JP2008281181A - Rolling bearing and its restoration method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily take a countermeasure, without repairing and processing a raceway surface, when inconvenience such as a torque variation or acoustic failure is caused by strain of the raceway surface. <P>SOLUTION: A tap hole 10 is arranged on a bearing end surface or an inner peripheral surface or an outer peripheral surface, and when the inconvenience such as the torque variation or the acoustic failure is caused by polygonal strain of the raceway surface, a raceway surface shape having strain of the number different from prerestoration is formed by inserting and fastening a bolt. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing and a method for repairing the rolling bearing, and more particularly to improvement of an acoustic problem accompanying rotation of the rolling bearing.

Polygonal distortion of the bearing raceway surface can cause quality (torque, acoustic) problems. For example, in the gantry bearing device of the CT scanner device disclosed in Patent Document 1, a patient passes through the inner diameter portion of the bearing due to the structure of the device. Therefore, a large-diameter bearing having an inner diameter of 1000 mm or more is used. The amount of polygonal distortion on the raceway surface tends to increase. If a rolling element passes through a bearing raceway with a large amount of strain under a load, vibration (sound) is likely to occur due to resonance, and this causes a burden on the patient. There is a demand for it.
JP 2005-273713 A

  Polygonal distortion that may cause acoustic problems may occur during machining on the inner ring or outer ring raceway surface. However, the larger the bearing, the more difficult it is to modify the raceway surface. In particular, if the number of polygonal strains due to the processing of the bearing raceway surface is equal to or greater than the number of rolling elements, the total number of rolling elements enters and exits the strain on the raceway surface, and acoustic problems are likely to occur. That is, the entire number of rolling elements enters or exits the concave portion of the raceway surface during rotation of the bearing, so that the rotating inner ring or outer ring moves (vibrates) in the axial and radial directions, There is a possibility that the acoustic value increases due to this repetition.

  An object of the present invention is to make it possible to easily take measures without repairing a raceway surface when a problem such as torque fluctuation or acoustic failure due to polygonal distortion of the raceway surface occurs.

  The invention according to claim 1 is a rolling bearing in which a tapped hole is provided in the bearing ring, and a raceway surface shape of the bearing ring can be changed by inserting and tightening a bolt into the tapped hole.

  The invention of claim 2 is a rolling bearing in which a raceway surface shape of the raceway ring can be changed by providing a hole in the raceway ring and press-fitting a pin into the hole.

  According to the invention of claim 3, when a polygonal distortion occurs on the raceway surface of the raceway, a part of the raceway surface is repaired to form a raceway surface shape having a different number of strains from that before the repair. A rolling bearing machining method characterized by the following.

  The invention of claim 4 provides a plurality of tap holes in at least one raceway of the end face of the inner ring or outer ring of the rolling bearing, and when polygonal distortion occurs on the raceway surface of the raceway provided with the tap holes, In this rolling bearing machining method, a bolt is inserted into a tapped hole near a strain and tightened to form a raceway having a different number of strains from that before repair.

  According to the invention of claim 5, when a plurality of holes are provided in at least one raceway of the end face of the inner ring or outer ring of the rolling bearing, and polygonal distortion occurs in the raceway surface of the raceway provided with holes, This is a rolling bearing machining method characterized in that a raceway surface having a different number of strains from that before restoration is obtained by press-fitting a pin into the hole.

  According to the present invention, by providing a tapped hole on the bearing end surface or the inner peripheral surface or the outer peripheral surface, when trouble such as torque fluctuation or acoustic failure due to the distortion of the raceway surface occurs, even without repairing the raceway surface, By inserting and tightening the bolts, the raceway shape has a different number of strains from that before the repair, so that it can be easily implemented as a countermeasure for acoustic problems. The same effect can be obtained by pressing a pin into the hole instead of tightening the bolt into the tap hole. Furthermore, by connecting a tapped hole (or hole) provided on the fixed side of the bearing inner ring or outer ring with other parts in the actual machine, the bearing rigidity is improved, and vibration and sound are improved.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 are examples applied to a deep groove ball bearing. The deep groove ball bearing includes an inner ring 2, an outer ring 4, a plurality of balls 6 as rolling elements interposed between a raceway formed on the outer peripheral surface of the inner ring 2 and a raceway formed on the inner peripheral surface of the outer ring 4. A cage 8 that holds the balls 6 at predetermined intervals in the circumferential direction is a main component. What is indicated by reference numeral 10 is a tapped hole.

  The tap hole 10 is provided in at least one of the inner ring 2 or the outer ring 4. Further, the tap hole 10 is usually extended in the axial direction or the radial direction. In the former case, it opens to the end face of the inner ring 2 or the outer ring 4. In the latter case, the inner ring 2 opens on the inner peripheral surface, and the outer ring 4 opens on the outer peripheral surface. A bolt (not shown) is inserted into the tap hole 10 and tightened. As a result, the shape of the raceway surface of the inner ring 2 or the outer ring 4 can be changed to take measures against vibration (sound) due to resonance. This point will be specifically described with reference to FIG.

  FIG. 3 shows a considerably exaggerated example in which the same number of strains as the number of rolling elements are generated on the raceway surface of the inner ring 2. If the raceway surface strain is equal to or greater than the number of rolling elements and is present at the same interval as the pitch interval of the rolling elements, the total number of rolling elements easily enters and exits the unevenness of the distortion, which tends to adversely affect sound and vibration. When the rolling element 6 moves from the position shown in FIG. 3 (A) to the position shown in FIG. 3 (C) along with the rotation, the outer ring 4 is displaced by an amount indicated by reference numeral δ due to the distortion of the inner ring 2. As a result, problems such as bearing torque fluctuations or acoustic defects occur. Therefore, by inserting a bolt (12 is a set screw) into the tap hole 10 and tightening, the distorted raceway surface is repaired as indicated by reference numeral α in FIG. If the number of strains on the raceway surface is less than the number of rolling elements, or even if the number of strains is greater than the number of rolling elements, the total number of rolling elements will not enter the concave strain on the raceway surface. The amount of movement δ due to rotation is reduced, and problems such as torque fluctuations or acoustic defects are reduced.

  The tap hole into which the bolt is inserted is tightened at a portion close to the concave portion in order to inflate and repair the concave portion of the distortion as indicated by symbol α in FIG. The tapped holes provided on the raceway surface cannot specify the position where the concave strain is formed. However, if there are the same number of concave strains as the rolling elements, it is effective if one can be taken. Is desirable. In addition, when a large number of tapped holes are equally or unevenly arranged in about 1/2 of the circumference (a range of about 180 degrees), the tapped holes are not suitable because the tread holes may reduce the rigidity of the raceway surface. It is desirable to provide it so that it is in the non-load zone of the machine used.

  Here, a deep groove ball bearing has been described as an example, but the present invention is not limited to this and can be applied to various types of bearings. Further, the same effect can be obtained by pressing a pin into the hole instead of tightening the bolt into the tap hole as described above. Furthermore, in the actual machine, tighten the screw into the tapped hole provided in the inner ring or outer ring of the bearing to fasten the bearing and other parts, or the other part to be connected to the bearing in the hole provided in the inner ring or outer ring of the bearing. By press-fitting the convex portion, it is possible to improve the bearing rigidity and improve the vibration and sound.

  As for the bolt shape to be tightened in the tap hole, it is desirable to use a set screw so as not to interfere with other parts, and it is desirable that the entire length does not protrude from the bearing. Also, when a pin is press-fitted into the hole, it is desirable that the length does not protrude from the bearing so as not to interfere with other parts. Since the relationship between the tap hole and the bolt and the hole and the pin is repaired by expanding the concave distortion of the raceway surface of the raceway, the fitting of the screw part and the hole part is tight.

Cross section of deep groove ball bearing Side view of deep groove ball bearing Schematic diagram exemplifying the case where the raceway surface strain is equivalent to the number of rolling elements

Explanation of symbols

2 Inner ring 4 Outer ring 6 Ball (rolling element)
8 Cage 10 Tap hole 12 Set screw

Claims (5)

  A rolling bearing in which a tapped hole is provided in a bearing ring, and a raceway surface shape of the bearing ring can be changed by inserting and tightening a bolt into the tapped hole.   A rolling bearing in which a raceway surface shape of the raceway ring can be changed by providing a hole in the raceway ring and press-fitting a pin into the hole.   When polygonal distortion occurs on the raceway surface of the raceway, the raceway surface shape having a number of strains different from an integer multiple of the number of rolling elements is obtained by repairing a part of the raceway surface. A method for repairing rolling bearings.   A plurality of tapped holes are provided in at least one of the end surfaces of the inner ring or the outer ring of the rolling bearing, and when polygonal distortion occurs due to machining on the raceway surface of the tapped hole, bolts are formed in the tapped holes near the strain. A rolling bearing repairing method characterized in that a raceway surface having a different number of strains from that before the repairing is obtained by inserting and tightening.   A plurality of holes are provided in at least one of the bearing rings on the inner ring or outer ring of the rolling bearing, and a pin is inserted into a hole near the distortion when polygonal distortion occurs on the raceway surface of the bearing ring provided with the hole. Thus, a rolling bearing repairing method is characterized in that the raceway surface has a different number of strains from that before repairing.

Images