JP7165385B2 - Composite bearing device - Google Patents

Description

The present invention relates to a composite bearing arrangement with improved load carrying capacity.

Ball bearings are widely used as bearing devices for rotating bodies. Ball bearings generally have a structure in which a plurality of balls (spheres) are provided between an inner surface member called an inner ring and an outer surface member called an outer ring. Therefore, rolling resistance is low and it can withstand high-speed rotation, making it suitable for bearings for high-speed shafts. On the other hand, the point contact of individual balls with the inner ring and the outer ring also has the negative side of a small contact area. That is, the load on the bearing must be small.

Various improvements have been made in consideration of such characteristics of ball bearings. For example, in the complete rolling type ball bearing of Patent Document 1, (a) two sets of spheres in the first row are placed in two grooves of the same type that are dug in parallel on the inner surface of the bearing, and three or more sets are arranged in the same manner. Place at intervals. (b) Between each pair of spheres and in the middle of the groove, another second row of spheres, which is half the number of spheres, is arranged so as not to touch the bearings. (c) Arrange a center shaft with a single groove dug on the outer surface so as to touch the second row of spheres. The configuration as described above is disclosed. The purpose of this technique is to control heat from bearing friction. In this technology, individual spheres contact other members at multiple points, so the load at each contact point can be distributed. There are difficulties in

In Patent Document 2, an inner ring having a through-hole axially penetrating through the center thereof, at least one pair of ball retaining rings covering the inner ring, and ball retaining rings respectively formed on opposite side surfaces of the two ball retaining rings. a surface, a ball assembly consisting of a plurality of balls sandwiched in the two ball retaining surfaces, and an outer ring provided on the outer surface of the two ball retaining rings for positioning the balls together with the two ball retaining rings. A ball bearing structure has been proposed in which the number of rows of balls can be increased or decreased. This technology aims to adjust the load resistance by increasing or decreasing the number of rows of balls between the inner ring and the outer ring. However, it is difficult to increase or decrease the number of rows of balls after they are actually installed in the device, and the thickness of the inner ring must be increased in order to increase the number of rows of balls, so the places where it can be used are limited. There is a problem that

Further, in Japanese Patent Laid-Open No. 2002-100003, a housing having a ball accommodating portion whose inner surface is formed on a ball guide surface, and having a plurality of openings, and a plurality of rotatably arranged along the guide surface of the housing. A small ball is accommodated in the ball accommodating portion of the housing in such a manner as to protrude from one of the openings, and is rotatably supported by the small ball so as to movably support a contacting moving body by its own rotation. A free ball, comprising: a large ball; and detection means disposed facing an open surface of the large ball exposed from the other opening in the housing and detecting a rotation state of the large ball. A bearing device is disclosed. This technology does not relate to an ordinary annular ball bearing device, but to a free ball bearing device in which a large number of ball bearings are arranged on a plate-like housing. In such a free ball bearing system, each ball bearing contacts the load object at one point on one side. In this technique, a plurality of small balls are arranged around each large ball, but this is not for the purpose of distributing the load, but for detecting the information of the large ball, that is, the rotation speed, rotation angle, rotation direction, etc. is.

JP-A-2000-337369 Japanese Patent Application Laid-Open No. 2001-165156 JP 2013-72544 A

In a general ball bearing device, the balls can only contact the inner ring and the outer ring at the same circumferential length. This is because when the balls come into contact with each other at points with different circumferences, the velocities at the points of contact are different, so the ball cannot rotate unless slippage occurs. Therefore, it does not function as a ball bearing device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a composite bearing assembly which can prevent slippage and improve load capacity by increasing the number of contact points with the main rolling bearing.

In order to solve the above-mentioned problems, the composite bearing device according to the present invention is a bearing device provided with a main rolling bearing train composed of a plurality of rolling bearings between an annular outer ring and an inner ring, wherein each of the rolling bearings contacting the outer ring and the inner ring at two points having the same circumference length, and providing bearing cushioning members between the main rolling bearing row and the outer ring and between the main rolling bearing row and the inner ring, respectively; is in contact with the outer ring and the inner ring and each of the bearing cushioning members, and auxiliary bearing mechanisms are provided between the main rolling bearing train and the outer ring and between the main rolling bearing train and the inner ring, respectively; Each is in contact with the main rolling bearing row via the bearing cushioning member .

Each of the main rolling bearing rows is preferably a sphere or a rotationally symmetrical body, more preferably an elliptical body or a part thereof in the case of a rotationally symmetrical body.

The auxiliary bearing mechanism is desirably a row of ball bearings, a row of needle bearings, or a row of sliding bearings, and the number of rows of the auxiliary bearing mechanism may be singular or plural.

In the composite bearing device according to the present invention, auxiliary bearing mechanisms are provided between the main rolling bearing train and the outer ring and between the main rolling bearing train and the inner ring, respectively. Heat generation can be suppressed by reducing the sliding friction caused by the difference in the number of bearings, and the load bearing performance can be improved by increasing the number of points of contact of each main rolling bearing.

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a composite bearing device according to the invention. In this embodiment, a row of ball bearings is provided as a plurality of main rolling bearings 30 between an annular inner ring 10 and an outer ring 20 . Furthermore, auxiliary bearing rows each comprising a plurality of auxiliary balls 40 and 50 are provided outside and inside the main rolling bearing row. Between the main rolling bearing 30 and the respective auxiliary balls 40, 50 are arranged auxiliary bearing damping members 42, 52, and between the respective auxiliary balls 40, 50 and the inner ring 10 and outer ring 20 are arranged auxiliary bearing support members. The members 41 and 51 are arranged. The auxiliary bearing cushioning members 42 and 52 are arranged with a gap with respect to the inner ring 10 and the outer ring 20 respectively, and are in contact only with the main rolling bearing 30 and the auxiliary balls 40 or 50 . With this configuration, the auxiliary balls 40 and 50 are rotatably held by the auxiliary bearing cushioning members 42 and 52 and the auxiliary bearing support members 41 and 51, respectively. Further, the auxiliary bearing cushioning members 42 and 52 are rotatably held. The auxiliary bearing support members 41, 51 are fixed to the inner ring 10 or the outer ring 20, respectively.

In this embodiment, the main rolling bearing 30 is in contact with the outer ring 20 at two points of equal circumference on the outside, and is connected to the auxiliary balls 50 via the auxiliary bearing damping member 52 . Further, the main rolling bearing 30 is in contact with the inner ring 10 at two points having the same circumferential length, and is connected to the auxiliary balls 40 via the auxiliary bearing cushioning member 42 .

In the above embodiment, the main rolling bearing 30 is in contact with the outer ring 20 at two points having the same circumferential length, so that it can rotate at a speed corresponding to the rotation of the outer ring 20 without slipping on the outer ring 20 . Further, since the main rolling bearing 30 is also in contact with the inner ring 10 at two points having the same circumferential length, it can rotate at a speed corresponding to the rotation of the inner ring 10 without slippage. Therefore, when the load is small, contact between the main rolling bearing 30 and the inner ring 10 and the outer ring 20 causes this embodiment to function as a ball bearing device.

On the other hand, the main rolling bearing 30 is connected to the auxiliary balls 50 via the auxiliary bearing damping member 52 . The auxiliary balls 50 are rotatably supported with respect to the main rolling bearing 30 via auxiliary bearing cushioning members 52 , and the auxiliary balls 50 are rotatably supported with respect to the outer ring 20 via auxiliary bearing support members 51 . there is Also, the auxiliary bearing cushioning member 52 is independent from the outer ring 20 by a gap. Therefore, both the auxiliary balls 50 and the auxiliary bearing cushioning member 52 rotate at a corresponding speed with respect to the outer ring 20 and the main rolling bearing 30 to support a constant load between the outer ring 20 and the main rolling bearing 30 .

Similarly, the main rolling bearing 30 is connected to the auxiliary balls 40 via the auxiliary bearing cushioning member 42 . The auxiliary balls 40 are rotatably supported with respect to the main rolling bearing 30 via auxiliary bearing cushioning members 42, and the auxiliary balls 40 are rotatably supported with respect to the inner ring 10 via auxiliary bearing support members 41. there is Also, the auxiliary bearing cushioning member 42 is independent from the inner ring 10 by a gap. Therefore, both the auxiliary balls 40 and the auxiliary bearing cushioning member 42 rotate at a corresponding speed with respect to the inner ring 10 and the main rolling bearing 30, supporting a constant load between the inner ring 10 and the main rolling bearing 30.

As a result, the load applied to the outer ring 20 and the inner ring 10 is supported not only through the direct contact points with the main rolling bearing 30, but also through the auxiliary balls 40 and 50, thereby distributing and reducing the load at each contact point. be. Therefore, the load resistance is improved.

FIG. 2 shows a second embodiment of a composite bearing device according to the invention. The difference from the first embodiment is the auxiliary bearings, in which the auxiliary balls 40, 50 arranged in the first embodiment are replaced with auxiliary needles 43, 53. FIG. Due to the change in the shape of the auxiliary bearings, it is necessary to change the shapes of the auxiliary bearing cushioning members 42, 52 and the auxiliary bearing support members 41, 51 as well. Although cylindrical auxiliary needles 43 and 53 are used in the embodiment of FIG. 2, it is also possible to use so-called drum-shaped needles with a larger central diameter.

FIG. 3 shows a third embodiment of a composite bearing device according to the invention. In this embodiment, the auxiliary balls and needles used in Embodiments 1 and 2 are omitted, and the sliding between the auxiliary bearing cushioning members 42, 52 and the auxiliary bearing support members 41, 51 is utilized. Although it is difficult to rotate as high as the first and second embodiments due to increased friction, the load can be sufficiently distributed at low rotation.

FIG. 4 shows a fourth embodiment of a composite bearing device according to the invention. What differs from the first embodiment is the main rolling bearing 30, which uses an elliptical body instead of a ball bearing. It is also possible to use a partial ellipsoid of revolution obtained by cutting the top and bottom horizontally instead of this ellipsoid of revolution.

FIG. 5 shows a fifth embodiment of a composite bearing device according to the invention. In this embodiment, the auxiliary balls of the first embodiment shown in FIG. 1 are vertically arranged in two stages. In FIG. 1, the main rolling bearing 30 is in contact with the inner ring 10 and the outer ring 20 at the upper and lower contact points, but in this embodiment, it is in contact at the central portion. Then, a set of auxiliary bearing cushioning members, auxiliary balls, and auxiliary bearing support members is placed above and below the contact portion with the outer ring 20 (52A, 50A, 51A; 52B, 50B, 51B) and above and below the contact portion with the inner ring 10 (42A). , 40A, 41A; 42B, 40B, 41B). The principle is almost the same as the first embodiment.

FIG. 6 shows a sixth embodiment of a composite bearing device according to the invention. In this embodiment, the auxiliary needles of the second embodiment shown in FIG. 2 are vertically arranged in two stages.

FIG. 7 shows a seventh embodiment of a composite bearing device according to the invention. In this embodiment, the set of the auxiliary bearing cushioning member and the auxiliary bearing support member of the third embodiment shown in FIG. 3 is arranged in two stages.

FIG. 8 shows an eighth embodiment of a composite bearing device according to the invention. In this embodiment, the set of the auxiliary bearing cushioning member and the auxiliary bearing support member of the fourth embodiment shown in FIG. 4 is arranged in two stages.

Although the preferred embodiments of the present invention have been described above based on the examples, it goes without saying that many modifications can be made without departing from the spirit of the present invention.

In the composite bearing device according to the present invention, auxiliary bearing mechanisms are provided between the main rolling bearing train and the outer ring and between the main rolling bearing train and the inner ring, respectively. It is possible to reduce heat generation by reducing sliding friction caused by the difference in the rolling bearings, and to increase the contact points of each of the main rolling bearings, thereby improving the load bearing performance.

1 shows a first embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. Figure 2 shows a second embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. 3 shows a third embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. 4 shows a fourth embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. 5 shows a fifth embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. 6 shows a sixth embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. Fig. 7 shows a seventh embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA. 8 shows an eighth embodiment of a composite bearing device according to the invention; (a) is a cross-sectional view, and (b) is a partial cross-sectional view taken along line AA.

10 Inner ring 20 Outer ring 30 Main rolling bearings 40, 40A, 40B Inner auxiliary balls 41, 41A, 41B Inner auxiliary bearing support members 42, 42A, 42B Inner auxiliary bearing cushioning members 43, 43A, 43B Inner auxiliary needles 50, 50A, 50B Outer Auxiliary balls 51, 51A, 51B Outer auxiliary bearing support members 52, 52A, 52B Outer auxiliary bearing cushioning members 53, 53A, 53B Outer auxiliary needle

Claims (7)

In a bearing device having a main rolling bearing train composed of a plurality of rolling bearings between an annular outer ring and an inner ring, each of the rolling bearings is in contact with the outer ring and the inner ring at two points having the same circumferential length. death,
A bearing cushioning member is provided between the main rolling bearing train and the outer ring and between the main rolling bearing row and the inner ring, and each of the rolling bearings is in contact with the outer ring and the inner ring and each of the bearing cushioning members,
Auxiliary bearing mechanisms are provided between the main rolling bearing train and the outer ring and between the main rolling bearing row and the inner ring, and each of the auxiliary bearing mechanisms is connected to the main rolling bearing mechanism via the bearing buffer member. A composite bearing device, characterized in that it is in contact with a row of rolling bearings. 2. A composite bearing arrangement according to claim 1, wherein each of said rolling bearings of said main rolling bearing row is spherical or rotationally symmetrical. 2. A composite bearing assembly according to claim 1 , wherein each of said rolling bearings of said main rolling bearing train is an elliptical body of revolution or a portion thereof. 4. A composite bearing device according to claim 1 , wherein said auxiliary bearing mechanism is a row of ball bearings. 4. A composite bearing device according to claim 1 , wherein said auxiliary bearing mechanism is a row of needle bearings. 4. A composite bearing device according to claim 1 , wherein said auxiliary bearing mechanism is a sliding bearing train. 7. The composite bearing device according to claim 1, wherein said auxiliary bearing mechanisms are arranged in two rows in the axial direction .

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