JP2002168256A - Rolling bearing and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance durability and reliability of a cylindrical roller bearing, and to save time for manufacturing the cylindrical roller bearing, and also to provide ease of manufacturing. SOLUTION: A roller-finish treatment is applied to the external peripheral surface 2 of a second material 1 of an inner metal ring that constitutes the cylindrical roller bearing. When the roller-finish treatment is applied, the second material 1 and a finishing roller 3 are rotated in reverse each other with constant velocity with respect to peripheral velocity of a contact part in a state that the external peripheral surface of the finishing roller 3 having a cylindrical face shape is depressed to the external peripheral surface 2 of the second material 1 with a specified load. The length L3 in the direction of the busbar on the external peripheral surface of the finishing roller 3 is made longer than the length L2 (L3>=L2) in the direction of the busbar on the external peripheral surface 2 of the second material 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the production of races and rolling elements constituting rolling bearings to be incorporated into various types of rotary machinery, and to an improvement in the surface properties of these members.

[0002]

2. Description of the Related Art Rolling contact between a first race such as an outer race, a second race such as an inner race, and a surface of a rolling element, which constitutes a rolling bearing incorporated in various types of rotating machinery, during use, comes into contact with the surface of a mating member during use. A lubricating oil film is formed between the parts to prevent the metal members facing each other from coming into direct contact with each other. In addition, the lubricating property between the surfaces that are in rolling contact with each other via the lubricating oil film can be expressed by a so-called oil film parameter 、. The greater the oil film parameter Λ, the better the lubricating property. . In order to increase the oil film parameter Λ (to improve lubricity), the so-called combined roughness (= the roughness waveform of each surface) is determined by the amplitude of the roughness waveform of each surface in rolling contact with each other. (Mean-square value of the amplitude). For this reason, conventionally, in order to reduce this combined roughness, after forming each of the above-mentioned surfaces into a predetermined shape and dimensions by grinding, super finishing is performed, and the amplitude of the waveform of the roughness of each of the above-mentioned surfaces is reduced. Smaller things are being done.

[0003]

On the other hand, at least the surface of the outer ring, the inner ring, and the rolling element that is in rolling contact with the surface of the mating member at the time of use (rolling contact surface) simply has the amplitude of the roughness waveform. In addition to making it smaller, as shown in FIG.
It is preferable to make the so-called roughness skewness (R _sk ) negative, in which the number of protrusions of roughness is small and a relatively deep concave portion is appropriately present. It is noted that the roughness skewness is negative when the ratio of the length of the average line 1 of the roughness to the portion existing outside (upper side in FIG. 5) of the average line 1 is inward (lower in FIG. 5). Side) is a state that is larger than the ratio related to the portion existing on the side. If negative and the skewness of the roughness of the rolling contact surface in this manner, the projections of the roughness less, the contact surfaces are rolling each other, it is possible to suppress the locally metallic contact, these two-sided Substantial reduction of the contact pressure between the rolling contact surfaces can be prevented, and the rolling contact surface can be prevented from being damaged. Also, in this case, a relatively deep concave portion can be appropriately provided on the rolling contact surface, and each of the concave portions serves as an oil reservoir, so that lubricity can be improved.

[0004] On the other hand, in the case of the conventional method of manufacturing a rolling bearing, a super-finishing process is performed on the rolling contact surface,
The amplitude of the roughness waveform of the rolling contact surface is reduced, and the skewness of the roughness is made negative. In this super-finishing process, while the fine grinding wheel is pressed against the surface of the workpiece with a predetermined load, while vibrating the grinding wheel,
This is performed by rotating the workpiece, and can be said to be a kind of grinding. However, when performing such super-finishing, in order to satisfactorily finish the rolling contact surface, the pressing force of the grindstone against the workpiece, the vibration speed of the grindstone, the rotation speed of the workpiece, and the like. It is necessary to strictly adjust various processing conditions in consideration of the relationship with other processing conditions. Such adjustment work is troublesome and requires skill of the operator.

If the length of the workpiece is larger than the length of the grinding wheel, it is necessary to perform a feeding operation for displacing the grinding wheel in the length direction of the workpiece surface of the workpiece. Therefore, the time required for the work of manufacturing the workpiece increases. In particular, when the workpiece is a component of a large-sized rolling bearing, the time required for the manufacturing operation of the rolling bearing becomes extremely long. Therefore, in this case, the cost of the rolling bearing increases. The rolling bearing and the method of manufacturing the same according to the present invention have been made in view of such circumstances.

[0006]

According to the rolling bearing and the method of manufacturing the same according to the present invention, the rolling bearing according to the first aspect forms the first track in the same manner as the conventionally known rolling bearing. A first raceway, a second raceway that forms a second raceway facing the first raceway, and is provided so as to roll freely between the first raceway and the second raceway. And a plurality of rolling elements. In particular, in the rolling bearing according to claim 1, the surface of at least one member of the first and second races and the plurality of rolling elements, and at least the surface of the mating member at the time of use. Roller finishing is applied to the parts that come into rolling contact.

Further, the method for manufacturing a rolling bearing according to claim 2 is characterized in that at least one of the first and second races and the plurality of rolling elements is formed on a surface of a material constituting at least one member. In a state where the processing roller is pressed against a portion that comes into rolling contact with the surface of the mating member at the time of use, the processing roller and the material are rotated in the opposite directions at a constant speed with respect to the peripheral speed of the contact portion. Is subjected to roller finishing.

[0008]

According to the rolling bearing and the method of manufacturing the same according to the present invention, the surface of the rolling contact surface of at least one of the first and second races and the plurality of rolling elements is provided. The amplitude of the roughness waveform can be reduced, and the skewness of the surface roughness can be made negative. For this reason, lubrication between the surfaces that are in rolling contact with each other can be sufficiently ensured, and the wear resistance and seizure resistance of the rolling bearing can be sufficiently ensured. Furthermore, with the rolling contact surface is work hardening, since the compressive residual stress in the rolling contact surfaces around is applied, thereby improving the rolling fatigue life of a rolling bearing under Cyclic fatigue.

[0009]

FIG. 1 shows a first embodiment of the present invention corresponding to all of the first to third aspects of the present invention. The rolling bearing of this example, which is a cylindrical roller bearing, includes an inner ring having a cylindrical inner raceway formed on an outer peripheral surface, an outer ring having a cylindrical outer raceway formed on an inner peripheral surface, and an inner raceway and an outer raceway. And a plurality of cylindrical rollers, each of which is a rolling element, provided so as to be able to freely roll between them. The inner ring, the outer ring, and the cylindrical rollers are made of a ferrous metal such as high carbon chromium bearing steel such as SUJ2. FIG. 1 shows a state in which the inner raceway formed on the outer peripheral surface of the inner race is subjected to finish machining. When forming the inner ring raceway, first, subjected to a forging or the like to the iron-based metal constituting the inner ring has a rough shape and dimensions, making a cylindrical first material (not shown). Next, in the outer peripheral surface of the first material, at least at the time of use, a portion that is in rolling contact with the rolling surface of each of the cylindrical rollers, which is a mating member, is subjected to grinding, and the portion is finished to a predetermined shape and dimensions. And the second material 1.

Next, the outer peripheral surface 2 of the second material 1 is subjected to roller finishing, and the portion subjected to the roller finishing is defined as the inner raceway. Roller finishing is a process in which a pair of members rotate in opposite directions at a constant speed with respect to the peripheral speed of a contact portion while applying a contact load. This is a processing method of crushing a minute convex portion to make the surface smooth, and is a so-called roller burnishing process. A roller finishing machine for performing such a roller finishing process is capable of freely rotating a processing roller 3 having a single cylindrical outer peripheral surface and a support shaft (not shown) on a part of a support table (not shown). I support it. Further, the processing roller 3 and the support shaft are arranged in a state where their center axes are parallel to each other. When the roller finishing process is performed, the second material 1 is kept in a state where the outer peripheral surface is subjected to the grinding process on the intermediate portion of the support shaft.
And the outer peripheral surface of the processing roller 3 is pressed against the outer peripheral surface 2 of the second material 1 with a predetermined load F.

In the case of the method for manufacturing a rolling bearing of the present embodiment,
A processing surface of the processing roller 3, the length L ₃ about the generatrix direction of the outer peripheral surface, and the length L ₂ or about generatrix direction of the outer peripheral surface 2 of the inner ring of the material 1 (L ₃ ≧ L _2).
The hardness of the surface of the processing roller 3 is higher than the hardness of the surface of the inner ring 1. For example, as a material constituting the processing roller 3, ceramics, cemented carbide, etc.
A material having sufficiently higher hardness than the material constituting the inner ring can be preferably used.

Then, as described above, the second material 1 for the inner ring is used.
The support shaft is rotated at a predetermined rotation speed in a state where the outer peripheral surface of the processing roller 3 is pressed against the outer peripheral surface 2 of the support roller. With the rotation of the support shaft, the second material 1 and the processing roller 3 rotate at a constant speed in directions opposite to each other, and the outer peripheral surface 2 of the second material 1 of the inner ring is gradually plastically deformed. The outer diameter of the two materials 1 gradually decreases. Therefore, when the support shaft is rotated for a predetermined time, the outer peripheral surface 2 of the second material is finished in a predetermined shape and dimensions, and becomes an inner raceway.

According to the rolling bearing and the method of manufacturing the same according to the present invention, the outer peripheral surface of the second material 1 is formed by the outer peripheral surface which is the processing surface of the processing roller 3 based on the roller finishing. it is possible to crush the surface roughness projections.
For this reason, the amplitude of the waveform of the surface roughness of the inner ring raceway, which is the portion that is in rolling contact with the rolling surfaces of a plurality of rollers at least during use on the outer peripheral surface of the completed inner ring, can be reduced, and this surface roughness can be reduced. it can be the skewness in the negative. That is, by reducing the projection of the surface roughness, the inner ring raceway and rolling surface of each roller to be in rolling contact with the inner ring raceway along with can be suppressed to locally metallic contact with each other,
Substantially lower contact surface pressure between the inner raceway and the rolling surfaces of the rollers that come into contact with each other can be achieved. Further, since the relatively deep recesses formed in the inner raceway remain until the grinding, the relatively deep recesses are appropriately provided in the inner raceway so that each of these recesses serves as an oil reservoir. You can do things. Therefore, according to the present invention, lubrication between the inner ring raceway and the rolling surface of each roller can be sufficiently ensured, and the abrasion resistance and seizure resistance of the cylindrical roller bearing incorporating the inner ring and the plurality of rollers can be ensured. Nature can be sufficiently secured. Further, since the inner raceway is finished by roller finishing, the surface of the inner raceway is work-hardened, and a compressive residual stress is applied to the vicinity of the surface of the inner raceway, so that the rolling fatigue of the cylindrical roller bearing which is repeatedly subjected to fatigue is performed. The life can be improved.

Further, in the case of the method of manufacturing a rolling bearing of this embodiment, the length L ₃ of the outer peripheral surface, which is the processing surface of the processing roller 3 used for roller finishing, in the generatrix direction is determined by the second material of the inner ring. It has a length L ₂ or about 1 generatrix direction of the outer peripheral surface _{2 (L 3 ≧ L 2)} . For this reason, during finishing
There is no need to perform a feeding operation for relatively displacing the processing roller 3 and the second material 1 in the axial direction, and the time required for manufacturing the inner ring and the cylindrical roller bearing incorporating the inner ring can be reduced. Also, the when the second applying roller finishing the outer peripheral surface 2 of the material 1, and the magnitude of the load F to press towards the processing roller 3 in the second material 1, and the rotational speed of the second material 1 Can be adjusted to predetermined values, respectively.
It is not necessary to adjust the feed speed of the processing roller 3 and the second material 1. The second material 1 can be rotated at a relatively low speed. However, when the second material 1 is rotated at a relatively low speed, it must be strictly adjusted when performing the roller finishing process. The only thing that does not occur is the magnitude of the pressing load F of the processing roller 3. For this reason, it is possible to reduce the time and labor required for performing the finishing work, and to eliminate the need for the skill of the operator, thereby facilitating the manufacturing operation of the inner ring and the cylindrical roller bearing incorporating the inner ring.

In the present embodiment, the outer peripheral surface of the processing roller 3 is a single cylindrical surface. However, as shown in another example shown in FIG. In addition to forming the arc-shaped crowning, the radius of curvature of the crowning can be reduced toward both ends in the axial direction of the processing roller 3a. When in this way, the axial end portion the second material of the inner ring from the outer peripheral surface 1 of the processing roller 3a
The edge load applied to the outer peripheral surface of FIG. 1 can be reduced. Further, at least the portion of the crowning near both ends in the axial direction may be formed into a logarithmic curve, and the surface pressure applied to the outer peripheral surface of the second material 1 of the inner ring by the processing roller 3a may be substantially constant.

FIG. 3 shows a second embodiment of the present invention.
As an example, a state is shown in which an outer peripheral surface of an inner ring constituting a tapered roller bearing is subjected to finish processing to form a conical convex inner raceway on the outer peripheral surface. In addition, a small-diameter flange portion 4 and a large-diameter flange portion 5 each having an outward flange shape are formed on the outer peripheral surfaces of both ends of the inner ring so as to sandwich the inner ring raceway. An outer ring (not shown) having a conical concave outer ring track formed on the inner circumferential surface is arranged around the inner ring, and a plurality of rollers (not shown) are provided between the inner ring track and the outer ring track.
Are provided so that they can roll freely, thereby forming a tapered roller bearing.
In the case of this example, the above-mentioned inner raceway having a conical convex shape is
In order to finish to a predetermined shape and dimensions, an outer peripheral surface 2a of the second material 1a constituting the inner ring is subjected to a roller finishing process using a processing roller 3b whose outer peripheral surface has a conical convex shape. The extension of the generatrix of the outer peripheral surface of the processing roller 3b intersects on the central axis of the second material 1a.

On the other hand, in order to finish the inner raceway, the outer peripheral surface 2a of the second material 1a is formed on the outer peripheral surface 2a in the same manner as in the above-described first example. It is also conceivable to perform roller finishing using (see FIG. 1). However, the processing rollers 3 the outer peripheral surface is a cylindrical surface in a state pressed against the outer circumferential surface 2a of the second material 1a, when rotating the second material 1a, the outer peripheral surface and the above processing roller 3 a caused the differential slip between the outer peripheral surface 2a of the two materials 1a, to finish better the properties of the inner ring raceway it is difficult. In the case of this example, since the outer peripheral surface has a conical convex shape and the processing roller 3b in which the extension of the generatrix of the outer peripheral surface intersects on the central axis of the second material 1a is used, the differential sliding is performed. Does not occur. Therefore, the properties of the inner raceway can be satisfactorily finished. For the other configurations and operations are the same as those in the first embodiment described above.

FIG. 4 shows a third embodiment of the present invention.
As an example, a state is shown in which the rolling surface of a cylindrical roller constituting a cylindrical roller bearing is finished. In the case of this example, in order to finish the rolling surface of the cylindrical roller, a processing roller 3 having a cylindrical outer peripheral surface is used for the outer peripheral surface 7 of the material 6 of the cylindrical roller. Apply finishing. For this reason, in the case of the present example, a pair of guide rollers 8, 8 are provided at two positions on the part of the support base (not shown) that are substantially opposite to the processing roller 3 with respect to the cylindrical roller material 6. Each is supported rotatably. Outer peripheral surface 7 of cylindrical roller blank 6
When the roller finishing process is performed on the material, the material 6 of the cylindrical roller is supported above the pair of guide rollers 8, 8, and the outer peripheral surface, which is the processing surface of the processing roller 3, is It is pressed against the outer peripheral surface by a predetermined load F. Then, in this state, a member (not shown) supporting the material 6 is rotationally driven, and the material 6 and the processing roller 3 are separated from each other.
With respect to the peripheral speed at the contact portion, the outer peripheral surface of the cylindrical roller material 6 is subjected to roller finishing by rotating in the opposite directions at a constant speed. By performing the roller finishing process on the outer peripheral surface 7 of the raw material 6 of the cylindrical roller according to the manufacturing method of the rolling bearing of the present example, the properties of the rolling surface of the cylindrical roller can be improved.
Other configurations and operations are the same as those in the first example.

In each of the above-described examples, the case where the rolling contact surfaces of the inner ring and the rolling element constituting the rolling bearing are finished is described. However, the present invention is not limited to these cases, and can also be applied to the case where the outer raceway formed on the inner peripheral surface of the outer race constituting a rolling bearing such as a cylindrical roller bearing or a tapered roller bearing is subjected to finish machining. In each of the above-described examples, the case where the rolling contact surface of the bearing ring and the rolling element constituting the rolling bearing is directly subjected to roller finishing is described. In the case of the present invention, however, the manganese phosphate is applied to the rolling contact surface. After the formation of the chemical conversion coating film, a roller finishing process can be applied to this chemical conversion coating portion. According to the rolling bearing constituted by the member on which the chemical conversion coating is formed, rust prevention and lubricity at the beginning of operation can be improved. Further, the present invention can be applied not only to a radial rolling bearing but also to a thrust rolling bearing.

Further, the technology of the present invention is not limited to the rolling bearing, and the rolling sliding member other than the above-mentioned rolling bearing constituent member or the rolling contact member whose surface comes into contact with at least the surface of the mating member at the time of use in relative displacement. The present invention can be applied to a device having this rolling sliding member. For example, a cam, a driven member provided to face the cam, and displaced by the movement of the cam, and a part of the driven member rotatably in a state of contacting the outer peripheral surface of the cam. comprising a supported outer ring, with regard to the cam follower device, it can be applied the technique of the present invention. When the technology of the present invention is applied to such a cam follower device, a surface of at least one of the cam and the outer ring, each of which is a rolling sliding member, and a surface of a mating member when used. Rolling finish is applied to the part that comes into rolling contact with the roller. As described above, even when the technology of the present invention is applied to a device having a rolling sliding member other than the components of the rolling bearing, the surface properties of the rolling sliding member can be improved, and the abrasion resistance and anti-burning property can be improved. It is possible to improve the adhesion and prevent the surface from being damaged for a long period of time.

[0021]

Since the present invention is constructed and operates as described above, the wear resistance and seizure resistance of the rolling bearing can be improved, and the rolling fatigue life can be sufficiently ensured. As a result, it is possible to improve the durability and the reliability of the rolling bearing and the rotary machine device incorporating the rolling bearing.
Further, the time required for the manufacturing operation of the rolling bearing can be shortened, and the manufacturing operation can be facilitated, so that the manufacturing cost of the rolling bearing can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first example of an embodiment of the present invention in a state in which an inner raceway of an inner race constituting a cylindrical roller bearing is finished by roller finishing.

FIG. 2 is a diagram showing another example of a processing roller.

FIG. 3 is a view showing a second example of the embodiment of the present invention in a state where an inner raceway of an inner race constituting a tapered roller bearing is finished by roller finishing.

FIG. 4 is a perspective view showing a third example of the embodiment of the present invention in a state where a rolling surface of a cylindrical roller constituting a cylindrical roller bearing is finished by roller finishing.

FIG. 5 is a diagram showing a waveform of a surface roughness having a negative skewness.

[Explanation of symbols]

 1, 1a Second material 2, 2a Outer surface 3, 3a, 3b Processing roller 4 Small diameter flange 5 Large diameter flange 6 Material 7 Outer surface 8 Guide roller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshifumi Yamamoto 1-5-150 Kugenuma Shinmei, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (reference) 3J101 AA13 AA16 AA62 BA04 BA53 BA54 CA12 DA11 FA02 FA32 FA44

Claims (3)

[Claims] 1. A first bearing ring forming a first track,
A second orbital ring forming a second orbit opposed to the first orbit, and a plurality of rolling elements provided rotatably between the first and second orbitals. In the rolling bearing, the surface of at least one of the first and second races and the plurality of rolling elements, at least in a portion which is in rolling contact with the surface of the mating member at the time of use, has a roller finish. Rolling bearings that have been machined. 2. A surface of a material constituting at least one of the first and second races, the outer race, and the plurality of rolling elements, and at least a portion which is in rolling contact with a surface of a mating member during use. The roller finishing process is performed on the portion by rotating the processing roller and the material in opposite directions to each other at a constant speed with respect to a peripheral speed of a contact portion in a state where the processing roller is pressed. Rolling bearing manufacturing method. 3. A material forming at least one member of the first and second races and a plurality of rolling elements, the length in the generatrix direction of the outer peripheral surface being the processing surface of the processing roller. 3. The method for manufacturing a rolling bearing according to claim 2, wherein the surface has a length in the generatrix direction that is at least a portion that comes into rolling contact with the surface of the mating member during use.