JP2013148116A - Deep groove ball bearing and bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a torque loss in the deep groove ball bearing having large thrust load capacity.SOLUTION: A ball 31 is incorporated between an outer race 11 and an inner race 21 different between right and left shoulder heights, and the ball 31 is held by a cage 40. A recessed part 48 is respectively formed on an inner surface of a plurality of semispherical pocket parts 44 arranged in a pair of waveform dividing cages 41 and 42 for forming the cage 40, shearing resistance is reduced when the ball 31 shears an oil film interposed between pocket inner surfaces, and the torque loss in the bearing is reduced.

Description

  The present invention relates to a deep groove ball bearing and a bearing device using the deep groove ball bearing.

  The input shaft and the output shaft are arranged on the same axis, the countershaft is provided in parallel to both axes, and a plurality of gear-type reduction gears with different gear ratios are provided between the two parallel axes to rotate the input shaft. In a transmission that shifts to multiple stages and outputs from the output shaft, a helical gear is generally used for the gear-type reduction gear, so input torque is transmitted from the input shaft to the output shaft. A thrust force is applied to each of the shaft, the output shaft, and the counter shaft.

  For this reason, it is necessary to use a bearing that can support both a radial load and a thrust load as a bearing that supports the input shaft, the output shaft, and the counter shaft.

  Tapered roller bearings are suitable for transmission bearings because they have a large load capacity and can receive both thrust loads and radial loads. However, in the tapered roller bearing, there is a problem that the rotational torque is large and the amount of fuel consumption increases. In order to save fuel consumption, there are many cases in which deep groove ball bearings having a small rotational torque are used.

  By the way, in a standard deep groove ball bearing, when an excessive thrust load is applied, there is a concern that the ball rides on the load-side shoulder receiving the thrust load and the shoulder edge is damaged.

  In order to eliminate such inconvenience, in the deep groove ball bearing described in Patent Document 1, of the shoulders formed on both sides of the outer ring raceway groove and the inner ring raceway groove, the shoulder receiving the thrust load Is increased to prevent the ball from climbing, to suppress a decrease in the durability of the bearing, and to receive a large thrust load.

  In addition, a pair of corrugated split cages in which hemispherical pockets are formed at equal intervals in the circumferential direction, band plate-shaped coupling plates formed between adjacent pockets overlap each other, and the hemispherical pockets are spherical The retainer is formed by combining the connecting plate portions that overlap each other in a state in which the balls are accommodated in the pockets by caulking rivets.

JP 2011-7288 A

  By the way, in the deep groove ball bearing having a large thrust load capacity described in Patent Document 1, the ball rotates in a state where the ball is in full contact with the inner surface of the pocket, and during the rotation, the ball is interposed between the inner surfaces of the pocket. Shear the oil film. At this time, since the ball is in a state of being in full contact with the inner surface of the pocket as described above, the amount of oil film to be sheared is large, and the shear resistance of the oil film becomes rotational resistance, resulting in a large torque loss and a low bearing. The point which should be improved in aiming at torque-ization was left.

  An object of the present invention is to provide a deep groove ball bearing and a bearing device having a large thrust load capacity with little torque loss.

In order to solve the above problems, in the deep groove ball bearing according to the present invention, an outer ring having a raceway groove on the inner diameter surface, an inner ring having a raceway groove on the outer diameter surface, a raceway groove of the outer ring, and a raceway groove of the inner ring A ball built in between and a holder for holding the ball, and the height of at least one of the shoulder on one side of the raceway groove on the outer ring and the shoulder on the other side of the raceway groove on the inner ring, The height of the shoulder on the other side of the outer ring and the height of the shoulder on one side of the inner ring is set to H ₁ , and the ball diameter of the ball is d. A pair of corrugations in which the ratio H ₁ / d of the shoulder height H ₁ is in the range of 0.25 to 0.50, and the cage has a plurality of hemispherical pocket portions provided at intervals in the circumferential direction. It consists of split cages, and a pair of corrugated split cages are formed between adjacent pockets. In deep groove ball bearings in which the band-shaped coupling plate portions overlap and the hemispherical pocket portions are combined to form a spherical pocket for accommodating a ball, the outer periphery of the ball A configuration in which a ball non-contact portion that is non-contact with the spherical surface is provided, and the area of the ball non-contact portion is 15 to 30% of the area of the inner surface of the pocket portion when the ball non-contact portion is not formed. Was adopted.

  As described above, by providing the ball non-contact portion on the inner surface of the pocket portion, the contact area of the pocket inner surface with the ball can be reduced, and the amount of oil film interposed between the ball and the inner surface of the pocket can be reduced. As a result, the shear resistance of the oil film by the ball is reduced, and torque loss can be reduced.

  Here, if the area of the ball non-contact portion is less than 15% of the area of the pocket portion inner surface in a state where the ball non-contact portion is not formed, the torque loss cannot be sufficiently reduced, and 30% If it exceeds, the strength of the cage will decrease.

  In the deep groove ball bearing according to the present invention, the area of the ball non-contact portion is 15 to 30% of the area of the inner surface of the pocket portion when the ball non-contact portion is not formed, so that the strength of the cage is reduced. Torque loss can be reduced without causing it to occur.

  In the deep groove ball bearing according to the present invention, the ball non-contact portion may be formed of a groove-like recess that is long in the cage circumferential direction, or may be formed of a slot that is long in the cage circumferential direction. . If the ball non-contact part is provided at a position that is offset toward the inner diameter side or the outer diameter side from the pitch circle of the ball, the shear resistance of the oil film at the position where the ball has a high peripheral speed is reduced, so that the rotation of the ball The resistance is reduced and torque loss can be further reduced.

  For forming the cage, press forming with metal, forming by casting, or manufacturing method by cutting can be employed. If it is a press-molded product made of metal or a molded product made by casting, it can be easily manufactured and the cost can be reduced.

  In the bearing device according to the present invention, in the bearing device in which a shaft provided with a helical gear is rotatably supported by a pair of rolling bearings partially immersed in an oil bath, the pair of rolling bearings described above is used as the pair of rolling bearings. The structure uses a deep groove ball bearing.

  In the deep groove ball bearing according to the present invention, as described above, a ball non-contact portion that is not in contact with the outer peripheral spherical surface of the ball is provided on each inner surface of the pocket portion, and the area of the ball non-contact portion is set. The torque loss can be reduced without lowering the strength of the cage by reducing the area of the inner surface of the pocket portion to 15 to 30% when no ball non-contact portion is formed. Can be achieved.

Longitudinal sectional view showing an embodiment of a deep groove ball bearing according to the present invention Sectional view along the line II-II in FIG. Front view of FIG. Front view showing only another part of the cage Cross-sectional view showing still another example of cage Front view of FIG. Front view showing still another example of cage and showing only a part Schematic showing an embodiment of a bearing device according to the present invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, in the deep groove ball bearing A, a ball 31 is incorporated between a raceway groove 12 formed on the inner diameter surface of the outer ring 11 and a raceway groove 22 provided on the outer diameter surface of the inner ring 21. Is held by the cage 40.

  Of the pair of shoulders 13a and 13b formed on both sides of the raceway groove 12 of the outer ring 11, the height of the shoulder 13a located on one side of the raceway groove 12 is higher than the height of the shoulder 13b located on the other side. It has become. On the other hand, of the pair of shoulders 23a and 23b formed on both sides of the raceway groove 22 of the inner ring 21, the height of the shoulder 23b located on the other side of the raceway groove 22 is higher than the height of the shoulder 23a located on one side. It is high.

  Here, the shoulder heights of the low shoulders 13b and 23a are the same as the shoulders of the standard depth groove ball bearings, but even if they are lower than the shoulder heights of the standard depth groove ball bearings. Good.

  For convenience of explanation, the high shoulders 13a and 23b are referred to as thrust load side shoulders 13a and 23b, and the low shoulders 13b and 23a are referred to as thrust non-load side shoulders 13b and 23a.

Thrust load side of the shoulder 13a, the shoulder height of 23b as _{H 1,} when the spherical diameter of the ball 31 is d, the ratio _H 1 / d of the shoulder height _{H 1} relative to the spherical diameter d of the ball _{31, H} 1 / It is set as the range of d = 0.25-0.50.

  As shown in FIGS. 1 and 2, the holder 40 includes a first waveform division holder 41 and a second waveform division holder 42. Each of the first waveform division holder 41 and the second waveform division holder 42 has a configuration in which a plurality of hemispherical pocket portions 44 are formed at equal intervals in the circumferential direction of the annular holding plate 43. The outer diameter and inner diameter of the annular holding plate 43 of the retainer 41 are smaller than the outer diameter and inner diameter of the annular retaining plate 43 of the second waveform division retainer 42.

  Further, the first waveform division retainer 41 can be inserted into the bearing from the shoulder 13 a having a high height of the outer ring 11. On the other hand, the second waveform division retainer 42 can be inserted into the bearing from the shoulder 13b having a low height of the outer ring 11.

  In the first waveform division holder 41 and the second waveform division holder 42, the band plate-like coupling plate portions 45 formed between the adjacent pocket portions 44 overlap each other, and the hemispherical pocket portion 44 accommodates the ball 31. The wave-like cage 40 is formed by combining the ends of the rivets 47 that pass through the two connecting plate portions 45 and are combined to form a spherical pocket 46.

  A concave portion 48 as a non-ball contact portion is formed on the inner surfaces of the hemispherical pocket portions 44 of the first waveform division holder 41 and the second waveform division holder 42. The recess 48 has a groove shape and extends long in the circumferential direction of the cage.

  Here, the recess 48 is provided in order to reduce the shear resistance of the oil film during the rotation of the ball 31 so as to reduce the torque loss of the bearing, and the pocket area in the state where the opening area is not formed. If it is less than 15% of the area of the inner surface of 44, torque loss cannot be reduced sufficiently, and if it exceeds 30%, the strength of the cage will be reduced.

  Therefore, in the embodiment, the area of the opening of the recessed portion 48 is 15 to 30% of the area of the inner surface of the pocket portion 44 when the recessed portion 48 is not formed in the pocket portion 44.

  Each of the 1st waveform division | segmentation holder | retainer 41 and the 2nd waveform division | segmentation holder | retainer 42 which form the holder | retainer 40 is made into the press molding product of a metal plate. A recess 48 is formed at the stage of manufacturing by press molding, and as a result, as shown in FIGS. 2 and 3, a protrusion 49 is provided on the outer periphery of the hemispherical pocket 44 at a position corresponding to the recess 48. It has been.

  As shown in FIG. 1, the concave portion 48 formed in the pocket portion 44 of the first waveform division holder 41 is formed at a position offset toward the inner diameter side from the pitch circle PC of the ball 31, while the second waveform division holding The concave portion 48 formed in the pocket portion 44 of the vessel 42 is formed at a position offset from the pitch circle PC of the ball 31 toward the outer diameter side.

  In FIG. 1 to FIG. 3, each of the first waveform division holder 41 and the second waveform division holder 42 forming the cage 40 is a metal plate press-molded product, but may be molded from a synthetic resin, You may form by casting. Alternatively, it may be formed by cutting.

  As shown in the embodiment shown in FIGS. 1 to 3, by providing the recess 48 as a non-ball contact portion on the inner surface of the pocket portion 44, the contact area of the inner surface of the pocket 46 with the ball 31 is reduced. The amount of oil film interposed between the inner surfaces of 46 can be reduced. As a result, the shear resistance of the oil film by the balls 31 is reduced, and torque loss can be reduced.

  In addition, since the recess 48 has a size that does not exceed 30% of the area of the inner surface of the pocket portion 44 in a state where the recess 48 is not formed, torque loss is maintained while maintaining the strength of the cage 40. Reduction can be achieved.

  As shown in FIG. 1, the concave portion 48 formed in the pocket portion 44 of the first waveform division holder 41 is set to the inner diameter side from the pitch circle PC, and the concave portion 48 formed in the pocket portion 44 of the second waveform division holder 42. By making the outer diameter side of the pitch circle PC, the site where these recesses 48 are formed is a position where the peripheral speed of the ball 31 is fast, and the shear resistance of the oil film at that position is reduced. For this reason, compared with the case where the recessed part 48 is formed on the pitch circle PC of the ball 31, the rotational resistance of the ball is also reduced, and the torque loss can be further reduced.

  2 and 3, the concave portion 48 formed in the pocket portion 44 of the first waveform division holder 41 is set to the inner diameter side of the pitch circle PC, and the concave portion 48 formed in the pocket portion 44 of the second waveform division holder 42. Is the outer diameter side of the pitch circle PC, but the concave portion 48 formed in the pocket portion 44 of the first waveform division holder 41 is the outer diameter side of the pitch circle PC, and the pocket portion 44 of the second waveform division holder 42 is. As shown in FIG. 4, the concave portion 48 formed in may be arranged on the inner diameter side from the pitch circle PC.

  In FIG. 2, the concave portion 48 is a ball non-contact portion, but the ball non-contact portion is not limited to the concave portion 48. 5 and 6, a slot 50 that is long in the circumferential direction of the cage is formed in each of the pocket portions 44 of the first waveform division holder 41 and the second waveform division holder 42, and the slot 50 is used as a non-ball contact portion. Yes. The slot 50 has the same size as the recess 48 shown in FIG.

  As described above, when the slot 50 is a non-ball contact portion, the fluidity of the lubricating oil between the ball 31 and the inner surface of the pocket 46 can be increased, so that the shear resistance of the oil film can be reduced, and the bearing Torque loss can be further reduced.

  5 and 6, the slot 50 formed in the pocket portion 44 of the first waveform division holder 41 is set to the inner diameter side from the pitch circle PC, and the slot 50 formed in the pocket portion 44 of the second waveform division holder 42. Is the outer diameter side of the pitch circle PC, but the slot 50 formed in the pocket portion 44 of the first waveform division holder 41 is the outer diameter side of the pitch circle PC, and the pocket portion 44 of the second waveform division holder 42 is. As shown in FIG. 7, the slot 50 formed in the shape may be located on the inner diameter side from the pitch circle PC.

  FIG. 8 shows a bearing device that rotatably supports a shaft 61 that supports the helical gear 60 on the driven side using the deep groove ball bearing A shown in the embodiment. In this case, the deep groove ball bearing A is assembled so that the shoulder 23b on the thrust load side of the inner ring 21 is located on the helical gear 60 side. The deep groove ball bearing A is assembled so that a part thereof is immersed in an oil bath.

  In the bearing device, when the rotation is transmitted from the driving side helical gear 62 to the driven side helical gear 60, a thrust force is applied to the shaft 61, and the thrust force is applied to the thrust load side shoulder 23b of the inner ring 21 in the deep groove ball bearing A and the outer ring. 11 on the thrust load side shoulder 13a.

  At this time, a thrust force is also applied to the ball 31, and when the thrust load side shoulder 23b of the inner ring 21 and the thrust load side shoulder 13a of the outer ring 11 are lower than necessary, the ball 31 rides on the shoulders 13a, 23b, There is a possibility of damaging the edges of the shoulders 13a and 23b.

In the embodiment, since the ratio H ₁ / d of the shoulder height H ₁ to the ball diameter d of the ball 31 is set to 0.25 or more, the riding of the ball 31 can be reliably prevented.

11 outer ring 12 raceway groove 13a shoulder 13b shoulder 21 inner ring 22 raceway groove 23a shoulder 23b shoulder 31 ball 40 cage 41 first waveform segmented retainer 42 second waveform segmented retainer 44 pocket portion 45 coupling plate portion 46 pocket 48 recess (ball Non-contact part)
50 slots (ball non-contact part)
60 Helical gear 61 Shaft A Deep groove ball bearing

Claims (8)

An outer ring having a raceway groove on the inner diameter surface, an inner ring having a raceway groove on the outer diameter surface, a ball incorporated between the raceway groove of the outer ring and the raceway groove of the inner ring, and a cage for holding the ball, The height of at least one of the shoulder on one side of the raceway groove in the outer ring and the shoulder on the other side of the raceway groove in the inner ring is made higher than the height of the shoulder on the other side of the outer ring and the shoulder on one side of the inner ring, When the shoulder height of the high shoulder is H ₁ and the ball diameter is d, the ratio H ₁ / d of the shoulder height H ₁ to the ball diameter d is 0.25 to 0.50. The cage is composed of a pair of corrugated cages having a plurality of hemispherical pockets spaced apart in the circumferential direction, and the pair of corrugated cages is arranged between adjacent pockets. The band-plate-shaped coupling plate portions formed on each other overlap, and the hemispherical pocket portions are for ball accommodation In ball bearings each deep coupled together in combination to form the shape of the pocket,
Provided on each inner surface of the pocket portion is a ball non-contact portion that is not in contact with the outer peripheral spherical surface of the ball, and the area of the ball non-contact portion is a pocket in a state where the ball non-contact portion is not formed. A deep groove ball bearing characterized by being 15 to 30% of the area of the inner surface of the part.   The deep groove ball bearing according to claim 1, wherein the ball non-contact portion is formed of a groove-like recess that is long in the circumferential direction of the cage.   The deep groove ball bearing according to claim 1, wherein the ball non-contact portion includes a slot that is long in a circumferential direction of the cage.   The deep groove ball bearing according to any one of claims 1 to 3, wherein the ball non-contact portion is positioned on an inner diameter side or an outer diameter side from a pitch circle of the ball.   The deep groove ball bearing according to any one of claims 1 to 4, wherein the cage is made of a press-formed product made of metal.   The deep groove ball bearing according to any one of claims 1 to 4, wherein the cage is made of a molded product by casting.   The deep groove ball bearing according to any one of claims 1 to 4, wherein the retainer is formed by cutting a metal. In a bearing device in which a shaft provided with a helical gear is rotatably supported by a pair of rolling bearings partially immersed in an oil bath,
The bearing device, wherein the pair of rolling bearings comprises the deep groove ball bearing according to any one of claims 1 to 7.

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