JP6965674B2 - Double row roller bearing - Google Patents

Description

The present invention relates to double row roller bearings.

In double row roller bearings, the load acting on both rows may differ significantly depending on the application. For example, in gear reducers, gear speed reducers, gear distributors, etc., double row roller bearings may be used as bearings to support gears and support shafts, and are usually close to the load point, that is, the position where the gears are located. A large load acts on the row.

Therefore, for example, Patent Document 1 proposes a double-row roller bearing in which the length in the axial direction of the rolling elements forming a row that receives a large load is lengthened.

Further, in the double row roller bearing, two rows of rolling elements are arranged between the inner ring and the outer ring, and the rolling elements are held by a cage in each row. As the cage, a pin type cage, a punching cage, a punching cage such as a cage type cage, and the like, as well as a stud type cage are also used.

As described in Patent Documents 2, 3 and the like, and as shown in the drawings described later, the stud type cage is integrated with the stud pins 8 arranged at equal intervals on the annular side plate 6a. This is a cage in which the head portion 8a of the stud pin 8 is locked to the recesses 4a provided at the centers of both end faces of the rolling element 4 to hold the rolling element 4. Unlike the pin-type cage, this stud-type cage does not have a pin hole that penetrates the inside along the axis, so cracks that start from the pin hole do not occur when a high load is applied to the bearing. There are advantages. Further, as compared with a punching cage such as a punching cage or a cage-shaped cage, the number of rolling elements can be increased, and there is an advantage that resistance to a high load is increased. In the following description, the absence of cracks starting from the pin holes and the increased resistance to high loads are collectively referred to as "excellent in load resistance".

Japanese Unexamined Patent Publication No. 2005-147331 Jikkenhei 7-20423 Japanese Unexamined Patent Publication No. 11-173334

As described above, the stud type cage is excellent in load bearing capacity, but the manufacturing cost is higher than that of the pin type cage, the punched cage, and the punched cage. Therefore, if the cages for holding the rolling elements in both rows of the double row roller bearing are of the same type as in Patent Document 1 and the stud type cages are used in both rows, the entire bearing becomes expensive.

Therefore, an object of the present invention is to provide a double row roller bearing having excellent load bearing capacity while suppressing the manufacturing cost of the bearing as a whole.

In order to solve the above problems, the present invention provides the following double row roller bearings.
(1) In a double-row roller bearing in which rolling elements are interposed in two rows between the inner ring and the outer ring.
The rolling elements that make up one of the two rows and the rolling elements that make up the other row have different axial lengths and are different from each other.
The cage that holds the rolling elements that make up one row is a stud-shaped cage, and the cage that holds the rolling elements that make up the other row is a cage other than the stud-shaped cage. Features double row roller bearings.
(2) The above-mentioned (1), wherein the rolling element held by the stud-shaped cage has a longer axial length than the rolling element held by a cage other than the stud-shaped cage. Double row roller bearing.
(3) From a material in which the rolling element held by the stud-shaped cage has a slower crack growth rate or less non-metal inclusions than the rolling element held by a cage other than the stud-shaped cage. The double row roller bearing according to the above (1) or (2).
(4) The number of rolling elements held by a cage other than the stud-shaped cage is smaller than the number of rolling elements held by the stud-shaped cage (1) to (3). ), The double row roller bearing according to any one of the items.
(5) The double row roller bearing according to any one of (1) to (4) above, wherein the stud pin of the stud type cage has a hole for passing a lubricant.
(6) The double row roller bearing according to any one of (1) to (5) above, wherein the stud pin of the stud type cage has a lubricant reservoir hole.

In the double row roller bearing of the present invention, one of the two rows of rolling elements is held by a stud type cage and the other is held by another cage, and only the rolling element on the side to which a high load is applied is held. It is configured to be held by a stud type cage with excellent load resistance. Therefore, the bearing as a whole can be made excellent in load bearing capacity while suppressing the manufacturing cost.

It is sectional drawing in the axial direction which shows the double row roller bearing (double row cylindrical roller bearing) of this invention, and shows a part of a rolling element (cylindrical roller) notched. It is a partial notch sectional view which shows an example of a stud pin. It is a partial notch sectional view which shows another example of a stud pin. It is a partial notch sectional view which shows another example of a side plate. It is an axial sectional view which shows another example of a double row roller bearing, and shows a part of a rolling element (tapered roller) notched.

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the double row roller bearing of the present invention, rolling elements are interposed between the inner ring and the outer ring in two rows. In addition, the cages that hold the rolling elements that make up one row are stud-shaped cages, and the cages that hold the rolling elements that make up the other row. Is a cage other than the stud type cage.

For example, in the double-row roller bearing (double-row cylindrical roller bearing) 1 shown in FIG. 1, two rows of rolling elements (cylindrical rollers) 4 and 5 are arranged between the outer ring 2 and the inner ring 3, and the cage 6 , 7 is held so that it can roll freely, but the axial length L1 of the rolling element 4 in one row is longer than the axial length L2 of the rolling element 5 in the other row, and further. A stud type cage (hereinafter referred to as "stud type cage 6") is used for the cage 6 for holding the rolling element 4, and a cage other than the stud type cage (hereinafter referred to as "stud type cage") is used for the cage 7 for holding the rolling element 5. It is referred to as "another cage 7").

The stud type cage 6 is a cage that holds the rolling element 4 by locking the head portion 8a of the stud pin 8 to the recesses 4a provided at the centers of both end faces of the rolling element 4, and is excellent in load bearing capacity. .. Since the longer the axial length of the rolling element is, the better the load bearing capacity is. Therefore, by holding the rolling element 4 having a long axial length with the stud type cage 6, the synergistic effect of both makes the rolling element more excellent in the load bearing capacity. It becomes a thing.

Therefore, by using the row in which the rolling element 4 having a long axial length is held by the stud-shaped cage 6 on the side where the high load of the bearing acts, the rolling element 5 having a short axial length is used as another cage. The high load does not act on the row held in 7. Therefore, it is not necessary to use an expensive stud type cage 6 for the other cage 7, and it is possible to handle a high load while suppressing an increase in the manufacturing cost of the bearing as a whole. Further, in order to facilitate manufacturing and shorten the manufacturing period, it is preferable that the diameter of the surface on which the rolling elements (cylindrical rollers) of the inner ring 3 and the outer ring 2 roll is the same in both rows.

The other cage 7 is not limited as long as it is a stud type cage, and may be a general cage used as a cage for roller bearings. For example, a pin type cage or a punching cage. , A punching cage such as a cage cage can be used. In FIG. 1, a pin-shaped cage is used as the other cage 7. With such a configuration, it is possible to increase the total cross-sectional area of the rolling elements in the row on the side where the high load is applied, and it is possible to cope with the high load.

In addition to the above configuration, the rolling element 4 on the side held by the stud-shaped cage 6 is made of a material having a slower crack growth than the material of the rolling element 5 held by the other cage 7, or a non-metal. It is preferably formed of a material with few inclusions. The slower the crack growth and the less non-metal inclusions, the lower the risk of bearing-related accidents due to cracks, wear, cracks, and peeling of the rolling element 4, and the synergistic effect of using the stud type cage 6. Is higher.

Carburized steel is a material with slow crack growth. Specifically, SNCM815, which is a typical carburized steel specified by JIS, and 9310H, which is a typical carburized steel specified by ASTM, are preferable. Further, the metal structure is preferably fine.

Further, in bearing materials, oxide-based, nitride-based, sulfide-based, carbide-based, etc. are generally used as non-metal inclusions, and cracks, cracks, and peeling occur from these. Therefore, the amount of these non-metal inclusions in the rolling element 4 held by the stud-shaped cage 6 is less than that of the material of the rolling element 5 held by the other cage 7.

As the material of the rolling element 5 on the side held by the other cage 7, a material having a slow crack growth or a material having a small amount of non-metal inclusions can be used, but it is costly because a high load does not act. From the viewpoint of suppressing the amount of In the rolling elements of the above, carburized steel or the like having a general amount of non-metal inclusions can be used.

In addition, the number of rolling elements 5 held by the other cage 7 may be smaller than the number of rolling elements 4 held by the stud-shaped cage 6. The specific amount of reduction in the number of rolling elements may be appropriately set according to the size of the load, the diameter of the rolling elements, the axial length, the material, and the like.

As described above, the double row roller bearing having a structure in which the rolling element 4 on the side on which the high load acts is held by the stud type cage 6 is particularly effective under the conditions (1) to (3) below.
(1) (Radial load acting on the bearing: P) ÷ (Basic dynamic load of the bearing: C)> 0.7 (2) When the center of the bearing width in the double row roller bearing is G, the bearing When the acting radial load is offset with respect to G and (bearing width) x 0.05 <(distance from the center of the radial load acting on the bearing to G) (note that (bearing width) x 0 .05 can be considered as the minimum value from G to the end of the middle jaw.)
(3) When a large load acts on the row closer to the center of the radial load acting on the bearing due to the offset of (2).

By the way, in the stud type cage 6, since the recess 4a formed in the rolling element 4 and the head 8a of the stud pin 8 slide, the head 8a of the stud pin 8 is likely to be worn. Therefore, as shown in FIGS. 2 and 3, it is preferable to form the lubricant passing hole 9 and the lubricant collecting hole 10 in the stud pin 8.

That is, in the stud pin 8 shown in FIG. 2, a lubricant reservoir 10 is formed in the center of the end surface of the head 8a on the rolling element (roller) side, and the body is continuously coaxially aligned with the lubricant reservoir 10. A lubricant passage hole 9 that penetrates the portion 8b is provided. Further, in the stud pin 8 shown in FIG. 3, a similar lubricant pool hole 10 is formed in the head portion 8a, and the inner diameter surface or outer diameter of the side plate 6a is continuously formed in the lubricant pool hole 10 from the middle of the body portion 8b. A lubricant passage hole 9 having a substantially L-shaped cross section extending to the surface is provided.

In such a stud type cage 6, by periodically supplying a lubricant into the bearing, the lubricant lubricates the stud pin 8 from the inner diameter surface or the outer diameter surface of the side plate 6a or the end surface of the stud pin 8. It is sent to the lubricant reservoir 10 of the head 8a through the agent passage hole 9. Then, the lubricant from the lubricant reservoir 10 passes through the gap between the head 8a of the stud pin 8 and the recess 4a of the rolling element 4, and the outer peripheral surface 11 of the head 8a, that is, the sliding contact surface between the head 8a and the recess 4a. Will be sent to. As a result, wear of the head portion 8a of the stud pin 8 is suppressed.

In addition, in FIGS. 2 and 3, the lubricant passage hole 9 and the lubricant reservoir 10 are continuously formed, but even if only the lubricant passage hole 9 or only the lubricant reservoir 10 is formed. good. Although not shown in each case, in the case of only the lubricant through hole 9, the lubricant through hole 9 is formed through the stud pin 8 without forming the lubricant reservoir hole 10, and the lubricant is applied to the head. It is sent to the tip of 8a. On the other hand, in the case of only the lubricant reservoir 10, the recess 4a of the rolling element 4 is filled with the lubricant in advance at the time of assembling the bearing, and the head 8a of the stud pin 8 is locked and held in the recess 4a. , Lubricate the bearings on a regular basis.

Since the wear of the head 8a of the stud pin 8 is suppressed by such a lubrication method, it is not necessary to manufacture the stud pin 8 from an expensive material having excellent wear resistance, and the stud type cage 6 and the bearing as a whole are manufactured. The cost can be kept even lower.

There is no limitation on the lubricant, and grease may be used as the lubricating oil, but in the case of grease, it is necessary to adjust the viscosity to an appropriate level so that the grease can be satisfactorily supplied through the lubricant through hole 9.

Various modifications can be made in the present invention. For example, in another embodiment shown in FIG. 4, the rolling element side of the side plate 6a of the stud type cage 6 is tapered. The tapered shape makes it easier for the lubricant inside the bearing to flow into the sliding surface.

The present invention is also applicable to double-row tapered roller bearings as shown in FIG.

1 Double row roller bearing 2 Outer ring 3 Inner ring 4, 5 Rolling element 6 Stud type cage 7 Other cage 8 Stud pin 9 Lubricant passage hole 10 Lubricant reservoir hole

Claims (6)

In a double-row roller bearing in which rolling elements are interposed between the inner ring and the outer ring in two rows.
The rolling elements that make up one of the two rows and the rolling elements that make up the other row have different axial lengths and are different from each other.
The cage that holds the rolling elements that make up one row is the stud-shaped cage, and the cage that holds the rolling elements that make up the other row is the pin-shaped holding of the row next to the stud-shaped cage. Double row roller bearing characterized by being a vessel. 1. A rolling element held by the stud-shaped cage has a longer axial length than a rolling element held by a pin-shaped cage in a row next to the stud-shaped cage. The described double row roller bearing. Rollers held by the stud cage have fewer materials or non-metal inclusions that have a slower crack growth rate than rolls held by the pin cages in the row next to the stud cage. The double row roller bearing according to claim 1 or 2, wherein the double row roller bearing is made of a material. Claims 1 to 3 characterized in that the number of rolling elements held by the pin-shaped cages in the row next to the stud-shaped cage is smaller than the number of rolling elements held by the stud-shaped cages. The double row roller bearing according to any one of the above items. The double row roller bearing according to any one of claims 1 to 4, wherein the stud pin of the stud type cage has a lubricant passage hole. The double row roller bearing according to any one of claims 1 to 5, wherein the stud pin of the stud type cage has a lubricant reservoir hole.

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