JP4948254B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing and, for example, relates to a technique for solving grease leakage of a ball bearing used for a rotation support portion and the like, and realizing muddy water resistance.

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 there are problems such as grease leakage resistance and mud water resistance. If the seal type is a contact type, the muddy water resistance is increased, but the torque is increased. In addition, a so-called respiration phenomenon causes grease leakage and adsorption, resulting in high torque. 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) The axial thickness of the seal lip is defined (for example, Patent Document 2).
JP 2001-140907 A Japanese Patent No. 3062673

The one disclosed in Patent Document 1 prevents grease leakage and muddy water intrusion, and does not discharge muddy water in the seal groove portion of the bearing ring. Therefore, there is a problem that the seal lip is worn by the muddy water that has entered the seal groove of the race. Further, the one disclosed in Patent Document 1 lacks versatility because the axial thickness of the seal lip is not constant and cannot be defined.
Since the thing disclosed by the said patent document 2 does not prescribe | regulate a fastening allowance, a sealing performance cannot be ensured.

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

In the first rolling bearing according to the present invention, a plurality of balls interposed between inner and outer rings are held by a cage, a contact seal is fixed to the outer ring, and a tip of a seal lip of the contact seal is provided on the outer peripheral surface of the inner ring. was in contact with the inner wall of the seal groove, the bearing space between the inner ring and the outer ring tightly sealed in the rolling bearing grease is sealed in the bearing space, the tip of the seal lip of the contact seal, said seal groove The retainer is brought into contact with the inner wall of the seal groove at a contact position lower than the upper end position of the outer wall facing the inner wall, and the retainer has pockets respectively holding a plurality of balls at a plurality of positions in the circumferential direction. The inner surface of the pocket is a ring-shaped cage in which the portion on the inner diameter side of the ball arrangement pitch circle becomes a concave curved surface having a smaller diameter as it approaches the cage inner diameter side opening edge, on the inner surface of each pocket, Cage inner diameter side Opening edge Ru extends cage outer diametric side from and providing a concave viewed part to eliminate the grease adhering to the inner ring of the outer peripheral surface.

According to this configuration, when the tip of the seal lip of the contact seal is brought into contact with the inner wall of the seal groove at a contact position lower than the upper end position of the outer wall facing the inner wall of the seal groove, the scattered muddy water is directly Since it does not hit the tip of the seal lip, even if it is used in an environment where muddy water etc. scatters, the tip of the seal lip is stably in contact with the inner wall of the seal groove, ensuring sufficient sealing performance of the contact seal can do.
Furthermore, the inner surface of each cage pocket is provided with a recess extending from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage, making it difficult for grease to adhere to the seal groove of the inner ring and preventing grease leakage. . 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, for example, a slinger 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 of the second invention in this invention, a plurality of balls interposed between inner and outer rings are held by a cage, and a seal groove formed on the side of the race of the inner ring and an end of the inner ring Forming a shoulder in between, attaching a seal member to the inner peripheral surface of the outer ring facing the seal groove, and a main lip contacting the track-side groove wall of the seal groove on the inner peripheral portion of the seal member; set only a labyrinth lip projecting above the shoulder, in the rolling rising bearing grease in the bearing space between the inner and outer rings is sealed, the inner peripheral side leading end portion of the sealing member, and the main lip and the labyrinth lip Providing an inner peripheral surface facing the seal groove on the main lip, and forming an inclined surface gradually increasing in diameter toward the tip of the labyrin slip on the inner periphery of the labyrin slip, , Multiple balls each Rings with holding pockets at multiple locations in the circumferential direction, and the inner surface of each pocket having a concave curved surface shape whose inner diameter side of the ball arrangement pitch circle becomes smaller as it approaches the cage inner diameter side opening edge a Jo of the cage, said the inner surface of each pocket, the cage Ru extends radially inner side cage outer diametric side from an opening edge of, providing a concave viewed part to eliminate the grease adhering to the inner ring of the outer peripheral surface Features.

According to this configuration, the inner lip is provided with an inner peripheral surface facing the seal groove, and an inclined surface that gradually increases in diameter toward the tip of the labyrin slip is formed on the inner periphery of the labyrin slip. The muddy water accumulated in the seal groove moves from the inner peripheral surface of the main lip along the inclined surface of the labyrin slip by the centrifugal force generated by the rotation of the seal member, and is discharged outside the bearing.
Furthermore, the inner surface of each cage pocket is provided with a recess extending from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage, making it difficult for grease to adhere to the seal groove of the inner ring and preventing grease leakage. . Other operations and effects similar to those of the first invention are provided.

The rolling bearing of the reference proposal example is a seal in which a plurality of balls interposed between inner and outer rings are held by a cage, a contact seal is fixed to the outer ring, and the tip of the seal lip of the contact seal is provided on the outer peripheral surface of the inner ring. In a rolling bearing that contacts the inner wall of the groove and seals the bearing space between the inner ring and the outer ring, the tip of the seal lip of the contact seal is positioned higher than the upper end position of the outer wall facing the inner wall of the seal groove. The retainer is brought into contact with the inner wall of the seal groove at a low contact position, and the retainer has pockets for retaining a plurality of balls at a plurality of positions in the circumferential direction, and a retainer having an inner diameter of a circumferential portion with the pocket The radius from the center is larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets.

According to this configuration, when the tip of the seal lip is brought into contact with the inner wall of the seal groove at a contact position lower than the upper end position of the outer wall facing the inner wall of the seal groove, muddy water directly hits the tip of the seal lip. Therefore, the tip of the seal lip can be stably brought into contact with the inner wall of the seal groove, and the sealing performance of the contact seal can be sufficiently ensured.
Furthermore, 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 rolling bearing of the reference proposal example , a plurality of balls interposed between inner and outer rings are held by a cage, and a shoulder portion is formed between a seal groove formed on a side of the inner ring raceway and an end of the inner ring. And a seal member is mounted on the inner peripheral surface of the outer ring facing the seal groove, and a main lip that contacts the track-side groove wall of the seal groove is formed on the inner peripheral portion of the seal member, and the shoulder portion In a rolling bearing provided with a labyrinth slip protruding upward, the main lip and the labyrinth slip are provided at the inner peripheral side tip of the seal member, and an inner peripheral surface facing the seal groove is provided on the main lip. An inclined surface that gradually increases in diameter toward the tip of the labyrin slip is formed on the inner periphery of the labyrin slip, and the cage has pockets for holding a plurality of balls at a plurality of locations in the circumferential direction. And the pocket Radius from the cage center of the inner diameter of the circumferential portion of the a, characterized by being larger than the radius of the circumferential portions cage center of the inner diameter of between pocket.

According to this configuration, the inner lip is provided with an inner peripheral surface facing the seal groove, and an inclined surface that gradually increases in diameter toward the tip of the labyrin slip is formed on the inner periphery of the labyrin slip. The muddy water accumulated in the seal groove moves from the inner peripheral surface of the main lip along the inclined surface of the labyrin slip by the centrifugal force generated by the rotation of the seal member, and is discharged outside the bearing.
Furthermore, 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 rolling bearing of the reference proposal example , a plurality of balls interposed between inner and outer rings are held by a cage, and a seal lip formed by an elastic member of a contact seal is pressed against a seal sliding contact surface provided on the inner ring or outer ring. In the rolling bearing that seals the bearing space between the inner ring and the outer ring, the pressing force of the seal lip against the seal sliding contact surface is set to 1.6 N or more and 4.0 N or less, and the cage includes a plurality of balls. Each holding pocket has a plurality of locations in the circumferential direction, and the inner surface of each pocket is formed into a concave curved surface shape whose inner diameter side is closer to the cage inner diameter side opening edge than the ball arrangement pitch circle. In the ring-shaped cage, a concave portion extending from the opening edge on the cage inner diameter side to the cage outer diameter side is provided on the inner surface of each pocket.

According to this configuration, by setting the pressing force of the seal lip to the seal sliding contact surface to 1.6 N or more, only the pressing force is defined so as to indirectly include the tightening margin of the seal lip, and the seal lip This ensures a good contact state with the seal sliding contact surface, and can ensure the sealing performance of the rolling bearing accurately with simple and versatile regulations. Furthermore, by setting the pressing force of the seal lip to the seal sliding contact surface to 4.0 N or less, the tightening margin of the seal lip is not undesirably increased, and the seal is prevented from warping outside the bearing, It is possible to prevent surface contact between the lip side surface and the seal sliding surface. Thereby, the sealing property can be kept good. The rigidity of the seal is large, 10 N / mm, and the maximum allowance is 0.4 mm.
Therefore, the upper limit pressing force obtained by multiplying the rigidity of 10 N / mm by the tightening allowance of 0.4 mm is 4.0 N. When the pressing force of the seal lip against the seal sliding contact surface exceeds 4.0 N, the sealing performance is inferior. Further, the upper limit value of the tightening allowance is defined as 0.4 mm. On the other hand, when the tightening allowance is larger than 0.4 mm, the seal warps to the outside of the bearing, and the lip side surface and the seal sliding surface come into surface contact with each other, resulting in poor sealing performance.
Furthermore, the inner surface of each cage pocket is provided with a recess extending from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage, making it difficult for grease to adhere to the seal groove of the inner ring and preventing grease leakage. . 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, for example, a slinger 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 of the reference proposal example , a plurality of balls interposed between inner and outer rings are held by a cage, and a seal lip formed by an elastic member of a contact seal is pressed against a seal sliding contact surface provided on the inner ring or outer ring. In the rolling bearing that seals the bearing space between the inner ring and the outer ring, the pressing force of the seal lip against the seal sliding contact surface is set to 1.6 N or more and 4.0 N or less, and the cage includes a plurality of balls. Each holding pocket has a plurality of circumferential positions, and the radius from the cage center of the inner diameter of the circumferential portion with the pocket is the radius from the cage center of the inner diameter of the circumferential portion between the pockets. It is characterized by being larger than.

According to this configuration, by setting the pressing force of the seal lip to the seal sliding contact surface to 1.6 N or more, only the pressing force is defined so as to indirectly include the tightening margin of the seal lip, and the seal lip This ensures a good contact state with the seal sliding contact surface, and can ensure the sealing performance of the rolling bearing accurately with simple and versatile regulations. Furthermore, by setting the pressing force of the seal lip to the seal sliding contact surface to 4.0 N or less, the tightening margin of the seal lip is not undesirably increased, and the seal is prevented from warping outside the bearing, It is possible to prevent surface contact between the lip side surface and the seal sliding surface. Thereby, the sealing property can be kept good.
Furthermore, the radius from the cage center of the inner diameter of the circumferential portion with the pocket of the cage is made larger than the radius from the cage center of the inner diameter of the circumferential portion between the pockets. Grease hardly adheres to 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.

In the present invention, it is preferable that the surface roughness of the seal sliding contact surface is 0.5 μm or more and 2.0 μm or less in terms of Rmax.
By setting the surface roughness of the seal sliding surface to Rmax of 2.0 μm or less, preferably 1.2 μm or less, it is possible to prevent an increase in torque loss due to friction with the seal lip and to suppress wear of the seal lip. Thus, the pressing force of the seal lip against the seal sliding contact surface can be stably held. Furthermore, by defining the surface roughness of the seal sliding contact surface as Rmax of 0.5 μm or more, it is possible to easily ensure the roughness accuracy when turning the seal groove, for example. Thereby, the yield of a product can be improved and the manufacturing cost can be reduced.

In the first rolling bearing of the present invention, the tip of the seal lip of the contact seal is brought into contact with the inner wall of the seal groove at a contact position lower than the upper end position of the outer wall facing the inner wall of the seal groove. the inner surface of each pocket of the cage, the cage Ru extends radially inner side cage outer diametric side from an opening edge of, by providing the concave viewed part to eliminate the grease adhering to the inner ring of the outer peripheral surface, low torque, resistance to Grease leakage, muddy water resistance and space saving can be achieved simultaneously and at low cost.

In the second rolling bearing of the present invention, an inner peripheral surface facing the seal groove is provided on the main lip, and an inclined surface that gradually increases in diameter toward the tip of the labyrin slip is formed on the inner periphery of the labyrin slip. formed, further, on the inner surface of each pocket of the cage, Ru extends cage outer diametric side from an opening edge of the retainer inner diameter side, by providing the concave viewed part to eliminate the grease adhering to the inner ring of the outer peripheral surface In addition, low torque, grease leakage resistance, mud water resistance and space saving can be achieved simultaneously and at low cost.

  An embodiment of the present invention will be described with reference to FIGS. This rolling bearing includes an inner ring 1, an outer ring 2, a plurality of balls 3 provided so as to freely roll between the inner ring 1 and the outer ring 2, a cage 4 that holds these balls 3, an inner ring 1, and And an annular contact seal 5 fitted to both axial end surfaces of the outer ring 2. An inner ring raceway 1 kd on which the balls 3 roll is provided on the outer diameter surface of the inner ring 1, and an outer ring raceway 2 kd facing the inner ring raceway 1 kd is provided on the inner diameter surface of the outer ring 2.

The contact seal 5 has a metal core 5a and an elastic member 5b, and an axially inward seal lip 5c is provided on the inner peripheral side of the elastic member 5b. Inner diameter D _L of the tip of the seal lip 5c before incorporation into the bearing of the contact seal 5, is smaller than the diameter D ₁ of the upper end position of the outer wall 1b of the sealing groove 1a provided on the outer peripheral surface of the inner ring 1 The difference D _L −D ₁ between the inner diameter D _L and the diameter D ₁ is defined as a value of −0.2 mm or more so that the contact seal 5 can be easily incorporated into the bearing.

When the contact seal 5 is fixed to the locking groove 2a of the outer ring 2 and incorporated in the bearing, the tip 5ca of the seal lip 5c is connected to the inner wall 1c of the seal groove 1a of the inner ring 1, as shown in FIG. The contact is made at a contact height position that is lower in the radial direction by δ than the upper end position of the outer wall 1b facing these. Therefore, even if this rolling bearing is used in an environment where water, mud, etc. scatter, the water, mud, etc. do not directly contact the tip 5ca of the seal lip 5c, and the tip of the seal lip 5c is inside the seal groove 1a. Stable contact with the wall 1c.

The above-described rolling bearing is attached to a rotating test machine in an environment where water and mud foreign matter scatters intermittently, and the contact height position δ of the seal groove 1a of the tip 5ca of the seal lip 5c to the inner wall 1c is changed. A foreign matter intrusion test was conducted to investigate the amount of foreign matter intruded into the bearing space. The contact height position δ is −0.1 mm, −0.05 mm (example) lower in the radial direction than the upper end position of the outer wall 1b, and is equal to or higher than the upper end position of the outer wall 1b. It was changed to 0 mm, 0.05 mm, and 0.1 mm (comparative example). The amount of foreign matter intrusion was determined by measuring the mass increase W of the bearing before and after the test. The test conditions are as follows.
・ Bearing speed: 2000rpm
・ Test time: 3 hours

  FIG. 3 shows the result of the foreign matter penetration test. In FIG. 3, white circles represent examples, and black circles represent comparative examples. As can be seen from this test result, in each comparative example in which the contact height position δ of the tip 5ca of the seal lip 5c is the same as or higher than the upper end position of the outer wall 1b, the bearing mass increase amount W However, in each of the examples in which the contact height position δ is lower than the upper end position of the outer wall 1b, the bearing mass increase amount W is not significantly recognized, and foreign matter almost penetrates. Not. Therefore, by making the contact height position δ of the tip 5ca of the seal lip 5c lower than the upper end position of the outer wall 1b of the inner ring 1, the tip 5ca of the seal lip 5c is stably attached to the inner wall 1c of the seal groove 1a. It was confirmed that a sufficient sealing property can be secured by contacting them and preventing the entry of foreign matter.

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 1a 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. 4, the retainer 4 has pockets 50 for holding the balls 3 (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. 5 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. 6 is a diagram in the case where the pocket inner surface is a monotonous spherical surface in a portion corresponding to FIG. In FIG. 6, a portion A indicated by a two-dot chain line indicates a circumferential band in which the flat plate portions 51 a in 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. 7, the inner surface of the pocket 50 (spherical shell plate portion 50 </ b> A) of the retainer 4 of this embodiment is formed on the inner diameter side portion 50 </ b> Ai of the retainer 4 from the opening edge on the inner diameter side of the retainer. 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 3 (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 3 and is less than 1.05 of the radius of the ball 3.

  FIG. 8 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 more specifically, as shown in FIG. 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 3. 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. 9 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 shown in FIG. 8, the cross-sectional shape (the 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. The other configuration in this embodiment is the same as the example of FIG.

  FIG. 10 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. 8 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. 6 to 10, 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. 12 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. 12A, 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 composed of a concave side press die 57 is prepared, and the ring-shaped metal band 55 is sandwiched between the convex side press die 56 and the concave side 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 cage halves 51 thus obtained are overlapped as shown in FIG. 12C, and the portion where the flat plate portion 51a of the cage half 51 is overlapped as shown in FIG. To form a cage 4.

  FIG. 13 shows the convex half pressing die 56 and the concave side pressing die 57 used for the finishing pressing step in press molding for molding the cage half 51 shown in 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. 8 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.

  Further, the shape and surface roughness of the hemispherical convex surface of the convex press die 56 used in the finishing pressing step are transferred to the inner surface of the cage pocket 50, and the pocket inner surface is inserted into the ball 3 ( 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.

14 to 16 show test results of confirming the grease adhesion state. In this test, a ball bearing incorporating the cage 4 of this embodiment (the embodiment of FIG. 7 and the embodiment of FIG. 8) 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. 14 and FIG. 15 show the grease adhesion state of the ball bearing using the cage 4 of this embodiment (the embodiment of FIG. 7 and the embodiment of FIG. 8, respectively), and FIG. The grease adhesion state of the ball bearing using

From the test results of FIGS. 14 to 16, in the ball bearing (FIG. 16) in which a general steel plate punching cage is incorporated, grease adheres to the inner ring seal groove, but the ball bearing in which the cage 4 of this embodiment is incorporated. (Examples of FIGS. 14 and 15) 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-described embodiments, an iron plate punched cage is shown, but the present invention can also be applied to a resin cage 59 as shown in FIGS. 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 configuration of the rolling bearing described above, the tip 5ca of the seal lip 5c of the contact seal 5 is lower in the radial direction by δ than the upper end position of the outer wall 1b facing the inner wall 1c of the seal groove 1a of the inner ring 1. By making contact with the inner wall 1c of the seal groove 1a at a position, the scattered muddy water is prevented from directly hitting the tip of the seal lip 5c, so that the tip of the seal lip 5c can be used even in an environment where muddy water or the like scatters. 5ca can be stably brought into contact with the inner wall 1c of the seal groove 1a, and the sealability of the contact seal 5 can be sufficiently ensured.
Further, the cages 4 and 59 have pockets 50 that respectively hold a plurality of balls 3 at a plurality of locations in the circumferential direction, and the inner surface of each pocket 50 has a portion on the inner diameter side of the ball arrangement pitch circle PCD. The ring shape is a concave curved surface having a smaller diameter as it approaches the opening edge on the inner diameter side of the cage, and a recessed portion 54 (54A) extends on the inner surface of each pocket 50 from the opening edge on the inner diameter side of the cage to the outer diameter side of the cage. , 54B, 54C), it is difficult for grease to adhere to the seal groove 1a 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. 7, 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. 8, the recesses 54A are provided at a plurality of positions on both sides of the center OW50 in the cage circumferential direction at the opening edge of the pocket 50, and the inner shape of each recess 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.

  In addition, as shown in FIGS. 10 and 11, for example, as shown in FIGS. 10 and 11, 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.

19 to 21 show reference proposal examples . The rolling bearing retainer 4A according to this reference proposal example 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 the balls 3 in 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. 19 and 21, the cage 4 </ b> A has a range overlapping in the axial direction with the inner ring outer diameter surface 1 g which is the shoulder height on both sides of the inner ring raceway 1 kd 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 positioned on the inner ring outer diameter surface 1g, which is the shoulder height on both sides of the inner ring raceway 1kd, of the inner ring 1 thinner than the plate thickness t0 of the flat plate portion 51a. The inner ring outer diameter surface 1g which becomes the shoulder height is an outer diameter surface portion continuing at the height of the shoulder portion of the inner ring raceway 1kd of the inner ring 1, and when the seal groove 1a is formed, the inner ring raceway 1kd and the seal are sealed. It is an outer diameter surface portion between the grooves 1a. In the spherical shell-shaped plate portion 50A, the plate thickness t1 of the portion located in the axial range W of the inner ring outer diameter surface 1g is made thinner than the plate thickness t0 of the other portions. In addition, in FIG. 19, the cross-sectional shape in case the spherical shell-shaped board part 50A is not thinned is shown by the 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 reference proposal example , as shown in FIG. 20, in the arc-shaped range along the inner diameter edge of the spherical shell-shaped plate portion 50A, both ends are left and the whole is thinned. Depending on the relationship between the inner ring outer diameter surface 1g and the width of the cage 4A, the thin-walled portion 50Aa having a reduced plate thickness is formed on both sides excluding the center of the arc of the inner diameter edge of the spherical shell-like plate portion 50A as shown in FIG. 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, and this thin-walled portion 50Aa is the inner ring outer diameter at the height of the shoulder of the inner ring 1. It is a portion that overlaps the surface 1g in the axial direction, and is a portion where the grease adhering to the surface of the ball 3 is scraped by the cage 4A, or the scraped grease moves. If the plate thickness t1 of the 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 1g of the inner ring 1 decreases, and as a result, the grease goes outside 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 plate thickness is reduced only in the range W that overlaps the inner ring outer diameter surface 1g serving as the shoulder portion of the inner ring 1 in the axial direction, 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 4A for the rolling bearing, the frequency and amount that can reach the inner ring outer diameter surface 1g 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 1a 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 1a 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 from a circular plate having a uniform thickness by a press, the clearance distribution between a pair of molds is reduced so that only the thickness of the region shown in FIGS. 20 and 22 is reduced. It may be changed. Further, 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. .

23 to 25 show reference proposal examples . A rolling bearing cage 4B according to this reference proposal example 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 the balls 3 (FIG. 1) as the balls 3 are formed at equal intervals in the circumferential direction. The inner circumferential 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 reference proposal example , 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.

Since the retainer 4B of this reference proposal example 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, 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. 29 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 reference proposal example 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. The state of adhesion of grease to each part of the bearing after the operation was stopped was as shown in FIG. For comparison, the bearing incorporating the conventional cage Hr shown in FIG. 29 was also tested under the same conditions. 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 reference proposal example , 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 this case, as in the cage 4C shown in FIGS. 26 and 27, the coupling plate portion 64b is provided with an engagement claw 66 and an engagement 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. 28 shows different reference proposal examples . 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, this reference proposal example shows that the radius from the cage center of the inner diameter of the circumferential portion with the pocket is 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 larger than that.
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 5c (FIG. 1), 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, another embodiment of the present invention will be described with reference to FIGS. 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.

As shown in FIGS. 31 and 32, the rolling bearing according to this embodiment has an inclined surface 22 that gradually increases in diameter toward the tip of the labyrin slip on the inner periphery of the labyrin slip described later in the seal member 5A. It differs from the above-described embodiment in that it is formed. Other configurations are the same as those in the above-described embodiment.
Circumferential seal grooves 1a and 1a are formed on both sides of the inner ring raceway 1kd of the inner ring 1 of the rolling bearing, and locking grooves 2a and 2a are formed on the inner peripheral surface of the outer ring 2 facing the seal grooves 1a. . The outer peripheral edge 9 of the sealing member 5A is press-fitted and fixed in the locking groove 2a.

  As shown in FIG. 32, the seal groove 1 a includes a groove wall 14 on the inner ring raceway 1 kd side of the inner ring 1, that is, a raceway side groove wall 14, a bottom surface 21, and a shoulder side groove wall 23. The shoulder portion side groove wall 23 is a groove wall on the shoulder portion 15 side formed between the bottom surface 21 and the outer peripheral surface 24 of the shoulder portion 15 of the inner ring 1. The shoulder-side groove wall 23 is formed so as to be inclined outward in the axial direction and to be continuous with the outer peripheral surface 24 of the shoulder 15.

  The seal member 5 </ b> A is obtained by reinforcing an elastic body 11 made of synthetic rubber or the like with a cored bar 10. As the synthetic rubber or the like used for the elastic body 11, for example, hydrogenated nitrile rubber or ester acrylic rubber can be employed. The hydrogenated nitrile rubber has superior heat resistance and no problem with chemical resistance compared to nitrile rubber generally used as a sealing member, so it maintains stable properties and is used at higher temperatures. Can do. The ester-resistant acrylic rubber is superior in heat resistance to nitrile rubber as well as hydrogenated nitrile rubber, and has improved chemical resistance against chemicals such as ester oil of acrylic rubber and compressor oil of air conditioner. , Maintain stable properties and can be used at higher temperatures.

  The seal member 5 </ b> A has a constricted portion 12 having a small thickness at the portion of the elastic body 11 on the inner periphery thereof. The constricted portion 12 is formed to be thinner toward the outer diameter side from a main lip 16 or a labyrinth slip 17 which will be described later or from both of them including a boundary thereof. A seal lip 13 is provided at the inner peripheral end of the constricted portion 12, and the seal lip 13 is provided above the shoulder lip 16 and the main lip 16 that is in contact with the track-side groove wall 14 of the seal groove 1a. That is, it has a labyrinth slip 17 protruding outward in the radial direction.

The main lip 16 faces the track-side groove wall 14 of the seal groove 1a and has an inclined wall surface 19 whose diameter increases outward, and is positioned radially inward of the inclined wall surface 19 and faces the bottom surface 21 of the seal groove 1a. And an end portion 27 that makes the inner peripheral surface 20 of the inclined wall surface 19 continuous.
When the outer peripheral edge portion 9 of the seal member 5A configured as described above is press-fitted and fixed in the seal member locking groove 2a of the outer ring 2, the tip portion 27 of the main lip 16 is brought into contact with the track-side groove wall 14 of the seal groove 1a. Make sliding contact. The main lip 16 is provided at the distal end portion of the constricted portion 12 formed to be thin, and the constricted portion 12 is elastically deformed in the axial direction, so that the followability of the seal groove 1a in sliding contact with the track-side groove wall 14 is achieved. Is maintained. Thereby, it is possible to prevent grease inside the bearing from leaking into the seal groove 1a, and further to prevent foreign matter and muddy water from entering the inside of the bearing.

  The labyrinth slip 17 faces the range from the shoulder 15 to the shoulder-side groove wall 23 of the seal groove 1a, and a labyrinth seal 18 is formed. An inclined surface 22 is provided on the inner peripheral portion of the labyrinth slip 17 to reduce the diameter inward. The inclined surface 22 is set to have an inclination angle α of 10 degrees or more and 40 degrees or less with respect to the outer peripheral surface 24 of the shoulder portion 15 of the inner ring 1. When the inclination angle α of the inclined surface 22 of the labyrin slip 17 is set in this way, the muddy water adhering to the inclined surface 22 of the labyrin slip 17 moves along the inclined surface 22 by centrifugal force due to the rotation of the seal member 5A. It moves outward in the axial direction and is discharged to the outside of the bearing.

  The reason why the inclination angle α is defined as described above is that when the inclination angle α is less than 10 degrees, the centrifugal force due to the rotation of the seal member 5A does not sufficiently act on the muddy water adhering to the labyrin slip 17, so that the muddy water It is because it becomes difficult to be discharged. If the inclination angle α exceeds 40 degrees, the clearance between the outer peripheral surface 24 of the shoulder portion 15 of the inner ring 1 and the inclined surface 22 of the labyrinth slip 17 becomes wide, and the sealing performance by the labyrinth seal 18 decreases. It is.

  In addition, the labyrinth slip 17 is provided at a tip portion near the shoulder side wall 23 of the seal groove 1a. By doing so, the muddy water adhering to the labyrin slip 17 is inclined by the centrifugal force due to the rotation of the seal member 5A, compared to the case where the tip of the labyrin slip 17 is also provided near the end of the inner ring 1. The distance traveled on the surface 22 is shortened, and the muddy water accumulated in the seal groove 1a is more easily discharged.

  Further, a step portion 25 is provided between the inner peripheral surface 20 of the main lip 16 and the inclined surface 22 of the labyrin slip 17, and this step portion 25 is directed toward the shoulder side groove wall 23 of the seal groove 1a. Protrusively provided. As a result, the inner peripheral surface 20 of the main lip 16 is formed continuously to the inclined surface 22 of the labyrin slip 17 through the step portion 25, so that muddy water accumulated in the seal groove 1a is rotated by the seal member 5A. It is easy to be discharged to the outside of the bearing along the inclined surface 22 of the labyrin slip 17 by the centrifugal force.

  Further, when the step portion 25 is provided so as to protrude, a narrowed portion is formed between the outer peripheral edge portion of the inner peripheral surface 20 of the main lip 16 and the shoulder side groove wall 23 of the seal groove 1a. With this narrowed portion, the sealing performance by the labyrinth seal 18 can be secured. Further, since a narrowed portion is also formed between the crest 26 of the boundary between the seal groove 1a and the shoulder 15 of the inner ring 1 and the inclined surface 22 of the labyrinth slip 17, further sealing by the labyrinth seal 18 is performed. Sex can be secured.

  In order to confirm the effect of the present invention, a test conducted by the applicant will be described. In order to clarify the relationship between the inclination angle of labyrin slip and the sealing performance, this test verified the inclination angle of labyrin slip and muddy water discharge performance, and operated under the following operating conditions. The muddy water was sprayed for a predetermined time, and the residual state of the muddy water in the bearing after the test was confirmed.

(Operating conditions)
・ Muddy water: Kanto loam powder JIS 8 types 10wt%
・ Bearing speed: 2000 rpm
・ Test time: 3 hours (specimen)
Material: Synthetic rubber (acrylonitrile butadiene rubber; abbreviated NBR)

The structure of the seal lip of each example and comparative example is as shown below.
Example 1: The inclination angle α formed by the inclined surface 22 of the labyrinth slip 17 and the outer peripheral surface 24 of the shoulder 15 of the inner ring 1 is set to 40 degrees.
Example 2: The inclination angle α is set to 10 degrees. Other structures are the same as those in the first embodiment.
Comparative Example 1: As shown in FIG. 33, the inclination angle α formed by the inclined surface 22 of the labyrinth slip 17 and the outer peripheral surface 24 of the shoulder 15 of the inner ring 1 is 0 degree, that is, the inclined surface and the outer peripheral surface are Those set in parallel. Other structures are the same as those in the first embodiment.
Comparative Example 2: As shown in FIG. 34, the inclination angle α is minus 20 degrees, that is, the inclined surface 22 of the labyrin slip 17 is reduced outward, and the inclination angle of the shoulder 15 with respect to the outer peripheral surface 24 is 20 degrees. What was set. Other structures are the same as those in the first embodiment.

As described above, in any of the first embodiment in which the inclination angle α is 40 degrees and the second embodiment in which the inclination angle α is 10 degrees, no muddy water remains and the muddy water collected in the seal groove 1a of the bearing is drained. It was easy to be done.
However, in the case of the comparative example 1 in which the inclination angle α shown in FIG. 33 is 0 degree, the muddy water remains in the bearing and the muddy water is hardly discharged. Further, in the case of Comparative Example 2 in which the inclination angle α shown in FIG. 34 is −20 degrees, as in Comparative Example 1, the muddy water remains inside the bearing and the muddy water is hardly discharged.
As described above, by defining the inclination angle α of the inclined surface 22 of the labyrinth slip 17 with respect to the outer peripheral surface 24 of the shoulder 15 of the inner ring 1, muddy water can be easily discharged to the outside of the bearing.
Furthermore, in the rolling bearing according to this embodiment, by applying the cages 4 and 59, it is difficult for grease to adhere to the seal groove 1a 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.

Next, a reference proposal example will be described with reference to FIGS. The rolling bearing according to this reference proposal example is different from the embodiment described above in that the pressing force of the seal lip against the seal sliding contact surface is set to 1.6 N or more and 4.0 N or less. Other configurations are the same as in exemplary form status or references proposed example described above.
As shown in FIGS. 35 and 36, the contact seal 5B includes a cored bar 5a and an elastic member 5b. A neck portion 5cn is provided at a portion extending from the core bar 5a of the elastic member 5b, that is, an inner diameter portion. A seal lip 5d is provided at the distal end portion of the neck portion 5cn on the radially inner side. The seal lip 5d is pressed from the outside in the axial direction against the seal sliding contact surface 1sm provided on the side wall of the seal groove 1a extending in the circumferential direction on the outer peripheral surface of the inner ring 1. As described above, the pressing force P of the seal lip 5d against the seal sliding contact surface 1sm is set to 1.6 N or more and 4.0 N or less. Further, the surface roughness Rmax of the seal sliding contact surface 1 sm is 0.5 μm or more and 2.0 μm or less, preferably 1.2 μm or less.

  As an example, a deep groove ball bearing as shown in FIG. 35 in which the pressing force P of the seal lip 5d was set to 1.6 N or more and 4.0 N or less was prepared. As a comparative example, the same deep groove in which the ratio P / L between the pressing force P of the seal lip and the axial tightening allowance L is 4.8 N / mm or more and 8.8 N / mm or less and the pressing force P is less than 1.6 N A ball bearing was prepared. As shown in FIG. 37, the pressing force P of each seal lip is such that the outer ring 2 fitted with the contact seal 5B is set horizontally on the frame KD of the compression tester AS, and the pressure lip HD1 is used to seal the seal lip of the contact seal 5B. Was obtained by measuring the load when a vertical displacement amount corresponding to a predetermined axial interference was pressed.

  The deep groove ball bearings of the example and the comparative example both have a ratio a between the radial length a including the neck portion 5cn and the seal lip 5d of the contact seal 5B and the axial thickness b of the neck portion 5cn shown in FIG. / B was set to 3.2. Further, the surface roughness Rmax of the seal sliding contact surface 1 sm was set to 0.5 μm or more and 1.2 μm or less in both the examples and the comparative examples.

The deep groove ball bearings of the above-described examples and comparative examples were attached to a rotating test machine in an environment where muddy water was sprayed, and a muddy water resistance test was conducted to investigate the amount of muddy water entering the bearing space. The amount of muddy water permeation was determined by measuring the mass increase W of the bearing before and after the test. The test conditions are as follows.
・ Muddy water: Kanto loam powder JIS 8 types (mud concentration 5 mass%)
・ Bearing speed: 2000 rpm
・ Test time: 3 hours

  FIG. 38 shows the result of the mud water resistance test. In FIG. 38, each white circle represents each bearing of the example, and each black circle represents each bearing of the comparative example. It can be seen that any of the examples in which the pressing force P of the seal lip is set to 1.6 N or more and 4.0 N or less does not show a significant increase in the mass W of the bearing, and has excellent sealing properties. On the other hand, when the pressing force P is less than 1.6 N, the ratio P / L between the pressing force P of the seal lip and the axial tightening allowance L is within the scope of the invention described in Patent Document 1. However, the increase in the mass W of the bearing is remarkably recognized and sufficient sealing performance is not ensured.

  According to the configuration of the rolling bearing described above, by setting the pressing force of the seal lip 5d against the seal sliding contact surface 1sm to 1.6 N or more, only the pressing force is included so as to indirectly include the tightening margin of the seal lip 5d. This ensures the good contact state of the seal lip 5d with the seal sliding contact surface 1sm, and the sealability of the rolling bearing can be ensured accurately with a simple and versatile rule. Further, by setting the pressing force of the seal lip 5d against the seal sliding contact surface 1sm to 4.0 N or less, the tightening margin of the seal lip 5d does not become undesirably large, and the seal warps outside the bearing. It is possible to prevent the lip side surface 5ds and the seal sliding surface 1sm from coming into surface contact with each other. Thereby, the sealing property can be kept good. The rigidity of the seal is large, 10 N / mm, and the maximum allowance is 0.4 mm.

Therefore, the upper limit pressing force obtained by multiplying the rigidity of 10 N / mm by the tightening allowance of 0.4 mm is 4.0 N. When the pressing force of the seal lip 5d against the seal sliding contact surface 1sm exceeds 4.0N, the sealing performance is inferior. Further, the upper limit value of the tightening allowance is defined as 0.4 mm. On the other hand, when the tightening allowance is larger than 0.4 mm, the seal warps to the outside of the bearing, and the lip side surface 5ds and the seal sliding contact surface 1sm come into surface contact, resulting in poor sealing performance.
Further, by setting the surface roughness of the seal sliding contact surface 1 sm to Rmax of 2.0 μm or less, preferably 1.2 μm or less, an increase in torque loss due to friction with the seal lip 5d can be prevented, and the seal lip 5d Wear can be suppressed and the pressing force of the seal lip 5d against the seal sliding contact surface 1sm can be stably held. Furthermore, by defining the surface roughness of the seal sliding contact surface 1 sm as Rmax of 0.5 μm or more, for example, it is possible to easily ensure the roughness accuracy when turning the seal groove. Thereby, the yield of a product can be improved and the manufacturing cost can be reduced.

Furthermore, in the rolling bearing according to this reference proposal example , by applying the cages 4 and 59, it is difficult for grease to adhere to the seal groove 1a 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.

It is sectional drawing of the rolling bearing which concerns on one Embodiment of this invention, Fig.1 (a) is sectional drawing showing the relationship between a contact seal and the seal groove of a bearing ring, FIG.1 (b) incorporates a contact seal. It is sectional drawing of a rolling bearing. It is sectional drawing which expands and shows the principal part of the contact seal. It is a graph which shows the result of a foreign material penetration test. 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 a rolling bearing incorporating a cage according to a reference proposal example . 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 same 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 the example of a reference proposal . 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 sectional drawing of the rolling bearing which concerns on other embodiment of this invention. It is sectional drawing which expands and represents the principal part of the sealing member of the rolling bearing. 10 is an enlarged cross-sectional view illustrating a main part of a seal member of Comparative Example 1. FIG. 10 is an enlarged cross-sectional view illustrating a main part of a seal member of Comparative Example 2. FIG. It is sectional drawing of the rolling bearing which concerns on a reference proposal example . It is sectional drawing which expands and represents the principal part of the contact seal of the rolling bearing. It is sectional drawing of the contact seal etc., (a) is sectional drawing which shows the method of measuring the pressing force of the seal lip of a contact seal, (b) is sectional drawing which expands and represents the principal parts, such as a contact seal. . It is a chart showing the result of a muddy water resistance test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a ... Seal groove 1b ... Outer wall 1c ... Inner side wall 1kd ... Inner ring track 1sm ... Seal ring contact surface 2 ... Outer ring 3 ... Ball 4 ... Cage 4A-4D ... Cage 5 ... Contact seal 5A ... Seal member 5B ... contact seals 5c, 5d ... seal lip 5ca ... tip 14 ... raceway groove wall 15 ... shoulder 16 ... main lip 17 ... labyrin slip 20 ... inner peripheral surface 22 ... inclined surface 50 ... pocket 54 ... dents 54A-54C ... dent Part PCD ... Ball arrangement pitch circle Rp, Ri ... Radius

Claims (2)

A plurality of balls interposed between the inner and outer rings are held by a cage, a contact seal is fixed to the outer ring, and the tip of the seal lip of the contact seal is brought into contact with the inner wall of a seal groove provided on the outer peripheral surface of the inner ring. , the bearing space between the inner ring and the outer ring tightly sealed in the rolling bearing grease is sealed in the bearing space,
The tip of the seal lip of the contact seal is brought into contact with the inner wall of the seal groove at a contact position lower than the upper end position of the outer wall facing the inner wall of the seal groove;
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. according to a ring-shaped retainer having a concave curved surface whose diameter, said the inner surface of each pocket, the cage Ru extends cage outer diametric side from an opening edge of the inner diameter side, of the grease into the inner ring of the outer peripheral surface rolling bearing and providing a concave viewed part to eliminate adhesion. A plurality of balls interposed between the inner and outer rings are held by a cage, a shoulder is formed between a seal groove formed on a side of the race of the inner ring and an end of the inner ring, and the seal groove A seal member is mounted on the inner peripheral surface of the opposed outer ring, and a main lip that contacts the track-side groove wall of the seal groove and a labyrinth slip protruding above the shoulder portion are provided on the inner peripheral portion of the seal member. only, the rolling rising bearing grease in the bearing space between the inner and outer rings is enclosed,
The main lip and the labyrinth slip are provided at the inner circumferential tip of the seal member, the inner lip is provided on the main lip so as to face the seal groove, and the labyrin slip is formed on the inner circumference of the labyrin slip. Form an inclined surface that gradually expands toward the tip,
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. according to a ring-shaped retainer having a concave curved surface whose diameter, said the inner surface of each pocket, the cage Ru extends cage outer diametric side from an opening edge of the inner diameter side, of the grease into the inner ring of the outer peripheral surface rolling bearing and providing a concave viewed part to eliminate adhesion.

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