JP5929543B2 - Rolling bearings and spindles for machine tools - Google Patents

Description

  The present invention relates to a rolling bearing and a main spindle device for machine tools, and more particularly to a main spindle device for machine tools that rotates at high speed, a rolling bearing used for a high-speed motor, and a main spindle device for machine tools using the same.

  In recent spindles of machine tools, the speed has increased due to high-efficiency machining, and the conventional gear drive and belt drive have poor transmission efficiency such as friction at the tooth meshing part and heat generated by belt slip. A drive motor direct connection type using a ring or a so-called motor built-in type in which a motor is mounted inside the main shaft dominates. In the case of these high-speed main shafts, the dmn value of the bearing used for the main shaft is almost 500,000 or more. Also, there are cases in which the dmn value exceeds 1 million or more in a bearing in which a lightweight ceramic material (for example, silicon nitride) having a small specific gravity is used for the rolling element of the bearing to suppress the centrifugal force of the rolling element during high-speed rotation. is there.

  In a cage used for such a bearing for high-speed rotation applications, as a lightweight and wear-resistant synthetic resin material cage, for example, phenol, polyamide, polyphenylene sulfide (abbreviation: PPS), polyether ether ketone ( Abbreviation: PEEK), polyimide, and the like are used, and glass fiber, carbon fiber, aramid fiber, or the like may be added as a reinforcing material.

  The cage places the rolling elements at equal intervals in the circumferential direction by pockets formed at equal intervals in the circumferential direction. As a matter of course, in order to smoothly rotate the rolling element within the pocket, it is necessary to provide an appropriate clearance (pocket clearance) between the pocket inner surface and the rolling element. The cage also has a clearance in the radial direction of the bearing between the inner and outer rings, and the radial movement of the cage is between the outer ring inner peripheral surface and the cage outer peripheral surface, or between the inner ring outer peripheral surface and the cage inner Regulated by the smaller clearance (guide clearance) between the peripheral surfaces.

  In a rolling bearing incorporating such a cage, noise or vibration called cage noise may occur. As rolling bearings that suppress the generation of cage noise and the like, for example, rolling bearings disclosed in Patent Documents 1 to 3 are known.

JP 2004-19921 A Japanese Patent Laid-Open No. 11-344035 Japanese Patent Laid-Open No. 2000-81042

  However, the rolling bearings of Patent Documents 1 to 3 have room for improvement in terms of suppressing the generation of cage noise.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a rolling bearing and a machine tool spindle device capable of suppressing cage noise.

The above object of the present invention can be achieved by the following constitution.
(1) An outer ring, an inner ring, a plurality of rollers that are rotatably arranged between the outer ring and the inner ring, and a plurality of rollers that are formed at predetermined intervals in the circumferential direction and hold the plurality of rollers, respectively. A rolling bearing having a pocket and a guide method of the cage being an outer ring guide or an inner ring guide,
The cage has cage guide surfaces on one side and the other side in the axial direction of the rollers, respectively.
When the width of each cage guide surface on one side is ΔL1, the width of the cage guide surface on the other side is ΔL2, and the axial pocket clearance is ΔP, the following equations (I) and (II) are satisfied. Characteristic rolling bearing.
ΔP ≦ ΔL1 ≦ 4 × ΔP (I)
ΔP ≦ ΔL2 ≦ 4 × ΔP (II)
(2) An outer ring, an inner ring, a plurality of rollers that are rotatably arranged between the outer ring and the inner ring, and a plurality of rollers that are formed at predetermined intervals in the circumferential direction and hold the plurality of rollers, respectively. A rolling bearing having a pocket and a guide method of the cage being an outer ring guide or an inner ring guide,
The retainer has a retainer guide surface on one of the axial direction one side and the other side of the roller,
A rolling bearing characterized by satisfying the following formula (III) where ΔL is the width of the cage guide surface and ΔP is the axial pocket clearance.
ΔP ≦ ΔL ≦ 4 × ΔP (III)
(3) Used in grease lubrication,
The cage is provided with a grease reservoir between the roller and the cage guide surface,
The rolling bearing according to (1) or (2), wherein a width of the grease reservoir is equal to or greater than a width of the cage guide surface.
(4) In the cage, the cage guide surface is provided on the inner side in the axial direction from the guide surface end of the guide wheel,
The rolling bearing according to any one of (1) to (3), wherein a distance from the cage guide surface to a guide surface end of the guide wheel is equal to or greater than a width of the cage guide surface.
(5) Any one of (1) to (4), wherein a radial pocket clearance between the roller and the cage is not less than twice the guide clearance and not more than a chamfer length of the guide wheel. Rolling bearings as described in
(6) The cage includes a pair of ring portions arranged side by side in the axial direction and a plurality of column portions arranged at predetermined intervals in the circumferential direction so as to connect the ring portions. And
The column part has a claw part protruding to the roller side at an axially intermediate part on both sides in the circumferential direction,
The radial pocket clearance is a distance between an intersection of the roller and a line drawn in parallel with a line connecting the rotation axis of the cage and the rotation axis of the roller from the inner surface of the claw portion. The rolling bearing according to (5), which is characterized.
(7) The roller includes a crowning portion formed by gradually reducing the diameter over the entire circumference toward both ends in the axial direction, and a roller straight line formed by continuing the crowning portion with a constant diameter. And
In the pocket, a pocket straight portion having a straight shape is formed in a portion facing the roller straight portion,
The length of the said pocket straight part is below the length of the said roller straight part, The rolling bearing in any one of (1)-(6) characterized by the above-mentioned.
(8) The rolling bearing according to (7), wherein a length of the pocket straight portion is less than a length obtained by subtracting the axial pocket clearance from a length of the roller straight portion.
(9) A machine tool spindle device comprising the rolling bearing according to any one of (1) to (8).

  According to the rolling bearing described in the above (1) and (2), the area where the cage guide surface and the guide wheel slide is reduced by narrowing the width of the cage guide surface. The friction between the wheels is reduced, and the generation of cage noise can be suppressed. Further, the grease can easily enter the cage guide surface, the cage noise can be suppressed, and the life of the bearing can be extended by improving the lubrication characteristics.

  According to the rolling bearing described in (3) above, by providing a grease reservoir near the roller, it is possible to extend the life of the bearing by further improving the lubrication characteristics.

  According to the rolling bearing described in (4) above, there is a concern that the cage guide surface may protrude from the guide surface end of the guide wheel due to inaccuracy or a difference in axial thermal expansion between the rotating wheel and the fixed wheel. Even if it is a case, the tolerance | permissible_quantity with respect to the shift | offset | difference of an axial direction can be ensured, and it is suppressed that a cage guide surface protrudes from the guide surface edge part of a guide wheel.

According to the rolling bearing described in (5) above, since the radial pocket clearance between the roller and the cage is more than twice the guide clearance, the cage is whirled during high-speed rotation with a force according to the rotational speed. Even if the outer ring is pressed and deformed, the radial pocket clearance is kept sufficiently large, so that the generation of cage noise can be suppressed. In the present specification, the term “hoir” means that the cage is deformed into an ellipse due to the influence of the variation of the cage density, etc., around the rotating shaft and centrifugal force.
Further, since friction between the cages does not increase, seizure can be prevented by abnormal temperature rise.
Furthermore, since the radial pocket clearance is less than the chamfered length of the guide wheel, the roller will interfere with the end of the outer ring when inserting the assembly with the inner ring, cage, and roller into the outer ring from the axial direction. Can be suppressed, and deterioration of incorporation can be suppressed.

  According to the rolling bearing described in (6) above, it is possible to reliably prevent the rollers from falling off by the claw portion while suppressing the generation of the cage sound.

  According to the rolling bearing described in (7) above, since the length of the pocket straight portion is equal to or less than the length of the roller straight portion, the roller straight portion end and the cage straight portion are in sliding contact when the cage is tilted. This can be suppressed, and the cage sound can be suppressed.

  According to the rolling bearing described in (8) above, since the cage can move in the axial direction by the axial pocket clearance, the length of the pocket straight portion of the cage is changed from the length of the roller straight portion to the shaft. By making the length less than the length obtained by subtracting the direction pocket clearance, the cage noise can be suppressed even when the cage moves by the axial pocket clearance.

  According to the spindle device for machine tools described in the above (9), the cage noise can be suppressed even when the machine tool is rotated at a high speed.

It is sectional drawing of the rolling bearing of one Embodiment of this invention. It is a perspective view of the holder | retainer of FIG. It is a top view which shows a part of rolling bearing of FIG. It is CC sectional view taken on the line of FIG. (A) is a top view of a roller, (b) is a top view of a holder | retainer. It is sectional drawing of the rolling bearing explaining the movement and deformation | transformation of a holder | retainer. (A) It is a figure explaining the grease pool in the rolling bearing of FIG. 1, (b) It is a figure explaining the grease pool in the rolling bearing of a comparative example. (A) It is a figure explaining the sliding allowance in the rolling bearing of FIG. 1, (b) It is a figure explaining the sliding allowance in the rolling bearing of a comparative example. It is sectional drawing of the rolling bearing which concerns on a modification. It is a top view which shows a part of rolling bearing of FIG. It is a top view which shows a part of rolling bearing of the comparative example in the state where the holder | retainer inclined.

  Hereinafter, a rolling bearing according to an embodiment of the present invention will be described in detail with reference to the drawings. 1 is a sectional view of a rolling bearing according to an embodiment of the present invention, FIG. 2 is a perspective view of the cage of FIG. 1, FIG. 3 is a plan view showing a part of the rolling bearing of FIG. 1, and FIG. FIG. 5A is a plan view of the roller, and FIG. 5B is a plan view of the cage.

  As shown in FIG. 1, a rolling bearing 1 according to an embodiment of the present invention includes an outer ring 2 having an outer ring raceway surface 2a on an inner peripheral surface, an inner ring 3 having an inner ring raceway surface 3a on an outer peripheral surface, and an outer ring raceway surface. 2a and a plurality of rollers (rolling elements) 4 that are movably arranged between the inner ring raceway surface 3a and a plurality of pockets 11 that are formed at predetermined intervals in the circumferential direction and hold the plurality of rollers 4 respectively. The cage 10 is used for grease lubrication.

  As shown in FIG. 5 (a), the roller 4 includes crowning portions 5 and 5 that are gradually reduced in diameter over the entire circumference toward both ends in the direction of the rotation axis Q, and the crowning thereof. The roller linear part 6 which consists of the parts 5 and 5 with a fixed diameter dimension is comprised. The lengths of the crowning portions 5 and 5 and the roller straight portion 6 and the inclination angle between the crowning portions 5 and 5 and the straight portion 6 may be arbitrarily set according to the use conditions and purpose of use. There is no particular limitation here.

  As shown in FIGS. 2 to 4, the cage 10 is disposed at a predetermined interval in the circumferential direction so as to connect the pair of ring portions 12 arranged in the axial direction and the ring portions 12. The pocket 11 is composed of a plurality of pillar portions 13 and the pillar portions 13 adjacent to the pair of ring portions 12.

  As shown in FIG. 5B, pocket linear portions 15 having a linear shape are formed in the axial intermediate portions on both sides in the circumferential direction of the column portion 13. The pocket straight portion 15 is formed so as to be parallel to the rotation axis R of the cage 10 and constitutes a circumferential side wall portion 16. Therefore, in a state where the cage 10 is not inclined, the rotation axis R of the cage 10 and the rotation axis Q of the four coincide with each other in a plan view, so that the pocket straight portion 15 (circumferential side wall portion 16) and the straight portion 6 are Parallel (see FIG. 3). The circumferential side wall portion 16 faces the roller straight portion 6 which is a rolling surface of the roller 4 and functions as a rolling element holding surface.

  Further, at the axially intermediate portions on both sides in the circumferential direction of the column portion 13, there are claw portions 14 that slightly protrude from the circumferential side wall portion 16 of the column portion 13 toward the roller 4 side and securely hold the cylindrical roller 4. The column portion 13 is provided so as to protrude from the outer surface in the radial direction.

  As shown in FIG. 4, the circumferential side wall portion 16 forms a flat surface when viewed from the direction of the rotation axis, and is a line drawn parallel to a line segment X connecting the rotation axis R and the rotation axis Q from the inner surface of the claw portion 14. A radial pocket clearance ΔD is provided between the intersection Z with the Y place 4 and the inner surface of the claw portion 14 of the cage 10 (see FIG. 4). In the axial direction, an axial pocket clearance ΔP (ΔP / 2 on both sides in the circumferential direction of the roller 4) is provided between the roller 4 and the pocket 11 (see FIG. 3).

  Further, grease reservoirs 17 are provided at both ends in the axial direction on both sides in the circumferential direction of the column portion 13 so as to be recessed from the circumferential side wall portion 16.

  An annular projection 18 having a larger diameter than the outer surface in the radial direction of the column portion 13 is formed in the axial direction intermediate portion of the ring portion 12 in the circumferential direction. The outer circumferential surface 18a of the annular projection 18 is a cage. It functions as a guide surface. That is, the cage 10 is an outer ring guide system in which the outer peripheral surface 18a of the annular protrusion 18 is guided by the outer ring raceway surface 2a.

Here, the outer peripheral surface 18a of the annular protrusion 18 has a width (axial length) of the outer peripheral surface 18a on one side as ΔL1, and a width (axial length) of the outer peripheral surface 18a on the other side as ΔL2. To satisfy the expressions (I) and (II).
ΔP ≦ ΔL1 ≦ 4 × ΔP (I)
ΔP ≦ ΔL2 ≦ 4 × ΔP (II)
The widths ΔL1 and ΔL2 of the outer peripheral surface 18a mean actual widths taking into account fluctuations such as deflection, and can have the relationship of ΔL1 <ΔL2, ΔL1 = ΔL2, and ΔL1> ΔL2. However, it is set so as to satisfy the expressions (I) and (II).

  The annular protrusion 18 does not necessarily need to be formed at the axially intermediate portion of the ring portion 12 as long as the above formulas (I) and (II) are satisfied. However, the outer peripheral surface 18a of the annular protrusion 18 is the ring portion 12. By forming it at a position away from both end portions, preferably at an intermediate portion in the axial direction, the effects described below can be obtained.

Fig.7 (a) is sectional drawing of the rolling bearing of this embodiment, (b) It is sectional drawing of the rolling bearing of a comparative example.
In the rolling bearing 100 of the comparative example, the retainer 110 is an outer ring guide system in which the outer peripheral surface 12a of the ring portion 12 is guided by the outer ring raceway surface 2a, and as shown in FIG. The outer peripheral surface 12a of both ring portions 12 having a larger diameter than the radially outer surface functions as a cage guide surface. The widths ΔL1 and ΔL2 of the outer peripheral surface 12a are ΔL1> 4 × ΔP and ΔL2> 4 × ΔP, and have the same configuration as the rolling bearing 1 of the present embodiment except for the widths ΔL1 and ΔL2 of the outer peripheral surface 12a. ing.

  According to the conventional rolling bearing 100, since the cage guide surface (outer peripheral surface 12a) is wide and has a large area in sliding contact with the outer ring raceway surface 2a, the cage guide surface (outer peripheral surface 12a) and the outer ring raceway surface 2a The friction was large and the cage sound was loud.

  Further, since the cage guide surfaces (outer peripheral surface 12a) are immediately on both sides of the roller 4, when the bearing rotates, a grease reservoir 19a is formed outside the cage 110, but the cage guide surface (outer peripheral surface 12a) is wide. And the base oil are difficult to enter between the cage guide surface (outer circumferential surface 12a) and the outer ring raceway surface 2a, and the friction of the cage 110 increases. Further, due to the increase in friction of the cage 110, there is a problem that cage noise is likely to be generated and the bearing life is reduced.

  Further, when the bearing rotates, a grease reservoir 19a is formed on the outside of the cage 110, and it is difficult for the grease to accumulate in the vicinity (on both sides) of the roller 4, so that the base oil is difficult to reach the roller 4 and the oil film is easily cut off. There was a problem that the bearing life was slightly reduced.

  Further, assuming that the conventional rolling bearing 100 is incorporated in the main spindle for machine tools, the main spindle for machine tools is mainly the case of rotating the inner ring, and the temperature distribution of the spindle is the rotation side member (inner ring side) temperature. > Stop side member (outer ring side) temperature. Further, in the case of a so-called motor built-in main shaft in which a motor is provided between the main shaft front side bearing (fixed side) and the rear side bearing (free side), the influence of heat generation of the motor is added. As a result, in the conventional outer ring guide cage 110, the inner ring side expands and moves rearward of the main shaft with respect to the outer ring 2 in the main bearing portion serving as a free side bearing, and the cage guide surface (outer peripheral surface 12a) is the outer ring raceway surface 2a. There is a risk of overhanging.

  On the other hand, according to the rolling bearing 1 of the present embodiment, as shown in FIG. 7A, the cage guide surface (outer peripheral surface 18a) and the cage guide surface (outer peripheral surface 18a) are reduced by narrowing the width of the cage guide surface (outer peripheral surface 18a). Since the area in which the outer ring raceway surface 2a comes into sliding contact is reduced, the friction between the cage guide surface (outer peripheral surface 18a) and the outer ring raceway surface 2a is reduced, and the generation of cage noise can be suppressed. Further, the base oil can easily enter between the cage guide surface (outer circumferential surface 18a) and the outer ring raceway surface 2a, the cage noise can be suppressed, and the life of the bearing can be extended by improving the lubrication characteristics.

  Further, since the widths ΔL1 and ΔL2 of the cage guide surface (outer peripheral surface 18a) are narrowed and the cage guide surface (outer peripheral surface 18a) is formed at a position separated from the end portion in the roller axial direction, the annular protrusion 18 is formed. However, a grease reservoir 19b can be ensured between 4 and 4, that is, on both sides of the roller 4. The width of the grease reservoir 19b (length in the axial direction) is preferably equal to or greater than the widths ΔL1 and ΔL2 of the annular protrusion 18. Thus, by providing the grease reservoir 19b in the vicinity of the roller 4, more grease can be left in the bearing, so that the life of the bearing can be extended by improving the lubrication characteristics.

  Furthermore, the cage guide surface (outer peripheral surface 18 a) is provided on the inner side in the axial direction from the end of the outer ring raceway surface 2 a of the outer ring 2, which is a guide wheel, as compared with the conventional rolling bearing 100. The distance Δr1 from the annular projection 18 to the end of the outer ring raceway surface 2a is preferably equal to or greater than the widths ΔL1 and ΔL2 of the cage guide surface (outer peripheral surface 18a). Thus, by increasing the distance Δr1 from the cage guide surface (outer peripheral surface 18a) to the end of the outer ring raceway surface 2a, the accuracy of the members constituting the spindle device when incorporated into the machine tool spindle device is increased. The cage guide surface may protrude from the end of the guide surface (outer ring raceway surface 2a) of the guide wheel (outer ring 2) due to the assembly accuracy or the difference in thermal expansion between the rotating wheel and the fixed wheel during operation. Even if there is a concern, the limit value of the sliding amount of the inner ring 3 is larger than that of the conventional cage 110 (Δr2 <Δr1), so that the allowable amount for the extension of the shaft can be increased, and the cage guide surface ( The outer peripheral surface 18a) is prevented from protruding from the end portion of the guide surface (outer ring raceway surface 2a) of the (outer ring 2).

  If the widths ΔL1 and ΔL2 of the cage guide surface (outer peripheral surface 18a) are made smaller than the axial pocket clearance ΔP, the posture of the cage 10 may become unstable and the cage noise may increase. The pocket clearance is set to be greater than ΔP.

  Furthermore, in the rolling bearing 1 of the present invention, as shown in FIGS. 3 and 5, the length B of the pocket straight portion 15 of the cage 10 is equal to or shorter than the length A of the roller straight portion 6 of the roller 4. It is preferably set.

  Here, as a comparative example, FIG. 11 shows a rolling bearing in which the length B of the linear pocket portion 15 of the cage is set to be larger than the length A of the linear roller portion 6 of the roller 4. FIG. 11 shows a case where B = 1.1 × A.

  In the rolling bearing 100 of this comparative example, when the cage 110 is tilted during rotation, the linear portion end 7 that is a connecting portion between the roller straight portion 6 and the crowning portion 5 is constituted by the pocket straight portion 15 of the cage 110. A large frictional force is generated in sliding contact with the circumferential side wall 16. In FIG. 11, the crowning portion 5 is not in contact with the circumferential side wall portion 16, but since the actual distance between the crowning portion 5 and the circumferential side wall portion 16 is about several μm, In addition, the crowning portion 5 may also come into contact with the circumferential side wall portion 16, and a larger frictional force may be generated. As described above, the linear portion end 7 of the roller 4 and the crowning portion 5 come into contact with the circumferential side wall portion 16 to generate a large frictional force, thereby generating a cage sound.

  On the other hand, by setting the length B of the pocket straight portion 15 of the cage 10 to be equal to or less than the length A of the roller straight portion 6 of the roller 4, even if the cage 10 is inclined during rotation, The straight portion end 7 and the crowning portion 5 are prevented from coming into contact with the circumferential side wall portion 16, so that a large frictional force is not generated and the generation of the cage noise is suppressed.

  More preferably, the length B of the pocket straight portion 15 of the cage 10 is less than the length A of the roller straight portion 6 of the roller 4, and the cage 10 has an axial pocket clearance ΔP (see FIG. 3). The length B of the pocket straight portion 15 of the cage 10 is less than A−ΔP, which is obtained by subtracting the axial pocket clearance ΔP from the length A of the roller straight portion 6 of the roller 4. Is more preferable. However, since the strength of the cage 10 cannot be obtained if the length B of the pocket straight portion 15 is too small, the length B of the pocket straight portion 15 is preferably 0.5 mm or more.

  Furthermore, in the rolling bearing 1 of the present invention, the radial pocket clearance ΔD is determined by the outer ring inner diameter (the radial distance between the outer ring raceway surfaces 2a passing through the rotation axis of the rolling bearing 1) and the cage outer diameter (the rotation axis of the rolling bearing 1). If the guide clearance, which is the difference in the radial distance between the outer peripheral surfaces 18a of the annular projections 18 passing through, is ΔE, it is at least twice the guide clearance ΔE and the chamfer length F of the outer ring 2 that is a guide wheel (see FIG. 1) The size is preferably set so as to be the following.

The reason will be described below with reference to FIG. FIG. 6 is a cross-sectional view of a rolling bearing for explaining movement and deformation of the cage.
In the rolling bearing 1, guide clearances ΔE / 2 are secured on the roller 4 side shown in FIG. 6 and on the opposite side (position 180 ° from the roller 4 shown in FIG. 6). Therefore, on the roller 4 side shown in FIG. 6, the cage 10 can move toward the inner diameter side by ΔE / 2. In FIG. 6, the solid line indicates the neutral position when the cage 10 is not rotated, that is, the position of the cage 10 in a state where the roller revolution axis (the axis of rotation of the rolling bearing 1) and the axis of rotation of the cage 10 coincide. The alternate long and short dash line indicates a state in which the cage 10 has moved by ΔE / 2 toward the inner diameter side. Therefore, theoretically, if the radial pocket clearance ΔD is larger than ΔE / 2, the roller 4 will not come into contact with the cage 10.

  However, when the cage 10 is whirled during high-speed rotation, the cage 10 is pressed against the outer ring 2 with a force corresponding to the rotational speed and deforms. That is, when the cage 10 moves toward the inner diameter side by ΔE / 2 and is further pressed against the inner peripheral surface of the outer ring, it is deformed into an elliptical shape, and the cage 10 further moves toward the inner diameter side on the roller 4 side shown in FIG. It will be. A two-dot chain line in FIG. 6 shows a state in which the cage 10 is further moved (deformed) to the inner diameter side by the whirl. In FIG. 6, the deformation of the cage 10 in the circumferential direction is ignored.

  When the cage 10 further moves toward the inner diameter side by the whirl, the radial pocket clearance ΔD further decreases. Although the amount of decrease in the radial pocket clearance ΔD due to the whirl varies depending on the material, shape, etc. of the cage 10, in the present invention, the movement of the cage 10 due to the whirl is secured at least 1.5 times the guide clearance ΔE. In consideration of the movement of ΔE / 2, the overall radial pocket clearance ΔD is set to be not less than twice the guide clearance ΔE. Thereby, even if the retainer 10 is whirled, the rollers 4 are prevented from slidingly contacting the retainer 10. Therefore, an increase in frictional force due to the roller 4 being in sliding contact with the cage 10 is suppressed, and generation of cage noise is suppressed.

  On the other hand, if the radial pocket clearance ΔD is too large, the rollers 4 are displaced, and when the assembly including the inner ring 3, the cage 10, and the rollers 4 is inserted into the outer ring 2 from the axial direction, the rollers 4 are attached to the end of the outer ring. Interfere and become difficult to incorporate. Therefore, the radial pocket clearance ΔD is set to be equal to or less than the chamfer length F (see FIG. 1) of the outer ring 2 that is a guide wheel. Thereby, when inserting the assembly which assembled | attached the inner ring | wheel 3, the holder | retainer 10, and the roller 4 to the outer ring | wheel 2 from an axial direction, it is suppressed that the roller 4 interferes in an outer ring | wheel edge part, and suppresses a deterioration of assemblability. be able to.

  In the above embodiment, the annular protrusion 18 having a larger diameter than the outer surface in the radial direction of the column portion 13 is formed in the axial direction intermediate portion of the pair of ring portions 12 over the circumferential direction. It is not necessary that the annular protrusions 18 are formed on both of them, and the annular protrusions 18 may be formed on only one of them.

  FIG. 9 is a sectional view of a rolling bearing according to a modification, and FIG. 10 is a plan view showing a part of the rolling bearing of FIG. In addition, about the component same as the rolling bearing 1 of the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the rolling bearing 1A according to this modification, the annular protrusion 18 is formed only at the axially intermediate portion of the ring portion 12 on one side of the cage 10A, and the outer peripheral surface 18a of the annular projection 18 serves as a cage guide surface. It is functioning. Further, the roller 4A is a simple cylindrical roller configured by the straight portion 6 in which the crowning portions 5 and 5 are not formed.

Here, the outer peripheral surface 18a of the annular protrusion 18 is set so as to satisfy the following expression (III), where ΔL is the width (axial length) of the outer peripheral surface 18a of the annular protrusion 18.
ΔP ≦ ΔL ≦ 4 × ΔP (III)

  Thus, by satisfy | filling said Formula (III), there exists an effect similar to the rolling bearing 1 of the said embodiment also in the rolling bearing 1A which concerns on this modification. In addition, the relationship between the length B of the linear pocket portion 15 of the cage 10 and the length A of the four linear roller portions 6 described in the rolling bearing 1 of the above embodiment, the radial pocket clearance ΔD and the guide clearance ΔE With respect to the relationship, the same effects as the rolling bearing 1 of the above embodiment can be obtained by applying the rolling bearing 1A according to the present modification.

<Retainer sound evaluation 1>
Then, the effect of this invention was verified based on the Example and comparative example which are shown below.
First, a rolling bearing having a nominal number N1011KR (inner diameter φ55 mm, outer diameter φ90 mm, width 18 mm, no outer ring collar, inner ring ribs, roller diameter φ8 mm, roller length 8 mm) was prepared. The radial clearance after incorporation was set to -15 μm, and 1.5 cc of NBU8EP (manufactured by NOK Cruber Co., Ltd.) was filled as a lubricant.

  The cage is a resin cage made of polyetheretherketone (PEEK) containing carbon fibers, and the widths ΔL1 and ΔL2 of the cage guide surface are changed to 1 to 6 times the axial pocket clearance ΔP. The cage sound at a rotational speed of 4000 to 12000 rpm was evaluated. Note that this cage has cage guide surfaces provided on both sides like the cage shown in FIG. 1, and ΔL1 and ΔL2 are equal.

  As shown in Table 1, when the cage guide surface widths ΔL1 and ΔL2 are equal to the axial pocket clearance ΔP, Example 1 is obtained, and 2 to 4 times ΔP is obtained as Examples 2 to 4 and ΔP of 5 respectively. Comparative examples 1 and 2 were obtained by multiplying 6 times, respectively. In Examples 1 to 4 and Comparative Examples 1 and 2, all the conditions other than the widths ΔL1 and ΔL2 of the cage guide surfaces are the same.

  Table 1 shows the results of cage sound evaluation in three stages. Evaluation was made into three steps of (circle), (triangle | delta), and x. ○ indicates that there is no cage sound and there is no problem in use. △ indicates that there is a small cage sound but there is no problem in use. × indicates a large cage sound. Indicates that it cannot be used.

  From the results of Table 1, in Comparative Examples 1 and 2 in which the widths ΔL1 and ΔL2 of the cage guide surfaces are 5 times and 6 times the axial pocket clearance ΔP, the cage is so large that it cannot be used regardless of the rotational speed. As a result, sound was generated. On the other hand, in Examples 1 to 4 in which the widths ΔL1 and ΔL2 of the cage guide surfaces are 1 to 4 times the axial pocket clearance ΔP, the cage noise is small or the cage noise is independent of the rotational speed. It is categorized as no, and it can be seen that the cage sound is suppressed.

  As described above, according to the rolling bearing 1 of the present invention, ΔP ≦ ΔL1 ≦ 4 × ΔP and ΔP ≦ ΔL2 when the widths ΔL1 and ΔL2 of the cage guide surface and the axial pocket clearance are ΔP. By setting ≦ 4 × ΔP, the area where the cage guide surface and the guide wheel slide is reduced, so that the friction between the cage guide surface and the guide wheel is reduced, and the generation of the cage noise can be suppressed. I understood.

<Evaluation of lubrication characteristics>
Subsequently, a rolling bearing having an identification number N1011KR (inner diameter φ55 mm, outer diameter φ90 mm, width 18 mm, no outer ring collar, inner ring collar, roller diameter φ8 mm, roller length 8 mm) was prepared. The radial clearance after incorporation was set to −5 μm, and 1.5 cc of NBU8EP (manufactured by NOK Cruber Co., Ltd.) was filled as a lubricant.

  The cage is a resin cage made of polyether ether ketone (PEEK) containing carbon fiber, and a 2000 hour durability test is performed at 12000 rpm to evaluate the residual ratio of grease, the oil separation rate, and the amount of iron powder. did.

  As shown in Table 2, Example 5 was obtained by setting the cage guide surface widths ΔL1 and ΔL2 to be three times the axial pocket clearance ΔP, and Comparative Example 3 was obtained by making it six times ΔP.

  From the results of Table 2, in Example 5 in which the widths ΔL1 and ΔL2 of the cage guide surfaces are three times the axial pocket clearance ΔP, the widths ΔL1 and ΔL2 of the cage guide surfaces are 6 times the axial pocket clearance ΔP. Compared to Comparative Example 3, the residual ratio of grease was large, the oil separation rate was low, and the amount of iron powder was also low. This is because in Example 5, there was a large amount of remaining grease, and the remaining amount of grease was large, and since there was a large amount of remaining grease, the rollers and cage guide surfaces were sufficiently lubricated and no wear occurred. it is conceivable that.

<Cage sound evaluation 2>
Subsequently, the length B of the pocket straight line portion B is obtained by using Example 4 in the above <Cage sound evaluation 1>, that is, using the cage guide surface widths ΔL1 and ΔL2 that are four times the axial pocket clearance ΔP. However, the cage sound at a rotational speed of 4000 to 12000 rpm was evaluated by changing the relationship with the length A of the linear portion.

  As shown in Table 3, in relation to the length B of the pocket straight portion and the length A of the straight portion, B = 0.6 × A was set as Example 4a, and B = A−ΔP. Example 4b, B = A was Example 4c, and B = 1.5 × A was Example 4d. Note that the evaluation criteria are the same as the above <Retainer sound evaluation 1>.

  From the results of Table 3, in Examples 4a to 4c in which the length B of the pocket linear portion of the cage is set to be equal to or shorter than the length A of the roller linear portion, the cage noise is small regardless of the rotational speed. Or it is classified as no retainer sound, and it can be seen that the retainer sound is suppressed.

  As described above, in addition to setting the widths ΔL1 and ΔL2 of the cage guide surfaces to ΔP ≦ ΔL1 ≦ 4 × ΔP and ΔP ≦ ΔL2 ≦ 4 × ΔP, the length of the pocket straight portion 15 of the cage 10 is set. By setting B to be equal to or less than the length A of the roller straight portion 6, it is possible to prevent the roller straight portion end 7 and the pocket straight portion 15 from being in sliding contact with each other when the cage 10 is tilted. It can be suppressed more.

<Cage sound evaluation 3>
Subsequently, Example 4 in the above <Retainer sound evaluation 1>, that is, the diameter of the roller and the retainer using the retainer guide surface widths ΔL1 and ΔL2 that are four times the axial pocket clearance ΔP. The cage noise at a rotational speed of 4000 to 12000 rpm was evaluated by changing the direction pocket clearance ΔD.

  As shown in Table 4, Example 4e was obtained by setting the radial pocket clearance ΔD to 1.5 times the guide clearance ΔE, and Example 4f was obtained by setting the radial pocket clearance ΔD to be twice the guide clearance ΔE. . Note that the evaluation criteria are the same as the above <Retainer sound evaluation 1>.

  From the results in Table 4, in Example 4f in which the radial pocket clearance ΔD is twice the guide clearance ΔE, the cage sound is classified as low or no cage noise regardless of the rotational speed. It can be seen that the cage sound is suppressed. In Example 4f in which the radial pocket clearance ΔD is twice the guide clearance ΔE, the decrease in the radial pocket clearance ΔD due to the whirl is secured by 1.5 × ΔE except for the movement of ΔE / 2. (2 × ΔE−ΔE / 2), it is considered that the radial pocket clearance ΔD is sufficiently secured, the rollers do not come into contact with the cage, and the generation of the cage noise is suppressed.

  As described above, in addition to setting the widths ΔL1 and ΔL2 of the cage guide surfaces to ΔP ≦ ΔL1 ≦ 4 × ΔP and ΔP ≦ ΔL2 ≦ 4 × ΔP, the radial pocket clearance ΔD is set to the guide clearance ΔE. Since the cage 10 is whirled during high-speed rotation and is deformed by being pressed against the outer ring 2 by a force corresponding to the number of rotations, the radial pocket clearance is kept sufficiently large. Generation of sound can be further suppressed. Further, since the friction between the cages 10 and 4 does not increase, seizure can be prevented by abnormal temperature rise.

<Retainer sound evaluation 4>
Subsequently, Example 4 in the above <Retainer sound evaluation 1>, that is, the widths [Delta] L1 and [Delta] L2 of the retainer guide surface are four times the axial pocket clearance [Delta] P, and <Retainer sound evaluation 1> In Comparative Example 1, that is, using the cage guide surface widths ΔL1 and ΔL2 that are five times the axial pocket clearance ΔP, the relationship between the pocket straight portion length B and the straight portion length A is as follows. B = A−2 × ΔP, and radial pocket clearance ΔD between the roller and the cage was ΔD = 2 × ΔE, and cage noise at a rotational speed of 4000 to 12000 rpm was evaluated.

  As shown in Table 5, Example 4g corresponds to Example 4 in <Retainer Sound Evaluation 1>, and Comparative Example 1a corresponds to Comparative Example 1 in <Retainer Sound Evaluation 1>. . Note that the evaluation criteria are the same as the above <Retainer sound evaluation 1>.

  From the results of Table 5, in Example 4g in which the cage guide surface widths ΔL1 and ΔL2 are four times the axial pocket clearance ΔP and other conditions are suitable, the cage guide surface widths ΔL1 and ΔL2 are It can be seen that the cage noise is suppressed as compared with Comparative Example 1a in which the other conditions are set to five times the direction pocket clearance ΔP.

In addition, this invention is not limited to the said embodiment, A change, improvement, etc. are possible suitably.
For example, in the above embodiment, the crowning type roller 4 is adopted for the rolling bearing 1 and the simple cylindrical roller 4A is adopted for the rolling bearing 1A according to the modified example, but any of the rollers 4, 4A may be adopted.
Further, for example, the circumferential side wall portion 16 may have an arc surface along the curvature of the roller 4 as viewed from the rotation axis direction as long as it has the pocket straight portion 15 having a linear shape in plan view.
In the above embodiment, the rolling bearing 1 in which the guide method of the cage 10 is the outer ring guide has been described, but the guide method of the cage 10 may be the inner ring guide.

DESCRIPTION OF SYMBOLS 1, 1A Rolling bearing 2 Outer ring 3 Inner ring 4, 4A Roller 5 Crowning part 6 Roller linear part 10, 10A Cage 11 Pocket 12 Ring part 13 Pillar part 14 Claw part 15 Pocket linear part 18 Annular protrusion 18a Outer peripheral surface (Cage Guide surface)
19b Grease reservoir A Length of roller straight portion B Length of pocket straight portion ΔD Radial pocket clearance ΔE Guide clearance F Chamfering length ΔL1 Width of one cage guide surface ΔL2 Width of cage guide surface on the other side ΔL Cage guide surface width ΔP Axial pocket clearance Q Roller rotation axis R Cage rotation axis

Claims (9)

An outer ring, an inner ring, a plurality of rollers disposed between the outer ring and the inner ring so as to be freely rollable, and a plurality of pockets formed at predetermined intervals in the circumferential direction and respectively holding the plurality of rollers. A rolling bearing, wherein the cage is guided by an outer ring guide or an inner ring guide,
The cage has cage guide surfaces on one side and the other side in the axial direction of the rollers, respectively.
When the width of the cage guide surface on one side is ΔL1, the width of the cage guide surface on the other side is ΔL2, and the axial pocket clearance is ΔP, the following equations (I) and (II) are satisfied. Rolling bearing.
ΔP ≦ ΔL1 ≦ 4 × ΔP (I)
ΔP ≦ ΔL2 ≦ 4 × ΔP (II) An outer ring, an inner ring, a plurality of rollers disposed between the outer ring and the inner ring so as to be freely rollable, and a plurality of pockets formed at predetermined intervals in the circumferential direction and respectively holding the plurality of rollers. A rolling bearing, wherein the cage is guided by an outer ring guide or an inner ring guide,
The retainer has a retainer guide surface on one of the axial direction one side and the other side of the roller,
A rolling bearing characterized by satisfying the following formula (III) where ΔL is the width of the cage guide surface and ΔP is the axial pocket clearance.
ΔP ≦ ΔL ≦ 4 × ΔP (III) Used in grease lubrication,
The cage is provided with a grease reservoir between the roller and the cage guide surface,
The rolling bearing according to claim 1, wherein a width of the grease reservoir is equal to or greater than a width of the cage guide surface. In the cage, the cage guide surface is provided on the inner side in the axial direction from the guide surface end of the guide wheel,
The rolling bearing according to any one of claims 1 to 3, wherein a distance from the cage guide surface to a guide surface end portion of the guide wheel is equal to or greater than a width of the cage guide surface.   The radial pocket clearance between the roller and the cage is not less than twice the guide clearance and not more than the chamfering length of the guide wheel. Rolling bearing. The retainer has a pair of ring portions arranged side by side in the axial direction, and a plurality of pillar portions arranged at predetermined intervals in the circumferential direction so as to connect the ring portions,
The column part has a claw part protruding to the roller side at an axially intermediate part on both sides in the circumferential direction,
The radial pocket clearance is a distance between an intersection of the roller and a line drawn in parallel with a line connecting the rotation axis of the cage and the rotation axis of the roller from the inner surface of the claw portion. 6. A rolling bearing according to claim 5, wherein The roller has a crowning portion that is gradually reduced in diameter over the entire circumference toward both ends in the axial direction, and a linear roller portion that is formed by continuing the crowning portion with a constant diameter. Have
In the pocket, a pocket straight portion having a straight shape is formed in a portion facing the roller straight portion,
The rolling bearing according to claim 1, wherein a length of the pocket straight portion is equal to or less than a length of the roller straight portion.   The rolling bearing according to claim 7, wherein a length of the pocket straight portion is less than a length obtained by subtracting the axial pocket clearance from a length of the roller straight portion.   A spindle device for machine tools, comprising the rolling bearing according to any one of claims 1 to 8.

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