JP2012184802A - Tapered roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tapered roller bearing having excellent rigidity while having a simple structure easy to be manufactured, capable of improving of load capacity of the bearing (prolonging a bearing life) and including a retainer constitutable into a size corresponding to needs at a low cost.SOLUTION: This tapered roller bearing includes a hollow annular retainer 8 for holding a plurality of rolling elements 6 which are incorporated in a freely rolling manner along mutual bearing rings (an inner ring 2 and an outer ring 4) and have rolling surfaces 6s formed into truncated conical shapes. In a state of each rolling element 6 incorporated between mutual bearing rings, an apex Ap of a cone angle of each rolling element 6 is converged on one point on a rotational axis Ax of the bearing. In each rolling element 6, a through-hole 66 passing from a head part side end face 6a to a tail part side end face 6b is punched along the rolling axis. The retainer 8 includes a plurality of pins 8p to be inserted one by one from the head part side end face 6a into the through-hole 66 of each rolling element 6 and a hollow annular retainer body 8m for positioning and supporting each pin 8p at prescribed intervals along a peripheral direction.

Description

  The present invention has a simple structure that is easy to manufacture, has excellent rigidity, can improve the load capacity of the bearing (prolong the life of the bearing), and can be sized according to needs. The present invention relates to a tapered roller bearing having a configurable low-cost cage.

  Conventionally, various types of tapered roller bearings are known as bearings that can receive a radial load and one axial load. In this case, as a cage applied to each of these tapered roller bearings, a cage shape or a machined shape (for example, see Patent Document 1) and a pin shape (for example, see Patent Document 2) are generally used. It is.

JP 2010-91048 A JP 2000-81035 A

  By the way, in a conventional cage, for example, a cage-shaped or machined-type cage has a pair of annular parts constituting the cage and a plurality of annular parts arranged at equal intervals along the circumferential direction between the annular parts. A certain cross-sectional dimension (thickness) is required due to the rigidity requirements of the column. In this case, the size (size) and the number of rolling elements (rollers) that can be held by the cage are limited. For this reason, there is a certain limit in improving the load capacity of the bearing (in other words, increasing the fatigue life of the bearing, that is, extending the life of the bearing). The value representing the load capacity of the bearing is defined based on the dynamic load rating and the static load rating.

  Further, in a conventional cage, for example, a pin-shaped cage is formed by inserting a long pin into a through-hole drilled along a rotation center of a rolling element (roller), and rolling elements on both ends of the pin. By attaching an annular member so as to sandwich the (roller), a plurality of rolling elements (rollers) are held along the circumferential direction. In this case, the number of rolling elements (rollers) that can be held by the cage can be increased, but it is difficult to configure the size according to the needs. In other words, it can be used only for large bearings, and there are certain restrictions on the types of rolling elements (rollers) that can be used (for example, roller length).

  In addition, the cage, the machined shape, the pin shape, and the like as described above have a relatively complicated structure, which complicates the manufacturing process and, as a result, reduces the manufacturing cost. There are certain limits.

  The present invention has been made in order to solve such problems, and the object thereof is to provide a simple structure that is easy to manufacture, while being excellent in rigidity and improving the load capacity of the bearing (prolonging the life of the bearing). It is an object of the present invention to provide a tapered roller bearing having a low-cost cage that can be configured to a size according to needs.

In order to achieve such an object, the present invention is incorporated into a hollow annular race ring opposed to each other so as to be relatively rotatable, and to be freely rollable between the race rings. A plurality of rolling elements having a trapezoidal shape and a hollow annular retainer that rotatably holds the plurality of rolling elements one by one. Each rolling element has a circular head on both sides of the rolling surface. It has a side end surface and a circular tail side end surface, and forms a tapered truncated cone shape as it goes from the head side end surface to the tail side end surface. A tapered roller bearing in which the apex of the tapered angle of the rolling element converges to one point on the rotating shaft of the bearing, and each rolling element has an end surface on the tail side from the head side end surface along the rolling axis. One through-hole penetrating through each of the rolling elements is drilled, and the cage is attached to each through-hole of each rolling element. Includes a plurality of pins to be inserted one by one from the head-side end face, and one of the holder body of the hollow annular positioning supported at predetermined intervals along each pin in the circumferential direction.
In the present invention, in the cage, each pin has a length that is at least 1/2 or more and less than or equal to the total length along the rolling axis of each rolling element from the head-side end surface to the tail-side end surface. Is set to
According to the present invention, in the cage, each pin is positioned and supported on the cage main body with a taper gradient radially toward the apex of the conical angle of each rolling element.
In the present invention, in each rolling element, each through-hole is configured to have the same hole diameter from the head-side end surface to the tail-side end surface.
In the present invention, in each rolling element, each through hole is configured such that the hole diameter of the portion extending from the tail side end surface is different from the hole diameter of the portion into which each pin is inserted from the head side end surface.

  According to the present invention, although it is a simple structure that is easy to manufacture, it has excellent rigidity, and it is possible to improve the load capacity of the bearing (prolong the life of the bearing) and meet the needs. A tapered roller bearing having a low-cost cage that can be configured in size can be realized.

(a) is sectional drawing which partially expands and shows the structure of the holder | retainer applied to the tapered roller bearing which concerns on one Embodiment of this invention, (b) is the holder | retainer shown by the same figure (a) Sectional drawing of the tapered roller bearing to which is applied. Sectional drawing of the tapered roller bearing which concerns on other embodiment of this invention.

Hereinafter, a tapered roller bearing according to an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 (a) and 1 (b), the tapered roller bearing of the present embodiment includes a hollow annular raceway (inner ring 2, outer ring 4), an inner and outer ring 2, A plurality of rolling elements 6 which are incorporated so as to roll freely along each other (specifically, between the inner ring raceway surface 2s and the outer ring raceway surface 4s), and the rolling surfaces 6s form a truncated cone shape; And a hollow annular retainer 8 that rotatably holds the plurality of rolling elements 6 one by one.

  The inner ring raceway surface 2 s is continuous in the circumferential direction along the outer peripheral surface of the inner ring 2 and is configured with a predetermined inclination angle, while the outer ring raceway surface 4 s is formed on the inner peripheral surface of the outer ring 4. Along the circumferential direction, a predetermined inclination angle is formed. The inner ring raceway surface 2s is formed with a pair of flange portions T1 and T2 that are continuous in the circumferential direction along both sides thereof. In this case, the flange portions T1 and T2 on both sides of the inclined inner ring raceway surface 2s have one collar portion T1 (hereinafter referred to as a small diameter collar portion) and the other collar portion T2 (hereinafter referred to as a large diameter collar portion). ), And a positional relationship with a small diameter.

  Each rolling element 6 has a circular head-side end surface 6a and a circular tail-side end surface 6b on both sides of the rolling surface 6s, and tapers from the head-side end surface 6a toward the tail-side end surface 6b. It has a conical trapezoidal shape. In this case, each rolling element 6 is configured as a tapered roller (hereinafter referred to as a roller) in which the rolling surface 6s forms a truncated trapezoidal shape.

  In such a tapered roller bearing, the apex Ap of the tapered angle of each rolling element (roller) 6 is the rotational axis of the bearing in a state in which each rolling element (roller) 6 is incorporated between the inner and outer rings 2 and 4. Focus on one point on Ax. In FIG. 1A, only the cage 8 is shown, and the apex Ap converging on the rotation axis Ax is schematically shown.

  Further, in the tapered roller bearing, each rolling element (roller) 6 has one through-hole 66 penetrating from the head-side end surface 6a to the tail-side end surface 6b along the rolling shaft (not shown). Perforated. In this case, the through-hole 66 of each rolling element (roller) 6 is formed in a cylindrical shape, and has the same hole diameter from the head-side end surface 6a to the tail-side end surface 6b. It is configured. In addition, since the hole diameter of each through-hole 66 is set according to the magnitude | size, shape, use purpose, or use environment of the rolling element (roller) 6, for example, it does not specifically limit here.

  Here, the cage 8 has a plurality of pins 8p to be inserted one by one from the head-side end surface 6a into the through holes 66 of the respective rolling elements (rollers) 6, and each pin 8p is predetermined along the circumferential direction. A hollow annular retainer body 8m that is positioned and supported at intervals (for example, at equal intervals) is provided. Each pin 8p has a cylindrical shape. In this case, since the diameter of the pin 8p is set corresponding to the diameter of the through hole 66 of each rolling element (roller) 6 described above, the numerical value is not particularly limited here.

  Each pin 8p is positioned and supported by the cage main body 8m with a taper gradient radially toward the apex Ap of the conical angle of each rolling element (roller) 6 as a whole. In this case, each pin 8p is at least 1/2 or more of the total length 6L (also referred to as roller length) along the rolling axis of each rolling element (roller) 6 extending from the head-side end surface 6a to the tail-side end surface 6b. In addition, the length is set to 8L with a total length of 6L or less.

  In such a retainer 8, each pin 8p may be integrally formed with the retainer body 8m, or may be formed separately and retrofitted to the retainer body 8m. The cage 8 (pin 8p, cage body 8m) may be formed of a resin material (eg, polyamide resin, phenol resin, etc.), or a metal material (eg, carbon steel, copper alloy, etc.). ).

  As described above, according to the present embodiment, for example, the through holes 66 of the rolling elements (rollers) 6 are inserted into the respective pins 8p of the cage 8 one by one from the head-side end face 6a, and each pin 8p is inserted. In a state where the plurality of rolling elements (rollers) 6 are held by the cage 8 (that is, the cage body 8m is in contact with the head-side end surface 6a of each rolling element (roller) 6), the inner ring 2 Is pushed in from the cage body 8m side. Specifically, the inner ring 2 is pushed in from the small-diameter collar portion T1 side.

  At this time, a pressing force acts on each rolling element (roller) 6 by the small-diameter collar portion T1. At this time, the pressing force acting on each rolling element (roller) 6 passes through each rolling element (roller) 6. By acting on the pin 8p and elastically deforming each pin 8p, the small-diameter collar portion T1 gets over each rolling element (roller) 6 (in other words, each rolling element (roller) 6 has a small-diameter collar portion T1). The rolling elements (rollers) 6 can be incorporated into the inner ring 2.

  In this state, each rolling element (roller) 6 is freely rollable along the inner ring raceway surface 2s while being guided in the circumferential direction by the pair of collar portions T1 and T2. Then, the outer ring 4 is disposed opposite to the outer side of the inner ring 2. Specifically, the outer ring 4 is fitted to the outside of each rolling element (roller) 6. Thereby, the tapered roller bearing of this embodiment can be assembled.

  According to such an assembling process, one rolling element (roller) 6 is inserted into each pin 8p of the cage 8 and the inner ring 2 is pushed in by utilizing the elastic force of each pin 8p. A plurality of rolling elements (rollers) 6 can be incorporated into the inner ring 2. As a result, the assembly efficiency of the tapered roller bearing can be dramatically improved, so that the time and labor required for the assembly can be greatly reduced. As a result, the manufacturing cost of the tapered roller bearing can be greatly reduced.

  Further, according to the present embodiment, the cage 8 is composed of only one hollow annular cage body 8m and a plurality of pins 8p shorter than the total length 6L (roller length) of the rolling elements (rollers) 6. Since the structure is extremely simple and simple, the cage 8 can be easily manufactured and less material is required for manufacturing. In this case, for example, the resin cage 8 has a very simple mold structure and is easy to manufacture. For example, the metal cage 8 can be manufactured by simple cutting or welding. Thereby, a dramatic improvement in the manufacturing efficiency of the tapered roller bearing and a significant reduction in manufacturing cost can be realized at the same time.

  Further, in the present embodiment, each rolling element (roller) 6 is in a state where its head-side end surface 6a is in contact with the cage main body 8m, and each rolling element (roller) 6 is subjected to the assembly process described above. Is supported by the cage 8 so as to be rotatable around a plurality of pins 8p shorter than the total length 6L (roller length).

  According to such a support structure, the size (size) of the cage 8 can be arbitrarily configured only by increasing the diameter of the cage body 8m applied to the head-side end surface 6a of each rolling element (roller) 6. can do. Thereby, the tapered roller bearing of the size according to the use purpose, use environment, etc. can be comprised.

  Further, according to the present embodiment, the length 8L of each pin 8p of the cage 8 is at least 1/2 or more than the total length 6L (roller length) of each rolling element (roller) 6, and Since the total length is set to 6 L or less, it can be configured shorter than the conventional long pins described above. In this case, the stress acting on the root of each pin 8p (that is, the connecting portion between each pin 8p and the cage body 8m) can be extremely reduced. Thereby, the rigidity of the entire cage 8 can be dramatically increased.

  Furthermore, according to the present embodiment, the length 8L of each pin 8p is set to at least 1/2 or more of the total length 6L (roller length) of each rolling element (roller) 6 and to a total length of 6L or less. The rigidity of each pin 8p (that is, the rigidity of the entire cage 8) can be increased. In this case, the size (size) and the number of rolling elements (rollers) that can be held by the cage 8 can be given a degree of freedom. Thereby, the load capacity of the bearing can be improved (in other words, the fatigue life of the bearing, that is, the life of the bearing can be extended). The value representing the load capacity of the bearing is defined based on the dynamic load rating and the static load rating.

  In the above-described embodiment, it is assumed that the through-hole 66 of each rolling element (roller) 6 has the same hole diameter from the head-side end surface 6a to the tail-side end surface 6b. 2, in each rolling element (roller) 6, each through hole 66 has a hole diameter of a portion 66 a into which each pin 8 p is inserted from the head-side end surface 6 a (hereinafter referred to as a pin insertion portion). In contrast, the hole diameter of a portion 66b (hereinafter referred to as a gap portion) extending over the tail side end surface 6b may be different.

  In this case, the hole diameter of the gap portion 66b may be set larger than or smaller than the hole diameter of the pin insertion portion 66a. Note that the degree of difference in the hole diameters of the portions 66a and 66b is not particularly limited because it is set according to, for example, the size and shape of each rolling element (roller) 6 or the purpose of use and environment of use. FIG. 2 shows, as an example, a case where the hole diameter of the gap portion 66b is set smaller than the hole diameter of the pin insertion portion 66a.

  According to the through-hole 66 (FIGS. 1B and 2) of each rolling element (roller) 6 as described above, a portion other than the portion into which each pin 8p is inserted is used as a lubricant (for example, oil, grease). Can be used for storage (holding). In this case, since the lubrication state inside the bearing can be kept constant by the lubricant stored (held) in the part, the rotational performance of the tapered roller bearing can be maintained and improved, and the bearing component (inner ring 2, seizure of the outer ring 4 and the rolling elements (rollers) 6) and the accompanying deterioration of the bearing components can be prevented. Thereby, the tapered roller bearing can be used continuously over a long period of time.

2 Inner ring 4 Outer ring 6 Rolling elements (rollers)
6a Head side end surface 6b Tail side end surface 6s Rolling surface 8 Cage 8p Pin 8m Cage body 66 Through-hole Ap Apex of conical angle of rolling element Ax Rotating shaft of bearing

Claims (5)

A hollow ring raceway disposed opposite to be relatively rotatable;
A plurality of rolling elements which are incorporated so as to be freely rollable between the races, and whose rolling surfaces form a truncated cone shape;
A hollow annular retainer that rotatably holds a plurality of rolling elements one by one,
Each rolling element has a circular head-side end surface and a circular tail-side end surface on both sides of the rolling surface, and forms a tapered truncated cone shape from the head-side end surface toward the tail-side end surface. ,
A tapered roller bearing in which each of the rolling elements is assembled between the races, and the apex of the tapered angle of each rolling element converges to one point on the rotation axis of the bearing,
Each rolling element has a through-hole penetrating from the head-side end surface to the tail-side end surface along the rolling axis.
The cage is
A plurality of pins that are inserted one by one from the end surface on the head side with respect to the through holes of each rolling element,
A tapered roller bearing comprising: a hollow annular retainer body that positions and supports each pin at a predetermined interval along a circumferential direction.   In the cage, each pin is set to a length that is at least 1/2 or more and less than or equal to the total length along the rolling axis of each rolling element from the head side end surface to the tail side end surface. The tapered roller bearing according to claim 1, wherein:   3. The cage according to claim 1, wherein each pin is positioned and supported by the cage body with a taper in a radial direction toward the apex of the conical angle of each rolling element. Tapered roller bearings described in 1.   In each rolling element, each through-hole is comprised from the head side end surface to the tail part side end surface so that the same hole diameter may be comprised, The cone in any one of Claims 1-3 characterized by the above-mentioned. Roller bearing.   In each rolling element, each through hole is configured such that the hole diameter of the portion extending from the head side end surface to the tail side end surface is different from the hole diameter of the portion into which each pin is inserted. The tapered roller bearing according to any one of claims 1 to 3.

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