JP2007270988A - Rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device which has a clutch connecting and disconnecting a rotary shaft and a rotator and a rolling bearing with a long life disposed between the rotary shaft and the rotator. <P>SOLUTION: The bearing device is provided with tapered roller bearings 7, 8 arranged between a first inner circumference face 20 of a first clutch gear 2 and a clutch shaft 1, and outer rings 41, 42 of the tapered roller bearings 7, 8 are clearance fitted in the first inner circumference face 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rolling bearing device.

  Conventionally, as a power transmission device, there is one described in JP-A-11-267722 (Patent Document 1). The power transmission device includes a rotary shaft, a drive gear, an intermittent device that connects or disconnects the rotary shaft and the drive gear, and an inner peripheral surface of the drive gear and an outer peripheral surface of the rotary shaft. And an arranged bearing.

In the power transmission device, the rotating shaft and the drive gear are coupled by the interrupting device, thereby rotating the rotating shaft and the drive gear synchronously to transmit the power of the rotating shaft to the drive gear. The rotary shaft and the drive gear are separated by the interrupting device so that the power of the rotary shaft is not transmitted to the drive gear.
Japanese Patent Laid-Open No. 11-267722 (FIG. 2) Japanese Patent No. 2815243

  However, the present inventors have found that when a rolling bearing is used as a bearing in the apparatus having the above-described configuration, fretting corrosion occurs on the raceway surface of the outer ring or the inner ring, and the life of the rolling bearing is shortened. discovered. This is because in the apparatus having the above-described configuration, the rolling bearing rotates in the circumferential direction with the relative rotational speed between the outer ring and the inner ring being zero when the gear is connected, and the drive gear Since the load due to its own weight and transmission torque is applied, the rolling elements and the raceway surfaces of the inner and outer rings are located at substantially the same position, and the raceway surfaces of the inner and outer rings where the rolling elements are located. Oil film breakage is likely to occur in the portion, and is repeated between the raceway surface of the outer ring and the raceway surface of the outer ring and between the raceway surface of the rolling element and the inner ring at the substantially same position every rotation of the entire rolling bearing in the circumferential direction. The outer ring raceway surface and the rolling element, and the rolling element and the inner ring raceway surface repeatedly contact with each other with slight elastic deformation of the rolling element at approximately the same position and in the vicinity thereof. This is presumed to be due to wear.

  Accordingly, an object of the present invention is to provide a rolling bearing device having an interrupting device for connecting or disconnecting the rotating shaft and the rotating body, and a rolling bearing having a long life arranged between the rotating shaft and the rotating body. There is.

In order to solve the above problems, the rolling bearing device of the present invention is
A rotation axis;
An annular rotating body located radially outward of the rotating shaft;
A rolling bearing having an inner ring fixed to the outer peripheral surface of the rotating shaft, an outer ring fitted to the inner peripheral surface of the rotating body, and a rolling element disposed between the outer ring and the inner ring;
By connecting the rotating shaft and the rotating body, the rotating shaft and the rotating body are synchronously rotated to transmit the power of the rotating shaft to the rotating body, while the rotating shaft and the rotating body are connected to each other. And an intermittent device that prevents the power of the rotating shaft from being transmitted to the rotating body by being separated.

  According to the present invention, since the outer ring is clearance-fitted to the inner peripheral surface of the rotating body, the rotating shaft and the rotating body are connected, and the rotating shaft and the rotating body rotate synchronously. In the state, the outer ring revolves at a very small angular velocity with respect to the rotating body. Therefore, the rolling element moves relative to the inner and outer raceway surfaces, particularly the outer raceway surface, due to the revolution of the outer ring with respect to the rotating body. And the rotating body are not connected to each other at the same position on the raceway surface of the inner and outer rings, and a repetitive load around the same position of the inner and outer rings is not applied. Accordingly, since fretting corrosion does not occur on the raceway surfaces of the outer ring and the inner ring, the life of the rolling bearing can be significantly increased, and the life of the rolling bearing device is significantly increased as compared with the prior art.

  In the rolling bearing device according to one embodiment, the rotating body is connected to the first inner peripheral surface and the first inner peripheral surface via a step portion, and the inner diameter is smaller than that of the first inner peripheral surface. And at least a part of one end surface in the axial direction of the outer ring is in contact with the step portion of the rotating body, and the end surface of the outer ring has a diameter of the rotating shaft. A groove extending substantially in the direction is formed.

  According to the embodiment, since at least a part of the end surface of the outer ring is in contact with the stepped portion of the rotating body, the outer ring is also fitted with a clearance with respect to the inner peripheral surface of the rotating body. Regardless, it is possible to prevent the outer ring from moving toward the stepped portion in the axial direction. Therefore, since the arrangement position of the rolling bearing in the axial direction does not move, the rotating shaft can be stably and rotatably supported with respect to the rotating body.

  Further, according to the above embodiment, since the groove extending in the radial direction is formed on the end face of the outer ring, the lubricant can be smoothly introduced into the groove by centrifugal force. Therefore, even if the outer ring rotates with respect to the rotating body and the end face slides on the stepped portion, seizure can be prevented from occurring on the end surface and the stepped portion.

  According to the rolling bearing device of the present invention, since the outer ring is clearance-fitted to the inner peripheral surface of the rotating body, the rotating shaft and the rotating body are connected, and the rotating shaft and the rotating body are synchronized. In the rotating state, the outer ring revolves at a very low angular velocity relative to the rotating body, so that the rolling element does not exist at the same position on the raceway surface of the inner and outer rings. The moving body does not repeatedly load around the same position of the inner and outer rings. Therefore, it is possible to suppress the occurrence of fretting corrosion on the raceway surfaces of the outer ring and the inner ring, so that the life of the rolling bearing can be significantly increased, and the life of the rolling bearing device is significantly increased compared to the conventional one. be able to.

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

  FIG. 1 is a sectional view in the axial direction of a speed increasing device of a rolling mill according to an embodiment of the rolling bearing device of the present invention. The speed increaser of this rolling mill increases the rotation of the drive motor and transmits it to the rolling roll.

  The speed increaser is disposed on a clutch shaft 1 as an example of a rotating shaft, a first clutch gear 2 as an example of a rotating body, a second clutch gear 3 as an example of a rotating body, and the clutch shaft 1. And an annular clutch coupling 5 disposed outside the clutch 4 in the radial direction (the radial direction of the clutch shaft 1). The clutch 4 and the clutch coupling 5 constitute an interrupting device. The speed increaser includes a first tapered roller bearing 7 as an example of a rolling bearing disposed between the clutch shaft 1 and the first clutch gear 2 and a second tapered roller bearing 8 as an example of a rolling bearing. A third tapered roller bearing 9 as an example of a rolling bearing disposed between the clutch shaft 1 and the second clutch gear 3 and a fourth tapered roller bearing 10 as an example of a rolling bearing are provided.

  The first clutch gear 2 is an annular member and is disposed radially outward of the clutch shaft 1, and the second clutch gear 3 is an annular member and radially outward of the clutch shaft 1. Has been placed. The clutch 4 is an annular member, and is fitted on the outer peripheral surface of the clutch shaft 1 and fixed. The first clutch gear 2 and the second clutch gear 3 are opposed to each other in the axial direction with the clutch 4 interposed therebetween. The first clutch gear 2 has an annular meshing portion 12 that extends from the end face of the first clutch gear 2 on the clutch 4 side in a substantially normal direction of the end face, and the second clutch gear 3 is a second clutch gear. It has an annular meshing portion 13 that extends from the end face of the gear 3 on the clutch 4 side in a direction substantially normal to the end face. The first clutch gear 2 is connected to the first inner peripheral surface 20 and the first inner peripheral surface 20 via a step portion 21 and has a second inner peripheral surface 22 having an inner diameter smaller than that of the first inner peripheral surface 20. And have. Similarly, the second clutch gear 3 is connected to the first inner peripheral surface 25 and the first inner peripheral surface 25 via a step portion 26, and the second inner peripheral surface has a smaller inner diameter than the first inner peripheral surface 25. Surface 27.

  A spline extending in the axial direction is formed on the outer peripheral surface of the clutch 4, and a spline that engages with the spline of the clutch 4 is formed on the inner peripheral surface of the clutch coupling 5. Further, splines that are spline-fitted with the splines of the clutch coupling 5 are formed on the outer peripheral surfaces of the meshing portions 12 and 13. The clutch coupling 5 is movable in the axial direction indicated by an arrow A in FIG.

  As shown in FIG. 1, when the clutch coupling 5 moves to the left in FIG. 1, the rotational power of the clutch shaft 1 is transmitted through the clutch 4, the clutch coupling 5, and the meshing portion 12 to the first clutch gear. 2 is transmitted. On the other hand, when the clutch coupling 5 moves rightward in FIG. 1, the rotational power of the clutch shaft 1 is transmitted to the second clutch gear 3 via the clutch 4, the clutch coupling 5, and the meshing portion 13. It has become. When the rotational power of the clutch shaft 1 is transmitted to the first clutch gear 2, the rotational power of the clutch shaft 1 is not transmitted to the second clutch gear 3. Further, when the rotational power of the clutch shaft 1 is transmitted to the second clutch gear 3, the rotational power of the clutch shaft 1 is not transmitted to the first clutch gear 2. The clutch coupling 5 can be engaged with and disengaged from the meshing portion 12 of the first clutch gear 2 and the meshing portion 13 of the second clutch gear 3.

  Each of the first to fourth tapered roller bearings 7, 8, 9, 10 includes an outer ring, an inner ring, and tapered rollers disposed at a predetermined interval in the circumferential direction between the outer ring and the inner ring. The inner ring of each tapered roller bearing has flanges at both ends in the axial direction of its outer peripheral surface, and the tapered rollers are restrained in the axial direction by these two flanges. Each member of each tapered roller bearing 7, 8, 9, 10 is made of bearing steel. Further, the contact portions between the inner and outer rings of the tapered roller bearings 7, 8, 9, 10 and the tapered rollers are lubricated with a lubricant such as oil. Large end surfaces (end surfaces having a larger area) of the outer rings of the first and second tapered roller bearings 7 and 8 are in contact with the step portion 21 of the first clutch gear 2. Further, the large end surfaces (end surfaces having a larger area) of the outer rings of the third and fourth tapered roller bearings 9 and 10 are in contact with the step portion 26 of the second clutch gear 3. The first tapered roller bearing 7 and the second tapered roller bearing 8 are spaced apart in the axial direction so that the small end faces of the tapered rollers are opposed to each other. The tapered roller bearings 10 are arranged at intervals in the axial direction so that the small end surfaces of the tapered rollers face each other.

  The first tapered roller bearing 7 and the second tapered roller bearing 8 are engaged when the clutch of the first clutch gear 2 is engaged, that is, the meshing portion of the clutch coupling 5 and the meshing portion 12 of the first clutch gear 2 ( In the state where the clutch shaft 1, the clutch 4, the clutch coupling 5, and the first clutch gear 2 are rotating synchronously, the transmission of the gear is performed with the relative rotational speeds of the inner and outer rings being zero. It rotates while receiving a load due to torque. On the other hand, when the clutch is released, that is, when the clutch shaft 1 and the first clutch gear 2 are not engaged with each other, the first and second tapered roller bearings 7 and 8 are connected to each other. High-speed relative rotation is performed without any load due to the transmission torque.

  The third tapered roller bearing 9 and the fourth tapered roller bearing 10 are engaged when the clutch of the second clutch gear 3 is engaged, that is, the meshing portion 13 of the clutch coupling 5 and the meshing portion 13 of the second clutch gear 3 mesh. When the clutch shaft 1, the clutch 4, the clutch coupling 5, and the second clutch gear 3 are rotating synchronously, the load due to the transmission torque of the gear is applied when the relative rotational speed of each inner and outer ring is zero. It is designed to rotate while receiving. On the other hand, the third tapered roller bearing 9 and the fourth tapered roller bearing 10 are not connected to each other when the clutch is released, that is, when the clutch shaft 1 and the second clutch gear 3 are not engaged (see FIG. 1). The wheels are designed to rotate at a high speed without any load due to the transmission torque of the gear.

  The outer rings of the first and second tapered roller bearings 7 and 8 are fitted into the first inner peripheral surface 20 of the first clutch gear 2 with a gap, and the outer rings of the third and fourth tapered roller bearings 9 and 10 are fitted. Is fitted into the first inner peripheral surface 25 of the second clutch gear 3. The fitting clearance between the outer rings of the first and second tapered roller bearings 7 and 8 and the first inner peripheral surface 20 of the first clutch gear 2 is several tens of microns, and the third and fourth tapered roller bearings 9 and 9 The fitting clearance between each outer ring 10 and the first inner peripheral surface 25 of the second clutch gear 3 is several tens of microns.

  By setting the fitting clearance between the outer rings of the first and second tapered roller bearings 7 and 8 and the first clutch gear 2 to several tens of microns, The outer rings of the first and second tapered roller bearings 7 and 8 rotate with a delay of about (several tens of microns) × π with respect to the first clutch gear 2. Further, by setting the fitting clearance between the outer rings of the third and fourth tapered roller bearings 9 and 10 and the second clutch gear 3 to several tens of microns, the revolution of the second clutch gear 3 with respect to one revolution. Thus, the outer rings of the third and fourth tapered roller bearings 9 and 10 rotate with a delay of about (several tens of microns) × π with respect to the second clutch gear 3.

  FIG. 2 is a detailed axial sectional view of the periphery of the first clutch gear, showing the fitting gap (exaggeratedly drawn). FIG. 3 is a cross-sectional view taken along the line BB of FIG. 2 and shows a radial load direction and a fitting gap (exaggeratedly drawn). 2 and 3, the direction indicated by the arrow A indicates the radial load direction.

  As shown in FIGS. 2 and 3, the first clutch gear 2 and the outer ring are caused by the outer rings 41 and 42 of the tapered roller bearings 7 and 8 being fitted into the inner periphery of the first clutch gear 2. A gap d is formed between 41 and 42 on the side opposite to the direction in which the radial load is applied. Also, as shown in FIG. 3, a plurality of grooves 60 extending in the radial direction are formed at substantially equal intervals in the circumferential direction on the large end surface of the outer ring 42 that is in contact with the stepped portion.

  The present inventor conducted a durability test on the speed increaser of the rolling mill having the above configuration. As described above, when the outer ring of the tapered roller bearing is fitted into the clutch gear with a gap, the outer ring of the tapered roller bearing is placed on the raceway surface of the outer ring as compared with the case where the outer ring of the tapered roller bearing is fitted into the clutch gear. It was confirmed that the time required for fretting corrosion can be greatly increased. In addition, it was confirmed that the time required for fretting corrosion to be formed on the raceway surface of the inner ring can be increased as compared with the case of intermediate fitting or interference fitting.

  According to the speed increaser of the above embodiment, since the outer rings 41 and 42 of the tapered roller bearings 7 and 8 are loosely fitted to the inner peripheral surface of the first clutch gear 2, the clutch shaft 1 and the first clutch In the state where the gear 2 is connected and the clutch shaft 1 and the first clutch gear 2 are rotating synchronously, the outer rings 41 and 42 of the tapered roller bearings 7 and 8 have a very small angular velocity with respect to the first clutch gear. Will revolve around. Therefore, the tapered rollers of the tapered roller bearings 7 and 8 are caused by the revolution of the outer rings 41 and 42 of the tapered roller bearings 7 and 8 with respect to the first clutch gear 2, and particularly the raceway surfaces of the inner and outer rings, particularly the outer rings. 41 and 42, the tapered rollers of the tapered roller bearings 7 and 8 can move relative to the inner and outer rings when the first clutch gear 2 rotates synchronously with the clutch shaft 1. Are not present at the same position on the raceway surface, and a repetitive load around the same position of each inner and outer ring is not applied. Therefore, since the fretting corrosion does not occur on the outer races 41 and 42 of the tapered roller bearings 7 and 8 and the raceway surfaces of the inner races, the service life of the tapered roller bearings 7 and 8 can be significantly increased. The life of the speed increaser is remarkably longer than before (this is also true for the tapered roller bearings 9 and 10).

  Further, according to the speed increaser of the above embodiment, the large end surfaces of the outer rings 41 and 42 of the tapered roller bearings 7 and 8 are in contact with the stepped portion 21 of the first clutch gear 2. The outer rings 41, 42 of the tapered roller bearings 7, 8 move toward the axial step portion even though the outer rings 41, 8 of the, 8 are fitted with clearances with respect to the first inner peripheral surface 20. Can be prevented. That is, since the large end surfaces of the outer rings 41, 42 of the tapered roller bearings 7, 8 are in contact with the stepped portion 21 of the first clutch gear 2, the outer rings 41, 42 of the tapered roller bearings 7, 8 are Even when the rotation relative to the clutch gear 2 is applied, pressure is applied to the large end surfaces of the inner rings of the tapered roller bearings 7 and 8 to give a predetermined initial preload to the tapered roller bearing 7. , 8 can be prevented from moving in the axial direction. Therefore, the tapered roller bearings 7 and 8 can support the clutch shaft 1 with respect to the first clutch gear 2 in a stable and rotatable manner (this applies to the tapered roller bearings 9 and 10 as well. Established).

  Moreover, according to the speed increaser of the said embodiment, since the groove | channel 60 extended in radial direction is formed in the large end surface which is contact | abutting to the step part 21 in the outer ring | wheel 42 of the tapered roller bearing 8, lubricant. Can be smoothly introduced into the groove 60 by centrifugal force. Therefore, even if the outer ring 42 rotates with respect to the first clutch gear 2 and the large end surface of the outer ring 42 slides in the circumferential direction with respect to the step portion 21, the outer ring 42 is seized on the large end surface and the step portion 21. Can be prevented.

  In the rolling bearing device of the above embodiment, the tapered roller bearing is disposed between the clutch gear 2 as the rotating body and the clutch shaft 1 as the rotating shaft. However, in the present invention, the rotating body and the rotating shaft are arranged. Between them, a rolling bearing other than the tapered roller bearing such as a ball bearing or a cylindrical roller bearing may be disposed.

  In the rolling bearing device of the above embodiment, each member of the tapered roller bearing is a bearing steel. However, in the present invention, the invention is not limited to the bearing steel. For example, case hardened steel or high-speed tool steel is used. It may be used.

It is sectional drawing of the axial direction of the speed up gear of the rolling mill of one Embodiment of the rolling bearing apparatus of this invention. FIG. 3 is a detailed axial sectional view around the first clutch gear of the speed increaser. FIG. 3 is a sectional view taken along line AA in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Clutch shaft 2 1st clutch gear 3 2nd clutch gear 4 Clutch 5 Clutch coupling 7 1st tapered roller bearing 8 2nd tapered roller bearing 9 3rd tapered roller bearing 10 4th tapered roller bearing 12,13 Mating part 20, 25 First cylindrical surface 21, 26 Stepped portion 22, 27 Second cylindrical portion 60 Groove d Clearance

Claims (2)

A rotation axis;
An annular rotating body located radially outward of the rotating shaft;
A rolling bearing having an inner ring fixed to the outer peripheral surface of the rotating shaft, an outer ring fitted to the inner peripheral surface of the rotating body, and a rolling element disposed between the outer ring and the inner ring;
By connecting the rotating shaft and the rotating body, the rotating shaft and the rotating body are synchronously rotated to transmit the power of the rotating shaft to the rotating body, while the rotating shaft and the rotating body are connected to each other. A rolling bearing device comprising: an intermittent device that prevents the power of the rotating shaft from being transmitted to the rotating body by being separated. The rolling bearing device according to claim 1,
The rotating body has a first inner peripheral surface and a second inner peripheral surface that is continuous with the first inner peripheral surface via a step portion and has an inner diameter smaller than that of the first inner peripheral surface.
At least a part of one end surface in the axial direction of the outer ring is in contact with the stepped portion of the rotating body,
A rolling bearing device, wherein a groove extending substantially in a radial direction of the rotating shaft is formed on the end face of the outer ring.

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