JP2008281072A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low torque rolling bearing having resistance to grease leakage, resistance to dust, and a space saving property at the same time and at low cost. <P>SOLUTION: The quantity of grease penetrating to a grease reservoir 24 through a labyrinth seal is decreased by sealing with the labyrinth seal formed by a sub-lip 17 and a contact seal formed by a main lip 16. About an inner surface of each pocket of a retainer 4, a part closer to an inner diameter side than a ball array pitch circle is formed as a recessed curved surface of which diameter becomes smaller as becoming closer to an opening edge of an inner diameter side of the retainer and a recessed part extending from the opening edge of an inner diameter side of the retainer to an outer diameter side of the retainer is provided for the inner surface of each pocket. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing and, for example, relates to a technique for realizing a solution to grease leakage and a reduction in torque of a ball bearing used for a rotation support portion or the like.

Of the bearings used for the rotation support portion, as a countermeasure against grease leakage of a bearing that uses balls as rolling elements, a countermeasure is usually taken with a seal shape. However, when the seal type is a non-contact type, the torque is low, but grease leakage resistance and dust resistance are problematic. If the seal type is a contact type, the dust resistance is increased, but the torque is increased. In addition, grease leakage also occurs due to a so-called breathing phenomenon. In order to solve these problems, it is conceivable to employ the following techniques.
(1) The seal lip shape is changed and a labyrinth clearance is formed (for example, Patent Document 1).
(2) A pair of slinger is fitted and fixed to a fixed shaft to which a sealed rolling bearing is fitted so as to sandwich the rolling bearing in the axial direction (for example, Patent Document 2).
JP 2005-330986 A JP 2003-262234 A

In the one disclosed in Patent Document 1, a radial labyrinth and an axial labyrinth must be formed between a proximity lip close to the ball and a raceway facing the proximity lip. Further, it is necessary to change the inner ring seal groove, which increases the processing cost.
The thing disclosed in Patent Document 2 requires a space for providing a slinger in the axial direction of the bearing, which increases the number of parts and increases the manufacturing cost.

  An object of the present invention is to provide a rolling bearing capable of simultaneously achieving low torque, grease leakage resistance, dust resistance and space saving at low cost.

  In the rolling bearing according to the first aspect of the present invention, a plurality of balls interposed between inner and outer rings are held by a cage, a seal groove is formed in the circumferential direction on the outer diameter surface of the inner ring, and faces the seal groove. The outer peripheral edge of the seal member is fixed to the inner surface of the outer ring, the main lip and the sub lip are provided on the inner peripheral portion of the seal member, and the main lip is brought into contact with the seal groove to form a contact seal. In the rolling bearing formed by forming a labyrinth seal close to the seal groove or the vicinity thereof, a branch portion is provided at a position near the height of the inner ring outer diameter surface of the seal member, and protrudes in the inner diameter direction from the branch portion. The main lip is formed by a portion, the tip of the main lip is brought into contact with the outer groove wall of the seal groove to form the contact seal, and the front portion is projected by a portion protruding axially inward from the branch portion. The labyrinth seal is formed between the tip of the sub lip and the inner groove wall of the seal groove, and the cage has a pocket for holding a plurality of balls in the circumferential direction. A ring-shaped cage having a plurality of locations, the inner surface of each pocket, a concave curved surface in which the portion closer to the inner diameter side than the ball arrangement pitch circle becomes closer to the cage inner diameter side opening edge, The inner surface of each pocket is provided with a recess extending from the opening edge on the inner diameter side of the cage toward the outer diameter side of the cage.

According to this configuration, the labyrinth seal formed by the sub lip and the contact seal formed by the main lip are sealed, and leakage of grease to the outside of the bearing is prevented. Further, the entry of foreign matter from the outside of the bearing is prevented by these contact seals and labyrinth seals. A branching portion is provided at the “position near the height of the inner ring outer diameter surface” of the seal member, because there is a branching portion on the extension line in the axial direction of the inner ring outer diameter surface or in the vicinity of the extension line. Thus, the auxiliary lip extends from the branch portion toward the inner ring at the height of the outer surface. Since the outer diameter surface of the secondary lip extends in the axial direction at the same height as the outer diameter surface of the inner ring, the grease pushed out from the rolling groove side smoothly moves to the outer diameter surface side of the secondary lip. Therefore, the amount of grease that passes through the labyrinth seal and enters the so-called grease reservoir can be reduced, and further lower torque and higher seal can be achieved from this point.
Also, by providing a recess on the inner surface of each pocket of the cage that extends from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage, it is difficult for grease to adhere to the seal groove of the inner ring, and grease leakage can be prevented. . Therefore, it is not necessary to change the design of the shape of the seal groove, and it is not necessary to secure a space for providing a slinger or the like in the axial direction of the bearing. Therefore, the number of parts can be made smaller than that described in the above patent document, and the manufacturing cost can be reduced.

  In the rolling bearing according to the second aspect of the present invention, a plurality of balls interposed between the inner and outer rings are held by a cage, a seal groove is formed in the circumferential direction on the outer diameter surface of the inner ring, and faces the seal groove. The outer peripheral edge of the seal member is fixed to the inner surface of the outer ring, the main lip and the sub lip are provided on the inner peripheral portion of the seal member, and the main lip is brought into contact with the seal groove to form a contact seal. In the rolling bearing formed by forming a labyrinth seal close to the seal groove or the vicinity thereof, a branch portion is provided at a position near the height of the inner ring outer diameter surface of the seal member, and protrudes in the inner diameter direction from the branch portion. The main lip is formed by a portion, the tip of the main lip is brought into contact with the outer groove wall of the seal groove to form the contact seal, and the front portion is projected by a portion protruding axially inward from the branch portion. The labyrinth seal is formed between the tip of the sub lip and the inner groove wall of the seal groove, and the cage has a pocket for holding a plurality of balls in the circumferential direction. The radius from the cage center of the inner diameter of the circumferential portion having the pocket is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets. .

According to this configuration, the labyrinth seal formed by the sub lip and the contact seal formed by the main lip are sealed, and leakage of grease to the outside of the bearing is prevented. Further, the entry of foreign matter from the outside of the bearing is prevented by these contact seals and labyrinth seals. Since the outer diameter surface of the secondary lip extends in the axial direction at the same height as the outer diameter surface of the inner ring, the grease pushed out from the rolling groove side smoothly moves to the outer diameter surface side.
In addition, since the radius from the cage center of the inner diameter of the circumferential portion with the pocket of the cage is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets, the inner ring shoulder and inner ring Grease hardly adheres to the seal groove. This appears particularly when the outer ring rotates. Thereby, leakage of grease can be prevented regardless of whether the seal is a contact type or a non-contact type. Further, since it is not necessary to increase the tightening force of the seal lip, the torque does not increase.

In the present invention, the main lip and the sub lip that are continuous in an inverted L shape through the branch portion and the inner groove wall of the seal groove facing the lip are communicated with the inside of the bearing in the labyrinth seal, and the contact A grease reservoir closed at the seal may be formed. In this case, the grease reservoir acts to alleviate the pressure at which the grease leaks. Thereby, the tightening margin of the main lip can be reduced to reduce the torque, and at the same time, the seal can be increased.
In the second invention, the inner circumferential surface of the circumferential portion having the pocket may have a polygonal shape having a plurality of corners when viewed from the axial direction. This polygonal cage does not cause a decrease in the strength of the cage as a whole, and can prevent leakage of grease from the seal groove portion of the bearing when incorporated in the bearing. The number of the corners is not particularly limited. Further, the shape may be asymmetric with respect to a straight line in the radial direction.
In this invention, the radius of the maximum diameter portion of the auxiliary lip is made larger than the radius of the inner ring outer diameter surface, and the taper at which the inclination angle with respect to the outer diameter surface of the inner ring is 90 degrees or more is provided at the tip of the auxiliary lip. A surface may be formed. In this case, it is possible to prevent the tip surface of the sub lip from becoming an obstacle to the grease moving from the inner ring outer diameter side toward the outer diameter surface of the sub lip. It becomes possible to smoothly move the grease along the inclination angle.
In this invention, the inner lip surface of the sub lip is inclined at a constant angle with respect to the outer surface of the inner ring, and a labyrinth seal is formed between the inclined inner lip surface of the sub lip and the inner groove wall of the seal groove. You may do it. Thus, a desired labyrinth seal can be obtained by inclining the inner surface of the auxiliary lip.

  In the rolling bearing of the first invention, a branch portion is provided at a position near the height of the inner ring outer diameter surface of the seal member, and the main lip is formed by a portion protruding in the inner diameter direction from the branch portion. The tip of the lip is brought into contact with the outer groove wall of the seal groove to form the contact seal, and the secondary lip is formed by a portion protruding inward in the axial direction from the branch portion, and the tip of the secondary lip The labyrinth seal is formed between the inner groove wall of the seal groove and the inner surface of each pocket of the cage. A ring-shaped cage having a concave curved surface shape that has a smaller diameter as it approaches, and a concave portion that extends from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage is provided on the inner surface of each pocket. Leakage and dust resistance - saving space at the same time and can realize rolling bearing can be achieved at low cost.

  In the rolling bearing of the second invention, a branch portion is provided at a position near the height of the inner ring outer diameter surface of the seal member, and a main lip is formed by a portion protruding from the branch portion in the inner diameter direction. The portion is brought into contact with the outer groove wall of the seal groove to form a contact seal, and a sub lip is formed by a portion protruding inward in the axial direction from the branch portion, and the tip end portion of the sub lip and the inner groove wall of the seal groove A labyrinth seal is formed between the inner diameter of the circumferential portion with the cage pocket and the radius from the cage center of the inner diameter of the circumferential portion between the pockets is larger than the radius from the cage center of the inner diameter portion between the pockets. Therefore, the same operation and effect as the rolling bearing of the first invention are exhibited.

  An embodiment of the present invention will be described with reference to FIGS. In this rolling bearing, annular seal grooves 9 and 9 are formed along the circumferential direction on the inner ring outer diameter surfaces 3 and 3 on both sides of the rolling groove 2 provided on the outer circumferential surface of the inner ring 1. Seal member fixing grooves 6, 6 are provided on the inner diameter surface of the outer ring 5 facing the seal grooves 9, 9. A rolling groove 7 facing the rolling groove 2 is provided on the inner peripheral surface of the outer ring 5, and a ball 8 is interposed between both the rolling grooves 2 and 7. The balls 8 are held by the cage 4 at regular intervals in the circumferential direction.

  An annular seal member 11 is interposed between each seal groove 9 and the seal member fixing groove 6. The seal member 11 is obtained by molding a synthetic rubber 13 on a metal core 12, and the outer peripheral edge 10 is fitted and fixed in the seal member fixing groove 6. The inner diameter R1 of the cored bar 12 is larger than the outer diameter R2 of the inner ring outer diameter surface 3 of the inner ring 1. As shown in FIG. 2, a constriction 14 is formed in the synthetic rubber 13 between the inner diameter of the cored bar 12 and the axial extension line L of the inner ring outer diameter surface 3. The thickness of the rubber 13 is small.

  A portion extending linearly from the constricted portion 14 in the inner diameter direction is formed, and a branch portion 15 is provided in the middle thereof. A portion extending in the inner diameter direction from the branch portion 15 becomes the main lip 16, and a portion divided in the inward axial direction becomes the sub lip 17. The main lip 16 and the sub lip 17 continue in an inverted L shape at the branch portion 15.

  The branch portion 15 is a range where the portions obtained by extending the thickness of the main lip 16 and the thickness of the sub lip 17 intersect each other, and is a portion surrounded by an alternate long and short dash line in FIG. Further, the branch portion 15 is located at a position separated by a minute amount ΔX on the inner diameter side from the extension line L of the inner ring outer diameter surface 3. Due to the presence of such a distance ΔX, a step formed by subtracting the radius R3 from the radius R2 occurs between the inner ring outer diameter surface 3 and the auxiliary lip 17. The step does not become an obstacle to the grease moving from the inner ring outer diameter surface 3 side to the sub lip 17 side as indicated by an arrow a in FIG. However, if the distance ΔX increases, the volume of the grease reservoir 24 described later decreases and the action of reducing the leakage pressure of grease decreases. Therefore, the size of the distance ΔX is limited to a range that does not impair the relaxation action. . Since the position of the branching portion 15 is closer to the outer diameter side, the outer peripheral radius R3 of the sub lip 17 is larger than the radius R2 of the inner ring outer diameter surface 3, that is, R3> R2, and the stepped portion is grease. In the case of an obstacle to the movement, it is desirable to take measures to provide the tapered surface 27 as in the embodiment shown in FIG.

The tip of the sub lip 17 is formed on an inclined surface parallel to the inclined inner groove wall 18 of the seal groove 9, and a labyrinth seal 19 is formed between the inner groove wall 18.
The seal groove 9 has a groove bottom 21, an outer groove wall 21, and an outer land 22. The radius R4 of the outer land 22 is smaller than the radius R2 of the inner ring outer diameter surface 3.

  A sliding contact portion 23 slightly warped in the direction of the outer surface is provided at the distal end portion of the main lip 16, and the sharpened tip portion thereof is brought into contact with the outer groove wall 21 of the seal groove 9 with a required tightening margin. As a result, the contact seal 25 is formed as shown in FIG. In FIG.3 (b), the shape in the natural state of the front-end | tip part of the sliding contact part 23 is shown with a dashed-dotted line. The shape deformed by the front end portion of the sliding contact portion 23 coming into contact with the outer groove wall 21 is indicated by a solid line, and the contact seal 25 is formed at the deformed portion. In other drawings, for convenience, the contact seal 25 is shown only in the shape in the natural state.

  The main lip 16 and the sub lip 17 have an inverted L shape through the branching portion 15, and the portion surrounded by the inverted L-shaped portion and the inner groove wall 18 of the seal groove 9 facing this has a relatively large volume. A large grease reservoir 24 is obtained. The grease reservoir 24 communicates with the inside of the bearing through the labyrinth seal 19 and is closed with a contact seal 25. As a countermeasure against pressure reduction when the bearing internal pressure rises abnormally, small groove portions 26 are provided at two positions at symmetrical positions on the entire circumference at the tip of the sliding contact portion 23.

  The seal structure of the first embodiment is as described above, and the grease is enclosed in the bearing for use. The tightening allowance of the main lip 16 on the contact seal 25 reduces the grease leakage pressure by the labyrinth seal 19 existing on the inner side of the contact lip 16. Therefore, when the pressure is directly received, that is, compared to the shape in which the main lip is disposed on the inner side. , Can be set small. The tightening allowance can be adjusted by changing the thickness of the constricted portion 14, the thickness of the main lip 16, the sliding contact portion 23, and the like.

  In the case of the present invention, the tightening allowance of the contact seal 25 can be further reduced for the following reason. That is, one reason is that a part of the grease pushed outward from the rolling groove 2 side through the inner ring outer diameter surface 3 is formed on the outer diameter surface of the sub lip 17 as shown by an arrow a in FIG. Is to move. Since the outer diameter surface of the auxiliary lip 17 is a surface parallel to the shaft, the grease is prevented from being pushed back. In the conventional seal structure in which the outer diameter surface of the secondary lip is inclined inward, the grease tends to be pushed back inward, which increases the pressure of the grease. Since it is weak, the influence on the pressure of the grease is reduced, and the movement of the grease toward the labyrinth seal 19 shown by the arrow b in FIG. 2 is reduced. As a result, an increase in pressure inside the grease reservoir 24 is suppressed.

The second reason is that the grease reservoir 24 is relatively surrounded by the main lip 16 having the inverted L shape continuous through the branch portion 15, the sub lip 17, and the inner groove wall 18 of the seal groove 9 facing these. It is formed with a large volume. Thereby, the internal pressure of the grease reservoir 24 is further reduced.
In order to confirm the above effects, a comparative experiment was performed on the product of the first embodiment (both sealed products) and the following current product.

(1) Current product As for the shape of the main lip and the sub lip, the tip portion of the synthetic rubber constituting the seal member is formed in a bifurcated shape. This is manufactured based on the type in which one main lip divided into two forks is arranged on the inside and the sub lip is arranged on the outside (see Japanese Patent Publication No. 46-39361, FIG. 1) (both seal products).
(2) Details of Experiment The torque value under an axial load of 4 kgf was measured for the invention product and the current product. The measured values are shown in FIG. In FIG. 4, “X” is the torque value of the current product and “A” is the torque value of the invention product. In addition, a grease leakage performance test was performed under a radial load of 20 kgf. The test results are shown in FIG. In FIG. 5, “X” is the current product and “A” is the amount of grease leakage of the invention.

  With respect to the torque values shown in FIG. 4, the invention product A is about 40 gf · cm (20%) lower than the current product X on average, indicating that a reduction in torque is achieved. In addition, with regard to the grease leakage amount shown in FIG. 5, the cumulative leakage amount until the stable time after 3 hours is reduced to about 1/4 of the current product X in the invention product A, and the sealing performance is reduced. It turns out that it has improved.

  Further, in the rolling bearing according to this embodiment, by using the cage 4 shown below, it is difficult for grease to adhere to the seal groove 9 of the inner ring 1, and grease leakage can be reliably prevented. The cage 4 will be described with reference to FIGS.

  As shown in a perspective view in FIG. 6, the cage 4 has pockets 50 for holding the balls 8 (FIG. 1) at a plurality of locations in the circumferential direction, and the inner surface of each pocket 50 has a concave spherical shape. It is ring-shaped. The retainer 4 is formed by joining two annular retainer halves 51 shown in a perspective view in FIG. 7 so as to face each other in the axial direction and joining them together by a rivet 53 inserted through a rivet hole 52. Composed. These cage halves 51 have a plurality of spherical shell-shaped plate portions 50A whose inner surfaces form half of the pockets 50, and a flat plate portion 51a serving as a portion between adjacent pockets 50; The spherical shell plate portions 50A are alternately arranged in the circumferential direction. The spherical shell-shaped plate portion 50A is a part that becomes a part of the spherical shell, in other words, a counter-sink-shaped bulged portion in which both the inner and outer surfaces are spherical. The projected shape in the axial direction of the cage half 51 is a ring shape having a constant radial width over the entire circumference.

  A part of the cage half 51 is enlarged and shown in a perspective view in FIG. FIG. 8 is a diagram in the case where the pocket inner surface is a monotonous spherical surface in a portion corresponding to FIG. 9. In FIG. 8, a portion A indicated by a two-dot chain line indicates a circumferential band in which the flat plate portions 51a of the cage half 51 are arranged in the circumferential direction. The spherical shell plate portion 50A, which is a half of the pocket 50, is formed at a portion of the circumferential band A that is not the flat plate portion 51a. One side portion of the spherical shell plate portion 50 </ b> A in the drawing is an inner diameter side portion 50 </ b> Ai of the cage 4, and the other side portion of the spherical shell plate portion 50 </ b> A is an outer diameter side portion 50 </ b> Ao of the cage 4.

  As shown in FIG. 9, the inner surface of the pocket 50 (spherical shell plate portion 50 </ b> A) of the cage 4 according to this embodiment is formed on the inner diameter side portion 50 </ b> Ai of the cage 4 from the opening edge on the cage inner diameter side. A recess 54 extending toward the outer diameter side is provided, and a cross-sectional shape of the inner surface of the recess 54 along the circumferential direction of the cage (that is, a cross-sectional shape taken along a plane perpendicular to the cage central axis) is defined as the inner surface of the pocket 50. An arc shape having a radius of curvature Rb smaller than the radius of curvature Ra of the concave spherical surface.

  The recessed portion 54 is provided at one location so as to spread from the center OW50 in the cage circumferential direction at the opening edge of the pocket 50 to one side, and the width W54 of the recessed portion 54 is the width W50 in the cage circumferential direction of the pocket 50. The width is almost the whole. The width W54 of the recessed portion 54 is preferably larger than half of the width W50 of the pocket 50, and more preferably 2/3 or more, or 3/4 or more.

  The inner surface shape of the recessed portion 54 is a cylindrical surface shape substantially along the surface of the virtual cylinder V centered on the straight line L in the radial direction of the cage 4 as shown in FIG. The virtual cylinder V may be the surface of a grindstone that processes the recess 54. The concave portion 54 extends from the opening edge on the inner diameter side of the cage to the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases, that is, gradually, from the inner diameter edge of the cage to the ball arrangement pitch circle PCD. The shape is shallow and narrow. In this embodiment, the dent 54 extends to the ball arrangement pitch circle PCD. However, the dent 54 may extend slightly to the outer diameter side of the cage from the ball arrangement pitch circle PCD, or slightly to the ball arrangement pitch circle PCD. You may not reach it. The ball arrangement pitch circle PCD is also called a pocket PCD.

  The depth of the concave portion 54 is such that the distance Rc from the center O50 of the concave spherical surface of the pocket inner surface to the deepest position of the concave portion 54 is 1.05 times or more the radius of the ball 8 (just 1.05 times). Preferably). The radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 50 is slightly larger than the radius of the ball 8 and is less than 1.05 of the radius of the ball 8.

  FIG. 10 shows another example of the shape of the inner surface of the pocket 50 (spherical shell plate portion 50A) of the cage 4. In this example, two recessed portions 54A provided in the inner diameter side portion 50Ai of the inner surface of the pocket 50 (spherical shell-shaped plate portion 50A) are positioned on both sides of the center OW50 in the cage circumferential direction at the opening edge of the pocket 50. It is said. The inner surface shape of each recess 54A is such that the cross-sectional shape along the circumferential direction of the cage (that is, the cross-sectional shape taken along the plane perpendicular to the central axis of the cage) is larger than the radius of curvature Ra of the concave spherical surface serving as the inner surface of the pocket 50. It has an arc shape with a small radius of curvature RAb, and in detail, as shown in FIG. 5B, it has a cylindrical surface shape substantially along the surface of each virtual cylinder VA centered on the radial straight line LA of the cage 4. is there. The recessed portion 54A extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the inner diameter edge of the cage to the ball arrangement pitch circle PCD. The shape gradually becomes shallower and narrower.

The positions of the two recessed portions 54A are, for example, two symmetrical places where the circumferential orientation angle with respect to the center OW50 in the circumferential direction of the cage at the opening edge of the pocket 50 is 40 ° ± 15 °. Also in this example, the depth of the recessed portion 54A is such that the distance RAc from the center O50 of the concave spherical surface of the pocket inner surface to the deepest position of the recessed portion 54A is 1.05 times or more the radius of the ball 8. Is preferable (it may be just 1.05 times).
In this embodiment, the number of the recessed portions 54A is two, but may be three or more.

  FIG. 11 shows still another example of the shape of the inner surface of the pocket 50 (spherical shell plate portion 50A) of the cage 4 (FIG. 1). In this embodiment, in the embodiment of FIG. 10, the cross-sectional shape (cross-sectional shape along the circumferential direction of the cage) of the recessed portion 54A is a polygonal shape instead of an arc shape. Specifically, as shown in FIG. 5B, a polygonal shape substantially along the surface of each polygonal column (regular decagonal column in the illustrated example) VC centered on the straight line LA in the radial direction of the cage 4. It is. The recessed portion 54C extends from the opening edge on the cage inner diameter side to the vicinity of the ball arrangement pitch circle PCD in the radial direction of the cage, and gradually decreases from the cage inner edge to the ball arrangement pitch circle PCD. The shape gradually becomes shallower and narrower. Other configurations in this embodiment are the same as those in the example of FIG.

  FIG. 12 shows still another example of the shape of the inner surface of the pocket 50 (spherical shell plate portion 50A) of the cage 4. In this example, the recessed portions 54B provided in the inner diameter side portion 50Ai of the inner surface of the pocket 50 (spherical shell-shaped plate portion 50A) are positioned on both sides of the center OW50 in the cage circumferential direction at the opening edge of the pocket 50. Although it is the same as that of embodiment of FIG. 6 by being provided in the location, each recessed part 54B is extended to the cage | basket outer-diameter edge vicinity. The cross-sectional shape along the circumferential direction of the cage of the inner surface of the recessed portion 54B is an arc shape having a curvature radius RBb smaller than the curvature radius Ra of the concave spherical surface serving as the inner surface of the pocket 50. FIG. As shown, the shape is substantially along the surface of one virtual ring VB. The virtual ring VB may be an outer peripheral surface of a grindstone that processes the recess 54B. The virtual ring VB has a ring outer diameter that fits in the pocket 50 and has a donut shape with a circular cross-sectional shape at an arbitrary circumferential position, and the ring center OVB is placed on the cage center axis O as shown in FIG. It has an inclination to it.

In addition, in this invention, the cross-sectional shape along the cage circumferential direction of the recessed portions 54A to 54C is not limited to the shape of each example of FIGS. 8 to 12, but a partial oval shape, a rectangular groove shape, a trapezoidal groove shape, Any other cross-sectional shape may be used. In addition, the cross-sectional shape of the recesses 54A to 54C may be asymmetric with respect to the center of the recess.
The inner surface shape of the pocket 50 is not limited to a spherical shape, and may be any shape as long as the inner diameter side portion of the pocket arrangement pitch circle PCD becomes a smaller diameter as it approaches the cage inner diameter side opening edge, for example, the ball arrangement pitch circle PCD. Further, the outer diameter side portion may be a cylindrical surface shape, and the inner diameter side portion may be a conical surface shape.

  FIG. 14 shows a method for manufacturing the cage 4. This manufacturing method is a method of manufacturing an iron plate punching cage, in which a steel plate is first pressed to punch a ring-shaped metal strip 55. Next, as shown in FIG. 14A, a convex press die 56 for molding the inner surface of the spherical shell plate portion 50A of the cage half 51 and the outer surface of the spherical shell plate portion 50A are molded. A press die set 58 comprising a concave press die 57 is prepared, and the ring-shaped metal strip 55 is sandwiched between the convex press die 56 and the concave press die 57, and FIG. The cage half 51 is press-molded as in B). This press molding may be performed in two stages of rough pressing and finishing pressing, or may be performed once.

Although only one convex press die 56 and one concave press die 57 are shown in the drawing, each of the convex press die 56 and the concave press die 57 is a cage half 51. The same number of the spherical shell plate portions 50A are arranged in the circumferential direction as a single mold, and a plurality of spherical shell plate portions 50A are formed at the same time.
The two retainer halves 51 thus obtained are overlapped as shown in FIG. 14C, and the portion where the flat plate portion 51a of the retainer half 51 is overlapped as shown in FIG. To form a cage 4.

  FIG. 15 shows the convex side press die 56 and the concave side press die 57 used for the finish pressing step in press molding for molding the cage half 51 of FIG. The hemispherical convex surface of the convex side press die 56 is partially formed with a concave portion molding die portion 56a for molding the inner surface of the concave portion 54A in the pocket 50 (spherical shell plate portion 50A). Further, the concave side press mold 57 is partially formed with a concave portion back surface molding die portion 57a for molding the outer surface of the concave portion 54A in the pocket 50 (spherical shell plate portion 50A). Although a convex part will be formed in the outer surface side of a holder | retainer pocket, if it is non-contact with a seal | sticker, there is no functional problem. In this case, the convex-side press die 56 and the concave-side press die 57 are also provided as a single die corresponding to the number of the spherical shell plate portions 50A of the cage half 51, and have a plurality of spherical shell shapes. The plate portion 50A is formed at the same time.

When the cage half 51 shown in FIG. 10 is formed, the inner surface of the spherical shell-like plate portion 50A has a shape having a concave portion 54A in a part of a simple hemispherical concave surface. If the concave portion 54A is further press-molded into a part of the hemispherical concave surface after forming the concave shape, the manufacturing process is increased by one step as compared with the case of forming a conventional steel punching cage. .
In this embodiment, as described above, for forming a concave portion, the inner surface of the concave portion 54A in the pocket 50 (spherical shell plate portion 50A) is formed on the hemispherical convex surface of the convex press die 56 used in the finishing pressing step. Since the mold portion 56a is partially formed, the recessed portion 54A can be formed at the same time in the finishing pushing process, and the cage 4 can be efficiently manufactured without increasing the manufacturing process.

  Moreover, the shape and surface roughness of the hemispherical convex surface of the convex pressing die 56 used in the finishing pressing step are transferred to the inner surface of the cage pocket 50, and the inner surface of the pocket 8 ( In order to come into contact with FIG. 1), it is necessary to reduce the surface roughness of the pocket inner surface. Since the inner surface of the pocket is a simple concave spherical surface in the conventional iron plate punching cage, the surface roughness is reduced by polishing the hemispherical convex surface of the convex press die with a concave grinding stone or the like. However, in the case of this embodiment, as described above, the hemispherical convex surface of the convex-side press die 56 is a part of a simple hemispherical convex surface, and a concave portion molding die portion 56a corresponding to the concave portion 54A of the pocket inner surface. The surface roughness cannot be reduced by polishing with a concave-shaped grindstone or the like as in the conventional example.

  Therefore, in this embodiment, the convex convex spherical surface of the convex press die 56 used in the finishing pressing step is surface-finished by shot blasting, polishing with an electron beam, or lapping by injection of an abrasive. In this case, lapping is generated by obtaining abrasive material having elasticity and adhesiveness by adding moisture to the abrasive grains and sliding the abrasive material on the surface of a mold as a workpiece at high speed. A method of surface finishing by frictional force is preferred. As such wrapping, aero wrapping (Yamashi Towers Co., Ltd.) sold as a mold ultra-mirror finishing device can be employed. As described above, the surface of the convex spherical surface of the convex press die 56 is finished by shot blasting, electron beam, or lapping by jetting an abrasive, so that there is no need for manual polishing, and there is no unevenness and low cost. The surface roughness of the convex convex spherical surface of the side press die 56 can be reduced.

FIGS. 16-18 shows the test result which confirmed the grease adhesion state. In this test, a ball bearing incorporating the cage 4 of this embodiment (the embodiment of FIG. 9 and the embodiment of FIG. 10) and a ball bearing incorporating a general iron plate punched cage are shown in the following table. A comparison was made by driving under the condition of 1.
FIG. 16 and FIG. 17 show the grease adhesion state of the ball bearing using the cage 4 of this embodiment (the embodiment of FIG. 9 and the embodiment of FIG. 10 respectively), and FIG. 18 is a general iron punching cage. The grease adhesion state of the ball bearing using

From the test results shown in FIGS. 16 to 18, in the ball bearing (FIG. 18) incorporating a general steel plate punched cage, grease adheres to the inner ring seal groove, but the ball bearing incorporating the cage 4 of this embodiment. (Examples of FIGS. 16 and 17) show that there is no adhesion of grease.
In the rolling bearing cage 4 according to this embodiment, the shape of the pocket 50 is different from that of the conventional example as described above, so that the adhesion of grease to the shoulder portion of the inner ring can be eliminated. In other words, since a recess is provided at the opening edge on the inner diameter side of the cage, where the grease adheres most to the ball, scraping of the surface of the ball when grease scraping occurs reduces the inner diameter of the cage. The amount of grease that accumulates on the surface is reduced.

  Therefore, grease does not adhere to the inner ring seal groove, and no grease leakage occurs regardless of whether a contact type or non-contact type seal is used. This effect is characteristic especially when the outer ring rotates. Therefore, there is no problem caused by the grease adhering to the seal unlike a general iron plate punched cage. Furthermore, since it is not necessary to add an element for preventing grease leakage to the sealing function, a seal design specialized for muddy water resistance, dust resistance, and low torque is possible. Further, since the ball bearing retainer 4 of this embodiment can be pressed, a high-strength one can be manufactured at a low cost, and the distance from the seal does not change as compared with a general iron punching retainer.

  In each of the above embodiments, the case of the iron plate punched cage is shown, but the present invention can also be applied to the case of the resin cage 59 as shown in FIGS. 19 and 20. The resin cage 59 has two annular bodies 60, 60 made of a resin molded product. A plurality of hemispherical pockets 61A along the outer periphery of the ball are formed at equal intervals in the circumferential direction on one side surface of each annular body 60 that abuts each other. Between the adjacent pockets 61 </ b> A and 61 </ b> A, an engagement hole 62 and an engagement claw 63 serving as a coupling portion are provided, and the engagement claw 63 of one annular body 60 is connected to the engagement hole 62 of the other annular body 60. By inserting, both annular bodies 60 are joined together to form a cage 59.

  According to the structure of the rolling bearing described above, the labyrinth seal 19 formed by the sub lip 17 and the contact seal 25 formed by the main lip 16 are sealed, and leakage of grease to the outside of the bearing is prevented. Further, the entry of foreign matter from the outside of the bearing is prevented by the contact seal 25 and the labyrinth seal 19. Since the outer diameter surface of the secondary lip 17 extends in the axial direction at the same height as the outer diameter surface 3 of the inner ring, the grease pushed out from the rolling groove 2 side smoothly enters the outer diameter surface side of the secondary lip 17. Moving. Therefore, the amount of grease that passes through the labyrinth seal 19 and enters the grease reservoir 24 can be reduced. From this point, it is possible to further reduce the torque and increase the seal.

  The cages 4 and 59 have pockets 50 that respectively hold a plurality of balls 8 at a plurality of locations in the circumferential direction, and the inner surfaces of the pockets 50 are held by the inner diameter side of the ball arrangement pitch circle PCD. It is a ring-shaped ring that has a concave curved surface that becomes smaller in diameter as it approaches the opening edge on the inner diameter side of the cage, and has a recess 54 (54A, 54B) that extends from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage. , 54C), it is difficult for grease to adhere to the seal groove 9 of the inner ring 1, and grease leakage can be prevented. Therefore, it is not necessary to change the design of the shape of the seal groove, and it is not necessary to secure a space for providing a slinger or the like in the axial direction of the bearing. Therefore, the number of parts can be made smaller than that described in the aforementioned patent document, and the manufacturing cost can be reduced.

  For example, as shown in FIG. 9, the recessed portion 54 is provided at one position so as to spread from the center in the circumferential direction of the cage at the opening edge of the pocket 50 to a width W50 in the circumferential direction of the cage 50. The inner surface shape of the recess 54 is a cylindrical surface shape substantially along the surface of the virtual cylinder V centered on the straight line L in the radial direction of the cage 4. The recess 54 extends from the opening edge on the inner diameter side of the cage to the vicinity of the ball arrangement pitch circle PCD, and gradually becomes shallower and narrower as it approaches the ball arrangement pitch circle PCD from the inner diameter edge of the cage. Thus, the above-described actions and effects are achieved.

  Further, for example, as shown in FIG. 10, the recessed portions 54A are provided at a plurality of locations on both sides of the center OW50 in the cage circumferential direction at the opening edge of the pocket 50, and the inner surface shape of each recessed portion 54A is The concave portion 54A extends from the opening edge on the inner diameter side of the cage to the ball arrangement pitch circle PCD. The cylindrical surface shape is substantially along the surface of each virtual cylinder VA around the straight line LA in the radial direction of the cage 4. The shape is gradually shallower and narrower as it approaches the ball arrangement pitch circle PCD from the inner diameter edge of the cage, thereby providing the above-described operations and effects.

  Further, as shown in FIGS. 12 and 13, for example, as shown in FIGS. 12 and 13, the recessed portions 54 </ b> B are provided at two locations on both sides of the center OW50 in the circumferential direction of the cage at the opening edge of the pocket 50. The inner surface shape of these two recessed portions 54B extends to the vicinity of the edge, and is substantially along the surface of one virtual ring VB. The virtual ring VB has a ring outer diameter that fits in the pocket 50, and has an arbitrary circumference. The cross-sectional shape of the directional position is circular, and the ring center OVB has an inclination with respect to the cage center axis O, so that the above-described operations and effects are achieved.

21 to 23 show an embodiment corresponding to the second invention. The rolling bearing retainer 4A according to this embodiment is the same as the retainer 4 described above with reference to FIGS.
This retainer 4A is a retainer used for the rolling bearing described above with reference to FIG. 1 and has a ring shape having pockets 50 for retaining balls 8 at a plurality of positions in the circumferential direction, and retains two annular bodies. The container half 51 is overlapped facing each other in the axial direction. Each of these cage halves 51 has a shape in which spherical shell-shaped plate portions 50A whose inner surfaces form half of the respective pockets and flat plate portions 51a that are portions between adjacent pockets 50 are alternately arranged in the circumferential direction. Is done. Each cage half 51 is a press-formed product of a metal plate (for example, an iron plate punched product), and the two cage halves 51 are mutually connected by a rivet 53 inserted into a rivet hole 52 provided in the flat plate portion 51a. Joined and constructed integrally. The above configuration is the same as that of the embodiment shown in FIGS.

Further, as shown in FIGS. 21 and 23, the retainer 4 </ b> A has a range overlapping in the axial direction with the inner ring outer diameter surface 3 which is the shoulder height on both sides of the rolling groove 2 of the inner ring 1.
The cage 4A of this embodiment has a thin portion 50Aa in the inner diameter side portion of the ball arrangement pitch circle PCD which is the ball arrangement pitch in the spherical shell plate portion 50A in the above configuration. The thin portion 50Aa is obtained by making the plate thickness t1 of the portion located on the inner ring outer diameter surface 3 which is the shoulder height on both sides of the rolling groove 2 of the inner ring 1 thinner than the plate thickness t0 of the flat plate portion 51a. . The inner ring outer diameter surface 3 that becomes the shoulder height is an outer diameter surface portion that continues at the height of the shoulder of the rolling groove 2 of the inner ring 1, and when the seal groove 9 is provided, the rolling groove 2. And the outer diameter surface portion between the seal groove 9 and the seal groove 9. The spherical shell plate portion 50A reduces the plate thickness t1 of the portion located in the axial range W of the inner ring outer diameter surface 3. In addition, in FIG. 21, the cross-sectional shape when not reducing the thickness of the spherical shell plate portion 50A is indicated by an imaginary line.

  In the form in which the plate thickness t1 is reduced, the entire range from the portion corresponding to the ball arrangement pitch circle PCD to the inner diameter side in the radial direction of the cage may be reduced. Also, the ball arrangement pitch circle PCD and the inner diameter edge of the cage The range from the midway point to the inner diameter edge may be made thinner. In these cases, the plate thickness t1 may gradually become thinner toward the inner diameter side in the radial direction of the cage so that the inner diameter edge becomes the minimum plate thickness. You may do it. Furthermore, while maintaining the shape of the inner surface of the pocket of the spherical shell-shaped plate portion 50A, even if the plate thickness is reduced so that the shape of the outer surface changes, or while maintaining the shape of the outer surface of the spherical shell-shaped plate portion 50A, The plate thickness may be reduced so that the shape on the inner surface side of the pocket changes.

  Further, in this embodiment, as shown in FIG. 22, both ends are left thin in the arc-shaped range along the inner diameter edge of the spherical shell-like plate portion 50 </ b> A. Depending on the relationship between the inner ring outer diameter surface 3 and the width of the cage 4A, as shown in FIG. 24, the thin-walled portion 50Aa is formed on both sides excluding the center of the arc of the inner diameter edge in the spherical shell-like plate portion 50A. It may be divided into two places.

  In this cage 4A, a thin-walled portion 50Aa is formed on the inner diameter portion of the spherical shell-shaped plate portion 50A constituting the pocket 50 in this way. It is a portion that overlaps the surface 3 in the axial direction, and is a portion where the grease adhering to the surface of the ball 8 is scraped off by the cage 4A, or a portion where the scraped grease moves. If the plate thickness t1 of this portion 50Aa is thin, the amount of grease that can be deposited here decreases, and therefore the frequency and amount that can reach the inner ring outer diameter surface 3 of the inner ring 1 decreases, and as a result, the grease goes out of the bearing. Leakage can be prevented. That is, the grease easily moves to the outer diameter side of the cage 4A, and the amount of grease that can stay on the inner diameter side decreases.

However, reducing the overall plate thickness of the cage reduces the strength of the cage alone, so that the cage may be damaged when repeated stress is applied to the cage under misalignment or external vibration. It is difficult to occur.
Therefore, in the inner diameter portion of the cage 4A, the thickness of only the range W that overlaps the inner ring outer diameter surface 3 serving as the shoulder portion of the inner ring 1 in the axial direction is thinned, thereby substantially increasing the strength of the cage 4A. The ball bearing retainer 4A that can prevent the grease leakage is formed.

  Therefore, by using the cage in the rolling bearing, the frequency and amount that can reach the inner ring outer diameter surface 3 of the inner ring 1 is reduced, and as a result, leakage of grease to the outside of the bearing can be prevented. That is, the grease easily moves to the outer diameter side of the cage 4A, and the amount of grease that can stay on the inner diameter side can be reduced. Therefore, it is difficult for grease to adhere to the seal groove 9 of the inner ring 1, and grease leakage can be prevented. Further, according to the configuration of this rolling bearing, it is not necessary to change the design of the shape of the seal groove 9 of the inner ring 1, and it is not necessary to secure a space for providing a slinger or the like in the axial direction of the bearing, and the number of parts is also described above. The manufacturing cost can be reduced by reducing the manufacturing cost as described in the literature.

  In order to reduce the plate thickness t1, only the inner diameter side of the flat plate initially punched into the ring may be thinned and press molded. Further, in a press mold when a cage is formed by pressing from a circular plate having a uniform thickness, the clearance distribution between a pair of molds is reduced so that only the thickness of the region shown in FIGS. 22 and 24 is reduced. It may be changed. In this embodiment, the case of a deep groove ball bearing punch made of iron plate is shown. However, the second invention can be applied to the two-part resin cage described above with reference to FIGS. .

25 to 27 show an embodiment of the present invention. The rolling bearing cage 4B according to this embodiment is a cage used in the rolling bearing described above with reference to FIG. This cage 4B is a ring-shaped member, and the same number of window-like pockets 4Ba for accommodating and holding balls 8 (FIG. 1) as the balls 8 are formed at equal intervals in the circumferential direction. The inner peripheral surface 4Bb of the circumferential portion with the pocket 4Ba is inclined so as to be recessed toward the outer diameter side, and the radius Rp from the cage center of the inner diameter of the circumferential portion with the pocket 4Ba is between the pockets 4Ba. Is larger than the radius Ri from the center of the cage (Rp> Ri). In this embodiment, the inner peripheral surface 4Bb has a curved surface shape that is a concave curve when viewed from the axial direction, specifically, an arcuate surface.

  The cage 4B is composed of, for example, two annular members 64 manufactured by punching and forming an iron plate by pressing. Each annular member 64 is arranged in the circumferential direction at equal intervals, and a plurality of hemispherical pocket wall portions 64a each constituting the inner wall surface of the pocket 4Ba and a flat plate-like coupling plate that connects adjacent pocket wall portions 64a to each other. The portions 64b are alternately formed. A rivet hole 64c is formed in the coupling plate portion 64b of the annular member 64 made of iron plate. The two annular members 64 are joined by overlapping the respective coupling plate portions 64b with each other, inserting a rivet 65 into the rivet hole 64c, and crimping both ends of the rivet 65. In this way, if the two annular members 64 are coupled to each other to form one cage 4B, the radius from the cage center having the inner diameter as described above is different in each part, but is retained. The processing of the vessel 4B is easy.

  The cage 4B of this embodiment has a shape in which the inner peripheral surface 4Bb of the circumferential direction portion with the pocket 4Ba is recessed toward the outer diameter side, so there is a concern that the overall strength may be lowered. However, most of the damage of the conventional standard shape cage Hr (Rp = Ri) as shown in FIG. 31 is the R portion from the circumferential portion between the pockets Hra to the circumferential portion with the pockets Hra. It is empirically known to occur with Hr7. Since the cage 4B of this embodiment does not change the shape of this portion, it can be said that the overall strength does not decrease.

  In order to investigate the state of grease during operation of this rolling bearing, a test was conducted under the conditions shown in Table 2. FIG. 27 shows the state of adhesion of grease to each part of the bearing after the operation was stopped. For comparison, a test was conducted under the same conditions for a bearing incorporating the conventional cage Hr shown in FIG. The state of adhesion of grease to each part of the bearing after the operation was stopped was as shown in FIG.

  According to this test, the grease G adheres to the inner ring seal groove Hr1a in the case of the bearing incorporating the conventional cage Hr. However, in the rolling bearing incorporating the cage 4 of the present invention, the grease does not adhere to the inner ring seal groove. I understood. For this reason, in a rolling bearing provided with a seal, it is inferred that leakage of the grease G from the portion of the inner ring seal groove due to breathing can be prevented.

  Next, a grease leakage frequency confirmation test was performed using a bearing assembled with a contact-type seal (LU seal manufactured by NTN Corporation). The test conditions were changed from the conditions shown in Table 2 to 15 minutes. When it was confirmed by visual inspection that grease of an amount of about 30 to 100 mg had jumped out of the bearing, grease leakage was assumed. The test results are shown in Table 3.

  Nine out of 10 grease leaks were found in the bearings incorporating the conventional cage Hr, but none of the bearings incorporating the cage 4 of the present invention produced any grease leaks. This proved that the reasoning was correct.

In the above embodiment, the two annular members 64 constituting the cage 4B are made of iron plate, but the annular member 64 may be made of resin. In that case, like the retainer 4C shown in FIGS. 28 and 29, the coupling plate portion 64b is provided with an engaging claw 66 and an engaging hole 67, and the two 66 and 67 are fitted to each other, so that It can be set as the structure which couple | bonds the annular member 64. FIG. Also in this case, the radius Rp from the cage center at the inner diameter of the circumferential portion with the pocket 4Ca is made larger than the radius Ri from the cage center at the inner diameter of the circumferential portion between the pockets 4Ca (Rp> Ri). . Further, two annular members 64 made of resin may be joined with an adhesive or the like.
As the synthetic resin material used for the cage, for example, polyamide resins such as PA66 and PA46 and polyphenyl sulfide resins are suitable, and a reinforcing fiber material such as glass fiber may be mixed as necessary.
Further, the structure is not limited to a structure in which the two annular members 64 are joined to form a single retainer, but may be a machined retainer that cuts out a steel material into a predetermined shape, or a molded retainer that is integrally molded with a resin material. It is good also as a vessel.

  FIG. 30 shows a different embodiment. In the retainer 4D, the shape of the inner peripheral surface 4Db in the circumferential portion with the pocket 4Da is a polygonal shape when viewed from the axial direction. Specifically, the inner peripheral surface 4Db includes a pair of inclined surface portions 4Dba that are inclined toward the outer diameter side with respect to the inner peripheral surface 4Dc in the circumferential portion between the pockets 4Da, and both ends of the outer peripheral surfaces 4Dba are outside the pair of inclined surface portions 4Dba. It has a trapezoidal shape composed of a constant-diameter surface portion 4Dbb that is connected to the radial end and has a constant inner diameter. Similarly to the cages 4B and 4C of the above-described embodiment, the cage 4D is inclined so that the inner circumferential surface 4Db of the circumferential portion with the pocket 4Da is recessed in the outer diameter side, and the pocket 4Da The radius Rp from the cage center of the inner diameter of a certain circumferential portion is larger than the radius Ri from the cage center of the inner diameter of the circumferential portion between the pockets 4Da (Rp> Ri).

  In this way, the cage 4D having a polygonal shape when viewed from the axial direction in the inner circumferential surface 4Db of the circumferential portion having the pocket 4Da is also reduced in overall strength, like the cages 4B and 4C of the above embodiment. When it is incorporated in a rolling bearing as shown in FIG. 1, leakage of grease from the inner ring seal groove portion of the bearing can be prevented.

  In addition, when making inner peripheral surface 4Db of the circumferential direction part with pocket 4Da into the polygonal shape which has a some corner | angular part, the number of the corner | angular part is not specifically limited. Further, the shape may be asymmetric with respect to a straight line in the radial direction. Furthermore, the inner peripheral surface 4Db of the circumferential direction portion with the pocket 4Da may be a combination of a flat surface and a curved surface.

In short, regardless of the material and processing method of the present invention, the radius from the cage center of the inner diameter of the circumferential portion with the pocket is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets. It can be applied to a cage having a shape that satisfies the condition of large.
As described above, in the rolling bearing, the cage incorporated in the bearing has a radius from the center of the inner diameter of the circumferential portion having the pocket, and the inner diameter of the circumferential portion between the pockets. By making it larger than the radius from the center, it becomes difficult for grease to adhere to the inner ring shoulder and the inner ring seal groove. This appears particularly when the outer ring rotates. Thereby, leakage of grease can be prevented regardless of whether the seal is a contact type or a non-contact type. Further, since it is not necessary to increase the tightening force of the seal lip, the torque does not increase. Each of the above-described actions can be obtained in any case where the inner diameter surface of the circumferential portion having the pocket is a curved surface having a concave curve when viewed from the axial direction, or a polygonal shape having a plurality of corners.

  Next, an embodiment of the present invention will be described with reference to FIG. In the following description, portions corresponding to the matters described in the above-described embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

  The seal structure according to the embodiment shown in FIG. 33 (a) is basically the same as the seal structure according to the embodiment shown in FIGS. The difference is that the radial position of the branch portion 15 is at a position including the extension line L of the inner ring outer diameter surface 3, and most of the auxiliary lip 17 is higher than the extension line L (the outer diameter side of the seal member 11). Is to exist. The radius R3 of the maximum diameter portion of the auxiliary lip 17 is larger than the radius R2 of the inner ring outer diameter surface 3. For this reason, although the volume of the grease reservoir 24 increases, there arises a problem that the tip surface of the sub lip 17 becomes an obstacle to the grease moving from the inner ring outer diameter surface 3 side toward the outer diameter surface of the sub lip 17. As a measure for avoiding this, a tapered surface 27 is formed at the tip of the auxiliary lip 17 so that the inclination angle θ with respect to the inner ring outer diameter surface 3 is 90 ° or more.

Further, the inner diameter surface of the sub lip 17 is inclined with a certain angle α (for example, 5 ° or more and 10 ° or less) with respect to the inner ring outer diameter surface 3, and the inclined surface 29 and the inner groove wall 18 of the seal groove 9 A labyrinth seal 19 is formed between the two.
A tapered surface 28 is also formed on the inner surface of the front end portion of the main lip 16 so that the angle β formed by the tapered surface 28 and the outer groove wall 21 of the seal groove 9 is 90 ° or more. When there is such a wide angle β, the grease passes through the contact seal 25 of the main lip 16 as compared with the case of a narrow angle β ′ such as less than 90 ° as shown in FIG. It becomes difficult to do. Other configurations, operations, and effects are the same as those of the seal structure of the embodiment shown in FIGS.

  In the seal structure having the configuration shown in FIG. 33A described above, an experiment similar to that of the configuration shown in FIGS. 1 to 3 was performed. In FIG. 4, the measured value of this torque value is indicated by “B”. Further, in FIG. 5, the measured value of the grease leakage amount is indicated by “B”. As can be seen from this result, the torque and seal can be reduced to the same extent as in the case of the embodiment shown in FIGS. Furthermore, in the rolling bearing according to this embodiment, by applying the retainers 4 and 59, it is difficult for grease to adhere to the seal groove of the inner ring, and grease leakage can be prevented. Therefore, it is not necessary to change the design of the shape of the seal groove, and it is not necessary to secure a space for providing a slinger or the like in the axial direction of the bearing. Therefore, the number of parts can be made smaller than that described in the aforementioned patent document, and the manufacturing cost can be reduced.

Further, a reference proposal example of the present invention will be described with reference to FIG. The reference proposal examples shown in FIGS. 34 (a) and 34 (b) were proposed in the previous stages of conceiving the seal structures shown in FIGS. 1 to 3 and FIG. 33, respectively.
In the case of the seal structure shown in FIG. 34 (a), the lip of the seal member 11 is only the main lip 16, the main lip 16 has a constant width, and the end face 30 in the width direction is formed at the tip. Yes. A contact seal 25 is formed by bringing the outer corner portion of the end face 30 into contact with the outer groove wall 21 of the seal groove 9. Compared to the above-described embodiment, the point that the auxiliary lip is not provided is peculiar.

  It was confirmed that the torque value C when the tightening allowance of the main lip 16 was set to the same level as in the above-described embodiment was the same as the torque value A of the invention as shown in FIG. As shown in FIG. 5, “C” was about ½ of the current product X, and it was found that the sealing performance was inferior to that of A and B. This is considered to be due to the fact that the auxiliary lip 17 and the grease reservoir 24 in the embodiment are not provided, but conversely, the auxiliary lip 17 and the grease reservoir 24 in the embodiment contribute to the improvement of the leakage performance. means.

  In the example of reference proposal shown in FIG. 34 (b), the inner diameter portion of the cored bar 12 is bent inwardly in a dogleg shape, and the synthetic rubber 13 approaches the inner groove wall 18 of the seal groove 9 along the bending. The second sub lip 17a, 17b is provided on the surface facing the inner groove wall 18, and the third sub lip 17c is provided along the groove bottom 20 of the seal groove 9. . Labyrinth seals 19a, 19b, and 19c are formed by these auxiliary lips 17a to 17c. A constricted portion 14 is formed on the surface opposite to the sub lips 17a to 17c, that is, on the outer surface, and the outer surface of the main lip 16 is continuous with the tip of the constricted portion 14, and the tip of the third-stage sub lip 17c is formed. The inner surface of the main lip 16 is continuous. A tip portion where the inner surface and the outer surface intersect with each other contacts the outer groove wall 21 of the seal groove 9 to form a contact seal 25.

  Compared with the above-described embodiment, the reference proposal example has three sub lips 17a to 17c (three labyrinth seals 19a to 19c), the sub lips 17a to 17c, the sub lip 17c, and the main lip. 16 The volume of the grease pool formed between the groove walls of the seal grooves 9 facing each other is small, the protruding amount of the auxiliary lip 17a in the axial direction is small, and the base of the auxiliary lip 17a is inclined inward. There is a remarkable difference in that it is continuous with the inner surface of the synthetic rubber 13.

  In this reference proposal example, the torque value D measured with the tightening allowance of the main lip 16 set to the same level as in the above-described embodiment is about the same as the torque value A of the invention as shown in FIG. It was confirmed that there was. As shown in FIG. 5, the sealing property D was not significantly different from C, and it was found that the sealing property was inferior to that of A and B. This is because the effect of the three-stage auxiliary lips 17a to 17c is not seen, the volume of the grease reservoir is small, the protruding amount of the auxiliary lip 17a in the axial direction is small, the outer diameter surface is inclined, and the synthetic rubber 13 is inclined. It is considered that the approach to the surface 31 has an influence.

It is sectional drawing of the rolling bearing which concerns on one Embodiment of this invention. It is sectional drawing which expands and represents the principal part of the rolling bearing. 3A is an enlarged sectional view showing a small groove portion of the sliding contact portion, and FIG. 3B is an enlarged sectional view showing a contact seal of the sliding contact portion. It is a chart showing the actual measurement result of the torque value of each embodiment. It is a chart showing the actual measurement result of the seal leakage amount of each embodiment. It is a perspective view of the holder | retainer of this embodiment. It is a perspective view of the retainer half which is a structural member of the retainer. It is a partial expansion perspective view which simplifies and shows a pocket shape about a part of the cage half. (A) is a partial enlarged perspective view highlighting an example of the inner surface of the spherical shell plate portion in the cage half, and (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. (A) is a partial enlarged perspective view highlighting another example of the inner surface of the spherical shell plate in the cage half, (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view. is there. (A) is a partial enlarged perspective view highlighting still another example of the inner surface of the spherical shell plate portion in the cage half, and (B) is a perspective view showing a state in which a virtual polygonal column is added to the perspective view. FIG. (A) is a partial enlarged perspective view highlighting still another example of the inner surface of the spherical shell plate portion in the cage half, (B) is a perspective view showing a state in which a virtual cylinder is added to the perspective view It is. It is explanatory drawing which shows the relationship between the spherical shell-shaped board part and a virtual ring in a cross section. It is explanatory drawing which shows the manufacturing process of the holder | retainer of this embodiment. It is a perspective view of the press die set used for the manufacturing process. It is explanatory drawing of the result of the grease leak test of the rolling bearing incorporating the cage | basket of the structure shown in FIG. It is explanatory drawing of the result of the grease leak test of the rolling bearing incorporating the cage | basket of the structure shown in FIG. It is explanatory drawing of the result of the grease leak test of the ball bearing incorporating the general iron plate punching cage. It is a disassembled perspective view of the resin-made cage to which the cage of this embodiment is applicable. It is sectional drawing of the resin cage. It is a partially broken perspective view of the rolling bearing incorporating the retainer concerning other embodiments of this invention. It is a partial expansion perspective view which shows the spherical shell-shaped board part in the cage half body of the same cage. It is a top view which shows the assembly which integrated the holder | retainer of the embodiment in the inner ring | wheel. It is a partial expansion perspective view which shows the modification of the spherical shell-shaped board part in the cage half body of the same cage. It is a front view of the holder | retainer integrated in the rolling bearing concerning one Embodiment of this invention. It is AA sectional drawing of FIG. It is a figure which shows the test result performed with respect to the ball bearing incorporating the said holder | retainer. It is a front view of a different holder. It is a disassembled perspective view which shows the principal part of the annular member of the holder. It is a front view of the holder | retainer concerning different embodiment of this invention. It is a front view of the conventional cage | basket. It is a figure which shows the test result performed with respect to the ball bearing incorporating the said holder | retainer. It is a figure showing other embodiment etc. of this invention, FIG.33 (a) is a principal part expanded sectional view of Embodiment 2, and FIG.33 (b) is a partially expanded sectional view of a comparative example. FIG. 34A is a partially enlarged cross-sectional view of Reference Proposed Example 1 and FIG. 34B is a partially enlarged cross-sectional view of Reference Proposed Example 2;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner ring 3 ... Inner ring outer diameter surface 4, 4A, 4B ... Cage 4Ba ... Pocket 5 ... Outer ring 6 ... Seal member fixing groove 8 ... Ball 9 ... Seal groove 11 ... Seal member 15 ... Branching part 16 ... Main lip 17 ... Sub lip 18 ... inner groove wall 19 ... labyrinth seal 21 ... outer groove wall 25 ... contact seal 50 ... pocket 54 ... recessed portion Rp, Ri ... radius

Claims (6)

A plurality of balls interposed between the inner and outer rings are held by a cage, a seal groove is formed in the circumferential direction on the outer diameter surface of the inner ring, and the outer peripheral edge of the seal member is fixed to the inner diameter surface of the outer ring facing the seal groove. The main lip and the sub lip are provided on the inner peripheral portion of the seal member, the main lip is brought into contact with the seal groove to form a contact seal, and the sub lip is brought close to the seal groove or the vicinity thereof to form a labyrinth seal. In the rolling bearing formed by
A branch portion is provided at a position near the height of the inner ring outer diameter surface of the seal member, the main lip is formed by a portion protruding in the inner diameter direction from the branch portion, and a tip end portion of the main lip is formed on the seal groove. The contact seal is formed in contact with the outer groove wall, the sub lip is formed by a portion protruding inward in the axial direction from the branch portion, and the tip of the sub lip and the inner groove wall of the seal groove Forming the labyrinth seal between,
The cage has pockets for holding a plurality of balls at a plurality of locations in the circumferential direction, and the inner surface of each pocket is closer to the inner diameter side opening edge of the cage than the ball arrangement pitch circle. A ring-shaped cage having a concave curved surface shape having a small diameter according to the above, wherein the inner surface of each pocket is provided with a recessed portion extending from the opening edge on the cage inner diameter side to the cage outer diameter side. bearing. A plurality of balls interposed between the inner and outer rings are held by a cage, a seal groove is formed in the circumferential direction on the outer diameter surface of the inner ring, and the outer peripheral edge of the seal member is fixed to the inner diameter surface of the outer ring facing the seal groove. The main lip and the sub lip are provided on the inner peripheral portion of the seal member, the main lip is brought into contact with the seal groove to form a contact seal, and the sub lip is brought close to the seal groove or the vicinity thereof to form a labyrinth seal. In the rolling bearing formed by
A branch portion is provided at a position near the height of the inner ring outer diameter surface of the seal member, the main lip is formed by a portion protruding in the inner diameter direction from the branch portion, and a tip end portion of the main lip is formed on the seal groove. The contact seal is formed in contact with the outer groove wall, the sub lip is formed by a portion protruding inward in the axial direction from the branch portion, and the tip of the sub lip and the inner groove wall of the seal groove Forming the labyrinth seal between,
The cage has pockets for holding a plurality of balls at a plurality of locations in the circumferential direction, and the radius from the cage center of the inner diameter of the circumferential portion with the pockets is set to the circumferential portion between the pockets. A rolling bearing characterized by having a larger inner diameter than the radius from the cage center.   3. The main lip and the sub lip that are continuous in an inverted L shape through the branch portion, and an inner groove wall of the seal groove that faces the lip, and communicate with the interior of the bearing in the labyrinth seal. And a rolling bearing in which a grease reservoir closed in the contact seal is formed.   3. The rolling bearing according to claim 2, wherein an inner diameter surface of a circumferential portion having the pocket has a polygonal shape having a plurality of corner portions when viewed from the axial direction.   The radius of the maximum diameter portion of the sub lip is made larger than the radius of the inner ring outer diameter surface according to any one of claims 1 to 4, and the tip end portion of the sub lip is based on the inner ring outer diameter surface. A rolling bearing having a tapered surface with an inclined angle of 90 degrees or more.   6. The labyrinth seal according to claim 5, wherein an inner diameter surface of the sub lip is inclined at a constant angle with respect to the outer diameter surface of the inner ring, and a labyrinth seal is formed between the inclined inner diameter surface of the sub lip and the inner groove wall of the seal groove. Formed rolling bearing.

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