JP2004100754A - Method for processing smooth surface of inner surface of outer ring of bearing device and bearing device subjected to the processing method - Google Patents

Abstract

An inner surface of an outer ring is smoothed by finishing a complete bite without a feed, and further, the inner surface is barrel-finished, so that even if there is a fine foreign matter attached later, it is easier to clean. It is to make it easy to drop.
A bearing device in which a plurality of rolling elements are incorporated between an outer ring and an inner ring or a shaft, and an inner diameter surface 1a, a raceway groove 1b, and a seal plate groove 1c of the outer ring 1 are completely connected. Finish the tool bite and then barrel finish. The overall cutting tool 8 simultaneously turns the entire inner diameter surface 1a of the outer ring 1, the raceway groove 1b, and the seal plate groove 1c.
[Selection] Figure 2

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is used for a bearing device used for a disk memory spindle motor such as a VTR drum spindle motor, a tape storage drum spindle motor, an HDD motor, and other motors.
[0002]
[Prior art]
The inner surface of the outer ring constituting this type of bearing device is generally subjected to cutting or grinding. That is, the inner ring surface before processing has a large surface roughness and may have burrs and burrs. Therefore, in order to eliminate such surface roughness and burrs, etc., such cutting and grinding are performed. Processing has been applied. In addition, super-finish polishing is made on the raceway surface on which the rolling elements roll.
However, according to the cutting process or the grinding process, fine foreign matters such as fine chips and fine abrasive grains are generated by the processing. Therefore, the fine foreign substances may adhere to the concave portion of the rough surface. It was difficult to remove even after washing. And if this minute foreign matter falls rarely due to grease stirring etc. in the bearing state and gets caught between the ball and the raceway surface, it will make an abnormal noise or rough the surface, worsening the sound and worsening the acoustic life of the bearing There was a risk of shortening.
In view of this, Japanese Patent Application Laid-Open Nos. 2001-121416 and 2001-124094 have been disclosed as techniques for eliminating such harmful effects caused by burrs and fine foreign matters remaining on the inner surface of the outer ring after cutting or grinding.
[0003]
[Problems to be solved by the invention]
In Japanese Patent Laid-Open No. 2001-121416, by pressing a finishing roller having a hardness higher than the hardness of the outer ring against the inner surface of the outer ring, fine foreign matter adhering to the inner surface of the outer ring due to the pressing of the finishing roller is applied to the inner surface. A method of embedding and smoothing the inner surface is disclosed.
On the other hand, in Japanese Patent Laid-Open No. 2001-124094, a ball having a hardness larger than the inner diameter dimension and higher than the hardness of the outer ring is passed through the outer ring inner diameter surface, so that it adheres to the outer ring inner diameter surface by pressing the large-diameter ball. A method of embedding fine foreign matter to be embedded in the inner diameter surface and finishing the inner diameter surface smoothly is disclosed.
However, in Japanese Patent Application Laid-Open Nos. 2001-121416 and 2001-124094, as described above, fine foreign substances adhering to the inner surface of the outer ring are forcibly embedded in the inner surface by using a finishing roller or a large-diameter ball. However, it was very difficult to completely embed or scrape all the deposits, and it was not completely achieved. In addition, even if a fine foreign object is forcibly embedded in the inner diameter surface, the foreign object may fall from the inner diameter surface during use of the bearing. In such a case, the concave portion after embedding the fine foreign object remains on the inner diameter surface. End up.
For this reason, the purpose of completely removing burrs and fine foreign matters from the inner surface of the outer ring to make the inner surface smooth is not always achieved sufficiently.
The present invention has been made in view of the above-mentioned problems of the prior art, and the object of the present invention is to smooth the inner ring surface of the outer ring by finishing a complete bite with no feed, By barrel finishing, even if fine foreign matter adheres later without any burrs, it can be easily removed by washing.
[0004]
[Means for achieving the object]
In order to achieve the above object, according to the present invention, there is provided a bearing device in which a plurality of rolling elements are incorporated between an outer ring and an inner ring or a shaft, and the inner ring surface of the outer ring is finished with a complete bite finish. Then, the smooth surface finishing method for the inner ring surface of the outer ring is employed in which the inner surface is barrel-finished.
Further, as described above, the inner ring surface of the outer ring is finished with a complete bite and then subjected to barrel finishing, whereby a bearing device having an inner diameter surface formed as a smooth surface is obtained.
This bearing device can also incorporate an inner ring guide or a shaft outer diameter surface guide cage. For example, in this case, a deep groove ball bearing using balls as rolling elements is an example. Further, a shaft bearing having a double row raceway surface on the shaft, an outer ring corresponding to each raceway surface, and preloaded via a coil spring between the outer rings may be provided. At this time, a shaft outer diameter surface guide or rolling element guide retainer can be incorporated.
For example, a turning tool that simultaneously turns the inner ring surface of the outer ring and the entire raceway groove and seal plate groove, a turning tool that simultaneously turns the entire outer ring raceway groove and the entire inner surface, and the entire inner ring surface of the outer ring. Turning tool that simultaneously turns, turning tool that simultaneously turns the entire outer ring seal groove and inner diameter surface, turning tool that simultaneously turns one inner diameter surface of the outer ring, one sealing plate groove of outer ring and the entire inner diameter surface As a representative example, a turning tool that simultaneously turns can be used.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described.
The bearing device of the present invention is intended for all bearing devices in which a plurality of rolling elements are incorporated between an outer ring and an inner ring or between an outer ring and a shaft. This bearing device has a deep groove ball bearing or the like incorporating a cage for an inner ring guide or a shaft outer diameter guide, a double row raceway surface on the shaft, and an outer ring corresponding to each raceway surface. For example, a bearing with a shaft preloaded via a coil spring can be used. At this time, a cage for guiding the outer diameter of the shaft or guiding the rolling element can be incorporated. In this embodiment, for the sake of explanation, a rolling bearing using balls as rolling elements is used. However, the present invention is not limited to this, and can be appropriately selected and changed within the scope of the present invention, such as a roller bearing. is there.
Then, the inner surface of the outer ring (inner diameter surface, raceway groove or seal plate groove in the case of having a seal) in the bearing device is subjected to a complete bite finish without a feed, and then barrel finish.
As described above, by finishing the inner surface of the outer ring with a seamless bite, first the surface roughness of the inner ring is reduced to a smooth surface, and then the inner surface of the outer ring is finished by barrel finishing. The remaining burrs and fine foreign matters are removed, and the inner surface is made smoother.
[0006]
FIG. 1 shows an embodiment of a shaft bearing subjected to a smooth surface finishing method for the inner surface of an outer ring. 1 is an outer ring, 2 is a shaft having a double row of grooves 2a, 3 is a plurality of rolling elements incorporated between the outer ring 1 and the shaft 2, 4 is a spring disposed between the outer rings 1 and 1, and 5 is a spring. A seat 6 indicates a sealing plate. Reference numeral 7 denotes a cage, which is a ball guide cage in the embodiment of FIG. Each of the above components constituting the bearing device with the shaft has a known configuration except that any one or all of the inner surface 1a, the raceway groove 1b, and the seal plate groove 1c of the outer ring 1 are subjected to a smooth surface finishing process. Thus, the present invention is not particularly limited and can be changed within the scope of the present invention.
[0007]
FIG. 2 shows a first embodiment of the overall bite finishing according to the present invention. In this embodiment, the desired turning bit 8 shown in the drawing is used to seal the inner diameter surface 1a, the raceway groove 1b and the left and right seals of the outer ring 1. A state in which the whole of the plate grooves 1c and 1c are finished with a complete bite simultaneously is shown.
While rotating the outer ring 1 (R direction in the figure), the cutting edge 8a of the turning bit 8 that is aligned over the entire axial direction of the inner diameter surface 1a, the raceway groove 1b, and the left and right seal plate grooves 1c, 1c is pressed simultaneously. By finishing, the inner diameter surface 1a, the raceway groove 1b, and the left and right seal plate grooves 1c and 1c are made into a smooth finished surface without a feed. The turning tool 8 is not particularly limited as long as it is within the scope of the present invention.
Then, when barrel finishing and bright barrel finishing are performed thereafter, the inner diameter surface 1a, the raceway groove 1b, and the left and right seal plate grooves 1c and 1c are finished to a smoother surface (smooth surface) without burrs. FIG. 11 shows, for reference, a state in which a turning tool is sent in the axial direction of the inner surface 1a of the outer ring while the outer ring 1 is rotated to finish the inner surface by turning. Therefore, the surface roughness of the inner diameter surface 1a becomes rough as shown in FIG. 11B.
For the barrel finishing, polishing processing by a known barrel apparatus is appropriately selected, and when a barrel with a relatively large margin for removing burr and rounding corners is combined with a bright barrel for finishing the surface, Although more effective can be expected, it is appropriately selected within the scope of the present invention without limitation. Note that various conditions such as selection / mixing ratio of polishing stones (media), barrel rotation speed, polishing time, and the like are appropriately set as necessary.
In particular, in a shaft bearing provided with a double row groove 2a directly on the shaft 2 and preloaded with a spring 4 between the outer rings 1 and 1, the side on which the rolling element 3 is assembled after both rows as shown in FIG. The spring seat 5 becomes obstructive, and the cage 7 needs to be assembled from the opposite side (shaft end side) of the spring 4 of the outer ring 1 (upper side in the case of FIG. 1). For this reason, it is necessary to enclose the grease G from the back surface (the non-pocket side) 7a of the cage 7 in order to enclose the rolling element 3 at a later time. For this reason, since grease G is sealed through the clearance between the cage outer diameter surface 7b and the outer ring inner diameter surface 1a, the effect of the cleanliness of the outer ring inner diameter surface 1a is large (in this case, foreign matter adheres to the inner diameter surface 1a. If this is the case, it is considered that foreign matter is pushed into the raceway groove 1b together with the grease G.), the effect of the present invention can be expected.
Furthermore, the effect can be expected with a small shaft bearing with the shaft diameter of 4 mm or less and the inner diameter of the outer ring 1 of 6.5 mm or less. For smaller drum spindles such as DVC (Digital Video Cassette Recorder) and MICROMV (Micro MV) Since lower torque is required and higher speed rotation is required, the viscosity of grease, etc., must be reduced, and the oil film formation becomes thinner, so it is easily affected by even the smallest foreign matter caught in. Since it is easy to influence the sound, a very small shaft bearing having a shaft diameter of 3 mm or less and an outer ring inner diameter of 5 mm or less can be expected to be more effective.
[0008]
FIG. 3 shows a second embodiment of the overall bite finishing according to the present invention. In this embodiment, the entire inner diameter surfaces 1a and 1a of the outer ring 1 are simultaneously formed using the desired turning bit 8 shown in the figure. Shows the finished state.
While the outer ring 1 is rotated (R direction in the figure), the cutting edge 8a of the turning bit 8 that matches the entire axial direction of each of the inner diameter surfaces 1a and 1a is simultaneously pressed to finish the bite. As a result, the inner diameter surfaces 1a and 1a have smooth finished surfaces that are free from eyes due to the feeding of the cutting tool.
FIGS. 4 to 6 are explanatory views for the processing of the raceway groove 1b and the seal plate grooves 1c and 1c up to the completion of the overall bite of the inner diameter surface in the second embodiment. That is, FIG. 4 shows a state in which the raceway groove 1b and the seal plate grooves 1c and 1c are processed in advance in another step, and then the process proceeds to the step in FIG.
5 shows a step of processing the raceway groove 1b, and FIG. 6 shows a step of processing the seal plate grooves 1c and 1c. After passing through the respective steps, the process proceeds to the step of FIG. . Note that either step of FIG. 5 or step of FIG.
[0009]
FIG. 7 shows a third embodiment of the overall bite finishing according to the present invention. In this embodiment, the desired inner surface 1a, 1a of the outer ring 1 and the raceway groove 1b are formed using a desired turning bit 8 shown in the drawing. At the same time, it shows the state of finishing with a total tool.
While the outer ring 1 is rotated (R direction in the figure), the cutting edge 8a of the turning bit 8 that coincides over the entire axial direction of each of the inner diameter surfaces 1a and 1a and the raceway groove 1b is simultaneously pressed to finish the bite. As a result, the inner surface 1a, 1a and the raceway groove 1b have a smooth finished surface in which no eyes are generated by the feeding of the cutting tool.
[0010]
FIG. 8 shows a fourth embodiment of the overall bite finishing according to the present invention. In the present embodiment, the desired turning bit 8 shown in the drawing is used, and the inner diameter surfaces 1a and 1a of the outer ring 1 excluding the raceway groove 1b. The state where the whole and the sealing plate grooves 1c, 1c are finished with a total bite simultaneously is shown.
While rotating the outer ring 1 (R direction in the figure), the cutting edge 8a of the turning bit 8 that coincides with each other in the axial direction of each of the inner diameter surfaces 1a and 1a and the seal plate grooves 1c and 1c is simultaneously pressed to finish the bite. Yes. As a result, the inner surface 1a, 1a and the seal plate groove 1c, 1c have a smooth finished surface that is free from eyes caused by the feeding of the cutting tool.
[0011]
FIG. 9 shows a fifth embodiment of the overall bite finishing according to the present invention. That is, in the present embodiment, the entire turning tool 8 is simultaneously finished on the entire inner diameter surface 1a of the outer ring 1 by using the desired turning tool 8 shown in the drawing.
While the outer ring 1 is rotated (R direction in the figure), the cutting edge 8a of the turning bit 8 that matches the entire axial direction of one inner diameter surface 1a is simultaneously pressed to finish the bite. As a result, the inner surface 1a has a smooth finished surface that is free of eyes due to feeding of the cutting tool.
FIG. 10 shows a sixth embodiment of the overall bite finish according to the present invention. In other words, in the present embodiment, the desired turning tool 8 shown in the drawing is used to finish the inner diameter surface 1a of the outer ring 1 and the one seal plate groove 1c at the same time.
While rotating the outer ring 1 (R direction in the figure), the cutting edge 8a of the turning bit 8 that coincides over the entire axial direction of one inner diameter surface 1a and one seal plate groove 1c is simultaneously pressed to finish the bite. As a result, one inner diameter surface 1a and one seal plate groove 1c have a smooth finished surface that is free of eyes due to feeding of the cutting tool.
According to these fifth and sixth embodiments, one inner diameter surface 1a or one inner diameter surface 1a and one seal plate groove 1c are processed, and the cutting resistance is halved. There is no longer any problem due to chatter.
Further, the cutting of the cutting tool for finishing the inner diameter surface 1a on one side is stopped, and the cutting can be further smoothly finished by sending it in the axial direction.
[0012]
【The invention's effect】
According to the present invention, the inner surface of the outer ring is finished with a full bite without a feed, and further barrel-finished, so that the inner surface becomes very smooth, there are no burrs and burrs, and even if fine foreign matter adheres later, it is cleaned It becomes easy to drop easily.
Also, in bearings incorporating rolling element guide cages, inner ring guide cages or shaft outer diameter surface guide cages, the cage never touches and slides on the inner surface of the outer ring. There was no need to do. However, in recent years, there has been a demand to reduce the loss torque of bearings by reducing the size and power consumption (for example, reducing the battery size), and in order to cope with this, the amount of grease to be filled is reduced, the viscosity is lowered, and the rolling surface is reduced. The oil film becomes thinner, and it is becoming affected even if very fine foreign matter is bitten. Therefore, it is necessary to improve the cleanliness of the bearing, and as shown in the present invention, the inner surface of the outer ring is smoothly finished with a complete bite without a feed and further barrel finished, so that the adhering foreign matter can be easily cleaned. The effect of improving the cleanliness in the bearing can be expected.
In the case of a bearing device in which a double row raceway surface is provided on the shaft, an outer ring corresponding to each raceway surface is provided, and a preload is applied between the outer rings via a coil spring, cleaning after the bearing is incorporated is more effective than a single row ball bearing. Although it may be difficult, according to the present invention, even in a bearing device of this type, the inner surface of the outer ring is barrel-finished after finishing the complete bite without a feed, so that cleaning is easy. Has an effect.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a shaft bearing according to an embodiment of the bearing device of the present invention.
FIG. 2 is a schematic view showing a state in which the inner ring surface of the outer ring, the raceway groove, and the seal plate groove are finished with a complete cutting tool.
FIG. 3 is a schematic view showing a state in which an inner diameter surface of an outer ring is finished with a complete bite.
FIG. 4 is a schematic view showing a state in which a raceway groove and a seal plate groove of an outer ring are previously processed in different steps.
FIG. 5 is a schematic view showing a state in which a raceway groove of an outer ring is previously processed in another step.
FIG. 6 is a schematic view showing a state in which the seal plate groove of the outer ring is processed in advance in another step.
FIG. 7 is a schematic view showing a state in which the inner ring surface and the raceway surface of the outer ring are finished with a complete bite.
FIG. 8 is a schematic view showing a cross-sectional view of the inner ring surface of the outer ring and the seal plate groove being finished with a full-length tool.
FIG. 9 is a schematic view showing a state in which one inner diameter surface of the outer ring is finished with a complete bite.
FIG. 10 is a schematic cross-sectional view showing a state in which one inner diameter surface of the outer ring and one seal plate groove are finished with a complete bite.
FIGS. 11A and 11B are schematic reference views showing a state in which a cutting tool is pressed against an inner diameter surface of an outer ring and the tool is turned in an axial direction, and FIG. 11B is an enlarged view showing an inner diameter surface after turning. Partial reference diagram.
[Explanation of symbols]
1: outer ring 1a: inner diameter surface 1b: raceway groove 1c: seal plate groove 2: shaft 3: rolling element 8: turning tool 8a: cutting edge

Claims (12)

A bearing device in which a plurality of rolling elements are incorporated between an outer ring and an inner ring or a shaft, and the inner ring surface of the outer ring is finished with a complete bite, and then the inner ring surface is barrel-finished. A smooth surface finishing method for an inner ring surface of an outer ring of a bearing device. A bearing device in which a plurality of rolling elements are incorporated between an outer ring and an inner ring or a shaft. Is formed on a smooth surface. 2. The method of finishing a smooth surface of an inner ring surface of an outer ring of a bearing device according to claim 1, wherein the total form bit is a turning bit that simultaneously turns the inner ring surface of the outer ring, the entire raceway groove and the seal plate groove. The bearing device according to claim 2. 3. The method of finishing a smooth surface of an inner ring surface of an outer ring of a bearing device according to claim 1, wherein the total form bit is a turning bit that simultaneously turns the entire raceway groove and the entire inner diameter surface of the outer ring. The bearing device described. 3. The method for smoothing a smooth surface of an inner ring surface of a bearing device according to claim 1, or the bearing device according to claim 2, wherein the total shape bite is a turning bite that simultaneously turns the entire inner diameter surface of the outer ring. . 3. The method of finishing a smooth surface of an inner ring surface of an outer ring of a bearing device according to claim 1, wherein the total form bit is a turning bit that simultaneously turns the entire seal plate groove and the entire inner diameter surface of the outer ring. The bearing device described in 1. 3. The smooth surface finishing method according to claim 1, wherein the overall shape bite is a turning bite that simultaneously turns the entire inner diameter surface of one of the outer rings. Bearing device. 2. The method of finishing a smooth surface of an inner ring surface of an outer ring of a bearing device according to claim 1, wherein the total form bit is a turning bit that simultaneously turns one seal plate groove of the outer ring and the entire inner diameter surface. The bearing device according to claim 2. 9. The bearing device according to claim 2, wherein a cage for inner ring guide or shaft outer diameter surface guide is incorporated. 9. The bearing device according to claim 2, wherein the bearing device is a deep groove ball bearing using a ball as a rolling element and incorporating a cage for inner ring guide or shaft outer diameter surface guide. 9. A shaft bearing provided with a double row raceway surface on a shaft, an outer ring corresponding to each raceway surface, and a preload via a coil spring between the outer rings. The bearing device described. The bearing device according to claim 11, wherein a cage for a shaft outer diameter surface guide or a rolling element guide is incorporated.

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