JP2013139881A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing which has stable acoustic and vibrational characteristics and is excellent in seizure resistance.SOLUTION: The rolling bearing includes: an outer ring 2 and an inner ring 3; a plurality of rolling elements 4; and a cage 5 which rotatably retains the plurality of rolling elements. The cage 5 satisfies the relationship of L1-M1/2≥DP-DW and L2≥DP-DW, wherein DW denotes the outer diameter of the rolling element, DP denotes the inner diameter of a pocket 6 in the circular direction of the cage, L1 denotes the length of a line segment from the point on an inner ridge 6b formed by an inner circumferential surface 5a of the cage and an inner surface 6a of the pocket to an intersection point 4a at which a line drawn in parallel to a line made by connecting the center O1 of the pocket and the center O2 of the cage intersects the surface of the rolling element, L2 denotes the length of a line segment from the point on an outer ridge 6c formed by an outer circumferential surface 5b of the cage and an inner surface 6a of the pocket to a point 4b at which a line drawn in parallel to a line made by connecting the center O1 of the pocket and the center O2 of the cage intersects the surface of the rolling element, and M1 denotes an amount of increase in diameter dimension of the inner diameter of the cage, the increase being caused by a centrifugal force.

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing in which a cage having excellent acoustic and vibration characteristics, and wear resistance and seizure resistance of a guide surface is incorporated.

  In the rolling bearing, a plurality of rolling elements are rotatably arranged between an outer ring and an inner ring, which are raceways. The rolling elements are rotatably held in pockets formed in the cage to prevent contact between the rolling elements, thereby preventing damage such as wear and seizure of the rolling elements. When the rolling bearing rotates, there is a difference in the relative rotational speed (revolution speed) between the rolling element and the cage, and the rolling element rotates further, causing the cage to behave in an unstable manner. Colliding with rolling elements contributed to the generation of cage noise and vibration. In addition, this causes wear of the guide surface of the cage, and in an extreme case, seizure may occur.

  In order to cope with these problems, the patent applicant of the present invention secures a clearance with the rolling element and prevents interference with the rolling element even when the cage moves to the maximum extent in the rolling bearing. The pocket-shaped dimensions suppress cage noise and abnormal vibration, and facilitate the inflow of lubricant into the sliding surfaces of the cage and rolling elements, improving the wear resistance and seizure resistance of the sliding surfaces. Propose that. Patent Document 1 also describes the pocket-shaped dimensional regulation that takes into account thermal expansion due to the temperature rise of the cage. (For example, refer to Patent Document 1).

Japanese Utility Model Publication No. 2005-61509

By the way, in a rolling bearing for a high-speed motor used for an industrial machine, a machine tool main shaft, or the like, the cage is deformed in the radial direction by centrifugal force expansion of the cage during high-speed rotation. In particular, in the region where the dmn value (dm: rolling element pitch circle diameter (mm), n: rotational speed (min ⁻¹ )) is 700 to 900,000 or more, this centrifugal force expansion cannot be ignored, and the cage Depending on the amount of movement in the radial direction, problems such as the above-mentioned cage noise and abnormal vibration may occur.

  However, in the rolling bearing disclosed in Patent Document 1, thermal expansion due to temperature rise of the cage is considered, but centrifugal expansion of the cage during high-speed rotation is not considered.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a rolling bearing having stable acoustic and vibration characteristics even when used at high speed rotation and having excellent seizure resistance performance. It is in.

  1) A rolling bearing according to the present invention includes a race ring including an outer ring and an inner ring, a plurality of rolling elements rotatably disposed between the outer ring and the inner ring, and an annular ring provided on one axial side. And a plurality of pillars extending in the axial direction at predetermined intervals in the circumferential direction, and the plurality of rolling elements are housed in a substantially cylindrical pocket partially opened and held rotatably. A rolling bearing guide-type crown-shaped cage, wherein the pocket has an inner ridge line formed between an inner peripheral surface of the crown-shaped cage and an inner surface of the pocket. A pair of locking portions having surfaces substantially parallel to a line connecting the center of the crown-shaped cage and the center of the crown-shaped cage are respectively provided on the column portions, and the crown-shaped cage has an outer diameter of the rolling element. DW, the inner diameter of the pocket in the circumferential direction of the crown type cage is DP, the point on the inner ridge line is the front The line drawn parallel to the line connecting the center of the pocket and the center of the crown-shaped cage is L1, the length of the line segment to the intersection intersecting the rolling element surface, and the inner diameter of the crown-shaped cage is When the amount of increase in the diameter dimension increased by centrifugal force is M1, L1-M1 / 2 ≧ DP-DW and DP-DW <0.2 (mm).

  2) Further, a rolling bearing according to the present invention is provided on one side in the axial direction, a raceway ring composed of an outer ring and an inner ring, a plurality of rolling elements rotatably disposed between the outer ring and the inner ring. It has an annular part and a plurality of pillars extending in the axial direction at a predetermined interval in the circumferential direction, and the plurality of rolling elements are housed in a partially cylindrical pocket partially opened to be rotatable. A rolling bearing guide-type crown-type cage that is held in the pocket, and the inside of the pocket is formed from an inner ridge line formed by an inner peripheral surface of the crown-type cage and an inner surface of the pocket A pair of locking portions each having a surface substantially parallel to a line connecting the center of the pocket and the center of the crown-shaped cage is provided on each of the pillars, and the crown-shaped cage is located outside the rolling element. The diameter is DW, the inner diameter of the pocket in the circumferential direction of the crown cage is DP, and the point on the inner ridge line L1 is the length of the line segment extending from the line connecting the center of the pocket and the center of the crown-shaped cage to the intersection where it intersects the rolling element surface. The linear expansion coefficient is α1, the linear expansion coefficient of the bearing ring is α2, the inner diameter of the crown cage is SD, the temperature rise value inside the rolling bearing is T when the rolling bearing is rotated, and the crown cage is L1−M1 / 2−SD × (α1−α2) × T / 2 ≧ DP-DW, where DP−DW <0. 2 (mm).

  In the rolling bearing of 1) or 2), the rolling bearing is drawn in parallel to a line connecting the center of the pocket and the center of the cage from a point on the outer ridge line formed by the outer peripheral surface of the cage and the inner surface of the pocket. L2 ≧ DP−DW, where L2 is the length of the line segment to the intersection where the drawn line intersects the rolling element surface.

  It should be noted that the length of the line segment of the present invention is, when there is a cage part between each intersection and the inner ridge line or the outer ridge line on a line drawn in parallel with the line connecting the respective centers, It means the gap between the part and the intersection.

  As described above, according to the rolling bearing of the present invention, L1-M1 / 2 ≧ DP-DW is satisfied, so that the change due to the centrifugal force expansion of the cage is taken into consideration even during high-speed rotation. Since the cage radial movement amount (e.g., equivalent to the radial clearance between the ball locking portion and the ball in the embodiment) is set to be larger than the pocket gap, the movement of the cage is It is regulated by. Therefore, a clearance can be ensured between the rolling element and the inner ridge line of the pocket to prevent interference. Moreover, this can prevent generation | occurrence | production of a holder | retainer sound etc. and can rotate a rolling bearing quietly. Furthermore, the lubricant can easily flow into the sliding surfaces of the cage and the rolling elements, and the wear resistance and seizure resistance of the sliding surfaces can be improved. Further, since DP−DW <0.2 (mm), even when the amount of movement in the cage radial direction is set larger than the pocket gap, the amount of swinging of the cage can be suppressed.

  In addition, according to the rolling bearing of the present invention, L1-M1 / 2-SD × (α1-α2) × T / 2 ≧ DP-DW is formed into a pocket shape that also takes into account thermal expansion due to temperature rise of the cage. Furthermore, even if the temperature inside the rolling bearing rises due to the rotation of the rolling bearing and the cage expands thermally and the inner diameter of the cage increases, it is possible to prevent the rolling element and the inner ridge line of the pocket from interfering with each other. it can. Moreover, this can prevent the generation of interference sound between the rolling elements and the cage. Further, since DP−DW <0.2 (mm), even when the amount of movement in the cage radial direction is set larger than the pocket gap, the amount of swinging of the cage can be suppressed.

It is a principal part expanded longitudinal sectional view of the ball bearing which concerns on 1st Embodiment of the rolling bearing of this invention. It is a principal part expanded longitudinal cross-sectional view which shows the positional relationship with a holder | retainer when the rolling element in FIG. It is a principal part expanded longitudinal sectional view of the ball bearing which concerns on 2nd Embodiment of the rolling bearing of this invention. It is a principal part expanded longitudinal sectional view of the ball bearing which concerns on 3rd Embodiment of the rolling bearing of this invention. The ball bearing which concerns on 4th Embodiment of the rolling bearing of this invention is shown, (a) is sectional drawing which shows the holder | retainer of a ball bearing with the ball along the V'-V 'line of (c), (B) is a partial enlarged top view, (c) is a sectional view taken along the line V-V in (a), and (d) is an enlarged sectional view of a main part in (a). It is a graph which shows the comparative experiment result of the generation | occurrence | production condition of the cage | basket | torney sound with the conventional product and the rolling bearing of 4th Embodiment. The double row roller bearing which concerns on 5th Embodiment of the rolling bearing of this invention is shown, (a) is sectional drawing of a roller bearing, (b) is sectional drawing of the holder | retainer of a double row roller bearing, (C) is the side view seen from the VII direction of (b).

Hereinafter, embodiments of a rolling bearing according to the present invention will be described in detail with reference to FIGS.
(First embodiment)
FIG. 1 is an enlarged vertical sectional view of an essential part of a ball bearing according to a first embodiment of the present invention, and FIG. 2 is an enlarged longitudinal view of an essential part showing a positional relationship with a cage when rolling elements are positioned at four locations, up, down, left and right. FIG. As shown in FIG. 1, the ball bearing 1 includes a plurality of rolling elements that are disposed between an outer ring 2, an inner ring 3, and an outer ring 2 and an inner ring 3 that constitute a pair of race rings. And a retainer 5 that rotatably holds the plurality of balls 4.

  The outer ring 2, the inner ring 3 and the balls 4 are manufactured using high carbon chromium bearing steel, carburized bearing steel, rolling bearing stainless steel, or the like. The ball 4 is disposed between the outer ring 2 and the inner ring 3 which are raceways so as to be freely rollable.

  The retainer 5 is a so-called machined-type retainer in which a plurality of pockets 6 are formed by cutting at a predetermined interval in the circumferential direction in a cylindrical main body, and the embodiment shown in FIG. It is a rolling element guide type cage 5. The cylindrical main body is made of, for example, a brass alloy such as high-strength brass, an iron alloy such as structural carbon steel, a synthetic resin, or the like.

  The shape of the pocket 6 is a concave spherical surface, the outer diameter of the rolling element 4 is DW, and the inner diameter of the pocket 6 in the circumferential direction of the cage 5 is DP. Further, a line drawn in parallel to a line connecting the center O1 of the pocket 6 and the center O2 of the cage 5 from a point on the inner edge line 6b formed by the inner peripheral surface 5a of the cage 5 and the inner surface 6a of the pocket 6. However, the length of the line segment to the intersection 4a intersecting the surface of the rolling element 4 (hereinafter referred to as the inner contact length) is L1. Further, a line drawn in parallel with a line connecting the center O1 of the pocket 6 and the center O2 of the cage 5 from a point on the outer edge line 6c formed by the outer peripheral surface 5b of the cage 5 and the inner surface 6a of the pocket 6 is. The length of the line segment (hereinafter referred to as the outer contact length) to the intersection 4b that intersects the surface of the rolling element 4 is defined as L2.

  Here, as shown in FIG. 2, when the cage 5 moves upward, for example, in a state where the centrifugal force expansion of the cage is not considered during the low-speed rotation, the rolling elements 4 </ b> B positioned on the left and right sides (FIG. 1) When only the center of the pocket 6 of the cage 5 comes into contact with the lower portion of the rolling element 4A and the cage 5 which are positioned above (only a part of the cage 5 is displayed), the cage 5 is further , Can not move up. That is, the maximum movable distance of the cage 5 is DP-DW.

  If the inner contact length L1 is longer than the maximum movable distance (DP-DW) of the cage 5, the shape of the pocket 6 is as follows. DW), even in the rolling element 4A in which the inner ridge 6b is closest to the rolling element 4 even when it moves upward, the diagonally downward position of the rolling element 4A and the diagonally downward position of the inner surface 6a of the pocket 6 are A gap C is maintained between the point on the inner ridge line 6b and the rolling element 4 so that there is no interference. At this time, the point on the outer ridge line 6c approaches the rolling element 4C positioned below, but the outer contact length L2 is longer than the maximum movable distance (DP-DW) of the cage 5. If this is the case, the gap C is maintained between the point on the outer edge 6c and the rolling element 4, and there is no interference.

  Similarly, when the cage 5 moves downward, the maximum movable distance of the cage 5 is DP-DW, and the inner contact length L1 and the outer contact length L2 are the maximum movable distance (DP-DW). Therefore, the point on the outer ridge line 6c and the rolling element 4 and the point on the inner ridge line 6b and the rolling element 4 do not interfere with each other.

  On the other hand, during high-speed rotation with a dmn value of 700 to 900,000 or more, the amount of radial expansion due to centrifugal force becomes so large that it cannot be ignored. For this reason, at the time of high speed rotation, the inner ridge line 6b of the pocket 6 moves outward in the radial direction. Accordingly, if the amount of increase in the diameter dimension in which the inner diameter SD of the cage 5 increases due to centrifugal force is M1, if L1-M1 / 2 is longer than the maximum movable distance (DP-DW) of the cage 5. 2, even if the cage 5 moves upward by the maximum movable distance (DP-DW), the gap C is maintained between the points on the inner ridge line 6b and all the rolling elements 4. And will not interfere. In addition, since the outer contact length L2 is displaced in the direction that becomes longer due to the centrifugal force, the point on the outer ridge line 6c and the rolling element 4 are moved away from each other and do not interfere with each other by the centrifugal force.

  Accordingly, the cage 5 of the present embodiment is formed so that L1-M1 / 2 ≧ DP-DW and L2 ≧ DP-DW. Thereby, all the rolling elements 4 of the ball bearing 1 do not interfere with the points on the inner ridge line 6b and the points on the outer ridge line 6c, and no interference sound is generated. Further, since the gap C is maintained between the inner ridge line 6b and the outer ridge line 6c and the rolling element 4, the lubricant can easily enter the sliding surface from the gap C, and sufficient lubrication can be performed. Can prevent wear and seizure.

  Further, as shown in FIG. 1, the shape of the pocket 6 is such that the linear expansion coefficient of the cage 5 is α1, the linear expansion coefficients of the race rings (inner ring 3 and outer ring 2) are α2, the inner diameter of the cage 5 is SD, and rolling. Assuming that the internal temperature rise when the bearing 1 is rotated is T, L1−M1 / 2−SD × (α1−α2) × T / 2 ≧ DP−DW and L2 ≧ DP−DW. Is formed.

  When the rolling bearing 1 rotates and the internal temperature rises, the temperature of the cage 5 also rises and thermally expands, and the inner diameter SD increases (the outer ring 2, the inner ring 3, and the rolling element 4 also thermally expand, but the synthetic resin In the case of a cage made of plastic, it is smaller than the thermal expansion coefficient α1 of the cage made of synthetic resin and can be ignored). As a result, the inner contact length L1 is shortened. However, since the inner contact length L1 is set to a value that takes into account the dimensional change due to thermal expansion, the cage 5 moves in the radial direction as described above. Even if, the point on the inner ridgeline 6b and the rolling element 4 do not interfere. In addition, since the outer contact length L2 is displaced in a direction that becomes longer due to thermal expansion, the point on the outer ridge line 6c and the rolling element 4 do not move away and interfere with each other.

  Therefore, even if the usage conditions of the rolling bearing 1 change, such as temperature changes and load fluctuations, the points on the inner ridge line 6b and the points on the outer ridge line 6c of the cage 5 due to vibration, touching, dimensional changes, etc. of the cage 5. A quiet and stable rotation can be obtained without the rolling element 4 interfering with the rolling element 4.

(Second Embodiment)
Next, a second embodiment of the ball bearing will be described with reference to FIG. FIG. 3 is an enlarged vertical sectional view of a main part of the ball bearing. The retainer 15 used in the ball bearing 10 of the second embodiment is a so-called machined mold retainer formed by cutting a plurality of pockets 16 at predetermined intervals in the circumferential direction on a cylindrical main body. The embodiment shown in FIG. 3 is a rolling element guide type retainer 15.

  The shape of the pocket 16 is formed such that the outer shape from the center in the thickness direction of the main body and the inner shape are different. The outer shape is a straight hole (cylindrical hole) drilled from the radially outer side to the center of the main body, and the inner shape is a semi-concave formed continuously to the straight hole. It is a spherical surface. Similarly to the cage 5 of the first embodiment, the semi-concave spherical surface is L1-M1 / 2-SD × (α1-α2) so that L1-M1 / 2 ≧ DP-DW and considering thermal expansion. × T / 2 ≧ DP−DW.

  Since other parts are the same as those of the ball bearing 1 according to the first embodiment of the present invention, the same parts are denoted by the same or corresponding reference numerals, and description thereof will be simplified or omitted.

(Third embodiment)
Next, a third embodiment of the ball bearing of the present invention will be described with reference to FIG. FIG. 4 is an enlarged vertical sectional view of a main part of the ball bearing. The retainer 25 used in the ball bearing 20 of the third embodiment is a so-called machined mold retainer formed by cutting a plurality of pockets 26 at a predetermined interval in the circumferential direction in a cylindrical main body. The embodiment shown in FIG. 4 is a rolling element guide type retainer 25.

  The shape of the pocket 26 is a straight hole (cylindrical hole) drilled from the radially outer side of the main body portion toward the center, and a locking portion 25c is formed at the inner diameter side top portion of the straight hole. The locking portion 25c may be provided over the entire circumference of the inner ridge line of the pocket 26, or may be provided by being divided into surfaces facing each other.

  Here, as in the above embodiment, the outer diameter of the ball 4 is DW, and the inner diameter of the pocket 26 in the circumferential direction of the cage 25 is DP. The inner contact length L1 is a line connecting the center O1 of the pocket 26 and the center O2 of the cage 25 from a point on the inner ridge line 26b formed by the inner circumferential surface 25a of the cage 25 and the inner surface 26a of the pocket 26. The length of the line segment extending to the intersection 4a where the line drawn in parallel with the surface intersects the surface of the ball 4 is assumed to be the length of the line segment. Note that, unlike the present embodiment, the pair of locking portions 25c is formed with a surface substantially parallel to the line connecting the centers O1 and O2 from the inner ridge line 26b, not the shape with the sharp tip of the inner ridge line 26b. In such a case, the inner contact length L1 means a gap between the intersection 4a and the locking portion 25c on the line.

  Similarly to the cage 5 of the first embodiment, the locking portion 25c is L1-M1 / 2-SD × (α1-α2) so that L1-M1 / 2 ≧ DP-DW and considering thermal expansion. ) × T / 2 ≧ DP−DW.

  Since other parts are the same as those of the ball bearing 1 according to the first embodiment of the present invention, the same parts are denoted by the same or corresponding reference numerals, and description thereof will be simplified or omitted.

(Fourth embodiment)
Next, a fourth embodiment of the ball bearing of the present invention will be described with reference to FIG. Fig.5 (a) is sectional drawing which shows the holder | retainer of a ball bearing with the ball along the V'-V 'line of (c), FIG.5 (b) is a partial expanded top view, 5 (c) is a cross-sectional view taken along line VV in FIG. 5 (a), and FIG.

  The cage 30 used for the ball bearing of the fourth embodiment is a rolling element guide system, and has a ring portion 34 on one side, and a plurality of column portions 35 extending in the axial direction at predetermined intervals in the circumferential direction. This is a so-called crown-type cage that has a plurality of substantially cylindrical pockets 31 that are partially open. The retainer 30 is partially provided with a pair of locking portions 32 in the vicinity of the inner ridge line of each pocket 31.

  The cage 30 is made of a synthetic resin material such as polyamide, polyphenylene sulfide, polyacetal, polyimide, or polyether ether ketone as a cage material in order to reduce the cage weight and improve the wear resistance.

  Here, as in the above embodiment, the outer diameter of the ball 4 is DW, and the inner diameter of the pocket 31 in the circumferential direction of the cage 30 is DP. The inner contact length L1 is a line connecting the center O1 of the pocket 31 and the center O2 of the cage 30 from a point on the inner ridge line 31b formed by the inner peripheral surface 30a of the cage 30 and the inner surface 31a of the pocket 31. The length of the line segment extending to the intersection 4a where the line drawn in parallel with the surface intersects the surface of the ball 4 is assumed to be the length of the line segment. Also in this embodiment, the pair of locking portions 32 is formed with a surface 32a that is substantially parallel to the line connecting the centers O1 and O2 from the inner ridge line 31b, rather than having a sharp shape at the inner ridge line 31b. The inner contact length L1 means a gap between the intersection 4a and the locking portion 32 on the line.

  Similarly to the cage 5 of the first embodiment, the locking portion 32 is L1-M1 / 2-SD × (α1-α2) so that L1-M1 / 2 ≧ DP-DW and considering thermal expansion. ) × T / 2 ≧ DP−DW.

  Here, Table 1 shows the deformation due to the centrifugal force of the inner diameter SD of the cage when the crown type cage 30 is used for the deep groove ball bearing for the high speed motor of the present embodiment. The design specifications A-1 and A-2 have the same shape, differ only in material, and the same applies to the design specifications B-1 and B-2.

  The set value of the radial motion amount of the standard rolling element guide type cage applied to these uses is approximately 0.3 to 1.0 mm (diameter dimension). It can be seen that the amount of radial expansion due to the centrifugal force of the cage is a level that cannot be ignored with respect to the change in the amount of radial movement. This is due to the fact that the cage is crown-shaped and has a single-side ring structure, so that the ring strength is smaller than that of a machined cage with a double-sided ring structure, so that the centrifugal force expansion is large. The amount of movement in the radial direction is determined by the inner contact length L1 in FIG. Since the locking portion 32 is in the vicinity of the inner diameter surface of the cage, the centrifugal force expansion of the inner diameter surface corresponds to a change in the value of approximately L1. Therefore, in particular, in a crown-shaped synthetic resin cage used in a ball bearing for a high-speed motor, in order to prevent cage noise and abnormal vibration, and to prevent wear of the contact portion, deformation due to centrifugal force ( It is also necessary to consider the change in the amount of movement in the cage radial direction.

  Here, FIG. 6 shows a comparative experiment result of the generation state of the cage sound between the conventional product and the invention product when the inner contact length during high-speed rotation is ΔL1 (= L1−M1 / 2). As can be seen from this graph, it was confirmed that no cage noise was generated for the cage adopting the setting region of the present invention.

  In particular, in the case of a ball guide system as shown in FIG. 5 in which a locking portion 32 is provided inside the pocket, when the ball 4 and the locking portion 32 collide or come into contact with a strong load in the radial direction, Due to the so-called wedge action that bites into the locking portion 32, the load on the contact portion increases, and heat generation or local melting / wearing may occur due to an increase in surface pressure. These inconveniences are likely to occur under high-speed rotation with a large centrifugal force effect. However, as in the present invention, by setting the dimensions in consideration of the amount of expansion due to the centrifugal force of the cage 30, the locking portion 32 is set. In this case, the frequency of contact is extremely low, and even if contact is made, the contact remains at a light load, and these problems can be prevented.

  Also, considering the thermal expansion due to temperature rise and the expansion due to centrifugal force, the cage radial movement amount (corresponding to the radial clearance between the locking portion 32 and the ball 4) is set larger than the pocket clearance. Thus, even when the internal temperature of the bearing rises due to the influence of heat generated by the motor or the like, the movement of the cage 30 is restricted by the pocket gap. Therefore, the contact frequency between the locking portion 32 and the ball 4 is very low, or even if it comes into contact, the contact is very slight, and the above-described problems are more reliably solved.

Further, since there is a relationship of radial movement amount (considering thermal expansion amount + centrifugal force)> pocket clearance, if the pocket clearance is too large, the radial clearance must be increased accordingly. In that case, the swinging amount of the rotating cage also increases, and problems such as vibration due to unbalance appear at high speed rotation.
For this reason, as an appropriate pocket clearance, in view of the experimental results of FIG. 6 and an increase in the circumferential pocket clearance due to centrifugal force expansion, the following values are more preferable.
0 <(DP-DW) <0.2 (mm)

  Since other parts are the same as those of the ball bearing 1 according to the first embodiment of the present invention, the same parts are denoted by the same or corresponding reference numerals, and description thereof will be simplified or omitted.

(Fifth embodiment)
Next, as a fifth embodiment of the rolling bearing of the present invention, a double row roller bearing will be described with reference to FIG. 7A is a cross-sectional view of a roller bearing, FIG. 7B is a cross-sectional view of a cage of a double row roller bearing, and FIG. 7C is a view from the VII direction of FIG. FIG.

  The double row roller bearing 40 is capable of rolling between an outer ring 41 and an inner ring 42 constituting a pair of race rings, and a double row outer ring raceway surface 41 a of the outer ring 41 and a double row inner ring raceway surface 42 a of the inner ring 42. A plurality of rollers 43, which are rolling elements arranged in a double row, and a holder 44 that rotatably holds the plurality of rollers 43 are provided.

  The cage 44 is made of a synthetic resin by a rolling element guide system. The retainer 44 has an annular portion 51 on one side, and includes a plurality of column portions 52 extending in the axial direction at predetermined intervals in the circumferential direction, and the circumferential direction of the annular portion 51 and the adjacent column portions 52 is provided. A pocket 53 is formed with the side surface 52a.

  As for the shape of the pocket 53, the circumferential side surface 52 a of the column part 52 is arcuate, the outer diameter of the roller 43 is DW, and the inner diameter of the pocket 53 in the circumferential direction of the cage 44 is DP. Further, from the point on the inner ridge line 44b formed by the inner peripheral surface 44a of the cage 44 and the inner surface of the pocket 53 (the circumferential side surface 52a of the column portion 52), the center O1 of the pocket 53 and the center O2 of the cage 44 are defined. The length of the line segment (hereinafter referred to as the inner contact length) to the intersection 45a where the line drawn parallel to the connecting line intersects the surface of the roller 43 is defined as L1. Further, the center O1 of the pocket 53 and the center O2 of the cage 44 are connected from a point on the outer ridge line 44d formed by the outer peripheral surface 44c of the cage 44 and the inner surface of the pocket 53 (the circumferential side surface 52a of the column portion 52). The length of the line segment to the intersection 45b where the line drawn in parallel with the line intersects the surface of the roller 43 (hereinafter referred to as the outer contact length) is L2.

  Also in the case of the present embodiment, similarly to the above embodiment, L1−M1 / 2 ≧ DP−DW and L2 ≧ DP−DW, and L1−M1 / 2−SD × considering thermal expansion (Α1-α2) × T / 2 ≧ DP-DW and L2 ≧ DP-DW.

  The other parts are the same as those of the above-described embodiment of the present invention. Therefore, the same parts are denoted by the same reference numerals or equivalent signs, and description thereof is simplified or omitted.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  Further, in the present invention, the cage has been described as a rolling element guide type machined type cage, but is not limited to this, punching a plate material such as a low carbon steel plate, a brass plate, a stainless steel plate, A so-called punched die cage formed by bending may be used, or a so-called synthetic resin cage formed by injection molding a synthetic resin such as polyamide, for example. Further, the cage may be a rolling element guide type cage that is constrained to the outer diameter, and may further be a raceway guide type cage that is guided by an inner ring or an outer ring.

1,10,20 ball bearings (rolling bearings)
2,41 Outer ring (Raceway)
3,42 Inner ring (Raceway)
4, 43 Rolling elements 5, 15, 25, 30, 44 Cage 5a, 15a, 25a, 44a Cage inner peripheral surface 5b, 15b, 25b, 44c Cage outer peripheral surface 6, 16, 26, 31, 53 Pocket 6a, 16a, 26a, 52a Pocket inner surface 6b, 16b, 26b, 44b Inner ridge line 6c, 44d Outer ridge line 32 Locking part 40 Double row roller bearing (rolling bearing)
DW Outer diameter of rolling element DP Inner diameter of pocket in the circumferential direction of the cage L1 Internal contact length (from the point on the inner ridge line between the inner circumferential surface of the cage and the inner surface of the pocket, the center of the pocket and the center of the cage The length of the line segment up to the intersection where the line drawn parallel to the line that intersects the rolling element surface)
L2 Outer contact length (A line drawn parallel to the line connecting the center of the pocket and the center of the cage from the point on the outer ridge formed by the outer peripheral surface of the cage and the inner surface of the pocket intersects the rolling element surface. The length of the line segment to the intersection
M1 Amount of radial movement due to centrifugal force (Increase in diameter of cage where the inner diameter of the cage increases due to centrifugal force)
α1 Linear expansion coefficient of cage α2 Linear expansion coefficient of bearing ring SD Inner diameter of cage T Temperature rise inside rolling bearing O1 Center of pocket O2 Center of cage

Claims (3)

A raceway composed of an outer ring and an inner ring;
A plurality of rolling elements rotatably disposed between the outer ring and the inner ring;
A substantially cylindrical pocket having an annular part provided on one side in the axial direction and a plurality of column parts extending in the axial direction at a predetermined interval in the circumferential direction and partially opening the plurality of rolling elements A rolling bearing guide type crown-shaped cage that is housed in and rotatably held,
The inside of the pocket has a surface substantially parallel to a line connecting the center of the pocket and the center of the crown type cage from the inner ridge line formed by the inner peripheral surface of the crown type cage and the inner surface of the pocket. A pair of locking portions provided on the column portions,
The crown type cage has an outer diameter of the rolling element of DW, an inner diameter of the pocket in a circumferential direction of the crown type holder of DP, a center on the pocket and a crown type cage from the point on the inner ridge line. The line drawn in parallel with the line connecting the center of the roller L1 is the length of the line segment up to the intersection intersecting the surface of the rolling element, and the inner diameter of the crown cage is increased by the centrifugal force. When the amount is M1,
L1-M1 / 2 ≧ DP-DW, and DP-DW <0.2 (mm). A raceway composed of an outer ring and an inner ring;
A plurality of rolling elements rotatably disposed between the outer ring and the inner ring;
A substantially cylindrical pocket having an annular part provided on one side in the axial direction and a plurality of column parts extending in the axial direction at a predetermined interval in the circumferential direction and partially opening the plurality of rolling elements A rolling bearing guide type crown-shaped cage that is housed in and rotatably held,
The inside of the pocket has a surface substantially parallel to a line connecting the center of the pocket and the center of the crown type cage from the inner ridge line formed by the inner peripheral surface of the crown type cage and the inner surface of the pocket. A pair of locking portions provided on the column portions,
The crown type cage has an outer diameter of the rolling element of DW, an inner diameter of the pocket in a circumferential direction of the crown type holder of DP, a center on the pocket and a crown type cage from the point on the inner ridge line. L1 is the length of the line segment to the intersection intersecting with the surface of the rolling element, the linear expansion coefficient of the crown type cage is α1, the line of the race ring The expansion coefficient is α2, the inner diameter of the crown type cage is SD, the temperature rise value inside the rolling bearing is T when the rolling bearing is rotated, and the inner diameter SD of the crown type cage is increased by centrifugal force. When the amount of increase is M1,
L1-M1 / 2-SD × (α1-α2) × T / 2 ≧ DP-DW and DP-DW <0.2 (mm).   A line drawn in parallel to a line connecting the center of the pocket and the center of the cage intersects the surface of the rolling element from a point on the outer edge line formed by the outer peripheral surface of the cage and the inner surface of the pocket. The rolling bearing according to claim 1, wherein L2 ≧ DP−DW, where L2 is a length of a line segment to the intersection.

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