JP2732035B2 - Manufacturing method of ball bearing made of outer ring steel plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ball bearing made of an outer ring steel plate, and more particularly to a method of manufacturing a small ball bearing whose outer ring is formed by pressing a steel plate.

[0002]

2. Description of the Related Art Conventionally, the existence of ball bearings as means for holding a rotating shaft or the like is well known, and is often used in various rotating mechanisms. Conventional ball bearings are used for supporting a rotating body that rotates at a relatively high speed, and are therefore manufactured with high precision, for example, as a cutting outer ring type ball bearing.

On the other hand, in fields where relatively low speed and high precision are not required, slide bearings made of a low friction material called a so-called bush are widely used. Although the former ball bearing is excellent in shaft holding accuracy and rotational resistance, it has a problem that it is expensive. On the other hand, in the case of the latter bush, the price is low, but the rotational resistance due to frictional contact with the shaft is large, and the field of use is limited.

[0004] As described above, the application fields of the ball bearing and the bush are clearly separated in terms of performance and price. However, there are very many fields that do not require the accuracy and high-speed rotation resistance of a ball bearing as a performance requirement from the viewpoint of use and are inexpensive in terms of price. In other words, although expensive ball bearings are used, there are many fields in which reasonable accuracy and performance and inexpensive ones are sufficient as a practical problem.

If the conventional bush-based friction bearing is used in such a field, it is certainly inexpensive in terms of price, but the rotational resistance of the shaft becomes too large as compared with the ball bearing, and the purpose of use is It is also true that there are a wide range of fields that do not conform to.

Therefore, as shown in FIGS. 10 and 11, a simple and inexpensive ball bearing 1 using an outer ring formed by pressing a steel plate has been considered. This type of conventional ball bearing 1 shown in FIGS.
Was referred to as a total ball type in which two-piece outer ring members 2a and 2b were assembled.

In the above-described conventional simple all-ball type bearing, since the balls 3 are arranged close to each other, the rolling resistance due to the contact friction between the balls 3 is increased, thereby reducing the rolling resistance which is a characteristic of the ball bearing. Performance was diminished. Note that FIG.
In FIG. 11, reference numeral 4 indicates an inner ring.

Therefore, in order to prevent the increase of the rolling resistance, as shown in FIGS. 7 and 8, a plurality of balls arranged between the inner ring and the outer ring are held at predetermined intervals by parts called retainers. Ball bearings made from steel were considered.

The ball bearing 10 made of an outer ring steel plate is
A plurality of balls 13 are held by a retainer 14 as shown in FIG. 9 between an inner ring 11 and an outer ring 12 formed by pressing a one-piece steel plate.

The inner race 11 is formed of a material such as iron or stainless steel with high precision by, for example, cutting, as in the prior art, and has a circumferential groove portion 11a for seating a ball on its outer peripheral surface. The plurality of balls 13 arranged between the inner race 11 and the outer race 12 are held at equal intervals in the circumferential direction and immovable in the axial direction by the retainer 14.

As shown in FIG. 9, the retainer 14 is formed of a synthetic resin material in a ring shape having a ring shape. In this retainer 14, six arc-shaped recesses 14a for accommodating the balls 13 are formed at equal intervals in the circumferential direction. Therefore, the recesses 14a are formed at intervals of 60 degrees at the central angle. The balls 13 are arranged in these recesses 14a in a loosely fitted state.

Therefore, each of the recesses 14a is a part of a circle having a diameter slightly larger than the diameter of the ball 13, and is formed by an arc including a maximum diameter portion as is apparent from FIG. In other words, it is formed by an arc larger than a semicircle. Therefore, the balls 13 fitted into the respective recesses 14a do not fall off in the axial direction and are held immovably.

On the other hand, the outer race 12 has a cylindrical shape as a whole, and as seen from FIG.
A closed portion is formed at one end in the axial direction by folding one end inward so as to assume a shape. That is, the closing portion is formed by the tip 12a of the folded end.

A bulging portion 12b protruding toward the center is provided on the outer periphery near the other end in the axial direction of the outer ring 12, and the bulging portion 12b allows the other axial end of the outer ring 12 to be formed. Blockage has been made. As described above, the outer ring 12 is formed with the closed portions 12a and 12b at both ends in the axial direction, and prevents the ball 13 located therebetween between the outer ring 12 from moving in the axial direction. Has been prevented.

[0015]

In the meantime, Japanese Patent Application Laid-Open Publication No. Hei 1-210612 discloses a double-row angular contact ball bearing and a method of manufacturing the same.
This makes the sphere function as a support member at the time of roll or press working by the press roller 8 as is clear from FIG. In this manufacturing method, there is a problem that only a double-row angular contact ball bearing in which two balls are arranged can be manufactured.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem. An object of the present invention is to form a swelling portion for closing an axially open end formed on a smooth inner surface of an outer ring made of a steel plate, It is an object of the present invention to provide a method for manufacturing a ball bearing made of an outer ring steel plate, which prevents generation of abnormal noise and vibration due to contact with a ball and enables mass production thereof.

[0017]

SUMMARY OF THE INVENTION The present invention is a method of manufacturing a ball bearing having an outer ring made of a steel plate having two closed portions for fixing a ball in an axial direction. In other words, the method of manufacturing a ball bearing made of an outer ring steel plate according to the present invention is a semi-molded product for an outer ring in which a first closed portion is previously formed on one end side in the axial direction of a steel plate cylindrical body formed with the same inner diameter as the outer ring. Is placed on a rotating support, and an inner ring is disposed inside from the other end in the axial direction, and a predetermined number of balls are disposed between the inner ring and the semi-molded product for the outer ring. Inserting a ball positioning tool from the other end of the molded product in the axial direction to forcibly hold the balls at equal intervals in the circumferential direction, and then rotating the outer ring semi-molded product inner peripheral surface and the ball with a rotating forming roll The other end in the axial direction of the semi-molded product for outer ring is pressed from the outside from the inner contact to form an arc-shaped reduced diameter portion linearly inscribed along the spherical surface of the ball to form a second closed portion The outer peripheral forming part of the forming roll The cross-sectional shape is substantially the same as the arc shape linearly inscribed along the spherical surface of the ball from the inner contact surface between the inner peripheral surface of the outer ring semi-molded product and the ball. I do.

Further, the present invention relates to a method of manufacturing a ball bearing comprising a steel plate outer ring having two closed portions for fixing a ball in the axial direction, wherein the ball bearing has the same inner diameter as the outer ring. A semi-molded product for an outer ring in which a first closed portion is formed on one end side in the axial direction of a tubular body made of a steel plate has an outer diameter slightly smaller than the inner diameter of the semi-molded product for an outer ring and a groove formed on an outer peripheral surface. A second step in which the mandrel is placed on a rotating support provided protruding from the center of the upper surface, the semi-molded product for the outer ring is pressed from the outside by a rotating forming roll, and the diameter of the groove of the mandrel is reduced as a molding die. Forming an outer ring by press-forming the closed portion, and thereafter, assembling the outer ring with an inner ring and a retainer that is disposed on the outer periphery thereof and has a ball rotatably fitted in a recess formed at equal intervals in the circumferential direction so as to be able to rotate on the outer ring. Press-fit And forming the outer peripheral surface of the forming roll so that the shape from the deep part of the groove formed on the outer peripheral surface of the mandrel to the lower outer peripheral surface thereof substantially matches the cross-sectional arc shape of the ball. The cross-sectional shape of the portion is substantially the same arc shape corresponding to the shape from the deep portion to the lower outer peripheral surface of the groove of the mandrel.

[0019]

According to the method of manufacturing a ball bearing made of an outer ring steel plate of the present invention, a semi-molded product for an outer ring in which an axial closing portion for a ball is formed in advance by bending one end of the steel plate inward by press working or the like is supported. Place on a table. At this time, the other end in the axial direction of the semi-molded product for the outer race is open. Next, the inner ring is inserted into the outer ring tubular body from the other end opening portion in the axial direction and is held at a position by a spindle of a rotary support table, and a plurality of balls are interposed between the inner ring and the outer ring tubular body. Be placed.

Thereafter, a ball positioning jig is inserted from the open end of the semi-molded product for the outer ring, and a plurality of balls are forcibly held at equal intervals in the circumferential direction. However, the ball is allowed to rotate. Then, the other end side in the axial direction of the semi-molded product for the outer ring is pressed from the outside by the inner contact between the inner peripheral surface of the semi-molded product for the outer ring and the ball by a rotating forming roll, so that the inner side is linearly formed along the ball spherical surface. A converging arc-shaped reduced diameter portion is formed as a second closed portion. After that, the ball positioning tool is inserted and removed, the retainer is inserted, and the ball is held in the circumferential direction. Here, when the retainer which is arranged on the outer periphery of the inner ring and is rotatably fitted with a ball in a recess formed at equal intervals in the circumferential direction is used as the ball positioning tool,
The above procedure is omitted.

At that time, it is important that the cross-sectional shape of the outer peripheral forming portion of the forming roll is such that the arc is linearly inscribed along the spherical surface of the ball from the inner contact surface between the inner peripheral surface of the semi-finished product for the outer ring and the ball. That is, it is formed in almost the same shape as the shape.

As described above, in the ball bearing made of the outer ring steel plate of the present invention, unlike the conventional manufacturing method, the outer ring semi-formed product made of the steel plate closed only at one end in advance is supported by the rotary support table and the inner portion thereof is formed. After inserting the inner ring from the open side, place a plurality of balls, fix these balls in the circumferential direction with a positioning jig inserted from the open side, and use a unique forming roll to reduce the diameter along the spherical surface of the ball Forming part
, The inner surface of the second closed portion of the outer ring with which the ball comes into contact is formed smoothly in the circumferential direction, and as a result, generation of abnormal noise and vibration is prevented.

According to another manufacturing method of the ball bearing made of an outer ring steel plate according to the present invention, an outer ring having a first closed portion formed at one axial end of a steel plate cylindrical member having the same inner diameter as the outer ring. The semi-molded product is mounted on a rotary support having an outer diameter slightly smaller than the inner diameter of the semi-molded product for the outer ring and a mandrel having a groove formed on the outer peripheral surface thereof protruding from the center of the upper surface.

Then, the semi-molded product for the outer ring is pressed from the outside by the rotating forming roll, and the second closed portion having a reduced diameter is press-formed using the groove portion of the mandrel as a forming die to form an outer ring. Thereafter, an assembly of the inner ring and a retainer in which balls are rotatably fitted in recesses arranged on the outer periphery thereof and formed at equal intervals in the circumferential direction is pressed into the outer ring to assemble.

At this time, the shape from the deep portion of the groove formed on the outer peripheral surface of the mandrel to the lower outer peripheral surface thereof is formed substantially in conformity with the arc-shaped cross section of the ball. It is important that the cross-sectional shape of the portion is formed in substantially the same arc shape corresponding to the shape from the deep portion to the lower outer peripheral surface of the groove portion of the mandrel.

[0026]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a method of manufacturing a ball bearing made of an outer ring steel plate according to the present invention. FIG. 1 shows one process of a method for manufacturing a ball bearing 10 made of an outer ring steel plate according to an embodiment of the present invention.

In the method of manufacturing a ball bearing made of an outer ring steel plate in this embodiment, first, the semi-finished product 20 for the outer ring is formed by pressing a steel plate as described above. That is, the semi-molded product 20 for the outer race is a tubular body having one end horizontally bent inward so that one side has an L-shape as viewed in the axial cross section as is apparent from FIG.
Function as a first blocking portion that prevents the ball from moving in the axial direction.

The semi-molded product for outer ring 20 is supported by being mounted on a rotatable support table 21 with one end side in the axial direction, that is, the closed end side facing downward. At this time, the semi-molded outer ring product 20 is arranged so that a spindle 21 a erected around the rotation center axis is inserted into the upper surface of the rotation support stand 21. Thereafter, the inner ring 11 is inserted into the outer ring tubular body 20 from the open end (the upper end in FIG. 1) at the other end in the axial direction so as to be exterior to the spindle 21a.

At the same time, a plurality of balls 13 are placed in the annular space between the inner race 11 and the semi-molded product 20 for the outer race. Thereafter, the ball positioning jig 22 is inserted from the open end of the outer ring semi-molded product 20, and the plurality of balls 13 are forcibly held at equal intervals in the circumferential direction. That is, the ball positioning jig 22 will be briefly described. The jig has a predetermined number of pins 22a hanging down on a circle so as to hold the balls 13 at equal intervals in the circumferential direction. In other words, it can be considered that the comb is curved in a circular shape.

The jig 22 is for positioning the ball 13 in the circumferential direction, and the ball 13 itself can rotate. Then, the inner contact 2 between the inner peripheral surface of the semi-finished product for outer ring 20 and the ball is formed by the rotating forming roll 23.
4, the other end side in the axial direction of the outer ring semi-molded product 20 is pressed from the outside to form an arc-shaped reduced diameter portion linearly inscribed along the spherical surface of the ball 13 to form the second closed portion 12b. I do. Thereafter, the ball positioning tool 22 is inserted and removed, and the retainer 14 as shown in FIG. 9 is inserted to hold the ball 13 in the circumferential direction.

As the ball positioning tool, the retainer 14 can be used as it is. That is, the inner ring 11
Retainer 1 in which ball 13 is rotatably fitted in recesses 14a which are arranged on the outer periphery and are formed at equal intervals in the circumferential direction.
4 is held at a plurality of positions by the pins 22a of the ball positioning jig 22, the ball positioning jig 22
Exactly the same function can be exhibited. By doing so, the outer ring steel ball bearing of the invention can be manufactured at the same time as forming the bulging portion for closing the axial open end formed by a smooth inner surface on the outer ring made of steel plate, and mass production of the ball bearing is possible. Is what you do.

At this time, the cross-sectional shape of the outer peripheral forming portion 23a of the forming roll 23 is changed along the spherical surface of the ball 13 from the first inner contact 24 between the inner peripheral surface of the outer ring semi-formed product 20 and the ball as shown in FIG. It is very important that they are formed in a shape that is substantially the same as the arc shape inscribed linearly. That is, the use of the forming roll 23 having the outer peripheral molding portion 23a and the forced position holding of the ball 13 in the circumferential direction are combined with each other, so that the ball 13 has a shape that conforms to the cross-sectional curved surface shape, and the inner surface has a smooth contraction. Press forming of the diameter part becomes possible.

Thus, in the ball bearing made of the outer ring steel plate of the present invention, unlike the conventional manufacturing method, the outer ring semi-formed product 20 made of a steel plate closed at one end in advance is supported by the rotary support 21. A plurality of balls 13 are arranged inside the inner ring 11 from the open side, and these balls 13 are fixed in the circumferential direction by a positioning jig 22 inserted from the open side, and then a unique forming roll 23 is used. Since the reduced diameter portion is formed along the curved cross-sectional shape of the ball 13 to form the second closed portion 12b, the inner surface of the second closed portion 12b of the outer ring 12 with which the ball 13 comes into contact is formed smoothly in the circumferential direction. As a result, generation of abnormal noise and vibration can be prevented. In addition, since the inner wall of the outer ring 12 is formed in substantially the same shape as the arc shape of the ball 13, the outer ring 12 and the ball 13 are not in point contact but in line contact, and the mutual contact area is increased, and There is an advantage that the contact force (surface pressure) per area is reduced and the life of the outer ring 12 is extended.

As a method of manufacturing the outer ring steel plate ball bearing according to the second invention, as shown in FIGS. 3 to 6, one end in the axial direction of a steel plate cylindrical member having the same inner diameter as the outer ring 12 is used. Is horizontally bent inward to form the first closed portion 12.
The semi-molded product for outer ring 20 formed with a is formed on a rotary support having an outer diameter slightly smaller than the inner diameter of the semi-molded product for outer ring, and a mandrel 26 having a groove 25 formed on the outer peripheral surface provided at the center of the upper surface. 27 (FIG. 4).

Then, the rotating forming roll 23
Press the semi-molded product for outer ring 20 from the outside with
The outer ring 12 is formed by press-forming the second closed portion 12b having a reduced diameter using the groove portion 6 as a forming die (FIG. 5). that time,
The semi-molded product 20 for the outer ring is formed by a rotating forming roll 2.
While being pressed against the mandrel 26 at 3, the self-rotation itself is performed and a reduced diameter portion is formed over the entire circumference. At this time, the operation relationship between the outer ring semi-molded product 20 and the mandrel 26 is as follows.
The movement is similar to that of an inscribed gear.

When the outer race 12 having the two axially closed portions for balls formed as described above, the mandrel 2 is formed.
6 (FIG. 6), and thereafter, an assembly of the inner ring 11 and a retainer 14 which is rotatably fitted with the ball 13 in recesses 14a arranged on the outer periphery thereof and formed at equal intervals in the circumferential direction is mounted on the outer ring. Press into 12 and assemble.

At this time, as shown in FIG. 3, from the deep portion 25a of the groove 25 formed on the outer peripheral surface of the mandrel 26 to the upper outer peripheral surface thereof (this portion corresponds to the shape of the outer ring reduced diameter portion that comes into contact with the ball). It is necessary that the shape of the so-called "shoulder" 25b is substantially coincident with the cross-sectional arc shape of the ball 13. Simultaneously with this, the cross-sectional shape of the outer peripheral forming portion 23 a of the forming roll 23 is changed to the deep portion 2 in the groove 25 of the mandrel 26.
It is also necessary to be formed in substantially the same arc shape corresponding to the shape of the "shoulder" 25b from 5a to the upper outer peripheral surface.

According to such a manufacturing method, the outer race 12 is continuously formed, and the assembly of the retainer 14 holding the balls and the inner race 11 is pressed into the outer race 12 to complete the assembly. Since the manufacturing method is greatly simplified and the inner surface of the reduced diameter portion, which is the second closing portion with which the ball 13 contacts, is formed smoothly in the circumferential direction, abnormal noise and vibration due to sliding contact of the ball 13 are obtained. Since no occurrence occurs, mass production of a ball bearing made of an outer ring steel plate having excellent performance can be achieved.

[0039]

As described above, according to the method for manufacturing a ball bearing made of an outer ring steel plate of the present invention, unlike the conventional manufacturing method, a semi-finished product for an outer ring made of a steel plate closed only at one end in advance is provided. After supporting with a rotating support and inserting the inner ring into the inside from the open side, arranging a plurality of balls, fixing these balls in the circumferential direction with a positioning jig inserted from the open side, then forming a unique forming roll Since the reduced diameter portion is formed along the spherical surface of the ball to be used as the second closed portion, the inner surface of the second closed portion of the outer ring with which the ball comes into contact is formed smoothly in the circumferential direction. Generation of abnormal noise and vibration can be prevented.

Further, according to the method of manufacturing a ball bearing made of an outer ring steel plate of the present invention, the outer ring can be continuously formed by the mandrel and the forming roll, and the retainer holding the ball and the inner ring can be formed by the mandrel and the forming roll. Since the assembly is completed by press-fitting the assembly, the manufacturing method is greatly simplified, and the inner surface of the reduced diameter portion, which is the second closing portion with which the ball contacts, is formed smoothly in the circumferential direction. Therefore, since there is no generation of abnormal noise or vibration due to the sliding contact of the ball, mass production of a ball bearing made of an outer ring steel plate having excellent performance can be achieved.

[Brief description of the drawings]

FIG. 1 shows a method of manufacturing a ball bearing made of an outer ring steel plate according to one embodiment of the present invention, in which an assembly of an inner ring and a retainer, which is one of the steps, is incorporated inside to open the other end in the axial direction of a semi-molded product for an outer ring. It is sectional drawing which shows the process of forming a closure part in a part.

FIG. 2 is a partially enlarged cross-sectional view showing an enlarged shape of an outer peripheral forming portion of a forming roll in the apparatus for manufacturing a ball bearing made of outer ring steel plate shown in FIG.

FIG. 3 is a process diagram when the outer ring is molded so that it can be mass-produced in the method of manufacturing a ball bearing made of an outer ring steel plate according to the present invention.

FIG. 4 is a process drawing following the outer ring forming process shown in FIG. 3;

FIG. 5 is a process drawing following the outer ring forming process shown in FIG. 4;

FIG. 6 is a process drawing following the outer ring forming process shown in FIG. 5;

FIG. 7 is a front view of an outer ring steel ball bearing made by the manufacturing method of the present invention, with its upper half portion cut away.

FIG. 8 is a side view showing the outer ring steel ball bearing shown in FIG. 7 with its upper half cut along line 8-8.

FIG. 9 is a perspective view showing a retainer constituting the ball bearing made of the outer ring steel plate shown in FIG. 7;

FIG. 10 is a front view of a conventional full-ball type ball bearing made of an outer ring steel plate, with its upper half portion cut away.

FIG. 11 is a cross-sectional view of the ball bearing made of an outer ring steel plate of the total ball type shown in FIG. 10 taken along line 11-11.

FIG. 12 is a cross-sectional view illustrating a method for manufacturing a conventional double-row angular contact ball bearing.

[Explanation of symbols]

 Reference Signs List 10 ball bearing made of outer ring steel plate 11 inner ring 11a circumferential groove portion for ball seating 12 outer ring 12a first closing portion 12b reduced diameter portion (second closing portion) 13 ball 14 retainer 14a recess 20 semi-molded product for outer ring 21 rotation Supporting stand 21a Spindle 22 Ball positioning jig 22a Pin 23 Forming roll 23a Forming roll outer peripheral molding part 24 Internal contact 25 Groove part 25a Deep part 25b Shoulder part 26 Mandrel 27 Rotation support stand

Claims (3)

(57) [Claims] 1. A method of manufacturing a ball bearing comprising an outer ring made of a steel plate having two closed portions for fixing a ball in an axial direction, comprising a tube made of a steel plate formed with the same inner diameter as the outer ring. A semi-molded product for an outer ring, in which a first closed portion is formed in advance on one end side in the axial direction of the body, is placed on a rotary support table, and an inner ring is arranged inside from the open other end portion in the axial direction, and a predetermined number of balls are arranged. Is disposed between the inner ring and the semi-molded product for the outer ring, and a ball positioning tool is inserted from the other axial end of the semi-molded product for the outer ring to forcibly hold the balls at equal intervals in the circumferential direction. Then, the other end in the axial direction of the semi-molded product for the outer ring is pressed from the outside by an inner contact between the inner peripheral surface of the semi-molded product for the outer race and the ball by a rotating forming roll, and the spherical surface of the ball is pressed. The arc-shaped reduced diameter part inscribed linearly along the To form a second closed portion, wherein the cross-sectional shape of the outer peripheral forming portion of the forming roll is linear along the spherical surface of the ball from the inner contact surface between the inner peripheral surface of the outer ring semi-formed product and the ball. A ball bearing made of an outer ring steel plate, wherein the ball bearing is formed in substantially the same shape as the arc shape inscribed therein. 2. The outer race according to claim 1, wherein a retainer is provided on the outer periphery of the inner race and in which a ball is rotatably fitted in a recess formed at regular intervals in the circumferential direction. Manufacturing method of steel plate ball bearings. 3. A method for manufacturing a ball bearing comprising an outer ring made of a steel plate having two closed portions for fixing a ball in an axial direction, comprising a tube made of a steel plate having the same inner diameter as the outer ring. An outer ring semi-molded article having a first closed portion formed at one end in the axial direction of the body is provided with a mandrel having an outer diameter slightly smaller than the inner diameter of the outer ring semi-molded article and having a groove formed on an outer peripheral surface thereof. The outer ring semi-molded product is pressed from the outside by a rotating forming roll, and the second closed portion whose diameter is reduced by using the groove of the mandrel as a molding die is pressed. Molding to form an outer ring, and then press-fit an assembly of an inner ring and a retainer which is disposed on the outer periphery thereof and which is rotatably fitted with a ball in a recess formed at equal intervals in the circumferential direction into the outer ring. Assembling The shape from the deep part of the groove formed on the outer peripheral surface of the mandrel to the lower outer peripheral surface thereof is formed to substantially match the cross-sectional arc shape of the ball, and furthermore, the outer peripheral forming part of the forming roll A method of manufacturing a ball bearing made of an outer ring steel plate, wherein a cross-sectional shape is formed in substantially the same arc shape corresponding to the shape from the deep portion to the lower outer peripheral surface of the groove portion of the mandrel.