JP2003097549A - Rolling bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing device adaptable for a machine tool of high-speed run or the like, having saved space and lower cost. SOLUTION: A rotating shaft 14 is supported by two cylindrical roller bearings 15 and one rolling bearing. The bearing has a plurality of rollers 6 incorporated between an outer ring 1 and an inner ring 2, and the outer ring 1 and the inner ring 2 each have a raceway groove consisting of raceway surfaces 4, 5 with their diameters larger than the radius of the roller 6, in which at least one bearing ring consists of two raceway surfaces 4a.4b (5a.5b). The rollers 6 each having an outer diameter 6a as a rolling contact surface with a curvature in the axial direction are alternately arranged crossing one another on a circumference. The outer diameters 6a of the rollers 6 contact one another at one point each, or two points in total, one point being one raceway surface 4a of the outer ring 1 and one raceway surface 5b of the inner ring 2 facing thereto and the other point being between one raceway surface 4b of the outer ring and one raceway surface 5a of the inner ring 2 facing thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing device used for a spindle of a machine tool or other general high speed rotating equipment.

[0002]

2. Description of the Related Art Conventionally, as shown in, for example, FIGS. 15 to 17, a bearing used for a high-speed rotating machine such as a machine tool spindle has an angular contact ball bearing and a four-point bearing because of its high speed and axial rigidity. Contact ball bearings are used.
Reference numeral 400 in the figure denotes a rotation axis. In FIG. 15, two cylindrical roller bearings 100 apply a radial load, and two angular ball bearings 200 implement a bidirectional axial load load or axial displacement limitation. In FIG. 16, the radial load is applied together with one cylindrical roller bearing 100 while the four angular ball bearings 200 limit the axial load in two directions or the axial displacement. In FIG. 17,
As in FIG. 15, two cylindrical roller bearings 100 apply a radial load, but one four-point contact ball bearing 300 as shown in FIG. 18 realizes a bidirectional axial load load or axial displacement limitation. To do. In the figure, 301 is an outer ring, 30
2 is an inner ring, 303 is a rolling element, and 304 is a cage.

[0003]

As described above, the above conventional technique has the following problems. In the structure using the angular ball bearings 200 as shown in FIGS. 15 and 16, one angular ball bearing 200 can only receive an axial load in one direction, and therefore, in order to receive an axial load in both directions, usually two or more angular ball bearings are used. Angular contact ball bearing 20
0 is used in combination. However, bearings used in high-speed rotating machines such as machine tool spindles are very expensive because high precision is required, and the angular ball bearing 20
Since the axial dimension of the bearing device increases as the number of 0's arranged increases, there is a problem that not only the bearing device, but in fact, the entire system cannot be made compact, but also the cost of the entire device increases. Further, as shown in FIG. 17, in the structure using the four-point contact ball bearing 300 shown in FIG. 18,
Radial load and axial load in both directions with one bearing,
A moment load can be received and the function of two angular contact ball bearings can be realized by one 4-point contact ball bearing 300, so there are advantages of compactness and low cost. However, when the radial load is dominant with respect to the axial load or when the pure radial load is received, in the case of the four-point contact ball bearing 300, each ball 303 has the bearing rings 301, 302 and 4 respectively.
Since the balls contact each other at points, the spin of the ball 303 is large, and there is a problem that a small spin wear performance cannot be obtained. Especially in the case of a high-speed machine tool, this problem is remarkable due to the action of centrifugal force. Furthermore, in order to improve the spin wear performance even a little, the bearing clearance is usually set to a positive value, resulting in a reduction in the rigidity of the bearing, which adversely affects the overall rigidity of the bearing system supporting the rotating shaft. I will end up. The present invention is
The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a rolling bearing device which is space-saving and low-cost and suitable for high-speed rotation of a machine tool or the like.

[0004]

Means for Solving the Problems To achieve the above object, the technical means of the present invention is a bearing device in which a rotating shaft is supported by a bearing, and the bearing device includes a pair of raceways. A plurality of rolling elements are incorporated between the rings, and each of the above-mentioned races has a raceway groove formed of a raceway surface having a diameter larger than the radius of the rolling body, and at least one raceway ring has two raceway surfaces. Each of the rolling elements has an outer diameter serving as a rolling contact surface which also has a curvature in the axial direction, and the outer diameters of the respective rolling elements face each other in an alternating manner on the circumference. That is, at least one rolling bearing is used, which is in contact with each of the raceway surfaces of one raceway ring and the raceway surface of the other raceway ring at one point at a total of two points. Further, the rolling bearing device has a rotating shaft supported by one rolling bearing and two cylindrical roller bearings having the above-mentioned configuration. Further, the rolling bearing device has two rolling bearings having the above-described structure and a rotating shaft supported by one cylindrical roller bearing.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the rolling bearing device of the present invention will be described below with reference to the drawings. Note that the present embodiment is merely one embodiment of the present invention and should not be construed as being limited thereto.

In the rolling bearing device of the present invention, the main shaft of a machine tool and other rotating shafts of general high-speed rotating equipment are supported by using at least one rolling bearing having the following structure. That is, the number of rolling bearings supporting the rotating shaft is not particularly limited, and may be one or more than one, and is appropriately selected as necessary. Further, this rolling bearing may be used in combination with other type bearings such as a cylindrical roller bearing.

The rolling bearing comprises a plurality of rolling elements 6, 6 ... In a raceway groove 3 formed between an inner diameter of a raceway ring (outer ring) 1 and an outer diameter of a raceway ring (inner ring) 2. Bearing rings 1, 2
May be integrally formed, or one or both of them may be axially divided into two parts at arbitrary positions in the width direction and integrally assembled by a fixing method such as a bolt and a rivet without limitation. In the case of splitting into two, if there is a flange portion, the fixing of the flange portion may also serve as the fixing action of the split raceway ring. In this case, the shape structure of the flange is not particularly limited,
The axial dimension of the flange may be symmetrical or asymmetrical and is not particularly limited and the design can be changed within the scope of the present invention. In addition, a spigot or the like may be formed on the flange to improve the mounting position accuracy of the flange and the mounting counterpart component.

The raceway groove 3 is formed by raceway surfaces 4 and 5 having a radius larger than that of the rolling element 6. The raceway surfaces 4, 5 of the raceway groove 3 of at least one of the raceways 1, 2 are composed of two raceway surfaces 4a, 4b or 5a, 5b each having a radius larger than the radius of the rolling element 6. ing. The raceway surfaces 4 (or 4a and 4b) and 5 (or 5a and 5b) may have any shape such as an arched section or a V shape as long as they have a shape suitable for rolling of the rolling elements 6. In addition, the shape may be curved or straight, and is not particularly limited, but, for example, a Gothic arch formed by both arcs having circular centers arranged in a cross is applied. Further, in the present embodiment, the structure is such that the grinding relief is formed at the intersection of the raceway surfaces 4a, 4b (5a, 5b) to facilitate the grinding process, but it is a continuous elliptical shape without forming the grinding relief. It is also possible to form a raceway groove. FIG. 1 shows an outer ring integrated / inner ring split type, each of which has two raceway surfaces 4a, 4b and 5a, 5b. FIG. 4 shows an outer ring integrated / inner ring split type, in which the outer ring has one raceway surface. Raceway surface 5a consisting of 4 and two inner rings,
5b, FIG. 5 shows an example of an outer ring split / inner ring integrated type, each of which has two raceway surfaces 4a, 4b and 5a, 5b.

The rolling element 6 has an outer diameter 6a serving as a rolling contact surface.
Has a curvature in the axial direction, and the raceway surfaces 4 (4a, 4b),
5 (5a, 5b) has an arbitrary shape having a smaller radius than each of the radii of 5 (5a, 5b), and the rolling elements 6 are arranged such that rolling elements 6 adjacent in the circumferential direction are alternately arranged in an intersecting manner. The outer diameter 6a of 6 is always opposite to the raceway surface 4 of one of the races 1.
(4a) and the raceway surface 5 (5b) of the other raceway ring 2, and one raceway surface 4 (4b) of the one raceway ring 1 and the raceway surface 5 (5a) of the other raceway ring 2 respectively for a total of two points. Touching at points. For example, the rolling element 6 shown in FIG. 1 (b) has upper and lower cut balls having a pair of flat surfaces (relative surfaces) 6b and 6b (the upper and lower parts of the ball are cut to form the relative surfaces 6b and 6b). The same shall apply hereinafter.), The respective rolling elements 6, 6 ... Are incorporated so that the rotation center axes 6c perpendicular to the planes 6b, 6b are respectively crossed, and the outer diameter of each rolling element 6 is 6a
However, the raceway surface 4 (4a) of one raceway ring 1 and the raceway surface 5 (5b) of the other raceway ring 2 and the raceway surface 4 (4b) of one raceway ring 1 and the other raceway ring 2 that are always opposite to each other Orbital plane 5
In (5a), each point is in contact with two points in total. 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 and 6b of the rolling element 6 may be symmetrical or asymmetrical, and both are within the scope of the present invention.

FIGS. 6 (a) and 6 (b) show an embodiment of a rolling element in which a pair of planes are asymmetric, and this embodiment is used especially in the case of high speed rotation. The rolling element 6 of the present embodiment has asymmetrical flat surfaces (relative surfaces) 6b and 6d,
By arranging the large ends 6d of 6b and 6d so as to face the inner ring 2 of the bearing, the rotation of the rolling elements 6 becomes more stable and a lower torque can be realized. 6a indicates an outer diameter, and 6c indicates a rotation center axis. The other components and effects are the same as those of the rolling element 6 shown in FIG. 1, and the description thereof is omitted.

As shown in FIGS. 7 (a) and 7 (b), the rolling element 6 has a ball shape (one side cut spherical shape) formed by forming one plane (cut surface) 6e by cutting one of the upper and lower sides. May be The cut (cutting) width of the one-sided cut surface 6e is not particularly limited, and the shape of the cut surface 6e is not limited to a flat surface, and an arbitrary shape can be selected. If the one-side cut spherical structure is used in this manner, the number of processed portions is smaller than that of the above-described upper and lower cut balls, so that the ball can be manufactured at a lower cost.

The overall shape of the rolling element 6, the relative surfaces 6b, 6
The presence or absence of b (6d), the magnitude of the curvature in the outer diameter 6a in the axial direction, and the like are not limited to the above specific shapes, and can be arbitrarily changed within the scope of the present invention. That is, for example, instead of the relative surfaces 6b and 6b, both surfaces may be non-parallel and the rotation center axis 6c may be perpendicular to the both surfaces.

The rolling elements 6, 6 ... Are incorporated so that the rotation center axes 6c, 6c perpendicular to the relative surfaces 6b, 6b, 6b, 6b of the adjacent rolling elements 6, 6 are alternately crossed. However, the intersecting 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 number is the same in both cases, that is, the rolling elements 6 may intersect one by one and do not intersect each one. If both of them are the same in number, they may cross each other, such as two, one, one, two, etc., 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 cage 7 shown in FIG. 2 and the separator 9 shown in FIG.
The cage 7 of FIGS. 8 to 11 and the separator 9 of FIG. 12 are for the one-side cut spherical rolling element 6. Each of the cages 7 and the separator (spacer) 9 has a pocket 8 for holding and guiding the rolling element 6 ... Or grooves 10 and 10 (concave surface 12).
The shape is not particularly limited as long as it has respective shapes, and can be arbitrarily selected and changed within the scope of the present invention. The guide system of the cage 7 is not particularly limited, and may be inner ring guide, outer ring guide, or rolling element guide. Further, the structure and shape of the cage 7 are not particularly limited,
For example, it may be an integral type or may be formed from several parts. The material of the cage is not particularly limited, and a cage cage, a press cage, a resin cage or the like is appropriately selected. ) Resin, polypropylene (PP) resin, polyacetal (POM) resin, polyarylene sulfide resin typified by polyphenylene sulfide (PPS) resin, polyamide 66 (nylon 66), polyether ether ketone (PEEK), polyether nitrile (PEN), aromatic polyimide (P
I), thermoplastic polyimide (TPI), polyamideimide (PAI), aromatic polyester (LCP) and various fluorine-containing resins such as synthetic resins are selected within the scope of the present invention.

For example, in the cage 7 shown in FIG. 2, pockets 8 ... In which the rolling elements 6 and 6 adjacent to each other can be alternately inserted so that the rotation center axes 6c and 6c thereof intersect with each other, are annular bodies. Is an embodiment in which the same number as the number of rolling elements 6 ... Is arranged on the circumference of the circle at equal intervals and alternately in a cross shape. Both side surfaces 8a, 8b in the axial direction of each pocket 8 ...
Are alternately parallel and are neither perpendicular nor parallel to the rotation axis of the bearing, and are at a constant angle (inclined) at the same level as the contact angle of the rolling elements 6. The distance between the axially opposite side surfaces 8a and 8b of each pocket 8 is set to be slightly larger than the width of the rolling element 6. The pocket 8 has inclined parallel side surfaces 8a and 8b, and both side surfaces 8a and 8b.
If the distance between them is formed to be slightly larger than the width of the rolling element 6, the overall shape of the pocket is not particularly limited and can be changed within the scope of the present invention.
In the present embodiment, the same number of pockets 8 as the number of rolling elements 6 are arranged on the circumference at equal intervals and alternately in a cross shape. If they are the same, they may cross each other or may cross each other such as two, one, two, etc., and are within the scope of the present invention. Due to the influence of various factors, spin or skew may occur in the rolling element that is rotating.If the posture of the rolling element cannot be controlled well, the rolling resistance of the bearing may become large or it may not be able to rotate smoothly. there's a possibility that. Therefore,
According to the present embodiment, the pocket 8 of the cage 7 is the rolling element 6
The two parallel side surfaces 8a, 8b, which are substantially the same as the contact angle of the contact angle, are provided on both side surfaces 8a, 8b of the pocket.
By b, a change in the posture of the rolling element 6 due to a spin or a skew of the rolling element 6 is suppressed, and the posture of the bearing can be maintained, so that the torque of the bearing can be reduced.

The separator 9 shown in FIG. 3 has a diameter smaller than the diameter of the rolling element 6, and the rolling central axes 6c and 6c of the rolling elements 6 and 6 which are held adjacent to each other are intersected as described above. The concave arcuate grooves 10, 10 held on the relative surfaces 11, 1.
1 is formed in a cross shape. The radius of curvature of the circular 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 way, the entire bearing can be made compact.

The retainer 7 shown in FIG. 8 has a rotation center axis 6 which makes adjacent rolling elements 6, 6 perpendicular to the cut surfaces 6e, 6e.
The pockets 8, 8 ... Which can be alternately assembled are formed alternately in the circumferential direction so that c and 6c are crossed with each other.

The pocket 8 is formed in a dome shape in plan view by an arc surface 8c having a diameter slightly larger than that of the rolling element 6 and a flat surface 8d connecting between the ends of the arc surface 8c. 7
The side 8e on the a side and the side 8f on the inner side 7b are the outer diameter 7a.
From the side toward the inner diameter 7b side with the inclined surface 8g, and the outer diameter 7
The opening width w2 on the inner diameter 7b side is configured to be larger than the opening width w1 on the a side (FIGS. 8 and 9A). The centers of the circular arc surfaces 7a of the pockets 7 that are adjacent to each other in the circumferential direction are arranged on the same circumference and one side 8 on the outer diameter 7a side in the width direction in plan view.
It is arranged with the position of e shifted. That is, the circumferentially adjacent pockets 7 have the inclined surfaces 8g alternately arranged on the left and right sides (see FIG. 8).

Therefore, when the cage 7 shown in this embodiment is used, the rolling elements 6 arranged in the respective pockets 8 are arranged such that the rotation center axes 6c and 6c of the rolling elements 6 and 6 adjacent to each other alternate with each other. So that the respective cut surfaces 6e, 6e have an outer diameter of 7
It is held so as to face the a side, that is, the outer ring 1 side.

Further, as shown in FIG. 9B, the inclined surface 8
It is also possible to adopt a structure in which a one-sided fall prevention piece 8h is formed on the extension line of g so as to rise to the outer diameter 7a in the same inclined shape. The one-side tilt prevention piece 8h is not particularly limited to the illustrated shape, and is within the scope of the present invention as long as it does not affect the rotation of the rolling element 6.

The cage structure shown in FIG. 10 can be adopted for the cage 7. In the present embodiment, the pocket 8 is formed in a rectangular shape in plan view and has an outer diameter 7a extending in the circumferential direction.
Side 8e on one side and side 8f on the side of the lower inner diameter 7b
Is connected by an inclined surface 8g from the outer diameter 7a side toward the inner diameter 7b side, and the opening width w2 on the inner diameter 7b side is configured to be larger than the opening width w1 on the outer diameter 7a side (FIG. 10 and FIG. 11).

The pockets 8 arranged in the circumferential direction
Are alternately arranged in the width direction in plan view. That is, as for the pockets 8 that are adjacent to each other in the circumferential direction, the inclined surfaces 8g are alternately arranged on the left and right sides of each pocket 8 (see FIG.
0). The retainer 7 of this embodiment has the retainer 7 of FIG.
The grease holding space can be made larger than that. Other functions and effects are similar to those of the cage structure shown in FIG.

It is also within the scope of the present invention to arrange a separator (spacer) 9 having a concave surface 12 as shown in FIG. The separator 9 has a diameter smaller than the diameter of the rolling element 6, and the rolling elements 6 and 6 that are held adjacent to each other are perpendicular to the cut surfaces 6e and 6e as described above.
concave surface 12 for holding c and 6c so that they intersect each other,
12 is formed in a cross shape on the relative surfaces 11, 11. That is, the cut surface 6e of the rolling element is formed on the step portion 12a of the concave surface 12.
Hold them facing each other. The shape of the separator shown in this embodiment is only one embodiment, and the design can be arbitrarily changed without any limitation.

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 is within the scope of the present invention. . When a preload is applied, it is advantageous for improving the rigidity of the bearing. Also, the internal clearance of the bearing is set to be small or negative (negative) if necessary. As a result, higher moment rigidity of the bearing can be realized.

The presence or absence of the sealing plate is not particularly limited, and it is within the scope of the present invention whether the sealing plate is installed or not installed as required. The sealing plate corresponds to either a contact type seal, a non-contact type seal, or a shield, and the shape thereof is not particularly limited, and a well-known shape within the scope of the present invention is appropriately selected. The material of the seal or shield is not particularly limited, but
Nitrile rubber or stainless steel is preferred. The arrangement method of the sealing plate is not particularly limited, and may be arranged on both sides or one side as necessary, and both are within the scope of the present invention. Whether the sealing surface is the outer ring side or the inner ring side,
Both are within the scope of the present invention. The shape of the seal, such as the lip shape, is not particularly limited, and both the line contact and the surface contact with the sealing surface are within the scope of the present invention. In addition, the presence or absence of a cored bar is optional, and a type with a cored bar and a type without a cored bar may be used separately, and are not particularly limited. In FIG. 5, the inner ring 2 is integrated, the outer ring 1 is divided into two parts, and a sealing plate (contact seal) 13 is provided on the end surface of the outer ring 1. In the figure, 13a seals closely to the inner bottom of the inner ring sealing groove. Surface sealing plate 13
Shows the sealing surface of. Further, 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 materials of the outer ring 1, the inner ring 2, and the rolling elements 6 are not particularly limited, and may be bearing steel, carburized steel, stainless steel, heat-resistant steel such as M50, or ceramics.
Both are within the scope of the present invention. The components of the stainless steel are not particularly limited, and may be ostenite stainless steel, martensitic stainless steel, or precipitation hardening stainless steel, and can be changed within the scope of the present invention. The type of ceramic material is not particularly limited, and structural ceramic materials such as alumina-based, zirconia-based, silicon nitride-based, and silicon carbide-based can be selected. Further, the outer ring 1, the inner ring 2, and the rolling element 6 are not limited to being made of the same material, but may be made of different materials (hybrid) if necessary, and can be changed within the scope of the present invention. For example, the outer ring 1 and the inner ring 2 may be made of bearing steel, and the rolling element 6 may be made of ceramics (silicon nitride).

The surface treatment of the outer ring 1, the inner ring 2 and the rolling elements 6 is not particularly limited, but surface strengthening treatment such as carburizing or nitriding may be performed, and the outer ring 1, the inner ring 2 or the rolling element 6 may be surface-coated. However, it is within the scope of the present invention. When the coating treatment is performed, the coating material is appropriately selected from metals, metal compounds and ceramic coatings. The coating may be a single coating or a composite coating, both within the scope of the invention. For example,
The surface of the rolling element 6 is coated with silicon nitride.

The bearing lubricant is not particularly limited, and may be grease, oil, or water. The lubrication method is not particularly limited, and grease, circulation lubrication, spray lubrication,
Oil-air refueling, jet refueling, etc. are appropriately selected.

[0029]

[Embodiment] "First embodiment (FIG. 13)" In this embodiment, two normal cylindrical roller bearings 15 are used on the outer periphery of the shaft 14 and one of the above-mentioned rolling bearings is used. There is. That is, in the present embodiment, the outer ring 1 and the inner ring 2 are composed of two raceway surfaces 4a, 4b, 5a, 5b having different curvatures, and the inner ring 2 is integrally divided into the outer ring 1 and the rolling bearing shown in FIG. Is used as a substitute for the two angular ball bearings in the conventional bearing device. Further, the internal clearance of the bearing is set to be negative in order to improve the axial rigidity of the bearing device. "Second Embodiment (Fig. 14)" In this embodiment, one normal cylindrical roller bearing 15 is used on the outer periphery of the shaft 14 and the above-mentioned two rolling bearings are used. That is, in the present embodiment, the outer ring 1 and the inner ring 2 are composed of two raceway surfaces 4a, 4b, 5a, 5b having different curvatures, and the inner ring 2 is integrally divided into the outer ring 1 and the rolling bearing shown in FIG. Are used instead of the four angular bearings in the conventional bearing device. In the present embodiment, the spacer 16 is arranged between the two rolling bearings.

Therefore, since the rolling elements 6 are arranged between the outer and inner races 1 and 2 so as to alternately intersect with each other on the circumference, one bearing can receive the radial load, the axial load in both directions, and the moment load. . One bearing works as two angular bearings. Further, since each rolling element 6 is in contact with the outer and inner races 4, 5 only at two points, the slip due to the large spin in the conventional four-point contact ball bearing is small, and the spin wear resistance can be improved. Further, since the bearing gap can be set small or negative as necessary, high rigidity can be realized. Furthermore, since the rolling elements 6 and the outer and inner rings 1 and 2 are in point contact with each other, rolling resistance is low and high-speed rotation can be realized.

[0031]

According to the present invention, by using the bearing shown in FIG. 1 in a high-speed rotary bearing device such as a machine tool spindle, one bearing can realize the functions of two angular bearings and a four-point contact ball bearing. Since it has more spin wear resistance and low torque and high rigidity, it is possible to make the axial dimension smaller than the conventional support bearing device, and as a result, it is possible to reduce the size and weight of the entire device and improve the durability, and to reduce the cost. Can be down.

[Brief description of drawings]

FIG. 1A is an enlarged cross-sectional view showing a part of a rolling bearing that constitutes a rolling bearing device of the present invention, and FIG. 1B is a perspective view of a rolling element incorporated in the bearing shown in FIG.

FIG. 2 is a perspective view showing an embodiment of a cage.

FIG. 3 is a perspective view showing an embodiment of a separator.

FIG. 4 is a sectional view showing another embodiment of the rolling bearing.

FIG. 5 is a sectional view showing another embodiment of the rolling bearing.

6A is a sectional view showing another embodiment of the rolling bearing, and FIG. 6B is a perspective view of a rolling element incorporated in the bearing shown in FIG.

7A is a cross-sectional view showing another embodiment of a rolling bearing, and FIG. 7B is a perspective view of a rolling element incorporated in the bearing shown in FIG. 7A.

8 is a partially enlarged view showing an embodiment of a cage incorporated in the bearing of FIG. 7. FIG.

9 (a) is a partial sectional view of a pocket of the cage shown in FIG.
FIG. 6B is a partial cross-sectional view showing another form.

FIG. 10 is a partially enlarged view showing another embodiment of the cage.

FIG. 11 is a partial sectional view of a pocket of the cage shown in FIG.

12 is a perspective view of the rolling element separator shown in FIG. 7 (b).

FIG. 13 is a sectional view showing an embodiment of the bearing device of the present invention.

FIG. 14 is a cross-sectional view showing another embodiment of the bearing device of the present invention.

FIG. 15 is a sectional view of a conventional technique.

FIG. 16 is a cross-sectional view of another prior art.

FIG. 17 is a cross-sectional view of another prior art.

18 is a sectional view of the four-point contact ball bearing used in FIG.

[Explanation of symbols]

1: Bearing ring (outer ring) 2: Race ring (inner ring) 4: Outer ring raceway 5: Inner ring raceway 6: Rolling element 14: Rotation axis 15: Cylindrical roller bearing

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J101 AA04 AA32 AA42 AA54 AA62                       BA01 BA02 BA21 BA23 BA34                       BA51 BA53 BA54 BA64 EA03                       EA06 EA41 FA44 FA53 GA31

Claims (3)

[Claims] 1. A bearing device in which a rotating shaft is supported by a bearing, wherein a plurality of rolling elements are incorporated between a pair of bearing rings, and each of the bearing rings has a radius of a rolling element. Each of the rolling elements 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 serving as a rolling contact surface even in the axial direction. It has a curvature and is arranged alternately in a cross shape on the circumference, and the outer diameter of each rolling element is a total of one point each on the raceway surface of one of the opposing raceways and the raceway surface of the other raceway ring. A rolling bearing device comprising at least one rolling bearing which is in contact with two points. 2. A plurality of rolling elements are incorporated between a pair of races, and each of the races has a raceway groove formed of a raceway surface having a diameter larger than the radius of the rolling body, and at least one of them is provided therein. Each race consists of two raceways, and each rolling element has an outer diameter that serves as a rolling contact surface that also has a curvature in the axial direction. The outer diameter of the moving body is rotated by one rolling bearing and two cylindrical roller bearings, which are in contact with each other on the raceway surface of one raceway ring and the raceway surface of the other raceway ring, one point each. A rolling bearing device characterized in that a shaft is supported. 3. A plurality of rolling elements are incorporated between a pair of races, and each race has a raceway groove formed of a raceway surface having a diameter larger than the radius of the rolling body, and at least one of the raceways is formed therein. Each race consists of two raceways, and each rolling element has an outer diameter that serves as a rolling contact surface that also has a curvature in the axial direction. The outer diameter of the moving body is rotated by two cylindrical roller bearings and two rolling bearings that are in contact with each other on the raceway surface of one raceway ring and the raceway surface of the other raceway ring, one point each. A rolling bearing device characterized in that a shaft is supported.