JP6186833B2 - Rolling bearing with seal ring - Google Patents

Description

  The present invention is used to rotatably support a rotating member such as a rotating shaft with respect to a fixed part such as a housing part in a state where it is incorporated in a rotation supporting part of various rotating devices such as an automobile transmission. The present invention relates to an improvement of a rolling bearing with a seal ring.

  Various types of single-row or double-row rolling bearings such as ball bearings, roller bearings, and tapered roller bearings are widely used as bearings for incorporation into various rotation support portions. As such rolling bearings, rolling bearings with seal rings in which the opening in the axial direction is closed with a seal ring are also described in, for example, Patent Documents 1 to 4 and have been widely known. FIG. 6 shows an example of a conventional rolling bearing with a seal ring described in Patent Document 1.

  The ball bearing 1 with a seal ring includes an outer ring 3 having a deep groove type outer ring raceway 2 on an inner peripheral surface in the axial direction center portion, an inner ring 5 having a deep groove type inner ring raceway 4 on an outer peripheral surface in the axial direction center portion, and these outer ring raceways 2. And the inner ring raceway 4 are provided so as to be freely rollable, and each ball 6 is a rolling element. These balls 6 are rotatably held by a cage 7 in a state where they are arranged at equal intervals in the circumferential direction. Further, both end portions in the axial direction of the internal space 8 between the inner peripheral surface of the outer ring 3 and the outer peripheral surface of the inner ring 5 where the balls 6 are arranged are respectively provided with ring-shaped seal rings 9, 9 respectively. It is blocked by.

  Each seal ring 9 includes a metal core 10 and a seal material 11. Of these, the metal core 10 is formed into an annular shape by subjecting a metal plate such as a steel plate to press working such as punching and bending. The sealing material 11 is made of an elastic material such as an elastomer such as rubber, and is molded into an annular shape in a state where the core metal 10 is embedded, and is reinforced by the core metal 10. Further, the outer peripheral edge of each seal ring 9 is provided with an elastic locking part 12 formed by projecting the sealing material 11 radially outward from the outer peripheral edge of the cored bar 10. . On the other hand, the seal material 11 is sufficiently protruded radially inward from the inner peripheral edge of the cored bar 10 at the inner peripheral edge portion of each seal ring 9, and an axial seal lip is formed at a part thereof. A seal lip 13 is provided.

  In order to mount the seal rings 9 and 9 as described above, a concave groove-like locking groove 14 corresponding to the seal fixing portion described in the claims is formed on the inner peripheral surface of both end portions in the axial direction of the outer ring 3. , 14 are formed over the entire circumference. Further, on the outer peripheral surface of both end portions in the axial direction of the inner ring 5, concave groove-like seal grooves 15, 15 corresponding to the seal sliding contact portion described in the claims are formed over the entire circumference. Then, in the assembled state, the elastic locking portions 12 and 12 provided on the outer peripheral edge portions of the seal rings 9 and 9 are respectively locked to the locking grooves 14 and 14 and also provided on the inner peripheral edge portion. Further, the seal lips 13 and 13 are inserted into the seal grooves 15 and 15, respectively, and the inner surfaces of the seal lips 13 and 13 are slid around the outer surfaces of the seal grooves 15 and 15 over the entire circumference. Touching. As a result, the internal space 8 and the external space are blocked to prevent grease (not shown) existing in the internal space 8 from leaking to the external space, and foreign matter such as moisture and dust existing in the external space. Is prevented from entering the internal space 8.

  In recent years, there has been an increasing demand for lowering the torque of a rolling bearing with a seal ring, for example, for reducing the power consumption of various rotating devices in which the rolling bearing with a seal ring is incorporated. In view of such circumstances, in the case of the conventional structure described in Patent Document 1, by removing the distortion generated in the outer ring 3 and the inner ring 5 due to the heat treatment, the seal torque by the seal ring is kept low, The rotational torque of the ball bearing 1 with a seal ring is reduced. Specifically, the outer ring raceway 2 and the locking grooves 14 and 14 are ground simultaneously, and the inner ring raceway 4 and the seal grooves 15 and 15 are ground simultaneously. Thereby, the accuracy of the coaxiality between the outer ring raceway 2 and the locking grooves 14 and 14 and the accuracy of the coaxiality between the inner ring raceway 4 and the seal grooves 15 and 15 are increased, respectively. The surface roughness of each of the seal grooves 15 and 15 is lowered (the surface unevenness is restricted to 2 μm or less).

  Patent Documents 2 and 3 also describe techniques for reducing the rotational torque of a ball bearing with a seal ring by removing distortion generated in the outer ring and the inner ring due to heat treatment. Among these, Patent Document 2 describes that, similarly to Patent Document 1, grinding is simultaneously performed on the outer ring raceway and the locking groove, and grinding is simultaneously performed on the inner ring raceway and the seal groove. Patent Document 3 describes that the outer ring raceway and the locking groove are simultaneously cut and the inner ring raceway and the seal groove are simultaneously cut.

  However, even when the processing for reducing the rotational torque as described above is performed, in the case of the conventional structure, it is difficult to say that the rotational torque can be sufficiently reduced for the following reason. That is, as shown in FIG. 6, in the case of the ball bearing 1 with a seal ring, in order to fix the seal ring 9 to the outer ring 3, it is formed on the inner peripheral surface of the axial end portion of the outer ring 3. A structure is employed in which the elastic locking portion 12 provided on the outer peripheral edge of the seal ring 9 is locked in the concave groove-shaped locking groove 14 in a state of being elastically contracted in the axial direction. When such a fixing structure is adopted, the outer diameter dimension of the seal ring 9 is normally set smaller than the inner diameter dimension of the groove bottom of the locking groove 14. A radial gap 16 exists between the bottom of the locking groove 14. That is, in the case of the conventional structure, the radial position of the seal ring 9 is determined not only by the groove bottom of the locking groove 14 but also by the influence of the groove width of the locking groove 14. For this reason, no matter how much the accuracy of the concentricity of the locking groove 14 with respect to the outer ring raceway 2 is improved (even if the value of the concentricity is lowered), the concentric accuracy of the seal ring 9 with respect to the outer ring 3 is increased. It is not possible to make full use of this (reducing the amount of deviation of the center axis of the seal ring 9 from the center axis of the outer ring 3). In addition, the radial position of the seal ring 9 can change according to the degree of elastic deformation of the elastic locking portion 12. Therefore, in the case of the conventional structure, it is difficult to suppress the fluctuation of the leading edge of the seal lip 13, and it is necessary to secure a certain margin for the seal lip 13. For this reason, it becomes difficult to sufficiently reduce the rotational torque of the ball bearing 1 with a seal ring.

JP 2007-92793 A JP 2005-299730 A JP-A-6-246546 JP 2007-239919 A JP 2007-218378 A

  In view of the circumstances as described above, the present invention has been invented to realize a rolling bearing with a seal ring that can suppress the tightening margin of the seal lip and can sufficiently reduce the rotational torque.

The rolling bearing with a seal ring of the present invention includes an outer ring, an inner ring, a plurality of rolling elements, and a seal ring.
Of these, the outer ring has an outer ring raceway on the inner peripheral surface.
The inner ring has an inner ring raceway on an outer peripheral surface.
Each of the rolling elements is, for example, a ball or roller (including a cylindrical roller or a tapered roller), a needle, or the like, and is provided between the outer ring raceway and the inner ring raceway so as to roll freely.
The seal ring is present between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring, and closes the axial end opening of the space in which the rolling elements are installed. And a sealing material made of an elastic material reinforced by the cored bar.
Also, one of the inner and outer peripheral portions of the seal ring is provided on one peripheral surface of the inner peripheral surface of the outer ring in the axial direction and the outer peripheral surface of the inner ring in the axial direction. A seal lip provided on the seal material constituting the other peripheral edge portion of the inner peripheral surface of the outer ring in the axial direction and the outer peripheral surface of the inner ring in the axial direction. It is made to slidably contact with the seal | sticker slidable contact part provided in the other peripheral surface over the perimeter.

In particular, in the case of the present invention, the seal fixing portion and one peripheral edge portion of the seal ring fixed to the seal fixing portion are each formed in a cylindrical surface shape.
Specifically, one peripheral portion of the seal ring has a cylindrical shape as a peripheral surface, and the peripheral surface of the cylindrical portion provided on the core metal is entirely covered by a cylindrical cover provided on the seal material. It is configured by covering the circumference.
The wall thickness of the cylindrical cover is constant over the entire circumference and is 1/10 to 1/2 times the plate thickness of the cored bar.
The cylindrical portion is fitted and fixed (cylindrical fitting) with no gap to the seal fixing portion via the cylindrical cover portion .
Further, the coaxiality between the raceway surface provided on one raceway ring to which the seal ring is fixed and the peripheral surface of the seal fixing part among the outer ring and the inner ring is set to be the seal in the free state. It is 50% or less of the concentricity between the inner and outer peripheral edges of the ring.
Furthermore, the seal lip has a U-shaped cross section in its free state, and a radial seal in which the tip edge thereof is in sliding contact with the peripheral surface of the seal sliding contact portion, which is a grinding surface facing in the radial direction, over the entire circumference It is a lip.
In the present specification and claims, the term “concentricity” is used when referring to the deviation between the centers of two circles existing on the same virtual plane, and the two not existing on the same virtual plane are used. The term “coaxiality” is used to indicate the deviation between the central axes of circles (cylindrical surfaces).
“Concentricity” and “coaxiality” are dials for the diameter of the other circle (cylindrical surface) while rotating the other of the two circles (cylindrical surfaces) as a reference. This is the maximum value (twice the value of the misalignment) when measured multiple times with a gauge or the like, and is affected by machining accuracy and machining variations.

When carrying out the rolling bearing with a seal ring of the present invention, for example, as in the invention described in claim 2, the rolling element is held by a cage so as to be able to roll , and the cylindrical portion and the seal lip are It is also possible to superimpose the retainer in the radial direction.
When implementing this invention, the bus-line shape of the said seal sliding contact part can also be made into linear form.
The case of this, for example, as in the invention described in claim 3, wherein also may seal sliding portion as a cylindrical surface shape, or, as in the invention described in claim 4, the seal sliding The part may be a conical surface (inclined surface).

According to the rolling bearing with a seal ring of the present invention having the above-described configuration, it is possible to reduce the tightening margin of the seal lip and realize a structure that can sufficiently reduce the rotational torque.
That is, in the case of the present invention, the seal fixing portion provided on one of the race rings for fixing the seal ring is formed into a cylindrical surface, and one peripheral portion of the seal ring fixed to the seal fixing portion is formed into a cylindrical shape. It has a planar shape, and one peripheral part of the seal ring is fitted and fixed to the seal fixing part. For this reason, the accuracy of the concentricity of the seal fixing portion with respect to the raceway surface can be influenced substantially, and the concentric accuracy of the seal ring with respect to the one raceway can be influenced. Further, as in the conventional structure described above, it is caused by the elastic deformation of the elastic locking portion that occurs when the elastic locking portion constituting the seal ring is elastically locked in the locking groove of the race ring. There is no deviation in the radial position of the seal ring.
In addition, in the case of the present invention, the seal fixing portion has a simple cylindrical surface shape, and it is not necessary to form a concave groove (locking groove). Can be high. For this reason, the concentricity between the raceway surface provided on the one raceway ring and the seal fixing portion is restricted to 50% or less of the concentricity between the inner and outer peripheral edge portions of the seal ring.
Therefore, in the case of the present invention, one peripheral portion of the cylindrical seal ring is fitted and fixed (cylindrical fitting) to the cylindrical seal fixing portion, and the raceway surface. The concentric accuracy of the seal ring fixed to the seal fixing portion with respect to the one raceway ring can be sufficiently increased together with the fact that the accuracy of the concentricity of the seal fixing portion with respect to can be increased.
As a result, the runout of the tip edge of the seal lip can be kept small, and the tightening allowance of the seal lip can be kept small. For this reason, the rotational torque of the rolling bearing with seal ring can be sufficiently reduced. In addition, it is possible to employ a radial seal lip that has been difficult to employ in the conventional structure. Furthermore, since the seal fixing part has a cylindrical surface shape and it is not necessary to process the groove, the processing cost can be kept low.

Further, according to the third and fourth aspects of the invention, the processing of the seal sliding contact portion is facilitated and the processing accuracy can be increased, so that the surface roughness of the seal sliding contact portion can be reduced. Therefore, it is advantageous in reducing the rotational torque of the rolling bearing with seal ring. Further, since it is not necessary to form a concave groove (seal groove) as in the conventional structure described above in the seal sliding contact portion, the processing cost can be kept low.

The fragmentary sectional view equivalent to the left half part of FIG. 6 which shows the ball bearing with a seal ring of the 1st example of embodiment of this invention. The figure similar to FIG. 1 which shows the reference example regarding this invention . The figure similar to FIG. 1 which shows the 2nd example of embodiment of this invention . The figure similar to FIG. 1 which shows the 3rd example similarly. The figure similar to FIG. 1 which shows the 4th example similarly. The fragmentary sectional view which shows the ball bearing with a seal ring of an example of the conventional structure.

[First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention. The feature of this example is that the structure for fixing the seal ring 9a to the outer ring 3a is devised in order to reduce the rotational torque of the ball bearing 1a with seal ring. The configuration and operational effects of the other parts are basically the same as those of the conventional structure described above. Therefore, the following description will be focused on the part not described above and the characteristic part of this example.

  The ball bearing 1a with a seal ring has a deep groove type outer ring raceway 2 on the inner peripheral surface in the axial direction central portion, and an outer ring 3a that is a stationary ring that does not rotate during use, and a deep groove type inner ring on the outer peripheral surface in the axial direction central portion. An inner ring 5a that is a rotating wheel that has a track 4 and rotates during use, a ball 6 that is a rolling element provided between the outer ring track 2 and the inner ring track 4, and each of which is a rolling element. A ring-shaped seal ring 9a is provided which closes both axial end openings of the internal space 8 between the inner peripheral surface of the outer ring 3a and the outer peripheral surface of the inner ring 5a, where the balls 6 are arranged. . The balls 6 are held by a cage 7 so as to be able to roll while being arranged at equal intervals in the circumferential direction. The internal space 8 is filled with grease (not shown).

  Cylindrical fixing cylindrical surface portions 17 corresponding to the seal fixing portions recited in the claims are formed on the inner peripheral surfaces of both end portions in the axial direction of the outer ring 3a over the entire circumference. The fixing cylindrical surface portion 17 is formed over the entire width of the shoulder portion of the outer ring 3a, and is adjacent (continuous) to the outer ring raceway 2 in the axial direction. On the other hand, a cylindrical surface portion 18 for sliding contact corresponding to the seal sliding contact portion described in the claims is formed on the outer peripheral surface of both end portions in the axial direction of the inner ring 5a over the entire circumference. Yes. The sliding contact cylindrical surface portion 18 is formed over the entire width of the shoulder portion of the inner ring 5a and is adjacent (continuous) to the inner ring raceway 4 in the axial direction.

  In the case of this example, in order to increase the accuracy of the coaxiality of the fixing cylindrical surface portion 17 and the sliding contact cylindrical surface portion 18 and to keep the surface roughness of the sliding contact cylindrical surface portion 18 low, these fixing The cylindrical surface portion 17 for sliding and the cylindrical surface portion 18 for sliding contact are respectively processed as follows. First, the fixing cylindrical surface portion 17 will be described. After the outer ring 3a is subjected to heat treatment such as quenching or carburizing, the outer peripheral surface of the outer ring 3a is ground. Thereafter, with reference to the outer peripheral surface of the outer ring 3a, the inner peripheral surface of the axial end portion of the outer ring 3a is cut, and the fixing cylindrical surface portion 17 is formed on the inner peripheral surface of the axial end portion. Similarly, the outer ring raceway 2a is ground using the outer peripheral surface of the outer ring 3a as a reference. The coaxiality between the outer ring raceway 2 and the fixing cylindrical surface portion 17 is 50% of the concentricity between the inner and outer peripheral portions of the seal ring 9a in a free state (state before mounting) (1 / 2) The following. In addition, the surface roughness of the fixing cylindrical surface portion 17 is restricted to a range of 0.8 to 3.2 Ra (relatively rough value) in terms of arithmetic average roughness from the surface that prevents the axial displacement of the seal ring 9a. doing. In addition, after heat-treating the outer ring 3a, in the state where the axial end portion inner peripheral surface of the outer ring 3a is not cut, the value of the coaxiality of the axial end portion inner peripheral surface with respect to the outer ring raceway 2 is determined. Is about three times as large as that when cutting is performed due to the influence of heat treatment deformation.

  Next, the sliding cylindrical surface portion 18 will be described. After the inner ring 5a is subjected to heat treatment such as quenching and carburizing, the inner ring raceway 4 and the outer peripheral surface of the inner ring 5a in the axial direction are simultaneously ground using a grinding wheel. The sliding cylindrical surface portion 18 is formed on the outer peripheral surface of the end portion. The coaxiality between the inner ring raceway 4 and the sliding cylindrical surface portion 18 is set to 50% (1/2) or less of the concentricity between the inner and outer peripheral portions of the seal ring 9a in a free state. Yes. Further, in order to reduce the sealing torque of the seal lip 21 which will be described later, the surface roughness of the sliding contact cylindrical portion 18 is restricted to a range of 0.2 to 0.4 Ra in terms of arithmetic average roughness.

  The seal ring 9a includes an annular cored bar 10a and a sealing material 11a made of an elastic material such as an elastomer such as rubber reinforced by the cored bar 10a. Such a seal ring 9a is formed by placing the cored bar 10a in a cavity of a mold (not shown) and then molding an elastic material constituting the sealing material 11a on the cored bar 10a. Nitrile rubber, acrylic rubber, silicon rubber, fluorine rubber, ethylene propylene rubber, or the like can be used as an elastic material constituting such a sealing material 11a, and hydrogenated nitrile rubber that is difficult to plastically deform can be used.

  The core bar 10a is formed by bending a metal plate such as a mild steel plate, and has a substantially L-shaped cross section and an annular shape as a whole, and a cylindrical portion 19 having a cylindrical outer peripheral surface, and the cylindrical portion And an annular portion 20 bent at a right angle from the 19 axial outer end edges (the left end edge in FIG. 1) radially inward.

  The sealing material 11a is coupled to the core metal 10a by baking, vulcanization adhesion, or the like. The sealing material 11a covers the entire outer periphery of the cylindrical portion 19 and the single sealing lip 21 attached and supported on the inner peripheral edge of the annular portion 20 over the entire periphery. A thin-walled cylindrical cover portion 22 and a thin-walled annular cover portion 23 covering the outer surface of the circular ring portion 20 over the entire circumference. In the illustrated example, the inner end surface in the axial direction of the cylindrical portion 19 is also covered with the sealing material 11a. The seal lip 21 is a radial seal lip and has a substantially U-shaped cross section (in a U shape), and a portion closer to the base end is directed toward the axially central side (right side in FIG. 1) as it goes radially inward. The intermediate portion is arranged in the radial direction substantially parallel to the annular ring portion 20 constituting the cored bar 10a, and the portion closer to the tip is axially outward as it goes radially inward (see FIG. 1 in the direction toward the left side. The cylindrical cover 22 has a constant wall thickness over the entire circumference (1/10 to 1/2 times the plate thickness of the core metal 10a), and its outer peripheral surface has a cylindrical surface shape.

  In order to fix the seal ring 9a having the above-described configuration to the outer ring 3a, the cylindrical portion 19 provided at the outer peripheral edge of the cored bar 10a is wound around the outer peripheral surface of the cylindrical portion 19 over the entire circumference. It is fitted and fixed (cylindrical fitting) to the fixing cylindrical surface portion 17 formed on the inner peripheral surface of the axial end portion of the outer ring 3a via the covered cylindrical covering portion 22. More specifically, the cylindrical cover portion 22 is press-fitted into the fixing cylindrical surface portion 17 (internally fitted and fixed by an interference fit) in a state where the cylindrical cover portion 22 is slightly elastically deformed in the radial direction. In this state, the leading edge (inner peripheral edge) of the seal lip 21 provided at the inner peripheral edge of the seal ring 9a is tightened with respect to the slidable contact cylindrical surface 18 in the radial direction. It is slid in contact with the entire circumference with the FIG. 1 and FIGS. 2 to 5 described later show the shape of the seal lip 21 in a free state.

According to the ball bearing 1a with the seal ring of this example having the above-described configuration, the tightening margin γ of the seal lip 21 can be reduced, and the rotational torque can be sufficiently reduced.
That is, in the case of this example, the fixing cylindrical surface portion 17 which is a seal fixing portion has a cylindrical surface shape, and the cylindrical cover portion 22 located at the outer peripheral edge portion of the seal ring 9a has a cylindrical surface shape. . When the seal ring 9a is fixed to the outer ring 3a, the cylindrical cover portion 22 is fitted and fixed to the fixing cylindrical surface portion 17 (cylindrical fitting). Therefore, the concentric accuracy of the seal ring 9a with respect to the outer ring 3a can be made substantially the same as the accuracy of the coaxiality of the fixing cylindrical surface portion 17 with respect to the outer ring raceway 2. Therefore, as in the conventional structure shown in FIG. 6, this elastic locking portion 12 is produced when the elastic locking portion 12 constituting the seal ring 9 is elastically locked in the locking groove 14. There is no occurrence of a radial position shift (decrease in concentric accuracy) due to elastic deformation.

  In addition, in the case of this example, the fixing cylindrical surface portion 17 has a simple cylindrical surface shape, and it is not necessary to form a concave groove (locking groove). Therefore, the fixing cylindrical surface portion 17 can be easily processed. Therefore, processing accuracy can be increased. For this reason, in the case of this example, by the processing method as described above, the coaxiality between the outer ring raceway 2 and the fixing cylindrical surface portion 17 is set so that both the inner and outer peripheral edges of the seal ring 9a in a free state. It is regulated to 50% (1/2) or less of the concentricity between the parts.

  Therefore, in the case of this example, the cylindrical cover portion 22 having a cylindrical surface shape is fitted and fixed (cylindrical fitting) to the fixing cylindrical surface portion 17 having a cylindrical surface shape. Combined with the fact that the accuracy of the coaxiality of the cylindrical surface portion 17 with respect to the outer ring raceway 2 can be increased, the concentric accuracy of the seal ring 9a fixed to the fixing cylindrical surface portion 17 with respect to the outer ring 3a can be sufficiently increased. (The amount of deviation between the central axes can be made sufficiently small). As a result, the deflection of the tip edge of the seal lip 21 can be kept small, and the tightening allowance γ of the seal lip 21 can be kept small. In addition, the cylindrical surface portion 18 for sliding contact which is a seal sliding contact portion can be easily processed and the processing accuracy can be increased, so that the surface roughness of the cylindrical surface portion 18 for sliding contact can be effectively reduced. Thereby, the rotational torque of the ball shaft 1a with a seal ring can be sufficiently reduced. In addition, it is possible to employ a radial seal lip (shaft seal type sliding contact structure) that has been difficult to adopt in the conventional structure.

Further, the fixing cylindrical surface portion 17 and the sliding contact cylindrical surface portion 18 are formed into a cylindrical surface shape, and concave grooves are respectively formed on the inner peripheral surface of both end portions in the axial direction of the outer ring 3a and the outer peripheral surface of both end portions in the axial direction of the inner ring 5a. Since there is no need to process, the processing cost can be kept low.
Other configurations and operational effects are the same as those of the conventional structure described above.

[ Reference example ]
FIG. 2 shows a reference example related to the present invention. The feature of this reference example is that the cylindrical cover 22 (see FIG. 1) provided in the first example of the embodiment is omitted from the outer peripheral edge of the seal ring 9b, and the outer peripheral edge of the seal ring 9b is omitted. The cylindrical portion 19 constituting the cored bar 10a positioned is directly fitted and fixed to the fixing cylindrical surface portion 17 formed on the inner peripheral surface of the axial end portion of the outer ring 3a. In the case of the present reference example having such a configuration, it is possible to prevent the radial position from being shifted due to the elastic deformation of the cylindrical cover portion 22, and therefore, compared with the case of the first example of the embodiment. The concentricity of the seal ring 9b with respect to the outer ring 3a can be improved.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

[ Second Example of Embodiment]
FIG. 3 shows a second example of the embodiment of the present invention. The feature of this example is that a large-diameter stepped portion 24 having a larger inner diameter than the portion adjacent to the axially central side is formed on the inner peripheral surface (a part of the shoulder portion) of both ends in the axial direction of the outer ring 3b. The inner peripheral surface of the large-diameter stepped portion 24 is a cylindrical surface portion 17a for fixing corresponding to the cylindrical surface corresponding to the seal fixing portion. In the case of this example having such a configuration, a gap in the radial direction between the inner peripheral surface of the cylindrical portion 19 and the outer peripheral surface of the cage 7 constituting the cored bar 10a can be increased, and the seal ring 9a and the cage 7 can be effectively prevented from interfering. In addition, if the configuration in which the end surface in the axial direction of the seal ring 9a is abutted against the side surface of the large-diameter stepped portion 24, the seal ring 9a can be positioned accurately and easily in the axial direction.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

[ Third example of embodiment]
FIG. 4 shows a third example of the embodiment of the present invention. A feature of this example is that a small-diameter stepped portion 25 having a smaller outer diameter than the portion adjacent to the axially central side is formed on the outer peripheral surface (a part of the shoulder portion) of both ends in the axial direction of the inner ring 5b. The outer peripheral surface of the small diameter step portion 25 is a cylindrical surface portion 18a for sliding contact corresponding to the seal sliding contact portion. In the case of this example having such a configuration, a gap in the radial direction between the seal lip 21 and the inner peripheral surface of the cage 7 can be increased, and it is effective that the seal ring 9a and the cage 7 interfere with each other. Can be prevented.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

[ Fourth Example of Embodiment]
FIG. 5 shows a fourth example of the embodiment of the present invention. The feature of this example is a conical inclined surface portion for sliding contact corresponding to a seal sliding contact portion, which is inclined in a direction in which the radial dimension decreases toward the outer side in the axial direction on the outer peripheral surface of both end portions in the axial direction of the inner ring 5c. 26 is formed. In the case of this example having such a configuration, the change in the tightening allowance of the seal lip 21 can be reduced even when the outer ring 3a and the inner ring 5c are relatively inclined with respect to the bearing center. Further, since the grease adhering to the sliding contact inclined surface portion 26 can be effectively supplied toward the balls 6 using centrifugal force, the lubrication state of the rolling contact portion can be improved.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

In the case of each example of the above-described embodiment, the case where the seal fixing portion (fixed cylindrical surface portion) is cut and the outer ring raceway is ground with reference to the outer peripheral surface of the outer ring has been described. When the present invention is carried out, the outer ring raceway and the seal fixing portion (fixing cylindrical surface portion) may be simultaneously ground using a grindstone. On the contrary, although not within the technical scope of the present invention, the inner ring raceway and the seal sliding contact portion (sliding contact cylindrical surface portion) of the inner ring may be cut with reference to the inner peripheral surface of the inner ring.

  In each example of the above-described embodiment, the outer peripheral edge of the seal ring is fixed to the outer ring that is a stationary ring, and the tip edge of the seal lip provided on the inner peripheral edge of the seal ring is the inner ring that is a rotating ring. However, the present invention is not limited to such a structure, and the inner peripheral edge of the seal ring is fixed to the inner ring, which is a stationary ring, and is provided on the outer peripheral edge of the seal ring. It can also be applied to a structure in which the tip edge of the seal lip is in sliding contact with an outer ring which is a rotating wheel.

  Moreover, the rolling bearing with seal ring of the present invention is not limited to the structure in which the rolling elements are arranged in a single row, but may have a structure in which the rolling elements are arranged in a double row (two rows or more). Further, the rolling elements are not limited to balls, and various conventionally known ones such as rollers and needles can be employed. Furthermore, it is needless to say that the structures of the examples of the above-described embodiments can be implemented in appropriate combination.

DESCRIPTION OF SYMBOLS 1, 1a Ball bearing with a seal ring 2 Outer ring raceway 3, 3a, 3b Outer ring 4 Inner ring raceway 5, 5a, 5b, 5c Inner ring 6 Ball 7 Cage 8 Internal space 9, 9a, 9b Seal ring 10, 10a Core metal 11, 11a Seal material 12 Elastic locking part 13 Seal lip (Axial seal lip)
14 Locking groove 15 Sealing groove 16 Radial gap 17, 17a Cylindrical surface portion for fixing 18, 18a Cylindrical surface portion for sliding contact 19 Cylindrical portion 20 Ring portion 21 Seal lip (radial seal lip)
22 Cylindrical cover part 23 Ring cover part 24 Large diameter step part 25 Small diameter step part 26 Sliding surface inclined surface part

Claims (4)

An outer ring having an outer ring raceway on an inner peripheral surface, an inner ring having an inner ring raceway on an outer peripheral surface, a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway, and an inner circumference of the outer ring A ring-shaped seal ring that is present between the surface and the outer peripheral surface of the inner ring and closes the axial end opening of the space in which each of the rolling elements is installed, and the seal ring includes an annular core A seal member made of an elastic material reinforced by the metal core, and one of the inner and outer peripheral portions of the seal ring is connected to the inner peripheral surface of the axial end portion of the outer ring and the inner ring The seal lip provided on the seal material constituting the other peripheral portion is fixed to the seal fixing portion provided on one of the outer peripheral surfaces of the axial end portion and the shaft of the outer ring. The other of the inner circumferential surface of the directional end and the outer circumferential surface of the axial end of the inner ring The seal sliding portion provided on the surface is brought into sliding contact over the entire circumference, in the attached seal ring rolling bearing,
The seal fixing part is cylindrical,
One peripheral part of the seal ring fixed to the seal fixing part has a cylindrical surface shape, and the sealing material covers the entire peripheral surface of the cylindrical part provided on the core metal over the entire circumference. It is composed of a cylindrical cover,
The wall thickness of the cylindrical cover is constant over the entire circumference, and is 1/10 to 1/2 times the plate thickness of the core metal,
The cylindrical portion is fitted and fixed without a gap to the seal fixing portion via the cylindrical cover portion ,
Of the outer ring and the inner ring, the concentricity between the raceway surface provided on one raceway ring to which the seal ring is fixed and the peripheral surface of the seal fixing part is the inside and outside of the seal ring in a free state. 50% or less of the concentricity between both peripheral portions,
The seal lip is a radial seal lip having a U-shaped cross section in a free state and having a tip edge thereof slidably contacted with a peripheral surface of the seal slidable contact portion which is a grinding surface opposed in the radial direction.
Rolling bearing with a seal ring characterized by this. 2. The rolling bearing with a seal ring according to claim 1, wherein the rolling element is rotatably held by a cage, and the cylindrical portion and the seal lip overlap in a radial direction with respect to the cage. . The seal sliding portion is a cylindrical surface shape, the seal ring rolling bearing as set forth in any one of claims 1-2. The seal sliding portion is a conical surface shape, the seal ring rolling bearing as set forth in any one of claims 1-2.

Images