JP5145958B2 - Combination seal ring with encoder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a combination seal ring 11b equipped with an encoder capable of enhancing the sealing performance and the durability without bringing about a rise of the torque at low costs. <P>SOLUTION: A cylinder part 31 for sealing is formed at the peripheral edge of the encoder 14a, and the peripheral surface of the cylinder part 31 is arranged and attached along the inside circumferential surface of a resilient piece 16c over the whole circumference, the piece 16c being attached alongside to a stationary cylindrical portion 17 of a core metal 15, and in this part a labyrinth seal 25b is provided. The outer end edge in the axial direction of the cylinder part 31 is protruded largely to the outside in the axial direction more than one side surface of a rotary ring part 23c constituting a slinger 13c, wherein the thickness in the radial direction of the cylinder part 31 is formed smaller than the thickness in the axial direction of the rotary ring part 23c. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention covers, for example, an opening end of a rolling bearing incorporated in a rotation supporting portion of various mechanical devices such as a wheel supporting rolling bearing unit for supporting a wheel of a vehicle (automobile) on a suspension device. The present invention relates to an improvement of a combined seal ring with an encoder for detecting the rotational speed of a supported rotating member. Specifically, the sealing performance, that is, the performance of preventing the entry of foreign matter such as muddy water into the internal space where the rolling elements are installed, and the leakage of grease enclosed in the internal space are prevented from leaking to the outside. In addition to improving the performance, the friction and the wear are reduced, and the running performance and durability of the vehicle centering on fuel efficiency and acceleration performance are improved.

  In order to detect the rotation speed of this wheel in order to control the anti-lock brake system (ABS) and the traction control system (TCS) while supporting the wheel of the automobile rotatably with respect to the suspension system, an encoder is conventionally used. A rolling bearing unit is used (see, for example, Patent Document 1).

  6 to 8 show an example of a conventional rolling bearing unit with an encoder. The hub 1 is provided with a wheel fixing flange 2 at the outer end of the hub 1 in the axial direction (outside with respect to the axial direction means the side that is the outer side in the width direction when mounted on an automobile, and the left side in each figure). An inner ring raceway 3a is formed on the outer peripheral surface of the intermediate portion. Also, the inner end of the hub 1 in the axial direction (inner with respect to the axial direction means the side that becomes the center side in the width direction when mounted on an automobile, and the right side in each figure). An inner ring 4 having a track 3b is externally fitted. The inner ring 4 and the hub 1 constitute a rotating wheel.

  A mounting portion 6 for supporting the outer ring 5 on a suspension device is formed on the outer peripheral surface of the outer ring 5 which is a stationary ring, and double-row outer ring raceways 7a and 7b are formed on the inner peripheral surface, respectively. Yes. A plurality of rolling elements 8, 8 are provided between the outer ring raceways 7a, 7b and the inner ring raceways 3a, 3b, respectively, inside the outer ring 5 supported by the suspension device by the mounting portion 6. The hub 1 is rotatably supported.

  Among the rolling bearing units with an encoder as described above, grease is sealed in the internal space 9 in which the rolling elements 8 and 8 are installed, the rolling surfaces of the rolling elements 8 and 8, and the outer rings. The rolling contact portions between the tracks 7a and 7b and the inner ring tracks 3a and 3b are lubricated. Further, a seal ring 10 is provided between the outer peripheral surface of the outer ring 5 in the axial direction and the outer peripheral surface of the intermediate portion of the hub 1 so as to close the opening of the inner space 9 in the axial direction. It is out. On the other hand, a combined seal ring 11 with an encoder, which is an object of the present invention, is provided between the inner peripheral surface of the outer ring 5 in the axial direction and the outer peripheral surface of the inner ring 4, and the axial direction of the inner space 9 is provided. The inner end opening is blocked.

  As shown in detail in FIG. 7, the combined seal ring 11 with an encoder is made of a seal ring 12 that is fitted and fixed to the end of the outer ring 5 that is a stationary ring, and a magnetic metal plate such as a steel plate or a stainless steel plate. A slinger 13 that is externally fitted and fixed to an end of the inner ring 4 that is a rotating wheel, and an encoder 14 that is supported and fixed to the slinger 13 are provided.

  Among these, the seal ring 12 includes a core metal 15 having a substantially L-shaped cross section and an annular shape as a whole, and an elastic material 16. The core metal 15 is formed of a metal plate such as a mild steel plate and is formed in an annular shape as a whole with a substantially L-shaped cross section, and is a fixed cylinder that is fitted and fixed to the inner peripheral surface of the end portion of the outer ring 5 by an interference fit. A portion 17 and a fixed annular portion 18 bent inward in the diametrical direction from the outer edge in the axial direction of the fixed cylindrical portion 17 toward the outer peripheral surface of the inner ring 4. The elastic member 16 is attached over the entire circumference of the core metal 15 and has three seal lips 19 to 21 on the outer side, the middle, and the inner side. Generally, the elastic material 16 is made of rubber and is bonded to the core metal 15 by baking.

  On the other hand, the slinger 13 has an inner peripheral surface of the outer ring 5 from a rotating cylindrical portion 22 that is fitted and fixed to the outer peripheral surface of the end portion of the inner ring 4 by an interference fit, and an axial inner end edge of the rotating cylindrical portion 22. And a rotating circular ring portion 23 bent in the diameter direction. Further, the slinger 13 does not include an elastic material, and is provided on the outer peripheral surface of the rotating cylindrical portion 22 and one side surface (the axially outer side surface, the left side surface in FIG. 7) of the rotating annular portion 23. The portions where the tip edge of 21 is in sliding contact are each a smooth surface.

  The tip edge of the outer seal lip 19, which is called the side lip and protrudes inward in the axial direction, is called the side lip among the seal lips 19 to 21. The one side of the portion 23 is in sliding contact with the entire circumference. In contrast, the remaining two leading edges of the middle and inner seal lips 20 and 21 are in sliding contact with the outer peripheral surface of the rotating cylindrical portion 22 over the entire circumference.

  Further, as shown in FIG. 8, the encoder 14 is made of a permanent magnet (made of rubber magnet) in which S poles and N poles are alternately arranged in the circumferential direction. That is, the encoder 14 is a rubber magnet in which ferrite powder is mixed in rubber and formed in an annular shape, and is magnetized in the axial direction. The magnetization direction is changed alternately and at equal intervals over the circumferential direction. Accordingly, on the side surface of the encoder 14, S poles and N poles are alternately arranged at equal intervals along the circumferential direction. Such an encoder 14 is supported on the other side surface (the inner side surface in the axial direction, the right side surface in FIG. 7) of the rotating ring portion 23. And the detection part of the sensor 24 for the rotational speed detection supported by the non-rotating part, such as a suspension apparatus, is made to oppose the to-be-detected surface which is the side surface of the said encoder 14. FIG.

  Further, the outer peripheral edge of the encoder 14 and the outer peripheral edge of the rotating ring portion 23 of the slinger 13 are close to the inner peripheral surface of the elastic member 16 attached to the fixed cylindrical portion 17 over the entire circumference. They are facing each other. Thereby, the labyrinth seal 25 for preventing intrusion of foreign matters such as rainwater, muddy water, and dust existing in the external space is formed in the portion.

  In the case of a rolling bearing unit with an encoder having a conventional structure as described above, the wheel fixed to the flange 2 provided at the axially outer end of the hub 1 can be rotatably supported with respect to the suspension device that supports the outer ring 5. Further, by closing both axial openings of the internal space 9 with the seal ring 10 and the combined seal ring 11 with an encoder, foreign matter such as muddy water can be prevented from entering the internal space 9 and the internal space 9 Prevents the grease enclosed inside from leaking to the outside. Further, when the slinger 13 fitted and fixed to the inner ring 4 rotates with the rotation of the wheel, the output of the sensor 24 facing the encoder 14 that rotates with the slinger 13 changes. The frequency at which the output of the sensor 24 changes is proportional to the rotational speed of the wheel. Therefore, if the output signal of the sensor 24 is input to a controller (not shown), the rotational speed of the wheel can be obtained and the ABS and TCS can be controlled appropriately.

  However, the conventional combined seal ring with encoder 11 as shown in detail in FIG. 7 still has room for improvement from the viewpoint of further improving the sealing performance. That is, as described above, the combined seal ring 11 with an encoder is between the outer peripheral edge portion of the encoder 14 and the rotating ring portion 23 and the inner peripheral surface of the elastic member 16 attached to the fixed cylindrical portion 17. A labyrinth seal 25 is provided to prevent foreign matter from entering. However, the labyrinth seal 25 is not sufficiently long (axial length) from the viewpoint of effectively preventing foreign matter from entering, and it is difficult to ensure sufficient sealing performance by the labyrinth seal 25. For this reason, it is difficult to effectively prevent foreign matter from entering the internal space 9.

  In view of such circumstances, Patent Document 2 describes a combination seal ring provided with a labyrinth seal having a long overall length. FIG. 9 shows a combination seal ring 26 described in Patent Document 2. The basic structure of the combination seal ring 26 except that it does not include an encoder is substantially the same as the above-described combination seal ring 11 with an encoder (see FIG. 7), and the seal ring 12a including the core 15 and the elastic material 16a. And a slinger 13a.

  In particular, in the case of the combined seal ring 26, a sealing cylinder portion 27 that is bent toward the fixed ring portion 18 side (axially outer side) of the core metal 15 is provided on the outer peripheral edge portion of the slinger 13a. Then, the outer peripheral surface of the sealing cylinder portion 27 is made to face and oppose the inner peripheral surface of the elastic member 16a attached to the fixed cylindrical portion 17 of the core metal 15 over the entire circumference. Further, the axial outer end edge of the sealing cylinder portion 27 is made to face and oppose the axial inner side surface of the elastic member 16 a attached to the fixed ring portion 18. Further, by providing a bulging portion 28 on a part of the inner surface in the axial direction of the elastic member 16 a attached to the fixed ring portion 18, the outer peripheral surface of the bulging portion 28 can be connected to the sealing cylinder portion 27. The inner peripheral surface is closely opposed over the entire circumference.

  With the configuration as described above, a labyrinth seal 25a having a crank section is formed between the elastic member 16a constituting the seal ring 12a and the sealing cylinder portion 27. Since the labyrinth seal 25a has a sufficiently long overall length as compared with the labyrinth seal 25 (see FIG. 7) provided in the above-described combined seal ring with an encoder 11, sufficient sealing performance can be secured.

However, in the case of the combination seal ring 26 described in Patent Document 2, since the sealing cylinder 27 is provided on the outer peripheral edge of the slinger 13a, the front edge of the outer seal lip 19 is slidably contacted. Therefore, the width dimension W _23a extending in the radial direction on one side surface of the rotating ring portion 23a is smaller than that in the case where the sealing cylinder portion 27 is not provided. Specifically, the radial thickness dimension T ₂₇ of the sealing cylinder portion 27 and the diameter of the bent surface 29 that continues the inner peripheral surface of the sealing cylinder portion 27 and one side surface of the rotating ring portion 23a. The width dimension W _23a extending in the radial direction on one side surface of the rotating ring portion _23a is reduced by the sum (T ₂₇ + H ₂₉ ) with the direction height dimension H ₂₉ . For this reason, the range in which the front end edge of the outer seal lip 19 can slide is narrowed.

  In general, the space for installing the combination seal ring as described above is slightly different depending on the size of the bearing, but the width dimension in the axial direction is about 5 to 6 mm and the width dimension in the radial direction is as small as about 7 to 8 mm. The space in which the outer seal lip 19 can be disposed is smaller than the installation space of the entire combined seal ring. On the other hand, in order to ensure sufficient sealing performance, it is necessary to ensure a certain length of the cross-sectional length of the outer seal lip 19 as will be described later. Therefore, as described above, when the width dimension in the radial direction of one side surface of the rotating ring portion 23a is reduced and the range in which the tip edge of the outer seal lip 19 is slidable is reduced, the outer seal lip 19 is reduced. The design becomes difficult.

  That is, as described above, when the width dimension in the radial direction of one side surface of the rotating ring portion 23a is reduced, the length (cross-sectional length) from the proximal end portion to the distal end edge of the outer seal lip 19 is also shortened. There is a need to. For this reason, the rigidity of the outer seal lip 19 is increased, and the contact load of the sliding contact portion between the tip edge of the outer seal lip 19 and one side surface of the rotating ring portion 23a increases. As a result, the sliding resistance (seal torque) of the outer seal lip 19 is increased, and the end edge of the outer seal lip 19 is easily worn or sagged, so that the durability of the outer seal lip 19 is ensured. It becomes difficult.

  In particular, when the combination seal ring 26 as described above is incorporated in a rolling bearing unit for supporting a wheel of an automobile, the contact load increases remarkably, and the running performance centering on the fuel efficiency performance and the acceleration performance is deteriorated. Cause problems. This point will be described with reference to FIG. 6 showing a rolling bearing unit for supporting a wheel of an automobile and FIG. 10 newly added. In FIG. 10, the combined seal ring 11 with an encoder is shown with the encoder omitted.

  As shown by the arrows in FIG. 6, the case where the moment M accompanying the turning travel is applied to the hub 1 in the clockwise direction of FIG. 6 will be described. In this case, the central axis of the hub 1 is displaced by the angle θ from the α position representing the neutral state to the β position due to elastic deformation of each part. As a result, the rotating ring portion 23 of the slinger 13 fitted and fixed to the inner end portion of the inner ring 4 is also inclined substantially by the angle θ. In the case of the state shown in FIG. 6, the rotating ring portion 23 is displaced in the direction away from the core metal 15 as shown in FIG. As a result, the allowance for tightening the outer seal lip 19 is reduced in the upper portion. On the other hand, in the lower part of FIG. 6, the rotating ring portion 23 is displaced in a direction approaching the core metal 15 as shown in FIG. As a result, the tightening margin of the outer seal lip 19 increases in the lower portion.

  And in the part which the interference of the said outer side seal lip 19 fell too much, the foreign material penetration | invasion prevention effect is impaired. For this reason, the outer seal lip 19 is tightened so that even if the central axis of the hub 1 is inclined based on the moment M and the tightening margin is partially reduced, the sealing performance of the portion can be secured. It is required to set a bill. Specifically, the tightening allowance of the outer seal lip 19 in a state where the central axis is not inclined is set to be large, and even if the central axis is inclined, the allowance for the outer seal lip 19 is set to the entire circumference. Therefore, it is necessary to leave as much sealing as possible.

  As described above, a combination seal ring for incorporation in a wheel bearing rolling bearing unit is required to have a large tightening margin for the outer seal lip. For this reason, even when the combination seal ring 26 as described above is incorporated into a rolling bearing unit for supporting a wheel of an automobile, it is naturally necessary to set a large allowance for the outer seal lip 19. Accordingly, the increase in the contact load becomes remarkable due to the increase in the contact load due to the short overall length of the outer seal lip 19 and the increase in the contact load due to the increase in the tightening allowance. As a result, the rotational resistance (rotational torque) of the hub constituting the wheel support rolling bearing unit is increased, and as described above, the running performance centering on the fuel efficiency performance and the acceleration performance is deteriorated.

  Further, in the case of the combination seal ring 26, the cylinder portion 27 for sealing is provided on the slinger 13a made of stainless steel which is expensive and has high rigidity. For this reason, material costs increase and processing costs for performing plastic processing such as press processing also increase. Therefore, the cost increase of the combined seal ring 26 as a whole due to the provision of the sealing cylinder portion 27 becomes significant.

  On the other hand, Patent Document 3 describes a combined seal ring with an encoder in which, instead of omitting the labyrinth seal, a seal lip for preventing intrusion of foreign matter is newly provided. FIG. 11 shows a combined seal ring 11a with an encoder described in Patent Document 3. Similar to the combined seal ring 11 with an encoder shown in FIG. 7, the combined seal ring with an encoder 11 a includes a seal ring 12 b including a cored bar 15 and an elastic material 16 b, a slinger 13 b, and an encoder 14.

  In particular, in the case of the combined seal ring 11 a with an encoder, a seal lip 30 is provided on the inner peripheral surface of the intermediate portion of the elastic member 16 b attached to the fixed cylindrical portion 17 constituting the core metal 15. And the front-end edge of this seal lip 30 is slidably contacted with the outer peripheral edge part of the rotating ring part 23b which comprises the said slinger 13b.

  With the above-described configuration, in the case of the combined seal ring with encoder 11a, the outer peripheral edge portion of the rotating ring portion 23b and the inner peripheral surface of the elastic member 16b supported by the fixed cylindrical portion 17 are provided. A gap therebetween is closed by the seal lip 30. In particular, in the case of the structure described in Patent Document 3, the tip edge of the seal lip 30 is elastically slidably brought into sliding contact with the outer peripheral edge of the rotating ring portion 23b. Even when the slinger 13b (rotating ring portion 23b) is inclined based on a moment or the like, the seal lip 30 can effectively prevent foreign matter from entering.

However, even in the case of the combined seal ring 11a with an encoder as described above, it is necessary to make the tip edge of the seal lip 30 slidably contact the outer peripheral edge of the rotary ring portion 23b. The width dimension W _23b extending in the radial direction of the side surface is smaller than when the seal lip 30 is not provided. Therefore, as in the case of the combination seal ring 26 (see FIG. 9) described in Patent Document 2 described above, the design of the outer seal lip 19 becomes difficult, and the leading edge of the outer seal lip 19 and the rotating ring The contact load of the sliding contact part with the one side of the part 23b is increased. Further, when the combination seal ring 11a with an encoder is incorporated into a rolling bearing unit for supporting a wheel of an automobile, it is necessary to set a larger margin for tightening the outer seal lip 19, so that it is described in Patent Document 2. This creates a problem similar to the structure described. Furthermore, since the seal lip 30 is exposed to the external space and is directly exposed to rainwater, muddy water, etc., it is difficult to ensure durability because of rapid progress of sag and wear.

As described above, in any of the structures described in Patent Documents 2 and 3, the sealing performance can be improved, but the sliding contact between the tip edge of the outer seal lip and one side surface of the rotating ring portion. The contact load of the portion increases, and this causes new problems such as an increase in sliding resistance of the outer seal lip and a decrease in durability.
In recent years, in the automobile industry, there has been a tendency to emphasize fuel efficiency and acceleration performance, and the conditions required for seal rings have become more severe. For this reason, realization of a structure capable of ensuring sealing performance (durability) over a long period of time and suppressing the sliding resistance of the seal lip is required.

JP 2002-62305 A JP 2006-342827 A JP 2006-322536 A

  In view of the circumstances as described above, the present invention has been invented to realize a combined seal ring with an encoder capable of improving seal performance and durability without increasing torque, at a low cost.

The combined seal ring with an encoder of the present invention is used to block the opening end of the space existing between the peripheral surface of the stationary wheel and the peripheral surface of the rotating wheel and detect the rotational speed of the rotating wheel. .
A seal ring fixed to the peripheral surface of the stationary wheel, a slinger fixed to the peripheral surface of the rotating wheel, and an encoder supported and fixed to the slinger.
The seal ring includes a fixed cylindrical portion that is fitted and fixed to the peripheral surface of the stationary ring, and a cored bar that is bent from an edge of the fixed cylindrical portion toward the peripheral surface of the rotating wheel. And an elastic material having a seal lip attached over the entire circumference of the cored bar.
The slinger includes a rotating cylindrical portion that is fitted and fixed to the peripheral surface of the rotating wheel, and a rotating annular portion that is bent from an edge of the rotating cylindrical portion toward the peripheral surface of the stationary wheel, A portion where the tip edge of the seal lip is slidably contacted with the peripheral surface of the rotating cylindrical portion and one side surface of the rotating annular portion is a smooth surface.
The encoder is made of a permanent magnet, which is a plastic magnet in which S poles and N poles are alternately arranged in the circumferential direction, and is supported on the other side of the rotating annular portion.
In particular, in the case of the combined seal ring with an encoder of the present invention, the peripheral edge on the stationary wheel side of the encoder protrudes more toward the stationary wheel side than the peripheral edge on the stationary wheel side of the rotating ring portion, and the encoder The edge of the stationary ring side is positioned on the stationary ring side at the peripheral edge of the stationary ring side, and the axial thickness of the rotating ring part is 1 A cylindrical portion for sealing is formed by projecting 5 times or more and having a radial thickness dimension less than 2/3 of the axial thickness dimension of the rotating ring portion . As a result, the peripheral surface of the sealing cylinder portion on the stationary wheel side and the fixed cylindrical portion or the peripheral surface of the elastic material attached to the fixed cylindrical portion on the rotating wheel side are closely opposed across the entire circumference. Thus, a labyrinth seal is provided in the portion. Further, a tapered surface portion inclined in a direction in which the diameter becomes smaller as it approaches the stationary ring portion is provided on the peripheral surface of the sealing cylinder portion on the stationary ring side, and this tapered surface portion is provided in the labyrinth seal. The gap in the radial direction at the portion is made smaller as the distance from the fixed ring portion increases.

According to the combined seal ring with an encoder of the present invention configured as described above, the stationary cylinder side peripheral surface of the sealing cylinder portion formed on the peripheral edge portion of the encoder and the fixed cylindrical portion or the fixed cylindrical portion are attached. A labyrinth seal having a long overall length in the axial direction can be formed between the elastic material and the peripheral surface on the rotating wheel side. For this reason, the sealing performance by this labyrinth seal can be sufficiently secured, and the sealing performance of the combined seal ring with an encoder can be improved.
Particularly in the case of the present invention, since the sealing cylinder is formed on the peripheral edge of the encoder and not on a part of the slinger, the conventional technique described in Patent Document 2 (and Patent Document 3) is used. Compared with the case of the structure, the bending surface 29 is not required, and therefore, a large width dimension in the radial direction of one side surface of the rotating annular portion for sliding the tip edge of the seal lip can be secured. For this reason, the design of the seal lip can be facilitated, and an increase in the contact load of the sliding contact portion between the tip edge of the seal lip and one side surface of the rotating ring portion can be prevented. Therefore, it is possible to secure durability by suppressing wear and sag of the leading edge of the seal lip.
In addition, an encoder having a sealing cylinder as described above can be made of a plastic magnet material , which is cheaper than a steel material such as stainless steel constituting a slinger. The increase in material cost can be suppressed to a lower level than when the sealing cylinder is provided on the slinger (in the case of the structure described in Patent Document 2). Furthermore, the encoder provided with the above-mentioned sealing cylinder part uses a part of a manufacturing die for making a conventional annular encoder (see FIG. 8) with a slight design change. Can be manufactured. For this reason, in the case of this invention, the raise of processing cost can also be suppressed low and the raise of the cost by providing the said cylinder part for sealing can be suppressed low.
Therefore, according to the present invention, a combined seal ring with an encoder that can improve sealing performance and durability without increasing torque (seal torque) can be realized at low cost.
For this reason, when the combined seal ring with an encoder of the present invention is incorporated into a rolling bearing unit for supporting a wheel of a vehicle, for example, the durability of the rolling bearing unit for supporting a wheel is improved, and at the same time, fuel efficiency performance and acceleration performance are improved. The running performance of the vehicle as the center can be improved.

Further, according to the present invention, the foreign substance can be pushed out from the inside of the labyrinth seal toward the external space along the inclination of the tapered surface portion by the action of the centrifugal force, so that the sealing performance can be further improved.
Furthermore, according to the present invention, it is possible to ensure a sufficiently large width dimension in the radial direction on one side surface of the rotating annular ring portion. For this reason, the design of the seal lip (outer seal lip) can be facilitated, and the contact load at the sliding contact portion between the tip edge of the seal lip and one side surface of the rotating ring portion, and hence the sliding resistance ( An increase in seal torque can be effectively prevented.

[First example of reference example related to the present invention]
1 and 2 show a first example of a reference example related to the present invention. The feature of this reference example is that a cylindrical sealing cylinder 31 is provided on the outer peripheral edge of the encoder 14a in order to prevent the entry of foreign matter such as rainwater, muddy water, and dust. Since the configuration and operation of the other parts are almost the same as those of the conventional structure described above, common parts are denoted by the same reference numerals, and duplicated descriptions are omitted or simplified. The explanation is centered.

  A combination seal ring 11b with an encoder shown in FIG. 1 includes a seal ring 12c that is fitted and fixed to the outer ring 5 (see FIG. 6) and a slinger that is fitted and fixed to the inner ring 4 (see FIG. 6). 13c and an encoder 14a supported and fixed on the other side surface (the inner side surface in the axial direction, the right side surface in FIGS. 1 and 2) of the rotating ring portion 23c constituting the slinger 13c. In the case of this reference example, the encoder 14a has an outer diameter dimension larger than the outer diameter dimension of the rotating ring portion 23c and protrudes radially outward from the rotating ring portion 23c. A sealing cylinder portion 31 is provided on the outer peripheral edge portion. The cylindrical portion 31 for sealing is cylindrical as described above, and its axial outer end edge is more than one side surface (the axially outer side surface, the left side surface in FIGS. 1 and 2) of the rotating ring portion 23. The metal core 15 constituting the seal ring 12c is protruded toward the fixed ring portion 18 side (axially outer side).

In particular, in the case of this reference example, as shown in FIG. 2, the amount of projection δ of the outer edge in the axial direction of the sealing cylinder portion 31 from one side surface of the rotating annular portion 23c is defined as the rotational circle. The ring portion 23c is approximately twice as thick as the axial thickness dimension _T23c ( _δ≈2T23c ). Further, the radial thickness _{T 31} of the sealing cylindrical portion 31, is set to approximately 0.6 times the axial thickness dimension _{T 23c} of the rotating annular portion _{23c (T 31 ≒ 0.6T 23c)} .

  As shown in FIG. 1, the outer peripheral surface of the sealing cylinder portion 31 is close to the inner peripheral surface of the elastic member 16 c attached to the fixed cylindrical portion 17 constituting the core metal 15 over the entire circumference (use) The labyrinth seal 25b is formed in the portion facing each other (through a gap as small as possible) to the extent that they do not slide on each other. In the case of the present reference example, in order to ensure the axial length of the labyrinth seal 25b, the axial inner end edge of the fixed cylindrical portion 17 is more axially inward than the other side surface of the rotating ring portion 23c. The inner end edge in the axial direction of the elastic member 16c provided in a state of covering the fixed cylindrical portion 17 is positioned substantially on the same plane as the inner side surface in the axial direction of the encoder 14a. Therefore, in the case of the present reference example, the labyrinth seal 25b is formed in a range extending from the inner end in the axial direction of the combined seal ring with encoder 11b to the intermediate portion.

  In the case of this reference example, the elastic material 16c is provided with outer, intermediate and inner seal lips 19a, 20, and 21a, respectively. And the tip edge of the outer seal lip 19a located on the outermost diameter side, called the side lip, is slid over the entire circumference to one side of the rotating ring portion 23c constituting the slinger 13c. Yes. The leading edge of the intermediate seal lip 20 is brought into sliding contact with the outer peripheral surface of the rotating cylindrical portion 22 constituting the slinger 13c over the entire circumference, and the leading edge of the inner sealing lip 21a is brought into contact with the rotating cylindrical portion. The outer peripheral surface of 22 is placed in close proximity to each other.

  Furthermore, in the case of this reference example, the minimum thickness part 32 is provided in the base end part of the said outer side seal lip 19a. The minimum thickness portion 32 has a circular arc cross-section with a convex surface on the inner peripheral surface side (a concave surface on the outer peripheral surface side), and has a smaller thickness than other portions, and is elastically deformed over the entire periphery. It is easy. The cross-sectional shape of the outer seal lip 19a is a wedge shape in which the thickness gradually increases from the minimum thickness portion 32 toward the tip portion. In the case of this reference example, a bent portion 33 is formed near the tip of the outer seal lip 19a, and a bending point is provided on the inner peripheral surface of the outer seal lip 19a. Of the surface, the inclination angle of the distal end portion with respect to the central axis of the bending point is smaller than the inclination angle of the proximal end portion with respect to the central axis.

  A maximum thickness portion 34 having a maximum thickness is provided in the vicinity of the tip of the outer seal lip 19a. Further, the portion closer to the tip of the outer seal lip 19a, which is located closer to the tip than the thickest portion 34, has a tapered shape in which the portion closer to the outer diameter is removed over the entire circumference. The overall shape of the outer seal lip 19a is inclined in the direction toward the rotating ring portion 23c of the slinger 13c (to the right in FIG. 1) as it goes toward the tip edge (radially outer end edge).

  In the case of the combined seal ring 11b with an encoder of the present reference example having the above-described configuration, a labyrinth seal 25b having a long overall length can be formed as in the case of the combined seal ring 26 shown in FIG. For this reason, the sealing performance by the labyrinth seal 25b can be sufficiently ensured, and the sealing performance of the encoder combined seal ring 11b can be improved. Furthermore, since the sealing performance by the labyrinth seal 25b can be sufficiently secured, foreign matters such as rain water, muddy water, and dust are brought into sliding contact with the leading edge of each of the outer, middle, and inner seal lips 19a, 20, and 21a and the mating surface. It is possible to effectively prevent biting into the part. For this reason, the durability of the combined seal ring with encoder 11b can be improved.

In the case of this reference example, the sealing cylinder portion 31 for constituting the labyrinth seal 25b as described above is formed not on the outer peripheral edge portion of the slinger 13c but on the outer peripheral edge portion of the encoder 14a. Moreover, it is sufficiently small (approximately 0.6-fold in the case of the present embodiment) with respect to axial thickness dimension T _23c of the rotating annular portion 23c and the radial thickness T _31. For this reason, the degree of reducing the outer diameter of the rotating ring portion 23c is reduced with the formation of the sealing cylinder portion 31, and the tip edge of the outer seal lip 19a is slidably contacted. The width W _23c in the radial direction of one side surface of the rotating ring portion 23c can be ensured larger than in the conventional structure (structures described in Patent Documents 2 and 3) (W _23c > W _23a , W _23b ). For this reason, in the case of this reference example, it is not necessary to make a design change accompanying the provision of the sealing cylinder portion 31 to the outer seal lip 19a, or even a slight design change is sufficient. Therefore, in the case of this reference example, the design of the outer seal lip 19a can be facilitated.

  That is, since the overall length of the outer seal lip 19a can be secured long, it is possible to prevent the rigidity of the outer seal lip 19a from increasing. For this reason, it is possible to prevent an increase in the contact load of the sliding contact portion between the distal end edge of the outer seal lip 19a and one side surface of the rotating ring portion 23c. Further, in the case of the present reference example, the deformation of the outer seal lip 19a is concentrated on the minimum thickness portion 32 provided at the base end, and the change in the tightening margin of the outer seal lip 19a is caused by this outer seal lip 19a. The influence exerted on the contact force of the sliding contact portion between the tip edge of 19a and one side surface of the rotating ring portion 23c can be reduced. As a result, an increase in the sliding resistance (seal torque) of the outer seal lip 19a can be effectively prevented, and the wear and sag of the tip edge of the outer seal lip 19a can be suppressed, and the durability of the outer seal lip 19a can be reduced. Ensuring the sex.

Furthermore, the encoder 14a provided with the sealing cylinder portion 31 as described above can be made of a magnet material (plastic in the case of the present invention) such as rubber or plastic, which is cheaper than a steel material such as stainless steel. Therefore, an increase in material cost due to the provision of the sealing cylinder portion 31 can be suppressed to be lower than that in the case of the conventional structure (the structure described in Patent Document 2). Furthermore, the encoder 14a can be manufactured by using a part of a manufacturing mold for manufacturing a conventional ring-shaped encoder (see FIG. 8) with a slight design change. For this reason, in the case of this reference example, the increase in the processing cost can be suppressed to a low level, and the increase in the cost of the combined seal ring with encoder 11b due to the provision of the sealing cylinder portion 31 can be suppressed to a low level.

  As described above, in the case of this reference example, the combined seal ring 11b with an encoder that can improve the sealing performance and durability without increasing the torque can be realized at low cost. For this reason, when this combined seal ring with encoder 11b is incorporated in a rolling bearing unit for supporting a wheel of a vehicle as shown in FIG. 6, for example, the durability of the rolling bearing unit for supporting a wheel is improved at the same time. In addition, it is possible to improve the running performance of the vehicle centering on fuel efficiency and acceleration performance.

As described above, in the case of this reference example, the protrusion amount δ of the sealing cylinder portion 31 from one side surface of the rotating annular portion 23c is set as the axial thickness dimension of the rotating annular portion 23c. Although it is set to approximately twice _T23c, the protrusion amount δ is not limited to such a value. However, this protrusion amount δ is equal to or greater than the axial thickness dimension T _{23c of the} rotating ring portion 23c (δ from the viewpoint of securing the axial length of the labyrinth seal 25b and ensuring the sealing performance of the labyrinth seal 25b. ≧ T _23c ), more preferably 1.5T _23c or more (δ ≧ 1.5T _23c ) as in the present invention . In this case, the upper limit of the protrusion amount δ varies depending on the application of the bearing in which the combined seal ring with encoder 11b is incorporated. For example, in the case of the combined seal ring with encoder incorporated in the wheel bearing rolling bearing unit, Regardless of the moment acting on the wheel-supporting rolling bearing unit, the outer peripheral surface of the sealing cylinder portion 31 is restricted to a range that does not interfere with the inner peripheral surface of the elastic member 16c.

Further, in the case of this reference example, the radial thickness dimension T ₃₁ of the sealing cylinder portion 31 is about 0.6 times the axial thickness dimension T _23c of the rotating ring portion 23 c (T ₃₁ ≈ 0.6T _23c ), but the radial thickness T ₃₁ is not limited to such a value. However, from the securing large surfaces the width over the radial side surface of the rotating annular portion 23c, the radial thickness T _31, the axial thickness T _23c of the rotating annular portion 23c Less than (T ₃₁ <T _23c ), and further, the design change of the outer seal lip 19a is not required, as in the present invention, the axial thickness dimension T _23c of the rotating ring portion _23c is 2 / Less than 3 (T ₃₁ <2 / 3T _23c ).

The configuration related to the detected surface of the encoder 14a used in this reference example is the same as that of the encoder 14 having the conventional structure shown in FIG. 8, and the method for fixing the encoder 14a to the slinger 13c is particularly limited. Alternatively, injection molding or compression molding with an insert may be used, or only the encoder 14a may be fixed to the slinger 13c after molding by adhesion or the like. In the case of this reference example, a chamfer 35 is provided on the outer peripheral edge of the inner end portion in the axial direction of the encoder 14a (the inner end portion in the axial direction of the sealing cylinder portion 31), but this chamfer 35 is omitted. Also good.
Other configurations, operations and effects are the same as those of the conventional structures described above.

[First example of embodiment]
FIG. 3 shows a first example of an embodiment of the present invention corresponding to claim 1 . The feature of this example is that a tapered surface portion 36 is provided on a part of the outer peripheral surface of the sealing cylinder portion 31a. Specifically, the tapered surface portion 36 is provided in a portion of the outer peripheral surface of the sealing cylinder portion 31a that protrudes axially outward from one side surface of the rotating ring portion 23c constituting the slinger 13c. Further, the tapered surface portion 36 is inclined in a direction in which the diameter (outer diameter dimension) decreases as it goes outward in the axial direction.

In the case of this example, as in the case of the first example of the reference example described above, the inner surface of the elastic member 16c attached to the outer peripheral surface of the sealing cylinder portion 31a and the fixed cylindrical portion 17 of the core metal 15 is also included. The labyrinth seal 25b is formed in the said part by making the surrounding surface face and face. In particular, in the case of this example, since the tapered surface portion 36 is provided on the outer peripheral surface of the sealing cylinder portion 31a, the gap in the radial direction of the labyrinth seal 25b is increased from the axial outer end portion to the axial intermediate portion. In between, it is made small so that it goes inward in the axial direction. In the case of this example employing such a configuration, when the slinger 13c and the encoder 14b rotate, the foreign matter that has entered the labyrinth seal 25b due to the centrifugal force acts along the inclination of the tapered surface portion 36 to the outside. It can be pushed out toward the space (inward in the axial direction). Therefore, in the case of this example, the sealing performance can be further improved as compared with the case of the first example of the reference example described above.
Other configurations and operations are the same as those of the first example of the reference example described above and the conventional structure described above.

[Second Example of Embodiment]
FIG. 4 shows a second example of the embodiment of the present invention, which also corresponds to the first aspect. The feature of this example is that a tapered surface portion 36a is provided on the entire outer peripheral surface of the sealing cylinder portion 31b. In the case of this example employing such a configuration, it is possible to more effectively exhibit the foreign matter discharging action by the centrifugal force obtained by the first example of the embodiment described above.
Other operations and effects are the same as those of the first example of the embodiment described above, the first example of the reference example described above, and the conventional structure.

[Second example of reference example related to the present invention]
FIG. 5 shows a second example of a reference example related to the present invention. The feature of this reference example is that the outer diameter of the rotating ring portion 23d constituting the slinger 13d is made larger than those of the reference examples and the embodiments of the embodiment described above, and the outer diameter of the rotating ring portion 23d is increased. The peripheral portion is embedded and supported on a part of the inner peripheral surface of the sealing cylinder portion 31. By adopting such a configuration, in the case of this reference example, it is possible to secure a high coupling strength between the slinger 13d and the encoder 14a. In the case of this reference example, the encoder 14a is fixed to the slinger 13d by injection molding or compression molding using an insert. Further, the structure of this reference example is provided with a tapered surface portion 36 (36a) on the outer peripheral surface of the sealing cylinder portion 31a (31b) as described in the first and second examples of the above-described embodiment. It can also be implemented in combination with other structures.
Other configurations and operations are the same as those of the first example of the reference example described above and the conventional structure described above.

  In addition, the combined seal ring with an encoder of the present invention is a rolling bearing that constitutes a rotation support portion of various mechanical devices in addition to a rolling bearing unit for rotatably supporting a vehicle wheel as described above with respect to a suspension device ( Ball bearings, cylindrical roller bearings, tapered roller bearings, etc.). It is used to prevent the grease enclosed in the internal space of this rolling bearing from leaking to the outside, and to prevent foreign matter such as rainwater, muddy water, dust, etc. existing outside from entering this internal space. it can. Further, the combined seal ring with an encoder of the present invention is not limited to the inner ring rotating / outer ring fixing structure, but can be incorporated into the outer ring rotating / inner ring fixing structure.

The figure equivalent to FIG. 7 which shows the 1st example of the reference example relevant to this invention. The figure which takes out and shows only a slinger and an encoder from FIG. The figure similar to FIG. 1 which shows the 1st example of embodiment of this invention. The figure similar to FIG. 1 which shows the same 2 example. The figure similar to FIG. 1 which shows the 2nd example of the reference example relevant to this invention. Sectional drawing of the rolling bearing unit with an encoder of the conventional structure. The partial expanded sectional view of the combination seal ring with an encoder assembled | attached to the A section of FIG. FIG. 8 is a perspective view showing only the encoder extracted from FIG. 7. The figure equivalent to FIG. 7 which shows the combination seal ring of the conventional structure described in patent document 2. FIG. The partial expanded sectional view which shows the displacement state of the slinger of the combination seal ring with an encoder when each part which comprises the rolling bearing unit for wheel support elastically deforms by the moment load added at the time of vehicle travel. The figure equivalent to FIG. 7 which shows the combination seal ring with an encoder of the conventional structure described in patent document 3. As shown in FIG.

DESCRIPTION OF SYMBOLS 1 Hub 2 Flange 3a, 3b Inner ring track 4 Inner ring 5 Outer ring 6 Mounting part 7a, 7b Outer ring track 8 Rolling element 9 Inner space 10 Seal ring 11, 11a, 11b Combination seal ring with encoder 12, 12a-12c Seal ring 13, 13a ˜13d Slinger 14, 14a, 14b Encoder 15 Core 16, 16a-16c Elastic material 17 Fixed cylindrical portion 18 Fixed annular portion 19, 19a Outer seal lip 20 Intermediate seal lip 21, 21a Inner seal lip 22, Rotating cylindrical portion 23, 23a to 23d Rotating ring part 24 Sensor 25, 25a, 25b Labyrinth seal 26 Combination seal ring 27 Sealing cylinder part 28 Swelling part 29 Bending surface 30 Seal lip 31, 31a, 31b Sealing cylinder part 32 Minimum thickness part 33 Bent part 34 Maximum thickness 35 Chamfer 36, 36a Tapered surface

Claims (1)

A combination seal ring with an encoder used for closing an opening end of a space existing between a peripheral surface of a stationary wheel and a peripheral surface of a rotating wheel and detecting the rotational speed of the rotating wheel, A seal ring fixed to the peripheral surface of the stationary wheel, a slinger fixed to the peripheral surface of the rotating wheel, and an encoder supported and fixed to the slinger,
The seal ring includes a fixed cylindrical portion that is fitted and fixed to the peripheral surface of the stationary ring, a fixed metal portion that is bent from an edge of the fixed cylindrical portion toward the peripheral surface of the rotating ring, An elastic material having a seal lip attached to the entire circumference of the core metal;
The slinger includes a rotating cylindrical portion that is fitted and fixed to the peripheral surface of the rotating wheel, and a rotating circular ring portion that is bent from an edge of the rotating cylindrical portion toward the peripheral surface of the stationary wheel. The portion where the tip edge of the seal lip is slidably contacted with the peripheral surface of the portion and one side surface of the rotating ring portion is a smooth surface,
The encoder is made of a permanent magnet, which is a plastic magnet in which S poles and N poles are alternately arranged in the circumferential direction, and is supported on the other side of the rotating annular part,
The peripheral edge of the encoder on the stationary wheel side protrudes toward the stationary wheel side from the peripheral edge of the rotating ring portion on the stationary wheel side, and the stationary annular portion on the stationary wheel side periphery of the encoder The edge on the side protrudes more than 1.5 times the axial thickness dimension of the rotating annular part from the one side surface of the rotating annular part to the fixed annular part side, and the radial thickness dimension is A cylindrical tube for sealing that is less than 2/3 of the axial thickness of the rotating ring is formed, and the peripheral surface on the stationary ring side of the cylindrical tube for sealing and the fixed cylindrical portion or the fixed cylindrical portion A labyrinth seal is provided on the peripheral surface of the elastic material attached to the peripheral surface of the rotating wheel in close proximity to the entire periphery, and the peripheral surface of the sealing cylinder portion on the stationary wheel side is provided. A tapered surface portion inclined in a direction in which the diameter decreases as it approaches the fixed ring portion is provided. Combination seal ring with an encoder, characterized in that the gap in the radial direction is reduced with increasing distance from the fixed annular portion of a portion where the tapered surface portion is provided within the rinsing seal.

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