JP2002013540A - Double row slewing bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double row slewing bearing in which a rolling element can be easily inserted into a rolling path through an insertion hole in an inner ring or an outer ring, a proper preload can be applied to the rolling elements, and the insertion hole can be easily closed. SOLUTION: In the double row slewing bearing 10 comprising the outer ring 11 provided with rows of rolling grooves 18, 18 around the inner periphery thereof, the inner ring 12 which is arranged inside of the outer ring 11 and is provided with rows of rolling grooves 19, 19 around the outer periphery thereof in the positions corresponding to those of the rolling grooves 18, 18 of the outer ring 11, and a plurality of rolling element 13 which are loaded in the rolling paths 20, 20 formed between the rolling grooves of the inner and outer rings, the insertion holes 21 penetrating radially through the outer ring 11 (or the inner ring 12) which enable insertion of the rolling elements 13 are provided in the outer ring 11 (or the inner ring 12). The insertion hole 21 are arranged for each rolling path 20, 20 individually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double row slewing bearing in which rolling elements such as rollers are loaded on a plurality of rows of rolling paths provided between inner and outer rings.

[0002]

2. Description of the Related Art Generally, a slewing bearing having a double row of rolling paths between inner and outer rings has a rolling groove for receiving a rolling element in each of the inner and outer rings, and a line of action of a load on the rolling elements is determined by a rolling path. It has a structure in which it faces a different direction every time. Therefore, how to load the rolling elements on the rolling paths of each row becomes a problem.

[0003] As a double-row slewing bearing that solves this problem, Japanese Patent No. 3032054 discloses that an inner ring is divided into a plurality of pieces at the position of a rolling path, and each piece of the inner ring is bolted after a rolling element is assembled. A double-row slewing bearing having a structure in which the slewing bearing is connected by a fastening body is disclosed. In addition, as shown in FIG. 6, the outer ring 1 and the inner ring 2 are integrally formed while a part of the outer ring 1 penetrates the outer ring 1 in the radial direction to reach the two rows of rolling paths 3 as shown in FIG. A double-row slewing bearing is also disclosed in which an insertion hole 4 is formed, and rollers 5... 5 as rolling elements are inserted from the insertion hole 4 and then the insertion hole 4 is closed with a plug 6.

[0004]

When the inner ring has a divided structure, a misalignment may occur when the divided pieces are connected, and the operation of the rolling element may be deteriorated.
On the other hand, as shown in FIG. 6, when the outer ring 1 and the inner ring 2 are integrated, and the roller 5 is loaded using the insertion hole 4, such inconvenience does not occur. However, the structure of FIG. 6 has the following problem.

The surfaces 3a, 3b, 3c surrounding the rolling paths 3, 3
3d, when the surface 3a of the outer ring 1 and the surface 3b of the inner ring 2 opposed thereto are used as the rolling surface of the roller 5, the surface 3a
It is necessary to apply a preload to the roller 5 by making the distance between a and 3b smaller than the diameter of the roller 5. However, if the distance between the surfaces 3a and 3b is so narrow, the roller 5
Cannot be inserted between the surfaces 3a and 3b. On the other hand, when the surfaces 3c and 3d are used as rolling surfaces of the roller 5, a resultant force that pushes the plug 6 radially outward is generated by a load applied from the roller 5 to each surface 3c of each of the rolling paths 3 and 3. The plug 6 may come off. To cope with this, the plug 6 must be firmly fixed to the outer ring 1.

According to the present invention, although the rolling element is inserted into the rolling path from the insertion hole of the outer ring or the inner ring, it is possible to apply an appropriate preload to the rolling element and to easily close the insertion hole. It is an object of the present invention to provide a double-row slewing bearing that can perform the following.

[0007]

The present invention will be described below. In addition, in order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

The double row slewing bearing of the present invention is provided with an outer ring (11) provided with a plurality of rows of rolling grooves (18, 18) on the inner circumference, and disposed inside the outer ring, and on the outer circumference of the outer ring. An inner ring (12) provided with a plurality of rows of rolling grooves (19, 19) corresponding to the rolling grooves and a rolling path (20, 20) formed between the rolling grooves of the inner and outer rings. In the double-row slewing bearing (10) provided with a number of rolling elements (13), at least one of the outer ring and the inner ring radially penetrates the outer ring or the inner ring to extend to the rolling path. The above-described problem is solved by providing an insertion hole (21) for inserting a rolling element individually for each rolling path.

According to the present invention, since the rolling elements are loaded into the rolling path from the insertion holes penetrating the outer ring or the inner ring in the radial direction, there is no need to divide the outer ring or the inner ring at the position of the rolling path. By forming the inner races into a so-called integral type, it is possible to prevent the misalignment due to the coupling after the rolling elements are assembled, and to guarantee the smooth movement of the rolling elements. In this specification, the term "integral type" means that the rolling element has a form as an outer ring or an inner ring before assembling of the rolling element, and the outer ring is formed only after the rolling element is assembled by using a fastening means such as a bolt. The purpose is to exclude those that can be obtained as an inner ring. For example, even if it has a structure that is divided into two pieces or more due to material and molding reasons, it is already completed before the rolling elements are loaded and the outer ring or inner ring is formed. What is being done may be included in the integrated concept.

Further, according to the present invention, since the insertion holes are individually provided for each rolling path, the wall surface (for example, 18) forming the rolling groove of the outer ring or the inner ring by each insertion hole.
a, 18b) are cut out over the entire width in the axial direction of the bearing, so that the rolling element can be easily inserted into the rolling groove ahead of the insertion hole. After the rolling element is inserted, the outer ring and the inner ring are relatively rotated to guide the rolling element gradually between the rolling surfaces and gradually compress the rolling element, so that an appropriate preload can be easily applied to the rolling element. it can. Since the insertion hole is different for each rolling path, even when the insertion hole is closed with a plug, the load applied to the plug from the rolling element tilts in one direction with respect to the axial direction of the insertion hole, and Applies only the component force of the load. Therefore, the force for pushing out the plug is weaker than in the related art, and the insertion hole can be easily closed.

In the double-row slewing bearing of the present invention, an embedding plug (22) having a concave portion (25) functioning as a part of the rolling groove is provided at one end of the insertion hole (21). Is also good. With this configuration, the rolling groove cut out by the insertion hole is supplemented by the concave portion, and continuity of the rolling surface of the rolling element can be secured.

The insertion holes (21) for each rolling path may be shifted from one another in the circumferential direction. In this case, as compared with a structure in which the insertion holes are provided side by side at the same location in the circumferential direction of the outer ring or the inner ring,
The rigidity of the outer ring or the inner ring at the position where the insertion hole is formed is small, and the size of the insertion hole can be set to a degree sufficient for mounting the rolling element.

The insertion hole (21) for each rolling path may be provided so as to be limited to a part of less than half a circumference in the circumferential direction of the bearing. In this case, a double-row slewing bearing suitable for receiving a radial load can be provided.

The insertion holes (21) for each rolling path may be provided at substantially equal intervals in the circumferential direction of the bearing. In this case, a double-row slewing bearing suitable for receiving a moment load can be provided.

In the double-row slewing bearing of the present invention, the line of action of the load of each rolling element in one row is directed in a fixed direction relative to the radial direction of the bearing on a cross section along the axial direction of the bearing. A structure in which the line of action of the load of the rolling element on at least one rolling path and the line of action of the load of the rolling element on another rolling path intersect on the inner peripheral side or the outer peripheral side of the rolling path. Row slewing bearings are included. Rollers or balls can be used for the rolling elements. When the rolling element is a roller, the line of action of the load can be defined as a line extending in a direction orthogonal to the rolling surface of the roller (the surface on which the roller in the rolling groove rolls). When the rolling element is a ball, the line of action of the load can be defined as a line connecting the contact points between the ball and a pair of rolling surfaces sandwiching the ball.

[0016]

FIG. 1 is an external view of a double-row slewing bearing to which the present invention is applied, and FIG. 2 is a cross-sectional view along the axial direction. The double-row slewing bearing 10 has an outer ring 11, an inner ring 12 disposed inside the outer ring 11, and rollers 13 as rolling elements interposed between the outer ring 11 and the inner ring 12. Each of the outer ring 11 and the inner ring 12 is formed in a ring shape having a rectangular cross section. The outer ring 11 and the inner ring 12 are formed with bolt mounting holes 14 and 15 that penetrate the outer ring 11 or the inner ring 12 in the axial direction from one side surface 11a, 12a to the opposite side surface 11b, 12b.
As shown in FIG. 1, bolts 16, 17 are mounted on the bolt mounting holes 14, 15 from the side surfaces 11 a, 12 a side and screwed into respective mating parts (not shown) of the outer ring 11 and the inner ring 12, thereby forming the side surface 11 b. , 12b can be fixed to the mating part to fix the outer ring 11 and the inner ring 12.

As shown in FIG. 2 and FIG. 3B in which the lower part is enlarged, the inner peripheral surface 11c of the outer race 11 and the outer peripheral surface 12c of the inner race 12 have rolling grooves 18 and 1 having a V-shaped cross section, respectively.
9 are formed in two rows. Each of the rolling grooves 18 and 19 makes one round of the outer ring 11 and the inner ring 12, respectively. These rolling grooves 18, 19 form two rows of rolling paths 20, 20 between the outer ring 11 and the inner ring 12, and these rolling paths 20, 20 are formed.
Are loaded with rollers 13. The wall surfaces 18a, 18b of the outer ring side rolling groove 18 intersect at right angles, and the inner wall side rolling groove 19 wall surfaces 19a, 19b also intersect at right angles. Therefore, the wall surface 18a and the wall surface 19a are parallel to each other, and the wall surface 18b and the wall surface 19b are parallel to each other.

The wall surfaces 18a, 19a of the rolling grooves 18, 19
Is formed as a rolling surface on which the roller 13 rolls. In order to apply an appropriate preload to the roller 13, the distance between the wall surface 18 a and the wall surface 19 a is set to be smaller than the diameter of the roller 13 by a predetermined amount. In contrast, the wall 18b and the wall 1
9b is the same as the axial length of the roller 13;
Slightly larger than that.

As is clear from FIG. 2 and FIG. 3 (a) showing the upper portion thereof enlarged, the outer race 11 is formed with one insertion hole 21 for each rolling path 20 penetrating in the radial direction. . Each insertion hole 21 is provided for loading the roller 13 in each of the rolling paths 20, 20, and the position of the center line of each insertion hole 21 is aligned with the center position of the rolling path 20 in the axial direction of the bearing 10. It is. The diameter of each insertion hole 21 is determined by the rolling path 20 in the axial direction of the bearing 10.
Greater than the width of. As a result, the rolling groove 18 is cut off at the position where the insertion hole 21 is provided, and the rolling groove 19 on the inner race 12 can be seen from outside the insertion hole 21.

When the rollers 13 are incorporated in the double-row slewing bearing 10, a predetermined number of rollers 13 are inserted into the rolling grooves 19 of the rolling path 20 one by one from the insertion holes 21. Each time one roller 13 is inserted into the rolling groove 19, the outer ring 11 or the inner ring 12 is rotated so that a space on the rolling groove 19 for receiving the next roller 13 is fed into the insertion hole 21. At this time, the roller 13 located in the insertion hole 21 gradually enters between the wall surfaces 18a and 19a as rolling surfaces and is gradually compressed, and accordingly, the preload amount of the roller 13 gradually increases. Therefore, unlike the conventional example shown in FIG.
3, an appropriate preload can be applied without difficulty.

When a predetermined number of rollers 13 are loaded in the rolling path 20, plugs 22 are mounted in the respective insertion holes 21. A pin hole 23 is provided in the outer ring 11 so as to cross the insertion hole 21. The plug 22 is prevented from coming off by a pin 24 as a plug fixing means mounted in the pin hole 23 from the side surface 11 a of the outer ring 11. The pin 24 can be a taper pin or a straight pin. As shown in FIG.
A through-hole 22a for passing the pin 24 is formed in advance. A V-shaped recess 25 is formed at one end of the plug 22. The wall surfaces 25a and 25b of the recess 25 intersect at right angles with each other. When the plug 22 is fixed by the pin 24, the wall surfaces 25 a and 25 b are flush with the wall surfaces 18 a and 18 b of the rolling groove 18, respectively, and substantially function as a surface forming the rolling path 20. That is, the wall surfaces 18a, 18b cut out by the insertion holes 21 are the wall surfaces 25a, 25
b, so that the continuity of the rolling surface with respect to the roller 13 is ensured.

Since the wall surface 25a of the plug 22 functions as the rolling surface of the roller 13 like the wall surface 18a of the rolling groove 18, the compression reaction force of the roller 13 and the input from the inner ring 12 to the roller 13 are applied thereto. The applied load acts in a direction substantially perpendicular to the wall surface 25a. However, each of the insertion holes 21 is in the rolling path 2
0, the acting direction of the load applied to the plug 22 of each insertion hole 21 is only inclined in one direction with respect to the axial direction of the insertion hole 21. Does not coincide with the axial direction of the insertion hole 21. Therefore, compared with the example of FIG. 6, the force for pushing out the plug 22 is weak, and the stopper 22 can be easily prevented from coming off.

As shown in FIGS. 1 and 5B, the positions of the insertion holes 21 and 21 of each rolling path 20 are shifted from each other in the circumferential direction. In the example of FIG. 1 and FIG. 5A, the positions of the insertion holes 21 and 21 for each rolling path 20 are limited to a part of less than half a circumference in the circumferential direction of the bearing. Specifically, 2
The extension lines L, L of the axes of the two insertion holes 21 and 21 are
5A is 30 degrees in the example of FIG.
° is set. The structure in which the insertion hole 21 is provided in such a narrow range is suitable when a radial load (a load in a radial direction) is mainly applied to the bearing 10. For example, in a usage example in which the outer ring 11 is fixed and the inner ring 12 is rotated, when a radial load (a radial load) is relatively concentrated on a part of the outer ring 11 in the circumferential direction, the area where the load is applied By shifting the region where the insertion hole 21 is provided and the region where the insertion hole 21 is provided in the circumferential direction, the load that the wall surface 25a of the plug 22 bears can be reduced. Thus, the angle θ in the case of two rows of rolling paths is 180
Less than 120 °, preferably generally 120 °, preferably 60 °, and more preferably 30 °.

When the rolling paths 20 are provided in three or more rows, the angle θ between the two insertion holes 21 which are most distant in the circumferential direction with respect to the center C is within 180 °, and all angles are within the range of the angle θ. It is sufficient that the insertion hole 21 exists. The angle θ is within 120 °, preferably within 60 °, and more preferably within 30 °.

However, when the direction of the radial load changes, the above setting is desirable. However, when the radial load is applied only from a fixed direction, the angle θ is set to 180 ° in consideration of the preload effect. It is optimal to set.

On the other hand, the moment load (bearing 1
When the axis of 0 is imagined, a load that tilts the axis obliquely. ) Is added, the insertion holes 21 may be shifted around the center C at equal intervals. When the rolling path 20 has two rows, as shown in FIG.
Are provided 180 degrees apart in the circumferential direction. The same applies to the case where three or more rows of rolling paths are provided.
When the four insertion holes 21 are provided, they are shifted by 90 °. Note that such a setting is desirable when the direction of the moment load changes. However, when the direction of the moment load does not change, the angle θ may be set to 180 °. Furthermore, even when three or more rows of rolling paths are provided, when a moment load acts from a fixed direction, it is desirable that the insertion holes 21 of each row be arranged 180 ° apart in each row.

In short, the following modes exist for the arrangement of the insertion holes 21. (1) A structure in which the rolling paths are two rows, and the insertion holes for each of the rolling paths are provided in a range of less than half a circumference in the circumferential direction of the bearing. (2) A structure in which the number of rolling paths is three or more, and the insertion holes for each of the rolling paths are provided in a range within half a circumference in the circumferential direction of the bearing. (3) When the rolling paths are two or more rows, and the insertion holes for each of the rolling paths are provided at equal intervals in the circumferential direction of the bearing. (4) The case where the rolling paths are two or more rows and the insertion holes for each of the rolling paths are provided by being shifted by 180 ° with respect to the circumferential direction of the bearing.

In the above embodiment, each of the rolling grooves 18, 19
Although the wall surfaces 18a and 19a of the rolling grooves 18 and 19a are the rolling surfaces on which the roller 13 rolls, the present invention is also applicable when the wall surfaces 18b and 19b of the rolling grooves 18 and 19 are the rolling surfaces. The rolling elements are not limited to the rollers 13, but may be balls. The roller is not limited to a cylindrical type, but may be a drum type. A plurality of rows of rolling paths exist between the inner and outer rings, and the line of action of the load of the rolling elements on at least one rolling path and the line of action of the loads of the rolling elements on the other rolling paths are closer to the inner circumference than the rolling paths. Alternatively, there is an advantage that the present invention is applied to a slewing bearing having a structure that intersects on the outer peripheral side. The insertion hole 21 is replaced with the inner race 12 instead of the outer race 11.
May be provided.

[0029]

As described above, according to the present invention, since the rolling elements are loaded into the rolling path from the insertion holes penetrating the outer ring or the inner ring in the radial direction, the outer ring and the inner ring are each formed as a so-called integrated type. To prevent the misalignment due to the coupling after the rolling element is assembled, and to guarantee the smooth movement of the rolling element. Since the insertion holes are individually provided for each rolling path, the wall surfaces of the rolling grooves of the outer ring or the inner ring are cut out by the respective insertion holes over the entire width in the axial direction of the bearing. Then, the rolling element can be easily inserted into the rolling groove ahead of it, and then, by simply rotating the outer ring and the inner ring relatively, an appropriate preload can be easily applied to the rolling element. Since the insertion hole is different for each rolling path, even when the insertion hole is closed with a plug, the load applied to the plug from the rolling element tilts in one direction with respect to the axial direction of the insertion hole, and Applies only the component force of the load. Therefore, the force for pushing out the plug is weaker than before, and the insertion hole can be easily closed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall configuration of a double-row slewing bearing to which the present invention is applied.

FIG. 2 is a sectional view along the axial direction of the double-row slewing bearing in FIG. 1;

FIG. 3 is an enlarged view of a main part of the sectional view of FIG. 2;

FIG. 4 is a perspective view showing an embedding plug used in the double-row slewing bearing of FIG. 1;

FIG. 5 is a view showing the arrangement of insertion holes for each rolling path in the double-row slewing bearing of FIG. 1;

FIG. 6 is a sectional view showing a conventional double-row slewing bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Double row slewing bearing 11 Outer ring 12 Inner ring 13 Roller (rolling element) 18 Outer ring rolling groove 18a, 18b Outer ring side rolling groove wall surface 19 Inner ring rolling groove 19a, 19b Inner ring rolling groove wall surface 20 Rolling path 21 Insertion hole 22 Plug 23 Pin hole 24 Pin 25 Recess of plug

Claims (5)

[Claims] 1. An outer ring having a plurality of rows of rolling grooves provided on an inner periphery thereof, and a plurality of rows of rolling grooves corresponding to the outer ring rolling grooves are provided on an inner periphery of the outer ring. The inner ring, and a double-row slewing bearing comprising a number of rolling elements loaded on the rolling path formed between the rolling grooves of the inner and outer rings, at least one of the outer ring or the inner ring,
A double-row slewing bearing, wherein an insertion hole which penetrates the outer ring or the inner ring in the radial direction and allows the rolling element to be inserted into the rolling path is provided individually for each rolling path. 2. The double-row slewing bearing according to claim 1, wherein an embedding plug having a concave portion functioning as a part of the rolling groove is provided at one end of the insertion hole. . 3. The double-row slewing bearing according to claim 1, wherein the insertion holes for each rolling path are shifted from each other in a circumferential direction. 4. The double-row slewing bearing according to claim 3, wherein the insertion hole for each rolling path is provided so as to be limited to a part of less than a half circumference in the circumferential direction of the bearing. . 5. The double-row slewing bearing according to claim 3, wherein the insertion holes for each of the rolling paths are provided at substantially equal intervals in the circumferential direction of the bearing.