JP5252101B2 - Rolling bearing with encoder - Google Patents

Description

  The rolling bearing with an encoder according to the present invention is used to support a wheel of a motorcycle such as a motorcycle or a scooter so as to be rotatable with respect to a frame, and to determine the rotational speed of the wheel.

An anti-lock brake system (ABS) is widely used as a device for stabilizing the running state for automobiles. Such ABS has been widely used mainly in four-wheeled vehicles, but has recently begun to be used in motorcycles. As is well known, since it is necessary to determine the rotational speed of the wheel in order to control the ABS, it is necessary to incorporate a rotational speed detection device into the wheel bearing rolling bearing unit for rotatably supporting the wheel on the suspension device. It has been widely practiced. However, the structure of the rotational speed detection device for a four-wheeled vehicle cannot be directly applied to a motorcycle. There are two main reasons for this (1) and (2).
(1) The wheel bearing rolling bearing unit for motorcycles is considerably smaller than the wheel bearing rolling bearing unit for automobiles.
(2) Most of the wheel bearing rolling bearing units for four-wheeled vehicles are of the inner ring rotating type, whereas many of the wheel supporting rolling bearing units for motorcycles are of the outer ring rotating type.

FIG. 9 shows a structure of a portion that rotatably supports a front wheel of a relatively small motorcycle such as a scooter as an example of a structure of a wheel support portion of the motorcycle. In this structure, a pair of support plates 2 and 2 are fixed in parallel to each other at the lower ends of a pair of left and right forks 1 and 1 constituting the suspension device. The both ends of the support shaft 3 are supported and fixed between the support plates 2 and 2. Further, a pair of rolling bearings 4 and 4 are installed at two positions of the intermediate portion of the support shaft 3. Specifically, the inner rings constituting the both rolling bearings 4 and 4 are fitted onto the support shaft 3, and the axial positions of the inner rings are regulated by the inner ring spacers 5a, 5b and 5c. A cylindrical hub 6 is arranged around the support shaft 3 concentrically with the support shaft 3. And the outer ring | wheel which comprises the said both rolling bearings 4 and 4 is internally fitted and fixed to the inner peripheral surface near both ends of the said hub 6. FIG. Further, a wheel 7 is supported and fixed to the outer peripheral surface of the hub 6.

  On the other hand, a structure described in Patent Document 1 is conventionally known as a rotational speed detection device for obtaining the rotational speed of a wheel in order to incorporate ABS in a motorcycle. Although the structure described in Patent Document 1 is a rotational speed detection device for a motorcycle, it is intended to detect the rotational speed of a hub constituting a wheel bearing rolling bearing unit of an inner ring rotation type. For this purpose, an encoder having an outer peripheral surface as a detected surface is fixed at an intermediate portion of the rotating shaft that rotates together with the wheel, between the pair of rolling bearing units. Further, the detection part of the sensor supported on the non-rotating outer ring is placed in close proximity to the outer peripheral surface of the encoder. Although such a structure can be applied to a relatively large motorcycle, it cannot be applied to a structure using a wheel bearing rolling bearing unit of an outer ring rotation type, which is common in a small motorcycle.

  On the other hand, in Patent Documents 2 and 3, an encoder is attached to a part of the seal ring that closes the end opening of the rolling bearing unit, and the rotational speed of the rotation-side bearing ring constituting the rolling bearing unit can be measured. Is described. Of Patent Documents 2 and 3, Patent Document 2 describes an outer ring rotation type structure, and Patent Document 3 describes an inner ring rotation type structure. However, the wheel bearing rolling bearing units with encoders described in Patent Documents 2 and 3 are all intended to detect the rotational speed of wheels of a four-wheeled vehicle, and the rolling bearing units are relatively It is large. For this reason, for example, even when the structure described in Patent Document 2 which is an outer ring rotating type is used when detecting the rotational speed of a wheel of a motorcycle, it is difficult to ensure the width dimension of the encoder in the radial direction. Problems such as difficulty in ensuring reliability with respect to speed detection occur.

In particular, in the case of the rolling bearing with an encoder described in Patent Document 2, since the encoder and the seal lip are arranged in series in the radial direction, the distance between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. As a result, the ratio of the width dimension of the encoder becomes smaller. In the case of a rolling bearing unit for supporting a wheel of a motorcycle, since the distance between the two peripheral surfaces is originally small, when the ratio is small, the absolute value of the width dimension of the axially outer side surface that is the detected surface of the encoder is equivalent. Becomes smaller. As a result, the change in the output signal of the sensor having the detection unit opposed to the detected surface becomes small, which is disadvantageous in terms of ensuring the reliability of rotation speed detection. In short, the structures described in Patent Documents 2 and 3 cannot be used as they are to detect the rotational speed of the wheels of the motorcycle.

JP-A-5-105158 JP 2005-121669 A JP 2005-233923 A

  The present invention has been invented in order to realize a rolling bearing with an encoder capable of detecting the rotational speed of a motorcycle wheel with high reliability in view of the circumstances as described above.

The rolling bearing with an encoder of the present invention includes an outer ring, an inner ring, a plurality of rolling elements, and an encoder.
Of these, the outer ring has an outer ring raceway on the inner peripheral surface and rotates during use.
The inner ring has an inner ring raceway on the outer peripheral surface and does not rotate during use.
Each rolling element is provided between the inner ring raceway and the outer ring raceway so as to roll freely.
The encoder is made of a permanent magnet in which magnetic powder is dispersed in a polymer material, and S poles and N poles are alternately arranged on the outer side surface in the axial direction, which is the side surface opposite to the rolling element. Thus, the magnetic characteristics of the outer surface in the axial direction are alternately changed in the circumferential direction. An annular recess is provided over the entire circumference at the outer diameter side end of the axially outer side surface of the encoder, and a gate for injection molding the encoder is positioned on the bottom surface of the annular recess.
Further, the outer peripheral edge portion of the encoder is supported and fixed to the outer end portion in the axial direction of the outer ring in a state in which a sealing property between the outer ring and the outer ring is ensured. The entire circumference is in sliding contact or in close proximity.

When carrying out the present invention as described above, for example, as in the invention described in claim 2, an encoder including a cored bar and a permanent magnet is used as the encoder. Of these, the metal core is formed of a magnetic metal plate such as a steel plate, a ferritic or martensitic stainless steel plate, etc., in a ring shape as a whole. And the cylindrical part formed in the outer periphery of the said metal core is fitted and fixed to the inner peripheral surface of the axial direction outer end part of the said outer ring by interference fitting .

Further, when the present invention is carried out, preferably, as in the invention described in claim 3, the inner circumference of the outer circumferential surface of the outer ring in the axial direction outer end is larger than the portion adjacent to the inner side in the axial direction. A surface-side large diameter portion is provided. Then, the outer peripheral edge portion of the encoder is fitted and fixed to the inner peripheral surface side large diameter portion.
Alternatively, as in the invention described in claim 4, instead of omitting the inner peripheral surface side large diameter portion, or providing this inner peripheral surface side large diameter portion, the outer peripheral surface of the inner ring in the axial direction outer end portion is provided. A small-diameter portion on the outer peripheral surface side having an outer diameter smaller than that of the portion adjacent to the inside in the axial direction is provided. Then, the inner peripheral edge portion of the encoder enters the outer peripheral surface side small diameter portion, and the inner peripheral edge portion and the portion adjacent to the inner side in the axial direction are overlapped with each other in the axial direction.

According to the present invention configured as described above, it is possible to realize a rolling bearing with an encoder that can detect, for example, the rotational speed of a wheel of a motorcycle with high reliability. That is, in the case of the present invention, the outer peripheral edge of the encoder is supported and fixed to the outer end in the axial direction of the outer ring, and the inner peripheral edge of the encoder itself is slidably contacted or closely opposed to the inner ring over the entire circumference. Therefore, the width dimension of the encoder in the radial direction can be ensured. For this reason, it is possible to increase the change in the output signal of the sensor in which the detection unit is opposed to the outer surface in the axial direction, which is the detection surface of the encoder, and it is easy to ensure the reliability of rotation speed detection.
That is, with a structure using an encoder including an annular permanent magnet, the change in the output signal of the sensor can be increased by increasing the magnetic flux entering and exiting the detected surface of the encoder.
In particular, if the structure of the invention described in claims 3 and 4 is adopted, the width dimension of the encoder in the radial direction is set so that the portion adjacent to the inner peripheral surface side large-diameter portion in the inner peripheral surface of the outer ring and the inner ring It can be larger than the interval between the outer peripheral surface and the portion adjacent to the outer peripheral surface side small diameter portion. For this reason, the width dimension of the encoder can be further increased, the change in the output signal of the sensor can be increased, and the reliability of rotation speed detection can be further improved. Further, in the case of the structure according to the third aspect of the invention, in addition to the above effects, the outer diameter side end portion of the inner surface in the axial direction of the encoder is formed in a step portion existing in the inner diameter surface side large diameter portion. By matching, it is possible to obtain the effect that the axial position of the encoder can be easily and reliably regulated.
In the case of the present invention, since the gate is positioned on the bottom surface of the annular recess, the presence of the gate adversely affects the density of magnetic flux entering and exiting from the outer surface in the axial direction of the permanent magnet as the detection surface. You can prevent things.

The fragmentary sectional view which shows the 1st example of embodiment of this invention. The fragmentary sectional view which shows the 2nd example. The fragmentary sectional view which shows the 3rd example. The fragmentary sectional view which shows the 4th example. The fragmentary sectional view which shows the 5th example. The fragmentary sectional view which shows the 6th example. The fragmentary sectional view showing the 7th example. The fragmentary sectional view which shows the 8th example. Sectional drawing which shows an example of the rotation support part of the wheel of a motorcycle. The figure equivalent to the A section of FIG. 1 which shows another example of the encoder used as the object of this invention.

[First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention corresponding to claims 1 to 3 . The rolling bearing 8 with an encoder of this example includes an outer ring 9, an inner ring 10, a plurality of rolling elements 11, and an encoder 12. The inner diameter R (of the inner ring 10) of the rolling bearing with encoder 8 is, for example, about 12 to 25 mm, and the outer diameter D (of the outer ring 9) is about 35 to 50 mm. In use, for example, as shown in FIG. 9 described above, the hub 6 is assembled between the outer peripheral surface of the support shaft 3 and the inner peripheral surface of the hub 6 so that the hub 6 can be freely rotated around the support shaft 3. To support. Incidentally, in the case of applying the present invention with respect to the structure of FIG. 9, only one of the rolling bearing of the rolling bearings 4, 4 pair shown in FIG. 9, and the encoder rolling bearing 8. The other rolling bearing is a general rolling bearing without an encoder.

As described above, for example, the outer ring 9 constituting the rolling bearing 8 with the encoder assembled between the outer peripheral surface of the support shaft 3 and the inner peripheral surface of the hub 6 has the outer ring raceway 13 on the inner peripheral surface. Have. In the illustrated example, the outer ring raceway 13 is a deep groove type having a circular arc cross section. Such an outer ring 9 rotates together with the hub 6 while being fitted and fixed to the hub 6 at the time of use.
The inner ring 10 has an inner ring raceway 14 on the outer peripheral surface. In the illustrated example, the inner ring raceway 14 is also of a deep groove type. Such an inner ring 10 does not rotate while being fitted and fixed to the support shaft 3 during use.
Each rolling element 11 is provided between the outer ring raceway 13 and the inner ring raceway 14 so as to be freely rollable while being held by a cage 15. In the illustrated example, balls are used as the rolling elements 11.

The encoder 12 is formed by integrally connecting and fixing a metal core 16 and a permanent magnet 17 each having an annular shape. Of these, the core 16 is made of a magnetic metal plate such as a steel plate, a ferritic or martensitic stainless steel plate, and the outer peripheral edge of the annular portion 18 is axially outward (the space in which the rolling elements 11 are installed). On the opposite side, the cylindrical portion 19 is formed by being bent at right angles toward the left side of FIG. 1, and is formed into an annular shape with an L-shaped cross section.
The core metal 16 constituting the encoder 12 is not limited to the structure shown in FIG. 1, and the cylindrical portion 19 for fitting to the inner peripheral surface of the end of the outer ring 9 and the permanent magnet 17 are held. What is necessary is just a structure provided with the annular ring part 18. FIG. For example, as shown in FIG. 10 , the metal core 16 constituting the encoder 12 has a configuration in which a locking portion 32 having a crank-shaped cross section is provided between the outer peripheral edge portion of the annular ring portion 18 and the cylindrical portion 19. You can also do things. When such a configuration is adopted, the cylindrical portion 19 and the inner peripheral surface of the end of the outer ring 9 are directly fitted (without the permanent magnet 17), and the locking portion 32 and the outer ring are fitted. Since the position in the radial direction of the permanent magnet 17 can be regulated between the inner peripheral surface 9 and the inner peripheral surface 9, it is possible to improve the detection accuracy related to rotation speed detection.

  On the other hand, the permanent magnet 17 is formed by dispersing magnetic powder such as iron or ferrite in a polymer material such as elastomer such as rubber or plastomer such as synthetic resin. Such a permanent magnet 17 is manufactured by injection molding, in which the polymer material containing the magnetic powder is fed into a mold cavity. At the time of injection molding, the core metal 16 is set in the cavity. deep. In addition, a primer (adhesive) is applied in advance to the surface of the core bar 16 that contacts the permanent magnet 17. Accordingly, the permanent magnet 17 and the cored bar 16 are joined and fixed simultaneously with the injection molding of the permanent magnet 17. The permanent magnet 17 is magnetized in the axial direction, and the magnetization direction is alternately varied at equal intervals in the circumferential direction. Therefore, the south pole and the north pole are alternately arranged at equal intervals on the outer surface in the axial direction of the permanent magnet 17 that is the detected surface. The number of these S poles and N poles is regulated by design depending on the performance required for the ABS, etc., but at most 50 poles on the entire circumference of the permanent magnet 17 (a total of 100 S poles and N poles). Extreme).

  The inner peripheral edge of the permanent magnet 17 protrudes radially inward from the inner peripheral edge of the cored bar 16. Therefore, the inner peripheral edge of the encoder 12 as a whole is the inner peripheral edge of the permanent magnet 17. As described above, the permanent magnet 17 is manufactured by injection molding of the polymer material. Therefore, the inner diameter of the permanent magnet 17 and the inner diameter of the encoder 12 as a whole can be finished with high accuracy. Moreover, the axial direction outer side surface of the permanent magnet 17 is an outer diameter side end portion, and is axially inner than the intermediate portion or inner diameter side portion (on the space side where the rolling elements 11 are installed, on the right side in FIG. 1). It is recessed. Accordingly, the annular recess 20 exists on the outer diameter side end of the outer surface of the encoder 12 over the entire circumference. Then, a gate for injection molding the permanent magnet 17 is positioned on the bottom surface of the annular recess 20, and the presence of the gate is a surface to be detected. The magnetic flux entering and exiting from the outer surface of the permanent magnet 17. Prevents negative effects on density. Further, the outer surface of the permanent magnet 17 in the axial direction is present at a position recessed inward in the axial direction from the end surfaces of the outer ring 9 and the inner ring 10. Therefore, before the rolling bearing 8 with the encoder is assembled between the hub 6 and the support shaft 3, the encoder 12 may collide with another object and be damaged in the state of the rolling bearing 8 with the encoder alone. Can be prevented.

  Furthermore, an inner peripheral surface side large-diameter portion 21 having an inner diameter larger than that of the portion adjacent to the inner side in the axial direction is formed at the axially outer end portion of the inner peripheral surface of the outer ring 9. The encoder 12 as described above is fitted inside the end portion of the outer ring 9 by fitting the cylindrical portion 19 formed on the outer peripheral edge portion of the core metal 16 into the inner peripheral surface side large-diameter portion 21 with an interference fit. It is fixed to the peripheral surface. In this state, the sealing performance between the inner peripheral surface of the end portion of the outer ring 9 and the outer peripheral edge of the encoder 12 is ensured. Further, the inner peripheral edge of the encoder 12 is closely opposed to the outer peripheral surface of the end portion of the inner ring 10 over the entire periphery, and a labyrinth seal is formed between the inner peripheral edge and the outer peripheral surface. As described above, the inner diameter of the encoder 12 can be processed with sufficiently high accuracy, and the outer diameter of the inner ring 10 is also processed with high accuracy. Therefore, the width dimension in the radial direction of the labyrinth seal can be made sufficiently small, and the sealing performance of the labyrinth seal can be made sufficiently good.

According to the rolling bearing with an encoder of this example configured as described above, for example, the rotational speed of a wheel of a motorcycle can be detected with high reliability. That is, in the case of this example, the labyrinth seal is configured by making the inner peripheral edge of the encoder 12 itself face and face the outer peripheral surface of the inner ring 10. Therefore, unlike the structure described in Patent Document 2 described above, the encoder 12 and the seal lip are arranged in series in the radial direction, and the width dimension of the encoder 12 in the radial direction can be increased. For this reason, the change in the output signal of the sensor in which the detection unit is opposed to the outer surface in the axial direction, which is the detection surface of the encoder 12, can be increased. In other words, the hub in which the outer ring 9 is fitted and fixed by increasing the magnetic flux entering and exiting from the outer surface in the axial direction of the permanent magnet 17 constituting the encoder 12 to increase the degree to which the output signal of the sensor changes. 6. As a result, it becomes easy to ensure the reliability of detecting the rotational speed of the wheel coupled and fixed to the hub 6.

  Moreover, in the case of this example, since the outer peripheral edge of the encoder 12 is fitted into the inner peripheral surface side large diameter portion 21 formed at the end of the outer ring 9, the outer diameter of the encoder 12 is set to the outer ring. 9 can be larger than the inner diameter of the portion adjacent to the inner peripheral surface side large-diameter portion 21. For this reason, the width of the encoder 12 can be made larger, the change in the output signal of the sensor can be made larger, and the reliability of rotation speed detection can be further improved. Further, the axial position of the encoder 12 can be easily achieved by abutting the outer diameter side end portion of the inner surface in the axial direction of the encoder 12 with the step portion 22 existing in the inner diameter surface side large diameter portion 21. And it can be regulated reliably (with high accuracy). For this reason, in addition to reliably preventing the encoder 12 from interfering with the retainer 15, the distance between the detected surface of the encoder 12 and the detection portion of the sensor is properly regulated, and from this surface, The reliability related to the rotational speed detection can be improved. If the encoder 12 is made of an elastomer, the inner peripheral edge of the encoder may be brought into sliding contact with the outer peripheral surface of the inner ring 10.

[Second Example of Embodiment]
FIG. 2 also shows a second example of the embodiment of the present invention corresponding to claims 1 to 3 . In the case of this example, the concave grooves 23 and 24 are formed over the entire circumference on the outer surface inner diameter side portion and the inner peripheral edge of the permanent magnet 17a. Of these concave grooves 23 and 24, the concave groove 23 near the inner diameter of the outer surface is attached to the outer surface in the axial direction of the encoder 12a and collects foreign matters moving on the outer diameter surface in the axial direction. It serves to prevent foreign matter from reaching the inner periphery of the encoder 12a. The concave groove 24 on the inner peripheral edge serves to increase the number of times the labyrinth seal is squeezed between the inner peripheral edge and the outer peripheral surface of the inner ring 10 to improve the sealing performance of the labyrinth seal. Therefore, the structure of this example is superior to the structure of the first example described above in terms of preventing foreign matter from entering the space where the rolling elements 11 are installed. Since the structure and operation of the other parts are the same as those in the first example described above, redundant description will be omitted.

[Third example of embodiment]
FIG. 3 shows a third example of the embodiment of the invention corresponding to claims 1 to 4 . In the case of this example, an outer peripheral surface side small-diameter portion 25 having an outer diameter smaller than that of a portion adjacent to the inner side in the axial direction is provided on the outer peripheral surface of the inner ring 10a in the axial direction outer end portion. The inner peripheral edge portion of the encoder 12b is inserted into the outer peripheral surface side small diameter portion 25, and the inner peripheral edge portion and the portion adjacent to the inner side in the axial direction are overlapped with each other in the axial direction. Further, a portion closer to the inner diameter of the inner surface in the axial direction of the encoder 12b and a step portion 26 existing in the back of the outer diameter surface side small diameter portion 25 are made to face each other. In the case of this example, the width dimension of the encoder 12b in the radial direction is made larger than the width dimension of the encoders 12 and 12a in the first example and the second example described above, and the rotation speed detection is performed. Reliability can be further improved. In addition, the length of the labyrinth seal existing between the inner peripheral edge of the encoder 12b and the surface of the inner ring 10a can be increased to improve the sealing performance. Since the structure and operation of the other parts are the same as those in the first example described above, a duplicate description is omitted.

[Fourth Example of Embodiment]
FIG. 4 also shows a fourth example of the embodiment of the invention corresponding to claims 1 to 4 . In the case of this example, the inner diameter of the inner peripheral edge of the encoder 12c is made larger than the inner diameter of the outer half of the axial direction, and a stepped portion 27 is formed on the inner half of the axial direction. Is formed. For this reason, a portion having a larger volume than the both side portions exists in an intermediate portion between the step portion 27 and the outer peripheral surface side small diameter portion 25 provided on the outer peripheral surface of the outer end portion of the inner ring 10a. As a result, the number of times the labyrinth seal is squeezed between the inner peripheral edge of the encoder 12c and the outer surface of the inner ring 10a can be increased, and the sealing performance of the labyrinth seal can be improved. Therefore, the structure of this example is superior to the structure of the third example described above in terms of preventing foreign objects from entering the space where the rolling elements 11 are installed. Since the structure and operation of the other parts are the same as those in the third example described above, a duplicate description is omitted.

[Fifth Example of Embodiment]
FIG. 5 also shows a fifth example of the embodiment of the invention corresponding to claims 1 to 4 . In the case of this example, the inner half in the axial direction of the inner periphery of the encoder 12d is a partially conical concave surface that is inclined in a direction in which the inner diameter increases toward the inner surface in the axial direction. Further, a portion formed on the outer peripheral surface of the outer end portion of the inner ring 10b, which is inclined in a direction in which the outer diameter becomes larger toward the center of the inner ring 10b, the stepped portion 26a existing at the rear end portion of the outer peripheral side small diameter portion 25. It has a conical convex surface. The inner half of the inner periphery of the encoder 12d is in close proximity to the stepped portion 26a. Such a structure of this example makes it difficult for the inner half of the axial direction and the stepped portion 26a to slip even when the axial position of the inner peripheral edge of the encoder 12d is slightly shifted (gap thickness of the labyrinth seal portion). If the same is used, the tolerance for the displacement in the axial direction is increased). Since the structure and operation of the other parts are the same as those in the third example described above, redundant description is omitted.

[Sixth Example of Embodiment]
FIG. 6 also shows a sixth example of an embodiment of the present invention corresponding to claims 1 to 4 . In the case of this example, the inner peripheral edge of the cored bar 16 and the inner peripheral surface of the cylindrical part 19 are covered with a polymer material constituting the permanent magnet 17b of the encoder 12e. In the case of this example, the length of the labyrinth seal is increased by this configuration to improve the sealing performance. In addition, even when the metal core 16 is made of a metal plate having no corrosion resistance, the metal plate can be prevented from corroding. Since the structure and operation of the other parts are the same as those in the fifth example described above, a duplicate description is omitted.

[Seventh example of embodiment]
FIG. 7 also shows a seventh example of the embodiment of the invention corresponding to claims 1 to 4 . In the case of this example, the concave groove 28 is formed over the entire circumference in the inner half in the axial direction of the outer peripheral surface side small diameter portion 25a formed on the outer peripheral surface of the end portion of the inner ring 10c. Further, the inner peripheral edge of the encoder 12f is formed in a bifurcated shape, and a concave groove 24a is formed in the inner peripheral edge over the entire periphery. Of the inner peripheral edge portion, the outer side portion in the axial direction than the concave groove 24a is close to and opposed to the outer peripheral surface of the outer half portion in the axial direction of the outer peripheral surface side small diameter portion 25a. On the other hand, the inner side surface of the inner peripheral edge of the inner side portion in the axial direction from the concave groove 24a is made to face and oppose the stepped portion 26b existing at the inner end of the outer peripheral surface side small diameter portion 25a. According to such a structure of this example, the number of times of labyrinth seal throttling between the inner peripheral edge of the encoder 12f and the outer surface of the inner ring 10c is increased, and the volume of the space existing between the throttling is increased. The sealing performance of the labyrinth seal can be improved. Since the structure and operation of the other parts are the same as those in the fifth example described above, a duplicate description is omitted.

[Eighth Example of Embodiment]
FIG. 8 also shows an eighth example of the embodiment of the present invention corresponding to claims 1 to 4 . In the case of this example, a concave groove 23a having a deep outer diameter side and a shallow inner diameter side is formed over the entire circumference in a portion closer to the inner diameter of the outer surface of the encoder 12g. The concave groove 23a collects foreign matter that adheres to the outer surface in the axial direction of the encoder 12g and moves to the inner diameter side of the outer surface in the axial direction , and prevents the foreign matter from reaching the inner peripheral edge of the encoder 12g. Has a role to play. Therefore, the structure of this example is superior to the structure of the seventh example described above in terms of preventing foreign matter from entering the space where the rolling elements 11 are installed. Since the structure and operation of the other parts are the same as in the seventh example described above, a duplicate description is omitted.

DESCRIPTION OF SYMBOLS 1 Hawk 2 Support plate 3 Support shaft 4 Rolling bearing 5a, 5b, 5c Inner ring spacer 6 Hub 7 Wheel 8 Rolling bearing with an encoder 9 Outer ring 10, 10a, 10b, 10c Inner ring 11 Rolling element 12, 12a-12g Encoder 13 Outer ring track 14 Inner ring raceway 15 Cage 16 Core metal 17, 17a, 17b Permanent magnet 18 Circular ring part 19 Cylindrical part 20 Annular recess 21 Inner peripheral surface side large diameter part 22 Step part 23, 23a Concave groove 24, 24a Concave groove 25, 25a Outer peripheral side small diameter part 26, 26a, 26b Step part 27 Step part 28 Concave groove
32 locking part

Claims (4)

An outer ring that has an outer ring raceway on the inner peripheral surface and that rotates when used, an inner ring that has an inner ring raceway on the outer peripheral surface and does not rotate even when used, and is provided between the inner ring raceway and the outer ring raceway so as to be able to roll. The encoder includes a plurality of rolling elements and an encoder that rotates together with the outer ring. The encoder is made of a permanent magnet in which magnetic powder is dispersed in a polymer material, and has an S pole and an N pole on the outer surface in the axial direction. By alternately arranging, the magnetic characteristics of the outer surface in the axial direction are alternately changed with respect to the circumferential direction, and the outer peripheral edge of the encoder is arranged at the outer end in the axial direction of the outer ring. The inner peripheral edge of the encoder itself is in sliding contact with or close to the inner ring with respect to the inner ring, and the outer peripheral surface of the encoder in the axial direction is outside. An annular recess is located around the entire circumference on the radial end. To a bottom surface of the annular recess, a rolling bearing with an encoder that is positioned the gate at the time of injection molding the encoder. The encoder includes a cored bar made entirely of a magnetic metal plate in a ring shape, and a permanent magnet attached to the axially outer side surface of the cored bar, and a cylindrical part formed on the outer peripheral edge of the cored bar The rolling bearing with an encoder according to claim 1, wherein the inner ring is fixed to the inner peripheral surface of the outer end in the axial direction of the outer ring by an interference fit. An inner peripheral surface side large-diameter portion whose inner diameter is larger than a portion adjacent to the inner side in the axial direction is provided on the inner peripheral surface of the outer end in the axial direction of the outer ring, and the outer peripheral portion of the encoder is large on the inner peripheral surface side. The rolling bearing with an encoder according to any one of claims 1 and 2 , which is internally fitted and fixed to a diameter portion. An outer peripheral surface side small diameter portion having an outer diameter smaller than a portion adjacent to the inner side in the axial direction is provided on the outer peripheral surface of the inner end in the axial direction of the inner ring, and the inner peripheral edge portion of the encoder is connected to the outer peripheral surface side small diameter portion. The rolling bearing with an encoder according to any one of claims 1 to 3 , wherein the inner peripheral edge portion and the portion adjacent to the inner side in the axial direction overlap each other in the axial direction.

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