as those of the first embodiment. Further, similarly to the present embodiment, the outer ring 1 and the inner ring 2 are each composed of two raceways, the outer ring 1 is of an integral type, the inner ring 2 is of a split type, and both the outer ring 1 and the inner ring 2 are respectively. The same applies to the two-split type.

[0036]

According to the present invention, since the rolling elements are arranged so as to alternately intersect on the circumference between the outer and inner rings, one bearing receives the radial load and the axial load and the moment load in both directions. Can be Since each rolling element is always in contact with the outer and inner races at only two locations, slippage due to large spin in the conventional four-point contact ball bearing or three-point contact ball bearing is small, and the anti-spin wear characteristics can be improved. Since the bearing clearance can be set small or negative as required, high moment rigidity can be realized. Further, since the rolling element is a ball and the rolling element and the bearing ring make point contact, the rolling resistance is lower and the torque can be reduced as compared with the cross roller. As a result, the overall device can be made more compact, lighter and more durable, and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view 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 an enlarged perspective view showing another embodiment of a rolling element.

FIG. 4 is a perspective view showing one embodiment of a retainer.

FIG. 5 is a perspective view showing one embodiment of a separator.

FIG. 6 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing a third embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a cross roller bearing according to an example of the related art.

FIG. 9 is a longitudinal sectional view of a four-point contact ball bearing as an example of the prior art.

FIG. 10 is a longitudinal sectional view of a three-point contact ball bearing as an example of the prior art.

[Explanation of symbols]

 1: raceway ring (outer ring) 2: raceway ring (inner ring) 3: raceway groove 4 (4a, 4b): outer raceway side raceway surface 5 (5a, 5b): inner raceway side raceway surface 6: rolling element 6a: outer diameter 6b: Relative surface 6c: central axis 12: contact point 13: contact point

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J101 AA15 AA25 AA32 AA33 AA41 AA54 AA62 BA06 BA13 BA14 BA34 BA44 BA53 BA54 BA55 BA56 BA64 DA05 EA02 EA06 EA13 EA31 EA36 EA41 FA15 FA31 FA44 FA51 FA53 FA60 GA31 GA55

Claims (1)

[Claims] A plurality of rolling elements are incorporated between a pair of races, and each of the races has a raceway groove having a raceway surface having a diameter larger than the radius of the rolling body, and at least one raceway groove is provided therein. One race is composed of two raceways, and each rolling element has a rolling contact surface whose outer diameter also has a curvature in the axial direction,
The rolling elements are arranged alternately in an intersecting manner on the circumference, and the outer diameter of each rolling element is always one point each on the raceway surface of one of the raceways and the raceway surface of the other raceway. A rolling bearing characterized by being in contact.