JPH11190347A - Ball bearing and motor equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball bearing which can be simply assembled, and in which components are processed at a low cost in comparison with a conventional one. SOLUTION: An inner race 10 has a lower part which is an inner flat part 11 having a linear sectional shape, and the inner surface of the inner flat part 11 is an inscribed cylindrical surface 11a fitted on the outer peripheral surface 1a of a shaft 1. The upper part of the inner race 10 is an inner curved part 12 smoothly curved outward from the inner flat part 11 and having an outer surface serving as the outer surface 12a having an arcuate contour. Meanwhile, The upper part of an outer race 20 is an outer flat part 21 having an outer surface which is a circumscribed cylindrical surface 21a. The lower part of the outer race 20 is an outer curved part 22 smoothly curved inward from the outer flat part 21 having an inner surface which serves as the inner surface 22a of a ball bearing, having an arcuate contour.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ball bearing and a motor using the same.

[0002]

2. Description of the Related Art Conventionally, ball bearings used for various mechanical sliding parts as a shaft support structure of a shaft body include a ball made of a material having a high hardness such as a steel ball and a ball held between inside and outside. It is composed of an annular inner ring and an outer ring. The inner ring and the outer ring are configured to reduce sliding resistance at the time of rotation of the shaft body due to the rolling of the balls held therebetween. In addition, a retainer for retaining the ball is provided between the inner ring and the outer ring as needed.

[0003] In such a ball bearing, extremely high machining accuracy is required in order to reduce the sliding resistance inside the bearing and to increase the durability, and it is necessary to process and assemble parts such as balls, inner rings and outer rings. Since a complicated and complicated operation is required, mass production of a high-quality product is difficult and expensive.

As a method for solving the above problem, there is a ball bearing disclosed in Japanese Utility Model Laid-Open No. 57-149323.
In this ball bearing, the outer ring is formed in an arc-shaped cross section opened to one side in the axial direction, and the inner ring is formed in an arc-shaped cross section opened to the other side in the axial direction. Can be inserted in the axial direction and assembled. According to this method, the assembling work is easy and the assembling accuracy is easily obtained, so that there is an advantage that it can be manufactured at low cost. Further, the inner ring can be incorporated when assembling the equipment.

[0005]

However, in the above-mentioned conventional ball bearing, not only the arc-shaped ball receiving outer surface and the ball receiving inner surface which receive the ball in the machining of the inner ring and the outer ring in order to obtain the ball holding accuracy. Also, it is necessary to accurately form the inscribed cylindrical surface of the inner ring (the surface where the outer peripheral surface of the shaft body contacts) and the circumscribed cylindrical surface of the outer ring (the surface that fixes the bearing to the surroundings) in the axial direction. For this reason, in the manufacture of ball bearing parts, it is necessary to process all dimensions of each part with high precision,
Since it is difficult to use plastic working such as press working, cutting processing is used, and even when plastic working is used, many processing steps are provided and processing is performed in stages, so the processing cost of parts is reduced. There is a problem that reduction is difficult. In the ball bearing disclosed in Japanese Utility Model Application Laid-Open No. 57-149323, since the thicknesses of the inner ring and the outer ring are largely changed, it is difficult to manufacture parts by plastic working with a small number of steps, and the manufacturing cost is reduced. Is insufficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a ball bearing that can be easily assembled and that can reduce the processing cost of parts as compared with the related art. Is to do.

[0007]

Means taken by the present invention to solve the above-mentioned problems are to provide a ball having a plurality of balls, an insertion hole for inserting a shaft body, and receiving the balls.
An inner ring having a ball receiving outer surface having a cross-sectional shape having a substantially arc-shaped profile having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the ball surface, and having a radius of curvature substantially equal to the radius of curvature of the ball surface for receiving the ball; An outer ring having a ball bearing inner surface with a cross-sectional shape having a substantially arc-shaped profile with a slightly larger radius of curvature,
In a ball bearing configured to hold the ball between the inner ring and the outer ring and to support the shaft by inserting a shaft through the insertion hole, a cross-sectional shape of the inner ring is an axis of the shaft. An inner flat portion that extends linearly in the direction, and an inner curved portion that forms the ball receiving outer surface that curves outward in a substantially arc shape on one side in the axial direction, and that extends substantially in the axial direction as a whole. The outer ring has a shape with a uniform width, and the inner surface of the outer ring includes a cylindrical surface portion extending in the axial direction and the ball receiving inner surface curved inward from the cylindrical surface portion toward the other side. Features.

According to this means, the cross-sectional shape of the inner ring comprises an inner flat portion extending in the axial direction and an inner curved portion curved outward on one side, and the inner surface of the outer ring extends on the other side on the cylindrical surface portion extending in the axial direction. Since it is composed of a curved ball receiving inner surface, it is possible to easily assemble the ball by storing it in the outer ring and insert the inner ring as it is, so that productivity can be improved and assembly costs can be reduced, Since the cross-sectional shape of the inner ring is a shape with a substantially uniform width extending in the axial direction, the overall thickness does not change significantly, and processing can be performed easily and with high precision even by plastic processing such as pressing. Therefore, the manufacturing cost can be reduced, and the precision can be improved to improve the bearing performance.

The above-mentioned one side means a side opposite to the other side. For example, in FIG. 1 of the embodiment, one side is an upper side (upper side) in the drawing and the other side is a lower side in the drawing of FIG. Side (lower). Further, in the case of a motor provided with ball bearings at both ends, one side and the other side have meaning only in the respective ball bearings. For example, in the upper bearing shown in FIG. One side is the lower side in the figure (lower) and the other side is the upper side in the figure (upper). In the lower bearing in FIG. 3, one side is the upper side in the figure (upper) and the other side is the lower side in the figure (lower). is there. That is, in this case, one side means the inside of the motor, and the other side means the outside of the motor.

In addition, the ball has a plurality of balls, an insertion hole for inserting a shaft body, and a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the ball for receiving the balls. Inner ring having a ball receiving outer surface having a cross-sectional shape, and an outer ring having a cross-sectional shape ball receiving inner surface for receiving the ball, having a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the surface of the ball. And a ball bearing configured to hold the ball between the inner ring and the outer ring and to support a shaft by inserting a shaft into the insertion hole, wherein an outer surface of the inner ring is A cylindrical surface portion extending in the axial direction, and the ball receiving outer surface curved outward from the cylindrical surface portion toward one side in the axial direction, the cross-sectional shape of the outer ring is an outer line extending linearly in the axial direction. A flat portion and the axial direction The outer flat portion is curved in a substantially arc shape from the outer flat portion to the inner side, and has an outer curved portion forming the ball receiving inner surface, and has a substantially uniform width extending in the axial direction as a whole. Features.

According to this means, it is possible to assemble easily as in the case of the above means, so that productivity can be improved and assembling cost can be reduced. Because the shape has a width, the overall thickness does not change significantly, and processing can be performed easily and with high precision even by plastic working such as press working. Accuracy can be improved to improve bearing performance.

[0012] Further, a plurality of balls, an insertion hole for inserting the shaft body, and a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the ball surface for receiving the balls are provided. Inner ring having a ball receiving outer surface having a cross-sectional shape, and an outer ring having a cross-sectional shape ball receiving inner surface for receiving the ball, having a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the surface of the ball. In the ball bearing configured to hold the ball between the inner ring and the outer ring and to support the shaft by inserting a shaft into the insertion hole, the cross-sectional shape of the inner ring is: An inner flat portion extending linearly in the axial direction of the shaft body; and an inner curved portion forming the ball receiving outer surface, which is curved in a substantially arc shape outward from the inner flat portion on one side in the axial direction. And extend as a whole in the axial direction. The outer ring has a cross-sectional shape that has a substantially uniform width, an outer flat portion that extends linearly in the axial direction, and a substantially arc shape inward from the outer flat portion on the other side in the axial direction. An outer curved portion that forms the inner surface of the ball receiver, and has a substantially uniform width extending in the axial direction.

According to this means, the productivity can be improved and the assembly cost can be reduced because the assembling can be easily performed similarly to the above means, and the sectional shapes of both the outer ring and the inner ring in the axial direction can be improved. Since the shape has a substantially uniform width that extends, the manufacturing cost can be further reduced, the accuracy can be improved, and the bearing performance can be improved.

[0014] In the above three means, it is preferable that the inner flat portion linearly extends to the other side in the axial direction from the tip of the outer curved portion. According to this means, since the inner flat portion of the inner ring is formed to be long, the state of contact with the shaft can be stabilized, and uneven wear and noise can be suppressed.

It is preferable that the one end of the inner race protrude toward the one side from the one end of the outer race. According to this means, since one end of the inner ring projects beyond the end of the outer ring, it is easy to press the inner ring toward the other side, and it is possible to reliably apply a preload to the inner ring.

Further, it is preferable that both ends of the inner ring extend on both sides in the axial direction than both ends of the outer ring. According to this means, the axial length of the inner race is formed longer than the axial length of the outer race and extends on both sides of the outer race, so that the contact area of the inner race with the shaft body can be increased and stabilized. At the same time, by shortening the outer ring, the volume of the bearing can be reduced,
It becomes easy to apply a preload to the inner ring.

In each of the above-mentioned means, an overhang portion is formed at the one end portion of the outer race, the end portion being bent and protruding outward and having a contact surface facing the other side. It is desirable. According to this means, the outer ring can be reliably supported by the surface by supporting the contact surface of the overhang portion, and there is no need to support the end of the outer ring in the axial direction. By paying attention to the easy contact surface, the required accuracy for the shape of the other portion of the outer ring other than the ball receiving inner surface can be reduced, so that the manufacturing can be more easily performed.

In each of the above means, the other end of the inner ring further projects so as to overlap the end of the outer curved portion as viewed in the axial direction, and the inner ring and the outer ring It is desirable to have a protruding portion having flexibility so as to be able to cross over each other in the axial direction. According to this means, the inner ring is pressed into the outer ring so that the protruding portion is mounted over the end of the outer ring, so that the inner ring does not come off from the outer ring after mounting,
It is possible to prevent the inner ring from falling off during assembly and the inner ring from coming off due to thrust stress applied to the shaft body.

In each of the above-mentioned means, the outer race further includes a thin-walled molded portion formed on the one side of the outer curved portion so as to be thinner than the outer curved portion by pressing both inner and outer surfaces. It is desirable that the outer surface of the thin-walled molded portion be configured as a support surface for the outer ring. According to this means, the outer surface of the thin molded portion can be molded with high accuracy by forming one side of the outer curved portion as a thin molded portion formed by pressing both the inner and outer surfaces, and this outer surface is supported by the outer race. By using the surface, the accuracy of supporting the outer ring can be further improved.

In each of the above means, a ball accommodating recess for accommodating the ball is provided between the inner race and the outer race, and the inner curved portion and the outer curved portion are curved with respect to the axial direction. It is desirable to dispose a retainer having a cross-sectional shape extending in an inclined direction, which is rotated in an angle range of less than 90 degrees in the direction. According to this means,
The retainer contacts the inner ring and the outer ring by making the direction of extension of the cross-sectional shape of the retainer an inclined direction in which the direction of rotation of the inner curved portion and the outer curved portion is rotated by less than 90 degrees with respect to the axial direction. Since it is possible to eliminate the possibility of the bearing, a bearing having a high yield, a low resistance, and a high durability can be configured.

Instead of providing the retainer, the ball receiving outer surface of the inner ring or the ball receiving inner surface of the outer ring is provided with a concave / convex structure for holding a plurality of balls, which is formed in a circumferential direction for holding the balls. It may be formed. According to this means, since the ball can be held at a predetermined position by the inner ring or the outer ring, a cage is not required, the number of parts is reduced, the labor for assembly is reduced, and the manufacturing cost is further reduced. Can be.

In each of the above-mentioned means, it is preferable that the outer ring is received by at least the support surface facing the one side, and a support having an annular frame portion having a side surface outside the support surface is preferable. . According to this means, it is possible to easily assemble by inserting the outer ring inside the annular frame-shaped portion, then putting the ball inside the outer ring, and further inserting the inner ring inside the ball.

[0023] In this case, further, a cover portion for covering at least a part of the opening on the other side between the inner ring and the outer ring is provided integrally with the support or attached separately. It is desirable. According to this means, the opening between the inner ring and the outer ring can be restricted by the cover, so that leakage of the lubricant filled in the bearing and intrusion of dust from the outside can be suppressed.

Further, there is provided a motor having the ball bearing described in each of the above means as a support structure for a rotary output shaft.

In this case, it is particularly preferable that the support is constituted by a part of a case body for accommodating the motor structure in order to reduce the number of parts, facilitate assembly, and reduce the manufacturing cost of the motor. Further, in this case, the shaft support structures are further provided at both ends of the case body with the outside of the case body facing the other side, and the inner ring in each shaft support structure is connected to the rotation output shaft. In order to simplify the structure of the motor and reduce the manufacturing cost, it is desirable to provide elastic bodies for pressing the outer sides of the case body. In addition, of the two bearing structures at both ends, a member which is directly pressed by an elastic body against the inner ring of one bearing structure and is fixed to the rotary output shaft with respect to the inner ring of the other bearing structure. By pressing the inner ring, the inner rings of the two shaft support structures at both ends can be simultaneously pressed toward the outside of the case body by a single elastic body.

[0026]

Next, an embodiment according to the present invention will be described with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a schematic end view showing the structure of a first embodiment of a ball bearing according to the present invention. In this embodiment, an inner ring 10 and an outer ring 20 formed by pressing a plate having a uniform thickness and made of stainless steel or the like for supporting the shaft 1 by pressing, and the inner ring 10 and the outer ring 20 And a ring-shaped holder 30 made of synthetic resin or metal for positioning and holding the ball 2 in a circumferential direction around the shaft 1. Inner ring 10
The cross-sectional shape of the outer ring 20 extends substantially along the axial direction (vertical direction in the drawing), and has a substantially uniform thickness in the extending direction.

The lower portion of the inner ring 10 is formed to have a diameter substantially equal in the axial direction, and the inner flat portion 1 has a straight cross section.
1, the inner surface of the inner flat portion 11 is an inscribed cylindrical surface 11a fitted to the outer peripheral surface 1a of the shaft body 1. Inner ring 1
The upper portion of 0 is an inner curved portion 12 smoothly curved outward from the inner flat portion 11, and the outer surface of the inner curved portion 12 is a ball receiving outer surface 12a having an arcuate contour.
The ball receiving outer surface 12a is formed to have a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the ball 2 when viewed in the axial direction.

The upper portion of the outer ring 20 has an outer flat portion 2 having a diameter substantially equal to the axial direction and a straight cross section.
1, the outer surface of the outer flat portion 21 is a circumscribed cylindrical surface 21.
a. The lower portion of the outer ring 20 is the outer flat portion 2
An outer curved portion 22 smoothly curved inward from 1;
The inner surface of the outer curved portion 22 is a ball receiving inner surface 22a having an arcuate contour. The ball receiving inner surface 22a is formed to have a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the ball 2 when viewed in the axial direction.

A plurality (for example, eight) of balls 2 are arranged between the inner ring 10 and the outer ring 20, and a retainer 30 for holding the plurality of balls 2 in a circumferential direction around the shaft 1 is provided. Have been. As shown in FIG. 6, the retainer 30 has a ring shape having a width in the axial direction, and includes a plurality of holding concave portions 31 that are formed at intervals in the circumferential direction and that open upward. Each holding recess 31 accommodates one ball 2 one by one.

The circumscribed cylindrical surface 21a of the outer ring 20 has an annular frame-like portion 4a formed in an L-shaped cross section at the opening edge of the support 4 having openings at portions corresponding to the shaft 1 and the inner ring 10.
And the lower end of the outer curved portion 22 is supported on the bottom surface of the frame-shaped portion 4a. On the other hand, the upper end of the inner curved portion 12 of the inner ring 10 is in contact with the ring-shaped pressing plate 5. A spring (not shown) is provided on the pressing plate 5.
A pressing force directed downward in the figure is given by a magnet, elastic rubber, or the like, and presses the inner ring 12 downward.
That is, the ball bearing shown in FIG. 1 is a preload bearing. The space between the inner race 10 and the outer race 20 may be filled with a lubricant such as grease (not shown).

In the present embodiment, since the inner ring 10 and the outer ring 20 are formed to have a uniform thickness, the inner ring 10 and the outer ring 20 are formed.
Can be easily formed by press working, and the manufacturing cost can be reduced. The cross-sectional shape of the inner race 10 and the outer race 20 is such that the ends of a material having substantially the same thickness are curved outward and inward to form the inner curved portion 12 and the outer curved portion 22. The outer receiving surface 12a and the outer surface of the inner flat portion 11 are smoothly (continuously) connected, and the ball receiving inner surface 22a of the outer ring 20 and the inner surface of the outer flat portion 21 are smoothly (continuously) connected. The position of the ball 2 is easily stabilized, and there is no risk of damaging each part even during assembly.

In the present embodiment, the width of the inner ring 10 in the axial direction (vertical direction in the drawing) is formed larger than the width of the outer ring 20.
In particular, the vertical width of the inner flat portion 11 is increased. By increasing the vertical width of the inner flat portion 11, the accuracy of the position and direction of the inner ring 10 with respect to the shaft 1 can be improved, and the inner ring 10 when the shaft 1 is rotating.
Can be improved in stability. Further, since the vertical width of the inner ring 10 is made larger than the vertical width of the outer ring 20, it is possible to prevent an increase in the size of the ball bearing while improving the accuracy and stability as described above. This is because the size of the ball bearing is substantially determined by the vertical width of the outer ring 20, and is hardly affected by the vertical width of the inner ring 10.

In manufacturing the inner ring 10 and the outer ring 20,
After a drawing process is performed on a plate-like body having a constant thickness, a center portion is punched out. After the punching, the ball receiving inner surface or the ball receiving outer surface is formed as necessary. FIG. 9 shows a manufacturing process of the outer ring 20 by press working. Here, FIG. 9A shows a drawing process, and FIG. 9B shows a punching process. In the drawing process, a flat plate is drawn by using the punch A and the die B, and the inner surface of the ball receiver is formed by the shape of the tip corner a of the punch A. In the punching process, an annular whole shape is formed by punching with the punch C and the die D.

In the case of the inner ring 10, drawing is performed as shown in FIG. 9A. In this case, the outer surface of the ball receiving surface is formed by the shape of the shoulder b of the concave portion of the die B. Here, a punch A ′ as shown by a dotted line in the drawing may be used to reliably reflect the shape of the shoulder b of the die B. FIG. 10 shows a step of punching the inner ring 10 using the punch E and the die F. In this step, the inscribed cylindrical surface is formed together with the punching, and the ball receiving outer surface is formed again. As described above, the method of performing the molding a plurality of times in the portion where the accuracy is required may be performed on the ball receiving inner surface or the circumscribed cylindrical surface of the outer ring 20.

The manufacturing method is not limited to the above-mentioned method, and other plastic working such as forging may be used. Also, only the above-mentioned inner curved portion and outer curved portion are formed using a pipe material instead of a flat plate. You may do so. In either method, the inner ring 10 and the outer ring 20 of the present embodiment have a substantially uniform wall thickness, and can be formed by applying pressure in only one direction as can be seen from the final shape. Therefore, the molding can be easily performed without applying any pressure, and the mold used at the time of the plastic working is not burdened, the accuracy can be increased, and the manufacturing cost can be reduced. In addition, even if the plastic working material is not optimal, the optimum material can be selected as the material of the bearing component, so that the bearing performance such as durability and sliding resistance can be improved.

(Second Embodiment) Next, a ball bearing according to a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, an overhanging portion 23 is formed at the upper end of the outer flat portion 21 of the outer ring 20 so as to project outward in a flange shape. The overhang 23 can be easily and integrally formed by the processing method described in the first embodiment.

The lower surface 23a of the overhang portion 23 is formed flat by plastic working, and is in contact with the shoulder 4a of the support 4. The surface accuracy and surface position of the outer surface 21a of the outer flat portion 21 of the outer ring 20 and the lower surface 23a of the overhang portion 23 can be formed with high accuracy by plastic working.
The positional accuracy of the outer ring 20 with respect to the support 4 can be improved. Since the support accuracy between the outer race 20 and the support 4 in the first embodiment is determined by the shape of the lower end portion of the outer curved portion 22 of the outer race 20 which is difficult to obtain the shape accuracy, the present embodiment is different from the first embodiment. Is also advantageous in terms of supporting accuracy.

In the present embodiment, since the position of the outer ring 20 is determined by the contact between the planes, accuracy can be easily obtained, and the shapes of the bent portion and the bent portion of the outer ring 20 and the support 4 are formed roughly. Therefore, there is an advantage that molding is easy.

(Third Embodiment) Next, a third embodiment of the motor according to the present invention will be described with reference to FIG. This embodiment is a motor including the ball bearing of the first embodiment. In the motor of the present embodiment, the ball bearings including the balls 2, the inner ring 10, the outer ring 20, and the retainer 30 are supported by the frame-shaped portions 6a, 6'a formed at the opening edges of the motor cases 6, 6 '. It is. Here, the frame portions 6a, 6
a ′ corresponds to the frame portion 4a of the support 4 described above. Cases 6 and 6 'are fixed to each other. Further, the rotary output shaft 1 'corresponds to the above-mentioned shaft body 1, and the pressing plates 5' and 5 "correspond to the above-mentioned pressing plate 5.

A rotor 7 is attached to the rotation output shaft 1 ', and the rotor 7 has a magnetic pole structure facing the magnetic poles on the inner peripheral portion of the stator 8 fixed to the cases 6, 6'. The upper end of the rotor 7 in the axial direction contacts the pressing plate 5 ', and the coil spring 9 is housed in a compressed state between the lower end of the rotor 7 and the pressing plate 5 ".

In this motor, the pressing plate 5 'is pressed upward by the coil spring 9 and the pressing plate 5 "is pressed downward by the drawing, so that the balls supported on the upper and lower portions of the cases 6, 6'. The inner ring 20, 20 is in a state of receiving pressure upward and downward with respect to the outer ring 20, 20 of the bearing.

To assemble this motor, the case 6,
After inserting the outer ring 20 into the frame-shaped portions 6a and 6'a of the 6 'and introducing the retainer 30 and the plurality of balls 2 into the outer ring 20, the inner rings 10 are arranged inside the plurality of balls 2 in an annular shape. , And finally the rotary output shaft 1 ′ fixed to the rotor 7
Is inserted easily into the inner ring 10 after passing through the pressing plates 5 ′ and 5 ″.

In this motor, a part of the case 6, 6 'serves as a support for the outer race 20, and the frame 6a, 6a,
Assembly is easily completed simply by inserting the outer ring 20, the ball 2, the inner ring 10, and the rotary output shaft 1 'in this order in 6'a. Therefore, the assembling work is reduced, and the assembling work can be easily automated. Further, the number of parts is small, and the manufacturing cost can be significantly reduced as compared with the related art.

In the motor shown in FIG. 3, the ball bearing of the second embodiment may be used instead of the ball bearing of the first embodiment, or the ball bearing of each embodiment described later. May be used.

(Fourth Embodiment) Next, a ball bearing according to a fourth embodiment of the present invention will be described with reference to FIG. Also in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a plurality of protrusions 13 projecting outward from the lower end of the inner flat portion 11 of the inner ring 10 are formed. Each of the protrusions 13 is gradually thinner toward the tip, and has flexibility. Further, the tip of the protruding portion 13 reaches slightly outside the lower end 22 b of the outer curved portion 22 of the outer ring 20. The lower end portion 22b of the outer race 20 is formed so as to gradually decrease in thickness toward its tip end, and has flexibility.

Between the inner ring 10 and the outer ring 20, a cage 3
0 ′ holds the plurality of balls 2 in the ball holding recess 31 ′. The retainer 30 'has substantially the same shape as the retainer 30 of the first embodiment shown in FIG. 6, but has an overall configuration that is slightly open upward and has a sectional shape of As compared with the retainer 30 of the first embodiment shown in FIG.
As shown in FIG. 4, the inner curved portion 12 of the inner race 10 and the outer race 2
0 to the bending direction of the outer bending portion 22 is 20 to 30 in the axial direction.
It has an inclined posture inclined in the direction rotated by degrees.

The frame portion 4 ′ a of the support 4 ′ supporting the outer ring 20 is formed by the outer flat portion 21 of the outer ring 20 and the outer curved portion 2 ′.
2 is formed into a shape that fits almost exactly on the outer surface that is loosely curved. That is, the curvature of the outer surface of the outer curved portion 22 of the outer ring 20 is formed to be equal to the curvature of the support surface of the frame-shaped portion 4'a of the support 4 '. Therefore, the positioning posture of the outer race 20 is stabilized, and the accuracy of the position and posture is also improved.

In this embodiment, the frame portion 4 'of the support 4'
a, the ball 2 and the retainer 30 '
Are introduced into the outer ring 20 and then the inner ring 10
Is inserted so as to pass between the balls 2 so that the protruding portions 13 do not touch the balls 2, and is press-fitted so that the protruding portions 13 get over the lower end portions 22 b of the outer race 20. By doing so, in the ball bearing once assembled, the inner ring 10 does not come off in the upper part of the drawing, so that the inner ring 10 is prevented from falling off in the assembly process. Further, even after the assembly, even if a strong upward stress is applied to the shaft body 1, the inner race 10 is
Is prevented from deviating from the inside.

In this embodiment, since the retainer 30 'has an upwardly open shape as described above, the direction in which the cross-sectional shape of the retainer extends is determined based on the axial direction of the inner curved portion and the outer curved portion. In other words, the tilt direction is obtained by rotating the bending direction by an angle of less than 90 degrees. Thus, the possibility that the cage contacts the upper end of the inner race and the lower end of the outer race can be substantially eliminated, so that a bearing with a high yield, less resistance and high durability can be configured.

(Fifth Embodiment) Next, a fifth embodiment of the ball bearing according to the present invention will be described with reference to FIG. Also in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the outer race 20 is composed of the outer flat portion 21 'and the outer curved portion 22, but the inner surface 21'b of the outer flat portion 21' is not continuous with the ball receiving inner surface 22a, and the step Through the ball receiving inner surface 22a.

In this embodiment, when the outer race 20 is formed by plastic working, the inner and outer surfaces of the outer race 20 are formed by pressing the inner and outer surfaces of the outer race 20 with a punch G and a die H as shown in FIG. Since the punch G and the die H are thinned by sandwiching the outer flat portion 21 'of the outer ring 20, the circumscribed cylindrical surface 21'a of the outer flat portion 21' can be accurately formed. Therefore, the outer race 20 can be accurately supported by the support 4.

(Sixth Embodiment) Next, a sixth embodiment of the ball bearing according to the present invention will be described with reference to FIG. This embodiment is the same as the above embodiments except for the inner ring and the retainer, and a description thereof will be omitted. In this embodiment, as shown in FIG. 7A, the inner ring 40 has a cross-sectional shape in which the inner flat portion 41 and the inner curved portion 42 are formed continuously as described above, and the ball receiving outer surface 42a is formed. The ball receiving portion 40a and the thick ball holding portion 40b having no ball receiving outer surface 42a are formed in an alternately uneven shape.

In this embodiment, the inner race 40 is
As shown in (b), a plurality of balls 2 are placed in respective ball receiving portions 4.
Since it is configured to be held within 0a, there is no need to provide a holder. Therefore, the number of parts is reduced,
Since the assembling process is also simplified, manufacturing costs can be reduced. Here, the radius of curvature of the ball receiving portion 40a in the circling direction is formed slightly larger than the radius of curvature of the surface of the ball 2 as shown in FIG.

By providing a ball receiving portion and a ball holding portion similar to those described above on the inner surface of the outer race instead of the above-described configuration, it is possible to completely eliminate the need for a cage.

(Seventh Embodiment) Next, a seventh embodiment of the ball bearing according to the present invention will be described with reference to FIG. In the present embodiment, the inner ring 10, the outer ring 20, the retainer 30, the shaft 1, the ball 2, and the support 4 are completely the same as in the first embodiment, and the description thereof will be omitted. In this embodiment, the lower end surface of the frame portion 4a of the support 4
A ring-shaped shield plate 4c having an opening slightly wider than the shaft diameter of the shaft body 1 is attached. This shield plate 4c
Can be made of a synthetic resin, metal, or the like. Shield plate 4c
May be fixed to the support 4 by welding, welding, or the like, or may be formed integrally with the support 4 in advance.

According to this embodiment, the lubricant such as grease filled between the inner ring and the outer ring can be made hard to leak, and the intrusion of dust from the outside can be suppressed. In particular, when this ball bearing is incorporated in the motor shown in FIG. 3, lubricant leaks out or dust enters through the opening between the case serving as the support and the rotary output shaft serving as the shaft. Can be prevented.

The shield plate (covering portion) 4c desirably covers the entire opening between the inner ring and the outer ring as shown in the figure, but is formed so as to cover at least a part of the opening. You may.

In the ball bearing or motor of each of the embodiments described above, the outer ring is mounted on the support or the case, and then the ball set in the retainer is accommodated in the outer ring together with the retainer. Assembly can be completed in substantially three steps of inserting the inner ring. The ball can be held in a retainer via a lubricant such as grease, and this operation can be performed in parallel with the process of attaching the outer ring to the support or the case, thereby reducing the assembly time. can do. If no cage is required, the assembly process is further simplified. By the way, conventionally, after combining the outer ring and the inner ring, a plurality of balls are introduced between the outer ring and the inner ring in the wide part after the inner ring is eccentric with respect to the outer ring to make a wide portion, and after introduction, The number of steps of distributing a plurality of balls at equal intervals and finally setting the cage is large, which has been a laborious operation.

In each of the above embodiments, both the inner race and the outer race have a substantially uniform thickness, that is, a sectional shape having a width substantially equal in the axial direction. Even if at least one of them has a substantially uniform thickness and the other does not, the above-mentioned effects can be obtained as compared with the related art.

The above-mentioned ball bearings can be used not only for motors but also for various devices or structural parts.
A structure in which the case body is used as a support and the outer ring is directly supported on the case body can also be used as a structure of a bearing portion of various devices or structural parts.

[0062]

As described above, according to the present invention, the productivity can be improved, the assembly cost can be reduced, and the thickness of the inner ring and / or the outer ring does not largely change as a whole. In addition, since the working can be easily and accurately performed by plastic working such as press working, the manufacturing cost can be reduced, and the precision can be improved to improve the bearing performance.

[Brief description of the drawings]

FIG. 1 is a vertical end view showing a schematic structure of a first embodiment of a ball bearing according to the present invention.

FIG. 2 is a longitudinal end view showing a schematic structure of a ball bearing according to a second embodiment of the present invention.

FIG. 3 is a longitudinal end view showing a schematic structure of a third embodiment of the motor according to the present invention.

FIG. 4 is a longitudinal end view showing a schematic structure of a ball bearing according to a fourth embodiment of the present invention.

FIG. 5 is a vertical end view showing a schematic structure of a ball bearing according to a fifth embodiment of the present invention.

FIG. 6 is a schematic perspective view showing the entire structure of the retainer according to the first embodiment.

FIG. 7 is a schematic perspective view (a) and a cross-sectional view partially showing the structure of an inner race in a sixth embodiment of the ball bearing according to the present invention.

FIG. 8 is an explanatory diagram showing a state in which an outer ring in a fifth embodiment is formed by plastic working.

FIG. 9 is a process explanatory view showing the steps of drawing and punching for manufacturing the outer ring in the first embodiment (a).
And (b).

FIG. 10 is a process explanatory view showing a punching process for forming an inner ring in the first embodiment.

FIG. 11 is a longitudinal end view showing a schematic structure of a ball bearing according to a seventh embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 shaft body 1a outer peripheral surface 2 ball 4 support 4a frame 4b shoulder 4c shield plate 5 pressing plate 6, 6 'case 6a, 6'a opening edge 7 rotor 8 stator 9 coil spring 10 inner ring 11 inner flat portion 11a Inscribed cylindrical surface 12 Inner curved portion 12a Ball receiving outer surface 13 Projection portion 20 Outer ring 21 Outer flat portion 21a External circumscribed cylindrical surface 22 Outer curved portion 22a Ball receiving inner surface 23 Overhang portion 23a Lower surface 30 Cage 31 Ball holding concave portion

Claims (16)

[Claims] 1. A plurality of balls and a substantially arc-shaped contour having a through hole for inserting a shaft body and having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the balls for receiving the balls. An inner ring having a ball receiving outer surface having a cross-sectional shape,
For receiving the ball, an outer ring having a ball receiving inner surface having a cross-sectional shape having a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the ball, In a ball bearing configured to be held between an outer ring and a shaft body inserted into the insertion hole to support the shaft, a cross-sectional shape of the inner ring has an inner side extending linearly in an axial direction of the shaft body. A shape having a flat portion and an inner curved portion forming an outer surface of the ball receiving portion that curves outwardly in a substantially arc shape on one side in the axial direction, and has a substantially uniform width extending in the axial direction as a whole. An inner surface of the outer ring has a cylindrical surface portion extending in the axial direction,
A ball bearing comprising: the ball receiving inner surface curved inward from the cylindrical surface toward the other side. 2. A plurality of balls and an insertion hole through which a shaft body is inserted, and a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the balls for receiving the balls. An inner ring having a ball receiving outer surface having a cross-sectional shape,
For receiving the ball, an outer ring having a ball receiving inner surface having a cross-sectional shape having a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the ball, In a ball bearing configured to be held between an outer ring and supported by inserting a shaft into the insertion hole, an outer surface of the inner ring has a cylindrical surface portion extending in the axial direction,
The ball receiving outer surface curved outward from the cylindrical surface portion toward one side in the axial direction, the cross-sectional shape of the outer ring is an outer flat portion linearly extending in the axial direction, and the outer flat portion in the axial direction. An outer curved portion which forms an inner surface of the ball receiving portion, which is curved in a substantially arc shape inward from the outer flat portion on the other side, and which has a substantially uniform width extending in the axial direction as a whole. Ball bearing. 3. A plurality of balls and an insertion hole through which a shaft body is inserted, and a substantially arc-shaped profile having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the balls for receiving the balls. An inner ring having a ball receiving outer surface having a cross-sectional shape,
For receiving the ball, an outer ring having a ball receiving inner surface having a cross-sectional shape having a substantially arc-shaped contour having a radius of curvature substantially equal to or slightly larger than the radius of curvature of the surface of the ball, In a ball bearing configured to be held between an outer ring and a shaft body inserted into the insertion hole to support the shaft, a cross-sectional shape of the inner ring has an inner side extending linearly in an axial direction of the shaft body. A flat portion and an inner curved portion forming an outer surface of the ball receiving portion, which is curved in a substantially arc shape from the inner flat portion to the outside on one side in the axial direction, and is substantially uniform extending in the axial direction as a whole. A cross-sectional shape of the outer ring, the outer flat portion extending linearly in the axial direction, and curving in a substantially circular arc shape inward from the outer flat portion on the other side in the axial direction. An outer curved portion forming the inner surface of the ball receiver A, ball bearing, which is a shape with a substantially uniform width extending in the axial direction. 4. One of claims 1 to 3
3. The ball bearing according to claim 1, wherein the inner flat portion linearly extends to the other side in the axial direction from the tip of the outer curved portion. 5. The method according to claim 1, wherein:
3. The ball bearing according to claim 1, wherein the one end of the inner ring projects toward the one side from the one end of the outer ring. 6. Any one of claims 1 to 3
3. The ball bearing according to claim 1, wherein both ends of the inner ring extend on both sides in the axial direction than both ends of the outer ring. 7. One of claims 1 to 6
3. The ball bearing according to claim 1, wherein the one end of the outer ring is formed with a projecting portion having a contact surface that is bent and protrudes outward and faces the other side. . 8. One of claims 1 to 7
In the paragraph, the other end of the inner ring projects from the end of the outer curved portion so as to overlap with the end of the outer curved portion when viewed in the axial direction, and the inner ring and the outer ring are mutually displaced in the axial direction. A ball bearing provided with a flexible protrusion for enabling the ball bearing to pass over. 9. Any one of claims 1 to 8
In the item, the outer ring is provided on the one side with respect to the outer curved portion, a thin-walled molded portion that is formed to be thinner than the outer curved portion by pressing both inner and outer surfaces, and the outer surface of the thin-walled molded portion is formed as the outer surface. A ball bearing comprising a support surface for an outer ring. 10. The ball bearing according to claim 1, further comprising a ball housing recess for housing the ball between the inner ring and the outer ring, wherein the ball is provided on the basis of the axial direction. A ball bearing comprising a retainer having a cross-section extending in an inclined direction and rotated by an angle of less than 90 degrees in a bending direction of the inner bending portion and the outer bending portion. 11. The ball bearing according to claim 1, wherein the ball receiving outer surface of the inner ring or the ball receiving inner surface of the outer ring is formed in a circumferential direction for holding a plurality of the balls. A ball bearing characterized in that an uneven structure for holding a formed ball is formed. 12. An annular frame according to any one of claims 1 to 11, wherein the outer ring is received by at least a support surface facing the one side, and a side surface is provided outside the support surface. A ball bearing comprising a support having a portion. 13. The supporting body according to claim 12, wherein a cover portion for covering at least a part of the opening on the other side between the inner ring and the outer ring is provided integrally or separately. A ball bearing characterized by being attached. 14. A motor having the ball bearing according to any one of claims 1 to 13 as a shaft support structure for a rotation output shaft. 15. The motor according to claim 14, wherein the support is constituted by a part of a case body that accommodates a motor structure. 16. The shaft support structure according to claim 15, wherein the shaft supporting structures are provided at both ends of the case body with the outside of the case body facing the other side, and the inner ring in each shaft supporting structure is rotated. A motor provided with elastic bodies for pressing the output shaft toward the outside of the case body.